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15625 75TH PL W.PDF15625 75TH PL W 4111- 41, ADDRESS: TAX ACCOUNT/PARCEL #: BUILDING PERMIT (NEW STRUCTURE) #: COVENANTS (RECORDED) FOR:A- �— CRITICAL AREAS #: DETERMINATION: ❑ Conditional Waiver ❑ Study Required ❑ Waiver CRITICAL AREAS #: DETERMINATION: ❑ Conditional Waiver ❑ Study Required ❑ Waiver DISCRETIONARY PERMIT #'S: 5 DRAINAGE PLAN DATED: PARKING AGREEMENTS DATED: EASEMENT(S) RECORD FOR: PERMITS (OTHER - list permit #'s): PLANNING DATA CHECKLIST DATED: Q SCALED PLOT PLAN DATED: SEWER LID FEE $: • LID #: SHORT PLAT FILE: LOT: BLOCK: SIDE SEWER AS BUILT DATED: g SIDE SEWER PERMIT(S) #: GEOTECH REPORT DATED: STREET USE/ENCROACHMENT PERMIT #: % FOR: WATER METER TAP CARD DATED: OTHER: - .. L:\TEMP\DST's\Forms\Jana's Street File Checklist 5-14-08.doc PLANNING CONDITIONS: (1) 30% native vegetation to be retained as shown. (2) Determined by Director to meet the intent of the variance (V-2005-162 and BLD-2006-544). (3) Contact the Planning Division immediately if anticipated grading exceeds 500 cubic yards of cut, as review under the State Environmental Policy Act (SEPA) is required. A 0 M. .ANNING DATA le LE FAMILY RESIDENTIAL 11 STREET FILE Name: Y-tjJt&JuliealnY1 R.laLJ Date: O(r.30. >-Doer Site Address: 115(p2.93 3-STH P 1 a c1e, Mileyf Plan Check #: BLD - "0 g. 0 31 b Project Description: New 5pR vv; S y L kiA - ( Prwtau5 blct."D .n5") Reduced Site Plan Provided: (YES / NO) Zoning: F-S—'y0 Map Page: Corner Lot: (YES IF)) Flag Lot: (YES /©O Critical Areas Determination #: Gray yoo�. i89 1 Pax r�evf ew one. 5tte p Study Required -��Y G6YV=P �e Isa ejw ❑ Waiver (Cote, 0 t} yg .0 8 qevitch+ 0tV1- *i *, e,A & s Ile. SEPA Determination: `i9 2- CGLJ d5 C' kAf* + 15 ccid S fl i I S Exempt El Needed will revvtcUn 5D0 per pLi clt . Re uiced Setbacks. Street: if, y �l5.5) SICIe. '>��10 Side:35 (10 1p.s Rear: I S Actual Setbacks WStreet- Syr 5- Side: tot Sig O i RT-1 Detached Structures • Rockeries • et, *nina Walls Fences • Trellises • Arbors Ba Windows • Projecting Modulation • Stairs • overed Deck Covered Porc • Eaves Chimney Elevator Penthouse • Uncovered Unenclosed <30" Deck • Porch • Patio Parking Required: j. Parking Provided: Lot Area: O •ti3 o,c rC5 f t o, 01 it 5 Lot Coverage: •/. Lot Coverage 'y 15D(o �J 0 S'"W Calculations. % Building Hei ht . Datum Point: VW0kJCff YAj,- f fN' Datum Elevation: 1�0 tj Maximum Hei ht: g 'yrj t � (ytj 3� Actual Height: (?i�}. �- S % Z'}•: 3�'S ADU Created: (YES / O) Subdivision: Legal Nonconforming Land Use Determination Issued: (YES / O b� 61A106JAVJf d 11iuSY1 Other VW& r V."06.1(02 appwv-ed iitfioac1- var(anccr A: q2A 401.IF •Frav" f(A nn td row) A i o � t 0 0.3 .G: S0U� l0.5 A orm - d�tcvw�.ine-d (� Oi rcCfi�� �"° mee-'f" i h-Ii' o t +ZS� �•3�'S v a VI a pi c1b Mo�X ... 'tYc,e'r2 -To p.? l aiv'tol5 "e •1:. [ (GiM Plan Review By: 9 na •J y none - e,?- ?4A- 8 jCI 1eMt�r'. :> •'GITY OF EDMONDS _ - PUBLIC WORKS DEPA1n ., R FIS TION CALL Permit SIDE SEWER PERMIT 7�.5:2;52t5 Ext. -2_2Q ` Issue Date /0 R1i;�`� 7 - 3202 Z , �.* PERMITL MUST BE POSTED ON JOB SITE =-AWA1WANFAWMWAMVAVA■► FL�NPIWOGD LIP 1. Address o.f Construction 2. Property Legal Description (include all: easements) ���(iri L� 9-1,+�/(7/7IJO ..���%1 •`• sl,.�.t� F`�.t �, l�r.(i'� ,,,1 '; l` n 3. Single Family Residence`V Multi -Family No.l of Units Commercial 4. Owner and/or Builder �_l�f' 5. Contractor & License NO. 1"Y(AJ-7 PA 0 6. Invasion into City Right -of -Way: No V Yes (If Yes Right -of way Construction Permit Required - Call Dial Dig X13141?�13/41fy before excavation) . 1-800-454-5555 zH 7. Cross other private property: Yes No ✓ Easement required - U attach legal description and county easement number. H a READ THE FOLLOWING AND SIGN: a 4 a. Property owners must obtain a permit to install side sewers on >-I their property. A licensed side sewer contractor must be employed to construct side.sewers in the public right-of-way. w b. The side sewer contractor assumes full reponsibility for each E4 installation for one year. aC. Commercial establishment requires a minimum of a six inch (6") X side sewer line. o d. Side sewers may not be installed closer than thirty inches (30") to any structure. e. Side sewer lines must be laid at a minimum grade. of 2% (1.150) 0 and maximum grade of 100% (45°). 0 H f. No turn in side sewer greater than 45 (1/8,bend) is allowed between cleanout. All 90 turns must be constructed of a 450 (1/8 bend) and Wye with removable cap. g. No down spouts, footing drains or floor drains can be connected to side sewer system. h. Pea gravel is required for bedding when installing sewer lines through other than granular soil. i., Cleanouts are required at 30"-60" from each plumbing exit line and at minimum intervals of 100' along sewer line run. j. Trenches within City right-of-way must be restored to original conditions. Contractors shall be responsible for right-of-way failure due to poor compaction of fill. k.. Side sewer must be left uncovered until inspected and approved by the City. 1. Inspection during normal working hours only. Two (2) working days notice required. / DATE: / I certify that I` have read and shall comply with the above H PERMIT FEE:, gin, (gyp DISAPPROVED BY: Date: i Yu �?% �j'i�i (C4(& _4� • 0 0 AB: Date: tn CONNECTION FEE:APPROVED By Date :Q __ * PERMIT MUST BE POSTED ON JOB 5ITE ;w Lo O 0 iz :z >- wo C-4: pq W z C5 Z < 5", C) z Z** 0 Co c CO z u w 0 < z v� LO u w A pq I I i Im 'm vi P '46 I V,P.V.C. . C- C4 WE Ln NOTICE: No warranty of accuracy. The information shown on the attached map(s) was compiled for use by the City of Edmonds, its Employees and Consultants. The City of Edmonds does not warrant the accuracy of anything set forth on these map(s). Any person or entity requesting a copy should conduct an independent inquiry regarding the information shown on the map(s), including, but not limited to, the location of any sewer stub shown. Such sewer stubs may or may not exist and may or may not exist at the location shown. Neither the City of Edmonds nor its employees or officers shall be liable for the information given on this map(s), nor for any one representation provided based upon said map(s). PLANNING CONDITIONS: (1) 30% native vegetation to be retained as shown. - (2) Determined by Director to meet'the intent of the variance :A N N I N G DATA (V-2005-162 and BLD-2006-544). (3) Contact the Planning Division immediately if anticipated LE FAMILY RESIDENTIAL grading exceeds 500 cubic yards of cut, as review under the State Environmental Policy Act (SEPA) is required. (MO MN.W r•W1111111111111 STREET FILE Name: 1�'y��ib.Jt�1�141V1Y1 P-ay Date: 0(g.30.9.00iS Site Address: 15 (# 2, SP (a Lf, W41;rf Plan Check #: BLD - "D Project Description: NQW vv; S g I...R PMODIA6 bld.2o© .05+4) Reduced Site Plan Provided: (YES / NO) Zoning: %•ej-'f�Q Map Page: Corner Lot: (YES / O) Flag Lot: (YES /a Critical Areas Determination #: GiQ. 189 p C mv(.e,w 6Yle, Study Required ZDD�• - CyKP1e,� ❑ Waiver ( co.GG o +. yg . o 8 leootcch l + + 44e• SEPA Determination: 4,Cl1. CAJ Ct5 CkA + 115 CAJd 5 f i I ® Exempt \ El Needed �i W I 1 Y�WLCU Y1 L S'0O pPX Pl.i G�" Re wired Setbacks Street: l sIN 35(!� Side: '•Sr�'(10 (p•5 Rear: ActualSetbacks Street: 5 Sidi: `O t Si�dde: to 4 Rear: Detached Structures • Rockeries • inin V' Its • F nces • Trellises • Arbors Ba endows • Projecting Modulation • Stairs • (Covered Deck Covered Porc • Eaves Chimney Elevator Penthouse • Uncovered Unenclosed <30" Deck • Porch • Patio Parking Required: go Parking Provided: Jfi Lot Area: O.'y?j ae. rGS L 0, 01 T. g Lot Coverage: ?,oG V. Lot Coverage wo(0 Cp max 1--).+0 9 "'0W h Calculations: 2�21✓,� =., $0(-+ ! Building Height Datum Point: Wa-JCY Y1rWJeov- Datum Elevation: (ioO 5 Maximum Height: 'j.S i / 1Zfj 7j�Cj Actual Height: ADU Created: (YES / O) Subdivision: Legal Nonconforming Land Use Determination Issued: (YES / O bIAt 51A106tAVJ Iy, 4I1W Other YAMS v.�oo5.t�v2 app►vv-ed 6-ef�(oacl- var�knCC5 �: q2.o I�.r, �►�: weOt 16.5' (5.5' -f� plo s".ntd row U: off. 00.3 A•G: norm- d-tC*" yVA (a, 01 �e(,fT✓ t-D Mtl- - i VOC4 � d ' 101 +2-51 : � •3�'S / b o vanaF1 � MAX iy-c eh -top- l a/vtid5 "� ` t•�i [ (UM� Plan Review By: P"11, .J y none TbR pair 91q le-Me�. f _ -' f ON 4 Prepared by. �/0� , h��srsf AKf 0.3 �/�j�e Z has srrra//isf D S. ea�o�.c.� �✓ bas„� . 3 Sole ljvpy�% Drainage Basin Analysis ROVED AS NOTED Y ENGINEERING for Kyle & Julianne � .�e:������ Edmonds Application #: BLD20080376 Date Prepared: June 9, 2009 Fev(5 ion -f f I Jv( 1+1 200q Prepared for: Kyle & Julianne Ray Site Address: 15625 75t' PL W Edmonds, WA 98026 Revlsi on I) Add Sec -Ron .7: Ca(culafionS �or undefaiAed too- Yr fbak +-low k-ro*I j deUe(oped 5ife Z)- Re vise Tc 5heef � Iow -b be 300' i-ofal wi+ Su�sec eht Shaflovi Row I �ehg fhs t-hEv'ea�te�' Upper BdS;11a ReviS-e (= " gjMtr Donna L. Breske, P.E. 6621 Foster Slough Road, Snohomish, Wa. 98290 Phone: (425) 334-9980, Fax: (425) 334-7380 Email: donnabreske@comcast.net 8"171"EET EXPIRES: 1 1 /05/09 ca ES, accordi►lgly . REVISION JUL 24 2008 FILE BUILDING DEPARTMENT CITY OF EDMONDS TABLE OF CONTENTS Section 1: Narrative Vicinity Map City of Edmonds Storm Pipe Schematic Section 2: Drainage Basin Maps Section 3: Drainage Basin Calculations Section 4: Flow Splitter Analysis 5ect-lan S: Undefa('4ecf too- Yr Peak Flow �nM DeUe (opec� s► e Section 6 0 Downstream Pipe Conveyance Capacity Analysis 0 SECTION 1 Narrative Vicinity Map City of Edmonds Storm Pipe Schematic DRAINAGE BASIN ANALYSIS KYLE & JULIANNE RAY — SINGLE FAMILY HOME 15625 75TH PL. W., EDMONDS, WA June 9, 2009 REASON FOR REPORT: Per the city of Edmonds, the on -site detention system may be eliminated if it can be demonstrated that the downstream pipe conveyance system, which outfalls to Puget Sound, had sufficient capacity to accept the un-detained flows. CONCLUSION: The downstream pipe conveyance system has sufficient capacity to accept the un-detained flows from the new impervious area at 15625 75" PL W. OVERVIEW: The site is located at 15625 75"' PL. W. It is located in very close proximity to the shores of Puget Sound, approximately 300 feet to the west. A single family home is currently under construction on the site. The building permit issued by the city included installation of a detention system consisting of 46 LF of 30" diameter pipe with a Type 1 CB on the south end and a Type 2 CB at the north end. Due to the size and complexity of installation, (proximity of a power pole to the north, 15 foot depth of cut for placement of the Type 2 CB), the applicant is seeking an alternative. DRAINAGE BASINS DISCUSSION: The Meadowdale Drainage Basin has two discharge points into Puget Sound, a north discharge and a south discharge. (See enclosed city of Edmonds storm pipe schematic). Flows from the subject site are routed to the north discharge point. Drainage Basin Maps are included with this report and reflect field reconnaissance work required to ascertain the boundaries of the basins. Kyle & Julianne Ray — Drainage Basin Analysis Page 1 of 2 FLOW SPUTTER DISCUSSION: A survey was conducted by Pacific Coast Surveys to obtain the downstream pipe conveyance data. This survey revealed that a flow splitter is located at the intersection of 75" PL W & 158t' ST SW. This splitter has a 12" FROP Tee to the north and a 12" unrestricted outlet pipe to the south. The FROP Tee outlet to the north is 4.8" higher than the outlet to the south. An analysis to determine the function of this flow splitter is included within Section 4 of this report. Based upon this analysis of flows it was concluded that the FROP Tee to the north is an overflow measure, and the 25-year design storm flows entering the CB are routed to the south outfall. PIPE CAPACITY ANALYSIS: Per the 1992 DOE Manual Page III-2-6, each pipe within a conveyance system is. to be designed such that its barrel capacity at normal full flow is equal to or greater than the 25-year design storm. Peak rate of flow calculations for the contributing basin area of 14.6 acres were calculated using the 25-year 24-hour storm. The 0.08 cfs of un-detained 100- Yr peak flow from the site was then added to the calculated 25-year peak rate of flow from the drainage basin. Analysis was then conducted on each of the pipe segments in the downstream conveyance path. Each pipe segment was found to have sufficient capacity to accept the un-detained flow of 0.08 cfs from the developed site. Kyle & Julianne Ray — Drainage Basin Analysis Page 2of 2 t �. MEADOWDALE -- n•*�. ^«� :x r+a .so-, j 156TH ST, SW a COUNT1Y. PARK ir /SITE , Al MEADOWDALE MARINA �9 2ND M ST SW ^ <� w 3 Q RD - F w MEADOWDALE='' f PL'AYFlELDS r 168TH ST. SW VICINITY MAP KYLE & JULIANNE RAY 15625 751H PL W EDMONDS, WA KYLE &. JULIANNE R1qy ^-."5FR pp w 9STP,M UNKNOWN UNKNOWN �O UNKNOWN I 15524 15514 15515 7105 7103 UNKNOWN 15516 � 7003 ' M20 7215 15508 7111 7107 703/ ESIT 6 E 1-294 32 - 7/01 7609 NKNOWN IWO51- 73 1-272 1-2 -2 - - _ _15 7222 1.23 -236 7124 7100 1-2 3 15601 15610 702e 15600 1-153 1-238 m ' 2 UNKNOWN 1588/5 1-25 Q 7120 7110 1 %562; 15625 UNKNOWN C 1-2 1-23 7029 7019 15631 15711 I 7117 1-158 1 2 1 1-27 � 1-2 159 1 157 1-1 - 15631 1-2 7119 _ 1-2 2 1-24 UNKNOWN 156211 1-28 - 15703 15715 15702 ,-28 �N0RThI 1- so r57o/ � 1-243 - 7930 7022 791e 15708 M— W VT1(.1. f57og -249 15719 F5712 1-288 15709 BAS /N OUTFA LL 15714 15722 15728 ' �p UNKNOWN 15732 15731 -OCf}TIOIV p f" 1UNKNOWN 158th St 1-142 1205 1 ,-186 ST L.1 7TEP ,5Bo6 - 5, 74aa _ 44 - - ,5'73o i-18 2,9 •` VAULT 1-140 1-11-190 1-1 7324 UNKNOWN 15" 15BOB 1-218 f5e[ 15612 1-149 UNKNOWN UNKNOWN 15821 UNKNOWN 15811 S 15624 15925 - UNKNOWN 1-216 1-148 15915 15824 1-217 15 . 15908 1-147 1-202 SOU yY H _ 158a5 15305 ' 15911 M / 1-2$ UNKNOWN MEADOWDA 15910-301- 15925 1-20115917 15910 4) 11INKNOWN 1 -814.51N OVT�� 1-1 8 15927 1-204 15902 15915 15912 1 2 1 199 ; 26 C 15917 UNKNOWN 1-215 I-178 0. 7429 1_ 309 15920w -220 16000 ^ 1_ 5 1-66 \ 15920 1-21 692 UNKNOWN �� _ 1-2 15931 -212 13 -113 1-24 .� u 21 1.82 \ 1-81 1 Boos / 1-85 16121 18008 16012 f6000 16123 16008 1_35 -277 1- 76010 n69: uvn9 zo r— UNKNOWN 1-27 _ 1-11 16021 1B010 1 16105 1601 16008 16031 1-275 16116 1- 3 1 2 1 95 `.. 16020 ^ -17 G: ,- 47 1-37 ' 1-17 UNKNOWN 16105 UNKNOWIg,le -71\ 10105 UNK OWN _2 01-29 - / 1-1 /� 169 18100 1 7 U1' - SECTION 2 Drainage Basin Maps LUL,ti I/UIV Ur Y-LII lt-K IN TYPE 2 CATCH BASIN WITH FROP TEE BASIN AREA EXHIBIT FOR KYLE & JULIANNE RAY 15625 75TH PL W a/NE A 2009 EDMONDS, WA SECTION 3 Drainage Basin Calculations LOWER BASIN RESIDENTIAL 8.56 AC PER ECDC 18.30.010. CC & RR & TT P2 = 1.5 P10 2.0 P100 = 3.0 LOWER BASIN CALCULATIONS• THE UPPER BASIN INCLUDES 51 BUILDING LOTS SFR PER ACRE = 51 26.61 = 1.9 DU/AC INTGERPOLA 17ON OF TABLE N-1.3 IN TH E 1992 DOE MANUAL RESULT IN 24% IMPERVOUS FOR THE RESIDENTIAL AREA IMPERVIOUS CALCULATIONS. 0.24x26.61 AC= 6.39AC CN = 98 LOWER BASIN CALCULA 110NS• THE LOWER BASIN INCLUDES 22 BUILDING LOTS SFR PER ACRE = 2218.56 = 257 DU/AC INTGERPOLA77ON OF TABLE III-1.3 IN 7H E 1992 DOE MANUAL RESULT IN 31% IMPERVIOUS FOR THE RESIDENTIAL AREA IMPERVIOUS CALCULATIONS• 0.31 x 8.56 AC = 2.65 AC N - 98 PERVIOUS CALCULA 110NS• SECOND GROWTH FOREST 6.04 AC CN=81 RESIDENTIAL LANDSCAPING. 556 AC CN=86 CALCULATE WEIGHTED CN =(6.04 X 81) + (5.56 X 86) (6.04 + 5.56) WEIGHTED CN = 83.4 TOTAL AREA = 11.6 AC PERVIOUS CALCULA770NS- SECOND GROWTH FOREST' 3.14 AC CN=81 RESIDENTIAL LANDSCAPING.- 2022.AC CN=86 CALCULATE WEIGHTED CN =(3.14 X 81) + (20.22 X 86) (3.14 + 20.22) m TED CN = 85.33 AREA = 23.36 AC CALCULA 110N EXHIBIT KYLE & JULIANNE RA Y 15625 75TH PL W EDMONDS, WA AINE A 2009 3:0:10 pm -----------------Kyle -Ray, Basin Calculations, 25-yr page 1 --------------------- BASIN SUMMARY ---_-_-_ BASIN ID: B25X SBUH METHODOLOGY TOTAL AREA.......: RAINFALL TYPE....: PRECIPITATION....: TIME INTERVAL....: NAME: 25 YR STORM LOWER BASIN 14.25 Acres TYPElA 2.60 inches 10.00 min ABSTRACTION COEFF: 0.20 TcReach - Sheet L: 270.00 ns:0.1500 p2yr: 1.50 s:0.1300 TcReach - Sheet L: 242.00 ns:0.1500 p2yr: 1.50 s:0.4130 PEAK RATE: 13.40 cfs VOL: 1.64 Ac-ft TIME: 480 min BASEFLOWS: AREA..: CN..... TC BASIN ID: D25X SBUH METHODOLOGY TOTAL AREA.......: RAINFALL TYPE....: PRECIPITATION....: TIME INTERVAL....: 0.00 cfs PERV 11.60 Acres 83.40 23.63 min NAME: 25 STORM UPPER BASIN 29.75 Acres TYPElA 2.60 inches 10.00 min ABSTRACTION COEFF: 0.20 TcReach - Sheet L: 300.00 ns:0.4000 p2yr: 1.50 s:0.0840 TcReach - Shallow L: 588.00 ks:5.00 s:0.0840 TcReach - Shallow L: 157.00 ks:5.00 s:0.1274 TcReach - Shallow L: 280.00 ks:5.00 s:0.0710 PEAK RATE: cfs VOL: 3.75 Ac-ft TIME: 480 min BASEFLOWS: AREA..: CN..... TC 0.00 cfs PERV 23.36 Acres 85.33 54.28 min IMP 2.65 Acres 98.00 10.00 min IMP 6.39 Acres 98.00 10.00 min . U-j -� LA„i . lcn r. � cam- , Q % l� CEJ a C) W H o ro j\ / 0 i 1 4J Ln o �. a J C LLJ cw- H i 30 sm I frC i',.I l ,�, ' �_� �1 :B- a ,,.�.d Y'e - _ 4 € �i����� ..nl.,�.., I ..i' �Ar' •u tia��`� � "`V �r - �tiT,•_� �^ Ej ,�' . � .a.�Gt�o � ��t�� �u`�, �•~ems. �� 0 ••. j'e. 20 11 " � i 63@@ e _ � I� !d P T�8''°a' aic SfJ� ti r� :�,� ice,!- d •�.�1 L.1 ff 3...: sif ue■' ��. ���*s,• t �ti Via_ . 10 k6CNA VV SIff .ram i 40 OT m t �M.,.r� j "�-P_'ta,�• j' `. A ;�(p�.., .E • OFF' i �.�'i..�,-�t�.7® E'... r 5` TIME OF CONCENTRA LION EXHIBI T FOR UPPER & LOWER BASINS KYLE & JULIANNE RAY 15625 75TH PL W JJNE 5, 2M EDMONDS, WA STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN Table III-1.3 SCS Western Washington Runoff Curve Numbers (Published by SCS in 1982) Runoff curve numbers for selected agricultural, suburban and urban land use for Type lA rainfall distribution, 24 hour storm duration. I LAND USE DESCRIPTION Cultivated land(1): winter condition Mountain open areas: low growing brush & grasslands Meadow or pasture: Wood or forest land: undisturbed Wood or forest land: young second growth or brush Orchard: with cover crop Open spaces, lawns, parks, golf courses, cemeteries, landscaping. Good condition: grass cover on Z75% of the area Fair condition: grass cover on 50-75% of the area Gravel roads & parking lots: Dirt roads & Earking lots:. 7O�enwater surfaces, pavement, roofs etc. bodies: lakes, wetlands, ponds etc. Single family reeidential(2):- Dwelling Unit/Gross Acre BImpervious(3) 1.0 DU/GA 15 1.5 DU/GA 20 2.0 DU/GA 25 2.5 DU/GA 30 3.0 DU/GA 34 3.5 DU/GA 38 4.0 DU/GA 42 4.5 DU/GA 46 5.0 DU/GA 48 5.5 DU/GA 50 6.0 DU/GA 52 6.5 DU/GA 54 7.0 DU/GA 56 PUD's, condos, apartments, commercial businesses & $impervious must be industrial areas computed CURVE NUMBERS BY HYDROLOGIC SOIL GROUP A B C D 86 91 94 95 74 82 89 92 65 78 85 89 42 64 76 81 55 72 0 86 81 88 92 94 68 80 86 90 77 85 90 92 76 85 89 91 72 82 87 89 98 98 & 98 100. 100 100 100 Separate curve number shall be selected for pervious & impervious Portions of the site or basin (1) For a more detailed description of agricultural land use curve numbers refer to National Engineering Handbook, Sec. 4, Hydrology, Chapter 9, August 1972. (2) Assumes roof and driveway runoff is directed into street/storm-system. (3) The remaining pervious areas (lawn) are considered to be in good condition for these curve numbers. III-1-12 FEBRUARY, 1992 SECTION 4 Flow Splitter Analysis ' Y TYPE 2 CB TOP=89.19 fROP TEE IE=84.19-IN OVERFLOW=87J4 FROM 158TH ST SW TO NORTH 12' PIPE MEADOWDALE TO SOU TH DRAINAGE BASIN �— 12" PIPE MEADOW LE OUTFALL DRAINAGE BASIN OUTFALL ao IE=84.19 ORIFICE SIZE IE=83.79 SURVEYOR UNABLE TO OBTAIN NOT TO SCALE 4 DETERMINE THE SPLIT OF THE AREA OF FLOW AND SUB EN1LY RATE OF FLOW /N NORTH 12D PIPE THE SIZE OF ORIRCE ON THE PROP TEE IS NOT OW, CONSERVATIVELY ASSUME NO RESTRICTION OF FLOW. AREA OF FLOW FOR UPPER BASIN, = 0. SF, (SEE SEPARATE CALCULATION SHEET.geXf , p THE 0.375 SF IS SPUT BETWEEN THE SOUTH AND NORTH OUTGOING PIPES AS SHOWN BELOW PIPE TO NORTH FROM c FLOW SPUTTER 3 CT S 2, PIPE TO SOUTH FROM �• FLOW SPUTTER D• IE=84.19 IE=84.25 0.343SF 'q jaz�orc nl.P'r" A=0.02 SF IE=83.79 NOTE. - BASED UPON THIS ANALYSIS, THIS ENGINEER, DEDUCTIVELY CONCLUDES THAT THE INTENDED FUNCTION OF FLOW SPUTTER FROP TEE TO THE NORTH IS FOR OVERFLOW FLOWS ABOVE THE 25—)EAR CONVEYANCE SYSTEM DESIGN STORM. HENCE, FOR PURPOSES OF THIS UPSTREAM BASIN ANALYSIS� THE FLOWS FROM THE LOWER BASIN ONLY WILL BE USED TO ANALYZE FLOWS ROUTED TO THE NORTH MEADOWDALE BASIN OUTFAIL. MEADOWDALE UPPER DRAINAGE BASIN FLOW SPUTTER LOCATED AT THE 1N7ERSEC110N OF 75TH PL W & 158171 ST. SW KYLE & JULIANNE RAY 15625 75TH PL W JUNE 5, 2009 EDMONDS, WA ',?'( STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN tgg2 inlet control conditions, which may be present or anticipated in the system, are not specifically addressed. Each pipe within the system is sized and sloped such that its barrel capacity at normal full flow (computed by Manning's Equation) is equal to or greater than the 25-Year design flow. The nomograph in Figure III-2.1 can be used for an approximate i.on or Manning's Equation. For more precise results, or for partial pipe full conditions, solve Mapping's Equation directly: V = 1.49 Ry3 81n n or, using the continuity equation, Q = AV where: Q = 1.49 AR7-"s"7 n Q = Discharge in cfs V = Velocity in fps A = Area in ft2 n = Manning's roughness coefficient in 9-ft'16 (see Table III-2.2) R =.Hydraulic radius = area/wetted perimeter, in ft. s = Slope of the energy grade line in ft/ft For pipes flowing partially full, the actual velocity may be estimated from the hydraulic properties shown in Figure III-2.1 by calculating Qf,11 and Vbll and using the ratio of Qdes;¢n/Q�„�� to find V and c•(depth of flow) . Table:III-2.2 provides the recommended Manning's "n" values for preliminary design using .the Uniform Flow Analysis Method for pipe systems. (Note, the "n" valves for this method are 15% higher in order to account entrance, exit, junction, and bend head losses.► 12•8 -From Fi9u�e 11-2. 1 = QFvll "��� -� 41= � Z- 7 �oY 12 PVC Pik tO vtvll �cf-s QF�1l � 5)2 fke Sou tti From Flow 3 I i. 3 5 p I i fi-er s 1ru c tva� SL. _ l l 70, h ` • 01 Z Fr o rr► UUa{er Works Pr', oot - fea Ic. 25 - Ymr' rafe for Upper Bar,;n- I ,AREA y •6, E' wE7TED PtQI M ETER �� ...---_--- - _........-..,..._ ..----- ... . NOhIOGRAPH FOR SIZING CIRCULAR DRAINS FLOWING FULL 1000 900 PIPE FLDwiN4800 �urff FRool FLOW S rw T FR CB 0001 2.0 700 600 pyC n — o �z 0002 500 , Gr,O(JA(n SLOpE F•PZPj ;+To •0003 Minimum 400 (�(S $ PO .� 12. .0005 •0001 Allowable Velocity -. 300 . I USE Pjp� S� L- Il o(o .0006 (Flowing Full) 3.0 120 v .0008 .0002 CN 108 0 001 0003 200 6 96 a .0004 90 c 84 .002 .0005 4.0 — Ir 78 p .003 .0006 0008 72 LL 66 w .004 •005 .001 5.0 100 60 p .006 N U 90 .008 .002 O 80 - -18 .01 o w 6.0 70 60 w 2 42 V .003 .004 c D � [C 7-0 u_ 50 Z 36 02 -.005 .006 p LL w CL Ci z 33 30 UJ • - 008 LU a w 8.0 _Z w 40 w a 27 .04 .OtQ O � 9.0 a .05 .06 i z — 30 _ LL 14 O .08 .020 >- 10.0 = 21 w 10 t- U) 20 H 18 .030 J LLJ.040 g Q 15 .050 060 Lu j :080 Cis --to 9 8 7 6 5 4 3 2 10 SAMPLE USE //��� 8 24" dia. CMP @ 2% slope yields 20.OVt'VIt 17cfs @ 5.2 FPS velocity Z0� Jr (n = 0.024) 6 Values per Manning's Equation Q= ( 1A9) AR'/3S%z n ° 30.0 This table can be converted to other "n" values by applying formula: I L 40.0 1 Section 5 Undetained 100-Year Peak flow form Developed Site DOSIING DRINNG SURFACE 714 SF (BUILT PRIOR TO JJLY 1977) , DECK 112 SF DRIVEWAY 460.7 TOTAL POST JUL Y 1977 IMPERVIOUS AREA: 3, 372 SF TOTAL IMPERVIOUS AREA: 4,086 SF ROOIFWP Z800 SF IMPERVIOUS AREA EXHIBIT KYLE RAY 15625 751N PL W. SCALD 1'=20' EDMONDSy WA 98026 9-15-06 TIME OF CONCENTRA TION EXHIBIT K11E RAY 15625 757H PL W. EDMONDS, WA 98026 SCALE 1 "=20' 10-15-08 ` 10/10/08 2:46:43 pm page 1 RAY, 75TH, EDMONDS Match Peak for 10 & 100 yr pre-existing BASIN SUMMARY BASIN ID: B100D SBUH METHODOLOGY TOTAL AREA.......: RAINFALL TYPE....: PRECIPITATION....: TIME INTERVAL....: NAME: 100 YR, 24 HR DEVELOPED 0.17;Acres BASEFLOWS: 0.00 cfs TYPEIA 'PERV 3.00 inches -AREA..: 0.08 Acres 10.00 min CN.... : 86.00 TC.... . 10.00 min ABSTRACTION COEFF: 0.20 PEAK RATE: 0.08 cfs VOL: 0.03 Ac-ft TIME: 480 min IMP .0.09 Acres 98.00 10.00 min SECTION 6 Downstream Pipe Conveyance Capacity Analysis DOWNSTREAM DRAINAGE CONVEYANCE EXHIBIT KYLE & JULIANNE RAY 15625 75TH PL W EDMONDS, WA N ScAL_E: I " -(op, CB RIM=10.08 INV 12" CMP (E)=5.68 INV 18" CMP (S)=5.18 3 CB RIM=13.84 INV 12" CMP (E)=7.84 INV 12" CMP (W)=7.44 Y v O J N O O vTO 6 O CB RIM=30.27 INV 12" CMP (E)=27 27 SDMH RIM=82.61 INV 12" CMP (E)=75.61 I INV 12" CMP (W)=75.11- INV 12" PVC (S)=75.61 I I 7-� CB RIM=68.25J I INV 12" CMP (E)=64.25 i INV 12" CMP (W)=64.05 INV 12" CMP (W)=27.17 CB RIM=38.64 INV 12" CMP (E)=35.64 INV 12" CMP (W)=35.44 INV 4" PVC (NE)=36.44 O CB RIM=10.01 INV 18" CMP (N)=.4.71 INV 18" CMP (W)=4.51 APPROX LOCATION 18" OUTFALL INV=1.00+/- PIPE IS NOT VISIBLE UNDER LARGE RIP RAP FLAW 5 PL-17eK SDMH RIM=89.19 INV 12" CMP (N&E)=84.19 INV 12" PVC (S)=83.79 FROP TEE ON PIPE TO NORTH OVERFLOW ELEV=87.34 � 1 R an ] AM . 1 4 rm-.• ` m �•uv ezc 7fsn_ . train, xz CB-TYPE 2-48" TO =85.61 ° IEN)=80.25- 12" CMP- OIE S))=79.73-12" CMP- 9 1 SDMH RIM=81.99 INV 12 CMP (N)=76.59 INV 12" CMP (W)=76.29 CB RIM=86.37 INV 12" PVC (N)=81.57 INV 12" PVC (S)=81.97 2 � 158TH ST SW ___uts a oe . TO SOUTH OUTFALL AINE 4 2009 N u_ (3 Z W O Q S U N 10 1000 900 800 700 :Yir: 500 400 300 200 100 90 80 70 60 50 40 ix NONIOGRAPH FOR SIZING CIRCULAR DRAINS FLOWING FULL PIPE -S L- T OZ%, .0001 • I a C" P=� t)Z, a 29 .0002 2.0 .0003 Minimum a,C ONVE (�/ s Ld w� k 0004 .0001 Allowable BASIN ZS'- YR FLOW .0005 Velocity lFlowin .0006 g -11 3.0 Full) 3 ."T CtS 120 Q .0008 .0002 001 108 0 0003 96 a .0004 90 c .002 .0005 84 .0006 78 O .003 .0008 ' 72 LL 004 66 w .005 .001 60 CL p 006 _N `4 V) 008 .002 48 .01 0 N .003 u -T 42 .004 ir U 36 .02 -.005 p - .006 LL z 33 U�. .00A LU a - 30 .04 _ .010 .0 a 27 .05 a .06 u 14 Q 21 .10 .020 L W .030 .040 W 050 Q 15 .060 p 080 12 .100 10 10 9 8 SAMPLE USE 7 8 24" dia. CMP @ 2% slope yields 6 17cfs @ 5.2 FPS velocity (n = 0.024) 5 d n CApt4e(Ty 6 4 Values per Manning's Equation ��ii r�•- ? 'T.4 CTS% 7 C Q= ( 1.49) AR2/3so'/z 3 n kThis table can be converted to other "n" values by applying 2 ---- formula: ipo-l�r deve*J �tvws AJd undefalned = O.oSCfs -Coy-15-6255 7S PL w• 3.-t8 4.0 5.0 z O U 6.0 w U) W 7.0 a 1- W w 9.0 >- F--10.0 20.0 30.0 40.0 NOMOGRAPH FOR SIZING CIRCULAR DRAINS FLOWING FULL P1 PE a 900 800 S L z .0001 700 (8" CM P �Yl ' 024 2• 600 , 0002 500 . C.O\1VE7YS L_0WjFjQ, Minimum 400 0003 Allowable BASIN FLO WS .0004 .0001 G �/ .0005 Velocity 3.4 C f ICY- (Ir .0006 (FI I) g � 3.0 300 �' G�F 120 cll�r/h v •0008 .0002 108 0 .001 .0003 200 96 11 .0004 90 c .002 .0005 4.0 - 84 rr .000 78 O .003 8 .0 72 LL.004 .001 66 w 005 5.0 100 60 0 .006 N 90 54 0 .002 O 80 � 18 .01 .003 11 0 L 6.0 660 w 42 c .004 -.005 p m 7.0 u: 50 Z 36 .02 .006 u- a Z -33 Z 30 W _ .00A aLJJ w 8.0 w 40 w .04 .010 O a- 27 J u. 9.0 n 06 td..1 z Q 30. U- 14 .08 .020 } 10.0 _ cr 2 .10 r t- U) E 20 w .030 F- 18 .040 -� 050 Q 15 _ 060 w ) p 080 E.100 12 10 . 10 9 8 SAMPLE USE 7 8 24" dia. CMP @ 2% slope yields 20.0 6 17cfs @ 5.2 FPS velocity (n = 0.024) 6 4 Values per Manning's Equation 2/3 Y2 3 n 30.0 CA PAc This table can be converted 4t 2 c 7 314 c� to other "W values by applying 2 s formula: 40-0 r ' add v vtdefaI nod (00 - Yr Peak rate d e ue to fed �(®ws 4or IS- ZS 7 -ib PL W, = 0.09 C(S 3,48 44, Z N u- U Z u, CD X Q. v Ln rep ........... ....... --- -.... . NOMOGRAPH FOR SIZING CIRCULAR DRAINS I -LOWING FULL -1019" PI PE ,3` 51-= 22 7,o 900 - 12 ' ® 5 L =,q' lD - 800 700 .0001 121'0 SL= 22,350b -600171 S I _ dJ 0002 .0003 Minimum -400 of JAL-= 20,.s°l .0004 0001 Allowable Velocity 1219 s L' q` 7 °ld .0006 (Fl owln 9��- 300 120 ALL PI PFs oI .0008 .001 .0002 Full) 108 .0003 200 3 - 8 �� 9 i 000 GMP 8 .002 .0 .00068 72 O LL .003 .0008 pIQ�haSso a_oo •004 .001 90 r-n ni(num slope : 8 .002 C14 _ o100 p 80 70 /'iDtf1C./r' w .�8 .01 003C U) = 60 1fe5 42 .004 Cr Cr ®C I Z_ 50 greafer56p z 36 33 .02 u� .. -.005 .006 p w � �J - 40 have 0( CI Gr�tJ a 30 27 .04 _• .008 .010. a p w w JJ 30. yeakr �n U- 24 .05 .08 } 21 .10 .030 20 Call (( w A II ICilpr 18 .040 �. J j -g Q1 a 15 .050 Q .080 10 9 8 7 6 5 4 9 2 100 10 SAMPLE USE 8 24" dia. CMP @ 2% slope yields 17cfs @ 5.2 FPS velocity (n = 0.024) 6 Values per Manning's Equation Q = ( 1.49) AR3 s%z n ° 9.1 cis > 3 , `Fo This table can be converted to other "n" values by applying formula: D % Add vndefaNltod (oo- Yr- o(ewoIcy L �%ws Fo►r (.-&ZS 7sib rL - W, = p, 08 clF; - 2.0 • 3.0 4.0 5.0 6.0 r 8.0 9.0 _. 10.0 20.0 30.0 40.0 NOMOGRAPH FOR SIZING CIRCULAR DRAINS FLOWING FULL 000 PIP I0 900 800 ,5L� /Q '3' 7 c7 0001 v 700 2.0 600 . 12" C 02f .0002 500 w (fONUEYS LOWER 6116i)( 0003 Minimum G ( Allowable 400 FLOWS OmtY ..0004 0005.0001 Velocity .0006 lFlowing� 3.0 300 3K4o ,� Q 00081.0002 Full) •� ; 08 0 .001 o .0003 200 96 a .0004 90 c .002 .0005 4.0 84 Cr .0006 78 p .003 .0008 72 � 00 66 w 004 .001 5.0 100 60 p .006 _N 90 54 V) .008 .002 O Z 80 • •18 .01 O 6.0 70 w .003 �� w = 42 C 80 U .004 � Z .02 -.005 p 7.0 36 V 50 — .0 LL Z Z 33 U�.. .O08 Lu a w 8.0 w 40 Lu 20 .04 .010. J uw. (D — (4r z 9.0 06 30 24 _ O .08 .020 > 10.0 = 21 10 '= E- uVi w 18 .030 20 w -� .040 050 w Q 15 .060 080 12 .100 -10 10 -9 _ 8 SAMPLE USE — 7 8 24" dia. CMP @ 2% slope yields 6 17cfs @ 5.2 FPS velocity - 5 (n = 0.024) 6 - 4 Values per Manning's Equation Q = ( 1.49) AR2h s% -3 n ° e CapotCThis table can be converted 2 to other "n" values by applying 3,q C 5 3i-C'�formula: 1 14dd Uhdefzrr+76v( too- Yr deve6peel QOW5 �Y- 156,9SS�' 7pL (Al = 0.0S Ce 3.48q 20.0 30.0 40.0 ce(e6Iralinq 2,5 ''ears Q f so' ice FAX Transmittal Date: 11/2/09 To: City of Edmonds, Bldg. Dept. Project Ray Residence Remodel -Jeanie McConnell Name: Permit No. BLD2008-0376 From: Eric Lim, P.E. Project No: KE050550B FAX #: 425-771-0221 # of pages: 14 including cover Revised Final Letter for Geotechnical Construction Monitoring Services necelvEp NOV 4_200 ENGINEERING DIVISION This transmittal is intended of the use of the addressee named herein and may contain legally privileged and confidential information. If you are not the intended recipient of this transmittal, you are hereby notified that any distribution or reproduction of this transmittal is strictly prohibited. If you receive this transmittal in error, please notify AESI by telephone immediately. Thank you. 911 5`b Ave., Ste. 100 • Kirkland, WA 98033 • Phone: 425-827-7701 • Fax: 425-827-5424 w Associated Earth Sciences, Inc. U lid N 91 0 &Ufi�'r Owr25'Years.o f Service November 2, 2009 Project No. KE050550B Kyle and Juliann Ray 702 4" Avenue South Edmonds, Washington 98020 Subject: Revised Final Letter for Geoteclrnical Construction Monitoring Services Ray Residence Reconstruction 15625 75" Place West Edmonds, Washington Permit No. BLD2008-0376 Dear Mr. and Mrs. Ray: As required by the City of Edmonds, Associated Earth Sciences, Inc. (AESI) has prepared this final letter regarding geotechnical construction monitoring observations for your project at the above -referenced site. AESI performed periodic site visits from December 4, 2008 through October 24, 2009 to observe general site monitoring, temporary shoring, site preparation, excavation and grading, structural fill and compaction/proof-rolling, soil bearing verification, retaining walllblock wall placement, backfill and drainage, subsurface drainage, perimeter footing drains, and temporary and permanent erosion control, as required by the City of Edmonds. The results of our observations are summarized in our Field Report Nos. 1 through 8, attached to this letter. A start of work letter statement was made in the first field report. As requested by the City of Edmonds, we have also confirmed that the Lock -Blocks behind the short driveway rockery are alleviating the surcharge on the rockery. Based on our observations, it is our opinion that the project earthwork has been completed in general accordance with the approved project plans, the recommendations presented in our geotechnical engineering report dated January 10, 2008, and subsequent recommendations during construction. Kirkland a Everett Tacoma 425-827-7701 425-259-0522 253-722-2992 www.aesgeo.com We appreciate the opportunity to be of service to you on this project. Should you have any questions regarding this letter, please call us at your earliest convenience. Sincerely, ASSOCIATED EARTH SCIENCES, INC. Kirldand, Washington Eric J. Lim, T. E. Senior Projec E ineer Attachments: Field Report Nos. 1 through 8 cc: Hoover Premier Homes Attn: Mr. Scott Hoover Scott@lioovcrpremierhomes.com City of Edmonds Building Department Attn: Ms. Jeanie McConnell Fax: (425) 771-0221 ULAb KL-05055006 11rnjws\20050550\KL\W1' Q`ON Mctij�c 1 1 1 OWA.y�y�'S,9� ti h i ww 33222 F FGlSTEP� � G S"T/ANAL G. Aaron McMichael, P.E., P.E.G. Associate Engineer FIELD REPORT Associated Earth Sciences, Inc. 911 Fifth Avenue, Suite 100 Kirkland, Washington 98033 425-827-7701 FAX 827-5424 TO: _Kyle and Juliann Ray 702 - 4"' Avenue South Edmonds, WA 98020 ATTN: Kyle Ray AS REQUES'rED BY Scott Hoover THE. FOLLOWING WAS NOTED: Page 1 of 2 Date Project Dame Project No. 4 Dec 08 111'.IyResidence KE050550B Location W ea lher 15625 75"' Place W Clear, 50s F Municipality Rcporl Number City of Edmonds I Engineer/Architect Donna Breske / Hanson Design Client/Owner Kyle and Juliann Ray General Contractor/Superintendent Hoover Premier Homes / Scott Hoover Grading ContractorlSuperintendent Buchanan Land Construction / Duncan Buchanan AESI was onsite today to for the preeonstruction meeting. In attendance were Jeanie McConnell and Jennifer Collins with the City of Edmonds, Scott Hoover with Hoover Prenuer Homes, and Duncan Buchanan with Buchanan Land Construction. On arrival, the site ground surface is well vegetated with grass and landscape shrubs, and appears not to have changed from previous site visits. No indications of seepage were observed at the bottom of the east slope. AESI has previously submitted a wet season grading request letter, dated October 2, 2008, outlining recommendations for wet season grading. Topics of geotechnical discussion for this meeting were: 1) TESC BMPs; Prior to grading, the contractor will install silt fence downgradient of all excavations, establish a rock -arniored construction entrance, and keep street clean. The City requested a filter sock or fabric be placed in the CB in the street near the NW corner of the site. A filter fabric is already in place in the CB near the SW corner of the site. if a CB exists fiirther downgradient to the south where the contractor had parked his truck, then the City requested a filter fabric be placed in that CB as well. The contractor will notify City for inspection once installed. The contractor is responsible for inspecting and maintaining B.MPs. 2) Wet Season site monitoring: AESI will visit the site after all significant rain events (more than 1 inch per 24 hours) to observe site conditions and adequacy of BMPs. 3) Interceptor Trench: After TESC are installed, contractor will begin with installing interceptor trench at east edge of'lot. Foundation excavations will follow the interceptor trench. 4) Shoring: Contractor will use Lock -Blocks for shoring east side of basement excavation up to 10 feet high. The contractor informed us that the planned 7.5-ft high shoring for the north side of the basement, which is in the interior of the building conflicts with the footings for the main floor, Since these main floor footing need to tie into the basement wall footings, they will be stepped down to match. AESI agreed and recommended 1.5H:1V temporary slopes in this area only and must be covered in plastic. The main shoring wall along the east wall must be maintained since it protects the larger slope to the east and is of concern to the City. COPIES TO: City, Hoover, Hanson, Bieske, file FiELD REP.: Eric Lim. PL• DATE PRINCIPAL / PM: Aaron McMichael, PE, EEG'.�tn MAILED. DEC 0 8 2008 FIELD REPORT To: Kyle Ray Project Name: Ray Residence Date: 4 Dec 08 Project Number: KE0505.50B 2 5) "Native" landscape areas: One approved plan sheet shows a "native" growth area to remain undisturbed in the landscaped slope along the northern half of the western property line. IIowever, the stormwater detention pipe is planned to be located in that area, so the contractor indicated this area will be disturbed. Also, a water meter appears to conflict with the detention pipe location. Ms. McConnell informed us she would look into this issue with the building department. G) "Start of Work I_,etter": one special inspection requirement was to provide a Start of Work letter once the permit was issued and the contractor is ready to begin actual work. AESI spoke with Ann Bullis with the City of Edrnonds, who agreed that this field report for the pre -con meeting would be accepted as the Start of Work letter. Conditions for the site appear not to have changed fion previous site visits or that assurned during design. We understand that the duration for each construction task will remain as described in out Oct. 2, 2008 letter, except that the schedule of dates would be pushed back. according with today as the start date. Copies To: City, Hoover, Hanson, Breska, file _ Field Rep- Eric Lien, PE Date Mailed: �_ Principal /PM: Aaron McMic PE, PEG FIELD REPORT Associated Earth Sciences, Inc. }. 91 I Fillh Avenue. Suite 100 Kirkland, Washington 98033 425-827-7701 FAX 827-5424 TO: Kyle and Juliann Ray 702 - 4rh Avenue South Edmonds, WA 98020 ATTN: Kyle Ray AS REQUESTED BY Scott Hoover THE FOLLOWING WAS NOTED: Permit No. BLD2008-037 Page 1 of 1 Date Project Name Project No. 12-11 08 Ray Residence KE0505508 Location weather 15625 75"' Place W Clear, 40's f Ylunicipulity Rcport Numbcr City of Edillonds 2 Engineer/Arehiteet Donna Breslce / Hanson Design C hrlitlowncr Kyle and Juliann Ray Ceteral Con tractor/Snperiniendent Hoover Premier Homes / Scott Hoover Ceding Contractor/Snperintendent Buchanan Land Construction / Duncan Buchanan AES1 was onsite today to observe excavation progress and conditions, soil subgrade conditions and to perform a weekly TESC inspection. Excavation Progress/Conditions: Upon arrival onsite, we met with Duncan Buchanan of Buchanan Land Construction, They had begun excavation of the basement area. and were in the process of loading trucks to export the excess soil. The excavation was ranged from approximately 7 to I 1 feet below the existing ground surface. The north, east, and south cut slopes of the basement area were cut in a near vertical configuration. A temporary Lock Block shoring wall will be placed along the east cut slope when the excavation is completed. At this time, there were no sights of groundwater seepage out of the cut slopes and there were no observed signs of caving. Currently, the bottom of the excavation was at 1 foot below the design pad elevation, Soil Sttbgrade Conditions: The exposed soil at the base of the excavation was a moist to wet, light brown to gray, tine to medium sand with silt (ancient colluvium). There was some blue gray silt with some gravel in the SE corner of the excavation. Using a steel soil probe, the exposed soils were penetrated 8 to 24 inches under full body weight. 'The soil stiffened with depth, even in the areas where it was penetrated 18-24". The contractor wanted to attempt to compact the native soils in place, and then place 1 foot of compacted 2-inch clean crushed rock to the design subgrade elevation. Upon trying to compact the native soils with a hoe pack, the subgrade began to yield slightly. At this time, we recommended that the contractor excavate an additional foot of the native soil and then place a two feet of the 2" clean crushed rock, compacted in two lifts, to the design subgrade elevation, as specified in our geoteehnical report. TESC Inspection: While onsite, we performed a TESL inspection, Buchanan Land Construction had installed the interceptor swale on the east edge of the lot. The v-shaped trench had been lined with filter fabric, a 6" perforated pipe was installed and the trench was backf lled with washed drain rock. The ends of the drain were still exposed, and there was a small pile of drain rock at each end, to bed the pipe after the connection is made. Silt fence had been installed along the south side of the site and was in good condition. The construction entrance was lined with quarry spalls and sediment track out from the recenttruck traffic was minimal. Duncan Buchanan said that they were sweeping up at the end of each day. Inlet protection was adequate and there was no runoff from the site at the time of our visit. Scott Hoover arrived onsite and we spoke briefly about the interceptor Swale and future scheduling of our site inspections. A.ESI will return as necessary to perform required inspections. COPIES T0: Cite, Room, Hanson, Breslce, file FIELD REP.: Andrew Glandon, PEG, CPfSC DATE DEC 15 2008 MAILED: PRINCIPAL / PM: _Aaiun McMichael, PC. PEG �� FIELD REPORT Associated. Earth Sciences, Inc. 911 f-iftli Avenue, Suite 1.00 Kirkland, Washington 98033 425-827-7701 FAX 827-5424 TO: Kyle aad Juliann Ray 702 - 4"' Avenue South Edmonds, WA 98020 ATTN: Kyle Ray AS REQUESTED BY Scott Hoover THE FOLLOWING WAS NOTED: Permit No, BLD2008-037 Page 1 of 1 Date Project Name Project No. 12-29 08 Ray Residence KE050550B Location Weather 15625 751° Place W Windy, 40's Municipality Report Number City of Edmonds 3 Engineer/Architect Donna Breske / Hanson Design Ctient/Owner Kyle and Juliann Ray General Contractor/Superintendent Hoover Premier I. -Tomes / Scott Iioover Grading Contractor/Superintendent Buchanan Land Construction / Duncan Buchanan AESI was onsite today to perform a weekly TESC inspection. TESC inspection: An. erosion control inspection was not performed last week due to the snow and hazardous road conditions. There was no earthwork going on while we were onsite today. Previously, Buchanan Land Construction had installed the temporary shoring (Lock -Block) wall along the cast excavation cut slope along the east edge of the lot. The blocks had been set 4 blocks high and were set in the orientation specified in the design Plastic sheeting had been spread over the excavation cut sloped and on the soil that had been stockpiled for export. The plastic sheeting was in generally good condition, thought there were a few areas that the plastic had been blown out of place by the heavy wind. The construction entrance was covered with quarry spalls and there was no sediment track -out or runoff from the site. The adjacent catch basins had filter inserts and were not in need of maintenance. Based on the field conditions observed, it is our opinion that the BMPs currently in place are perforniing properly and no additional erosion control measures are required at the time. Prior to arriving on site, we spoke with Scott. Hoover on the telephone. He said that they plarmed on resuming site earthwork on Monday, January 5"', 2009. AESI will coordinate with Scott Hoover for future required inspections. COPIES TO: City, Hoover, Hanson, Breske, file FIELD REP.: Andrew Glandon, PEG, CPESC DATE DEC 31 2008 MAILED: PRINCIPAL / PM, Aaron McMichael, PE-, PEG FIELD REPORT Assuciated. Earth Sciences, Inc. 911 Fifth Avenue, Suite 100 Kirkland, Washington 98033 425-827-7701 FAX 827-5424 TO: Kyle and Juliann Ray 702 - 4'" Avenue South Edmonds, WA 98020 _ ATTN: Kyle Ray AS REQUESTED BY Scott hoover THE FOLLOWING WAS NOTED: Permit No, BLD2008-037 Page 1 of 1 Date Project Name Project No. 1-8-09 Ray Residence KE050550B Location weather 15625 75" Place W Cloudy, 40's Municipality Report Number City of Edmonds 4 rutgrueer/Architect Donna Breske / Hanson Design Clientlowner Kyle and Juliann Ray General Contractor/Superintendent Hoover Premier Humes / Scott Hoover Grading Contractor/Superintendent Buchanan Land Construction / Duncan Buchanan AESI was onsitc today to observe the garage area subgrade and to perform a weekly TESC inspection. Subgrade Observations: Buchanan Land Construction had continued to overexeavatc soil from the garage area and place back 2 feet of 2" clean crushed rock back to the planned subgrade elevation. Duncan Buchanan was onsite working at the time of our site visit; compacting the crushed rock with a hoe -pack and fine grading the cn.rshcd rock with the track -hoe, using an I -beans in the bucket and thumb of the hoe to smooth out the surface. Based on field performance observations and the exposed soil near the edge of the crushed rock, the prepared subgrade is suitable for support at the design bearing capacity of 2,000 pounds per square foot. Duncan said that the last bit of the garage, near the future garage door would be somewhat time consuming to finish, due to the access challenges and having to move some excess soil on site. At this time, the entire garage subgrade area had not been completed, but what has been done has been done properly and in a manner that is consistent with the reconulieridations in our geotechnieal report. TESL Inspection: Whine onsite we observed the condition of the site BMP's. Some excess soil had been stockpiled on the northern portion of the site over the past few days and was currently covered with plastic sheeting, which was in good condition. The construction entrance was covered with quarry spalls and there was no sediment track -out or runoff from the site. The adjacent catch basins had filter inserts and were not in need of maintenance. The interceptor swale along the east edge of the lot was in place and appeared to be working. Duncan had inserted. steel sheets up against the soil on the north side and south sides of the temporary Lock -Block shoring wall. This was done to make a better transition at the wall edges. Based on the field conditions observed, it is our opinion that the BMPs currently in place are performing properly and no additional erosion control measures are required at the time. AESI will return to observe subgrade conditions and construction progress at the request of Scott Hoover and to perform weekly TESC inspections. COPIES TO DATE MAILED: City, Hoover, Hanson, Breske, file FIELD REP JAN 1 5 2009 PRINCIPAL / PM Andrew Glandon, PEG, CPESC Aaron McMichael, PE, PEGS 911 Filch Avenue • Suite 100 Kirkhtnd, WA 98033 425-827-7701 FAX 425-827-5424 ATTN. Qa AS REQUESTED BY: THE FOLLOWING WAS NOTED: A9 FIELD REPORT # 291.1 1/2 Hewitt Avenue • Suite 2 Everett, WA 98201 425-259-0522 FAX 425-252-3408 PAGE 1 OF l D, �) Project � N�om 1 CA — P`rro}�ec�ll.No. Location m, es 7;011t '1 `1v W other c�/ u� V s Munie' ali . j� Bid . Pe mit No. En i eer/Architect Client O er rl Ml Ce tractor SuperinI ndent jarthwark Contra for/Su eAi rr ndent j 1 iC/l�p•it 1 '� i, V v j Cn¢- sY"� i.%t�' �t-za� �,+:v C•/ /n's•J•a c)., �i�✓S.�C,i Cs*-, % fbls'�-C�7i:c9 �... v A� S.y will ' l n-^ � � '✓t /� i c1 L �bc�i� 3��►�� 5 c:y� C.an$►/i'e�}�i2n�,�J Yc SS `t 5 i"[�:u�Yzsit � y-st.°7�yye�?Lrr' .+.- /C TZty, FIELD COMPACTION EQUIPMENT UTILIZED: 11J/� e -n - AREAS OF ADDITIONAL CONCERN: ADDITIONAL TESTS REQUIRED: [} YES 0 NO WHERE? COPIES TO:F;. ",� R-v DATE MAILED: JAN 1 6 FIELD REP: 'PROJECT MANAGER:: • Field Report subject to review by AESI Project Manager AF.Sl_Fltl. rev 3/2006 911 fifffi Awmue 9 Suite 100 Associated Earth Sciences, Inc. Kirkland, WA 98033 425-827-7701 FAX 425-827-5424 FIELD REPORT FIELD REPORT # .,/,c -x TO: /11 hZy ATTN- AS REQUESTED BY. A-1 D%?-41'- THE FOLLOWING WAS NOTED., 2911 16 Hewitt Avenue - Suite 2 F.vp-mtt, WA 98201 425-259-0522 FAX 425252-3408 PAGE /- OF joc, Nome P SLNO. sly Z' 7— �N. 5 Location -s6z.5 '75" It/ her - I lvc�- M 'I 011ty 101� /41'1'.�. Bldg Permit Nb. 0'3-7 �4 E ine6r/Archilec Client ownt 1; Co-ntr c 5r/Superintend nt Jarthwork Confrqctor/S "te Oent U•=crl�:;I.,,, z, M�Q 4,,A J%J V ye- Tx;l�,eAd t-,7,zZi .11; V1 a IV; il; e, y J.444-1 A' "At 15. 04.1 1�1 1 -40 al:" ' ar V i't'L-A'V'L sro; 'ffN Aa Vltk —4-SkA VV FIELD COMPACTION EQUIPMENT UTIUZED: AREAS OF ADDITIONAL CONCERN: ADDITIONAL TESTS REQUIRED: [] YES jig NO WHERE?_ COPIES TO.,r, dd FEB 0 6 2009 DATE MAILED: FIELD REP - *PROJECT MANAGER: ' Field Report subject to review by AESI Project Manager ALSI-r-RL rev 3/2006 911Fik6Avenue • Suite 100 Associated Earth Sciences, Inc- 291.1TkHewitt Avenue oSuite 2 - Everett, WA 98201 Kirkland,WA 98033 425-827-7701 a 425-259-0522 FAX 425-827-5424 FIELD REPORT FAX 425-252-3408 FIELD REPORT!! PAGE Z OF TO: l r�,.,/ 7V Z_ ATfN: AS REQUESTED BY: r.. bt/'4- qyozo THE FOLLOWING WAS NOTED: Date Proiecf Name Proi�ct No. tr Location 7,y � { ,:• L� �I t �� VI•� ath � g i i , G'.�' Yo I Muni 'polity / C.. s • . ' Bldg. Pert o^ Engi er/Arehite4t LLs Clint Oy+ner� Ge eral Contr tar/Superinte� nt <.�L / L� r /��Jr {A✓ IYJVFti � E rfhwork Contractor/Superintendent r .� FIELD COM PACTION EQUIPMENT UTILIZED: AREAS OF ADDITIONAL CONCERN: ADDITIONAL TESTS REQUIRED: ❑ YES I/�d� NO WHERE? COPIES TO: FIELD REP: DATE MAILED: 'PROJECT MANAGER; Field Report subject to review by AESI Project Manager s AESI_ -RL. rcv 3/2006 FIELD REPORT Associated Earth Sciences, Inc. CE%fi►vr�tyz� Z%mrro been*cee 911 Fifth Avenue, Suite 100 Kirkland, Washington 98033 425-827-7701 FAX 827-5424 TO: Kyle and Juliann Ray 702 - 4'h Avenue South Edmonds, WA 98020 ATTN: ICyle RayAS REQUESTED BY Scott Hoover TI-IE FOLLOWING, WAS NOTED: Permit No. BLD2008-037 Page 1 of I Date Project Name Project No. 2-23-09 Ray Residence ICi, 050550B Location Weather 15625 751h Place W Cloudy, 40's Municipality Report Number City or Edmonds 7 Engineer/Architect Donna Breslce 1 Hanson Design Client/Owner Kyle and Juliann Ray General Contractor/Superintendent Hoover Premier Homes / Scott Hoover Grading Contractor/Superinteudent Buchanan Land Construction / Duncan Buchanan AF-.S1 was onsite today to observe footing drain installation and to perform a TESC inspection. Footing Drain Installation: Since our previous site visit, the perimeter stem wall and the interior grid footings had been placed. Using a steel soil probe, the crushed rock over soil subgrade was penetrated approximately 1-2 inches under full body weight and it is our opinion that the footing subgrades are suitable for support at the design bearing capacity of 2,000 pounds per square foot. Buchanan Land Construction had installed footing drain pipe along the east, north and west side of the building. The footing drain had been bacicfilled along the west side, but was exposed along the north and east. A 4" perforated PVC pipe had been set at the base of the footing. At the northwest comer, the pipe had been set, it was bedded in washed rock to approximately 1 foot over the top of the pipe and filter fabric was placed over the washed rock. In our opinion, the footing drains that were observed today had been installed properly and where they were in progress, the steps taken so far were in accordance with the plans and our drainage recommendations. Based on a later conversation with Eric Lim (AESI), it is our opinion that on the east side of the house, the upper footing drain and drain rock on the north half of the house should be capped at the transition to the lower footing drain and should not be connected to the lower footing drain that serves the southern portion. Subgrade Observations: Since our last visit, the perimeter stem walls and interior footings had been placed in the northern portion of the house. While onsite, we spoke with Duncan Buchanan (Buchanan Land Constnuction). He asked about fill inside the crawlspace. •WP ta1d hirn�t. p gd-s(;i1 afietrbaelEf�ll l-'31't-'t91�Spr�2dg9�.. �fZ��:•Cif'f%T2 i L!cJ r�Jt�ltS�C., L: S}S�<L--17X�2 I?.q-6F(U c� ��i�isi �S"!�•i TESC Inspection: While onsite we observed the condition of the site BMP's. Buchanan Land Construction was hauling off excess soil-, loading dump trucks with soil. The construction entrance was covered with quarry spalls and there was no sediment track -out or runoff from the site. The adjacent catch basins had filter inserts and were not in need of maintenance. The interceptor swale along the east edge of the lot was in place and appeared to be working. The temporary Lock -Block shoring wall along the north side of the excavation was in place and there were no observed signs of caving or sloughing. Based on the field conditions observed, it is our opinion that the BMPs / currently in place are performing properly and no additional erosion control measures are required at the time. AESI will return to observe subgrade conditions and construction progress at the request of Scott Hoover and to perform weelc�ly TESC lnsl>ect►nu� (Cv i `�� /kc7rLo�5 �5. orVL� Srtt -iZ Lt,*LL P&577 .S lZ hit%'c �t+l2c /j i-e�z t-• 7 a ,hES ( 'Vc Fflw�.tt�•-rrZc rJ l�(.�1 ;Vu '')4' !�G 4LJJI-'I•Ls kV eia7:v�i',4t�. i v c • A, so /vo McL�:� �=v� r-2�sT�'L 3�- Zvn/ %�t,2 d L — �u OP TD c>tv G?c�5rte t2.ai,/•� i:r�l G�� zv(��o �' COPIES TO: City, Hoover, Hanson, Breske, file A•s -�s- � I " FIELD REP.: ���drcw Glandon, PEG, CPESC MATFD: FEB 7 2009 PRINCIPAL / PM: �� Aaron McMichael, PE, PEG FIELD REPORT Associated Earth Sciences, Inc. q:. x 1._ f &66"bl yz 911 Fiflh Avenue, Suite 100 Kirkland, Washington 98033 425-827-7701 FAX 827-5424 TO: Kyle and Juliann Ray 702 - 41" Avenue South Edmonds, WA 98020 ATIV: Kyle Ram AS REQUESTED BY Scott Hoover THE FOLLOWING WAS NOTED: Pennit No. BLD2009-037 Pagc 1 of I Date Project Name Project No. 2-23-09 Ray Residence KE050550B Location weather 15625 75"' Place W Cloudy, 40's Municipality Report Number City of Edmonds 7 Engineer/Architect Donna Breslce / Hanson Design Client/Owner Kyle and Juliann Ray General Contractor/Superintendent Hoover Premier Homes / Scott Hoover Grnding Contractor/Superintendent Buchanan Land Construction / Duncan Buchanan AES1 was onsite today to observe footing drain installation and to perform a TESC inspection. Footing Drain Installation: Since our previous site visit, the perimeter stem wall and the interior grid footings had been placed. Using a steel soil probe, the crushed rock over soil subgrade was penetrated approximately 1-2 inches under fiill body weight and it is our opinion that the footing subgrades are suitable for support at the design bearing capacity of 2,000 pounds per square foot. Buchanan Land Construction had installed footing drain pipe along the east, north and west side of the building. The footing drain had been backfilled along the west side, but was exposed along the north and east. A 4" perforated PVC pipe had been set at the base of the footing. At the northwest corner, the pipe had been set, it was bedded in washed rock to approximately 1 foot over the top of the pipe and filter fabric was placed over the washed rock. In our opinion, the footing drains that were observed today had been installed properly and where they were in progress, the steps taken so far were in accordance with the plans and our drainage recommendations. Based on a later conversation with Eric Lim (AESI), it is our opinion that on the east side of the house, the upper footing drain and drain rock on the north half of the house should be capped at the transition to the lower footing drain and should not be connected to the lower footing drain that serves the southern portion. Subgrade Observations: Since our last visit, the perimeter stem walls and interior footings had been placed in the northern portion of the house. While onsite, we spoke with Duncan Buchanan (Buchanan Land Construction). He asked about fill inside the crawlspace. We told him that compacted soil would be suitable for foundation backfill and the soil should be placed up to the top of the spread footings. TESC Inspection: While onsite we observed the condition of the site BMP's. Buchanan Land Construction was hauling off excess soil; loading dump trucks with soil. The construction entrance was covered with quarry spalls and there was no sediment track -out or runoff from the site. The adjacent catch basins had filter inserts and were not in need of maintenance. The interceptor swale along the east edge of the lot was in place and appeared to be working. The temporary Lock -Block shoring wall along the north side of the excavation was in place and there were no observed signs of caving or sloughing. Based on the field conditions observed, it is our opinion that the BMPs currently in place are performing properly and no additional erosion control measures are required at the time. AES1 will return to observe subgrade conditions and construction progress at the request of Scott Hoover and to perform weekly TESC inspections. COPIES TO: City, Hoover, Hanson, Breske, file FIELD REP.: 0 & 6/e ndrew Glandon, PEG, CPLSC DATE PRINCIPAL / PM: Aaron McMiclinel, PE, PEG MAILED: _ FEB 2 7 Z009__—_ _ !' �z FIELD REPORT Associated Earth Sciences, Inc. T Cr/tifIW�ity n"of'oea i, 911 Fifth Avenue, Suite 100 Kirkland, Washington 98033 425-827-7701 FAX 827-5424 TO: Kyle and Juliann Ray 702 - 4"' Avenue South Edmonds, WA 98020 ATTN: Kyle Ray AS REQUESTED BY Scott Hoover THE FOLLOWING WAS NOTED: Permit No. BLD2008-037 Page 1 of 1 Date Project Name Project No. 10/24l09 Ray Residence KE050550B Location Weather 15625 75rh Place W Overcast, 60s F Municipality Report Number City of Edmonds 8 Engineer/Architect Donna Breske / Hanson Design Client/Owner Kyle and Juliann Ray General Contractor/Superintendent Hoover Premier Homes / Scott Hoover Grading Contractor/Superintendent Buchanan Land Construction / Duncan Buchanan We visited the site to observe final site conditions'prior to occupancy and address City staff comments regarding the rockery along the south side of the driveway. On arrival, we observed that the exterior house construction was complete and that landscaping in the font yard was complete. The landscaping in the rear yard was nearly complete with sod being installed during our visit. We observed the rockery along the south side of the driveway. We measured the rockery to be approximately 12'8" long and approximately 3' 10" in maximum height. The rockery extended west from. the north foundation wall of the hotise and tapered down in height to match grade in the front yard. It appears that the rockery was necessary since a slope would have placed soil against the finished wood siding of the house. Mr. Hoover informed its that 2 rows of Lock -Blocks were left in -place along the south edge of the driveway and are directly behind the rockery. We hand -probed between the rockery stones and felt a block where we could penetrate the crushed rock backfill. In our opinion, the Lock -Blocks are alleviating surcharge on the rockery, and the short retaining structure is suitable for support of the driveway and anticipated vehicle loads. COPIES TO: City, Hoover, Hanson, Breske, file DATE MAILED: FIELD REP.: Eric Lim, PF_. i PRINCIPAL / PM: Aaron McMichael; PE, PEG Associated Earth Scien es, lake id NJ 91 *, Cep ra6iy Over 25'Jean o f Service November 2, 2009 Project No. KE050550B Kyle and Juliann Ray 702 4`h Avenue South Edmonds, Washington 98020 NOV — 4 2009 DEVELOPMENT SERVICES CTR. CITY OF EDMONDS Subject: Revised Final Letter for Geotechnical Construction Monitoring Services Ray Residence Reconstruction 15625 75"' Place West Edmonds, Washington Permit No. BLD2008-0376 Dear Mr. and Mrs. Ray: As required by the City of Edmonds, Associated Earth Sciences, Inc. (AESI) has prepared this final letter regarding geotechnical construction monitoring observations for your project at the above -referenced site. AESI performed periodic site visits from December 4, 2008 through October 24, 2009 to observe general site monitoring, temporary shoring, site preparation, excavation and grading, structural fill and compaction/proof-rolling, soil bearing verification, retaining wall/block wall placement, backfill and drainage, subsurface drainage, perimeter footing drains, and temporary and permanent erosion control, as required by the City of Edmonds. The results of our observations are summarized in our Field Report Nos. 1 through 8, attached to this letter. A start of work letter statement was made in the first field report. As requested by the City of Edmonds, we have also confirmed that the Lock -Blocks behind the short driveway rockery are alleviating the surcharge on the rockery. Based on our observations, it is our opinion that the project earthwork has been completed in general accordance with the approved project plans, the recommendations presented in our geotechnical engineering report dated January 1.0, 2008, and subsequent recommendations during construction. STREET FILE IC.irkland o Everett o Tacoma 425-827-7701 425-259-0522 253-722-2992 www.aesgeo.coni We appreciate the opportunity to be of service to you on this project. Should you have any questions regarding this letter, please call us at your earliest convenience. Sincerely, ASSOCIATED EARTH SCIENCES, INC. Kirkland, Washington Eric J. Lim, f.E. Senior Project.E; Attachments: Field Report Nos. 1 through 8 cc: Hoover Premier Homes Attn: Mr. Scott Hoover Scott@hooverpremierhomes. com City of Edmonds Building Department Attn: Ms. Jeanie McConnell Fax: (42.5) 771-0221 U Utb KL0505500G 11rojccts\20050550 E\WP Fa PAN MCIy1C OF WASy�� 'S9 vi l W 33222 0 �� tC FG/ST6P� G\ G. Aaron McMichael, P.E., P.E.G. Associate Engineer Associated Earth Sciences, Inc. 911 Fifth Avenue, Suite 100 Kirkland, Washington 98033 42.5-827-7701 FAX 827-5424 TO: Kyle and Juliann Ray 702 - 4"' Avenue South Edmonds, WA 98020 ATTN: Kyle Ray AS REQUESTED BY Scott Hoover THE FOLLOWING WAS NOTED: FIELD REPORT Page I of 2 Date Project Name iRayResidence Project No. 4 Dec 08 KE050550B Location Weather 15625 75"' Place W Clear, 50s r Municipality Report Number City of Edmonds I Engineer/Architect Donna Breske / Hanson Design Client/Owner Kyle and Juliann Ray General Contractor/Superintendent Hoover Premier Homes / Scott Hoover Grading Contractor/Superintendent Buchanan Land Construction / Duncan Buchanan AESI was onsite today to for the preconstruction meeting. In attendance were Jeanie McConnell and Jertnifer Collins with the City of Edmonds, Scott Hoover with Hoover Premier Homes, and Duncan Buchanan with Buchanan Land Construction. On arrival, the site ground surface is well vegetated with grass and landscape shrubs, and appears not to have changed from previous site visits. No indications of seepage were observed at the bottom of the east slope. AESI has previously submitted a wet season grading request letter, dated October 2, 2008, outlining recommendations for wet season grading. Topics of geotechnical discussion for this meeting were: 1) TESC BMPs: Prior to grading, the contractor will install silt fence downgradient of all excavations, establish a rock -armored construction entrance, and keep street clean. The City requested a filter sock or fabric be placed in the CB in the street near the NW corner of the site. A filter fabric is already in place in the CB near the SW corner of the site. If a CB exists further downgradient to the south where the contractor had parked his truck, then the City requested a filter fabric be placed in that CB as well. The contractor will notify City for inspection once installed. The contractor is responsible for inspecting and maintaining BMPs. 2) Wet Season site monitoring: AESI will visit the site after all significant rain events (more than 1 inch per 24 hours) to observe site conditions and adequacy of BMPs. 3) Interceptor Trench: After TESC are installed, contractor will begin with installing interceptor trench at east edge of lot. Foundation excavations will follow the interceptor trench. 4) Shoring: Contractor will use Lock -Blocks for shoring east side of basement excavation up to 10 feet high. The contractor informed us that the planned 7.5-ft high shoring for the north side of the basement, which is in the interior of the building conflicts with the footings for the main floor. Since these main floor footing need to tie into the basement wall footings, they will be stepped down to match. AESI agreed and recommended 1.514: IV temporary slopes in this area only and must be covered in plastic. The main shoring wall along the east wall must be maintained since it protects the larger slope to the east and is of concern to the City. COPIES TO: City, Hoover, Hanson, Breske, file FIELD REP.: Eric Lim, PE LL C DATE PRINCIPAL, / PM: Aaron McMichael, PE, PEG MAILED: DEC 0 8 2008 r�i FIELD REPORT To: Kyle Ray Project Name: Date: 4 Dec 08 Project Number: Ray Residence KE050550B Fiz 5) "Native" landscape areas: One approved plan sheet shows a "native" growth area to remain undisturbed in the landscaped slope along the northern half of the western property line. However, the stormwater detention pipe is planned to be located in that area, so the contractor indicated this area will be disturbed. Also, a water meter appears to conflict with the detention pipe location. Ms. McConnell informed us she would look into this issue with the building department. 6) "Start of Work Letter": one special inspection requirement was to provide a Start of Work letter once the permit was issued and the contractor is ready to begin actual work. AESI spoke with Ann Bullis with the City of Edmonds, who agreed that this field report for the pre -con meeting would be accepted as the Start of Work letter. Conditions for the site appear not to have changed from previous site visits or that assumed during design. We understand that the duration for each construction task will remain as described in out Oct. 2, 2008 letter, except that the schedule of dates would be pushed back according with today as the start date. Copies To: City, Hoover, Hanson, Breske, file Field Rep: Eric Lim, PE Date Mailed: Principal /PM: Aaron McMi PEG Associated Earth Sciences, Inc. J 911 Fifth Avenue, Suite 100 Kirkland, Washington 98033 425-827-7701 FAX 827-5424 TO: Kyle and Juliann Ray 702 - 4"' Avenue South Edmonds, WA 98020 ATTN: Kyle Ray AS REQUESTED BY Scott Hoover THE FOLLOWING WAS NOTED: FIELD REPORT Permit No. BLD2008-037 Page 1 of 1 Date Proiect Name 1 Project No. 12-11 08 Ray Residence KE050550B Location weather 15625 75"' Place W Clear, 40's F Municipality liepm•t Number City of Edmonds 1 2 Engineer/Architect Donna Breske / Hanson Design Client/Owner Kyle and Juliann Ray General Contractor/Superintendent Hoover Premier Homes / Scott Hoover Grading Contractor/Superintendent Buchanan Land Construction / Duncan Buchanan AESI was onsite today to observe excavation progress and conditions, soil subgrade conditions and to perform a weekly TESC inspection. Excavation Progress/Conditions: Upon arrival onsite, we met with Duncan Buchanan of Buchanan Land Construction. They had begun excavation of the basement area and were in the process of loading trucks to export the excess soil. The excavation was ranged from approximately 7 to 11 feet below the existing ground surface. "file north, east, and south cut slopes of the basement area were cut in a near vertical configuration. A temporary Lock Block shoring wall will be placed along the east cut slope when the excavation is completed. At this time, there were no signs of groundwater seepage out of the cut slopes and there were no observed signs of caving. Currently, the bottom of the excavation was at i foot below tine design pad elevation. Soil Subgrade Conditions: The exposed soil at the base of the excavation was a hoist to wet, light brown to gray, fine to medium sand with silt (ancient colluvium). There was some blue gray silt with some gravel in the SE corner of the excavation. Using a steel soil probe, the exposed soils were penetrated 8 to 24 inches under full body weight. The soil stiffened with depth, even in the areas where it was penetrated 18-24". The contractor wanted to attempt to compact the native soils in place, and then place 1 foot of compacted 2-inch clean crushed rock to the design subgrade elevation. Upon trying to compact the native soils with a hoe pack, the subgrade began to yield slightly. At this time, we recommended that the contractor excavate an additional foot of the native soil and then place a two feet of the 2" clean crushed rock, compacted in two lifts, to the design subgrade elevation, as specified in our geotechnical report. TESC Inspection: While onsite, we performed a TESC inspection. Buchanan Land Construction had installed the interceptor swale on the east edge of the lot. The v-shaped trench had been lined with filter fabric, a 6" perforated pipe was installed and the trench was backfilled with washed drain rock. The ends of the drain were still exposed, and there was a small pile of drain rock at each end, to bed the pipe after the connection is made. Silt fence had been installed along the south side of the site and was in good condition. The construction entrance was lined with quarry spalls and sediment track out from the recent truck traffic was minimal. Duncan Buchanan said that they were sweeping up at the end of each day. Inlet protection was adequate and there was no runoff from the site at the time of our visit. Scott Hoover arrived onsite and we spoke briefly about the interceptor swale and future scheduling of our site inspections. AES] will return as necessary to perform required inspections. COPIES TO: City, Hoover, Hanson, Breske, file FiELD REP.: Andrew Glandon, PEG, CPESC DATE MAILED: DEC 1 5 2008 PRINCIPAL / PM: Aaron McMichael, PE, PEGS Associated. Earth Sciences, Inc. r J 911 Fifth Avenue, Suite 100 Kirkland, Washington 98033 42.5-827-7701 FAX 827-5424 TO: Kyle and Juliann Ray 702 - 4" Avenue South Edmonds, WA 98020 ATTN: Kyle Ray AS REQUESTED BY Scott Hoover THE FOLLOWING WAS NOTED: FIELD REPORT Permit No. BLD2008-037 Pape 1 of 1 Date Project Name Project No. 12-29 08 Ray Residence KE050550B Location Weather 15625 75"' Place W Windy, 40's Municipality Report Number City of Edmonds 1 3 Engineer/Architect Donna Breske / Hanson Design Client/Owner Kyle and Juliann Ray General Contractor/Superintendent Hoover Premier Homes / Scott Hoover Grading Contractor/Superintendent Buchanan Land Construction / Duncan Buchanan AESI was onsite today to perform a weekly TESC inspection. TESC Inspection: An erosion control inspection was not performed last week due to the snow and hazardous road conditions. There was no earthwork going on while we were onsite today. Previously, Buchanan Land Construction had installed the temporary shoring (Lock -Block) wall along the east excavation cut slope along the east edge of the lot. The blocks had been set 4 blocks high and were set in the orientation specified in the design Plastic sheeting had been spread over the excavation cut sloped and on the soil that had been stockpiled for export. The plastic sheeting was in generally good condition, thought there were a few areas that the plastic had been blown out of place by the heavy wind. The construction entrance was covered with quarry spalls and there was no sediment track -out or runoff from the site. The adjacent catch basins had filter inserts and were not in need of maintenance. Based on the field conditions observed, it is our opinion that the BMPs currently in place are performing properly and no additional erosion control measures are required at the time. Prior to arriving on site, we spoke with Scott Hoover on the telephone. He said that they planned on resuming site earthwork on Monday, January 51h, 2009. AESI will coordinate with Scott Hoover for future required inspections. COPIES TO DATE MAILED: City, Hoover, Hanson, Breske, file FIELD REP DEC 3 12008 PRINCIPAL. / PM Andrew Glandon, PEG, CPESC /! ecz:&I Aaron McMichael, PE, PEG Associated. Earth Sciences, Inc. 911 Fifth Avenue, Suite 100 Kirkland, Washington 98033 425-827-7701 FAX 827-5424 TO: Kyle and Juliann Ray 702 - 4" Avenue South Edtnonds, WA 98020 ATTN: Kyle Ray AS REQUESTED BY Scott Hoover THE FOLLOWING WAS NOTED: FIELD REPORT Permit No. BLD2008-037 Page I of 1 Date Project Name Project No. 1-8-09 Ray Residence KE050550B Location Weather 15625 75"' Place W Cloudy, 40's Municipality Report Number City of Edmonds 4 Engineer/Architect Donna Breske / Hanson Design Client/Owner Kyle and Juliann Ray General Contractor/Superintendent Hoover Premier Homes / Scott Hoover Grading Contractor/Superintendent Buchanan Land Construction / Duncan Buchanan AESI was onsite today to observe the garage area subgrade and to perform a weekly TESC inspection. Subgrade Observations: Buchanan Land Construction had continued to overexcavate soil from the garage area and place back 2 feet of 2" clean crushed rock back to the planned subgrade elevation. Duncan Buchanan was onsite working at the time of our site visit; compacting the crushed rock with a hoe -pack and fine grading the crushed rock with the track -hoe, using an I-beam in the bucket and thumb of the hoe to smooth out the surface. Based on field performance observations and the exposed soil near the edge of the crushed rock, the prepared subgrade is suitable for support at the design bearing capacity of 2,000 pounds per square foot. Duncan said that the last bit of the garage, near the future garage door would be somewhat time consuming to finish, due to the access challenges and having to move some excess soil on site. At this time, the entire garage subgrade area had not been completed, but what has been done has been done properly and in a manner that is consistent with the reconunendations in our geotechnical report. TESC Inspection: While onsite we observed the condition of the site BMP's. Some excess soil had been stockpiled on the northern portion of the site over the past few days and was currently covered with plastic sheeting, which was in good condition. The construction entrance was covered with quarry spalls and there was no sediment track -out or runoff from the site. The adjacent catch basins had filter inserts and were not in need of maintenance. The interceptor swale along the east edge of the lot was in place and appeared to be working. Duncan had inserted steel sheets up against the soil on the north side and south sides of the temporary Lock -Block shoring wall. This was done to make a better transition at the wall edges. Based on the field conditions observed, it is our opinion that the BMPs currently in place are performing properly and no additional erosion control measures are required at the time. AESI will return to observe subgrade conditions and construction progress at the request of Scott Hoover and to perform weekly TESC inspections. COPIES TO DATE MAILED: City, Hoover, Hanson, Breske, file JAN 1 5 2009 FIELD REP.: Andrew Glandon, PEG, CPESC �'� PRINCIPAL. / PM: Aaron McMichael, PE, PEG ,71 911F&thAvenue • Suite 100 Associated Earth Sciences, Inc. Kirkland, WA 98033 _ 425-827-7701 S` FAX 425-827-5424 F I RILD REPORT FIELD REPORT # TO: /ll/l ,/ 70 Z z-%fit �� S ATTN: .k \Li/ AS REQUESTED BY: THE FOLLOWING WAS NOTED: L 2911 1/2 Hewitt Avenue -Suite 2 1verett,NVA 98201 425-259-0522 FAX 425-252-3408 r PAGE / OF Date d -r .5 v.' Project Nam � ���« P ject No. EvSc�S�c ZS�ather / �Location Munnpolity/. ._ / J/ Bid . P mit No. 7 En i eer/Architect , Client O�er lle_ : Xral Co t7 ctor/Superintte/ndent C Earthworlc Contra for/Su erintendent 1Ccl7i? Yrclr <'r. C_�� ?S i� cJ:� :=v!<•n:.., T.?.-t:..�.-+ems lh,' VX) s iAi&�_ , A, s, ,s r,,f' C/. �,�,ra/f� ;', d�� - v V 'U1\ e- 7ue- Jwri'nK 11L A--1 /'(tr! ' k,t '/d yam. '.111[ 511.1 541 :5 1, ,?r` L.QLk l 14L r L. !' Ste' �4r �!! 11crj7 rlrr7C c/ ,vas pwY .L n,»« .M, In. i'�r�.> ••il� !^r,.. �.d :;ti�t�J.t �'YL:I +:(L1�•S :,cif !_lr�tt[.,� �/% F'L J .SG'/�•. ,L!./ r- rim c&�it %A. 1L:s_ E?{tY77itCL Ax f i / L u:i �' f ' •r/� � g� .�,�Yi �r�z'txi:� S �s'1� L�:;51h'/u•�� 9�-•rcSS ��s �t5 �r�xcs�� � Sr.r7��r�tzsr.:- r I FIELD COMPACTION EQUIPMENT UTILIZED: l'/0z -Lts /C�rcy+ �- AREAS OF ADDITIONAL CONCERN: Ale, ADDITIONAL TESTS REQUIRED: ❑ YES JX NO WHERE? COPIES TO:F;e�f� sY 60uLY�__�y_ DATE MAILED: JAN 1 6 2DO9 ` Field Report subject to review by AESI Project Manager FIELD REP:/.,/,, "PROJECT MANAGER- • -7 AGSI_FRL, rev 3/2006 911 Fifth Avenue - Suite 100 Associated Earth Sciences, Inc. Kirkland, WA 98033 425-827-7701 FAX. 425-827-5424 FIELD RE P ORT 76 .� /Of ATTN• AS REQUESTED BY, THE FOLLOWING WAS NOTED: FIELD COMPACTION EQUIPMENT UTILIZED: / //J� AREAS OF ADDITIONAL CONCERN: FIELD REPORT # 2911 'A Hewitt Avenue a Suite 2 Everett, WA 98201 425-259-0522 FAX 425-252-3408 PAGE / OF ate - Project Flame P 'PcLNo. Loocation ' zs � % i. ui other Munjcs lity Bldg. Permit Wo. E in r/Architect T r Client Owner ' �l Ge ral Contr c r/Superintend nt Earthwork Contractor S pe%r ntegent K/8:�::•�C.:� L: ( ".i5�:.y7l��r NIiG:•'1 ,w'f.1�G�H:i ADDITIONAL TESTS REQUIRED: ❑ YES J] NO WHERE? COPIES TO: - 1. FIELD REP:-G- DATE MAILED: ® 62009 PROJECT MANAGER: ' Field Report subject to review by AESI Project Manager / AESI FRL rev 312006 911 Fifth Avenue 0 Suite 100 Kirkland, WA 98033 425-827-7701 FAX 425-827-5424 y/, TO: ATTN• 41 e I/ AS REQUESTED BY: THE FOLLOWING WAS NOTED: FIELD COMPACTION EQUIPMENT AREAS OF ADDITIONAL CONCERN: FIELD REPORT FIELD REPORT # 2911 �/z Hewitt Avenue -Suite 2 Everett, WA 98201 425-259-0522 FAX 425-252-3408 PAGE Z OF Z Date r Pro ect Name Project No. .� loc/aJtioon 7 A/ V� ath{qTr, Muni 'pality C.. ' dg. Per o. _ �,r 9) 7. - -nS7 Engi er/Aprchitec� Client 0 ne " G erol Cant r forP /Su erinte nt r- -,Y/l.� r l,•.i?;' I rthw�ork Contr/actor//Supeerrintendent f J ._J2t k?� �.7'Y '71.2.4t ADDITIONAL TESTS REQUIRED: ❑ YES NO WHERE? COPIES TOt / FIELD REP: i i� _� f :! t DATE MAILED: `PROJECT MANAGER: % �G Field Report subject to review by AESI Project Manager AESI FRL. rev 3/2006 Associated Earth Sciences, Inc. Cclfrnriiu� 2j zJtarr o/'�1'e�vrcc 911 Fifth Avenue, Suite 100 Kirkland, Washington 98033 425-827-7701 FAX 827-5424 TO: Kyle and Juliann Ray 702 - 4'h Avenue South Edmonds. WA 98020 ATTN: Kyle Ray AS REQUESTED BY Scott Hoover THE FOLLOWING WAS NOTED: FIELD REPORT Permit No. BLD2008-037 Page 1 of 1 Date Project Name Project No. 2-23-09 Ray Residence KE050550B Location Weather 15625 75'h Place W Cloudy, 40's Municipality Report Number City of Edmonds 7 Engineer/Architect Donna Breslce / Hanson Design Client/Owner Kyle and Juliann Ray General Contractor/Superintendent Hoover Premier Homes / Scott Hoover Grading Contractor/Superintendent Buchanan Land Construction / Duncan Buchanan AESI was onsite today to observe footing drain installation and to perform a TESC inspection. Footing Drain Installation: Since our previous site visit, the perimeter stem wall and the interior grid footings had been placed. Using a steel soil probe, the crushed rock over soil subgrade was penetrated approximately 1-2 inches under full body weight and it is our opinion that the footing subgrades are suitable for support at the design bearing capacity of 2,000 pounds per square foot. Buchanan Land Construction had installed footing drain pipe along the east, north and west side of the building. The footing drain had been backfilled along the west side, but was exposed along the north and east. A 4" perforated PVC pipe had been set at the base of the footing. At the northwest corner, the pipe had been set, it was bedded in washed rock to approximately 1 foot over the top of the pipe and filter fabric was placed over the washed rock. In our opinion, the footing drains that were observed today had been installed properly and where they were in progress, the steps taken so far were in accordance with the plans and our drainage recommendations. Based on a later conversation with Eric Lim (AESI), it is our opinion that on the east side of the house, the upper footing drain and drain rock on the north half of the house should be capped at the transition to the lower footing drain and should not be connected to the lower footing drain that serves the southern portion. Subgrade Observations: Since our last visit, the perimeter stem walls and interior footings had been placed in the northern portion of the house. While onsite, we spoke with Duncan Buchanan (Buchanan Land Construction). He asked about fill inside the crawlspace. •�Ve t�?� him th^+-sempac-serl�i �t o Av flit6�5 3 3 0�'( r S/ OtSCus5��7 Az 1 ca t•YCa A-4xA'71\/57 «V_115721--L r-cvT7,1e-5 W Lam! 5T?2t,CC�iZc�.9-L 1 u tn/ SLR /1L L= . TESC Inspection: While onsite we observed the condition of the site BMP's. Buchanan Land Construction was hauling off excess soil; loading dump trucks with soil. The construction entrance was covered with quarry spalls and there was no sediment track -out or runoff from the site. The adjacent catch basins had filter inserts and were not in need of maintenance. The interceptor swale along the east edge of the lot was in place and appeared to be working. The temporary Lock -Block shoring wall along the north side of the excavation was in place and there were no observed signs of caving or sloughing. Based on the field conditions observed, it is our opinion that the BMPs currently in place are performing properly and no additional erosion control measures are required at the time. AESI will return to observe subgrade conditions and construction progress at the request of Scott Hoover and to perform wee -------------- — --- - - - -- '-V ,-' �� MU2c) S F-0 Foonr-c<S 12cWtltloc at,c<a, o-z Tzzi-tz i2l>"� t , 7t-r CCG . .4 l 2��lr t �'4.�_ Fow�.ra -rZ; rJ Pt�t rvl -- ,v�: S1 l �q rZ cuj lam- �s c-�r C- 04WIVi9� . 'h. '0 N6' /Vc'-L- !- v7i- i-R G57—/��C7Z�7Z 'i -2e u, ", &Ai GZc.i5,4L-:9, i a o� - 7D Lt COPIES TO: City, Hoover, Hanson, Breske, file FIELD REP.: :rrdrew Glandon, PEG, CPESC DATE PRINCIPAL / PM: Aaron McMichael, PE, PEG MAILED: _ FEB 2 7 2009 �,�, 7 Associated Earth Sciences, Inc. 911 Fifth Avenue, Suite 100 Kirkland, Washington 98033 425-827-7701 FAX 827-5424 TO: Kyle and Juliann Ray 702 - 4"' Avenue South Edmonds, WA 98020 ATTN: Kyle Ray AS REQUESTED BY Scott Hoover THE FOLLOWING WAS NOTED: FIELD REPORT Permit No. BLD2008-037 Page I of I Date Project Name Project No. 2-23-09 Ray Residence KE050550B _ Location Weather 15625 75'1' Place W Cloudy, 40's Municipality Report Number City of Edmonds 7 Engineer/Architect Donna Breslce / Hanson Design Client/Owner Kyle and Juliann Ray General Contractor/Superintendent Hoover Premier Homes / Scott Hoover Grading Contractor/Superintendent Buchanan Land Construction / Duncan Buchanan AESI was onsite today to observe footing drain installation and to perform a TESC inspection. Footing Drain Installation: Since our previous site visit, the perimeter stem wall and the interior grid footings had been placed. Using a steel soil probe, the crushed rock over soil subgrade was penetrated approximately 1-2 inches under full body weight and it is our opinion that the footing subgrades are suitable for support at the design bearing capacity of 2,000 pounds per square foot. Buchanan Land Construction had installed footing drain pipe along the east, north and west side of the building. The footing drain had been backfilled along the west side, but was exposed along the north and east. A 4" perforated PVC pipe had been -set at.the base of the footing. At the northwest corner, the pipe had been set, it was bedded in washed rock to approximately i foot over the top of the pipe and filter fabric was placed over the washed rock. Li our opinion, the footing drains that were observed today had been installed properly and where they were in progress, the steps taken so far were in accordance with the plans and our drainage recommendations. Based on a later conversation with Eric Lim (AESI), it is our opinion that on the east side of the house, the upper footing drain and drain rock on the north half of the house should be capped at the transition to the lower footing drain and should not be connected to the lower footing drain that serves the southern portion. Subgrade Observations: Since our last visit, the perimeter stem walls and interior footings had been placed in the northern portion of the house. While onsite, we spoke with Duncan Buchanan (Buchanan Land Construction). He asked about fill inside the crawlspace. We told him that compacted soil would be suitable for foundation backfill and the soil should be placed up to the top of the spread footings. TESC Inspection: While onsite we observed the condition of the site BMP's. Buchanan Land Construction was hauling off excess soil; loading dump trucks with soil. The construction entrance was covered with quarry spalls and there was no sediment track -out or runoff from the site. The adjacent catch basins had filter inserts and were not in need of maintenance. The interceptor swale along the east edge of the lot was in place and appeared to be working. The temporary Lock -Block shoring wall along the north side of the excavation was in place and there were no observed signs of caving or sloughing. Based on the field conditions observed, it is our opinion that the BMPs currently in place are performing properly and no additional erosion control measures are required at the time. AESI will return to observe subgrade conditions and construction progress at the request of Scott Hoover and to perform weekly TESC inspections. COPIES TO DATE MAILED: City, Hoover, Hanson, Breske, file FIELD REP.: ��� d'_/Zlrew Glandon, PEG, CPESC FEB 2 7 2009 PRINCIPAL / PM: l� Aaron McMichael, PE, PEG Associated Earth Sciences, Inc. eek-A n(riy fynrr of :, I've 911 Fifth Avenue, Suite 100 Kirkland, Washington 98033 425-827-7701 FAX 827-5424 TO: Kyle and Juliann Ray 702 - 4`" Avenue South Edmonds, WA 98020 ATTN: Kyle Ray AS REQUESTED BY Scott Hoover THE FOLLOWING WAS NOTED: FIELD REPORT Permit No. BLD2008-037 Page I of I Date I Project Name Project No. 10/24/09 Ray Residence KE050550B Location Weather 15625 75"' Place W Overcast, 60s F Municipality Report Number City of Edmonds 8 Engineer/Architect Donna Breske / Hanson Design Client/Owner Kyle and Juliann Ray General Contractor/Superintendent Hoover Premier Homes / Scott Hoover Grading Contractor/Superintendent Buchanan Land Construction / Duncan Buchanan We visited the site to observe final site conditions prici to occupancy and address City staff comments regarding the rockery along the south side of the driveway. On arrival, we observed that the exterior house construction was complete and that landscaping in the front yard was complete. The landscaping in the rear yard was nearly complete with sod being installed during our visit. We observed the rockery along the south side of the driveway. We measured the rockery to be approximately 12' 8" long and approximately 3' 10" in maximum height. The rockery extended west from the north foundation wall of the house and tapered down in height to match grade in the front yard. It appears that the rockery was necessary since a slope would have placed soil against the finished wood siding of the house. Mr. Hoover informed us that 2 rows of Lock -Blocks were left in -place along the south edge of the driveway and are directly behind the rockery. We hand -probed between the rockery stones and felt a block where we could penetrate the crushed rock backfill. In our opinion, the Lock -Blocks are alleviating surcharge on the rockery, and the short retaining structure is suitable for support of the driveway and anticipated vehicle loads. COPIES TO: City, Hoover, Hanson, Breske, file FIELD REP DATE PRINCIPAL / PM: MAILED: Eric Lim, PE. i Aaron McMichael, PE, PEG Message Page 1 of 2 Harrison, Marie From: Bullis, Ann Sent: Wednesday, November 04, 2009 11:02 AM To: Harrison, Marie Cc: Steinike, Russell Subject: FW: Ray Residence - Revised Final Letter Marie, Please print for the file -- the report is acceptable Thanks, Ann Bullis, CBO Building Official City of Edmonds 121 5th Ave N Edmonds, WA 98020 425-771-0220 -----Original Message ----- From: Scott Hoover [mailto:hoover1969@hotmail.com] Sent: Wednesday, November 04, 2009 10:28 AM To: Bullis, Ann Cc: Steinike, Russell Subject: FW: Ray Residence - Revised Final Letter Scott-haavew 16300 M ab creek/ 3 l vd/ S" tei (52 M aL Creek,, WA 98012 Raave rl 96 9@hates zLa.. com 425 -745 -1370 Office 425 -745 -1466 Fax/ From: hoover1969@hotmail.com To: mcconnell@ci.edmonds.wa.us Subject: FW: Ray Residence - Revised Final Letter. Date: Mon, 2 Nov 2009 16:36:27 -0700 Scutt,} aovor 11 /4/2009 Message Page 2 of 2 16300 M C& creek B Z vcL. S uitel C72 MabCreek,, WA 98012 74oxaver196 9@hotwt,call co-vw 425-745-1370 Offtcel 425 -745 -1466 Fcixw Subject: Ray Residence - Revised Final Letter Date: Mon, 2 Nov 2009 15:12:41 -0800 From: elim@aesgeo.com To: hoover1969@hotmail.com CC: edmondswills@yahoo.com Scott, please find attached the revised final letter. We also faxed to Jeanie at the Building Dept. Thanks, Eric Eric Lim, PE Associated Earth Sciences, Inc. (425) 827-7701 office (425) 766-6752 cell elim@aesgeo com Bing brings you maps, menus, and reviews organized in one place. Try it now_ Windows 7: Unclutter your desktop. Learn more. 11 /4/2009 15WE 7s+-- f 1 v� I J � f Mii..W hM f� ':'� f�! %fyl�f• it '4'. I �JII�.1�'I Cefe&a(M525 VerrsT�5 4 FILE FAX Transmittal Date: 10/26/09 To: City of Edmonds -Jeanie McConnell From: Eric Lim, P.E. FAX #: 425-771-0221 Final Letter Project Ray Residence Name: Permit # BLD2008-0376 Project No: KE050550B # of pages: 14 including cover This transmittal is intended of the use of the addressee named herein and may contain legally privileged and confidential information. If you are not the intended recipient of this transmittal, you are hereby notified that any distribution or reproduction of this transmittal is strictly prohibited. If you receive this transmittal in error, please notify AESI by telephone immediately. Thank you. 911 5`h Ave., Ste. 100 • Kirkland, WA 98033 • Phone: 425-827-7701 • Fax: 425-827-5424 Associated Earth Sciences, Inc. U H1 N W1, . Ce%W ra6nq Over 25 Veargf service October 26, 2009 Project No. KE050550B Kyle and Juliann Ray 702 401 Avenue South Edmonds, Washington 98020 Subject: Final Letter for Geotechnical Construction Monitoring Services Ray Residence Reconstruction 15625 7.5" Place West Edmonds, Washington Permit No. BLD2008-0376 Dear Mr. and Mrs. Ray: As required by the City of Edmonds, Associated Earth Sciences, Inc. (AESI) has prepared this final letter regarding geotechnical construction monitoring observations for your project at the above -referenced site. AESI performed periodic site visits fiorn December 4, 2008 through October 2-4, 2009 to observe temporary erosion control measures, wet season site monitoring, interceptor trench installation, site cut slopes and shoring, foundation subgrade preparation, and foundation drainage installation, as required by the City of. Edmonds. The results of our observations are summarized in our Field Reports Nos. 1 through 8, attached to this letter. As requested by the City of Edmonds, we have also confirmed that the Lock -Blocks behind the short driveway rockery are alleviating the surcharge on the rockery. Based on. our observations, it is our opinion that the project earthwork has been completed in general accordance with the approved project plans, the recommendations presented in our geotechnical engineering report dated January 10, 2008, and subsequent recommendations during construction. Kirkland 0. Everett a Tacoma 425-827-7701 425-259-0522 253-722-2992 www.aesgeo.com We appreciate the opportunity to be of service to you on this project. Should you have any questions regarding this letter, please call us at your earliest convenience. Sincerely, ASSOCIATED EARTH SCIENCES, INC. Kirkland, Washington Cl— Eric J. Lim, P. Senior Project Attaclunents: Field Reports Nos_ 1 through 8 cc: Hoover Premier Homes Attn-. Scott Hoover Scott@liooverpremierlionies. com City of Edmonds Building Department Attn: Jeanie McConnell Fax: (425) 771-0221 U UIJ KI305055003 IIItojectst0050550kKE WP 2 G. Aaron McMichael, P.E., P.E.G. Associate Engineer r FIELD REPORT Associated Garth Sciences, Inc. 911 Filth Avenue, Suite 100 Kirklund, Wtishington 98033 423-827-7701 FAX 827-5424 TO: Kyle and Juliann Ray 702 - 41' Avenue South Edmonds, RYA 98020 ATTN: Kyle Ray AS REQUESTED BY Scott Hoover THE FOLLOWING WAS N07'ED: Page I of. 2 Date Project Nnme Project No. 4 Dec 08 lRayResidence KE050550D Location lventher 15625 75°i Place W Clear, 50s F Municipality Report Ntnnher City of Edmonds t Engineer/Architect Donna Breslee / Hanson Design Client/Owner Kyle and Juliann Ray General Cnntractor/Superintendent Hoover Premier Homes / Scott Hoover Grading Contraclor/Superintendent Buchanan Land Construction / Duncan Buchanan AES1 was onsite today to for the preconstruction meeting. In attendance were Jeanie McConnell and Jennifer Collins with the City of Edmonds, Scott Hoover with Hoover Premier Homes, and Duncan Buchanan with Buchanan Land Construction. On arrival, the site ground surface is well vegetated with. grass and landscape shrubs, and appears not to have changed from previous site visits. No indications of seepage were observed at the bottom of the east slope. AESI has previously submitted a wet season grading request letter, dated October 2, 2008, outlining recommendations for wet season grading. Topics of geotechnical discussion for this meeting were: 1) TESC BMPs: Prior to grading, the contractor will install silt fence downgradient of all excavations, establish a rock -armored construction entrance, and keep street clean. The City requested a filter sock or fabric be placed in the CB in the street near the NW corner of the site. A filter fabric is already in place in the CA near the SW corner of the site. If a CB exists further downgradient to the south where the contractor had parked his truck, then the City requested a filter fabric be placed in that CB as well. The contractor will notify City for inspection once installed. The contractor is responsible for inspecting and maintaining BNIPs. 2) Wet Season site monitoring: AESI will visit the site after all significant rain events (more than 1 inch per 24 hours) to observe site conditions and adequacy of BMPs. 3) Interceptor Trench: After TESC are installed, contractor will begin with installing interceptor trench at east edge of lot. Foundation excavations will follow the interceptor trench. 4) Shoring: Contractor will use Lock -Blocks for shoring east side of basement excavation up to 10 feet high. The contractor informed us that the planned 7.5-ft high shoring for the north side of the basement, which is in the interior of the building conflicts with the footings for the main floor. Since these main floor footing need to tie into the basement wall footings, they will be stepped down to match. AES1 agreed and recommended 1.51I: IV temporary slopes in this area only and must be covered in plastic. The main shoring wall along the east wall must be maintained since it protects the larger slope to the east and is of concern to the City. COPIES TO: DATE MAILED: City, Hoover. Hanson; Breslee; rile FIELD REP DEC 0 8 2008 PRINCIPAL. / PM Eric Lim, PE e� Aaron McMichael. PE, PEGS FIELD REPORT To: Kyle Ray Project Name: Date: 4 Dec 08 Project Number: Ray Residence ICE050550B 5) "Native" landscape areas: One approved plan sheet shows a "native" growth area to remain undisturbed in the landscaped slope along the northern Half of the western property line, However, the stormwater detention pipe is plaruned to be located in that area, so the contractor indicated this area will he disturbed. Also, a water meter appears to conflict with the detention pipe location. Ms. McConnell informed us she would look into this issue with the building department. 6) "Start of Work Letter": one special inspection requirement was to provide a Start of Work letter once the pennit was issued and the contractor is ready to begin actual work. AESl spoke with Ann Bullis with the City of Edmonds, who agreed that this field report for the pre -con meeting would be accepted as the Start of Work letter. Conditions for: the site appear not to have changed from previous site visits or that assumed during design. We understand that the duration for each construction task will remain as described in out Oct. 2, 2008 letter, except that the schedule of dates would be pushed back according with today as the start date. Copies To: Date Mailed: City, Hoover, Hanson, Breske, file Field Rep: Eric Lim, PE Principal /PM: Aaron McMic PE, PEG FIELD REPORT Associated Earth Scielices, Inc. f 911 fifth Avenue. Suite 100 Kirkland, Washington 98033 425-827-7701 FAX 827-5424 TO: Kyle and Juliann Ray 702 - 41" Avenue South Edmonds, WA 98020 ATTN: Kyle Ray _ AS REQUESTED BY Scott Hoover THE FOLLOWING WAS NOTED: Permit No. BLD2008-037 Page I of I Date ProjcctNaote Project No. 12-11 08 I Ray Residence KE050550B Location Weather 15625 75"' Place W Cleat-, 40's F Municipality Report Number City of Edmonds 2 Enaincer/Architect Donna Breslte / Hanson Design Clieul/Owner Kyle and Juliann Ray General Contractor/Supetintendeat Hoover Premier Homes / Scott Hoover Grading Contractor /Superintendent Buchanan Land Construction / Duncan Buchanan AESI was onsite today to observe excavation progress and conditions, soil subgrade conditions and to perform a weekly TESC inspection. Excavation Progress/Conditions: Upon arrival onsite, we suet with Duncan Buchanan of Buchanan Land Construction. They had begun excavation of the basement area and were in the process of loading trucks to export the excess soil. The excavation was ranged from approximately 7 to I 1 feet below the existing ground surface. The north, east, and south cut slopes of the basement area were cut in a near vertical configuration. A temporary Lock Block shoring wall will be placed along the east cut slope when the excavation is completed. At this time, there were no signs of groundwater seepage out of the cut slopes and there were no observed signs of caving. Currently, the bottom of the excavation was at 1 foot below the design pad elevation. Soil Subgrade Conditions: The exposed soil at the base ofthe excavation was a inoist to wet, light brown to gray, fine to medium sand with silt (ancient colluviutn). There was some blue gray silt with some gravel in the SE corner of the excavation. Using a steel soil probe, the exposed soils were penetrated 8 to 24 inches under full body weight. The soil stiffened with depth, even in the areas where it was penetrated 18-24". The contractor wanted to attempt to compact the native soils in place, and then place 1 foot of compacted 2-inch clean crushed rock to the design subgrade elevation. Upon trying to compact the native soils with a hoe pack, the subgrade began to yield slightly. At this time, we recommended that the contractor excavate an additional foot of the native soil and then place a two feet of the 2" clean crushed rock, compacted in two lif.ts, to the design subgrade elevation, as specified in our geotechnical report. TESC Inspection: While onsite, we performed a TESC inspection. Buchanan Land Construction had installed the interceptor swale on the cast edge of the lot, The v-shaped trench had been lined with filter fabric, a 6" perforated pipe was installed and the trench was backfilled with washed drain rock. The ends of the drain were still exposed, and there was a small pile of drain rock at each end, to bed the pipe after the connection is made. Silt fence had been installed along the south side of the site and was in good condition. The construction entrance was lined with quarry spalls and sediment track out from the recent truck traffic was minimal. Duncan Buchanan said that they were sweeping up at the end of each day. Inlet protection was adequate and there was no runoff from the site at the time of our visit. Scott Hoover arrived onsite and we spoke briefly about the interceptor swale and future scheduling of our site inspections. AESI will return as necessary to perform required inspections. COPIES TO: City, Hoover, Hanson, Breske, file FIELD RF.P.: Andrew Gltuidon, PEG, CPL•SC DATE DEC 1 5 2008 MAILED: PRINCIPAL / PM. Aaron McMichael, PE, PEG FIELD REPORT Associated Earth Sciences, Inc. 911 Fifth Avenue, Suite 100 Kirkland, Washington 98033 425-827-7701 FAX 827-5424 TO: Kyle and Juliann Ray 702 - 4`a Avenue South Edmonds, WA 98020 ATTN.' Kyle Ray AS REQUESTED BY Scott Hoover THE: FOLLOWING WAS NOTED: Permit No. BLD2008-037 Page 1 of 1 Dale Project Name Project No. 11-29 08 Ray Residence KT050550B Locution weather 15625 7514 Place W Windy, 40's _ Municipality Report Number Cit • of Edmonds 3 Engineer/Architect Donna Breske / Hanson Design Client/Owner Kyle and Juliann Ray Genenal Contractor/Superintendent Hoover Preinie_r Homes / Scott Hoover Grading Contractor/Superintendent Buchanan Land Construction / Duncan Buchanan AESI was onsite today to perform a weekly TESC inspection. TESC inspection: An erosion control inspection was not performed last week due to the snow and hazardous road conditions. There was no earthwork going on while we were onsite today. Previously, Buchanan Land Construction had installed the temporary shoring (Lock -Block) wall along the cast excavation cat slope along the east edge of the lot. The blocks had been set 4 blocks high and were set in the orientation specified in the design Plastic sheeting had been spread over the excavation cut sloped and on the soil that had been stockpiled for export. The plastic sheeting was in generally good condition, thought there were a few areas that the plastic had been blown out of place by the heavy wind. The construction entrance was covered with quarry spalls and there was no sediment track -out or runoff front the site. The adjacent catch basins had filter inserts and were not in need of maintenance. Based on the field conditions observed, it is our opinion that the BMPs currently in place arc pertbrlling properly and no additional erosion control measures are required at the time. Prior to arriving on site, we spoke with Scott .Hoover on the telephone. He said that they planned on resuming site earthwork on Monday, January 5"', 2009. AESI will coordinate with Scott Hoover for future required inspections. COPIES TO: City, Hoover, Hanson, Breske, file FIELD REP.: DATE DEC 31 20D$ PRINCIPAL / PM MAILED: Andrew Glandon, PEG, CPESC Aaron McMichael, PE, PEG .. FIELD REPORT Associated Earth Sciences, Inc. 911 Fifth Avenue, Suite 100 Kirkland, Washington 98033 425-827-7701 FAX 827-5424 TO: Kyle and Juliann Ray___ 702 - 41h Avenue South Edmonds, WA 98020 A7TN: Kyle Ray AS REQUESTED BY Scott Hoover THE FOLLOWING WAS NOTED; Permit No..BLD2008-037 Page 1 of 1 Dote Project Name Project No. 1-8-09 I Ray Residence KE050550B Location Weather 15625 75" Place W Cloudy, 40's Municipality Report Number City of Edmonds 4 Engineer/Architect Donna Breske / Hanson Design Client/owner Kyle and hiliann Ray_ General Contractor/Superhrtendent Hoover Premier Homes / Scott Hoover Grading Contractor/Superintendent Buchanan Land Construction / Duncan Buchanan AESI was onsite today to observe the garage area subgrade and to perform a weekly TESC inspection. Subgrade Observations: Buchanan Land Construction had continued to overexcavate soil from the garage area and place back 2 feet of 2" clean crushed rock back to the planned subgrade elevation. Duncan Buchanan was onsite working at the time of our site visit; compacting the crushed rock with a hoe -pack and fine grading the crushed rock with the track -hoe, using an I-beam in the bucket and thumb of the hoe to smooth out the surface. Based on field performance observations and the exposed soil near the edge of the crushed rock, the prepared subgrade is suitable for support at the design bearing capacity of 2,000 pounds per square foot. Duncan said that the last bit of the garage, near the future garage door would be somewhat time consuming to finish, clue to the access challenges and having to move some excess soil on site. At this time, the entire garage subgrade area had not been completed, but what has been done has been done properly and in a manner that is consistent with the recomniendations in our geotechnical report. TESC Inspection: Whine onsite we observed the condition of the site BMP's. Some excess soil had been stockpiled on the northern portion of the site over the past few days and was currently covered with plastic sheeting, which was in good condition. Tine construction entrance was covered with quarry spal)s and there was no sediment track -out or runoff from the site. The adjacent catch basins had filter inserts and were not in need of maintenance. The interceptor swale along the east edge of the lot was in place and appeared to be working. Duncan had inserted steel sheets up against the soil on the north side and south sides of the temporary Lock -Block shoring wall. This was done to make a better transition at the wall edges. Based on the field conditions observed, it is our opinion that the BMPs currently in place are performing properly and no additional erosion control measures arc required at the time. AESI will return to observe subgrade conditions and construction progress at the request of Scott Hoover and to perform weekly TESC inspections. COPIES TO: City, Hoover, Hanson, Breske, file FIELD REP DATE PRINCIPAL / PM MAILED: JAN 1 5 2009 Andrew Glandon, PEG, CPESCCs G �; Aaron McMichael, PE, PEG��,�,yL 911Fifth Avenue•Suite 100 Associated. Earth Sciences, Inc. Kirkland WA 98033 425-827-7701 in FAX 425-827-5424 FIELD REPORT FIELD REPORT # Cj To: le ATTNt -x" ` AS REQUESTED BY: THE FOLLOWING WAS NOTED: A9 2911 1/2 Hewitt Avenue • Suite 2 Everett, WA 98201 425-259-0522 FAX 425-252-3408 PAGE / OF ! Date r!5-U Projects Namg r�. 5t�� cam. P ject No. C- 051r,%3 Location /5r,-,S 7 �W jpther U y'+C• & Men polityr. ' C� ,v- fr:, � Bldg. Pt No. es7 En r er/Architect J' me . fart Client O er 1, .7 eroI Co tractor/Superintendent Arthwork Contra for/Su erin pndent t�ia:,re G 7to .vrc r /br.s/'e-c" X'C', A i1 /"C' rr� �O L7d•)'t/C. 7% 3"t'Ixi/4° S Rer-Lri:5�1a<!'L�K i'��?ylfsj FeS iG�uaSTe �� Sr•c//elL'e'o'v.•_ CY lei FIELD COMPACTION EQUIPMENT UTILIZED: ' t_ -1'ae_ AREAS OF ADDITIONAL CONCERN: Ale? ADDITIONAL TESTS REQUIRED: ❑ YES ;ff NO WHERE? COPIES TO:F.1J BY uz' 66 DATE MAILED:- 1 JAN ] 6 2D • Field Report subject to review by AESI Project Manager FIELD REP.-,, G. LS7wa6-����' 0---S — `PROJECT MANAGER:_;Y�l/ AES1„FRL rev V2006 911 Fifth Avenue • Suite 100 Kirkland, WA 98033 425.827-7701 FAX 425-927-5424 Associated. Earth Sciences, Inc. FIELD REPORT FIELD REPORT # TO: /'- 4 ``JK/ilLhit Ike, l� r,# 9 ATTN: /F AS REQUESTED BY: THE FOLLOWING WAS NOTED: 2911 '/r Hewitt Avenue • Suit 2 Everett, WA 98201 425-259-0522 FAX 425-252-3408 PAGE / OF Date Project Name P 20SLNo. Locatio uni TZ lily Bldg. Permit . Ertgine�r/Arrcchitect , T Clio f Qwn Ge 1 Contr c r/Superintend nt CC Earthwork Cont ctor/S p/e�_J��eo ent AV r .:e .., : rr•�"a G :i lac.�i U:, rrlil4; +1� •' /I %:t • i Vs .> V I e � 1 l.., . sc D �IV,14''r rlF /t //C.� . :a eA_ _ t/�� 8.� e-i . "WaC44 �•nS�r1 .,� ''T �Q� oZe 14/ r All_ It' 4iAi Af • s/./ " il. / � /'�� .�1_.. wr;?'r itt_Tr.� � i i 4r� � / C%1J[? � c,P �l�'� �. %ifbt . 41 m L s /y:>r - .% � - f✓G ts•.' �)ri2. V ' /�' w, jst'.L G�/�i / "� ` ����•=ri+L' ail �5� / ✓� �Vir15 V1� {zM�T C:�Tt'Lt a/lY7l/L'�r i A 'la i X •'��, •� 'S��`r� ci:� � FIELD COMPACTION EQUIPMENT UTILIZED: AREAS OF ADDITIONAL CONCERN:= ADDITIONAL TESTS REQUIRED: ❑ TES T] NO WHERE?_ COPIES TO: 'i%1 FEB DATE MAILED: ® 6 2DD9 • Field Report subject to review by AESI Project Manager FIELD REP: I'I !�%/�YC .- ,r � 1 �.C- 'PROJECT MANAGER: / 1^m AESI FRL. rev 3/2006 911 Fifth Avenue • Suite 100 Kirkland, WA 98033 425-827.7701 FAX 425-827-5424 Associated Earth Sciences, Inc. FIELD P .T , FIELD REPORT # ATTN: ' AS REQUESTED BY- THE FOLLOWING WAS NOTED: 2911 % Hewitt Avenue • Suite 2 Everett, WA 98201 425-259-0522 FAX 425-252-3408 PAGE-- OF Date Project Name Project No. Location yip ath Muni .Ii Mdg. Permft No. Engi er/Architect 1 �V� Fi' 5�=� //,:•5e Client Oyvner Ge eral Conh or/SuPerinte5c nt r l j r I -Ire f 7�S Ep�rthw�ork Contractor/Superintengent PN?ir ��.. /�L."rf ��✓Zn1tt�M �wtst:2 i, .%..rH'w.G y., fi K lr ..6xf.+it%.Zi U FIELD COMPACTION EQUIPMENT UTILIZED: AREAS OF ADDITIONAL CONCERN: �^ ADDITIONAL TESTS REQUIRED; ❑ YES NO WHERE? _ COPIES TO t' ld _ FIELD REP: =� DATE MAILED: _ 'PROJECT MANAGER:... • Field Report subject to review by AESI Project Manager AL•Sl_FRL rev 312UUG FIELD REPORT Associated Earth Sciences, Inc. 444nilit y 2,;� Zfcnr,' of.�'ert�ice 911 Fifth Avenue, Suite 100 Kirkland, Washington 98033 425-827-7701 FAX 827-5424 TO: Kyle and Juliann Ray 702 - 4°i Avenue South Edmonds, WA 98020 _ ATTN' Kyle Ray AS REQUESTED BY Scott Hoover THE FOLLOWING WAS NOTED: Permit No. BLD2008-037 Page I of. I Date Project Name Project No. 2-23-09 I Ray Residence XE050550B Location weather 15625 75'4 Place W Cloudy, 40's Municipality Report Number City of Edmonds 7 Engineer/Architect Donna Breske I Hanson Design Client/Owner Kyle and Juliann Ray General Contractor/Superintendent Hoover Premier Homes / Scott Hoover Grading Contra ctor/Superintendent Buchanan Land Construction / Duncan Buchanan AESI was onsite today to observe footing drain installation. and to perform a TFSC inspection. Footing Drain Installation: Suice our previous site visit, the perimeter stem wall and the interior grid footings had been placed. Using a steel soil probe, the crushed rock over soil subgrade was penetrated approximately 1-2 inches under full body weight and it is our opinion that the footing subgrades are suitable for support at the design bearing capacity of 2,000 pounds per square foot. Buchanan I..and Construction had installed footing drain pipe along the east, north and west side of the building. The footing drain had been backfilled along the west side, but was exposed along the north and east. A 4" perforated PVC pipe had been set at the base of the footing. At the northwest coiner, the pipe had been set, it was bedded in washed rock to approximately 1 foot over the top of the pipe and filter fabric was placed over the washed rock. In our opinion, the footing drains that were observed today had been installed properly and where they were in progress, the steps taken so far were in accordance with the plans and our drainage recommendations. Based on a later conversation with Eric Lim (AESn, it is our opinion that on the east side of the house, the upper footing drain and drain rock on the north half of the house should be capped at the transition to the lower footing drain and should not be connected to the lower footing drain that serves the southern portion. Subgrade Observations: Since our last visit, the perimeter stem walls and interior footings had been placed in the northem portion of the house. While onsite, we spoke with Duncan Buchanan (Buchanan Land Construction). He asked about fill inside the crawlspace. for fauu�atiea-baelydi11-aud— •��I859�1-Sli3e>3�-be-placed ro-a �s w t= � u r:✓� kV&A-7N>; rrv; Vi2rvf, Po-,F7.14S LAY ci_r( 5772L.tC"1ti-.7'- -L. (,�vc„• rN , � L �?C TESC Inspection: While onsite we observed the condition of the site BMP's. Buchanan Land Construction was hauling off excess soil; loading dump trucks with soil. The construction entrance was covered with quarry spalls and there was no sediment track -out or runoff from the site. The adjacent catch basins had filter inserts and were not in need of maintenance. The interceptor swale along the east edge of the lot was in place and appeared to be working. The temporary Lock -Block shoring wall along the north side of the excavation was in place and there were no observed signs of caving or sloughing. Based on the field conditions observed, it is our opinion that the BMPs / currently in place are performing properly and no additional erosion control measures are required at the time. AESI will return to observe subgrade conditions and construction progress at the request of Scott Hoover and to perform wee • pections 5rCiZ F_tcirZnC,. S 12G-OL4012I-115)2d2 l,=� C S 1-rj i� Gi:. �i t� ( (L�=V c t✓— � FE wvG�-t7�tcani pt ee v`� rV� Rc .5 N� nrr 7 i=viL f=rZe�ST—r�iz�—L=c77vn/ ;?�t�2 3t, e>rv, C:2�a,42, c�Z LiJ GS AwGS?� e71 l� l h�E Z, COPIES TO: City, Hoover, Hanson, Breske, file FIELD REP.: ,�� dft$drew Glandon PEG, CPESC DATE _ PRINCIPAL / PM: Aaron McMichael, PE, PEG MAILED: FEB 2 7 2009 �� FIELD REPORT Associated Earth Sciences, Inc. Crl�ir.�/i1�.?j y �rrCfl�rs� 911 Fifth Avenue, Suite 100 Kirkland, Washington 98033 425-827-7701 FAX 827-5424 TO: Kyle and Juliann Ray 702 -4"' Avenue South Edmonds, WA 98020 ATTN: Kyle Ray AS REQUESTED BY Scott Hoover THE FOLLOWING WAS NOTED: Permit No_ BLD2008-037 Page IofI Date Project Name Project No. 2-23-09 I Ray Residence ICE050550B Location Weather 15625 75"' Place W Cloud 40's Municipality Report Number City of Edmonds 7 Engineer/Architect Donna Breslce / Hanson Design Client/Owner Kyle and Juliann Ray J General Con trattor/Supet-in tend cat Hoover Premier Homes / Scott Hoover Grading Contractor/Saperinlendent Buchanan Land Construction / Duncan Buchanan .AESI was onsite today to observe footing drain installation and to perform a TESC inspection. Footing Drain Installation: Since our previous site visit, the perimeter stein wall and the interior grid footings had been placed. Using a steel soil probe, the crushed rock over soil subgrade was penetrated approximately 1-2 inches under full body weight and it is our opinion that the footing subgrades are suitable for support at the design bearing . capacity of 2,000 pounds per square foot. Buchanan Land Construction had installed footing drain pipe along the east, north and west side of the building. The footing drain had been backfrlled along the west side, but was exposed along the north and east. A 4" perforated PVC pipe had been set at the base of the footing. At the northwest corner, the pipe had been set, it was bedded in washed rock to approximately 1 foot over the top of the pipe and fi Iter fabric was placed over the washed rock. In our opinion, the footing drains that were observed today had been installed properly and where they were in progress, the steps taken so far were in accordance with the plans and our drainage recommendations. Based on a later conversation with Eric Lim (AESI), it is our opinion that on the east side of the house, the upper footing drain and drain rock on the north half of the house should be capped at the transition to the lower footing drain and should not be connected to the lower footing drain that serves the southern portion. Subgrade Observations: Since our last visit, the perimeter stein walls and interior footings had been placed in the northern portion of the house. While onsite, we spoke with Duncan Buchanan (Buchanan Land Construction). He asked about full inside the crawlspace. We told him that compacted soil would be suitable for foundation backfil.l and the soil should be placed up to the top of the spread footings. TESC Inspection: While onsite we observed the condition of the site BMP's. Buchanan Land Construction was hauling off excess soil; loading dump trucks with soil. The construction entrance was covered with quarry spalls and there was no sediment track -out or runoff from the site. The adjacent catch basins had filter inserts and were not in need of maintenance. The interceptor swale along the east edge of the lot was in place and appeared to be working. The temporary Lock -Block shoring wall along the north side of the excavation was in place and there were no observed signs of caving or sloughing. Based on the field conditions observed, it is our opinion that the BM -Ps currently in place are perforining properly and no additional erosion control measures are required at the time. .AESI will return to observe subgrade conditions and construction progress at the request of Scott Hoover and to perform weekly TESC inspections. /J COPIES TO: City, Hoover, Hanson, Breske, file FIELD REP.: r", 4� rew Glandon, PEG, CPESC DATE PRINCIPAL / PM: Aaron McMichael, Pr, PEG MAILED: FEB 21 2009 FIELD REPORT Associated Earth Sciences, Inc. /'rit•.Finfrly251167601,GY,ce 911 Fitlh Avenue. Suite 100 Kirkland, Washington 98033 425-827-7701 FAX 827-5424 TO: Kyle and Juliann Ray 702 - 4'h Avenue South Edmonds, WA 98020 ATTN: Kyle Ray AS REQUESTED BY Scott Hoover THE FOLLOWING WAS NOTED: Permit No. BLD2008-037 Page 1 of I Datc Project Name Project No. 10/24/09 I Ray Residence KE050550D Location Weather 156ZS 75"' Place W Overcast 60s F Municipality Report Number City of Edmonds 8 Engineer/Architect _ Donna Breske / Hanson Design Client/Owner Kyle and Juliann Ray General Contractor/Superintendent Hoover Premier Homes / Scott Hoover Grading Contractor/Superintendent Buchanan Land Construction / Duncan Buchanan We visited the site to observe final site conditions prior to occupancy and address City staff corrunents regarding the rockery along the south side of the driveway. On arrival, we observed that the exterior house construction was complete and that landscaping in the front yard was complete. The landscaping in the rear yard was nearly complete with sod being installed during our visit. We observed the rockeryy along the south side of the driveway. We measured the rockery to be approximately 12'8" long and approximately 3' 10" in maximum height. The rockery extended west from the north foundation wall of the house and tapered down in height to match grade in the front yard. It appears that the rockery was necessary since a slope would have placed soil against the finished wood siding of the house. Mr. Hoover informed us that 2 rows of Lock -Blocks were left in -place along the south edge of the driveway and are directly behind the rockery. We hand -probed between the rockery stones and felt a block where we could penetrate the crushed rock backfill. In our opinion, the Lock -Blocks are alleviating surcharge on the rockery, and the short retaining structure is suitable for support of the driveway and anticipated vehicle loads. COPIES TO: City, Hoover, Hanson, Breske, file DATE MAILED: FIELD REP.: Eric Lim, PE i PRINCIPAL / PM: Aaron McMichael, PE, PEG 0 0 Associated Earth. Sciences, Inc. 0 E NJ }:. Cefehraiin Over25 Veayso of Service October 26, 2009 Project No. KE050550B Kyle and Juliann Ray 702 4°i Avenue South Edmonds, Washington 98020 Subject: Final Letter for Geotechnical Construction Monitoring Services Ray Residence Reconstruction 15625 75" Place West Edmonds, Washington Permit No. BLD2008-0376 Dear Mr. and Mrs. Ray: "live OCT 27 2009 DEVELOPMENT SERVICES CTR. CITY OF EDMONDS As required by the City of Edmonds, Associated Earth Sciences, Inc. (AESI) has prepared this final letter regarding geotechnical construction monitoring observations for your project at the above -referenced site. AESI performed periodic site visits from December 4, 2008 through October 24, 2009 to observe temporary erosion control measures, wet season site monitoring, interceptor trench installation, site cut slopes and shoring, foundation subgrade preparation, and foundation drainage installation, as required by the City of Edmonds. The results of our observations are summarized in our Field Reports Nos. 1 through 8, attached to this letter. As requested by the City of Edmonds, we have also confirmed that the Lock -Blocks behind the short driveway rockery are alleviating the surcharge on the rockery. Based on our observations, it is our opinion that the project earthwork has been completed in general accordance with the approved project plans, the recommendations presented in our geotechnical engineering report dated January 1.0, 2008, and subsequent recommendations during construction. Kirkland o Everett Tacoma 42.5-827-7701 425-259-0522 253-722-2992 www.aesgeo.com F We appreciate the opportunity to be of service to you on this project. Should you have any questions regarding this letter, please call us at your earliest convenience. Sincerely, ASSOCIATED EARTH SCIENCES, INC. Kirkland, Washington c_ Eric J. Lim, P. Senior Project Attachments: Field Reports Nos. 1 through 8 cc: Hoover Premier Homes Attn: Scott Hoover Scott@hooverpremierhomes.com City of Edmonds Building Department Attn: Jeanie McConnell Fax: (425) 771-0221 U L /Id KE050550B5 1110jects\20050550\K G\W P 2 G. Aaron McMichael, P.E., P.E.G. Associate Engineer 0 Associated Earth Sciences, Inc. Nt r Cc�fintr��: j ���nrr%.ti'r�Y�rcc 911 Fifth Avenue, Suite 100 Kirkland, Washington 98033 425-827-7701 FAX 827-5424 TO: Kyle and Juliann Ray 702 - 4"' Avenue South Edmonds, WA 98020 ATTN: Kyle Ray AS REQUESTED BY Scott Hoover THE FOLLOWING WAS NOTED: FIELD REPORT Permit No. BLD2008-037 Paize 1 of I Date I Project Name Project No. 10/24/09 Ray Residence KE050550B Location Weather 15625 75"' Place W Overcast, 60s F Municipality Report Number City of Edmonds 1 8 Engineer/Architect Donna Breske I Hanson Design Client/Owner Kyle and Juliann Ray General Contractor/Superintendent Hoover Premier Homes / Scott Hoover Grading Contractor/Superintendent Buchanan Land Construction / Duncan Buchanan We visited the site to observe final site conditions prior to occupancy and address City staff comments regarding the rockery along the south side of the driveway. On arrival, we observed that the exterior house construction was complete and that landscaping in the front yard was complete. The landscaping in the rear yard was nearly complete with sod being installed during our visit. We observed the rockery along the south side of the driveway. We measured the rockery to be approximately 12'8" long and approximately Y10" in maximum height. The rockery extended west from the north foundation wall of the house and tapered down in height to match grade in the front yard. It appears that the rockery was necessary since a slope would have placed soil against the finished wood siding of the house. Mr. Hoover informed us that 2 rows of Lock -Blocks were left in -place along the south edge of the driveway and are directly behind the rockery. We hand -probed between the rockery stones and felt a block where we could penetrate the crushed rock backfill. In our opinion, the Lock -Blocks are alleviating surcharge on the rockery, and the short retaining structure is suitable for support of the driveway and anticipated vehicle loads. COPIES TO: City, Hoover, Hanson, Breske, file DATE MAILED: R� OCT 27 2009 DEVELPMENTSERViCES CTR. CITY OF EDMONDS FIELD REP.: Eric Lim, PE i PRINCIPAL / PM: Aaron McMichael, PE, PEG y of E D41 Y OF EDMONDS i 121 5TH AVENUE NORTH - EDMONDS,WA 98020 PHONE: (425) 771-0220 - FAX: (425) 771-0221 R90 *PERMIT MUST BE POSTED ON JOBSITE* STATUS: ISSUED ENG20080429 SIDE SEWER PERMIT (I -Single Fa"Iy) Permit Number: ENG20080429 Expiration Date: 11/26/2010 Job Address: 15625 75TH PL W, EDMONDS KRISTIN HANSON R H HOOVER INC 652 ALDER ST 16300 MILL CREEK BLVD #108 EDMONDS, WA 98020 MILL CREEK, WA 98012 425-745-1370 LICENSE #: RHHOO**313LZ EXP: 11/7/2009 N N I DESCRIPTION REPAIR N PROPOSE TO REUSE LATERAL LID NUMBER: GRINDER PUMP N PROPOSE TO REUSE SIDE SEWER Connect to eAsting SS lateral EASEMENT INFORMATION N PROJECT CROSSES OTHER PRIVATE PROPERTY N VERIFICATION OF RECORDED EASEMENTS COMPLETE INDEMNITY The Applicant has signed an application which states helshe holds the City of Edmonds harmless from injuries, damages or claims ofany kind or description whatsoever, foreseen or unforeseen, that may be made against the City of Edmonds or any ofits departments or employees, including but not limited to the defense ofany legal proceedings including defense costs and atiorneyfees by reason ofgranting this permit. CALL DIAL -A -DIG (1-800-424-5555) BEFORE ANY EXCAVATION CALL FOR WSPECnON (425) 771-0220 EXT. 1326 24 HOUR NOTICEREQUIRED FOR ALL INSPECTION REQUESTS 'MISAPPLICATION IS NOT PERMIT UNTIL SIGNED BY THE CITY ENGINEER OR HIS/HER DEPUTY: AND FEES ARE PAID, AND RECEIPT IS ACKNOWLEDGED IN SPACE PROVIDED. RELEASED BY Printed: Wednesday. November DA' FILE COPY INSPECTOR COPY ❑ APPLICANT COPY STATUS: ISSUED ENG20080429 • Refer to City of Edmonds Side Sewer Information handout forppproved pipe materials, inspections and other requirements. • A 6" cleanout with 12" locking cast iron lamphole cover is required at the property line. • Maintain 10' separation between the sanitary side sewer and the water service line. • Applicant shall repair/replace all damage to utilities or frontage improvements in City right-of-way per City standards that is caused by or occurs during the permitted project. • E-Sanitary Side Sewer Inspection • &Engineering Final PARTIAL INSPECTION DATE: PARTIAL INSPECTION DATE: FINAL INSPECTION APPROVED DATE: INITIAL: NOTES: INITIAL: NOTES: INITIAL: A&ciated Earth SciencesAkc. 0 N ru Qd 0 Cg"y25 VeaffO[S'ert ce July 20, 2006 Project No. KE05550A Mr. Kyle Ray 15625 75' Place West Edmonds, Washington 98026 Subject: Response to City of Edmonds Peer Review Comments Proposed Ray Residence Remodel 15625 75' Place West Edmonds, Washington RESU SEP 1 7 2006 .. a. o �` Ma Reference: Zipper Zeman Associates, Inc. Meadowdale Earth Subsidence and Landslide Hazard Area — Geotechnical Review Dated: March 28, 2006 Dear Mr. Ray: Associated Earth. Sciences, Inc. (AESI) has received the above -referenced letter regarding geotechnical peer review of our October 27, 2005 geotechnical report and the project plan set submitted to the City of Edmonds. This letter has been prepared to address the comments by Zipper Zeman Associates, Inc. (ZZA) that were prepared as part of the City's peer review process. For reference, we have numbered our response to correspond with ZZA's comment number used in their letter (attached). 1. We recommend that Site Class "D" should be used for 2003 International Building Code (IBC) structural design. 2. The unusually wet winter season from December 2005 to February 2006 produced approximately 20 inches of rain, which was approximately 7 inches over normal for that period according to National Weather Service data available online (http://www.weather.gov/climate/index.php?wfo=sew). During that period, we asked the owner and occupant of the house to report any seepages emanating from the hillside or standing water in the backyard. The owner -occupant reported that no seepages were observed during this season or in seasons past since purchasing the property in 1999. We also visited the site approximately 1 month after this higher than normal wet period and looked for lag -time seepages. During this visit and subsequent visits since, we did not observe evidence of ground water seepage on the property, hydrophilic plants that may indicate active seepage zones, or signs of instability of the steep slope area above the project site. The Geotech Consultants explorations were performed in January 1997 after an unusually wet period and prior to the installation of surface water drainage improvements, including drainage berms Kirkland Office* 911 Fifth Avenue, Suite 100 - Kirkland, WA 98033 - P (425) 827-7701- F (425) 827-5424 Everett Office - 2911 1/2 Hewitt Avenue, Suite 2 - Everett, WA 98201- P (425) 259-0522 - F (425) 252-3408 www.aesgeo.com and catch basins, on the streets and properties above the project site. These improvements have reduced surface water runoff from saturating the hillside, which has been linked to past slides in the area. A suitable amount of vegetative ground cover and foliage are also present on the slope to contribute to rainfall interception and transpiration. Based on these factors, especially the surface water drainage improvements by the City of Edmonds and private property owners above the site, we anticipate low ground water conditions and seepage on and above the property throughout most years. Furthermore, although the buildup and creep of colluvium is likely to have occurred over the time period since GeoEngineers, Inc. updated the Roger Lowe landslide probabilities, the surface water improvements described above have mitigated the increase in that probability, in our opinion. 3. This project is a remodel of an existing structure with significant portions to remain. Risks to the existing structure is present and has been accepted by the owner whether or not the proposed improvements are constructed. The proposed improvements do not further encroach on the steep slope area; therefore, the risk will not be increased. We understand that the owner opted not to include the catchment wall design on the final design because the catchment wall could not be constructed on the portions to remain without razing those portions of the house. Therefore, required mitigations of impacts from potential slides should be limited to the proposed improvements. We recommend that the catchment wall requirement should be .limited to constructing the 3-foot catchment wall on the portions of the east side of the dwelling that will require new foundations and walls, which are the guest bedroom and bathroom on the main floor on the south half of the house. The catchment wall may be constructed by extending the foundation stemwall to extend 3 feet above finish exterior grade and suitably reinforced to retain active earth pressures provided in the geotechnical report. 4. We recommend the 3-foot-high, reinforced -concrete catchment wall as a reasonable mitigation against typical soil debris -flow buildup that would otherwise damage conventional wood -framing near the ground surface. The catchment wall may not provide adequate protection against falling trees striking above the catchment wall or high velocity impacts from trees, soil, and other debris. Our rational basis for the 3- foot height is based on our experience in designing such structures and observations of typical debris -flow buildup heights against exterior walls in similar settings. The 3-foot height also takes into consideration the approximate 25- to 35-foot length of the slope runout in the backyard and possible deflection of debris flows around the south side of the structure. 5. We have recommended revisions to the plans to include details of the 2 feet of structural fill under the footings. We understand that the foundation details on the project plans will show that the previously proposed expansion of the existing footings along the back of the guest bedroom have been changed to reflect an entirely new footing with the 3-foot-high catchment/stemwall discussed above. Therefore, the existing footings will be removed and undermining will not be an issue. PA 0 We trust that this letter meets you immediate needs. Please call if we may be of further assistance. Sincerely, ASSOCIATED EARTH SCIENCES, INC. Kirkland, Washington Project Engineer O� Mc�I o f wasN�ti�� p 33222 �O w ' CISTFR sIpNALti� EXPIRES 2/27 G. Aaron McMichael, P.E., P.E.G. Associate Engineer Attachment: Zipper Zeman Associates, Inc. "Meadowdale Earth Subsidence and Landslide Hazard Area - Geotechnical Review" letter, dated March 28, 2006 cc: Mr. Phil King, Phil King Designs, Fax: (425) 745-4078 Mr. Nick Lehtinen, HNLehtinen Engineering, Fax: (425) 259-4328 EJ Usn KE05550A3 Projects\2005055M EM P 3 MAY-10-2006 10:23 M 3 s- AM K RAY ATTY 4256�7147 er As d s c Geotechnical and Environmental Consulting A Iromeon Company P.02 J-2427 March 28, 2006 City of Edmonds Development Services Department — Building sGd 121 — 5ch Avenue North, P Floor '( Edmonds, Washington 98020 MAR 2 6 Attention: Ms. Marie Harrison 8U'LDIIVG Subject: Meadowdale Earth Subsidence and Landslide Hazard Area — Geotechnical Review Proposed Ray Residence Addition 15625 — 75"' Place West Edmonds, Washington Dear Ms Marie Harrison: Zipper Zeman Associates, Inc. (ZZA) has completed our review of the provided plans and geotechnical report for compliance with the City of Edmond Meadowdale Earth Subsidence and Landslide Hazard Area code provisions. We were provided with a set of the plans (Sheets l - 8) revised March 8, 2006, a copy of the geotechnical report by Associated Earth Sciences, Inc. (AESI) dated October 27 2005, a copy of the geotechnical engineer plan review letter dated February 7, 2006, and a site topographical survey dated October 19, 2005. The conclusions and recommendations contained in AESI's geotechnical report regarding site stability, foundations, retaining walls, floor slabs, and structural fill have been provided. In general, it appears that the recommendations to date appear reasonable, with the exceptions below. In addition, it appears that not all of the recommendations are incorporated into the project plans. The following is a list of questions, comments, or inconsistencies noted during our geotechnical review: 1. The shallow explorations performed with the subject property encountered loose fill soil and old landslide debris to depth, The geotechnical report recommends that a Site Class C be used for the development of the response spectra, However, the 2003 IBC suggests that a Site Class D be used in cases where limited information is available onsite. We recommend that the geotechnical engineer provide further evidence and calculation verification that the site should classified as Site Class C soils, Otherwise, Site Class D should be used. 2. The geotechnical report indicates within the Geologic Reconnaissance section that "an oversteepened area interpreted to be an old slide scarp was observed directly east of the project site.....1Vlost of the deciduous trees had bowed trunks indicating slope creep...." Yet later, the report and plan review letter concur with Roger Lowe's and Geoengineer's assessment of the hazard from an encroaching landslide as only 2 percent probability in 25 years. In addition, the borings by Geotech Consultants to the southeast encountered permeable soils overlying the relatively impermeable silts acid clays with indicated 18905 3r Avenue West #117, Lynnwood, WA 98036 425-771-3304 Fax: 425.771-3549 MAY-10-2006 10:23 AM K& RAY ATTY 425607147 P-03 6-11�Aw Proposed Ray Residence -- Edmonds, Washingom lob No, 1.2427 March 28, 2006 Page 2 groundwater and/or wet soil conditions near 15 feet in depth at the soil transition, No discussion in the geotechnical report was provided regarding the expected absence or presence of groundwater seepage on the slope above the residence or within the site soils throughout the year, only a discussion of groundwater conditions in late summer. We recommend that the geotechnical engineer provide conclusions regarding the anticipated high groundwater conditions at the site and provide further discussion/justification for the assessed risk from an encroaching landslide. 3. The geotechnical report provides a recommendation for mitigating the risk of a landslide debris flow into the residence. It appears that this recommendations has not been incorporated into the project plans. The Meadowdale Landslide and Earth Subsidence Hazard Area Summary Report by Landau Associates, dated March 17, 2004 provides definition of the hazards of an encroaching landslide, and the current code states that all impacts that could affect human safety trust be mitigated and prevent avoidable damage to structures. It is our opinion that this is the case for the risk of landslide debris encroaching into the residence (mainly bedrooms) on the east side. We recommend that the project plans incorporate the 3 foot high catchment wall above the east ground level per the geotechnical engineer's recommendation, 4. It should be noted that the catchment wall only provides protection from soil debris flow and not protection from things such as trees that may be part of the debris flow. We recommend that the geotechnical engineer clearly provide the possible impacts that are and are not mitigated by the catchment wall. In addition, we recommend that the geotechnical engineer provide calculations or a rational basis substantiating the recommended 3 vertical feet of the catchment wall, For example, the catchment wall basis could be provided by hand probing colluvium depths on the steep slope, 5. The geotechnical report recommends that new footings be underlain by at least two feet of structural fill prior to placement. The plans show that new footings are being placed directly adjacent to existing footings and it is unclear on; the plans how the recommendation is incorporated in the project plans. Please provide a detail and associated notes to clarify the incorporation of the recommended structural fill. We recommend that the plans and other submitted documents be returned to the applicant for action. The applicant should make corrections necessary in order to be, iz accordance to the geotechnical report and the City of Edmond Code. In addition, the project geotechnical engineer should review and comment on the specific review comments provided. 7-2427 RBY Reaidaice Roview.doc MAY-10-2006 10:24 AM KV RAY ATTY 4256#7147 P.04 Proposed Ray Residence — Edmonds, Washln��ootn 0 &�PA%job No. J-2427 March 28, 2006 Page 3 We trust that this letter meets your needs at this time. Please call us with any questions regarding this project, Respectfully Submitted, Zipper Zeman Associated, Inc, �OV,4 B R T �+ ExWges Kristopher T. Hauck, P,E, Project Engineer l l�� Lt.►n,y C John E. Zipper, P.E. Principal J-2427 Ray Reaidwee Jievlew,dec Zipper ZEW'n Associates, Inc. Geotechnical and Environmental Consulting A 1rerxaccln Company City of Edmonds I - Development Services Department — Building 121 — 5`h Avenue North, 2"d Floor Edmonds, Washington 98020 Attention: Ms. Marie Harrison 81052427 September 20, 2006 RECEIVED S E P 2 5 2006 BUILDING DEPT. Subject: Meadowdale Area — Geotechnical Review; Plan Review Number 2006-0544 Proposed Ray Residence Addition: Resubmittal dated September 7, 2006 15625 — 75`h Place West Edmonds, Washington Dear Ms Harrison: Zipper Zeman Associates, Inc. (ZZA) has completed our review of the provided plans and geotechnical report for compliance with the City of Edmond Meadowdale Earth Subsidence and Landslide Hazard Area code provisions. The resubmittal includes revised Architectural and Structural Plans which incorporate the recommendations of the geotechnical engineer and review comments (1), (4) and (5) of our March 28, 2006 letter. The geotechnical engineer submitted technical information in a letter dated July 20, 2006 that adequately addresses review comments (2) and (3) of our March. 28, 2006 letter. We conclude that the revised plans, geotechnical report dated October 27, 2005, geotechnical engineer plan review letter dated February 7, 2006, and supplemental letter dated July 20, 2006 are in accordance with generally accepted geotechnical engineering practice and in compliance with ECDC requirements under section 19.010.030 regarding submittal requirements for: • Vicinity Map; • Topographic Map; • Geotechnical Report; • Architectural and Structural Plans. Other documents listed within section 19.10.040 of the ECDC were not contained with the information submitted for our review. We recommend that the City determine whether those additional items have been submitted and comply with code requirements. We trust that this letter meets your needs at this time. Please call us with regarding this project. Respectfully Submitted, Zipper Zeman Associates, Inc. to John E. Zipper, P.E. .p 611 Principal . � cls'l," , - 18905 33rd Avenue West # 1 17, Lynnwood, WA 98036 425-771-3304 Fax: 113fi$$ / O-] QAt�p* LOG ITEM # , q19 ZZAZipper Zeman Associates, Inc. Nd _Q§ft Geotechn*nd Environmental Consulting A 1% Company City of Edmonds Development Services Department —Building 121 — 5d' Avenue North, 2nd Floor Edmonds, Washington 98020 Attention: Ms. Marie Harrison 81052427 September 20, 2006 Subject: Meadowdale Area — Geotechnical Review; Plan Review Number 2006-0544 Proposed Ray Residence Addition: Resubmittal dated September 7, 2006 15625 — 75`h Place West Edmonds, Washington Dear Ms Harrison: Zipper Zeman Associates, Inc. (ZZA) has completed our review of the provided plans and geotechnical report for compliance with the City of Edmond Meadowdale Earth Subsidence and Landslide Hazard Area code provisions. The resubmittal includes revised Architectural and Structural Plans which incorporate the recommendations of the geotechnical engineer and review comments (1), (4) and (5) of our March 28, 2006 letter. The geotechnical engineer submitted technical information in a letter dated July 20, 2006 that adequately addresses review comments (2) and (3) of our March 28, 2006 letter. We conclude that the revised plans, geotechnical report dated October 27, 2005, geotechnical engineer plan review letter dated February 7, 2006, and supplemental letter dated July 20, 2006 are in accordance with generally accepted geotechnical engineering practice and in compliance with ECDC requirements under section 19.010.030 regarding submittal requirements for: • Vicinity Map; • Topographic Map; • Geotechnical Report; • Architectural and Structural Plans. Other documents listed within section 19.10.040 of the ECDC were not contained with the information submitted for our review. We recommend that the City determine whether those additional items have been submitted and comply with code requirements. We trust that this letter meets your needs at this time. Please call us with regarding this project. Respectfully Submitted, Zipper Zeman Associates, Inc. 5 John E. Zipper, P.E. � 611 Principal cJS'11:.4 1 18905 33rd Avenue Wert #1 17, Lynnwood, WA 98036 425-771-3304 Fax: 1 13fi2$ / o-] RECEIVED LOG 9 _� S EP 10 2006 BUILDING DEPT. ZZA FAX'fRANSMITTAL For: ► ►` 5 - r r Lajlj bff�S 01i-- Company: C� -hg of "4VI an U S Fax No.: y Phone No.: (42,!5) -7 -7 r - b Z?-� From- A h Z pp e,+- Date: Subject: Wtadowdak, Ore. ❑ 811 First Ave., #404 Seattle, WA 98104 T: 206-264-8295 F: 206-264-4818 No. of pages including cover: L Job. No.: 0105-- Zipper Zeman Associates, Inc. Geotechnlcal and Environmental Consulting A lfiw=tm Company 0 18905 33n' Ave. W. # 117 Lynnwood, WA 98036 T: 425-771-3304 F: 425-771-3549 RECEIVED S E P 2 0 2006 BUILDING DEPT. ❑ 2501 East "D" St. #200 Tacoma, WA 98421 T: 253-573-9939 F. 253-573-9959 LOG ITEM #.._ • 9 RETURN ADDRESS: City of Edmonds, City Clerk 121 5 th Avenue North Edmonds, WA 98020 CONFORMED 601 PGS 200611 M70 W 1712006 9:09am $$37.00 SNOHONISH COUNTY, WASHINGTON COVENANT OF NOTIFICATION AND INDEMNIFICATION/HOLD HARMLESS Reference #: r;9,�, Grantor(s): (1) l VA(. (2) J U -(160! Additional on pg. Grantee(s): City of Edmonds Legal Description (abbreviated): Sec TwnXZ _Rng_Qtr,5&) OR Lot Block Plat V6 Assessor's Tax Parcel 10#(s): (1) 00:g3l -0 -OZy -62-- (2) Assessor's Tax Parcel EM not yet assigned CITY OF EDMONDS APPROVED FOR RECORDING BY:L DATE:* PAGE I— OF Under the review procedures established pursuant to the State Building Code, incorporating amendments promulgated by the City of Edmonds, and as a prerequisite to the issuance of a building permit for the construction of a residential structure and attendant facilities, the undersigned OWNERS of.property do hereby. covenant, stipulate and promise as follows: APPR��FOR REC, 1iY: DATE:/ PAGE OF 1. Description of Subject Property. This covenant of notification and indemnification/hold harmless relates to a �t(ract of land at the street address of 1562- 75� P1 , W. t✓Jfflond`55 WA- 90 . insert street address), Edmonds Snohomish County, Washington and legally described as: Parcel Legal Description MEADOWDALE BEACH BLK 000 D-02 TH PTN LOT 24 PLAT OF MAEDOWDALE BEACH & LOT 25 PLAT OF MAEDOWDALE BEACH SUPPLEMENTAL PLAT DAF: COM AT CONC MON IN STEEL CASE AT INT 158TH ST SW & 75TH AVE W TH NO2*48 171E ALG C/L 75TH AVE W 389. l5FT TH N87*48 41 E 30.12FT TO E LN IOFT STRIP OF LAND DEEDED TO CITY OF EDM VOL 5 OF DEEDS PG 53 REC SD CO & POB TH NO2*48 17E L0.256FT TO S LN SD LOT 24 TH N88*09 43 W ALG SD S LN IOFT TO SW COR SD LOT 24 TH N00*39 53 W ALG W LN SD LOT 24 82FT TH S88*09 43E PLW S LN SD LOT 24 f20FT TH SOO*39 53E PLW W LN SD LOT 24 49.80FT TH N88*09 43 W 1838FT TH S00*39 53E 32.20FT TO S LN SD LOT 24 TH N88*09 43 W ALG SD LN 20FT TH S76*23 13 W 25.50FT TH S87*38 4I W 47.34FT TO POB PER CITY OF EDM BLA NO S-3-91 REC AF NO 9105020156 2. Notification and Covenant of Notification. The above referenced site (hereinafter "subject site") lies within an.area which has been identified by the City of Edmonds as having a potential for earth subsidence or landslide hazard. The risks associated with development of the site have been evaluated by technical consultants and engineers engaged by the applicant as a part of the process to obtain a building permit for the subject site. The results of the consultant's reports and evaluations of the risks associated with development are contained in building permit file number 05 - l 7 7 . (insert number) on file with the City of Edmonds Building Department. Conditions, limitations, or prohibitions on development may have been imposed in accordance with the recommendations of APPROVED OR RECORDING: BY: &M DATE: PAGE _ OF the consultants in the course of permit issuance. The conditions, limitations, or prohibitions may require ongoing maintenance on the part of any owner or lessee or may require modifications to the structures and earth stabilization matters in order to address future or anticipated changes in soil or other site conditions. The statements and conditions proposed by the OWNERS' geotechnical engineer, geologist, architect and/or structural engineer are hereby incorporated by reference from the contents of the file as fully as if herein set forth. Any future purchaser, lessee, lender or any other person acquiring or seeking to acquire an interest in the property is put on notice of the existence of the content of the file and the City urges review of its contents. The file may be reviewed during normal business hours or copies obtained at the Building Department, City of Edmonds, 121 Sth Avenue North, Edmonds, Washington 98020. 3. Indemnification and Hold Harmless. The undersigned OWNERS hereby waive any and all liability associated with development, stating that they have fully informed themselves of all risks associated with development of the property and do therefore waive and relinquish any and all causes of action against the City of Edmonds, its officers, agents and employees arising from and out of such development. In addition, the OWNERS on behalf of themselves, their successors in interest, heirs and assignees, do hereby promise to indemnify and hold harmless the City of Edmonds, its officers, agents and employees from any loss, claim, liability or damage of any kind or nature to persons or property either on or off the site resulting from or out of earth subsidence or landslide hazard, arising from or out of the issuance of any permit(s) authorizing development of the site, or occurring or 'PP RO D FOR RECORDING: BY: DATE:. PAGE OF_ arising out of any false, misleading, or inaccurate information provided by the OWNERS, their employees, or professional consultants in the course of issuance of the building permit. 4. Insurance Requirement. In addition to any bonding which may be required during the course of development, the Community Services Director has/has not (strike one) specifically required the maintenance of an insurance policy for public liability coverage in the amount and for the time set forth below in order to provide for the financial responsibilities established through the indemnification and hold harmless agreement above: S. Covenant to Touch and Concern the Land. This covenant of notification and indemnification/hold harmless touches and concerns the subject tract and shall run with the land, binding, obligating and/or inuring to the benefit of future owners, heirs, successors and interests or any other person or entity acquiring an interest in property, as their interest may appear. This provision shall not be interpreted to require a mortgagor or lender to indemnify the City except to the extent of their loss nor to obligate such persons to maintain the insurance above required_ APPR VED FOR RECORDING: BY: AW DATF/Qok PAGE _ OF (� 41^- yin a vOCp DONE this �" 1 day of 'v t a rai OWNER(S) By: % t By: By STATE OF WASHINGTON ) ) COUNTY OF 3 ao ho- YI I5 h ) ss: I certify that I know or have satisfactory evidence that Vm u— ar.c- j u I G.n n 292jsigned this instrument and acknowledged it to be ( is/her) free and voluntary act for the purposes mentioned in this instrument. -1'ti- DATED this day of LATEMPIBU[LDINGIMEADO WOVENANT a c, I r NO ARY PUVLIC My commis ' n expires: cDA SioN 140f Awy %ta EXHIBIT "A" LEGAL DESCRIPTION That portion of Lot 24, PLAT OF MEADOWDALE BEACH, according to the plat thereof recorded in .Volume 5 of Plats, page 38, and Lot 25, PLAT OF MEADOWDALE BEACH SUPPLEMENTAL PLAT, according to the plat thereof recorded in Volume 5 of Plats, page 42, records of Snohomish County, Washington, described as follows: Commencing at a concrete monument in steel case at the intersection of 158`s Street Southwest and 75`h Avenue West; thence North 2*48' 17" East along the centerline of 75`s Avenue West 389.15 feet; thence North 87*48'41" East 30.12 feet to the East line of a 10.00 foot strip of land Deeded to the City of Edmonds in Volume 5 of Deeds, page 53, records of said County, and the point of beginning; thence North 2*48' 17" East 10.256 feet to the South line of said Lot 24; thence North 88*09'43" West along said South line 10.00 feet to the Southwest corner of said Lot 24; thence North 0*39'53" West along the West line of said Lot 24 82.00 feet; thence South 88*09'43" East parallel with the South line of said Lot 24 120.00 feet; thence South 0*39'53" East parallel with the west line of said Lot 24 49.80 feet; thence North 88*09'43" West 18.38 feet; thence South 0*39'53" East 32.20 feet to the South line of said Lot 24; thence North 88*09'43" West along said line 20.00 feet; thence South 76*23' 13" West 25.50 feet; thence South 87*38'41" West 47.34 to the point of beginning. 005131-000-024-02 15625 75 h PL W; EDMONDS, WA 98026-4520 20052901814460 265229801f RETURN ADDRESS: City of Edmonds, City Clerk 121 5th Avenue North Edmonds, WA 98020 200810090471 CONFORMED 50PY PGS SNOHOMISHCOONT�,m jag. 0NG10N COVENANT OF NOTIFICATION AND INDEMNIFICATION/HOLD HARMLESS Reference #: Granter(s): (I) �� (2) Additional on pg. Grantee(s): City of Edmonds Legal Description (abbreviated): Sec ,!! TwnRng�Qtr� OR Lot 2q pdrtfaj dock 0 Plat Mom- 6E-ACa- Assessor's Tax Parcel ID#(s): (1) O 0 10 0 00 2 y 0 2 (2). Assessor's Tax Parcel ID# not yet assigned .CITY OF EDMONDS APPROVED FOR RECORDING BY:2 DATE: �d AGE L OF Under the review procedures established pursuant to the State Building Code, incorporating amendments promulgated by the City of Edmonds, and as a prerequisite to the issuance of a building permit for the construction of a residential structure and attendant facilities; the undersigned OWNERS of property do hereby covenant; stipulate and promise as follows: STREET FILE. ��P 0 1. Description of Subject Property. APPROVED FOR RECO G: BY: DATE: D PAGE OF This covenant of notification and indemnification/hold harmless relates to a tract of land at the street address of 19 fB 2 V�7 1 GJ t� FL Val street address), Edmonds Snohomish County, Washington and legally described as: I L.- . MEADOWDALE BEACH BLK 000 D-02 TH PTN LOT 24 PLAT OF MAEDOWDALE BEACH & LOT 25 PLAT OF MAEDOWDALE BEACH SUPPLEMENTAL PLAT DAF: COM AT CONC MON IN STEEL CASE AT INT 158TH ST SW & 75TH AVE W TH NO2*48 17E ALG C/L 75TH AVE W 389.15FT TH N87*48 41E 30.12FT TO E LN LOFT STRIP OF LAND DEEDED TO CITY OF EDM VOL 5 OF DEEDS PG 53 REC SD CO & POS TH NO2*48 17E 10.256FT TO S LN SD LOT 24 TH N88*09 43W ALG SD S LN LOFT TO SW COR SD LOT 24 TH.N00*39 53W ALG W LN SD LOT 24 82FT TH S88*09 43E PLW S LN SD LOT 24 120FT TH S00*39 53E PLW W LN SD LOT 24 49.80FT TH N88*09 43W 18.38FT TH S00*39 53E 32.20FT TO S LN SD LOT 24 TH N88*09 43W ALG SD'LN 20FT TH 576*23 13w 25.50FT TH S87*38 41w 47.34FT TO POB PER CITY OF EDM BLA NO S-3-91 REC AF NO 9105020156 2. Notification and Covenant of Notification. The above referenced site (hereinafter "subject site") lies within an area which has been identified by the City of Edmonds as having a potential for earth subsidence or landslide hazard. The risks associated with development of the site have been evaluated by technical consultants and engineers engaged by the applicant as a part of the process to obtain a building permit for the subject site. The results of the consultant's reports and evaluations of the risks associated with development are contained in building permit file number (insert number) on file with the City of Edmonds Building Department. Conditions, limitations, or prohibitions on development may have been imposed in accordance with the recommendations of • E ED OR REDATOF the consultants in the course of permit issuance. The conditions, limitations, or prohibitions may require ongoing maintenance on the part of any owner or lessee or may require modifications to the structures and earth stabilization matters in order to address future or anticipated changes in soil or other site conditions. The statements and conditions proposed by the OWNERS' geotechnical engineer, geologist, architect and/or structural engineer are hereby incorporated by reference from the contents of the file as fully as if herein set forth. Any future purchaser, lessee, lender or any other person acquiring or seeking to acquire an interest in the property is put on notice of the existence of the content of the file and the City urges review of its contents. The file may be reviewed during normal business hours or copies obtained at the Building Department, City of Edmonds, 121 5th Avenue North, Edmonds, Washington 98020. 3. Indemnification and Hold Harmless. The undersigned OWNERS hereby waive any and all liability associated with development, stating that they have fully informed themselves of all risks associated with development of the property and do therefore waive and relinquish any and all causes of action against the City of Edmonds, its officers, agents and employees arising from and out of such development. In addition, the OWNERS on behalf of themselves, their successors in interest, heirs and. assignees, do hereby promise to indemnify and.;hold harmless the City:of Edmonds, its officers, agents and employees from:any loss, claim, liability or damage of any kind or nature . to :persons or property either on or off the site resulting from or out of.earth subsidence or landslide hazard, arising.from or out of the issuance of any permit(s) authorizing development of the site, or occurring or rr JAPPRO E FOR RECO G: BY: DATE: Q PAGE OF arising out of any false, misleading, or inaccurate information provided by the OWNERS, their employees, or professional consultants in the course of issuance of the building permit. 4. Insurance Requirement. In addition to any bonding which may be required during the course of development, the Community Services Director has/has not (strike one) specifically required the maintenance of an insurance policy for public liability coverage in the amount and for the time set forth below in order to provide for the financial responsibilities established through the indemnification and hold harmless agreement above: S. Covenant to Touch and Concern the Land. This covenant of notificationand indemnification/hold harmless touches and concerns the subject tract and shall run with the land; binding, obligating and/or inuring to the benefit of future owners, heirs, successors and interests or any other person or entity acquiring an interest in property, 'as their interest may appear. This provision shall not, be interpreted. to require a mortgagor or lender t6zindemnify the City except to the extent. of their loss -nor to obligatesue persons'to maintain the insurance above required. E APPROV D F R RD : BY: ARECOTE: G ?J g PAGE OF DONE this day of OWNER(S By: By: By STATE OF WASHINGTON ) ss: COUNTY OF K I certify that I know or have satisfactory evidence that 1 signed this instrument and acknowledged it to be (his/her) free and voluntary act for the purposes mentioned in this instrument. do� DATED this day of �J �yS(oNIrPUBL `C �OTgRy� My:commisslon 60jr.es: ®ems N� L: dated Earth Scienceslac. S EE N 0 0, Ce(Ws^afin'y Obw 2,y'Yean' o f Yen&e April 25, 2008 Project No. KE050550B Kyle and Juliann Ray 702 4' Ave South Edmonds, Washington 98020 Subject: Geotechnical Hazard Identification/Declaration and Mitigation Statement of Risk Proposed Ray Residence Reconstruction 15625 75 h Place West Edmonds, Washington Parcel No. 00513100002402 References: Hanson Design Architectural and Foundation Plans Dated April 2008 Donna L. Breske, P.E. Civil Plans Dated April 14, 2008 Associated Earth Sciences, Inc. Revised Subsurface Exploration, Geologic Hazard, and Geotechnical Engineering Study Dated January 10, 2008 Dear Mr. and Mrs. Ray: Associated Earth Sciences, Inc. (AESI) has reviewed the above -referenced project plans. In accordance with City of Edmonds requirements in earth subsidence and landslide hazard areas, we have prepared the following statements: • In our judgment, the plans prepared by the architectural designer, structural engineer, and civil engineer conform to the recommendations in our January 10, 2008 geotechnical report. • In our opinion, the risk of damage to the proposed development, or to adjacent properties from soil instability will be minimal, subject to the conditions set forth in the report, and the proposed development will not increase the potential for soil movement-`_, v -, STR e, r> • t); FILE Kirkland Everett 425-827-7701 425-259-0522 ' 253=_72 2 9=.,41i DEPT. www.aesgeo.com • In our opinion, the probabilities for earth movement on the property within a 25-year period are approximately: a 30 percent chance of occurrence for slumps in previously failed material and a 2 percent chance of occurrence for debris avalanches of encroaching landslide materials. These values were determined by using the values shown on the City's Landslide Hazard Map, developed by Lowe Associates and updated by GeoEngineers. In our opinion, the values are still applicable since the drainage in the site vicinity has been improved since these studies have been performed and, therefore, should not increase. • In our opinion, the erosion and sediment control plans by the civil engineer should be adequate for the proposed improvements, provided the contractor is diligent in inspecting and maintaining the BMPs. Furthermore, AESI will provide construction monitoring services to periodically observe the effectiveness of the BMPs, and recommend modifications, if necessary. • As discussed on Page 8 of our January 10, 2008 geotechnical report, the subject site lies within Zones B and C, as described by the 2007 Landau Summary Report. The house will be located only within Zone B. Zone-C hazards would include debris flows initiating from the steep slope to the east of the proposed house, which will be mitigated by the 3-foot-high concrete catchment wall (i.e., raised foundation stemwall) on the east side of the house. Since the writing of our report, the new house footprint has been moved to the . east approximately 10 feet. In our opinion, this location will not significantly increase the risk to the house since the 3-foot high catchment wall will mitigate debris flow risk after such flows reach the flat backyard area. Zone-B hazards include movement of the ancient landslide mass underneath the new house. This risk has been partially mitigated by suitable foundation subgrade preparation (i.e., 2-foot structural fill pad), and use of a grid -connected footing system to mitigate differential displacement. See the following paragraph and the above -referenced geotechnical report for additional information. • The subject site is located within the North Edmonds Earth Subsidence and Landslide Hazard Area (NEESLHA) formerly known as the Meadowdale Earth Subsidence and Landslide Hazard Area, which is a complex mix of ancient, large-scale earth movements and recent shallow slides. Therefore, it is our opinion that it is not practical for one lot owner to fully mitigate the risk of deep-seated or large-scale earth movement. The risks not fully mitigated include unusually large debris flow avalanches, with trees, boulders, and other projectiles that may penetrate the wooden structure of the house, and large scale earth movements of the foundation subgrade soils underneath the house. The main purpose of the grid -foundation is to prevent collapse of the house should the ground beneath move, and not to prevent the house from moving with large scale earth movements. 2 We trust that this letter meets your needs. Please call if you have any questions. Sincerely, ASSOCIATED EARTH SCIENCES, INC. Kirkland, Washington .7 33222 IST C�,- �a EXPIRES 2/27 B Eric J. Lim, P.E. G. Aaron X4 ichael, P.E. , P.E.G. Senior Project Engineer Associate Engineer cc: Hanson Design (4 copies) 652 Alder Street Edmonds, WA 98020 Attn: Kristin Hanson EJUdr KE050550B2 Projects\20050550 BWP 3 Ll EDMONDS BUH DING DEPARTMENT KYLE & JULIANNE RAY 15625 75m PLACE WEST MARCH 4, 2008 APPLICANT LIABILITY & LANDSLIDE ACKNOWLEDGEMENT WE BELIEVE THE ACCURACY OF ALL THE PERMIT SUBMITTAL INFORMATION IS WARRANTED BY THE OWNER IN A FORM WHICH RELIEVES THE CITY OF EDMONDS AND IT'S STAFF FROM ANY LIABILITY ASSOCIATED WITH RELIANCE ON SUCH A PERMIT APPLICATION SUBMITTALS. WHILE THE APPLICATION MAY REFERNCE THE REPORTS OF PRIOR PUBLIC CONSULTANTS TO THE CITY,_ALL CONCLUSIONS SHALL BE THOSE OF THE APPLICANT OR OWNER AND THEIR DESIGN PROFESSIONALS. WHILE THE APPLICANT OR OWNER UNDERSTANDS AND ACCEPTS THE RISK OF DEVELOPING IN AN AREA WITH POTENTIAL UNSTABLE SOILS AND UNDERSTANDS THE REQUIRED TEMPORARY AND PERMANENT EROSION CONTROL AND SITE MAINTENANCE ISSUES ASSOCIATED WITH SPECIFIC GEOLOGICAL HAZARDS OR CONDITIONS OF THE SITE MAY AFFECT SLOPE STABILITY OVER Taff. THE APPLICANT OR OWNER WILL ADVISE, IN WRITING, ANY PROSPECTIVE PURCHASERS OF THE SITE, OR ANY PROSPECTIVE LESSEES OF STRUCTURES ON THE SITE OF THE SLIDE POTENTIAL AND ON=GOING N[AU471ENANCE ISSUES OF THE AREA AND ON THE PROPERTY. KYLE RAY. ® a C) MAY - 2 20P9 BUILDING DEPT. ematz�2 STREET FIDE f-low sc. E APPROVED FOR RECORDING: BY: PAGE OF DATE_ STATE OF WASHINGTON ) ss: COUNTY OF I certify that I know or have satisfactory evidence that signed this instrument and acknowledged it to be (his/her) free and voluntary act for the purposes mentioned in this instrument. DATED this day of tNOY ll0� P LIC My commission expires: t 0 LATEMMuannvGUM&ADOVACOVE vANr IOTA l4Yrr 0 cr3 o PUBItGN. .0 Z� VYAS�� r 0 6 City of Edmonds Developmental Services Dept 12150'AveN Edmonds 98020 Re: Ray Project 15625 75 h Place West Edmonds 98026 Job: G10-945 Custom Design 8t Engineering, Inc has reviewed the Associated Earth Sciences, Inc Geo- Technical Report (Project No: KE050550B) and have explained the risk of loss due to slides on the site. The design of structure has incorporated the recommendations of the geo-technical report to reduce the potential risk of injury or damage due to any earth movement predicted in the report. We have also noted and advised the owner of the risk, hazards and any potential problems from earth movement not mitigated by the design of the structure. sincerely, P t S' jr RECEIVE® MAY - 2 2009 BUILDING DEPT. ./Alr04 � HANSON DESIGN KRISTIN HANSON 652 ALDER STREET EDMONDS WA 98020 FEBRUARY 12, 2008 EDMONDS BUILDING DEPARTMENT KYLE & JUTANNE RAY PROJECT 15625 76' PLACE WEST LEAD PROFESSIONAL DESIGNATION AND STATEMENT THIS LETTER IS TO VERIFY THAT THE UNDERSIGNED IS THE 'LEAD DESIGN PROFESSIONAL' AND HAS REVIEWED THE GEO- TECHNICAL REPART, UNDERSTANDS IT'S RECOMMENDATIONS AND HAVE INCORPORATED INTO THE DESIGN THE ESTABLISHED MEASURES TO REDUCE THE POTENTIAL RISK OF INJURY OR DAMAGE FROM ANY EARTH MOVEMENT PREDICTED IN THE REPORT. KRISTIN HANSON. 425-774-7129 n" C7-:lVED EUILDING DEPT. hansondesign@hotmail.com STREET FILE 0 • Donna L. Breske, P.E. 6621 Foster Slough Road, Snohomish, Wa. 98290 Phone: (425) 334-9980, Fax: (425) 334-7380 April 14, 2008 Kyle & Julianne Ray 702 0 Ave. S. Edmonds, Wa 98020 Subject: Civil Engineer's Statement of Risk for Geological Hazardous Area. Reference: Kyle & Junlaanne Ray, Single Family Home, New Construction 15625 75" Place West Civil Design Plans dated 4-14-08 Dear Mr. & Mrs. Ray, The two sheet plan set prepared by this Civil Engineer dated 4-14-08, conform to the recommendations of the Associated Earth Sciences Report dated January 10. 2008. Page 15 of the report specifies, "Drainage Considerations". The report states that perimeter drains for the foundation should be installed. Additionally, roof and surface runoff should not discharge into the footing drain system. In order to facilitate this, my Road & Drainage Drawing dated provides two drainage connection 6" PVC leads. One for the footing drain system and the other for the roof drain system. Additionally, yard drains and an interceptor swale in the back yard are designed with a tight line conveyance system that conveys flows directly to the CB in the city right-of-way of 75'h Place West. Sincerely, Donna L. Breske, P.E. RECEIVED MAY — 2 2@n9 BUILDING DEPT. jar. 18`P North Edmonds � INV, Earth Subsidence and ;r,.l,r: aF� Landslide Hazard iE L Y r �if alt 1 n- Areas Ma Legend " . ^ North Edmonds Earth Subsidence and1rf— Landslide Hazard Area f Q(See ECDC 23.80.020 B.1 and ECDC 19.10) (Note: Boundaries are the approximate extent of previous landsliding; hazards are presents �; ��� adjacent to the landslide boundaries) t �r'if � ,a c p I . Slope of 4Q% or steeper andcm with a vertical relief of ten 10 ft or more (See ECDC 23.80.020 B.2) Minimum buffer equal to the height of the steep slope or 50 feet, whichever ) is greater (see ECDC 23.80.070 A.1 ) ' 7 _ (The buffer shown is the minimum buffer C „w L t Ire gr 2 adjacent to the North Edmonds Subsidence and Landslide Hazard Area; a similar r buffer would apply to steep slope areas, r but is not shown on this map for clarity) � r 1f�t �'l,; 2 It Topographic Contour Vertical datum: NAVD88 �� t7w f ( I .`. Pi x f- Parcel ;IfAA -77 41 Map created by Landau Associates. Inc. (May M06) Aerial photo: City of Edmonds Topographic contours endsteep slopes data denved from LOAR data. City or Edmonds (February 27, 2005) ZOO BUIIDVNG DEPT. STREET FILE 0 0 4 s m m 7R 34 V) caM 5 QW, ;tl Ln 11 • STREET FILF EDMONDS WILLS & TRUSTS KYLE G. RAY, ATTORNEY AT LAW. P.S. KEVIN COPP, ATTORNEY AT LAW 1 14 SECOND AVENUE SOUTH. SUITE 1 01 . EDMONDS. WA 98020 PHONE (425) 71 2-0279 FAX (425) 672-7147 January 9, 2006 Mayor Gary Haakenson City of Edmonds Third Floor City Hall 121 Fifth Avenue North Edmonds, WA 98020 a 221,1107 C�;,��i�.DN,NIS DEP7', Re: Building Permit for remodel of residence located at 15625 75th Pl. W Dear Mr. Mayor: My wife and I are long time residents and business owners in the City of Edmonds. We love our city and have never had cause to complain about anything here. However, we have become tremendously disenchanted with the process involved in obtaining a building permit to remodel our residence. I must confess at the outset that some of the problems have arisen as a result of the designer we originally hired (now fired) to draw our plans. Nonetheless, aside from Steve Bullock and Gina Coccia (who were very helpful and pleasant), we have oftentimes been treated rudely by the City's plan review professionals; to say they have been unhelpful would be putting it mildly. I hesitate to name names as we will likely have to deal with them for some time to come. We first submitted plans to the City over two years ago. Each time the various city departments review the plans, new requirements are asserted by the City. This moving target approach has made it nearly impossible to complete the process. For example, on a recent review the City asserted that our garage will be too close to the street, even though this garage will be no closer to the street than the existing structure (currently our basement). The proposed garage had been in this location on our plans for over two years, and this issue was never previously brought to our attention. We had previously obtained a street setback variance that we thought had dealt with any such issue. Another example is we have recently been told that because we have hired a new designer (Kristin Hanson), our plans need to be completely re -drawn and re -engineered, again costing thousands of dollars and many months of further delay. I could understand this if we had hired an architect initially LOG ITEM # .��' ✓ 0 0 and then changed architects. However, for residential design, a designer (or even the owners themselves) can draw the plans so long as a structural engineer stamps the plans and performs the required structural calculations. I do not understand why our new designer cannot simply clarify and make the necessary changes to the existing plans; rather than starting from scratch after two years and many thousands of dollars. The irony is that although our remodel is in the Meadowdale Landslide Area, aside from some new footings (which will actually increase the structural integrity of the home), almost no earth will be disturbed during the remodel. Absolutely no grading will be done. Aside from extending a second floor kitchen out a couple of feet, the remodel will be entirely within the footprint of the existing structure. To make a property owner jump through all the Meadowdale Landslide hoops for a project like this is unconscionable. I understand that the City is concerned about its liability for permitting projects in this area, however, it seems to me that the City is opening itself up to even greater risk of liability by constantly imposing new requirements on a relatively simple, non-invasive project such as ours. Presently we are in danger of our variances expiring, having to pay the plan review fee a third time, and losing crucial time on our remodel. This will cost us thousands of dollars. All the while, our home is in disrepair (in anticipation of the remodel) and getting worse by the day. I invite you to our home so you can see the conditions we have been living in. I thank you for taking the time to review our concerns. Any assistance you can provide would be greatly appreciated. Sincerely, Kyle G. Ray Attorney at Law CC: Kristin Hanson, Designer Eric Lim, PE Zipper Zeman Associates City of Edmonds Building Department LOG ITEM #1-94/1 L7 40 Mr. Ray January 16, 2007 Page Two Regarding other comments in your letter we have the following responses: • Decision to change designers The City did not require your new designer to re -draw plans —that was solely her decision and choice. However, be advised no one other than Neil Lehtinen, P.E. is permitted to alter plans that he has stamped and signed. The plans still need to be changed however to address outstanding City requirements to date. Variance Approval Expiration The Variance approval granted by the City Hearing Examiner continues to be a valid decision (original decision date 3/24/06, variance expiration date 3/24/07) because the variance approval now runs with the time line of your building permit application which expires on May 5, 2007. Please note the building permit application cannot be extended further so the permit must be issued by May 5, 2007 or the application for the building permit and variance shall expire and there is no code provision to grant further extensions on either application. • Earth Subsidence Landslide Hazard Area Ordinance The City did impose the following Earth Subsidence Landslide Hazard Area (ESLHA) Ordinance requirements on this project; the geotechnical investigation and peer review, the owner's covenant, the lead design professional statement, the structural engineers' statement and the site restoration bonding requirement. The reason for this is due to the fact that the property is located in the ESLHA. As Director, I have determined that the site restoration bonding requirement is excessive and will waive this requirement based on the scope of your project. The City continues to study our policies, procedures and practices to improve service. We are committed to streamlining the building permit process and we value your comments. If you would like to meet with me to discuss any other concerns please feel free to contact me at 425- 771-02220 extension 1316. � Sin /erellyy �. V. Bowman Director Development Services -1 1890 w 46 CITY OF EDMONDS 121 5TH AVENUE NORTH • EDMONDS, WA 98020 • (425) 771-0220 • FAX (425) 771-0221 Website: wwwdedmonds.wa.us DEVELOPMENT SERVICES DEPARTMENT Planning • Building • Engineering January 16, 2007 Kyle G. Ray 114 Second Avenue South, Suite 101 Edmonds, Washington 98020 RE: Permit application #BLD20060544 @ 15625 751h Place West Dear Mr. Ray, GARY HAAKENSON MAYOR The Mayor has requested a response from my Department to your letter dated January 9, 2007 concerning your building permit application. After meeting with the reviewing members of my staff, we are at a loss to explain your comment concerning rude treatment. In fact, staff members recall positive interactions with Mrs. Ray during the review process to date and no one recalls any contact with you directly. As with any customer service based business we want to know immediately when our citizens' feel badly treated as it is the only way that we can improve service. Although you may hesitate in holding back names, it is the only way that I can address this concern so I invite you to telephone me separately on this matter. Sometimes during the plan review process we are accused of `adding on' requirements. Often times it is because the initial submittal is either too vague or missing critical details and then once that information is provided additional comments are generated based on the complete information. Regarding the garage driveway setback issue, the record is clear the City Hearing ,Examiner granted a variance for a 15'6" setback from the street setback. However, Engineering plan review comments dated 10/3/06 are still applicable and must be addressed. One particular issue is Engineering comment #2 concerning a possible street vacation (to purchase undeveloped City right-of-way) in order to accommodate an approved driveway access/turning radius into the garage. This is an issue that you need act promptly on. Another option is to re -grade the southwest corner of your property (this would require a retaining wall along the south property line) and access directly perpendicular from the street, or the plans could be altered to eliminate the south garage bay. Our Engineering review staff is available to meet with you and your designer directly on this and other outstanding Engineering issues. If you would like such a meeting, simply call the Permit Coordinator assigned to your project (Marie Harrison) and she will gladly setup a meeting. E-ET. FILE _ ___ • Incorporated August 11, 1890 EDMONDS SOILS REPORT # 40 ASSOC. EARTH SCIENCES 1997 PROJECT: G97224A IMPROVEMENT OF CONDITION; SINCE 1990. REDUCED SLIDE TO 30% IN 25 YRS. EDMONDS SOILS REPORT # 48 DAVID BRUCE, PE 1999 NO EVIDENCE OF SLIDES. I EDMONDS SOILS REPORT #54 ASSOC. EARTH SCIENCES 10/05 & 3/06 PROJECT:KE05550A 'Q EDMONDS SOILS REPORT # 31 SHANNON B WILSON 1994 PROJECT: W-6114-02 NO MOVEMENT. THESE REPORTS REFERENCED IN ASSOCIATED EARTH SCIENCES, INC. REPORT OF JAN. 10, 2008 S ITS , NO EXPECTED SLIDES DUE TO LOCATION OF STRUCTURE, IMPROVED RUN-OFF. AfT,KoK. loo FT SOILS REPORT # 19 HEMPHILL ASSOC. 1990 PROJECT # 1636 NO MOVEMENT SINCE 1941 3 W a 4 ^ L iJ THIS VICINITY MAP BASED ON THE GEO-TECHNICAL REPORT BY ASSOCIATED EARTH SCIENCE, N INC AND REVIEW OF THE CITY OF EDMONDS RECORDS / SOILS REPORTS. NO IDENTIFIED ko RECENT LANDSLIDES, MUD NOR DEBRIS SLIDES WITHIN 100 FEET OF THE PROPERTY -AT �/ 15625 75TH AVE WEST. RECEI V Ems+ 7 MAY - 2 2000 VICINITY MAP BUILDING DEPT�l STR IT FILE � .i A96dated Earth Sdences*c. N 0— &(ekra6nj dver.25 ZJeaffOlS'erldev April 25, 2008 Project No. KE050550B Kyle and Juliann Ray 702 4`' Ave South Edmonds, Washington 98020 Subject: Geotechnical Hazard Identification/Declaration and Mitigation Statement of Risk Proposed Ray Residence Reconstruction 15625 75`h Place West Edmonds, Washington Parcel No. 00513100002402 References: Hanson Design Architectural and Foundation Plans Dated April 2008 Donna L. Breske, P.E. Civil Plans Dated April 14, 2008 Associated Earth Sciences, Inc. Revised Subsurface Exploration, Geologic Hazard, and Geotechnical Engineering Study Dated January 10, 2008 Dear Mr. and Mrs. Ray: OQ G3ECEDVED MAY 2 1 2008 EECE Associated Earth Sciences, Inc. (AESI) has reviewed the above -referenced project plans. In accordance with City of Edmonds requirements in earth subsidence and landslide hazard areas, we have prepared the following statements: • In our judgment, the plans prepared by the architectural designer, structural engineer, and civil engineer conform to the recommendations in our January 10, 2008 geotechnical report. • In our opinion, the risk of damage to the proposed development, or to adjacent properties from soil instability will be minimal, subject to the conditions set forth in, the report, and the proposed development will not increase the potential for soil movemet��N�I�® MAY - 2 2000 Kirkland a Everett p BUILDING DEPT. 425-827-7701 425-259-0522 STRUIFILE Dwww.aesgeo.com • In our opinion, the probabilities for earth movement on the property within a 25-year period are approximately: a 30 percent chance of occurrence for slumps in previously failed material and a 2 percent chance of occurrence for debris avalanches of encroaching landslide materials. These values were determined by using the values shown on the City's Landslide Hazard Map, developed by Lowe Associates and updated by GeoEngineers. In our opinion, the values are still applicable since the drainage in the site vicinity has been improved since these studies have been performed and, therefore, should not increase. • In our opinion, the erosion and sediment control plans by the civil engineer should be adequate for the proposed improvements, provided the contractor is diligent in inspecting and maintaining the BMPs. Furthermore, AESI will provide construction monitoring services to periodically observe the effectiveness of the BMPs, and - recommend modifications, if necessary. • As discussed on Page 8 of our January 10, 2008 geotechnical report, the subject site lies within Zones B and C, as described by the 2007 Landau Summary Report. The house will be located only within Zone B. Zone-C hazards would include debris flows initiating from the steep slope to the east of the proposed house, which will be mitigated by the 3-foot-high concrete catchment wall (i.e., raised foundation stemwall) on the east side of the house. Since the writing of our report, the new house footprint has been moved to the east approximately 10 feet. In our opinion, this location will not significantly increase the risk to the house since the 3-foot high catchment wall will mitigate debris flow risk after such flows reach the flat backyard area. Zone-B hazards include movement of the ancient landslide mass underneath the new house. This risk has been partially mitigated by suitable foundation subgrade preparation (i.e., 2-foot structural fill pad), and use of a grid -connected footing system to mitigate differential displacement. See the following paragraph and the above -referenced geotechnical report for additional information. • The subject site is located within the North Edmonds Earth Subsidence and Landslide Hazard Area (NEESLHA) formerly known as the Meadowdale Earth Subsidence and Landslide Hazard Area, which is a complex mix of ancient, large-scale earth movements and recent shallow slides. Therefore, it is our opinion that it is not practical for one lot owner to fully mitigate the risk of deep-seated or large-scale earth movement. The risks not fully mitigated include unusually large debris flow avalanches, with trees, boulders, and other projectiles that may penetrate the wooden structure of the house, and large scale earth movements of the foundation subgrade soils underneath the house. The main purpose of the grid -foundation is to prevent collapse of the house should the ground beneath move, and not to prevent the house from moving with large scale earth movements. 2 0 0 We trust that this letter meets your needs. Please call if you have any questions. Sincerely, ASSOCIATED EARTH SCIENCES, INC. Kirkland, Washington Eric J. Lim, P.E. Senior Project Engineer cc: Hanson Design (4 copies) 652 Alder Street Edmonds, WA 98020 Attn: Kristin Hanson EIL/dr KE050550B2 Projects\20050550UCEMP w Ls 4-1Z31-2aeV- EXPIRES 2/27 e G. Aaron Mc ichael, P.E., .P.E.G. Associate Engineer 3 ZZA Zipper 2, 'on Associates, Inc. , tTREET FILE Geotechnical and Environmental Consulting A 1reffacon Company J-2427 March 28, 2006 City of Edmonds Development Services Department —Building RECEIVED 121 — 51h Avenue North, 2nd Floor Edmonds, Washington 98020 MAR 3 G 2006 Attention: Ms. Marie Harrison BUILDING DEPT. Subject: Meadowdale Earth Subsidence and Landslide Hazard Area — Geotechnical Review Proposed Ray Residence Addition 15625 — 75`h Place West Edmonds, Washington Dear Ms Marie Harrison: Zipper Zeman Associates, Inc. (ZZA) has completed our review of the provided plans and geotechnical report for compliance with the City of Edmond Meadowdale Earth Subsidence and Landslide Hazard Area code provisions. We were provided with a set of the plans (Sheets 1- 8) revised March 8, 2006, a copy of the geotechnical report by Associated Earth Sciences, Inc. (AESI) dated October 27 2005, a copy of the geotechnical engineer plan review letter dated February 7, 2006, and a site topographical survey dated October 19, 2005. The conclusions and recommendations contained in AESI's geotechnical report regarding site stability, foundations, retaining walls, floor slabs, and structural fill have been provided. In general, it appears that the recommendations to date appear reasonable, with the exceptions below. In addition, it appears that not all of the recommendations are incorporated into the project plans. The following is a list of questions, comments, or inconsistencies noted during our geotechnical review: The shallow explorations performed with the subject property encountered loose fill soil and old landslide debris to depth. The geotechnical report recommends that a Site Class C be used for the development of the response spectra. However, the 2003 IBC suggests that a Site Class D be used incases where limited information is available onsite. We recommend that the geotechnical engineer provide further evidence and calculation verification that the site should classifib- &-as Site Class C soils. Otherwise, Site Class D should be used. 2. The geotechnical report indicates within the Geologic Reconnaissance section that "an oversteepened area interpreted to be an old slide scarp was observed directly east of the project site.....Most of the deciduous trees had bowed trunks indicating slope creep...." Yet later, the report and plan review letter concur with Roger Lowe's and Geoengineer's assessment of the hazard from an encroaching landslide as only 2 percent probability in 25 years. In addition, the borings by Geotech Consultants to the southeast encountered permeable soils overlying the relatively impermeable silts and clays with indicated 18905 33r1 Avenue West•#1 17, Lynnwood, WA 98036 425-771-3304 Fax: 425-771-3549 LOG ITEM #—/�_ -- ZZA• Proposed Ray . We — Edmonds, Washingotn Job No. 1-2427 March 28, 2006 Page 2 groundwater and/or wet soil conditions near 15 feet in depth at the soil transition. No discussion in the geotechnical report was provided regarding the expected absence or presence of groundwater seepage on the slope above the residence or within the site soils throughout the year, only a discussion of groundwater conditions in late summer. We recommend that the geotechnical engineer provide conclusions regarding the anticipated high groundwater conditions at the site and provide further discussion/justification for the assessed risk from an encroaching landslide. 3. The geotechnical report provides a recommendation for mitigating the risk of a landslide debris flow into the residence. It appears that this recommendation has not been incorporated into the project plans. The Meadowdale Landslide and Earth Subsidence Hazard Area Summary Report by Landau Associates, dated March 17, 2004 provides definition of the hazards of an encroaching landslide, and the current code states that all impacts that could affect human safety must be mitigated and prevent avoidable damage to structures. It is our opinion that this is the case for the risk of landslide debris encroaching into the residence (mainly bedrooms) on the east side. We recommend that the project plans incorporate the 3 foot high catchment wall above the east ground level per the geotechnical engineer's recommendation. 4. It should be not that the catchment wall only proYiues protection from soil debris flow and not protection from things such as trees that may be part of the debris flow. We recommend that the geotechnical engineer clearly provide the possible impacts that are and are not mitigated by the catchment wall. In addition, we recommend that the geotechnical engineer provide calculations or a rational basis substantiating the recommended 3 vertical feet of the catchment wall. For example, the catchment wall basis could be provided by hand probing colluvium depths on the steep slope. 5. The geotechnical report recommends that new footings be underlain by at least two feet of structural fill prior to placement. The plans show that new footings are being placed directly adjacent to existing footings and it is unclear on the plans how the recommendation is incorporated in the project plans. Please provide a detail and associated notes to clarify the incorporation of the recommended structural fill. We recommend that the plans and other submitted documents be returned to the applicant for action. The applicant should make corrections necessary in order to be in accordance to the geotechnical report and the City of Edmond Code. In addition, the project geotechnical engineer should review and comment on the specific review comments provided. J-2pp4��27 Ray Residence Review.doc LOG 1 lV! #--1-6- ZZA i Proposed Ray. . Once — Edmonds. Washingotn Job No. J-2427 March 28, 2006 Page 3 We trust that this letter meets your needs at this time. Please call us with any questions regarding this project. Respectfully Submitted, Zipper Zeman Associated, Inc. n. R T S �,� �l 3/ZiI- D 41,17 t E) iv;�iiA�✓ �•' j� EXPIRES Ga / 27 / � 7 Kristopher T. Hauck, P.E. Project Engineer C, John E. Zipper, P.E. Principal J-2427 Ray Residence Review.doc ag"&y25 Vean ofYeniee July 20, 2006 Project No. KE05550A Mr. Kyle Ray 15625 75`h Place West Edmonds, Washington 98026 Subject: Response to City of Edmonds Peer Review Comments Proposed Ray Residence Remodel 15625 75"' Place West Edmonds, Washington STRER FILE.,-_ ResuB SEP 07 2006 etnl_anxa DEPARTMEIV I CrrY OF EDMONDS Reference: Zipper Zeman Associates, Inc. Meadowdale Earth Subsidence and Landslide Hazard Area - Geotechnical Review Dated: March 28, 2006 Dear Mr. Ray: Associated Earth Sciences, Inc. (AESI) has received the above -referenced letter regarding geotechnical peer review of our October 27, 2005 geotechnical report and the project plan set submitted to the City of Edmonds. This letter has been prepared to address the comments by Zipper Zeman Associates, Inc. (ZZA) that were prepared as part of the City's peer review process. For reference, we have numbered our response to correspond with ZZA's comment number used in their letter (attached). 1. We recommend that Site Class "D" should be used for 2003 International Building Code (IBC) structural design. 2. The unusually wet winter season from December 2005 to February 2006 produced approximately 20 inches of rain, which was approximately 7 inches over normal for that period according to National Weather Service data available online (http://www.weather.gov/climate/index.php?wfo=sew). During that period, we asked the owner and occupant of the house to report any seepages emanating from the hillside or standing water in the backyard. The owner -occupant reported that no seepages were observed during this season or in seasons past since purchasing the property in 1999. We also visited the site approximately 1 month after this higher than normal wet period and looked for lag -time seepages. During this visit and subsequent visits since, we did not observe evidence of ground water seepage on the property, hydrophilic plants that may indicate active seepage zones, or signs of instability of the steep slope area above the project site. The Geotech Consultants explorations were performed in January 1997 after an unusually wet period and prior to the installation of surface water drainage improvements, including drainage berms LOG ITEM # ca�eMKWand office • 911 Fifth Avenue, Suite 100 • Kiddand, WA 98033 • P (425) 827-7701 • F (425) 827-5424 rett Office • 2911 1/2 Hewitt Avenue, Suite 2 • Everett, WA 98201 • P (425) 259-0522 • F (425) 252-3408 www.aesgeo.com 0 • and catch basins, on the streets and properties above the project site. These improvements have reduced surface water runoff from saturating the hillside, which has been linked to past slides in the area. A suitable amount of vegetative ground cover and foliage are also present on the slope to contribute to rainfall interception and transpiration. Based on these factors, especially the surface water drainage improvements by the City of Edmonds and private property owners above the site, we anticipate low ground water conditions and seepage on and above the property throughout most years. Furthermore, although the buildup and creep of colluvium is likely to have occurred over the time period since GeoEngineers, Inc. updated the Roger Lowe landslide probabilities, the surface water improvements described above have mitigated the increase in that probability, in our opinion. 3. This project is a remodel of an existing structure with significant portions to remain. Risks to the existing structure is present and has been accepted by the owner whether or not the proposed improvements are constructed. The proposed improvements do not further encroach on the steep slope area; therefore, the risk will not be increased. We understand that the owner opted not to include the catchment wall design on the final design because the catchment wall could not be constructed on the portions to remain without razing those portions of the house. Therefore, required mitigations of impacts from potential slides should be limited to the proposed improvements. We recommend that the catchment wall requirement should be limited to constructing the 3-foot catchment wall on the portions of the east side of the dwelling that will require new foundations and walls, which are the guest bedroom and bathroom on the main floor on the south half of the house. The catchment wall may be constructed by extending the foundation stemwall to extend 3 feet above finish exterior grade and suitably reinforced to retain active earth pressures provided in the geotechnical report. 4. We recommend the 3-foot-high, reinforced -concrete catchment wall as a reasonable mitigation against typical soil debris -flow buildup that would otherwise damage conventional wood -framing near the ground surface. The catchment wall may not provide adequate protection against falling trees striking above the catchment wall or high velocity impacts from trees, soil, and other debris. Our rational basis for the 3- foot height is based on our experience in designing such structures and observations of typical debris -flow buildup heights against exterior walls in similar settings. The 3-foot height also takes into consideration the approximate 25- to 35-foot length of the slope runout in the backyard and possible deflection of debris flows around the south side of the structure. 5. We have recommended revisions to the plans to include details of the 2 feet of structural fill under the footings. We understand that the foundation details on the project plans will show that the previously proposed expansion of the existing footings along the back of the guest bedroom have been changed to reflect an entirely new footing with the 3-foot-high catchment/stemwall discussed above. Therefore, the existing footings will be removed and undermining will not be an issue. LOG ITEM #,2 We trust that this letter meets your immediate needs. Please call if we may be of further assistance. Sincerely, ASSOCIATED EARTH SCIENCES, INC. Kirkland, Washington 4 t Eric J. Lim, I .E Project Engineer EXPIRES 2/27 G. Aaron McMichael, P.E., P.E.G. Associate Engineer Attachment: Zipper Zeman Associates, Inc. "Meadowdale Earth Subsidence and Landslide Hazard Area - Geotechnical Review" letter, dated March 28, 2006 cc: Mr. Phil King, Phil King Designs, Fax: (425) 745-4078 Mr. Nick Lehtinen, HNLehtinen Engineering, Fax: (425) 259-4328 Ef use KE05550A3 Projects\20050550\KE\W P LOGITEIIq��_ 3 MAY-10-2006 10:23 AM K - RAY ATTY 425f*7147 P.02 VAU,� ' er As d s c Geotechnlcal and Environmental Consulting A 1%rrncran Company J-2427 March 28, 2006 City of Edmonds Development Services Department — Building 121 -- 5th Avenue North, 2hd Floor (, Edmonds, Washington 98020 MAR 2 9 Zip Attention: Ms. Marie Harrison Bu-tD!N G D Ep.r. Subject: Meadowdale Earth Subsidence and Landslide Hazard Area — Geotechnical Review Proposed Ray Residence Addition 15625 — 75th Place West Edmonds, Washington Dear Ms Marie Harrison: Zipper Zeman Associates, Inc. (ZZA) has completed our review of the provided plans and geotechnical report for compliance with the City of Edmond Meadowdale Earth Subsidence and Landslide Hazard Area code provisions. We were provided with a set of the plans (Sheets l - 8) revised March 8, 2006, a copy of the geotechnical report by Associated Earth Sciences, Inc. (.AESI) dated October 27 2005, a copy of the geotechnical engineer plan review letter dated February 7, 2006, and a site topographical survey dated October 19, 2005. The conclusions and recommendations contained in AESI's geotechnical report regarding site stability, foundations, retaining walls, floor slabs, and structural hill have been provided. In general, it appears that the recommendations to date appear reasonable, with the exceptions below. In addition, it appears that not all of the recommendations are incorporated into the project plaits. The following is a list of questions, comments, or inconsistencies noted during our geotechnical review: 1. The shallow explorations performed with the subject property encountered loose fill soil and old landslide debris to depth, The geotechnical report recommends that a Site Class C be used for the development of the response spectra. However, the 2003 IBC suggests that a Site Class D be used in cases where limited information is available onsite. We recommend that the geotechnical engineer provide further evidence and calculation verification that the site should classified as Site Class C soils. Otherwise, Site Class D should be used. 2. The geotechnieal report indicates within the Geologic Reconnaissance section that "an oversteepened area interpreted to be an old slide scarp was observed directly east of the Project site.....Most of the deciduous trees had bowed trip ks indicating slope creep...." yet later, the report and plan review letter concur with Roger Lowe's and Geoengineer's assessment of the hazard from an encroaching landslide as only 2 percent probability in 25 years. In addition, the borings by Geotech Consultants to the southeast encountered permeable soils overlying the relatively impermeable silts and clays with indicated 18905 331 Avenue West #117, Lynnwood, WA 98036 425-771-3304 Fax: 425-771-3549 MAY-10-2006 10:23 AM KID RAY ATTY 425107147 P'03 Proposed Ray Residence -- Edmonds, Washingotn +� job No. 1-2427 March 28, 2006 Page 2 groundwater and/or wet soil conditions near 15 feet in depth at the soil transition. No discussion in the geotechnical report was provided regarding the expected absence or presence of groundwater seepage on the slope above the residence or within the site soils throughout the year, only a discussion of groundwater conditions in late summer. We recommend that the geotechnical engineer provide conclusions regarding the anticipated high groundwater conditions at the site and provide further discussion/justification for the assessed risk from an encroaching landslide. The geotechnical report provides a recommendation for mitigating the risk of a landslide debris flow into the residence. It appears that this recommendation has not been incorporated into the project plans. The Meadowdale Landslide and .Earth Subsidence Hazard Area Summary Report by Landau Associates, dated March 17, 2004 provides definition of the hazards of an encroaching landslide, and the current code states that all impacts that could affect human safety must be mitigated and prevent avoidable damage to structures. It is our opinion that this is the case for the risk of landslide debris encroaching into the residence (mainly bedrooms) on the east side. We recommend that the project plans incorporate the 3 foot high catchment wall above the east ground level per the geotechnical engineer's recommendation, 4. It should be noted that the catchment wall only provides protection from soil debris flow and not protection from things such as trees that may be part of the debris flow. We recommend that the geotechnical engineer clearly provide the possible impacts that are and are not mitigated by the catchment wall. In addition, we recommend that the geotechnical engineer provide calculations or a rational basis substantiating the recommended 3 vertical feet of the catchment wall. For example, the catchment wall basis could be provided by hand probing colluvium depths on the steep slope. 5. The geotechnical report recommends that new footings be underlain by at least two feet of structural fill prior to placement. The plans show that new footings are being placed directly adjacent to existing footings and it is unclear on the plans how the recommendation is incorporated in the project plans. Please provide a detail and associated notes to clarify the incorporation of the recommended structural fill. We recommend that the plans and other submitted documents be returned to the applicant for action.. The applicant should make corrections necessary in order to be in accordance to the geotechnical report and the City of Edmond Code. In addition, the project geotechnical engineer should review and comment on the specific review comments provided. I-2427 Ray Residaue Rmiew.doe LOG ITEM#�- MAY-10-2006 10:24 AM K4 RAY ATTY 4251f7147 P_04 t 0KProposed Ray Residence —Edmonds, Washln�oto 0 &. wm Jw6ILA Job No. J-242 7 March 28, 2006 Page 3 We trust that this letter meets your needs at this time. Please call us with any questions regarding this project, Respectfully Submitted, Zipper Zeman Associated, Inc, 6R �,rA, T, r ERTME6 0 Kristopher T, Hauck, ,P,E, Project Engineer John E. Zipper, P.E. Principal 1-2427 Rsy Raidamme Revlaw,dac LOG ffEPA # r Associated Earth Sciences, Inc. Cc(c�inr��2j �carra%lcrvrc� 911 Fifth Avenue, Suite 100 Kirkland, Washington 98033 425-827-7701 FAX 827-5424 TO: Kyle and Juliann Ray 702 - 4`h Avenue South Edmonds, WA 98020 ATTN: Kyle Ray AS REQUESTED BY Scott Hoover THE FOLLOWING WAS NOTED: FIELD REPORT FILE STRET Permit No_BtH2Nk037 Page I of I Date ect i ame Project No. 2-23-09 ay Residence KE050550B Location Weather 15625 75`h Place W Cloudy, 40's Municipality Report Number City of Edmonds 7 Engineer/Architect Donna Breske / Hanson Design Client/Owner Kyle and Juliann Ray General Contractor/Superintendent Hoover Premier Homes / Scott Hoover Grading Contractor/Superintendent Buchanan Land Construction / Duncan Buchanan AESI was onsite today to observe footing drain installation and to perform a TESC inspection. Footing Drain Installation: Since our previous site visit, the perimeter stem wall and the interior grid footings had been placed. Using a steel soil probe, the crushed rock over soil subgrade was penetrated approximately 1-2 inches under frill body weight and it is our opinion that the footing subgrades are suitable for support at the design bearing capacity of 2,000 pounds per square foot. Buchanan Land Construction had installed footing drain pipe along the east, north and west side of the building. The footing drain had been backfilled along the west side, but was exposed along the north and east. A 4" perforated PVC pipe had been set at the base of the footing. At the northwest corner, the pipe had been set, it was bedded in washed rock to approximately 1 foot over the top of the pipe and filter fabric was placed over the washed rock. In our opinion, the footing drains that were observed today had been installed properly and where they were in progress, the steps taken so far were in accordance with the plans and our drainage recommendations. Based on a later conversation with Eric Lim (AESI), it is our opinion that on the east side of the house, the upper footing drain and drain rock on the north half of the house should be capped at the transition to the lower footing drain and should not be connected to the lower footing drain that serves the southern portion. - Subgrade Observations: Since our last visit, the perimeter stem walls and interior footings had been placed in the northern portion of the house. While onsite, we spoke with Duncan Buchanan (Buchanan Land Construction). He asked about fill inside the crawlspace. We told him that compacted soil would be suitable for foundation backfill and the soil should be placed tip to the top of the spread footings. TESC Inspection: While onsite we observed the condition of the site BMP's. Buchanan Land Construction was hauling off excess soil; loading dump trucks with soil. The construction entrance was covered with quarry spalls and there was no sediment track -out or runoff from the site. The adjacent catch basins had filter inserts and were not in need of maintenance. The interceptor swale along the east edge of the lot was in place and appeared to be working. The temporary Lock -Block shoring wall along the north side of the excavation was in place and there were no observed signs of caving or sloughing. Based on the field conditions observed, it is our opinion that the BMPs currently in place are performing properly and no additional erosion control measures are required at the time. AESI will return to observe subgrade conditions and construction progress at the request of Scott Hoover and to perform weekly TESC inspections. COPIES TO: DATE MAILED: City, Hoover, Hanson, Breske, file FIELD REP.: ,., s! rew Glandon, PEG, CPESC FEB � 7 2009 PRINCIPAL / PM: r Aaron McMichael, PE, PEG ;d '� Associated Earth Sciences, Inc. I C47)rnlilyz zJcnr� %!'e�Y�irc 911 Fifth Avenue, Suite 100 Kirkland, Washington 98033 425-827-7701 FAX 827-5424 TO: Kyle and Juliann Ray 702 - 4`h Avenue South Edmonds, WA 98020 ATTN: Kyle Ray AS REQUESTED BY Scott Hoover THE FOLLOWING WAS NOTED: FIELD REPORT STRIET FILE Permit No. BLD2008-037 Page 1 of 1 Date Project Name Project No. 10/24/09 I Ray Residence KE050550B Location Weather 15625 75`h Place W Overcast, 60s F Nlunicipality Report Number City of Edmonds 8 Engineer/Architect Donna Breske / Hanson Design Client/Owner Kyle and Juliann Ray General Contractor/Superintendent Hoover Premier Homes / Scott Hoover Grading Contractor/Superintendent Buchanan Land Construction / Duncan Buchanan We visited the site to observe final site conditions prior to occupancy and address City staff comments regarding the rockery along the south side of the driveway. On arrival, we observed that the exterior house construction was complete and that landscaping in the front yard was complete. The landscaping in the rear yard was nearly complete with sod being installed during our visit. We observed the rockery along the south side of the driveway. We measured the rockery to be approximately 12' 8" long and approximately 3' 10" in maximum height. The rockery extended west from the north foundation wall of the house and tapered down in height to match grade in the front yard. It appears that the rockery was necessary since a slope would have placed soil against the finished wood siding of the house. Mr. Hoover informed us that 2 rows of Lock -Blocks were left in -place along the south edge of the driveway and are directly behind the rockery. We hand -probed between the rockery stones and felt a block where we could penetrate the crushed rock backfill. In our opinion, the Lock -Blocks are alleviating surcharge on the rockery, and the short retaining structure is suitable for support of the driveway and anticipated vehicle loads. COPIES TO: City, Hoover, Hanson, Breske, file DATE MAILED: FIELD REP.: Eric Lim, PE i PRINCIPAL / PM: Aaron McMichael, PE, PEG M Havaa t149L 9 Z 9 9 T i GLL u nnJ 1� co tt 1 V coo as P z tLL N m r • 03 � . Q v..e Drainage Report for Kyle & Julianne Ray Edmonds Application #: BLD20080376 Date Prepared: September 15, 2008 Revision #1: October 15, 2008 Prepared for: Kyle & Julianne Ray Site Address: 15625 75t" PL W Edmonds, WA 98026 OVED .AS NOTED Y ENGINES. NG' / Date: ' 0 �o EXPIRES: 11 /05/09 Prepared by: Donna L. Breske, P.E. 6621 Foster Slough Road, Snohomish, Wa. 98290 OCT 16 2008 Phone: (425) 334-9980, Fax: (425) 334-7380 BUILDING DEPARTMENT Email: breske@consultmoore. com CITY OF EDMONDS STREET FILE KYLE & JULIANNE RAY — SINGLE FAMILY HOME 15625 75" PL. W., EDMONDS, WA September 15, 2008 Revision #1: October 15, 2008 — Remove 2-year design storm from "match peak" calculations. REASON FOR REPORT: Per city of Edmonds Engineering Review Comments dated 9-10-08, "The city sotrmwater engineer has determined that interpretation of ECDC 19.10.030(F) is stricter than that of ECDC 18. 30. 060 when proposed development is within the ESLHA. Therefore, the term "calculations" with regard to storm design must include calculations o'f how the proper sizing of the drainage system is arrived at. As such, the use of Handout E72 to size the system is not sufficient to this purpose." The previous design completed by this engineer used city Policy #E72 which is incorporated by reference in ECDC 18.30.060.A.1. The detention system sizing per policy #E72 resulted in a required volume of 87 cf. This revised sizing per the SBUH method for the total impervious area of 4,086 results in a required volume of 247.17 cf. A single family home is proposed for construction at 15625 751h PL W. in Edmonds, WA. A previous house once existed on the site, but has since been demolished. The lot area is 9,724 square feet in size. The site has two distinct topography characteristics. The west 2/3rd of the site slopes downward to the west at an average of 13.8% The north 1 /3 of the site has more significant slopes at 55-60% downward from east to west. Soils on site are Alderwood with a Hydraulic Group "C". The area of development for the sub -basin calculation is 7,352 sf (0.17 acres), and does not include some of the steep slopes on the east part of the site since an interceptor trench is designed to capture flows and relieve and undue burden on the house footing drain system. See the Time of Concentration Exhibit for the Developed Tc input parameters and the Sub -Basin area. The total impervious area rooftop and driving surfaces, (including 714 sf of pre- 1977 existing asphalt), used for Kyle & Julianne Ray — Detention Design Narrative Page I of 3 calculating the detention system is 4,086 sf, (0.09 acres). The time of Concentration for the Developed condition is set at 10 minutes as a default input. At the beginning of a storm event it is necessary to wet the rooftops and driving surfaces before flow can occur. This 10-minute default setting takes this into account. An interceptor trench is designed behind the house at the edge of the residentially landscaped back yard, and at the base of the steep slope. This is designed due to surface flows that are anticipated to enter the site from the upstream properties and hillside. This interceptor trench is to be installed as a preventative measure to capture and route surface flows that may otherwise travel toward the house and either enter the footing drain system or the crawl space. This engineer has designed this interceptor trench on three other single family homes in the immediate vicinity, which are located at 15911 74`h PL. W, 15915 74" PL. W., and 15917 74`h PL. W. DESIGN: The site is less than one acre in size and is located within the Meadowdale drainage basin. Flows are released to the drainage conveyance system in the Public right- of-way and travel to Puget Sound. Flows leaving the site do not enter a known stream. The storm water detention system is therefore sized in accordance with ECDC 18.30.060.A.I.c for the 10 and 100 year 24-hour storm events. A sizing modeling program using the SBUH was used. The release structure is designed to release developed flows at pre -developed peak rates for the 10, and 100-year storm events. A chart of the pre -developed and post -developed flows is shown below: DESCRIPTION PRE -DEVELOPED FLOWS DEVELOPED FLOWS CONTROLLED RELEASE DEV FLOWS 10-YR, 24-HR 0.04 cfs 0.07 cfs 0.04 cfs 100-YR, 24-HR 0.05 cfs 0.08 cfs 0.05 cfs Flows are designed to be detained in a buried 2.5' diameter detention pipe. The calculations result in a pipe 54' long. However, the length is reduced to 46' feet when the storage volume in each of the two catch basins at either end of the pipe are taken into Kyle & Julianne Ray — Detention Design Narrative Page 2 of 3 consideration. Proposed driving impervious area is under 5,000 SF and hence no water quality control is proposed per ECDC 18.30.060.B.1.a. DOWNSTREAM PATH: Flows leaving the site enter at Type 2 catch basin in the public right-of-way of 75`h PL. W. at the southwest corner of the property. Flows then travel southward approximately 100 feet in a pipe to a catch basin on the east side of 75`h PL. W. at which point they turn to the west. Flows continue west under 75'h PL: W. in conveyance pipe, and down a slope, again m pipe and eventually outfall to Puget. Sound. See the attached city Pipe Conveyance System Schematic and Photos. MAINTENANCE OF STORM DRAINAGE FACILITIES: Information concerning maintenance of the on -site storm drainage facilities per the 1992 DOE Manual is included with this report. Kyle & Julianne Ray — Detention Design Narrative Page 3 of 3 DOWNSTREAM PATH KYC.E 8< JUL-IANNE RAY "*,5Ftq i0-14-0� UNKNOWN J UNKNOWN 'O UNKNOWN 15524 15514 15515 710�103 UNKNOWN 15516 7025 7003 re15520. 1_294 7215 15508 32 7111 7707 7101 7031 7009 NKNOWN IM051- 73 1-272 1-2 -2 -152 7222 1-23 -236 7124 . 7100 15610 1_ 3 15001 -15 1-238 7026 ' 15800 1 UNKNOWN -25 Q 7120 7110 1 15821 15825 UNKNOWN C 1-2 -117 - 1-23 7029 15717 7117 7119 7012 15B3f 1-158 1 2 1 t5031 1-24 _ 1-2 2 1 -27 -2� 1-2 159 1-24 1-2 1 157 UNKNOWN 15620 15715 15702 1-28 15703 1- 60 15701 1-243 - 7030 7022 7018 15708 15706 -249 15719 15712 1-288 15709 15714 15728 15722 15720 UNKNOWN 'UNKNOWN 158g1$t 1-142 1_ 1205 1-157 2 15731 w 15730 1-1 1 219 1566e 1 1 7400' - 44 VAULT 1-140 1-1 9 1-190 1-1 15808 - 7324 UNKNOWN "15" 1-218 15812 1-149 UNKNOWN f 6C /5821 UNKNOWN UNKNOWN 16811 � isez4 16825 - UNKNOWN J 1-216 1-148 .15915 15824 1-217 it 15908 1-147 1-202 . _ 15605 16805 30 1 159251-201 15917 15910 m UNKNOWN UNKNOWN 1_ 15911 i5D10 1-1 8 15027 Q 1-204 15902 3 15912 1-2 _ 1-199 C 15917 15D15 178-LWK� 2 7429 7309 159201-26 UNKNOWN 1- 1-215 000 !� _ 1- 5 1_ 1$6 UNKNOWN 16SOW 75928 1-21 _212a2 15931 -113 _ y1 181 18009 1-85 . 1-24 / 13 ief2f 18012 16004 1 73 18123 16008 2� 1 18008 7z20 iBofo 69. UNKNOWN 1-27 .., 1-11 16024 16010 IBM 1 1- 16105 1601 18031 0 1-275 fella 1- 17 1-2 1195 16020 . a 1- 47 137 18105 UNKNOW 1.17 UNKNOWN 16118 1-7 10105 UNK OWN _2 0 01- _ 1_1 - ........_. ^ 1-7 16209 Uh .. . 169 10100 ne,�"`° tit °i.`-("''t'��T � �`",� }Z'�,�3&' ay�s,�•�� r'� ��E 'S 3h TG �.rj�' C.� I �,5, 'K: `, i". �.-� :► 'SJ..�.i �7.I`�a�'; .>�` i14r.'`i,`C,�.�t''�y. r_ a� t i �J^-. •'l��5 rf �• c.�_i.+„ �1•-� �i.�.,'N�Y" �;43 '��� �.��0"i'S�'*�r �b'1 S � ��� �}v i'iiqN^ti'�r S •` i� y��T'`.eP�A p ti �;-t��,�. �YPq � "'4y�i •- �r7 � ��` � ��� � ' � /.(�-I�G ����ft�.iL w � �.ri� �...-,. c,...���f ��r',�`3Y_•�7� �., ���r"�l ry �i�^4'`.4� F_�"ew�ut IG ro�"/ sw��;,its = V4 r�l'�7• a � "G ��' ti L���j��y��kb»j�i✓r� � ��,���� ��R wry, � �- vs �� ��"1�/�..„''� _ +r- r- ��, � 'a' �. r♦ � mil-' SST ~ n, Ji'L�.lydJ' � a• �_ _ ,y� G(a� � ��,r•�� � ?' ��-�s4 Kyle & Julianne Ray 15625 75, PL. W Flows travel west in a pipe conveyance system under 76`h Ave. W. MAINTENANCE GUIDELINES STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN IV-4.10 BMP S2.00 MAINTENANCE OF STORM DRAINAGE FACILITIES Proper maintenance of public and private stormwater facilities is necessary to insure they serve their intended function. In a study recently completed by the King County Conservation District (3), almost one-half the BMPs installed on large construction sites were not maintained. Without adequate maintenance, sediment and other debris can quickly clog facilities, making them useless. Rehabilitation of such facilities is expensive, and in the case of infiltration systems may be impossible. Polluted water and sediments removed during the cleaning operation must be properly disposed of. MAINTENANCE STANDARDS Local governments shall develop standards for the maintenance of public and private stormwater facilities. These standards shall include but need not be limited to the following• 1. Catchbasins, stormwater detention and treatment systems shall be inspected at least annually. A representative of the local government shall also inspect private facilities at least annually to insure compliance by the owner of the following maintenance requirements. 2. Any deterioration threatening the structural integrity of the facilities shall be immediately repaired. These include such things as replacement of clean - out gates, catchbasin lids, and rock in emergency spillways. 3. A catchbasin shall be cleaned if the depth of deposits are equal to or greater than 1/3 the depth from the basin to the invert of the lowest pipe into or out of the basin. If a catchbasin is found during the annual inspections to significantly exceed this standard, it shall be cleaned every 6 months. If woody debris is likely to accumulate in a catchbasin, it should be cleaned on a weekly basis. 4. Warning signs (e.g. "Dump No Waste - Drains to Ground Water", "Streams", "Lakes" etc.) shall be painted or embossed on or adjacent to all storm drain Inlets. They shall be repainted as needed. 5. Debris shall be regularly removed from surface basins used for either peak - rate control or stormwater treatment. 6. Stormwater treatment facilities shall be maintained according to criteria or procedures presented in Volume III. (Maintenance requirements are detailed at the end of each BHP description). 7. Parking lots shall be swept when necessary to remove debris. FINAL DISPOSAL OF CONTAMINATED WATER (Ecology policy regarding disposal is under development by the Urban Non -Point Management Unit and is not available at this time.) FINAL DISPOSAL OF CONTAMINATED SEDIMENTS (Ecology policy regarding disposal is under development by the Urban Non -Point Management Unit and is not available at this time.) IV-4-25 FEBRUARY, 1992 STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN Table III-2.10 Maintenance of Control Structures and Catchbasins Maintenance Component Defect Conditions When Maintenance is Needed Results Expected When Maintenance is Performed 1. Corttrol Swcwrd Flow Restrictor - ~ General Trash & Debris (includes Distance between debris buildup & All truh & debris removed. sediment) bona of orifice is <1'A feet Structural Damage Structure is not securely anached to Structure securely attached to wall & manhole wall & outlet pipe structure outlet pipe. should support at least 10001 of up or down pressure. Structure is not in upright position (up Structure in correct position. to 10% from plumb allowed). Connections to outlet pipe are not Connections to outlet pipe are watertight & show signs of rust watertight; structure repaired or replaced and works as designed. Any holes - other than designed Structure has no holes other than holes - in strucuue. designed holes. Cleanest Gate Damaged or mining Ckanout gate is not watertight or is Gate in watertight and works as missing. designed. Gate cannot be moved up & down by Gate moves up and down easily mod one maintenance person. is watertight - Chain leading to gate is missing or Chain is in place & works as damaged. designed. Gate is rusted over 50% of its surface Gale is repaired or replaced to meet area. design standards. Obstructions Trash, debris, sediment or vegetation Plate is free of all obstructions & blocking the plate. works as designed. OveAbw Pipe Obstructions Trash or debris is blocking or Pipe is free of all obstructions & potentially blocking the overflow pipe. works as designed. Manhole See *Pipes/Tanks' standard, Section See 'Pipes/ranks' standard. Section M 4.6.1. M 4.6.1. 11. Catchbasms - Trash & Debris (mchdea Trash & debris 2 % &I which is No trash or debris immediately in General sediment) locatod immediately in front of the front of the atchbuin opening. atchbasm opening of is blocking capacity by > 10%. Trash or debris in the basin that No trash or debris in the atchbasin. exceeds % the depth from the bonom of basin to the invert of the lowest Pipe - Trash or debris in any mkt or pipe Inlet & outlet pipes free of trash or blocking more than % of its height debris. Dead animals or vegetation that could No dead animals or vegetation generate odors or dangerous gases present within the catchbasin. (e.g. methane). III-2-67 FEBRUARY, 1992 STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN Mee Componeot Defect Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Catehbasms - No condition present which would General. don't. attract or support the breeding of insects or rodents. • Strucwnl Damage to Frame Frame is even with curb. and/or Top Slati Top slab is free of holes dt cracks. Frame is sitting flush on top slab. Cranks is Bois Walls or Bum repaired or replaced to design Bottom standards. No cracks mote than u in. wide at the joint of inlet/outlet pipe. Settkumt/mtsahgnment Bum replaced or repaired to design standards. Fire Hazard No flammable chemicals present. vegetation No vegetation blocking opening to basin. No vegetation or root growth present. Pollution No pollution present other than surface film 68'PCiderthan riS in. k longer than 1 ft. at the joint of any mkt or outlet pipe or any evidence of soil particles entering the estchbasm through cracks. Bum has sealed > 1 in. or bet rotated > 2 in. out of alignment. Presence of chemicals such as namral sea. Oil and gasoline. Vegetation growing seross & blocking > 10% of the bum Wig• III-2— 8 FEBRUARY, 199 DETENTION SYSTEM CALCULATIONS EXISTING DRIVING SURFACE 714 SF (BUILT PRIOR TO JULY 1977) - DEM 112 SF DRIVEWAY 460 SF TOTAL POST JULY 1977 IMPERVIOUS AREA: 3,372 SF TOTAL IMPERVIOUS AREA: 4,086 SF ROOFTOP Z800 SF IMPERIOUS AREA EXHIBIT KYLE RAY 15625 757H PL W. SCALE 1'40' EOMOND$ WA 98026 9-15-08 TIME OF CONCENTRA 11ON EXHIBIT KYLE RAY 15625 751H PL W. MONK WA 98026 SCALE 1'=20' 10-15-08, 10/10/08 2:46:43 pm page 1 RAY, 75TH, EDMONDS Match Peak for 10 & 100 yr pre-existing BASIN SUMMARY BASIN ID: A10OX SBUH METHODOLOGY TOTAL AREA.......: RAINFALL TYPE....: PRECIPITATION....: TIME INTERVAL....: NAME: 100 YR, 24 HR EXISTING 0.17 Acres TYPElA 3.00 inches 10.00 min BASEFLOWS: AREA..: CN..... TC..... 0.00 cfs PERV 0.17 Acres 85.00 12.96 min ABSTRACTION COEFF: 0.20 TcReach - Sheet L: 87.00 ns:0.4000 p2yr: 1.50 s:0.1380 PEAK RATE: 0.05 cfs VOL: 0.02 Ac-ft TIME: 480 min BASIN ID: AlOX SBUH METHODOLOGY TOTAL AREA.......: RAINFALL TYPE....: PRECIPITATION....: TIME INTERVAL....: NAME: 10 YR 24, HR 0.17 Acres TYPElA 2.50 inches 10.00 min BASEFLOWS: AREA..: CN..... TC..... 0.00 cfs PERV 0.17 Acres 85.00 12.96 min ABSTRACTION COEFF: 0.20 TcReach - Sheet L: 87.00 ns:0.4000 p2yr: 1.50 s:0.1380 PEAK RATE: 0.04 cfs VOL: 0.02 Ac-ft TIME: 480 min__ BASIN ID: B100D SBUH METHODOLOGY TOTAL AREA.......: RAINFALL TYPE....: PRECIPITATION....: TIME -INTERVAL .... NAME: 100 YR, 24 HR DEVELOPED 0.17 Acres TYPElA 3.00 inches 10.00 min IMP 0.00 Acres 0.00 0.00 min _ T, m e- of ancerditVb 1 Iryvf IMP 0.00 Acres 0.00 0.00 min -Tme of Co ncenigat goo I npof BASEFLOWS: 0.00 cfs PERV IMP AREA..: 0.08 Acres 0.09 Acres CN.... : 86.00 98.00 TC.... : 10.00 min 10.00 min ABSTRACTION COEFF: 0.20 PEAK RATE: 0.08 cfs VOL: 0.03 Ac-ft TIME: 480 min BASIN ID: B10D SBUH METHODOLOGY TOTAL AREA.......: RAINFALL TYPE....: PRECIPITATION....: TIME INTERVAL....: NAME: 10 YR 24 HR, DEVELOPED 0.17 Acres TYPElA 2.50 inches 10.00 min BASEFLOWS: AREA..: CN.... . TC.... . 0. 00 cfs PERV 0.08 Acres 86.00 10.00 min ABSTRACTION COEFF: 0.20 PEAK RATE: 0.07 cfs VOL: 0.03 Ac-ft TIME: 480 min IMP 0.09 Acres 98.00 10.00 min 10/10/08 2:46:43 pm RAY, 75TH, EDMONDS Match Peak for 10 & 100 yr pre-existing HYDROGRAPH SUMMARY PEAK TIME VOLUME HYD RUNOFF OF OF Contrib NUM RATE PEAK HYDRO Area cfs min. cf\AcFt Acres 1 0.011 480 277 cf 0.17 2 0.037 480 723 cf 0.17 3 0.053 480 974 cf 0.17 4 0.033 480 571 cf 0.17 5 0.065 480 1113 cf 0.17 6 0.082 480 1397 cf 0.17 11 0.008 700 571 cf 0.17 12 0.041 510 1113 cf 0.17 13 0.055 510 1397 cf 0.17 page 2 10/10/08 2:46:43 pm RAY, 75TH, EDMONDS Match Peak for 10 & 100 yr pre-existing STORAGE STRUCTURE LIST UNDERGROUND PIPE ID No. Pi Description: DETENTION PIPE Diameter: 2.50 ft. Length: 54.00 ft. Slope...: 0.0000 ft/ft upstr: dnstr: Cu Icula+2 due- �o Redo c + (ova S✓a5e- t h 84110-L k3e 1-11!f Z Z7.63 req q i rec/ C8S page 3 �(pe le•�Z4 �r 28 3z 'x 2.2 13, 68 E ev i valent- Npz 1-&n91h Z xL = 27, 63 `13 _ 9.42 �t 10/10/08 2:48:17 pm RAY, 75TH, EDMONDS Match Peak for 10 & 100 yr pre-existing DISCHARGE STRUCTURE LIST MULTIPLE ORIFICE ID No. 01 Description: ORIFICE Outlet Elev: 83.80 Elev: 83.65 ft Orifice Diameter: 0.5000 in. Elev: 85.30 ft Orifice 2 Diameter: 1.4000 in. )age 10/10/08 2:48:31 pm Page 2 RAY, 75TH, EDMONDS Match Peak for 10 & 100 yr pre-existing LEVEL POOL TABLE SUMMARY MATCH INFLOW -STO- -DIS- <-PEAK-> STORAGE M hTr H <-------- DESCRIPTION --------- > (cfs) (cfs) --id- --id- <-STAGE> id VOL (cf) C t-s 10 YR 24 HR .................. 0.04 0.07 P1 01 85.66 12 211.58 cf 0.0 9' 100 YR 24 HR ................. 0.05 0.08 P1 01 86.00 13 247.17 cf o 05 d j*EDM 06-12 JJ IE I wil October 27, 2005 Project No. KE05550A Associate-d Earth Sciences, Inc. Str 13 20 O 06 ZZA Mr. Kyle Ray 15625 75`h Place West Edmonds, Washington 98026 Subject: Subsurface Exploration, Geologic Hazard, and Geotechnical Engineering Study Proposed Ray Residence Remodel 15625 75`' Place West Edmonds, Washington Dear Mr. Ray: E C E �V ED MAR t 5 Zoos EECE RESUB MAR 13 2006 BUILDING DEPARTMENT CITY OF EDMONDS Associated Earth Sciences, Inc. (AESI) is pleased to present this subsurface exploration, geologic hazard, and geotechnical engineering study for the referenced project. This letter is based on our discussions with you, architectural plans by Phil King Designs dated April 21,' 2005 and supplied by you, our site observations, and our experience on other projects in the site vicinity. The purpose of this study was to gather geotechnical data and provide geotechnical conclusions and recommendations for the proposed remodel.' This letter was prepared using field observations, subsurface explorations, and published sources of geotechnically pertinent information. This letter has been prepared for the exclusive use of the Mr. Kyle Ray and his agents for specific application to this project. Within the limitations of scope, schedule, and budget, our services have been performed in•accordance with generally accepted geotechnical d 1 ractices in effect in this area at the ti 1-1r was engineering an engineering geo ogy p �a prepared. No other warranty, express or implied; is made. 'D l� C L� FEB 2 0 2007 SITE AND PROJECT DESCRIPTIONS ' EECE The project site is located on the east side of 75`'' Place West in Edmonds, Washington (see Figure 1, Vicinity Map). The project site is a developed single-family residential lot with ,an existing dwelling. The existing dwelling consists of a one-story rambler with a partial daylight, basement under the approximate southern half of the residence. We understand that the north half of the residence was constructed in the 1950s with the south half, including the basement-, added on in the 1970s. A wood deck is located on the west side of the house. The residence is bounded on the west by 75''' Place West, on the north and south by single-family residences, 911 Fifth Avenue, Suite 100 • Kirkland, WA 98633 • Phone 425 827-7701 • Fax 425 827-5424 and by a steep, west -facing slope on the east. The Burlington Northern Railroad right-of-way is located adjacent the shoreline of Puget Sound west of the project site and adjacent properties. We understand that the major structural improvements of the proposed remodel will include: • Remodeling the south half of the residence, including construction of a second story - and conversion of the basement into, a garage with slab -on -grade floors;. • Expansion of the kitchen (adding approximately 5'6"'by 14'9" on the west side of the existing residence, including construction of a new wall foundation;. • -Construction of three deck footings on the west edge of the residence; and • Foundation improvements to the south half of the residence in the existing_ footprint. r _ . -- =� We understand that the proposed improvements will limit excavation to those necessary to construct foundations and install buried utilities, largely within the approximate existing footprint of the existing structure. We further understand that final site grades will not be changed from the existing grades. SITE OBSERVATIONS i� Our site observations were made during two site visits in August and September of 2005. The following sections describe our visual observations. Ell KI Geologic Reconnaissance The existing dwelling is located on a 'flat bench -on the lower half of a large slope system, which begins on the order of 100 feet above to the east. The slope system drops down to. the west from 75`h Place West to Puget Sound across a vertical relief on the order of 100 feet. The steep slope on the east edge of the property appears to be. inclined at 2H:1V to 1H:1V . (Horizontal; Vertical), based on visual estimates. An over -steepened- area interpreted to be an old- slide scarp was observed directly east of the project site approximately 50 feet above the existing dwelling. The scarp was, visually estimated to be on the order of 40 feet in length and 5 to 10 feet in height. The slope is densely vegetated with ferns, maple trees, and Othe'shrubs. Most of- the deciduous trees had bowed trunks indicating slope creep; but several evergreen trees higher up the slope appeared relatively straight, Some of the larger trees near the base of the slope appear to have been topped and trimmed in the past. A concrete, masonry block wall on the order of 2 feet in height is located near the toe of the slope. The toe of the steep slope is approximately -25 to 35 feet east of the existing dwelling. In the streets.and unimproved right-of-ways at the top of the slope, we observed asphalt berms and catch basins that ,appeared designed to collect surface water from the streets and easements. We understand that drainage improvements were completed near the upper developed portions of the slope in the late 1990s after some shallow slides occurred on the slope several properties to the north and one property to the south. Structure Reconnaissance We examined accessible areas of - the existing structure for visible signs of settlement or distress. We observed that the. southwest corner of the basement -level foundation had settled away from the bottom of the wall approximately 1 inch. The foundation appeared to consist of concrete masonry units (CMU) embedded approximately 6 inches into the ground. No visible structural connection :was observed between the wood -framed wall and the CMU block foundation. We observed a concrete basement retaining wall on the east side of the furnace room of the portion built in, the 1970s that appeared to be in good condition. -� Other than the area described above, we did not observe other signs of distress in the structure, such as wall cracks and out -of -square windows and doorways. The owner informed us that. he was not aware of problems with sticking doors or windows or other indicators of settlement. SUBSURFACE CONDITIONS The following subsurface conditions are based on our limited explorations andour literature review of previous studies performed in the project vicinity. y Limited Subsurface Explorations Our field study included four hand -auger exploration borings (HA-1 through.HA-4) performed in August 2005 and a visual geologic reconnaissance performed in September 2005 to -gain - information about the site. - Materials encountered in the explorations were classified in .the field by an engineer from our firm. Dynamic Cone Penetrometer (DCP) blow counts were recorded at select depths in the explorations to aid in determining the relative density of the soils. The explorations were allowed to stand open for, several hours to observe potential ground water seepage and were backfilled prior to -departing the site. Selected samples from the explorations were transported to our 'laboratory for further visual classification, as necessary. The various types of sediments, as well as the depths where characteristics of the sediments' changed, are indicated on the exploration logs presented • in the Appendix. The depths indicated on the logs, where conditions changed may represent gradational variations between sediment types in the field. Our explorations were approximately located in the field by measuring from known site features- shown on the aforementioned Site and Exploration Plan - (Figure 2). 3 Literature Review We reviewed our .in-house files and publicly available exploration data from the GeoMapN.W website(http://ge6mapnw.ess.washington.edu/index.php) at the University of Washington for previous geotechnical studies ..performed in the project vicinity. Our research revealed - exploration logs from the following, studies: • "Subsurface Exploration, Geologic Hazards, and Preliminary Geotechnical Engineering Report, Aldridge Short Plat, Edmonds,* Washington," dated. October 24, 1997 by AESI (from AESI in-house files). This study included the two lots directly across 75"' Place West from the project site (1,5604 75"' Place West). Three exploration borings and four exploration pits were performed at the Aldridge site, which generally encountered fill over disturbed silts/clays over very dense fine sands. Slope inclinometers were installed intwo of the borings and were measured periodically over a period of approximately 3 years. Measurements ;indicated shallow downslope creep of the fill in the upper 10 feet on the order- of 1 inch or, less over the measurement period, with the - majority of the movement occurring .near the top of an uncontrolled fill slope on the west side of the property. The site has remained undeveloped at the time of this letter. • "Revised Geotechnical Report, Proposed Residence -at Lots 1 and 2 75"' Place P p West, Edmonds, Washington," dated January 26, 1994 by Shannon and Wilson, Inc. (GeomapNW excerpts only). This study included two lots across 75"' Place West to the southwest of the project site (15620 15' Place West). One exploration boring was performed at the site and two exploration pits by Earth Sciences were included in the report, which. generally encountered fill/slide debris over stiff to hard silts/clays. (According to Snohomish County tax records, a two-story dwelling was constructed in d 199.7). • "Geotechnical Engineering Study, Recent Landslide, 15620 - 72°d Avenue West, Edmonds, Washington," dated February 24, 1997 by Geotech Consultants, Inc. (GeomapNW excerpts only). This study included the lot upslope (east) and one property south of the project site. Three exploration borings were performed at the site, which generally encountered dense gravelly sands over medium dense' to dense silty sands over very dense sands. • "Subsurface, Exploration, Geologic Hazards, and Preliminary Geotechnical- Engineering Report, Summers Residential. Property, Edmonds, Washington," dated December 31, 1991 by AESI (from AESI in-house files). This study included a lot upslope from the . northeast corner of the project- site, (7222 72°d Avenue West). Three exploration borings were performed at the Summers site, which encountered very dense lodgement till and advance sands in one boring. i • "Geotechnical Evaluation, Proposed Hansen -Residence Addition Project, 15615-75" Place West, Edmonds,.' Washington," dated June 1, 1999 by Dennis M. Bruce, P.E. (from AESI in-house files). This study included the adjacent lot. immediately north of the" project site. Two test holes were, dug on the property using a power hand auger'' Which generally encountered moderately dense to dense clean sand over very dense silt and silty sand with cobbles. "Report of Geologic Evaluation, 'Meadowdale Area, Edmonds, Washington-," dated -� September 23, 1968 by Dames & Moore (provided by the City of Edmonds). This study evaluated the overall stability of the area from a geologic standpoint based largely on literature review and surface reconnaissance for installation of a proposed sanitary' sewer system. • "Final Report, Landslide Hazards Investigation, Meadowdale Area, Edmonds, Washington," dated October 16, '1979 by Roger Lowe Associates, Inc. (provided by the City of Edmonds). This study analyzed the subsurface conditions and slope stability based on previous studies -and .seven borings performed for the study. The study provided a landside hazard map of the Meadowdale area, which quantified landslide risk by type and probability of occurrence in a 25-year period. • "Report of Geotechnical Consultation; Property Value Appraisals and Assessments, Meadowdale Landslide Area, Edmonds, Washington," dated February 28, 1985 by GeoEngineers, Inc. (provided by the City of Edmonds). This study updated. the probability of landslide occurrences as provided in the 1979 Lowe study after installation of storm and sanitary sewers in the Meadowdale area. Our literature review was not meant to be all inclusive, as other studies in the project vicinity may exist but were not available for- our review.. Pertinent information from these studies is discussed 'in subsequent sections of this letter, where appropriate. The logs for the above - referenced explorations have been included in the Appendix of this letter. Soil Conditions Subsurface conditions .on the project site were inferred from the field explorations accomplished for this study, visual reconnaissance of the site, and review of applicable geologic/geotechnical literature. As shown on the field logs, the explorations on the project site generally encountered silty sand with various gravel fill over sandy silt to silty sand soils interpreted to be old landslide material. The following section presents more 'detailed subsurface information organized- from the upper (youngest) to - the .lower (oldest) sediment types. i �ILI Fill Material interpreted to be man -placed fill was encountered in all the explorations on the project site. The fill consisted chiefly of medium dense, silty sand with various gravel, concrete debris, cinders, and asphalt debris. nia r _A_1.A_ Material interpreted to be old landslide soils were encountered in all the explorations on the project site: The old landslide soils consisted chiefly of medium stiff to stiff, fine sandy silt and medium dense, silty fine sand with a variously jumbled matrix. Exploration boring HA-1 encountered an approximately 4'/246ot layer of fine to medium sand within the interpreted old "landslide deposit. Explorations from the other studies in the project vicinity listed above indicate similar landslide materials that extend well below existing grades in the project area on the order. of 30 to 60 below existing grades. The soil conditions encountered in our explorations were consistent with the *soils mapped in the Preliminary Surficial Geologic Map of the Edmonds East and. Edmonds West Quadrangles, Snohomish and King Counties, Washington (Smith, 1975). The geologic. map indicates that the site is characterized by Qols (old landslides) on the southwest portion of the site. The northeast portion of the- site appears to be mapped as Qw (Whidbey formation), although no explorations were performed there to confirm this. , The maps also indicate Qdb (Double Bluff) and Qe (Esperance sand) in the project vicinity. Ground Water Conditions No seepages or ground water were observed within our explorations. In addition, no seepages were observed daylighting on any of the steep slopes on the property. -However, it should be noted that our site reconnaissance was performed at the end of summer when ground' water levels are typically lower. Ground water conditions should be expected to fluctuate with season, precipitation, site usage, and other on- and off -site factors. GEOLOGIC HAZARDS The following discussion of potential geologic hazards is based on the geologic, slope, and shallow ground water conditions as observed and discussed herein. Landslide Hazards and Mitigation The potential landside risk can be divided into two depth categories:. shallow and deep. The potential shallow (on the order of f to 10 feet thick) landslide risk includes slumps, debris avalanches, and earth flows of the .colluvial soils and trees on the steep slopes to the east of the project site. The potential deep landslide risks for the site have been identified by previous studies in, the site vicinity as continued movement of the ancient landslide blocks. 11 6 7 The potential for shallow slides will be greatest after extended periods of heavy rainfall and/or snow. events. Such weather events occurred during the winters of 1996 and 1997 and resulted in numerous shallow slides in the Meadowdale area and around Puget Sound. Mitigation for such slides include proper handling and discharge of surface storm water, reduction in ground water levels, and trimming Ior removal of large trees in the potential slide zone. We understand that since the 1996 and 1997 events, City . improvements to surface water management of the ,right -of ways above the slope to the east have been implemented, ' including installation of street drainage berms, catch basins, and prevention of storm water discharges onto or. near the slope. These improvements will reduce the potential for sat uration turatton of .the colluvial soils and the contribution from upgradient surface water infiltration to ground water levels and _seepages. The large deciduous trees directly upslope from the, proposed project area appear to ,have been trimmed and topped some time in the past, reducing the potential for direct fall damage. The structure. appears suitably set back from the toe of the - slope approximately 25 to 35 feet .for the dissipation of most shallow slides. The risk of earth and debris flow damaging. the dwelling already exists .for the current structure and will not be increased by the improvements. 'However, "additional debris -flow mitigation could be achieved f by extending the basement foundation wall 3 feet above the outside finish ground surface. ' Extension of the foundation wall would allow for debris -flow material to impact the back of the residence without buckling wood framing or:.flooding the living space. t Deep-seated landslides ' risks at the project site would most likely be related to reactivation of, the ancient landslide blocks estimated to have occurred thousands of years ago. after the retreat of glacial ice and subsequent draining of glacial lakes. The large-scale i g g owering of regional ground water levels and continued erosion of the toe of the slopes by wave action resulted in unstable, oversteepened" coastal bluff conditions. Mitigations for deep-seated slides at coastal bluffs include armoring of the base of the bluff to prevent wave erosion. The riprap embankment placed during. the construction of the Burlington Northern Railroad tracks has provided protection from wave -action erosion. To .our knowledge, no evidence of recent movement of the' deep-seated slide planes. has since been documented. The 1980s .drainage t improvements in the 75' Place West right-of-way and 1990s drainage improvements at the top of the steep slope have also reduced the potential for reactivation of the deep-seated slide planes. Therefore, no further mitigations for deep-seated landslides should be required. It .should be noted -that no amount of engineering and mitigation measures can eliminate the potential for earth -movement. Some risk s.will-always remain and have been estimated in the next section. Meadowdale Earth Subsidence Landslide Hazard Area Designation The project site is mapped within the Meadowdale Earth Subsidence Landslide Hazard Area. A 1979 report by Roger Lowe Associates, Inca and update study by GeoEngiheers, Inc. , in 1985 assess the site as, having the following landslide risks: i7. —� • 2CO2 - Hazards from encroaching landslide materials by the process of debris avalanches with a 2' percent probability of occurrence during a 25-year period. Based on the current surface conditions, including densely vegetated slopes, lack of evidence of recent ground movement directly upslope from the project site, and surface drainage improvements at the.top of the slope, we concur with this assessment. • , 4A30 - Hazards from ground,' failure in ,previously failed material by the process of slumps -.with a 30 percent probability of occurrence during a 25-year period. This probability was reduced from the 1979 assessment of 90 percent after the installation of the storm and sanitary sewers in the Meadowdale area.. Based on the current conditions j and additional drainage improvements upslope from the project site, we concur with J this assessment. We. understand that the City of Edmonds has requested the following items to be provided per the Meadowdale Earth Subsidence Landslide Hazard Area Checklist Permit Submittal' rr Requirements: • Critical Areas Determination and/or Hearing Examiner Decision; • Lead .Design Professional Designation and Statement; • Vicinity Map; • Topographic Map; J • Geotechnical Report; • Grading Plan; • Architectural and Structural Plans; 1 •: Applicant/Owner Liability & Landslide Acknowledgement; 1 • Geotechnical Declaration and Statement of Risk; • Architect and/or Structural Engineer Declaration; • Applicant/Owner Covenant to Notify and Hold Harmless. - -� This letter will provide a vicinity map (Figure 1) and serve as the geotechnical report. We will provide'a geotechnical declaration and statement of risk after confirming that the architect and structural engineer have incorporated our recommendations into the final plan set-. Since excavations will be limited to those required for foundations in the same approximate'footprint of the existing structure and no change of grades are proposed, ;it is our opinion that a grading plan is not necessary for successful, completion of this project. We understand that a property boundary/topographic survey will be obtained by the owner. The remaining items should be addressed by the owner, architect, and structural engineer. Seismic Hazards and Recommended Mitigation Earthquakes occur in the Puget . Lowland with great regularity. The vast majority of these events are small and are usually not felt by people. However, large earthquakes do occur as evidenced by the 1949, 7.2-magnitude event; the 2001,� 6.8-magnitude event; and the 1965, 6.5-magnitude event. The 1949 earthquake appears to have been the largest in this region ^� 8 ' duringrecorded history and was centered in the Olympia area. Evaluation- of earthquake Yq return rates indicates -that an earthquake of the magnitude between 5.5 and 6.0 is likely every 25 to 40 years in the Puget Sound basin. Generally, there are four types of potential geologic hazards, as with large -seismic events:, 1) surficial ground rupture; 2) seismically induced landslides; 3) -liquefaction; and 4) ground motion. The potential for each of these hazards to adversely impact the proposed project is discussed below. Surficial Ground Rupture The nearest known fault trace to the project. is the South Whidbey Island -Lake Alice Fault. Recent studies by the U.S. Geological Survey (USGS) suggest that a trace of the northwest - southeast trending 'thrust 'fault zone may project through the Meadowdale area. The recognition of this fault is relatively new, and data pertaining to it are limited with the studies still ongoing. According to the USGS studies, the recurrence interval of movement along this, fault system is still unknown, although it is hypothesized to be in excess of several thousand years. Due to the suspected long recurrence interval, the potential for, surficial ground rupture. at the subject property, is considered to be low during the expected life ;of the structure. Seismically Induced Landslides The project site is located in the Meadowdale Earth Subsidence Landslide Hazard Area, of which the risks of landslides have been quantified most recently by the 1985 GeoEngineers - report and are discussed above. We interpret the probabilities associated with the above - described risks as low to moderate given static conditions-. Ground accelerations.associated _ with a strong earthquake may reactivate movement along the old slide planes and result in- a higher potential for landslides and ground displacements. This risk already exists for the current structure and will not be increased by the proposed improvements. We recommend mitigating damage to the proposed improvements by structurally tying together, isolated ,footings, as described in the Foundations section of this letter. The resulting foundation system will serve primarily to prevent collapse of the structure during differential. ground displacements, but not necessarily prevent unrepairable damage to the structure. Liquefaction Liquefaction is a condition where loose, saturated, sand soils lose strength when sub ected to Y g J high intensity, cyclic loads of very short duration, such as occur during earthquakes, pile driving, and blasting. The resulting loss in bearing strength can cause differential foundation settlements and slope failures. Loose, saturated, clean, fine-grained sands, which cannot dissipate the buildup of .pore water pressure, are the predominant type of sediments subject to liquefaction. Based on our review of the samples, obtained from our explorations, it is "our opinion that the potential for liquefaction is low due to the combination of a lack of ground water in the loose sands encountered, and due to the high fines content of the other soils encountered. Ground Motion Structural design of the building should follow 2003 International Building Code (IBC) standards using Site Class C as defined in Table 1615; 1. L The 2003 IBC seismic design -_� parameters for short period (Ss) and 1-second period (S) spectral acceleration values can be computed' using the USGS National Seismic Hazard Mapping Project website (http://earthquake.usgs.gov/hazmaps/). Using the 2002 data, the USGS website computed ground motions at the project site to be 1.24g and 0.44g for 'building periods of 0.2 and 1.0 seconds, respectively, with a 2 percent chance of exceedence in 50 years. , CONCLUSIONS AND RECOMMENDATIONS The project site is currently developed with an occupied single-family residence within the Meadowdale Earth Subsidence Landslide Hazard. Area. Therefore, the risks described above are already present for. the existing structure. It is our. understanding that the owner fully understands and accepts the risks of the landslide hazards as discussed in this letter. We also understand that potential future owners will be aware of the risks associated with owning property in the Meadowdale area because such a notice is on the property title. The purpose of our study was to assess these risks based on current, site -specific, slope and soil conditions and provide recommendations for minimizing and mitigating adverse impacts to the slope by the proposed improvements. Since the project chiefly involves replacing the existing south half of.the structure in the same approximate footprint, it is our opinion that the overall impact to the stability of the slope will not be adversely affected provided our recommendations are followed. 'Furthermore, the improvements will result in a safer structure since the improvements will be constructed to current building codes and replace the -CMU block foundation under the south half of the residence with structurally connected foundations that will mitigate differential displacements.. The following sections -present our recommendations for design and constructionof the proposed improvements. Temporary Excavation Slopes We anticipate -that temporary cut slopes may be necessary for overexcavation in footing areas and for installatiorl_ of buried utilities. In our opinion, stable construction slopes should be the responsibility of the contractor and should be determined during construction.' For estimating purposes, however, we anticipate that temporary, unsuppoFted cut slopes over 4 feet can be made at a maximum slope of 1.5H:1V in the site soils. Typical trench -box shoring for excavations deeper than 4 feet should be considered to minimize site disturbance. As is typical. with earthwork operations, some sloughing and raveling may occur -and cut slopes may have to be. adjusted in 'the field. In addition, WISHA/OSHA regulations should be followed at all times. 10 --'�� Structural Fill Structural fill will be.necessary to provide suitable footing and slab -on -grade floor subgrades and for backfill of utility trenches. All references to structural fill in this letter refer to subgrade preparation, fill type, placement, and compaction of materials as discussed in this _ section. If a percentage of compaction is specified under another section of this letter, the value given in that section should be used. --� After stripping, planned excavation, and any required overexcavation has been performed to the satisfaction of the geotechnical engineer or his. representative, the, upper 12 inches of exposed ground should be compacted to a firm and unyielding condition, as determined by the geotechnical engineer or his representative. If the subgrade contains too much moisture, adequate compaction may be difficult or impossible to obtain' and should, probably not be jattempted. In lieu of compaction,' the area to receive fill, should be blanketed with, clean, coarse, crushed rock oruarr s alls to act as a capillary break between the new fill and the q Y P P Y wet subgrade. Where the exposed ground remains soft and further overexcavation is All, impractical, placement of an engineering stabilization fabric may also be necessary to prevent contamination of the free -draining layer by silt migration from below. -_ After compaction ofthe exposed ground is tested and approved, or a free -draining rock course is laid, structural fill may be placed to attain desired grades. Structural fill is defined as non - organic soil, acceptable to the geotechnical : engineer, placed in maximum 8-inch loose lifts ��. with each lift .being compacted to at least 95 percent of American Society for Testing and Materials (ASTM):D-1557. In the case of roadway and utility trench filling in the City right- of-way; the backfill should also be placed and compacted in accordance with City codes and standards. The contractor should note that any proposed fill soils must be evaluated by AESI prior to their use. This would require that we have a sample of the material at least 72 hours in.advance to either perform a Proctor test and/or determine its field suitability_ Soils in which the amount of fine-grained material (smaller than the No. 200 sieve) is greater than approximately 5 percent (measured on the minus No. 4 sieve size) should be considered moisture -sensitive. Use of moisture -sensitive soil in structural fills should be limited to favorable dry weather and dry subgrade conditions. The on -site soils contained substantial amounts of silt and are considered highly moisture -sensitive when excavated and used as fill materials. At the'time of �77 our exploration program, soil moisture contents were at or above optimum for structural fill use., We anticipate that the some of the excavated- site soils may require aeration and drying prior to compaction in structural fill applications. Construction equipment traversing the site when the soils are wet can cause considerable disturbance. If fill is placed during. wet weather or if proper compaction cannot be obtained, a select, import material consisting of a clean, free -draining gravel and/or sand should be used. Free -draining fill consists of non -organic soil with the amount of fine-grained material limited/to 5 percent by weight, when measured on the minus. No. 4 sieve fraction and at least 25 percent retained on the No. 4 sieve. i 1 1111, Foundations We understand that ,the new foundations will remain within the approximate footprint of the existing basement and deck and not further encroach the west property line. With proper. design, subgrade preparation, embedment; and construction, it is our opinion that the proposed foundations will not decrease- the stability of the existing slopes provided the recommendations of this letter are followed. _ The. observed foundation settlements on the -west side of the existing basement level were likely due to poor subgrade preparation and construction on uncontrolled fill. We have discussed with the owner, the option of supporting the improvements' on deep foundations to mitigate potential excessive settlements due to the presence of the 'uncontrolled fill and possible continued movement of the old landslide materials. Based on the expected 30- to 60-foot depth of old landslide materials on the project site, we anticipate that deep foundations would only provide vertical support and could not practicably . be constructed to resist the lateral displacements should the old, deep-seated landslide block become active. We understand that the owner wishes to use spread footings for foundation support and has accepted the risk that even static, post -construction settlements may result in. drywall cracks, tilting of window/door jambs, and other largely cosmetic damages may occur, especially near the connections between the improvements and the north half of the dwelling to remain.• Due to the presence of uncontrolled fill and variations : in old landslide soils present at the anticipated bottom of footing elevations, we recommend that all . new ' footin s•. bear on 'a minimum, 2-foot-thick layer of structural fill. The width of the structural fill pad should be 2 feet wider than the width of the -footing. Structural fill. type, placement, and compaction recomm ndations are provided in the - Structural Fill section of this letter. The existing fill soils mutt be removed under new foundations or overexcavated and recom acted as structural fill if moisture conditions allow. All organics, debris, and soft/loosened sol -must be removed from the footingprior areas p to placement of structural fill; and be confirmed by a representative from AESI. We recommend that foundation excavations be completed with an excavator equipped with a.smooth digging late to limit'disturbance of the subgrade. During � gg g P wet weather, it is highly recommended that footing subgrades_be protected from disturbance with several inches of compacted crushed rock. Continuous and isolated spread footings -may be used for building support when founded on the t approved 2-foot-thick layer of structural fill discussed above. Isolated footings should be t ' structurally tied together in two directions_ to mitigate excessive ground displacements. The owner should be aware that the primary purpose -of tying together found4tion elements is to 1171 prevent collapse of the structure due to excessive displacements; therefore; the structure may be damaged beyond repair in some cases. P We recommend that a maximum allowable foundation soil bearing pressure of 2,000 pounds per square foot (psf) be utilized for design purposes, including both dead and live loads, for footing subgrades prepared as described herein. An increase of one-third may be used for. short-term .wind or seismic loading. . All . footings should have a- minimum width of 14 inches for single -.story structures, 16 inches for two-story structures, and 18 inches for three-story structures. ' 12 It should be noted that the area bounded by lines extending downward at 1H:1V from any footing must not inte'rsect another footing. In addition, a 1.5H:1V line extending down from any footing must not daylight because sloughing or raveling may eventually undermine the footing. Thus, footings'should not be placed near the edge of steps or cuts in the bearing soils unless adequately embedded. Anticipated settlement of footings founded on approved structural fill as described above should be approximately 1 inch or less. Disturbed soil not removed from footing excavations prior to footing placement could result in increased settlements. All footing areas should be inspected by AESI prior'to placing concrete to verify that the design bearing capacity of the soil has been attained and that construction conforms to the recommendations contained irr this letter. Such inspections may be required by the City. Perimeter footing drains should be provided as discussed under the section on Drainage Considerations. Lateral Earth Pressures " All backfill behind walls or around foundation units should be placed as per our recommendations for structural fill and as described in this section of the letter. Horizontally backfilled walls, which are free to yield laterally at least 0.1 percent of their height, may be .a designed using an equivalent fluid equal to 35 pounds per cubic foot (pcf). Fully restrained, horizontally backfilled, rigid walls that cannot yield should be designed for an equivalent fluid of 55 pcf. A surcharge equivalent to 2 feet of "soil should be added to -the wall height for walls with sloping backfill, heavy construction equipment, or adjacent parking or roads. The. lateral pressures presented' above are based on the conditions of a uniform backfill . consisting of structural fill compacted to 90 to 92 percent of ASTM:D 1557. A higher degree of compaction is not recommended as this will increase the pressure acting on the walls. A lower.. degree of compaction may result in settlement. Thus, the compaction level is critical and should be tested by our firm during placement.- In addition, only hand -operated or walk - behind compaction equipment should be used within 5 feet of the walls to prevent excessive surcharge loads from heavy equipment. Perimeter footing drains should be provided. for all :retaining walls as discussed under the section on Drainage Considerations. f It is imperative that proper drainage be provided so that hydrostatic pressures do not develop against -the walls. This would involve installation of a minimum, 1-foot wide blanket drain for the- full wall height using imported, washed gravel against the. walls. The blanket drain and wall backfill should be capped with 12 inches of relatively y impermeable soils and sloped to drain away from the walls to prevent surface water intrusion directly into the drain system. Passive Resistance and Friction- Factors ' Footings/keyways cast directly against undisturbed, dense soils in a trench may be designed for an allowable passive resistance against lateral translation using an equivalent. fluid density equal , to 250 pcf. The passive equivalent fluid pressure. diagram begins at the .top of the footing. This value applies only'to footings/keyways where concrete is placed directly against t; 13 a the trench sidewalls without the use of forms. If footings are placed on -grade and then backfilled, the top of the compacted backfill must be horizontal and extend outward from the footing for a minimum lateral distance equal to three times the height of the backfill before tapering down to grade. With backfill placed as discussed, footings may be designed for passive resistance against lateral translation using an equivalent fluid equal, to 250 pcf. Passive resistance values include a factor of safety equal to 1.5 in order to reduce the amount of movement necessary to generate passive resistance. The allowable friction coefficient of 0.3 may be used for footings cast directly on the structural fill pads described in the Foundations section of this letter. This is an allowable value and includes a safety factor of 1.5. Slab -On -Grade Floors Typical concrete slab -on -grade floors appear feasible when supported on a minimum, 12-inch thick layer of approved structural fill compacted to a firm and unyielding condition. Above the 12 inches of structural fill, we recommend 4 inches of washed pea gravel to .act as a capillary break.. A plastic vapor retarder of minimum 6-mil thickness should be placed directly over the capillary break. Construction of crawl spaces should also include covering, the soil below the floor system with a plastic vapor retarder to reduce interior dampness. The contractor must take care to protect the plastic vapor barriers from punctures during construction. More stringent moisture protection details should be considered by the owner and .architect if { necessary to protect interior finishes. -"] Drainage Considerations To facilitate drainage away from foundation elements, perimeter footings should be provided with a drain near the footing elevation. Drains should- consist of 4-inch-diameter, rigid, perforated, polyvinyl chloride (PVC) pipe surrounded by, at least 6 inches of washed drain, gravel. The minimum diameter of the drain rock: must be larger than the diameter of the perforations in the pipe. The level of the perforations in the pipe should -be set approximately 2 inches below the bottom of the footing (perforations down) and the drains should be constructed .with sufficient gradient to allow gravity flow away from the building to a suitable j� discharge. Cleanouts should.be installed at appropriate, intervals. Roof and surface runoff should not discharge into the footing drain system, but should be handled by a separate, rigid,. tightline drain. Exterior grades, adjacent to walls, should be sloped downward away from the structure to achieve positive surface drainage. All collected ' water should be directed to an engineered storm drain system that. drains away ,from the 'buildings, and not near, over, or onto steep slopes. r Utility Connections Due to the potential for differential soil displacements at the project site, we recommend flexible connections between all utilities and the residence. The connections should allow up to 6 inches of ground movement. CLOSURE We appreciate the opportunity to be of service to you on this project. Should you have any i questions regarding this letter or other aspects of the project, please do not.hesitate to call. We look forward to providing continued geotechnical services as the project progresses. " Sincerely, —� ASSOCIATED EARTH - SCIENCES, INC. ..:, Kirkland, Washington y �p •Q 33222.. 4 .�CISTER�(``j EXPIRES 2/27 Zc Eric J. Lim, P. fu G. Aaron McMichael, P.E., P.E.G. Engineer Project En J g� Associate Engineer � Attachments: Figure 1: Vicinity Map � - Figure,2: Site and Exploration Plan i Appendix: Exploration Logs EIUsn K E05550A t Projects\2005550\KE\WP �;; 15 'ON VOSSS03V Y'OHd N�33NMIS32IAV2fWa3 ® ® ® ® ® 90/603XV0 A dVW ALIN131A •aul 'naaueln 4>a$3 Peselaevoy fl 13Mnou '3NI'SN33NIJN303EJ:aouaja;a8 3TfOSON a V „N f T - fs `{''� t Y d ■ EP 4 97 '.1997'STUDY' TYP ■ EP r: EB 1 91 • EB 3-97 EB 1 97 "CEP 'i•97 f �, - f f r z DB TH-1 • EB-?- V_: • DB- TH-2 ■ gFeM7 r, HA-4 . SITE'. "HA1 T f 0H A 3 £:., E & TP 3 P-2' GC81.• .yi s ri° FRN x w F r t �- 1 LOG OF EXPLORATION NO. HA-1 �P- -5 CL This log is part of the report prepared by Associated Earth Sciences, Inc. (AESI) for the named project and should be read together with that report for complete interpretation. This summary applies only to the location of this trench at the time of Subsurface location (V o excavation. conditions may change at this with the passage of time. The data presented are a simplfication of actual conditions encountered. DESCRIPTION Fill 2" of crushed rock over medium dense, moist, brown, SILTY SAND with gravel and scattered 1 concrete debris and cinders. 2 Old Landslide Stiff, moist, tan, jumbled SILT with little fine sand and scattered rootlets (DCP at 2' _12, 8, 8).— 3 — — — Loose, damp to moist, gray, fine to medium SAND with trace silt (DCP at 5' = 6, 6, 7). 4 5 Becomes finer. 6 Becomes coarser with iron oxide stains. 7 8 ----------------------------------------------------- Medium stiff to stiff, wet, tan, fine sandy SILT to silty fine SAND with occasional lenses of clayey silt (DCP at 8' = 13, 10). 9 10 11 12 Bottom of exploration pit at depth 11 feet No ground water seepage observed at time of exploration or 4 hours after exploration. No caving observed. 13 14 15 16 17 18 19 N Ray Residence E N Edmonds, WA Associated Earth Sciences, Inc. Project No. KE05550A Pro Logged by: EJL 1 N Approved by: 8/13105 U Y a w ,A 0 0 N LOG OF EXPLORATION NO. HA-2 L This log is part of the report prepared by Associated Earth Sciences, Inc. (AESI) for the named project and should be read together with that report for complete interpretation. This summary applies to the location oC- only of this trench at the time of excavation. Subsurface conditions may change at this location with the passage of time. The data presented are a simplfication of actual conditions encountered. DESCRIPTION Fill 1 Medium dense, moist, brown, GRAVELLY SILTY SAND with scattered concrete debris. 2 3 4 5 -------------------------- --------------------------- Landscape Rocks 1"diameter rounded gravel._ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Relic Topsoil/Fill 7 Loose, moist to wet, brown to dark brown, SILTY SAND with scattered asphalt pieces. Old Landslide Medium stiff to stiff, moist, tan, jumbled fine SANDY SILT (DCP at 8 1/2' = 10, 9). 8 9 Bottom of exploration pit at depth 8.5 feet No ground water or caving observed at time of exploration. 10 11 12 13 14 15 16 17 18 19 on tD E Ray Residence Edmonds, WA a Associated Earth Sciences, Inc. Logged by: EJL Project No. KE05550A a Approved by: 8/13105 v LOG OF EXPLORATION NO. HA-3 This log is part of the report Prepared by Associated Earth Sciences, Inc. (AESI) for the named project and should be read together with that report for complete interpretation. This summary applies only to the location of this trench at the CL time of excavation. Subsurface conditions may- change at this location with the passage of time. The data presented are o a simplfication of actual conditions encountered. DESCRIPTION Fill Medium dense, moist, brown, silty SAND with few gravel and scattered concrete debris. Sewer pipe 1 in east sidewall (trench backfill). 2 3 Old Landslide Medium stiff, moist, tan, FINE SANDY SILT to SILTY FINE SAND with scattered wood debris (DCP 4 at 4 1/2' = 7, 7, 7). 5 6 (DCP at 6 1/2' = 10, 12, 12) 7 Bottom of exploration pit at depth 7 feet 8 No ground water or caving observed at time of exploration. 9 10 11 12 13 14 15 16 17 18 19 Ray Residence Edmonds, WA Associated Earth Sciences, Inc. Project No. KE05550A Logged by: Approved by:: 9 R% N a 8113/05 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 LOG OF EXPLORATION NO. HA-4 This log is part of the report prepared by Associated Earth Sciences, Inc. (AESI) for the named project and should be read together with that report for complete interpretation. This summary applies only to the location of this trench at the time of excavation. Subsurface conditions may change at this location with the passage of time. The data presented are a simplfication of actual conditions encountered. DESCRIPTION Fill Sod over medium dense, damp to moist, brown, SILTY SAND with few gravel. Old Landslide Medium dense, moist, tan, SILTY FINE SAND to FINE SANDY SILT, slightly jumbled. Bottom of exploration pit at depth 7 feet No ground water or caving observed at time of exploration. Ray Residence Edmonds, WA Associated Earth Sciences, Inc. Project No. KE05550A Logged by: Approved by:: 0 0 R% N U8113/05 k 2 EXPLORATION PIT LOG Number EP-1 Soft, moist, brown with gray, silty CLAY to clayey SILT with roots. (Ditturbed Fill) Medium soft to stiff, moist, bluish -gray, silty CLAY to clayey SILT, brecciated; slickensides; layers of moist to wet, brown, fine sand; upper 'I'slide debris. (Possession Drift) BOH @ 15' Note- No seepage; no caving. Number EP-2 Loose, moist, brown SAND AND GRAVEL mixed with silty clay/silt (Fill) 5 Stiff to very stiff, moist, bluish -gray, clayey SILT to silty CLAY. (Possession Drift) 10 15 BOH @ 18' Note_ No seepage; no caving. Subsurface conditions depicted represent our observation at the time and location of this exploratory tole, modified by geologic We will not interpretation, engineering analysis, and judgment They are not necessarily representative of otttet times and locatlons accept responsibility for the use or interpretation by others of irdorrnation Presented on this log. Reviewed By Associated Earth Sciences, Inc. Aldridge Short Plat 911 Fifth Avenue, Suite 100 Edmonds, Washington Kirkland, Washington 98033 Project No. G97224A Phone: - 425-827-7701 September 1997 Fax: 425-827-5424 , EXPLORATION PIT LOG i Number EP-3 Loose/soft, moist, dark brown, silty, fine SAND with roots. (Fill) Loose, moist, brown, medium SAND. Loose, moist, reddish -brown, medium SAND with occasional gravel. (Fill) Stiff to very stiff, moist, bluish -gray, silty CLAY. (Possession Drift) BOH @ 18' Note: No seepage; caving. Number EP-4 Loose, dry, dark brown, silty, fine SAND with occasional gravel, roots, chunks of asphalt. (Fill) 5�Loose, damp, reddish -brown, medium SAND wtih occasional gravel. (Fill) 0-]Stiff to very stiff, moist, bluish -gray, silty CLAY; slickensided surfaces; upper 1' slide debris. (Possession Drift) 5 BOH @ 16' Note: No seepage, caving 0 to 8'. Subsurface conditions depicted represent our observation at the time and location of this exploratory hole, modified by geologic interpretation. engineering anaysis. and judgment They are not necessarily representative of other times and locations. We will not accept responsibility for the use or interpretation by others of information presented on this log. Reviewed By. A ii 4ssociated Earth Sciences, Inc. 911 Fifth Avenue, Suite 100 Aldridge Short Plat Edmonds, Washington Kirkland, Washington 98033 project No. G97224A Phone: 425-827-7701 September 1997 Fax: 425-827-5424. EXPLORATION BORING LOG Number E13-1 Page 1 of 2 STANDARD PENETRATION I=- Z w °" RESISTANCE SEDIMENT DESCRIPTION a. Blows/Foot 0 10 20 30 40 Damp, light brown, silty, fine SAND with trace roots; 8A bottom of sample damp, light brown with gray SILT I with trace fine sand. Damp, brown, silty, fine SAND with lenses of silt with 5 A 4 trace fine sand; tip of sample damp, reddish -brown SAND with some small gravel. Damp, reddish -brown SAND with trace gravel. I 5 A No recovery. (Fill) 10 A 4 ` ...... _.-.-. �.-..-..-_..-..---�-----------------_�....-----...------..._....... _._...._..._. _. �.. Moist to wet, light brown, silty, fine SAND; top of sample T 1 8A black charcoal with fine sandy silt. SAND: tiny roots observed. 15 I 6A Moist, brown, silty, fine to moist, blue, silty CLAY, plastic. IDamp A" I CLAY, laminated. 20 : I I 12 I A I Moist, blue, silty Moist, blue, silty CLAY to clayey SILT. I ' A I i Moist, blue, silty CLAY to clayey SILT. 25 I 1 i ! A 22 I Moist, blue, silty CLAY to clayey SILT. I 1 18 I A I Moist, blue, silty CLAY to clayey SILT with lenses of 30 A 22 fine, oxidized sand; slickensided surfaces observed. 1 (Possession Drift) ' Damp to moist, light brown, silty, fine SAND, upper 70 portion oxidized. (Double Bluff Drift) subsurface conalm d Wkt d representry our obsed= at the ffine and beatlon of Us ePbratory none, moamea W g�wF bteryretatbns, ugbeerbg anatOK and judgment They are nol necessary/ mpresenw- of cd- times and bcad— We wW not accept ,esp yfw#w use or bii,pretadon by others of informUm presented on fhb be• Reviewed By Wal Associated Earth Sciences, Inc. 911 Fifth Avenue, Suite 100 Kirkland, Washington 98033 Phone: 425-827-7701 Fax: 425-827-5424 Aldridge Short Plat Edmonds, Washington Project No. G97224A September 1997.. ,aI EXPLORATION BORING LOG Number EB-1 . Page 2 of 2 = STANDARD PENETRATION �- � Z w RESISTANCE a- Bbws/Foot SEDIMENT DESCRIPTION o Q 0 co 10 20 30 40 48A (Double Bluff Drift) BOH @ 36-1/2' Note: Slope inclinometer installed. 40 FT. I { f 45 j 50 55 I I I i 60 f { 65 - -... _.�.. ..d loc2& n of this exploratory hole, trtodVied by geologic Subsurface coratlorm depicted repro— our vvsci.a- Interpretations. enghreering analysts. and OdMI-ML They are not neceesa* represerrF*4e of other times and tocadona. We Will not accept mspormyoW for the use or Interpretation by others of Informatlon presented on uds log- Reviewed By J Associated Earth Sciences, Inc. Aldridge Short Plat 911 Fifth Avenue, Suite 100 Edmonds, Washington Kirkland, Washington 98033 Project No. G97224A Phone: 425-827-7701 September 1997 Fax: 425-827-5424 a: EXPLORATION BORING LOG tvt tmhPr FR-2 Paae 1 of 2 � STANDARD PENETRATION Z W RESISTANCE SEDIMENT DESCRIPTION w g o Q Blows/Foot o N 0� 10 20 30 40 Damp, brown, fine to coarse SAND with trace fine (Fill) T 1 � _gravel. - ------ Damp, light brown SILT in top of sample; damp, light 5 I 7A t gray, clayey SILT to silty CLAY in bottom of sample. Damp, gray, silty CLAY. (Slide Debris) 1 I �12 (- Damp, gray, silty CLAY. 10 � 16• Moist, bluish -gray, clayey SILT to silty CLAY. I Moist, light brown, fine SAND in top of sample;. moist, 15T 10A I i bluish -gray, silty CLAY in bottom of sample. 1 I Moist, bluish -gray, silty CLAY; wet, medium SAND in I 1 f 30 tip of sample. - 20 4 =I Moist, bluish -gray, silty CLAY. I Moist, bluish -gray, silty CLAY; fine sand lense in middle I l i 34 A of sample. 1 4 Moist, bluish -gray, silty CLAY; medium sand lense in. 25 27 A middle of sample. (Possession Drift) Damp to moist, light brown, fine SAND at top of sample; }I I 38 � medium sand lower half of sample. I I 30 I � ,' 73i Damp to moist, light brown, fine SAND. Damp to moist, light brown, fine SAND. I 65 (Double Bluff Drift) Subsurface oondWOM depland reps ow obKerVadons at the ume ano tocaaon or urs exp+vrai y Y br. InterDretadom eq#WWft and pidgalwit They are not neeessan'y representative of other *nes and locawns. We will not accept resporalay fot the use or knerp,etatlon by others of Information P""enW On d1h 108. Reviewed By Associated Earth Sciences, Inc. Aldridge Short Plat 911 Fifth Avenue, Suite 100 Edmonds, Washington Kirkland, Washington 98033 Project No. G97224A Phone: 425-827-7701 September 1997 Fax: 425-827-5424 �y EXPLORATION BORING LOG Number E13-2 Paqe 2 of 2 SEDIMENT DESCRIPTION Double Bluff BOH @ 36-1/2' STANDARD PENETRATION Imo— z w RESISTANCE W =O Q BIMS/Foot a U) W3 40 45 50 55 65 10 20 30 40 I I 62 A Subsurface c wM) ns depkded our observations at Um mne ano mcawm m Uw � .r -- •a- interprobdoM engWneWbV anaHs. and Axigmmt Tbw are not necessarily mWe wntae a of other ibises and toeaaora we fain not aeexpt responsbm for the use or Interpmtatlon by others of Inforr w&m presented on ads log. Reviewed By Associated Earth Sciences, Inc. Aldridge Short Plat 911 Fifth Avenue, Suite 100 Edmonds, Washington Kirkland, Washington 98033 Project No. G97224A Phone: 425-827-7701 September 1997 Fax: 425-827-5424 '7 EXPLORATION BORING LOG Ni imher FR-3 Paae 1 of 2 STANDARD PENETRATION I=_ a z W RESISTANCE SEDIMENT DESCRIPTION o Q O !R Blows/Foot fn 0 10 _ 20 30 40 Moist, orangish-brown, silty SAND. (Fill) T 1 5 A ......-----•-- Moist, gray, clayey SILT (Slide Debris) 5 7- Moist, gray, silty CLAY to clayey SILT. IA 1 12 I Moist, bluish -gray, silty CLAY with moist, brown, fine 10T 1 14 sand lenses 4' thick in middle of sample. Moist, bluish -gray, silty CLAY; fine sand tense in I 15 middle of sample. bluish -gray CLAY; 6" thick Tense of peat with. silt; 15 IMoist, 28 A sltckenside surfaces. (Possession Drift) ....................................... fine SAND. I 34 A Damp, light brown, Damp, light brown, fine SAND; very fine sand to silt tense 20 i 30 in middle of sample. I Damp, light brown to gray, fine to medium SAND. 57 Damp, light brown, fine SAND; moist, brown, fine SAND 25 T 1 I 69 in bottom of sample. Moist, brown, fine SAND. I 1 81 Moist, brown, fine SAND. 30 I 71 I 82 Moist, brown, fine SAND. 1 nerd our observations at me nine ana wv-duw. -. „w •a , •• --_ — .----o-- Sterpreace --- Interpretations. enlotrs depkted rep re tatNe of other *nes and locations. we will not interpretations. eng'aretring anaysls, and jud�nent They are not necessarily presen accept responsibility for the use or Interpretation by others of Information presenW on this log. Reviewed By Associated Earth Sciences, Inc. Aldridge Short Plat 911 Fifth Avenue, Suite 100 Edmonds, Washington Kirkland, Washington 98033 Project No. G97224A Phone: 425-827-7701 September 1997 Fax: 425-827-5424 ��_ EXPLORATION BORING LOG Number EB-3 Page 2 of 2 STANDARD PENETRATION f � 4 ? H RESISTANCE SEDIMENT DESCRIPTION Q Btms/Foat o 0 rn _. 10 20 30 40 I 64 (Double Bluff Drift) 1 BOH @ 36-1/2' Note: Slope inclinometer installed. 40 I I 45 I I i 50 . I E 55 I f i 60 E 65 i " f E i A Subsurface conrdttions depicted represent our observations at the time aW tocatron or mrs aXProraWq no®, mODUI v vy interprefadons, eMbeertng analysts, and Judgment They are not necessarily representative of other times and loaadons. We we'll not accept responsibility for the use or Interpretation by others of Inforrnatlon presented on this tog. Reviewed By associated Earth Sciences, Inc. Aldridge Short Plat )11 Fifth Avenue,Suite 100 Edmonds, Washington <irkland, Washington 98033 Project No. G97224A 'hone: 425-827-7701 September 1997 : ax: 425-827-5424 J7 .. I EXPLORATION BORING. LOGEB-1 _ - , j Z ¢ STANDARD PEiO=RATION RESISTANCE (a SEDIMENT DESCRIPTION W O Q t3lowslFoot H is 10 20 30 40 Moist; gray, gravelly, silty, fine TT 50/6" to medium sand. Becomes sandier l with depth. (Lodgement Till) 5 I 50/5' .10 6 I 50/4" t 15 . } 6 I 50/4" i BOH @ 18' 20 w s C face conditions deported represent our observations at the tine arrd bcstloe of this exploratory hole` modBed by 9aobpic Nad^.Wvkwsr*w anakws. arw L They we not necessw* rePresenUrIt" Of other tines and locations. We WN rat t rosponwbity for the use or interprstadon by others of Infornradon presented on the lOg. i 9110-06H October-1991 Summers Residential Property. , Edmonds,. Washington ; ok . MASSOCIATED.. EARTH SCIENCES, INC -2 EXPLORATION BORING LOG b" isce conditions depicted represent our observations at the time and location of this exploratory hole, modified by geologic *rpretation, engirwerig analysis. and Ndprnw L They am not necessarily representative of other times and logati m& we will not .rapt responsWity for the use. or interpretation by others of Monrrtation presented on this log. Summers Residential Property Edmonds, Washington. 9110-06H I October 1991 /AMMASSOCIATED EARTH SCIENCES, INC 47 EXPLORATION BORING LOG �-3 zz 1-►W- SVMAFID PErcRnnoN RESISTANCE < N SEDIMENT DESCRIPTION IL Blows/Foot. co 0 1: 10 20 30 40 d Moist, tan, silty 'fine to medium sand with some gravel. .(Fill) I 18 F Moist,.gray, gravelly, silty, fine 5 - E to medium sand. (Lodgement Till) • 50/5,: !. 10 �. Y I 50/61, F 15 Z 50/4" 4 , --�-- . 20 Moist, gray, fine sand. (Advance . mod) - I 50/59 1. BOH @ 24' 25 I t - ►surface condtions.depicted represent our observations at the time and location of this exploratory hole. nwdfied by geologic. i 1 WI)MIlation, etgi mwirq analys* and judgment. They am not necessarily representative of other times and locations. We will not E :ept resporwbty f w the use or interpretation by others of information. prsswftd on this lop. 9 9110-06H October 1991 Summers Residential. Property Edmonds, Washington ;. . " EARTH AMMASS.DCIATEM SCIENCESONC STERLG 1126194 SOIL DESCRIPTION Surface Elevation: 98 Feet Loose, brown, silty, fine SAND; moist; wet @ 18 ft. mixed with clayey SILT with mottled disturbed appearance with possible slide plane @ 20 ft. (Fill and Slide Debris) SM. 20.9 Stiff to very stiff, gray, fine sandy SILT to slightly clayey SILT; wet; with laminated structure; ML. 36.0 Hard, gray, silty CLAY; moist; laminated . with fine sand partings and wet sand layer at 46.3 ft.; CL . 56.0 Very stiff, gray, silty CLAY; moist; with scattered iron stained sand layers and 6t.5 disturbed blocky appearance; (Possible ancient slide plane) CL. BOTTOM OF BORING COMPLETED ON 11 /19/93 LEGEND v, u Standard Penetration Resistance n c d (140 W. weight, 30" drop) E 0-gon A Blows per foot N 0 20. 40 60 I - 0i.. = c 20 CD 30 40 50 - ..:.. = 60 70 ...... Sample Not Recovered EM Surface Seal = 2' O.D. Split Spoon Sample ® Annular Sealant 1L 3" O.D. Shelby Tube Sample Piezometer Screen ® Grout Q Water Level NOTES 1. The stagcation fines represent the approximate boundaries between soil types, and the transition may be gradual. 2. The' discussion in the text of this report is necessary for a proper understanding of the nature of subsurface materials. 3. Water level, if indicated above, is for the date specified and may vary. 4. Refer to KEY for explanation of 'Soil Log' symbols and definitions. 5. USC letter symbol based on visual classification. 80 90 0 20 40 6 o % Water Content Plastic Limit [--♦—i liquid Limit Natural Water Content Ursula Schluter 15620 75th Place West Edmonds, Washington LOG OF BORING'S 1 January 1994 W-5385-02 SHANNON & WILSON, INC. FIG. 3 Gmtsa":ce " Evko *MW ConsOmft TEST PIT LOGS #1 0' - Duff, topsoil, and roots 1:3' - Variable brown silty fine sand with gravel and clasks of silt -clay mixture (slide debris) (loose) 13.0' - Completed February 25, 1986; no groundwater encountered ill 0' - Duff, topsoil, and roots 1.1' - Variable sandy silt and silty sand (slide debris) ±13.5' - Sandy gravel, slight groundwater seepage throughout ±15.5' - Blue -gray silty clay (severely fissured and with slickensides) ±17.0' - Completed February 25, 1986 0' - Variable silt -sand -gravel mixture (saturated) (slide debris) 3.0' - Blue-gray.silty clay (med stiff) (old slide debris) 8.1' - Tan silt (hard) Completed February 25, 1986; groundwater flow from upper 3 feet 14 0' - Highly variable silt -sand -clay mixture (slide debris) 7.0' - ..Blue -gray silty clay (fissured, ancient slide debris) 11.0' - Tan silt (hard) 13.0' - Blue -gray silt (hard) 16.0' - Completed February 25, 1986; seepage from 4-1 feet FIG. 7 go 36 74 18 1 26 33 BORING 1 -- USCS Descrl ti n Brown, gravelly SAND with some silt, coarse -grained; moist, very dense - becomes less gravelly - becomes wet Brown, slightly sandy and silty SAND, low plasticity, wet, stiff Mostly very fine-grained, silty SAND Gray, silty SAND, moist, dense Test boring -was terminated at 31.5 feet below grade on 1=18-97 No groundwater seepage was encountered during drilling. TEST BORING LOG GEi OTECH 15620 -+76TH AVENUE WEST V corrsui,Tnrrrs, INC. EDMONDS, WA Job No: Date: Lo�gad by: Plate. 97001 JAN 1997 DRW 3 [0 is z0 3 ,0 X as �o 33 18 1 33 1' 24 1 35 1. M30psoil G YGMYYY MI 1!11MwYrl k.II I�KKMYI • M1®rown/mottled, silty SAND with gravel, -wet, loose to medium -dense IMI .rww.wrYl �1({M k.MMYMI IIYMM.YMNI Y.MMM.MY M MYY kM 5 �!•:J''J !J5 ! �i•it•�i �i IIKYMKMYYI NMMMMM.1 .. YIIY/ M M.11r11K/ k.MY.MMI YY M.MMrY/Tan,very silty SAND, of • 1111 M.MM.MrI MN1MIi Y1,I V medium -dense - fIMIMMMIMIYIM1I1I M MMYMMMM1( 1MI MM YNMMIM1I1 MC M MMMMMNM II (1II 1I /MMM MI IIMMMMyyMrI MYM,MM M/ 11. M.MMrMI becomes moist, dense M MMYM.11MI MMMrMMrM) i M1IlNiii�YYi becomes wet, lensof M iN.NM1111n MM.M.MMMI C.M..Y NI . M.RYM.1 NYNNYCC.NI IMi MIMiM.11N MI N MM.NMII r/ M.YNr rl 1.N.MMMI M M. YM YI • • , es sa - • M Mf.M MI Gray, sandy silt, low plasticity, wet, very stiff Test boring was terminated at 31.5 feet below grade on 1-18-97. Groundwater seepage was encountered at 16' and 30' during drilling. GEOTECH CONSMUM'S, INC. TEST BORING LOG 15620 - 76TH AVENUE WEST ' EDMONDS, WA Job No., Date: Logged by: Plate: Mai JAN 1997 DR W 4 BORING 3..--.._..---- --------..__.---:--- - ° USCS Desc ' tion Toysoil Brown/mottled, silty SAND with gravel; very wet, loose lens of silt 1 50/4" . Brown, gravelly SAND, some silt, coarse -grained, wet, dense SP 2 24 Gray, silty SAND, very fine-grained, wet, medium -dense - becomes less silty, moist 3 25 - sM becomes wet -lens of silt 4 20 1 - . - sp Gray SAND, medium -grained, moist, dense 5 53 Test boring was terminated at 26.5 feet below grade on 1-18-97. Groundwater seepage was encountered at 3' during drilling. GEOTECH COMULTANTS, INC. TEST BORING LOG 156.20 - 76TH AVENUE WEST EDMONDS, WA Job No: Date: 1178RW�eerdy: Plate: JAN 1997 3 �` Ge 3 Hansen Page two Pt VN l5 P4. 5Z(A oE-1 Fe- J LA n�G- t ,tq I I The extreme rear (easterly) portions of the Hansen property encompass the steep slope portions of the region. The slope exists at an approximate forty percent (40%) grade. The slope contains mature stable trees, with dense brush (see photographs). No evidence of any geotechnical distress, slides, nor erosional degradation was observed immediately above and behind the Hansen property. This engineer understands that a localized surticial slide has occurred one to two properties to the north, and is a direct result of up slope bad drainage practices. It is understood that the localized slide to the north is currently undergoing stabilization and drainage improvements. As stated in the 1979 Roger Lowe Associates, Inc., report, drainage and ground water control are the best practices for landslide risk reduction. This engineer concurs. EVALUATION: In order to augment the existing site geotechnical information, power hand auger test holes were dug under this engineer's observation on May 22, 1999. Two test holes were dug to seven foot (7') depths (see photographs and site plan for locations). Test Hole No. 1 was dug at the approximate south foundation line of the proposed addition, approximately twelve feet (12') east of the existing house. Test Hole No. 2 was dug approximately ten feet (10') south of the hot tub deck on the relatively level soil bench. Both test holes revealed similar subsurface conditions, namely: 0" to 6" Organics, roots, and organic silt 6" to approx. 3.5' Brown sand, relatively clean, moderately dense 3.5' to 4.5' Increasingly dense sand with cobbles 4.5' to 7' (bottom of hole) Very dense silt and silty sand with cobbles No water was encountered in either of the test holes. Both test holes remained vertical and stable. No sloughing or caving occurred. This engineer conducted a visual examination of the slope above the Hansen property. A small historic cave" (?) zone was observed. It is understood that this "cave" was used for historic bootleg storage purposes. This cave was approximately ( ) 9 Y approximately ( ) p "cave" three foot 3' high b a roximatel three foot 3' deep along the face of the bluff slope. The "cave" revealed no evidence of any geotechnical distress. Additionally, this "cave" zone allowed further verification of the dense sandy silt and gravel soils present. This engineer did observe a mature fir tree growing immediately above the tad. 7 '. � • .{'. € •. f � , r � •. 1 ��i r 4 � ' TI i S a.Sis , 1 f ,• l : � ° z •'y � rod...:_ �'� �� • z �• N x 5 r t• �• 1 �'�Yr . � � a � �, t � r � �,� :. ry4 i r•+'y.r�EW � r a !- i � ^y`� d V. �• 91f �_.•` 7r .. t., rr `� J.f .•� a .. -, rF tom.. �•i'ii• '.-i..;1.�L �' � c-T i.. �'�,�:' J L't•" � S �i r�.. r4 Y t"t ..;' a'�ryek{f.-�ti_ '� iL .° Wit, � r � a � tx � s�..,". �r � � ;,.J� .a�,? ��ar ` a' ��� � � �-"`e �S •�;•r �'� s �•i �t _Y -r f r F,.� y"L -.'^•' Y-� g � >>¢•`'�•w s rs Ltisay"T ,,��,,�� n- at � �''��� d .7_4a�i l.. c��r tj � `..' �, � t• �A� �r �k'7..t� 2 � � '+i _ !� h' sy � c r � �� �'. ;• �' A:-fS i � � X y.�..yi Fk. axs�..g r y e� A J ���, x�3a� �ti -: J"3 `, a � ^'`kb 1 L� Associated Earth Sciences, Inc. M FE NJ 0 10 016abnj Owr25 Vean of S'enwe January 10, 2008 Project No. KE050550B Mr. Kyle Ray 702 0' Avenue South Edmonds, Washington 98020 Subject: Revised Subsurface Exploration, Geologic Hazard, and Geotechnical Engineering Study Proposed Ray Residence Re -Construction 15625 75' Place West Edmonds, Washington Parcel No. 00513100002402 Dear Mr. Ray: �m G? -" Associated Earth Sciences, Inc. (AESI) is pleased to present this revision of our subsurface exploration, geologic hazard,. and geotechnical engineering study for the referenced project. This study is based on our discussions with you, architectural plans by Hanson Design, our site observations, and our experience on other projects in the site vicinity. This study is a revision of our October 27, 2005 study for the previously proposed remodel, which was changed to a complete demolition and re -construction of the house due to plan/field conflicts. In addition, this study has been updated to comply with the revised Critical Areas Ordinance 3632 for the North Edmonds Earth Subsidence and Landslide Hazard Area. The purpose of this study was to gather geotechnical data and provide geotechnical conclusions ' and recommendations for the proposed re -construction. This study was prepared using field observations, subsurface explorations, and published sources of geotechnically pertinent t information. This study has been prepared for the exclusive use of Mr. Kyle Ray and his agents for specific application to this project. Within the limitations of scope, schedule, and budget, our services have been performed in accordance with generally accepted geotechnical ' engineering and engineering geology practices in eff=Lin this area at the time our letter was prepared. No other warranty, express or implied, is WF C IP N V 2 D I RECEgVED u MAY 2 12008 U EECE Kirkland Everett ■ 425-827-7701 425-259-0522 MAY - 2 2008 BUILDING DEPT. Tacoma�TREET FILE 253-722-2992 www.aesgeo:com 1 1 1 1 SITE AND PROJECT DESCRIPTIONS The project site is located on the east ,side of 75' Place West in Edmonds, Washington (see Figure 1, "Vicinity Map"). The project site is currently a vacant, single-family, residential lot. A previous dwelling, which was .demolished the summer of 2007, consisted of a one-story rambler with a partial daylight basement under. the approximate southern half of the residence. We understand that the north half of the residence was constructed in the 1950s with the south half, including the basement, added .on in the 1970s. A wood deck was located on the West side of the house. The lot is bounded on the west by 75 h Place West, on the north and south by single-family residences, and by a steep, west -facing slope on the east. The Burlington Northern Railroad right-of-way is located adjacent the shoreline of Puget Sound west of the project site and adjacent properties. We understand that in 2007 a remodel of the existing residence was permitted by the City of Edmonds. However, conflicts between the designed structure and the field measurements;' as well as structural defects in the portions of the house to remain,. prompted a complete demolition and re -construction of the house. Our initial review of the new plan set by Hanson. Design indicates that the proposed footprint will be similar to the previous structure and permitted remodel. The major structural differences between the proposed structure and the previous structure are: . • Construction of a second story on the south half of the house and conversion of the basement into a garage with slab -on -grade floors; • Expansion of the kitchen (adding approximately 5 feet 6 inches, by 15 feet on the west side of the previous existing residence, including construction of a new wall foundation and retaining wall in place of the previous rockery); • Construction of two deck footings on the west edge of the residence; and • Deletion of the backdoor alcove to provide a straight rear (east) wall with a 3-foot-high catchment wall for mitigation of debris flows. We understand that the proposed improvements will limit excavations to those necessary to construct foundations and install buried utilities, largely within the approximate existing footprint of the existing structure. We further understand that final site grades will not be. significantly changed from the existing grades. tSITE OBSERVATIONS Our site observations were made during two site visits in August and .September of 2005; as well as ongoing erosion controli inspections during the winter/spring of 2007-2008... The following sections describe our visual observations. t u I 1 1 I I Geologic Reconnaissance The previous and proposed house location is a flat bench on the lower half of a large slope system, the top of which is on the order of 100 feet above and 150 feet to the east. The slope system drops down to the west from 75" Place West to Puget Sound across a vertical relief on the order of 100 feet. The steep slope on the east edge of the property ranges from 2H:1V to 1H:1V (Horizontal: Vertical) inclinations, based on visual estimates. An over -steepened area interpreted to be an old slide scarp was observed directly east of the project site approximately 50 feet above the existing dwelling. The scarp was visually estimated to.be on the order of 40 feet in length and 5 to 10 feet in height. The slope is densely vegetated with ferns, maple trees, and other shrubs. Most of the deciduous trees had bowed trunks indicating slope creep, but several evergreen trees higher up the slope appeared relatively straight. Some of the larger trees near the base of the slope appear to have been topped and trimmed in the past. A concrete, masonry block wall on the order of 2 feet in height is located near the toe of the slope. The toe of the steep slope is approximately 25 to 35 feet east of the existing dwelling. This slope area and scarp are part of the North Edmonds Earth Subsidence and Landslide Hazard Area, formerly known as the Meadowdale Earth Subsidence Landslide Hazard Area. This landslide complex. is comprised of both ancient, deep-seated failures and recent shallow debris flow failures. Studies by others have generally concluded that the deep-seated movements have stopped or been minimal over the last few decades since the toe of the slope system has been buttressed by the railroad ballast and drainage improvements have kept ground water levels relatively low. Shallow movements in the lower, previously failed portions of. the slide complex and debris flows in the steep upper portions near the ancient slide scarp continue to experience occasional failures in recent years. Since this landslide complex is well - .documented and studied by others over the last half century, a complete history is beyond the scope of this letter. Additional information regarding this slide complex can be found in the studies by others listed in the "Literature Review" section of this letter. In the streets and unimproved right-of-ways at the top of the slope, we observed asphalt berms and catch basins that appeared designed to collect surface water from the streets and easements. We understand that drainage improvements were completed near the upper, developed portions of the slope in the late 1990s after some shallow slides occurred on the slope several properties to the north and one property to the south. The site is currently winterized for temporary erosion control after demolition of the previous dwelling. Winterization measures included construction of a silt fence on the downgradient side of the lot, placement of crushed rock on the construction entrance and driveway pavement edges, and placement of. hydroseeded mulch over the bare ground. Grass growth from the hydroseed has been established on the site. The erosion control measures have performed well since implemented. 3 11 1 Previous Structure Reconnaissance Prior to demolition, we examined accessible areas of the previous structure for visible signs of settlement or distress. We observed that the southwest corner of the basement -level foundation had settled away from the bottom of the wall approximately 1 inch. The foundation appeared to consist of concrete masonry units (CMUs) embedded approximately 6 inches into the ground with the block openings oriented in the vertical direction. No visible structural connection was observed between the wood -framed wall and the CMU block foundation. We observed a concrete basement retaining wall on the east side of the furnace room of the portion built in the 1970s that appeared to be in good condition. Other than the area described above, we did not observe other signs of distress in the structure, such as wall cracks and out -of -square windows and doorways. The owner informed us that he was not aware of problems with sticking doors or windows or other indicators of settlement. SUBSURFACE CONDITIONS The following subsurface conditions are based on our limited explorations and our literature review of previous studies performed in the project vicinity. .. Subsurface Explorations Our field, study included four hand -auger exploration borings (HA-1 through HA-4) performed in August 2005 and a visual geologic reconnaissance performed in. September 2005 to gain information about the site. Materials encountered in the explorations were classified in the field by an engineer from our firm. Dynamic Cone Penetrometer (DCP) blow counts were recorded at select depths in the explorations to aid in determining the relative density of the soils in accordance with American Society for Testing and Materials (ASTM).Special Technical Publication #399.. The explorations were allowed to stand open for several hours to observe potential ground water seepage and were backfilled prior to departing the site. Selected samples from the explorations were. transported to our laboratory for further, visual classification, as necessary. The various types of sediments, as well as the depths where characteristics of the sediments changed, are indicated on the exploration logs presented in the Appendix. The depths indicated on the logs where conditions. changed. may represent gradational variations between sediment types in the field. Our explorations were approximately located in the field by measuring from known site features shown on the aforementioned "Site and Exploration Plan" (Figure 2). I Literature Review We reviewed our in-house files, select City of Edmonds reports, and publicly available exploration data from the GeoMapNW website . (http://geomapnw.ess.washington.edu/index.php) at the University of Washington for previous 4 t 1 1 1 1 1 1 1 1 1 1 1 1 1 geotechnical studies performed in the project vicinity. Our research revealed exploration logs from the following studies: • "Subsurface Exploration, Geologic Hazards, and Preliminary Geotechnical Engineering Report, Aldridge Short Plat, Edmonds, Washington," dated October, 24, 1997 by AESI (from AESI in-house files). This study included the two lots directly across 75'. Place West from the project site (15604 75`' Place West). Three exploration borings and four exploration pits were performed at the Aldridge site, which generally encountered fill over disturbed silts/clays over very dense fine sands. Slope inclinometers were installed in two of the borings and were measured periodically over a period of approximately 3 years. Measurements indicated shallow, downslope creep of the fill in the upper 10 feet on the order of 1 inch or less over the measurement period, with the majority of the movement occurring near the top of an uncontrolled fill slope on the west side of the property. The site has remained undeveloped at the time of this letter. • "Revised Geotechnical Report, Proposed Residence at Lots 1 and 2, 75`'' Place West, Edmonds, Washington," dated January 26, 1994 by Shannon and Wilson, Inc. (GeomapNW excerpts only). This study included two lots across 75'h Place West to the southwest of the project site (15620 751h Place West). One exploration boring was performed at the site and two exploration pits by Earth Sciences were included in the report, which generally encountered fill/slide debris over stiff to hard silts/clays. (According to Snohomish County tax records, a two-story dwelling was constructed in 1997). • "Geotechnical Engineering Study, Recent Landslide, 15620 - 72Id Avenue West, Edmonds, Washington," dated February 24, 1997 by Geotech. Consultants, Inc. (GeomapNW excerpts only). This study included the lot upslope (east) and one property south of the project site. Three exploration borings were performed at the site, which generally encountered dense, gravelly sands over medium dense to dense, silty sands over very dense sands. • "Subsurface Exploration, Geologic Hazards, and Preliminary Geotechnical Engineering Report, Summers Residential Property, Edmonds, Washington," dated December 31, 1991 by AESI (from AESI in-house files). This study included a lot upslope from the northeast corner of the project site (7222 72" Avenue West). Three exploration borings were performed at the Summers site, which encountered very dense lodgement till and advance. sands in one boring. • "Geotechnical Evaluation, Proposed Hansen Residence Addition Project, 15615-75`' Place. West, Edmonds, Washington;" dated June 1, .1999 by .Dennis M. Bruce, ' P.E. (from AESI in-house files). This study included the adjacent lot immediately north of the project site. Two test holes were dug on the property using a power hand auger, which generally encountered moderately dense to dense, clean sand over very dense silt . and silty sand with cobbles. 5 ' • "Report Geologic Evaluation, Meadowdale Area Edmonds Washington," " dated epo t of Geo og c o g , September 23, 1968 by Dames & Moore (provided by the City of Edmonds). This study evaluated the overall stability of the area from a geologic standpoint based largely on literature review and surface reconnaissance for installation of a proposed sanitary sewer system. • "Final Report, Landslide Hazards Investigation, Meadowdale Area, Edmonds, ' Washington," dated October 16, 1979 by Roger Lowe Associates, Inc. (provided by the City of Edmonds). This study analyzed the subsurface conditions and slope stability based on previous studies and seven borings performed for the study. The study ' provided a landside hazard map of the Meadowdale area, which quantified landslide risk by type and probability of occurrence in a 25-year period. • "Report of Geotechnical Consultation, Property Value Appraisals and Assessments, Meadowdale Landslide Area, Edmonds, Washington," dated February 28, 1985 by GeoEngineers, Inc. (provided by the City of Edmonds). This study updated the ' probability of landslide occurrences as provided in the 1979 Lowe study after installation of storm and sanitary sewers in the Meadowdale area. • "North Edmonds Earth Subsidence and Landslide Hazard Area Summary Report, Edmonds, Washington" dated March 14, 2007 by Landau Associates. This study ' included review of the previous Meadowdale landslide area studies by Lowe and GeoEngineers.. Landau also recommended several revisions to critical areas ordinance in earth subsidence and landslide hazard areas, including the designation of five hazard ' zones based on relative location within the landslide complex. Furthermore, the study recommends specific report requirements, which will be discussed subsequently in this letter.. This study uses the name "North Edmonds Earth Subsidence and Landslide Hazard Area" (NEESLHA) instead of the previous "Meadowdale" area name. 1 Our literature review was not meant to be all inclusive, as other studies in the project vicinity may exist but were not available for our review. Pertinent information from these studies is discussed in subsequent sections of this letter, where appropriate. Relevant logs for the above - referenced explorations have been included in the Appendix of this letter. Soil Conditions 1 Subsurface conditions on the project site were inferred from the field explorations accomplished. for this study, visual reconnaissance of . the site, and review of applicable geologic/geotechnical literature. As shown on the field logs, the explorations on the project site generally, encountered silty sand with various gravel fill over. sandy silt to silty sand soils interpreted to be old landslide material. The following section presents more detailed subsurface information organized from the upper (youngest) . to the lower (oldest) sediment types. 6 1 I it 1 Material interpreted to be man -placed fill was encountered in all the explorations on the project site. The fill consisted chiefly of medium dense, silty sand with various gravel, concrete debris, cinders, asphalt debris, and landscaping rocks. n1A T nnAc1; ,- Material interpreted to be old landslide soils were encountered in all the explorations on the project site. The old landslide soils consisted chiefly of medium stiff to stiff, fine sandy silt and medium dense, silty fine sand with a disturbed, blocky texture. Exploration boring HA-1 encountered an approximately 41t2-foot layer of fine to, medium sand within the interpreted old landslide deposit.Explorations from the other studies in the project vicinity listed above indicate similar landslide materials that extend well below existing grades in the project area on the order of 30 to 60 feet below existing grades. The soil conditions encountered in our explorations were consistent with the soils mapped in the Preliminary Surficial Geologic Map of the Edmonds East and Edmonds West Quadrangles, Snohomish and King Counties, Washington (Smith, 1975). The geologic map indicates that the site is, characterized by Qols . (old landslides) on the southwest portion of the site. The northeast portion of the site appears to be mapped as Qw (Whidbey formation), although no explorations were performed there to confirm this. The maps also indicate Qdb (Double Bluff) and Qe (Esperance sand) in the project vicinity. Ground Water Conditions No seepages or ground water were observed within our explorations. In addition, no seepages were observed daylighting on any of the steep slopes on the property during our exploration and subsequent site visits for construction monitoring and erosion control. Based on the exploration logs reviewed for this study, ' we estimate that the highest water level near the subject site may be approximately at elevation 80. This estimate is based on ground water encountered in the Shannon and Wilson boring attached to this letter. Based on the "moist" moisture contents described below the seepage zone encountered at a depth of 18 feet, this seepage may be indicative of perched. ground water above less permeable sediments. Ground water conditions wshould be expected to fluctuate with season, precipitation, site usage, and other on- and off -site factors. The following discussion of potential geologic hazards is, based on the geologic, slope, and shallow ground water conditions.as observed and discussed herein. 7 Landslide Hazards and Mitigation ' The 2007 Landau study divides the potential landsliding locations within the NEESLHA into five zones, A through E. The subject site is located in Zones B and C, with the proposed house located in Zone B only. Zone B in the vicinity of the subject site is the relatively flat bench area between 75' Avenue West and the steep slope area of Zone C to the east. Zone B is described by Landau as including the majority of the landslide mass or complex consisting of ' typically disturbed soils with occasional intact blocks, localized small-scale failures, and potential for large-scale sliding of the slide .complex. Zone C is described by Landau as the area near the edge of the landslide complex that is most affected by slides that initiate on the steep slopes on the east side of this zone. Small-scale failures are possible within Zone C, and this zone is the highest risk to public safety. In our opinion, we concur with these generalized ' assessments and believe the primary risks of earth movement on the subject site that may affect the proposed dwelling will be from debris flows initiating on the steep slopes above the house. Another risk with a much lower likelihood of occurrence would be soil movement under the proposed foundation from reactivation of the main landslide mass. Risks of shallow and deep- seated slides, and the associated mitigations, are discussed further in the following paragraphs. The potential landside risk can be divided into two depth categories: shallow and deep. The potential shallow (on the order of 1 to 10 feet thick) landslide risk includes slumps, debris avalanches, and earth flows of the colluvial soils and trees on the steep slopes to the east of the project site. The potential deep landslide risks for the site have been identified by previous studies in the site vicinity as continued movement of the ancient landslide blocks. The potential for shallow slides is moderate and will be greatest after extended periods of heavy rainfall and/or snow events. Such weather events occurred during the winters of 1996 and 1997 and resulted in numerous shallow slides in the Meadowdale area and around Puget 1 Sound. Mitigation for such slides include proper handling and discharge of surface storm water, reduction in ground water levels, and trimming or removal of large trees in the potential slide zone. We understand that since the 1996 and 1997 events, City improvements to surface water management of the right of -ways above the slope to the east have been implemented, including installation of street drainage berms, catch basins, and prevention of storm water 1 discharges onto. or near the slope. These improvements will reduce the potential for saturation of the colluvial soils and the contribution from upgradient surface water infiltration to ground water levels and seepages. The large deciduous trees directly upslope from the proposed project area appear to have been trimmed and topped some time in the past, reducing the potential for direct fall damage. The proposed structure will be set back from the toe of the slope approximately 25 to 35 feet, which should provide suitable distance for the dissipation of ' minor, shallow slides/masses. The moderate risk of earth and debris flow damaging the dwelling was present for. the previous structure and will not be increased by the re- construction. However, additional debris -flow mitigation is recommended by extending the ' basement foundation wall 3 feet above the outside finish ground surface to create a catchment wall. Extension of the foundation wall would allow for debris -flow material to impact the back of the residence without buckling wood framing and damaging the structure. 1 1 8 _' i Deep seated landslides risks at the project site would most likely be related to reactivation o the ancient landslide blocks estimated to have occurred thousands of years ago after the retreat of glacial ice and subsequent draining of glacial lakes. The large-scale lowering of regional ground water levels and continued erosion of the toe of the slopes by wave action resulted in ' unstable, oversteepened coastal bluff conditions. Mitigations for. deep-seated slides at coastal bluffs include armoring of the base of the bluff toprevent wave erosion. The riprap embankment placed during the construction of the Burlington Northern Railroad tracks has ' provided protection from wave -action erosion. To our knowledge, no evidence of recent movement of the deep-seated slide planes has since been documented. The 1980s drainage improvements in the 75' Place West right-of-way and 1990s drainage improvements at the top ' of the steep slope have also reduced the potential for reactivation of the deep-seated slide planes. Mitigations for deep-seated landslides should include design and construction of a relatively rigid, grid -type shallow foundation system designed to mitigate differential foundation soil displacement. The primary purpose of the rigid grid foundation will be to create a monolithic foundation unit, which will be able to bridge potential, localized areas of settlement or resist soil creep movement. Specific foundation recommendations are discussed in the "Foundations" section of this letter. ' It. should be noted that no amount of engineering and mitigation measures can eliminate the potential for earth movement. Some risks will always remain inherent for properties located on or adjacent to steep slopes. Seismic Hazards and Mitigations Earthquakes occur in the Puget Lowland with great regularity. The vast majority of these events are small and are usually not felt by people. However, large earthquakes do occur as evidenced by the 1949, 7.2-magnitude event; the 2001, 6.8-magnitude event; and the 1965, ' 6.5-magnitude event. The 1949 earthquake appears to have been the largest in this region during recorded history and was centered in the Olympia area. Evaluation of earthquake return rates indicates that an earthquake of the magnitude between 5.5 and 6.0 is likely every 25 to 40 years in the Puget Sound basin. 1 Generally, there are four types of potential geologic hazards associated with large seismic events: 1) surficial ground rupture; 2) seismically induced landslides; 3) liquefaction; and 4) .ground motion. The potential for each of these hazards to adversely impact the proposed project is discussed below. Surficial Ground Rupture ' The nearest known fault trace to the project is the South Whidbey Island -Lake Alice Fault. Recent studies by the U.S. Geological Survey (USGS) suggest that a trace of the northwest - southeast trending thrust fault zone may project through the North Edmonds area. The recognition of this fault is relatively new, and data pertaining, to it are limited with the studies still ongoing. According to the USGS studies, the recurrence interval of movement along this fault system is still unknown, although it is hypothesized to be in excess of several thousand .9 years. Due to the suspected long recurrence interval, the potential for surficial ground rupture at the subject property is considered to be low to moderate during the expected life of the structure with associated seismically induced ground displacements also contributing to the surface rupture. Mitigations for ground rupture and/or displacements should include design and construction of a relatively rigid, grid -type shallow foundation system, as described above and discussed in the "Foundations" section of this letter. Seismically Induced Landslides The project site is located in the North Edmonds Earth Subsidence and Landslide Hazard Area, of which the risks of landslides have been discussed most recently in the 2007 Landau report and are discussed above. In our opinion, the risks associated with the above -described hazards are low to moderate under static conditions. Ground accelerations associated with a strong earthquake may reactivate movement along the old slide planes and result in a higher potential for landslides and ground displacements. This risk was present for the previous structure under which the project was originally permitted as a remodel. The .current proposed structure will be in the same approximate footprint and the seismic landslide, risk will not be increased by 'the proposed re -construction. We recommend mitigating damage to the proposed improvements' by design and construction of a relatively rigid, grid -type, shallow foundation ' system as described in the "Foundations" section of this letter. The resulting foundation system will serve primarily to mitigate damage to the structure during differential ground displacements. Liquefaction • Liquefaction is a condition where loose, saturated, sandy soils lose strength when subjected to high intensity, cyclic loads of very short duration, such as occur during earthquakes, pile ' driving, and blasting. The resulting loss 'in bearing strength can cause differential foundation settlements and slope failures. Loose, saturated, clean, fine-grained sands, which cannot I 1 dissipate the buildup of pore water pressure, are the predominant type of sediments subject to liquefaction. Based on our review of our explorations and our literature review of other explorations in the project vicinity, it is our opinion that the potential for liquefaction is low due to the high fines content and/or high relative density of the soils encountered. Ground Motion The guidelines presented in the 2006 International Building Code (IBC) Section 1613 should be used in.the seismic. design of the project. The USGS Earthquake Hazards Program web site (http://6arthquake.usgs.gov/hazmaps/) was used to determine interpolated probabilistic ground motion values in percent of gravity (g) for an event with a return period of 2 percent exceedance in 50 years. Using the web site, the project area was submitted using latitude and longitude for mapped spectral accelerations of Ss = 1.24 for short periods (0.2 seconds) and S i 0.44 for a 1-second period. Based on the results of our subsurface exploration and literature review., and our . estimation of soil properties at depth utilizing available geologic data, Site Class "D" in conformance with Table 1613.5.2 of the IBC may be used. These. values 10 'coefficientsF = 1. and F, = 1.56 in conformance with IBC Tables correspond to site a 0 1613.5.3(1) and 1613.5.3(2), respectively. 1 ' CONCLUSIONS AND RECOMMENDATIONS Prior to demolition of the previous dwelling, the project site was developed with an occupied ' single-family residence within the North Edmonds Earth Subsidence and Landslide Hazard Area. Therefore, the risks described above were already present for the existing structure. It is our understanding that the owner fully understands and accepts the risks of the landslide ' hazards as discussed in this letter. We also understand that potential future owners will be aware of the risks associated with owning property in the North Edmonds Earth Subsidence and Landslide Hazard Area because such a notice is required on the property title. 1 The purpose of our study was to assess these risks based on current, site -specific, s ope and ' soil conditions and provide recommendations for minimizing and mitigating adverse impacts to the slope by the proposed improvements. Since the project chiefly involves replacing the structure in the same approximate footprint, it is our opinion that the overall impact to the ' stability of the slope will not be adversely affected provided our recommendations are followed. Furthermore, the improvements will result in a safer structure since the improvements, will be constructed on a relatively rigid foundation system and built to current building codes and replace the CMU block foundation under the south half of the residence. The following sections present our recommendations for design and construction of the proposed improvements. Temporary Excavation Slopes We anticipate that temporary cut slopes may be necessary for overexcavation in footing areas and for installation of buried utilities. In our opinion, stable construction slopes should be the responsibility of the contractor and should be determined during construction. For estimating. tpurposes, however, we anticipate that temporary, unsupported cut slopes over 4 feet can be made at a maximum slope of 1.5H:1V in the site soils. Typical trench -box shoring for ' excavations deeper than 4 feet should be considered for safety of workers and to minimize site disturbance. As is typical with earthwork operations, some sloughing and raveling. may occur and cut slopes may have to be adjusted in the field. In addition, WISHA/OSHA regulations should be followed at all times. Structural Fill ur 1 r provide suitable footing and slab -on -grade a fill. will be necessary to prov d s abl foo ng s ab on -grade floor subgrades and for backfill of utility trenches.. Significant thicknesses of additional fill on the site are not anticipated nor recommended. All references to structural fill in this letter refer to subgrade preparation, fill type, placement, and compaction of materials as. discussed in this section. If a percentage of compaction is specified under another section of this letter, the value given in ' that section should be used. 11 [1 I fl After stripping, planned excavation, and any required overexcavation has been performed to the satisfaction of the geotechnical engineer or his representative, the upper 12 inches of exposed ground should be compacted to a firm and unyielding condition, as determined by the geotechnical engineer or his representative. If the subgrade contains too much moisture, adequate compaction may be difficult or impossible to obtain and should probably not be attempted. In lieu of compaction, the area to receive fill should be blanketed with clean, coarse, crushed rock or quarry spalls to act as a capillary break between the new fill and the wet subgrade. Where the exposed ground remains soft and further overexcavation is impractical, placement of an engineering stabilization fabric may also be necessary to prevent contamination of the free -draining layer by silt migration from below. After compaction of the exposed ground is tested and approved, or a free -draining rock course is laid, structural fill may be placed to attain desired grades. Structural fill is defined as non - organic soil, acceptable to the geotechnical engineer, placed in maximum 8-inch loose lifts with each lift being compacted to at least 95 percent of ASTM:D 1557. In the case of roadway and utility trench filling in the City right-of-way, the backfill should also be placed and compacted in accordance with City codes and standards. The contractor should note that any proposed fill soils must be evaluated by AESI prior to their use. This would require that we have a sample of the material at least 72 hours in advance to either perform a Proctor test .and/or determine its field suitability. Soils in which the amount of fine-grained material (smaller than the No. 200 sieve) is greater than approximately 5 percent (measured on the minus No. 4 sieve size) should be considered moisture -sensitive. Use of moisture -sensitive. soil in structural fills should be limited to favorable dry weather and dry subgrade conditions. The on -site soils contained substantial amounts of silt and are considered highly moisture -sensitive when excavated and used as fill materials. At the time of our exploration program, soil moisture contents were at or above optimum for structural fill use. We anticipate that the some of the excavated site soils may require aeration and drying prior to compaction in structural fill applications. Construction equipment traversing the site when the soils are wet can cause considerable disturbance. If fill is placed during wet weather or if proper compaction cannot be obtained, a select, import material consisting of a clean, free -draining gravel and/or sand should be used. Free -draining fill consists of non -organic soil with the amount of fine-grained material limited to 5 percent by weight when measured on the minus No. 4 sieve fraction and at least 25 percent retained on the No. 4 sieve. Foundations We understand that the new foundations will remain within the approximate footprint of the previous house and deck. With proper design, subgrade preparation, embedment, and construction, it is our opinion that the proposed foundations will not decrease the stability of the .existing slopes provided the recommendations of this letter are followed. 11 12 f the existing basement level were likely The observed foundation settlements on the west side o g y due to inadequate footing size, and poor subgrade preparation and construction on uncontrolled fill. We have discussed with the owner, the option of supporting the improvements on deep foundations to mitigate potential excessive settlements due to the presence of the uncontrolled fill and possible continued movement of the old landslide materials. Based on the expected 30- ' to 60-foot depth of old landslide materials on the project site, we anticipate that deep foundations would only provide vertical support and could not practicably be constructed to ' resist the lateral displacements should the old, deep-seated landslide block become active. We understand that the owner wishes to use spread footings for foundation support and has accepted the risk that even static, post -construction settlements may result in drywall cracks, tilting of window/door jambs, and other largely cosmetic damages may occur. Due to the presence of uncontrolled fill and variations in old landslide soils present at the ' anticipated bottom of footing elevations, we recommend that ,all new footings bear on a minimum, 2-foot-thick layer of structural fill. The width of the structural fill pad should be 2 ' feet wider than the width of the footing. Structural fill type, placement, and compaction recommendations are provided in the "Structural Fill" section of this letter. The existing fill soils must be removed under new foundations or overexcavated and recompacted as structural fill if moisture conditions allow. All organics, debris, and soft/loosened soil must be removed from the footing areas prior . to placement of structural fill, and be confirmed by a representative from AESI. During wet weather, it is highly recommended that footing subgrades be protected from disturbance with several inches of compacted crushed rock. Continuous and column pad spread footings may be used for building support when founded on the approved 27foot-thick layer of structural fill discussed above. Column pad footings should be structurally tied together in two directions in a grid -type formation to mitigate excessive ground displacements. The foundation system should be designed to span a loss of support of 10 feet. The owner should be aware that the primary purpose of tying together foundation elements is to prevent mitigate or lessen damage to the structure due to potential soil displacements, as discussed previously. We recommend that a maximum allowable foundation soil bearing pressure of 2,000 pounds per square foot (psf) be utilized for design purposes, including both dead and live loads, for footing subgrades prepared as described herein. An increase of one-third may be used for short-term wind or seismic loading. It should be noted that the area bounded by lines extending downward at 1H:1V from any footing must not intersect another footing. In addition, a 1.5H:1V line extending down from any footing must not daylight because sloughing or raveling may eventually undermine the footing. Thus, footings should not be placed near the edge of steps or cuts in the bearing soils unless adequately embedded. Anticipated settlement of footings founded on approved structural fill as described above ' should be approximately l inch or less. Disturbed soil not removed from footing excavations prior to footing placement could result in'increased settlements. All footing areas should be inspected by AESI prior to placing concrete to verify that the design bearing capacity of the ' soil has been. attained and that construction conforms to the recommendations contained.in this 13 1 1 1 1 1 letter. Such inspections may be required by the City. Perimeter footing drains should be provided as discussed under the section on "Drainage Considerations." Lateral Earth Pressures All backfill behind walls or around foundation units should be placed as per our recommendations for structural fill and as described in this section of the letter. Horizontally backfilled walls, which are free to yield laterally at least 0.1 percent of their height, may be designed using an equivalent fluid density equal to 35 pounds per. cubic foot (pcf). Fully restrained, horizontally backfilled, rigid walls that cannot yield should be designed for an equivalent fluid density of 55 pcf. A surcharge equivalent to 2 feet of soil should be added to the wall height for walls with adjacent parking or driveway areas. Surcharges due to sloping backfill or adjacent foundations should be included in the wall design. Due to the potential for landslide debris soils to rest against the back foundation stem wall, this wall should be designed to resist at least 3 feet of soil pressure above the outside finish ground elevation. The lateral pressures presented above are based on the conditions of a uniform backfill consisting of structural fill compacted to 90 to 92 percent of ASTM:D 1557. A higher degree of compaction is not recommended as this will increase the pressure acting on the walls. A lower degree of compaction may result in settlement. Thus, the compaction level is critical and should be tested by our firm during placement. In addition, only hand -operated or walk - behind compaction equipment should be used within 5 feet of the walls to prevent excessive surcharge loads from heavy equipment. Perimeter footing drains should be provided for all retaining walls as discussed under the section on "Drainage Considerations." It is imperative that proper drainage be provided so that hydrostatic pressures do not develop against the walls. This would involve installation of a minimum, 1-foot wide blanket drain for the full wall height using imported, washed gravel against the walls. The blanket drain and wall backfill should be capped with 12 inches of relatively impermeable soils and sloped to drain away from the walls to prevent surface water intrusion directly into the drain system. Passive Resistance and Friction Factors Lateral loads can be resisted by friction between the foundations and the supporting structural fill soils, and/or by passive earth pressure acting on the buried portions of the foundations. The foundations must be backfilled with compacted structural fill to achieve the passive resistance provided below.. We recommend the following design parameters. • Passive equivalent fluid .= 250 pcf • Coefficient of friction = 0.30 The above values are allowable and include a factor of safety of at least 2.0. 14 L u H L� Slab -On -Grade Floors Typical concrete slab -on -grade floors appear feasible when supported on a minimum, 12-inch thick layer of approved structural fill compacted to a firm and unyielding condition. Above the 12 inches of structural fill, we recommend 4 inches of washed pea gravel or approximately 5/8-inch clean crushed rock (no fines) to act as a capillary break. A plastic vapor retarder of minimum 10-mil thickness should be placed directly over the capillary break. Construction of crawl spaces should also include covering the soil below the floor system with a plastic vapor retarder to reduce interior dampness:. The contractor must take care to protect. the plastic vapor barriers from punctures during construction. More stringent moisture protection details. should be considered by the owner and architect if necessary to protect interior finishes. Drainage Considerations To facilitate drainage away from foundation elements, perimeter footings should be provided with a drain near the footing elevation. Drains. should consist of 4-inch-diameter, rigid, perforated, polyvinyl chloride (PVC) pipe surrounded by at least 6 inches of washed drain gravel. The minimum diameter of the drain rock must be larger than the diameter of the perforations in the pipe.. The level of the perforations in the pipe should be set approximately 2 inches below the bottom of the footing (perforations down) and the drains should be constructed with sufficient gradient to allow gravity flow away from the building to a suitable discharge. Cleanouts should be installed at appropriate intervals. Roof and surface runoff should not discharge into the footing drain system, but should be handled by a separate, rigid, tightline drain. Exterior grades, adjacent to walls, should be sloped downward away from the structure to achieve positive surface drainage. All collected water should be directed to an engineered storm drain - system that drains away. from the buildings, and not near, over, or onto steep slopes. Utility Connections Due to the potential for differential. soil displacements at the project site, we recommend flexible connections between all utilities and the residence. The connections should allow up to 6 inches of ground movement. 15 1 1 1 1 1 1 1 1 1 1 1 CII.YII We appreciate the opportunity to be of service to you on this project. Should you have any questions regarding.this letter or other aspects of the project,.please do not hesitate to call. We look forward to providing continued geotechnical services as the project progresses. Sincerely, ASSOCIATED EARTH SCIENCES, INC. Kirkland, Washington Eric J. Lim, P Senior Project Attachments: Figure 1: Vicinity Map Figure 2: Site and Exploration Plan Appendix: Exploration Logs cc: Hanson Design Attn: Kristin Hanson 652 Alder Street Edmonds, Washington 98020 Custom Design and Engineering Attn: Alex Moroseos, P.E. 11006 60`' Avenue West Mukilteo, Washington 98275 Donna L. Breske, P.E. 6621 Foster Slough Road Snohomish, Washington 98290 Construction Specialties, LLC Attn: Milynn Wetzel 7209 193' Place SW Lynnwood, Washington 98036 EJUts - KE050550BI - Projects\20050550\KE\WP 16 I /II /Zen$ 33222 ISTB� EXPIRES 2/27 Zc,, G. Aaron McMichael, P.E., P.E.G. Associate Engineer BOSSO903M 'ON TOad - N�30N 804 31` O QIISSMIaViIWa3 dVW AJJNI3IA •auj'saouams viva pair!DossV t 3anou '�NI'Sa33NIJN3O3J�a�uaia}aa 3 VOS ON H 1 C 1 11 1 ' LEGEND ❑ APPROXIMATE LOCATION OF ES EARTH SCIENCES EXPLORATION.PIT (EP) OR TEST PIT (TP) GC GEOTECH CONSULTANTS, INC. N W O APPROXIMATE LOCATION OF SW SHANNON AND WILSON EXPLORATION BORING (EB)(B), m HAND AUGER (HA) OR TEST DB DENNIS BRUCE HOLE (TH) NO SCALE o Reference: Snohomish County Online Property Information d Associated Earth Sciences, Inc. SITE AND EXPLORATION PLAN FIGURE 2 RAY RESIDENCE EDMO DS, WASHINGTON DATE 1/08 PROJ. NO. KE050550B ° o ° Well -graded gravel and Terms Describing Relative Density and Consistency u_ - o° o" o 0 0 Gw 9 ravel with sand, little to Density SPTt�bfows/foot ty • 0 no fines Very Loose 0 to 4 °, i4 CD Coarse - Loose 4 to 10 ° ° ar > O_N � u>°°°°o ° ° ° ° ° Poorly -graded gravel Grained Soils Medium Dense 1 o to 30 Test Symbols ° U In w o ° ° ° ° ° GP and ravel with sand, g Dense 30 to 50 o ° 6 ° ° 0 0 000 little to no fines Very Dense > 50 G =Grain Size o Z ° ° 00000 (�1 M =Moisture Content 6 o q Consistency SPT blows/foot A = Atterberg Limits 0 D z c v . . Silty gravel and silty Very Soft 0 to 2 C = Chemical o y �y GM gravel with sand Fine- Soft 2 to 4 DID = Dry Density ° ° 0 . 0 Grained Soils Medium Stiff 4 to 8 K = Permeability tY IeStiff 8 to 15 tp Clayey gravel and Very Stiff 15 to 30 w GC clayey gravel with sand Hard. >30 Component Definitions o m Descriptive Term Size Range and Sieve Number Well -graded sand and swi sand with gravel, little Boulders Larger than 12" to no fines Cobbles 3' to 12" tiC CDiz ••,•••.•.• ' Gravel 3' to No. 4 (4.75 mm) ' :' :' Poorly -graded sand > Coarse Gravel 3' to 3/4' r°n 0.4) VU '`. '• SP and sand with gravel, Fine Gravel 3/4" to No. 4 (4.75 mm) o little to no fines Sand No. 4 (4.75 mm) to No. 200 (0.075 mm) c 0 z Z. Coarse Sand No. 4 (4.75 mm) to No. 10 (2.00 mm) Silty sand and Medium Sand No. 10 (2.00 mm) to No. 40 (0.425 mm) !2° y .: SM silty sand with Fine Sand No. 40 (0.425 mm) to No. 200 (0.075 mm) m U cc o a c gravel Silt and Clay Smaller than No. 200 (0.075 mm) U9 LL y ' Clayey sand and (3) Estimated Percentage Moisture Content sc clayey sand with gravel Percentage by Dry - Absence of moisture, coAll• Component Weight dusty, dry to the touch e Slightly Moist - Perceptible Silt, sand silt, ravel) silt, y gravelly Few 5 to 10 moisture > ML silt with sand or gravel Little 15 to 25 Moist - Damp but no visible U N m With - Non -primary coarse water 0o ca y constituents: > 15% Very Moist - Water visible but — Clay of low to medium N d H cL plasticity; silty, sandy, Or - Fines content between not free draining Z @ = gravelly clay, lean Clay 5°k and 15°�6 Wet - Visible free water, usually a — Organic clay or silt of low Symbols Blows/6" ' a s cr S iD _— OL plasticity or 0 _ Sampler portion of 6" Cement grout Type / surface seal ' Elastic silt, clayey silt, silt with micaceous or 2 0" OD „ Sampler Type ° Description A4) Bentonle o MH Split -Spoon 20 seal � ar o diatomaceous fine sand or Sampler 3.0' OD Split -Spoon Sampler. Filter pack with m ' o a moo silt (SPT) 3.25' OD Split Spoon Ring Sampler lit Bulk - : ;; blankcasing 9 section Clay of high plasticity, N CH sandy or gravelly clay, fat sample p 3.0" OD Thin -Wall Tube Sampler = Screened casing ° m E clay with sand or gravel (including Shelby tube) wHfter p i fi :wpack with filler T 'C? c 2-' �cn :n 'o Grab Sample o Portion not recovered End cap , Organic clay or silt of tL -' �i ��%i off medium to high lit (4) Percentage by dry weight Depth of ground water plasticity (z) (SPT) Standard Penetration Test 1 ATD = At time of drilling ' Peat, muck and other (ASTM D-1586) Q Static water level (date) (3) In General Accordance with ti (5) o, Co PT highlyorganic soils Standard Practice for Description Combined USCS symbols used for = O and Identification of Soils (ASTM D-2488) fines between 5% and 15% Classifications of soils in this report are based on visual field and/or laboratory observations, which include density/consistency, moisture condition, grain size, and plasticity estimates and should not be construed to imply field or laboratory testing unless presented herein. Visual -manual and/or laboratory classification D methods of ASTM D-2487 and D-2488 were used as an identification guide for the Unified Sol Classification System. 0 Associated Earth Sciences, Inc. EXPLORATION LOG. KEY FIGURE Al a L This log is part of the report prepared by Associated Earth Sciences, Inc. (AESI) for the named Project and should be read together with that report for complete interpretation. This summary applies only to the location of this trench at the W time of excavation. Subsurface conditions may change at this location with the passage of time. The data presented are o a simplfication of actual conditions encountered. DESCRIPTION Fill 2" of crushed rock over medium dense, moist, brown, SILTY SAND with gravel and scattered 1 concrete debris and cinders. 2 Old Landslide Stiff, moist, tan, blocky, SILT with little fine sand and scattered rootlets (DCP at 2' = 12, 8, 8). 3 _ _ _ _ _ Loose, damp to moist, gray, fine to medium SAND with trace silt (DCP at 5' = 6, 6, 7). 4 5 Becomes finer. 6 Becomes coarser with iron oxide stains. 7 8 ------------------------------------------------------ Medium stiff to stiff, wet, tan, fine sandy SILT to silty fine SAND with occasional lenses of clayey silt (DCP at 8' = 13, 10). 9 10 11 Bottom of exploration pit at depth 11 feet 12 No ground water seepage observed at time of exploration or 4 hours after exploration. No caving observed. 13 14 15 16 17 18 19 0 0 N O Ray Residence Re -Construction Edmonds, WA a C9 Associated Earth Sciences, Inc. Project No. KE050550A Logged by`. EJL '.. Approved by:V 8/13/05 Y 1 1 1 1 1 1 1 1 L This log is part of the report Prepared by Associated Earth Sciences, Inc. (AESI) for the named project and should be -. . read together with that report for complete interpretation, This summary applies only to the location of this trench at the m time of excavation. Subsurface conditions may change at this location with the passage of time. The data presented are 0 a simplfication of actualconditions encountered. DESCRIPTION Fill 1 Medium dense, moist, brown, GRAVELLY SILTY SAND with scattered concrete debris. 2 3 4 5 --------------------------------=-------------------- Landscape Rocks 6 1" diameter rounded _gravel .________________ __ ' ------------------� Relic Topsoil/Fill Loose, moist to wet, brown to dark brown, SILTY SAND with scattered asphalt pieces. 7 Old .Landslide Medium stiff to stiff, moist, tan, blocky, fine SANDY SILT (DCP at 8 1/2' = 10, 9). 8 9 Bottom of exploration pit at depth 8.5 feet No ground water or caving observed at time of exploration. 10 11 12 13 14 15 16 17 18 19 co 0 N O Ray Residence Re -Construction Edmonds, WA 'Associated Earth Sciences, Inc: Project No. KE050550A Logged by: EJL ' FGN Approved by:. � � .� '� • 8/13/05 Y LOG OF EXPLORATION PIT NO. HA-3 1 • w This log is part of the report prepared ly Associated Earth Sciences, Inc. (AESI) for the named pproject and should be read together with that report for complete interpretation. This summary applies only to the location of this trench at the time Subsurface may change at this location with the of time. The data are o of excavation. conditions passage presented a simplfication of actual conditions encountered. ' DESCRIPTION Fill Medium dense, moist, brown, silty SAND with few gravel and scattered concrete debris. Sewer pipe ' 1 in east sidewall (trench backfill). 2 3 Old Landslide '4 Medium stiff, moist, tan', FINE SANDY SILT to SILTY FINE SAND with scattered wood debris (DCP at 4 1/2' = 7, 7, 7). 5 6 (DCP at 6 1/2' = 10, 12, 12) ' 7 ' 8 Bottom of exploration pit at depth 7 feet No ground water or caving observed at time of exploration. 9 10 12 13 14 15 16. 17 18 19 CS z Ray .Residence Re -Construction Edmonds, WA o Associated Earth Sciences, Inc. o togged by: EJL Project,No. KE050550A �.,, .,.. Approved by: 8113/05 C� ���,,� ,`'.�a: ''�a� J Y ' LOG OF EXPLORATION PIT NO. HA-4 t 1. i 1 t This log is part of the report prepared by Associated Earth Sciences, Inc. (AESI) for the named project and should be read together with that report for complete interpretation. This summary applies only to the location of this trench at the time of excavation. Subsurface conditions may change at this location with the passage of time. The data presented are o a simplfication of actual conditions encountered. DESCRIPTION Fill Sod over medium dense, damp to moist, brown, SILTY SAND with few gravel. 1 2 3 4 Old Landslide 5 Medium dense, moist, tan, SILTY FINE SAND to FINE SANDY SILT, slightly blocky. 6 7 8 Bottom of exploration pit at depth 7 feet No ground water or caving observed at time of exploration. 9 10 11 12 13 14 15 16 17 18 19 20 0 Ray Residence Re -Construction Edmonds, WA o Associated Earth Sciences, Inc. Logged by: `EJt Project No. KE050550A 1 o Approved by � ;< �' � "�� 8/13/05 a y. 0 5 10 15 ' Number EP-2 0 Loose, moist, brown SAND AND GRAVEL mixed with silty clay/silt (Fill) 5 1 Stiff to very stiff, moist, bluish -gray, clayey SILT to silty CLAY. (Possession Drift) . 10 - 15 ' No no caving. BOH @ 18' Note: seepage; Subsurface conditions depicted represent our observation at the time and location of this exploratory hole, modified by geologic and judgment. They are not necessarily representative of other times and locations. we win not interpretation, engineering analysis, accept responsibility for the use or interpretation by others of information presented on this log. Reviewed By Associated Earth Sciences, Inc., Aldridge Short Plat , ' . 911 Fifth Avenue, Suite 100 Edmonds,. Washington Kirkland, Washington 98033 Project No. G97224A Phone: - 425-827-7701 September,1997 Fax: 425-827-5424 0 5 10 15 — Looselsoft, moist, dark brown, silty, fine SAND with roots. (Fill) Loose, moist, brown, medium SAND. (Fill) Loose, moist, reddish -brown, medium SAND with occasional gravel. (Fill) Stiff to very stiff, moist, bluish -gray, silty CLAY. (Possession Drift) BOH @ 18' Note: No seepage; caving. ' Number EP-4 15- � Loose, dry, dark brown, silty, fine SAND with occasional gravel, roots, chunks of asphalt. (Fill) Loose; damp, reddish -brown, medium SAND wtih occasional gravel. (Fill) Stiff to very stiff, moist, bluish -gray, silty CLAY; slickensided surfaces; upper 1' slide debris. (Possession Drift) BOH @ 16' Note: No seepage; caving 0 to 8'. 3 ' Subsurface conditions depicted represent our observation at the time and location of this exploratory hole, modified by geologic interpretation, engineering analysis. and judgment They are not necessarily representative of other times and locations. We will not I ccept responsibility for the use or interpretation by others of information presented on this log. Reviewed By..� Associated Earth Sciences, Inc. Aldridge Short Plat 911 Fifth Avenue, Suite 100. Edmonds, .Washington Kirkland Washington 98033 9 Phone: 425-827-7701 Project No. G97224ASeptember 1997 Fax::425-827-5424 . t 1 1 1 1 1 1 1 J STANDARD PENETRATION I.—. Z W RESISTANCE SEDIMENT DESCRIPTION 0-¢ 0 < Blows/Foot co 10 20 ao 40 Damp, light brown, silty, fine SAND with trace roots; 8A bottom of sample damp, light brown with gray SILT I with trace fine sand. 1 Damp, brown, silty, fine SAND with lenses of sift with 5 4 trace fine sand; tip of sample damp, reddish -brown . SAND with some small gravel. Damp, reddish -brown SAND with trace ravel.. g I 5 No recovery. (Fill) 10 4� ------- ---•-?.......-.-......�.-----•--•---......:A...........-•---••..--?.....................??............ Moist to wet, light brown, silty, fine SAND; top of sample T 8� black charcoal with fine sandy silt. 1 Moist, brown, silty, fine SAND: tiny roots observed. 15 I 6♦ Damp to moist, blue, silty CLAY, plastic. 1 A CLAY, laminated. 20 : I : 2 I � Moist, blue, silty I. Moist, blue, silty CLAY to clayey SILT. I Moist, blue, silty CLAY to clayey SILT 25 T I1 - 22 Moist, blue, silty CLAY to clayey SILT. T 18A Moist, blue, silty CLAY to clayey SILT with lenses of 30 T I - 22I1 fine, oxidized sand; slickensided surfaces observed. (Possession Drift) ---.... Damp to moist, light brown, silty, fine SAND, upper 70 portion oxidized. (Double Bluff Drift) , Subsurfacondom depicted represent our observations at the tone, and bcation of thla erptoratory hole. nrodCled try geobgie ce Interpratatlorrs, engtnee*V anaiysle, and Judgment They are riot necessarily representatbe of other *nes and bcatlorrs. We wW not ' accept rmponsibW (wto use or kftrMtatlon by others of Informalon presented on tMs log. Reviewed By Associated Earth Sciences, Inc. AldridgeShortPlat. ' 911 Fifth Avenue;.Suite 100 Edmonds, Washington Kirkland, .Washington 98033, Project. No. G97224A.. Phone: 425-827-7701 September 1997. ' Fax: 425-827-5424 � EXPLORATION BORING LOG Number EB-1 Page 2 of 2 STANDARD PENETRATION E.- Z w RESISTANCE. SEDIMENT DESCRIPTION o n a Wws/Foot 0 3. 10 20 30 40 48A (Double Bluff Drift) BOH @ 36-1/2' Note: Slope inclinometer installed. 40 .I 45 50 55 60 I 65 _ —t— --d laatlar cf this e=bratory hole. modMed by 9e0i0910 Subsurface conditlrns 0eP►cm " Pre' of other *nes and bcaflm& We wiz not interpretations. engineering analysts. and judgment They are not necessa* repre�ia0m for the use or Interpretation by others of information Presented onaccept responsibioty We log. Reviewed By 1 Associated Earth Sciences, Inca Aldridge Short Plat . ' 911 Fifth Avenue, Suite 100 Edmonds, Washington Kirkland, Washington. 98033. Project No. G97224A. Phone: 425-827-7701 September 1997 '. Fax 425-827-5424 a: i I EXPLORATION BORING LOG Number EB-2 Page 1 of 2 16A 20 � 4 h, 11 ' Subsurface 000ditlons deplded represent our observations at the time and location of this exploratory dl8 hole, moed by geologic grt,p,e fayo,re, errghr Wit arr 14SIS, and Judgment. They are not neoessarfly representatNe of other times and locations. We wM not - accept responsbW for the use or Interpretation by others of Information presented on this tog. Reviewed By 1 Associated Earth Sciences, Inc.. Aldridge Short Plat 911 Fifth Avenue, Suite 100 Edmonds, Washington ' Kirkland Washington 98033 Project No. G97224A. . Phone:' 425-827-7701 September.1997 Fax: 425-827-5424 �y. 1 EXPLORATION BORING LOG Number E13-2 PaaQe 2 of 2 SEDIMENT DESCRIPTION w 0 LLJ CL Z W g O - N w� 0. STANDARD PENETRATION RESISTANCE Blows/Foot 10 20 30 40 (Double Bluff Drift) _ 62 BOH @ 36-1/2' 40 45 50 I I 55 60 65 I Subsurface conditions depicted represent our observations at the time and location of this exploratory hole, modified by geologic interprgtatiorm, engineering anayals, and judgment They are not necessafr representative of other tines and locations. We wig not .. accept responslb" for the use or Inl erpretatbn by others of Information presented on this log. Reviewed By Associated Earth Sciences, Inc. Aldridge Short Plat ' 911 Fifth Avenue, Suite 100 Edmonds, Washington Kirkland, Washington 98033 Project No. G97224A Phone: 425-827-7701 Fax: 425-827-5424 September 1997 11 1 1 1 EXPLORATION BORING LOG Number F6-3 Paae 1 of 2 STANDARD PENETRATION _ a Z W RESISTANCE . SEDIMENT DESCRIPTION o Q � � s1owslF00f . CO 0 10. 20 30 40 Moist, orangish-brown, silty SAND. (Fill) I 5 Moist, gray, clayey SILT (Slide Debris) 5 T 7- Moist, gray, silty CLAY to clayey SILT- IA 12 Moist, bluish -gray, silty CLAY with moist, brown, fine 10 T 1 • 14 sand lenses 4 thick in middle of sample. Moist, bluish -gray, silty CLAY; fine sand lense in T 15 A middle of sample. 1 Moist, bluish -gray CLAY; 6" thick lense of peat with silt: 15 I 28 siickenside surfaces. (Possession Drift) 1 -----------..................... ..._... -.......... ........................................................... 34 Damp, light brown, fine SAND. I A Damp, light brown, fine SAND; very fine sand to silt lense 20 30 in middle of sample. Damp, light brown to gray, fine to medium SAND. I 57 Damp, light brown, fine SAND; moist, brown, fine SAND 25 I 69 in bottom of sample. Moist, brown, fine SAND. I 81 Moist, brown, fine SAND. 30 I 71 fine SAND.. I 82 Moist,. brown, A A Subsurface condltlons depicted represent our observations at the time and beatlon of thls.e�bratory hole Modified by geologic . Interpretations, enpineerin9 N .and judgment They are rwt necessarily necessarily of other ftes and bead.ons. We wM not accept resporrsb ft for the use or Intetpretatlon by others of Information presorted an 11" log. Reviewed By Associated Earth Sciences, Inc_ Aldridge Short Plat 911 Fifth Avenue, Suite 100 Edmonds, Washington Kirkland, Washington 98033 Project No: G97224A �. Phone: 425-827-7701 September 1997. fax:.425=827-5424 EXPLORATION BORING LOG Number EB-3 Page 2 of 2 SEDIMENT DESCRIPTION o a Z W ¢ 0 STANDARD PENETRATION RESISTANCE Biows/Foa - 10 20 30 40 (Double Bluff Drift) . 1 64 BOH c@ 36-1/2' Note: Slope inclinometer installed. 40 45 ' I 50 I I I 55 i 60 65 i n Subsurface wnditions depicted represent our observations at the time and location of this exploratory hole, modMed by geologic Interpretations, engkieering analysis, and Judgment They are not necessarily representative of other times and locations. We vn'U not accept respons[WMy for the use or Interpretation by others of Informallon presented on this log. Reviewed By . Associated Earth Sciences, Inc. Aldridge Short Plat 911 Fifth Avenue, Suite 100 Edmonds, Washington Kirkland, .Washington 98033 Project No. G97224A Phone: 425-827-7701. Fax: 425-827-5424 September 1997 47 �EXPLORATION BORING LOG E8-3 � SEDIMENT DESCRIPTION o. J : ° ¢ 2 C . SUNDARD PENEIMION RESISTANCE Blows/Feet. lu t7 H (3 10 20 30 40.... .Moist, tan, silty, fine to medium sand with some gravel. (Fill) I 18 Moist:, . gray, gravelly, silty, fine 5. to medium sand. (Lodgement Till) • 50/5'1 I 10 - I 50/6" 15 50/4" --�— 20 . Moist, gray, fine sand. (Advance Sand) I. 50/5` BOH @ 24' 25 Subetsface conddons.deploted represent our observations at the tine and location of thisexplomtory hol% enodrfied by 600160c. interpretation, o"Oftwirp analysis, and Xm pment They are not necessardt/ nepnWW tathro of other times and locations,. We will not wxW msponst ty for the u" or interpretation by. others of infonm *m. presented on this lop. 9110-06H. October 1991 Summers Residential: Property . Edmonds, Washington -- ASSOCIATED EARTH . SCIENcr=S 1NC, 1 1 1 1 1 1 1 1 i MAZII cnw SOIL DESCRIPTION y u- Standard Penetration Resistance t -1 a :.«: t (140 14. weight,30" drop) CL = m 0- o A Blows per foot Surface Elevation: 98 Feet o rn 00 0 20. 40 60 Loose, brown, silty, fine SAND; moist; _ wet @ 18 ft. mixed with clayey SILT with mottled disturbed appearance with = = ' possible slide plane @ 20 ft. (Fill and _ _.._10. _ , .... :: Slide Debris) SM. _ �.... zos = m 20-- -`- - -- --- - -- stiff to very stiff, gray, fine sandy SILT to slightly clayey SILT; wet; with laminated o :.. . structure; ML c = o' 30 - - • 36.0 = • . Hard, gray, silty CLAY; moist; laminated with fine sand partings and wet sand layer = 40 - at 46.3 ft.; CL _ 50 56.0 = • Very stiff, gray, silty CLAY; moist; with scattered iron stained sand layers and = 60 - -, - disturbed blocky appearance; (Possible 67 5 ancient slide plane) CL. BOTTOM OF BORING COMPLETED ON 11/19/93 70 80 90. :. 0 20 40 .60 LEGEND • % Water Content • Sample Not Recovered Surface Seal Plastic Limit Liquid Limit = 2" O.D. Split Spoon Sample ® Annular Sealant ar C Naturall WWater tContent , M 3" O.D. Shelby Tube Sample i Piezometer Screen ® Grout Ursula Schluter $Z Water Level 15620 75th Place West Edmonds, Washington .. NOTES . t. The stratification fines represent the approximate boundaries between LOG OF BORING •Br !1 soil types, and the transition may be gradual. . 2. The discussion in the text of tNs report is necessary for a proper understanding of the nature of subsurface materials. January 1994 W-5385-02. 3. Water level, if indicated above, is for the date specified and may vary. 4. Refer to KEY for explanation of 'Soil Log' symbols and definitions. SHANNON & WILSON, INC. FIG..3 5. USC letter symbol based on visual classification., caomd� m wand Emimnantd.cormwtowr s TEST PIT LOGS 0' - 'Duff, topsoil, and roots 1:3' - Variable brown silty fine sand with gravel and clasks of silt -clay mixture (slide debris) (loose) 13.0' - Completed February 25, 1986; no groundwater . encountered 0' - Duff, topsoil, and roots Variable sandy silt and silty sand (slide debris) ±13.5' - Sandy gravel, slight groundwater seepage throughout Blue 'gray silty clay (severely fissured and with slickensides) ±17.0' - Completed February 25, 1986 0' - Variable silt -sand -gravel mixture (saturated) (slide debris) 3.0' - Blue -gray silty clay _(med stiff) (old slide debris) 8.1' - Tan silt (hard) 14.5' - Completed February 25, 1986; groundwater flow from upper 3 feet 0' - Highly variable silt -sand -clay mixture (slide debris) 7.0' - Blue -gray' silty. clay (fissured,: ancient slide debris) Tan. silt (hard) :f.•:J •.Y •-J�.JBrov�n, gravelly SAND with some -siltO=rse-grained� rnoist� verydense tJ•.J becomes less gravelly Jt J• •J•. J t'J ✓.5 J kMM. MkrMk rrwrr k 1 • CMkkr GM • kGkGG�G� rM•kr Brown, 1 =&A and low I• . . ` IM.... �i GiYGG 25 • r�® k Myr yyrrrQ 11 GMY`C 111�Mostlyveryfine-grained, silty SAND CG`k �G k� GkCgqp Ck"kG"p rkkr 1 lei Gray, silty SAM,1 •dense 35 TESTBORING LOG 1M20 - 76TH AVENUE .WEST EDMONDS, WA Job No: Date Load by: Pete: 97WI JAN 7997 10 15 20 25 30 35 wLi IM-M I 18 33 24 35 •. • F.YM�1 `w MwM Ni MMr YI rMMMNMY` M WWI k��iMi • � i 11 • 1 � 1 1 !• • • • 11 . 1 • - 1 Y IYIY MNFMri k NrkMMr� N YNMYY Y t'J iJ!'J iJS •J!J•.��'�'S •.J5J 5"l.•.Jt J.J.' •V''. . iIYNN�I�N MI rrYY Y r YN NrNK� NCNNNM{ k NkrrYYl / ,lenses • M rFFNr{{11 YI - • FM!!YCr Mrr Yrl FN rrN ■1 M NYFrr p� 1rI/1 YFry Y/ {I FIINFCNFI MMM r:1MYNNNI �MOP, Ml iNkMNNrNI becomes a moist, dense FF r1111 NI Y Mrllhrrl MYCrMFN rI YMNNI NYI-becomes of FM NYMYYMNI kkk.rrCkl kMMYFrNNI kN NYY FMI rMrYCrrl NMrYYMMMI k rYCN MN� IIkNr Mkrrl C FFNMFMYI becomes saturated • CN FYNIIN Y� Yr rY r NNFkItrwY rereeM��� Test boring was terminated at 31.5 feet below grade on 1-18-97. Groundwater seepage was encountered at 16' and 30' during drilling. TEST BORING LOG 15620 - 76TH AVENUE. WEST EDMONDS, WA Job Na Date:Logged by: Plate: 97001JAN 1097 � ORW 4 15 ' .3 25 20 ' 4 20 ' zs 5 53 BORING 3 Gray, silty SAND, very fine-grained, wet, medium -dense becomes less silty, moist -becomes wet. lens of silt MNC�M„ MMM AM MMMMM� r .Mi�MM m - moist, t� Hansen. Page two ' The extreme rear (easterly) portions of the Hansen property encompass the steep slope portions of the region. The slope exists at an approximate forty percent (40%) grade. The slope contains mature stable trees, with dense brush (see ' photographs).. No evidence of any geotechnical distress, slides, nor erosional degradation was observed immediately above and behind the Hansen property. This engineer understands that a localized surficial slide has occurred one to two properties to the north, and is a direct result of up slope bad drainage practices. It is understood that the localized slide to the north is currently undergoing stabilization and drainage improvements. As stated in the 1979 Roger Lowe Associates, Inc., ' report, drainage and ground water control are the best practices for landslide risk reduction. This engineer concurs. EVALUATION: In order to augment the existing site geotechnical information, power hand auger test.holes were dug under this engineer's observation on May 22, 1999. Two test holes were dug to seven foot (7) depths (see photographs and site plan for ' locations). Test Hole No. 1 was dug at the approximate south foundation line of the proposed addition, approximately twelve feet (12') east of.the existing house. ' Test Hole No. 2 was dug approximately ten feet (10) south of the hot tub deck on the relatively level soil bench. Both test holes revealed similar subsurface conditions, namely: 0 to 6 - Organics, roots, and organic silt 6" to approx. 3.5' Brown sand, relatively clean, moderately ' dense 3.5' to 4.5' Increasingly dense sand with cobbles 4.5' to 7' (bottom of hole) Very dense silt and silty sand with cobbles No water was encountered* in either of the test holes. Both test holes remained ' vertical and stable. No sloughing or caving occurred. This engineer conducted a visual examination of the slope above the Hansen . property. A small historic "cave".(?) zone was observed. It is understood that this "cave" was used for historic bootleg storage purposes. This "cave". was approximately three foot (3') high by approximately three foot (3') deep along the face of the bluff ' slope. The "cave" revealed no evidence of any geotechnical distress. Additionally, this cave zone allowed further verification of the dense sandy silt. and gravel soils . present. This engineer did observe a mature fir tree growing immediately above the I Associated Earth Sciences, Inc. r Ce��vafinJc �Jve�25 ZJeas�af S'evuice October 2, 2008 ' Project No. KE050550B Kyle and Juliann Ray 702 4`' Avenue`South Edmonds, Washington 98020 Subject: Wet Season Grading Request and Temporary Shoring Design Proposed Ray Residence Reconstruction 15625 75' Place West Edmonds,. Washington Permit No. BLD2008-0376 Dear Mr. and Mrs. Ray: Associated Earth Sciences, Inc. (AESI) has prepared this letter to support your request to commence phased earthwork during the wet season grading restricted from October 1 to April 30 of each year in the North Edmonds Earth Subsidence and Landslide Hazard Area. Project Understanding We understand that the contractor plans on limiting the amount of excavation during the wet season grading period to that necessary to construct the foundations for the proposed dwelling. We had previously recommended temporary slope cuts for the daylight basement level, which would normally be suitable for the dry season. During the wet season, the temporary slopes would be required to be covered with plastic sheeting to prevent erosion, but this would also result in the rainwater runoff being directed into the excavation. The result would .be wet subgrade soils and increased difficulty in subgrade preparation. After discussing this issue with Mr. Scott Hoover of Hoover Homes (general contractor), we concluded that a temporary shoring system consisting of Lock -Block (Utlrablock) modular blocks would be preferable to the temporary cut slope during the wet season. We have prepared a temporary Lock -Block shoring plan and calculations (attached). Recommendations In our opinion, the site is stable for the temporary foundation/shoring grading and work may continue past the ordinance deadline of September 30, providing the following recommendations are followed: Kirkland 0 Everett ■ 425-827-7701 425-259-0522 FILE Tacoma 253-722-2992 =�us OCT - 7 2008 BUILDING DEPARNENT GITY OF EDMONDS www.aesgeo.com • A preconstruction meeting is attended by the general contractor, the excavation subcontractor, the City inspector, and the geotechnical engineer to discuss temporary erosion and sedimentation controls (TESL) and earthwork sequencing. • The erosion control measures currently shown on the plans should be implemented and inspected on a continual basis by the contractor and maintained, as necessary. Additional erosion ; control measures may need to be installed if site and weather conditions warrant. • Soil stockpiles are covered with plastic sheeting, not placed on slopes or above shoring, placed higher than 6 feet, or left on -site more than 3 days, as required by the City. • AESI observes the excavation for and installation of the Lock -Block shoring. • AESI provides earthwork -related construction special inspections, including weekly TESC inspections, or within 48-hours after a significant rainfall event (greater than 1 inch in 24 hours), as required by the City. Schedule of Work As requested by the City, we have included the following schedule of work based on our conversations with the contractor. This schedule assumes that the permit will be issued approximately mid -October 2008. Actual schedule may vary, depending on start date, actual site conditions, and other factors. However, since the contractor is opting to use shoring, the site should remain stable during the wet season. Task Duration Tentative Dates TESC, temp. cuts, shoring installation 1 week 10/13 - 10/20 Prepare footing subgrades 1 week 10/20 - 10/27 Construct footings, foundation walls 2 weeks 10/27 - 11/10 Subsurface drainage, waterproofing, backfill walls 2 weeks 11 / 10 - 11 /24 Framing, interior, hardscape, landscape 6 months 11/24 - 5/24/09 We trust that this letter meets you needs. Please call if you have any questions. Sincerely, ASSOCIATED EARTH SCIENCES, INC. Kirkland, Washington Eric J. Lim, P.E. Senior Project En G. Aaron McMichael, P.E., P.E.G. Associate Engineer Attachments: Temporary Shoring Design and Calculations cc: Hanson Design 652 Alder Street Edmonds, WA 98020 Attn: Kristin Hanson EILdr KE050550B4 Projects\20050550\KE\W LOCK -BLOCK GRAVITY WALL CALCULATIONS Description of Parameters DESIGN EXAMPLE y Y, �\ P, w5 iwe - i go Y; �wa�y--- j 1H2 W 1 •1 6b` r' —_— Heel Wall Crass -Section Source: Ultrablock Design Manual for Lock -Block Gravity and MSE Wall Systems (Adettiwar, 2003). LOCK -BLOCK GRAVITY WALL CALCULATIONS SHEET 1 OF 3 Parameters and methodology based on Ultrablock Design Manual for Lock -Block Gravity and MSE Wall Systems (Adettiwar, 2003). Project: KE050550A Ray Residence Shoring Date: 09/25/2008 Checked: EJL ENTER VALUES IN BLUE. i`:•.`SHA6ED C t'1MV E ED Ch.. w1....��"nimencinnc �kxd Paramelerl Value Units Descri tion HW 7.50 ft inclined wall height Hemb 1.00 ft wall embedment He a4h6;tg4"0 dt ft exposed vertical wall height H Pi;8 j;3 ft design wall height Bb 2.50 ft bottom width of wall Bt 2.50 ft top width of wall deq inclination of back of wall measured clockwise from horiz plane (3 15 deg inclin. of ground slope behind wall - counterclockwise from horiz plane a 9.5 deg wall batter measured clockwise from the vertical Yblocks 0.140 kcf unit weight of blocks Soil Parameters Parameter Value Units Description rretained 0.120 kcf retained soil unit weight (total) retained 30 deg friction angle of retained soil sretained 22.5 deg friction angle retained/wall (sands=3/4�, sandy silts/clays=1/2�) Cretained 0.000 ksf soil cohesion of backfill ka lu?286 - active earth pressure coefficient P a11;Q5:j`i kip/ft resultant of active earth pressure PH Sil,MQ51, kip/ft horizontal component of P Pv 5024i3Fi;i€. kip/ft vertical component of P Surrharaes Parameter Value Units Description qU_ 0.000 ksf traffic or other uniform live load PgLL ;?MO„OU'`'sat! k/ft resultant horizontal load from uniform live load based on p = kagLL Qline XLINE 0.00 7.00 k/ft 1 ft continuous footing or other dead line load Idistance of line load from face of wall m=`0896�' PLINE ;ale±F4 Q, 3'�1 k/ft 1horiz. resultant from line load (NAVFAC 7.2-74) applied at R = H * 0.6 Seismic Parameters a 0.00 g design horizontal ground acceleration Am g AASHTO recommended adjustment, Am = (1.45-A)A PiRxiaQ00;5 k/ft horizontal inertial force, applied at 0.5H PAE,;Oe k/ft dynamic horizontal thrust, 50 /o applied at 0.61­1 Moment Arms Parameter Value Units Description a hF1 85 s ft horizontal arm of W measured from toe in XY lanes b I b"2 -A19 E ft vertical arm of Ph measured from toe in XY planes e �ii�T2?.r ,;,Ij ft horizontal arm of P, measured from toe in XY planes bgLL;f 403p9bi dye ft vertical arm of POLL measured from toe in XY planes oline ;11'�4 694B,,j­� ft vertical arm of P„ measured from toe in XY planes PIR`•;m;3•'90,�`;il: rb ft vertical arm of P„ measured from toe in XY planes t'+ ft vertical arm of P measured from toe in XY planes Associated Earth Sciences, Inc. LOCK -BLOCK GRAVITY WALL CALCULATIONS SHEET 2 OF 3 Geometry # Blocks Height (ft) 8 20 Y USE "BORDER" TOOL TO OUTLINE FULL OR HALF BLOCKS 7 17.5 6 15 5 12.5 4 10 3 7.5 2 5 1 2.5 origin x of W011 Mass Unit Area (sq ft) X11 (ft) Y'l (ft) Weight (k/ft) Mass Moment X (k-ft per linear ft) Mass Moment Y' (k-ft per linear ft) Block 1 6.25 1.25 1.25 k 1.� � - "' t� �� i� e— �.W,iuh iiE� �R;3'1 luh��ODN 00m ljg� �g5 gj t 1 � g Block 2 6.25 1.25 3.75 `88 PY' Block 3 6.25 1.25 6.25 �i PR 0111 0411_1411,101r� .1 � iRTBAII-'Ili, im ' 747� `111M 110751 1�1 Block 4 mg ovag "innmpl"g r`M51-1, RI 5: u"K. v, T Block 5 !�Op"g j, PRIM� yp.7.�,Imo p 'i Block 6 Vol Block 7 11-111ME0 d! Al;� RaW C _QQ! 1�1 Hmm mil W, Block 8 N E R. 11;5-i§� 'id' � Q, iiw� 4N F!IPIQ i W � TH, I `�`R i `ii i 10 OR QUE Soil I no. t fg- 4 -vpg -.-00!�v um"+4,p.,MwPj;�v 1 t . , � , t Soil 2 iF Ni 3 f,!g .0-po'.Vgq%g;�i�g!lqp gp,�g�� �: 7 "1 �VQ P, t�-; �4 65111.1 -OF 2§,1i 11E25; �l?+t 4P,P; 26 4,l M �ETotal x ,j pl. ij4 J; �1 a 144 IM WelfiftA Y, T 'ZiEFh ,j Associated Earth Sciences, Inc. LOCK -BLOCK GRAVITY WALL CALCULATIONS SHEET 1 OF 3 Parameters and methodology based on Ultrablock Design Manual for Lock -Block Gravity and MSE Wall Systems (Adettiwar, 2003). Project: KE050550A Ray Residence Shoring Date: 09/25/2008 Checked: EJL ��`cun'nrii•i^ci'i'C'A`[?F'.r:Al�Rlll"ATFI]� �� Structural Dimensions Value 10.00 Units ft ---- Description inclined wall height Parameter HW Hemb 1.00 ft wall embedment ft ft ft exposed vertical wall height design wall height bottom width of wall M ft top width of wall de deg inclination of back of wall measured clockwise from horiz lane inclin. of ground slope behind wall - counterclockwise from horiz plane 6 ,2 90, 5i �_gi 0 a a 9.5 deg wall batter measured clockwise from the vertical Yblocks 0.140 kcf unit weight of blocks Soil Parar Parametei Yretained retained 6retained Cretained ka P PH Pv 'teters Value Units Description 0.120 kcf retained soil unit weight (total) 30 deg friction angle of retained soil 22.5 deg friction angle retained/wall (sands=3/4(�, sandy silts/clays=1/2�) 0.000 ksf soil cohesion of backfill 0233 - ki p /ft kip/ft /ft kip/ft active earth pressure coefficient resultant of active earth pressure horizontal component of P Ivertical component of P '4' Q' 55� '' ry3�0:36� Surcharaes Parameter Value qLL 0.000 PqLL Qllne 0.00 XLINE 7.00 LINE r �1�......,s:-._ Seismic Parameters a 0.00 Am PIR a�..v. ;z PAE0'OQ Units Description ksf traffic or other uniform live load k/ft resultant horizontal load from uniform live load based on p = kagLL k/ft continuous footing or other dead line load ft distance of line load from face of wall m k/ft horiz. resultant from line load (NAVFAC 7.2-74) applied at R = H * g design horizontal ground acceleration g AASHTO recommended adjustment, Am = (1.45-A)A k/ft horizontal inertial force, applied at 0.5H k/ft dvnamic horizontal thrust, 50% applied at 0.6H W. Moment Arms Units Description Parameter Value af`' 3F56'* ft ft ft ft ft ft ft horizontal arm of W measured from toe in XY planes vertical arm of Ph measured from toe in XY planes horizontal arm of P„ measured from toe in XY planes vertical arm of POLL measured from toe in XY planes vertical arm of P,, measured from toe in XY planes vertical arm of P, measured from toe in XY planes vertical arm of P, measured from toe in XY planes 74. e`,a5"53` bgLL ;-n bOline bplR5r3;4y bpAE„fi'„4�1 I LOCK -BLOCK GRAVITY WALL CALCULATIONS SHEET 2 OF 3 Geometry # Blocks Height (ft) 8 20 Y USE "BORDER" TOOL TO OUTLINE FULL OR HALF BLOCKS 7 17.5 6 15 5 12.5 4 10 3 7.5 2 5 1 2.5 origin x L,V11L=1 LPA %alOVILY Mass Unit. — •-- Area X11 Y'l Weight Mass Moment X' Mass Moment Y' (sq ft) (ft) (ft) (k/ft) (k-ft per linear ft) (k-ft per linear ft) Block 1 12.50 2.50 1.25 Block-2 12.50 2.50 3.75 Block 3 6.25 3.75 6.25 '0-- .8 31284' ?-T5'4 7 C`i� ti Block 4 6.25 3.75 8.75 Blocks 0: 0 0: i!�" % Block 6 4 Block? Block 8 ;00. e' 'At0' 00!k�-i� i` 7'�Z- f 1002 Soil i 4 Soil 2 -.0TW, 0 Z�! Total U'20'001$4 3V, Ni%�17-s X, 2 92`1'1'11'1,, Y, Associated Earth Sciences, Inc. LOCK -BLOCK GRAVITY WALL CALCULATIONS i SHEET 3 OF 3 Evawatlon or UVer1U nirig a►aullu ameter Value Units Description Mr 4j 20:68, k-ft / ft resistingmoment dslafic '= '`f# 26" k-ft / ft driving moment, static d seismic [FS'o,static ' :`426* T, k-ft / ft driving moment, seismic ;-OK static > 2 ? , seismic' c e !J:.--. Oa.. L.a:�.• tvaruativn Parameterl vl Ouuuly Value %JLOSJI ILY Units Description �fdn 40 deg friction angle of base pad soils (min. 6 in. of crushed rock recommended) ssubgrade F 30.0 F. .. deg - friction angle blocks/subgrade (sands and gravels = 0.756) coefficient of friction between wall and foundation soil Nslabc{5:r79` k/ft reaction at base of wall, static Nselsmic v.5 t7,.9;.< k/ft reaction at base of wall, seismic FfSfetic42GY Fr,seismic k/ft k/ft sum of forcesproviding,resistance to sliding, static sum of forces providing resistance to sliding, seismic Fdsta6c `tat153# k/ft sum of forces driving the wall in sliding, static Fdxeismic a1° 53 k/ft sum of forces driving the wall in sliding; seismic FSs,static OK static > 1.5 ? FSs,seismic OK seismic > 1.1 ? ..A a^"neinfinn Stahility tValuailon VI Qeal11lu va,,ia—r .+ - ••---•-• ---- Parameterl Value Units Description Bf I width of wall footing J 0.125 kcf subgrade soil unit weight (total) Yfdn �fdn 30 1 deg friction angle of subgrade soil ssubgrade 22.5 deg friction angle blocks/subgrade (sands=0.750, sandy silts/clays=0.56) Gdn 0.000 ksf soil cohesion of subgrade f Q 1,8 iA „ ksf overburden surcharge (assume 6" base pad) q Nc - bearing cap. factor, Eqn. 12.5, Fund. Of Geotech. Eng. , (Das 2005) rv`309g1;4'" Nq " � bearing cap. Factor, Eqn. 12.4, Fund. Of Geotech. Eng. , (Das 2005) NYquIt t 22Iq}p'r - bearing cap. Factor, Eqn. 12.6, Fund. Of Geotech. Eng. , (Das 2005) ksf ultimate bearing capacity gall 446> q`.. `�i�a'lk-„c,...Wa�.,X ksf allowable bearing capacity (qu,t/2.5) Eccentricity and Bearing Pressures Parameter Static Seismic Units Description N 5�79 5r79:: k/ft reaction at base of wall Nv5:a7.1;.... ,M5.71 k/ft vertical component of reaction at base of wall NH ti0 95 0 95,,` k/ft horizontal component of reaction at base of wall X w"�u'2 80,E 2 80' ft horizontal distance of normal force from toe ex ft eccent. of base rxn from ctr of wall base meas. along plane �� to base check r a OK:`'rOKz - Bb/3 <= X / cos a ? check :,. , s.K" ... y'OK ' `` `` - _ Bb -X /Cosa <= 213 3 ? (7 -IIOe � °� "0689�'`�'",'r0689}w 'J.�'.,, ksf maximum bearing pressure gneel1 627t9`627' y;46.86�;6�86 `" ksf - minimum bearing pressure factor of safety for bearing capacity (min. 2.5 static, 1.5 seismic) FSbearmg Associated Earth Sciences, Inc. �. Associated Earth Sciences, Inc. Rd ad NJ 0 0 Ce166Na6T aer25'Jeaffof sen ce August 15, 2008 Project No. KE050550B Kyle and Juliann Ray 702 4 h Avenue South Edmonds, Washington 98020 Subject: Addendum to Geotechnical Report Proposed Ray Residence Reconstruction 15625 75' Place West Edmonds, Washington Permit No. BLD2008-0376 References: Associated Earth Sciences, Inc. Revised Subsurface Exploration, Geologic Hazard, and Geotechnical Engineering Study Dated January 10, 2008 City of Edmonds Plan Review Comments Dated June 26, 2008 Landau Associates Geotechnical Peer Review for Earth Subsidence and Landslide Hazard Area Submittal Package - Building Permit No. BLD20080376 Dated June 16, 2008 Dear Mr. and Mrs. Ray: Associated Earth Sciences, Inc. (AESI) has reviewed the above -referenced documents and prepared this addendum to our geotechnical report, dated January 10, 2008, in response to the review comments. This letter should be considered supplemental to the findings and recommendations in our January 10, 2008 report. City of Edmonds Review Comments The following geotechnical-related comment was in the above -referenced City of Edmonds memorandum: T` FILE.RESUB AUG 1 q 1008 Kirkland Everett Tacoma BUILDING DEPARTMENT 425-827-7701 425-259-0522 253-722-2992 CITY OF EDMONDS www.aesgeo.com 1. The submittal appears to have the following minimum submittal items missing: c) Temporary Shoring plan (4 copies) with appropriate shoring details. In our opinion, shoring is not needed for this project. The excavations for the daylight basement level can be accomplished using temporary cut slopes on the east and north sides of the basement, which is only under the south half of the house. The cut slopes may be planned for a 1.511:1V (Horizontal: Vertical) inclination per our geotechnical report. There appears to be sufficient room to make these temporary cuts in the backyard and to the north side of the basement. Landau Associates Review Comments The following bullets provide excerpts from the Landau Associates (Landau) review letter followed by our responses. • The City's Geotechnical Report Guidelines requires that the Geotechnical Consultant provide at least one cross-section extending across the site drawn perpendicular to the contours showing soil and groundwater conditions in relation to the proposed site grading and structures... We recommend that a cross section be provided. Figure 1, attached to this letter, provides the location of a representative cross-section superimposed on the grading plan. Figure 2, attached to this letter, provides an interpreted geologic cross-section using explorations performed for the subject site, and incorporating the boring data from the adjacent property to the south. Due to an apparent difference in elevation datum and lack of topographic plan showing both properties, the locations of the Hemphill borings are not shown on Figure 1. We incorporated the deeper boring data in our cross- section, but did not incorporate the shallower test pit data, due to the location of the Spiro property in the gully. The Hemphill site plan and boring logs are included in the Appendix. At the time of exploration, no ground water was encountered in the AESI explorations performed for this study or observed on the lower portions of the slope above the subject site. Wet soils were logged, but no free ground water reported by Hemphill in their explorations. Some seepage was reported from the sand/clay intersection higher on the slope, but they report no evidence of any effect on the site. Hemphill could not determine the source of the seepage, but they surmised that it may be from the property to the north. • If AESI has not already done so, the Hemphill report on the adjacent property should be reviewed and considered, relative to the conditions and design approach on the Ray property. We have reviewed the report titled, "Geotechnical Engineering for the Proposed Spiro Residence to be Located at 15631 75`' Place West, Edmonds, Washington" by Hemphill Consulting Engineers (Hemphill), .dated 10 December 1990. The report provides subsurface data from two borings in the proposed building area and two test pits on the slope above 2 the building. Hemphill reports that the Spiro property appears to be a gully with the head of the gully on the east side of the property. The Hemphill report also shows an existing interceptor drain located at the toe of the steep slope system. The Hemphill report states that the largest recorded slide in the Meadowdale area occurred in 1945, when this gully and a large gully to the south experienced large movements. Hemphill does not provide a reference for the slide records, but later states that according to neighbors, the site has not noticeably moved since 1947. The Hemphill report stated that the proposed house will be supported on pile foundations designed to resist the lateral force of the sliding soils. A soldier pile wall is also proposed for the permanent driveway cut. Some structures, such as the back porch, spiral stairs, and deck footings, would be designed for spread footings. These spread footings were termed "temporary" by Hemphill, due to the possibility that they are placed on potentially unstable soils that are capable of support until a slide occurs. The temporary footings would be placed on structural fill pads similar to that recommended.by AESI. We considered the Hemphill findings and design approach on the Ray project. In our opinion, the Spiro' site appeared to have a greater risk of movement. than the Ray property, due to its location in a gully. A site located in a gully has a greater potential to accumulate surface water runoff, experience resulting debris flows emanating from much further up the slope system, and has greater depths of undocumented fill placed over the original gully grade, which may possibly contain older slide debris. We explained to the Rays during our initial consultation that, since their. site is located in a known landslide hazard area, a pile foundation would be the lowest risk option for foundation support should movement below the house occur. However, pile foundations would also increase the cost of the project substantially. If some degree of risk can be tolerated, another option for foundation support could include shallow ground improvement using structural fill pads and rigidly tying the footings together to mitigate differential movement, should it occur. Our explorations around the existing building showed this option to be feasible, and we understood that the owners accepted the risk that the building foundation was being designed primarily for life -safety, but that future earth movement could damage the building beyond practical repair. This option is similar to the "temporary" foundation concept in the Hemphill report. Furthermore, the debris -flow hazard from the slope above the site will be mitigated by the 3-foot-high, above -exterior -grade catchment wall incorporated into the foundation stemwall facing the slope. • We recommend that basic landscaping plans for the property be provided that confirm that the steep slope areas on the east side of the property will remain protected by native vegetation, and that additional cuts, fills, or retaining- walls are not planned as a part of landscaping improvements to the property. We concur with this recommendation and understand that a basic landscaping plan showing these protections will be provided as part of the submittal. 3 • These requirements should be noted on the Grading and TESC sheet and the owner or lead design professional 'should arrange for these services with the Geotechnical Engineer of Record. We concur with the TESC and pre -construction requirements. AESI has already been retained by the owner to provide construction monitoring services. We trust that this letter meets you needs. Please call if you have any questions. Sincerely, ASSOCIATED EARTH SCIENCES, INC. Kirkland, Washington . F' �OF W ASl�rj�C Sri iy� ti �r32� v �`SS/ONAL�� 4 Eric J. Lim; G. Aaron McMichael, P.E., P.E.G. . Senior Project Engineer Associate Engineer Attachments: Figure 1: Site and Exploration Plan Figure 2: Geologic Cross -Section A -A' Appendix: Hemphill Site Plan and Exploration Logs cc: Hanson Design 652 Alder Street Edmonds, WA 98020 Attn: Kristin Hanson EJUdr KE050550B3 Projects\2005055MEM P 4 -4 ZS; li n ui Q z a. L) 0 j uj LU OZ c CL &il. Z.: 1, V) ji z a) m 0 JPO'@O-L A88 3idx3 pUe OpS 09990 \ a' 3p!seU ,tea 099SO M N r0 O O O O O O O r r r r r O O r O N a 3N111.1'13dObd 11dM 3d`dOSaNVI ONIISIX3 Milll=W...QIT0j:I S ,OOI- Z-9-dW3H �-- 6-`dH IS3M 30VIdH1SL a \ rT v o rn OD on CD LO v (133=0 NOUVA313 O4 OZl r ON 09 09 Ob w� w u �Z U O Z QUJ OZ c� o� W Z J Q O Lu Bmp•uoiloos 09990 \ 00 N 00 m w O "p W O Q W LO LL m Y O z U w O w IL Q Q Z _O Z ~ O �Z O W z Z � O Co U) of 3: U p U w o U U o (� W w O 09 w v V mtl N -N W V O � t japisaa Aea 09990 LOG OF EXPLORATION PIT NO. HA-1 w This log Is part of the report prepared by Associated Earth Sciences, Inc. (AESI) for the named project and should be together that for interpretation. This to the location this trench the aa, read with report complete summary applies only of at time of excavation. Subsurface conditions may change at this location with the passage of time. The data presented are o a simplfication of actual conditions encountered. DESCRIPTION Fill 2" of crushed rock over medium dense, moist, brown, SILTY SAND with gravel and scattered 1 concrete debris and cinders. 2 Old Landslide Stiff, moist, tan, blocky, SILT with little fine sand and scattered rootlets (DCP at 2' = 12, 8, 8). 3 _ _ _ _ _ Loose, damp to moist, gray, fine to medium SAND with trace silt (DC.P at 5' = 6, 6, 7). 4 5 Becomes finer. 6 Becomes coarser with iron oxide stains. 7 8 ------------------------------------------------------ Medium stiff to stiff, wet, tan, fine sandy SILT to silty fine SAND with occasional lenses of clayey silt (DCP at 8' = 13, 10). 9 10 11 12 Bottom of exploration pit at depth 11 feet No ground water seepage observed at time of exploration or 4 hours after exploration. No caving observed. 13 14 15 16 17 18 19 Ray Residence Re -Construction Edmonds, WA Associated Earth Sciences, Inc. Logged by: EJL Approved by. Project No. KE060550A 8/13/05 LOG OF EXPLORATION PIT NO. HA-2 L This log is part of the report prepared by Associated Earth Sciences, Inc. (AESI) for the named project and should be read together with that report for com�fete interpretation. This summary applies only to the location of this trench at the n time of excavaUori. Subsurface conditions may change at this location with the passage of time. The data presented are O a simplfication of actual conditions encountered. DESCRIPTION Fill 1 Medium dense, moist, brown, GRAVELLY SILTY SAND with scattered concrete debris. 2 3 4 5 --------------- ---------------------- Landscape Rocks 1" diameter rounded gravel. ' J 6 ----------------------------------------------- ----- Relic Topsoil/Fill Loose, moist to wet, brown to dark brown, SILTY SAND with scattered asphalt pieces. 7 Old Landslide Medium stiff to stiff, moist, tan, blocky, fine SANDY SILT (DCP at 8 1/2' = 10, 9). 8 9 Bottom of exploration pit at depth 8.5 feet No ground water or caving observed at time of exploration. 10 11 12 13 14 15 16 17 18 19 Ray Residence Re -Construction Edmonds, WA Associated Earth Sciences, Inc. Logged by: EJL Approved by: .; . s a• ®r Project No. KE050550A 8/13/05 LOG OF EXPLORATION PIT NO. HA-3 This log is part of the report prepared by Associated Earth Sciences, Inc. (AESI) for the named project and should be read together with that repori for complete interpretation. This summary applies only to the locafion of this trench at the a time of excavation. Subsurface conditions may change at this location with the passage of time. The data presented are o a simplfication of actual conditions encountered. DESCRIPTION Fill Medium dense, moist, brown, silty SAND with few gravel and scattered concrete debris. Sewer pipe 1 in east sidewall (trench backfill). 2 3 Old Landslide Medium stiff, moist, tan, FINE SANDY SILT to SILTY FINE SAND with scattered wood debris (DCP 4 at 4 1/2' = 7, 7, 7). 5 6 (DCP at 6 1/2' = 10, 12, 12) 7 8 Bottom of exploration pit at depth 7 feet No ground water or caving observed at time of exploration. 9 10 11 12 13 14 15 16 17 18 19 Ray Residence Re -Construction Edmonds, WA Associated Earth Sciences, Inc. Logged by: EJL Approved by: C� = R N' Project No. KE060550A 8/13105 LOG OF EXPLORATION PIT NO. HA-4 w This log is part of the report prepared by Associated Earth Sciences, Inc. (AESI) for the named project and should be together with that for interpretation. This summary applies only to the location of this trench at the c read report complete time of excavation. Subsurface conditions may change at this location with the passage of time. The data presented are o a simplfication of actual conditions encountered. DESCRIPTION Fill Sod over medium dense, damp to moist, brown, SILTY SAND with few gravel. 1 2 3 4 Old Landslide 5 Medium dense, moist, tan, SILTY FINE SAND to FINE SANDY SILT, slightly blocky. 6 7 Bottom of exploration pit at depth 7 feet 8 No ground water or caving observed at time of exploration. 9 10 11 12 13 14 15 16 17 18 -19 Ray Residence Re -Construction Edmonds, WA a' Associated Earth Sciences, Inc. Project No. KE050550A Logged by: EJL g Approved by: "� lid. 8/13105 (� U Y APPENDIX FIGURE 9 LOCATIONS of FIELD TESTS (Hempk(U-, lg 9,6) W2r,,4DD1f mif jvw I \ t 1 Q 1 I Qom_ �Ile SPIRO RESIDENCE FIELD TESTS TEST PITS (tq10M?H(L'L111Qq0) page 11 of 67 pages 2 test pits were conducted, located approximately as shown in Figure 9. The test pits were conducted to locate the hard clay below the loosely deposited silts and sands. HEMPHILL conducted field penetration tests within the exposed undisturbed soils in the test pits to determine the approximate strength characteristics and other properties of the potential foundation soils for the house and the proposed soldier pile retaining wall and/or other type retaining wall to be determined after the grading has revealed the true soil conditions along the upper bench along the east side of the site. Logs of the test pits are shown in Figure 10. The logs show visual descriptions of the soils, depths of changes .in the soil types, groundwater observations, and any other pertinent observations or field tests. FIGURE 10 LOGS of TEST PITS depth TEST PIT 3 --0 - ---------------- 1 MEDIUM 2 DENSEM L E G E N 0: -"'--'------ DISTINCT CHANGE BETWEEN SOIL TYPES 3 RUSTY XXXXXXXXXXXXX GRADUAL CHANGE BETWEEN SOIL TYPES 4 SILTY BOTTOM of TEST PIT $ GRAVELY TOP of FREE GROUNDWATER 6 SAND 7 --------------- 8 HARD GRAY 9 SILT and CLAY 10 11 12 13 NOTE: 1. TEST PIT SILT AND 14 CLOSER TO 15 2. NO FREE GR TEST PIT 4 MEDIUM DENSE RUSTY SILTY GRAVELY SAND 3 ENCOUNTERED HARD GRAY CLAY AT A HIGHER LEVEL THE SLOPE OUNOUATFR vac cure wrcocn depth 1 2 3 4 5 6 7 8 9 10 12 13 14 15 HEM P H I LL FIGURE 12 LOG of BORING 1 PTH COLOR CONSISTENCY DESCRIPTION of SOILS MOISTURE COMMENTS SPT DEPTH GY HARD VERY FINE SANDY SILT DAMP 9000+ (FILL?) 18 3 5?????????????????????????????????????????????7????????????????????????????????????????????????????????????????? GRAY MED DENSE VERY FINE SAND & FINE SAND WET SOUPY FROM SAMPLER 14 8 I 0 GRAY MED DENSE VERY FINE SAND & FINE SAND WET 5000+ 10 13 5 7?????????????????????????????????????????????????????????????????????????????????????????????????????????????? .............. GRAY HARD CLAYEY SILT DAMP 9000+ 26 1 0 GRAY HARD CLAYEY SILT DAMP 9000+ 41 23 4+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ L E G E N D----------- DISTINCT CHANGE in SOIL DESCRIPTION GRADUAL CHANGE in SOIL DESCRIPTION ??????????? LOCATION of CHANGE NOT ENCOUNTERED in SAMPLE * ; * TOP of GROUNDWATER +++++++++++ BOTTOM of BORING SPIRO RESIDENCE page 13 of 67 pages • FIGURE 13' LOG of BORING 2 DEPTH. COLOR CONSISTENCY DESCRIPTION of SOILS MOISTURE COMMENTS SPT DEPTH BROWN LOOSE GRAVELLY SAND WET FILL 8 3 5 BROWN and 0 7 GRAY and MED DENSE SILTY FINE SAND WET CHANGE NOT LOCATED 7 8 RUST 0 9 10 BROWN 8 GRAY MED DENSE COARSE SILTY FINE SAND WET 4 13 15 BROWN & GRAY MED DENSE COARSE SILTY FINE GRAVELY SAND WET 14 18 20 GRAY FIRM VERY FINE SANDY SILT WET 3000+ 12 23 25 GRAY HARD SILT DAMP 9000+ 24 28 30 GRAY HARD SILT DAMP 9000+ (LAYERS DIPPED 30 DEG) 40 33 34 ♦++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ L E G E N D----------- DISTINCT CHANGE in SOIL DESCRIPTION GRADUAL CHANGE in SOIL DESCRIPTION ??????????? LOCATION of CHANGE NOT ENCOUNTERED in SAMPLE • * ' TOP of GROUNDWATER +++++++++++ BOTTOM of BORING HEMPHI LL CUSTOM DESIGN & ENGINEERING, INC STRUCTURAL ANALYSIS & DESIGN W FOOT RETAINING WALL Date: October 2, 2008 Reference project: RAY RESIDENCE RETAINING WALL —8' qa = 0.00 psi 0 —�I pa = 300.0 Design parameters Y S = 120 Ib/ft3 =30° a=0° µ = 0.350 Surcharge, q = 0.0 psf H = 9.50 ft H pe,si„e = 1.50 ft (Requires special inspection) 1.50'� 11006 60T' AVE WEST - MUKILTEO WA 9827S PHONE (425) 343-7517 - FAX (425) 493-8388 UTREEr FILE Fmnt- Passive OCT - 7 2008 BUILDING DEPARTMENT CITY OF EDMONDS CUSTOM DESIGN & ENGINEERING, INC STRUCTURAL ANALYSIS & DESIGN Heel, b2 = 3.67 ft Toe, b, = 1.50 ft Wall thickness, t, = 0.67 ft Footing thickness, t, = 0.83 ft Coefficient of acting earth pressure Ka = tan2 (45 - 0 /2) = tan (45-30.0° /2) = 0.333 Coefficient of passive earth pressure Kp = tang (45 + � /2) = tan (45-30.0° /2) = 3.00 Active earth pressure Pa = Ka Y s H = 0.333(120.0)(9.5) = 380.00 psf Passive earth pressure - based ob soil in front of the wall (Requires special inspection) Pp = KpY s H passive = 3.000(120.0)(1.5) = 720.00 psf Active force Rax = 1 /2Pa H = 1 /2(380.000)(9.5) = 1805.00 lb/ft @ H /3 = 3.17 ft Passive force Rp. = 1 /2Pp H passive = 1/2(720.000)(1.5) = 540.00 Wit @ H passive /3 = 0.50 ft Surcharge pressure qa = Ka q = 0.333(0.G) = 0.00 psf Qax = qa H = 0.000(9.5) = 0.00 lb/ft @ H /2 = 4.75 ft. Compute overturning moment Mo = Kax H /3 + Qax H /2 = 1805.0(9.5)/3 + 0.0(9.5)/2 = 5715.83 ft-lb/ft Compute Restoring moment Section I Area I Weight per unit length I Arm from toe I Moment 11006 60" AVE WEST - MUKILTEO WA 98275 PHONE (425) 343-7517 - FAX (425) 493-8388 CUSTOM DESIGN & ENGINEERING, INC STRUCTURAL ANALYSIS & DESIGN ftZ Ib/ft3 X t ft ft-lb 1 3.1 459 4.00 1836 2 0.6 83 1.83 153 3 1.2 187 0.75 141 4 5.8 867 1.83 1589 5 31.8 3817 121 4.00 15274 Sum 5413 18992 1 bu pct (2) y , = 120 Ib/ft3 Compute resisting moment M, = 18992 ft-lb/ft (from table above) FSor = KIM, = 18992/5716 = 3.32 3.32 > 2.00, RESULT = PASS FS against sliding FSsL = (E V )µ / (Re + Q. - RP,,) = (5413)(0.350) / (1805 + 0 - 540) = 1.50 1.50 < 1.50, RESULT = OK Base eccentricity at service loads Width of ftg B = 5.84 ft e=(EM,+E%)/(E W)-B/2=(18992+5716)/5413-5.8472=1.65in. 6e /B = 6(1.65) / 5.84' = 1.69 > 1, therefore no tension develops Compute un-factored pressures q E V /B 0 t 6e /B) = 5413/5.84[1 t 6(1.65)/5.84] _ (2496.7,-641.9) psf Compute factored pressures U = 1.4D + 1.7H ACI 9-4 Mo = 1.40836 + 153 + 141 + 1589) = 5205 ft-lb/ft 11006 60TH AVE WEST - MUKILTEO WA 98275 PHONE (425) 343-7517 - FAX (425) 493-8388 CUSTOM DESIGN & ENGINEERING, INC STRUCTURAL ANALYSIS & DESIGN ML = 1.7(15274) = 25965 ft-lb/ft Mu = 5205 + 25965 = 31171 ft-lb/ft VD = 1.4(459 + 83 + 187 + 867) = 2235 lb/ft VL = 1.7(3817) = 6489 lb/ft Vu = 2235 + 6489 = 8723 lb/ft qu (max,min>= E VulB (1 t 6e /B) = 8723/5.84[l t 6(1.65)/5.84] _ (4023.6,-1034.4) psf CONCRETE RETAINING WALL DESIGN Heel - Design Critical section for shear, L, ; Ls = bh = 3.67 ft. Critical section for moment, Lb; Lb = bh + tH,aIl l2 = 3.67 + 0.67/2 = 4.00 ft. Compute factored load, wuacting on H. Neglect the effect of earth press, since it subtracts the effect of wu . wu= 1.4wo+ 1.7wL Concrete weight, w,= 150 pcf theeI= 0.83 ft. (10.00 in.) Soil weight, ws = 120 pcf. H, = H - th., = 7.17 ft. wu= 1.4[w� (th�j) + ws (Hs )] = 1.4[150(0.83) + 120(7.17)] = 1379 lb/ft/ft Check shear Vu = wu L.,= 1379(3.67) = 5061 lb/ft 0 Vu= 0 (2r." bwd ) = 0.85 11006 60T" AVE WEST - MUKILTEO WA 98275 PHONE (425) 343-7517 - FAX (425) 493-8388 CUSTOM DESIGN & ENGINEERING, INC STRUCTURAL ANALYSIS & DESIGN f, = 2500 psi b,,= 12.00 in. d = th,,i (12) - 3 in cover - 1/2 in bar dia = 0.83 ft(12 in/ft) - 3" 1/2" = 6.50 in � Vu= 0.85[2(2500)(12.00)(6.50)] = 6626 Ibs (� Vu= 6626 Ib/ft) > (Vu= 5061 Ib/ft) OK Check bending Mu= 1/2(wu)(Lb)2= 1/2(1379)(4. 00)2 = 11059ft-lb/ft Required steel area, As= Mu / [o fy y d )] Assume j d = d - a /2 = 0.875d = 0.875(6.50) = 5.68 in As= 11059(12) / [0.90(60000)(5.68)] = 0.432 in2/ft Check if As? A,,in As -min= 3(f�)1nlfyx (bald) = 0.19 in2/ft < 0.43 in2/ft As = 0.43 in /ft = 200(b,,)(d )lfy = 0.26 in2 /ft < 0.43 in /ft As = 0.43 in /ft Reinforcement , Try No 5 @ 8.00 in., Abef= 0.307 sq.in. Provided, As_p,.,= Aba,(12 in/ft)/ spacing = 0.307(12)/8.000 = 0.460 in2/ft Compute a and check if fs= fyand if tension controls a = As_pmvfy/ (.85f�b v) = 0.460(60000) / [0.85(2500)(12.00)] =1.083 in. a /d = 1.083/6.496 = 0.167 ab /d = 0.582, Table A-4 - Compute ab ld > a ld , Therefore fs = fy OK 11006 60T' AVE WEST - MUKILTEO WA 98275 PHONE (425) 343-7517 - FAX (425) 493-8388 CUSTOM DESIGN & ENGINEERING, INC STRUCTURAL ANALYSIS & DESIGN Check if tension controls a /dt= a /d= 0.167 (one layer) atd/dt= 0.319, Table A-4 - Compute atdldt> a ldt, Tension controls & 0 = 0.90 0 M„ = [As-p., fy (d - a /2)]/12 = 0.90(0.460)(60000)[6.50 - 1.08/2] = 12331 ft-lb/ft (0 M„= 12331 ft-lb/ft) > (Mu= 11059 ft-lb/ft) OK Check development Ldl db= fya R 2,l [25(f,)'/2] Ldldb = 60000(1.00)(1.00)(1.00) / [25(2500)1'2 ] = 48.00 Lb = 48.00(0.63) = 30.00 in. Available length to develop reinforcement, t,a„+ bt= 8.04 + 18.00 = 26.04 in. < (Lb= 30.00 in.), therefore hook is required provide hook analysis Toe - Design p,-mtn = -1034 psf/ft p„-max = 4024 psf%ft Compute point of zero shear, footing width, B = 5.84 ft. x = 1-1034.01(5.84) / (1-1034.01 + 4024.0) = 1.19 ft. Critical shear location (from x ), Ls= B - x - bt+ d /12 = 5.8 - 1.19 - 1.5 + 6.50/12 = 3.69 ft. Critical bending location (from x ), Ls= B - x - bt = 5.8 - 1.19 - 1.5 = 3.15 ft. Check shear 1 Factored load at shear location = Ls (AaX) / (B - x) = 3.7(4024) / (5.84 - 1.19) = 3194 psf/ft VU,o= 1.4(w�)(tt.) = 1.4(150 pcf)(0.83 ft) = 174.9 lb/ft VUL = 1/2(press @ shear loc + p„ _,ax) = 1/2(3194 + 4024) = 3609 lb/ft 11006 60" AVE WEST - MUKILTEO WA 98275 PHONE (425) 343-7517 - FAX (425) 493-8388 CUSTOM DESIGN & ENGINEERING, INC STRUCTURAL ANALYSIS & DESIGN Vc= -VUo+ VU,L= -175 + 3609 = 3434 Ib/ft < (� Vu= 6626 Ib/ft) OK Check bending Factored load at bending location = Lb (pu-max) / (8 - x) = 3.1(4024) / (5.84 - 1.19) = 2725 psf/ft MU,t,= 1.4[ 1/2(wc)(bt)2] = 1.4[1/2(150)(1.50)2= 236 ft-lb/ft Mu,L= [1 /2(pu-max)(bt)2x 2/3 + 1/2(press @ bending loc)(bt)2x 1/3 MU,L= [1/2(4024)(1.50)2x 2/3 + 1/2(2725)(1.50)2x 1/3 = 4040 ft-lb/ft Use Mu = MU,L , Mv = 4040 ft-lb/ft Assume j d = d - a /2 = 0.875d = 0.875(6.50) = 5.68 in As= 4040(12) / [0.90(60000)(5.68)] = 0.158 in2/ft Check if As>_ A,,,;,, A,,i,= 3(f,)"2/fyx (b„,d) = 0.19 in2/ft> 0.16 in2/ft Use AS = 0.19 in /ft A�,n;,,= 200(b,,)(d )lfy= 0.26 in2/ft > 0.19 in2/ft As= 0.26 in2/ft Reinforcement Try No 5 @ 14.00 in., Abar= 0.307 sq.in. Provided, As-p,o„= Ata,(12 in/ft)/ spacing = 0.307(12)/14.000 = 0.263 in2/ft Compute a and check if fs= fyand if tension controls a = AS-povfyl (.85f,bw) = 0.263(60000) / [0.85(2500)(12.00)] = 0.619 in. a /d = 0.61916.496 = 0.095 ab/d = 0.582, Table A-4 - Compute ab ld > a ld , Therefore fs= fy OK Check if tension controls 11006 60" AVE WEST - MUKILTEO WA 98275 PHONE (425) 343-7517 - FAX (425) 493-8388 CUSTOM DESIGN & ENGINEERING, INC STRUCTURAL ANALYSIS & DESIGN a /df= a /d = 0.095 (one layer) at,/dr= 0.319, Table A-4 Compute at,ildt> a /dt, Tension controls & � = 0.90 � M„= 0 [A. -Pro fy(d - a /2)]/12 = 0.90(0.263)(60000)[6.50 - 0.62/2] = 7321 ft-Ib/ft (� M„= 7321 ft-Ib/ft) > (Mu= 4040 ft-Ib/ft) OK Check development Ldl db= fya R X / [25(f�)12] Ldldb= 60000(1.00)(1.00)(1.00) / [25(2500)12J = 48.00 Lb = 48.00(0.63) = 30.00 in. Available length to develop reinforcement, t,,,,a„+ bh = 8.04 + 44.04 = 52.08 in. > (Lb = 30,00 in.), therefore OK Wall - Design Total height of wall, HW= H - ttoe = 8.00 - 0.83 = 7.17 ft. w I = K,, y H., = 0.333(120)(7.17) = 286.7 psf/ft w 2 = K,, pQ = 0.333(0) = 0.0 psf/ft Factored Shear at base Vu= 1.7(1/2w 1 Hs+ w 2 Hs) = 1746 Ib/ft Factored Moment (check this) at base Mu= 1.7[1/3(1/2w I H,)(H,,) + 1/2(w2 H,,)H,] = 4172 Ib/ft Check shear Vu= � (2fc'r bwd) � = 0.85 f,= 2500 psi b,,= 12.00 in. d = t„,,„(12) - 3 in cover - 1/2 in bar dia = 0.67 ft(12 in/ft) - 3" - 1/2" = 4.54 in 11006 60'" AVE WEST - MUKILTEO WA 98275 PHONE (425) 343-7517 - FAX (425) 493-8388 CUSTOM DESIGN & ENGINEERING, INC STRUCTURAL ANALYSIS & DESIGN � Vu= 0.85[2(2500)(12.00)(4.54)] = 4631 Ibs (� Vu= 4631 Ib/ft) > (Vu= 1746 Ib/ft) OK Check Bending Assume j d = d - a /2 = 0.875d = 0.875(6.50) = 5.68 in As= 4172(12) / [0.90(60000)(5.68)] = 0.163 in /ft Check if As? A,j, As -min= 3(f,)'r'lfy- (bN,d) = 0.19 in2/ft> 0.16 in2/ft Use As= 0.19 in2/ft A,,,,;n= 200(b,,)(d)/fy= 0.26 in2/ft > 0.19 in2/ft As= 0.26 in2/ft Reinforcement Try No 5 @ 14.00 in., Aba,= 0.307 sq.in. Provided, AS�Pm= AbAl2 in/ft)/ spacing = 0.307(12)/14.000 = 0.263 in2/ft Compute a and check if fs= fyand if tension controls a = A".vfyl (.85f�b„,) = 0.263(60000) / [0.85(2500)(12.00)] = 0.619 in. a Id = 0.619/6.496 = 0.095 ab /d = 0.582, Table A-4 - Compute ab ld > a /d , Therefore f, = fy OK Check if tension controls a /dt= a /d = 0.095 (one layer) at,/dr= 0.319, Table A-4 - Compute at,/dt> a /dr, Tension controls & 0 = 0.90 � Mn = � [A�P,o„ fy (d - a /2)]/12 = 0.90(0.263)(60000)[6.50 - 0.62/2] = 7321 ft-lb/ft 11006 60T" AVE WEST - MUKILTEO WA 98275 PHONE (425) 343-7517 - FAX (425) 493-8388 CUSTOM DESIGN & ENGINEERING, INC STRUCTURAL ANALYSIS & DESIGN (� M„= 7321 ft-Ib/ft) > (Mu= 4172 ft-Ib/ft) OK Check development Ldl d, = fy a R ), / [25(f, )" ] Ldldb= 60000(1.00)(1.00)(1.00) / [25(2500)'/2] = 48.00 Lb = 48.00(0.63) = 30.00 in. r ' ` R �O �G -;Z �G`��� �SS�OIVAL �G` 11006 60T' AVE WEST - MUKILTEO WA 98275 PHONE (425) 343-7517 - FAX (425) 493-8388 1 Associated Earth Sciences, Inc. M IN W ' Cefekrab Over25 -Jean of Semce ' January 10, 2008 Project No. KE050550B 1 Mr. Kyle Ray 702 4`h Avenue South Edmonds, Washington 98020 Subject: Revised Subsurface Exploration, Geologic Hazard, and Geotechnical Engineering Study Proposed Ray Residence Re -Construction 15625 75t' Place West Edmonds, Washington Parcel No. 00513100002402 1 Dear Mr. Ray: Associated Earth Sciences, Inc. (AESI) is pleased to present this revision of our subsurface exploration, geologic hazard, and geotechnical engineering study for the referenced project. This study is based on our discussions with you, architectural. plans by Hanson Design, our site observations, and our experience on other projects in the site vicinity. This study is a revision of our October 27, 2005 study for the previously proposed remodel, which was changed to a complete demolition and re -construction of the house due to plan/field conflicts. In addition, this study has been updated to comply with the revised Critical Areas Ordinance 3632 for the North Edmonds Earth Subsidence and Landslide Hazard Area. The purpose of this study was to gather geotechnical data and provide geotechnical conclusions ' and recommendations for the proposed re -construction. This study was prepared using field observations, subsurface explorations, and published sources of geotechnically pertinent 1 information. This study has been prepared for the exclusive use of Mr. Kyle Ray and his agents for specific application to this project. Within the limitations of scope, schedule, and budget, our services have been performed in accordance with generally accepted geotechnical engineering and engineering geology practices in effect in this area at the timerouZ'letter.�was�,® prepared. No other warranty, express or implied, is made. MAY - 2 Z9VI tBUILDING DEPT_ 1 STREET FILE Kirkland Everett Tacoma ' 425-827-7701 425-259-0522 253-722-2992 www.aesgeo.com 1 ' DESCRIPTIONS .SITE AND PROJECT The project site is located on the east side of 75t' Place West in Edmonds,. Washington (see Figure 1, "Vicinity Map"). The project site is currently a vacant, single-family, residential lot. A previous dwelling, which was demolished the summer of 2007, consisted of a one-story rambler with a partial daylight basement under the approximate southern half of the residence. We understand that the north half of the residence was constructed in the 1950s with the south half, including the basement, added on in the 1970s. A wood deck . was located on the west side of the house. The lot is bounded on the west by 75`h Place West, on the north and south by single-family residences, and by a steep, west -facing slope on the east. The Burlington Northern Railroad right-of-way is located adjacent the shoreline of Puget Sound west of the project site and adjacent properties. We understand that in 2007 a remodel of the existing residence was permitted by the City of Edmonds. However, conflicts between the designed structure and the field measurements, as well as structural defects in the portions of the house to remain, prompted a complete ' demolition and re -construction of the house. Our initial review of the new plan set by Hanson Design indicates that the proposed footprint will be similar to the previous structure and permitted remodel. The major structural differences between the proposed structure and the . previous structure are: • Construction of a second story on the south half of the house and conversion of the basement into a garage with slab -on -grade floors; • Expansion of the kitchen (adding approximately 5 feet 6 inches by 15 feet on the west side of the previous existing residence, including construction of a new wall foundation and retaining wall in place of the previous rockery); r • Construction of two deck footings on the west edge of the residence; and • Deletion of the backdoor alcove to provide a straight rear (east) wall with a 3-foot-high catchment wall for mitigation of debris flows. We understand that the proposed improvements will limit excavations to those necessary to construct foundations and install buried utilities, largely within the approximate existing footprint of the existing structure. We further understand that final site grades will not be significantly changed from the existing grades. SITE OBSERVATIONS Our site observations were made during two site visits in August and September. of 2005,: as well as ongoing erosion control inspections during the winter/spring of 2007-2008. The following sections describe,our visual observations. t ' 2 Geologic Reconnaissance The previous and proposed house location is a flat bench. on the lower half of a large slope system, the top of which is on the order of 100 feet above and 150 feet to the east. The slope system drops down to the west from 75`h Place West to Puget Sound across a vertical relief on the order of 100 feet. The steep slope on the east edge of the property ranges from 2H:1V to 1H:1V (Horizontal: Vertical) inclinations, based on visual estimates. An over -steepened area interpreted to be an old slide scarp was observed directly east of the project site approximately 50 feet above the existing dwelling. The scarp was visually estimated to be on the order of 40 feet in length and 5 to 10 feet in height. The slope is densely vegetated with ferns, maple trees, and other shrubs. Most of the deciduous trees had bowed trunks indicating slope creep, ' but several evergreen trees higher up the slope appeared relatively straight. Some of the larger trees near the. base of the slope appear to have been topped and trimmed in the past. A ' concrete, masonry block wall on the order of 2 feet in height is located near the toe of the slope. The toe of the steep slope is approximately 25 to 35 feet east of the existing dwelling. This slope area and scarp are .part of the North Edmonds Earth Subsidence and .Landslide Hazard Area, formerly known as the Meadowdale Earth Subsidence Landslide Hazard Area. This landslide complex is comprised of both ancient, deep-seated failures and recent shallow debris flow . failures. Studies by others have generally concluded that the deep-seated movements have stopped or been minimal over the last few.decades since the toe of the slope system has been buttressed by the railroad ballast and drainage improvements have kept ground water levels relatively low. Shallow movements in the lower, previously failed portions of the slide complex and debris flows in the steep upper portions near the ancient slide scarp continue ' to experience occasional failures in recent years.. Since this landslide complex is well - documented and studied by others over the last half century, a complete history is beyond the scope of this letter. Additional information regarding this slide complex can be found in the ' studies by others listed in the "Literature Review" section of this letter. 1 In the streets and unimproved right-of-ways at the top of the slope, we observed asphalt berms and catch basins that appeared designed to collect surface water from the streets and easements. We understand that drainage improvements were completed near the upper,, developed portions of the slope in the late 1990s after some shallow slides occurred on the t slope several properties to the north and one property to the south. The site is currently winterized for temporary erosion control after demolition of the previous dwelling. Winterization measures included construction of a silt fence on the downgradient side of the lot, placement of crushed rock on the construction entrance and. driveway .pavement . edges, and placement of hydroseeded mulch over the bare ground. Grass growth from the hydroseed has been established on the site. The erosion control measures have performed. well . since implemented. 3 ' Previous Structure Reconnaissance ' Prior to demolition, we examined accessible areas of the previous structure for visible signs of settlement or distress. We observed that the southwest corner of the basement -level foundation. had settled away from the bottom of the wall approximately 1 inch. The foundation appeared to consist of concrete masonry units (CMUs) embedded approximately 6 inches into the ground with the block openings oriented in the vertical direction. No visible structural connection was observed- between the wood -framed wall and .the CMU block foundation. We observed a concrete basement retaining wall on the east side of the furnace room of the portion built in the 1970s that appeared to be in good condition. Other than the area described above, we did not observe other signs of distress in the structure, such as wall cracks and out -of -square windows and doorways. The owner informed us that he was not aware of problems with sticking doors or windows or other indicators of settlement. SUBSURFACE CONDITIONS The following subsurface conditions are based on our limited explorations and our literature review of previous studies performed in the project vicinity. Subsurface Explorations Our field study included four hand -auger. exploration borings (HA-1 through HA-4) performed ' in August 2005 and a visual geologic reconnaissance performed. in September 2005 to gain information about the site. Materials encountered in the explorations were classified in the field by an engineer from our firm. Dynamic Cone Penetrometer (DCP) blow counts were recorded at select depths in the explorations to aid in determining the relative density of the soils in accordance with American Society for.Testing and Materials (ASTM) Special Technical Publication #399. The explorations were allowed to .stand open for several hours to observe ' potential ground water seepage and were backfilled prior to departing the site. Selected samples from the explorations were transported to our laboratory for further visual classification, as necessary. The various types of sediments, as well as the depths where characteristics of the sediments changed, are indicated on the exploration logs presented in the Appendix. The depths indicated on the logs where conditions changed may represent gradational variations between sediment types in the field. Our explorations were approximately located in the field by measuring from known site features shown on the aforementioned "Site and Exploration Plan" (Figure 2). Literature Review We reviewed our in-house files, select City of Edmonds-. reports,. and publicly available , exploration data from the GeoMapNW website . (http://geomapnw.ess.washington.edu/index.php) at.the University of Washington for previous 1 4 'geotechnical studies performed in the project vicinity. Our research revealed exploration logs from the following studies: • "Subsurface Exploration, Geologic Hazards, and Preliminary Geotechnical Engineering Report, Aldridge Short Plat, Edmonds, Washington," dated October 24, 1997 by AESI (from AESI in-house files). This study included the two lots directly across 751' Place West from the project site (15604 75' Place West). Three exploration borings and four exploration pits were performed at the Aldridge site, which generally encountered fill over disturbed silts/clays over very dense fine sands. Slope inclinometers were installed in two of the borings. and were measured periodically over a period of ' approximately 3 years. Measurements indicated shallow, downslope creep of the fill in the upper 10 feet on the order of 1 inch or less over the measurement period, .with the majority of the movement occurring near the top of an uncontrolled fill slope on the ' west side of the property. The site has remained undeveloped atthe time of this letter. • "Revised Geotechnical Report, Proposed Residence at Lots 1 and 2, 75`h Place West, Edmonds, Washington," dated January 26, 1994 by Shannon and Wilson, Inc. (GeomapNW excerpts only):. This study included two lots across 75t' Place West to the southwest of the project site (15620 '75`h Place West). One exploration boring was performed at the site and two exploration pits by Earth Sciences were included in the report, which generally encountered fill/slide . debris over . stiff to hard . silts/clays. (According to Snohomish County tax records, a two-story dwelling was constructed in 1997). • "Geotechnical Engineering Study, Recent Landslide, 15620 - 72"d Avenue West, Edmonds, Washington," dated February 24, 1997 by Geotech - Consultants, Inc. (GeomapNW excerpts only). This study included the lot upslope (east) and one property south of the project site. Three exploration borings were performed at the site, which generally encountered dense, gravelly sands over medium dense to dense, silty sands over very dense sands. 1 • "Subsurface Exploration, Geologic Hazards, and Preliminary Geotechnical Engineering 1 Report, Summers Residential Property, Edmonds, Washington," dated December 31, 1991 by AESI (from AESI in-house files).. This study included a lot upslope from the northeast corner of the project site (7222 72"d Avenue West). Three exploration ' borings were performed at the Summers site, which encountered very dense lodgement till and advance sands. in one boring. • "Geotechnical Evaluation, Proposed Hansen Residence Addition Project, 15615-75`' Place West, Edmonds, Washington," dated June 1, 1999 by Dennis. M. Bruce, P.E.. (from AESI in-house files). This study included the adjacent lot immediately north of the project site. Two test holes were dug on the property using a power hand'auger, which generally encountered moderately, dense to dense, ' clean sand over very dense silt and silty sand with cobbles. 1 5 LJ '•"Report fGeologic Evaluati n Meadowdale Area Edmonds Washington,'.' " dated • po t o o, g , ' September 23, 1968 by Dames & Moore (provided by the City of Edmonds). This study evaluated the overall stability of the area from a geologic standpoint based largely on literature review and surface reconnaissance for installation of a proposed sanitary - sewer system. • "Final Report, Landslide Hazards Investigation, Meadowdale Area, Edmonds, Washington," dated October 16, 1979 by Roger Lowe Associates, Inc. (provided by the City of Edmonds). This study analyzed the subsurface conditions and slope stability based on previous studies and seven borings performed for the study. The study provided a landside hazard map of the Meadowdale area, which quantified landslide risk by type and probability of occurrence in a 25-year period. ' • "Report of Geotechnical Consultation, Property Value Appraisals and Assessments, Meadowdale Landslide Area, Edmonds, Washington, dated February 28, 1985 by ' GeoEngineers, Inc. (provided by the City of Edmonds). This study updated the probability of landslide occurrences as provided in the 1979 Lowe study after installation of storm and sanitary sewers in the Meadowdale area. • "North Edmonds Earth Subsidence and Landslide Hazard Area Summary Report, Edmonds, Washington" dated March 14, 2007 by Landau Associates. This study included review of the previous Meadowdale landslide area studies by. Lowe and GeoEngineers. Landau also recommended several revisions to critical areas ordinance in earth subsidence and landslide hazard areas, including the designation of five hazard zones based on relative location within the landslide complex. Furthermore, the study recommends specific report requirements, which will be discussed subsequently in this letter. This study uses the name "North Edmonds Earth Subsidence and Landslide ' Hazard Area" (NEESLHA) instead of the previous "Meadowdale" area name. Our literature review was not meant to be all inclusive, as other studies in the project vicinity may exist but were not available for our review. Pertinent information from these studies is discussed in subsequent sections of this letter, where appropriate. Relevant logs for the above - referenced explorations have been included in the Appendix of this letter. Soil Conditions Subsurface conditions on the project site were inferred from the field explorations accomplished for this study, visual reconnaissance of the site, and review of applicable geologic/geotechnical literature. As shown on the field logs, the explorations on the project site generally encountered silty sand with various gravel fill over sandy silt to silty sand soils interpreted to be old landslide material. The following section presents morel detailed ' subsurface information organized from the upper (youngest) to the lower (oldest) sediment types. 6 Fill Material interpreted to be man -placed fill was encountered in all the explorations on the project site. The fill consisted chiefly of medium dense, silty sand with various gravel,. concrete debris, cinders, asphalt debris, and landscaping rocks. Old Landslide Material interpreted to be old landslide soils were encountered in all the explorations on the project site. The old landslide soils consisted chiefly of medium stiff to stiff, fine sandy silt ' and medium dense, silty fine sand with a disturbed, blocky texture. Exploration boring HA-1 encountered an approximately 41/2-foot layer of fine to medium sand within the interpreted old landslide deposit.. Explorations from the other studies in the project vicinity listed above indicate similar landslide materials that extend well below existing grades in the project area on the order of 30 to 60 feet below existing grades. The soil conditions encountered in our explorations were consistent with the soils mapped in the Preliminary Surf cial Geologic Map of the Edmonds East and Edmonds West Quadrangles, ' Snohomish and King Counties, Washington (Smith, 1975). The geologic map indicates that the site is characterized by Qols (old landslides) on the southwest portion of. the site. The northeast portion of the site appears to be mapped as Qw (Whidbey formation), although no explorations were performed there to confirm this. The maps also indicate Qdb (Double Bluff) and Qe (Esperance sand) in the project vicinity. IGround Water Conditions No seepages or ground water were observed within our explorations. In addition, no seepages were observed daylighting on any of the steep slopes on the property during our exploration and subsequentsite visits for construction monitoring and erosion control. Based on .the exploration logs reviewed, for this . study, we estimate that the highest water level near the ' subject site may be approximately at: elevation 80. This estimate is based on ground water encountered in the Shannon and. Wilson boring attached to this letter. Based on the "moist" moisture contents. described below the seepage zone. encountered at a depth of 18 feet, this seepage may be indicative of perched. ground water above less permeable sediments: Ground water conditions should be expected to fluctuate with season, precipitation, site usage, and other on- and off -site factors. GEOLOGIC HAZARDS The following discussion of potential geologic hazards is based on the geologic, slope, and shallow ground water conditions as observed and discussed herein. 1 Landslide Hazards and Mitigation ' The 2007 Landau study divides the potential landsliding locations within the NEESLHA into five zones, A through E. The subject site is located in Zones B and C, with the proposed house located in Zone B only. Zone B in the vicinity of the subject site is the relatively flat bench area between 75`h Avenue West and the .steep slope area of Zone C to the east- Zone B is described by Landau as including the majority of the landslide mass or complex consisting of ' typically disturbed soils .with occasional intact blocks, localized small-scale failures, and potential for large-scale sliding of the slide complex. Zone C is described by Landau as the area near the edge of the landslide complex that is most affected by slides that initiate on the ' steep slopes on the east side of this zone. Small-scale failures are possible within Zone C, and this zone is the highest risk to public safety. In our opinion, we concur with these generalized assessments and believe the primary risks of earth movement on the subject site that may affect the proposed dwelling will be from debris flows initiating on the steep slopes above the house. Another risk with a much lower likelihood of occurrence would be soil movement under the proposed foundation from reactivation of the main landslide mass. Risks of shallow and deep- ,. seated slides, and the associated mitigations, are discussed further in the following paragraphs. The potential landside risk can be divided into two depth categories`. shallowand deep. The potential shallow (on the order of 1 to 10 feet thick) landslide risk includes slumps, debris avalanches, and earth flows of the colluvial soils and trees on the steep slopes to the east of the I project site. The potential deep landslide risks for the site have been identified by previous studies in the site vicinity as continued movement of the ancient landslide blocks. 1 The potential for shallow slides is moderate and will be. greatest after extended periods of heavy rainfall and/or snow events. Such weather events occurred during the winters of 1996 and 1997 and resulted in numerous shallow slides in the Meadowdale area and around Puget Sound. Mitigation for such slides include proper handling and discharge of surface storm water, reduction in ground water levels, and trimming or removal of large trees in the potential slide zone. We understand that since the 1996 and 1991 events, City improvements to surface water management of the right-of-ways above the slope to the east have been implemented, including installation of street drainage berms, catch basins, and prevention of storm ' water discharges onto or near the slope. These improvements will reduce the potential for saturation of the colluvial soils and the contribution from upgradient surface water infiltration to ground water levels and seepages. The large deciduous trees directly up slope* from the proposed project area appear to have been trimmed and topped some time in the past,. reducing the . potential for direct fall damage.. The proposed structure will be .set.back from the toe of the slope approximately 25 to 35 feet, which should provide suitable distance for the dissipation of minor, shallow slides/masses. The moderate risk of earth and debris flow damaging the dwelling was present for. the previous structure and will not be increased by the re- construction. However, additional debris -flow mitigation is recommended _ by extending the basement foundation wall 3 feet above the outside finish ground surface to create a- catchment wall. Extension of the foundation wall would allow for debris -flow material to impact the back of the residence without buckling wood framing and damaging. the structure. 1 Deep-seated landslides risks at the project site would most likely be related to reactivation of the ancient landslide blocks estimated to have' occurred thousands of years ago after the retreat of glacial ice and subsequent draining of glacial lakes. The large-scale lowering of regional ground water levels and continued erosion of the toe of the slopes by wave action resulted in unstable, oversteepened coastal bluff conditions. Mitigations for deep-seated slides at coastal bluffs include armoring of the base of the bluff to prevent wave erosion. The riprap embankment placed during the construction of the Burlington Northern Railroad tracks .has ' provided protection from wave -action erosion. To our knowledge, no evidence of recent movement of the deep-seated slide planes has since been documented. The 1980s. drainage improvements in the 75`h Place West right-of-way and 1990s drainage improvements at the top ' of the steep slope have also reduced the potential for reactivation of, the deep-seated slide planes. Mitigations for deep-seated landslides should include design and construction of a relatively rigid, grid -type shallow foundation system designed to mitigate differential ' foundation soil displacement. The primary purpose of the rigid grid foundation will be to create a monolithic foundation unit, which will be able to bridge potential, localized areas of settlement or resist soil creep movement. Specific foundation recommendations are discussed in the "Foundations" section of this letter. It should be noted that no amount of engineering and mitigation measures can eliminate the potential for earth movement. Some risks will always remain inherent for properties located on or adjacent to steep slopes. ' Seismic Hazards and Mitigations ' Earthquakes occur in the Puget Lowland with great regularity. The vast majority of these events are small and are usually not felt by people. However, large earthquakes do occur as evidenced by the 1949, 7.2-magnitude event; the 2001, 6.8-magnitude event; and the 1965, 6.5-magnitude event. The 1949 earthquake appears to have been the largest in this region during recorded history and was centered in the Olympia area. Evaluation of earthquake return rates indicates that an earthquake of the magnitude between 5.5 and 6.0 is likely every ' 25 to 40 years in the Puget Sound basin. Generally, there are four types. of potential geologic hazards associated with large seismic ' events: 1) surficial ground rupture; 2) seismically induced landslides; 3) liquefaction; and 4) ground motion. The potential for each of these hazards to adversely impact the proposed ' project is discussed below. Surficial Ground' Rupture l i The nearest known fault trace to the project is the South Whidbey Island -Lake _A ce Fault. Recent studies by the U.S. Geological Survey (USGS) suggest that a trace of the northwest - southeast.. trending thrust fault zone may project through the North Edmonds ,area: The'-,... recognition of this fault, is relatively new, and data pertaining to it are limited with the studies still ongoing. According to the USGS studies, the recurrence interval of movement along this fault system is still unknown, although it is hypothesized to be in excess of several thousand � 9 years. Due to the suspected long recurrence interval, the potential for surficial ground rupture at the subject property is considered to be low to moderate during the expected life of the ' structure with associated seismically induced ground displacements also' contributing to the surface rupture. Mitigations for ground rupture and/or displacements should include design and construction of a relatively rigid, grid -type shallow foundation system, as described above and discussed in the "Foundations" section of this letter. ' Seismically Induced Landslides The project site is located in the North Edmonds Earth Subsidence and Landslide Hazard Area, of which the risks of landslides have been discussed most recently in the 2007 Landau report and are discussed above. In our opinion; the risks associated with the above -described hazards are low to moderate under static conditions. Ground accelerations associated with a strong earthquake may reactivate movement along the old slide planes and result in a higher potential for landslides and ground displacements. This risk was present for the previous structure under which the project was originally permitted as a remodel. The current proposed structure will be in the same approximate footprint and the seismic landslide risk will . not be increased by the proposed re -construction. We recommend mitigating damage to the proposed ' improvements by design and construction of a relatively rigid, grid -type, shallow, foundation system as described in the "Foundations " section of this letter. The resulting foundation system will serve primarily to mitigate damage to the structure during differential -ground ' displacements. Liquefaction ' Liquefaction is a condition where loose saturated, sand soils lose strength when subjected to q Y g subjected high intensity, cyclic loads of very short duration, such as occur during earthquakes, pile I. driving, and blasting. The' resuiting loss in bearing strength can cause differential foundation settlements and slope failures. Loose, saturated, clean,. fine-grained sands, which cannot dissipate the buildup of pore water pressure, are the predominant type of sediments subject to liquefaction. Based on our review of our explorations and our literature review of other explorations in the project vicinity, it is our opinion that the potential for liquefaction is low due to the high fines content and/or high relative density of the soils encountered. Ground Motion ' The guidelines resented in the 2006 International Building Code IBC Section 1613 should g P 8 (IBC) be used in the seismic design of the project. The USGS Earthquake Hazards Program web site (http://earthquake.usgs.gov/hAzmaps/) was used to determine interpolated probabilistic ground. . motion values in percent of: gravity (g) for an event. with a return period of 2 percent exceedance in 50 years. Using the web site, the project area was submitted using latitude and ' longitude for mapped spectral accelerations of Ss = 1.24 for short periods (0.2 seconds) and S = 0.44 for a 1-second period. Based on the results of our subsurface exploration and literature review and our estimation of soil properties at depth utilizing available geologic data; Site ' Class "D" in conformance with Table 1613.5.2 of the IBC may be used. These .values ' .10 1 1 1 1 H fl correspond to site coefficients Fa = 1.0 and Fv = 1.56 in conformance with IBC Tables 1613.5.3(l) and 1613.5.3(2), respectively. CONCLUSIONS AND RECOMMENDATIONS Prior to demolition of the previous dwelling, the project site was developed with an occupied single-family residence within the North Edmonds Earth Subsidence and Landslide Hazard Area. Therefore, the risks described above were already present for the existing structure. It is our understanding that the owner fully understands and accepts the risks of the landslide hazards as discussed in this letter. We also understand that. potential future owners will be aware of the risks associated with owning property in the North Edmonds Earth Subsidence and Landslide Hazard Area because such a notice is required on the property title. The purpose of our study was to assess these risks based on current, site -specific, slope and soil conditions and provide recommendations for minimizing and mitigating adverse impacts to the slope by the proposed improvements. Since the project chiefly involves replacing the structure in the same approximate footprint, it is our opinion that the overall impact to the stability. of the slope will not be adversely affected provided our recommendations are followed. Furthermore, the improvements will result in a safer structure since the improvements will be constructed on a relatively rigid foundation system and built to current building codes and replace the CMU block foundation under the south half of the residence. The following sections present our recommendations for design and construction of the proposed improvements. Temporary Excavation Slopes We anticipate that temporary cut slopes may be necessary for overexcavation in footing areas and for installation of buried utilities. In our opinion, stable construction slopes should be the responsibility of the contractor and should be determined during construction. For estimating purposes, however, we anticipate that temporary, unsupported cut slopes over 4 feet can be made at a maximum slope of 1.5H:1V in the site soils.. Typical trench -box shoring for excavations deeper than 4 feet should be considered for safety of 'workers and to minimize site disturbance. As istypical with earthwork operations, some sloughing and raveling may occur and cut slopes may have to be adjusted in the field. In addition, WISHA/OSHA regulations should be followed at all times. Structural Fill Structural fill will be necessary to provide, suitable footing and slab -on -grade floor subgrades and for backfill. of utility trenches. Significant thicknesses of additional fill on the site are not anticipated nor recommended. All references to structural fill in this letter refer to subgrade preparation, fill type, placement, and compaction of materials as discussed in this section. 'If a percentage of compaction is specified under another section of this letter, the value, given in that section should be used. ,. 11 ' excavation, and an required overexcavation has been performed to After stripping, planned excavat o y q the satisfaction of the geotechnical engineer or his representative, the upper, 12 inches of ' exposed ground should be compacted to a firm and unyielding condition, as determined by the geotechnical engineer or his representative. If the subgrade contains too much moisture, adequate compaction may be difficult or impossible to obtain and should probably not be attempted. In lieu of compaction, the area to receive fill should be. blanketed with clean, coarse, crushed rock or quarry spalls to act as a capillary break between the new fill and the wet subgrade. Where the exposed ground remains soft and further overexcavation is impractical, placement of an engineering stabilization fabric may also be necessary to prevent contamination of the free -draining layer by silt migration from below. ' After compaction of the exposed round is tested and approved, or a free -draining rock course P P g PP is laid, structural fill may be placed to attain desired grades. Structural fill is defined as non - organic soil, acceptable to the geotechnical engineer, placed in maximum 8-inch loose lifts with each lift being compacted to at least 95 percent of ASTM:D 1557. In the case of roadway and utility trench filling in the City right-of-way, the backfill should also be placed and ' compacted in accordance with City codes and standards. ' The contractor should note that any proposed fill soils must be evaluated by AESI prior to their use. This would require that we have a sample of the material at least 72 hours. in advance to either perform a Proctor test and/or determine its field suitability. Soils in which the amount of fine-grained material (smaller than the No. 200 sieve) is greater. than approximately 5 ' percent (measured on the minus No. 4 sieve size) should be considered moisture -sensitive. Use of moisture -sensitive soil in structural fills should be limited to favorable dry weather and dry subgrade conditions. The on -site soils contained substantial amounts of silt and ..are considered highly moisture -sensitive when excavated and used as fill materials. At the time of our exploration program, soil moisture contents were at or above optimum for .structural fill iuse. We anticipate that the some of the excavated site soils may require aeration and drying prior to compaction in structural fill applications. Construction equipment traversing the site when the soils are wet can cause considerable disturbance. If fill is placed during wet weather or if proper compaction cannot be obtained, a select, import ' material consisting of a clean, free -draining gravel and/or sand should be used. Free -draining fill consists of non -organic soil with the amount of fine-grained material limited to 5 percent by weight when measured on the minus No. 4 sieve fraction and at least 25 percent retained on ' the No. 4 sieve. Foundations We. understand that the new foundations will remain within the approximate footprint of the previous house .and deck. With proper design, subgrade preparation, embedment, and construction, it is our opinion that the proposed foundations will not decrease the stability of the existing slopes provided the recommendations of this letter are followed. 1 12 ' The served foundation settlements on the west side of the existing basement level were likely observed g y due to inadequate footing size, and poor subgrade preparation and construction on uncontrolled ' fill. We have discussed with the owner, the option of supporting the improvements on deep foundations to mitigate potential excessive settlements due to the presence . of the uncontrolled fill and possible continued movement of the old landslide materials. Based on the expected 30- to 60=foot depth of old landslide materials on the project site, , we anticipate that deep foundations would only provide vertical support and could not practicably be constructed to ' resist the lateral displacements should the old, deep-seated landslide block become active. We understand that the owner wishes to use spread footings for foundation support and has accepted the risk that even static, post -construction settlements may. result in drywall cracks, tilting of window/door jambs, and other largely cosmetic damages may occur. Due to the presence of uncontrolled fill and variations in old landslide soils present at the ' anticipated bottom of footing elevations, we recommend that •all new footings bear on a minimum, 2-foot-thick layer of structural fill. The width of the structural fill pad should be 2 ' feet wider than the width of the footing. Structural fill type, placement, and compaction recommendations are provided in the "Structural Fill" section of this letter. The existing fill. soils must be removed under new foundations or overexcavated and recompacted as structural ' fill if moisture conditions allow. All organics, debris, and soft/loosened soil must be removed from the .footing areas prior to placement of structural fill, and be confirmed by a representative from AESI. During wet weather, it is highly recommended that footing _ ' subgrades be protected from disturbance with several inches of compacted crushed rock. Continuous and column pad spread footings may be used for building support. when founded on ' the approved 2-foot-thick layer of structural fill discussed above. Column pad footings should be structurally tied together in two directions in a grid -type formation to, mitigate excessive ground displacements. The foundation system should be designed to span a loss of support of ' 10 feet.. The owner should be aware that the primary purpose of tying together foundation elements is to prevent mitigate or lessen damage to the structure due to potential soil displacements, as discussed previously. We recommend that a maximum allowable foundation. ' soil bearing pressure of 2,000 pounds per square foot (psf) be utilized for design purposes, including both dead and live loads, for footing subgrades prepared as described herein. An ' increase of one-third may be used for short-term wind or seismic loading. It should be noted that the area bounded by lines extending downward at 1H:1V from any ' footing must not intersect another footing. In addition, a 1.5H:1V line extending down from any. footing must not daylight because sloughing or raveling may eventually undermine the footing. Thus, footings should not be placed near the edge of steps or cuts in the bearing soils unless adequately embedded. Anticipated settlement of footings founded on approved structural fill as described above. should be. approximately 1-inch or less.. Disturbed soil not removed from footing excavations prior to footing placement could result inincreased settlements. All footing areas should be inspected by AESI prior to placing concrete to verify that the: design bearing capacity of. the ' soil has been attained and that construction conforms to the recommendations contained in this ' 13 1 letter. Such inspections may be required by the City. Perimeter footing drains should be provided as discussed under the section on "Drainage Considerations." Lateral Earth Pressures ' All backfill behind walls or around foundation units should be .placed as per our recommendations for structural fill and as described in this section of the letter. Horizontally ' backfilled walls, which are free to yield laterally at least 0.1 percent of their height, may be designed using an equivalent fluid density equal to 35 pounds per cubic foot (pcf). Fully restrained, horizontally backfilled, - rigid walls that cannot yield should be designed for an equivalent .fluid density of 55 pcf. A surcharge equivalent to 2 feet of soil should be added to ' the wall height for walls with adjacent parking or driveway areas. Surcharges due to sloping backfill or adjacent foundations should be included in the wall design. Due to the potential for rlandslide debris soils to rest against the back foundation stem wall, this wall should be designed to resist at least 3 feet of soil pressure above the outside finish ground elevation. The lateral pressures presented above are based on the conditions of a uniform backfill consisting of structural fill compacted to 90 to 92 percent of ASTM:D 1557. A higher degree of compaction is not recommended as this will increase the pressure acting on the .walls. A ' lower degree of compaction may result in settlement. Thus, the compaction level is critical and -should be tested by our firm during placement. In addition, only hand -operated. or walk - behind compaction equipment should be used within 5 feet of the walls to prevent excessive surcharge loads from heavy equipment. Perimeter footing drains should be provided for all retaining walls as discussed under the section on "Drainage Considerations." It is imperative that proper drainage be provided so that hydrostatic pressures do not develop against the walls. This would involve installation of a minimum, 1-foot wide blanket drain for the full wall height using imported, washed gravel against, the walls. The blanket drain and wall backfill should be capped with 12 inches of relatively impermeable soils .and sloped to drain away from the walls to prevent surface water intrusion directly into the drain system. Passive Resistance and Friction Factors ' Lateral loads can be resisted by friction between the foundations and the supporting structural fill soils, and/or by passive earth pressure, acting on the buried portions of the foundations. ' The foundations must be backfilled with compacted structural fill to achieve the passive resistance provided below. We recommend the following design parameters. • Passive equivalent fluid. = 250 pcf • Coefficient of friction = 0.30 Slab -On -Grade Floors Typical concrete slab -on -grade floors appear feasible when supported on a minimum, 12-inch thick layer of approved structural fill compacted to a firm and unyielding condition. Above the 12 inches of structural fill, we recommend 4 inches of washed pea gravel or approximately 5/8-inch clean crushed rock (no fines) to act as a capillary break. A plastic vapor retarder .of minimum 10-mil thickness should be placed directly over the capillary break. Construction of crawl spaces should also include covering the soil below the floor system with a plastic vapor retarder to reduce interior dampness. The contractor must take care to protect the plastic vapor barriers from punctures during construction. More stringent moisture protection details should be considered by the owner and architect if necessary to protect interior finishes. Drainage Considerations To facilitate drainage away from foundation elements, perimeter footings should be provided with a drain near the footing elevation. Drains should consist of 4-inch-diameter, rigid, perforated, polyvinyl chloride (PVC) pipe surrounded by at least 6 inches of washed drain gravel. The minimum diameter of the drain rock must be larger than the diameter of the perforations in the pipe. The level of the perforations in the pipe should be set approximately 2 inches below the bottom of the footing (perforations down) and the drains should be constructed with sufficient gradient to allow gravity flow away from the building to a suitable discharge. Cleanouts should be installed at appropriate intervals. Roof and surface runoff should not discharge into the footing drain system, but should be handled by a separate, rigid, tightline drain. Exterior grades; adjacent to walls, should be sloped downward away from the structure to achieve positive surface drainage. All collected water should be directed to an engineered storm drain system that drains away from the buildings, and not near, over, or onto steep slopes. Utility Connections Due to the potential for differential soil displacements at the project site, we recommend flexible connections between all utilities and the residence. The connections should allow up to 6 inches of ground movement. 15 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 CLOSURE We appreciate the opportunity to be of service to you on this project. Should you have any questions regarding this letter or other aspects of the project, please do not hesitate to call. We look forward to providing continued geotechnical services as the project progresses. Sincerely, ASSOCIATED EARTH SCIENCES, INC. \.A:i�:., r. Kirkland, Washington �0 .�.� Ark:! `` •\,n'..-r, � %�� �O. fir'„ 33222 Eric J. Lim, P.Lgineer Senior Project Attachments: Figure 1: Vicinity Map Figure 2: Site and Exploration Plan Appendix: Exploration Logs cc: Hanson Design Attn: Kristin Hanson 652 Alder Street Edmonds, Washington 98020 Custom Design and Engineering Attn:. Alex Moroseos, P.E. 11006 60`' Avenue West Mukilteo, Washington 98275 Donna L. Breske, P.E. 6621 Foster Slough Road Snohomish, Washington 98290 Construction Specialties, LLC Attn: Milynn Wetzel 7209 193`d Place SW EXPIRES 2/27 Za,-G G. Aaron McMichael, P.E., P.E.G. Associate Engineer. e09130903N oN roaa NOl'JNIHSVM'SUNOW03 9011 31VO 33NMIS3H AVM dVW AlINI3IA •aui'saOuaiaS g4zycg pairpossYr aanaid '0NI'S2133NI0N3030:93ueJ9;ea 31VOSON R I 1 I N � LEGEND ■ APPROXIMATE LOCATION OF ES EXPLORATION PIT (EP) OR TEST PIT (TP) GC W • APPROXIMATE LOCATION OF SW EXPLORATION BORING (EB)(B), HAND AUGER (HA) OR TEST DB HOLE (TH) o Reference: Snohomish County Online Property Information EARTH SCIENCES GEOTECH CONSULTANTS, INC. AN A SHANNON AND WILSON DENNIS BRUCE NO SCALE Associated Earth Sciences, Inc. SITE AND EXPLORATION PLAN FIGURE 2 RAY RESIDENCE ti MEMO EDMONDS, WASHINGTON DATE ��0s PROJ. NO. KE0505508 °o Well graded gravel and Terms Describing Relative Density and Consistency, m h cl o• 0 0 GW gravel with sand, little to Density SPTt�blows/foot d • no fines Very Loose 0 to 4 R > ° ° Coarse- Loose 4 to 10 y w ° ° ° ° ° o° o° o Poorly -graded gravel Grained Soils Medium Dense 10 to 30 Test Symbols rn `� ° ° ° ° ° GP and ravel with sand, g Dense 30 to 50 G = Grain Size N Z ° o ° o ° c 0 0 o little to no fines Very Dense > 50 M= Moisture Content d o O c o 0 0 Consistency SPTt2lblows/foot A = Atterberg Limits . z �° ° ° Silty gravel and silty Very Soft 0 to 2 C = Chemical o � r �y GM gravel with sand Fine- Soft 2 to 4 DD = Dry Density a) a) .m ° 0 ° 0 Grained Soils Medium Stiff 4 to 8 K = Permeability c -9 o ii 2 z Stiff 8 to 15 a) Clayey gravel and Very Stiff 15 to 30 GC clayey gravel with sand Hard >30 o Component Definitions Wel l-graded sand and Descriptive Term Size Range and Sieve Number co c g - ,: Syy sand with gravel, little Boulders Larger than 12" d C.)m ;-; : }:• to no fines Cobbles 3' to 12- tLc iz :•.•-•-•-• Gravel 3" to No. 4 (4.75 mm) N , ' :` : ' Poorly graded sand Coarse Gravel 3" to 3/4' U) 0 e VU '`• SP and sand with gravel, Fine Gravel 3/4" to No. 4 (4.75 mm) d `o � little to no fines Sand No. 4 (4.75 mm) to No. 200 (0.075 min) c Z Coarse Sand No. 4 (4.75 mm) to No. 10 (2.00 mm) Silty sand and Medium Sand No. 10 (2.00 mm) to No. 40 (0.425 mm) w a o w sM silty sand with Fine Sand No. 40 (0.425 min) to No. 200 (0.075 min) m rc o a .: •.. gravel . Silt and Clay Smaller than No. 200 (0.075 min) � LL • Clayey sand and (3) Estimated Percentage Moisture Content � � All SC clayey sand with gravel D Absence of moisture, Percentage by Dry - U) Component Weight dusty, dry to the touch Trace <5 Slightly Moist - Perceptible Si". sandy silt, gravelly silt, Few 5 to 10 moisture > U MIL silt with sand or gravel Little 15 to 25 Moist - Damp but no visible U) H t With -Non-primary coarse water m w Clay Of low to medium constituents: > 15% Very Moist - Water visible but N v �_� plasticity; silty, sandy, or - Fines content between not free draining z c m ' CL . gravelly clay, lean clay 5°� and 15°6 Wet - Visible free water, usually v, w E from below water table N J a5 —= Organic clay or silt of low Symbols 27 — oL plasticity Blows/6" or 0 __ Sampler portion of 6". Cement grout —= Type surface.seal % Elastic silt, Clayey silt, silt 2.0" OD Sampler Type o MH with micaceous or �5 Description Bentonile Split -Spoon „ N) seal o diatomaceous fine sand or Sampler, 3.0' OD Split -Spoon Sampler - ,; Filter pack with rn b m o silt Clay of high plasticity, (SPT) blank casing 3.25' OD Split -Spoon Ring Sampler at : g : section Bulk sample 0 to CH sand or ravel) clay, fat Y gravelly Y, 3.0.OD Thin -Wall Tube Sampler Screened casing c m E clay with sand or gravel (including Shelby tube) or Hydrotip : with filler pack ' C7 c -- v a, I Organic clay or silt of Grab Sample End cap . O Portion not recovered OH medium to high nl 14l Percentage by dry weight Depth of ground water plasticity f2t (SPT) Standard Penetration Test 1 ATD = At time of drilling I Peat, muck and other (ASTM D-1586) S[ Static water level (date) lit In General Accordance with. T C N i� rn rn "o PT highly organic soils Standard Practice for Description Combined USCS symbols used for = p rn and Identification of Soils (ASTM D-2488) fines between 5% and 15% d 'Classifications of soils in this report are based on visual field and/or laboratory observations, which include dens! consistency, moisture condition, gram size, an plasticity estimates and should not be construed to imply field or laboratory testing unless presented herein. Visual -manual and/or laboratory classification methods of ASTM D-2487 and D-2488 were used as an identification guide for the Unified Soil Classification System. 0 Associated Earth Sciences, Inc. [4. Axt aid . ME a EXPLORATION. LOG KEY i LOG OF EXPLORATION PIT NO. HA-1 L This log is part of the report prepared by Associated Earth Sciences, Inc. (AESI) for the named project and should be together that for interpretation. This applies only to the location of this trench at the CL read with report complete summary time of excavation. Subsurface conditions may change at this location with the passage of time. The data presented are o a simplfication of actual conditions encountered. DESCRIPTION. Fill 2" of crushed rock over medium dense, moist, brown, SILTY SAND with gravel and scattered 1 concrete debris and cinders. 2 Old Landslide Stiff, moist, tan, blocky, SILT with little fine sand and scattered rootlets (DCP at 2' = 12, 8, 8). 3 Loose, damp to moist, gray, fine to medium SAND with trace silt (DCP at 5' = 6, 6, 7). 4 5 Becomes finer. 6 Becomes coarser with iron oxide stains. 7 8 ------------------------------------------------------ Medium stiff to stiff, wet, tan, fine sandy SILT to silty fine SAND with occasional lenses of clayey silt (DCP at 8' = 13, 10). 9 10 11 Bottom of exploration pit at depth 11 feet 12 No ground water seepage observed at time of exploration or 4 hours after exploration. No caving observed. 13 14 15 16 17 18 19 , o. Ray Residence Re -Construction ' Edmonds; WA Associated Earth Sciences, Inc. o Logged by: EJL`. Project No: KE050550A Cl)" Approved by: '' ;.',r$ 8/13/05 11 LOG OF EXPLORATION PIT NO. HA-2 w This log is part of the report prepared by Associated Earth Sciences, Inc. (AESI) for the named project and should be read together with that report for complete interpretation. This summary applies only to the location of this trench at the O time of excavation. Subsurface conditions may change at this location with the passage of time. The data presented are o a simplfication,of actual conditions encountered. DESCRIPTION Fill 1 Medium dense, moist, brown, GRAVELLY SILTY SAND with scattered concrete debris. 2 3 4 5 ----------------- ---------------------- Landscape Rocks . 6---------------- 1" diameter rounded gravel. _ _ _ _ _ _ _ _ _ _ _ ' --------------------� _ Relic Topsoil/Fill Loose, moist to wet, brown to dark brown, SILTY SAND with scattered asphalt pieces. 7 Old Landslide Medium stiff to stiff, moist, tan, blocky, fine SANDY SILT (DCP at 8 1/2' = 10, 9). 8 9 Bottom of exploration pit at depth 8.5 feet No ground water or caving observed at time of exploration. 10 11 12 13 14 15 16. 17 18 19 S Ray Residence Re -Construction Edmonds, WA Associated Earth Sciences, Inc.. Logged by: EJL project No. KE050550A Ul * .L. Approved by: apJ 8/13/05 LOG OF EXPLORATION PIT NO: HA-3 . This log is part of the report prepared by Associated Earth Sciences, Inc. (AESI) for the named project and should be read to with that report for compplete interpretation. This summary applies only to the location of this trench at the time of excavation. Subsurface conditions may change at this location with the passage of time. The data presented are CD o a simplfication of actual conditions encountered. DESCRIPTION Fill Medium dense, moist, brown, silty SAND with few gravel and scattered concrete debris.. Sewer pipe in east sidewall (trench backfill). 2 3 Old Landslide 4 Medium stiff, moist, tan, FINE SANDY SILT to SILTY FINE SAND with scattered wood debris.(DCP at 4 1 /2' = 7, 7, 7). 5 6 7 (DCP at 6 1/2' = 10, 12, 12) Bottom of exploration pit at depth 7 feet 8 No ground water or caving observed at time of exploration. 9 10 11 1 12 13 14 ' 15 16 17 ' 18 19 .10 o o - Ray Residence Re -Construction Edmonds, WA o a Logged by: EJL Associated Earth Sciences, Inc. Project No. KE050550A ' Approved by: �� X, � °? �, , �,; 'u. L 8/13/05 ri . _ LOG OF EXPLORATION PIT NO. HA4 1 w This log is part of the report prepared by Associated Earth Sciences, Inc. (AESI) for the named project and should be read together with that report for complete interpretation. This summary applies only to the location of this trench at the time of excavation. Subsurface conditions may change at this location with the passage of time. The data presented are o a simplfication of actual conditions encountered. DESCRIPTION Fill Sod over medium dense, damp to moist, brown, SILTY SAND with few gravel. 1 2 3 4 Old Landslide 5 Medium dense, moist, tan, SILTY FINE SAND to FINE SANDY SILT, slightly blocky. 6 7 Bottom of exploration pit at depth 7 feet 8 No ground water or caving observed at time of exploration. 9 10 11 12 13 14 15 16 17 18 19 m S Ray Residence Re -Construction Edmonds, WA o .. Associated Earth" Sciences, Inc. Project No: KE050550A o Logged by: EJL 'Approved by: 8113105 a r Y EXPLORATION -PIT LOG Number EP-1 Soft, moist, brown with gray, silty CLAY to clayey SILT With roots. (Ditturbed Fill) Medium soft to stiff, moist, bluish -gray, silty CLAY to clayey SILT, brecciated; slickensides; layers of moist to wet, brown, fine sand; upper 1' slide debris. (Possession Drift) BOH @ 15' Note: No seepage; no caving. Number EP-2 Loose, moist, brown SAND AND GRAVEL mixed with silty clay/silt (Fill) Stiff to very stiff, moist, bluish -gray, clayey SILT to silty CLAY. (Possession Drift) BOH @ 18' Note: No seepage; no caving. Subsurface oondidons depicted represent our observation at the dme and location of this exploratory hole, modified by geologic . We will not interpretation, engineeringlysianas. and judgment. They are not necessarily representative of other times and locations accept responsibility for the use or interpretation by others of information presented on this log. Reviewed By Associated Earth Sciences; Inc. Aldridge Short Plat ' 911 Fifth Avenue, Suite 100 Edmonds, Washington Kirkland, Washington 98033 Project No. G97224A Phone: - 425-827-7701 September 1997 Fax: 425-827-5424 � EXPLORATION PIT LOG 1Numler Ea.3 1 ._ 1 1 Loose/soft, moist, dark brown, silty, fine SAND with roots. (Fill) Loose, moist, brown, medium SAND. (Fill) Loose, moist, reddish=brown, medium SAND with occasional gravel. (Fill) Stiff to very stiff, moist, bluish -gray, silty CLAY. (Possession Drift) BOH @ 18' Note: No seepage; caving. ' Number EP-4 0 5 10 1 15 Loose, dry, dark brown, silty, fine SAND with occasional gravel, roots, chunks of asphalt. (Fill) Loose, damp, reddish -brown, medium SAND wtih occasional gravel. (Fill) Stiff to very stiff, moist, bluish -gray, silty CLAY, slickensided surfaces; upper 1' slide debris. (Possession Drift) BON @ 16' Note: No seepage; caving 0 to 8'. ' Subsurface conditions depicted represent our observation at the time and location of this exploratory hole, modified by geologic interpretation, engineering analysis. and judgment They are not necessarily representative of other tines and locations. We wdl not accept responsibility for the use or irrierpretation by others of information presented on this log. Reviewed By: Associated Earth Sciences, Inca Aldridge.Short Plat 911 Fifth Avenue, Suite 100 Edmonds, Washington Kirkland, Washington 98033 Project. No. G97224A Phone: 425-827-7701 September 1997 Fax: 425-827-5424 EXPLORATION BORING LOG ' Number 'EB-1 Page 1 of 2 STANDARD .PENETRATION aZ w RESISTANCE SEDIMENT DESCRIPTION o Q Blows/Foot co 10 20 30 40 Damp, light brown, silty, fine SAND with trace roots; 8 bottom of sample damp, light brown with gray SILT I A with trace fine sand. Damp, brown, silty, fine SAND with lenses of silt with 5 4 trace fine sand; tip of sample damp, reddish -brown SAND with some small gravel. Damp, reddish -brown SAND with trace gravel. I 5 � No recovery. (Fill) 10 I A 4 �. ---------------------- 7...................... 't............ Moist to wet, light brown, silty, fine SAND; top of sample I 8� ` black charcoal with fine sandy silt. Moist, brown, silty, fine SAND: tiny roots observed. 15 I 6A I blue, silty CLAY, Damp to moist, plastic. CLAY, laminated. 20 : I Al2 Moist, blue, silty I CLAY to clayey SILT. I 1 ; Moist, blue, silty Moist, blue, silty CLAY to clayey SILT. 25 I - 22 Moist, blue, silty CLAY to clayey SILT. T 1 18A, I Moist, blue, silty CLAY to clayey SILT with lenses of 30 I , 22l j fine, oxidized sand; slicke.nsided surfaces observed. (Possession Drift) Damp to moist, light brown, silty, fine SAND, upper 70 portion oxidized. (Double Sluff Drift) subsurface condmns depleted represent our observaWns at the time and location of this exploratory hcle, modtlled by geomw Interpretations, eraneeft anaysls, and )udpment They are not necessarily repnesentatIve of other *nm and loeadons. We wM not accept responslbW for the use or brterpretadon by others of Information presented on this lop. Reviewed By r r Associated Earth Sciences, Inc. 911 Fifth Avenue, Suite .100 Kirkland, Washington 98033. r Phone?,..425-827-7701 Fax: 425-8277-5424 Aldridge Short Plat ` Edmonds, Washington Project No. G97224A September 199T 1� n 11 EXPLORATION BORING LOG Number EB-1 Page 2 of 2 W STANDARD PENETRATION JI Z W RESISTANCE 4. Bbws/Fod SEDIMENT DESCRIPTION o Q 0 fn 10 20 30 40 48A (Double Bluff Drift) -7 T BOH @ 36-1/2' Note: Slope, inclinometer installed_ 40 I - 45 j 50 55 I - 60 I 65 at the time and bcadw of this egbratory hob. moWled by 9�c9b Subsurface condltbns depleted represent our observatbns We vn11 not . interpretatbns, engieering n analysts; and Judgment They are not necessan7Y representathre of othertimea and bcatbna accept resPonsibW for the use or Interpretation by others of lnformalbn Presented on this log. Reviewed By Associated Earth -Sciences, Inc. Aldridge Short Plat 911` Fifth Avenue, Suite 100 Edmonds, Washington Kirkland, Washington 98033 Project No.. G97224A Phone: 425-827-7701 September 1997 ' Fax: 425-827-5424 a: u 1 EXPLORATION BORING LOG Number EB-2 Paqe 1 of 2 STANDARD PENETRATION Z W RESISTANCE SEDIMENT DESCRIPTION W (L � F 2 BIowslFoot 10 20 30 40 Damp, brown, fine to coarse SAND with trace fine (Fill) T 1 ---••..........................•---------........................ Damp; light brown SILT in top of sample; damp, light 5 I 7A gray, clayey SILT to silty CLAY in bottom of sample. Damp, gray, silty CLAY. (Slide Debris) I �12 Damp, gray, silty CLAY. 10 . T 1 16A ; Moist, bluish -gray, clayey SILT to silty CLAY. I. Moist, light brown, fine SAND in top of sample;. moist, 15 I 101 bluish -gray, silty CLAY in bottom of sample. . Moist, bluish -gray, silty CLAY; wet, medium SAND in 1 I 30 tip of sample. Moist, bluish -gray, silty CLAY. 20 I = 4 I Moist, bluish -gray, silty CLAY; fine sand lense in middle I 34 of sample. 1 I Moist, bluish -gray, silty CLAY; medium sand lense in. 25 I � 1 27 A middle of sample. (Possession Drift) 1 ...................... :..............--....----._.....------------------•--••-----...---.........------...----.....--- Damp to moist, light brown, fine SAND at top of sample; I 38 A medium sand lower half of sample. 1 30 73 Damp to moist, light brown, fine SAND. 1 Damp to moist, light brown, fine SAND. I 65 (Double Bluff Drift) subsuriace conditlons depicted represent our observations at the tlme and bcatlon of this explore Wry hole modtfled by geologic IMe,r„etatlons. enginewing amysis, and Judgment. They are not necessanly.represerd3e4e of other times and locations. We will not accept responeRMY for the use or Interpretation by others of Infonnatlon presented on d& log. Reviewed By Associated. Earth Sciences, Inc. Aldridge Short Plat 911 Fifth Avenue, Suite 100 Edmonds, Washington ' .Kirkland Washington 98033 Phone- 425-827--7701 Project No. G97224A ' September 1997 Fax: 425-827-5424 �y STANDARD PENETRATION aW j RESISTANCE ' SEDIMENT DESCRIPTION Q Q O Q Blows/Foot U) 0 ' 10 20 30 40 62 (Double Bluff Drift) BOH @ 36-1/2' 40 i 45 t 50 55 i 60 ' 65 Sutrstuface conditions depldod m our observations at the than and beatbn of this exploratory hole. modN*d bygeologb presets Interpretattons, engineering anaysle, and judgment They aro not necessarily mmser h&a of other times and locations. We will not ac cW resportslbl8ty for the use or interpretation by omers of Inftmatbn wesentad on this'tog. Reviewed By Associated Earth Sciences, Inc. Aldridge Short Plat ' 911 Fifth Avenue, Suite 100 Edmonds, Washington Kirkland, Washington 98033 Project No. G97224A Phone: 425-827-7701 September 1997 Fax: 425=827-5424 �7 STANDARD PENETRATION E= Z W RESISTANCE., SEDIMENT DESCRIPTION w g Q Blows/Foot o U) �3 10 20 30 - 40 , silty SAND. Moist, orangish-brown, (Fill) I = Moist, gray, clayey SILT (Slide Debris) 5 I ,- Moist, gray, silty CLAY to clayey SILT. I -12 Moist, bluish -gray, silty CLAY with moist, brown, fine 10 T -14 sand lenses 4" thick in middle of sample. 1 Moist, bluish -gray, silty CLAY; fine sand lense in I -15 middle of sample. Moist, bluish -gray CLAY, 6" thick lense of peat with silt; 15 T 28 - slickenside surfaces. (Possession Drift) 1 .........._....__._......._.._..........._............. _....._..•••....._......I....... fine SAND. 34 - Damp, light brown, Damp, light brown, fine SAND; very fine sand to silt lense 20 30 in middle of sample: Damp, light brown to gray, fine to medium SAND. I 57 Damp, light brown, fine SAND; moist, brown, fine SAND 25 T 1 69 in bottom of sample.. Moist, brown, fine SAND. I 81 brown, fine SAND. 3o IMoist, 71 fine SAND. 82 Moist, brown, Subsurface conditions depicted represent our observations at the time and location of this expbratory hole, modMW by geologic interpretations, engineering anaN a and judgment They are Trot neceasanty representatNe of other times and locatbna We wi0 not L 2=ept responsibiBtY for the use or brterpretation by others of information presented on this log.. Reviewed By Associated Earth Sciences, Inc. Aldridge Short Plat 911 Fifth Avenue, Suite 100 Edmonds, Washington Kirkland, Washington . 98033 Project No. 'G97224A Phone:. 425-827' 7701 September 1997 �. Fax 425-827-5424 ��_ .1 1-1 L EXPLORATION BORING LOG Number EB-3 Page 2 of 2 j SEDIMENT DESCRIPTION o In a Z w Q 0 U) STANDARD PENETRATION RESISTANCE BlowslFoot _. 10 20 30 40 (Double Bluff Drift) I 1 64 BOH @ 36-1/2' Note: Slope inclinometer installed. 40 45 I 50 1 1 1 55 i i 60 i 65 II � 1 Subsurface conditions depicted represent our observations at the ttme and location of this exploratory hole, modified by geologic Interpretations, engineering analysis, and judgment. They are not rieeessariy representative of other times and locations. We vn'il not accept responsibility for the use or interpretation by others of informalfon presented on this log. RevieWed By Associated Earth Sciences, Inc. Aldridge Short Plat 911 Tifth Avenue,. Suite 100 Edmonds, Washington Kirkland, Washington 98033 Project No. G97224A Phone: 425-827-7701 September 1997 Fax: 425-827-54247 EB-2 EXPLORATION BORING LOG Y x 5 z ¢ STANDARD PENERATION RESISTANCE IL H SEDIMENT DESCRIPTION W C a Blows/Foot . . t�7 to Cq; 10: 20 30 40 Moist,. gray,'gravelly, silty, fine 50/4' to medium sand., ...(Lodgement Till) T 5 I 50/4' BOH @ 8' • 1 &&=wface conditions depicted represent our observations at the lime aed location of this axploratory bole. moMad by Wolo* interpretation, erginearig analysis, and judOnreot. They are not necessariy repnmerrtatim of other tines arrd locations. We will not accept re sty for the useor interpMation W others of Mom ation presented on. thk lop. 9110-06H . October 1991 Summers Residential Property Edmonds, Washington ASSOCIATED • _ EARTH : . SCIENCESs INC .' .. EXPLORATION BORING- LOG :.EB-3. _ -C w y SEDIMENT DESCRIPTION _ W A zz a Q svwD,wo FESZIANCE Bbws/Foot. o H a 10 20 30 40 .Moist, tan, 'silty,.'fine to medium sand vith some gravel. .(Fill) I 18 • Moist,.gray, gravelly, silty, fine 5 to medium sand. (Lodgement Till) 10• I 50/6'1 15 I 50/4" .20 Moist, gray, fine sand. (Advance - Sand) I: 50/5' BOH @ 24' 25 ` ISubsurface oorxfitions.depiotsd represent our observations at the tone and location of this exploratory hole. modified by pe01000. interpretatiory engineering analysis, and WWnenL They am not nec ewly reprowdadve of other tines and locations.. We wig not accept responsilAty for the use or interpretation by others of infonnetion.presented on. this Ie% . 9110-OOH October 1991 Summers Residential. Property Edmonds, Washington ASSOCIATED . EARTH SCIENCES, INC 1 1 1 1 1 1 1 MASILKLa 114-1 . SOIL DESCRIPTION u o, m Standard Penetration Resistance _ -i a = a; _ (140 lb'. weight, 30" drop) _ E o Cc o ♦ Blows per foot` Surface Elevation. 98 Feet o p 0 20. 40 60 Loose, brown, silty, fine SAND; moist; SILT i wet @ 18 ft. mixed with clayey with _ `• mottled disturbed appearance with I possible slide plane. @ 20 ft. (Fill and 10 Slide Debris) SM. i 20.9 _ 20 = I Stiff to very stiff, gray, fine sandy SILT to slightly clayey SILT; wet; with laminated _C51: structure; ML 30 36.0 = • i ! Hard, gray, silty CLAY; moist; laminated with fine sand partings and wet sand layer = 40 at 46.3 ft.; CL . = 50 ... 56.0 = • : . Very stiff, gray, silty CLAY; moist; with scattered iron stained sand layers and 61 5 = 60 - -- - - ♦ . •... , disturbed blocky appearance; (Possible ancient slide plane) CL. BOTTOM OF BORING COMPLETED ON 11/19/93 70 ..._.: _............ 80 90 0 20 40 .60 LEGEND • % Water Content " Sample Not Recovered Surface Seal Plastic Limit I-- ♦ —� Liquid Limit = 2" O.D. Split Spoon Sample ® Annular Sealant Natural Water Content ZL 3" O.D. Shelby Tube Sample Piezometer Screen ® Grout Ursula Schluter g Water Level 15620 75th Place West Edmonds, Washington NOTES 1. The stratification Ones represent the approximate boundaries between LOG. OF BORING. soil types, and the transition may be gradual. , 2. The discussion in the text of this report is necessary for a proper understanding of the nature of subsurface materials. 3. Water level, if. indicated above, is for the date specified and may vary. JanlJary1994'. W-5385 02 .4. Refer to'KEY for explanation of 'Soil Log' symbols and definkions. SHANNON & WILSON, INC. FIG. 5. USC letter symbol based on visual dassification. ceatadv ieel WW. Em mm td C..kw s 3`1 iKT?4 SGr r q8� TEST PIT LOGS Al of - Duff, topsoil, and roots 1:3' - -gravel..and Variable brown silty fine sand with clasks of silt -clay mixture (slide debris) (loose ) ' 13.0' - Completed February 25, 1986; no groundwater encountered 112 0 Duff, topsoil, and roots Variable sandy silt and silty sand (slide debris) ±13.5' - Sandy gravel, slight groundwater seepage throughout ±15.5' _ Blue -gray silty clay (severely fissured and with slickensides) ±17.0' - Completed February 25, 1986 13 OR - Variable silt -sand -gravel mixture (saturated) (slide debris) 3.011 - Blue -gray silty clay (med stiff) (old slide debris) 8.1' - Tan silt (hard) ' 14.5' - Completed February 25, 1986; groundwater flow from upper 3 feet ` 114 0 - Highly variable silt -sand -clay mixture (slide debris) 7.0' - Blue -gray' silty clay (fissured, ancient 'slide ' 11.0' debris) - Tan silt (hard) 13.0' - I' Blue -gray silt (hard) 16.0' - Completed February 25, 1986; seepage from 4-7 feet BORING. 1 �' USCS D scri ti n Brown, gravelly SAND with some silt, coarse -grained, moist, very dense s 80 ' GP • 10 36. - becomes less gravelly 15 74 - becomes wet 20 18 : Brown, slightly sandy and silty SAND, low plasticity, wet, stiff zs 26" Mostly very fine-grained, silty SAND 30 33 sM ; Gray, silty SAND, moist, dense ' Test boring was terminated at 31.5 feet below grade on 1=1&97. No groundwater seepage was encountered during drilling. 35 O 1 -7 __ CONSULTANTS, INC. TEST BORING LOG 15620 - 76TH AVENUE WEST 7' EDMONDS, WA Job No: DOW Lo�ged.by; 97WI JAN 7997 DR{9i. 3 5 BORING 2 0 S USCS Des lion Topsoil _ sm Brown/mottled, silty SAND with gravel,_wet, loose to medium -dense 35 10 33 is 18 20 25 30 �-- T 35 33 24 35 Brown/mottled, .gravelly SAND with some silt; very moist; dense a Tan, very silty SAND, lenses of silt, fine-grained, very wet, medium -dense - becomes very moist, dense sM - becomes wet, lens of silt - becomes saturated Gray, sandy silt, low plasticity, wet, very stiff Test boring was terminated at 31.5 feet below grade on 1-18-97. Groundwater seepage was encountered at 16' and 30' during drilling.. 40 TEST BORING LOG .� G EOTECH 75620 - 76TH AVENUE WEST COMMAMS,INC.. , EDMONDS, WA,, Job Nor Date:. L.ogggecl by: Plate:. 97n01, JAN 1997 DRW 4: , s to 30 1 r 35 r. r40 rM l 2 50/4" 24 .3 25 4 20 5 1 53 BORING 3�__-:-- Topsoil Brown/mottled, silty SAND with gravel; very wet, loose lens of silt Brown, gravelly SAND, some silt, coarse -grained, wet, dense Gray, silty SAND, very fine-grained, wet, medium -dense -becomes less silty, moist becomes wet -lens of silt sp Gray SAND, medium- grained, moist; dense Test boring was terminated at 26.5 feet below grade on 1-18-97. Groundwater seepage was encountered at 3' during drilling. ' Hansen Page two tThe extreme rear (easterly) portions of the Hansen property encompass the steep slope portions of the region. Theslope exists at an approximate forty percent (40%) grade. The slope contains mature stable trees, with dense brush (see ' photographs). No. evidence of any geotechnical distress, slides, nor erosional degradation was observed immediately above and behind the Hansen property. This engineer understands that.a localized surficial slide has occurred one to two properties to the north, and is a direct result of up slope bad drainage practices. It is understood that the localized slide to the north is currently undergoing stabilization and drainage improvements. As stated in the 1979 Roger Lowe Associates, Inc., ' report, drainage and ground water control are the best practices for landslide risk reduction. This engineer concurs. EVALUATION: ' In order to augment the existing site geotechnical information, power hand auger test holes were dug under this engineer's observation on May 22, 1999. Two test holes were dug to seven foot (7') depths (see photographs and site. plan for ' locations). Test Hole No. 1 was dug at the approximate south foundation line of the proposed addition, approximately twelve feet (12') east of the existing house. I Test Hole No. 2 was dug approximately ten feet (10') south of the hot tub deck on the relatively level soil bench. Both test holes revealed similar subsurface conditions, namely: 0" to 6" Organics, roots, and organic silt 6" to approx. 3.5' Brown sand, relatively clean, moderately dense 3.5' to 4.5' Increasingly dense sand with cobbles,. 4.5' to 7' (bottom of hole) Very dense silt and silty sand with cobbles No water was encountered in either of the test holes. Both test holes remained vertical and stable. No sloughing or caving occurred. This engineer conducted a visual examination of the slope above the .Hansen . property. A small historic "cave".(?) zone was observed. It is understood that this "cave" was, used for historic bootleg storage purposes. This "cave" was approximately three foot (3') high by approximately three foot (3') deep along; the face of the bluff slope. The "cave" revealed no evidence of any geotechnical distress. Additionally, this "cave" zone allowed further -verification of the dense sandy silt and gravel soils. present. This engineer did observe a mature fir tree growing immediately above the 2008 2aY o�, �s:ooa OME ED 51gP.�L __ NE�J 1JRAtNA611'� NElh7 DG�4�� R�P�JUZ 3 -tea kMa�Yi i�G4t�n'1 STREET --FILE----------- Imo' City of Edmonds 121 5TH AVENUE NORTH EDMONDS, WA 98020 • (425) 771-0220 FAX(425) 771-0221 Website: www.ci.edmondsma.us PUBLIC WORKS DEPARTMENT Engineering Division Engineering Plan Review CpAfen Application #: BLD20080376 Date: O er 8 20 Project Name/Address: Ray SFR / 15625 — 75 Place W Contact Person/Address, Fax or E-mail: Kristin Hanson / HANSONDESIGNAHOTMAIL.COM Reviewer: Edward Sibrel Division: Engineering During review of the civil drawings for the proposed project it was found that the following information, corrections, or clarifications will need to be addressed. Please resubmit 3 copies of the revised civil drawings and associated documents with a written response to each item to an Engineering Technician. Please contact me at 425-771-0220 or by e-mail at sibrel(a.ci.edmonds.wa.us if you have specific questions regarding these plan corrections. Review 1— July 2, 2008 Review 2 — September 10, 2008 Review 3 — October 8, 2008 --UTILITLES 1. OK 2. OK 3. OK TESC 4.OK 5.OK 6.OK DRAINAGE 7. ECDC 19.10.030(F) has the added condition that drainage designs shall be accompanied with calculations. This condition does not differentiate between impervious areas of greater or less than 5,000 square feet. The city stormwater engineer has determined that the interpretation of ECDC 19.10.030(F) is stricter than that of ECDC 18.30.060 when proposed development is within the ESLHA. Therefore, the term "calculations" with regard to storm design must include calculations of how the proper sizing of the drainage system is arrived at. As such, the use of Handout E72 to size the system is not sufficient to this purpose. Please find attached the comments from .Terry Shuster, PE — the City Stormwater Program Manager. 8. OK DATE E-MAILED October 8, 2008 PAGE(s) 1 of 1 r=� CITY OF EDMONDS PLAN REVIEW COMMENTS ENGINEERING DIVISION (425)771-0220 City Website: www.dedmonds.wa.us DATE: October 3, 2008 TO: File FROM: Jerry Shuster, P.E., Stormwater Engineering Program Manager RE: Application #: Bld2008O376 Project: Ray Residence Project Address: 15625 -75th Pl. W. Item reviewed: • Drainage report dated September 15, 2008 • Plan sheets 1-2 During review of the above noted application, it was found that the following information, corrections, or clarifications are needed. The major items regarding site drainage that require revising include: connecting the piping for roof runoff to the upstream side of the proposed detention tank, providing more detail on the design of the interceptor trench, and providing a note for minimum cover on a pipe that is proposed in the right-of-way. In the erosion and sediment control plan, several steps in the construction sequence need to be added as well as more clearly defining the limits of clearing and the location and extent of the temporary filter fence. These items and minor revisions are detailed in the enclosed checklists. Please contact me at 425-771-0220 or by e-mail at shuster(iW.edmonds.wa.us if you have specific questions regarding these plan corrections. October 27, Project No. Mr. -Kyle.R 15625 75`h Edmonds, Subject: ' Dear Mr.]. •----1-a..A As-socia.ted Earth Sciences,.Inc. ;SSOA - h , MAR 13 2006 . . WILDING F EDMaN S C West _ agton.98026 FILE bsurface Exploration, -Geologic Hazard, 3 Geotechnical Engineering Study . 1,posed Ray Residence Remodel - 625 75`h Place West lmonds,' Washington. Tnr IAFQTI is »leased 'to present this subsurface exploration, - uaZ&ru VIA vu. 2005 and supplied ,by you, .our. site observations, :and our experience on other projects in the ' ' site vicinity. ti The. purpose .of this,study was to`' ather geotechnical data and provide,geoteclinical conclusions and recommendations for the proposed remodel. This, letter was prepared, using field. observations, subsurface explorations, and published sources of geotechnically pertinent information. This letter has been prepared for the exclusive use of the Mr. Kyle Ray and his - ' agents .for. specific application to this project. Within the limitations of scope;, schedule, and - budget, our services have been performed in accordance with generally accepted geotechnical engineering and engineering geology practices in -effect in 'this area at the time our letter was prepared. No other warranty, express or. implied, is made. ' SITE AND PROJECT DESCRIPTIONS The"project site is .located on the east side, of 75`h Place West in Edmonds; Washington (see - t The ro'ect site is a developed single-family residential lof;with an Figure 1, Vicinity Map) p existing dwelling. The existing dwellini consists. of a- one-story rambler :with a partial daylight' basement under the approximate southern half of the residence._ We understand that the north y' constructed in the ,1950s with the south half, including the basement; . half of the residence was co - _ added on in the 1970s:' A wood deck is located on the west side of the house. The residence is •'' bounded on the west by 75' Place West, .on the north and south by single-family. residences, 911 Fifth Avenue, Suite 100 • Kirkland; WA 98033 • Phone 425 827-7701 • Fax 425 827-5424 and by a steep, west facing slope on the east. The Burlington. Northern Railroad right-of-way is located _adjacent the shoreline of Puget Sound west of the project site and adjacent properties. We. understand that the major'structural improvements'of the proposed remodel will include: • Remodeling the south half of -the residence; including construction of a second story and conversion of the basement into a garage with slab -on -grade floors; . • Expansion of the kitchen (adding approximately 5'67 by 14'9". on the west side of the - existing residence; including construction of :a -new wall foundation; . • . Construction. of three deck footings on the west edge of the residence; and , ' - • Foundation improvements to the south half of -the residence in the existing footprint. ' We understand that the proposed improvements will ' Jimit ' excavation to those necessary- to i construct foundations and install buried utilities, largely within the ' approximate ' , existing footprint of the, existing . structure. ' We further understand that ,final site grades will not be, ; changed from the existing grades. SITE .OBSERVATIONS Our site observations. were -made during .two- site visits in August and September of 2005. The following sections describe our visual observations. r Geologic Reconnaissance The existing dwelling is. located on a flat bench, on the. lower half of a. large slope system, which begins on the order 'of 100. feet above to the east. The slope system drops down to the west, from 75' Place West to Puget Sound across a vertical relief on the order of 100 feet. The steep slope on, the. east edge of the '. property ''appears to be inclined :at. 2H:1V -to 1H:1V-- . (Horizontal:Vertical),' based on visual estimates. An over -steepened area interpreted to be old slide,scarp was observed- directly - east of.the project site approximately.50 feet above the i' existing dwelling: The scarp was visually estimated tobe on the order, of 40 feet in length and 5 to 10 feet in height. The slope is densely vegetated with ferns, `maple trees, . and other shrubs! - Most of the deciduous trees had bowed trunks indicating slope, creep; but several evergreen ' trees higher up the slope appeared relatively straight.Some of the larger trees near the base of the slope appear to have been topped and trimmed in the past. A concrete, masonry block wall on the order of'2, feet in height is located near the toe of the, slope: The toe of the steep slope ' is approximately 25 to 35 feet east of the existing dwelling. 2 In the streets and unimproved right-of-ways at the -top of the slope, we observed asphalt berms and catch basins. that appeared designed to - collect surface water from, the '-streets and easements. We understand. that drainage improvements were, completed near ,the upper developed portions of the slope in the late 1990s after some shallow slides occurred on the slope several" properties to the north and one property to the south: Structure Reconnaissance ,.: We `examined accessible areas of the existing structure for _ visible signs „of settlement or distress. We observed that the` southwest corner of the basement -level '.foundation had settled ' away from the bottom .of the wall approximately 1 inch.. The; foundation appeared to consist of concrete masonry units (CMU) embedded:approximately.,6 inches intothe ground. No visible structural connection was . observed between'. the. wood -framed wall .and the CMU block foundation. , We observed a concrete basement `retaining wall..on the east side of the furnace room of the portion built in the 19.70s that appeared to be',in good -condition. P , pp . ' Other than the area describedabove, we did not observe other signs of distress in the structure,, such wall cracks and out -of -square windows and doorways. The 'owner informed us that he was not aware 4 problems with sticking doors or, windows or other 'indicators of settlement, SUBSURFACE CONDITIONS. - The following subsurface. conditions are based on our limited explorations and our. literature i review of previous studies performed in -the project vicinity. Limited Subsurface. Explorations Our -field study included four hand -:auger exploration borings (HA-1 through HA-4) performed , in August ,2005 and a-, visual geologic reconnaissance performed in September 2005 to gain. information about the site. Materials encountered in the explorations were. classified in the field by�'an engineer from our firm. Dynamic Cone Penetrometer (DCP) blow counts were recorded at select depths in ihe:explorations.to aid in determining the relative density of the ' soils. The explorations were. allowed to stand open for several hours to observe -potential ground water seepage and were backfilled prior to .departing the site.. , Selected samples: from the explorations were transported to -"our laboratory for further visual, classification, as ' necessary. The various types of sediments, as well as the depths where characteristics of the sediments changed., are''.indicated on the exploration logs -presented in the Appendix., The depths. indicated,on the logs where conditions changed. may represent gradational.,variations between sediment types in the field. Our explorations were approximately located, in the field by measuring -from known site: features shown on the 'aforementioned Site and Exploration Plan t(Figure 2). Literature Review . We reviewed ourin-house -files and publicly available exploration data from the GeoMapNW website(http•//geoinapnw.ess.washington.edu/index.php) -at the University of Washington for . previous geotechnical studies performed in' the_ project -vicinity.. Our research revealed exploration logs from the following studies: • "Subsurface Exploration, Geologic Hazards, and Preliminary 'Geotechnical, Engineering Report, Aldridge Short Plat, Edmonds, Washington," dated October. 24,, 1997 by AESI '(from AESI in-house files). - This .study included the two lots directly across,75' Place West.from the project site (15604 75`h Place West): Three exploration borings and four exploration pits -were performed at the_Aldridge site, Which generally encountered fill over disturbed silts/clays -over very dense fine sands.. Slope 'inclinometers ,were ' 'installed- in two of. the borings and, were. -measured periodically over, a period of approximately .3 years: Measurements indicated shallow downslop6 creep of the fillin the upper, 10 feet on the order of 1 inch or less over the measurement period, with' the. majority, of the movement occurring near the top of, an uncontrolled fill slope on the west side of the property. The site hasre'mained:undevelopgd at the time of this letter. •' "Revised Geotechriical Report, Proposed' Residence at Lots 1, and 2, 75`h'Place West, Edmonds, Washington," dated January 26, 1994' • by 'Shannon and Wilson, Inc. (GeomapNW excerpts. only). . This study -included two -lots across.75'' Place West to'the . southwest of the project site (15620 75`� Place West):. 'One exploration boring was performed of the site and two exploration pits by Earth Sciences, were included in the ' report, which generally encountered fill/slide : debris over stiff .to .hard silts/clays: (According to Snohomish. County tax, records,_ a two-story dwelling.was constructed in 1997) . • Geotechnical Engineering Study, Recent Landslide, '15620 72"d Avenue West, Edmonds, Washington," dated February 24, 1997 by Geotech Consultants,, Inc. ' (GeomapNW excerpts only). ' This study included the lot upslope (east) and one property,south, of.the project site. Three exploration.borings were performed: at the site, which- generally encountered ,dense gravelly sands over medium dense to dense silty, sands over very dense sands. ' • "Subsurface Exploration, Geologic Hazards, .and Preliminary Geotechnical Engineering Report,. Summers Residential Property, Edmonds, Washington;" dated December 31, 1991 by AESI (from- AESI in-house files). This study included' a lot upslope.�from-the northeast -corner, of the project site (7222..72°d, Avenue West). ' Three exploration, borings were performed at the Summers site, which encountered very, dense lodgement till and advance sands in one boring. - - 4 i • "CTeotechnical Evaluation, Proposed' Hansen Residence Addition, Project, 1.561.5-75`' Place West, Edmonds, Washington,". dated June 1, 1990 by 'Dennis M. Bruce, P.E.' 1 (from AESI -in-house -files). This study included the. adjacent' lot_ immediately north of the project site. , Two test holes were dug on the property using a power hand auger; - which generally encountered moderately dense to dense clean sand over very dense silt ' 1. and silty sand with cobbles. _ �j • "Report of Geologic Evaluation, Meadowdale Area, Edmonds, Washington," dated ■ September 23, 1968- by Dames & 'Moore' (provided -by the City, of Edmonds). This study evaluated the overall stability .of'the,area, from a geologic standpoint based_ largely on literature .review, and surface reconnaissance for installation of a proposed sanitary -sewersystem.. , • "Final 'Report, Landslide Hazards Investigation, Meadowdale` Area, ' Edmonds, Washington;," dated October 16, 1979.by'Roger Lowe Associates, Inca- (provided by the City . of Edmonds).. This study analyzed the, subsurface conditions and slope stability " 1 based on, previous 'studies and -'seven borings performed for the study. The .study, . " provided a landside hazard map of the Meadowdale area, which quantified landslide risk by type and probability of occurrence in a 25-year period. • "Report of Geotechnical. Consultation; Property Value Appraisals, and Assessments, Meadowdale Landslide Area,: Edmonds, Washington," dated February 28, 1985 by 1` GeoEngineers, Inc. (provided by the City of . Edmonds).. � This study- updated the probability of landslide occurrences as ` provided in the 1979 Lowe study after installation of storm and sanitary sewers in the Meadowdale area: Our literature review was- not meant tb be all inclusive, as. other studies in, the project vicinity. 1 may exist but were not available for our review.. Pertinent information, from these studies is discussed in .-subsequent sections of this letter,. where' appropriate. The' logs, for the above - referenced explorations have been included- in the Appendix of this. letter. Soil Conditions Subsurface conditions on the, project site were inferred from the field explorations accomplished for this ,study, visual reconnaissance of, the site; and review of applicable geologic/geotechnical literature. 'As shown.on the field logs, the explorations on the project site enerall encountered silt sand with various ravel fill over sandy silt � to silty sand soils " g Y Y g interpreted' to be ' old landslide material.. The following- section presents more detailed 'subsurface infoimation organized from the upper (youngest) to the lower (oldest) sediment 1 : types: 1 5 = - ' Fill� � • ' Material interpreted to be.man-placed fill was encountered. in all the explorations on the project site. The fill consisted chiefly ofmedium dense, silty sand .with various gravel", concrete debris, cinders, and asphalt debris. Old Landslide ' - Material interpreted ,to be old landslide soils' were .encountered in all the explorations on the project site. The.old landslide soils- consisted chiefly 'of- medium stiff • to stiff, fine sandy silt and medium dense, silty fine sand-with'a variously jumbled matrix. Exploration -boring HA-1 ' encountered an approximately' 41/z-foot layer of fine ,to medium sand within the interpreted old landslide deposit. Explorations from _the other -studies in the project vicinity listed above - indicate siinilar landslide materials that extend well below existing grades in the project4rea on ' r of 30 to 60 below existing . the order g grades: tThe soil, conditions encountered, in our explorations were consistent with .the soils mapped 'in the,PreliMinary Surficial Geologic.Map of the Edmonds East -and Edmonds "West. Quadrangles,' ; Snohomish and King Counties, Washington (Smith, -1975). The geologic map indicates that the, site is characterized by Qols (old _landslides) on the southwest portion of the site; The,., northeast portion ,of the, site appears ,to be mapped as Qw '(Whidbey 'formation), although no ' explorations were .performed there to confirm this'. The maps also indicate Qdb (Double Bluff) ,. and Qe (Esperance sand) in the project vicinity. Ground Water Conditions No, seepages or ground water were observed within our explorations. In addition, no seepages were observed daylighting on any of the steep slopes on the property. However, it should -be . " noted that our site reconnaissance was erformed at 'the end of summer' when ground water _ no e P levels are typically . lower. Ground water conditions should be' expected to fluctuate with. . ' season, precipitation, site usage, and other on- and off-site:factors.' ; ' . GEOLOGIC HAZARDS The following discussion of potential geologic hazards is based _on the geologic, :slope, and " shallow ground water conditions.as observed and discussed herein. Landslide Hazards and -Mitigation The potential landside risk can be divided. into two depth categories: shallow and deep. The. - potential shallow (on the. order. of 1 to 10. feet thick)' landslide'risk .includes slumps, debris avalanches, and earth'flows.of the coliuvial soils and trees on the steep slopes to the east of -the project site. The potential deep landslide risks for the site have been identified by previous . studies in the site "vicinity as continued movement of the ancient. landslide blocks. 6 _ The potential for shallow slides will be greatest, after extended, periods of heavy rainfall and/or . snow events. Such weather'events occurred during the winters of,1996 and 1997 and resulted in numerous ,shallow slides in the Meadowdale area and around Puget Sound. Mitigation for such slides include proper -handling and discharge of surface. storm .water, reduction in ground water -levels, and trimming or removal of large trees in the' potential slide zone: We understand that since the 1996 and 1997 events, City improvements to .surface . water management of the right-of-ways above the.slope to -the east have been implemented, including , installation of street' drainage berms, catch basins, and prevention of storm water. discharges onto or near the slope. ,These improvements will reduce the potential for. saturation of the colluvial soils and the contribution from upgradient surface water infiltration, to ground water .levels and seepages: The large deciduous. trees directly upslope from the proposed project area ` appear to have . been trimmed .and topped, some time in the past„ reducing the potential • for direct fall damage. The structure appears suitably set back� from . the toe .of the slope tapproximately- 25 to 35" feet for the dissipation of most shallow slides. The risk,of earth and,, d b fl dama in the dwellin already exists for the .current structure and .will not be e ris ow g g g increased by,,the improvements. However; additional debris -flow mitigation could -be achieved by extending the _basement. foundation wall 3 feet above the outside .finish ground' surface. Extension of the foundation -wall would allow for debris -flow material to. impact the back of the residence without buckling wood framing or, flooding the living space. ; Deep-seated landslides risks- at the project site would most likely be related, -to reactivation of, the, ancient landslide blocks estimatedto have occurred thousands of years ago after the retreat `. of glacial ice and subsequent draining of glacial lakes. The large-scale lowering of regional -ground water levels and. continued erosion of the toe 'of the slopes by wave action resulted in unstable, oversteepened coastal bluff conditions. Mitigations, for deep-seated \slides- at coastal. bluffs include- armoring of the' .base., of the bluff to prevent: wave erosion.. The riprap embankment placed during the construction, of -the Burlington Northern Railroad ltracks has 'provided protection from wave -action erosion. To" our knowledge, no evidence of recent, "movement of the deep=seated slide planes has since been documented. The 1980s drainage improvements 'in the 75' ,Place West right-of-way and 19909drainage improvements at the top ofthe steep slope have also .reduced the potential for reactivation . of -.the deep_seated slide' � planes. Therefore, no: further mitigations for deep-seated landslides should be required: It should be noted" that- no amount- of: engineering and mitigation measures -can eliminate the potential for earth movement. Some risks .will always remain, and have been estimated_ in the next section. Meadowdale Earth Subsidence Landslide Hazard Area Designation The project site is.maP ped within the Meadowdale Earth Subsidence .Landslide Hazard Area. P J, A 1979 report by Roger Lowe Associates, Inc. and update study by GeoEngineers, Inc. in . . ,' 1985 assess the site as having the following landslide risks: 1 ' • 2CO2 Hazards from encroaching landslide materials by the process of -debris . avalanches with a 2. percent, probability. of occurrence during a 25=year period. Based ' on the current surface conditions, including, densely vegetated slopes, lack of evidence of recent ground movement directly upslope from the project site, and surface drainage improvements at the top of the slope, we, concur with this assessment. • 4A30 = Hazards ftom ground failure in previously failed material by the process ,of ' slumps with a 30 percenf probability of ' occurrence during a 25-year period. This m ; probability was reduced frothe 1.979 assessment of 90 percent after the installation of ` the storm' and sanitary sewers In the Meadowdale area. Based on.the current conditions and additional drainage. improvements upslope from the project 'site, we concur with - this assessment. We understand that the City of Edmonds has requested the following. items to be provided_per, the Meadowdale, Earth Subsidence Landslide Hazard Area Checklist „Permit. Submittal Requirements • Critical' Areas Determination and/or. Hearing Examiner Decision; ' • Lead Design Professional Designation and Statement; • Vicinity Map; ' Topographic Map; ' • Geotechnical Report; - • Grading Plan; • Architectural and Structural Plans; • Applicant/Owner Liability & Landslide 'Acknowledgement; _ Geotechnical Declaration and Statement of Risk; - • Architect and/or Structural' Engineer Declaration; Applicant/Owner Covenant to Notify and Hold Harmless:. ; This letter will provide a vicinity map (Figure 1) and serve -as the geotechnical report. We will provide _a geotechnical declaration and statement of risk -after confirming that the architect and'. structural engineer have incorporated our recommendations into the final plan. set.- Since excavations will be limited to those required for foundations in the same approximate footprint of the existing structure and no change of grades are,proposed, it" is. our opinion'that a grading .. . plan is not necessary for successful completion of this project.. We understand that a property ' boundary/topographic survey will be obtained'by the owner. The remaining items should. be ; addressed by the owner, architect, and structural engineer. Seismic Hazards and Recommended Mitigation Earthquakes _occur in the Puget . Lowland with ,great regularity'' The vast' majority of these events are small and are usually not felt by people. However, large earthquakes do occur as - evidenced by the 1949, 7.2-inagnitude'event; the 2001, 6.8-magnitude event; -and the 1965,' 1 ' 6.5-magnitude event. The 1949 earthquake appears to have been the largest in this region during recorded history and. was centered in the Olympia area. Evaluation of earthquake. return rates indicates that an earthquake of the.magnitude between 5.5 "and 6.0 is.likely every 25 to 40 years in the Puget Sound basin Generally; there are four, types of potential' geologic hazards associated with, large -seismic events: 1) surficial ground rupture; 2) seismically, induced landslides; 3) liquefaction; and .4) ground .motion. The potential for each of these hazards -to adversely impact the proposed projecvis discussed below. ; Surficial Ground Rupture The* nearest known fault trace to the project is 'the South Whidbey Island -Lake Alice Fault. Recent studies by the U.S. Geological Survey (USGS) suggest that a trace of the northwest ­ southeast trending thrust . fault zone may project ..through the. Meadowdale area. The recognition of this fault is relatively new, and data pertaining to it are limited with the studies still ongoing.- According to the USGS studies, the recurrence interval of movement .along this . fault system is still unknown, although. it is hypothesized to .be ,in excess of several thousand years. , Due to the suspected along recurrence interval, the potential for surficial ground rupture at the subject property is.considered to be low.,during the expected life,of the structure. Seismically Induced Landslides The ro'ect site is located in the Meadowdale Earth Subsidence Landslide .Hazard Area, of project which'the risks of landslides have been quantified most recently by the 1985 GeoEngineers report and are, discussed above. -We. interpret the probabilities associated with the above - described risks .as low to moderate given static conditions. Ground accelerations associated. - .with a strong earthquake may reactivate movement along the. old slide planes .and result in a higher potential .for landslides and 'ground displacements. This risk already exists for -the � current structure and will not be increased by the . ro osed improvements.' .We recommend. R P P mitigating. damage I to the proposed improvements - by ; structurally ,tying together isolated ' . footings, as described in the Foundations section .of this' letter. The, resulting foundation -system .will serve primarily to prevent .collapse• of the structure during •differential' ground. displacements, but not necessarily prevent unrepairable damage to the structure. Liquefaction Lin is a condition where loose, saturated, sandy soils lose strength when subjected to ` q high intensity, cyclic loads of very short duration, such as occur'during earthquakes, !pile driving, and, blasting. The resulting loss in bearing strength can causedifferentiai foundation settlements- and *slope failures. Loose,. saturated, clean, fine-grained sands, • which. cannot, dissipate the buildup .of pore water pressure; are the predominant type of sediments subject to liquefaction. Based on our -review of the .samples obtained from our explorations, it is our opinion that the otential for liquefaction is low due to' the combination of a lack of ground P P q water in the loose sands encountered, and due to the high, fines content of the other soils i.encountered. -y - 1 9 Ground Motion Structural' design ,of the building should follow 2003 International. Building Code (IBC) standards using 'Site Class C as defined in Table .1615.1.1. The 2003 .IBC seismic design '. parameters' 'for _short period (Ss) and 1-second period (Si) spectral acceleration values can be computed - using . the USGS National -Seismic Hazard Mapping ..Project website (htto://earthouake.usgs.gov/hdzmaps/). Using the 2002 data, the USGS. website.computed ' ground motions at the project. site to be 1.24g and 0:44g for building periods of 0.2 and -1.0 , seconds, respectively, with a 2.percent chance of exceedence in 50 years: CONCLUSIONS AND RECOMMENDATIONS The, project site is .currently developed with an occupied, single-family, residence within the Meadowdale Earth .Subsidence \Landslide Hazard Area: Therefore, the risks described above are already present for the existing -structure.. It is our understanding, that the owner fully understands and accepts the risks of the landslide hazards as -discussed in this letter.. We also understand ,that potential future owners 'will be -aware of the risks associated -With owning ' property in the Meadowdale area because such a notice is on the property title., The purpose of our study was to assess -these risks based on current, site -specific, slope :and = soil conditions and provide recommendations for minimizing and -mitigating adverse impacts to the slope by the .proposed improvements. Since the project chiefly 'involves replacing the. existing south half of, the structure in the same approkimate footprint; it is our opinion that the overall ' impact\ to ,the stability of the, slope will not be adversely. affected provided our .recommendations are followed.. Furthermore, the improvements ;will result in,a safer structure since the improvements, will .be constructed to current building ' codes and replace the CMU . block, foundation .under the south half 'of *the' residence with structurally connected' foundations that . will mitigate differential displacements. The following - sections present our, - ' recommendations for design and construction of the proposed improvements. Temporary Excavation Slopes We anticipate that'temporary cut slopes may be necessary for overexcavation in footing areas ' and for installation of buried, utilities. In our opinion, stable -construction slopes should be the - responsibility of the contractor and should be ,determined during construction. ' For estimating - . purposes, however, we . anticipate that `temporary, unsupported cut slopes over 4 feet can be made at a :maximum slope of 17.5HAV in the site soils. Typical trench -box shoring for, excavations deeper than 4 feet should be considered to minimize. site disturbance. As is typical with earthwork operations, some sloughing and raveling-may'occur and cut slopes may have to , . be adjusted in the field. In addition, WISHA/OSHA regulation's should be. followed at all '. times. 10 Structural Fill Structural fill will'be necessary to provide suitable footing and slab -on -grade floor subgrades .and for backfill of utility, trenches. All references to structural' fill in this letter' refer to subgrade preparation, fill type, -placement, and compaction 'of materials 'as discussed in this, .' section. If, a .percentage of 'compaction is specified under another, section, of this letter, the value given in that section should be used. After stripping, planned excavation, and any required overexcavatiori has, been performed to the satisfaction of the geotechnical engineer or his � representative, . the upper 12 inches of exposed ground should be compacted to a firm arid.unyielding condition, :as determined by the ' geotechnical,. en 'ineer or' his' re resentative. If -the sub' rade. contains. too much moisture,. g P g adequate compaction may be' difficult or • impossible ' to obtain and should probably ' not be ' attempted. In lieu of compaction, the area to receive fill should be blanketed with clean; coarse, crushed rock or quarry spalls Ito 'act as a capillary break between the new fill' and the wet subgrade.. Where the, exposed ground' remains soft and. further overexcavation is, ' impractical, placement of an engineering stabilization fabric may also be necessary .to prevent contamination of the free -draining layer by silt migration from below. ' After. compaction of the exposed ground'is tested And -approved, of a,free-draining rock.course is laid, structural fill maybe placed to attain desired grades. Structural fill is defined as" non - organic soil, acceptable to the geotechnical engineer, placed in maximum 8-inch loose lifts with each lift being compacted to at least 95 percent of .American Society for Testing and Materials (ASTM):D-1557. In the case of roadway and utility trench filling in'the City right - of --way, the backfill 'should also be placed and compacted in accordance with City codes and ' ' standards. ' The contractor should note that any proposed fill soils must -be. evaluated .by AESI prior to. their t use: This would require, that we. have a sample -of the material at least 72 hours in advance to . either perform a Proctor test and/or' determine its field suitability. , Soils in which.the amount. `.' of fine-grained *material .(smaller than the. No. -200 sieve) is greater than'. approximately 5 percent (measured on the minus ,'No. 4 sieve size) 'should be considered moisture -sensitive. . Use of moisture -sensitive soil in.structural.fills should be limited 'to favorable dry weather, and ' dry . sub'grade conditions. • The" on -site soils contained substantial amounts of silt and -are ` considered highly, moisture -sensitive when excavated and used as fill materials. At the time of our exploration program, soil moisture, contents were at or above optimum 'for structural fill use. We anticipate that the some of the'excavated site soils may require aeration and drying, prior to compaction in structural fill applications. Construction equipment traversing, the site . when the soils are wet can cause considerable disturbance. If fill is placed during wet weather or if proper compaction cannot be,obtained, a'select,' import ' material consisting of a' clean, ,,free -draining gravel .and/or- sand should be used.. Free -draining fill consists76f non -organic soil with the amount of fine-grained material limited to' S percent by weight. when measured on the minus No.: 4 sieve fraction, and at least .25 percent retained on ' the No. 4' sieve. \ Foundations We understand that the new foundations will remain, within the approximate footprint -of the existing basement and deck and not further. encroach the west property ;line. With proper design; subgrade preparation, embedment; and \construction, it is our opinion that the proposed, , foundations will not decrease the stability .of the existing slopes provided "the recommendations of this letter me,followed. _ ' The observed foundation settlements on the west side of the existing basement. level were likely - 'due to .poor • subgrade preparation and construction on uncontrolled fill. We have discussed. with the owner, the option of supporting the improvements 'on . deep. foundations to mitigate ofentiaT excessive settlements "due to the -presence of - the - uncontrolled fill- and possible' - p continued movement of the old landslide -materials. Based on the expected 30- to 60-foot depth ' of. old landslide materials on the. project site, "we anticipate -that deep foundations would only. provide. vertical support and. could not practicably be constructed to resist the lateral displacements should the old, :deep-seated landslide' block become active We, understand that the .owner wishes to use spread footings for "foundation support and has- accepted the risk, that even static, post -construction settlements may result in drywall cracks, - tilting of, window/door jambs, and-other'lagely cosmetic damages, may occur, especially near the connections between ' the improvements and the north half of the dwelling to remain. Due to -the presence of uncontrolled fill ;and variations in old landslide soils present at -the - ' anticipated bottom of footing elevations, we recommend that "all new footings bear on a minimum; 2-foot-thick, layer of structural fill. ' The width . of the ,structural fill pad should be .2 feet -wider than the width of the footing. _Structural fill type, placement, and compaction recommendations are provided in the Structural Fill section of, this letter.,' :The existing fill , - . soils must be removed.-und'er new foundations or overexcavated and recompacted as structural ' . fill if moisture` conditions allow; All organics, debris", and soft/loosened soil must be removed. from the footing' areas prior to placement of .structural fill, and be confirmed by a representative from AESI. We recommend• that foundation excavations be completed with an ' excavator 'equipped with a smooth digging plate to limit disturbance of the subgrade. During Wet weather-, it is highly recommended that footing subgrades be' protected from disturbance with several inches of compacted crushed rock. Continuous and 'isolated spread footings may be used- for building support when founded:on the approved 2-foot-thick layer of structural fill discussed above. Isolated footings 'should ,be -structurally tied together in two directions to mitigate excessive ground displacements. ' The owner should be aware that the primary, purpose of tying" together; foundation elements is .to prevent collapse of the structure due to excessive displacements; therefore,= the structure may " be damaged beyond repair in some 'cases. We recommend that a maximum, allowable g Y foundation soil bearing pressure of 2;000 pounds per square foot "(psf) be, utilized, for "design .' purposes,. including bdih dead and . live loads' for footing subgrades prepared as described . _herein. ,An increase of one-third- may be used for ,short -term -wind or -seismic. loading. All footings should have a minimum -width of 14,inches for single -story structures; 16'inches for ' two-story structures; and 18 inches for three-story, structures. 12 - It should -be noted that the area bounded by lines extending, downward at 114:1V from any footing must not intersect another footing.. ,In -addition; a 1.511:1V line extending'down from any footing must not daylight because. sloughing'o'r raveling may eventually undermine the footing. Thus, footings should not be placed near the edge of steps or cuts in the bearing soils i unless adequately embedded. Anticipated settlement .of footings :founded on approved -structural'' fill as described -above = _ ' should be approximately 1 inch or less. Disturbed: soil' not removed from footing,excavations prior ,to ,footing placement could. result in increased settlements. All' footing areas .should -be inspected by AESI prior to placing concrete to verify that the design bearing capacity of the ' soil has been attained and that• construction conforms to: the recommendations contained in this . letter. - Such inspections may be required, by the City.. Perimeter footing. drains should be provided as discussed under the section on D•rdinage Considerations. ; Lateral Earth Pressures All backfill behind walls or around foundation units should be placed as per our recommendations for structural fill and as described in. this section of the letter. •Horizontally backfilled walls; -which are. free to yield laterally at least 0.1. percent of their height, .may be. designed using'an-equivalent fluid-equal.to 35 pounds per cubic foot (pcf). Fully restrained, , horizontally baekfilled,, rigid walls that cannot yield should bedesigned for an equivalent fluid of 55- pcf. A.surcharge equivalent. to 2 feet of soil should be added to the wall height for walls with sloping backfill, heavy construction equipment, or adjacent.parking or -roads. The. lateral pressures presented .above are based ,on the conditions of a, uniform backfill ,consisting -of -structural fill compacted to 90 to 92 percent.of ASTM:D 155,7. A higher degree of compaction is not recommended as this will increase_ the. pressure acting on the walls. A lower degree of compaction may result.in settlement: Thus,:'the compaction level is critical. and ""should be tested by our firm during- placement. In addition, only" hand -operated or walk - behind, compaction equipment should be • used -within 5 feet of the walls to prevent excessive ent. Perimeter footing drains should be provided for all -surcharge loads from "heavy, equipm retaining walls as discussed under the -section on -Drainage Considerations. ; ' It is imperative that proper drainage -be provided so that hydrostatic pressures do. not develop against the walls. This would involve installation of a minimum, 1-foot wide blanket drain for' ' -the full wall height using imported; washed gravel against the walls. The blanket drain and wall backfill should be capped with 12: inches of relatively impermeable soils and .sloped to drain away from the walls to prevent. surface water intrusion directly into the drain system. Passive Resistance. and Friction Factors ' Footings/keyways: cast directly 'against undisturbed, dense soils in a trench may -be designed for an allowable passive resistance• against lateral translation using an equivalent fluid density equal to 250 pef. The - passive equivalent fluid. pressure 'diagram begins at • the top of .the footing. This value applies only to footings/keyways where concrete is placed directly against ' 13 the .trench sidewalls without the use . of forms. If footings , are placed .on -grade and then. backfilled, the top of the compacted backfill must be horizontal and extend outward from the footing for a minimum, lateral distance equal 'to three times the height of the, backfill before tapering down to grade. With backfill placed as. discussed, footings.. may be- designed for passive resistance against lateral translation using an equivalent_ fluid equal to 250 pcf: Passive resistance values includea factor of safety. equal to 1.5 - in order to reduce -the amount of movement necessary to generate passive resistance: l allowable friction coefficient of-0.3 may be used for footings cast directly on the structural The allo -. fill pads described in the Foundations Section of this letter. This is an allowable- value. and ' includes a safety factor of 1.5: Slab -On -Grade Floors Typical concrete slab -on -grade floors appear feasible when supported on'a minimum, .12-inch. thick- layer of approved' structural fill compacted to a firm and unyielding condition.' Above the 12 inches of structural fill, we recommend 4 inches of: washed pea. gravel to act as a -capillary . break. A plastic vapor- retarder of minimum 6-mil thickness should••be placed directly over the ' capillary break. Construction of crawl spaces should also include covering the soil below the floor sys`tem".with.a plastic vapor retarder to reduce interior dampness.. The contractor must take care. to protect the plastic vapor barriers from, punctures during construction. More ' stririgent moisture protection details should be considered by the owner- and architect if necessary to protect interior finishes. r; Drainage Considerations To facilitate drainage away from foundation elements, perimeter footings should be provided ' with a- drain near the footing elevation. Drains should consist, of .4-inch=diameter, rigid, ` 'perforated, polyvinyl chloride (PVC) pipe surrounded by at least 6 inches of washed drain i gravel... The minimum diameter of the drain •rock "must be larger than the diameter of the, perforations in, the pipe-. The level of the .perforations in the. pipe should be set approximately 2 inches .below the bottom of the - footing (perforations down), and-' the drains should. be- ' constructed with sufficient gradient to • allow gravity flow: away from the building to a suitable discharge. Cleanouts should be installed at appropriate intervals. Roof and surface runoff should not discharge into the footing drain system, but should be *handled b •a separate, rigid, ti hiline drain.. Exterior grades, adjacent to' walls,. should be Y P g g sloped downward away from. the structure to achieve positive surface drainage. All collected ! water 'should be directed to an. engineered- storm drain system that drains. away from the ` buildings, and'not near, over,.or onto steep slopes. r 44" Utility Connections . Due to the- potential for differential soil. 'displacements at the project site., we recommend flexible connections between all utilities and the residence: The connections should allow up to•6'iriches of,ground movement: - ' CLOSURE We 'appreciate the opportunity to. be of service to -you on this, project. Should you have any questions regarding this letter or other aspects of the project, please do' not hesitate to call. We look forward to providing continued geotechnical: services as the project progresses. _Sincerely, - - ` • - . ` - `. - - ASSOCIATED EARTHSCIENCES, INC. Kirkland, Washington ' - O�Mgc�� • , , • dog w .'`WC - I . C 33222R�0 l STV, i SSIDNALti�� EXPIRES 2/27 Zr o77- Eric J. Lim; P. G..Aaron McMichael, P.E., P.E.G: iProject Engineer Associate Engineer ; Attachments: Figure 1, Vicinity Map, Figure 2: Site' and -Exploration Plan Appendix: Exploration Logs FJlrsn , - :' KE05550A1. , Projects\2005550\MW P . ' 15 V099903)4 *ON,roUd NCkL9NIHSVM'SGNowa3 90160 31VO 3ONmismi Avd dVW "N131A -*ul ls"uel:-S qljvg po4vpo99V t ainow 2WOS ON = = = = = m w m m m = = = m = = = m = t k t" i A N x 4 AZ 49 n. w 7 � r K1d t Pt y. -4cut -3-9fi W a x I LEGEND ■ APPROXIMATE LOCATION OF EXPLORATION PIT (EP) OR TEST PIT (TP) i APPROXIMATE LOCATION OF EXPLORATION BORING (EB)(B), HAND AUGER (HA) OR TEST HOLE (TH) ES EARTH SCIENCES GC GEOTECH CONSULTANTS, INC. SW SHANNON AND WILSON DB DENNIS BRUCE N A NO SCALE e a Associated Earth Sciences, Inc. VICINITYMAP FIGURE 2 ® ® RAY RESIDENCE DATE 10/05 EDMONDS, WASHINGTON PROJ. NO. KE05550A LOG OF EXPLORATION NO. HA-1 This log is part of the report prepared by Associated Earth Sciences, Inc. (AESI) for the named project and should be together that for interpretation. This summary applies only to the location of this trench at the ' read with report complete time of excavation. Subsurface conditions may change at this location with the passage of time. The data presented are o a simplfication of actual conditions encountered. ' DESCRIPTION Fill ' 1 2" of crushed rock over medium dense, moist, brown, SILTY SAND with gravel and scattered concrete debris and cinders. 2 Old Landslide ' Stiff, moist, tan, jumbled SILT with little fine sand and scattered rootlets (DCP at 2' = 12, 8, 8)_ 3 Loose, damp to moist, gray, fine to medium SAND with trace silt (DCP at 5' = 6, 6, 7). 4 5 Becomes finer. 6 Becomes coarser with iron oxide stains. ' 7 8 Medium stiff to stiff, wet, tan, fine sandy SILT to silty fine SAND with occasional lenses of clayey silt ' 9 (DCP at 8' = 13, 10). 10 ' 11 ' 12 Bottom of exploration pit at depth 11 feet No ground water seepage observed at time of exploration or 4 hours after exploration. No caving observed. 13 14 15 16 ' 17 18 19 o20 N n Ray Residence ' Edmonds, WA Associated Earth Sciences Inc. Project No. KE05550A N Logged by: EJL 'a Approved by: 8113/05 U Y LOG OF EXPLORATION NO. HA-2 This log is part of the report prepared by Associated Earth Sciences, Inc. (AESI) for the named project and should be t read together with that report for complete interpretation. This summary applies only to the location of this trench at the time of excavation. Subsurface conditions may change at this location with the passage of time. The data presented are o a simplfication of actual conditions encountered. DESCRIPTION Fill 1 Medium dense, moist, brown, GRAVELLY SILTY SAND with scattered concrete debris. 2 3 4 5 ----------------------------------------------------- Landscape Rocks 1 diameter roundedqtavel.----———— — — — — — — — — — — — — — — — — — — — - -_-------J 6---------- Relic Topsoil/Fill Loose, moist to wet, brown to dark brown, SILTY SAND with scattered asphalt pieces. 7 Old Landslide Medium stiff to stiff, moist, tan, jumbled fine SANDY SILT (DCP at 8 1/2' = 10, 9). 8 9 Bottom of exploration pit at depth 8.5 feet No ground water or caving observed at time of exploration. 10 11 12 13 14 15 16 17 18 19 N20 Ray Residence ID U) Edmonds, WA Associated Earth Sciences, Inc. Project No. KE05550A N Logged by: EJL Approved by: ® ® ® 8/13105 U Y 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 LOG OF EXPLORATION NO. HA-3 This log is part of the report prepared by Associated Earth Sciences, Inc. (AESI) for the named project and should be read to with that report for complete interpretation. This summary applies only to the location of this trench at the time of excavation. Subsurface conditions may change at this location with the passage of time. The data presented are a simplfication of actual conditions encountered. DESCRIPTION Fill Medium dense, moist, brown, silty SAND with few gravel and scattered concrete debris. Sewer pipe in east sidewall (trench backfill). Medium stiff, moist, tan, FINE SANDY SILT to SILTY. FINE SAND with scattered wood debris (DCP at 4 1/2' = 7, 7, 7). DCP at 6 1/2' = 10, 12, 12) Bottom of exploration pit at depth 7 feet No ground water or caving observed at time of exploration. Ray Residence Edmonds, WA Associated Earth Sciences, Inc. Project No. KE05550A Logged Approvedd by:: 8/13/05 LOG OF EXPLORATION NO. HA-4 w This log is part of the report prepared by Associated Earth Sciences, Inc. (AESI) for the named project and should be read together with that report for com lete interpretation. This summary applies only to the location of this trench at the time of excavation. Subsurface conditions may change at this location with the passage of time. The data presented are i p a simplfication of actual conditions encountered. 1 DESCRIPTION Fill ' 1 Sod over medium dense, damp to moist, brown, SILTY SAND with few gravel. 2 1 3 4 ' Old Landslide 5 Medium dense, moist, tan, SILTY FINE SAND to FINE SANDY SILT, slightly jumbled. ' 6 1 7 Bottom of exploration pit at depth 7 feet 8 No ground water or caving observed at time of exploration. ' 9 10 11 ' 12 13 ' 14 ' 15 16 ' 17 18 19 Ray Residence a N Edmonds, WA aAssociated Earth Sciences, Inc. Project No. KE05550A N Logged by: EJL Approved by: 8/13/05 U Y .. EXPLORATION PIT LOG ' 0 Number EP-1 Soft, moist, brown with gray, silty CLAY to clayey SILT with roots. (Ditturbed Fill) 5 Medium soft to stiff, moist, bluish -gray, silty CLAY to clayey SILT, brecciated; slickensides; layers of moist to ' wet, brown, fine sand; upper 1' slide debris. (Possession Drift) 10 1 15 BOH @ 15' ' Note: No seepage; no caving. ' Number EP-2 0 Loose, moist, brown SAND AND GRAVEL mixed with silty clay/silt (Fill) 5- Stiff to very stiff, moist, bluish -gray, clayey SILT to silty CLAY. (Possession Drift) 10 15 ' BOH @ 18' Note: No seepage; no caving. Subsurface conditions depicted represent our observation at the time and location of this exploratory hole, modified by geologic interpretation, engineering analysis, and judgment They are not necessarily representative of other times and locations. Wewiti not, acc,Pt tew sibiGty for the use or interpretation by others of information presented on this tog. Reviewed By Associated Earth Sciences, Inc. Aldridge Short Plat 911 Fifth Avenue, Suite 100 Edmonds, Washington Kirkland, Washington 98033 Project No. G97224A Phone: - 425-827-7701 September 1997 ' Fax: 425-827-5424 EXPLORATION PIT LOG 1 1 1 1 1 1 1 1 1 1 1 1 Number EP-3 5 10 — 15— Loose/soft, moist, dark brown, silty, fine SAND with roots. (Fill) Loose, moist, brown, medium SAND. (Fill) Loose, moist, reddish -brown, medium SAND with occasional gravel. (Fill) Stiff to very stiff, moist, bluish -gray, silty CLAY. (Possession Drift) BOH @ 18' Note: No seepage; caving. 0 Number EP-4 5 10 15 Loose, dry, dark brown, silty, fine SAND with occasional gravel, roots, chunks of asphalt. (Fill) Loose, damp, reddish -brown, medium SAND wtih occasional gravel. (Fill) Stiff to very stiff, moist, bluish -gray, silty CLAY; slickensided surfaces; upper 1' slide debris. (Possession Drift) BOH @ 16' Note: No seepage; caving 0 to 8'. subsurface conditions depicted represent our observation at the time and location of this exploratory hole, modified by geologic interpretation, engineering analysis, and judgment They are not necessarily representative of other times and locations. We will not accept responsibility for the use or interpretation try others of information presented on this log. Reviewed By.—� Associated Earth Sciences, Inc. Aldridge Short Plat 911 Fifth Avenue, Suite 100 Edmonds, Washington Kirkland, Washington 98033 Phone: 425-827-7701 Project No. G97224A Fax: 425-827-5424 September 1997 r 11 H H 17, 1� I EXPLORATION BORING LOG Number EB-1 Pacae 1 of 2 STANDARD PENETRATION Z W RESISTANCE SEDIMENT DESCRIPTION w g O ¢ Blows/Foot o co 10 W s0 40 Damp, light brown, silty, fine SAND with trace roots; 8 bottom of sample damp, light brown with gray SILT I A with trace fine sand. Damp, brown, silty, fine SAND. with lenses of silt with 5 T Il 4 trace fine sand; tip of sample damp, reddish -brown SAND with some small gravel. Damp, reddish -brown SAND with trace gravel. I 5 A recovery. (Fill) 10 INo A 4 ....... _.....�....... _-_....?--------- ---------�---------------------- q...........----------7............ Moist to wet, light brown, silty, fine SAND; top of sample T 8A black charcoal with fine sandy silt. 1 I Moist, brown, silty, fine SAND: tiny roots observed. 15 I 6A �. Damp to moist, blue, silty CLAY, plastic. 111 CLAY, laminated. 20 2 =I Moist, blue, silty Moist, blue, silty CLAY to clayey SILT. I '= blue, silty CLAY to clayey SILT. 25 IMoist, , 22 Moist, blue, silty CLAY to clayey SILT. I 18A Moist, blue, silty CLAY to clayey SILT with lenses of 30 I A 22 fine, oxidized sand; slickensided surfaces observed. (Possession Drift) - --*......... Damp to moist, light brown, silty, fine SAND, upper I 70 portion oxidized. (Double Bluff Drift) Subsurface conMm deplded represent our obsemoons at the tame and bcalton of this exploratory hole, modbW by goo* lnterpretatbns, errghraerb+0 anatysla, and Judgment They are not necessarily represerdaWe of other Umes and locadons. We w9l not . accept resporrslb64y for ttre use or brterprotatlon by others of enbmratbn presented on this log. Reviewed By Associated Earth Sciences, Inc. Aldridge Short Plat 911 Fifth Avenue, Suite 100 Edmonds, Washington Kirkland, Washington 98033 Project No. G97224A Phone: 425-827-7701 September 1997 ' Fax: 425-827-5424 ?< A 1 fl 1 11 F� 17� I 7 EXPLORATION BORING LOG P 2 of 2 Number EB-1 age STANDARD PENETRATION l = - LU Z W RESISTANCE F� SEDIMENT DESCRIPTION o n BlnvvslFoot 0 10 20 30 40 48A (Double Bluff Drift) BOH @ 36-1/2' Note: Slope inclinometer installed. 40 45 50 55 60 65 o— n„d location of this exPloratory hole, moditled by geologic Subsurface conditions depicted repmesem our —.a.,.. — -. - - of other timee and ioratlOtts We Will not Interpretations, engineering analysts. and Judgment They are not necessarily mprssentathre (� accept resporm Wit for the use or interpretation by others of Information presented on this log. Reviewed By �_ J Associated Earth Sciences, Inc. Aldridge Short Plat 911 Fifth Avenue, Suite 100 Edmonds, Washington Kirkland, Washington 98033 Project No. G97224A Phone: 425-827-7701 September 1997 Fax: 425-827-5424 a: I 1 it 1 11 EXPLORATION BORING LOG Number E13-2 Page 1 of 2 � STANDARD PENETRATION 0- Z w RESISTANCE SEDIMENT DESCRIPTION w =5 Q Blows/Foot o co �3 t� 10 20 30 40 Damp, brown, fine to coarse SAND with trace fine (Fill) T 1 gravel. ............ Damp, light brown SILT in top of sample; damp, light 5 T 7♦ gray, clayey SILT to silty CLAY in bottom of sample. 1 Damp, gray, silty CLAY. (Slide Debris) IA 12 Damp, gray, silty CLAY. 10 T 1 16• I Moist, bluish -gray, clayey SILT to silty CLAY. I Moist, light brown, fine SAND in top of sample;. moist, 15 I � 101 bluish -gray, silty CLAY in bottom of sample. l Moist, bluish -gray, silty CLAY; wet, medium SAND in I 1 i 30 tip of sample. I 20 = 4 Moist, bluish -gray, silty CLAY. I Moist, bluish -gray, silty CLAY; sand lense in middle AY; fi I 34 of sample. 1. I Moist, bluish -gray, silty CLAY, medium sand lense in. 25 I 27 middle of sample. (Possession Drift) 1 to moist, light brown, fine SAND at top of sample; IDamp 38 ♦ medium sand lower half of sample. 30 73 Damp to moist, light brown, fine SAND. Damp to moist, light brown, fine SAND. I 65 (Double Bluff Drift) Subsurfaoe c ondWow deplded represent our observations at the thne and location of this exploratory hole. modltied by geologic tnterpretetiorra, engpraering anaysK and Judgtnerd. They are not necessar0y representative of other trines and locations. We wl9 not accept resporsuft for the use or Interpretation by others of lnfom,atlon presented on this log. Reviewed By Associated Earth Sciences, Inc. Aldridge Short Plat 911 Fifth Avenue, Suite 100 Edmonds, Washington Kirkland, Washington 98033 project No. G97224A, Phone: 425-827-7701 September 1997 Fax: 425-827-5424 Ali EXPLORATION BORING LOG u 7 11 I Number EB-2 Paae 2 of 2 SEDIMENT DESCRIPTION W o � Z W M =O ¢ N 0� STANDARD PENETRATION RESISTANCE Biaws/FoOt 10 20 30 40 62 (Double Bluff Drift) BOH @ 36-1/2' 40 45 50 55 60 65 . Subsurface Conditions depicted represent our Observations at me mne anu www—o----o-- Interpretatlons, er96neeft analysis, and WMenL They are not necess * mWesentat - of other times and bcatlosns wa wf not accept responsU8ty for the use or interpretation by o0mrs of Inftirrnadon presented on d" 109- Reviewed By Associated Earth Sciences, Inc. Aldridge Short Plat 911 Fifth Avenue, Suite 100 Edmonds, Washington Kirkland, Washington 98033 Project No. G97224A Phone: 425-827-7701 September 1997 Fax: 425-827-542435 EXPLORATION BORING LOG Number E13-3 Page 1 of 2 r 1 1 1 1 1 1 1 1 1 1 1 1 1 i a A Subsurface condMons depicted represerd our observabons at &a time and baation of this exploratory hole, mode= by >�gk interpretations, engkwedng anabslo. and JudgmenL They are not necessarily representative of other times and bcadons. We wM not accept respor sbW for the use or interpretation by oftrs of hdonnadw presentW on this bg. Reviewed By Associated Earth Sciences, Inc. Aldridge Short Plat ' 911 Fifth Avenue, Suite 100 Edmonds, Washington Kirkland, Washington '98033 Project No. G97224A Phone: 425-827-7701 September 1997 �. Fax: 425-827-5424 If_ I STANDARD PENETRATION Z W RESISTANCE SEDIMENT DESCRIPTION w 2 0I" BiowWFoot o CD �� 10 20 30 40 Moist, orangish-brown, silty SAND. (Fill) I 5 � Moist, gray, clayey SILT (Slide Debris) I Moist, gray, silty CLAY to clayey SILT. I 2 Moist, bluish -gray, silty CLAY with moist, brown, fine 10 T A 14 sand lenses 4 thick in middle of sample. 1 Moist, bluish -gray, silty CLAY, fine sand lense in 15 middle of sample. I bluish -gray CLAY; 6" thick tense of peat with silt; ,5 IMoist, 28 A, slickenside surfaces. (Possession Drift) -----••---••....... . Damp, light brown, fine SAND. I 34 Damp, light brown, fine SAND; very fine sand to silt lense 20 30 in middle of sample. Damp, light brown to gray, fine to medium SAND. I 57 Damp, light brown, fine SAND; moist, brown, fine SAND 25 I 69 in bottom of sample. Moist, brown, fine SAND. I 81 Moist, brown, fine SAND. 30 I 71 SAND. I 82 Moist, brown, fine 11 rl EXPLORATION BORING LOG Number EB-3 Page 2 of 2 SEDIMENT DESCRIPTION o a Z W Q : t Cl) 0 STANDARD PENETRATION RESISTANCE Blow,/Foot - 10 20 30 40 (Double Bluff Drift) 64 BOH @ 36-1/2' Note: Slope inclinometer installed. 40 45 t I � 50 4 55 ` 60 i I 65 1 Subsurface =Witlons depicted represent our observations at fhe time and location of MIS exploratory now moameo oy geologic Interpretatlons, engineering analysis, and judgment. They are not necessarily representative of other times and locations. We val not accept responslblllly for the use or Interpretation by others of Information presented on this log. Reviewed By Associated Earth Sciences, Inc. Aldridge Short Plat 911 Fifth Avenue,. Suite 100 Edmonds, Washington Kirkland, Washington 98033 Project No. G97224A t Phone: 425-827-7701 September 1997 Fax: 425-827-5424 EXPLORATION BORING. LOG EB-1 x . J - °z ¢ ' STANDARD PENERATIott RESISTANCE Q v SEDIMENT DESCRIPTION W CL 0 a 8lorrs/Foot n C y 3 10 20 30 40 Moist; gray, gravelly-, silty, fine T 50/6'. to medium sand. Becomes sandier 1 with depth. (Lodgement*Till) 5 T 50/5" .10 I 50/4ra 15 . I 50/4" .. BOH @ 18, Subsurface awIdIdorw depicted represent our observations at.tlw tints and Iocafion of this exploratory halo, modrad by Seob* bdwpmtat w% enpirwsrin0 analysis. and judgnwnL They am not necsssarty representative of ather tines and iodations. We wiz not accept responau ity for the use or interpretadion by adws of Information presented on this log. 9110-06H October 1991 Summers Residential Property. , Edmonds,.Washington ASSOCIATED.. EARTH SCIENCES, INC `-2 EXPLORATION BORING LOG O ¢ STANDARD PF1MMION AESISTANC.E SEDIMENT DESCRIPTION IL a ¢ 4 Blows�Foot 10. 20 30 40 Moist,. gray,,gravelly, silty, fine ..to.medium sand. ...(Lodgement Till) I 5 I BOH @ 8' 1 Subsrrbce aonidam depicted n*reswd our obsw"t mw at the time and location of this exploratory ho* awMad by goolopic inter "wdorrr ergirrserig ar»Iyals. and )m*n nL They are nee necessarily represent 0m of other tirr>es ad iooations, We wn not accept moporwi i ty fa the use. or JwwpmUdIon by others of information presented on this Io% 9110-06H October 1991 Summers Residential Property Edmonds, Washington_ ASSOCIATED EARTH SCIENCES, .INC 1 50/4' 50/4' EXPLORA EB-3.. TION BORING LOG ' o. ro SEDIMENT DESCRIPTION J Z ¢ SM DAIiD PENERRION RESISTANCE 8lows/Foot. st. a C n M; 10 20 30 10 ' .Moist, tan, silty, fine to medium sand with some gravel. (Fill) T 18 Moist,.gray# gravelly, silty, fine 5 to medium sand. (Lodgement Till) 50/5", I 50/6', I . 15 . Z . 50/4" rMoist, fine (Advance 20 . gray, sand. - Sand) _ I 50/5r BOH @ 24r 25 Subsaaface oonMons.deputed represent our'e4servatbns at the time and bastion of this explore" ice. modified by peolopia, interpretation% eh*wwinp analysis. and judgment: They are not necessarray repnmenb Mm of outer dmea and boadons.. We wM not _ accept responsaft far the use or interpWation by others of 1nfanwdon.preseMed on this lop. 9110-06H- October 1991 Summers Residential.Property Edmonds, Washington ASSOCIATED'. EARTH . SCIENCES, INC 1 1 1 u L i MASTERLG 71t01:r SOIL DESCRIPTION " - o, ° COLL �; Standard Penetration Resistance 040 Ifs: weight, 30" drop) a E 40 a A Blows per foot Surface Elevation: 98 Feet p N to p 20 40 60 Loose, brown, silty, fine SAND; moist; 3:wet @ 18 ft. mixed with clayey SILT with I mottled disturbed appearance with = . . possible slide plane @ 20 ft. (Fill and _ 10 .__ __ = - Slide Debris) SM. -i----.. .. ...... 20.9 jU 20 _ _ Stiff to very stiff, gray, fine sandy SILT to slightly clayey SILT; wet; with laminated structure; ML. s = 0 30 36.0 Hard, gray, silty CLAY; moist; laminated . with fine sand partings and wet sand layer = 40 at 46.3 ft.; CL . 50 56.0 ` Very stiff, gray, silty CLAY; moist; with scattered iron stained sand layers and = 60 - - • disturbed blocky appearance; (Possible 61.5 ancient slide plane) CL. BOTTOM OF BORING COMPLETED ON 11119/93 70 80 .: _....... _ 90 ....:... .........._..:. 40 0 20 60 LEGEND • % Water Content Sample Not Recovered I717 Surface Seal Plastic Limit m---0--I Liquid Limit = 2" O.D. Split Spoon Sample ® Annular Sealant Natural Water Content IL 3" O.D. Shelby Tube Sample Piezometer Screen ® Grout Ursula Schluter 3Z Water Level — 15620 75th Place West Edmonds, Washington NOTES 1. The stratification lines represent the approximate boundaries between LOG OF BORING 'H soil types, and the transition may be gradual. 2. Thei discussion in the text of this report is necessary for a proper understanding of the nature of subsurface materials. January 1994 W-5385-02. 3. Water level, if indicated above, is for the date specified and may vary. 4. Refer to KEY for explanation of 'Soil Log' symbols and definitions. SHANNON & WILSON, INC.=.FIG. 5. USC letter symbol based on visual classification. Qxftc f" and Em"nmentsl cw,s eraMa ';• TEST PIT LOGS Al 0' - Duff, topsoil, and roots Variable brown silty fine sand with gravel and clasks of silt -clay mixture (slide debris) (loose) 13.0' - Completed February 25, 1986; no groundwater encountered ' 12 0' - Duff, topsoil, and roots Variable sandy silt and silty sand (slide debris) ±13.5' - Sandy gravel, slight groundwater seepage throughout ' - Blue -gray silty clay (severely fissured and with ' slickensides) ±11.0' - Completed February 25, 1986 0' 13 - Variable silt -sand -gravel mixture (saturated) (slide debris) 1 3.0' Blue -gray silty clay (med stiff) (old slide debris) 8.1' - Tan silt (hard) .14.51' - Completed February 25, 1986; groundwater flow from ' upper 3 feet ' 14 0' - Highly variable silt -sand -clay mixture (slide debris.) 7.0' ' .Blue -gray -silty clay (fissured, ancient slide debris) 11.0' - Tan silt (hard) 13.0' - Blue -gray silt (hard) ' 16.0' - Completed February 25, 1986; seepage from 4-1 feet FIG. 7 1 ------ -, o� wt' BORING S 0 �fiti4 �Qt USCS D scrf d n Brown, gravelly SAND with some silt, coarse -grained; moist, ' very dense 5 $0 ' 1 r10 GP -. 36 - becomes less gravelly 15 r. 74 - becomes wet t 20 18 , ' Brown, slightly sandy and silty SAND, low plasticity, wet, stiff u 26 Mt 1 .Mostly very fine-grained, silty SAND 30 33 sM Gray, silty SAND, moist, dense Test boring was terminated at 31.5 feet below grade on 1=18-97. No groundwater seepage was encountered during drilling. 35 1 r40 GEOTECH COM8ULTAMTS, MC. TEST BORING LOG 15620 - 76TH AVENUE :WEST V EDMONDS, WA Job No: DOW: LoV by: Pets: 970a1 JAN 1997 DRW 35 10 33 is 18 20 33 MX�XI XMXX MMM. G:iX n�ykrX X 1900 CXXI kXGI K�CI MrMM M 1 XXM� 40 BORING 2 sou Brown/mottled, silty SAND with gravel,_wet, loose to medium -dense Brown/mottled, gravelly SAND with some"silt; very'moist; dense Tan, very silty SAND, lenses of silt, fine-grained, very wet, medium -dense - becomes very moist, dense . - becomes wet, lens of silt - becomes saturated Gray, sandy silt, low plasticity, wet, very stiff Test boring was terminated at 31.5 feet below grade on 1-18-97. Groundwater seepage was encountered at 16' and 30' during drilling. GEOTECH COMMUM'S, INC. TEST BORING LOG 15620 - 76TH AVENUE WEST.. EDMONDS, WA Job No: Date: Logge Eby: PJate: 4 97001 JAN 1097 DD • ` ;�� fi��, �� S o�` BORING 3' RM - - k FEIN �ML�MwS_ Brown/mottled, gravel;very wet,• • se INNLiM.1,� S lens of silt 1 50/4" . Brown, gravelly SAND, some silt, coarse -grained, wet, dense SP 10 ■ — - -- .. .. _ 2 24 1s .3 25 20 u 30 ' 3s 40 4 5 20 53 -becomes less silty, moist becomes wet lens of silt Gray SAND, medium -grained, moist, dense Test boring was terminated at 26.5 feet below grade on 1-18-97. Groundwater seepage was encountered at 3' during drilling. �.r GEOTECH CONSULTANTS, INC. TEST BORING LOG 15620 - 76TH AVENUE WEST EDMONDS, WA , y: Job No: Date: Loq bPlate: 97001 JAN 1997 dU 5 1• 11 p r Ll 1� 1 PtA4N15 PA. 5jeu x; FE jLA&vG` ! 1lRI I Hansen Page two The extreme rear (easterly) portions of the Hansen property encompass the steep slope portions of the region. The slope exists at an approximate forty percent (40%) grade. The slope contains mature stable trees, with dense brush (see photographs). No evidence of any geotechnical distress, slides, nor erosional degradation was observed immediately above and behind the Hansen property. This engineer understands that a localized surficial slide has occurred one to two properties to the north, and is a direct result of up slope bad drainage practices. It is understood that the localized slide to the north is currently undergoing stabilization and drainage improvements. As stated in the 1979 Roger Lowe Associates, Inc., report, drainage and ground water control are the best practices for landslide risk reduction. This engineer concurs. IEVALUATION: ' In order to augment the existing site geotechnical information, power hand auger test holes were dug under this engineer's observation on May 22, 1999. Two test holes were dug to seven foot (7') depths (see photographs and site plan for ' locations). Test Hole No. 1 was dug at the approximate south foundation line of the proposed addition, approximately twelve feet (12') east of the existing house. ' Test Hole No. 2 was dug approximately ten feet (10') south of the hot tub deck on the relatively level soil bench. Both test holes revealed similar subsurface conditions, namely: 0" to 6" 6" to approx. 3.5' 3.5' to 4.5' 4.5' to 7' (bottom of hole) Organics, roots, and organic silt, Brown sand, relatively clean, moderately dense Increasingly dense sand with cobbles Very dense silt and silty sand with cobbles No water was encountered in either of the test holes. Both test holes remained vertical and stable. No sloughing or caving occurred. This engineer conducted a visual examination of the slope above the Hansen property. A small historic "cave" (?) zone was observed. It is understood that this "cave" was used for historic bootleg storage purposes. This "cave" was approximately three foot (3') high by approximately three foot (3') deep along the face of the bluff slope. The "cave" revealed no evidence of any geotechnical distress. Additionally, this "cave" zone allowed further verification of the dense sandy silt and gravel soils present. This engineer did observe a mature fir tree growing immediately above the U i'r In 7—mg- 7777777�777 � Us lw I , AFV.!� rZ. Ali; 7-7 ------ ------ ------- *M *a-201d L149-Z Nw PIXPR :AwhiiFvR:. 2 " Wb 2.2 NYfW -12HUNDURRendAM NXRWX o S? zi OZ (9NI$VV -40 SISVS) 3.zl,qpzoN 2 pN Ci >1 �i 4 44 , , 2 zz� O O 4 : o'IV - z CV411 1111 - ---------------- ------- Ni +O @ El M.- M g b O [14 8E C\l cQ CQ ZI IQ N r3 El CQ 0 lZ L IIJ, Lu oc cr, Ell R M a3VUd ,SL SZ99T NVId 31IS LU U- w LU C= u SA K 4 8T s n 5 5 K, g IM .1 6 S, 8 A T! 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