17306 73RD AVE W.PDF1111 lill lill
5737
17306 73RD AVE W
I ' A -Min I It. -I
Certificate of Occupanc
Building Division
-'I C . 1 16 1) -
This certificate is issued in accordance with the requirements of Section I 11 of the 09 International Building Code . -
certifying that at the time of issuance this single family residence was in compliance with the applicable provisions of
the codes and ordinances of the city regulating construction and use of build ings.
Description: 64 - Single Family Residence New
Site Address: 17306 73RD AVE W, EDMONDS
Construction Type: VB
Owner: WALLACE &HEIDI CHANG
17306 73RD AVE W
EDMONDS, WA 98026
wuilding Official
Permit No:
Parcel No:
Occupancy Group:
BLD20121103
00513100013908
R-3
I(Z-71-1-� -
9 Date Issued
POST IN A CONSPICUOUS PLACE
INS
IN 1;
z
Val
Nczjuo
74
�2'
W A
E
A
GRATE
CB
FILTER SOCK WITH
OVER FLOW HOLES
4
CATCH BASIN
4'
STRAW BALES MAY BE USED IN
CERTAIN CIRCUMSTANCES (SEE
DETAIL E1,1.1), THIS APPLICAITON
SHALL BE MAINTAINED AT ALL
TIMES DURING CONSTRUCITON
PERIOD.
CITY INSPECTION REQUIRED ON ALL EROSION CONTROL
MEASURES BEFORE WORK CAN BEGIN.
N."D S.--.
....-C.-I-TY*....'�-0-F':-..,..-- -.D:-M*,O.'
REVISIONS STANDARD DETAIL
APPRUVED BY VATE
1D. GEBERT 10/6/03 TEMPORARY SEDIMENT TRAP FOR CATCH MSINS
D. GEBERT 05/19/05 -T CALE NTS DWG NO. E-1.3
7890-1990 D, GEBERT 05/05/06 WE 7/24/01
FILTER FABRIC
SECURED TO 2' X 2'
14 GA. WIRE FABRIC
- -'IAL
2' X 2' WOOD OR
EQUIVALENT
CD
I
�u
PLACE 3/4'-1.5' WASHED GRAVEL IN
THE TRENCH AND ON BOTH SIDES OF
FILTER FABRIC FENCE ON THE SURFACE.
�u
FILTER FABRIC MATERIAL IN
CONTINOUS ROLLS. USE STAPLES
OR WIRE RINGS TO ATTACH
FABRIC TO WIRE.
WIRE MESH SUPPORT FEINkE
TO SUPPORT FILTER FAMIC.
T=I I �—1 I 1:=1
111.11 = �=l I u 11T Ifil I=
Ell -lrFII N.1 IEI�1-1 I P---
---4-4- - - - - - - - - - - - - - - - - - - - - - - 4- -4---
1
CBUR"Y BOTTOM OF FILTER
MATERIAL 8- TO 12-
6' MAX.
N L J
2' X 2' WOOD POSTS OR
EQUIVALENT
ONTRACTDR/DEVELOPER SHALL MAINTAIN AND REPLACE
TRAW BALES TO INSURE PROPER EROSION CONTROL.
I a9o-199U
CITY INSPECTION REQUIRED ON ALL
EROSION CONTROL METHODS BEFORE
OTHER WORK CAN BEGIN.
REVISIONS STANDARD DETAIL
APPROVED BY WE
FILTER FABRIC FENCE FILTRATION SYSTEMS
I DATE SCALE DWG NO.
1 7/24/01 1 NTS I E1.1
!PACM VAME13 (TYPJ
SEE WATTLE SPACING TABLE
M
rod
.W.-A
2x2 x 31 - (r WOODEN STAXE
SPACED EVERY e - W Or- (TYPJ
STAGGER JOINTS (TYP.)
SEE NOTE 2
SEDDAEPITTRAIMP04
AREA (!W�
----- ------
WATTLE SPACING TABLE
SLOPE
MA)WISMSPACM
1:1
la-v
21
W-v
3;1
W-Ir
4:1
40-V
SECTION 0
1. MWjes Shell be In acowdanoo WM Shindard Spedficafim
9-14.5(5). ftWd WoMes aloM contmm InsImMon shall
be In aomrdance mM Standard Spedficalkin 8-M.3(10).
2. Sectively MW eadl and d WaMe. AbUt SCQ&OM WatIleg
fthtly, end to end, wIthoiA overlappbig the ends.
3. PUr
w �r =drhon through ft Waffles mid Into ft
n X RIM rewre.
4. LIve sbdm may be wed lbr pamormit Instoillaffim wW shall
be In acoordance wfth St"ard Qpwftdan 9-14.6(8).
5. WaMn shall be Inspected Top", and hmedis" afbar
a raliffall pm&im nm#, to ermn they remain dwroughly
enbencW and In contad wtth dw a&
6. Pei bn mahtemoe In amordance whh Slarsdard Specl-
flodon U1.3(15).
TYPICALSEWICIN
WATTLE DLUAIL
SPACING VARIES (TYPJ
SEE WATIME SPACING TABLE
wArme - SEE oumi.
N'.
STATE OP
MAMMON
LODWAPE ARCHITECT
11
MARK W. MAURER
CEIMRCATE NO 000598
WATTLE INSTALLATION
ON SLOPE
STANDARD PLAN 1-30.30-00
BMW I OF I SHEET
AMOVED FM PI.FlUXATION
Pastao Bakodch 1H 09-20-07
"oh, ��— —
im W-bbo. am 0, clum"p-w"
A
till 9 11
a
51 VA
16
z
0 all
V)Irns)mn As Nmvva
N (�r
IV -fro
TO P�
r
END Lsr
AROUND (TYP.)
i SPACING
DIMRSED I SYR) - Gas 4
AREA n
ONTOUR LINE (rYPJ
KE,
�Mpj
SLOPE DMALLATION
9
2-2 x.T - Ir WOODEN STAKE .19
COMPOSTSOCK
SEE NOTE I
EROSION CONTROL BLANKET
SEE NOTE 3
TVPICAL SEC"
COMPOST SOCK DETAIL
EROSION CONrRDL BLANKET
-SEENOTE3
COMPOSTSOCK
SEE DETAIL
PROTECTED
AREA
SECTION 0
DRAINAGE GRATE (CIRMLAR
GRATE SHOWN)
2-2 - Y - 0"WOODEN STAXE,
SPACED EVERY V - Q'O.C. ("4
11 1 WA, W,
WIRE TIED
ISONIETRIC VIEW
CATCH BASIN INWALLATION
C4CMPO9T SOCK
- SEE DETAIL
11-01MIM.
OVERLAP
NOTES
1 . Compost Sock shall be in acomdanoe, with
Standard SpMMCatbn S-14.5(6). Compost
Sook sWi be a mWmum of 8* In dWffxdw
or Sized to suft Conditions as spedflet! by
the Engineer or Contrad
2. Compost material tD be dispersed an sb.
as detaimineff by the Engineer.
S. �Aftn plavins Cwnpost Sock on Slaves; use
Erosion Control Blanket If speollied by the
Enoineeir arx! In scoordance with SW%twd
V. 0-14.6(2). See StsuWard
4. ~ Install Compost Sock perpenflimilar
to slope and along Contour Ibiss.
6. Remove sedirnent ftm ft up Slope side of
ft Compost Sock when acoufruddon has
maolied 112 of the effiective hellft of the
Compost SoCk.
S. Uve stakes am be used In addfflm to wood-
en stakes Sniff shell be In aofortlanoe with
StwxIM SpedftaWn 9-14.60). See plane
for species seleCtion and spaclng.
IMATE OF
FMC99TEFMO
LANDSCAPE ARCHITECIr
ANDRA L. SALISBURY
'CERTWMTE NO.
COMPO" so"
STV"A" PLAN 1-30AO-00
SKEET I OF I $MEET
APPROVED FOR PUBLICATION
Pasco Bakofich N 10-1247
Ale, W�bwwua —
all
9
I
3 QUARRY
z - w senim oEPTm
�UMKE
1
—1 WALLS
GROUND
TEMPORARY OLT FENCE
OR COMPOST SOCK
SECM0N
OUTFLOW CMANNEL IS
CONSTRUCTED ffy
N=
cr a, MIN.
PLACE GE0TW7LE UNDM THE SPLLVWkY AND SIDE SLOPES. PROVIDE A
t - r DEPTH OVERFLOW -,,J
CONTINUOUS LAYEFt nTvwmN rmp GRAVELIROCK AND T?(E ISIATIVE EARTMN MATERIAL
—I— I
lt�z �61 COMPACTED NATIVE MATERIAL
CONSTRUCTED BY EXCAVATION
2 2 711OR EMBANKMENT
C�WD'
SEDIMENT TRAP BOTTOM T- ODEPTH
OF r - OROCK
V- Ir DEPIM OF 3W - I Vr -/
WASHED GRAVEL BACKFILL PROVIDE GEOTE)mUl
am am. SPEC. SECIM M
SECT= 0
TEWPORARY SEDIMENT TRAP
,r - r QUARRY SPALLS
AS REQUOM - iW MIK. -
EXCEPT MAY RE REDUCED
TO W UK FOR SITES %M
LESS TWO ONE ACRE OF
EXPOSED SOL
(1) PLACE comsTmxnoN GEoTExmg FOR V.
SOL STABILIZATION AND A WNIMIUM OF 0.1v
CRIUSHED ROCX UNDER TME WALLS, FIROM
EDGE OF THE BUSTING ROADWAY TO THE Rwus
RETUFOM OR AS DIRECTED BY TM ENGINEER.
ISCHETIM VIEW
STABILIZED CONSTRUCTION ENTRANCE
COARSE COMPOST
L 2X 1
X - V- WFOR SLOPES 41tiV OR FLATTER
X =V -V FOR SLOPES Sl THAN 4RIV
PROVIDE I= WIMM OF
INGRESS IEGRESS AM
IS -rim
TYPICALSECTION
COMPOST BERM DETAIL
frATE OF
WASHINffM
REGMTERED
640 ll� LMDSCAPE ARCHITE=
MARK W.MAURER
CERTIFICATE NO. OOOM
A
MISCELLANEOUS
EROSION CONYROL DETAILS
STANDARD PLAN t40.10-011
SHEET I OF I SIIEET
APPROVED FOR PUBLICATION
Pasco Bakatkh /it 08-11-0
gmTammm� we
CITY OF EDMONDS
121 5b Avenue North, Edmonds WA 98020
Phone: 425.771.0220 - Fax: 425.771.0221 - Web: www.ci.edmonds.wa.us
DEVELOPMENT SERVICES DEPARTMENT - PLANNING DIVISION
'11C. llg9-
Critical Areas Reconnaissance Report
7
Critical Areas File Number CRA20110005
Determination Study Required
d--
Site Location 17306 73r Avenue West, Edmonds
Tax Account Numb er 0051310001 3908
Property Owner HughlGay Morris
Applicant John Bischoff
F
Critical Areas Present 0 Geologically Hazardous Areas
0 Erosion -Hazard Are -as
Site Description
During review and inspection of the subject site, it was found that the site may contain (or be adjacent to) critical
areas, including Geologically Hazardous Areas (Erosion Hazard Area or Landslide Hazard Area), pursuant to
Chapter 23.40 of the Edmonds Community Development Code (ECDC). Geologically hazardous areas include areas
susceptible to erosion, land sliding, earthquake, or other geological events. They pose a threat to the health and
safety of citizens when incompatible development is sited in areas of significant hazard. Such incompatible
development may not only place itself at risk, but also may increase the hazard to surrounding development and
use. Cited sections of the Edmonds Community Development Code (ECDC) can be found on the City of Edmonds
website at www.ci.edmonds.wa.us.
The UDAR map (attached) indicates that there is an erosion hazard area of approximately 33% at the western
portion of the site (56'/165') and extending further off site. The site is generally comprised of a rolling slope of
10% across the entire property rolling from east to west. Soils on the property are identified as mostly Alderwood
urban land complex with the western most portions identified as the Alderwood gravelly sandy loam series, which
classifies the site as a potential erosion hazard. These slopes qualify as potential "geologically hazardous areas."
Allowed Activities & Exempt Proposals
Certain activities are allowed in or near critical area buffers as specified in ECDC 23.40.220. Similarly, certain
development proposals may be exempt from Critical Areas requirements (ECDC 23.40.230). If you have any
questions about whether your proposed development qualifies as an allowed or exempt activity, please contact
a Plannerfor more Information.
General Report Requirements
Critical Areas Reports identify, classify and delineate any areas on or adjacent to the subject property that may
qualify as critical areas. They also assess these areas and identify any potential impacts resulting from your specific
development proposal. If a specific development proposal results In an alteration to a critical area the critical
areas report will also contain a mitigation plan. You have the option of completing the portion of the study that
classifies and delineates the critical areas and waiting until you have a specific development proposal to complete
the study. You may also choose submit the entire study with your specific development application. Please review
the minimum report requirements for all types of Critical Areas which are listed in ECDC 23.40.090.D. There are
additional report requirements for different types of critical areas (see below). Note that it is important for the
report to be prepared by a qualified professional as defined in the ordinance. There are options on how to
complete a critical areas study and an approved list of consultants that you may choose from. You may contact the
Planning Division for more information. General Mitigation Requirements for all Critical Areas are discussed in
ECDC 23.40.110 through 23.40.140.
Erosion Hazard Areas
It appears that this property contains or is adjacent to an Erosion Hazard Area. Geologically hazardous areas
include areas susceptible to erosion, land sliding, earthquake, or other geological events. They pose a threat to the
health and safety of citizens when incompatible development is sited in areas of significant hazard. Such
incompatible development may not only place itself at risk, but also may increase the hazard to surrounding
development and use.
Erosion Hazard areas include Alderwood and Everett series soils on slopes of 15 percent or greater, among others.
Landslide Hazard Areas are further defined in ECDC 23.80.020.A. In addition to the general requirements for
Critical Areas reports referenced above, specific Critical Area report requirements for Erosion Hazard Areas (which
are one of the Geologically Hazardous Areas) are provided in ECDC 23.80.050.
Note that Stable Erosion Hazard Amos may have limited report requirements at the director's discretion. At a
minimum an erosion and sediment control plan prepared In compliance with the requirements in ECDC Chapter
1&30 shag be required.
Development is restricted within an Erosion Hazard Area and must meet additional criteria. For erosion hazard
areas with suitable slope stability, an erosion and sediment control plan prepared in compliance ECDC 18.30 will be
considered to meet the Critical Areas "Study Required" determination. The determination of "suitable slope
stability" will be made by both the Planning and Engineering divisions of the City of Edmonds. In areas where the
slope stability is not suitable, projects within Erosion Hazard Areas will require a report by a licensed Geotechnical
Engineer or other qualified professional. Note that it is important for the report to be prepared by a qualified
professional as defined in the ordinance. Report requirements are given in ECDC 23.80.050, and more generally in
ECDC 23.40.09O.D. Development standards are given in ECDC 23.80.060 and 23.80.070.
Page 12
Determination: Study Required
This review applies to the entire subject parcel. Depending on the location and project proposed relative to the
Identified critical areas, certain studies and reports maybe required. Please contact the Planning Division at
425.771.0220 if and when you have a specific development proposalfor this site in order to discuss the various
permits that will be required. Please note that tree removal on sites containing critical areas mayfirst require a
tree cutting permit, and the illegal removal of trees may result in penalties and steep flnes (ECDC 1&4S.070,
ordinance #3828).
Gina Coccia, Associate Planner
Name, Title
Signature
February 10, 2011
Date
Page 13
A
r
Y
ILI
9 /P�
L
EROSION HAZARD AREA
m APPROX 33% SLOPE
V
3
)0)
Tl AA N
02.10.2011 17306 73rd Ave W (RS-20 + RS-1 2) 1 inch = 50 feet
Pfamhg Oh -Wm (CC) 1121 ISM A m N. WA 9= 4.217 71.02,20 No --cror ofany kl7d is gkon.
Thh, map disptays UDAR data at approAmale 2-k , . . �A Umm of We rusp agree to ktolomMy &W #-. harottess the CAty of Edmwds.
Thb mp 1. for WomaUm purpows ony, and ahouW ftot be mUod Lpm lbr any action, b offlotals, ol5com anpbysss aidior agmts hm end agalrmt any cleft.
Achial topography sho,4d be �adfisd i. the field by W—y t. soc""ey N d"aw or aedw, """pe'th"I of *# nature of 00 =" of #'a cla"".
This —p 1. p,.,fdad with .0 faidta on sm 'as Wand 'm &WHONO'basi. cbma;: or actbn. afbhg otit of any �e orpossamlon of this map.
&
t!
ROLLING SLOPE ACROSS SITE
APPROX 10% (167152�
u
o
Response to Critical Areas Reconnaissance Report:
1. Erosion Hazard Area Approximately 33% slope (56'/165')
Response: After site preparation and access creation, a rockery will be
erected along the WEST property line.
2. Rolling Slope Across Site Approximately 10% (16'/152')
Response: After site preparation and access creation, a rockery will be
erected along the NORTHEAST corner of the property, especially to
address the area that may be affected by limited tree removal.
ink
AQ-SA
TIFIE V
ASBESTOS SURVEY
17306 73RD AVE W., EDMONDS, WA 98026
Page I of 5
#2110419
April 18, 2011
Wally Chang
8328 NE 187" Way
Kenmore, WA 98028
425-894-0879
anahc(i�u.washingtonxdu
On April 14, 2011, Asbesto-Test personnel conducted an Asbestos survey (per
U.S.E.P.AJA.H.E.R.A. guidelines', as designated and specified by Puget Sound Clean Air
Agency and Washington State) of the house located Q), 17306 73d Ave W., Edmonds,
Snohomish County, Washington 98026. This survey purpose is to identify any Asbestos
Containing Materials that may be present and will require professional removal prior to
demolition.
NARRATIVE OF FINDINGS
BASIC CONSTRUCTION: The house is one story wood frame on a concrete slab. The
siding is CMU brick. There is vermiculite inside the CMU brick cavities. The vermiculite was
sampled. The torch down roofing materials were also sampled.
INTERIOR CONSTRUCTION, FINISHES, AND FLOORINGS: The interior is wood
and drywall.- The drywall/taping materials were representatively sampled. The vinyl flooring
materials, with relating backings, and mastics, were uniformly sampled. The misc. mastic
materials were sampled. The masonry tile and relating mortar/mastic materials were also
uniformly sampled.
CONTINUE TO PAGE 2
1429 Ave. D. #187, Snobambb, WA 98290 425489-4040; c 206-914-5500; f775-665-0420
e maH Asbestotestamm.com ; web: www.asbestotestcom
LE1 I
Page 2 of 5
C82110419
April 18, 2011
Ashesto-Test, Inc 425-489-4040
17306 73dAve. W, Edmonds, Snohomish County, Washington 98026
INSULATION: The insulation materials were sampled.
ELECTRICAL SYSTEM: The electrical wiring insulation did not appear to be of the kind to
be ACM. The power may have been "on" at the time of the survey, thus sampling was not safe.
Any suspect electrical wiring insulation or any suspect TSI (Thermal System Insulation) found
in, around, or behind any locatedfuse or breaker boxes should be considered to be A CM
(Asbestos Containing Material), unless determined otherwise by laboratory'analysis.
HEATING AND VENTILATION SYSTEM: The heating source is boiler system. There
was no visible relating suspect ACM located. Note: It was not possible to dismantle the boiler
andpiping system to locate andlor evaluate any additional suspect ACMthat may be concealed,
inside the unit, or associated in hidden areas. It is our opinion anyfurther handling ofthe boiler
andpiping system should be coordinated by the project manager andlor abatement contractor. if
any additional relating suspect materials are locatedprior to andlor during any demolition, any
and all additional related suspect materials should be considered to be ACM (Asbestos
Containing Material), unless determined to be otherwise by laboratory analysis. Any additional
TSI that may be present inside or outside the boiler unit and/or piping system including but
not limited to all interior fire brick, mortar, internal insulating materials, gaskets, joint
compounds, sealants, and/or insulations, are PACM unless tested otherwise by laboratory
analysis. Any metal insulated chimney system that may be present is presumed asbestos
containing.
MISC.: None.
ADDITIONAL STRUCTURES ON SITE INCLUDED IN SURVEY: There is a garage
with a studio apartment above also on the property. The structure is wood frame. The sheet vinyl
flooring material was sampled. The misc. mastics were also sampled. The drywall/taping
materials were sampled. The torch down roofmg and window glazing materials were also
sampled. There was no visible suspect ACM located relating to any heating system.
# of structures included in survey: one house & one garage with studio
REQUESTED BY. Wally Chang
Carl Dykstra
Inspector, certified A.H.E.KA.
accred.#1067045 (Exp. June 2, 2011)
continue to page 3
LEL
01 1429 Ave. D. #187, Snobombb, WA 98290 425-489-4040; c 206-914-5500; f 775-665-0420 CID
e mail AsbestotestAmsn.com ; web: www,asbeslotest,com
Page 3 of 5
CB2110419
April 18, 2011
Asbesto-Test, Inc. 4254894040
17306 73dAve W, EW�rwnds, Snohomish County, Washington 9802
Any and all materials Identified as ACM or PACM In this report (and/or additional materials associated with the structure that
may be discovered and later Identified as ACM or PACM), must be professionally abated prior to demolition. ASSESSMENT AND
QUANTIFICATION OF ACM FOR ABATEMENT PURPOSES AND/Olk PRICING FOR REMOVAL SHOULD BE DETERMINED BY ON SITE
EVALUATION, AS LISTED QUANTITIES ARE NOT GUARANTEED AND ARE AN APPROXIMATION ONLY.
SAMPLE I IS ASBESTOS CONTAINING MA TERIAL
ANALYSIS ID ASBESTOS/f]rYPEHOUANTITY OTHER MATERIAL
NOTE.- Any metal insulated chimney system that may be present is presumed asbestos containing
GARAGE:
1.0 MTqDOW GLAZING yes // chrysotile 2% non -fibrous materials,
NON -FRIABLE ACM cellulose
Thick glazing on aluminum window frames on garage -doors (3)
MERE WAS NO ASBESTOS DETECTED IN ANY OF THE REMAINING SAMPLES
HOUSE:
2.0 vermiculite insulation - I — // --- H<I% non -fibrous materials,
inside brick an house
3.0 insulation
walls & ceiling
4.0 masonry splash tile
shower
5.0 mortar/mastic.
beneath previous sample listed
6.0 textured paint material
hall sample I
6.1 textured paint material
hall sample 2
6.2 textured paint material
hall sample 3
7.0 masonry floor tile
kitchen
8.0 mortar/mastic
beneath previous sample listed
LE1 I
NAD
NAD
NMI]
cellulose
cellulose, fiberglass
non -fibrous materials
non -fibrous materials,
cellulose
NAD paint, cellulose,
non -fibrous materials
NAD paint, cellulose,
non -fibrous materials
NAD paint, cellulose,
non -fibrous materials
NAD
NAD
continue to page 4
non -fibrous materials
adhesive, cellulose,
non -fibrous materials
1429 Ave. D. #187, Snobombb, WA "290 425-499-4040; c 206-914-5500; f 775-665-0420
t mall Asbestotest(a),mm.com ; web: www.asbestotest.com
CED1
Page 4 of 5 April 18,2011
CB2110419 Ashesto-Test, Ina 4254894040
17306 73dAyA W. Edmonds, Snohomish Countm, WashinVon 98026
ANALYSIS ID ASBESTOS//TYPEHOUAWITY OTHER MATERIAL
9.0 laminant mastic NAD adhesive, cellulose
kitchen countertop
10.0 torch down roofing NAD cellulose, tar,
& underlying materials fiberglass,
11.0 roofing vapor barrier
beneath previous sample listed
GARAGE/STLTDIO:
12.0 sheet vinyl flooring
@ base of stairs to studio — color: gray
13.0 mastic
beneath previous sample listed
14.0 laminant mastic
kitchen countertop
15.0 drywall
16.0 drywall taping compounds
SAMPLED PER AHERA PROTOCOL
EXTERIOR & MISC:
17.0 window glazing
house
18.0 torch down roofing
& underlying materials
19.0 roofing vapor barrier
beneath previous sample listed
20.0 insulation
Lit .
non -fibrous materials
NAD cellulose, tar
NAD non -fibrous materials,
cellulose, fiberglass
NAD adhesive
NAD, adhesive, cellulose
NAD non -fibrous materials
paint, gypsum
NAD non -fibrous materials,
cellulose, fiberglass
NAD non -fibrous materials,
cellulose
NAD cellulose, tar,
fiberglass,
non -fibrous materials
NAD cellulose, tar
NAD cellulose, fiberglass
continue to page 5
1429 Ave. D. #187, Snottomish, WA 98290 425-489-4040; c 206-914-5500; f 775-665-0420
e mait AsbestoteAQuisn.com ; web; www.asbestotest.com
i2ftn�o
Page 5 of 5
CB2110419
April 18, 2011
Asbesto-Test, Ina 4254894040
17306 73rdAve. W.Umonds, Snohomish County, W
ashinwon 98026
NOT TO SCALE
JV
H
----- S ---- ------
i 37" Ave. W 1
G
WHOUSE, S=STUDIO, G--GARAGE
Some sample analyses listed maybe a representativeanahmis of individual and separatesompfingsand analysis afhomagenous materiak as prescribed by AKERA protocol.
Samples taken are Wed with their corresponding andyses. ffosbestas is detected, fhasi� samples containing asbestos are listedfast and noted %ft the initials 'AaW.
If, during demolition or renovation, any additional hidden or covered siapect materials similar to those Wntifted in the su rvey we located [may Include but not limited to: sheet
viny1flooring, tileflooring, —11 or celling texturings m paints; concrete silifing or skirting, cement p1pes, cement wallbDa to, electrical doth, electrical wring, Insulation, thermal
paper, wallboard, joint compounds, vinyl wall cowrfngs� spadlifing compouftds� or any other suspect 19 (Thermal System Insulation)), they are presumed Asbestos Containing
Materials unless determined to be non -asbestos by laboratory analysis.
Asbesto-Test, ln� does not guarantee approidmations, of quantities of AC?4 whkh may be listed with the analyses. it is therefore recommended professionat abatement prim
andlor disposal quotes be obtained by Inquiring as to j5ees per arm of specifle ACM material (i.e. square or linearfoot etc.), or by an site assessment
Any and all materials identfied as ACM andIm PACM in this report must be abated prior to disturbance in renovation or demolition.
PLM (polarized light microsappy) has been known to miss asbestos in small percentages ofsome samples. which contain asbestos, thus negative PLM results cannot be
guaranteed Flw tiles and wipes should be tested with SEM (sconning electron microscope) or TEM (transmitting electron microscopel, to Insure analytical accuracy when
asbestos is reported in small percentage& I
Analytical test method. USEPA 606IR931126" (PLM), WAC 296-62-07753 App. I
Km ACM signiftes 'Asbestos Cantalidnillifaterfar I
PACM signifies Tresumed Asbestos Containing Materiar
CAB sigrdfles lConcrete Asbestos Boffd'
< signfts less than-
751 signifies AThermai System IASUkWanN
HVAC signilles 'Heating Ventilating Air-Condthming'
AAD signifies -No Asbestos Oetected-
"One percent is the USEPA regulatory Amitfiorasbestas in bulksarnliles.
END OF REPORT
ArLynn Hammond, Pres.
Ana/Wical Chem&4 B.Sa
AIHA profident
LAL
1429 Ave. D. #187, Snabomisb, WA 98290 425-499-4040; c 206-914-5500; f 775-665-0420
e mail Asbestotest(W),insn.com ; web: www.asbestotest.com
CD
Response to Asbestos Survey:
1. Window Glazing on Garage Doors.
Response: All glass garage door panels will be removed for other use
prior to the demolition process.
2. Boiler Heating System: Although there was no visible relating suspect
asbestos containing material located.
Response: The boiler will be independently removed and properly
disposed of, prior to the demolition process
0� ED Date Posted
Date Expires
Account No.
City of Edmonds
121 5'h Avenue North - Edmonds WA 98020 (425) 771-0220 Fax (425) 771-0221
Website: www.ci.edmonds.wa.us
DEVELOPMENT SERVICES DEPARTMENT
St. lg9 Planning - Building - Engineering
DEMOLITION FROZEN FUND ACCOUNT
Edmonds Building Permit Number f3L_0'-11_011_0f51
Project Address 17.3o6 - 7-360 4ik---2V64&--
WHEREAS, W?44�46C CA_6�A_l hereinafter referred to as "the Principal",
has secured Building Permit No. in conformance with the provisions of the
International Buildi orAesidential Code to demolish a structure or other improvements at
- within the City of Edmonds, and
I llt�
WHEREAS, in order to provide security for the obligations of the Principal under the Edmonds
Community Development Code Chapter 19.00.030 in the course of said demolition not to exceed 180
calendar days from the issuance of said Building Permit by the City of Edmonds, hereinafter referred to
as "the City" and to enable the City of Edmonds to secure completion of said obligations, including site
and public improvement restoration, site and street clean-up and final site grading,
N W TZ:HER,�FORE, this form will certify that this Banking/Financial institution
herein referred to as "the Institution" has a savings
account/loan or other security for the above -referenced developer for the project so identified. The
Institution hereby agrees that it will freeze and hold the following sums of money for the indicated
demolition work pending written authorization for release of said funds by the City of Edmonds in the
amount of $qMX,00 according to the following terrns and conditions:
1) In the event the demolition permitted under the above referenced building permit is not completed
in accordance with the provisions of the applicable Building Code and Ordinances of the City of
Edmonds within a period of /30 calendar days from the date of issuance of the building
permit. The financial institution shall, upon demand of the City and the failure to cure the noted
defects within a reasonable amount of time as determined and specified by the City, remit payment
to the City within ten (10) days of receipt said funds so that the demolition and site work be
completed to City standards. The institution shall not be liable to the owner for any disbursement
of said funds to the City of Edmonds.
2) If the Principal fails to cure any defect within the time period specified by the City, the City's
employees and agents are hereby authorized to enter into said property and perform said work. This
provision shall not be construed as creating an obligation on the part of the City or its representatives.
L\Building New Folder 2010\Fonns\BONDDEMOFF.doc6/29/2011
City of Edmonds Demolition Frozen Fund Account
Page Two
3) In the event any lawsuit is instituted by the City of Edmonds, the Principal or the Institution to
enforce the terms of this bond or to determine the rights of any party hereunder, the prevailing party in
such litigation shall be entitled to recover from the losing party its costs, including reasonable
attorneys' fees, incurred as a result of such lawsuit.
T)ATPT') thic linv of
Fina'n6-,al Institution
No-,-Lw al&0_02
�1641cer/T,itle I
�ddr�ss/Phone
AccountNumber
Address/Phone
FINANCIAL INSTITUTION ACKNOWLEDGEMENT
X 2 FA V-4
STATE OF WASHINGTON)
) ss.
COUNTY OF KI-P19
On this S44k day of 2W. before me, the undersigned, a
Notary Public in and for the State of Washington, -duly commissioned and sworn, personally appeared
n/j. MD14 to me known to be the � j . 11
VV -
Of the institution that executed the foregoing instrument,
and acknowledged the said instrument to be the free and voluntary act and deed of said corporation, for
the uses and purposes therein mentioned, and on oath stated that was
authorized to execute said instrument and the seal affixed is the corporate seal of said institution.
WITNESS my hand and official seal hereto affixed the day a0d year first above written.
- �AL
7
NO" Polk NOTARY PUBLIC in and for the State of
state of mal"ON
STACY L KUHNLE-YAWAMBON Washington, residing at
Appoinfamnt Expires-Jm 11, 2014
LABuilding New Folder 2010\Forms\BONDDEMOFF.doc6/29/2011
City of Edmonds Demolition Frozen Fund Account
Page Three
DEVELOPER/OWNER/PRINCIPAL ACKNOWLEDGEMENT
STATE OF WASHINGTON
ss.
COUNTY OF
Lo /t/a,�_-VA9f
IF r - ,
On this , day of .. before me, the under -signed,
a Notary Public in and for the State of Washington, duly commissioned and sworn, personally appeared
L60jj0_A2.e_- L"�Cj tomeknowntobethe 6QY7%_� of
_j
0102QIg,(�:W the general partnership that executed the foregoing instrument, and
T - V_ ___j
acknowledged the said instrument to be the free and voluntary act and deed of said partnership, for the
uses and purposes therein mentioned, and on oath stated that
(P� was authorized to execute said instrument.
WITNESS my hand and official seal hereto affixed the day and year first above written.
Notary Public
State of Washington
NANCY DALTHORP
My Appointmat Explires Aug 23, 2013
C46-Alw
NOTK�Y P$641C -i:-n- and 4 the State of
Washington, residj t
=&,(,jA-
LABuilding New Folder 20 1 0\Forrns\B0NDDEM0FF.doc6/29/201 I
Approved Transaction 11/6/11 1:35 AM
psc lean a i r.org
Puget Sound Clean Air Agency
Single -Family Notification Case #: 201103049
This page must be printed. A printout of the notification, all amendments to the notification, and the asbestos survey shall be
available for inspection at all times at the asbestos project or demolition site (Reg 111, 4.03(a)(6)).
Fee Amount Paid $65.00
Credit Card Transaction # VXHF7FD6269E
Transaction Date
11/06/11
Owner's Name
Wallace Chang
Project Street Address 17306 - 73rd Avenue W.
city
Edmonds
Contact Person
Wally
Mailing Address
8328 NE 187th Way
Kenmore, WA 98028
Phone (425) 894-0879
Zip 98026
Phone (42S) 894-0879
This project includes a demolition.
Demolition Start Date 11/28/11 Completion Date 12/18/11
Demolition will be completed by a demolition contractor
I certify that:
(1) This is a single-family residence project. The structure is used by one family who owns the property as their domicile.
(2) The information I have provided is to the best of my knowledge accurate and complete.
(3) 1 understand the fee for this Notification is nonrefundable.
Create Another Notification
View History
If you have questions, contact us at asbestos@pscleanair.org or 206.689.4058.
Log Out
https://secure.pscleanair.org/Asbestos/Approved.aspx Page 1 of 1
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'FILE No;
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Stormwater Report
for
Wallace Chang Residence
a
a new single fam ily detached residence
at
17306 73rd Avenue IN
Edmonds, WA '98026
City Building Permit No. BLD# 2011-0931
July, 2012
November, 2012
Revised: February, 2013
Prepared for:
Wallace Chang
.11;
Prepared By: John Yuen
LM
Lovell-Sauerland & Associates
19217 36th Avenue W.,' Bldg-B, Suite 106
Lynnwood, Washington 98036
LSA FILE No: 5298
Section 1: Pro*ect Information
Project Name: Wallace Chang Residence
Project Site Address: 17306 73"d Avenue W
Edmonds, WA 98026
City File Number: BLD4 2011-0931
Project Engineer: Lovell-Sauerland & Associates, Inc.
19217 361h Avenue W., Bldg. B - Suite 106
Lynnwood, Washington 98036
Phone: (425) 775-1951
Project Applicant: Wallace Chang
Email: gnahc@uw.edu
Phone: 425-894-0879
Parcel Number: 00513100013908
Project Total Area: 0.67Acres
Number of Lots: I - singlefamily residence
Soils Data: A lderwood- Urban land complex 0-8% slopes
City Drainage Watershed: Site is within the Creek Basin of Ou�fall Creek
Site Classification: Category 2 Small Site
Lovell-Sauerland & Associates Wallace Chang Residence
Stormwater Report BLD# 2011-0931
LSA#5298 February, 2013
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Lovell-Sauerland & Associates Wallace Chang Residence
Stormwater Report BLD# 2011-0931
LSA#5298 February, 2013
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Lovell-Sauerland & Associates Wallace Chang Residence
Stormwater Report BLD# 2011-0931
LSA#5298 February, 2013
1 t7 3 rld
JdS VA—t�VM M
41
Legend
Downtown Business
Waterfront
Edmonds city limits
BD1, Downtown Retail Core
CW, Commercial Waterfront
Zoning Designations
and Descriptions
BD2, Downtown
MP1, Master Plan Hillside Mixed Use
Single family
Mixed Commercial
MP2, Master Plan Hillside Mixed Use
RS-6, Single Family
BD3, Downtown
Convenience Commercial
Other
6,000 sq. ft. lots
=
MU, Medical Use
RS-8, Single Family
BD4, Downtown
Mixed Residential
P, Public Use
8,000 sq. ft. lots
BD5, Downtown Arts Corridor
OS, Open Space
RS-10, Single Family
10, 000 sq. ft. lots
OR, Office -Residential
RS-12, Single Family
Commercial
12,000 sq. ft. lots
BP, Planned Business
RSW-1 2, Waterfront Single
BN: Neighborhood Business
Family 12,000 sq. ft. lots
BC, Community Business
Pyget
R 2006 n.gftleFary�ily
S S
2 �, 0 sq . lots
BC-EW, Community Business
Dr, MA A %A1-
-
Sound
111UH 0 Y
I A, RS-MP, Single Family
v-v. MasterPlan CG, General Commercial
Multi Family CG2, General Commercial
-rPrT.0,TTP
Opo
RM-3, Multi Family 3,000
N
sq. ft. of lot area per unit
RM-2.4, Multi Family 2,400
sq. ft. of lot area per unit 0 1.250 2,500 5,000 ft
RM-1.5, Multi Family 1,500
sq. ft. of lot area per unit
CSHERRERA
RM-EW, Multi Family ENVIRONMENTAL CONSULTAWS
RM-Edmonds Way
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Figure 2-1. Existing land uses in the City.
== M = MM == = = = == == = mmift
F I G U R E 2-2
i�,Luh-d,!s Gulcli-
WATERSHED BOUNDARIES WITHIN THE CITY
Deer Creek
Perrinville
Edmonds Marsh
ki� Puget Sound
Edmonds. Way
in Puget Sound Piped
Frultdale
Shell Creek
Good Hope Pond
Shellabarger
Halls Creek
Southwest Edmonds A
Hindley Creek
L J Southwest Edmonds B
Lake Ballinger
Stilthouse Creek
Lund's Gulch
Talbot Park A
k�i�lp Meadowdale A
Talbot Park B
Meadowdale B
Terrace Creek
Northstream
Westgate Pond
4� =OutfallCreek
El�j-;.,
Willow Creek
�.A A
0 1,000 2,000
4,000 6,000
1 in = 2,000 ft
No warranty of any sort, including accuracy, fitness, or
merchantability accompany this product.
8,000
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=,"'U'NECOESORIBED AS NORTH UNE OF
m
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LOCATION OF PROPERTY
UWE PER PLAT OF SURVEY
A.F. NO, 2005032=65
(ACCEl"M AS BOUNDARY)
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S
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IE
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Lovell-Sauerland & Associates Wallace Chang Residence
Stormwater Report BLD# 2011-0931
LSA#5298 February, 2013
ISection 2 - Proeect Stormwater Requirements
Purpose: d
The Applicant is seeking City permits to construct a new single family home at 17306-73
Avenue W.
City stormwater requirements:
1. Based on Figure -A, the site is subject to Stormwater Management ECDC Chapter 18.30.
2. Based on Figure-B, City handout #E-72 (enclosed), the site is classified as a Category 2
Small Site and is subject to the City Stormwater Supplement, Chapter 5.
3. Based on Figure-C, the proposed impervious area is considered 'Regulated Replaced'.
4. Based on the above Chapter 5, Small Site Requirements, the Small Site Minimum
Requirements (MRs) are to be met.
Compliance with Small Site Minimum Requires:
1. A stormwater site plan has been prepared.
2. Applicable erosion and sediment control measures are shown in Sheet Cl
"StormwaterAJtility/Grading Plan".
3. A source control of pollutants is not required for single-family residence.
4. The natural drainage systems and outfalls have been maintained by infiltratin water at a
location that follows the existing topography. The City storm system in 73' Avenue is
higher than the site and cannot serve the site by a gravity system.
5. Post -construction Amended soils will be placed to provide onsite stormwater
management.
6. Natural Runoff treatment will be provided by infiltration into native soils.
7. Flow control will be provided by the Larger Size infiltration trench.
8. Wetland protection is not required since there are no on -site or adjacent off -site wetlands.
9. Operation and Maintenance of the BMPs (i.e. catch basin and infiltration trench) has been
included in this report's Appendix.
Lovell-Sauerland & Associates Wallace Chang Residence
Stormwater Report BLD# 2011-0931
LSA#5298 February, 2013
10. Offsite Analysis and Mitigation: The Liu & Associates Soils Report indicates that
downstream off -site impacts have been mitigated by locating the infiltration trench in a
suitable area and constructing the trench bottom to a minimum depth of 5.5 feet.
11. Financial liability: applies only to the stormwater systems constructed in or adjacent to
Critical Areas or their buffers. The Applicant will provide any City required
documentation to meet this requirement.
Lovell-Sauerland & Associates
Stormwater Report
LSA*5298
Wallace Chang Residence
BLD# 2011-0931
February, 2013
Figure -A
Determining Applicability of Stormwater Management Code ECDC Chapter 18.30
If any of the descriptions in the Blue Boxes apply to your project or pLoject site, the
Stormwater Management Code applies.
Does your Project Site require the issuance of a City
permit under any of the following:
ECDC Title 18 - Engineering Division
ECDC Title 19 - Building Division
A StorrnWater perMit2
No
Are you submitting a Subdivision application per
ECDC Chapter 20.75? 1
No
Does your Project site involve any of the following:
500 square feet or more of land -
disturbing activity, new impervious
surface, or replaced impervious
surface?
A utility or other construction project
consisting of 500 lineal feet or more
of trench excavation?
Is located in, adjacent to, or drains
into (currently or as a result of the
project) a Critical Area or a Critical
A
No
Stormwater Management
requirements of ECDC Chapter
18.30 are not aDvlicable to your
P�o_ject'or Site '
Yes
Yes
Stormwater
Yes Management
requirements of ECDC
Chapter 18.30 are
applicable to your
Project or Site.
Note: The definitions of the terms in italics are found in ECDC Chapter 18.30.010 and the Stormwater Code Supplement.
This chart provides an initial screening for determining the applicability of ECDC Chapter 18.30. The rrsults from using this chart
do not substitute for a determination of applicability by the Public Works Director or Designee per ECDC Chapter 18.30.030 and
the relevant portions of the Supplement.
2 If ECDC Chapter 18.30 is applicable to the proposed project and it does not require any other City -issued permit, a Stormwater
Permit and associated fees will be required.
Revised on 03.05.2012 E72-SWAt_Erosion—Control-03.05.12.doc Page 3 of 12
Figure-B
Project Classi fication
If you have detennined that the Storinwater Management Code
applies to your project (Figure -A), follow the Blue boxes in the chart
below to determine the Classification of your pLoject.
Does the project involve I - Yes
acre or more of land -
disturbing activity' ? I Large Site Project:
No
Is the project part of a larger
common plan of development or
sale where the total disturbed area
for the entire plan will total I -acre
or more of land -disturbing activity?
Does the Project involve one or more of the
following:
2,000 square feet (sf) or more of new
impervious surface, regulated replaced
impervious surface or new plus regulated
replaced impervious sur
fiace?
OR
7,000 sf or more of land -disturbing activity?
OR
50 cubic yards or more of either grading, fill, or
excavation as defined in Chapter 18.40.000
ECDC?
No
Minor Site Project:
See Stormwater Supplement
Chapter 6 for specific
requirements
Notes:
See Stormwater Supplement
Yes Chapt 4 for specific
10 requirements.
Does the project create or add 5,000 square feet or
more of new impervious surface, regulated
replaced impervious surface or new plus
Convert 3/4 acre or more of native vegetation to
lawn or landscaped area
OR
Through a combination of creating effective
impervious surface and converted pervious
surfaces, causes an increase of 0. 1 cubic feet per
second in the 100-year flow frequency from a
threshold discharge area as estimated using an
approved model?
No rx
Category 1 Small Site Project:
See Storinwater Supplement
Chapter 5 or specific
requirements
Category 2 Small Site Project:
See Stormwater Supplement
Chapter 5 for specific
requirements
Terms in bold italics are described in the Glossary on pages 10- 11. The definitions of the all terms in italics are found in ECDC
Chapter 18.30.0 10 and the Stormwater Code Supplement
The Classification flowchart assumes the project in question meets the applicability requirements of ECDC18.30.030.
Land -disturbing Activity: Any activity that results in the movement of earth, or a change in the existing soil cover (both
vegetative and non -vegetative) or the existing soil topography. Land disturbing activities include, but are not limited to grading,
filling, excavation, and compaction associated with stabilization of structures and/or road construction.
IRevised on 310512012 E72-SWAI�_Erosion—control-03.05.12.doc Page 4 of 12
Figure-D
What Qualifies as Replaced Impervious Surface?
Determining Replaced Impervious Surface Area
(Small and Minor Sites Only)
Is the Impervious Area being Area is NOT considered REPLACED
removed and replaced with new No
impermeable surface in the impervious surface area
same footp�nt? Refer to Figure E for regulation of New
Impervious Surface Areas
Yes
Was the existing impervious area created
prior to 7/7/1971
or
prior to the date the parcel was annexed from
Snohomish County?
No Y k yes
Is parcel zoned
Single-Fa.mily Residential?
No
Area is considered REGULATED REPLACED
impervious surface area
Area is considered
EXEMPT REPLACED
impervious surface area
Ves
Does the replaced
impervious area replace an
existing driveway, walkway
3r patio in the same footprini
AND will it remain the same
use after replacement? -
No
Revised on 310512012 E72-SWAf-Erosion-control-03.05.12.doc Page 8 of 12
OV EDV
City of Edmonds A. � -
Site Classification Worksheet
Page 1 of 2
The project's Site Classification will dictate the specific stormwater management
requirements applicable to your site. Completing this worksheet will help determine the amount of
regulated impervious surface and whether your project falls into the classification of a Small Site
(Category I or Category 2), or a AMnor Site. Please reference the GlossM (pp. 10- 11), Figures D and
E, (pp. 8-9), and Examples (pp. 11-12). to assist with completion of this worksheet.
1) Is Permeable Pavement' Proposed For Use on this Site? El Yes N N o
Refer to Stormwater Supplement Chapter 5.1
If YES, the subject area is. to be considered impervious for initial site classification purposes. Include total
permeable pavement area in the calculation of Non -Regulated, Replaced and/or New impervious surface
areas in the table below.
2) Determine the Amount and Type of Existing & Proposed Impervious Surface for the Site
Refer to Stormwater Supplement Chapter 2 and Fig. C
Line 1: Identify the Non -Regulated Impervious Surface Area.
Line 2: Identify the Replaced Impervious Surface Area, dividing the total between Exempt and Regulated; either or both
may be zero. Note: For project classification purposes, Replaced Impervious may only be considered exempt
under certain conditions. Refer to the Glossary and Figure D.
Line 3: Identify the New Impervious Surface Area for your project. All impervious areas created post -July 7, 1977 or
after the date of annexation into the City are regulated & should be included in this total unless they can be
categorized separately as a Replaced -Regulated area.
Line 4: Enter the sum of the total Replaced -Regulated plus the total New impervious areas.
Line 5: Identify the total area currently mitigated by an existing city -approved stormwater management system.
Line 6: Enter the sum of the value in Line 4 less the value in Line 5 to identify the total Regulated area in which
stormwater controls have not yet been applied.
Line 7: Identify the total area proposed to be mitigated through the use of Low Impact Development Techniques.
Line 8: Identify the total area proposed to be mitigated through conventional Stormwater Management Techniques.
** Provide a copy of the following table on the drainage plan sheet for the proposed project
Line
Type
Area (square feet)
1.
Non -Regulated
Exempt
Regulated
2.
Replaced
0
3.
4.
New (Post 1977)
Total Regulated Impervious Area
Mitigation required if in excess of 2000sf
+
8,000 SF
8,00 1 0 SF
5.
6.
Total Area Mitigated by Eidsting Stormwater Management System(s)
Regulated Area Not Yet Mitigated
0
8,000 SF
7.
A ea Proposed to be Mitigated by Low Impact Development Techniques
8,000 SF
8.
Area Proposed to be Mitigated through Conventional'SWM Techniques
0
I (e.g. porous asphalt, porous concrete, paver blocks, concrete open celled paving, grids, or plastic lattices filled with turf or stone)
IRevised on 310512012 E72-SWM—Erosion—Control-03.05.12.doc Page 5 of 12
City of Edmonds
Site Classification Worksheet
Page 2 of 2
1 3) Determine the Total Area of Land Disturbing Activity 23,700 sf
Refer to Stormwater Supplement Chapter 8 1
6
4) Determine the Quantity of Grading, Fill and/or Excavation Fill = 50 cy, Excavation = 1,200 cv
I
5) Will the project convert 3/4 Acre or More of Native Vegetation to Lawn or
Landscaped Area? 0 Yes Fx� No
I
6) Identify the Watershed the Existing Site Runoff Discharges to
Refer to Stormwater Supplement Chapter 2.3
Based on Site Location and Watershed Map — Figure-C. Check all that apply.
A. E:1 Direct Discharge B. El Creek or Lake Basin
• Edmonds Way Basin
• Puget Sound Basin
OUTFALL CREEK
• Puget Sound Piped Basin
DETERMINE PROJECT CLASSIFICATION USING THE INFORMATION ABOVE
AND THE PROJECT CLASSIFICATION CHART (Figure B, pg 4)
11 Small Site - Category 1 X Small Site - Category 2 1:1 Minor Site
Stormwater Supplement Stormwater Supplement Stormwater Supplement
Chapter 5 Chapter 5 Chapter 6
Revised on 310512012 E72-SWA�-Erosion-Control-03.05.12.doc Page 6 of 12
Section 3 - Stormwater system methodolou
Based on the recommendations of the Project Soils Engineer, Liu & Associates, (see enclosed
report in Appendix) an infiltration trench has been proposed. The city pre -sizing tables have not
been used. WVMM3 was used to size the facility, based on the Soils Report design infiltration
rate, to infiltrate 100% of the site impervious runoff directed to the trench. The VMHM3
calculations are included in this Section.
WWHM3 documentation
Efa Edt Yk-. &
D 2; 12 1 d3l 1PX fib P.
.1 1."
Infiltration rate: 3.8 x 0.5 = 1.9 in/hr
Depth of trench rock = 5.33'
Porosity = 30%
Percent of runoff Infiltrated = 100%
Must 1 outlet 2 OUUst3
ream Connection
Type
GUIATrench
My Bottom Elevation (111)
�y Dimensions
Lffoh
581�1111
Oudet Struchore
Botto. Wdh
Rim Hoot VQ rKH7-!�
.1rotaiDepth
I.-
Rim DwatwN
dope of Ttanch
OOM
Rita Type lFW
Notch Type
aterial Layers for
W. 1 Thic�— (ft)
4MI
rifice Diameter Height QMmc
oumbOF
501 P.
an) (ds)
fa 2 Thickruns (M
1 F57r-;-'1 W71 0
ver 2 poro*
2 F77-4 V71 o
Ver 3 Thic+ (it)
3 W77�� F74 o
sm 3 wo*
'20.
filtration FES— _1H
TorchVsksoodiffivarHoadjaw") M5
mosed Infication Rata C%)
Pandin—art 570— �711
�b�tion Radiction Facto F�i7�q
ShowPondTable Fow_Taw__:��
.WaftadS,.f—AoaJddah) rNW7
" Vokms [�Mgada=A) 147.506
Tota1VokmThr-ahFacftaowft) 147.513
.Voksw7hioughRoarfact") aM?
Pow m lalbated 10D
Required bottom area for a 5'- 4" deep rock trench = 58' x 16' = 928 sf
Lovell-Saueriand & Associates Wallace Chang Residence
Stormwater Report BLD# 2011-0931
LSA#5298 February, 2013
Flow Frequency Analysis
Ek Edt I[ew U*
D c3la I& 14
MLtF—j �W Mb2_MW--FIDw�
low Frequency
ME I
rlow(crs)
0801
2 Year -
0.00
5 Year -
(0) * 0::
10 Year -
:000
1GE U.
25 Year -
0.0000
So Year -
0.0000
100 Year -
0.0000
0
Yearly Peaks
10E-1
1940
(1 - 0:::
1941
0.0
1942
0.0600
1963
0.0000
�944
0.0000
lOE-21
1945
0.0000
1 10 20 30 40 50 60 70 80 90 99
1966
0.0000
Cumulative Probability
1947
0.0000
0.0000
Dwations Flow FreqLwicy watef Qu*
Hyftgraph Red.
1969
.0.0000
1950
0.0000
Anatpze datmets
1951
0.0000
1952
0.0000
tt I E —RI M36 E
1953
0.0008
ec
1954
1953
0.0000
0.0000
11' to POC;1IMWMKd
IWANIUM
1956
0.0000
10M GFaWjTF=—RNB!e� 1 4W.OUTLEj.S Mb—de—d
g—
2957
0.0000
kd1t9 =YM) 11 OUTLET
11
1958
0.0000
OUTLET MM=—�&
1959
0.0000
1960
0.0000
Al Dat sets �St- �Plwp Eap �PCC 1
1961
0.0000
F—hMFGj3M
1962
0.0000
—MkMjKjMWAjk,
III 17B
1963
1964
0.0000
0.0000
1965
0.0000
—FZ/25/2013 F1259PM
The analysis shows that no flow is released for the 100-year event, thus the facility is infiltrating
practically 100% of its received runoff.
Lovell-Sauerland & Associates Wallace Chang Residence
Stormwater Report BLD# 2011-0931
LSA#5298 February, 2013
DOE 2005 Volume 1113.3.7 48-hour drawdown analysis
Requirement: 'for an infiltration trench designed for treatment flow purposes, document that the
9 1 St percentile, 24-hour runoff volume can infiltrate through the infiltration basin surface within
48 hours'
Step 1:
Calculate the 91s' percentile, 24-hour runoff volume with W.WHM3:
Eb F& Jim heIp
D Go U lei �x ke
Wato Quality
DiRiff-518M
1 24 hour Volu
P����
011!j1n—e1BM
lacre feet]
Standard Flow Rate (ds)
Standard Flow Rate (drr)
15 MirpAe Flow Rate
15 Minute Flow rate
Durations Flow Frequency Water Quality Hydrograph W.dand —Mchd.
Analyze datatets
1 Puget East 36 Evap
2 Puget East 36 Precip
edeyeloped How
Mp,
801 POC 1 MkkWed flow
1 000 Gravel Trench Bed 1 ALL OUTLETS Mitigated
1001 Giavd Trench Bed 1 OUTLET 1 Mitigated
jOO2j5wdiromh.Bed-l-QQTLEt2,.M69Med_ 81
AUD te Evap ±K ii
, rb6dF;equ6nqjMeih6d
Log Pearson Type III 17B
WebA
112/25/2613 5162 Pm
Step 2: Calculate the volume drawndow in 48-hours
Volume = trench area x infiltration rate (in/hr) x 48 hr
= 928 sf x (1.9 in./hr) x (I ft/12in) x 48 hr = 7,052 cf > 1,290 cf (0.0296 ac-ft)
<ok>
Love 11-Sa uerland & Associates Wallace Chang Residence
Stormwater Report BLD# 2011-0931
LSA#5298 February, 2013
Western Washington Hydrology Model
PROJECT REPORT
Project Name:
5298
Site Address:
17306 73rd Avenue W
City :
Edmonds
Report Date
2/25/2013
MGS Regoin
Puget East
Data Start
1939/10/1
Data End
2097/08/31
DOT Data Number: 03
WWHM3 Version:
PREDEVELOPED LAND USE
Name : Basin 1
Bypass: No
GroundWater: No
Pervious Land Use Acres
C, Forest, Mod .67
Impervious Land Use Acres
Element Flows To:
Surface Interflow Groundwater
Name : Basin 1
Bypass: No
GroundWater: No
Pervious Land Use
Acres
C, Lawn, Mod
.486
Impervious Land Use
Acres
ROOF TOPS FLAT
0.109
DRIVEWAYS MOD
0.067
SIDEWALKS FLAT
0.008
Element Flows To:
Surface Interflow Groundwater
Gravel Trench Bed 1, Gravel Trench Bed 1,
Name Gravel Trench Bel I
Bottom Length: 58ft.
Bottom Width : 16ft.
Trench bottom slope 1 -. 0. 000 1 To 1
Trench Left side slope 0: 0 To 1
Trench right side slope 2: 0 To 1
Material thickness of first layer - 5.33
Pour Space of material for first layer : 0.3
Material thickness of second layer � 0
Pour Space of material for second layer: 0
Material thickness of third layer : 0
Pour Space of material for third layer: 0
Infiltration On
Infiltration rate : 3.8
Infiltration saftey factor 0.5
Discharge Structure.
Riser Height: 5.33 ft.
Riser Diameter: 6 in.
Element Flows To:
Outlet 1 Outlet 2
Gravel Trench Bed Hydraulic Table
Stage(ft) Area(acr)
Volume(acr-ft) Dschrg(cfs) Infilt(cfs)
0.000
0.021
0.000
0.000
0.000
0.069
0.021
0.000
0.000
0.041
0.137
0.021
0.001
0.000
0.041
0.206
0.021
0.001
0.000
0.041
0.274
0.021
0.002
0.000
0.041
0.343
0.021
0.002
0.000
0.041
0.411
0.021
0.003
0.000
0.041
0.480
0.021
0.003
0.000
0.041
0.548
0.021
0.004
0.000
0.041
0.617
0.021
0.004
0.000
0.041
0.686
0.021
0.004
0.000
0.041
0.754
0.021
0.005
0.000
0.041
0.823
0.021
0.005
0.000
0.041
0.891
0.021
0.006
0.000
0.041
0.960
0.021
0.006
0.000
0.041
1.028
0.021
0.007
0.000
0.041
1.097
0.021
0.007
0.000
0.041
1.165
0.021
0.007
0.000
0.041
1.234
0.021
0.008
0.000
0.041
1.303
0.021
0.008
0.000
0.041
1.371
0.021
0.009
0.000
0.041
1.440
0.021
0.009
0.000
0.041
1.508
0.021
0.010
0.000
0.041
1.577
0.021
0.010
0.000
0.041
1.645
0.021
0.011
0.000
0.041
1.714
0.021
0.011
0.000
0.041
1.782
0.021
0.011
0.000
0.041
1.851
0.021
0.012
0.000
0.041
1.920
0.021
0.012
0.000
0.041
1.988
0.021
0.013
0.000
0.041
2.057
0.021
0.013
0.000
0.041
2.125
0.021
0.014
0.000
0.041
2.194
0.021
0.014
0.000
0.041
2.262
0.021
0.014
0.000
0.041
2.331
0.021
0.015
0.000
0.041
2.399
0.021
0.015
0.000
0.041
2.468
0.021
0.016
0.000
0.041
2.537
0.021
0.016
0.000
0.041
2.605
0.021
0.017
0.000
0.041
2.674
0.021
0.017
0.000
0'.041
2.742
0.021
0.018
0.000
0.041
2.811
0.021
0.018
0.000
0.041
2.879
0.021
0.018
0.000
0.041
2.948
0.021
0.019
0.000
0.041
3.016
0.021
0.019
0.000
0.041
3.085
0.021
0.020
0.000
0.041
3.154
0.021
0.020
0.000
0.041
3.222
0.021
0.021
0.000
0.041
3.291
0.021
0.021
0.000
0.041
3.359
0.021
0.021
0.000
0.041
3.428
0.021
0.022
0.000
0.041
3.496
0.021
0.022
0.000
0.041
3.565
0.021
0.023
10.000
0.041
3.633
0.021
0.023
0.000
0.041
3.702
0.021
0.024
0.000
0.041
3.771
0.021
0.024
0.000
0.041
3.839
0.021
0.025
0.000
0.041
3.908
0.021
0.025
0.000
0.041
3.976
0.021
0.025
0.000
0.041
4.045
0.021
0.026
0.000
0.041
4.113
0.021
0.026
0.000
0.041
4.182
0.021
0.027
0.000
0.041
4.250
0.021
0.027
0.000
0.041
4.319
0.021
0.028
0.000
0.041
4.388
0.021
0.028
0.000
0.041
4.456
0.021
0.028
0.000
0.041
4.525
0.021
0.029
0.000
0.041
4.593
0.021
0.029
0.000
0.041
4.662
0.021
0.030
0.,000
0.041
4.730
0.021
0.030
0.000
0.041
4.799
0.021
0.031
0.000
0.041
4.867
0.021
0.031
0.000
0.041
4.936
0.021
0.032
0.000
0.041
5.005
0.021
0.032
0.000
0.041
5.073
0.021
0.032
0.000
0.041
5.142
01.021
0.033
0.000
0. 041
5.210
0.021
0.033
0.000
0.041
5.279
0.021
0.034
0.000
0.041
5.347
0.021
0.035
0.011
0.041
5.416
0.021
0.037
0.123
0.041
5.484
0.021
0.038
0.296
0.041
5.553
0.021
0.040
0.513
0.041
5.622
0.021
0.041
0.767
0.041
5.690
0.021
0.043
1.052
0.041
5.759
0.021
0.044
1.367
0.041
5.827
0.021
0.045
1.707
0.041
5.896
0.021
0.047
2.072
0.041
5.964
0.021
0.048
2.460
0.041
6.033
0.021
0.050
2.870
0.041
6.101
0.021
0.051
3.299
0.041
6.170
0.021
0.053
3,749
0.041
MITIGATED LAND USE
ANALYSIS RESULTS
Flow Frequency Return Periods for Predeveloped. POC #1
Return Period
Flow(cfs)
2 year
0
5 year
0
10 year
0
25 year
0
50 year
0
100 year
0
Flow Frequency Return
Periods for Mitigated. POC #1
Return Period
Flow(cfs)
2 year
0
5 year
0
10 year
0
25 year
0
50 year
0
100 year
0
Yearly Peaks for Predeveloped and Mitigated. POC #1
Year Predeveloped Mitigated
Ranked Yearly Peaks for Predeveloped and Mitigated. POC #1
Rank Predeveloped Mitigated
POC #1
The Facility PASSED
The Facility PASSED.
Flow(CFS) Predev
Dev Percentage Pass/Fail
0.0000 0
0
0
Pass
0.0000 0
0
0
Pass
0.0000 0
0
0
Pass
0.0000 0
0
0
Pass
0.0000 0
0
0
Pass
0.0000 0
0
0
Pass
0.0000 0
0
0
Pass
0.0000 0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
0.0000
0
0
0
Pass
Water Quality BMP Flow and Volume for POC 1.
On-line facility volume: 0.0296 acre-feet
On-line facility target flow: 0.01 cfs.
Adjusted for 15 min: 0.027 cfs.
Off-line facility target flow: 0.0144 cfs.
Adjusted for 15 min: 0.0149 cfs.
PerInd and ImpInd Changes
No changes have been made.
This program and accompanying documentation is provided 'as-4s' without warranty of any kind. The entire risk regarding the performance and results of this program is
assumed by the user. Clear Creek Solutions and the Washington State Department of Ecology disclaims all warranties, either expressed or implied, including but not limited to
implied warranties of program and accompanying documentation. Innoeventshall Clear Creek Solutions and/or the Washington State Department of Ecology be liable for
any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) ansing out of the
use of, or inability to use this program even if Clear Creek Solutions or the Washington State Department of Ecology has been advised of the possibility ofsuch damages.
Appendix
A. Small Site MR #9 - Operation & Maintenance
B. Project Soils Report
Lovell-Sauerland & Associates Wallace Chang Residence
Stormwater Report BLD# 2011-0931
LSA#5298 February, 2013
SMALL SITE MR #9 - OPERATION & MAINTENANCE
For Infiltration trench & catch basin
Lovell-Sauerland & Associates Wallace Chang Residence
Stormwater Report BLD# 2011-0931
LSA#5298 February, 2013
4.6 Maintenance Standards for Drainage Facilities
The facility- specific maintenance standards contained in this section are
intended to be conditions for determining if maintenance actions are
required as identified through inspection. They are not intended to be
measures of the facility's required condition at all times between
inspections. In other words, exceedence of these conditions at any time
between inspections and/or maintenance does not automatically constitute
a violation of these standards. However, based upon inspection
observations, the inspection and maintenance schedules shall be adjusted
to minimize the length of time that a facility is in a condition that requires
a maintenance action.
Table 4.5 — Maintenance Standards
N e. I DeteRtiGR PGRds
intenince
Defect
ConditionsWhen Maintenance Is
.��,klDsUltSZXpected When
0
C C 0�
o onent
Needed
Z/100,
-Ma n rf6rmed
1 tenanceis Pe
Genera
Trash & Debris
Any trash and debris which exceed 5
Trash and debris cleared fr sit
cubic feet per 1,000 square feet (this
i is about equal to the amount of trash
s about
it would
it would take to fill up one standard
ize arl
size garbage can). In general, there
should be no visual evidence of
i
dumping.
f less than t reshold all trash and
ris will be removed as part of next
sch led maintenance.
Poisonous
so u 0 r nu
Any poiso us or nuisance
isa<nce
No danger of poisonous vegetation
Vegetation and
on w h m a consti a
vegetation w i h may consti a
y
where maintenance personnel or the
noxious weeds
hazard to nce p nnel or
public might normally be. (Coordinate
the public.
with local health department)
>maint
Any evidence of ious eds as
Complete eradication of noxious weeds
defir b , t - or local re tions.
y St,, r 0 re ns.
,,ed b�� S I I tio
may not be possible. Compliance with
State or local eradication policies
irements of adopted I
r
required
X(Ap�plyr
or
Jcj 0 r t
polici or the use of herbicides).
t us of r ici S).
Contaminant
An evidence of oil, gasoline,
NO
and Pollut*
contaminants or other pollutants
(Coordinate removal/cleanup with
local water quality response agency).
Rodent Holes
Any evidence of rodent holes if
Rodents destroyed and or berm
facility is acting as a dam or berm, or
repaired. (Coordinate with I I health
any evidence of water piping through
department; coordinate with Ec y
dam or berm via rodent holes.
Dam Safety Office if pond exceeds
zoeolli
I
I acre-feet.)
1
4-30 Volume V —Runoff Treatment BMPs February 2005
1 1
INo. 2 — Infiltration
Maintenance
Defect
Conditions When'M,aintenance Is
Results Expected When,
Component
Needed
Maintenance Is
Performed
General
Trash & Debris
See "Detention Ponds" (No. 1).
See "Detention Ponds"
(No. 1).
Poisonous/Noxious
See "Detention Ponds" (No. 1).
See "Detention Ponds"
Vegetation
(No. 1).
Contaminants and
See "Detention Ponds" (No. 1).
See "Detention Ponds"
Pollution
(No. 1).
Rodent Holes
See "Detention Ponds" (No. 1).
See "Detention Ponds"
(No. 1)
Storage Area
Sediment
Water ponding in infiltration pond after
Sediment is removed
rainfall ceases and appropriate time
and/or facility is cleaned
allowed for infiltration.
so that infiltration system
(A percolation test pit or test of facility
indicates facility is only working at 90% of
works according to
design.
its designed capabilities. If two inches or
more sediment is present, remove).
Filter Bags (if
Filled with
Sediment and debris fill bag more than 1/2
Filter bag is replaced or
applicable)
Sediment and
full.
system is redesigned.
Debris
Rock Filters
Sediment and
By visual inspection, little or no water flows
Gravel in rock filter is
Debris
through filter during heavy rain storms.
replaced.
Side Slopes of
Erosion
See "Detention Ponds" (No. 1).
See "Detention Ponds"
Pond
(No. 1).
Emergency
Tree Growth
See "Detention Ponds" (No. 1).
See "Detention Ponds"
Overflow Spillway
(No. 1).
and Berms over 4
feet in height.
Piping
See "Detention Ponds" (No. 1).
See "Detention Ponds"
(No. 1).
Emergency
Rock Missing
See "Detention Ponds" (No. 1).
See "Detention Ponds"
Overflow Spillway
(No. 1).
Erosion
See "Detention Ponds" (No. 1).
See "Detention Ponds"
I
(No. 1).
Pre -settling
Facility or sump
6" or designed sediment trap depth of
Sediment is removed.
Ponds and Vaults
filled with Sediment
sediment.
I
and/or debris I
I
I
February 2005 Volume V —Runoff Treatment BMPs 4-33
1
INo. 5 — Catch Basins
Maintenance
Defect
Conditions When Maintenance is Needed
Results Expected When
Component
Maintenance is
performed
General
Trash &
Trash or debris which is located immediately
No Trash or debris located
Debris
in front of the catch basin opening or is
immediately in front of
blocking inlefting capacity of the basin by
catch basin or on grate
more than 10%.
opening.
Trash or debris (in the basin) that exceeds 60
No trash or debris in the
percent of the sump depth as measured from
catch basin.
the bottom of basin to invert of the lowest
pipe into or out of the basin, but in no case
less than a minimum of six inches clearance
from the debris surface to the invert of the
lowest pipe.
Trash or debris in any inlet or outlet pipe
Inlet and outlet pipes free
blocking more than 1/3 of its height.
of trash or debris.
Dead animals or vegetation that could
No dead animals or
generate odors that could cause complaints
vegetation present within
or dangerous gases (e.g., methane).
the catch basin.
Sediment
Sediment (in the basin) that exceeds 60
No sediment in the catch
percent of the sump depth as measured from
basin
the bottom of basin to invert of the lowest
pipe into or out of the basin, but in no case
less than a minimum of 6 inches clearance
from the sediment surface to the invert of the
lowest pipe.
Structure
Top slab has holes larger than 2 square
Top slab is free of holes
Damage to
inches or cracks wider than 1/4 inch
and cracks.
Frame and/or
Top Slab
(Intent is to make sure no material is running
into basin).
Frame not sifting flush on top slab, i.e.,
Frame is sifting flush on
separation of more than 3/4 inch of the frame
the riser rings or top slab
from the top slab. Frame not securely
and firmly attached.
attached
Fractures or
Maintenance person judges that structure is
Basin replaced or repaired
Cracksin
unsound.
to design standards.
Basin Walls/
Bottom
Grout fillet has separated or cracked wider
Pipe is regrouted and
than 1/2 inch and longer than 1 foot at the
secure at basin wall.
joint of any inletloutlet pipe or any evidence of
soil particles entering catch basin through
cracks.
Settlement/
If failure of basin has created a safety,
Basin replaced or repaired
Misalignment
function, or design problem.
to design standards.
Vegetation
Vegetation growing across and blocking more
No vegetation blocking
than 10% of the basin opening.
opening to basin.
Vegetation growing in inlet/outlet pipe joints
No vegetation or root
that is more than six inches tall and less than
growth present.
six inches apart.
1 4-36 Volume V —Runoff Treatment BMPs February 2005
INo. 5 — Catch Basins
Maintenance
Defect
Conditions When Maintenance is Needed
kesults Expected When
Component
Maintenance is.
peIrformed
Contamination
See "Detention Ponds" (No. 1).
No pollution present.
and Pollution
Catch Basin
Cover Not in
Cover is missing or only partially in place.
Catch basin cover is
Cover
Place
Any open catch basin requires maintenance.
closed
Locking
Mechanism cannot be opened by one
Mechanism opens with
Mechanism
maintenance person with proper tools. Bolts
proper tools.
Not Working
into frame have less than 1/2 inch of thread.
Cover Difficult
One maintenance person cannot remove lid
Cover Gan be removed by
to Remove
after applying normal lifting pressure.
one maintenance person.
(Intent is keep cover from sealing off access
to maintenance.)
Ladder
Ladder Rungs
Ladder is unsafe due to missing rungs, not
Ladder meets design
Unsafe
securely attached to basin wall,
standards and allows
misalignment, rust, cracks, or sharp edges.
maintenance person safe
access.
Metal Grates
Grate opening
Grate with opening wider than 7/8 inch.
Grate opening meets
(If Applicable)
Unsafe
design standards.
Trash and
Trash and debris that is blocking more than
Grate free of trash and
Debris
20% of grate surface inletting capacity.
debris.
Damaged or
Grate missing or broken member(s) of the
Grate is in place and
Missing.
grate.
meets design standards.
a ance
Defect
Condition When Maintenance is
Results Expected When
C6mpqn
Needed
Maintenance is 2�d
General
nd
Trash or debris that is plugging more
B:ard�e�red to design flow
De�bri
s
than 20% of the openings in the barrier.
c I Y.
Metal
Damaged/
Ba rs ent �out of
rn�®re�
Bars in place with no bends more
Missing
�shape
inche�s
than 3/4 inch.
Bars.
_7�a
Bars are ing (or entire
Bars in place according to design.
Bars are loose and rust is causing 50%
Bar laced or repaired to
c
deterioration to any part of barrier.
d s
�esign �stads.
Inlet/Outlet
Pipe
Debris barrier missing or not attached to
pipe
_
Barrier firmly atta3�� �e
L��
IFebruary 2005 Volume V —Runoff Treatment BMPs 4-37
PROJECT SOILS IREPORT
Lovell-Sauerland & Associates
Stormwater Report
LSA#5298
Wallace Chang Residence
BLD# 2011-0931
February, 2013
LIU & ASSOCIATES,. INC.
JUlk 77 1
Dr. Wallace Chaw?
10, 3 2 8 NTF 18 '17"' W'IV
Kerunorc, WA 986]28
Dear Dr, Chang:
SubJect: Gcotcclinical Fngineering Study
Chang Residence
73xx — 173"� Street SW
Edmunds. Washinoton
L&A Job No. 12-058
LNTRODUCTION
We understand that the development of a singic-laniily residence,.. replacing the existing
residence occupying the site. is planned for the subject property located at the abo-ve
address in E dmonds. Washington. We also undo -stand that onsite disposal of storniwater
is considered for the development.
At your request.. �Ne have completed a geolech-nical engineering study for the proposed
development of the site. The purpose ofthis study is to characterize the subsurface (soil
and groundwater) conditions of thes-itc, evaluate feasibilitk ol'onsite storniwater disposal
and, provide geotechnical recommendat ions for onsite stonnNkater disposal. grading, slope
stabilization. erosion mitivation, surface and groundwater drainage control. and building
foundation support. Presented in this report are our findings of the surface and
19213 Kenlake Place NE - Kenmore, Washington 98028
Phone (426) 483-9134� - Fax (425) 486-2746
JuN 7.101)
Chang Residence
L&A Job No. 12-058
P a zg c 2
subsurflice conditioi)-s k1i' ilie site and 9-cotechnical recklninicndatlon� for the proposed
development
SCOPE. OF SERVICES
Our proposed scopc of services for the geotechnical ciigiiicerinp- StudN. C0111priSeS
specifically the tbllowing:
Revic--,%,- geolovic and soil conditions at and in the vicinity ot'ihe sul project site
based on a pub] ]shed geologic map.
2. Explore subsurfacc conditions of the site with backhoe te,;t pits to depths where a
firm bearing soil stratum is reached or it) the maxinium depth (,about 10 feet, deep)
capable by tile backhoe used in test pit excavation. ",hiclivver is encountered fir'St.
3, Conduct laboratory gradation tests in accordance �vith AST"-%4, D4'-'-" on two soil
samples obtained from targeted. soil laycr(s) in test pits, the result of vN hich "iII be
used to detern)ine whether onsite soils are suitable for storniwater disposal by
infiltration, Determine soil type of soil samples in accordance with USDA Texture
Triangle and provide recommendation for design infiltration rate per Washington
State, Department of Ecology 2005 Stormwater Manaj�,Te ient Manual fjor Western
Washington for onsite infiltration facilities if suitable soil is found,
4. Perform necessan,' geotechnical engineering analysis based on soil data obtained
from the test pits.
5. Prepare a written report to present our findings, conclusions and geotechnical
recommendations.
LIU & ASSOCIATES1 INC.
7.
Chariv Residence
TAA Job No. 12-078
Page 3
A geotechnicial staff fron) our office xNas on slic to direct the iubsurfacc exploration
I.
prograrn, and exarnined the soil and geologic conditions encountered and i-naintained logs
of the test pits.
SITE CONDITIONS
SURFACE CONDITIONS
The general location ofthe project site is shown on Plate I - Vicinity Map. It is situated
on -)wn o
, and near the top of a niodffatel� to steep. westerly declining. hillside. As slit n
Plate 2 -- Site and Exploration T,ocation Plan, the site iss located at the end of 173"' Street
SW. bounded by, a J
Joint use driveway to its north, and is ad oined by residential
deN,Teloprnent to the south. east and west. Within the site, the ground generally slopes
down westward oently over niost of its interior (at about 9.5'Vo grrade), then moderately
steeply dwvn to the ,-,-est alone its central west boundary (at about 3 1 �,"o gradc), to the
northwest near its northNvest comer (as steep as 75% grade locally.) and to the southwest
near its southwest comer ('at about 3 1 % grade).
The existing house on the site was demolished and the site cleared during our site
exploration work. Still standing on the site are ve large and tall. evergreen and
ry
deciduous trees dotting the south side of -die site.
GEOLOGIC SETTING
The, Cipologic Map of the Edmonds East and Part of the Fdffionds West Quadrangles.
Washing -_ton, by James P. Minard, published by U. S. Gcological Survey- in 1983, was
referenced for the geologic and soil conditions at the residence site. According to, this
LIU & ASSOCIATES, INC.
July 7- 7-012
Chang Residence
L&MobNo. 1' ;1.-058
Page 4
publication.. the SUrficidl soils (at and in the vicinivy of the subject residence site is n1apped
as a Vashon till, (Qvt) soil unit underlain by an Advance Out%vash (Qv�,) soil unit.
17he deposits of the Vashon till soil unit were ploAcd directly under glacial ice during tile
most recent glaciation period as the glacier advanced over an eroded. irregular surface of
older l'bri-nations and sediments. This soil unit is composed of a mixture 01'Unsorted clay.
silt, sand, gravel, and scattered cobbi es and boulders. `fhc Vashon till soil over the top
tvv,o to three f`eet is normallN7 weathered to a medium-densc state,. and is moderately
permeable and compressible. The underlying fresh till soil, commonly ref'erred to as
"hard pan", is very dense and vveakly cemented. The fresh till soil possesses a
compressive strength comparable to that of low-grade concrete and can remain stable on
steep natural slopes or rnan-make cuts for a long period. The fresh till deposits are
practically impervious to storiiiwater infiltration. If remained undisturbed and well -
drained'. the fresh till soil can provide excellent foundation support to structures Mth little
settlement expected. This soil unit mainly existing on the subject project site and it uphill
vicinity.
The deposits of tile advance out%vash soil unit ate composed of stratified sand and _P-ravcl
with very minor amount of'silt and clay, laid down. by the meltwater of advancing glacial
ice of the last glacier then overridden by the still advancing glacier. Due to their
generally granular composition, the advance outwash deposits are of moderately high
permeability and drains fairly well. The advance outwash deposits are generally dense to
very dense in. their natural, undisturbed state. Where exposed on slopes with poor
vegetation cover and subjected to storm runoff erosion or groundwater seepage, the
LIU & ASSOCIATES, INC.
Ju I v 2 0 12
Chang I
., Residence
UA Job No, Q-058
Page 5
advance outwash soils in the top 22 to 4 leet can be gradually weathered Lind eroded and
mav slouoh and redeposit to a flatter inclination. Natural slopes or nian-madc cuts in
advance outwash deposits in iheir native slatc Can remain siable for an cx1cndcd period of
time. If remain undisturbed and properly drained thC underlying 1'resh advance oum-ash
I I -
soil can provide good foundation support with little settlement expected l'or light to
moderately heavy structures. Th-is soil unit exists mainly under the fill deposits and is
likely exposed on the hillside below the subject project site.
SOIL CONDITION
Subsurfiice conditions of the sub�ject plat site were explored with four test pits. These test
pits were excavated on June 2-0.. 1-0 122, with a nibber-tired backhoe. to depths from 8.0 to
11.0 Feet. The approximate locations oC the test pits are shown on Plate 2 - Site and
Exploration 1,ocation Plan. The test pits were located with either a tape measure or by
visual reference to existing topographic features in the field and on the topographic
survey map, and their locations should be considered only accurate to the measuring
method used.
A geotechnical engineer from our office was present during subsurface ex loration, who
p
examined the soil and geologic conditions encountered and completed logs of test pits.
Soil samples obtained from each soil layer in the test pits were visually classified in
general accordance ,Nrith United Soil Classification System, a copy of which is presented
on Plate 3. Detailed descriptions of sod layers encountered during site exploration are
presented in test pit logs on Plates 4 and 5.
LIU & ASSOCIATES., INC.
I
J U 1 7. 21 0 127
C'han- Ikesidence
I &A Job No. 12-058
Plave 6
C
Tile test pits encountered a layer of' loose organic topsoil, From 12 it) 19 inclies thick.
nian tl c site. The topsoil is undcr1ain b-, a lavcr of weathered soil of lip-lit-hi-mvii to
tling I
tan, niedi uni -dense, silty fine sand %\,fit) a trace to sorne gravel. 1rom 1.6 it) 4.5 f`eet thick.
Underivine this weathered soil to the depth explored is a light -,grade, fresh till deposit of
vcry dense. weakiv ceniented, -ravelk,. silt\% line sand. about .1.4 to 3.5 fi�et thick. This
till deposit is underlain to the depths explored by a gray ftesh advance OLIM-ash deposit of
dense. clean to slightly silty. line to medit.11-11 sand with a trace to sonic gravel.
GROUNDWATER CONDITION
Groundwater was not encountered by any of the four test pit excavated on the subject
project site. The very-denset wcakly-cciiientedt firesh till deposit underlying. the site at
shallow depth is of extremel V* lo-vv permeability and would perch stormwatcr infiltrating
I I —
into the mote permeable surficial soils. The amount of and the depth to this ticar-SUrl'ace
perched groundwater may fluctuate seasonally depending on precipitation'. vegetation
cover, site utilization', etc.. 'Ibis perched ground may accumulate and rise in theNvet
winter months and dry up in the dry suninier nionths.
GEOLOGIC HAZARDS AND MITIGATION
Erosion Hazard
The surficial topsoil and weathered soil are of low resistance against, erosion, while the
underlying very -dense fresh till and dense advance outivash deposits are of moderately -
high to high resistance against erosion. Tlicrc is a remote chance that erosion may occur
in the weaker surficial soils over the steeper areas of the site if it is devoid of vegetation
cover and overly saturated. Progressive erosion canlead to shallow, skin -type mudflow-s
LIU & ASSOCIATES, INC.
J U Iy 7.. 2 0 12
Chano Residence
C
L&A Job No. 121-058
Page 7
in the steeper area. To mitigate such erosion hazard., vegetation outside ofconstruction
limits should be preserved and maintained. Unpaved exposed finished g1,170LInd \Aithin the
site resulted from construction activities ShOUld be re -seeded and re-�cLetated as soon as
possible. Concentrated stormwaLer should not be discharged uncontrolled onto the
o-round %vithinflie site or the adJaccrit slopcs. Stormwatcr over impervious surfaces, such
as roofs and paved driveway. should be captured by an underg I
_-round drain line systern
connected to root' downspouts or bv catch basins installed in paved dri'vewax. Water
collected by these drain line systems sli(yuld be tip-htlined, to discharge into a storm sewer
or suitable stonilwater disposal facilities. such as infiltration trenches.
Landslide Hazard
't'he site is generally underlain at shallow depth by very -dense till and dense advance
OUtwash deposits. These soils arc of high to very -high shear strength and have high
resistance ap-ainst slope failure. Theretlore, as long as the site is property drained, the
potential for deep-seated slides to occur on the site should be minimal.
Seismic Hazard
The Puget Sound region is in an active seismic zone. The site is underlain at shallow
depth by veny-dcnse till and dense advance outwash deposits of high to vvq-high shear
strength. Therefore, the potential for seismic hazards, such as landslides, liquefaction,
lateral soil spreading, to occur on the site should be minimal if the erosion mitigation,
drainage control, site stabilization measures recommended in this report are fully
implemented. The proposed residences, however, should be designed for seistnic forces
induced by strong parthquakes. Based on the soil conditions encountered by the test pits,
LIU & ASSOCIATES., INC.
U 1%:, 7. 1
ChanL- Rcsidenco
L&A Job No. 1-1-058
P au, e 8
it is our opinion that Sekinic Use (7,roup I and Site Class D ShOUld be LISCd if) the SCi',n1iC-
design of the proposed residences in accordance with the 1,001) international Building
('ode (1110.
CONCLUSION AND RECOMMENDATIONS
GENERAL
1-he site is underlain at shallow depth by ,,ery-dense till. and dense a&-ance Wtw-ash
deposits. The proposed new residence may be supported on footing loundations poured
on or into these competent soils. Biiscd on the soil data obtained from the test pits,
excavated on the site. infiltration trenches may be constructed near the southwest corner
ol'the site to dispose stormwater onsite.
TEMPORARY DRAINAGE AND EROSION CONTROL
1-he onsite surficial topsoil and weathered soil contain a high percentage of fines which
are sensitive to moisture and can be easily disturbed by construction traffic. A layer of
clean, 21-to-4-inch quam� spalls should be placed over areas of frequent traffic, such as the
entrance to the site, as required, to protect the subgrade soils frorn disturbance by
construction trafflic.
A silt fence should be installed along the downhill side of construction areas to minimize
transport of sediment onto neighboring properties or the streets. The bottom of the filter
cloth of the silt fences shoul&be anchored in a trench filled with onsite soil..
LIU. & ASSOCIATES, INC.
July 7. 2012
("llano Residence
I.&A.1obN"o. 12-058
Pait"le 9
Ditehes or interceptor trench drains should be installed around the COnSti-LIC6011 areas.. Lis
required, it) intercept and drain away storm ninoff and ricar-surface groundwater see age.
p -
Water captured by such ditches or interceptor trench drains shotild be discharged into a
nearbv storm inlet or dispersed through perforated PVC dispersion pipes onto well-
Yegetated areas within the site. The dispersion pipes should sufficicritly long and_sei
liorizontal such that �vater flowing out ofthe pipes would be at a lo-,v velocity and spread
over a large area to not cause erosion problern. I'lic storm inlet.. IfInto \%.hich stormwater
is to be discharged, should be covered with it non -woven filter fabric sock to prevent
sediment from entering the storm sewer systern. The filter sock shoUld be cleaned
fr . equently during construction to prevent cloggin . and slic)uld be removed after
W - -- 9.1
completion ofconstruction.
Spoil soils should be hauled off* of the site as soon as possible. Spoil, soil's and imported
structural fill material to be stored on site should be located in areas where the ground
surface is no steeper than 15% gyadc. and should be covered with plastic tarps securely
Nveluhted down with sandbags, 4s required. for protection against erosion.
SITE PREPARATION AND GENERAL GRADING
Vegetation within construction limits should be cleared and grubbed. 'I-opsoil, unsuitable
soil in the root zone and loose weathered soils should be completely stripped within
building pad of the residences and in areas subject to traffic and structural load. The
exposed soils should be compacted to, a non -yielding state, as required . vvith a vibratory
compactor and proof -rolled with a piece ofheavy earthwork equipment where possible.
LIU & ASSOCIATES, INC.
Julv 2 0 1
Chanu Residence
L&A)ob No. 1 12-058
EXCAVA'HON AND FRI, SLOPES
1-inder no circurnstance should excavation slopes he steeper than the linlits specified by
local, state and federal safety regulations if workers have to perfonii construction Nvork in
excavated areas. Lhisupportcd temporary cuts greater than 4 feet in height should be no
steeper than l.H:.1V in surficial topsoil and weathered soils ol' si.lLy line sand and no
steeper ihan 1!'--)H: IV in underlying very-dcnse till and dense advance outwash soils with
an overall depth of'cut no more than 15 feet. Perivarient ctit banks should be no steeper
than --)-l/4H:lV in topsoil and ,Neathered soil,. and no itccper than I-L"11:1V in
underivine till and advance outwasb deposits \kith an overall depth of cut no more than 15
feet. The Soil units and the stability of cut slopes should be obsen7ed and verilled by a
geotechnical engineer during excavation.
Pen-nanent fill embankments required to support structural load should be constructed
with cornpactcd structural fill placed over proof -rolled, undisturbed, ver\.-dense till arid
dense advance out -wash deposits after the unsuitable surficial soils are stripped. Fill
embankments placed over areas steeper than 15% grade should be structurally supported.
Sloping ground steeper than
15% grade
should be benched with
vertical
steps not
exceeding 4 feet tall after
stripping of
the surficial unsuitable
soils and
prior to
constructing permanent fill embankment. The slope of permanent fill embankments
should be no steeper than 21-1/4MV. Upon completion, the sloping face of permanent
fill embankments should he thoroughly compacted to a non -yielding state with a hoe -
pack.
LIU & ASSOCIATES, INC.
July 7. 2012
Chatip- Resid,cticc
L&A Job No. 124*68
P'iale I I
The above recoinniendcd cut and fill slopes arc under (fie assumption that groundwater
seepage would not be encountered during construction.. If &IrO Lind wat cr is encowitcred.
r
the construction x�jork should be immediately halted and the slope stabilitN re-evMuated.
The slopes may have to be I'lattened and other measures taken to stabilize the slopes.
Stori-nwatcr should not
be
allowed to flow uncontrolled
over
cut and
fill
slopes.
Pemianent cut slopes or
fill
embankments should be seeded
and
vegetated
as
soon as
possible for erosion protcction and long-term stabilivy, and should be covercd xvith clear
plastic sheets., as required, to protect them from erosion until the vegetation is fully
established.
STRUCTURAL FILL
Structural fill is the fill that supports structural or traffic load. Structural fill should
consist of clean granular soils free of organic and other deleterious substances and with
particles not larger than three inches. Structural fill should have a moisture content
within one percent of its optimum moisture content at the time of placement. The
optimum moisture content is the water content in the soils that enable the soils to be
compacted to the highest dry density for a given compaction effort.
Onsitc, soils meeting the above requirements may be used as structural fill. Imported
material to be used as structural fill should be clean, frec-draining, granular soils
containing no more than 5 percent by weight finer than the No. �00 sieve based on the
fraction of the material passing No. 4 sieve, and should have individual particles not
larger than four inches.
LIU & ASSOCIATES, INC.
Julv 7. 2012
Chang Residence
1-&A Job No. 12-058
Page 12
The ground over which structural fill is to be placed should be prepared in. Laccordance
with recommendations in the SITI:-�' PREPARATION AND GENERAL GRADING and
EXCAVATION AND FITj, S1.0PES sections of this report. -Structural fill shoUld be
constructed in lifis no rnore than 10 inches thick iii its louse state. %�ilh each lift
compacted to a minimum percentage of(he maximLim dry density detemilned by AST -NI
D1557 (Modified Proctor Method) as follows:
Application
Within building pads and Linder I.bundatiuns
RoadwavildriveNN4ay subgrade
Retaining wall backfill
Utility trench backfill
BUILD-ING FOUNDATIONS
�1'4) of,maximurn I)M; 'Mris i tv
95%
9511-b for top 3 feet and 90" below
92%
95% for top 4 feet and 90"i-o below
Conventional footing
I _, foundations may be used to support the proposed residence. The
footing foundations should be constructed on orinto the underlying very -dense till andior
dense.advance outwash deposit, Water should not be allowed to accurnulate in excavated
footing trenches. Disturbed soils in footing trenches should be completely removed down
to undisturbed, native, fresh till soils prior to pourig concrete for the footings.
If the above recommendations are implemented,,and observed, our recom.niendcd design.
c . ritefia for footing foundations are as follms:
LM & ASSOCIATES, INC.
July 7. 2012
Chano Residence
C
L&A Job No. 12-058
Page 13
fhe allowable soil hearing pressure for design of footing foundations. inclUding
dead and live loads. �,houtd be no greilter than 3.000 psfif constructed on or into
the undedvin-4 verv-dense till and", or dense advance oumash soil. and should not
exceed 2,500 psf id constrm:ted on -strUCtural fill built on these competent bas.al
soil. The footing hearing soil should be verified onsite by a -eotechnical covineer
after the looting trenches are excavated and before the footings poured.
The n-iinimum depth to bottom of perimeter footings below adjjacent final exterior
grade should be no less than 18 inches. The minimuni depth to bottom of' the
interior footings below top of floor slab should be no less than 12 inches.
The minimum width should be no less than 16 inches for continuous footirip-s- and
no less than, 214 inches for individual I-Ootings. except those footings supporting
light -weight decks or porches.
A one-third increase in the above recommended allo%�ablc soil bearing pressure 111ay be
used when considering short-term, transiton-, wind or seismic loads. For looting
foundations designed and constructed per recommendations above., we estimate that the
maximum total post- construction settlement of the building should be 3/4 inch or less and
the, differential settlement across building width should be 1/2 inch or less.
Lateral loads on the proposed residence may be rcsistcd by the friction force betw-een the
foundations and the subgrade soils or the passive earth pressure acting on the below -grade
portion of the foundations., For the latter., the foundations must be poured "neat" against
undisturbed soils or backfilled with a clean., ftee-draining, compacted structural fill. We
recommend that an equivalent fluid density (EFD) of 300 pcf (pounds per -cubic foot) for
the passive earth pressure be used for lateral resistance. The above passive pressure
LIU & ASSOCIATES9 INC.
Juty 7. 2012
Chang Residence
1-&A Job No. 12-0,58
1) aue 14
�i,S.',LlMeS that the backfill i:-; level or incline�, upw-ard away froin the foundations for a
horizontal distance at le&,t l.'5 timeN the depth of'the foundations below die final gradc.
A coefficient of" f'riction of'0.55 betkveen the fiRind.a.tions and the subgrade soils may be
used. The above recommended soil parameters are unfactored values,. and a proper factor
of safety should he used in calculating the resisting lorces against lateral loads. on tile
proposed residence.
SE.kB-ON-GRADE FLOORS
Slab -on -grade floors, if used I -or the residence. should be placed on tinTi subgrade soils
prepared as outlined in the SITE PREPARATION AND GEN'FRAL EAR:rHWORK and
the STRUCTURAI, I' ILL sections of this report.. Where moisture control is critical. the
slab -on -grade floors should be placed on a capillary break, NNhich is in turn placed on the
compacted subgrade. The capillary break should consist of a minirnum four -inch -thick
lay-er ol'clean, free -draining, 7/8-inch crushed rock, containing no mote than 3 percent by
weight passing the No. 4 sieve. A vapor barrier. such as, a 6-mil plastic membrane.. may
be placed over the capillary break, as required, to keep moisture from migrating up-%'-ards.
DRIVEWAY PAVEMENT
Performance of drive-vv-dy pavement is critically related to the conditions of the underlying
subgrade soils. We recommend that the subgrade: soil under the drivmllly be treated and
prepared as described in the SITE PREPARATION AND GENERAL EARTHWORK
section of this report. Prior to placing base material, the subgr4de soil should be
com acted to a non-yi elding. state with a mechanical compactor and -proof -rolled with a
p
piece of hea construction equipment, such as a fully -loaded dump truck. Any areas
. VY I
LIU & ASSOCIATES, INC.
J it l" 1 7 .. 2 () 12
Chang Residenc--
L&A Job No. 12-058
Pai�_'e 15
�-N'Ith ;:XcC_'SikC fl%:x1t1g or PujllpiflV� S111OUld bc and re-conipacted or
replaced x\,111i i StrUCtUral rill or cruslicd ro�:k placcd and coniracicd in accordance Nvith
the recommendations provided in the STRI-'('Tl-'R,\l FUT iection of this report.
We recommend that a JaNer of compacted. 7i8-Inch crUshed r,-)ck- base (CRB), be placed
for the driveway. This crushed rock base should be at ]cast 4 inches thick. This crushed
rock base should be overlain willi a 2-incli asphalt treated basc (ATB) topped by a 2-inch-
thick Class B asphalt concrete (AC) surficial course -
INFILTRATION TRENCHES
General
A clean. fine to medium sand deposit was encountered at 55.0 feet deep in Test Pit _1
located near the southwest comer of the site. \xhich \vill be capable of supporting
infiltration trenches to dispose stormwater onsite. Our recommendat ions for the
construction of infiltration trenches is shown Plate 6. Construction of infiltration trenches
should be monitored by a geotechnical engineer.
The above -referenced geologic map shows that he steep slope west of the subject. project
site is composed of dense advance. out -wash soil. This advance outwash soil unit is
sandwiched by and underlying two Vashon till soil units lying uphill and downhill of the
steep slope. Therefore,. despite areas of locally steep slope hillside below the subject
project site should be quite stableand the construction of infiltration trenches in -the near
ofthe southwest comer of the project site should have minimal impact on the stability of
the hillside below.
LIU & ASSOCIATES, INC.
JUIv 7. 20 12
Chano Residence
L&A Job No, 12-058
Pat-,e 16
Particle Size Distribtition Tests
Two soil samples: Sample Xo. I from Test Pit A2 at, 6.0 fcct decp and Sanipic No. 2 from
Test Pit 4 at 8.0 feet deep, were uaken to HWA laboratory for Particle Size Distribution
iests to determine the infiltration rates of the iarL,,et advanCe oUtwash deposit. Soil
Sample I was classified as "poorly graded sand" while Soil Sample 2 was classified as
-silty sand". The report of these tests is presented on Plates A- I and A-2 in the attached
APPENT.NX.
As summarized on Plate A-2, Soil Sample I had d clay content of 0.9%. silt content of'
6.40/'0' and gravel.',Sand content of 92.70/'0' and Soil Sampic 2 had a clay content of 2.4q1A, silt
content of 19.5%. and gravel/sand content of 78.1�10'. According to the USDA (11T.S.
Department of Agriculture) Texture, Triangle chart. shown on Plate A-3 in the allached
Appendix, Soil Sample I can be classified its "sand" while Soil Sample 2 as
sand*.*.
0
Design Infiltration Rate for Infiltration Trenches
The Stormwater Management Manual for Western Washing -ton, 2005 Edition. published
by Washington State Department of Ecology, is used to determine the design infiltration
rate of the target advance outwash soil stratum for infiltration trenches to be consaructed
for dispose stormwatet onsite. According to the table of Recommended Infiltration Rates
Based on USDA Soil Textural Classification shown on Plate A-4., the estimated short-
term infiltration rate would be 8 i,ph (inches per hour) and the estimated longmterm.
infiltration rate with a Correction Factor of.2 would he 2 iph for Soil Sample 1, and
would be 2 iph and 0.5 iph, respectively, :for Soil Sample 2.
LIU & ASSOCIATES, INC.
J u I N, 7. 2 0 12
Chang Residence
,L&A Job No. 12-058
Page 1-1
As shown on Plate A-2, tile Dj(, Si7C (the size of loOr, pa;ing, 1" 0 09.1 inch for Soil
Sample I and 0.016 inch for Soil Sample 2 in accordance �vffh tile soil particle size
distribution test results. Accordin!2 to the table of Allemativc, Recommended Infiltration
Rates Based On AS"I'M Gradation "Festing presented on Ph-ite A-5, by interpolation.. the
estimated long-term infiltration rate is 1.91 ipIl_1 . or Soil Sainple No. j and 0.85 iph for
Soil Sample 2.
Based on the test results Libove.. \k,,e recornmend the infilirtation trenches be installed in the
vicinity of Test Pit 2. We recommend a design infiltration rale of 1.90 iph be uscd for the
dcsip-n ofinfiltration trenches to be constructed in the vicinity offest Pit 2.
Infiltration Trench Construction
Ilic trenches should be cut at least 6 inches into the advance out-vvash deposits ol,clean,
gray, fine to medium sand deposit. To reach this target soil stratuill tile infiltration
trenches should be excavated at least 5.5 feet deep or more. Yhe soil unit at bottom of
infiltration trenches should be verified by a geolechnical engineer.
The infiltration trenches should he set back at least 5 ileet 1rom property lines and 10 feet
from nearby, building foundations. The soil unit and trench cut bank stability -should be
verified by a gcotechnical engineer during, excavation. The trenches should be cut with
slopes recommended in the EXCAVATION AND FILL SLOPES section in this rcport.
Othenvise, a trench block, should be used to protect workers in the trenches.
The infiltration trenches should be at least 4 feet wide. The side walls of the trenches
should be lined with a laver of non -woven filter fabric.. such as MIRAF1 140NS. The
LIU & ASSOCIATES, INC.
JUIV 7. 20 12
Chanu Residence
L&A Job "No. 12-058
Page 18
trenches arc then filled with clean washed 31,4, to 1-l:i`2 inch gravel or crushed rock to
within about 10 inches of the finish orade.- The dispersion pipes should be constructed of
Z�
4-inch rigid PVC pipes Zand laid level In Lhe gravel or crushed rock filled trenches at. about
16 inches below the top oftrenches. The top of the gravel or crushed rock fill should also
be covered with the filter 1'abrllc liner. The remainiiqg trenches should then be backfilled
with compacted onsite clean soils. '17he gravel or crushed rock fill should be placed in
lifts no more than 10 inches thick in loose state, with each lift con1paCLed to a, null -
yielding state with a vibratory mechanical compactor. Stonivivater captured over paved
drivewav should be routed into a catch basin cqtjipped with an oil -water separator before
being released into the infiltration trenches.
DRAINAGE CONTROL
Building Footprint Excavation
Building footprint excavation for the proposed residence. if encountering groundwater
seepage, should have the bottom of excavations loped and ditches excavated along the
bases ot'cut banks to direct collected g
voundwater into sump pits from which water can
be pumped out. A laver of 2-inch crushed rock should be placed over footing bearing
subgrade soils, as required, to protect the soils fibm, disturbance bN, construction traffic.
This crushed rock base should be built to a few, inches above groundwater level, but not
less than 6 inches thick. The crush rock baseJshould be compacted in 12-inch lifts to a
non -yielding state with a vibratory mechanical compactor.
LIU & ASSOCIATES, -INC.
Rily 7. 20 12
Chang Residence
L&A. Job No. 12-058
Papae 19
Runoff Over Impervious Surfaces
Stom-i runoff' oNer iniper\�iou5 .,Urflice-s. ZAICII as roof and paved drive-v�-ay, should be
systems connected to doNvi-ispouts and by catch basins
collected bN underground drain lines,
installed in paved drive,.\-aN,. Storin�\,ater thus collected should be tightlined to discharge
into a ncarbv storm se\%.-er or a suitable stormwater disposal l'acility systeM. Such its
infiltration trenches.
Building Footing'Drain
A subdrain systein should be installed., around the perimeter footing-s of the new
residence. The subdrain should consist of a 4-inch-niinii-num-diameter.. perforated. rigid.
drain pipes, laid a few inches helow bottom of the perimeter footings of the building. The
trench and the drain line should have a sufficient gradient (0.5% minimum) to generate
flow by gravity, The drain line should be wrapped in a non -woven filter I'abric sock and
completely enclosed in clean washed gravel. The remaining trench may be backfilled
with clean onsite soil. Water collected by the perimeter footing subdrain system should
be tightlined, separately 1�om. the roof -md surface stormwater drain lines, to discharge
into a storm sewer or a suitable ston-nwater disposal facilivy,, such as infiltration trenches.
Surface Drainage
Water should not be allowed to stand in any areas where footings, on -grade -slabs, or
pavement is to be constructed. finish ground surfaces should be graded to direct surliice
runoff away from the proposed residence. We recommend the finished ground be sloped
at a gradient of 3 percent minimum for a distance of at least 10 feet away from. the
buildings, except in the areas to be paved.
LIU & ASSOCIATES, INC.
July 7. 2012
Chang- Residence
L&A job No. 12-059
Page 20
zn-
cleanouts
Sufficient number ol'cleanout,,-'� Lit straiegic locations ihould be pro-vided for Underground
drain lines. The underground drain lines should be cleaned and inalmained periodically
to prevent clogging.
RISK EVALUATION STATEMENT
The sub . ect site is underlain at shallow depth by very -dense till and dense ad\'ance
J
oum,--ash deposits. These basal soils are of high shcar strength and the site should be quite
stable. Proper and adequate erosion mitigation and surflace and 1groundwater drainage
control are key to maintain site stabill(v during and after cornpletion of construction. Tt i's
our opinion that if the recommendations in this report are fully implemented and observed
during construction and following the completion of construction., the areas disturbed will
be able to remain stable. and will not increase the potential for soil movci-nent. In our
opinion, the risk for damages to the proposed development and From the development to
adliacent properties fi-orn soil instability should be minimal.
MFFM# An, 401W
This report- has been prepared for the specific application to this project for the exclusive
use by Dr. Wallace Chang and his associates, representatives, consultants and contractors.
We recommend that this report, in its entirety, he included in the project contract
documents for the information of the prospective contractors for their estimating and
bidding purposes and for compliance with the recommendations in this report during
construction. The conclusions and interpretations in.this repon, however, should not be
LIU & ASSOCIATES,INC.
July 7. 2012
Chang Residence
C�
L&A Job No. 12-0519
construed aS d vkilrrantv of the sub,�LIITCICC conditions. The scope Of'thi', SILICIV d0e,� 110t
HICILide services relaLed it) CLMSIRW6011 Salet\ precautions and our recommendations are
not intended to direct the contractor',-; incthods. techniques, sequences or procedures,
except as specifically described in this report for design considerations. The geotechnical
construction of the sublect prQiect should be monitored and inspected by a geotec.hnic.al
enoinecr.
r,
Our recommendations and conclusions- arc, based on the geologic and soil conditions
encountered in the test pits.. and our experience and cngincering Judgment, The
conclusions and rccornmcndat ions arc professional opinions derived in a manner
consistent with the level of care and skill ordinarily exercised by other members of the
prot'ession cuffently practicing under siniflar conditions in this area. No warranty,
expressed or implied, is made.
The actual subsurface conditions of the site may vary from those encountered by the test
pits, The nature and extent of such variations may not become evident until construction
starts. If variations appear then., we should be retained to re-evaluate the
recommendations of this report, and to veriA, or modify them in -.vriting prior to
proceeding ftu-ther with the construction of the proposed dcvclopment,
CLOSURE
We are pleased.to be of service to you on this prt�ject. Please fleel free to contact us ifyou
have any questions regarding this report or need further consultation.
LIIJ & ASSOCIATES, INC.
July 7., 2012
Chang Residcncc
L&A Job'No. 12-058
Page22
Yours very truly,
LIU & ASSOCIATES. INC.
k S. (Julian) Liu, Ph.D., P.E.
Consulting Geotechnical Engineer
Six plates and Appendix attached
4
LIU & ASSOCIATES.-INC.
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VICINITY MAP
LIU & ASSOCIATES. INC. CHANG RESIDENCE
73XX — 173RD STREET SW
Geotechnical Fngineering - Enginteeft Geology - Faith Scienoe EDMONDS, WASHIN ON
[—JOB NO. 12-058 DATE 6/2012012 1 PLATE 1
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UNIFIED SOIL CLASSIFICATION SYSTEM
MAJOR DIVISIONS
GROUP GRO(P NAME
SYMB01-i
GRAVEL
CLEAN
GlAl F-,E 7;--� C,0,-�,RSE GR AV E--
COARSE-
M,3RE --4-AN OF
GRAVEL
P R L �G� R D E I', G XV H
GRAVEL '4`07H
Gfl
GRAINED
�LpAll-"�.CN
SOILS
R E C 0 N N C 4 5 IE V
FINES
GC
i C-- A "fz-- Y G R-Al VE7L
SAND
CLEAN
L - 7, -P A 0 E. C� S A N D P %'E TO C0 , AR S E 5 A N D
MORE THAN 50�
IIACRE Ti-',-*N 50% OF
SAND
SP
... . ...... . . ......... -- - - — - ------------ . .................
i P&ORLY-GRADEC' SAND
SAND WITH
S %fl,
SILTY SAND
RETAINEO ON THE
r�QARSE F:�ACTION
NO %ry SIEVE
PASS!NG %C 4 5��EVE
FINES
Sc
ICLAYE.",'SAND
FINE-
SILT AND CLAY
INORGANIC
ML
SILT
CL
LA Y
GRAINED
SOILS
LESS THAN 50%
ORGANIC
OL
ORGANI',� SILT ORG.ANi'-' ZLAY
SILTY AND CLAY
INORGANIC
m H,
S?Ll'OF HIGH PLAS7: �C -1 �e, ELAST-C SILT
MORE THAN 5C4,
CH
'---AY C= HK-3H PLAST�C-iTY, FAT CLAY
PASSING ON THE
��UtD LtMIT
NO. 20D S114EVE
�00h'--'R MORE
ORGANIC
OH
OPGANIC SILT, ORr-,AN;C Sli-
HIGHLY ORGANIC SOILS
PT
FEAT AWD OTHER HIGHLY ORGANZ:C SO�LS
NOTES.
SOIL MOISTURE MODIFIERS,
I FIELD CILASS';�[C.470N IS BASED ON VISUAL EXAMINATION
CRY -,ABSENCE OF WDISTURE, DUS7 Y DRY -0
OF SOIL IN GENERA- ACCORDANCE WITH ASTM 0248"3.
THE'rOUCH
2 SOIL CLAS&FiCAT KON-JSING LABORATORY TESTS IS BASED
SLIGHTLY MOIST - TRACE MOIST URE, NOT DUSTY
ON ASTM D2467-W
MOIST - DAMP. BUT NO VISIBLE WA�ER
3. DESCRtPTIONS OF SOIL DE%SITY OR CONSISTENCY ARE
VERY MOiST - VERY DAMP, MOISTURE FELT TO THE TOUCH
BASED ON INTERPRETATION OF BLOW -COUNT DATA, VISUAL
WET - VIS�BLE FREE WATER OR SATURATED,
APPEARANCE OF 50�LS, ANDIOR TEST DATA.
�jSLJALLY SOIL IS OBTAINED FROM BELOW
WATER TABLE
LIU & ASSOCIATES., INC.
UNIFIED SOIL CLASSIFICATION SYSTEM
Geotv"" Engvftnng FrVMWVV QW"y EWth 5cWvA
PLATE 3
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APPENDIX
Grain Size DistribWion Test Report
Chang Residence
73xx — 1,73'd Street SW
Edmonds," Washinuton.
LIU & ASSOCIATES, INC.
I
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a_
GRAVEL '--I
SAND
—Coarse Firle
SILT
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Coarse
Fine
U.S. STANDARD SIEVE. SIZES
XW'
50 10 5 1 U.:1 VA Q'U0
GRAIN SIZE IN MILLIMETERS
U u J V. J '1 -1
C CIC, I cl.i*05
j
SYMBOL S-AMPI, F, DEPTH (it) CIASSIFICATION Or-,3011� ASTPA D2487 Group Symt-ul and Nanio
I -, fol I, LL pt
Pi
0
TP-2
S-1
60-7.0
(SP-SM) Olive brum, poorly giaded SAND with silt
3
Ej:
TP-4
S-2
80-9.0
(SM) Grayish brown, silty SAND
14.2 J
PARTICLE -SIZE ANALYSIS
EWA Laboratory Testing for Liu & Associates OF SOILS
Chang Residence METHOD ASTM D422
HMGMSCIENCESINC
MAE", r IJC: 20 12-025 T 1100 1
.3R 2' ' -CZj I I I W,�GPJ �'47� I
J mic 29, 2) 0 12
HWA 111n)ject No. 2012-01-5-21
Table I — Summary of Sieve AnalysisTest Results
ampl.,
m %
CIAS'sification ty 'and
Gravel F S
Silt Clay
TP-2
6 ft
(SP) Olive brown poorly graded SAND with
3
1.5 91.2
6.4
o.9
0,093)
Silt
-4
8 �ft
(SM) Orayish brown silty SAND
.... .......
14, 2? _6 3
19,5
2.4
0.016
Task 0 11 Lib Rcpoil I IWA GcoScicmGes hw.
Ljs�l
f
100% COn4
Textural Triangle U.S.D.A.
ev 40 so
Pofteel Dead
Shaded area is applicable for desit,
,n of infiltration BM Ps.
Figure 3.27 USDA Textural TrIanglo
'Source: U.S, Department of Agricultlire
20 � 10 1001 G"t
III Hy&61� w Contiol BMPS Februarj(2005
'v&
FLATC- A 3
!'6r honiogenCOLIS S'OdS, J'hcs,� rates FlOt er t ffect S
lie e s of. it
variability and 10,19-term Clogging duc, to N tic). and bioMaNS bUildUP in
the infiltration lacili(N. ilta, q
Table 3.7 — Recommended Infiltration Rates
on USDA Soft Textural ClassMcatlon.
Estimated Long-
7'Short-Tertn
Term (Design)
larlitration
n
IT
Correction
'7n
Infiltration RAte
Rate (injhr)
I
r_r
Factor, CF
(Whr)
Clean sandy gavels and
gravelly wkndi (i.c_ 9(r/O of
the total soil sample is
retained in the #10 sieve)
Sand
4
Lowny Sand
2
4
0.5
Sandy Loam
4
U5
L ni
oa
4
i�. UYL 1. 1
- -Vat_v, J"8�
"Not rec(%nmended lig trealmen,
"'Refer to SSC-4 and SO,(-,'.6 fur treatment acccabilit-V Criteria
Bascd on experience with long-term full-scale infiltration pond
PerfOrmance, Ecology's Technical Advi!")ry Committee (TAC)
recommends that the short-term infiltration -rates be reduced as shown in
Table 3.7. dividing by a correction factor of 2 to 4, depending on the soil
textural clazificatiOn. The correction factors provided in Table 3.7
represent an average degree of long-term facility maintenance, TSS
reduction through prctreittment. and site variability in the subsurface
conditions. These conditions might include deposits of ancient landslide
debris, buried strewn channels, lateral grain size variability, and other
factors that affect homogeneity).
These correction factors could be reduced, subject to the approval of the
local jurisdiction, under the following conditions:
For sites with little soil variability,
Where there will he a high degree of long-term facility maintenance,
Where specific, reliable prebmtmenti is employed to reduce TSS
entering the infiltration facility
1n no cXW shall a cOrrcctiOu factor ka than 2.0 be ua�d.
3-76 VO6n_W111—_Hy&_O
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A
COrrectit)n factors ilizher than those provided in 'Iable 33should t�e
considered for situations where long-term maintenance Wi b di Yc I
it C f I U I
implement, where little or no pretreatnient is anticipated, or where site.
conditions arc highly variable or uncertain. These situations require t1le
use Of best Professional judgment by the site engineer and the approval of
tile local jurisdiction. An Operation and Maintenance plan and a financia!
honding plan may be required by tile local jurisdiction -
I ASTIvI Qrada
As an alternative to Table 3.7, recent -studies by Massmann and Butchart
(2000) were used to develop the correlation provided in Table 3.8, These
studies compare infiltration measurements; from full-scale infiltration
facilities to Soil gradation data developed qsing tile ASTM procedure
(ASTM D422). The primary source of the data used by Massaiann and
Butchart was from wiltsie (1999), who included limited infiltration
studies only on I'llurston County sites. However, N4assmann and Butchart
also included limited data from King and Clark County sites in their
analysis. This table provides recommended long-term infiltration rates
that have been correlated to soil gradation pararacters using tile AS'F.%,l
soil gradation procedure.
Table 3.8 can be used to estimate long-term design infiltration rates
dire,ctlY from soil gradation data, ubject to the approval of the local
jurisdiction. As is true of Table 3.7, the long-term rates provided in Table
3.8 represent average conditions regarding site variability, the degree of
long-term maintenance and preuratnicrit for TSS control. The long-term
infiltration rates in Table 3.8 my need to be decrcased if the site is highly
variable, or if maintenance and influent characteristics are not well
controlled. The data that forms the basis for Table 3.8was from soils that
would be Classified as sands or sandy gravels. No data was available for
finer soils at the time the table was developed. Therefom Table 3.8 should
not be used for soils with a dio si7x (IWO passing the size listed) levs than
0.05 mm (U.S. Standard Sieve).
Table 3.9 — Aku=tN* PAconumnded Infiftration
- - ' edonAS Gradation Testing.
Die Sime from ASTM 0422 Soil
EsUm0ed Long -Tenn (Design)
Grsdttkn Test (mm)
Infiltr2tion Rate (in./hr)
?10.4
9
----------------- 03
6.5
0.2
3_5*
0.1
2-0#0
0.05
O's
*Not -
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1 3-77
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