BLD20080182.pdfOF ED,y70
�y Y " CITY OF EDMONDS
121 5TH AVENUE NORTH - EDMONDS,WA 98020
7hc. 1890
PHONE_ (425) 771-0220 - PAX: (425) 771-0221
Expiration Date
Parcel No: 00513105900800
a Lei
CITY PARK JAIME HAWKINS PROPERTY OWNER EXEMPTION TAKEN
121 5TH AVENUE N 121 5TH AVE N
EDMONDS, WA 98020 EDMONDS, WA 98020
425-771-0220
LICENSE#. EXP:
GRADINGTOCREATE ACITYPARK, IMORTEDBYAUGERCASTPILFS,DROUGHT
TOLLERANT LANDSCAPING.
a�.
VALUATION: $0
PERMIT TYPE: Commercial
PERMIT GROUP. 28 -Fill/Grade/Excavat
GRADING:N CYDS:O
T YPE OF CONSTRUC'r10N: RET. WALL
RETAINING WALL ROCKERY: Y
OCCUPANT GROUP.
OCCUPANT LOAD.
FENCE: N ( 0 X 0 FT.)
CODE. 2006
OTHER. N------- OTHER DESC,
ZONE. RS�20
NUMBER OF STORIES: 0
VESTED DATE:
NUMBER OF DWELLING UNITS: O
LO'f #'.
BASEMENT IST FLOOR.0 2ND FLOOR
IBASEMENT .0 IST FLOOR:0 2NDFLOOR:0
3RD FLOOR. 0 GARAGE:0 DECK: 0 OTHER: O
13RD FLOOR. 0 GARAGE: O DECK, 0 OTHER:0
REQUIRED.N 10 PROPOSED: 10+ IREQUiRED. S25 PROPOSED. 25+ REQUIRED:W 25 PROPOSED: 25+
HEIGHT ALLOWED:25 PROPOSED:O REQUIRED: E 25 PROPOSED: 25+
SETBACK NO"f ES. The maximum height of the retaining wall within the setback area is 3-feet as measured from top of Wall to original grade.
I AGREE TO COMPLY WITH CITY AND STATE LAWS REGULATING CONSI' RUCTION AND IN DOING THE WORK AUTHORIZED
THEREBY, NO PERSON WILL BE EMPLOYED IN VIOLATION OF THE LABOR CODE OF THE STATE OF W ASI IINGT ON RELATING TO
WORKMEN'S COMPENSATION INSURANCE AND RCW 18.27,
S APPLICATION IS NOT A PERMIT
ATTENTION
IT IS UNLAWFUL TO USE OR OCCUPY A BUILDING OR STRUCTURE UNTIL A FINAL INSPECTION HAS BEEN MADE AND APPROVAL OR A CERTIFICATE. OF
OCCUPANCY HAS BEEN GRANTED. UBC109/ IBC110/ IRCI10.
ARCHIVE APPLICANT = ASSESSOR OTHER JF3�
STATUS: ISSUED
BLD20080182
Pursuant to SM-2008-26:
(1) All fill shall be "nondissolving and nondecorrposting," and shall not contain organic or inorganic materials that would be
detrimental to water quality.
(2)'I'he maximum height of the retaining wall within the setback area is 3-feet as measured from top of wall to original grade.
(3) The Applicant shall provide one sign on the west side of the park or on 76th Place West in the vicinity of the private rail
crossing that wams visitors not to trespass onto the right-of-way. The specific language shall be at the City's discretion. The
City may remove or codify the sign ifthe circumstances ofthe rail crossing change, such as if the use changes from public to
private, or if safety devices or pemanent fences/barricades are installed.
• REQUIRED SPECIAL INSPI'.CI'IONS FOR THIS PROJECT:
1) Excavation, grading, & she preparation
2) Retaining wall construction, including auger cast pile installation, geogrid installation, block wall construction, drainage and
placement of fill & compaction
3) Final letter from geotechnical engineer of record
• Submit all special inspection reports to the City Building Inspector on a weekly basis.
• As required by Ordinance #3632 the geotechnical engineer of record shall monitor this she during construction for compliance
with the reconmrendations in the geotechnical report including: site excavation, shoring, soil support for foundation including
piles, soil bearing capacity, subdrainage installation, soil compactions, and other geotechnical aspects of the construction.
Specific recommendations contained in the approved geotechnical report must be implemented by the owner. The
geotechnical engineer shall make written, dated reports on the progress of the construction and submit the report to the
Building Official on a weekly basis until all she grading, drainage, foundation and associated gmund work is complete.
(missions or deviations from the approved geotechinical report and/or approved plans or specifications shall be highlighted
and immediately submitted in a seperate letter to the Chy for review.'Ihe City shall be advised in writing ofwork stoppages of
more than one week In addition to the geotechnical monitoring, special inspections based on the provisions of IBC Section
1704 are required when specified on the approved plans. Other special inspections may also be required by the geotechnical
engineer, architect, or structural engineer of record (refer to approved plan set). At the completion of final she grading and all
permitted structures, a final geotechnical report, prepared by the geotechnical engineer shag be submitted to the Building
Official. This report shall contain a statement that, based upon his/her professional opinion, site observations, and testing
during the monitoring ofthe construction, the completed development substantially complies with the recommendations in the
geotechnical report and with all geotechnical related pemnit requirements. Any deviations or omissions in the report, plans, or
specifications that occured during construction shall be addressed separately. Occupancy, final approval, or release ofthe
bond forthe project shall not be granted until the report has been reviewed and accepted by the Building Official.
• Any request for alternate design, modification, variance or other administrative deviation (hereinafter "variance") from
adopted codes, ordinances or policies must be specifically requested in writing and be called out and identified. Processing
fees for such request shall be established by Council and shall be paid upon submittal and are non-rel'undable.
Approval of any plat or plan containing provisions which do not comply with city code and for which a variance has not been
specifically identified, requested and considered by the appropriate city official in accordance with the appropriate provision
of city code or slate law does not approve any hens not to code specification.
• Sound/Noise originating from temporary construction sites as a result of construction activity are exempt from the noise limits
of ECC Chapter 5.30 only during the hours of 7:00am to 6:00pm on weekdays and IO:OOam and 6:00pm on Saturdays, excluding
Sundays and Federal Holidays. At all other times the noise originating from construction sites/activites most comply with the
noise limits of Chapter 5.30, unless a variance has been granted pursuant to BCC 5.30.120.
• Applicant, on behalfofhis or her spouse, heirs, assigns, and successors in interests, agrees to indcrnnity defend and hold
harmless the City of Edmonds, Washington, its officials, employees, and agents from any and all claims lbr damages of
whatever nature, arising directly or indirectly from the issuance fo this permit. Issuance of this pemnh shall not be deemed to
modify, waive or reduce any requirements of any City ordinance not limit in any way the City's ability to enforce any ordinance
provision.
• Applicant shall repair/replace all damage to utilities or frontage improvements in City Fight -of -way per City standards that is
caused by or occurs during the permitted project.
THIS PERMIT AUTHORIZES ONLY THE WORK NOTED. THIS PERMIT COVERS WORK TO BE DONE ON PRIVATE PROPERTY ONLY. ANY CONSTRUCTION ON THE
PUBLIC DOMAIN (CURBS, SIDEWALKS, DRIVEWAYS, MARQUEES, ETC.) WILL REQUIRE SEPARATE PERMISSION.
PERMIT TIME LIMIT: SEE ECDC 19.00 0aS(A)(6)
I BUILDING (425) 771-MO EVE 1333 1 MNGINUMING (42n 771-0220 EXr. 1326 1 M7RE(425) 771-0215 1
PUBLIC WORKS 425 771-0235 1 PRF 77tMA-IMUVI' 425 672-5755 1 RMICYCLPIG 425 275-4801
When calling for an inspection please leave the following information: Permit Number, Job Site Address,'Iype of Inspection being
requested Contact Name and Phone Number, Date Prefereed, and "ether you prefer morning or afternoon.
• B-Retaining Wall Special InspLction
• B-Setbacks
&Building Final
• P-Planning Final
MEMORANDUM
To: Tani Stafford / Gray & Osborne Inc.
From: Ralph Boirum / HWA GeoScienees Inc.
Date: April 1, 2008
JUL 101008
MiCROFILm
RF,: 162ND STREET PARK WALL
76T° AVENUE WEST/ 75Ti1 PLACE WEST WALKWAY IMPROVEMENTS
EDMONDS, WASHINGTON
Development of the new park at 162"d Street in Edmonds will include a low (4-foot
nominal) modular block (MSE) wall to retain fill along the north east corner of the park.
The purpose of this fill is to weight the toe of the slope and increase the stability of an
existing landslide. To further increase the stability of this slope, the wall will be founded
on auger cast concrete piles. These piles will extend through the slide plane to bear in
more stable soils. The following recommendations are presented for design and
construction of the piles and retaining wall:
■ Auger cast concrete piles should be 24-inches in diameter on 6-foot centers,
located along the centerline of the wall,
■ Concrete should achieve a 3,000psi 28-day compressive strength.
■ Piles should extend at least 10 feet below the existing grade.
■ A reinforcing cage consisting of four vertical No. 7 bars should extend to the
bottom of each pile.
■ A 24-inch wide (minimum) footing/pile cap should extend across the tops of the
piles to support the retaining wall.
■ Horizontal layers of geogrid consisting of Tensar BX-1200, or equivalent, should
be placed across the top of the modular blocks and extending at least 5 feet into
the fill at nominal depths of 16 and 36 inches below the top of the wall.
■ Prior to placing fill, a 12-inch thick layer of 1 %4-inch-minus crushed rock should
be placed over the existing subgrade as a drainage layer. The crushed rock should
contain no more than 5 percent fines (material passing the No 200 mesh sieve).
• The crushed rock should be compacted to a dense and unyielding condition.
■ Fill consisting of spoil excavated from other areas of the project may be placed
above the crushed rock, providing they are not too wet for proper compaction.
• Fill should be compacted to at least 92 percent of its modified Proctor maximum
density.
• A 4-inch (minimum) diameter slotted plastic drain pipe should be placed in the
crushed rock fill along the back of the retaining wall. This drain pipe may flow
into the trench subdrain or to the storm drain system.
Page ] of 1
Hawkins, Jaime
From: Tani Stafford [ttafford@g-o.com]
Sent: Tuesday, May 20, 2008 8:57 AM
To: Hawkins, Jaime
Subject: FW: 76thl75th Walkway and Park Slide Zone Modeling Results
Jaime — Here is the email that discusses the change in the depth of the trench subdrain. FYI - Tani
-----Original Message -----
From: Tani Stafford [mailto:tstafford@g-o.com]
Sent: Tuesday, February 26, 2008 11:36 AM
To: Fiene@ci.edmonds.wa.us
Cc: Gebert@ci.edmonds.wa.us; Hauss, Bertrand; Hawkins, Jaime; McIntosh, Brian; Lindsay, Rich;
SBlack@sbassociates.com; rboirum@hwageo.com
Subject: 76th/75th Walkway and Park Slide Zone Modeling Results
Don — Susan submitted the 90% park plans and special provisions today, so we will go ahead and forward them
to the City for review. These plan sheets for the park will replace the ones that were included in our last submittal
to you.
We also met with Ralph Boirum (HWA GeoSciences) today regarding the readings that were taken on the
inclinometer at the park site. A sufficient amount of time has elapsed for HWA to make a reading on the
inclinometer that was installed last October. Ralph has used the data to model the slide. The slide appears to be
confined to the sloped area along the east side of the park property, north of where the proposed rock climb is
located. The proposed trench subdrain (along the toe of slope at the park) needs to be only 4' deep, rather than
the 8' to 10' deep that we show on the plans. Based on the model, Ralph now has recommendations for the
amount of fill and placement of the fill along the park slope to stop the slide.
We would like to meet with the City to go over the model and recommendations for the placement of the fill.
These recommendations would require some changes to the grading in the area of the Park where the proposed
"sail boats" are shown.
Ralph and I are available to meet this week on W or TH.... Or the following week M, T, TH or F look good.
-Tani
Tani Stafford, P.E.
Gray & Osborne, Inc.
701 Dexter Ave N. Suite 200
Seattle WA, 98109
Ph(206)284-0860
Fx(206)283-3206
Electronic File Transfer -
Note that these electronic files are provided as a courtesy only. Gray & Osborne, Inc. in no way guarantees the
accuracy or completeness of the digital data contained within these files. Furthermore, Gray & Osborne, Inc.
assumes no liability for any errors or omissions in the digital data herein. Anyone using the information contained
herein should consult the approved or certified hard copy drawings or reports for the most current information
available.
5/20/2008
O) EU4f
of
CITY OF EDMONDS
SPECIAL INSPECTION AND TESTING AGREEMENT
PERMIT #
PROJECT SITE ADDRESS: I ia/I 3 `%SV-
PROJECT NAM
DATE:
It Lz>
SPECIAL INSPECTION AGENCY
*One form must be completed by each Special Inspection Agency or Inspector.
SPECIAL INSPECTIONS REQUIRED: Special inspections are required for this project in accordance
with IBC Chapter 17 or in accordance with IRC R109.2 as applicable. IBC Section 1704.1 requires the
owner or the registered design professional in charge to employ an independent testing/inspection
agency/special inspector to perform required special inspections. The independent agency hired to
perform the duties of special inspection is required to be a registered agency with WABO under the
Special Inspection Registration Program (SIRP). The special inspector shall be a qualified person with
competence for inspection of the particular type of construction or operation requiring special inspection
(SOQ may be required by the Building Official). The owner, registered professional, contractor and
special inspector/agency shall complete the attached form and submit directly to the Building Division.
WORK REQURING SPECIAL INSPECTION: Special inspections will be required for the following
categories of work in accordance with IBC Chapter 17 and IRC R109.2: FOR SPECIFIC
INFORMATION REGARDING REQUIRED SPECIAL INSPECTIONS SEE THE STATEMENT OF
SPECIAL INSPECTION I (ATTACHED I !APPROVED PLAN SHEET
❑ Fabrication (1704.2) - —
n Steel Construction (1704.3)
i t Concrete (1704.4) -- - -
i Special Moment Resisting Concrete Frames (I704.4)
u Structural Welding (1704.3.1)
u Masonry (1704.5)
u Structural Masonry for Seismic Resistance (1708.1)
u Insulating Concrete Fill (1704.4)
n Piling, Drilled Piers, and Caissons (1704.8, 1704.9)
❑ Pier Foundations (1707.5)
(Grading, Excavation, Fill, Proof Rolling (1704.7) .-
❑ Mechanical Components (1707.8)
❑ Storage Racks (1707.6)
❑ Structural Wood (1707.3)
n Seismic Isolation System (1707.10)
❑ Mastic, Intumescent Fire Resistant Coatings (1704.11)
1704.6.1)
n Wood Construction (1704.6) --- --
n Soils (1704.7)
u Bolts installed in Concrete (1704.1.3)
❑ Reinforcing Steel, Prestressial; Steel Tendons (1704.4)
❑ High Strength Bolting (1704.3.3)
u Reinforced Gypsum Concrete (1704.4)
❑ Structural Observation (1709)
❑ Spray Applied Fire -Resistive Materials (1704.10)
❑ Shotcrete (1704.4)
❑ Structural Steel (1707.2)
❑ Smoke -Control Systems (1704.14)
n Designated Seismic Systems (1707.9)
n Cold Fomted Steel Framing (1707.4) _
n Architectural Components
❑ Special Cases (1704.13)
BEFORE A PERMIT CAN BE ISSUED: The owner and contractor and special inspector shall
complete this agreement and the attached Special Inspection Information Form, including the required
acknowledgements and return to the Building Division for approval prior to permit issuance.
W:\13uilding\HAND0UT ICODF,S\FORMS\SPIiC1AL INSPECTION AGREEMENT FORM.doc7/07
APPROVAL. OF SPECIAL INSPECTORS: Each special inspector shall be approved by the Building
Official prior to performing any duties or inspections. The company performing inspections must be
WABO certified as well as the individual completing inspections. When required by the Building
Official, each special inspector shall submit Statement of Qualifications to the City for review. Special
inspectors shall display identification when performing special inspections on the project site. Special
inspection and testing shall meet the minimum requirements of IBC Chapter 17 and the following:
A. Duties and Responsibilities of the Special Inspector
1. OBSERVE WORK
The special inspector shall observe the site work for conformance with the approved (stamped)
plans and specifications and applicable workmanship provisions of the IBC. Architect or
Engineer reviewed shop drawings may be used only as an aid to inspection. Special inspections
are to be performed on a continuous basis —meaning that the special inspector is on site at all
times observing the work requiring special inspection. Periodic inspections are permitted only as
specifically noted in the approved project plans in accordance with IBC Chapter 17, and as
approved by the Building Official.
Continuous Inspection means the same inspector is on site day to day to observe the work
requiring special inspection.
Periodic Inspection means some inspections may be performed on a periodic basis to satisfy the
requirements of continuous inspection, provided these periodic inspections are performed as
outlined in the project plans and specifications, and approved by the Building Official.
2. REPORT NONCONFORMING ITEMS
The special inspector shall bring non -conforming items to the immediate attention of the
contractor and note all such items in the daily field report. Any item not resolved in a timely
manner shall be immediate cause of the special inspector to notify the Building Official by
telephone at (425-771-0220) or in person at City Hall, of the plan deviation, error, change or
omission. It shall also he the duty of the special inspector to promptly notify the engineer or
architect of record.
3. DAILY REPORTS KEPT ON SITE WITH CONTRACTOR
Each special inspector shall complete and sign a daily report for each day's inspections. The daily
reports shall remain at the jobsite with the contractor for review by the City Building Inspector.
4. WEEKLY REPORTS TO CITY
The special inspector or inspection agency shall furnish the City with weekly reports of tests and
inspections. The project engineer or architect, and others as designated shall also he copied on
reports. Weekly reports must include the following:
• Description and date of daily inspections and tests made with applicable locations
• List of all non -conforming items and locations
• Report on status of non -conforming items (how each was resolved or unresolved)
• Field changes authorized by the Architect, Engineer or City Inspector if not included in
non-conformance items.
W:\Building\HANDOUI' ICODES\FORMS\SPECIAI. INSPECTION AGREEMENT FORM.doc7/07
5. FINAL CONSTRUCTION REPORT
The special inspector or inspection agency shall submit a final signed report or Certificate of
Compliance to the City stating that all items requiring special inspection and testing were fulfilled
and reported. And, to the best of his/her knowledge the project is in conformance with the
approved plans and specifications, approved change orders and the applicable workmanship
provisions of the IBC. Items not in conformance, unresolved items or any discrepancies in
inspection coverage (i.e., missed inspections, periodic inspection when continuous inspections were
required, etc.) shall be specifically addressed in this report.
B. Contractor Responsibilities
1. NOTIFY THE SPECIAL INSPECTOR OF ALI, REQUIRED SPECIAL INSPECTIONS
It is the duty of the contractor to notify the special inspector when work is ready for special
inspection. Note, the items listed on the attached Special Inspection Information Form and as
noted on the approved plans and specifications are required to have special inspections. Adequate
notice shall be provided by the contractor so that the special inspector has time to become familiar
with the project. All work requiring special inspection must be approved prior to concealing or
covering said work.
2. PROVIDE ACCESSTO APPROVED PLANS
The contractor is responsible for providing the special inspector access to approved plans at the
jobsitc.
3. RETAIN SPECIAL INSPECTION RECORDS
The contractor is responsible to retain at the jobsite all special inspection records submitted by the
special inspector. These records are to be provided to the City building inspector upon request.
C. City of Edmonds Building Division Responsibilities
1. APPROVE SPECIAL INSPECTION
The Building Division shall approve all Special Inspectors and special inspection requirements.
2. MONITOR SPECIAL. INSPECTIONS AND APPROVE WEEKLY REPORTS
Work requiring special inspection and the performance of special inspectors shall be monitored
by the City Building Inspector. Building Inspector approval must be obtained prior to placement
of concrete or other similar activities in addition to that of the special inspector.
3. ISSUE CERTIFICATE OF OCCUPANCY
The Building Official may issue a Certificate of Occupancy after all weekly special inspection
reports including the final report have been submitted and accepted by the City.
D. Owner Responsibilities
1. The project owner or the engineer or architect of record acting as the owner's agent shall fund
special inspection services.
E. Engineer or Architect of Record Responsibilities
1. Prepare Statement of Special Inspections in accordance with IBC Section 1705.
2. Review the special inspection reports and provide corrective action for work that may not
conform to the approved plans.
WABuildingMANDOU'1' ICODES\FORMS\SPECIAL. INSPECTION AGREEMENT FORM.dec7/07
ACKNOWLEDGEMENTS
I have read and agree to comply with the terms and conditions of this agreement
Owner name C r ^4 C> r^ K q �'�'Qk L-CS
(pleas print or type)
r
Signature _ (�L-(>�U _ w Dated Vt
General Contractor Company/Owner name
(please print or type)
Signature Date
Special Inspector/Agency name
(please print or type)
Signature Date
Architect/Engineer of Record name
(please print or type)
Signature Date
Return the original signed agreement to the Building Division
City of Edmonds Building Division
121 51h Avenue North, City Hall Second Floor
Edmonds, WA 98020
ACCEPTED BY CITY OF EDMONDS BUILDING DIVISION:
City Official Signature Date
Title:
W:\Building\HANDOUT ICODESWORMSWECIAL INSPrCTION AGREEMENT FORM.doc7/07
HWAGEOSCIENCES INC.
deater6niud c- Parrmem Paginrrnng • Ityd... gra6.�r • t ."1i nrnwunruhd • My'., lion li-.tirng
C:T� COPY RECEIVED
July 14, 2008 JUL 21 1008
HWA Project No. 2006-171-21 DEVELOPMENT SERVICE,c
COUNTER
Gray & Osborne, Inc.
701 Dexter Avenue North, Suite 200
Seattle, Washington 98109
Attn: Ms. Tani Stafford, P.E.
Project Manager
LOGICAL HAZARDS ASSESSMENT
76TI1 AVENUE WEST AND 75TH PLACE WEST WALKWAY IMPROVEMENTS
EDMONDS, WASHINGTON
Dear Tani:
This letter is an addendum to the original geotechnical report as requested by the Ifearing
Examiner. In compliance with the City of Edmonds Critical Areas Ordnance ECDC 23.80.060,
Development Standards, we offer the following:
The proposed 76th Avenue West and 75th Place West Walkway Improvements Project,
including the proposed park at 162"d Street has been designed in such a way that it will not
increase surface water discharge or sedimentation to adjacent properties beyond predevelopment
conditions; it will not decrease slope stability on adjacent properties; and it will not adversely
impact other critical areas. The proposed construction will result in increased stability in some
areas, including the stabilization of an existing landslide on the park property, with no impact in
other areas. In our opinion buffers arc not applicable to this project as the work will include
construction of retaining walls and fill placement to increase the stability of steep slopes.
We appreciate the opportunity to provide geotechnical services on this project.
Sincerely,
IIWA GEOSCIENCES INI
Ralph N. Boirum, P.E.
Geotechnical Engineer, Principal
APPROVED BY PLANNING
lAUAi � 0l.24. D g
BL.P. W08. OI8 Z
SMp.-;-o og. 002.10
19730 � 641h Awnuc W,
Suite Z(N)
Lyntimmd, WA 98036.5957
Tel: 425.774.0106
Fax: 425.774.2714
w hwapax=
zn<'. lgyv
ITY OF EDMONDS
21 STH AWNUF NORTH • FDMONDS. WA 08020 • (425) 771 WA) • FAX (425) 771 0221
Websile w a edmondsma us
)EVELOPMENT SERVICES DLPAH I MEN r
Planning • Building • Engineering
October 31, 2008
Brian McIntosh, Director
Edmonds Parks, Recreation & Cultural Services
700 Main Street
Edmonds, WA 98020
RI: Request for waiver per ECDC 19.10.070
16113 75a' Place West, Edmonds
Dear Brian,
GAHY HAAKHNSON
MAYOR
We received your request for waiver to allow an irrigation system for the proposed park
at 16113 75°i Place W. The site is located in the Earth Subsidence landslide I lazard
Area which is regulated under ECDC 19.10. Irrigation systems are specifically
prohibited in the Earth Subsidence Landslide Hazard Area as set forth in ECDC
19.10.070D unless a waiver is first obtained per ECDC 19.10.0701;.
Your request for waiver was sent for peer review by our geotechnical consultant, Landau
Associates, as permitted in ECDC 19.10.070.E. It is their opinion that the information
contained in the request did not demonstrate that the requirements of ECDC 19.10.0701)
were addressed. A copy of their Technical Memorandum dated October 28, 2008 is
attached for your information.
It has not been clearly demonstrated that the irrigation system will have no reasonable
likelihood of triggering or otherwise contributing any landslide hazard or earth
subsidence risk either on the subject site or in the neighboring earth subsidence or
landslide hazard area as set forth in ECDC 19.10.070E. Therefore, it is my determination
that the request for waiver for the proposed irrigation system is denied.
Sincerely,
e
-"
Ann Bullis, C130
Building Official
• Incorporated August 11. 1890
Sister City - Hekinan, Japan
69oD�T-oi$a
LANDAU
14 ASSOCIATES
TECHNICAL MEMORANDUM W J�J MM
TO: Ann Bullis, Building Official
City of Edmonds Building Department
FROM: Dennis R. Stettler, Y.E. I
DATE: October 28, 2009
RE: GEOTECHNICAL REVIEW
162Ne STREET PARK iRRIC:ATION SYSTEM
EDMONDS, WASiIINGTON
INTRODUCTION
��M
RIECEIV ED
pfn 312003
BUILDING
This technical memorandum provides our geotechnical review comments related to the request by
the City of Edmonds Parks, Recreation & Cultural Services Department (City Parks) to waive the
requirements of Edmonds Community Development Code (ECDC) Chapter 19.10.070D.3 related to the
prohibition of irrigation systems as a part of the plans submitted to the City of Edmonds (City) Building
Official for the proposed 162nd Street Park. This geotechnical peer review was accomplished at the
request of the Building Official in accordance with Task Order No. 08-19 of Landau Associates' On -Call
Geotechnical Engineering Services Agreement with the City.
Landau Associates has previously provided review comments for the project to the City in a
technical memorandum dated May 5, 2008 for the original permit application submittal and in a technical
memorandum dated August 13, 2008 for a resubmittal of the permit application documents. In both of
those previous reviews, we pointed out that an irrigation system for the proposed park was shown on the
plans. In accordance with ECDC 19.10.070D.3, irrigation systems are prohibited within the North
Edmonds Earth Subsidence and Landslide Hazard Area (ESLHA). Irrigation systems, as well as other
surface water features with the potential to allow infiltration of storm water into the groundwater, are
prohibited because of the adverse impact of any increase in groundwater levels to overall slope stability
within this hazard area.
According to ECDC 19.10.070E, this prohibition shall apply unless the applicant "requests a
waiver bared upon the written analvsis of a geotechnical engineer which clearly establishes that the
proposed improvement will have no reasonable likelihood of triggering or otherwise contribute to any
landslide hazard or earth subsidence risk either on the site or in the neighboring earth subsidence or
landslide hazard urea." Further. "the burden of proof shall always be upon the applicant to establish by
a clear preponderance of the evidence that no such risk will be created by the intproventent. Any
geotechnical engineering report provided in any review shall consider not only the risk incurred titre to or
during construction of the otherwise prohibited improvement, but also the potential impacts due to failure
130 2nd Avenue South • Edmonds, WA 98020 • (425) 778-0907 • fax (425) 778-6409 • www.landauinc.com
to maintain the improvement, damage through reasonably foreseeable events such as earthquakes or
other acts of God, or the reasonably.firreseeable negligence of the owner or future owners." We have
used the stated criteria above in our review of the request for waiver.
We have received the following additional information forwarded by the City for review:
• Letter to the Edmonds Building Official from Brian McIntosh, Director, Edmonds Parks,
Recreation & Cultural Services, dated October 7, 2008.
• Letter regarding Irrigation of 162"`t ,Street Park, 76d' Avenue West and 7.5ih Place West
Walkway Improvements, Edmonds, Washington prepared by HWA Geosciences, Inc., dated
October 6, 2(X)8.
KF.vIEW COMMENTS
City Parks notes that it plans to use the irrigation system only in the dry season, at the end of the
dry season all irrigation pipes would be shutoff, and an automatic flow control valve would be installed
that could sense abnormal flow beyond what is programmed and shut the irrigation system down
automatically. These are all prudent steps to limit the potential for excessive surface water to be
introduced to the site. The letter from HWA points out that a shallow trench subdrain system will be
included to remove excess water from the site. The HWA letter alludes to the potential for the irrigation
system to leak and considers it likely that the leaking water would remain near the surface and not reduce
slope stability. However, the depth of this trench subdrain system appears to be only several feet deep
and it would probably remove some, but not all excess water that could potentially infiltrate. The HWA
letter also qualities their opinion on the provision that the irrigation system is properly maintained.
The proposed flow control valve and trench subdrain design elements address only the fact that
they may limit the introduction of surface water; however, the proposal of an irrigation system constitutes
an overall increase in the potential for introduction of surface water to groundwater and therefore an
increase of the potential for soil movement. Based on the specific wording of ECDC 19.10.70D, it is our
opinion that the applicant has not demonstrated that "...the Proposed improvement will have no
reasonable likelihood of triggering or otherwise contribute to ally landslide hazard or earth subsidence
risk..." or has not established that "...a clear preponderance of evidence that no such risk will be created
by the improvement. "
We suggest that the planting plan for the 162"I Street Park be reviewed and more
drought -tolerant planting materials be selected that are not dependent on an automatic irrigation system
for survival. We suggest that hand watering be accomplished, as necessary, until the planted materials are
initially established.
1828=\1Pdn tolprnjects�074\15MilenoanNi\782nd81Par Irngatwnnowew-IM.doo
2
LANDAU ASSOCIATES
CLOSURE
This technical memorandum has been prepared for use by the City of Edmonds in evaluating the
request for waiver of the prohibition of an irrigation system for the City's 162"I Street Park. This
geotechnical peer review by Landau Associates does not lessen the requirements for the applicant's
geotechnical consultant and other design professionals to prepare an appropriate design for the site
conditions.
We appreciate this opportunity to be of service to the City. Please contact us if you have any
questions, or if we may be of further service.
URS/rgm
1028108\\Ldm ta\pgert 74\1.0 OuRuam91\1621MStPark-lrtgatmRwn ,TM drc LANDAU ASSOCIATES
3
"'?(- Iti9,,
CITY OF EDMONDS
, ICInill"- e_,9,"o 4. ., _.. .nx tar', I!L );",
i'tft � _,,.1_ `if-4!l'IC k: `i i�EFAlr41 M
Ann Bullis, Building Official
City of Edmonds
121 5"' Avenue forth
Fdmonds, WA 99020
Dear Ms. 13ullis,
GARY RAAKI-NSuN
MAYON
October 7, 2009
Please accept this letter as an official request of waiver in regard to section 19.10.070
113, the Issuance and denial of pennits in the Edmonds City Development Code. This
section deals with the relationship of groundwater to stability within this earth subsidence
and landslide area.
The City of (almonds Parks & Recreation Department proposes to construct a
neighborhood park on land at 16211" Street & 75"' Place West that was acquired by the
City in 1991. The development plans call for a controlled irrigation system to ensure
survival of the planned vegetation and the small grassy area which are very important
comlxments of this park.
It should be noted that irrigation would take place only in the dry season so no water
would be added kt the site when the area is most prone to slides. At tite end of the dry
season all irrigation pipes would be shut off at the meter. In addition, the Parks
Department will install an "automatic flow control valve" that senses abnormal flow
beyond what is programmed and shuts the irrigation system down automatically.
Ralph Boirum of[ IWA Gcosciences is very familiar with this area and the design plans
for this prgject and his assessment is also attached.
Thank you for your consideration of this request and please let me know if have any
questions or need clarification.
Sincerely,
Brian McIntosh, Director
Ninionds Parks, Recreation & Cultural Services
• Naortlorotecl 1 I
sister City - I tekinan. Jr�pvi
v
October 6, 2008
1IWA Project No. 2006- 171-21
City of l-Anonds
Parks & Recreation
700 Maio Street
Edmonds, Washington 98020
Attn: Mr. Rrimi Mcintosh,
Parks & Recreation Director
RE: IRRIGATION OF 162"0 STRFFT PARI(
76"Tu AVENUE WF.4T AND757'H PLACE WEST WALKWAY IAIPROVEMENTS
Frt moNDS, WASHINGTON
Dear Mr. McIntosh:
We understand it systems are prohibited in the Meadowdale wren unless a waivcr is
granted based on the recommendation ofilte neoteehnical engineer. Based on the icsuhs of our
studies of the site, our recommendations lbr design and construction of the proposed park; and
our review ofthe pork's design, it is our recommendation that a waiver be granted allowing
installation ofan irrigation system.
The currcut design of the park includes installation ora trench subdrain systmn to rcmnvn excess
water front the tine as wall its construction of a buttressing fill to increase. Ilse stability of the ,iw
Considering ncc clayey naturc of the native soils at the site, it is likely that most water Icakint,
from the irrigation system would remain near the surface where it would not reduce slope
stability. Water seeping into the soils would be removed by the subdrain system. Ili ovi&og Ih:d
it is properly ntitiutaincrl trod tented off daring the w'el muulhs, it is our opinion that sm irripeaiiuu
systetn can safely be installed and operated on this site without increased risk of instability.
we appreciate tllc opportunity to provide gcotechnical scm ices on this prole t.
Sinccrcly,
I I WA C t:oScRt,\cr:s
19
Ralph N. Boirum, P.E.
Geotechnical Engineer, Principm
Cc: Tani Stafford, Gray & Osborne, Inc.
n..:. ,..l.,.,.,,.. .
:,..,,i. :�,�::, ..
ral
o
I
14rAOOM)AI F
COUNTY PARK
z
0
CITY ` op4,.._} LANDAU
ASSOCIATES
TECHNICAL MEMORANDUM rtw K.a ,Nw try=IKa�
1'O: Ann Bullis. Building Official
City of Edmonds Building Department
FROM: Dennis R. Stettler, P.E.1
DATE: August 13. 2008 �7
Rls: GFOTECIINICAL RESIIEP'1ITTAL REVIEW
162N') STREET PARK
EDMONDS, WASHINCPON
INTRODUCTION
This technical memorandum provides our geotechnical review nI a resubmitial of geotechnical
documents and plans submitted to the City of Edmonds (City) for the proposed development of the City's
162"" Street Park. The purpose of this geotechnical review was to review portions of the resubmittai
Package and assess whether our initial geotechnical peer review comments as contained in our Technical
Memorandum dated May 5, 2008 have been addressed, and to assess compliance with City development
and building permit requirements as contained in Edmonds Conumunity Development Code (ECDC)
Chapter 19.10, FCDC Chapter 23.80, and City of Edmonds Retaining Wall Permit Subtnival
Requiremcuts (as contained in City Handout B62). We were requested to focus our review on Plan
Sheets S-I I and L-I through L-16 (those.. plan sheets specifically pertaining to the proposed 162"" Street
Park) and not those pertaining to the proposed 70" Avenue West/75" Place West walkway improvements
portion of the overall project. This geotechnical peer review was accomplished in accordance with Task
Order No. 09-17 of Landau Associates' On -Call Geotechnical Engineering Services Agreement with the
City.
We have received the following information Forwarded by the City for review as a part of the
resuhulival:
• Construction Document Set plans fur 162" Suer! Purl' (owhuhta Sheets S-11 and 1, 1
through L-16) prepared by SB & Associates, Inc. and (fray & Osbome. Inc. I'ur the C'ily of
Edmonds Parks and Recreation Department, dated May, 2008.
• Revised Geoethnical Report, 70" Avenue West & 7.5'h Place West, N'albray Imprmamnalts,
Ednumds, Washington prepared for Gray & Osborne, Inc. by HWA GeoSciences. Inc.. dated
November 16, 2007 (Revised May 30, 2008).
• Memorrwrhtm Re: 162"" Street Pork Ntn/l, 76"' Avenue WesN75tb Plnee Vilest Walkwar
Improvements, Edmonds, Ntashington, prepared for Gray & Osborne by IIWA GcoScienccs,
Inc., dated April 1, 2008.
130 2nd Avonuo South • Edmonds. WA 98020 • (425) 779-0907 • lax (425) 178-6409 • w .landaumc.com
PLAN REVIEW
We reviewed the revised plans for the park development to assess their consistency with: our
May 5. 2008 review comments: geotechnical recommendations contained in the IIWA Geosciences. Inc.
(IIWA) report: and with the previsions of H('DU 19.10 and FCDC 23.80. The issues That we had
previously identified and their resolutions are outlined below:
The plans show it retaining wall and up In 10 11 of fill placed above existing grades un and
near the base of the slope on the park property. 'Pile park development plan considered in the
original geotechnical report did not address the elect of the proposed retaining wall and fill
on the slope stability. The revised IIWA report uses the results of slope inclinometer
monitoring and slope stability analyses to analyze the existing .slope configuration and the
cliccl of a proposed buttress fill at the toe ol'the slope that has shown recent slope movement.
Pile .stability analyses demonstrate an improvement in slope stability. Although the
configuration of the wall and fill currently planned is somewhat different than the slope
configuration analyzed in the revised geotechnical report, the heneficial ellect of placing till
near the toe ol'Ihe slope should still be beneficial.
• The plaits indicate that the retaining wall planned ou the park property would he supported on
2-11 diameter augercast piles installed to a depth of Ill It. The original submittal provided
limited inlonnelion related to (his design. 'flee revised IIWA report and the IIWA
Memorandum dated April 1, 2008 address the geotechnical recommendations for the wall
support and those recommendations have been incorporated into the plans.
'Pile planned retaining wall as shown on the original plans is composed of a modular block
wall, but the geogrid or geotextile reintorcement of the backlill behind the wall that was
recommended in the original IIWA report was not shown. Die resubmitted plans now show
geogrid reinfbrccmcnt consistent with file I IWA geotechnical report recommendations.
• The original retaining wall details did not show how the drainage pipe behind the wall will be
connected to the site drainage system. 'Phis iniormalion is now shown on the resubmitted
plans.
The original geotechnical report recommends a deep Trench suhdrain (8 to Ill fi deep) near the
lac ul the eastern slope on file park property. The revised geotechnical report recommends a
1 to 5 it deep trench drain. A subdnlin is shown on the plans (Sheet L-d) with a note to sec
the Civil Plans for the invert elevations. 'I lie invert elevation inlimnation was not apparent
on the plan sheets that we were provided for the original submittal and we are not able to find
that information in our current review of the resubmittal. Confirnt then nhc .vlope drain is at
un upp "In-loh' lnc'elion end depth eon.visleni with the geotechnic'el I'c'peli reeommendelions.
euul provide innerl elevations on the plans.
City requirements For retaining wall permits (see City I landunt 1362) and the provisions for
permits as contained in the C'ity's FSLI IA documents outline the requirements fur calling li r
Building Inspections by the City during construction, and Special Inspection Requirements
that call for the Geotechnical Engineer of Record to monitor the construclion to verily the site
conditions and construction and to subntil Picld Reports to the City. the reeliiremenis for
('inBuMlin,i,, hispertinns end Special hespertiens hr the GCoICCllttiCel lu{l;inerr of Record
Should he included on the de.vi,Qn glens.
HIEWR ttW nJaiu"uleu>W741150M1P�R1162nd5tPark RewbriiiNehe TM dw 2 IANDAu AsSOCIA I FS
• Plan sheets L-14 through L-16 relate to irrigation. However, the City has identified that site
improvements that introduce water into the ground within the ESLHA (including watering or
irrigations systems) are prohibited (ECDC 19.10.070.D). The plans should be revised to
reflect this requirement.
GEOTECHNICAL REPORT REVIEW
The original geotechnical report did not reference or address the specific requirements of ECDC
19.10 or ECDC 23.80 related to projects within the North Edmonds ESLHA. We had recommended that
the HWA report be updated to address the landslide hazard discussion and background as required by
ECDC 19.10. The revised geotechnical report is not substantially different than the original report and
does not specifically reference or address the specific requirements of ECDC 19.10 or ECDC 23.80.
The revised HWA report has considered the results of recent slope inclinometer readings and
addressed slope stability at the park by specific analyses of the slope before and after construction, as
requested in our previous review comments.
CLOSURE
This technical memorandum has been prepared for use by the City of Edmonds in evaluating the
adequacy of construction documents resubmitted for the City's 162nd Street Park. The focus of this
review was the geotechnical aspects of the documents. The purpose of the review was to assess the
adequacy of the documents for compliance with City requirements contained in ECDC 19.10, ECDC
23.80, City of Edmonds Retaining Wall Permit Submittal Requirements, and conformance with
conventionally accepted geotechnical engineering practices. This geotechnical peer review by Landau
Associates does not lessen the requirements for the applicant's geotechnical consultant and other design
professionals to prepare an appropriate design for the site conditions.
We appreciate this opportunity to be of service to the City. Please contact us if you have any
questions, or if we may be of further service.
DRS/rgm
W1=6 UEdmdaW*Miec W7441SOWPWt192ndStPar R..vb. .w.TMA. 3 LANDAU ASSOCIATES
Umbaugh,'1'heresa
Front: Bullis. Ann
Sent: 'ILursday, August 14, 2009 7:04 AM
'Lu: I I mbaugh, 'Ihcresa
Subject: PW: 162nd Street Park Geotechnical Review
Ann Bullis, ('I30
Building Official
City of Gduuntds
121 5th Ave N
Vdmnnnis, WA 99020
425-771-0220
----Original Message ----
From: Dennis S(elller Irnailto:I)Sleuler(ullandauinc.cnmI
Sent: Wednesday, August 13. 2008 5:05 PM
To: Bullis, Ann
Subject: 162nd Street Park (icotechuical Review
Ann
Attached is our Icdtmcal memorandum providing our review comments lift the resubmitted plans and revised geotechnical
report lix the 162ud Street Park. Please let us know it you have questions or tl'wc can be ul' further assistance.
I)cnnis
Dennis R. Witter, 1'. E. ' Principal
Landau Associates. Inc.
1.10 2ni1 Ave. S, Edmonds, WA 98020
4.'.5.77ti.0907 fax 425.778.0409
d SICItiCl4hlant1911lnc.con1 www.landaumc.com
/anal is n,cro/ainah!( runununiruliurr.e Inal please ( ons'te/or this hr(nre prin in,g.
Notice: 'Phis anmroumication may enntain privileged of other coniidcntiol mlittmatinn. If you have received n m enor, please advise the
sender by reply einaii and immcLuely delete the message and anv attachments wilhuw copying or disclosing the contents. '['hank vou-
8/21 /2008
14 LANDAU
ASSOCIATES
TECHNICAL MEMORANDUM
TO: Jeannine Graf, Building Official
City of Edmonds Building Department
FROM: Dennis R. Steltler, P.E. C%J
DATE: May 5, 2008
RE: GEOTECIINICAL PEER REVIEW
16211O STREET PARK
EDMONDS, WASHINGTON
INTRODUCTION
a `a
This technical memorandum provides our geotechnical peer review of technical documents and
plans submitted to the City of Edmonds (City) for the proposed development of the C'ity's 162"' Street
Park. The purpose of this geotechnical peer review was to review portions of the submittal package and
assess its compliance with City development and building permit requirements as contained in Edmonds
Community Development Code (ECDC) Chapter 19.10. ECDC Chapter 23.80, and City of Fdmonds
Retaining Wall Permit Submittal Requirements (as contained in City Handout B62). This geotechnical
peer review was accomplished in accordance with Task Order No. 08-07 of Landau Associates' On Call
Geotechnical Engineering Services Agreement with the City.
We have received the following information forwarded by the City for review:
• Construction Document ,Set Plans for 162"'1 Street Park (includes Comer .Sheer, ,Sheets 1. 1
through L-4, S ll, 1.-7. L-8, and L II through L-13 prepared by SB & Associates, Inc. and
Gray & Osborne, Inc. for the City of Edmonds Parks and Recreation Department. dated
February 25, 2008.
• Geotechnical Report, 76`t' Avenue West & 75'" Place West, Walkn•ay Improvements.
E'elmonds, Washington prepared by HWA Geosciences, Inc., dated November 16, 2007.
Development of the park will include grading, construction of retaining walls, and construction of
various park amenities. The project is located within the designated North Edmonds Earth Subsidence
and Landslide Hazard Area (ESLI IA) and is therefore subject to the provisions of ECDC 19.10 related to
the F,SLIIA and ECDC 23.80 related to Geologically hazardous Areas. Portions of the typical permit
application for development within the ESI.IIA (such as vicinity maps, North Edmonds ESLHA Map
with signatures, various owner and design team declarations) that are intended to inform the private
property owners of the risk associated with development do not apply to this project, since the City is the
property owner and is well aware of the risks posed by this landslide hazard area. However, other
130 2nd Avenue South • Edmonds, WA 98020 . (425) 778-0907 • tax (425) 778-6409 • w .Iandauinc.cum
technical requirements of ECDC 19.10 and ECDC 23.80 that address slope stability and hazard reduction
do apply to the proposed project.
PLAN REVIEW
We reviewed the plans for the park development to assess their consistency with the geotechnical
recommendations contained in the HWA Geosciences, Inc. (HWA) report and with the provisions of
ECDC 19.10 and ECDC 23.80. We identified a number of inconsistencies between the plans and the
geotechnical report that should be addressed:
The plans show a retaining wall and up to 10 ft of fill placed above existing grades on and
near the base of the slope on the park property. The park development plan considered in the
geotechnical report (see Figure 6 of the I IWA report) apparently did not consider the effect of
the proposed retaining wall and fill on the slope stability. The HWA report states on page G
"Because placement of fill on the downslope side of the road would add to the weight of a
potential landslide, reducing stability of the slope, we recommend that tilling be avoided to
the extent possible." The geotechnical report nerds to address the appropriateness of the
proposed retaining wall/rill configuration. The cfleet of this proposed grading on overall
slope stability needs to be addressed and it nnt.st be demonstrated that the stability is
improved over misting conditions or the grading needs to be altered.
The plans indicate that the retaining wall planned on the park property would be supported on
2-ft diameter augercast piles installed to a depth of 10 ft. The bottom of these piles would
still be within landslide debris. No geotechnical recommendations are provided specifically
for this wall to assess the appropriateness of this design. The HWA geotechnical report
recommends that elevated walkways and other structures should be supported on pin piles
installed to a depth of 20 to 25 ft (which in this area is thought to be through the existing
landslide debris). The proposed wall support and geotechnical recommendations need to be
consistent.
The planned retaining wall is composed of a modular block wall that extends to heights of up
to G to 7 ft above the final grade according to Plan Sheet S-11. No geogrid or geolexlile
reinforcement of the backfill behind the wall is indicated on the plans. The HWA
geotechnical report states that "Block walls higher than twice the block depth should include
geogrid reinforcing which extends back from the face of the wall a horizontal distance equal
to at least 0.7 times the free-standing wall height." !f the wall rentain.s at its planned height,
geogrid reinforcing needs to be provided or the tvpe of wall changed to be consistent with the
geotechnical mconnnetulations.
Retaining wall details appropriately show drainage material and a drainage pipe behind the
retaining wall. I lowever, it is not clear from the plans that the drainage pipe behind the wall
will be connected to the site drainage system. Provide a connection from the drainage pipe
behind the retaining wall to the site drainage sYstent.
The geotechnical report recommends a deep trench subdrain (8 to 10 ft deep) near the tax: of
the eastern slope on the park property. A slope drain is shown on the plans (Sheet IA) with a
note to see the Civil Plans for the invert elevations. That information was not apparent on the
plan sheets that we were provided for review. The slope drain appears to be located near the
YS9B PCJntla�abrolectsW ld\t lATFAan�w... VM 2ndSlPa� Ppedmfm TM.du
2 LANDAu ASSOCIATES
toe of the new slope instead of the toe of the existing slope. No typical detail for the deep
trench subdrain is provided on the plan sheets that we were provided for review. Confrnn
that the slope drain is at an appropriate location anel depth consistent with the geotechnical
report recommendations, and provide a typical detail consistent with the recommendations of
flee geotechnical report. In addition, consider con,structabilily issues with respect to
excavating an S to 10 ft deep trench near the toe ol'a potenlialhv unstable slope. it nuty he
appropriate to require temporary shoring or specifically limit the horizontal extent of trench
that can be open at any time in archer to reduce the potential for initiating a slope jaihere
(hiring construction.
• City requirements for retaining wall permits (see City handout B62) and the provisions for
permits as contained in the City's ESLIIA documents outline the requirements for calling for
Building Inspections by the City during construction, and Special Inspection Requirements
that call for the Geotechnical Engineer of Record to monitor the construction to verify the site
conditions and construction and to submit Field Reports to the City. 7'he requirements.%r
City Building Inspections and Special Inspections by the Geotechnical Engineer of Record
shroud be included on the design plans.
• The Drawing Index calls out plan sheets L-14 through L-16 related to Irrigation. Thcsc plan
sheets were not provided to us for review. however, the City has identified that site
improvements that introduce water into the ground within the ESLHA (including watering or
irrigations systems) are prohibited. 7'he plans should be revised to reQert this requirement.
GEOTECIINICAL REPOR'r W'vipm
The geotechnical report does not reference or address the specific requirements of ECDC 19.10
or ECDC 23.80. There are a number of requirements for grading and retaining wall permits for projects
within the ESLIIA that arc not addressed by the HWA geotechnical report. The geotechnical report
should be revised or supplemented to address the specific City requirements for geotechnical reports as
curtained in the C'ifv's "Geotechnical Report Guidelines- elornnuart (or projects in flit, North Edmonds
E:SLIIA.
The report references the 1979 Geotechnical Report by Roger Lowe Associates, but does not
reference any of the more recent comprehensive landslide hazard area studies of the area, including the
2007 Landau Associates report as required by BCD(' 19.10. HWA describes the landslide history and
references the Roger Lowe Associates report to conclude that large-scale ground movement occurred
between two and three thousand years ago. The HWA report further states that "No large-scale earth
movements have been recorded for this area in modem times." The implication of the discussion in the
report seems to be that no large-scale movements have occurred in historical times, and that is not
consistent with the available historical information. Significant landslides occurred in this area in 1947
and 19.55-56 that would be considered by most people to be large-scale. We recommend flit, NWA report
be updated to address the, landslide ho and (lisrtussion and background us required by ECDC 19.10.
:d'✓OO grJnWaw\piolaclg\O/ArP✓J\FJgRnnrrtlA`d 62nJ5iPaik PeerHewpw TMr ..
3 LANUAu ASSOCIATES
The HWA report addresses slope stability at the park and the influence of placing fill along the
toe of the slope in only a general way. It does not appear that stability analyses were conducted for either
the existing conditions or the stability after the planned fill and retaining wall is constructed. Placement
of the proposed fill and retaining wall may increase the stability of the slope above (east of) this location,
but since the wall and fill will be placed on about 20 ft of landslide debris, the stability downslope (to the
west) could be adversely affected. Slope stability analyses of the existing and proposed slope
configuration needs to be conducted.
The HWA report also provides the results from monitoring of an inclinometer on the adjacent
property that documents recent slope displacement and notes that another inclinometer was installed in
boring BH-I that was drilled on the park property as a part of this project. The HWA report states that "A
definitive stabilization design will require additional measurements in the two slope indicator casings
over the course of the coming winter to determine the location of the slide plane and performing stability
analyses to develop stabilization measures. That additional analysis is not within the present scope of
work; however, we recommend that this additional analysis be performed and the results incorporated
into the park design." To our knowledge, this work was not done. We recommend that additional
monitoring of the slope inclinometers be conducted and slope stability analyses be conducted to assess
current conditions and the expected slope stability conditions during and following construction of the
proposed park retaining wall, grading, and drainage improvements.
The site of the park and the proposed construction are within a Geologically Hazardous Area as
defined in ECDC 23.80. Consequently, the provisions and requirements of ECDC 23.80 apply to this
project. The geotechnical report for the project addresses some of the ECDC 23.80 requirements, but
limited information is provided for other issues. The geotechnical report should address all of the report
requirements of ECDC 23.80.050, including, but not limited to the extent of the geologic hazards area;
the relationship of the existing and proposed construction to the geologic hazard; a hazards assessment
of the overall slope; the history of the site regarding previous landslides, erosion, or grading; the
stability of the slope before and after the proposed retaining wall construction; a discussion of how the
proposed retaining walls maintains or reduces the pre-existing level of risk presented by the geologic
hazard; and related requirements outlined in ECDC 23.80.050.
CLOSURE
This technical memorandum has been prepared for use by the City of Edmonds in evaluating the
adequacy of construction documents submitted for the City's 162nd Street Park. The focus of this review
was the geotechnical aspects of the documents. The purpose of the review was to assess the adequacy of
the documents for compliance with City requirements contained in ECDC 19.10, ECDC 23.80, City of
&SM8 \EdmdatabrojWsWA150\FiI9RoomWk162nd8tPark_PwrRwWa TM.don
4 LANDAU ASSOCIATES
Edmonds Retaining Wall Permit Submittal Requirements, and conformance with conventionally accepted
geotechnical engineering practices. This geotechnical peer review by Landau Associates does not lessen
the requirements for the applicant's geotechnical consultant and other design professionals to prepare an
appropriate design for the site conditions.
We appreciate this opportunity to be of service to the City. Please contact us if you have any
questions, or if we may be of further service.
DRS/rgm
vsron ,vas,e�„a�.�i«„w�ayso,r�ion�w�„w�szoas�ra�k rae�na��aw_rM.eo�
R
LANDAU ASSOCiATLS
Inspection Comments
BLD20080182 38 - Incomplete/Abandoned Project
f'LUMI I
Applied: 03/05/2008 Issued: 06/23/2009 Expires:
12/23/2009
Address: 16113 75TH PL W. EDMONDS
INSPECTION DATE INSPECTOR
ACTION
1034 - E-Water Service Line 09/02/2010 HAWKINS
CMP
Comment: Ok to backfill water service line connection from main to meter and from meter to drinking fountain.
1053 - B-Retaining Wall Special Inspection
Comment:
1076 - E-Cross Connection Final 09/02/2010 HAWKINS
CMP
Comment: Ok to backfill.
1106 - B-Setbacks
Comment:
1158 - B-Building Final
Comment:
2000 - P-Planning Final 09/24/2008 JANICEK
CMP
Comment: Review to ensure conditions have been met, that landscaping was installed, and general compliance
with SM-2008-26.
12/13/2013 8 17:52 AM Page 1 of 1