Landau Geo Peer Review 2.pdfCITY COPY
LANDAU
TECHNICAL MEMORANDUM.
C, Tt S
TQ: Jeannine Graf,..Buildiug'Official,and'Rob Chavei.Planni-ng Manager
Ci`tY-0f:Eftqnds, Development servicesDepartment
l21 5 Menu& North
Edmonds.l. Washington .9.9020
RECEIVED
FROK; De .19, R. StettlerT. E.
SEP 12 2007
DATE: September 12,.2Q07
8UILDING DEPAfiTMEN'T
C'Ty OF EDMONDS
RE4 GEOTECBMCALPEER REViEw OF RESUBMITTAL
SOUPIN�SIN,GLE FAMILY REsuDENcE
103V76". PiAtEVEST
EDM0NbS,'W,ASFflNGTON
INTROMUCT19N.
This technical provide& the results of.a.geote.d.h.nical peer -review provided. on documents
resubmitted for braiding pe=t for a proposed single family residence at. 1-63:19" P
75lace Wegt:in Edmonds,
:
'Washington. 'The, geotechnical peerrey—Jew was acpqrnplisbed.fior th.a. City Qf Ed . mouds. (-C . ity) iia: accordance.
'wiih. Task. Order:N'o, 07-02 of an On -Call Geotechnical Engineering:: Services Agreement b
.9 etweentandau
Associales and1be
T16project is located within .the City's designated Earth Slibsidence and Landslide Hazard Area and
as such falls under the specific ,
requirements,.of Edmonds,.CoWmunity Developmentfode (ECDC) provisions.
related to development, in: landslide hazard areas as contained in ECDC 10, 10 and ECIC 23..80, Landau
AssociAtes previously provided a. geotechnical peer review of the plans. andproject:doopments and the results.
of:our, review are contained in our March 28,1007: techniptivorabrand umm
Alisv,of the documents that, we were:provided fur alis resubmittal peer review (with aresubmittal date,
o..f,August .1,3.12007.1igattached .t'a,this technical ,'memorandum p:. 06r peer review foduged...on, the geotechnical.
d6cUmerits. Other doicumcntswere -reviewed for consistency with4he. geot0c . hnioal recommendations.
However,, our peer review: did not m"cludea . technical feAewofthe :struc; -4 turaldesign,or . the civil design aspects
of the project,
GEoTEmNWALTEEP, REviEW COMMENTS AM)RESSED
'SpeeittQ.issues ,-.identified inpurgeo -technical peer.Teview memo of March 28, 2007 and the manner in
which. the issues were: addresEied,,arc:highlig4ted.btlbw.
1. Assess the slope stability of the proposed fill on. the west side of the property, and the mitigat iort
and�seque?icii?greqtni"emeiztsof.gCDC-2.3.40.,I.]Oa?7d23'.40.120,
IaOndAvenue :$ouffi.s Edmonds,.WAA862d'-0 (425)778-0907 a fEW025)778-6409 -www.laridadho.com
The grading plans have been revised to address the concern of placing additional fill on the slope
and HWA has addressed the issue in their August 9, 2007 letter responding to the review
comments. Although some fill is still planned in this area, the extent of the fill has been reduced
through the revised grading plans and HWA has analyzed the change in stability associated with
the proposed fill in this area. In our opinion, our review comment has been addressed
satisfactorily.
2. Modem the civil plans to include all details on the rockery construction.
The civil plans have been modified to include the rockery details. However, some clarification is
needed. Drawing C-1 by Harmsen & Associates (revision date 81212007) indicates a "7' max high
cut rockery," and top and bottom elevations of 108.01101.5 are noted for the rockery. Drawing
C-3, Detail 3IC3, of the same plan set shows a 4 ft maximum height rockery associated with a
2HAV slope above and below the wall. The drawings and details should be made consistent. If
the rockery will be greater than 4 ft in height, then the size of the lower rock should be increased.
Drawing C-3, Detail 2/3C shows a 3 man rock at the base of the rockery and the HWA rockery
report of April 23, 2004 shows a 4 man rock at the base of the rockery for a rockery height of 6 ft.
The 4 man rock size at the base of a 6 ft high rockery is consistent with City of Edmonds Rockery
Standards.
3. Evaluate the location of the rockery as compared to City requirements for setback from public
right-of-way and redesign or request formal waiver by the City Engineer.
The rockery location has been revised to satisfy setback requirements.
4. Address the planned hedge/tree removal east of the driveway and resolve the discrepancy between
the civil plans and the land clearing and tree cutting text from HWA.
This comment has been addressed.
5. The plans need to show specifically what is planned east of the driveway rather than presenting an
option. If a rockery is proposed at that location, HWA must confirm that their rockery
recommendations would also apply to the rockery east of the driveway.
This comment has been addressed. The hedge will remain and a short rockery will be constructed
between the driveway and the hedge in accordance with HWA rockery design criteria.
REVISED STEEP SLOPE BUFFER RECOMMENDATION
HWA had originally recommended a 60 -ft steep slope buffer and a 15 -ft building setback. HWA has
recommended reducing the buffer by 10 ft to a 50 -ft steep slope buffer and 15 -ft building setback in their
August 9, 2007 letter. This is apparently necessary to accommodate the current garage location. In our
opinion, the revised steep slope buffer is satisfactory.
USE OF THIS TECHNICAL MEMORANDUM
This technical memorandum has been prepared for use by the City of Edmonds in evaluating the
adequacy of permit application documents related to the proposed Shubin single family residence at 16319 75t`
Place West in Edmonds, Washington. The focus of our review was the geotechnical aspects of the project and
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the purpose of our review was to assess the adequacy of the application documents for compliance with ECDC
19.10 and 23.80 requirements for development within landslide hazard areas and conformance with
conventionally accepted geotechnical engineering practices. The 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 of Edmonds. Please contact us if you have
any questions or if we may be of further service.
DRS:rgm
Attachment: List of Documents
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LIST OF DOCUMENTS
CG Engineering. 2007. Shubin Residence Pin Piling. Oversize Plan Sheets: Sheet S7, Structural Notes; Sheet
SS, Foundation Plan; Sheet S9, Foundation Details; Sheet SIO, Foundation Details. Edmonds, Washington.
Revised May 14.
Harmsen & Associates Inc. 2007a. Shubin Residence, Edmonds, Washington. Oversize Plan Sheets: Cl,
Grading, Drainage, & Utility Plan; C2, TESC Plan; C3, Details & Notes. January 30.
Harmsen & Associates Inc. 2007b. Shubin Residence — 16319 75th Place W — Plan Revisions. Letter to
Kathleen Taylor, City of Edmonds. August 3.
Harmsen & Associates Inc. 2007c. Stormwater Drainage Letter for Shubin Residence, 16319 75°i Place
West.. Letter to Jeanie McConnell, City of Edmonds. July 31.
Harmsen & Associates Inc. 2007d. Shubin Residence —16319 75'h Place W. — Plan Revisions. Letter to Jenny
Readwin, City of Edmonds. August 3.
Harmsen & Associates Inc. 2007e. Prismoidal Volume Results, Shubin Residence 06-107. August 6.
HWA GeoSciences Inc. 2007a. Response to Planning Division Comments, Proposed Development at 16319
7? Place West, Edmonds, Washington.. Prepared for A. Shubin. August 9.
HWA GeoSciences Inc. 2007b. Geotechnical Peer Review Response Memo, Proposed Development at 16319
75i4 Place West, Edmonds, Washington. Prepared for A. Shubin. August 9.
HWA GeoSciences Inc. 2007c. Revised Land Clearing and Tree Cutting Plan, Shubin Property Development
16319 7514 Place West, Edmonds, Washington. Prepared for A. Shubin. Revised August 9.
HWA GeoSciences Inc. 2007d. Geotechnical Memo, Proposed Development at 16319 75t4 Place West,
Edmonds, WA, HWA Job No. 2003-174-21. Prepared for Denny Rockwell. February S.
HWA GeoSciences Inc. 2004a. Geotechnical Report, Rockwell Property Development, 16319 75th Place
West, Edmonds, WA, HWA Job No. 2003-174-21. Prepared for Denny Rockwell, February 25 — Page 5
revised August 13, 2007
NN Engineering. 2007. Shubin, Edmonds, Washington, Oversize Plan Sheets: Sheet S1, General Notes,
Standard Details; Sheet S2, Foundation Details; Sheet S3, Framing Details; Sheet S4, Foundation Main Floor;
Sheet S5, Upper Floor; Sheet S6, Roof Framing. Lakewood, Washington. Revised April 1 S.
Urban Design Group. 2007. Shubin Residence, Edmonds, Washington. Oversize Plan Sheets: Site Plan;
Sheet 1 of 7, Main Floor; Sheet 2 of 7, Upper Floor; Sheet 3 of 7, Front Elevation and Left Elevation; Sheet 4
of 7, Back Elevation and Right Elevation; Sheet 5 of 7, Roof Plan; Sheet 6 of 7, Building Section A -A and
Building Section B -B; Sheet 7 of 7, Miscellaneous Details; Sheet Al of 1, Notes. Tukwila, Washington.
Revised August 6.
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