15-101977CITY OF
Federal Way
March 29, 2017
Mr. Todd D. Wentworth, PE, LG
Amec Foster Wheeler
11810 North Creek Parkway North
Bothell, WA 98011
Todd-w-whvorth rt.arrtecRy.corn
CITY HALL
33325 8th Avenue South
Federal Way, WA 98003-6325
(253) 835-7000
www.cityoffederalway.com
FILE
Jim Ferrell, Mayor
Re: File #15-101977-00-AD; GEOTECHNICAL 3— PARTY REVIEW
JLHC Inc. (Youn Residence), N= SW Dash Point Road, Parcel 112103-9106, Federal Way
Dear Mr. Wentworth:
On March 27, 2017, the applicant resubmitted a revised geotechnical report for the JHLC Inc. single family
residence (city file 15-101479-00-SF). Please advise if additional peer review fees are necessary to continue with
your review of the abovementioned file. If so, the applicant will be contacted for additional fee payments.
If you have any questions regarding this letter, please contact me at 253-835-2644, or leila.willoughby-
oakes r:ccig�offederalway.coin.
Sincerely,
Leila Willoughby -Oakes
Associate Planner
enc: Revised Geotechnical Study (prepared by GeoResources LLC, March 24, 2017)
15-101977-00-AD Doc- 1.D- 75627
C
CITY OF
L Federal Way
December 21, 2017
John P. De Loma
MD Architects/MD Designs
3220 N. 26"' St.
Tacoma, WA 98407
CITY HALL
33325 8th Avenue South
Federal Way, WA 98003-6325
(253) 835-7000
www.cityoffederalway.com
Jim Ferrell, Mayor
Emailed: mdQmdarchitects.net
RE: File #15-101479-000-00-SF; PLANNING LETTER #3
JLHC Inc., 3901 SW Dash Point Rd. (Parcel: 112103 9106), Federal Way
Dear Mr. De Loma:
Planning Division staff have re -reviewed your residential building permit submitted per your November
7, 2017, request at the above -mentioned address for Federal Way Revised Code (FWRC) Title 19
compliance. The proposal includes a new 5,000 sq. ft. residence, which includes a 1,400 sq. ft. garage,
driveway and deck. The proposed living space is 3,000 sq. ft +/-.
Site Conditions
The subject property is designated as an erosion hazard and landslide hazard area. Geologically hazardous
areas and the associated buffer encumber a majority of the site. The proposal includes land surface
modification and tree removal (14 trees) on and within 25 feet of a geologically hazardous area. The area
is located within the 25 ft. critical area buffer.
A Type F 100-ft stream buffer encumbers a portion of the southwest property corner. Staff review
determined the improvements will not impact the stream buffer and as such do not require a third party
review, on the condition that the applicant does seek to re-classify the stream type pursuant to the wetland
report received on October 21, 2016. The city is aware of possible wetland plant communities identified
as hydrophytic in character (i.e. typical of wetland) southeast of the subject property (Habitat
Technologies, 2016, p. 6). This area was identified as a small wetland pocket associated with the stream
corridor and met all three wetland criteria.
Project Chronology
The city sent technical comments on June 10, 2015, April 21, 2015, October 2015 and January 6, 2017.
Planning followed up with the project manager, Alexey Ancheyev, for a status update on November 19,
2015. The city approved building permit extensions requests on December 24, 2015 and August 9, 2016,
as the city did not receive information within 180 days of a request for additional information.
The city received a wetland/stream delineation critical area report on October 21, 2016, and a revised
building plan -set on September 22, 2016, in response to 2015 comments. We received an authorization to
proceed with a geotechnical third party review of the applicant's geotechnical report on June 17, 2016.
The applicant paid peer review funds on October. 25, 2016. AMEC started their review after this date.
Mr. De Loma
December 21, 2017
Page 2 of 4
AMEC issued a review memo on November 9, 2016, sent by the city on November 15, 2016. The
applicant resubmitted a revised geotechnical report in response on March 27, 2017, with associated plans
revisions on August 21, 2017. The owner informed the city of a project manager change in October 2017.
VESTING -CRITICAL AREAS REGULATIONS
The application was deemed complete on March 27, 2015, before the city's critical area ordinance update
in June 2015. The permit will be reviewed under the old regulations, Federal Way Revised Code [FWRC]
19.160 `Geologically Hazardous Areas' and other applicable critical area code sections.
TECHNICAL COMMENTS
A review of the material you submitted indicates the following issues must be addressed prior to planning
division approval. Contact Associate Planner Leila Willoughby -Oakes regarding this letter if you have
questions.
1. Third Party Review Pending: Review by the city's consultant of the revised geotechnical report
received March 27, 2017, prepared by GeoResources, remains outstanding. The Department requires
final sign off by the city's on -call consultant, AMEC Foster Wheeler in writing. The applicant is
responsible for paying for the services of a qualified professional engineer retained by the city to
review the soils report and construction plans (FWRC 19.160.4.b). All review comments contained in
the AMEC technical memo (November 9, 2016) shall be addressed and a $1,000.00 resubmittal fee
remains outstanding to review the revised report (enclosed). The applicant shall revise the report if
AMEC requests further information.
You may pay by phone to the Pen -nit Center at 253-835-2607.
The city contacted the applicant/agent on August 8 and October 26, 2017, via email requesting the
revision fee deposit for AMEC's review. On receipt of these funds, allow 10 business days for
AMEC's review.
During the AMEC's review the residence footprint has shifted away from areas of a > 40% slope.
Please have GeoResources confirm that the revised driveway location and turn -around are acceptable.
The eastern portion of the site meets the definition of the Landslide Hazard Areas, and as such
building permit conditions under Item #1 apply.
Critical Area Conditions
2. Pursuant to FWRC 19.160.4, if the city approves a development activity in a geologically hazardous
area the following other appropriate approval conditions may apply:
a. Record a critical area restrictive covenant on title with King County at the applicant's expense.
Return a copy to the city. Attach the final site plan as an exhibit depicting the approved critical
area and critical area buffers. This is a condition of the final planning inspection and certificate of
occupancy.
b. Please ensure the recorded exhibit includes eastern portion of the site labeled as "Landslide
Hazard Area" per page 6 of the geotechnical report. How much of this area is a `landslide hazard
area'; what are the boundaries?
15-101479-00-SF Doc LD. 76947
Mr- De Loma
December 21, 2017
Page 3 of 4
c. Please label the off -site stream as a "Type F stream". The plan depicts a 100-ft buffer, and the
stream was classified by the city previously as `Major'. The applicant proposes no reclassification
of the existing stream and has chosen to retain the existing classification in order to forgo a
wetland/stream delineation peer review.
d. Place the following note on the critical area site plan recorded on title to restrict vegetation and
tree removal and land surface modification in a geologically hazardous area.
"Native preservation shall be preserved for the purpose of preventing harm to property and
the environment, including but not limited to, controlling surface water runoff and erosion,
maintaining slope stability, buffering and protecting plants, fish and animal habitat.
Removal or disturbance of vegetation and landscaping within the critical area or buffer is
prohibited except as necessary for maintenance or replacements with approval by the City
of Federal Way Community Development Department."
e. The geotechnical engineer shall stamp and sign off on all final construction drawings before
building permit approval. Please ensure all final plans sets are transmitted to GeoResources, LLC.
Figure 2 in the report appears to show a different building footprint/location than plans received
August 21, 2017.
f. A qualified geotechnical professional shall be on site during clearing and grading activities.
Submit special inspection report(s) during construction.
g. The applicant and contractor shall follow all GeoResources LLC report recommendations on
pages 6-13 as required by FWRC 19.160.4.
h. Please schedule a planning inspection to review construction and tree protection fencing
installation.
i. Any work conducted outside of the approved construction limits in geologically hazardous area
and buffers will be subject to a stop work order during construction until stabilized and
remediated. A geotechnical report may be required.
Height Survey
3. A height survey will be required during construction. The height limit in RS zones is 30 feet above
average building elevation. Please see Peter Lawrence's 2°d review letter.
Site Distance
4. Please contact Sarady Long, Senior Transportation Planning Engineer, regarding a `hidden driveway'
sign along SW Dash Pt. Rd.
Other Department Comments
5. Please revise all plans and materials requested per the Building and Public Works Development
Services Divisions, sent October 30 and November 20, 2017. Your permit will remain on hold until
all city comments and city consultant reviews have been satisfied.
15-101479-00-SF
Doc. LD, 76947
Mr. De Loma
December 21, 2017
Page 4 of 4
CLOSING
Please submit four copies of requested full size plans and four copies of requested reports with the
enclosed resubmittal form to the Permit Center, in addition to the pending peer review fee. If you have
any questions regarding this letter, please contact me at 253-835-2644 or Leila.willoughby-
oakes@cityoffederalway.com.
5incereI ,
ila Willoughby -Oakes
Associate Planner
enc: Resubmittal Form
Fee Invoice
FWRC 19.160 `Geologically Hazardous Areas'
FWRC 19.155 `General Site Design Requirements'
Sample Restrictive Covenant
10-26-17 Correspondence to John DeLoma, Architect from L. Willoughby -Oakes, City of Federal Way
8-23-2017 Email to Henry Youn, Owner from L. Willoughby -Oakes, City of Federal Way
c: Brad Biggerstaff, GeoResources LLC, Emailed: bradb(a eoresources.us
Henry Youn, 29204 131h Pl. South, Federal Way, WA 98003, Emailed: henrvvounPusmail.com (w/ encls)
Peter Lawrence, Plans Examiner, via email
Kevin Peterson, Engineering Plans Reviewer
Mike Fyles, Stormwater Inspector
Todd Wentworth, AMEC Foster Wheeler, Emailed: Todd. Wentworth@amecftv.com
15-101479-00-SF Doc. 1D. 76947
CITY OF
Federal Way
January 6, 2017
Mr. Henry Youn
7002 78th Avenue SE
Mercer Island, WA 98040
henryyoun[@gnail.com
CITY HALL
33325 8th Avenue South
Federal Way, WA 98003-6325
(253) 835-7000
www. d1yoffederalway. com
FILE
Jim Ferrell, Mayor
Re: File #15-101479-00-SF, PLANNING DIVISION REVIEW #2
JLHC Inc., *No Site Address* Dash Point Road SW, Federal Way (Parcel 112103-9106)
Dear Mr. Youn:
The city is in receipt of your September 22, 2016, building permit resubmittal. You provided a wetland and
stream critical areas assessment with this resubmittal. The following critical area reports are under third -party
review for the abovementioned project and are not approved. These reviews below are currently in process,
pending action from the applicant.
• "CriticalAreasAssessment, Parcel 1121039106"prepared by Habitat Technologies (April 11, 2012)
• "Geotechnical Engineering Report Proposed Single Family Residence, 3911 SW Dash Point Road,"
prepared by GeoResources LLC (May 1, 2014); and,
■ Response to Comments, Proposed Single Family Residence 3911 SWI Dash Point Road," prepared by
GeoResources LLC Qune 21, 2015). .
A peer review fee of $5,300.00 for the applicant's wetland/stream report and geotechnical report revisions in
response to November 9, 2016, review comments by the city's consultant (AMEC) remains outstanding.
Please note additional city consultant fees may apply to review the revised reports and drawings.
Prior to permit approval; please address the following Planning Division items:
CRITICAL AREAS -STREAMS
1. Sheets C1 and C5 show a 100-foot major stream buffer in the southwest corner of the parcel. However, a
critical areas report prepared by Habitat Technologies (received September 22, 2016), proposes to
reclassify the off -site stream to a Type `Ns' (Non -Fish Seasonal) requiring a 35-foot buffer. They city's
critical area inventory and city's stream inventory (conducted by URS) classify the stream segment which
impacts the subject property as a major stream with a 100-foot protective buffer.
2. The existing major stream 100-foot buffer impacts to the southwest corner are limited (approximately 80
square feet of buffer on -site). The applicant proposes no new structures or improvements there. You
have two options:
16-101479-00-SF
Doc. LD. 74886
Mr. Henry Youn
January 6, 2017
Page 2 of 3
Option #1: If you proceed with requesting the city re-classify the stream from major (fish
bearing) to a Non -Fish SQasonal (Ns), the submitted Habitat Technology report will
continue to be peer reviewed at the applicant's expense by the city's third -party consultant,
Landau (city file #162105115-AD).
Option #2: If you move forward with the proposal and a 100-foot regulated stream buffer,
and do not re-classify the existing stream, the Habitat Technology report received September
22, 2016, would be removed from the project files. Staff will cancel the ongoing third party
review with Landau. The Habitat Technology report proposing a lesser buffer would not be
reviewed, accepted, or approved by the city at this time. The single family building permit
was deemed complete under the critical areas codes prior to the city's critical area ordinance
update in June 2015.
Under Option #2, the final building plan -set must continue to depict a major stream and 100-foot buffer,
protected from all related construction, clearing, and grading activities.
If you proceed with Option #2 please submit a letter cancelling.peer review file #16-105115-AD.
PLAN -SET
3. Sheet C4 — Remove the final plat and City of Renton references. Please see the enclosed redlines
regarding landscaping note removal.
4. Tree Protection — Depict tree protection measures around the tree protected during construction on the site
plan per the "tree protection fence detail" drawing (Sheet C-4). Protection must be installed prior to
construction in order to protect critical root zones (Federal Wray Revised Code [FWRC] 19.120.160[2-3]).
5. The proposal may be subject to a height survey prior to final inspection.
CRITICAL AREAS- GEOLOGICALLY HAZARDOUS AREAS
6. There is an on -going third party review of the geotechnical report by the city's geotechnical consultant,
AMEC Foster Wheeler (city file #15-101977-AD). A written response/report/plan-set revisions
addressing AMEC's November 9, 2016, geotechnical review memo remains outstanding. Please note
additional city consultant fees may apply to review the revised reports and drawings.
7. Per page 3 of the AMEC review memo, additional soil stabilizing plantings/vegetation are required in
disturbed areas. The clearing limit should extend at least 8 to 10 feet from the foundation and stem wall.
These actions will make it necessary to remove additional trees compared to the September 22, 2106, site
plan.
8. Please revise the geotechnical study to depict the same proposal shown on building plans resubmitted
September 22, 2016.
File #15-101479-00-SF Doc. I.D. 74886
Mr. Henry Youn
ranuary 6, 2017
Page 3 of 3
9. Driveavay — Resubmitted plans depict a new 120 square foot parking area off of the driveway. Please confirm
that the new parking area (a land surface modification) was reviewed by the applicant's geotechnical
engineer and evaluated for impacts to the geologically hazardous area (FWRC 19.160.010[2-3]).
CLOSING
Please revise the plans as necessary and provide the additional information requested. When re -submitting,
provide four copies of all new and/or revised documents and a revised geotechnical report addressing
Planning and AMEC's comments. Any additional comments from the Building and Development Services
Divisions, and/or the city consultants, will be sent under separate cover.
Please contact me at 253-835-2644, or leila.wi]lnughby-oaken a@citvaffederalwaF.com, if you have any
questions about this letter.
Sincerely, r
Willoughby -Oakes
Associate Planner
enc: Redlined Site Plan (Sheet C-4) cinl
c: Peter Lawrence, Plans Examiner
Erik Preston, Senior Transportation Engineer
Kevin Peterson, Engineering Plans Examiner
Hagenson Consultants, LLC, 6484 48'h Avenue SW, Seattle, WA 98136; h.hagenson _ cnmU-t.ngt (w/enclosure)
Keith 5chemhs, GeoResources, k i a eoresoure . 1- ( W
File #15-101479-00-SF Doc. J.D. 74886
I., �Nhl Federal Way
Henry Youn
7002 78"' Ave SE
Mercer Island, WA 98040
Emailed: HenWoun@gma]I-coin
CITY HALL
33325 8th Avenue South
Federal Way, WA 98003-6325
(253) 835-7000
www. cityoffederalway.. com
Jim Ferrell, Mayor
November 15, 2016
RE: Permit 915-101977-00-AD (Rel. File: 15-101479-SF); GEOTECHNICAL REVIEW MEMO
JLIIC Inc. Geotechnical Peer Review *No Site Address* SW Dash Pt. Rd., Federal Way
Dear Mr. Youn:
On May 12, 2015, the City of Federal Way initiated a third party review of the Geotechnical Report
(dated May 1, 2014 and received by the City on March 27, 2015) and a subsequent response
memorandum `Response to Comments - Proposed Single Family Residence' (dated June 21, 2015)
prepared by GeoResources, LLC was sent. The subject property, tax parcel 112103 9106, is designated as
a geologically hazardous area.
The city forwarded your request to our geotechnical consultant, Amec Foster Wheeler after receiving peer
review fees, for their review. Amec completed the enclosed technical review memorandum on November
9, 2016. The following occurred between May 12, 2015 and November 9, 2016. The applicant requested
an extension to the building permit application, and the building permit application expired in July 2016
(15-101479-SF), on the grounds that the proponent did not provide additional information within 180
days in response to review comments provided by the Planning and Traffic Divisions on June 10, 2015.
The Public Works Development Services Division forwarded technical review comments on April 10,
2015. At the request of the applicant, the application expiry was reversed under the direction of the
Building Official. The application received a second extension in August 2016.
The memorandum from Amec contains comments on pages 2-4 that require revisions to the geotechnical
engineering report and plan -set and additional site testing. Please have GeoResources, LLC make these
changes and submit three (3) copies of updated documents and respond in writing on how the review
comments are addressed (cover letter) to the City of Federal Way Permit Center with a resubmittal form.
The geotechnical engineer should revise the original geotechnical report — notating the date of the
revisions for city third -party reviewer.
Should you have any questions about this letter, I can be reached at 253-835-2644, or leila.willoughby-
oakes@cityoffederalway.com.
Sincerely, ,
Leila Willoughby -
Associate Planner
enc; Amec Foster Wheeler, Geotechnical Review of Documents (dated November 9, 2016)
Project Resubmittal Form
C. Brad Biggerstaff, GeoResources LLC, 5007 Pacific Hwy E., Suite 16, Fife, WA 98424; Email: RradBf eenresourees.uz (w/encl)
Alexey Anchevev, 879 Rainier Ave. N., Suite A200, Renton, WA 98057, Email: (w/encl)
Hal Hagenson; Email: (t,l_tAgcltygnn_cj oo c: W.ncl (w/encl)
Todd Wentworth, Amec Foster Wheeler; Email: TUdd Wentwo th rtatne6y'com
Kevin Peterson, Engineering Plans Reviewer (w/encl)
Peter Lawrence, Building Plans Examiner
Doc I D 74964
.ti
June 10, 2015
Hal Hagenson
Hagenson Consultants
6484-48Fh Ave SW
Seattle, WA 98126
1
Jim Ferrell, Mayor
Emailed: fi.liag—eiisoii(@comeast.net
RE: PERMIT #15-100374-00-SF; PLANNING DIVISION REVIEW
JLHC Inc. (Youn) Single-Family/Critical Areas Review, *No Address * (112103 9106)
Dear Mr. Hagenson:
On behalf of your client, the Planning Division and Traffic Engineering Division have reviewed your
application for a 1,600 sq. ft. single-family dwelling with designated critical areas (Streams and
Geologically Hazardous Areas) on site, zoned RS 15.0. The comments below reflect applicable
requirements of the Federal Way Revised Code (FWRC) — Title 19 "Zoning and Development Code."
The Department has initiated a required third party review of the submitted Geotechnical Engineering
Report (15-101977-AD) dated May 1, 2014, received by the department on March 27, 2015 and prepared
by GeoResources, LLC. The following corrections and responses must be made prior to Planning
Division sign -off. On April 21, 2015, the Public Works Department- Development Services reviewed and
provided comments on the site plan and civil engineering plans submitted. City comments are subject to
change, if the third party consultant requests project design revisions in order to address geologically
hazardous area and buffer intrusions.
TECHNICAL REVIEW COMPLETION COMMENTS
PLANNING DIVISION
(Leila Willoughby -Oakes, 253-835-2644, leila.will_ou:lib)-oakes(a),cityoffederalway.com)
The Community Development Department has reviewed the plan set, particularly the critical area site plan
(Sheet No. C 1) and tree removal and retention plan (Sheet C4) based on the Federal Way Revised Code
(FWRC) and a staff site visit.
Zoning/General Comments
1. Clarify text and symbols on the site plan and increase text size. You may use additional sheets.
2. Clearly identify the property lines on the site plan drawing for zoning compliance review.
3. Please create a simplified "Sheet C4" dedicated to Critical Areas, in order to clarify critical area
designations, data, and associated buffers.
4. Show all site improvements including stairs and retaining walls, clearing limits, construction/silt fencing
on building permit plans/site plans. The building footprint in the Geotechnical Report and Plan set are not
consistent. Please address.
33325 8th Avenue South, Federal Way, WA 98003-6325 • (253) 835-7000 9 www.cityofederalway.com
Jim Ferrell, Mayor
Emailed: fi.liag—eiisoii(@comeast.net
RE: PERMIT #15-100374-00-SF; PLANNING DIVISION REVIEW
JLHC Inc. (Youn) Single-Family/Critical Areas Review, *No Address * (112103 9106)
Dear Mr. Hagenson:
On behalf of your client, the Planning Division and Traffic Engineering Division have reviewed your
application for a 1,600 sq. ft. single-family dwelling with designated critical areas (Streams and
Geologically Hazardous Areas) on site, zoned RS 15.0. The comments below reflect applicable
requirements of the Federal Way Revised Code (FWRC) — Title 19 "Zoning and Development Code."
The Department has initiated a required third party review of the submitted Geotechnical Engineering
Report (15-101977-AD) dated May 1, 2014, received by the department on March 27, 2015 and prepared
by GeoResources, LLC. The following corrections and responses must be made prior to Planning
Division sign -off. On April 21, 2015, the Public Works Department- Development Services reviewed and
provided comments on the site plan and civil engineering plans submitted. City comments are subject to
change, if the third party consultant requests project design revisions in order to address geologically
hazardous area and buffer intrusions.
TECHNICAL REVIEW COMPLETION COMMENTS
PLANNING DIVISION
(Leila Willoughby -Oakes, 253-835-2644, leila.will_ou:lib)-oakes(a),cityoffederalway.com)
The Community Development Department has reviewed the plan set, particularly the critical area site plan
(Sheet No. C 1) and tree removal and retention plan (Sheet C4) based on the Federal Way Revised Code
(FWRC) and a staff site visit.
Zoning/General Comments
1. Clarify text and symbols on the site plan and increase text size. You may use additional sheets.
2. Clearly identify the property lines on the site plan drawing for zoning compliance review.
3. Please create a simplified "Sheet C4" dedicated to Critical Areas, in order to clarify critical area
designations, data, and associated buffers.
4. Show all site improvements including stairs and retaining walls, clearing limits, construction/silt fencing
on building permit plans/site plans. The building footprint in the Geotechnical Report and Plan set are not
consistent. Please address.
33325 8th Avenue South, Federal Way, WA 98003-6325 • (253) 835-7000 9 www.cityofederalway.com
Mr. Hagenson
June10, 2015
Page 2
5. Building Height —Permitted building height in the RS 15.0 zone is 30 feet above Average Building
Elevation (ABE).' The proposed building elevations meet the city code requirements.
6. Rail Guard — Please un-bold and note on the site plan that the rail guard is existing.
7. Retaining Wall — Please indicate on the site plan any and all proposed retaining walls consistent with
FWRC 19.120.120(1)-(6), accordingly "when incorporating rockeries and retaining walls into site
design, the applicant shall work with the site topography in order to minimize the need for retaining
walls."
Retaining walls associated with a single family building permit and supporting a surcharge are subject
to review under a separate building permit application. Please submit a separate permit for any
retaining walls, and contact the Permit Center at 253.835.2607 for additional information.
Critical Area Review
1. Geologically Hazardous Area —The city's Critical Areas Map identifies the potential location of
geologically hazardous areas on and near the subject property. The submitted Geotechnical
Engineering Report (Page 6) identifies the more steeply sloping eastern portion of the site meets the
technical definition of a Landslide Hazard Area.
On Sheet Cl, the proposed structure encroaches 20 feet at the furthest point into the toe of the
geologically hazardous area (>40%), identified as a Landslide Hazard. Per FWRC 19.160.010, the
following criteria apply to land surface modifications in geologically hazardous areas:
"The director of community development may permit development activities, land surface
modifications or the installation and maintenance of landscaping normally associated with
residential, commercial or park use on or within 25 feet of a geologically hazardous area if no
reasonable alternative exists and only if the develo meni activity or land surface modi rcation ►gill
not lead to or create anv increased slide, seismic or erosion hazard. "
Further, the Federal Way Comprehensive Plan Section 9.3 Geologic Hazardous Areas, Policy NEP55
states the following:
"As slope increases, development intensity, site, coverage and vegetation removal should decrease
and thereby minimize drainage problems, soil erosion, siltation, and landslides. Slopes of 40 percent
or more should be retained in a natural state, free of structures and other land surface
modifications. "
Provide a narrative and explain why there are no reasonable alternative locations existing on site to
locate the building farther away from the landslide hazard area.
Please refer to FWRC 19.120.110 regarding clearing and grading standards for site with slopes of 15
percent or greater. The applicant may choose to refer to FWRC 19.120.110(6) regarding front setback
1 "Average building elevation (ABE) " means the average of the highest and lowest existing or proposed elevations, whichever is
lowest, taken at the base of the exterior walls of the structure, or it means five feet above the lowest of the existing or proposed
elevations, whichever is lowest. ABE is the elevation from which building height is measured.
15-101479 Doc. I.D. 69661
Mr. Hagenson
June10, 2015
Page 3
relief options from 20 feet to 10 feet for single family homes in areas with slopes of 15 percent or
greater, except for garage setbacks. Currently the front yard setback is 30 feet +/-.
2. Tree Removal and Vegetation — Per FWRC 19.160.010, tree clearing on or within designated
critical areas and regulated buffers shall require approval by the Community Development Director.
The applicant proposes the removal of six (6) trees greater than 6 inches in diameter from the eastern
landslide hazard area. Please indicate the area of disturbance for the removal of these trees.
a. Per FWRC 19.160(4) (e) as a condition of approval, plant additional stabilizing vegetation in and
around areas of disturbed slope on the eastern side of the house. Revise Sheet C4 to show
plantings.
3. Clearing and Grading (FWRC 19.120) — Please reference FWRC 19.120 for clearing and grading
plan requirements, include the proposed land disturbance limits, which establish the approved
permitted areas of clearing, grading, cutting and filling. Further, per FWRC 19.I20.160(2). mark the
required tree retention areas on the site plan with areas of no disturbance — 12 inches for every one
inch of tree diameter, for retained trees within clearing limits.
4. Stream Buffer — A major stream is located on the abutting property to the southwest and its 100-ft
required buffer extends onto the subject property. Please make the stream buffer clearer on the new
Sheet C4 "Critical Areas." No future improvements or silt fences (Sheet C2) are to be located in the
buffer, nor can trees/vegetation be removed.
PUBLIC WORKS TRAFFIC DIVISION (Erik Preston, PE, 253-835-2744, erik.PrestonPcityoffederalwvay.com)
Please contact Erik Preston for any questions on site distance requirements or Kevin Peterson regarding
the April 10, 2015, Public Works review letter.
CLOSING
Please respond in writing to each comment and resubmit four copies of requested sheets/reports to the
Permit Center with a covering resubmittal sheet (enclosed). Be advised that these comments are from the,
Planning Division and Public Works Departments only. Additional comments from the Building Division
and a third party geotechnical reviewer will be sent under separate cover. The above -referenced sections
of the Federal Way Revised Code may be accessed online at
littp://www.codel2tiblishing.com/wa/federL[way/.
You may contact me at 253.835.2644 or lei la.wi[louglibv-oakes@cityoffederalway.coin with any
questions regarding this letter.
Sincerely,
lVc 4&
Leila Willoughby -Oakes
Associate Planner
15-101479 Doc, I.D. 69661
Mr. Hagenson
June 10, 2015
Page 4
enc: Bulletin 129 - Resubmittal Information
Site Plan Mark-ups
Scott Sproul, Building Official
Kevin Peterson, Engineering Plans Reviewer
Brian Asbury, Lakehaven Utility District
Chung Youn, 29720 18'h Avenue South, Suite Z-203, Federal Way, WA 98003 (Email: hcainc@ho€mail.com)
Henry Youn, 7002 78's Avenue SE, Mercer Island, WA 98040 (Owner)
Brad Biggerstaff, GeoResources, LLC (Geotechnical Engineer) (Email: Bradbr.-ebeeoresourcesm
Amec Foster Wheeler, Todd Wentworth, Sr., Associate Geotechnical Engineer (Email: todd.went-%vorth(a'�amecfw.com)
15-101479 Doc I D 69661
CITY OF CITY HALL
�� Way
Federal
Way,
, Avenue South
Federal Way, WA 98003-6325
CITY of (253) 835-7000
Federal ` Way www.cityoffederalway..com
Jim Ferrell, Mayor
GEOTECHNICAL ENGINEER AUTHORIZATION FORM
Date: April 30, 2015
City: City of Federal Way
Community Development Department
33325 8th Avenue South, Federal Way, WA 98003
Consultant: William J. Lockard
Amec Foster Wheeler - Environment & Infrastructure
11810 North Creek Parkway North
Bothell, WA 98011
Project: JLHC Inc. (Proposed Youn Residence) — Geotechnical Engineering Report
Property Parcel# 112103 9106 (*No Site Address*)
File No.: 15- 101977-00-AD; Related Project File No. 15-101479-00-SF
Project Consultant Brad Biggerstaff
Contacts: GeoResources, LLC
5007 Pacific Hwy. E., Suite 16
Fife, Washington 98424
B radB (Rlgeoresources. us
Hal Hagneson, P.E.
Hagenson Consultants, LLC
Civil Engineering & Land Development Consultants
6484-48t' Avenue SW, Seattle WA 98126
h. hagensontcomcast. net
Project Applicant: Mr. Chung Youn
28720 18`' Avenue South, Suite Z-203
Federal Way, WA 98003
hcainc(@,hotmail.com
Project Planner: Leila Willoughby -Oakes
leila.willoughby-oakes a)cityoffederalway.com, 253-835-2644
Project Background: On March 27th, 2015 the applicant submitted a building permit and geotechnical report
concluding a single family home appears feasible on the subject property from a
geotechnical engineering standpoint. As various departments undergo compliance
review the City requests a third party review.
The applicant proposes to construct a 1600 sf single family home on a 20,000 sf +/- lot
PFN: 15- 101977-00-AD Document ID: 69184
zoned RS 15.0. The subject property contains designated erosion and landslide hazard
areas. The City of Federal Way Development Services Department has provided
comments on the proposed drainage system requesting revisions.
Please find the city's drainage comments requiring revisions to the proposed drainage
system. Separate plans will be forwarded to Amec for review when the applicant has
submitted new designs to the city.
On a site visit staff noted on the northern slope of the property (east property line) a
stand of trees has been removed.
Documents Provided: s Geotechnical Engineering Report, prepared by GeoResources LLC (May 1, 2014)
■ Plan -set, prepared by Hagneson Consultants LLC (July, 30, 2014)
• Development Services Review Completion Letter — Revision Comments
Task Scope: 1. Review submitted documents for conformance with FWRC 19.160 —
Geologically Hazardous Areas.
2. Provide memorandum identifying additional information requested as
necessary.
3. Conduct site visit as necessary.
4. Meetings on site and/or with applicant's Geotechnical Engineer/ City of
Federal Way staff if necessary.
5. Provide written response as to whether or not Amec concurs with
GeoResources's findings and conclusions.
Task Schedule: Provide task cost estimate by May 5, 2015.
Not to exceed $ without a prior written amendment to this Task
Authorization.
The total task amount completed by city staff after the third party consultant
returns this form. All spaces are to be completed including the total work
estimate, on the grounds that the estimate has been approved by the Project
Planner.
Acceptance:
Consultant
City of Federal Way Staff
Applicant
Date
Date
Date
PFN: 15- 101977-00-AD Document ID: 69184
s1a3� 1j� 3M s
' V
3906
'�. M
N i 00937
Ile
1zT Subject
039OD-1 t ; Property
Major
N9.15 0 c,
i5 DO'"0
�N RS15..63677ff j
1 ['
2103 0037 � 1
1i103 S�C;GO
73190 =i40
y�
i121D39003 11210390371*10390'a �058-,- 05
Figure 1. City of Federal Way Critical Areas Mapping
lagl�gras��s��'�
Dumas�-
�uary Pa.
i
Golf
Course
Figure 2. City of Federal Way Critical Areas Mapping (2016)
Source: http://www.eirvoffederalw4y.conVsitesldgfault/files/mays/sensiti've 2016,13df
File No. 16-xxxxxx-AD Doc. I.D. xxxxx
MGENSON FILE
CONSULTANTS, LLr
6484 — 48" Ave- SW
Seattle, WA 98136
Ph. (206) 938-6168
Fax (206) 938-7645
Email: H.Hagenson@comcast.net
June 23, 2015
City of Federal Way
Attn: Leila Willoughby -Oakes
33325 8th Ave South
Federal Way, WA 98003-6325
Re: Permit # 15-100374-00-SF
Henry Youn Residence (JLHC Inc.)
Dear Ms. Willoughby -Oakes:
We would like to take this opportunity to respond to the Planning Comments dated June 10th
2015 and Public Works comments dated April 21, 2015. Our responses appear in italics as
follows:
PLANNING DIVISION
(Leila Willoughby -Oakes, 253-835-2644, leila.willouclhby-oakes(r ci offederalway.com )
The Community Development Department has reviewed the plan set, particularly the critical area
site plan (Sheet No. Cl) and tree removal and retention plan (Sheet C4) based on the Federal
Way Revised Code (FWRC) and a staff site visit.
Zoning/General Comments
1. Clarify text and symbols on the site plan and increase text size. You may use additional sheets.
Response: Text now meets minimum size requirements and symbols have been updated.
2. Clearly identify the property lines on the site plan drawing for zoning compliance review.
Response: We revised the line types to provide additional clarityfor property lines, ROW lines, steep slope limits and
buffers and stream buffers. We also updated the legend.
3. Please create a simplified "Sheet C4" dedicated to Critical Areas, in order to clarify critical
area designations, data, and associated buffers.
Response: We prepared a new sheet C-5, Critical Areas Plan.
4. Show all site improvements including stairs and retaining walls, clearing limits,
construction/silt fencing on building permit plans/site plans. The building footprint in the
Geotechnical Report and Plan set are not consistent. Please address.
Response: We added stairs, foundation/retaining walls to the site plan sheet C-1. Sheet C-2, ESC plan shows clearing
limits, sill fence and esc details. The 5-14-2014 geotechnical report was based on reliminary site plans. The final site
and grading plans will be transmitted for review by the geotecltnical engineer.
RESUBMITTED
SEP 22 2016
CM OF FEDERAL WAY
■ Page 2 June 23, 2015
5. Building Height — Permitted building height in the RS 15.0 zone is 30 feet above Average
Building Elevation (ABE).' The proposed building elevations meet the city code
requirements.
Response: Acknowledged
6. Rail Guard — Please un-bold and note on the site plan that the rail guard is existing.
Response: We revised the plans as requested.
7. Retaining Wall — Please indicate on the site plan any and all proposed retaining walls
consistent with FWRC 19.120.120(1)-(6), accordingly "when incorporating rockeries and
retaining walls into site design, the applicant shall work with the site topography in order to
minimize the need for retaining walls."
Response: The north easterly wall of the foundation will act as a retaining wall with a 4 ' catchment per the
recommendations of the geotechnical report. This wall will be designed and submitted with the buildingpermit
package. The stairs will either be wooden supported or created with a small retaining wall.
Retaining walls associated with a single family building permit and supporting a surcharge
are subject to review under a separate building permit application. Please submit a separate
permit for any retaining walls, and contact the Permit Center at 253.835.2607 for additional
information.
Response: Acknowledged. Since no retaining walls supporting surcharge are planned, other than the foundation wall,
a separate building permit application for walls appears unnecessary at this point.
Critical Area Review
1. Geologically Hazardous Area —The city's Critical Areas Map identifies the potential
location of geologically hazardous areas on and near the subject property. The submitted
Geotechnical Engineering Report (Page 6) identifies the more steeply sloping eastern portion
of the site meets the technical definition of a Landslide Hazard Area.
On Sheet C 1, the proposed structure encroaches 20 feet at the furthest point into the toe of the
geologically hazardous area (>40%), identified as a Landslide Hazard. Per FVWRC
19.160.010, the following criteria apply to land surface modifications in geologically
hazardous areas:
"The director of community development may permit development activities, land surface
modifications or the installation and maintenance of landscaping normally associated with
residential, commercial or park use on or within 25 feet of a geologically hazardous area if
no reasonable aitemative exists and only if the development activity or land surface
modfcation will not lead to or create any increased slide, seismic or erosion hazard. "
Further, the Federal Way Comprehensive Plan Section 9.3 Geologic Hazardous Areas,
Policy NEP55 states the following:
"As slope increases, development intensity, site, coverage and vegetation removal should
decrease and thereby minimize drainage problems, soil erosion, siltation, and landslides.
Slopes of 40 percent or more should be retained in a natural state, free of structures and
other land surface modifications."
1 "Average building elevation (ABE) " means the average of the highest and lowest existing or proposed elevations,
whichever is lowest, taken at the base of the exterior walls of the structure, or it means five feet above the lowest of the
existing or proposed elevations, whichever is lowest. ABE is the elevation from which building height is measured.
■ Page 3 June 23, 2015
Provide a narrative and explain why there are no reasonable alternative locations existing
on site to locate the building farther away from the landslide hazard area.
Response: The site is impacted by steep slopes and their buffers both to the east of the site and to the west of the site
(offsite). The current building location was selected as having the least impact on steep slopes while meeting the
requirements for site driveway access. The southeast building corner is situated at the edge of the down slope steep
slope 25' setback. The driveway access slopes upward from Dash Point Road at zip to 15% (maximum recommended
driveway grade) and establishes the highest basement garage finish floor elevation achievable. By so doing, we have
minimized the amount of excavation necessary in the steep slope areas.
The driveway Entering sight distance (ESD) at Dash Point Road is sub -standard (see Public Works Comment 93,
other). Therefore, the driveway location is as far east as suitably feasible in order to maximize ESD. This, in turn,
further limits the potential building site.
The geotechnical report acknowledges the building site location in the steep slope and recommends that the building
foundation be constructed with a 4' raised catchment area in order to intercept any local fztture slz ffng from the
hillside.
Please refer to FWRC 19.120.110 regarding clearing and grading standards for site with
slopes of 15 percent or greater. The applicant may choose to refer to FWRC
19.120.110(6) regarding front setback relief options from 20 feet to 10 feet for single
family homes in areas with slopes of 15 percent or greater, except for garage setbacks.
Currently the front yard setback is 30 feet +/-.
Response: A garage is planned for the ground floor such that the front yard setback cannot be reduced beyond 20'.
Meanwhile, the driveway slope access slopes upward from Dash Point Road at up to 15% (maximum recommended
driveway grade) and establishes the highest basement garage finish floor elevation achievable. The longer driveway
and resulting 30' setback are necessary to make up the grade difference between the site and Dash Point Road.
2. Tree Removal and Vegetation — Per FWRC 19.160.010, tree clearing on or within
designated critical areas and regulated buffers shall require approval by the Community
Development Director. The applicant proposes the removal of six (6) trees greater than 6
inches in diameter from the eastern landslide hazard area. Please indicate the area of
disturbance for the removal of these trees.
Response: Clearing limits have been revised to minimize site disturbance. Removed trees are located only within the
clearing limits. Approximately 4,707 sf ofarea lies within the proposed clearing limits. A note has been added to
Sheet C-4 Tree plan accordingly.
a. Per FWRC 19.160(4) (e) as a condition of approval, plant additional stabilizing
vegetation in and around areas of disturbed slope on the eastern side of the house. Revise
Sheet C4 to show plantings.
Response: Laurel plantings have been added to the tree plan with planting notes and additional legend element.
3. Clearing and Grading (FWRC 19.120) — Please reference FWRC 19.120 for clearing and
grading plan requirements, include the proposed land disturbance limits, which establish the
approved permitted areas of clearing, grading, cutting and filling. Further, perFWRC
19.120.160(2). mark the required tree retention areas on the site plan with areas of no
disturbance —12 inches for every one inch of tree diameter, for retained trees within clearing
limits.
Response: All proposed removed trees are located within the clearing and grading limits. Consequently, no perimeter
tree fencing is shown.
4. Stream Buffer — A major stream is located on the abutting property to the southwest and its
100-ft required buffer extends onto the subject property. Please make the stream buffer
clearer on the new Sheet C4 "Critical Areas." No future improvements or silt fences (Sheet
C2) are to be located in the buffer, nor can trees/vegetation be removed.
Response: The .stream buffer has been made darker with distinctive line type. The sill fence and clearing limits have
been moved out of the stream buffer. No trees are proposed to be removed within the .stream buffer.
0 Page 4 June 23, 2015
The Public Works Department has reviewed the civil engineering plans submitted for the
above -referenced permit. Prior to permit approval, please address the following items:
All 'C' Sheets —
1) Label the road name — SW Dash Pt Rd — on the plan sheets.
Response: Dash Point Road has been labeled on all sheets
Sheet C2 —
1 ) The minimum width of the construction entrance shall be 15-feet, although I would
suggest looking into an entrance wider than that, given the constraints of the site and
the need for delivery and contractor vehicles access, parking, and areas needed for
storage of building materials, etc.
Response: We have widened the construction entrance to 1 S' and changed the detail to match. The contractor
may widen the entrance beyond the minimums if he so chooses.
2) Add a detail for the temporary construction entrance.
Response: We have added the temporary construction entrance detail.
3) The plan indicates to `See Detail' for silt fence, but no detail is provided. Please add
the detail.
Response: A silt fence detail is now on the plans.
Sheet C3 —
1 ) The proposed infiltration system lies on a slope that is greater than 15%. Additionally,
there is an area down -slope of this site that has evidence of significant erosion. This
erosion also appears to have impacted the stream that lies downslope of the site.
Because the infiltration and driveway dispersion system lie on or above a slope
greater than 15%, and because of the evidence of the eroded slope, please have the
geo-technical engineer review your storm water system design and provide
comments and/or recommendations, and address potential impacts to the slope,
specific to the proposed storm water driveway dispersion and downspout
infiltration/overflow design. The obvious concern is the discharge of storm water into
the site soils through infiltration, as well as above a slope where there is an indication
of past erosion, which may not only impact the slope and stream below the new
house, but should also be of concern regarding the stability of the soils supporting the
new home.
Response: We will submit the civil plans to the geotechnical engineer for their review andforward their response
to the City. We have tight lined the infiltration system over flow to avoid the slope.
2) If the geo-tech determines the infiltration/dispersion systems are impractical for the
site, please provide an alternative design.
Response: Acknowledged and awaiting Geotech's response.
3) If the geo-tech supports the storm water system design, please provide a detail of the
'drywell' that is specific to the design, and provide the size/type of yard drains/catch
basins, pipe size, etc., so that there is sufficient detail for a contractor to construct the
system accurately.
Response: We have added callouts to the plan view and details as requested.
4) Some of the text on the plan view is quite small. Please increase the size of that text.
Response: We have increased the drainage plan size from I "=20' to 1 "=10', with resulting text size increase.
m Page 5 June 23, 2015
Other —
1) The portion of the driveway approach between the edge of pavement on SW Dash
Point Road and the property line shall be constructed of AC pavement. Please
indicate this on the plans. A City Right of Way Permit will be required for construction
of the approach.
Response: We have added a call out in the driveway on Sheet C-1 Site Plan
2) Per Federal Way Revised Code (FWRC) Section 19.135.030, street improvements
are required in SW Dash Point Road, along the property frontage. However, you may
seek a waiver or modification to the required street improvements by submitting a
written request, as outlined in the attached handout `Right of Way Improvement
Modification Request'.
Response: We have prepared a written request and it .shall be submitted with the package.
3) The Sight Distance Analysis uses the advisory speed limit of 25 MPH; however, the
posted speed limit on SW Dash Point Road at this location is 35 MPH. Please revise
the analysis based on the posted speed limit.
Response: The site is impacted by steep slopes and their buffers both to the east of the site and to the west of the site
(offsite). The current building location was selected as having the least impact on steep slopes while meeting the
requirements for site driveway access. The southeast building corner is situated at the edge of the down slope steep
slope 25' setback. The driveway access slopes upward from Dash Point Road at up to 15% (maximum recommended
driveway grade) and establishes the highest basement garage finish floor elevation achievable. By so doing, we have
minimized the amount of excavation necessary in the steep slope areas.
The driveway Entering sight distance (ESD) at Dash Point Road is sub -standard, but meets requirements for ESD
based on 25 mph advisory speed limit throughout the approach curve to the west. The driveway location is as far east
as suitably feasible in order to maximize ESD. Moving the driveway further east than proposed would 1) fitrther
impact steep slopes and 2) create infeasible curvature geometryfor the driveway.
Given the circumstances, we ask the city for relieffrom this requirement.
Additional Comment: Per 6122115 conversation with Kevin Peterson, we have added a small turnaround at the
driveway to enable to resident to avoid backing out onto SW Dash Point Road. The building will have a 2 car garage
with a 27' wide driveway which, in combination with the turnaround, will provide ample room for maneuvers.
Please revise the plans as necessary, and provide the additional information requested.
When re -submitting, please provide 4 copies of all new and/or revised documents.
Thank you for the opportunity to respond to City comments. Please feel free to contact us
with any questions.
Sincerely,
Hal Hagenson, P.E.
Hagenson Consultants, LLC
15 101+M
RESUBMITTED
SEP- 2 2 2016
AN
CITY OF ,`- 7 CITY OF FEDERAL WAY
Federal Way CDS
GEOTECHNICAL ENGINEER AUTHORIZATION FORM
Date: April 30, 2015
City: City of Federal Way
Community Development Department
33325 8th Avenue South, Federal Way, WA 98003
Consultant: William J. Lockard
Amec Foster Wheeler - Environment & Infrastructure
11810 North Creek Parkway North
Bothell, WA 98011
Project: JLHC Inc. (Proposed Youn Residence) — Geotechnical Engineering Report
Property Parcel# 112103 9106 (*No Site Address*)
File No.: 15- 101977-00-AD; Related Project File No. 15-101479-00-SF
Project Consultant Brad Biggerstaff
Contacts: GeoResources, LLC
5007 Pacific Hwy. E., Suite 16
Fife, Washington 98424
13 radB @P,e ore.5o airces . u s
Hal Hagenson, P.E.
Hagenson Consultants, LLC
Civil Engineering & Land Development Consultants
6484-48 Avenue SW, Seattle WA 98126
h.ha enson(a),eomeast.net
Project Applicant: Mr. Chung Youn
28720 180' Avenue South, Suite Z-203
Federal Way, WA 98003
hcaincAhotmai i.com
Project Planner: Leila Willoughby -Oakes
Leila.wi11ouwh�-oaken tyoffederalwAy om, 253-835-2644
Project Background: On March 27th, 2015 the applicant submitted a building permit and geotechnical report
concluding a single family home appears feasible on the subject property from a
geotechnical engineering standpoint. As various departments undergo compliance
review the City requests a third party review.
The applicant proposes to construct a 1600 sf single family home on a 20,000 sf +/- lot
PFN: 15- 101977-00-AD Document ID: 69184
t-
zoned RS 15.0. The subject property contains designated erosion and landslide hazard
areas. The City of Federal Way Development Services Department has provided
comments on the proposed drainage system requesting revisions.
Please find the city's drainage comments requiring revisions to the proposed drainage
system. Separate plans will be forwarded to Amec for review when the applicant has
submitted new designs to the city.
On a site visit staff noted on the northern slope of the property (east property line) a
stand of trees has been removed.
Documents Provided: • Geotechnical Engineering Report, prepared by GeoResources LLC (May 1, 2014)
• Plan -set, prepared by Hagneson Consultants LLC (July, 30, 2014)
■ Development Services Review Completion Letter — Revision Comments
Task Scope: 1. Review submitted documents for conformance with FWRC 19.160 —
Geologically Hazardous Areas.
2. Provide memorandum identifying additional information requested as
necessary.
3. Conduct site visit as necessary. 'i �
4. Meetings on site and/or with applicant's Geotechni Engineer/ City of
Federal Way staff if necessary. ^v i r Jk--411A
5. Provide written response as to whether or not Amec concurs with
GeoResources's findings and conclusions.
Task Schedule: Provide task cost estimate by May 5, 2015.
Not to exceed $ 366n .. without a prior written amendment to this Task
Authorization.
The total task amount completed by city staff after the third party consultant
returns this form. All spaces are to be completed including the total work
estimate, on the grounds that the estimate has been approved by the Project
Planner.
Acceptance:
Consultant
—
Ity of Federal Way Staff
PFN: 15- 101977-00-AD
L Akv - CYuL%— it /4 fS
WIN"
Date
Date
Document ID: 69184
1k CITY OF
vz�. Federal
Way
Centered on opportunity
Mr. Henry Youn
7002 78th Avenue SE
Mercer Island, WA 98040
F eri , 'aho .co
FILE
Re: File #15-101977-00-AD; GEOTECHNICAL REVIEW #3
Youn/JHLC Inc., SW Dash Point Road, Federal Way (Parcel:112103-9106)
Dear Mr. Youn:
CITY HALL
33325 8th Avenue South
Federal Way, WA 98003-6325
(253) 835-7000
www.cityoffederalway.com
Jim Ferrell, Mayor
September 18, 2019
On August 12, 2019, the City of Federal Way re-engaged our third -party consultant to review a revised
Geotec$nicalEnineering Report for parcel number 112103-9106, prepared by GeoResources, LLC (revised March
2017) at your request after receiving the environmental review deposit.
GEOTECHNICAL REPORT
The city forwarded the revised report to our georechnical consultant, Wood, PLC (formerly Amec), for their
review. Wood completed their review, reviewed relevant documents, and prepared a technical memorandum
(August 21, 2019). The city concurs with Wood's review.
NEXT STEPS
Please review the peer review comments in the enclosed memorandum prepared by Wood.
Any future building plans will be peer reviewed at the applicant's expense in accordance with Federal Way
Reui,red Code (FWRC) 19.145.080(3). The city's consultant shall review the final project plans and other
documents evaluated and documented in the enclosed November 9, 2016, technical memo to the applicant.
Please coordinate directly with anyone else involved with this project, this letter will only be sent to you, the
applicant. If you have questions about this letter, I can be reached at.lei1a.willo hbv-Oakes ci tuff dexalwa r.cvm,
or 253-835-2644.
Sincerely,
Leila Willoughby -Oakes
Associate Planner
enc: August 21, 2019, Memorandum from Wood PLC
November 9, 2016, Memorandum from Wood PLC
15-101977-00-AD
Doi. I.D. 79626
s GeoRe�, .,urces, LLC
Ph. 253-896-1011 5007 Pacific Hwy. E, Suite 16
Fx. 253-896-2633 Fife, Washington 98424
MAR 2 7 2017
C[TY OF: FEDERAL WAY
Mr. Henry Youn COMMUNITY DEVELOPMENT
7002 7811 Ave SE
Mercer Island, WA 98040
(206) 910-2728
May 1, 2014
Revised March 24, 2017
Revised Geotechnical Engineering Report
Proposed Single Family Residence
3911 SW Dash Point Road
Federal Way, Washington
PN: 122103-9106
Job: Youn.3911 Dash Point.RG.rev01
INTRODUCTION
This revised geotechnical report presents the results of our geotechnical site
evaluation, subsurface explorations, laboratory testing, and geotechnical analyses for the
proposed residential development to be constructed at 3911 SW Dash Point Road in the Dash
Point area of Federal Way, Washington. The general location of the site is shown on the
attached Site Vicinity Map, Figure 1. New text is italicized and in bold. Deleted text is
struck through.
Our understanding of the project is based on our discussions with you and members of
the design team. Our report incorporates the data provided in the plans provided by
Hagenson Consultants, the available geologic and soils data, our subsurface explorations,
and our experience in the area. We understand that you propose to construct a new single
family residence on the natural topographic bench area located between two steep slope
areas at the site. The proposed site development will include a typical driveway and the
associated utilities. We anticipate the proposed residences will consist of two-story structure
(daylight) supported on a concrete foundation. We also expect that the north portion of the '
residence will be excavated into the toe of the north steep slope area, and therefore require
special design and construction considerations.
PURPOSE & SCOPE
The purpose of our services was to evaluate the surface and subsurface conditions at
the site as a basis for providing geotechnical recommendations and design criteria for the
proposed residential development. We also assessed potential adverse impacts to and from
the slopes located within the site area. Specifically, our scope of services for the project
included the following:
1. Visiting the site and conducting a geologic reconnaissance to evaluate the site's soil,
groundwater and slope conditions.
2. Exploring the subsurface conditions by excavating test pits at the proposed house
site, and hand excavations in the sloping areas.
3. Developing a slope profile and stability analyses using a computer model.
4. Addressing the appropriate geotechnical regulatory requirements for the proposed
site development.
Youn — SW Dash Pt. Rd
May 1, 2014
Revised March 24, 2017
,Page 2
5. Providing seismic design parameters for the proposed structure.
6. Providing geotechnical recommendations for site grading including site preparation,
subgrade preparation, fill placement criteria, suitability of on -site soils for use as
structural fill, temporary and permanent cut and fill slopes, and drainage and erosion
control measures.
7. Providing recommendations and design criteria for conventional shallow foundations
and floor slab support, including allowable bearing capacity, subgrade modulus,
lateral resistance values and estimates of settlement.
8. Providing recommendations and design criteria for conventional subgrade/retaining
walls, including backfill and drainage requirements, lateral earth pressure loads, and
lateral resistance values.
Our services were originally outlined in our March 24, 2014 Proposal for Geotechnical
Engineering Services. We received signed authorization to proceed with our scope of
services on April 1, 2014.
SITE CONDITIONS
Surface Conditions
The subject parcel is located along the southern side of SW Dash Point Road west of
391h Avenue SW and east of Dumas Bay Park in Federal Way, Washington. The parcel is
roughly triangular in shape, measuring approximately 275 feet north to south by 120 feet east
to west with approximately 240 feet of frontage along SW Dash Point Road. The Parcel
encompasses approximately 0.4 acres. The site is currently undeveloped but is traversed
with a gravel road. The site is bounded by SW Dash Point Road to the north, existing single
family residence to the east and wooded slopes and trails on the south and west. The lower
south slope extends down to a local drainage channel.
The site is situated along the west margin of the Federal Way glacial upland area. The
ground surface in the site area generally slopes down from northeast to southwest. Slope at the
site range from gently sloping in the bench area to 80 percent above and below the proposed
house location. The western portion of the site is flatter, with slopes ranging from about 5 to 20
percent. The slope areas of 20 to 39 percent and steeper than 40 percent are shown on the
Site and Exploration Plan, Figure 2. The total topographic relief across the site is on the order of
40 to 45 feet.
No surface water, seepage or evidence of erosion was observed at the site or the
surrounding area during the time of our visit. Evidence of minor erosion was observed within
the storm water utility easement west of the parcel entering the drainage swale. This erosion
is likely related to recent surface flow during the heavy March rains. No other evidence of soil
erosion or soil movement or deep-seated landslide activity was observed at the site or the
adjacent areas at the time of our site visit. No areas of slope instability were reported in the
published geological literature.
Site Soils
The USDA Natural Resource Conservation Service (NRCS) Web Soil Survey maps
the soils in the area of the site as Alderwood & Kitsap soil (AkF). The Alderwood soils are
derived from glacial till that form on 25 to 70 percent slopes and are listed as having "severe"
to "very severe" erosion hazards when exposed. The Kitsap soils are typically derived from
silty glacial lake sediments and also have a "severe" to "very severe" erosion hazard where
exposed. A copy of the SCS map for the site vicinity is attached as Figure 3.
Youn — SW Dash Pt. Rd
May 1, 2014
Revised March 24, 2017
Page 3
Site Geology
The draft Geologic Map of the Tacoma North 7.5-minute Quadrangle Pierce County,
Washington by Troost, Booth and Borden indicates the site is underlain by advance outwash
sands (Qva). These glacial soils were deposited during the most recent Vashon Stade of the
Fraser Glaciation, approximately 12,000 to 15,000 years ago. The advance outwash soils
typically consist of a poorly sorted, lightly stratified mixture of sand and gravel that may
contain localized deposits of clay and silt that were deposited by meltwater streams
emanating from the advancing ice mass. The advance outwash material was subsequent
over -ridden by the ice mass. As such, the advance outwash is considered over -consolidated
and exhibits high strength and low compressibility characteristics where undisturbed. These
soils have been disturbed through natural weathering processes since that time, and area
therefore in a loose to medium dense condition.
No areas of landslides or landslide debris are mapped on or within the vicinity of the site.
An excerpt of the above referenced map is included as Figure 4.
Subsurface Explorations
On April 1, 2014 GeoResources explored subsurface conditions at the site by
monitoring the excavation of three test pits in the proposed development area, and hand
explorations in the sloping areas of the site. The test pits were excavated by a small track
mounted machine operated by a licensed contractor. Table 1, below, summarizes the
approximate locations, surface elevations, and termination depths of our test pits explorations.
The locations of the test pits were selected by GeoResources personnel in the field
based on discussions regarding the proposed development, along with site access limitations.
A field geologist from our office continuously monitored the excavations, maintained logs of
the subsurface conditions encountered, obtained representative soil samples, and observed
pertinent site features. Representative soil samples obtained from the test pits were placed in
sealed plastic sample bags and taken to a laboratory for further examination and testing as
deemed necessary. Each test pit was then backfilled with the native soil material.
TABLE 1
APPROXIMATE LOCATIONS, ELEVATIONS, AND DEPTHS OF EXPLORATIONS
Test Pit/
Boring
Number
Functional Location
Surface
Elevation'
feet
Termination
Depth
(feet)
Termination
Elevation
feet
TP-1
NW corner of site
91
11
80
TP-2
25' east of SW property corner
99
9
90
TP-3
I Southern Corner of Right -of -Way Extension
106
8
98
Elevation datum: site plan prepared by Core Design using the City of Federal Way NGVD29 datum
The attached Test pit Logs describe the vertical sequence of soils encountered at each
pit location. Where a soil type changed between sample intervals, we estimated the contact
depth based measurement from original surface.
The test pits excavated for this evaluation indicate the subsurface conditions at
specific locations only, as actual subsurface conditions can vary across the site. Furthermore,
the nature and extent of such variation would not become evident until additional explorations
are performed or until construction activities have begun. Based on our experience in the
area and extent of prior explorations in the area, it is our opinion that the soils encountered in
the test pits are generally representative of the soils at the site. The approximate locations of
the test pits are indicated on the attached Site and Exploration Plan as Figure 2. Test pit logs
are presented in Appendix "A".
Youn — SW Dash Pt. Rd
May 1, 2014
Revised March 24, 2017
.Page 4
Subsurface Conditions
Our test pits and hand explorations encountered relatively uniform subsurface conditions
that generally confirmed the mapped stratigraphy. The test pits extended to depths ranging
from 8 to 11 feet below the existing ground surface. The hand explorations ranged from
several feet to about 5 feet in depth in the steeper portions of the site. The stratigraphy across
the site, as observed in our test pits, generally consisted of Y2 to 1 foot of forest duff and sandy
topsoil overlying 2 to 3 feet of loose to medium dense, silty sand with varying minor amounts of
gravel. We interpret these surficial soils to be weathered advance outwash deposits. The
underlying advance outwash sand encountered in the explorations was observed to be in a
medium dense to dense condition. Based on our experience, the Vashon advance outwash
material is underlain by older pre -Fraser glacial till or interglacial deposits at depth. The
glacial outwash was observed in all explorations to the full depth explored. The subsurface
conditions encountered in each test pit are included below in Table 2. Descriptions of the
various soil types encountered across the site are summarized in the following sections.
TABLE 2
APPROXIMATE THICKNESSES, DEPTHS, AND ELEVATIONS OF SOIL LAYERS
ENCOUNTERED IN EXPLORATIONS
Test Pit
Thickness of
Thickness of
Depth to
Elevation of
/Boring
Forest Duff /
Topsoil
Weathered
Advance Sand
Advance Outwash
Advance Outwash
Number
(feet)
(feet)
(feet)
(feet)
TP-1
1
3
4
88
TP-2
'/2
2%
3
96
TP-3
'/2
1'/2
2
104
Elevation datum: site plan prepared by Core Design using the City of Federal Way NGVD29 datum
The soils encountered were visually classified in accordance with the Unified Soil
Classification System (USCS) described in Appendix "A", Figure A-1. The test pit logs are
also included in Appendix "A" as Figure A-2.
Grain Size Analysis
Geotechnical laboratory tests were performed on select samples retrieved from the
test pits to determine soil index and engineering properties encountered. Laboratory testing
included visual soil classification per ASTM D: 2488, moisture content determinations per
ASTM D: 2216, and grain size analyses. Grain size analyses tests were performed in
accordance with the ASTM D: 422 standard procedures. The results of the laboratory tests
are described below in Table 3. The laboratory test results are included in Appendix "B".
TABLE 3
LABORATORY TEST RESULTS
FOR ON -SITE SOILS
Sample
Gravel
Sand
Silt/Clay
D10
Soil Type
Number
Content
Content
Content
Ratio
(percent)
(percent)
(percent)
(mm)
Advance Outwash
TP-3, 8-9
0
95
5
0.18
ND = Not determined
Groundwater Conditions
No groundwater seepage was observed in the test pits at the time of excavation, or on
the sloping areas of the site.
Youn — SW Dash Pt. Rd
May 1, 2014
Revised March 24, 2017
Page 5
GEOLOGIC HAZARDS
The City of Federal Way Critical Areas Ordinance for Geologically Hazardous Areas
(Chapter 19.05.0707G, 19.160, and Chapter 15.10) state "geologically hazardous areas shall
mean areas that, because of their susceptibility to erosion, landsliding, seismic or other
geological events, are not suited to siting commercial, residential or industrial development
consistent with public health or safety concerns". The Revised Code of Federal Way is copied
in italics, while our comments to the code are immediately following the code.
Erosion Hazard Areas per Federal Way Revised Code Chapter 19.05.070.G(1)
The City of Federal Way code defines erosion hazard areas as "those areas having a
"severe" or "very severe" erosion hazard due to natural agents such as wind, rain, splash,
frost action or stream flow."
The USDA NRCS maps the soils on the flatter upland area as the Alderwood soils, the
Alderwood soils typically have "slight" or "moderate to severe" erosion hazards, depending on
slope inclination. The soils along the more steeply sloping southern and western margin of the
site are mapped as the Alderwood-Kitsap formation which have a "servere" erosion hazard.
Based on the mapping, the more steeply sloping portions of the site meet the technical
definition of an Erosion Hazard area per the City code.
Landslide Hazard Areas per Federal Way Revised Code Chapter 19.05.070.G(2)
The Federal Way City Code defines landslide hazard areas as "those areas potentially
subject to episodic downslope movement of a mass of soil or rock including but not limited to
the following areas:
a. Any area with a combination of.•
1. Slopes greater than 15 percent,
2. Permeable sediment overlying a relatively impermeable sediment or
bedrock,
3. Springs or groundwater seeps.
b. Any area which has shown movement during the Holocene epoch, from 10, 000
years ago to the present, or which is underlain by mass wastage debris of that
epoch.
c. Areas potentially unstable as a result of rapid stream incision, stream bank erosion,
and undercutting by wave action.
d. Areas located in a canyon or on an active alluvial fan, presently or potentially
subject to inundation by debris flows or catastrophic flooding.
e. Areas that have a "severe" limitation for building site development because of slope
conditions, according to the USDA SCS.
f. Those areas mapped as Class U (Unstable), Uos (Unstable old slides), and Urs
(unstable recent slides) by the Department of Ecology.
g. Slopes having a gradient steeper than 80 percent subject to rock fall during seismic
shaking"
From the above listed indicators we offer the following comments. The slopes on the
east side of the parcel are steeper than 15 percent and have "severe" limitations for building
site development according to USDA SCS. No evidence of recent or Holocene epoch
movement, published geologic map indicate areas of landslide or mass wasting was noted on
the subject property at the time of our site visit. No area of alluvial fans was noted or was
observed on or within the vicinity of the subject site.
Youn — SW Dash Pt. Rd
May 1, 2014
Revised March 24, 2017
Page 6
Based on our observations and literature review, the more steeply sloping eastern
portion of the site meets the technical definition (15 percent slopes with "severe" limitations) of
the Landslide Hazard Area.
Seismic Hazards per Federal Way Revised Code Chapter 19.05.070.G(3)
The City of Federal Way Municipal Code defines seismic hazard areas as "those areas
subject to severe risk of earthquake damage as a result of seismically induced ground
shaking, slope failure, settlement or soil liquefaction, or surface faulting. These conditions
occur in areas underlain by cohesionless soils of low density usually in association with a
shallow groundwater table."
According the City of Federal Way Municipal Code, the proposed single family
residence will be required to be designed and constructed in accordance with the International
Building Code (IBC) 2012. Characterization of soil profile type is required to determine the
site class definition. Based on the inferred Standard Penetration Test (SPT) values as a result
of our test pit explorations and subsequent laboratory testing, it is our opinion that the project
site could be adequately classified as a Site Class D.
Steep Slope Hazard per Federal Way Revised Code Chapter 19.05.070.G(4)
The Federal Way City Code defines steep slope hazard areas as "those areas with a
slope of 40 percent or greater and with a vertical relief of 10 or more feet, a vertical rise of 10
feet or more for every 25 feet of horizontal distance. A slope is delineated by established its
toe and top and measured by averaging the inclination over at least 10 feet of vertical relief."
As shown on the site and exploration plan, based on the topographic survey prepared
by Core Design, there are several areas on the parcel that meet the criteria of a steep slope
area. L
Buffers/Setbacks per Federal Way RCC 19.05.160'
The Federal Way building code requires a 25-foot setback from geologically hazardous
areas. The proposed lot layout satisfies this requirement and provides lots that have sufficient
building area while maintaining the required 25-foot setback from the determined geologically
hazardous areas. Sections 19.160.010.(2) allows for reduction or modifications of the 25-foot
setback area if "no reasonable alternative exists and only if the development activity or land
surface modifications will not lead to or create any increased slide, seismic, or erosion
hazard." Provided our recommendations are followed and included in the plans, it is
our opinion that the proposed development should improve the stability at the site, not
create an increase in the slide, seismic or erosion hazards.
Where this regulated setback distance from the top of a steep slope cannot be met,
and per Sections 19.160.010.(2), the foundation elements of the structure can be extended
vertically to meet the horizontal setback distance, a "Structural Setback". Where the
foundation is extended vertically, we recommend that the setback be measured horizontally
from the lower outside edge of the foundation element to the face of the slope. This structural
setback is based on the foundation elements being embedded into the dense to very dense
underlying native soils. Once the final locations of the residence is determined and where the
setback criteria cannot be met, we can provide alternative foundation recommendations to
address the setback criteria, if required.
Typically, the options for creating the structural setback from a lower slope area
include over digging or extending the footing depth and constructing a taller stem wall, steel -
reinforced piers, and/or needle piling. Where reinforced piers or needle piling area used, the
footings should be designed as grade beams relative to the design loads of the structure. The
depths of the foundation extensions should be verified by GeoResources prior to placement of
the foundation forms.
Youn — SW Dash Pt. Rd
May 1, 2014
Revised March 24, 2017
Page 7
Where the prescriptive setback cannot be met from the toe of a steep slope,
engineered catchment/retaining walls will be required. Where the cuts into the slope exceed 4
feet, or where there is a steep slope above, temporary shoring may be required.
Slope Stability
We analyzed the global and internal slope stability of the existing and expected slope
geometries using subsurface profile A -A', as located on Figure 2. The Cross Sections are
included in Appendix C.
We used the computer program SLIDE version 6.028, from RocScience 2012, to
perform the slope stability analyses. The computer program SLIDE uses a variety of scientific
methods to calculate the factors of safety (FS) of a given slope configuration by analyzing the
shear and normal forces acting on a series of vertical "slices" that comprise a failure surface.
Each vertical slice is treated as a rigid body; therefore, the forces and/or moments acting on
each slice are assumed to satisfy static equilibrium (i.e., a limit equilibrium analysis). The FS
is defined as the ratio of the forces available to resist movement to the forces of the driving
mass. An FS of 1.0 means that the driving and resisting forces are equal; an FS less than 1.0
indicates that the driving forces are greater than the resisting forces (indicating failure). We
used the Generalized Limit Equilibrium method using the Morgenstern -Price analysis, which
satisfies both moment and force equilibrium, to search for the location of the most critical
failure surfaces and their corresponding FS. The most critical surfaces are those with the
lowest FS for a given loading condition, and are therefore the most likely to move.
Based on our review of the site geology, provided site topography, and
encountered subsurface soil and groundwater conditions based on our subsurface
explorations, we estimated both dry and saturated unit weight, isotropic strength
intercept (cohesion), and isotropic strength angle (phi angle) for the various soil types.
We backcalculated the soil parameters using an assumed horizontal seismic coefficient
of 0.12 to model a Nisqually type of event. In addition, Table 4, below, summarizes
index properties for various native soil types encountered in the Puget Sound based on
a paper titled "Geotechnical Properties of Geologic Materials". by Ko/oski, Schwarz,
and Tubbs and as presented in Volume 1, ENGINEERING GEOLOGY IN WASHINGTON
(Washington Division of Geology and Earth Resources Bulletin 78). We have
interpreted the advance outwash to be in the low to middle portion of the strength
parameters provided below, not at the top.
TABLE 4
PROPERTIES OF ON -SITE SOILS FOR STABILITY ANALYSIS
Dry Unit
Sat. Unit
Friction
Soil Type
Weight
Weight
Cohesion
Angle
(Pco
(pcf)
(PSO
(degrees)
Colluvium
... Variable ... Reflects parent material...
115-130
N/A
0-1,000
30-40
Glacial
Outwash
C Glacial Till
120-140
N/A
1,000-4,000
35-45
We analyzed the cross section for pre and post development conditions. Our revised
analyses used a lower cohesion value in the advance sand and includes an additional
layer modeling the weathered advance sand soil, in response to comments from the
third -party reviewer. However, the silt and fine sand content of the advance sand is
indicative of some cohesion in glacially consolidated soils, as indicated in the table
Youn — SW Dash Pt. Rd
May 1, 2014
Revised March 24, 2017
Page 8
above. The post development condition assumes a daylight basement style structure
modeled using concrete applying a 1,500 psf load. Strength parameters are shown on the
cross sections for each soil type assumed. Based on our analyses the FS for the current
conditions is about 1.36 and 0.90 for static and seismic conditions, respectively, while the
proposed conditions including grading within the 25-foot geo-setback have factors of safety of
1.65 and 1.10, respectively. Based on these results it is our opinion that the proposed site
development will improve the global slope stability, provided the recommendations in this
report and the approved plans and specifications are followed. Details of the revised slope
stability analyses are included in Appendix C.
CONCLUSIONS
Based on our site observations, data review, subsurface explorations and our
engineering analyses, it is our opinion that the proposed residential development is feasible
from a geotechnical standpoint, provided the recommendations included herein are
incorporated into the project plans.
The new residence and other ancillary structures may be supported on conventional
shallow foundations bearing on competent native soils or on structural fill placed above these
native soils. We expect that the rear or north wall of the residence will be constructed as a
retaining wall in the slope area. We recommend that the wall be designed as a deflection wall
in the upper portion with a minimum 4 feet of stickup. Alternatively, an independent retaining
wall may be constructed behind the residence with the recommended stickup, and the house
located a minimum of 8 feet from the retaining wall to allow for access.
The native soils at the site contain a variable percentage of fines (silt and clay -size
particles), which makes them potentially moisture sensitive. These soils may become difficult
to compact as structural fill in wet weather conditions. We therefore recommend that the
earthwork portion of the project be completed during the drier weather conditions.
Stormwater infiltration on the site is feasible in the native sandy outwash soils.
Site Preparation and Grading
All structural areas on the site to be graded should be stripped of vegetation, organic
surface soils, and other deleterious materials including existing structures, foundations or
abandoned utility lines. Clearing should be limited to the area within the geologically
hazardous areas limits identified on the Site and Exploration Plan, Figure 2.
Organic topsoil is not suitable for use as structural fill, but may be used for limited
depths in non-structural areas. Stripping depths ranging from 4 to 12 inches should be
expected to remove these unsuitable soils. Areas of thicker topsoil or organic debris may be
encountered in areas of heavy vegetation or depressions. Where placement of fill material is
required, the stripped/exposed subgrade areas should be compacted to a firm and unyielding
surface prior to placement of fill material. Excavations for debris removal should be backfilled
with structural fill compacted to the densities described in the "Structural Fill" section of this
report.
We recommend that a member of our staff verify the exposed subgrade conditions
after excavations are completed and prior to placement of structural fill or new foundations.
The exposed subgrade soil should be proof -rolled and compacted to a firm and unyielding
condition. We recommend that trees be removed by overturning in fill areas so that a majority
of the roots are removed. Excavations for tree stump removal should be backfilled with
structural fill compacted to the densities described in the "Structural Fill" section of this
report.
Soft, loose or otherwise unsuitable areas delineated during proof -rolling or probing
should be recompacted, if practical, or over -excavated and replaced with structural fill. The
depth and extent of overexcavation should be evaluated by our field representative at the time
Youn — SW Dash Pt. Rd
May 1, 2014
Revised March 24, 2017
Page 9
of construction. The areas of fill should be evaluated during grading operations to determine if
they need mitigation; recompaction or removal.
Structural Fill
All material placed as fill associated with mass grading, as utility trench backfill, under
building areas, or under roadways should be placed as structural fill. The structural fill should
be placed in horizontal lifts of appropriate thickness to allow adequate and uniform
compaction of each lift. Fill should be compacted to at least 95 percent of MDD (maximum
dry density as determined in accordance with ASTM D-1557).
The appropriate lift thickness will depend on the fill characteristics and compaction
equipment used. We recommend that the appropriate lift thickness be evaluated by our field
representative during construction. We recommend that our representative be present during
site grading activities to observe the work and perform field density tests.
The suitability of material for use as structural fill will depend on the gradation and
moisture content of the soil. As the amount of fines (material passing a US No. 200 sieve)
increases, soil becomes increasingly sensitive to small changes in moisture content and
adequate compaction becomes more difficult to achieve. During wet weather, we recommend
use of well -graded sand and gravel with less than 5 percent (by weight) passing the US
No. 200 sieve based on that fraction passing the 3/4-inch sieve, such as Gravel Backfill for
Walls (WSDOT 9-03.12(2)). If prolonged dry weather prevails during the earthwork and
foundation installation phase of construction, higher fines content (up to 10 to 12 percent) may
be acceptable.
Material placed for structural fill should be free of debris, organic matter, trash and
cobbles greater than 6-inches in diameter. The moisture content of the fill material should be
adjusted as necessary for proper compaction.
Suitability of On -Site Materials as Fill
During dry weather construction, non -organic on -site soil may be considered for use as
structural fill; provided it meets the criteria described above in the "Structural Fill" section and
can be compacted as recommended. If the soil material is over -optimum in moisture content
when excavated, it will be necessary to aerate or dry the soil prior to placement as structural
fill. We generally did not observe the site soils to be excessively moist at the time of our
subsurface exploration program.
The areas of native sandy outwash material are comparable to sandy "pit run" and
may be used for use as structural fill during moderate wet weather months, depending on their
fines content. We recommend that completed graded -areas be restricted from traffic or
protected prior to wet weather conditions. The graded areas may be protected by paving,
placing asphalt -treated base, a layer of free -draining material such as pit run sand and gravel
or clean crushed rock material containing less than 5 percent fines, or some combination of
the above.
In the Puget Sound area, wet weather generally begins about mid -October and
continues through about May, although rainy periods could occur at any time of year. If
possible, earthwork should be accomplished during the dry weather months of June through
September. Most of the soil at the site likely contains sufficient fines to produce an unstable
mixture when wet. Such soil is highly susceptible to changes in water content and tends to
become unstable and difficult or impossible to proof -roll and compact if the moisture content
significantly exceeds the optimum. In addition, during wet weather months, the groundwater
levels could increase, resulting in seepage into site excavations. Performing earthwork during
dry weather would reduce these problems and costs associated with rainwater, construction
traffic, and handling of wet soil. We recommend that requirements for wet weather/wet
Youn — SW Dash Pt. Rd
May 1, 2014
Revised March 24, 2017
Page 10
construction for the earthwork portion of the project be incorporated into your contract
specifications.
Temporary Excavations
All job site safety issues and precautions are the responsibility of the contractor
providing services/work. The following cut/fill slope guidelines are provided for planning
purposes only. Temporary cut slopes will likely be necessary during grading operations or
utility installation.
All excavations at the site associated with confined spaces, such as utility trenches
and retaining walls, must be completed in accordance with local, state, or federal
requirements. Based on current Washington Industrial Safety and Health Act (WISHA, WAC
296-155-66401) regulations, the shallow upper weathered soils on the site would be classified
as Type C soils, where as the deeper, sandy, dense soils would be classified as Type B soils.
According to WISHA, for temporary excavations of less than 20 feet in depth, the side
slopes in Type B soils should be laid back at a slope inclination of 1 H:1 V, and Type C soils
should be laid back at a slope inclination of 1.5H:1 V or flatter from the toe to top of the slope.
It should be recognized that slopes of this nature do ravel and require occasional
maintenance. All exposed slope faces should be covered with a durable reinforced plastic
membrane, jute matting, or other erosion control mats during construction to prevent slope
raveling and rutting during periods of precipitation. These guidelines assume that all surface
loads are kept at a minimum distance of at least one half the depth of the cut away from the
top of the slope and that significant seepage is not present on the slope face. Flatter cut
slopes will be necessary where significant raveling or seepage occurs, or if construction
materials will be stockpiled along the top of the slope.
Where it is not feasible to slope the site soils back at these inclinations, a retaining
structure should be considered. Where retaining structures are greater than 4-feet in height
(bottom of footing to top of structure) or have slopes of greater than 15 percent above them,
they should be engineered per Washington Administrative Code (WAC 51-16-080 item 5).
This information is provided solely for the benefit of the owner and other design consultants,
and should not be construed to imply that GeoResources assumes responsibility for job site
safety. It is understood that job site safety is the sole responsibility of the project contractor.
Foundation Support
Based on the subsurface soil conditions encountered across the site, we recommend
that spread footings for the new residences be founded on medium dense to dense native
soils or on appropriately prepared structural fill that extends to suitable native soils.
The soil at the base of the footing excavations should be disturbed as little as possible.
All loose, soft or unsuitable material should be removed or recompacted, as appropriate. A
representative from our firm should observe the foundation excavations to determine if
suitable bearing surfaces have been prepared, particularly in the areas where the foundation
will be situated on fill material.
We recommend a minimum width of 24 inches for isolated footings, at least 12 inches
for single story and 16 inches for two story continuous wall footings. All footing elements
should be embedded at least 18 inches below grade for frost protection. Footings founded as
described above can be designed using an allowable soil bearing capacity of 2,500 psf
(pounds per square foot) for combined dead and long-term live loads. The weight of the
footing and overlying backfill may be neglected. The allowable bearing value may be
increased by one-third for transient loads such as those induced by seismic events or wind
loads.
Lateral loads may be resisted by friction on the base of footings and floor slabs and as
passive pressure on the sides of footings. We recommend that an allowable coefficient of
Youn — SW Dash Pt. Rd
May 1, 2014
` Revised March 24, 2017
Page 11
friction of 0.35 be used to calculate friction between the concrete and the underlying soil.
Passive pressure may be determined using an allowable equivalent fluid density of 300 pcf
(pounds per cubic foot). Passive resistance from soil should be ignored in the upper 1 foot. A
factor of safety of 1.5 has been applied to these values.
We estimate that settlements of footings designed and constructed as recommended
will be less than 1 inch, for the anticipated load conditions, with differential settlements
between comparably loaded footings of 1/2 inch or less. Most of the settlements should occur
essentially as loads are being applied. However, disturbance of the foundation subgrade
during construction could result in larger settlements than predicted. We recommend that all
foundations be provided with footing drains.
Subgrade/Basement Walls
Based on existing topography, the new structure will include a retaining wall either as
a basement wall or a separate retaining walls behind the residence. We recommend that the
retaining wall include a minimum 4 foot stickup for catchment of potential debris from above,
and that the wall be constructed to withstand the impact of that material. If possible, the wall
should be designed to deflect the potential slide material. We can discuss this design concept
with you or your structural engineer.
The lateral pressures acting on subgrade and retaining walls (such as basement walls)
will depend upon the nature and density of the soil behind the wall. It is also dependent upon
the presence or absence of hydrostatic pressure. If the walls are backfilled with granular well -
drained soil, the design active pressure may be taken as 35 pcf (equivalent fluid density).
Where the walls are restrained from moving, we recommend an at -rest equivalent earth
pressure of 55 pcf above groundwater and 90 pcf below groundwater be used for design. We
assume a level backfill condition behind any proposed basement or subgrade wall. For the
condition of a sloping back slope, higher lateral pressures would act on the walls. For a 3 to 1
(Horizontal to Vertical) slope above the wall, the active pressure may be taken as 48 pcf; for a
2 to 1 (H: V) back slope condition, a wall design pressure of 55 pcf may be assumed. The
recommended pressure does not include the effects of surcharges from surface loads.
Adequate drainage behind retaining structures is imperative. Positive drainage which
controls the development of hydrostatic pressure can be accomplished by placing a zone of
coarse sand and gravel behind the walls. A minimum 4-inch diameter perforated or slotted
PVC pipe should be placed in the drainage zone along the base and behind the wall to provide
an outlet for accumulated water and direct accumulated water to an appropriate discharge
location. We recommend that a nonwoven geotextile filter fabric be placed between the
granular drainage material and the remaining wall backfill/native soils to reduce silt migration
into the drainage zone. The infiltration of silt into the drainage zone can, with time, reduce the
permeability of the granular material. The filter fabric should be placed such that it fully
separates the drainage material and the backfill, and should be extended over the top of the
drainage zone. The granular drainage material should contain less than 5 percent fines. The
drainage zone should extend horizontally at least 18 inches from the back of the wall. The
drainage zone should also extend from the base of the wall to within 1 foot of the top of the
wall. The drainage zone should be compacted to approximately 90 percent of the MDD.
Over -compaction should be avoided as this can lead to excessive lateral pressures. Typical
wall drainage and backfilling is shown on Figure 6.
Lateral loads may be resisted by friction on the base of footings and as passive
pressure on the sides of footings and the buried portion of the wall, as described in the
"Foundation Support" section. We recommend that an allowable coefficient of friction of
0.35 be used to calculate friction between the concrete and the underlying soil. Passive
pressure may be determined using an allowable equivalent fluid density of 350 pcf (pounds
per cubic foot). Factors of safety have been applied to these values.
Youn — SW Dash Pt. Rd
May 1, 2014
Revised March 24, 2017
Page 12
Floor Slab Support
Slab -on -grade floors, where constructed, should be supported on the medium dense
native soils or on structural fill prepared as described above. Areas of old fill material should
be evaluated during grading activity for suitability of structural support. Areas of significant
organic debris should be removed.
We recommend that floor slabs be directly underlain by a minimum 4-inch thick pea
gravel or washed 5/8 inch crushed rock. This layer should be placed and compacted to an
unyielding condition and should contain less than 2 percent fines.
A synthetic vapor retarder is recommended to control moisture migration through the
slabs. This is of particular importance where the foundation elements are underlain by the
silty till or lake sediments, or where moisture migration through the slab is an issue, such as
where adhesives are used to anchor carpet or tile to the slab.
A subgrade modulus of 400 kcf (kips per cubic foot) may be used for floor slab design.
We estimate that settlement of the floor slabs designed and constructed as recommended, will
be 1/2 inch or less over a span of 50 feet.
Utilities
We expect that underground utilities, such as sanitary sewer, storm, and water will
consist of a series of pipes, vaults, manholes, and catch basins. The utility excavations
should be performed in accordance with appropriate governmental guidelines. Utility pipes
should be bedded and backfilled in accordance with American Public Works Association
(APWA) specifications.
We anticipate that the on -site, non -organic soils will be suitable for use as structural
backfill. If import soil is used as utility trench backfill, it should consist of a material meeting
the wet weather fill recommendations provided in the "Structural Fill" section of this report.
We recommend that utility backfill soils be compacted according to the recommendations
provided in the "Structural Fill" section of this report.
Controlled -density fill (CDF) is most often suitable for use as backfill in any weather
condition and could be used as a convenient, but more expensive, alternative to granular
backfill soil.CDF backfill does not require compaction but should have a minimum
compressive strength of 250 psi commensurate with the application.
Erosion Control
Weathering, erosion and the resulting surficial sloughing and shallow land sliding are
natural processes that affect steep slope areas. As noted, no evidence of surficial raveling or
sloughing was observed at the site. To manage and reduce the potential for these natural
processes, we recommend the following:
• No drainage of concentrated surface water or significant sheet flow onto or near the
steep slope area.
• No fill should be placed within the buffer or setback zone unless retained by engineered
retaining walls or constructed as an engineered fill.
■ Grading should be limited to providing surface grades that promote surface flows away
from the top of slope to an appropriate discharge location beyond the toe of the slope,
such as into Puget Sound.
Erosion protection measures will need to be in place prior to the start of grading
activity on the site. Erosion hazards can be mitigated by applying Best management Practices
(BMP's) outlined in the Washington State Department of Ecology's (DOE) Stormwater
Management Manual for Western Washington and the City of Federal Way's stormwater
requirements (which uses the 2009 King County Surface Water Design Manual).
Youn — SW Dash Pt. Rd
May 1, 2014
Revised March 24, 2017
Page 13
Site Drainage
All ground surfaces, pavements and sidewalks at the site should be sloped away from
structure to the extent possible. Where the retaining wall includes a stickup, this may not be
possible, and enhanced drainage should be provided. The site should also be carefully graded
to ensure positive drainage away from all structures and property lines. Surface water runoff
from the roof area, driveways, perimeter footing drains, and wall drains, should be collected,
tightlined, and conveyed to an appropriate discharge point. Alternatively, the stormwater runoff
collected at the site can be directed to the stormwater system adjacent to the roadway.
We recommend that footing drains are installed for the residence in accordance with IBC
1807.4.2, and basement walls (if utilized) have a wall drain as describe above, effectively the full
height of the wall. The roof drain should not be connected to the footing drains.
Based on our site evaluation, it is our opinion that the infiltration of stormwater at the
site is feasible. Residential infiltration systems can be designed to infiltrate into the sandy
outwash material encountered. Based on our grain size analysis results, we recommend a
maximum long-term infiltration rate for residential downspout systems of 4 inch/hour.
Infiltration systems should be setback from any downslope areas of greater than 20 percent by a
minimum of 25 feet.
Appropriate design, construction, and maintenance are required to ensure the infiltration
rate can be effectively maintained over time. It should be noted that special care is required
during the grading and construction periods to avoid fine sediment contamination of the
infiltration system. All contractors working on the site (builders and subcontractors) should be
advised to avoid "dirty' stormwater flowing to the site's stormwater system during construction
and landscaping of the residences. No concrete trucks should be washed or cleaned on -site.
Suspended solids could clog the underlying soil and reduce the infiltration rate for the
pond. To reduce potential clogging of the infiltration systems, the infiltration system should not
be connected to the stormwater runoff system until after construction is complete and the site
area is landscaped, paved or otherwise protected. Temporary systems may be utilized through
construction. Periodic sweeping of the paved areas will help extend the life of the infiltration
system.
To manage and reduce the potential for the erosion processes, we recommend that no
drainage of concentrated surface water or significant sheet flow be directed onto or near steep
slope areas. Drainage from the roof area, driveways, perimeter footing drains and wall drains,
should be collected and tightlined to an appropriate discharge point.
Construction Observation c
We recommend that GeoRes s L_ C b�Z�dt ob er�sa#e nical
aspects ❑ cons ruction, particular) shoring (if neceations, retaining walls, fill'
acement an an and drainage ys ems. ese observa Eons i-aft s v veri y
e subsurface conditions as they are exposed during construction and to determine that work
is accomplished in accordance with our recommendations. If conditions encountered during
construction differ from those anticipated, we can provide recommendations for the conditions
actually encountered. Our goal is to provide an appropriate amount of monitoring during
earthwork activities to verify the soil conditions, make changes as appropriate, and provide
you with a economic but adequately designed and constructed project.
LIMITATIONS
We have prepared this report for Mr. Youn and members of the design team for use in
evaluating a portion of this project. The data used in preparing this report and this report
should be provided to prospective contractors. Our report analyses, conclusions and interpreta-
Youn — SW Dash Pt. Rd
May 1, 2014
Revised March 24, 2017
Page 14
tions are based on data from others, our subsurface explorations and limited site
reconna .uance, and should not be construed as a warranty of the subsurface conditions.
Variations in subsurface conditions are possible between the explorations and may also
occur with time. A contingency for unanticipated conditions should be included in the budget
and schedule. Sufficient monitoring, testing and consultation should be provided by our firm
during construction to confirm that the conditions encountered are consistent with those
indicated by the explorations, to provide recommendations for design changes should the
conditions revealed during the work differ from those anticipated, and to evaluate whether
earthwork and foundation installation activities comply with contract plans and specifications.
The scope of our services does not include services related to environmental
evaluations or construction safety precautions. Our recommendations are not intended to direct
the contractor's methods, techniques, sequences or procedures, except as specifically
described in our report.
If there are changes in the loads, grades, locations, configurations or type of facilities to
be constructed, the conclusions and recommendations presented in this report may not be fully
applicable. If such changes are made or site conditions change, we should be given the
opportunity to review our recommendations and provide written modifications or verifications, as
appropriate.
We have appreciated working for you on this project. Please do not hesitate to call at
your earliest convenience if you have questions or comments.
Respectfully submitted,
GeoResources, LLC
Brad P Biggerstaff, LEG
Principal
BPB:DCB/bpblsm
Doc ID: YOun.DashPtRd.RG.rev01
Attachments: Figure 1: Vicinity Map
Figure 2: Site Plan
Figure 3: SCS Soil Survey
Figure 4: USGS Geology Map
Figure 5: Structural Setback & Retaining Wall Stickup
Figure 6: Typical wall drainage and backfilling sketch
Appendix'A" Test Pit Logs
Appendix "B" Laboratory Test Results
Appendix'C" Revised Slope Stability Results
CIO �
50040 4
�0�`�ZCISTF, tti S,
11
Dana C. Biggerstaff, PE
Senior Geotechnical Engineer
\SW
3ZOth St
po 'Cy 11A1f1 u
s�
� Y
L
4
ti
SW i13tA 5[
SW h2th 5t
e
N jv6 St s SWI C-8"\D,$
:1
SW 330th St
0
Federal
Warr
s T.m'� St
lBr�t
am St,
3
5316th
5 314- q St 5 317th 9t
S 3=6 S! Y
M » f
S 330th St
4
Si faae St
5 336* St
Approximate Site Location
(map created from the King County Public GIS http://gismaps.kingcounty.gov/parceiviewer2/)
GeoResources, LLC
5007 Pacific Highway East, Suite 16
Fife, Washington 98424
Phone: 253-896-1011
Fax: 253-896-2633
ite Location Map
3roposed Residence
111 SW Dash Point Rd
feral Way, Washington
Job: Youn.3911SWDashPointRd March 2017
Not to Scale
Site Vicinity
(Map created from King County Public GIS http://www5.kingcounty.gov/iMAP)
GeoResources, LLC
5007 Pacific Highway East, Suite 16
Fife, Washington 98424
Phone: 253-896-1011
Fax: 253-896-2633
Q
Approximate locations, Not to Scale
Site Vicinity Map
Proposed Residence
3911 SW Dash Point Rd
Federal Way, Washington
Job: Youn.3911SWDashPointRd March 2017 _ Figure 2 f
SLOPED TO DRAIN
AWAY FROM STRUCTURE
PAVEMENT OR 18"
IMPERVIOUS SOIL -
WALL BACKFILL
SEE NOTE 2
EXCAVATION SLOPE
CONTRACTOR'S REPSONSIBILITY'
6" MIN ON SIDES OF PIPE;
2" BELOW
1. Washed pea gravel/crushed rock beneath floor slab could be
hydraulically connected to perimeter/subdrain pipe. Use of 1"
diameter weep holes as shown is one applicable method.
Crushed gravel should consist of 3/4" minus. Washed pea
gravel should consist of 3/8" to No. 8 standard sieve.
2. Wall backfill should meet WSDOT Gravel Backfill for walls
Specification 9-03-12(2).
3. Drainage sand and gravel backfill within 18" of wall should be
compacted with hand -operated equipment. Heavy
equipment should not be used for backfill, as such equipment
operated near the wall could increase lateral earth pressures
and possibly damage the wall. The table below presents the
drainage sand and gravel gradation.
4. All wall backfill should be placed in layers not exceeding
4' loose thickness for light equipment and 8" for heavy
equipment and should be densely compacted. Beneath
paved or sidewalk areas, compact to at least 95% Modified
Proctor maximum density (ASTM: 01557-70 Method C). In
landscaping areas, compact to 90% minimum.
5. Drainage sand and gravel may be replaced with a
geocomposite core sheet drain placed against the wall
and connected to the subdrain pipe. The geocamposile
core sheet should have a minimum transmissivity of 3.0
gallons/minutelfoot when tested under a gradient of 1.0
according to ASTM 04716.
GeoResources, LLC
5007 Pacific Highway East, Suite 16
Fife, Washington 98424
Ph: (253) 896-1011 Fax: (253) 896-2633
NOTES
GRADE WALL
DRAINAGE SAND AND GRAVEL
(SEE NOTE 3)
DAMP PROOFING
HOLES (SEE NOTE 1)
SLAB
RETARDER
Z
Co
T
WASHED PEA GRAVEL/CLEAN
CRUSHED GRAVEL
/ SUBDRAIN PIPE
6 The subdrain should consist of 4" diameter (minimum),
slotted or perforated plastic pipe meeting the
requirements of AASHTO M 304; 1/8-inch maximum slot
width; 3/16- to 3/8-inch perforated pipe holes in the
lower half of pipe, with lower third segment unperforated
for water flow; tight joints; sloped at a minimum of
6"/100' to drain; cleanouts to be provided at regular
intervals.
7. Surround subdrain pipe with 8 inches (minimum) of
washed pea gravel (2" below pipe) or 5/8" minus clean
crushed gravel. Washed pea gravel to be graded from
3/8-inch to No.8 standard sieve.
8. See text for floor slab subgrade preparation.
Materials
Sieve Size
% Passing by
Weight
3/4"
100
No 4
25-56
Nos
20-50
No SO
3-12
No 100
0-2
314" ME— C,—h—i (:ravel
Sieve Size
%Passing by
Weight
3/4 "
100
1/2"
1/4"
No 100
�Iasti
b wet sieving)
Wall Drainage and Backfilling Detail
Proposed Residence
3911 SW Dash Point Rd
Federal Way, Washington
Doc ID:
Youn.3911 DashPointRd May, 2014 Figure 6
SETBACK FROM TOE OF SLOPE
Standard Setback
Slope > 30%
& > 10 fto Relief
Setback Distance
Daylight Basement Setback
Slope > 30%
& > 10 ft. Relies
Ge®Resources, LLG
5007 Pacific Highway East, Suite 20
Fife, Washington 98424
Phone: 253-896-1011
Fax: 253-896-2633
Residential Structure
Residential Structure
Figures. Schematic Section
Building Setback
Appendix A
Subsurface Explorations and Logs
Approximate Site Location
An excerpt from the draft Geologic Map of the Tacoma North 7.5-minute Quadrangle Pierce County, Washington
by Troost, K.G., Booth, D.B., and Borden, R.K.
Qva -Advance Outwash
Qvt — Glacial Till
Qvr — Recessional Outwash
Qpf — Pre -Fraser Glacial Deposits
Qpog — Pre -Olympia Glacial Deposits
GeoResources, LLC
5007 Pacific Highway East, Suite 16
Fife, Washington 98424
Phone: 253-896-1011
Fax: 253-896-2633
Not to Scale
USGS Geologic Map
Proposed Residence
3911 SW Dash Point Rd
Federal Way, Washington
Job: Youn.3911SWDashPointRd I March 2017 Figure 4
Approximate Site Location
(map created from the USDA Natural Resource Conservation Service Web Soil Survey)
Soil
Soil Name
Parent Material
Slopes
Erosion Hazard
Hydrologic
Type
Soils Group
AgC
Alderwood gravelly sandy
Glacial Till
6 o 15
Moderate
C
loam
AkF
Alderwood and Kitsap soils,
Glacial Till
25 to 70
Severe
B/C
very steep
InC
Indianola loamy fine sand
Glacial Drift
4 to 15
1 Slight to Moderate
A
RaD
Ragnar fine sandy loam
Glacial Outwash
15 to 25
1 Moderate
A
GeoResources, LLC
5007 Pacific Highway East, Suite 16
Fife, Washington 98424
Phone: 253-896-1011
Fax: 253-896-2633
Not to Scale
MRCS SCS Soils Map
Proposed Residence
3911 SW Dash Point Rd
Federal Way, Washington
Job: Youn.3911SWDashPointRd I March 2017 1 Figure 3
rw N
m
I �
ri
C
F O
C C C m
f L y a Ld
c
LL a m
'a O`
Ca.a,a :
3 m LL i
•, Lyy
' � N
f
{ ! • ;?is zip - . .
i co
kn a rk .. ii.l M. !' V
Clj
y
.� �Cofn�
W
i _ L.�
'j • � � � � +,b� � i' •�arxti t
�LLLL
h d a
r �a �!.• f n In
$
CL
ul
et
ip
c'
I % o
+ / .. J+ • fA
. r
I Ei
r
3� '3Jd '-W 'dMi 'I l -03S V% l 3N
7
Cn
c
0
O
N
C
O
v
o
U
N
U
.�.
�
E
x
O
o
N
0
d
x
y
a
0
y
2
a
m
a.C:L
Q
m
o
a
o
y
a N
'
F-
m m
z° o
SOIL CLASSIFICATION SYSTEM
MAJOR DIVISIONS
GROUP
GROUP NAME
SYMBOL
—
GRAVEL
CLEAN
GW
WELL -GRADED GRAVEL, FINE TO COARSE
GRAVEL
GRAVEL
COARSE
GP
POORLY -GRADED GRAVEL
GRAINED
More than 50%
SOILS
Of Coarse Fraction
GRAVEL
GM
SILTY GRAVEL
Retained on
WITH FINES
No. 4 Sieve
GC
CLAYEY GRAVEL
More than 50%
SAND CLEAN SAND
SW
WELL -GRADED SAND, FINE TO COARSE SAND
Retained on
No. 200 Sieve
SP
POORLY -GRADED SAND
More than 50%
Of Coarse Fraction SAND
SM
SILTY SAND
Passes WITH FINES
No. 4 Sieve
SC
CLAYEY SAND
SILT AND CLAY
INORGANIC
ML
SILT
FINE
GRAINED
CL
CLAY
SOILS
Liquid Limit
Less than 50
ORGANIC
OL
ORGANIC SILT, ORGANIC CLAY
SILT AND CLAY
INORGANIC
MH
SILT OF HIGH PLASTICITY, ELASTIC SILT
More than 50%
Passes
CH
CLAY OF HIGH PLASTICITY, FAT CLAY
No. 200 Sieve
Liquid Limit
50 or more
ORGANIC
OH
ORGANIC CLAY, ORGANIC SILT
HIGHLY ORGANIC SOILS
PT
PEAT
NOTES:
1. Field classification is based on visual examination of soil
in general accordance with ASTM D2488-90.
2. Soil classification using laboratory tests is based on
ASTM D2487-90.
3. Description of soil density or consistency are based on
interpretation of blow count data, visual appearance of
soils, and or test data.
GeoResources, LLC
5007 Pacific Highway East, Suite 16
Fife, Washington 98424
Phone: 253-896-1011
Fax: 253-896-2633
SOIL MOISTURE MODIFIERS:
Dry- Absence of moisture, dry to the touch
Moist- Damp, but no visible water
Wet- Visible free water or saturated, usually soil is
obtained from below water table
Unified Soil Classification System
Proposed Residence
3911 SW Dash Point Rd
Federal Way, Washington
Job: Youn.391 1 SWDashPointRd May 2014 Figure A-1
Test Pit TP- 1
Location: W property extent, 40' S from NW property marker
Approximate Elevation 91 feet
Depth (feet) Soil Type Soil Description
0.0 1.0 - Forrest Duff/Topsoil
1.0 - 4.0 SM Brown with orange mottling silty medium SAND, numerous roots (loose, moist)
4.0 - 11 SM Tan silty medium SAND with trace gravel (medium dense to dense, moist)
Terminated at 11 feet below ground surface.
Moderate caving observed.
No groundwater seepage observed.
Test Pit TP- 2
Location: Southern Property Line, 25' from SW property marker
Approximate Elevation: 99 feet
Depth (feet) Soil Type Soil Description
0.0 - 0.5 - Forrest Duff/Topsoil
0.5 - 3.0 SM Brown grading to light brown silty SAND with gravel lenses, roots (loose, moist)
3.0 - 9.0 SM Tan silty medium SAND with trace gravel (medium dense to dense, moist)
Terminated at 9.0 feet below ground surface.
Moderate caving observed.
No groundwater seepage observed.
Test Pit TP- 3
Location: Southern Corner of Right -of -Way Easement
Approximate Elevation: 106 feet
Depth (feet) Soil Type Soil Description
0.0 - 0.5 - Forrest Duff/Topsoil
0.5 - 3.0 SM Brown grading to light brown silty SAND with gravel, roots (loose, moist)
3.0 - 8.0 SM Tan with brown mottling silty medium SAND with trace gravel (medium dense to dense,
moist)
Terminated at 8.0 feet below ground surface.
Moderate caving observed.
No groundwater seepage observed.
Logged by: STM
GeoResources, LLC
5007 Pacific Highway East, Suite 16
Fife, Washington 98424
Phone: 253-896-1011
Fax: 253-896-2633
Excavated on: April 1, 2014
Test Pit Logs
Proposed Residence
3911 SW Dash Point Rd
Federal Way, Washington
Appendix B
Laboratory Test Procedures and Results
APPENDIX B
LABORATORY TESTING PROCEDURES
The following paragraphs describe our procedures associated with the laboratory
tests that we conducted for this project. Graphical results of certain laboratory tests are
enclosed in this appendix.
Visual Classification Procedures
Visual soil classifications were conducted on all samples in the field and on
selected samples in our laboratory. All soils were classified in general accordance with
the United Soil Classification System, which includes color, relative moisture content,
primary soil type (based on grain size), and any accessory soil types. The resulting soil
classifications are presented on the exploration logs contained in Appendix A.
Moisture Content Determination Procedures
Moisture content determinations were performed on representative samples to
aid in identification and correlation of soil types. All determinations were made in
general accordance with ASTM:D-2216. The results of these tests are shown on the
exploration logs contained in Appendix A.
Grain Size Analysis Procedures
A grain size analysis indicates the range of soil particle diameters included in a
particular sample. Grain size analyses were performed on representative samples in
general accordance with ASTM:D-422. The results of these tests are presented on the
enclosed grain -size distribution graphs and were used in soil classifications shown on
the exploration logs contained in Appendix A.
z6C
LL
Z 5C
LU
U
W 4C
3C
2C
w is
C
Particle Size Distribution Report
o
II
IIY
■ISlIIIII
Ilelll�
n■11■IlIII
II�IIIIY
II■■■III
1110111111101111111011111
lW lu 1 V.1 V.V1 VAJV1
r0
U
c GRAIN SIZE - mm_
n %+3" % Gravel % Sand % Fines
Coarse Fine Coarse Medium Fine Silt Clay
0 0 1 0 0 26 69 5
e�
SIEVE
SIZE
PERCENT SPEC.- PASS?
FINER PERCENT (X=NO)
#10
100
#20
100
#40
74
#60
15
#100
7
#200
5.0
(no specification provided)
Location: TP3
Sample Number: 090817 Depth: 8' - 9'
GeoResources, LLC
Fife, WA
Material Description
Tan Sand
Atterbe[g Limits
PL= LL= Pl=
Coefficients
D90= 0.6590 D85= 0.5766 D60= 0.3755
D50= 0.3428 D30= 0.2857 D15= 0.2452
D10= 0.1830 Cu= 2.05 Cc= 1.19
Classification
USCS= AASHTO=
Remarks
Natural Moisture = 12.03%
Client: Youn
Project: 3911 Dash Point
Tested By: Seth Mattos Checked By: Dana Biggerstaff _
Date: 4/2/2014
Appendix C
Slope Stability Analyses and Results
�i
N
O
u
O +
O Lo O Ln O Ln O Lo O Ln O Ln O N O N O Lo O Ln O un O Lo O
ro0 N LO r- O N N f- O N u7 [- O N LO r- O N LO r- O N LO r- O
4 O O O O rl r-I rl N N N N
-P
(ll
W
O
N
Q
F
2
e
wooer 7.01e
Y ,esidence - 3911 DashPoint Road: Page 1 of 7
Slide Analysis Information
Youn Residence - 3911 DashPoint Road
Project Summary
File Name: Youn.3911SWDashPointRd.SS.A-A'.all.slmd - Group 2 - Proposed Seismic
Slide Modeler Version: 7.018
Project Title: Youn Residence - 3911 DashPoint Road
Analysis: A -A', Seismic -Proposed Conditions
Author: DCB
Company: GeoResources, LLC.
Date Created: 3/24/2017, 3:21:21 PM
General Settings
Units of Measurement:
Imperial Units
Time Units:
days
Permeability Units:
feet/second
Failure Direction:
Left to Right
Data Output:
Standard
Maximum Material Properties:
20
Maximum Support Properties:
20
Analysis Options
Slices Type:
Vertical
Analysis Methods Used
GLE/Morgenstern-Price with interstice force function: Half Sine
Number of slices:
25
Tolerance:
0.005
Maximum number of iterations:
50
Check malpha < 0.2:
Yes
Initial trial value of FS:
1
Steffensen Iteration:
Yes
Groundwater Analysis
Groundwater Method:
Water Surfaces
Pore Fluid Unit Weight [lbs/ft3]:
62.4
Use negative pore pressure cutoff:
Yes
Maximum negative pore pressure [psf]:
0
Advanced Groundwater Method:
None
You n.3911 S W Dash Po i ntRd. SS. A -A'. a l l. s l and
GeoResources, LLC. 3/24/2017, 3:21:21 PM
,
A]CEGREPPFET 7A18
Y �esiclence - 3911 DashPoint Road: Page 2 of 7
Random Numbers
Pseudo -random Seed: 10116
Random Number Generation Method: Park and Millerv.3
Surface Options
Surface Type:
Circular
Search Method:
Slope Search
Number of Surfaces:
10000
Upper Angle:
Not Defined
Lower Angle:
Not Defined
Composite Surfaces:
Enabled
Reverse Curvature:
Create Tension Crack
Minimum Elevation:
Not Defined
Minimum Depth [ft]:
6
Minimum Area:
Not Defined
Minimum Weight:
Not Defined
Seismic
Advanced seismic analysis: No
Staged pseudostatic analysis: No
Loading
Seismic Load Coefficient (Horizontal): 0.25
Material Properties
Property
Advanced sand
Concrete
Structural
Weathered Advance
Color
❑
❑
7
Strength Type
Mohr -Coulomb
Mohr -Coulomb
Mohr -Coulomb
Mohr -Coulomb
Unit Weight [lbs/ft3]
130
145
125
120
Cohesion [psf]
110
10000
0
0
Friction Angle [deg]
36
0
35
34
Water Surface
None
None
None
None
Ru Value
0
0
0
0
Global Minimums
Method: gle/morgenstern-price
Youn.3911SWDashPointRd.SS.A-A'.all.slmd GeoResources, LLC. 3/24/2017, 3:21:21 PM
� SLIDOMFAPREf 7.O1B
!: Y esidence - 3911 DashPoint Road: Page 3 of 7
irljence
FS 1.102570
Center: 17.775, 44.138
Radius: 31.044
Left Slip Surface Endpoint:-9.864, 30.000
Right Slip Surface Endpoint: 16.894, 13.106
Resisting Moment: 529261 lb-ft
Driving Moment: 480024 Ib-ft
Resisting Horizontal Force:
14967.8 lb
Driving Horizontal Force:
13575.4 lb
Total Slice Area:
184.451 ft2
Surface Horizontal Width:
26.7578 ft
Surface Average Height:
6.89337 ft
Valid /Invalid Surfaces
Method: gle/morgenstern-price
Number of Valid Surfaces: 9820
Number of Invalid Surfaces: 180
Error Codes:
Error Code -103 reported for 1 surface
Error Code -106 reported for 1 surface
Error Code -108 reported for 149 surfaces
Error Code -109 reported for 1 surface
Error Code -111 reported for 13 surfaces
Error Code -115 reported for 15 surfaces
Error Codes
The following errors were encountered during the computation:
-103 =Two surface / slope intersections, but one or more surface / nonslope external polygon intersections lie between them. This
usually occurs when the slip surface extends past the bottom of the soil region, but may also occur on a benched slope model with
two sets of Slope Limits.
-106 = Average slice width is less than 0.0001 * (maximum horizontal extent of soil region). This limitation is imposed to avoid
numerical errors which may result from too many slices, or too small a slip region.
-108 =Total driving moment ortotal driving force < 0.1. This is to limit the calculation of extremely high safety factors if the driving
force is very small (0.1 is an arbitrary number).
-109 = Soiltype for slice base not located. This error should occur very rarely, if at all. It may occur if a very low number of slices is
combined with certain soil geometries, such that the midpoint of a slice base is actually outside the soil region,even though the slip
surface is wholly within the soil region.
-111= safety factor equation did not converge
-115 = Surface too shallow, below the minimum depth.
Slice Data
Global Minimum Query (gle/morgenstern-price) - Safety Factor: 1.10257
Youn.3911SWDashPointRd.SS.A-A'.all.slmd GeoResources, LLC. 3/24/2017, 3:21:21 PM
r
woQrrrEnaaEr7,01e
j �i►:
Yk
esidence - 3911 DashPoint Road: Page 4 of 7
Angle
Base
Base
Effective
Base
Shear
Shear
Pore
Slice
Width
Weight
of Slice
Base
Friction
Normal
Normal
Cohesion
Stress
Strength
Pressure
Number
[ft]
[lbs]
Base
Material
Angle
Stress
Stress
[psf]
[psf]
[psfl
[psfl
[degrees]
[degrees]
[psf]
[psf]
Weathered
1
0.876489
83.9436
-61.2285
0
34
24.7392
27.2767
40.4393
0
40.4393
Advance
Weathered
2
0.876489
241.712
-58.0205
0
34
66.7706
73.6193
109.145
0
109.145
Advance
Advanced
3
1.08154
496.989
-54.763
110
36
180.274
198.765
122.175
0
122.175
sand
Advanced
4
1.08154
699.976
-51.4318
110
36
230.696
254.359
198.692
0
198.692
sand
Advanced
5
1.08154
880.753
-48.3294
110
36
272.979
300.978
262.859
0
262.859
sand
Advanced
6
1.08154
1043.3
-45.4064
110
36
311.406
343.347
321.174
0
321.174
sand
Advanced
7
1.08154
1190.4
-42.6281
110
36
349.542
385.394
379.047
0
379.047
sand
Advanced
8
1.08154
1324.11
-39.9691
110
36
390.755
430.835
441.592
0
441.592
sand
Advanced
9
1.08154
1445.99
-37.4101
110
36
438.481
483.456
514.018
0
514.018
sand
Advanced
10
1.08154
1545.52
-34.936
110
36
493.108
543.686
596.917
0
596.917
sand
Advanced
11
1.08154
1565.21
-32.5345
110
36
540.807
596.278
669.304
0
669.304
sand
Advanced
12
1.08154
1561.64
-30.1958
110
36
598.107
659.455
756.26
0
756.26
sand
Advanced
13
1.08154
1508.01
-27.9115
110
36
655.722
722.979
843.695
0
843.695
sand
Advanced
14
1.08154
1363.86
-25.6745
110
36
693.088
764.178
900.396
0
900.396
sand
Advanced
15
1.08154
1208.1
-23.4789
110
36
728.046
802.722
953.446
0
953.446
sand
Advanced
16
1.08154
1046.53
-21.3193
110
36
752.826
830.043
991.055
0
991.055
sand
Advanced
17
1.08154
979.798
-19.191
110
36
806.237
888.933
1072.11
0
1072.11
sand
Advanced
18
1.08154
991.622
-17.09
110
36
881.259
971.65
1185.96
0
1185.96
sand
Advanced
19
1.08154
997.372
-15.0124
110
36
928.264
1023.48
1257.29
0
1257.29
sand
Advanced
20
1.08154
985.037
-12.9549
110
36
932.04
1027.64
1263.02
0
1263.02
sand
Advanced
21
1.08154
841.072
-10.9142
110
36
819.163
903.185
1091.72
0
1091.72
sand
Advanced
22
1.08154
654.732
-8.88749
110
36
652.706
719.654
839.116
0
839.116
sand
Advanced
23
1.08154
462.895
-6.87194
110
36
473.594
522.17
567.303
0
567.303
sand
Advanced
24
1.08154
265.657
-4.86491
110
36
298.402
329.009
301.44
0
301.44
sand
Weathered
25
1.21099
86.1796
-2.74435
0
34
44.8943
49.4991
73.3854
0
73.3854
Advance
Interslice Data
Youn.3911SWDashPointRd.SS.A-A'.all.slmd
GeoResources, LLC.
3/24/2017,
3:21:21 PM
r �
S.IOE7rrtFiwxpr �.Ok6
Y esidence - 3911 DashPoint Road: Page 5 of 7
t3iooai minimum Lluerytgie/ morgenstern-prices - barety ractor: l.wzsi
x
Y
Interslice
Interslice
Interslice
Slice
coordinate
coordinate- Bottom
Normal Force
Shear Force
Force Angle
Number
[ft]
[ft]
[lbs]
[lbs]
[degrees]
1
-9.86356
30
0
0
0
2
-8.98707
28.4038
63.8295
8.96762
7.99733
3
-8.11058
27
218.89
61.1799
15.6157
4
-7.02904
25.4689
335.021
149.686
24.0749
5
-5.9475
24.1126
529.751
321.504
31.2534
6
-4.86596
22.8974
773.81
585.947
37.1339
7
-3.78443
21.8004
1049.81
939.96
41.8401
8
-2.70289
20.8049
1346.32
1372.01
45.5415
9
-1.62135
19.8984
1654.61
1863.73
48.4015
10
-0.539812
19.0712
1966.58
2390.48
50.5568
11
0.541726
18.3157
2270.07
2917.37
52.1127
12
1.62326
17.6258
2537.64
3385.33
53.1448
13
2.7048
16.9964
2756.47
3752.84
53.7026
14
3.78634
16.4235
2906.92
3973.66
53.8128
15
4.86788
15.9036
2965.64
4004.95
53.4803
16
5.94942
15.4338
2927.37
3841.25
52.6894
17
7.03096
15.0117
2792.27
3498.14
51.4026
18
8.11249
14.6352
2567.93
3012.77
49.5574
19
9.19403
14.3027
2256.08
2424.78
47.0641
20
10.2756
14.0127
1865.11
1788.66
43.8013
21
11.3571
13.7639
1416.53
1172.61
39.6181
22
12.4386
13.5553
967.604
661.132
34.3435
23
13.5202
13.3862
566.546
298.982
27.8219
24
14.6017
13.2559
243.476
88.5502
19.9859
25
15.6833
13.1638
14.5722
2.82408
10.9679
26
16.8942
13.1058
0
0
0
List Of Coordinates
External Boundary
Youn.3911SWDashPointRd.SS.A-A'.all.slmd GeoResources, LLC. 3/24/2017, 3:21:21 PM
r �4 RIDE NTBUq Ef 7.018
y '1-�sience Y )esidence - 3911 DashPoint Road: Page 6 of 7
X Y
75 -20
75 0
46 0
46 9
42.294 9
33.867 9
31.46 9
30.772 9
20 9
19 10
17 13
16 14
11 21
7 22
3.66667 27
3 28
0 30
-50 30
-50 27
-50 -20
Material Boundary
X Y
-50 27
2.04648 27
3.66667 27
Material Boundary
X Y
2.04648 27
6.58816 21.2589
10.5882 20.2589
15.5882 13.2589
16.5882 12.2589
18.5882 9.2589
19.5882 8.2589
21.0282 7.6189
31.46 3.54094
46 9
Material Boundary
x Y
20 9
21.0282 7.6189
24.064 3.54094
31.46 3.54094
31.46 0
46 0
Youn.3911SWDashPointRd.SS.A-A'.all.slmd GeoResources, LLC. 3/24/2017, 3:21:21 PM
FLEXURE SHEAR (ACI 318-05 SEC.9.3.2.3, 15.5-2, 11.1.3.1, & 11.3) (cont'd)
OV n = 2obd f c
LONGITUDINAL TRANSVERSE
Vu—-
---- — — — _ &62
-.. _ 0-75 0.75
�Un 31.3 30.2
Check Vu < �Vn [Satisfactory]
rSatlsfactar9
PUNCHING SHEAR (ACI 318-05 SEC.15.5.2, 11.12.1.2, 11.12.6, & 13.5.3.2)
OVn=(2+y)Of,Ap = 84.62 kips
where = 0.75 (ACI 31"5, Section 9.3.2.3)
R� = ratio of long side to short side of concentrated load = 1.00
bo = c, + c2 + bt + b2 + 4d = 66.1 in
AP = bo d = 564.1 inz
Y = MIN(2, 4/Oc, 40d/bo) = 2.0
_ 1 "+ci bz+cz 1l
Vu-I'u,max t BL( 2 +d)( 2 +d)1= 31.00 kips < 0 V n [Satisfactory]
7% SUMNTMU41k77.019
Yr . sidence - 3911 DashPoint Road: Page 7 of 7
Material Boundary
L3I
Y
20 9
.46 3.54094
Material Boundary
X Y
31.46 3.54094
31.46 9
Youn.3911SWDash PointRd. SS.A-A'.all.slmd
GeoResources, LLC. 3/24/2017, 3:21:21 PM
CITY OF
Federal Way
January 6, 2017
Mr. Henry Youn
7002 78th Avenue SE
Mercer Island, WA 98040
henW ountt`�Wafl&nm
CITY HALL
33325 8th Avenue South
Federal Way, WA 98003-6325
(253) 835-7000
wwwcityoffederalway. com
Jim Ferrell, Mayor
Re: File #15-101479-00-SF, PLANNING DIVISION REVIEW #2
JLHC Inc., *No Site Address* Dash Point Road SW, Federal Way (Parcel 112103-9106)
Dear Mr. Youn:
The city is in receipt of your September 22, 2016, building permit resubmittal. You provided a wetland and
stream critical areas assessment with this resubmittal. The following critical area reports are under third -party
review for the abovementioned project and are not approved. These reviews below are currently in process,
pending action from the applicant.
• `C' iialAreas Assessment, Parcel 1121039106 " prepared by Habitat Technologies (April 11, 2012)
• `Geotechnical En,gitreering Report Proposed .Single Family Residence, 3911 SW Dash Point Road,"
prepared by GeoResources LLC (May 1, 2014); and,
■ `Response to Comments, Proposed Sigle.Family Residence 3911 SW Dash Point Road," prepared by
GeoResources LLC Qune 21, 2015).
A peer review fee of $5,300.00 for the applicant's wetland/stream report and geotechnical report revisions in
response to November 9, 2016, review comments by the city's consultant (AMEC) remains outstanding.
Please note additional city consultant fees may apply to review the revised reports and drawings.
Prior to permit approval; please address the following Planning Division items:
CRITICAL AREAS -STREAMS
1. Sheets C1 and C5 show a 100-foot major stream buffer in the southwest corner of the parcel. However, a
critical areas report prepared by Habitat Technologies (received September 22, 2016), proposes to
reclassify the off -site stream to a Type `Ns' (Non -Fish Seasonal) requiring a 35-foot buffer. They city's
critical area inventory and city's stream inventory (conducted by URS) classify the stream segment which
impacts the subject property as a major stream with a 100-foot protective buffer.
2. The existing major stream 100-foot buffer impacts to the southwest corner are limited (approximately 80
square feet of buffer on -site). The applicant proposes no new structures or improvements there. You
have two options:
I5-101479-00-SF Doc. ID. 74886
Mr. Henry Youn
January 6, 2017
Page 2 of 3
Option #1: If you proceed with requesting the city re-classify the stream from major (fish
bearing) to a Non -Fish Seasonal (Ns), the submitted Habitat Technology report will
continue to be peer reviewed at the applicant's. pt M§e city's third -party consultant,
Landau (city file # -AD).
Option #2: If you move forward with the proposal and a 100-foot regulated stream buffer,
and do not re-classify the existing stream, the Habitat Technology report received Septemb
22, 2016, would be removed from the project files. Staff will cancel the ongoing third party
review with Landau. The Habitat Technology report proposing a lesser buffer would not be
reviewed, accepted, or approved by the city at this time. The single family building permit
was deemed complete under the critical areas codes prior to the city's critical area ordinance
bp.datc in June 2015. /
Under Option #2, the final building plan -Set must con and 100-foot buffer,
protected from all related construction, clearing, and grading activities.
If you proceed with Option #2 please submit a letter cancelling -.peer review file #16-105115-AD.
PLAN -SET
3. Sheet C-4 — Remove the final plat and City of Renton references. Please see the enclosed redlines
regarding landscaping note removal.
4. Tree Protection — Depict tree protection measures around the tree protected during construction on the site
plan per the "tree protection fence detail" drawing (Sheet C-4). Protection must be installed prior to
construction in order to protect critical root zones (Federal Way Revised Code [FWRq 19.120.160[2-3]).
5. The proposal may be subject to a height survey prior to final inspection
CRITICAL AREAS- GEOLOGICALLY HAZARDOUS AREAS
6. There is an on -going third party review of the geotechnical report by the city's geotechnical consultant,
AMEC Foster Wheeler (city file #15-101977-AD). A written response/report/plan-set revisions
addressing AMEC's November 9, 2016, geotechnical review memo remains outstanding. Please note
additional city consultant fees may apply to review the revised reports and drawings.
7. Per page 3 of the AMEC review memo, additional soil stabilizing plantings/vegetation are required in
disturbed areas. The clearing limit should extend at least 8 to 10 feet from the foundation and stem wall.
These actions will make it necessary to remove additional trees compared to the September 22, 2106, site
plan.
8. Please revise the geotechnical study to depict the same proposal shown on building plans resubmitted
September 22, 2016.
Fde 415-101479-00-SF Doc. I.D. 74886
Mc. Henry Youn
January 6, 2017
Page 3 of 3
9. Driveway — Resubmitted plans depict a new 120 square foot parking area off of the driveway. Please confirm
that the new parking area (a land surface modification) was reviewed by the applicant's geotechnical
engineer and evaluated for impacts to the geologically hazardous area (FWRC 19.160.010[2-3]).
CLOSING
Please revise the plans as necessary and provide the additional information requested. When re -submitting,
provide four copies of all new and/or revised documents and a revised geotechnical report addressing
Planning and AMEC's comments. Any additional comments from the Building and Development Services
Divisions, and/or the city consultants, will be sent under separate cover.
Please contact me at 253-835-2644, or if you have any
questions about this letter.
Sincerely,
Lc. t a Willoughby -Oakes
Associate Planner
enc: Redlined Site Plan (Sheet C-4) Cni.
c: Peter Lawrence, Plans Examiner
Erik Preston, Senior Transportation Engineer
Kevin Peterson, Engineering Plans Examiner
HagL:nson (:onsult.w.x, LLEC 6484 48dk 7lvcnuc S%V Seattle, WA 98136; h-iiI i , %oii iiicumr .n (w/enclosure)
Keith Schcmbs, Gcollcsources, t •i s 41 g Y> •+ v?mc • u ( I.J �e�LrLSc i )
Fk # 15- I01479-00-SF
Doc, I.D, 74886
^z
J
CITY OF
L. Federal Way
Todd D. Wenthworth, PE, LG
Amec Foster Wheeler
11810 North Creek Parkway North
Bothell; WA 98011
Email: bill.lockard!cLamecRv.com
33325 8th Avenue South
Federal Way, WA 98003-6325
(253) 835-7000
www. cityoffederalway.. com
Jim Ferrell, Mayor
October 26, 2016
RE: File No. 15-101977-AD; THIRD PARTY GEOTECHNICAL REPORT REVIEW
JLHC Inc. (Proposed Youn Residence), 39XX SW Dash Point Rd. (112103-9106)
Dear Mr. Wentworth:
Please find the enclosed task authorization form signed by the applicant (Mr. Henry Youn) for the above -
mentioned parcel and single family building permit. The applicant resubmitted revised building permit
materials on September 22, 2016, in response to city review letters sent on April 21, 2015 and June 10,
2015. The building permit was on hold until this time. The subject property is located in a geologically
hazardous area per the City's critical area inventory.
Enclosed application materials for your third -party review include:
• Revised site plan -set (Sheets CI-C4)
■ Geotechnical Engineering report (dated May 1, 2014)
• Geotechnical Response Memorandum, prepared by GeoResources LLC (dated June 21, 2016)
• Response Letter to Planning Division, prepared by Hagenson Consultants (received September 22, 2016)
• Planning Division Review Letter (dated June 10, 2015)
I have enclosed the applicable geologically hazardous area development regulations for your reference
(Federal Way Revised Code (FWRC) 19.160) during your review. The building permit was deemed
complete on March 27, 2015, prior to the city's critical area ordinance (CAO) update on June 30, 2015.
For the purposes of expediting review timelines the City requests the proposed tasks are completed within
1-2 weeks of receiving notice to proceed from the City.
Please contact the project planner at 253-835-2644 or leila.►villoughby-bakes. zeitvoffederalway.coin if
you have any questions regarding the third party review.
Sincerely.
e_�_ &
Leila Willoughby -Oakes
Associate Planner
c: Kevin Peterson_ Engineering Plans Reviewer
ene: Signed Consultant Task Authorization Form
GeoResources Geotechnical Engineering Report. 39XX SW Dash Point Rd. (dated May 2014)
September 22, 2016 SFR Plan -Set Res ubmittal
GeoResources. LLC Response Memo (dated .lone 2 L 2015)
Consultant Response letter to Planning Division (received September 22. 2016)
City Technical Review Letter (dated .June 10, 2015)
FWRC 19.160 -Geologically Hazardous Areas'
Doc I D 74877
CITY OF
Federal Way
October 31, 2016
Mr. Henry Youn
7002 78th Avenue SE
Mercer Island, WA 98040-5310
henntyoun QmO.com
CITY HALL
33325 8th Avenue South
Federal Way, WA 98003-6325
(253) 835-7000
wwww cityoffederalway. com
FILE
Jim Ferrell, Mayor
Re: File #16-105115-00-AD; 3- PARTY GEOTECHNICAL REVIEW COST ESTIMATE
JLHC Inc., Critical Area Review, 39XX SW Dash Point Road, (APN: 112103 9106), Federal Way
Dear Mr. Youn:
Please find the enclosed consultant task authorization, which includes a scope of work, to review the Critical
Areas Assessment, Parcel 112103-9106 prepared by Habitat Technologies (April 11, 2012) received on
September 22, 2016, for a new single family home (related file 15-101479-SF). The critical area report will be
reviewed by the city's third party consultant at the applicant's expense pursuant to former Federal Way Revised
Code (FWRC) 19.150.030 and now FWRC 19.145.080(3).
When authorized by you, the city will set up an account to be funded by the applicant and drawn down by the
city for work performed by Landau Associates Inc. If any funds are not used, they will be returned to the
applicant. A check in the amount of $5,300.00 made payable to the City of Federal Way, and your signature
on the authorization form must be submitted before the city can initiate the third party contract. Additional
reviews or meetings may require supplemental cost and authorization. The city will contact you if these are
necessary. Following receipt of the fee and signed task authorization, the project planner will authorize
Landau Associates Inc. to begin their formal review of the submitted report.
On June 5, 2015, the Public Works and Community Development Departments reviewed the building permit
plans and studies and provided technical comments. The city received a project resubmittal on September 22,
2016, which is currently under review. Review comments forwarded to you in June 2015 are subject to change
and there are required proposal changes per Landau's wetland/stream peer review.
If you have any questions regarding this letter or your third -party review request, please contact me at 253-
835-2644, or leila.willoughby-oakes@cityoffederalway.com.
Sincerely,
,6
Leila Willoughby-Oakes-----�_��
Associate Planner
enc: Signed Task Authorization Form
Peer Review Landau Associates Scope of Work
Peer Review Fee Invoice
c: Hal Hagenson, Lhngenson comcast.ne[ (Civil Engineer)
File # 1 G-10i11 i-00-AD
Doc. I.D. 74897
November 9, 2016
Project No. 5-917-17902-0
Ms. Leila Willoughby -Oakes
City of Federal Way
Community Development Department
33325 8th Avenue South
Federal Way, Washington 98003
Subject: Geotechnical Review of Documents
JLHC Inc. Proposed Youn Residence
3911 SW Dash Point Road
Federal Way, Washington
File No. 15-101977-00-AD
Dear Ms. Willoughby -Oakes:
amec
foster
wheeler
This letter presents the results of our third -party review of geotechnical engineering reports and
related documents for the proposed single family residence. At your request, we reviewed the
following documents:
• Geotechnical Engineering Report dated May 1, 2014, prepared by GeoResources, LLC;
• Planning Division Review Letter, dated June 10, 2015;
• Geotechnical Response Memorandum dated June 21, 2015, prepared by GeoResources,
LLC;
• Revised site plans (Sheets C1-C4), revision dated June 23, 2015, prepared by Hagenson
Consultants, LLC; and
■ Response letter to City of Federal Way Planning Division dated June 23, 2015 prepared by
Hagenson Consultants, LLC (received by City of Federal Way September 2, 2016)
As outlined within the Third -Party Geotechnical Report Review letter dated October 26, 2016, from the
City of Federal Way Planning Division our review tasks were:
1. Review submitted documents for conformance to 2012 Federal Way Revised Code (FWRC)
Chapter 19.160, as the permit application had been completed prior to the adoption of the
2015 update to the critical areas update.
2. Provide a memorandum identifying additional information requested as necessary.
3. Conduct site visit as necessary.
Amec Foster Wheeler Environment & Infrastructure, Inc.
11810 North Creek Parkway N
Bothell, Washington 98011
(425) 368-1000 Phone
www.amecfw.com \\SEA-FS1\WordProc\_Projects\17000s\17902 City of Federal Way\Review Letters\Youn Residence Review Letter 161109 docx
Ms. Leila Willoughby -Oakes
City of Federal Way
November 9, 2016
Page 2 of 4
amec
■
foster
wheeler
4. Provide written response as to whether or not we concur with GeoResources' findings and
conclusions.
SITE AND PROJECT DESCRIPTION
The proposed project is to consist of development of a vacant lot with a single-family residence
accessed by a paved driveway from Dash Point Road. The 0.4 acre lot is located at 3911 SW Dash
Point Road in Federal Way, Washington, on the south side of Dash Point Road east of Dumas Bay
Park. The site is situated on the eastern side of a northeastern trending drainage ravine with the site
topography sloping steeply down from the east property line to the approximate midpoint of the site
where a 20 foot to 30 foot wide, gently sloping bench is present. Beyond the bench is another
moderate to steep east -facing slope. Thus, the site has mapped Geologic Hazards including; Steep
Slope Hazard, Erosion Hazard, Landslide Hazard, and Seismic Hazard. The proposed residence is to
be located on the topographic bench; however, the location lies partially within the geological hazard
area. It is our understanding the base level of the structure will be a daylight garage with the east wall
requiring a cut of approximately 8 feet into the toe of the slope to accommodate the building footprint.
Once completed the east wall of the garage level will act as a retaining wall. A 4-foot-high catchment
wall will be incorporated into the design. Roof runoff and surface water from the yard area will be
collected and infiltrated within a dry well system on the north side of the residence.
REVIEW COMMENTS
Provided below are the comments for the pertinent documents which we reviewed. Our review and
comments have been based on the City of Federal Way 2012 critical area regulations and standard
engineering geology and geotechnical engineering practices in the Puget Sound region.
GeoResources Geotechnical Engineering Report
Below are review comments for the May 1, 2014, GeoResources report.
1. The soil conditions discussed within the text of the report do not correspond to the test pit logs.
Specifically, each test pit log indicates the relative soil density as loose for the entire depth of
the test pit, whereas within the text of the report the upper 2 to 3 feet are described as loose to
medium dense. Below the weathered zone, the advance outwash was described in the text as
medium dense to dense — which is the typical condition of advance outwash deposits. Please
resolve this inconsistency.
2. The stability modeling assumed one single, uniform soil horizon ("Advance Sand"), whereas
the report described two horizons (neglecting the upper topsoil/forest duff horizon).
Ms. Leila Willoughby -Oakes
City of Federal Way
November 9, 2016
Page 3 of 4
TV
amen QV
foster
wheeler
Additionally, the engineering properties assigned to the Advance Sand include cohesion of
250 psf. For modeling of long-term stability, cohesion is generally not assigned to clean
granular deposits such as advance outwash. Please present revised slope stability modeling
or provide further explanation for how the slope was modeled.
3. A statement from the geotechnical engineer, addressing the potential impact of the
development of the site per the requirements of FWRC 1a46 1 Q,z should be included.
M145-
The above comments, while needing to be addressed, will probably not impact the conclusions
reached by GeoResources concerning development of the site. The report by GeoResources
adequately addressed the requirements of FWRC 19.160. 'in our opinion. We agree with the
conclusions of the report and the subsequent Geotechnical Response Memorandum dated June 21,
2015. It appears the proposed residence has been located such that it minimizes impact upon the
geologic hazards and associated critical
Hagenson Consultants Response To Planning Division Letter
1. Zoning/General Comments (4.) Indicates the revised plans have been submitted to the
geotechnical engineer for review. Has this been completed?
2. Tree Removal and Vegetation (2.) The clearing limits indicated on Sheet C-4 do not reflect the
recommendations from GeoResources for a safe, temporary cut slope. As stated within the
Temporary Excavation section of the report, a maximum 1 H:1 V slope is required by WISHA for
the Type B soils found below approximately 3 feet. Thus, it appears that at a minimum the
clearing limit should extend at least 8 to 10 feet from the foundation and stem wall for worker
safety. As a result of the increase in area disturbed, additional plantings will be required.
3. Public Works Department Review of Plans — Sheet C3 (comments 2 & 3) The response
indicates the geotechnical engineer will review the drainage design. No response from the
geotechnical engineer was provided us regarding site drainage.
Plan Sheet Review
1. The geotechnical engineer should review the latest plan sheets to confirm the geotechnical
recommendations contained within their report have been properly interpreted and
implemented.
2. As noted above, the clearing limits will be larger than shown on Sheet C4 due to the required
temporary cut slopes, this should be reflected on Sheet C3 and C4.
3. The design and location of the roof downspout dry well and flow dispersal area should be
reviewed by the geotechnical engineer. Specifically, do the soils anticipated to be encountered
at the base of the drywell, 3 feet below existing grade, favorably compare with the soil
Ms. Leila Willoughby -Oakes 1.
City of Federal Way amen
November 9, 2016 faster
Page 4 of 4 wheeler
conditions assumed during design. Will the flow dispersal area adequately protect the slope
beyond the dispersal area from runoff generated by the driveway?
4. The footing drains are not shown on the drainage plans (Sheet C3). The footing drains should
be separately tight -lined to the dry well, or other discharge point, as appropriate.
Other Comments
Due to the steep slopes on site and the proposed temporary cut into the toe of the steep slope,
we recommend the work be performed during the dry season to minimize the potential for
erosion or slope failures associate with wet weather work. The length of time the temporary cut
slope is in place should be minimized to reduce the risk of sloughing or other slope movement.
2. We recommend GeoResources be on site during construction to monitor slope stability
conditions and confirm construction activities do not adversely affect site stability.
3 �+ n°'L [n� o off. C•� �;Vt
tCUn S�vu�( /LR-L
PeJs :/7
CLOSURE o�pA -a (
We appreciate her opportunity to be of service. It should be noted that our scope of work for this third
party review was limited to a review of the documents supplied to us. Our scope did not include
subsurface exploration or engineering analyses, nor does our review purport to verify the accuracy of
the geotechnical engineering results presented within the documents.
If you have any questions, please contact us at your convenience.
Sincerely,
Amec Foster Wheeler Environment & Infrastructure, Inc.
William J. Lockard, L.E.G.
Senior Geologist
Todd D. Wentworth, P.E., L.G.
Associate
��RpAST. 8;�j�4
r�
T
{4
FiLE
May 12, 2015 Jim Ferrell, Mayor
Chung Youn Emailed: hcainc@,botmail.com
28720 18"' Avenue South, Suite Z-203
Federal Way, WA 98003
RE: File #15-101977-00-AD; GEOTECHNICAL REPORT PEER REVIEW ESTIMATE
JLHC Inc. (H. Youn Proposed Residence), *No Site Address* (112103-9106), Federal Way
Dear Mr. Youn:
Please find the enclosed consultant task authorization which includes a scope of work in order to review
the `Geotechnical Engineering Report - Proposed Youn SFR' prepared on May 1, 2014, by
GeoResources. The department's geotechnical on -call engineer, Amec Foster Wheeler (Amec) was
requested to provide an estimate for their review of the information and submitted report. Please find the
Amec Foster Wheeler fee determination summary enclosed.
When authorized by the applicant, the City will set up an account to be funded by the applicant and drawn
down by the work performed by Amec's Environment and Infrastructure Division. If any fiends are not
used, they will be returned to the applicant. A check in the amount of $3, 000, made payable to the City of
Federal Way, and a signature on the consultant's authorization form must be submitted before the peer
review will begin. Additional reviews or meetings if necessary require supplemental cost and
authorization. Following receipt, the project planner will authorize Amec Foster Wheeler to begin their
Please note on April 21, 2015, the Public Works Department reviewed and provided comments on the site
and civil engineering plans submitted. These City comments are subject to change, if the City's third
party consultant requests revisions to the project design addressing soil stability.
If you have any questions regarding this letter or your third -party review request, please contact the
project planner at 253-835-2644 or leila.willoughby-oakes@cityoffederalway.com.
Sincerely,
.qd
Leila Willoughby -Oakes
Associate Planner
c: Henry Youn, 7002 78`h Avenue SE, Mercer Island, WA 98040 (Owner)
Brad Biggerstaff, GeoResources, LLC, (Geotechnical Engineer) (Emailed: BradbQgeoresources.us
Hagenson Consultants, LLC, (Civil Engineer) (Emailed: H.Hagenson ,,comcast.net )
enc: Geotechnical Consultant Authorization Form
City of Federal Way Fee Statement
Doc. I.D. 69200
33325 8th Avenue South, Federal Way, WA 98003-6325 (253) 835-7000 www.cityoffederalway.com
CCP �I
Ph. 253-896-1011
Fx. 253-896-2633
Mr. Henry You
7002 78Ave SE
Mercer Island, WA 98040
(206) 910-2728
GeoResources, LLC
5007 Pacific Hwy. E, Suite 16
Fife, Washington 98424
June 21, 2015
Response to Comments
Proposed Single Family Residence
3911 SW Dash Point Road
Federal Way, Washington
PN: 122103-9106
Job: Youn.3911 DashPoint.RC
This provides our response to City of Federal Way comments dated June 10, 2015 for
the proposed residential development to be constructed at 3911 SW Dash Point Road in the
Dash Point area of Federal Way, Washington. We previously provided a geotechnical report
for the project dated May 1, 2014.
Based on our review of the letter, and relative to geotechnical issues, we offer the
following responses:
Reasonable alternative locations - the proposed residence is situated on the lot to
provide the lease amount of impact/encroachment into the critical areas. The physical
constraints on the site, slopes both north and south or above and below, limit the
buildable area. Slope stability will be maintained by installing retaining walls in the
form of a daylight basement. As noted, where the residence extends into the slope
area, no openings (doors or windows) should be located in this area.
• The front yard setback, based on the plan we included in our report, does not indicate
any additional room to move the residence. The residence is situated between the
critical areas, wetland/buffer and slope. If the City is willing to reduce the wetland
buffer (averaging?), then the residence could be shifted to the SW and away from the
slope. Plan is attached.
• There would be no surface disturbance of the slope areas except where the stumps
are removed. That would appear to be limited to two per the plan attached. We would
recommend that unless the tree stumps interfere with the structure, they remain in
place, and the low growing vegetation be enhanced.
The clearing and grading requirements should be addressed on the plan prepared by
the project civil or architect. As noted above, tree removal should be limited those
directly impacted by the structure.
Youn — SW Dash Pt. Rd
June 21, 2015
Page 2
We have appreciated working for you on this project. Please do not hesitate to call at
your earliest convenience if you have questions or comments.
Respectfully submitted,
GeoResources, LLC
Brad P Biggerstaff, LEG
Principal
BPB:bpb
Doc ID: Youn.DashPtRd.RC
Attachments: Site Plan
....., SW DASH POINT RD.
r..
r
i
�{ rrn.ww
i
i
� ,aa"o..� icwru".rmmn<sounmvwnw
i
.rm .Qare ,
kc4v a,Na,N. +n
V ofc+.s r[ew�x n n�ww� r¢�im .�jv-,r-sea
rum V W
�HILLEBRAND ASSOCIATES LLC
Cp15ULiAN15 k lANO SURVEYtl25
JOB NIIIEYWN SUg4E1'
_ _ --• �-1mlar 1wN watr. ao
astt rr��nn
13-014
a
CITY OF
Federal Way
April 30, 2015
Ernailed: bill. lockard(cr7anle0w.com
William J. Lockard
Amec Foster Wheeler
11810 North Creek Parkway North
Bothell, WA 98011
CITY HALL
33325 8th Avenue South
Federal Way, WA 98003-6325
(253) 835-7000
www. cityoffederalway.. com
Jim Ferrell, Mayor
RE: File #15-101977-00-AD; REQUEST FOR THIRD PARTY GEOTECHNICAL REPORT REVIEW
JLHC Inc. (henry Youn Proposed Residence) — *No Site Address* (112103-9106), Federal Way
Dear Mr. Lockard:
Please find the enclosed task authorization form for tax parcel number 112103-9106 and related project
file #15-101479-SF. The Public Works and Community Development Departments conducted site visits
in April, and request a third. -party review pursuant to the agreed terms of the on -call contract to proceed
with the building permit review. Please review the scope of work contained in the task authorization form,
enter the task cost on page 2 of the document, and return to the city by email and the signed original by
mail. Following the deposit of funds by the applicant, staff will provide authorization to proceed with the
scope of work.
For the purposes of expediting review timelines the City requests the proposed tasks are completed within
10 business days of receiving notice to proceed from the City. Please note if Amec Foster Wheeler
requests additional information from the applicant's consultant.
Please contact the project planner at 253-835-2644 or leila.willou hby-oakes(a)cityofFederalway.com if
you have any questions regarding this task or the proposed scope.
Sincerely,
Leila Willoughby -Oakes
Associate Planner
enc: Consultant Task Authorization Form
Geotechnical Engineering Report —Proposed Single Family Residence (Prepared by GeoResources, LLC, May 1, 2014)
City of Federal Way Development Services review comments (April 21, 2015)
Plan Set- Sheets Cl-C4 (Prepared by Hagenson Consultants, LLC July 2014) (emailed)
15-101977-AD (Related File No. 15-101479-SF) Doc. I.D. 69199
. A��
CITY OF
Federal Way
GEOTECHNICAL ENGINEER AUTHORIZATION FORM
Date: April 30, 2015
City: City of Federal Way
Community Development Department
33325 8th Avenue South, Federal Way, WA 98003
Consultant: William J. Lockard
Amec Foster Wheeler - Environment & Infrastructure
11810 North CreglcParfway North
Bothell, WA 98011
Project: JLHC Inc. (Proposed Youn Residence) — Geotechnical Engineering Report
Property Parcel# 112103 9106 (*No Site Address*)
File No.: 15- 101977-00-AD; Related Project File No. 15-101479-00-SF
Project Consultant Brad Biggerstaff
Contacts: GeoResources, LLC
5007 Pacific Hwy. E., Suite 16
Fife, Washington 98424
BradB@,georesources.us
Hal Hagneson, P.E.
Hagenson Consultants, LLC
Civil Engineering & Land Development Consultants
6484-481h Avenue SW, Seattle WA 98126
h.ha eg nson @comcast.net
Project Applicant: Mr. Chung Youn
28720 18`' Avenue South, Suite Z-203
Federal Way, WA 98003
hcainc a,hotmail.com
Project Planner: Leila Willoughby -Oakes
leila.willotighby-oakes a,citypffederalway.cam, 253-835-2644
Project Background: On March 27th, 2015 the applicant submitted a building permit and geotechnical report
concluding a single family home appears feasible on the subject property from a
geotechnical engineering standpoint. As various departments undergo compliance
review the City requests a third party review.
The applicant proposes to construct a 1600 sf single family home on a 20,000 sf +/- lot
PFN: 15- 101977-00-AD Document ID: 69184
r
zoned RS 15.0. The subject property contains designated erosion and landslide hazard
areas. The City of Federal Way Development Services Department has provided
comments on the proposed drainage system requesting revisions.
Please find the city's drainage comments requiring revisions to the proposed drainage
system. Separate plans will be forwarded to Amec for review when the applicant has
submitted new designs to the city.
On a site visit staff noted on the northern slope of the property (east property line) a
stand of trees has been removed.
Documents Provided: • Geotechnical Engineering Report, prepared by GeoResources LLC (May 1, 2014)
• Plan -set, prepared by Hagneson Consultants LLC (July, 30, 2014)
■ Development Services Review Completion Letter — Revision Comments
Task Scope: 1. Review submitted documents for conformance with FWRC 19.160 —
Geologically Hazardous Areas.
2. Provide memorandum identifying additional information requested as
necessary.
3. Conduct site visit as necessary. -ii,,
4. Meetings on site and/or with applicant's Geotechni elEngineer/ City of
Federal Way staff if necessary. mow' +��fwi-��
5. Provide written response as to whether or not Amec concurs with
GeoResources's findings and conclusions.
Task Schedule: Provide task cost estimate by May 5, 2015.
Acceptance:
Consultant
of Federal
Applicant
Not to exceed $ C without a prior written amendment to this Task
Authorization.
The total task amount completed by city staff after the third party consultant
returns this form. All spaces are to be completed including the total work
estimate, on the grounds that the estimate has been approved by the Project
Planner.
A k, q aJ, (,( L,
/3
Date
Date
PFN: 15- 101977-00-AD
Document ID: 69184
Pr
NAGENSDN
CONSULTANTS, LW
6484 — 48' Ave. SW
Seattle, WA 98136
Ph. (206) 938-6168
Fax (206) 938-7645
Email: H.Hagenson@comcast.net
May 30, 2017
City of Federal Way
Attn: Leila Willoughby -Oakes
33325 8lh Ave South
Federal Way, WA 98003-6325
Re: Permit # 15-100374-00-SF
Henry Youn Residence (JLHC Inc.)
Dear Ms. Willoughby -Oakes:
We would like to take this opportunity to respond to the Planning Comments dated June 10�h
2015 and Public Works comments dated January 6, 2016. Our responses are as follows:
1. We have removed references to "final plat' and "City of Renton"
2. We have depicted tree protection measures and added signing to the tree protection
detail in compliance with RCFW 19.120.
3. We have extended the clearing limits 10' from the foundation and stem walls. We
also noted the additional trees to be removed in plan view and on the tree list and
revisited the tree retainage calc.
4. We have revised the tree plan notes per the city's redline plan.
5. We have depicted laurel plantings on the landscape plan with bolder linetypes. We
have added additional groundcover callouts and notes for distrurbed areas.
Thank you for the opportunity to respond to City comments. Please feel free to contact us
with any questions.
Sincerely,
Hal Hagenson, P.E.
Hagenson Consultants, LLC
CITY OF
Federal Way
DATE: March 29, 2017
9G
MEMORANDUM
Community Development Department
TO: Kevin Peterson, Engineering Plans Reviewer
Peter Lawrence, Plans Examiner
FROM: Leila Willoughby -Oakes, Planning
SUBJECT: JHLC Inc. 15-101479-00-SF ; Parcel: I ),D i 63
Please find a revised geotechnical report enclosed per the AMEC peer review and city comment. We have
not received a revised building plan -set. The rolled plans have a copy of the report.
With thanks,
Leila
DEPARTMENT OF COMMUNITY DEVELOPMENT
RESUBMITTED 33325 8`h Avenue South
CITY OF 253-8Federal Way, WA 98003-6325
35-2607;Fax 253-835-2609
Federal Way MAR z 7 20� w%vw.citvol`fcderalway.ccm
CITY OF FEDERAL WAY
COMMUNITY DEVELOPMENT
RESUBMITTAL INFORMATION
This completed form MUST accompany all resubmittals.
"Please note: Additional or revised plans or documents for an active project will not be accepted
unless accompanied by this completed form. Mailed resubmittals that do not include this form or that
do not contain the correct number of copies will be returned or discarded. You are encouraged to
submit all items in person and to contact the Permit Counter prior to submitting if you are not sure
about the number of copies required. **
ANY CHANGES TO DRAW/NGS MUST BE CLOUDED.
Project Number: / S - % 5� / q 7 7 - - ►�
Project Name: d�11 L
Project Address: / D as6 ID • /Z('
Project Contact: Phone: a-S2.>
RESUBMITTED ITEMS:
# of Copies ** Detailed Description of Item
** Always submit the same
number/ of copies as required foryour initial application.*'
Resubmittal Requested by: ��.11(G'u� r�ttetter Dated:
( s em er
OFFICE USE Oft
RESUB A• Distribution Date: IV EZ7 y.'
Dept/Div
Name
#
Description
uildin
Plannin
-41
PW
Fire
Other
Bulletin #129 — January 1, 2011 Page 1 of 1 k:\Iandouts\Resubmittal Information
DEPARTMENT OF COMMUNITY DEVELOPMENT SERVICES
33325 81h Avenue South
CITY OF Federal Way, WA 98003-6325
253-835-2607;Fax 253-835-2609
Federal Allay wwµ.citvoffedcralway.coin
RESUEMITi'AL INFORMATION
This completed form MUS T accompany all resubmittals.
**Please note.- Additional or re vised plans or documents for an active project will not be accepted
unless accompanied by this completed form. Mailed resubmittals that do not include this form or that
do not contain the correct number of copies will be returned or discarded. You are encouraged to
submit all items in person and to contact the Permit Counter prior to submitting if you are not sure
about the number of copies required. **
ANY CHANGES, TO DRAWINGS MUST BE CLOUDED.
Project Number:
Project Name: &5dw c alca J (4 L. C (nc
Project Address
Project Contact:
RESUBMITTED
O 1OL Phone: 2S'l3 —� Sb —
ITEMS:
** Always submit the same number of copies as required foryour initial application.**
Resubmittal Requested by : vU Letter Dated: 10 / 2a1
to enler
OFFICE USE Oft Y
RESUB A Distribution Date.-
Dept/Div
Name
#
Description
I } . 1
Building,
Planning
PW
Fire
Other
Bulletin #129 —January 1, 2011 Page 1 of 1 k:\Handouts\Resubmittal Information
NE 1/4 SEC. 11, TWP. 21N., RGE, H , W� M.
loo _
- �R' f��; ?, (A"! 1104 IR
90.00
-SD-
D ffl DR
FR
S
S E Vv'E U FPANC'UT
s
s 'Fs') Kim, 4",
F
y
NCL
ARD SETBACKS
PH: 253 u`2-8301,8 SHEETINDEX
x
"N
7 :MT
!J
P'
STEEP SLOP GAS/ELEC
TF-
_PHONE: N Qnivl S
T LIMIT (TYP)
S SU p
IELE L
LINOSION i A uw
�,U�\HNUL PLAN
y
ST
CABLE: Cap CIA
DRAINAR
p �540% S TE
�17 /Df
L-AN
SLOPE .(TYP) A i CRi
(,�\l Air,
Al% I Ll R AN
la
A
c
iN, j-F
AN AR
SHIALl- IDETERIMINE
BE IWI Y RE
I T �4F CASN
N D
L At
Q
BE
t
PERMIT W-D. XXXXX
C I T Y ar XXXX
I- 0 A P P U tk' V " B Y:
TREE LIST
YOUN FEDERAL WAY
LOT SIZE = 20.03E SF = 0.460ACRES; RETAIN 25 UNITS PER ACRES IN SF ZONE (FWCC 19,120.130);
REQUIRED RETENTION TREE UNITS = 0,46X25=12 PROVIDED RETENTION TREE UNITS = 26
���
� ! i iaGi�i
iii3i ! __ i � •
MIN
10
I���
# •
�
`
i3iiiii3i� � •
EDIT slim
�0=1
Erm
'
"
TREE REPLACEMENT NOTES,
1. NEW TREES SHOWN ON THE PLAN SHALL BE ACER CAMPESTRE (HEDGE MAPLE) Trees shall be a minimum 2'Y2—inch caliper measured six
inches above the ground and shall be installed as shown in City of Federal Way standard detail 3-29 (ANSII Standards). Trees shall not be
planted closer than ten feet from drivewoys f alleys, and 30 feet from intersections.
2. ALL REMOVED TREES ARE LOCATED WITHIN THE PROJECT CLEARING LIMITS, WHICH IS 4,707 S.F, IN AREA.
$ ORIPUNE DRIPLINE
3
d �
+
? OR JNE (TYP,)
(BRIGHT ORANGE PLASTIC MESH)
s "TREE PROTECTION FENCE"
c
.9 10'
slcN .
? C 14 GA. GALVANIZED WRE
z ,
n
XX
w .
1 31 1
} II t
3 GA. GALVANIZED WRE U �}
W
U U
STEEL FENCE POST &` HIGH MIN.
<
.
NOTE:
f. CUP'FENCE TO GALVANIZED WRE @ 5 FOOT ON -CENTER SPACING
Ct}
2 WRE FENCE TO STEEL. FENCE POSE
ry
Ld
NOTE PLACE BRIGHT ORANGE PLASTIC
<
MESH FENCE AT THE DRIPLINE AROUND
-3
ME TO BE RETAINED. (TYPICAL)
TREE PROTEC77ON FENCE f3ET,41C
NOT TO SCALE
x
0
CD
�c
L�
LLj
ram,
I
` � 1
4
t /
t
s
20
LANDSCAPE NOTES:
1. ALL DEFECTIVE, DISEASED OR DEAD PLANT MATERIAL SHALL BE REPL -\,CED i," iTHIN 3 MONTHS OR 1--Ju { _ s f _' N1TING SEASON IF THE LOSS DOES NET OC- UR IN A
PLANTING SEASON, PLANTS HAVE A 1 YEAR WARRANTY FROM THE DATE OF PROJECT SUBS , NAIEVL C !. R EUir iCAL LY i D' A i ED TO Sit /Eu OR i°r;I: JLiFE ARE
EXEMPT FROM THIS CONDITION.
2. THE LANDSCAPE CONTRACTOR SHALL FIELD LOCATE ALL UTILITY LINES PRIOR TO COMM EEN�CEMENT OF ,t<`u� � . _ �� ON —SITE TyHL IT PLANS AS A PART OF THIS
CONTRACT IS AVAILABLE FOR REVIEW,
3. THE PLANTS SHALL BE NAILED AND BURLAPPED OR CONTAINER GRC tty>> AS SPECIFIED. NO CONT�,iNER ,_< , l CL.E TE F i T IS t11-E P, r I� TO BE ROOT -BOUND.
ALL PLASTIC ROOT WRAPPING MATERIAL SHAL BE REMOVED, NO BARE- ROOT STOCK WILL BE ACCEP > LD.
4. ALL PLANTS SHALL MEET THE MINIMUM SIZE INDICATED ON THE PLAN. ONE PLANT FROM EACH GROUPING LL DE LABELED, INDICATING THE PLANT NAMP AND SIZE. TAGS
SHALL BE REMOVED AFTER THE REVIEW.
— n — -
5. ALL PLANTS SHALL BE SPRAYED WITH AN ANTI -DESICCANT WITHIN T- RRS 124 HOURS AF I FR i_ HL BE�II N1 :; vF T HEIR r IP` I V i! I AI .
6. ALL PLANTS SHALL BE INSTALLED PER THE PLANTING DETAILS. ALTERNATE TREE STAKING E MODS ,`trig, �` PL � LD FOR R� tJlt ', AND APPROVA_.
7. STOCKPILE PLANT MATERIAL UP DELIVERY TO THE SITE INA A SHADY LOCATION, EMBEEDED IN SA ,DUST, R: RK 1R , _._. STOCKS)1LL"_ PLANTS NEAR A ;tdAiER SOURCE ,�ivD WATER
AT LEAST ONCE A DAY TO MAINTAIN HEALTHY PLANT STOCK.
8. A PRE- M RGiT H I HA Pr ~,c F I ,; i _ I RATE F QUARTS t
I E cRB DIODE SHALL BE APPLIED TO ALL PLANTING _ �. HERBICIDE �E S t , B�. i v i : ; IX D UPI T I RC�I`aJ AT A 1 �.PER
ACRE. ADHERE TO ALL PRODUCT MANUFACTER'S DIRECTIONS AND RECCiiMrllt,/MENDATIOINS, ADHERE T C u,, N;T I IONAL ENVIRC"NIVIEP T AL REGULATiONS, DO NOT APPLY
WHEN THE WIND SPEED EXCEEDS 5 M.P,H.
9. ALL PLANTING BEDS SHALL HAVE A 2" DEEP LAYER OF MEDIUM SIZED DECORATIVE FIR OR REDWOODt't1 { L._ ARK SHALE_ B' ROUND NOT SHREDDED. RAKE PLANTING
BEDS SMOOTH PRIOR TO COMPLETION.
10. INSTALL ALL PLANT MATERIAL DURING FAVORABLE WEATHER AND WITHIN SEASOiNAL PLANTING LIM!i t;fvl :. I.0 I' STALL PLANT !,I E' THE J ,iYY iiGN i 1;=iPE tt�TURE
EXCEEDS 80 DEGREES OR LOW TEMPERATURES FALL BELOW 32 DEGREES.
I
{ t (1 :. f i
_ :li 4, r i CC �, .,., r 1 ,-1
L E G ENO11. FERTLIZER, TABLETS , I a - e S _
SHALL BE 21 GRAMS. PLACE EVENLY THROUCi �...1 P,_r,NTll`J�; PIT. FER i iLlv�_: , : , .�..�..� ..�, ,:. � , : I , ,� t { . f , r
_ _ �_ �_S AB� , �t I � �, U .,I I , r�J��_.1 R��tASE
r
r tR I ILt�.�tl,_, �fv,Pr �I�D B , D.F. I��iArCRS -- -- ;� i � F AND , APPROVAL. INC. 1 800 787-3802. FERTILI_�_, . PACKETS MAY �-,,_�O B� ___ �:��,lE� � �_.a r0� REVIEW �I�� r��PRC 1AL.
_... . ,_S- < I. - 1 ,: „a.. S F Y ,. .. r 1, fi l _I. P E;
12
_ ER� Au L,,ANUFAC (UR_D B , v� ,SON ,�RiGATED , Iv I:,»: AREAS,
>x —
# t k - -
d F(
,S a' 'R
. �> �>1 'l � ALLOW
_; t, �..� 3 � ; .. _�.� _ .. �. FOR t, ,r, I - ! EI DCD � THE Dt
„ r nt
I k, N
#`R a.,ztr;s..t_r��t..i� �'�s.. �._��.�,:�;--�, =�.V DURING TI"� 1 APPROPRIATE .,'l(-�'I,-,:; 1 ( 1 (-�! T
G E 'NEXT>_ L, I.IING SEASON, ni r'R>�t i,,,.:._ ,i i , SHA�L 8E REQUIRES TG I��SURG v�!�, L(„NCE.
tr L
t C i T
`llPROVIDE-I METHOD E X i S TI I�i G TREES . ,. THE ��� x�R �� R� Sr'OIY.,II_� rv;, THE CONTRACTUAL C78CIGATIONS L. Tf �E CON !RAC 1 OR i O ut_ '"�, �.Glf URf-,TRY IRRIGn ; vi, � f s i �Iv9 OR �tv,� � EPII Ik
3��APTO
I SUSTAIN PLANTS UNTIL ESTABLISHED.
15, ALL LANDSCAPE AREAS SHALL BE KEPT FREE OF TRASH, CONSTRUCTION DEBRIS AND OTHER DE_ I I iMi.
TREES TO BE REMC . E
GROUND COVER FOR DISTURBED AREAS
P! 1 P S C T U2.. RAKESCARIFY TOP o" OF NATIVE GROUND.
IN 2" OF IMPORTED TOPSOIL.
3. SMOOTH, SEED, AND COMPACT.
! 4. SEED MIX SHALL BE:
- 6, _ _ r ``,4U G AUCUS (47%)
EXISTING CONTOUR �— � � : _ST CA RUBRA (40%)
R S£ ° MPSIA C,AESPITOSA (12%)
PRUNUS LAUROCERASUS "OTTO LUYKEN"/OTTO LUYKEN
LAUREL 24" HEIGHT, B&B, •,_�L yOOT'EO,
FULL & BUSHY, 3' MAX O.C.
GROUND COVER FOR
DISTRURBED AREAS (SEE NOTES)
t -
4{
I
t
)rt
t
4
E
I
i
1
1
I
GRAPHIC � � LE
0 10 20
{INI'EET}
1 inch = 20 ft.
NOTE
THE LOCATION OF ALL EXISTING LINDE
SHOWN IN AN APPROXIMATE GNAT` ONtE
SHALL DETERMINE THE EXACT LOCATI(
UTILHES BEFORE COMMENC,,. W5RK.
i0 BE FULLY RESPONSIBLE FOR ANY
MIGHT BE OCCASIONED BY HIS FAILUR
AND PRESERVE ANY AND ALL UNDERC
BEFORE YO4
1-800-424-5
PERMIT NO, XXXXX
CITY OF XXXX
j APPROVED BY:
,I
I
t
DATE
Q ,