20-100103CITY OF
Federal Way
Centered on Opportunity
February 13, 2020
Mr. Aleksey Guyvoronsky
Ace Construction Services, LLC
1020 South 344th Street, Suite 201
Federal Way, WA 98003
alekse r24 ilx
CITY HALL
33325 8th Avenue South
Federal Way, WA 98003-6325
(253) 835-7000
www.cityoffederalway.com
Jim Ferrell, Mayor
FILE
Re: File #20-100103-00-SF; REQUEST FOR CRITICAL AREA RECONNAISSANCE LETTER
Khyluk Lot A Single -Family & ADU, 30329 215t Avenue SW, Federal Way
Dear Mr. Guyvoronsky:
The City of Federal Way's Community Development Department received your building pern-lit applications
(files 20-100103-00-SF & 20-100106-00-AU) on January 8, 2020, for the construction of a single-family home
and an auxiliary dwelling unit (ADU) on a nonconforming sized vacant lot located at 30329 21s' Avenue SW,
Federal Way, WA 98023 (parcel 01:2103-9158). This letter is to inform you that the city has become aware of
a potential wetland on this property, or in the vicinity. There is need for further evaluation of the site before
city staff can decide on your development permit applications._
BACKGROUND
On December 16, 2019, the city received two proposals to construct a single-family home and an auxiliary
dwelling unit on the property listed above. This property is owned by 304 & 21s' Ave LLC, along with four
adjoining properties (parcels 012103-9163, 012103-9099, 012103-9160, & 012103-9161), per Ding County
Department of Assessments records. Your permit applications arrived after the issuance of building permits
on December 20, 2019, for parcels 012103-9163 and 012103-9099.On December 26, 2019, clearing of
vegetation and grading on site began for these two permitted parcels. On the morning of December 27, 2019,
the city received messages from a concerned citizen regarding the development activities. On January 8, 2020,
a representative of the city's Planning Division conducted a site visit to visually inspect for potential indicators
❑Fwetlands (the observations are listed below). Staff continues to receive citizen concerns regarding
development in this area with regard to the presence of a potential environmentally critical area.
STAFF SITE ❑BSERVATIONS
On January 8, 2020, city staff visited the sites located on the north and west sides of the intersection between
215r Avenue SW and SW 3041h Street, Federal Way, WA 98023 (parcels 012103-9163, 012103-9099, 012103-
9158, 012103-9160, & 012103-9161). Staff observed site topography of a depression running From the south
of the parcels across SW 304th and continuing north towards the waterfront downhill along 21" Avenue SW,
and then 20sh Place SW. Standing water was observed in two locations within the depression on the parcels in
question, as well as a prevalence of red alder trees (alnus nasbm) and a large Oregon ash cf=inus latifolia) tree
within this area, which are commonly known as hydrophytic vegetation indicators of potential wetlands. Each
of these observations are an indication to city staff of the need for a wetland reconnaissance.
Mr. Aleksey Guyvoronsky
Page 2 of 2
February 13, 2020
REQUIREMENTS
Based on Federal Wray Revised Code (FWRC) 19.145.070(2) & (3), the city requests you provide a wetland
reconnaissance summary letter from a certified wetland biologist verifying if wetlands are present on or within
200 feet of the site. The reconnaissance summary letter needs to indicate whether or not further action is
required based on soils, vegetation, and hydrology. If wetlands are present, then a wetland delineation and
classification report must be prepared by a qualified professional in compliance with FWRC 19.145.080(2).
Those requirements include:
"(2) The critical area report shall be prepared by a qualified professional, incorporate best available
science, and include the following items:
(a) The name and contact information of the applicant, a description of the proposal, and
identification of the type of approval (use process, subdivision, building permit) requested;
(b) Vicinity map;
(c) The dates, names, and qualifications of the persons preparing the report and documentation of
any reconnaissance on site;
(d).A scaled site plan depicting critical areas, buffers, setbacks, and proposed improvements;
(e) Photographs of the site and critical areas;
(f) Identification and characterization of all critical areas adjacent to the proposed improvements;
(g) A description of efforts made to apply mitigation sequencing pursuant to FWRC 19.145.130 to
avoid, minimize, and mitigate impacts to critical areas;
(h) A copy of the Joint Aquatic Resource Permit Application QARPA) if applicable;'
(i) Additional information required for the individual critical area; and
0) Any additional information determined by the director to adequately review the proposed activity."
The wetland report will be peer reviewed for compliance with applicable FWRC requirements by the city's
third -party wetland reviewer at the applicant's expense. This review cost must be pre -funded by the applicant
prior to this peer review occurring per FWRC 19.145.080(3).
CONCLUSIONS
Your construction permit applications have been placed on -hold until the city receives a reconnaissance
summary letter from a certified wetland biologist verifying that there is, or is not a wetland on site. If you have
any questions regarding this letter, contact me at william.Wldin ciiyoffedcral,,vay.com, or 253-835-2622.
Sincerely,
0�/ /14Z-Y
William Golding
Planning,Intern
enc: January 8, 2020, Staff Observation Notes
c¢ Greg Kirk, Plans Examiner
Kevin Peterson, Senior Engineering Plans Reviewer
20-100103-00-SF Doc. LD. 80129
SW 304th ST & 21 st Ave. SW
118/2020, 1:34:21 PM 1:1,128
0 009 001 002mi
' Site Address Feature 0.01 0.02 0.04 km
Parcels Species of Wetland Indicators Present
Area of Potential Red alder
Wetland Oregon Ash
Standing Water Observations made on site visit 1/8/2020 at approximately 12:45 PM by William Golding in
response to citizen concerns expressed related to project area.
al
Reply to: clungeon@bnd-law.com
February 14, 2020
FILE
RECEIVED
FEB 14 2020
UTY OF FEDERAL WAY
COMMUNF Y DEVELOPMENT
VIA E-MAIL to brian.davis a.cityoffedera[way.co�n
Brian Davis
Community Development
33325 8th Avenue South
Federal Way, WA 98003
Re: Request to Halt Construction and Investigate Site and Permit Concerns on Parcels
0121039099, 0121039163, 0121039161, 0121039160, and 0121039158.
Dear Director Davis:
We represent, January Agnew -Parks, who lives across the street from five parcels under
development along 304th Street and 21 st Avenue SW in Federal Way. Our review of public records
and application materials reveals a number of issues requiring your attention, investigation, and
possible enforcement of city codes.
As we understand it, a single entity, 304 & 21st Ave SW, LLC, purchased five heavily wooded
and undeveloped lots with the intention of destroying the local greenspace, habitat, and potential
wetland in order to construct five large single family homes with detached or attached accessory
dwelling units. Building permit applications have been submitted for all five parcels. The building
permit applications for parcels 0121039099 and 0121039163 have been approved. The
applications for 0121039161, 0121039160, and 0121039158 remain pending.
We are sure you can appreciate the neighborhood's concern as they watch an area they believed
to be a protected greenspace stripped bare and waterlogged to allow construction of large homes —
some too large for the lot sizes —from a series of applicants who have no apparent connection to
the legal owner of the property. We understand that the parcels are zoned RS-15 and allow the
construction of single-family homes and accessory dwelling units. But we ask that the city require
the developer to fully comply with city code in the process.
For the following reasons, we ask that you halt construction, rescind permit approval, reject
pending permit applications, and require additional information and assurances from the applicant
before any further development takes place.
A. The Owner Should Be Required to Conduct a Wetlands Assessment on All Five
Parcels.
First, the, city. should verify that all five parcels do not contain wetlands prior to permitting the
development. We were informed that the application approvals for three of the parcels are on hold
pending a wetland assessment conducted by the applicant. The same information is needed before
any further work is undertaken on the other two parcels. The fact that clearing and construction
has begun does not absolve the applicant or city from critical area requirements pursuant to city
code.1
The following pictures of parcel 0121039099 were taken on January 31, 2020. The pictures
demonstrate that the parcels are fully saturated and there is significant pooling within the area.
Excluding these parcels from the wetland assessment is incongruous with the site conditions. The
city should issue a stop work order pending a wetland assessment of all five parcels.
Figure 1 Photograph ol'Parce10121039099 on January 31, 2020
"When a critical area or its buffer has been altered in violation of this chapter, all ongoing development work
shall stop and the critical area shall be restored. The city shall have the authority to issue a stop work order to cease
all ongoing development work, and order restoration, rehabilitation, or replacement measures at the owners or
violator's expense to compensate for violation of provisions of this chapter." FWRC 19.145.060(1).
2
Figure 2 Photograph ofTarce10121039099 on January 31, 2020
B. The City Should Investigate Violation of the Tree Retention Plan and Require a Bond
for Any Future Clearing.
It appears that the permit applicant is not adhering to tree retention plan submitted with the permit
application materials. While we understand that a significant portion of trees would be cut to
accommodate a single-family home, garage, and attached or detached accessory dwelling unit, the
current construction activity is inconsistent with the application materials relating to minimum tree
retention requirements pursuant to FWRC 19.120.130. The City Code requires 25 tree units per
acre in single family residential zones. Tree -units are determined by tree size and whether the tree
will be retained or added/replaced. Trees that are retained are allocated greater tree unit value than
similar or equivalent trees that are added or replaced. FWRC Table 19.120.130-2 (Tree Unit
Credits). The idea is that an established tree has greater value than a new planting.
The Tree Retention Plan for Parcel 0121039099 indicated that it would achieve the required 8.5
tree units for the parcel size by retaining 5 trees. However, our client has informed us that no trees
3
remain on the parcel. While this can be rectified by additional plantings post -construction, it
demonstrates a disregard for adhering to the permit conditions and city code requirements.
Therefore, we ask that you investigate the site to confirm violation of the applicant's tree retention
plan and require a bond from the applicant for each parcel as assurance that any further clearing
will conform to city standards pursuant to FWRC 19.120.240.
C. The City Should Require the Permit Applications Include Accurate Owner or Agent
Information.
It is established practice for the permitting agency to require that permit applications be submitted
by the owner or agent of the parcel. Yet practically every permit application for these parcels
contains inaccurate information regarding ownership of the property.
• Aleskey Onishchenko is listed as the owner and/or applicant on the following permits: 19-
102757-SF, 19102752-SF, 19-105985-EL, 19102759-SF, 19-102756-SF, and 19-102755-
AU.
• Lilia Stefoglo is listed as the owner for permit 19-105849-SF.
■ Liliya Stefoglo is listed as the owner for 19-105855-AU.
■ Esther Onischchenko is listed at the Owner on the application for 19-102758-AU.
Not one of these people is the legal owner of the properties at issue. All of the properties are owned
by 304 & 21st Ave, LLC.2 Furthermore, the Washington Corporation and Charities Filing System
reveals that none of these individuals are registered agents for 304 & 21 st Ave, LLC.
The city should reject the pending applications and rescind the permits because of the false
ownership information on the applications. The city should require that resubmissions be from the
correct owner of the property or the owner's authorized agent.
D. The City Should Enforce Lot Size and Coverage Requirements.
At least one of the permit applications violate the city's lot coverage requirements. The application
materials for parcel 0121039161 misrepresent the lot size of the parcel. Application 19-105849-
SF claims the lot is 19,000 square feet. This is wildly inaccurate. The King County Parcel Viewer
states that this property is 8,759 square feet. The site plan for the parcel says the parcel is 9,930
square feet. Even the smaller figure is off by well over 1,000 square feet from the recorded lot size.
This is particularly important as Federal Way Code limits lot coverage in the RS-15 zone to 50%.
The current proposal for this lot would exceed this maximum. The site plans for parcel 0121039161
(although confusingly also referred to as both 012103961 and 0121039163) indicate 6,088 square
feet of impervious surface on an 8,759 square foot lot. Using the parcel area indicated by the
County's records, that results in 69.5 % coverage, far in excess of the 50% maximum allowed by
code.4
304 & 21st Ave, LLC is the owner of all five parcels according to King County Parcel Viewer ownership records.
3 4,150 (Roof) + 1,938 (concrete slab) = 6,088. See FWRC 19.110.020 ("... [T]he area of all structures, pavement
and any other impervious surface on the subject property will be calculated as a percentage of the total lot area ... ")
4 6088/8759=.695.
1!
Even using the slightly larger lot area specified in the site plan (9,930 square feet), the 50%
threshold still would be exceeded.5 Only using the wildly inaccurate 19,000 square foot number
from the application would the lot coverage requirement be met.
It also appears that parcel 0121039158 will also exceed the 50% lot coverage requirement. The
site plan shows 5,790 square feet impervious surface on a 9,494 square foot lot, resulting in 61%
lot coverage.
Therefore, the city should halt construction and deny permit applications for parcel 0121039161
and 0121039158 until the applicants can demonstrate conformity with city code.
While we acknowledge that the building permits at issue may not require public notice, given the
dramatic changes to this sensitive forested site, the applicant and city could have done more than
the minimum required by code (i.e. nothing) and informed the neighbors about the project.
Furthermore, it appears that the applicant's contractor is not complying with state construction
notice requirements under RCW 60.04.230. The contractor has not posted any such notice.
Given the clear interest from the neighborhood and the untrustworthiness of the filings by the
applicants, we encourage the city to notify the neighbors of any updates, status changes, or
construction on these parcels moving forward.
We understand that most of these applications were submitted around the holidays and New Year
so maybe a few details fell through the cracks during the review process. Regardless, the City
Code requires compliance from the applicant6 and tasks the development director with execution
and enforcement of the code.' On behalf of our client, we ask that you halt construction and
investigate the issues presented in the application materials and construction practices prior to any
further development of these parcels.
Very truly yours,
BRICKLIN & NEWMAN, LLP
Audre Clungeon
David Bricklin
Attorneys for January Agnew -Parks
5 6088/9930= .665.
6 "Regardless of any review, approval, inspection, or other actions of the city, it is the responsibility of an
applicant and any owner to ensure that all work, actions, or conditions on the subject property comply with this title,
any permits or approvals granted under this title, and all other applicable laws or permits." FWRC 19.15.080.
"The community development director shall be responsible for directing the development and execution of
the city's comprehensive plan for development including growth projections, land use, housing, environmental
sensitivity, urban design, annexation, and zoning code modifications; reviewing and enforcing city development
including land use applications, code enforcement, plan review, and building inspection functions; overseeing human
resources programming; and supervising planning, program and other staff." FWRC 2.13.030.
5
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CITY Or�L{I
Federal-Waycz
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PERMIT NUMBER M� tJ 10
SITE ADDRESS
A
PROJECT VALUATION
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TYPE OF PERMIT
NAME OF PROJECT
PROJECT DESCRIPTION
Detailed description of u)ork to
be included on this permit only
PROPERTY OWNER
,Z-33142`q
CONTRACTOR
APPLICANT
PROJECT CONTACT
(The individual to receive and
respond to all correspondence
concerning this application)
PROJECT FINANCING
1{7hen value is $5,000 or more
(RCW 19.27.095)
PERMIT APPLICATION
a th +Federal Way, WA 98003-(i325
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I certify under penalty of perjury that I am the property owner or authorized agent of the property owner. I certify that to the best
of my knowledge, the information submitted in support of this permit application is true and correct. I certify that I will comply with
all applicable City of Federal Way regulations pertaining to the work authorized by the issuance of a permit. I understand that the
issuance of this permit does not remove the owner's responsibility for compliance with local, state, or federal laws regulating
construction or environmental laws.
I further agree to hold harmless the City of Federal Way as to any claim {including costs, expenses, and attorneys' fees incurred in
the investigation and defense of such claim), which may be made by any person, including the undersigned, and filed against the city,
but only where such claim arises out of the reliance of the city, including its officers and employees, upon the accuracy of the
information supplied to the city as a part o xcation. l r s]
SIGNA DATE + 0 b G lq
PRINT NAME: w
Bulletin #100 — January 29, 2016 Page I of 2 k:\Handouts\Perniit Application
MECHANICAL PERMIT
VALUE OF MECHANICAL WORK
-
$ Q
Indicate how many of each tPj d .
rlrLsh4etj or relocated as part of this RLoLecL Do not include e="fingfixtures to remain.
AIR HANDLING UNITS"
PPhAI " .'I
GAS PIPE OUTLETS
OTHER (Describe)
AIR CONDITIONER
FIREPLACE INSERTS
HOODS (Commercial)
BOILERS
FURNACES
HOT WATER TANKS )Gas)
COMPRESSORS
GAS LOG SETS _
w
REFRIGERATION SYST
DUCTING
GAS PIPING
WOODSTOVES
PLUMBING PERMIT
VALUE OF PLUMBING WORK
Z(J
U()-0
Indicate how TqnU o each n e o
Wure to be installed or relocated as
o pr
oject, ro ect, Do not include exis
' Ixtures to remain.
BATHTUBS (orTob/Shower Combo)
LAVS (Hand sinks) S
TOILETS
WATER PIPING
L DISHWASHERS
RAINWATER SYSTEMS
URINALS
OTHER (Describe)
DRAINS
SHOWERS
VACUUM BREAKERS
DRINKING FOUNTAINS
SINKS (xachco/Utday
WATER HEATERS (Electric)
HOSE BIBBS
SUMPS 1•
WASHING MACHINES
TOTAL FIXTURES
GENERAL INFORMATION
CRITICAL AREAS ON PROPERTY?
IgWw{A,�T['EER' PURVEYOR
4 KWOr
SEWER
SIEWWEER PU��R,,{VEEEY/�O'R(��!/
tf 11 �11� � v
VALUE OF EXISTING IMPROVEMENTS
EXISTING/PREVIOUS USE
LOT SIZE (In Square Feet))
2
1 9 0- Z
EXISTING FIRE SPRINKLER SYSTEM?
❑ Yes ray No
PROPOSED FIRE SUPPRESSION SYSTEM?
❑ Yes ❑ No
RESIDENTIAL - NEW OR ADDITION
AREA DESCRIPTION (in square feet)
EXISTING
PROPOSED
TOTAL
FOR OFFICE USE
BASEMENT
�S
-7 ► O
�f
"r
FIRST FLOOR (or Mobile Home)
SECOND FLOOR
COVERED ENTRY
Ito
I (PO
DECK
{(
GARAGE CARPORT ❑
OTHER (describe)
�q
1
PROPOSED
q
LAP j
TOTAL
Area Totals
EXISTING
.*NEW HOMES ONLY'
ESTIMATED SELLING PRICE O 0 U # OF BEDROOMS
COMMF.,RCIAL — NEW/ADDITION
AREA DESCRIPTION
Area in
Square Feet
Occupancy Group(s)
Construction
Tye
# of
Stories
Additional Information
NEW BUILDING
-
ADDITION
COMiMERCIAL — REMODEUTENANT IMPROVEMENTS
AREA DESCRIPTION
Area in
Square Feet
Occupancy Group(s)
Construction
a
# of
Stories
Additional Information
TOTAL BUILDING
.
TENANT AREA ONLY
PROJECT AREA ONLY
Bulletin #100 —January 29, 2016 Page 2 of 2 k:\IIandouts\Permit Application
APPENDIX E
Soils Report
- -j GGEO RESO U RCES
earth science & geotechnical engineering
5007 Pacific Hwy E., Suite 16 1 Fife, WA 98424 1 253.896.1011 1 www.georesources.rocks
ACS Ilc.
Aleksey Guyvoronsky
1020 - South 344th Street
Unit 201
Federal Way, Washington 98003
Aleksey24@gmail.com
(253) 732-7654
September 5, 2019
Stormwater Soils Report: Infiltration Feasibility
Proposed Single Family Residences
SW 304th Street
Federal Way, Washington
PN: 0121039163, 0121039099, 0121039158,
0121039160, 0121039161
Doc ID: ACSIIc.SW304st.SR
INTRODUCTION
This soils report addresses the feasibility of onsite infiltration for the five proposed single
family residences to be constructed along the north side of SW 304 Street between 21 st Avenue
Southwest and 23rd Avenue Southwest in Federal Way, Washington. The approximate site location
is shown on the attached Site Location Map, Figure 1.
Our understanding of the project is based on our conversations with you, our June 12, 2018
site visit, our understanding of King County development codes, and our experience in the area. We
understand that the site is currently undeveloped, and you are proposing to construct a single-
family residence on each parcel.
SCOPE
The purpose of our services was to evaluate the surface and subsurface conditions at the
site as a basis for developing and providing geotechnical stormwater recommendations for the
proposed development. Specifically, our scope of services for the project included the following:
1. Reviewing the available geologic, hydrogeologic, and geotechnical data for the site area;
2. Exploring surface and subsurface conditions by reconnoitering the site and logging the
previously excavated percolation test pits at the site;
3. Describing surface and subsurface conditions, including soil type, depth to groundwater,
and an estimate of seasonal high groundwater levels;
4. Providing our opinion about the feasibility of onsite infiltration in accordance with the
2016 King County Surface Water Design Manual (KCSWDM) and,
5. Preparing this written Soils Report summarizing our site observations and conclusions,
and our recommendations and design criteria, along with the supporting data.
ACSIIc.SW304st.SR.doc
September 5, 2019
page 12
The above scope of work was performed in general accordance with our discussion on
August 25, 2019 during which we received verbal notification to proceed with our scope of work
from you.
SITE CONDITIONS
Surface Conditions
The sites are located north of Southwest 304 Street in Federal Way, Washington within an
area of existing residential development. Each parcel is generally rectangular in shape, while the
total project site is generally "L" shaped. The parcel range in size from approximately 8,759 square
feet to 18,516 square feet. The total project site encompasses approximately 61,108 square feet or
1.40 acres. The site is bounded by existing residential development to the north, 23rd Avenue
southwest to the west, Southwest 304th Street to the south, and by 21 st Avenue Southwest to the
east.
The site is generally flat to gently sloping to the south at less than 5 percent. Total
topographic relief across the site is on the order of 5 feet. The existing site configuration and
topography is shown on the Site and Exploration Plan, Figure 2.
Vegetation across the site generally consists of a moderate to dense stand of mature native
deciduous and coniferous trees with a dense understory of mixed native and invasive low -growing
species. No areas of surface water were observed on the site at the time of our site visit.
Site Soils
The USDA Natural Resource Conservation Service (NRCS) Web Soil Survey maps the site as
being underlain by Alderwood gravelly sandy loam (AgB) soils. The Alderwood soils are derived from
glacial drift and/or glacial outwash over dense glaciomarine deposits that form on slopes 0 to 8
percent, have a "slight" erosion hazard when exposed, and are included in the hydrologic soils group
B. An excerpt of the NRCS Soil Survey Map for the site vicinity is included as Figure 3.
Site Geology
The Geologic Map of the Tacoma North 7.5-minute Quadrangle, Washington (Troost, Booth,
Borden in review) maps the site as being underlain by Fraser age advance outwash deposits (Qva).
The advance outwash typically consists of a poorly sorted, lightly stratified mixture of sand and
gravel that may locally contain silt and clay t at was deposited by meltwater streams issuing from
the a vancing continental ice mass. Post -deposition, the advance outwash was overridden by the
continental ice mass. As such, these deposits are typically encountered in a very dense condition
and exhibit high strength and low compressibility characteristics where undisturbed. An excerpt of
the referenced geologic map for the site area is included as Figure 4.
Subsurface Explorations
On June 12, 2018, a representative from GeoResources, LLC (GeoResources) visited the site
and monitored the ex ion ❑f 1 test it to a de th of 5 feet below the existing ground surface,
logged the subsurface conditions encountered in the test pit, and obtained representative soil
samples. The test pit was excavated by a small track -mounted excavator operated by a licensed
earthwork contractor working for you. The location of the test pit was selected in the field based on
project information provided by you at the time of excavation, our understanding of the proposed
GEORESOLIRCES
ACSIIc.SW304st.SR.doc
September 5, 2019
page 13
development, consideration for underground utilities, existing site conditions, and current site
usage. The test pit was then backfilled with the excavated soils and bucket tamped, but not
otherwise compacted.
The subsurface exploration excavated as part of this evaluation indicates the subsurface
conditions at a s ecific location onEy and 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. However, based on our
experience in the site vicinity, it is our opinion that the soils observed in the -test -pit -are generally
representative of the soils at the site.
The approximate test pit location is shown on the Site and Exploration Plan, Figure 2. The
location shown was determined by taping or pacing from existing site features and should be
considered accurate only to the degree implied by our measuring methods. The soils encountered
were visually classified in accordance with the Unified Soil Classification System (USCS) and ASTM D:
2488. The USCS is included in Appendix A as Figure A-1, while the escriptive log of our test pit is
included as Figure A-2.
Subsurface Conditions
Our explorations encountered subsurface conditions that generally disagreed with the
mapped stratigraphy within the vicinity of the site but are generally consistent with typical
stratigraphic relationships in the area. Our test pit generally encountered approximately 2 feet of
topsoil and forest duff mantling orange -brown to gray fine sandy SILT in a soft to medium stiff,
moist to wet condition to the full depth explored. We interpret these soils to be consistent with
recessional lacustrine deposits.
Groundwater Conditions
Moderate groundwater seepage was observed in our exploration at approximately 4.0 feet
below existing grades. Additionally, we observed mottlin ag s shallow as 2 feet below existin grades.
Mottling is often indicatiye_of_�ieasonal high groundwater levels for shallow groundwater regimes.
Based on our observations and experience in the vicinity of the site, it is our opinion that seasonal
high groundwater levels extend to within approximately 2 feet of the existing ground surface.
We interpret the seepage and mottling observed to be indicative of a perched groundwater
table. These shallow groundwater regimes may develop when a relatively permeable soil is underlain
at depth by a relatively impermeable soil. Based on the observed soil conditions, it appears the soft to
medium stiff silt soils function as an aquitard. We anticipate fluctuations in the oca groundwater
level I i e y occur in esponse to reci 1 ation patterns, off site construction activities, and site
utilization. As such, water level observations made at the time of our field investigation may vary
from those encountered during the construction phase.
CONCLUSIONS AND RECOMMENDATIONS
Based on the results of our site evaluation, it is our opinion that the onsite infiltration of
sta ater run ff ReneratQd by the r�sid�tces� and asso[1 te�jte
dev opment is_ not feasibl from a geotechnical standpoint.
Infiltration Recommendations
GEOR E5OLf ROES
ACSIIc.SW304st.SR.doc
September 5, 2019
page 14
Per the 2016 KCSWDM Appendix C, Section C.2.2.2, a minimum vertical separation of 3 feet is
required from the bottom of an infiltration facility to seasonal groundwater and a minimum of 3 feet
of permeable soil is required below the facility bottom. Additionally, infiltration facility bottoms must
be located within native soils in accordance with Chapter 5, Section 5.2 and Appendix C, Section
C.2.2.2. Groundwater seepage was encountered at 4 feet below existing grade in our exploration and
evidence of seasonal high groundwater was observed at 2 feet below existing grade. Based on the
above minimum vertical separation requirements and the observed subsurface conditions, Infiltrations
is not feasible a� t�� e.
Y- We recommend that alternative stormwater management methods be considered for
management of stormwater runoff generated by the proposed site development. All stormwater
facilities should be designed and constructed in accordance with the KCSWDM, and all minimum
setbacks and infeasibility criteria of the KDSWDM should be considered prior to the selection and
location of a stormwater facility.
LIMITATIONS
We have prepared this report for use by the ACS, LLC and other members of the design team,
for use in the design of a portion of this project. The data used in preparing this report and this report
should be provided to prospective contractors for their bidding or estimating purposes only. Our
report, conclusions and interpretations are based on our subsurface exploration, data from others
and limited site reconnaissance, and should not be construed as a warranty of the subsurface
conditions. We only evaluated the site for infiltration feasibility. No other recommendations with
regards to geotechnical engineering were expressed nor implied.
Variations in subsurface conditions are possible around the exploration 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 exploration, 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 remediation and
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 for
consideration in design.
If there are any 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, we should be given the opportunity to review our
recommendations and provide written modifications or verifications, as appropriate.
GEORESOURCES
ACSIIc.SW304st.SR
September 5, 2019
page 15
We have appreciated the opportunity to be of service to you on this project. If you have any
questions or comments, please do not hesitate to call at your earliest convenience.
Respectfully submitted,
GeoResources, LLC
R
Dana C. Biggerstaff, PE Seth Mattos, LG
Senior Geotechnical Engineer Project Geologist
DC:STM:DCB/dc
DoclD: ACSIIc.SW304st.SR.doc
Attachments: Figure 1: Site Location Map
Figure 2: Site and Exploration Map
Figure 3: NRCS Soils Map
Figure 4: Geologic Map
Appendix A: Subsurface Explorations
GEORESOURCES
i
W '!I jv-v 'o �C� MWI '''ram _-... :rt�■
Approximate Test Pit Location O-P
Map created from King County Public GIS (https://gismaps.kingcounty.gov/iMap/)
Not to Scale
Site and Exploration Map
_ Proposed Single Family Residences
SW 304" St
GEORESOURCES King County, Washington
PN: 0121039099, 0121039099, 0121039158, 0121039160,
earth science & geotechnical engineering 0121039161
5007 Pacific Hwy E., Suite 16 1 Fife, WA 98424 1 253-896.1011 1 www georesources. rocks
DocID: ACSIIc.SW3045t September 2019 Figure 2
Approximate Site Location
Map created from Web Soil Survey (http://websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx)
Soil
Type
Soil Name
I
Parent Material
Slopes
Erosion
Hazard
Hydrologic
Soils Group
AgB
Alderwood
gravelly sandy
Glacial drift and/or glacial outwash over dense
0 to 8
Slight
B
glaciomarine deposits
loam
Everett very
EvB
gravelly sandy
Sandy and gravelly glacial outwash
0-8
Slight
A
loam
�.
GEORESOURCES
earth science & geotechnical engineering
5007 Pacific Hwy E.. Sulte 16 1 Fife, WA 98424 1253.896.1011 1 www.8earesources.rocks
Not to Scale
NRCS Soils Map
Proposed Single Family Residences
SW 304Ih St
King County, Washington
PN: 0121039099, 0121039099, 0121039158, 0121039160,
0121039161
DocID: ACSIIc.SW304St I Sep[tember 2019 1 Figure 3
a-
Approximate Site Location
An excerpt from Geologic Map of the Tacoma North 7.5-minute Quadrangle, King County, Washington by Troost, Booth,
and Borden in review
Qf
Fan Deposits Holocene
Qvr
Recessional Outwash Deposits
Qvt
Vashon Subglacial Till
Qva
Advance Outwash
GEORESOURCES
earth science & geotechnical engineering
5007 Pacific Hwy E., Suite 16 1 Fife, WA 98424 1 253.896-1011 1 www georesources. rocks
Not to Scale
Geologic Map
Proposed Single Family Residences
SW 30411 St
King County, Washington
PN: 0121039099, 0121039099, 0121039158, 0121039160,
0121039161
DoclD: ACSIIc.SW304St C September 2019 Figure 4
Appendix
Subsurface Explorations
SOIL CLASSIFICATION SYSTEM
MAJOR DIVISIONS
GROUP
SYMBOL
GROUP NAME
GRAVEL CLEAN
GW
WELL -GRADED GRAVEL, FINE TO COARSE GRAVEL
GRAVEL
GP
POORLY -GRADED GRAVEL
COARSE
GRAINED More than 50% GRAVEL
GM
SILTY GRAVEL
SOILS Of Coarse Fraction WITH FINES
Retained on
GC
CLAYEY GRAVEL
No. 4 Sieve
SAND
CLEAN SAND
SW
WELL -GRADED SAND, FINE TO COARSE SAND
More than 50%
SP
POORLY -GRADED SAND
Retained on
No. 200 Sieve
More than 50%
SAND
SM
SILTY SAND
Of Coarse Fraction
WITH FINES
Passes
Sc
CLAYEY SAND
No. 4 Sieve
SILT AND CLAY
INORGANIC
ML
SILT
FINE
CL
CLAY
GRAINED
SOILS
Liquid Limit
ORGANIC
OL
ORGANIC SILT, ORGANIC CLAY
Less than 50
SILT AND CLAY
INORGANIC
MH
SILT OF HIGH PLASTICITY, ELASTIC SILT
More than 50%
CH
CLAY OF HIGH PLASTICITY, FAT CLAY
Passes
No. 200 Sieve
Liquid Limit
ORGANIC
OH
ORGANIC CLAY, ORGANIC SILT
50 or more
HIGHLY ORGANIC SOILS
PT
PEAT
NOTES:
2.
Field classification is based on visual examination of soil
in general accordance with ASTM D2488-90.
Soil classification using laboratory tests is based on
ASTM D2487-90.
Description of soil density or consistency are based on
interpretation of blow count data, visual appearance of
soils, and or test data.
GEORESOURCES
earth science & geotechnical engineering
5007 Pacific Hwy E., Suite 16 1 Fife, WA 91424 1253.896.1011 1 www.georesources.rocks
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 Soils Classification System
Proposed Single Family Residences
SW 304t' St
King County, Washington
PN: 0121039099, 0121039099, 0121039158, 0121039160, 0121039161
DocID: ACSIIc.SW304St I September 2019 1 Figure A-1
Test Pit TP-1
Location: Southwest potion of the site
Depth (ft) Soil Type Soil Description
0-2 Dark brown organic topsoil
2-4 ML Tan/orange fine sandy SILT (soft, moist to wet) (fe staining, lacustrine)
4-5 ML Grey/brown fin sandy SILT (medium stiff
Test pit terminated at 5 feet below existing grades
Groundwater encountered at about 4 feet
No caving observed
Mottling observed at 2 feet below existing grades
Logged by: DCB
GEORESOURCES
earth science & geotechnical engineering
5007 Pacific Hwy E., Suite 16 1 Fife, WA 98424 1253.896.1011 1 www.georesources.rocks
Excavated on: Jun 12, 2018
Hand Auger Logs
Proposed Single Family Residences
SW 304" St
King County, Washington
PN: 0121039099, 0121039099, 0121039158,
0121039160, 0121039161
DodD: ACSIIc.SW304St I August 2019 Figure A-2