HomeMy WebLinkAboutSR_ERC_Dye_Parking_Pad_070924STAFF
REPORT
A. BACKGROUND
ERG MEETING DA TE
Project Name:
Owner:
Applicant/Contact:
File Number:
Project Manager:
Project Summary:
Project Location:
Exist. Bldg. Area gsf:
Site Area:
City of Renton
Department of Planning I Building I Public Works
ENVIRONMENTAL REVIEW COMMITTEE REPORT
September 24, 2007
Dye Parking Pad
[Consent Agenda]
Patrick Dye; 7029 Ripley Lane N; Renton, WA 98055
Bob Dye; 7029 Ripley Lane N; Renton, WA 98055
LUA-07-094, SME, V-A, ECF
Elizabeth Higgins, AICP; Senior Planner
The applicant has requested approval to construct a concrete pad, supported
by a retaining wall, for vehicular parking abutting an existing, single-family
residence. The site is located within 200 feet of the Ordinary High Water Mark
of Lake Washington. It would require construction on a slope that has been
deemed a Critical Area by virtue of its grade. The proposed project requires
Environmental (SEPA) Review. An Administrative Variance, a Modification
from Critical Areas regulations, and a Shoreline Exemption would be
processed separately. The property is divided by the line between
unincorporated King County and the City of Renton. The project area would
be on the south portion of the property, which lies within Renton.
7029 Ripley Lane N (parcel no. 3343302780)
1,330 sf New Bldg. Area: NIA
3,990 sf (land area) Total Building Area gsf: 1,330 sf
RECOMMENDATIONS: Staff recommends that the Environmental Review Committee issue a
Determination of Non-Significance -Mitigated (DNS-M)
ERC rpt 07..()94.doc
City of Renton PIBIPW Depa nt Environmental, Variance Shoreline Exemption Staff Report
LUAOl--094, SME, V-A, ECF DYE PARKING PAD
REPORT AND DECISION OF SEPTEMBER24, 2007 Page 2 of 5
B. PROJECT DESCRIPTION:
The majority of the project site is in unincorporated King County including the north portion of
the residence. The south portion, which is the location of the proposed work, is within the City of
Renton. The applicant has requested approvals that would allow the construction of a concrete
pad for vehicular parking abutting an existing, single-family residence. The parking pad would
require construction of a cast-in-place; concrete retaining wall on a 45 percent(+/-) slope within
the side setback area of the residence.
The site, at 7029 Ripley Lane North, is approximately 55 feet west of the Burlington Northern
Santa Fe (BNSF) Railroad tracks and is about 80 feet from the Ordinary High Water Mark
(OHWM) of Lake Washington.
Proposed projects at locations within 200 feet of the OHWM of Lake Washington are subject to
regulations that conform with RMC 4-3-090, "Shoreline Master Program." Lake Washington is
designated as an Urban Shoreline Environment at this location. An exemption from the
requirement to obtain a Shoreline Substantial Development Permit has been requested
(Shoreline Exemption). Issuance of a Certificate of Shoreline Exemption would be a separate
procedure from this report and the recommendations made herein.
The location of the pad would require construction on a slope that has been deemed a Critical
Area by virtue of its grade. This construction, consisting of a 9-112 foot tall retaining wall, would
require a modification of Critical Areas regulations (Renton Municipal Code 4-3-050J, "Geologic
Hazards"). The construction of a retaining wall would be necessary to create a level area for the
parking space. The analysis of the requested modification is included in this report.
An existing planter, constructed from concrete rubble, is located approximately where the
parking pad would be sited. The planter would be removed.
The proposed structure would be situated within the setback area of the existing single-family
structure and in proximity to a similar structure on the abutting property. Therefore, a variance
from the development standards (RMC 4-2-110A, "Development Standards for Single-Family
Residential Zoning Designations") of the Residential 8 (R-8) zone would be required.
C. RECOMMENDATION
Based on analysis of probable impacts from the proposal, staff recommends that the
Responsible Officials make the following Environmental Determination:
DETERMINATION OF
NON-SIGNIFICANCE
Issue DNS with 14-day Appeal
Period.
Issue DNS with 15-day Comment
Period with Concurrent 14 day
Appeal Period.
ERG rpt 07-094.doc
DETERMINATION OF
NON -SIGNIFICANCE -
MITIGATED.
XX Issue DNS-M with 14-day
A eal Period.
Issue DNS-M with 15-day
Comment Period with
Concurrent 14 day Appeal
Period.
City of Renton P/8/PW Depa.
DYE PARKING PAD
,t
REPORT AND DECISION OF SEPTEMBER 24, 2007
D_ MIT/GA TION MEASURES
Environmental, Variance, Shoreline Exemption Staff Report
LUA07--094, SME, V-A, ECF
Page 3 of 5
1. The recommendations of the "Geotechnical Engineering Report (GER)," by
Associated Earth Sciences, Inc., dated March 13, 2007, shall be followed for project
design and construction.
2. The applicant shall be required to provide a Temporary Erosion and Sedimentation
Control Plan (TESCP) designed pursuant to the Department of Ecology's Erosion
and Sediment Control Requirements outlined in Volume II of the most recent
Department of Ecology Stormwater Management Manual.
3. If construction occurs during the "wet season" (October 1 to April 30), the project
shall be subject to special erosion control provisions detailed in Appendix D of the
King County Surface Water Manual.
E. ENVIRONMENTAL IMPACTS
In compliance with RCW 43.21 C. 240, the following project environmental review
addresses only those project impacts that are not adequately addressed under existing
development standards and environmental regulations.
1. Earth
Impacts: The topography of the project site is level at the street, but slopes sharply
down toward Lake Washington from the west edge of Ripley Lane. Due to concerns
about grade and slope stability, the applicant was required to submit a study,
"Geotechnical Engineering Report (GER)," by Associated Earth Sciences, Inc., dated
March 13, 2007.
The recommendations of the GER were based on review of geotechnical literature and
analysis of material removed from the site following subsurface exploration consisting of
2 exploratory borings. The borings were located at the east and west sides of the
proposed parking pad site.
A planter, supported by concrete rubble is located at the approximate site of the new
retaining wall. Based on analysis of material removed at the first boring, soil within the
planter would not be suitable for structural support, but could be used as backfill for the
new wall.
Below the planter fill, natural soils generally consist of dense to very dens, moist, fine-
to-coarse sand with silt and trace gravels. Due to compression over time, these soils
have high compressive strength and low permeability, therefore they would be suitable
to support the proposed retaining wall foundations.
The second boring revealed water seepage that could be an indication of the water
table associated with Lake Washington.
The GER made recommendations for design and construction of the proposed project,
including:
o Remove landscape features (planter, plants, and associated fill soil); dispose
of off site
o Remove of upper layer of organic topsoil; dispose of off site
o Grub roots; dispose of off site
o Relocate utilities that would be beneath structure(s)
o Backfill depressions left from removal of features
ERC rpt 07-094.doc
City of Renton P/8/PW Depa
DYE PARKING PAD
Environmental, Variance ' Shoreline Exemption Staff Report
LUA07--094, SME, V-A, ECF
REPORT AND DECISION OF SEPTEMBER 24, 2007 Page 4 of 5
o On-site determination by geotechnical engineer or their representative of
suitability of supporting soil (excavate to underlying dense sand)
o Limit temporary, unsupported native, unsaturated sand cut slopes to 1 H:1V
o Place shoring or make slopes more shallow where ground water seepage is
presen
o Follow WISHA/OSHA regulations to ensure safety of construction workers
and others at all times
o Permanent, unsupported cut slopes comprised of structural fill should not
exceed a gradient of 2H:1V.
o All permanent slopes should be revegetated or otherwise protected from
erosion as soon as possible after they are constructed.
Additional recommendations were provided for structural fill, compaction, foundations,
footing depth, foundation drainage, wall backfill, wall drainage, and construction
monitoring.
Staff recommends that the study provided with the application submittal, "Geotechnical
Engineering Report (GER)," by Associated Earth Sciences, Inc., dated March 13, 2007,
be used for structural design and construction.
The application states that the wall would be 9-1 /2 feet in height. Retaining walls with
height greater than 48 inches require a building permit.
Mitigation Measures: The recommendations of the "Geotechnical Engineering Report
(GER)," by Associated Earth Sciences. Inc., dated March 13, 2007, shall be followed for
project design and construction.
Nexus: RMC 4-4-060, "Grading, Excavation, and Mining Regulations, SEPA
2. Stormwater
Impacts: The proposed project lies in an area between the Ordinary High Water Mark
(OHWM) of Lake Washington and Ripley Lane, the west edge of which lies
approximately 96 feet from the OHWM.
The above-referenced engineering report, "Geotechnical Engineering Report (GER)," by
Associated Earth Sciences. Inc., dated March 13, 2007, made recommendations for
drainage of the wall and wall foundation. Following these recommendations is a
condition of approval for this project.
Staff recommends that the applicant be required to provide a Temporary Erosion and
Sedimentation Control Plan (TESCP) designed pursuant to the Department of Ecology's
Erosion and Sediment Control Requirements outlined in Volume II of the most recent
Department of Ecology Stormwater Management Manual.
If construction occurs during the "wet season" (October 1 to April 30), the project should
also be subject to special erosion control provisions detailed in Appendix D of the King
County Surface Water Manual.
Mitigation Measures:
1. The applicant shall be required to provide a Temporary Erosion and Sedimentation
Control Plan (TESCP) designed pursuant to the Department of Ecology's Erosion
and Sediment Control Requirements outlined in Volume II of the most recent
Department of Ecology Stormwater Management Manual.
ERC rpt 07-094.doc
City of Renton P/8/PW Depa nt Environmental, Variance 1 Shoreline Exemption Staff Report
LUA07--094, SME, V-A, ECF
Page 5o/5
DYE PARKING PAD
REPORT AND DECISION OF SEPTEMBER 24, 2007
2. If construction occurs during the "wet season" (October 1 to April 30), the project
shall be subject to special erosion control provisions detailed in Appendix D of the
King County Surface Water Manual.
Nexus: SEPA
3. Transportation
Impacts: The proposed project is located on Ripley Lane N, a minor street in terms of
size, but not in importance to the neighborhood. Ripley Lane is located between existing
development along the shore of Lake Washington and the toe of a slope on the east
side. Ripley Lane is at the bottom of a short, but steep slope up to the BNSF railroad
tracks. The Lane, in fact, is largely positioned inside the BNSF right-of-way, as are
portions of garages, houses, and driveways abutting Ripley Lane its entire length.
Because of the relationship of the shoreline to the railroad tracks, Ripley Lane is a
dead-end street. There is no alternative access to the neighborhood available. For this
reason, staff recommends a condition that particular attention be paid to the placement
of vehicles during the construction of the project and that, for emergency vehicle access
and egress, at least one travel lane be open at all times. Additionally, no construction
equipment or vehicles shall be parked in the travel lanes of the road over night.
Mitigation Measures:
1. At least one travel lane of Ripley Lane N shall be open at all times.
2. No construction equipment or vehicles shall be parked in the travel lanes of the road
overnight.
Nexus: RMC 10-10-13
Environmental Determination Appeal Process: Appeals of the environmental
determination must be filed in writing on or before 5:00 PM October 15, 2007. Appeals must be
filed in writing together with the required $75.00 application fee with: Hearing Examiner, City of Renton,
1055 South Grady Way, Renton, WA 98057. Appeals to the Examiner are governed by City of Renton
Municipal Code Section 4-8-110.B. Additional information regarding the appeal process may be
obtained from the Renton City Clerk's Office, ( 425) 430-6510.
Advisory Notes to Applicant:
The following notes are supplemental information provided in conjunction with the environmental
determination. Because these notes are provided as information only, they are not subject to the
appeal process for environmental determinations.
Planning
1. RMC section 4-4-030.C.2 limits haul hours between 8:30 am to 3:30 pm, Monday through Friday unless
otherwise approved by the Development Services Division.
2. Commercial, multi-family, new single family and other nonresidential construction activities shall be
restricted to the hours between seven o'clock (7:00) a.m. and eight o'clock (8:00) p.m., Monday through
Friday. Work on Saturdays shall be restricted to the hours between nine o'clock (9:00) a.m. and eight
o'clock (8:00) p.m. No work shall be permitted on Sundays.
Building
1. A grading license is required for the proposed work.
2. A fill source statement is required to be completed for the fill to be brought in.
3. A buildin ermit for the wall is re uired.
ERC rpl 07-094.doc