HomeMy WebLinkAboutSR_ERC_Report_Monroe_Ave_NE_Infiltration_Facility_230918_v1DEPARTMENT OF COMMUNITY
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SR_ERC_Report_Monroe_Ave_NE_Infiltration_Facility_230918_v1
ENVIRONMENTAL REVIEW COMMITTEE REPORT
ERC Meeting Date: September 18, 2023
Project File Number: PR19-000482
Project Name: Monroe Ave NE Infiltration Facility
Land Use File Number: LUA23-000284, ECF
Project Manager: Clark H. Close, Principal Planner
Owner: Segale Properties, LLC, 5811 Segale Park Drive C, Tukwila, WA 98188
Applicant/Contact: Kevin Evans, City of Renton, 1055 S Grady Way, Renton, WA 98057
Project Location: 301 Monroe Ave NE LOT, Renton, WA 98056 (APN 1623059059)
Project Summary: The applicant is requesting Environmental (SEPA) Review for a civil construction
project that would provide flow control and water quality treatment of stormwater
runoff for the 245-acre subbasin via a new treatment and infiltration facility. The
proposed Monroe Ave NE Infiltration Facility project would consist of underground
stormwater facilities, up to 36-inch diameter pipes, and structures that would
reside below a new maintenance access road and large grass field area. The vacant
14.4-acre site, known as the Upper Balch Pit, is zoned Residential-10 (R-10). All
proposed permanent improvements to the project site would be located within a
three-acre permanent utility easement at the north and northwest portions of the
property.
On March 27, 2019, the site received approval for a 10-year Special Fill and Grade
Permit to import 230,000 cubic yards of fill into the existing sand/gravel pit (LUA18-
000703). This allowed the site to continue to receive fill and to bring the final grades
to at or near the grades of the surrounding streets and land area by the completion
of the permit. No significant trees are proposed for removal. The applicant has
submitted a Geotechnical Engineering Evaluation and a Draft Technical Information
Report with the application.
Site Area: 14.4 acres Total Building Area GSF: N/A
STAFF
RECOMMENDATION:
Staff Recommends that the Environmental Review Committee issue a
Determination of Non-Significance - Mitigated (DNS-M).
NE 4th St
NE 2nd St
NE 4th St Monroe Ave NE DocuSign Envelope ID: 00997718-9B11-4D89-AD86-5EF6CC7CC14C
City of Renton Department of Community & Economic Development
Monroe Ave NE Infiltration Facility
Staff Report to the Environmental Review Committee
LUA23-000284, ECF
Report of September 18, 2023 Page 2 of 7
SR_ERC_Report_Monroe_Ave_NE_Infiltration_Facility_230918_v1
PART ONE: PROJECT DESCRIPTION / BACKGROUND
The applicant, City of Renton Public Works Department – Surface Water Utility, is requesting Environmental (SEPA)
Review for a construction project that would provide flow control and water quality treatment of stormwater
runoff for a 245-acre subbasin located in the Renton Highlands and President Park neighborhoods with a new
treatment and infiltration facility (Exhibit 2). The proposed location for the facility is a 14.4-acre (629,006 square
feet) site that is currently being used as a gravel pit, commonly known as the Upper Balch Pit, at 301 Monroe Ave
NE (APN 1623059059). The subject site is zoned Residential-10 (R-10) and the land use designation is Residential
High Density (RHD). The site is currently unusable and undeveloped, there are no structures or improvements on
the site other than a paved haul road and a perimeter-screening fence. Historically, flooding in the area has led to
an agreement between the City of Renton and Segale Properties to allow for the installation of high-flow overflows
to be directed from the trunkline into the subject property where the water could pond and infiltrate which
eliminated street flooding. A Temporary Storm Drainage Easement (AF#2007092800176) allowed construction of
one 18-inch and one 24-inch overflow pipe, which discharged flows into the pit during high flow events. This
temporary system has prevented roadway and property flooding for nearly the past two decades.
The proposed facility is part of a council-adopted utility system plan that would consist of underground stormwater
facilities, up to 36-inch diameter pipes, and structures that would reside below a new maintenance access road
and large grass field area (Exhibit 8). No above ground structures would be constructed. All proposed permanent
improvements to the project site would be located within a three-acre permanent utility easement at the north
and northwest portions of the property. At the location where the infiltration facility is proposed, the soil is highly
permeable glacial outwash with a conservative design infiltration rate of 20 inches per hour. In the location where
the infiltration facility is not proposed, the soil is fill comprising of silty sand, sand with gravel, and crushed rock .
Currently runoff ponds onsite and infiltrates into the soil. The applicant would obtain a permanent utility easement
that would allow the city to access and maintain the new stormwater facilities from Monroe Ave NE in perpetuity.
In addition, the facility has been sized for the maximum impervious areas that the full site could develop based on
the current zoning.
The applicant is proposing roughly 1,700 cubic yards of excavation and approximately 143,000 cubic yards of fill
from city-approved sources. Offsite improvements would be minor, including light pole replacement, pavement
restoration, stormwater pipe connection, and limited construction of sidewalk, driveway, and curb and gutter
(Exhibits 2, 8, and 16). Flaggers would be used to ensure flow of traffic when working along Monroe Ave NE. The
site contains four (4) significant trees and no significant trees are proposed for removal (Exhibits 5 and 6).
Historically, the Upper Balch Pit was permitted and authorized for gravel excavation operations from 1960-1982.
The subject site has been an upland fill and reclamation site since 1982, operating under Special Permits SP-032-
82, SP-033-87, LUA92-174, and LUA00-064, and LUA10-056. More recently the site received approval for a 10-year
Special Fill and Grade Permit to import 230,000 cubic yards of fill into the existing sand/gravel pit (LUA18 -000703)
(Exhibit 15). This allowed the site to continue to receive fill and to bring the final grades to at or near the grades of
the surrounding streets and land area by the completion of the permit.
Partial funding of this small-scale facility project is being provided by the Washington State Department of Ecology’s
(Ecology) Stormwater Grant Program. Additional funds required for project design and construction would be
provided by the Surface Water Utility’s capital improvement program. The applicant is proposing to start
construction on October 15, 2023 and complete construction on April 30, 2025. The proposed project would
generally adhere to City of Renton work hours by working from seven o’clock (7:00) a.m. to five o’clock (5:00) p.m.,
Monday through Friday (Exhibit 13). Work may be permitted on Saturdays and Sundays only if approved in writing
in advance by the Administrator.
Power lines run through the northeast portion of the site in a 150-foot wide Puget Sound Energy Easement
(AF#3425304 and #2571770) (Exhibit 14). The property presently has a large fill bench on the west side of the site
at the site entrance along Jefferson Ave NE. Transportation routes may vary depending on phase of work and
DocuSign Envelope ID: 00997718-9B11-4D89-AD86-5EF6CC7CC14C
City of Renton Department of Community & Economic Development
Monroe Ave NE Infiltration Facility
Staff Report to the Environmental Review Committee
LUA23-000284, ECF
Report of September 18, 2023 Page 3 of 7
SR_ERC_Report_Monroe_Ave_NE_Infiltration_Facility_230918_v1
contractor preference, but vehicles would enter from NE 4th St to either Monroe Ave NE or Jefferson Ave NE to
the project site, and leave from the same roads.
To the north of the site is a small commercial center including such stores as McDonald’s, Renton Collision Center,
U-Haul, and Discount Tires, to the east (across Monroe Ave NE) is the Greenwood Cemetery, to the south (across
NE 2nd St) is the City of Renton Transportation Department and Maintenance Shops, and to the west (across
Jefferson Ave NE) is King County Parks and Renton Shop, other King County owned properties and a vacant property
recently acquired by Renton Technical College (Exhibit 4). The applicant has indicated that best management
practices (BMPs) would be used during construction to minimize the erosion of exposed soils.
PART TWO: ENVIRONMENTAL REVIEW
In compliance with RCW 43.21C.240, the following environmental (SEPA) review addresses only those project
impacts that are not adequately addressed under existing development standards and environmental regulations.
A. Environmental Threshold Recommendation
Based on analysis of probable impacts from the proposal, staff recommends that the Responsible
Officials:
Issue a DNS-M with a 14-day appeal period.
B. Mitigation Measures
1. The applicant shall complete an inadvertent discovery plan (IDP). Consultation with concerned Tribes
shall occur prior to completion of the IDP. The IDP plan shall be provided to, and approved by, the
Current Planning Project Manager prior to permit issuance.
C. Exhibits
Exhibit 1: Environmental Review Committee (ERC) Report
Exhibit 2: Site Plan
Exhibit 3: Topography Map
Exhibit 4: Neighborhood Detail Map
Exhibit 5: Landscape and Tree Inventory Plan
Exhibit 6: Tree Retention and Credit Worksheet
Exhibit 7: Draft Technical Information Report, prepared by Otak, Inc., dated April 7, 2023
Exhibit 8: Utilities, Drainage Control, and Grading Plan, prepared by Otak, Inc.
Exhibit 9: Geotechnical Report, prepared by Aspect Consulting, LLC (Aspect), dated January 14,
2020
Exhibit 10: Comment Email from the Duwamish Tribe, dated August 25, 2023
Exhibit 11: Staff Response to Duwamish Tribe, dated September 6, 2023
Exhibit 12: Environmental (SEPA) Checklist, dated August 18, 2023
Exhibit 13: Construction Mitigation Description
Exhibit 14: Title Report
Exhibit 15: Hearing Examiner Special Clear and Grade Permit Decision (LUA18-000703)
DocuSign Envelope ID: 00997718-9B11-4D89-AD86-5EF6CC7CC14C
City of Renton Department of Community & Economic Development
Monroe Ave NE Infiltration Facility
Staff Report to the Environmental Review Committee
LUA23-000284, ECF
Report of September 18, 2023 Page 4 of 7
SR_ERC_Report_Monroe_Ave_NE_Infiltration_Facility_230918_v1
Exhibit 16: Advisory Notes
D. Environmental Impacts
The Proposal was circulated and reviewed by various City Departments and Divisions to determine whether the
applicant has adequately identified and addressed environmental impacts anticipated to occur in conjunction
with the proposed development. Staff reviewers have identified that the proposal is likely to hav e the following
probable impacts:
1. Earth
Impacts: The applicant provided a Geotechnical Report, prepared by Aspect Consulting, Inc. (Aspect),
dated January 14, 2020 (Exhibit 9). The report indicated that after review of the geologic map, the
Subbasin is underlain by Pleistocene Vashon Stade continental recessional stratified drift, glaciofluvial
deposits (Qpa), and Vashon Stade continental glacial till (Qgt). The glaciofluvial deposits consist chiefly
of well-sorted sand and gravel with few fines. Aspect mapped 94 subsurface locations to assess
feasibility for stormwater infiltration. Generally, higher permeability soils (infiltration observed at 0 -5
inches/hour) are more feasible for shallow stormwater infiltration. The steepness of the surface slope
is also a factor in potential for runoff to effectively infiltrate. Slopes with less than eight percent (8%)
slope were considered area with “good” infiltration potential. Erosion, landslide, and seismic hazard
areas were considered poor for shallow infiltration.
In previous geotechnical evaluations on the property, the soil conditions consisted of medium dense
to dense, inorganic fill material and approximately eight and one-half feet of medium dense fill material
overlying medium dense gravel with sand. Since a majority of the soils typically suitable for infiltration
have been removed from the site through the mining process, the ability to infiltrate site stormwater
would require that future facilities be located along the perimeter of the site and only a portion of the
facility would expose the native sand and gravel material. As such, it will be necessary to construct the
infiltration facilities by filling the facility with a free draining material that closely matches the hydraulic
conductivity of the native soils.
Approximately 3-acres of the site would be graded for the project (Exhibit 3), with roughly 1,700 cubic
yards of total excavation and 143,000 cubic yards of total fill from City-approved sources. The proposed
fill would include the following amounts: i) roughly 42,700 cubic yards of non-infiltration material used
for fill where infiltration is not required, which would be partially sourced from an existing stockpile on
the property; ii) roughly 800 cubic yards of crushed surfacing top course (CSTC) used on the surface
near stormwater vaults; iii) roughly 59,100 cubic yards of infiltration gravel used for storage and
infiltration of stormwater below the infiltration chamber gallery; iv) roughly 21,000 cubic yards of
select borrow used for between the infiltration gravel and native soil ; v) roughly 6,000 cubic yards of
gravel borrow and 2,400 cubic yards of gravel backfill for walls used for surrounding the infiltration
chamber gallery; and vi) roughly 10,100 cubic yards of topsoil and 600 cubic yards of mulch used for
landscaping. It is anticipated that the City’s existing grading regulations would be sufficient to mitigate
the impacts of the proposed project. Further geotechnical considerations would be evaluated under
the submitted building permit application (B23004461).
Mitigation Measures: No further mitigation required.
Nexus: Not applicable.
2. Air
Impacts: It is anticipated that some short-term air quality impacts could be associated with project
construction. Project development impacts during construction may include periods of increased dust
generated as a result of filling and grading and exhaust from vehicles and equipment. A stormwater
Pollution Prevention Plan (SWPPP) would be completed prior to any earth disturbing activities (Exhibit
12).
DocuSign Envelope ID: 00997718-9B11-4D89-AD86-5EF6CC7CC14C
City of Renton Department of Community & Economic Development
Monroe Ave NE Infiltration Facility
Staff Report to the Environmental Review Committee
LUA23-000284, ECF
Report of September 18, 2023 Page 5 of 7
SR_ERC_Report_Monroe_Ave_NE_Infiltration_Facility_230918_v1
Mitigation Measures: No further mitigation required.
Nexus: Not applicable.
3. Water
a. Ground Water
Impacts: The subject site is located in the Upper Balch Pit, generally between Jefferson Ave NE to
the west and Monroe Avenue NE to the east, NE 4th Street to the north, and NE 2nd Street to the
south. According to the geotechnical investigations, the seasonal high groundwater would be at
elevation 272.5 feet and the elevation of the native outwash material is at an average elevation of
280 feet across the footprint of the infiltration facility, although there is some variability to the
depth to native soils. According to the submitted Drainage Report (Exhibit 7), during excavation to
remove the existing fill material, geotechnical representatives would be onsite to ensure that the
native outwash material is exposed across the entire footprint of the proposed infiltration facility
footprint and would confirm that there has been no mobilization of fines into the native that would
result in a lowered infiltration rate.
Mitigation Measures: No further mitigation required.
Nexus: Not applicable.
b. Storm Water
Impacts: The applicant submitted a Draft Technical Information Report, prepared by Otak, Inc.,
dated April 7, 2023 (Exhibit 7) with the application. According to the drainage report, the existing
drainage patterns of the site would be maintained. The stormwater runoff from the basin
historically overflows and drains into the Upper Balch Pit and the Upper Balch Pit is the natural
discharge location for the project area.
The project proposes to install a 36-inch storm drainage pipe to connect to the existing trunkline
along Monroe Ave NE. The existing Monroe Avenue trunkline consists of a 36-inch trunkline north
of the intersection of Monroe Ave NE and NE 2nd St, and a 42-inch perforated pipe south of the
intersection. The proposed 36-inch storm drainage pipe would direct flow to the west into a
hydrodynamic separator, which would provide pre-treatment for the water quality flowrate for
the runoff from the contributing offsite basin. Runoff is directed from the hydrodynamic separator
into a flow splitter vault structure that routes flows up to the water quality flowrate to an enhanced
water quality treatment vault. Stormwater flows above the water quality flowrate are routed from
the flow splitter directly to the concrete manifold vault through a series of pipes and catch basins
that serves as a high flow bypass. Flows treated by the water quality vault are also routed to this
same concrete manifold vault. From the concrete manifold vault, runoff is routed into the primary
isolator rows. The isolator rows are designed with a geotextile at their invert to allow for long term
maintenance of sediment removal from the isolator chambers. From the isolator row, flow is
dispersed via a manifold across a 1.29-acre (56,000 square feet) plastic arch infiltration chamber
gallery situated below finished grade in the northwest corner of Upper Balch Pit. These plastic arch
chambers are 5-feet high, have void space within the chamber, and are surrounded by the
imported infiltration gravel to all sides. Flow is conveyed through the manifold by overtopping
internal weirs on either end of the manifold vault as the primary isolator rows stage up during peak
flow events. The infiltration gallery sits on 25.5-feet of an imported clean, washed, poorly graded,
and angular aggregate layer, which allows for permeation of water through the layer as well as
having a significant storage volume for additional detention. Flow permeates through the 25.5 -
feet of clean infiltration gravel and reaches a lens of imported well -graded material that is
analogous to the native outwash soils. From the imported fill/analogous native material, water
infiltrates into the native soils. The analogous native material is placed to achieve separation from
seasonal high groundwater.
DocuSign Envelope ID: 00997718-9B11-4D89-AD86-5EF6CC7CC14C
City of Renton Department of Community & Economic Development
Monroe Ave NE Infiltration Facility
Staff Report to the Environmental Review Committee
LUA23-000284, ECF
Report of September 18, 2023 Page 6 of 7
SR_ERC_Report_Monroe_Ave_NE_Infiltration_Facility_230918_v1
According to the drainage report, the project is in a Conservation Flow Control Area and must meet
Level 2 flow control standards for target surfaces. The drainage report further indicates that the
design of the facility has been sized for the maximum impervious area that the full site could
develop based on the current zoning and the facility is sized to capture runoff from the upstream
250-acre basin.
The project received an Ecology Grant and would be subject to the requirements of the grant
agreement. In addition, all engineered conveyance system elements for proposed projects have
been analyzed and designed to provide protection against overtopping, flooding, erosion, and
structural failure. The proposed flow control and water quality facilities would be maintained by
the City of Renton following City of Renton’s standard guidelines for alternative infiltration facilities
and proprietary water quality facilities. A full Operations and Maintenance Plan would be
developed prior to project closeout for the long-term operations and maintenance of the facility.
Mitigation Measures: No further mitigation required.
Nexus: Not applicable.
4. Environmental Health
a. Noise
Impacts: Noise impacts would result from construction of an approximately 3-acre regional
stormwater facility. Continued levels and types of noise from trucks and equipment operation
would occur. The construction noise would be regulated through the City’s adopted noise level
regulations per Chapter 8-7, RMC, Noise Level Regulations and RMC 4-4-030. The City’s
construction standards limit haul hours between 8:30 am to 3:30 pm, Monday through Friday
unless otherwise approved by the Development Services Division. Work on Saturdays is restricted
to the hours between 9:00 am and 8:00 pm. No work is permitted on Sundays.
The maximum noise levels for haul trucks is governed by Chapter 173-62 WAC, Motor Vehicle Noise
Performance Standards. No residences are located within 300 feet of the subject property and the
project impacts are anticipated to remain relatively minimal on the surrounding neighbors. In years
past, the City has not received any complaints on the current and past fill operation work regarding
unsightliness or noise.
Mitigation Measures: No further mitigation required.
Nexus: Not applicable.
5. Historic and Cultural Preservation
Impacts: The city received a comment (via email) from the Duwamish Tribe on August 25, 2023 (Exhibit
10) and responded on September 6, 2023 (Exhibit 11). The Tribe’s comment recommended an
inadvertent discovery plan (IDP) be performed for this project, especially if excavation cuts below fill.
In addition, the Duwamish Tribe requests that if any archaeological work or monitoring is performed
that they be notified and if or when an archaeologist is on site they have the opportunity to be present.
An IDP plan is required in the event of an unanticipated discovery of human remains, historic or
prehistoric resources. In addition, the IDP provides directions for on-site project staff on what to if,
who to contact, and how to secure an area if ground disturbing activities unearth an unanticipated
discovery. Use of this protocol reduces risk and liability. Finally, an IDP can be required as part of agency
terms and conditions for all grants, for any project that creates disturbance above or below the ground.
Since cultural and archaeological resources are non-renewable and are best discovered prior to ground
disturbance, staff recommends as a mitigation measure that the applicant complete an inadvertent
discovery plan (IDP). Consultation with concerned Tribes shall occur prior to completion of the IDP. The
IDP plan shall be provided to, and approved by, the Current Planning Project Manager prior to permit
issuance.
DocuSign Envelope ID: 00997718-9B11-4D89-AD86-5EF6CC7CC14C
City of Renton Department of Community & Economic Development
Monroe Ave NE Infiltration Facility
Staff Report to the Environmental Review Committee
LUA23-000284, ECF
Report of September 18, 2023 Page 7 of 7
SR_ERC_Report_Monroe_Ave_NE_Infiltration_Facility_230918_v1
Mitigation Measures: The applicant shall complete an inadvertent discovery plan (IDP). Consultation
with concerned Tribes shall occur prior to completion of the IDP. The IDP plan shall be provided to,
and approved by, the Current Planning Project Manager prior to permit issuance.
Nexus: State Environmental Policy Act (SEPA) Environmental Review ; City of Renton Comprehensive
Plan Policies L-45; RCW 27.53 Archaeological Sites and Resources; and RCW 27.44 Indian Graves and
Records.
E. Comments of Reviewing Departments
The proposal has been circulated to City Department and Division Reviewers. Where applicable, their
comments have been incorporated into the text of this report and/or “Advisory Notes to Applicant.”
✓ Copies of all Review Comments are contained in the Official File and may be attached to this report.
The Environmental Determination decision will become final if the decision is not appealed within the 14 -day
appeal period (RCW 43.21.C.075(3); WAC 197-11-680).
Environmental Determination Appeal Process: Appeals of the environmental determination must b e filed in
writing on or before 5:00 p.m. on October 2, 2023. Appeals must be submitted electronically to the City Clerk at
cityclerk@rentonwa.gov or delivered to City Hall 1st floor Lobby Hub Monday through Friday. The appeal fee,
normally due at the time an appeal is submitted, will be collected at a future date if your appeal is sub mitted
electronically. The appeal submitted in person may be paid on the first floor in our Finance Department. Appeals
to the Hearing Examiner are governed by RMC 4-8-110 and additional information regarding the appeal process
may be obtained from the City Clerk’s Office, cityclerk@rentonwa.gov.
DocuSign Envelope ID: 00997718-9B11-4D89-AD86-5EF6CC7CC14C
CITY OF RENTON
DEPARTMENT OF COMMUNITY AND ECONOMIC DEVELOPMENT
STAFF REPORT TO THE ENVIRONMENTAL REVIEW COMMITTEE
EXHIBITS
Project Name:
Monroe Ave NE Infiltration Facility
Land Use File Number:
LUA23-000284, ECF
Date of Meeting
September 18, 2023
Staff Contact
Clark H. Close
Principal Planner
Project Contact/Applicant
Kevin Evans
City of Renton
1055 S Grady Way, Renton,
WA 98057
Project Location
301 Monroe Ave NE LOT, Renton,
WA 98056 (APN 1623059059)
The following exhibits are included with the ERC Report:
Exhibit 1: Environmental Review Committee (ERC) Report
Exhibit 2: Site Plan
Exhibit 3: Topography Map
Exhibit 4: Neighborhood Detail Map
Exhibit 5: Landscape and Tree Inventory Plan
Exhibit 6: Tree Retention and Credit Worksheet
Exhibit 7: Drainage Report, prepared by Otak, Inc., dated April 7, 2023
Exhibit 8: Utilities, Drainage Control, and Grading Plan, prepared by Otak, Inc.
Exhibit 9: Geotechnical Report, prepared by Aspect Consulting, LLC (Aspect), dated January 14, 2020
Exhibit 10: Comment Email from the Duwamish Tribe, dated August 25, 2023
Exhibit 11: Staff Response to Duwamish Tribe, dated September 6, 2023
Exhibit 12: Environmental (SEPA) Checklist, dated August 18, 2023
Exhibit 13: Construction Mitigation Description
Exhibit 14: Title Report
Exhibit 15: Hearing Examiner Special Clear and Grade Permit Decision (LUA18-000703)
Exhibit 16: Advisory Notes
DocuSign Envelope ID: 00997718-9B11-4D89-AD86-5EF6CC7CC14C