Notice of Decision
Project Name: Waste Water Treatment Plant Biosolids Modernization
Permit Application Number: SEPA-2025-0007
Location: 13114 63rd Street East Sumner, WA 98390
Parcel(s) #: 4250001210, 4250001080 and 4250001220
Description of Proposal: Replace components of the existing Class A biosolids treatment system at the City’s WWTP that are either capacity limited or reaching the end of their service life. Scope of work includes:
- Expansion of the existing Solids Handling Building to house the new biosolids drying equipment. The building expansion will be a single-story structure, equal in height to the existing Solids Handling Building.
- Demolition of the existing Sludge Haul Truck Loading Bay on the south side of the Solids Handling Building, along with the existing canopy/roof structure.
- Install the following new/replacement equipment in the Solids Handling Building and building expansion: New dewatered biosolids conveyors; A new dewatered biosolids cake pump to feed the new dryer; A new indirect biosolids dryer; Two new thermal fluid heaters each capable of utilizing either digester gas or natural gas along with the associated thermal fluid pumping systems; Dried biosolids conveyance, cooling and screening systems; Replacement of the existing sludge storage hopper augers and drive motors; New waste activated sludge thickening system including a rotary screen thickener, sludge pumps, and polymer system; New in-line sludge grinders on the suction side of the digester recirculation pumps; New restroom; Odor control system modifications.
- Construction of a new Sludge Haul Truck Loading Bay on the south side of the new Solids Handling Building Expansion, including truck scales, automation of load distribution in the haul truck bed/container, and dust control systems.
- Construction and subsequent demolition of a temporary Sludge Haul Truck Loading Bay for use during the demolition of the existing Sludge Haul Truck Loading Bay and the construction of the new Solids Building Expansion and Loading Bay.
- Demolition of existing dissolved air floatation thickener and associated equipment in the Equipment Building 2.
- Replacement of the existing rotary lobe thickened primary sludge pumps with a new progressing cavity pump.
- Raise the walls of the existing central holding tank an additional 6 feet and removal and reinstallation of the existing mechanism bridge and covers once the walls have been raised.
- New digester gas compressor and treatment system, including H2S and moisture removal.
- New 4-inch enclosed waste gas burner that will meet all applicable Puget Sound Clean Air Agency regulations.
- Install new/relocated/modified process and yard piping, including drains, potable water, natural gas, digester gas, sludge, non-potable water and stormwater piping.
- Install new power distribution, controls and instrumentation systems for all modified and new treatment plant components. New motor control equipment will be installed in the existing Solids Handling Building Electrical Room or in the existing generator room that will be repurposed into a new electrical room.
- Demolish existing diesel fuel storage tank.
- Install a new diesel generator to provide standby power to the portions of the liquid stream system that are powered from the Solids Handling Building and to critical solids handling components. The generator will be housed in a stand-alone weatherproof acoustic enclosure with sub-base fuel storage.
- Pave currently pervious areas within the WWTP site including approximately 670 sf north of the UV Disinfection Facility and 220 sf between the new generator and the Solids Handling Building expansion.
- Install a gate across State Street and fence the north parking lot area to provide added security for the WWTP. The gate will be installed at the south end of State Street after the existing crosswalk, at approximately the intersection of State Street and 63rdStreet E.
Install a paved vehicle turn-around in the vicinity of the new gate on State Street. New paved area: approximately 1,180 sf. - Remove 18 ornamental shrubs, two fruit trees, one cedar tree and 3 pine trees. Plant native trees and shrubs, at a 2:1 ratio, to mitigate for the removal of vegetation.
Applicant: City of Sumner
Michael Kosa
1104 Maple Street, Ste 260
Sumner, WA 98390
Contact – Doug Welch, Gray and Osborne, Inc.
1130 Rainier Ave S, Seattle, WA 98144
206-283-3206
dwelch@g-o.com
Date of Application: March 27, 2025
Date of Complete Application: March 27, 2025
Hearing Date: No hearing is scheduled for this SEPA, zoning CUP and Shoreline permits will require hearings to be noticed at a future date.
Location/Zoom Link: N/A for SEPA
Zoning: Project takes place in the low density residential zone with a comprehensive plan designation of low-density residential and public/private utilities and facilities.
SEPA: MDNS is issued
Other Required Permits:
-Shoreline Substantial Development Permit
-Shoreline Variance (required for improvements located within the 200 of Urban Conservancy Buffer for the Puyallup and White Rivers)
-Shoreline Conditional Use Permit application (required for utility improvements in the Urban Conservancy Environment
-Zoning Conditional Use Permit (required for upgrading the WWTP within the Low Density Residential Zone (LDR) per SMC 18.12.050(F)).
-Habitat Management Plan (required per SMC 16.56.080 to assess potential project effects on
fish and wildlife habitat)
-Notice of Construction (NOC) Approval – Puget Sound Clean Air Agency.low-density
-Site development permit(s)
-Compliance with all State and Federal regulations
Associated Documents:
Comment Period(s): Any persons desiring to submit written comments concerning this application may submit written comments to Scott Waller of the Development Services Department. City of Sumner, 1104 Maple Street, Sumner, WA 98390 no later than July 24th, 2025. Administrative appeals must be filed with the City Clerk no later than 5:00pm on Wednesday July 30th, 2025.
Staff Contact: For comments/questions, please contact Scott Waller, Senior Planner 253-299-5527, scottw@sumnerwa.gov
MITIGATED DETERMINATION OF NON-SIGNIFICANCE
Project: Waste Water Treatment Plant Biosolids Modernization
Proposal: Replace components of the existing Class A biosolids treatment system at the City’s WWTP that are either capacity limited or reaching the end of their service life. Scope of work includes:
• Expansion of the existing Solids Handling Building to house the new biosolids drying equipment. The building expansion will be a single-story structure, equal in height to the existing Solids Handling Building.
• Demolition of the existing Sludge Haul Truck Loading Bay on the south side of the Solids Handling Building, along with the existing canopy/roof structure.
• Install the following new/replacement equipment in the Solids Handling Building and building expansion: New dewatered biosolids conveyors; A new dewatered biosolids cake pump to feed the new dryer; A new indirect biosolids dryer; Two new thermal fluid heaters each capable of utilizing either digester gas or natural gas along with the associated thermal fluid pumping systems; Dried biosolids conveyance, cooling and screening systems; Replacement of the existing sludge storage hopper augers and drive motors; New waste activated sludge thickening system including a rotary screen thickener, sludge pumps, and polymer system; New in-line sludge grinders on the suction side of the digester recirculation pumps; New restroom; Odor control system modifications.
• Construction of a new Sludge Haul Truck Loading Bay on the south side of the new Solids Handling Building Expansion, including truck scales, automation of load distribution in the haul truck bed/container, and dust control systems.
• Construction and subsequent demolition of a temporary Sludge Haul Truck Loading Bay for use during the demolition of the existing Sludge Haul Truck Loading Bay and the construction of the new Solids Building Expansion and Loading Bay.
• Demolition of existing dissolved air floatation thickener and associated equipment in the Equipment Building 2.
• Replacement of the existing rotary lobe thickened primary sludge pumps with a new progressing cavity pump.
• Raise the walls of the existing central holding tank an additional 6 feet and removal and reinstallation of the existing mechanism bridge and covers once the walls have been raised.
• New digester gas compressor and treatment system, including H2S and moisture removal.
• New 4-inch enclosed waste gas burner that will meet all applicable Puget Sound Clean Air Agency regulations.
• Install new/relocated/modified process and yard piping, including drains, potable water, natural gas, digester gas, sludge, non-potable water and stormwater piping.
• Install new power distribution, controls and instrumentation systems for all modified and new treatment plant components. New motor control equipment will be installed in the existing Solids Handling Building Electrical Room or in the existing generator room that will be repurposed into a new electrical room.
• Demolish existing diesel fuel storage tank.
• Install a new diesel generator to provide standby power to the portions of the liquid stream system that are powered from the Solids Handling Building and to critical solids handling components. The generator will be housed in a stand-alone weatherproof acoustic enclosure with sub-base fuel storage.
• Pave currently pervious areas within the WWTP site including approximately 670 sf north of the UV Disinfection Facility and 220 sf between the new generator and the Solids Handling Building expansion.
• Install a gate across State Street and fence the north parking lot area to provide added security for the WWTP. The gate will be installed at the south end of State Street after the existing crosswalk, at approximately the intersection of State Street and 63rdStreet E.
• Install a paved vehicle turn-around in the vicinity of the new gate on State Street. New paved area: approximately 1,180 sf.
• Remove 18 ornamental shrubs, two fruit trees, one cedar tree and 3 pine trees. Plant native trees and shrubs, at a 2:1 ratio, to mitigate for the removal of vegetation.
Applicant: City of Sumner
Michael Kosa
1104 Maple Street, Ste 260
Sumner, WA 98390
Contact – Doug Welch, Gray and Osborne, Inc.
1130 Rainier Ave S, Seattle, WA 98144
206-283-3206
dwelch@g-o.com
Project Number: SEPA-2025-0007
Location of Proposal: 13114 63rd Street East Sumner, WA 98390
Parcel Number(s): 4250001210, 4250001080 and 4250001220
Lead Agency: City of Sumner
Associated documents may be downloaded at: https://sumnerwa.gov/wwtp-modernization-nod/ or SEPA Register – (wa.gov)
The lead agency for this proposal has determined that it does not have a probable significant adverse impact on the environment. An environmental impact statement (EIS) is not required under RCW 43.21C.030 (2)(c). This decision was made after review of a completed environmental checklist and other information on file with the lead agency. This information is available to the public on request.
This DNS is issued under 197-11-340 (2); the lead agency will not act on this proposal for 14 days from the published date below. Comments are due July 24th and administrative appeals shall be filed with the City Clerk by July 30th 2025 by 5:00pm pursuant to SMC 16.04.
Responsible Official: Ryan Windish
Position/Title: Community & Economic Development Director
Phone: (253) 299- 5524
Address: 1104 Maple Street Suite 250, Sumner, WA 98390
Questions: Scott Waller, Senior Planner: scottw@sumnerwa.gov 253.299.5527
SEPA MITIGATION MEASURES
- Development within shoreline jurisdiction shall receive approval of necessary shoreline permits prior to development permit issuance for work in shoreline jurisdiction.
- Plans consistent with the approved Habitat Management Plan shall be submitted at time of development permits.
- As outlined in the HMP, BMPs implemented will include the following:
a. Clearing limits will be staked in the field prior to the start of construction.
b. Any temporarily disturbed areas will be replanted with native species.
c. Erosion control BMPs such as silt fence and strawbales, as outlined in the Temporary Erosion Sediment Control Plan for the project, will be used at all times.
d. All equipment will be checked daily for leaks and any necessary repairs made prior to the commencement of work.
e. A Spill Prevention Control and Countermeasures Plan will be prepared by the Contractor and approved by the City prior to the initiation of construction. - As applicable, boundary line adjustments and or lot consolidation must be started prior to development permit submittal and completed prior to final inspection.
- As applicable, ROW vacation must be completed prior to development permit issuance.
- At the time of construction, a permit will be required for the following items which shall be designed to the currently adopted codes at the time of permit application.
a. Retaining wall at the new turn-around on State Street.
b. Access gate entering the site as this will block the required fire apparatus access.
c. Structure alterations as well as the addition. - At the time of construction, a permit will be required for the following items which shall be designed to the currently adopted codes at the time of permit application.
a. Fire apparatus access gate at the main entry to the site.
b. Alterations and expansion of the Automatic Fire Alarm System.
c. Alterations and expansion of Automatic Fire Sprinkler System. - Noise –
a. Construction equipment will be required to be properly muffled.
b. Construction hours are limited to weekdays from 7:00 AM to 6:00 PM in accordance with SMC 15.34.010.
c. Dryer equipment will be installed in buildings.
d. The new generator will be in an acoustic enclosure.
e. Digester gas compression equipment will be installed in a small enclosure. - If contamination is suspected, discovered, or occurs during demolition or wastewater treatment plant modernization construction, testing of the potentially contaminated media must be conducted. If sediment, soil or water contamination is readily apparent, or is revealed by testing, the Department of Ecology must be notified. To notify Ecology, contact the Environmental Report Tracking System Coordinator at the Southwest Regional Office at (360) 407-6300. For assistance and information about subsequent cleanup and to identify the type of testing that will be required, contact Sandy Smith with the Toxics Cleanup Program at the Southwest Regional Office at (360) 999-9588.
- In addition to any required asbestos abatement procedures, the applicant should ensure that any other potentially dangerous or hazardous materials present, such as PCB-containing lamp ballasts, fluorescent lamps, and wall thermostats containing mercury, are removed prior to demolition. It is important that these materials and wastes are removed and appropriately managed prior to demolition. It is equally important that demolition debris is also safely managed, especially if it contains painted wood or concrete, treated wood, or other possibly dangerous materials. Please review the “Dangerous Waste Rules for Demolition, Construction, and Renovation Wastes,” posted at Ecology’s website. The applicant may also contact Katy Harvey of Ecology’s Hazardous Waste and Toxics Reduction Program at katy.harvey@ecy.wa.gov for more information about safely handling dangerous wastes and demolition debris.
- If ground disturbing activities encounter human skeletal remains during the course of construction, then all activity will cease that may cause further disturbance to those remains. The area of the find will be secured and protected from further disturbance until the State provides notice to proceed. The finding of human skeletal remains will be reported to the county medical examiner/coroner and local law enforcement in the most expeditious manner possible. The remains will not be touched, moved, or further disturbed. The county medical examiner/coroner will assume jurisdiction over the human skeletal remains and make a determination of whether those remains are forensic or non- forensic. If the county medical examiner/coroner determines the remains are non- forensic, then they will report that finding to the Department of Archaeology and Historic Preservation (DAHP) who will then take jurisdiction over the remains. The DAHP will notify any appropriate cemeteries and all affected tribes of the find. The State Physical Anthropologist will make a determination of whether the remains are Indian or Non-Indian and report that finding to any appropriate cemeteries and the affected tribes. The DAHP will then handle all consultation with the affected parties as to the future preservation, excavation, and disposition of the remains.
- Work shall immediately stop and the City of Sumner, the State Department of Archaeology and Historic Preservation (DAHP), the Puyallup Tribe of Indians, and the Muckleshoot Tribe shall be immediately notified if any artifacts of possible historic, cultural, or archaeological value are uncovered during excavation. In such cases, the developer shall be required to provide for a site inspection and evaluation by a professional archaeologist or historic preservation professional, as applicable, in coordination with the state and/or affected tribes to ensure that all possible valuable historic, cultural, or archaeological artifacts is properly protected or salvaged.
