981 88 38 39·669 278 974 Mon–Fri · International shipping
comercial.asb.sl@aguassb.com ISO 9001 · view certificate
Central · 981 88 38 39 Comercial · 669 278 974 Central de ventas · 616 600 780 comercial.asb.sl@aguassb.com ISO 9001 · view certificate

ES · English

Request a study
669 278 974 Request a study

World wastewater treatment plant observatory · data as reported by each inventory

Wastewater treatment plants in United States · Washington

← Back to the map

All countries

262 inventory records · EPA Clean Watersheds Needs Survey 2022

Data years: 2022. The inventory date does not establish current operation.

262 results

CompareNameNative sizeYear
RYDERWOOD STPRyderwood0.1 MGD (million gallons per day)2022
GLENWOOD STP & COLLECTIONGlenwood0.1 MGD (million gallons per day)2022
ST JOHN WWTPSaint John0.1 MGD (million gallons per day)2022
WISHRAM SEWER SYSTEMWishram0.097 MGD (million gallons per day)2022
BUENA WWTFBuena0.091 MGD (million gallons per day)2022
VANTAGE TREATMENTVantage0.09 MGD (million gallons per day)2022
Kitsap Co SD #7 WWTPBainbridge Island0.09 MGD (million gallons per day)2022
Woodbrook STPKelso0.088 MGD (million gallons per day)2022
Hangman Valley STPSpokane0.086 MGD (million gallons per day)2022
SPANGLE TOWN STPSpangle0.085 MGD (million gallons per day)2022
LaCrosse Wastewater FacilityLacrosse0.081 MGD (million gallons per day)2022
Lewis Co SD #6 WWTPMossyrock0.08 MGD (million gallons per day)2022
CLALLAM BAY STPClallam Bay0.08 MGD (million gallons per day)2022
LEWIS CO. STP #2Onalaska0.08 MGD (million gallons per day)2022
LIND STPLind0.075 MGD (million gallons per day)2022
Colton STPColton0.074 MGD (million gallons per day)2022
Coulee City STPCoulee City0.072 MGD (million gallons per day)2022
CONCONULLY POTWConconully0.07 MGD (million gallons per day)2022
CUSICK STPCusick0.07 MGD (million gallons per day)2022
GARFIELD STPGarfield0.07 MGD (million gallons per day)2022
GEORGE WWTPGeorge0.063 MGD (million gallons per day)2022
ALMIRA S/T FACILITYAlmira0.063 MGD (million gallons per day)2022
METALINE FALLS STPMetaline Falls0.063 MGD (million gallons per day)2022
MESA STPMesa0.062 MGD (million gallons per day)2022
WINTHROP S/T FACILITYWinthrop0.061 MGD (million gallons per day)2022
SACHEEN LAKE WATER & SEWER DISTRICTNewport0.06 MGD (million gallons per day)2022
Edison WWTFBow0.057 MGD (million gallons per day)2022
STEVENS PASS SEWER DISTRILeavenworth0.056 MGD (million gallons per day)2022
BOSTON HARBOR WWTFOlympia0.054 MGD (million gallons per day)2022
Fisherman Bay STPLopez Island0.053 MGD (million gallons per day)2022
WALLA WALLA WD #2 STPWalla Walla0.051 MGD (million gallons per day)2022
PENN COVE WWTPOak Harbor0.051 MGD (million gallons per day)2022
SPRINGDALE WWTPSpringdale0.05 MGD (million gallons per day)2022
TAMOSHAN WWTPOlympia0.05 MGD (million gallons per day)2022
SOUTH PRAIRIE STPSouth Prairie0.048 MGD (million gallons per day)2022
LAKE WENATCHEE POTWLeavenworth0.047 MGD (million gallons per day)2022
CRESTON STPCreston0.047 MGD (million gallons per day)2022
SPRAGUE STPSprague0.044 MGD (million gallons per day)2022
HOLMES HARBOR SEWER DISTRICT WRFFreeland0.04 MGD (million gallons per day)2022
IONE LAGOONIone0.04 MGD (million gallons per day)2022
MANSFIELD POTWMansfield0.04 MGD (million gallons per day)2022
METALINE MUNICIPAL STPMetaline0.04 MGD (million gallons per day)2022
Reardan Sewage LagoonReardan0.04 MGD (million gallons per day)2022
WASHTUCNA STPWashtucna0.04 MGD (million gallons per day)2022
CONCRETE STPConcrete0.038 MGD (million gallons per day)2022
UNIONTOWN STPUniontown0.036 MGD (million gallons per day)2022
LYLE POTWLyle0.036 MGD (million gallons per day)2022
WILKESON STPWilkeson0.036 MGD (million gallons per day)2022
CRESCENT BAR WWTFQuincy0.033 MGD (million gallons per day)2022
KLICKITAT STPKlickitat0.032 MGD (million gallons per day)2022
ADDY BLUE CREEK SEWER SYSTEMAddy0.03 MGD (million gallons per day)2022
STEPTOE SEWER DISTRICT 1Steptoe0.03 MGD (million gallons per day)2022
ALDER LAKE PARK STPEatonville0.023 MGD (million gallons per day)2022
Port of Kalama WWTFKalama0.02 MGD (million gallons per day)2022
RUSTLEWOOD DEV STPShelton0.02 MGD (million gallons per day)2022
FARMINGTON STPFarmington0.018 MGD (million gallons per day)2022
LIBERTY SCHOOL DISTRICT 362Spangle0.016 MGD (million gallons per day)2022
EASTSOUND ORCAS VILLAGE WWTPOrcas0.015 MGD (million gallons per day)2022
DRYDEN POTWDryden0.01 MGD (million gallons per day)2022
Main Street Sewer DistrictFreeland0.009 MGD (million gallons per day)2022
Newhalem Wastewater Treatment PlantMarblemount0.004 MGD (million gallons per day)2022
SELKIRK SCHOOL DIST 70Ione0.001 MGD (million gallons per day)2022

Regulatory context

General reference. This is not an exhaustive review of applicable law.

United States: Clean Water Act / NPDES

NPDES regulates pollutant discharges from point sources to waters of the United States. The permit sets limits and monitoring conditions. A CWNS code identifies an inventory record, not an NPDES permit.

  • Permit identifier and permitting authority: EPA or an authorized state.
  • Outfall and receiving water; sewer connections follow a different control route.
  • Current permit conditions, limits and dated measurements; these are not included in CWNS.

References reviewed: 2026-11-06. Individual applicability: undetermined. This profile does not establish authorization or compliance.