State system profile

PFAS in Washington drinking water

Active community water systems with complete EPA UCMR 5 monitoring, summarized using yearly averages from results available through January 15, 2026.

Source EPA UCMR 5 Period 2023–2025 Systems included 229 Release ucmr5-2026-01-15-analysis-v0.2
Systems with a yearly average at or above an EPA-based study benchmark
8.3%19 of 229 active community water systems

All 229 systems had enough required samples to calculate a yearly average. 19 had at least one yearly average at or above a study benchmark; 210 did not.

EPA-based study benchmark: the unrounded cutoff this research uses to reproduce EPA’s January 2026 technical-assistance classification around the April 2024 federal levels. It is not a current standard or compliance finding and cannot determine household exposure or health risk.

Check your area

Find your water system

ZIP codes are used only to route visitors to public water systems that reported serving them. Confirm the actual provider using a water bill or utility record.

Open the system lookup →Read the methodology
Compound summary

System counts in Washington

Each count shows how many included water systems had a yearly average at or above the named study benchmark.

Community water systems with yearly averages at or above the EPA-based study benchmarks used in the January 2026 research release for Washington.
Study benchmarkSystems at or above benchmarkWater systems includedPercent
PFOA: 4.05 ppt study benchmark (reproduces EPA classification around 4 ppt)42291.7%
PFOS: 4.05 ppt study benchmark (reproduces EPA classification around 4 ppt)182297.9%
PFHxS: 15 ppt study benchmark (reproduces EPA classification around 10 ppt)32291.3%
PFNA: 15 ppt study benchmark (reproduces EPA classification around 10 ppt)02290.0%
HFPO-DA: 15 ppt study benchmark (reproduces EPA classification around 10 ppt)02290.0%
Hazard Index: 1.5 study benchmark with at least two detected components (reproduces EPA classification around 1)32291.3%
System directory

Community water systems with complete monitoring

“Complete monitoring” means at least one sampling location had all required samples needed for a yearly average. Each PWSID appears once, preventing double counting across ZIP associations.

Active community water systems with complete UCMR 5 monitoring in Washington.
Public water systemPWSIDPopulation servedPrimary sourceSampling locationsStudy benchmark result
ABERDEEN CITY OFWA530005022,867Surface water1Below all study benchmarks
AIRWAY HEIGHTS CITY OFWA53006509,489Ground water2Below all study benchmarks
ALDERWOOD WATER DISTRICTWA5301300245,715Surface water purchased1Below all study benchmarks
ANACORTES CITY OFWA530220025,109Surface water1Below all study benchmarks
ARLINGTON WATER DEPTWA530295029,508Surface water purchased3Below all study benchmarks
ARTONDALE WATER SYSTEMWA53031605,828Ground water10Below all study benchmarks
Auburn City ofWA5303350107,655Ground water6Below all study benchmarks
BAINBRIDGE ISLAND CITY OFWA539765013,491Ground water4Below all study benchmarks
BAYSHOREWA5304900130Ground water1Below all study benchmarks
BEACON HILL WATER & SEWER DISTRICTWA531565011,969Ground water purchased1Below all study benchmarks
BELLEVUE CITY OFWA5305575321,349Surface water purchased2Below all study benchmarks
BELLINGHAM-WATER DIVISION CITY OFWA5305600141,127Surface water1Below all study benchmarks
BENTON CITY WATERWA53058005,626Ground water3At or above a study benchmark
BIRCH BAY WATER & SEWER DISTRICTWA53959049,046Ground water purchased3Below all study benchmarks
BLAINE CITY OFWA53073006,319Ground water3Below all study benchmarks
BONNEY LAKE WATER DEPARTMENT CITYWA530765043,371Surface water purchased5Below all study benchmarks
BOTHELL WATER CITY OFWA530790033,643Surface water purchased1Below all study benchmarks
BREMERTON CITY OFWA530820072,951Surface water7Below all study benchmarks
BUCKLEY WATERWA53090007,842Surface water purchased7Below all study benchmarks
CAMAS MUNICIPAL WATER SEWER SYSTEMWA531080031,794Ground water5At or above a study benchmark
CASTLE ROCK MUNICIPAL WATERWA53118004,367Surface water5Below all study benchmarks
CEDAR GROVE MOBILE PARKWA533683640Ground water1Below all study benchmarks
CEDAR RIVER WATER & SEWER DISTRICTWA534180028,671Surface water purchased2Below all study benchmarks
CENTRALIA PUBLIC WORKS - WATERWA531220028,164Ground water3At or above a study benchmark
CHELAN CO PUD 1WA531228416,190Ground water purchased1Below all study benchmarks
CHELAN WATER DEPT CITY OFWA53123009,425Surface water1Below all study benchmarks
CHENEY CITY OFWA531240016,954Ground water5Below all study benchmarks
CLARK PUBLIC UTILITIESWA5313333153,526Ground water10At or above a study benchmark
COAL CREEK UTILITY DISTRICTWA534175015,989Surface water purchased1Below all study benchmarks
COLFAX WATER DEPARTMENT CITY OFWA53140003,507Ground water3Below all study benchmarks
COLLEGE PLACE WATER DEPTWA53140508,147Ground water5Below all study benchmarks
COLVILLE WATER DEPARTMENTWA53142004,945Ground water2Below all study benchmarks
CONNELL CITY OFWA53146005,150Ground water3Below all study benchmarks
CONSOLIDATED IRRIG DIST 19 SYSTEM 1WA53102209,434Ground water3Below all study benchmarks
CONSOLIDATED IRRIG DIST 19 SYSTEM 2WA531022121,220Ground water4Below all study benchmarks
COUPEVILLE TOWN OFWA53155504,142Ground water1At or above a study benchmark
COVINGTON WATER DISTRICTWA534165056,172Surface water purchased3At or above a study benchmark
CRESCENT WATER ASSNWA53160202,360Surface water1Below all study benchmarks
CROSS VALLEY WATER DISTRICTWA531627024,695Surface water purchased6Below all study benchmarks
CRYSTAL MOUNTAIN INCWA53164004,154Surface water1Below all study benchmarks
Columbia Valley Water DistrictWA53661102,648Ground water3Below all study benchmarks
DEER PARK CITY OFWA53185005,435Ground water8Below all study benchmarks
DUNGENESS MEADOWSWA5320445488Ground water3Below all study benchmarks
DUPONT WATER SYSTEM CITY OFWA532050013,141Ground water2Below all study benchmarks
DUVALL CITY OFWA532075011,050Surface water purchased1Below all study benchmarks
EAST SPOKANE WATER DIST 1WA53216504,285Ground water4Below all study benchmarks
EAST WENATCHEE WATER DISTRICTWA532180026,519Ground water purchased1Below all study benchmarks
EASTERN WASHINGTON UNIVERSITYWA532190017,108Ground water1Below all study benchmarks
EASTSOUND WATER USERS ASSOCIATIONWA53221703,711Surface water4Below all study benchmarks
EATONVILLE WATER DEPTWA53223003,945Surface water1Below all study benchmarks
EDMONDS CITY OFWA532250034,065Surface water purchased1Below all study benchmarks
ELLENSBURG WATER DEPTWA532295020,900Ground water8Below all study benchmarks
EMERALD LAKEWA5323294331Ground water1Below all study benchmarks
ENUMCLAW WATER DEPARTMENTWA532360023,276Ground water4Below all study benchmarks
EPHRATA WATER DEPARTMENTWA53236508,718Ground water5Below all study benchmarks
EVERETT PUBLIC WORKS DEPT. CITY OFWA5324050215,774Surface water2Below all study benchmarks
EVERSON CITY OFWA53242003,893Ground water1Below all study benchmarks
FAIRCHILD AIR FORCE BASEWA53243509,544Ground water2At or above a study benchmark
FERNDALE WAWA532485019,305Ground water1Below all study benchmarks
FIRCREST CITY OFWA53251507,927Ground water4Below all study benchmarks
FIRGROVE MUTUAL INCWA532520036,168Surface water purchased13Below all study benchmarks
FORKS MUNICIPAL WATER DEPTWA53260003,468Ground water2Below all study benchmarks
FRIDAY HARBOR TOWN OFWA53265953,543Surface water1Below all study benchmarks
FRUITLAND MUTUAL WATER COMPANYWA532680015,313Ground water4Below all study benchmarks
GIG HARBOR WATER DEPTWA532760016,510Ground water6Below all study benchmarks
GOLD BAR CITY OFWA53283002,745Ground water2Below all study benchmarks
GOLDENDALE CITY OFWA53284504,314Ground water2Below all study benchmarks
GRANDVIEW CITY OFWA532897011,010Ground water9Below all study benchmarks
GRANGER WATER DEPARTMENTWA53290003,993Ground water1Below all study benchmarks
GRANITE FALLS CITY OFWA53290505,349Surface water purchased1Below all study benchmarks
GRAYS HARBOR CO WATER DIST 2WA53292505,112Ground water1Below all study benchmarks
HEIGHTS WATERWA53323002,051Ground water1Below all study benchmarks
HI VALLEY VIEWWA530043167Ground water1Below all study benchmarks
HIGHLINE WATER DISTRICTWA5340650100,170Surface water purchased3Below all study benchmarks
HOQUIAM WATER DEPARTMENTWA533435011,456Surface water1Below all study benchmarks
HORIZONS WESTWA53343753,454Ground water6Below all study benchmarks
IRVIN WATER DISTRICT #6WA53360504,150Ground water4Below all study benchmarks
ISSAQUAH WATER SYSTEMWA533635043,584Surface water purchased4Below all study benchmarks
JBLM LewisWA532605035,414Ground water6At or above a study benchmark
JBLM McChord FieldWA53522007,290Ground water7At or above a study benchmark
KALAMA CITY OFWA53375508,020Groundwater under influence of surface water1Below all study benchmarks
KELSO CITY OFWA533800015,775Groundwater under influence of surface water1Below all study benchmarks
KENNEWICK CITY OFWA5338100118,164Surface water2At or above a study benchmark
KENT WATER DEPARTMENTWA5338150166,421Surface water purchased6Below all study benchmarks
KING COUNTY WATER DISTRICT #125WA534199821,904Surface water purchased1Below all study benchmarks
KING COUNTY WATER DISTRICT #20WA533895048,469Surface water purchased1Below all study benchmarks
KING COUNTY WATER DISTRICT #49WA533980023,492Surface water purchased1Below all study benchmarks
KING COUNTY WATER DISTRICT #54WA53399505,373Surface water purchased1Below all study benchmarks
KING COUNTY WATER DISTRICT 119WA53419853,800Surface water purchased1Below all study benchmarks
KING COUNTY WATER DISTRICT NO 90WA534115020,100Surface water purchased2Below all study benchmarks
KIRKLAND CITY OFWA534225069,243Surface water purchased1Below all study benchmarks
LACEY WATER DEPARTMENTWA5343500105,178Ground water12Below all study benchmarks
LAKE CHELAN RECLAMATION DISTRICTWA53437836,798Surface water1Below all study benchmarks
LAKE CUSHMAN SYSTEM 5WA53035293,675Ground water7Below all study benchmarks
LAKE FOREST PARK WATER DISTRICTWA53409503,171Ground water3Below all study benchmarks
LAKEHAVEN WATER AND SEWER DISTRICTWA5341997148,809Surface water purchased16Below all study benchmarks
LAKEWOOD WATER DISTRICTWA534555082,425Ground water5At or above a study benchmark
LIBERTY LAKE SEWER & WATER DISTRICTWA534715014,500Ground water4Below all study benchmarks
LONG BEACH WATER DEPARTMENTWA53480004,628Surface water1Below all study benchmarks
LONGVIEW WATER DEPARTMENTWA534810057,617Ground water1Below all study benchmarks
LOST LAKE PROPERTY OWNERS ASSNWA5348345736Ground water1Below all study benchmarks
LUMMI TRIBAL WATER DISTRICT1053000023,699Surface water purchased7Below all study benchmarks
LYNDEN WATER DEPARTMENTWA534915020,062Surface water1Below all study benchmarks
LYNNWOOD CITY OFWA534927068,204Surface water purchased1Below all study benchmarks
Lake Meridian Water DistrictWA534190024,231Surface water purchased5Below all study benchmarks
MANCHESTER WATER DISTRICTWA535070010,475Ground water8Below all study benchmarks
MARYSVILLE UTILITIESWA535190088,582Surface water purchased5Below all study benchmarks
MCCORMICK WOODSWA53405292,760Surface water purchased2Below all study benchmarks
MEDICAL LAKE CITY OFWA53534004,982Ground water2Below all study benchmarks
MERCER ISLAND CITY OFWA535364031,057Surface water purchased1Below all study benchmarks
MILTON CITY OFWA53549508,078Ground water2Below all study benchmarks
MONROE WATER SYSTEM, WAWA535582023,467Surface water purchased1Below all study benchmarks
MONTESANO CITY OFWA53560006,204Ground water2Below all study benchmarks
MOSES LAKE CITY OFWA535630032,428Ground water18At or above a study benchmark
MOUNTAIN VIEW-EDGEWOOD WATER COWA53568209,680Ground water6Below all study benchmarks
MOUNTLAKE TERRACE CITY OFWA535725026,402Surface water purchased1Below all study benchmarks
MOXEE WATER DEPARTMENTWA53573005,599Ground water3Below all study benchmarks
MT. VISTA - DUNGENESS GOLF COURSE105388889517Ground water2Below all study benchmarks
Mattawa City ofWA53520005,370Ground water1Below all study benchmarks
Mukilteo Water & Wastewater DistrWA535755031,437Surface water purchased3Below all study benchmarks
NACHES TOWN OFWA53581003,512Ground water2Below all study benchmarks
NAVAL AIR STATION/WHIDBEY ISLANDWA530342016,595Surface water purchased1Below all study benchmarks
NAVAL BASE KITSAP AT BANGORWA530271416,828Ground water2Below all study benchmarks
NAVAL BASE KITSAP AT BREMERTONWA530346811,792Surface water purchased1Below all study benchmarks
NE SAMMAMISH SEWER & WATER DISTRICTWA53752659,702Ground water2Below all study benchmarks
NOB HILL WATER ASSOCIATIONWA535970038,050Ground water5Below all study benchmarks
NORTH BAINBRIDGE WATER COWA53599945,490Ground water1Below all study benchmarks
NORTH BEACH WATERWA53630008,093Ground water2Below all study benchmarks
NORTH BEND, CITY OFWA53601008,710Ground water2Below all study benchmarks
NORTH PENINSULAWA530512216,449Ground water6Below all study benchmarks
NORTH PERRY AVE WATER DISTRICTWA536095024,402Ground water9Below all study benchmarks
NORTHSHORE UTILITY DISTRICTWA534080099,789Surface water purchased1Below all study benchmarks
North City Water DistrictWA533960032,847Surface water purchased1Below all study benchmarks
OAK HARBOR CITY OFWA536265023,675Surface water purchased1Below all study benchmarks
OCEAN SHORES WATER DEPTWA53630089,347Ground water1Below all study benchmarks
OLYMPIA CITY OFWA5363450126,966Ground water6Below all study benchmarks
OLYMPIC VIEW WATER & SEWER DISTRICTWA536360017,784Surface water2Below all study benchmarks
OMAK CITY OFWA53637504,940Ground water3Below all study benchmarks
ORCHARD AVENUE IRRIGATION DIST 6WA53640004,330Ground water2Below all study benchmarks
ORTING CITY OFWA536450010,332Ground water5Below all study benchmarks
OTHELLO WATER DEPARTMENTWA53648508,755Ground water7Below all study benchmarks
PARKLAND LIGHT & WATER COMPANYWA536620033,775Ground water5At or above a study benchmark
PARKVIEW TERRACEWA53662153,730Ground water5Below all study benchmarks
PASADENA PARK IRR DIST 17WA53663006,269Ground water4Below all study benchmarks
PASCO WATER DEPARTMENTWA5366400115,102Surface water2Below all study benchmarks
PATTISONWA53665784,643Ground water7Below all study benchmarks
PEACOCK HILLWA53666377,401Ground water26Below all study benchmarks
POINT EVANSWA53680655,211Ground water8Below all study benchmarks
PORT ANGELES CITY OFWA536855028,067Surface water1Below all study benchmarks
PORT ANGELES COMPOSITEWA53432968,872Surface water5Below all study benchmarks
PORT TOWNSEND CITY OFWA536900017,053Surface water1Below all study benchmarks
POULSBO CITY OFWA536915018,400Ground water6Below all study benchmarks
PROSSER CITY OFWA536975012,070Ground water1Below all study benchmarks
PULLMAN WATER DEPARTMENT CITY OFWA536988031,315Ground water5Below all study benchmarks
PUYALLUP CITY OFWA537005094,520Surface water purchased7Below all study benchmarks
QUIMPERWA530578314,548Ground water8Below all study benchmarks
QUINCY WATER DEPARTMENT CITY OFWA53704508,415Ground water5Below all study benchmarks
QUISTORFFWA53705501,113Ground water4At or above a study benchmark
REDMOND WATER SYSTEM CITY OFWA5371650163,335Surface water purchased4Below all study benchmarks
RENTON CITY OFWA5371850108,091Ground water3Below all study benchmarks
RICHLAND CITY OFWA5372250106,499Surface water4Below all study benchmarks
RIDGEFIELD PUBLIC WORKSWA537240021,225Ground water6Below all study benchmarks
Raymond Water DepartmentWA53715004,620Surface water1Below all study benchmarks
SALLAL WATER ASSOCIATION INCWA53755606,600Ground water4Below all study benchmarks
SAMMAMISH PLATEAU WATER & SEWERWA534090079,362Surface water purchased7At or above a study benchmark
SEABECKWA5303134610Ground water1Below all study benchmarks
SEASCAPE WATER ASSOCIATIONWA530709528Ground water1Below all study benchmarks
SEATTLE PUBLIC UTILITIESWA53770501,161,961Surface water2Below all study benchmarks
SELAH CITY OFWA53774009,331Ground water3Below all study benchmarks
SEQUIM CITY OFWA537762014,293Ground water3Below all study benchmarks
SEVEN LAKES WATER ASSOCIATIONWA53776605,823Ground water4Below all study benchmarks
SHELTER BAY COMMUNITY INCWA53781552,212Surface water purchased1Below all study benchmarks
SHELTON CITY OFWA537817015,089Ground water3Below all study benchmarks
SHOALWATER BAY105300019898Ground water1Below all study benchmarks
SILVER LAKE WATER & SEWER DISTRICTWA537925065,033Surface water purchased1Below all study benchmarks
SILVERDALE WATER DIST 16WA537930035,163Ground water10Below all study benchmarks
SKAGIT COUNTY PUD 1 JUDY RESWA5379500111,415Surface water1Below all study benchmarks
SKYWAY WATER & SEWERWA533880012,036Surface water purchased3Below all study benchmarks
SNO PUD 1 - LAKE STEVENSWA538090767,710Surface water purchased2Below all study benchmarks
SNOHOMISH CITY OFWA538091516,367Surface water purchased2Below all study benchmarks
SNOQUALMIE PASS UTILITY DISTRICTWA53810485,832Ground water1Below all study benchmarks
SNOQUALMIE WATERWA538108020,222Ground water2Below all study benchmarks
SOOS CREEK WATER & SEWER DISTRICTWA534010074,172Surface water purchased1Below all study benchmarks
SOUTHWOOD WATER SYSTEMWA538284464,155Surface water purchased26At or above a study benchmark
SPANAWAY WATER COMPANYWA538285034,506Ground water10At or above a study benchmark
SPO CO WATER DIST 3 SYS 2WA539335119,035Ground water5Below all study benchmarks
SPO CO WATER DIST 3 SYS 3WA53933533,768Ground water2Below all study benchmarks
SPO CO WATER DIST 3 SYS 4WA53933546,233Ground water4Below all study benchmarks
SPOKANE CITY OFWA5383100346,138Ground water6Below all study benchmarks
STANWOOD WATER DEPT CITY OFWA538365017,586Ground water2Below all study benchmarks
STEILACOOM TOWN OFWA53840008,545Ground water1Below all study benchmarks
STEVENS CO PUD - SUNCRESTWA53852027,484Ground water8Below all study benchmarks
STEVENS CO PUD - VALLEYWA5305520550Ground water2Below all study benchmarks
SULTAN WATER DEPARTMENTWA53847708,424Surface water2Below all study benchmarks
SUMMIT WATER & SUPPLY COWA538505019,125Ground water7Below all study benchmarks
SUMNER CITY OFWA538512016,438Ground water7Below all study benchmarks
SUQUAMISHWA53864004,203Ground water4Below all study benchmarks
Snake River Housing Water SystemWA53007103,036Ground water2Below all study benchmarks
TACOMA WATER DIVISION CITY OFWA5386800446,170Surface water3Below all study benchmarks
TOPPENISH WATER DEPARTMENTWA53888508,950Ground water5Below all study benchmarks
TRENTWOOD IRRIGATION DISTRICT 3WA53892504,228Ground water4At or above a study benchmark
TUKWILA WATER DEPARTMENTWA538950036,298Surface water purchased1Below all study benchmarks
TULALIP BAY WATER DIST #11053000035,968Surface water purchased1Below all study benchmarks
TUMWATER CITY OFWA538970051,802Ground water5Below all study benchmarks
Tanglewilde-Thompson Place 600WA53043977,900Ground water1Below all study benchmarks
Tenino City ofWA53874003,336Ground water1Below all study benchmarks
UNION GAP WATERWA53902506,433Ground water4Below all study benchmarks
UNION HILL WATER ASSOCIATION INCWA53902608,720Ground water1Below all study benchmarks
VANCOUVER CITY OFWA5391200373,047Ground water10At or above a study benchmark
VERA WATER & POWERWA539145024,692Ground water6Below all study benchmarks
VINLANDWA53919234,801Ground water3Below all study benchmarks
WALLA WALLA WATER DIVISIONWA539250042,959Surface water1Below all study benchmarks
WAPATO WATERWORKSWA53928005,255Ground water3Below all study benchmarks
WARDEN CITY OFWA53928504,674Ground water4Below all study benchmarks
WASHINGTON STATE UNIVERSITYWA539320021,506Ground water4Below all study benchmarks
WATER DISTRICT 19WA53389005,335Surface water5Below all study benchmarks
WENATCHEE CITY OFWA539435043,690Ground water1Below all study benchmarks
WEST RICHLAND CITY OFWA539490021,231Surface water purchased3Below all study benchmarks
WEST SEQUIM BAY INCWA53541922,759Ground water1Below all study benchmarks
WESTPORT WATER DEPARTMENTWA53953005,346Ground water3Below all study benchmarks
WHATCOM COUNTY WATER DIST 13WA5395914795Ground water2Below all study benchmarks
WHITE SALMON CITY OFWA53963504,077Surface water2Below all study benchmarks
WHITWORTH WATER DISTRICT 2WA539660126,883Ground water9Below all study benchmarks
WOODINVILLE WATER DISTRICTWA534160066,699Surface water purchased1Below all study benchmarks
WOODLAND CITY OFWA539820010,640Groundwater under influence of surface water1Below all study benchmarks
West Sound Utility District #1WA530260028,930Ground water9Below all study benchmarks
YAK CO - TERRACE HEIGHTSWA53060298,410Ground water5Below all study benchmarks
YAKIMA WATER DIVISION CITY OFWA5399150112,858Surface water5Below all study benchmarks
YELM CITY OFWA539935017,355Ground water2Below all study benchmarks
How the count works

What is included

Each active community water system with enough required samples for a yearly average is counted once, even if it is linked with several ZIP codes. This does not mean every home was tested. Private wells are excluded, and UCMR 5 did not comprehensively monitor every small system. This page does not apply Washington's state-specific standards or determine compliance. Use the official state or territory drinking-water program for current regulatory information.

Continue exploring

Related links

PFAS Estimator system lookupNational state comparison tableFull methodology and limitationsCurrent EPA UCMR 5 Data FinderOfficial state and territory drinking-water programs