PFAS in Drinking Water in Washington
What residents of Washington need to know about PFAS ("forever chemicals") in drinking water — including contamination sources, which utilities have documented violations, and how to filter PFAS from tap water.
Source: EPA SDWIS, Washington Department of Health, CDC · Last reviewed: 2025-01-01
Quick Answer
Is PFAS in drinking water a real concern in Washington?
Yes. Washington State has significant PFAS contamination from Joint Base Lewis-McChord (JBLM) — one of the largest military installations in the Pacific Northwest — and Whidbey Island Naval Air Station in Island County. JBLM has documented extensive AFFF-related PFAS contamination in the surrounding Pierce and Thurston county groundwater. Whidbey Island NAS has contaminated groundwater affecting the small island community.
Where does PFAS come from in Washington?
Joint Base Lewis-McChord in Pierce County is Washington's primary military PFAS source, with AFFF plumes documented in the Chambers Creek drainage and surrounding aquifer systems in Pierce and Thurston counties. The base is located near the Lacey/Olympia area where groundwater is a primary water source for communities south of Tacoma. Whidbey Island NAS in Island County has contaminated the island's shallow aquifer, affecting communities that have no alternative water source.
What should Washington residents know?
Lakewood, DuPont, and communities south of Tacoma in Pierce County near JBLM face the most direct risk from military PFAS. Whidbey Island communities — particularly Oak Harbor and Coupeville — are especially vulnerable given the island's sole-source aquifer dependence. Washington DOH has conducted extensive PFAS monitoring and is among the more proactive state regulators on PFAS.
Key Facts
| EPA MCL (PFOA/PFOS) | 4 ppt — effective April 2024 |
| MCLG | Zero |
| Primary contamination sources | JBLM (Pierce/Thurston counties), NAS Whidbey Island (Island County) |
| Island aquifer concern | Whidbey Island sole-source aquifer — NAS contamination has no alternative water source for island |
| Oak Harbor status | Oak Harbor water system detected PFAS from NAS Whidbey — treatment installation underway |
| State regulator | Washington Department of Health (DOH) |
| Health effects | Cancer (kidney, testicular), thyroid disruption, immune effects, developmental toxicity |
| Effective treatment | GAC or RO; Oak Harbor and other WA utilities pursuing treatment under state and federal guidance |
Why PFAS Matters in Washington
JBLM — the largest military employer in Washington State — has generated documented PFAS plumes in the aquifer systems that supply communities south of Tacoma. The joint Army-Air Force base has both flight operations (McChord airfield) and extensive ground training areas, both of which have used AFFF. The contamination affects Pierce and Thurston county communities with a combined population of hundreds of thousands. Whidbey Island NAS represents a different but equally significant case: a naval air station on a geographically isolated island whose contamination has direct implications for the island's only aquifer. Oak Harbor, WA's water system has detected PFAS above health advisories from NAS Whidbey Island AFFF sources.
Washington PFAS Regulation
Washington DOH participates in UCMR5 monitoring and has assessed PFAS at Joint Base Lewis-McChord (Tacoma area) and Whidbey Island NAS. Washington's Tacoma area has documented PFAS contamination from JBLM affecting some community water systems. Washington follows the federal MCL with no additional state standard.
Largest Washington Water Utilities
No PFAS violations on record in EPA SDWIS for Washington utilities in our database. Browse the largest utilities to review their full water quality record.
What Are PFAS (“Forever Chemicals”)?
PFAS are a family of over 12,000 synthetic chemicals used in non-stick cookware, stain-resistant fabrics, food packaging, and AFFF firefighting foam. Their carbon-fluorine bonds do not break down in the environment or the body — hence the name “forever chemicals.” AFFF used at military bases is the single largest source of PFAS in U.S. drinking water.
Full PFAS overview — national data, health effects, all 50 statesWho Should Pay Closest Attention
Lakewood, DuPont, and southern Pierce County communities near JBLM; Oak Harbor and other Whidbey Island communities near NAS Whidbey Island; and private well users in the JBLM influence zone in Pierce and Thurston counties face elevated risk.
Residents near military bases with AFFF use history
Private well owners near military or industrial sites
Pregnant residents and families with young children
Residents in communities with documented PFAS detections
Anyone who has consumed water above 4 ppt for an extended period
Residents near airports, fire training areas, or industrial manufacturers
How to Check Your Situation in Washington
- 1
Identify your water utility using the ZIP lookup below or by browsing the Washington utility directory on this site.
- 2
Review your utility's Consumer Confidence Report (CCR) — it must report PFAS monitoring results under UCMR5 and the new MCL.
- 3
Check the EPA's ECHO database for your utility's monitoring history. Look for PFAS, PFOA, PFOS, and related compound results.
- 4
Contact your utility directly and ask for their most recent PFAS test results and whether they are implementing treatment under the 2024 MCL.
- 5
If you use a private well near a military base, airport, or industrial facility, order a PFAS panel test from a state-certified laboratory. Tests typically cost $150–$400.
- 6
If PFAS is detected above 4 ppt in your source water, install a certified NSF/ANSI 58 reverse osmosis system or an NSF/ANSI 53-certified activated carbon filter rated for PFAS removal.
How to Remove PFAS from Tap Water
Reverse Osmosis (Best)
90–99% removal — NSF/ANSI 58 certified systems only
Certified Activated Carbon
Effective with NSF/ANSI 53 or 58 certification — verify before buying
Boiling concentrates PFAS. Standard pitcher filters and water softeners do not remove PFAS. Always verify NSF certification before purchasing.
Take Action Now
Look up your Washington utility's PFAS monitoring history on the PFAS Watchlist below.
If your utility has detected PFAS above 4 ppt, install an NSF/ANSI 58-certified reverse osmosis system at your drinking tap.
Private well owners near military or industrial sites should order a PFAS panel test ($150–$400 at a state-certified lab).
Request your utility's most recent Consumer Confidence Report — PFAS results must be disclosed under the new 2024 MCL.
Frequently Asked Questions
Related Pages
PFAS — National Overview
All U.S. utilities with PFAS records
Washington PFAS Watchlist
Live utility PFAS monitoring data
Washington State Overview
All utilities and water quality data
Reverse Osmosis Guide
Removes 90–99% of PFAS
Activated Carbon Filter Guide
NSF/ANSI 53/58 certified options for PFAS
Arsenic in Drinking Water
Another priority contaminant
All Contaminants
Complete reference library
Data Sources & Provenance
All data on this page is sourced from official U.S. government or public datasets.
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Washington Department of Health ↗