Is Washington tap water safe?

If you're on a public system, mostly yes: Washington DOH reports most meet federal and state standards. The main caveat is nitrate, which the EPA has documented at elevated levels in Lower Yakima Valley groundwater. That especially affects private wells, so if you draw from a well in that region, the practical move is to get it tested.

Why is nitrate a concern in the Yakima Valley?

Nitrate comes largely from fertilizer and animal waste, and in parts of the Lower Yakima Valley the EPA says agricultural sources have pushed it above the 10 mg/L health standard. A 2024 federal court order even required nearby dairies to test wells and supply alternative water where levels are too high. If you're on a well there, this is the contaminant to test for first.

Does Washington regulate PFAS in drinking water?

Yes, and on two fronts. Washington DOH set state action levels for five PFAS in 2021, and the EPA's 2024 national rule adds enforceable maximum contaminant levels (the legal ceilings for a contaminant) with monitoring required by 2027. In short, the rules around these chemicals are tightening, not loosening.

Water quality

Washington water quality

Where your Washington water comes from matters more than the state line. If you're on a large public surface-water system, you're in fairly good shape: the Washington State Department of Health (DOH) requires monitoring for select PFAS (long-lasting synthetic chemicals) under state action levels adopted in 2021, and the EPA's 2024 federal PFAS rule adds enforceable limits on top. The bigger thing to know about is nitrate, a contaminant linked to fertilizer and animal waste: the EPA has documented widespread nitrate in groundwater across the Lower Yakima Valley from agriculture. That mostly hits private wells, so whether it's your problem depends a lot on whether you're on a well or a city system.

Documented considerations

Nitrates

According to the EPA, nitrate contamination is a concern throughout the Lower Yakima Valley; in December 2024 a federal court ordered three dairies to test nearby wells and provide alternative water where nitrate exceeds 10 mg/L.

What removes nitrates →

PFAS

According to Washington DOH, the state adopted action levels for five PFAS in 2021 and is collecting statewide testing results; the EPA's final federal PFAS rule requires initial monitoring before April 2027.

What removes pfas →

Lead

Lead in drinking water in Washington comes mainly from older service lines and home plumbing; utilities are completing service line inventories under the EPA Lead and Copper Rule.

What removes lead →

EPA compliance snapshot

From the EPA ECHO Safe Drinking Water Act database, Washington community water systems carrying one or more violations on record:

1,913

systems with a violation on record

with a health-based violation

flagged serious violators

Most common violation categories

Revised Total Coliform Rule (408)
Nitrate (251)
TTHM (99)
Total Haloacetic Acids (HAA5) (96)
Lead and Copper Rule (67)
Toluene (48)

Counts are public EPA ECHO figures. 'Health-based' means a system carries at least one health-based violation flag in ECHO. A violation on record is not a statement that current tap water is unsafe; most systems return to compliance. Always check your utility's Consumer Confidence Report for current status. Source: EPA ECHO, retrieved 2026-07-01.

Certified filters for Washington's main concerns

7.5
AquaTru Classic Countertop RO
A no-plumbing countertop 4-stage RO purifier certified to NSF standards for lead, PFAS, fluoride and arsenic with an efficient drain ratio.
nitrates, pfas, lead
6.6
Waterdrop G3P800 Tankless RO
A tankless 800 GPD reverse-osmosis system IAPMO-certified to NSF/ANSI 42, 53, 58 and 372 for a broad contaminant list including lead, PFAS, arsenic, nitrate and fluoride.
nitrates, pfas, lead
8.4
Brita Elite Pitcher (10-Cup)
A pour-through pitcher whose Elite filter is certified to reduce lead, mercury, cadmium and more, with a long 120-gallon cartridge.
pfas, lead
7.5
Culligan US-EZ-4 Under-Sink
An under-sink filter genuinely IAPMO certified to NSF/ANSI 42, 53 and 401 for lead, cysts, VOCs, mercury and PFOA/PFOS.
pfas, lead
7.2
Aquasana AQ-5200 Under-Sink
Certified for lead and PFAS, cheap per gallon, marketing matches the certified scope.
pfas, lead
4.9
ZeroWater 5-Stage Pitcher (7-Cup)
A five-stage ion-exchange pitcher certified for lead, chromium-6 and PFOA/PFOS - but a short 15-gallon filter makes it costly to run.
pfas, lead

FAQ

Is Washington tap water safe?: If you're on a public system, mostly yes: Washington DOH reports most meet federal and state standards. The main caveat is nitrate, which the EPA has documented at elevated levels in Lower Yakima Valley groundwater. That especially affects private wells, so if you draw from a well in that region, the practical move is to get it tested.
Why is nitrate a concern in the Yakima Valley?: Nitrate comes largely from fertilizer and animal waste, and in parts of the Lower Yakima Valley the EPA says agricultural sources have pushed it above the 10 mg/L health standard. A 2024 federal court order even required nearby dairies to test wells and supply alternative water where levels are too high. If you're on a well there, this is the contaminant to test for first.
Does Washington regulate PFAS in drinking water?: Yes, and on two fronts. Washington DOH set state action levels for five PFAS in 2021, and the EPA's 2024 national rule adds enforceable maximum contaminant levels (the legal ceilings for a contaminant) with monitoring required by 2027. In short, the rules around these chemicals are tightening, not loosening.

Sources

Not sure how to read your local report? See our guide on reading a water quality report.