CheckPFAS

City overview · King County

PFAS in Sammamish, WA

High Risk

EPA UCMR 5 tested 1 public water system serving the Sammamish area across 2 ZIP codes. At least one utility serving Sammamish has PFAS above the EPA's enforceable limit.

Water systems tested
1
Systems above EPA limits
1
ZIP codes covered
2
County
King County, Washington

Plain English

01What this means for Sammamish

Across the 1 public water systems tested in the Sammamish area under EPA UCMR 5, one or more measured a PFAS compound above the federal Maximum Contaminant Level. Contamination varies by utility and neighborhood — find your exact ZIP code below to see the system that serves you. If you're in an affected area, an NSF/ANSI 53 or 58 certified filter (carbon block or reverse osmosis) is the most reliable way to reduce PFAS at the tap.

By utility

02Water systems serving Sammamish

  1. SAMMAMISH PLATEAU WATER & SEWER

    6 detected · 2 above limit · PWSID WA5340900

    High Risk

By ZIP code

03Find your exact result

Contamination can differ block to block. Select your ZIP code for the precise reading at the utility that serves your address.

Source & Methodology

About this data

Source
EPA UCMR 5
Sampling period
January 2023 – December 2025
Aggregation
1 utilities across 2 ZIP codes
Detection threshold (MRL)
~1.5–2 ppt

City-level figures aggregate the individual public water systems tested under EPA UCMR 5 whose service area falls within the Sammamish area. Values reflect water quality at the treatment plant; your home's plumbing can affect what reaches your tap. Select your ZIP above for the utility-specific reading.