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Water system · PWSID WA5340900

SAMMAMISH PLATEAU WATER & SEWER

Sammamish, WA · ~79,362 people served

Check your exact address → Sammamish overview
67
Fair
PurityRadar safety score

PWSID

WA5340900

State

Washington

City

Sammamish

Population served

79,362

Primary source

SWP

Score history

▼ 33 points — the score moved from 100 to 67 on Jun 18, 2026, as newly published EPA data was incorporated.

Jun 18, 2026 · score 100 Jun 18, 2026 · score 67

2 score updates logged since tracking began Jun 18, 2026. Each future EPA re-score adds a point.

PFAS & contaminant readings

Latest detections from EPA’s UCMR5 monitoring (through Feb 2024). Levels in parts per trillion (ppt).

PFOS

Perfluorooctanesulfonic acid

8.2 ppt

limit 4 ppt

Above EPA limit · 2.1×

PFHxS

Perfluorohexanesulfonic acid

3.4 ppt

limit 10 ppt

Below EPA limit

PFBS

5.3 ppt

limit —

No federal limit

PFPeS

4.1 ppt

limit —

No federal limit

PFHxA

3.2 ppt

limit —

No federal limit

PFPeA

3 ppt

limit —

No federal limit

Violations & enforcement

8

Violations on record

0

Unaddressed

0

Health-based

8

Enforcement actions

From EPA ECHO (SDWIS), most recent enforcement Feb 2010. Official EPA record →

Monitoring & reporting · Nitrate began Jan 2009 Resolved
Monitoring & reporting · Nitrate began Jan 2009 Resolved
Monitoring & reporting · EPA contaminant 2946 began Oct 2007 Resolved
Monitoring & reporting · EPA contaminant 2931 began Oct 2007 Resolved
Monitoring & reporting · EPA contaminant 2032 began Oct 2007 Resolved
Monitoring & reporting · EPA contaminant 2931 began Jul 2007 Resolved
Monitoring & reporting · EPA contaminant 2946 began Jul 2007 Resolved
Monitoring & reporting · EPA contaminant 2032 began Jul 2007 Resolved

Recent enforcement actions

  • State action · SOX Feb 2010
  • State action · SOX Feb 2010
  • State action · SOX Jan 2008
  • State action · SOX Jan 2008
  • State action · SOX Jan 2008
  • State action · SOX Jan 2008
  • State action · SOX Jan 2008
  • State action · SIC Sep 1986

This profile is built from EPA public records for system WA5340900 — SDWIS violations and UCMR5 PFAS sampling. The score is system-level and can’t account for your home’s plumbing (older pipes can add lead at the tap). For health decisions, check your exact address, read the utility’s Consumer Confidence Report, and confirm with your provider.