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Water system · PWSID WI6320327

ONALASKA WATERWORKS

Onalaska, WI · ~18,000 people served

Check your exact address → Onalaska overview
100
Excellent
PurityRadar safety score

PWSID

WI6320327

State

Wisconsin

City

Onalaska

Population served

18,000

Primary source

Groundwater

Score history

No change since tracking began Jun 18, 2026.

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

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 Jul 2023). Levels in parts per trillion (ppt).

PFBS

3.3 ppt

limit —

No federal limit

Violations & enforcement

3

Violations on record

0

Unaddressed

2

Health-based

25

Enforcement actions

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

Max contaminant level (MCL) · Total coliform health-based began Jul 2010 Resolved
Monitoring & reporting · Nitrate began Jan 2001 Resolved
Max contaminant level (MCL) · Total coliform health-based began Aug 1997 Resolved

Recent enforcement actions

  • State action · SIF Aug 2010
  • State action · SOX Jul 2010
  • State action · SIA Jul 2010
  • State action · SIE Jul 2010
  • State action · SIF May 2001
  • State action · SOX May 2001
  • State action · SIE Apr 2001
  • State action · SIA Apr 2001

This profile is built from EPA public records for system WI6320327 — 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.