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Water system · PWSID 090605047

Colusa Southern System

Colusa, CA · ~3,474 people served

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

PWSID

090605047

State

California

City

Colusa

Population served

3,474

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

No PFAS detections are on record for this system from EPA’s UCMR5 monitoring (2023–25). Absence of a detection isn’t a guarantee — not every system was sampled, and this dataset doesn’t cover other contaminants.

Violations & enforcement

147

Violations on record

0

Unaddressed

0

Health-based

395

Enforcement actions

From EPA ECHO (SDWIS), most recent enforcement Dec 2011. Official EPA record →

Other · EPA contaminant 7000 began Jul 2005 Resolved
Other · EPA contaminant 7000 began Jul 2004 Resolved
Monitoring & reporting · EPA contaminant 2035 began Jan 2004 Resolved
Monitoring & reporting · EPA contaminant 2031 began Jan 2004 Resolved
Monitoring & reporting · EPA contaminant 2034 began Jan 2004 Resolved
Monitoring & reporting · EPA contaminant 2033 began Jan 2004 Resolved
Monitoring & reporting · EPA contaminant 2005 began Jan 2004 Resolved
Monitoring & reporting · Nitrate began Jan 2004 Resolved
Monitoring & reporting · EPA contaminant 2020 began Jan 2004 Resolved
Monitoring & reporting · EPA contaminant 2015 began Jan 2004 Resolved
Monitoring & reporting · EPA contaminant 2032 began Jan 2004 Resolved
Monitoring & reporting · EPA contaminant 2010 began Jan 2004 Resolved

Recent enforcement actions

  • EPA/federal action · EIC Dec 2011
  • EPA/federal action · EIC Jan 2011
  • EPA/federal action · EIC Oct 2010
  • EPA/federal action · EIC Sep 2010
  • EPA/federal action · EIC Jul 2010
  • EPA/federal action · EIC Apr 2010
  • EPA/federal action · EO8 Mar 2010
  • EPA/federal action · EIC Jan 2010

This profile is built from EPA public records for system 090605047 — 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.