Drinking water quality · 2026
· Verified
· PWSID CA4810003
What's in City of Fairfield, CA tap water
Only 0 of 27 core regulated contaminants were reported for City of Fairfield, CA. What was measured is clean — but most of the picture is missing.
- !1 open health-based violation on the federal record
- !0 of 27 core regulated contaminants reported — 27 never appear in this report
- ✓Nothing over a federal limit
+How this score is calculated
Every system starts at 100. Points come off for measured levels, for the federal violation record, and for how much of the core regulated set the utility actually reported. All three inputs are the utility's own published numbers and EPA's own records.
- −0 contaminants at or above a federal limit
- −0 contaminants within 20% of a limit
- −15 open health-based violations
- −3 open monitoring / reporting violations
- −0 health-based violations resolved in the last 5 years
- −30 core regulated contaminants never reported (0/27)
A 90–100 · B 80–89 · C 70–79 · D 60–69 · F below 60. A system reporting under a third of the core set is capped at C however clean its numbers look — a short report is not a clean bill of health.
Full grading methodology, constant for constant →What this report doesn't tell you
27 of the 27 contaminants a community water system normally reports do not appear anywhere in City of Fairfield, CA's data. Absent is not the same as absent-from-the-water — it means nobody published a number.
+Full detail: PFAS testing, water source, historical monitoring, and the federal violation record
Where your water comes from · EPA SDWIS
City of Fairfield, CA's drinking water comes from surface water, drawn from 3 sources.
Source
- NBR WTP - NORTH BAY AQUEDUCT - RAW
- NBR WTP - PUTAH SOUTH CANAL - RAW
- WATERMAN WTP - PUTAH SOUTH CANAL - RAW
Treatment
- NORTH BAY REGIONAL WTP - TREATED
- WATERMAN WTP-FINISHED WATER
Distribution
Compliance history
Federal Safe Drinking Water Act violation & enforcement records (EPA SDWIS). A violation is a regulatory determination by the state or EPA — separate from the measured levels above.
- Treatment technique violationHealth-based1 violation on record · most recent Oct 20241 open
- Maximum contaminant level exceededHealth-based1 violation on record · most recent May 1999resolved
- Reporting1 violation on record · most recent Oct 20241 open
Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗