Drinking water quality · 2026
· Verified
· PWSID CA1010003
What's in City of Clovis, CA tap water
Only 1 of 27 core regulated contaminants were reported for City of Clovis, CA. What was measured is not clean — but most of the picture is missing.
- !2 contaminants at or above a federal limit — worst is PFOS (Perfluorooctane sulfonic acid) at 10.3x
- !1 contaminant within 20% of a limit
- !1 of 27 core regulated contaminants reported — 26 never appear in this report
- ✓No open federal violations
+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.
- −60 contaminants at or above a federal limit
- −4 contaminants within 20% of a limit
- −0 open health-based violations
- −0 open monitoring / reporting violations
- −0 health-based violations resolved in the last 5 years
- −28 core regulated contaminants never reported (1/27)
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 to worry about
- PFOS (Perfluorooctane sulfonic acid)10.3× the federal limit41 ng/L · limit 4 ng/L
Linked to cancer, thyroid disease, and immune effects; the EPA set an enforceable limit of 4 parts per trillion.
Higher than 95% of CA systems that report it · higher than 95% of U.S. systems
- PFOA (Perfluorooctanoic acid)4.5× the federal limit18 ng/L · limit 4 ng/L
Linked to cancer, liver damage, and immune effects; the EPA set an enforceable limit of 4 parts per trillion.
Higher than 95% of CA systems that report it · higher than 95% of U.S. systems
- PFHxS (Perfluorohexane sulfonic acid)88% of the federal limit8.8 ng/L · limit 10 ng/L
Regulated by the EPA at 10 parts per trillion and included in the PFAS Hazard Index.
Higher than 80% of CA systems that report it · higher than 75% of U.S. systems
+7 contaminants were measured and came in below the limitShow all
| Contaminant | Measured | Federal limit |
|---|---|---|
| PFNA (Perfluorononanoic acid) | 6.8999999999999995 ng/L | 10 ng/L |
| PFDA | 0.0031 µg/L | — |
| PFHpA | 5.7 ng/L | — |
| PFBS | 7.9 ng/L | — |
| PFPeA | 8.4 ng/L | — |
| PFBA | 6.1000000000000005 ng/L | — |
| PFHxA | 8 ng/L | — |
What this report doesn't tell you
26 of the 27 contaminants a community water system normally reports do not appear anywhere in City of Clovis, 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
PFAS — EPA UCMR5 (2023–2025)
2 PFAS compounds above EPA limits in City of Clovis, CA
The EPA finalized the first-ever federal drinking-water limits for six PFAS compounds in April 2024. These numbers come straight from EPA's UCMR5 lab dataset — every U.S. system serving more than 3,300 people tested every PFAS sample at an entry point to its distribution system. PFAS not listed below were either tested and not detected, or not yet sampled.
PFOS (Perfluorooctane sulfonic acid)
● Over EPA limit (10.3×)PFOA (Perfluorooctanoic acid)
● Over EPA limit (4.5×)PFHxS (Perfluorohexane sulfonic acid)
● Approaching limit (88%)PFNA (Perfluorononanoic acid)
● Below limitPFDA
● Detected (no federal limit)PFHpA
● Detected (no federal limit)PFBS
● Detected (no federal limit)PFPeA
● Detected (no federal limit)PFBA
● Detected (no federal limit)PFHxA
● Detected (no federal limit)Where your water comes from · EPA SDWIS
City of Clovis, CA's drinking water comes from ground water, drawn from 38 sources.
Source
- WELL 40 - RAW STBY2025
- WELL 037 - RAW
- WELL 17 - RAW
- WELL 12 - BEFORE_GAC-DBCP&TCP
- + 34 more
Treatment
- WELL 41 - TRT CL
- WELL 05A - TRT CL
- WELL 14 - CL2
- + 35 more
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.
- Maximum contaminant level exceededHealth-based4 violations on record · most recent Mar 1993resolved
Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗