Drinking water quality · 2023
· Verified
· PWSID CA4010002
What's in Atascadero Mutual Water Co — Atascadero, Ca, CA tap water
3 contaminants in Atascadero Mutual Water Co — Atascadero, Ca, CA's water sat at or above a federal limit, led by PFOS at 8.0x the limit.
- !3 contaminants at or above a federal limit — worst is PFOS at 8.0x
- !13 of 27 core regulated contaminants reported — 14 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
- −0 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
- −9 core regulated contaminants never reported (13/27)
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
- PFOS8.0× the federal limit32 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
- PFOA3.8× the federal limit15 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
- Perfluorohexanesulfonic acid1.8× the federal limit18 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 90% of U.S. systems
+22 contaminants were measured and came in below the limitShow all
| Contaminant | Measured | Federal limit |
|---|---|---|
| Copper | 1 mg/L | 1.3 mg/L |
| TTHM | 61.1 ug/L | 80 ug/L |
| Perfluorononanoic acid | 5.5 ng/L | 10 ng/L |
| Nitrate | 5.1 mg/L | 10 mg/L |
| Arsenic | 3.1 ug/L | 10 ug/L |
| HAA5 | 16.2 ug/L | 60 ug/L |
| Chlorine | 0.9 mg/L | 4 mg/L |
| Nitrate Nitrite | 1.6 mg/L | 10 mg/L |
| Selenium | 7.6 ug/L | 50 ug/L |
| Fluoride | 0.23 mg/L | 4 mg/L |
| Barium | 0.11 mg/L | 2 mg/L |
| Gross Alpha | 0.46 pCi/L | 15 pCi/L |
| Boron | 140 ug/L | 1000 ug/L |
| Lead | 0.0 mg/L | 0.015 mg/L |
| Lithium | 14.3 | — |
| Vanadium | 7.2 ug/L | 50 ug/L |
| Perfluorobutanesulfonic acid | 16 | 500 |
| Perfluoroheptanoic acid | 2.1 | — |
| Perfluorohexanoic acid | 8.3 | — |
| Perfluoropentanoic acid | 7 | — |
| PFBA | 17 | — |
| Uranium | 2.6 pCi/L | 20 pCi/L |
What this report doesn't tell you
14 of the 27 contaminants a community water system normally reports do not appear anywhere in Atascadero Mutual Water Co — Atascadero, Ca, 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
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 May 1993resolved
Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗