Drinking water quality · 2023
· Verified
What's in Atascadero Mutual Water Co — Atascadero, Ca, CA tap water
25 contaminants were measured in the Atascadero Mutual Water Co — Atascadero, Ca, CA water system's 2023 annual report. Each is shown below against its federal limit — 3 sit at or above that limit.
- Reporting year
- 2023
- Contaminants measured
- 25
- Over federal limit
- 3
- Approaching the limit
- 0
- Worst contaminant
- PFOS
- Service area
- CA
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 Jun 1993resolved
Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗
PFAS ("forever chemicals")
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| PFOSPerfluorooctanesulfonic acid, a PFAS 'forever chemical' once used in firefighting foam and coatings. | 32 ng/LRangeSystem-wide | 6.5 ng/LNL | At or above the limit |
| PFOAPerfluorooctanoic acid, a PFAS 'forever chemical' once used in nonstick and stain-resistant products. | 15 ng/LRangeSystem-wide | 5.1 ng/LNL | At or above the limit |
| Perfluorohexanesulfonic acidPerfluorohexanesulfonic acid, a PFAS 'forever chemical.' | 18 ng/LRangeSystem-wide | 3 ng/LNL | At or above the limit |
| Perfluorononanoic acidPerfluorononanoic acid, a PFAS 'forever chemical.' | 5.5 ng/LRangeSystem-wide | 10 ng/LMCL | Within the limit |
| Perfluorobutanesulfonic acidPerfluorobutanesulfonic acid, a shorter-chain PFAS 'forever chemical.' | 16RangeSystem-wide | 500NL | Detected — no federal limit |
| Perfluoroheptanoic acidPerfluoroheptanoic acid, a PFAS 'forever chemical.' | 2.1RangeSystem-wide | None set | Detected — no federal limit |
| Perfluorohexanoic acidPerfluorohexanoic acid, a shorter-chain PFAS 'forever chemical.' | 8.3RangeSystem-wide | None set | Detected — no federal limit |
| Perfluoropentanoic acidPerfluoropentanoic acid, a shorter-chain PFAS 'forever chemical.' | 7RangeSystem-wide | None set | Detected — no federal limit |
| PFBAPerfluorobutanoic acid, a shorter-chain PFAS 'forever chemical.' | 17RangeSystem-wide | None set | Detected — no federal limit |
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| CopperA metal that enters water from corroding household plumbing. | 1 mg/L90th percentileAt the tap | 1.3 mg/LAction level | Within the limit |
| ArsenicA naturally occurring element that also enters water from industry and agriculture. | 3.1 ug/LRangeSystem-wide | None set | Within the limit |
| SeleniumA trace element from natural deposits and industrial discharge. | 7.6 ug/LRangeSystem-wide | None set | Within the limit |
| BariumA metal from erosion of natural deposits and industrial discharge. | 0.11 mg/LRangeSystem-wide | 2 mg/LMCL | Within the limit |
| LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. | 0.0 mg/L90th percentileAt the tap | 0.015 mg/LAction level | None detected |
| BoronA naturally occurring element from rock and soil. | 140 ug/LRangeSystem-wide | 1000 ug/LNL | Detected — no federal limit |
| LithiumA naturally occurring element found in some groundwater. | 14.3Reported levelSystem-wide | None set | Detected — no federal limit |
| Vanadium | 7.2 ug/LRangeSystem-wide | 50 ug/LNL | Detected — no federal limit |
Disinfection byproducts
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TTHMTotal trihalomethanes — a group of four chemicals (including chloroform) formed when chlorine reacts with natural organic matter. | 61.1 ug/LReported levelSystem-wide | None set | Within the limit |
| HAA5Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter. | 16.2 ug/LReported levelSystem-wide | None set | Within the limit |
Inorganic chemicals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| NitrateA compound from fertilizer runoff, septic systems, and erosion of natural deposits. | 5.1 mg/LRangeSystem-wide | 10 mg/LMCL | Within the limit |
| FluorideA mineral often added to drinking water to help prevent tooth decay. | 0.23 mg/LReported levelSystem-wide | 4 mg/LMCL | Within the limit |
Disinfectants
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| ChlorineA disinfectant added to drinking water to kill bacteria and viruses. | 0.9 mg/LReported levelSystem-wide | None set | Within the limit |
Other
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Nitrate Nitrite | 1.6 mg/LRangeSystem-wide | 10 mg/LMCL | Within the limit |
Radionuclides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Gross AlphaGross alpha particle activity — a combined measure of alpha-emitting radioactive substances. | 0.46 pCi/LReported levelSystem-wide | 15 pCi/LMCL | Within the limit |
| UraniumA naturally occurring radioactive metal from erosion of natural deposits. | 2.6 pCi/LRangeSystem-wide | 20 pCi/LMCL | Detected — no federal limit |
People also ask about Atascadero Mutual Water Co — Atascadero, Ca, CA's water
+Is Atascadero Mutual Water Co — Atascadero, Ca, CA tap water safe to drink in 2023?
The 2023 Consumer Confidence Report for the Atascadero Mutual Water Co — Atascadero, Ca, CA water utility lists 3 contaminants at or above the federal limit: PFOS, PFOA, and Perfluorohexanesulfonic acid. Whether that means the water is "unsafe" depends on which contaminant, how long the exposure, and individual health factors. The table on this page shows the measured value, the federal threshold, and the regulated statistic used for compliance.
+What contaminants are in Atascadero Mutual Water Co — Atascadero, Ca, CA tap water?
25 contaminants were measured in Atascadero Mutual Water Co — Atascadero, Ca, CA's 2023 Consumer Confidence Report, spanning pfas ("forever chemicals"), metals, and disinfection byproducts. 15 have an enforceable federal limit; the rest are detected but unregulated. Every measured value, in the utility's own units, is on this page.
+Which contaminants exceed federal limits in Atascadero Mutual Water Co — Atascadero, Ca, CA tap water?
3 contaminants in Atascadero Mutual Water Co — Atascadero, Ca, CA's 2023 report sit at or above the federal limit: PFOS (8.0× the limit); PFOA (3.8× the limit); Perfluorohexanesulfonic acid (1.8× the limit). The EPA enforces these limits against the regulated reporting statistic — typically a running annual average or 90th percentile — not a one-off sample spike.
+What is the worst contaminant in Atascadero Mutual Water Co — Atascadero, Ca, CA tap water?
The contaminant with the highest measured value relative to its federal limit in the 2023 report is PFOS, at 8.0× the federal threshold. It belongs to the pfas ("forever chemicals") family of contaminants.
+Where does the data on this page come from?
Every value is transcribed from Atascadero Mutual Water Co — Atascadero, Ca, CA's 2023 Consumer Confidence Report — the annual drinking-water report every U.S. public water utility is required by federal law to publish. The original source document is archived and viewable on this site. A water-quality report covers an entire service area, not a single address.
+How often is Atascadero Mutual Water Co — Atascadero, Ca, CA's water quality data updated?
Each U.S. public water utility publishes one Consumer Confidence Report per year, covering the prior calendar year's measurements. This page reflects the 2023 report; a new report will replace it once the utility publishes its next annual update.