We read 10 results from City of Atwater’s 2024 water quality report. No results over a legal limit; 3 above a health goal or guideline.
Serves about 29,479 people · Water system ID CA2410001 · Read the district’s 2024 report (opens in a new tab)
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Results from the 2024 report
Each number is copied from the district’s report and links to the page it’s printed on. Where the report lists several plants, wells or purchased water, the highest is shown.
| Contaminant | Result | Health goal | Legal limit | What it means |
|---|---|---|---|---|
| Arsenicaverage · range ND to 6.8 · sampled 2025 · Wells · 2024 report, page 5 | 3.7 ppb | 0.004 ppb | 10 ppb | Above the health goal925x the health goal |
| Chromium-6average · range 1.5 to 4.5 · sampled 2025 · Wells · 2024 report, page 5 | 2.9 ppb | 0.02 ppb | 10 ppb | Above the health goal145x the health goal |
| Dibromochloropropane (DBCP)average · range ND to 0.11 · printed as 28 ng/L · sampled 2025 · Wells · 2024 report, page 6 | 0.03 ppb | 0 ppb | 0.2 ppb | Above the health goalThe health goal is zero |
| Bariumaverage · range 0.07 to 0.17 · sampled 2025 · Wells · 2024 report, page 5 | 0.12 ppm | 2 ppm | 2 ppm | Below the health goal |
| Chlorineaverage · range 0.58 to 0.77 · sampled 2025 · Distribution system · 2024 report, page 7 | 0.65 ppm | None set | 4 ppm | Below the legal limit |
| Fluorideaverage · range 0.1 to 0.21 · sampled 2025 · Wells · 2024 report, page 6 | 0.16 ppm | 1 ppm | 2 ppm | Below the health goal |
| Nitrate (as N)average · range 1.5 to 8.3 · sampled 2025 · Wells · 2024 report, page 6 | 4.2 ppm | 10 ppm | 10 ppm | Below the health goal |
| Perchlorateaverage · range ND to 1.2 · sampled 2025 · Wells · 2024 report, page 6 | 0.27 ppb | 1 ppb | 6 ppb | Below the health goal |
| Hardnessaverage · range 2.28 to 8.19 · sampled 2025 · Wells · 2024 report, page 4 | 5.09 gpg (87 ppm) | — | — | Moderately hard |
| Sodiumaverage · range 22 to 43 · sampled 2025 · Wells · 2024 report, page 4 | 33 ppm | None set | None | No health limit |
Utility results describe the whole system, measured where water enters the pipes, not your tap. Your home’s plumbing can add lead or copper.
EPA testing for PFAS and lithium
EPA’s own nationwide testing (UCMR 5) found these in City of Atwater’s water between Oct 2023 and May 2024. These are EPA lab results, separate from the district’s report. Anything not listed was not detected.
- PFOA33 pptFound in 3 of 16 samples · highest resultAbove the federal limit that takes effect in 2029 (4 ppt)
- PFOS45 pptFound in 3 of 16 samples · highest resultAbove the federal limit that takes effect in 2029 (4 ppt)
- PFHxS59 pptFound in 8 of 16 samples · highest resultNo federal limit in force for this one
- PFBS7.8 pptFound in 3 of 16 samples · highest resultNo federal limit in force for this one
Source: EPA UCMR 5 occurrence data. The highest single result is shown; one high sample doesn’t mean every glass is that high.
What you can do
Nothing here is an emergency notice: if the district has a violation, it must tell customers directly. If you’d like to lower these at your tap, these are the treatments that remove them, and the catalog shows the models certified for each. Ranking is by certified removal; commissions never change the order.
Industrial chemicals and pesticides
Found: Dibromochloropropane (DBCP)
What removes it: Carbon block or RO.
PFAS ("forever chemicals")
Found: PFOA (EPA testing), PFOS (EPA testing)
What removes it: Reverse osmosis.
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