We read 15 results from City of Antioch’s 2025 water quality report. No results over a legal limit; 2 above a health goal or guideline.
Serves about 115,074 people · Water system ID CA0710001 · Read the district’s 2025 report (opens in a new tab)
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Results from the 2025 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 |
|---|---|---|---|---|
| Chromium-6single sample · City of Antioch · 2025 report, page 6 | 0.11 ppb | 0.02 ppb | 10 ppb | Above the health goal5.5x the health goal |
| Gross beta (radioactivity)average · range ND to 9.5 · Untreated source water · 2025 report, page 6 | 7.2 pCi/L | 0 pCi/L | 50 pCi/L | Above the health goalThe health goal is zero |
| Chloraminehighest running annual average · range 0.8 to 4.2 · City of Antioch · 2025 report, page 6 | 3.1 ppm | None set | 4 ppm | Below the legal limit |
| Chlorideaverage · range 17 to 130 · City of Antioch · 2025 report, page 7 | 73 ppm | — | 250 ppm guideline | Within the guideline |
| Copper90th percentile of 58 homes tested, 0 over the action level · sampled 2024 · Customer taps · 2025 report, page 6 | 0.08 ppm | 0.3 ppm | 1.3 ppm (action level) | Below the health goal |
| Disinfection byproducts (HAA5)highest running annual average · range ND to 11 · City of Antioch · 2025 report, page 6 | 9 ppb | None set | 60 ppb | Below the legal limit |
| Disinfection byproducts (TTHM)highest running annual average · range 31 to 75 · City of Antioch · 2025 report, page 6 | 53 ppb | None set | 80 ppb | Below the legal limit |
| Fluorideaverage · range 0.6 to 1 · City of Antioch · 2025 report, page 6 | 0.8 ppm | 1 ppm | 2 ppm | Below the health goal |
| Lead90th percentile of 58 homes tested, 2 over the action level · sampled 2024 · Customer taps · 2025 report, page 6 | Not detected | 0.2 ppb | 15 ppb (action level) | Not detected |
| Sulfateaverage · range 3.4 to 50 · City of Antioch · 2025 report, page 7 | 28 ppm | — | 250 ppm guideline | Within the guideline |
| Total dissolved solidssingle sample · City of Antioch · 2025 report, page 7 | 260 ppm | — | 500 ppm guideline | Within the guideline |
| Turbidity (cloudiness)highest measured · City treatment plant · 2025 report, page 6 | 0.3 NTU | None set | 1 NTU | Below the legal limit |
| Conductivityaverage · range 190 to 830 · City of Antioch · 2025 report, page 7 | 420 µS/cm | None set | None | No health limit |
| Hardnessaverage · range 2.63 to 5.38 · City of Antioch · 2025 report, page 7 | 4.21 gpg (72 ppm) | — | — | Moderately hard |
| Sodiumsingle sample · City of Antioch · 2025 report, page 7 | 63 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.
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.
Radium and uranium
Found: Gross beta (radioactivity)
What removes it: Reverse osmosis.
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