We read 23 results from San Gabriel Valley Wc - Fontana’s 2025 water quality report. No results over a legal limit; 3 above a health goal or guideline.
Serves about 237,700 people · Water system ID CA3610041 · 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-6average · range ND to 3.3 · Groundwater wells · 2025 report, page 4 | 1.4 ppb | 0.02 ppb | 10 ppb | Above the health goal70x the health goal |
| Gross alpha (radioactivity)average · range ND to 7.3 · Groundwater wells · 2025 report, page 4 | 0.83 pCi/L | 0 pCi/L | 15 pCi/L | Above the health goalThe health goal is zero |
| Total coliform bacteriahighest month · Distribution system · 2025 report, page 4 | 1.23 % positive | 0 % positive | 5 % positive | Above the health goalThe health goal is zero |
| Aluminumaverage · range ND to 0.03 · printed as 1.18 ppb · Groundwater wells · 2025 report, page 5 | 0.0012 ppm | — | 0.2 ppm guideline | Within the guideline |
| Chlorideaverage · range 3.5 to 38 · Groundwater wells · 2025 report, page 5 | 13.2 ppm | — | 250 ppm guideline | Within the guideline |
| Chlorineaverage · range 0.4 to 1.44 · Distribution system · 2025 report, page 7 | 0.96 ppm | None set | 4 ppm | Below the legal limit |
| Copper90th percentile of 50 homes tested, 0 over the action level · printed as 260 ppb · sampled 2024 · Customer taps (50 samples) · 2025 report, page 7 | 0.26 ppm | 0.3 ppm | 1.3 ppm (action level) | Below the health goal |
| Disinfection byproducts (HAA5)system-wide average · range ND to 7 · Distribution system · 2025 report, page 7 | 7 ppb | None set | 60 ppb | Below the legal limit |
| Disinfection byproducts (TTHM)system-wide average · range ND to 40 · Distribution system · 2025 report, page 7 | 21 ppb | None set | 80 ppb | Below the legal limit |
| Fluorideaverage · range 0.18 to 0.36 · Surface water, highest of 2 sources · 2025 report, page 6 | 0.27 ppm | 1 ppm | 2 ppm | Below the health goal |
| Ironaverage · range ND to 0.13 · printed as 11.27 ppb · Groundwater wells · 2025 report, page 5 | 0.01 ppm | — | 0.3 ppm guideline | Within the guideline |
| Lead90th percentile of 50 homes tested, 0 over the action level · sampled 2024 · Customer taps (50 samples) · 2025 report, page 7 | Not detected | 0.2 ppb | 15 ppb (action level) | Not detected |
| Manganeseaverage · range ND to 0.0027 · printed as 0.17 ppb · Groundwater wells · 2025 report, page 5 | 0.00017 ppm | — | 0.05 ppm guideline | Within the guideline |
| Nitrate (as N)average · range ND to 8 · Groundwater wells, highest of 2 sources · 2025 report, page 4 | 4.78 ppm | 10 ppm | 10 ppm | Below the health goal |
| Perchlorateaverage · range ND to 3.9 · Groundwater wells · 2025 report, page 4 | 0.7 ppb | 1 ppb | 6 ppb | Below the health goal |
| Sulfateaverage · range 15 to 26 · Groundwater wells · 2025 report, page 5 | 19.7 ppm | — | 250 ppm guideline | Within the guideline |
| Total dissolved solidsaverage · range 120 to 360 · Groundwater wells, highest of 2 sources · 2025 report, page 5 | 211 ppm | — | 500 ppm guideline | Within the guideline |
| Turbidity (cloudiness)highest measured · range 0.05 to 0.53 · Surface water plant · 2025 report, page 6 | 0.53 NTU | None set | 1 NTU | Below the legal limit |
| Alkalinityaverage · range 97 to 200 · Groundwater wells · 2025 report, page 5 | 164 ppm | None set | None | No health limit |
| Boronaverage · range ND to 0.06 · printed as 24.41 ppb · Groundwater wells · 2025 report, page 5 | 0.02 ppm | None set | None | No health limit |
| Calciumaverage · range 26.1 to 62.5 · Groundwater wells · 2025 report, page 5 | 48.4 ppm | None set | None | No health limit |
| Hardnessaverage · range 5.72 to 10.9 · Groundwater wells, highest of 2 sources · 2025 report, page 5 | 8.85 gpg (151 ppm) | — | — | Hard |
| Sodiumaverage · range ND to 25 · Groundwater wells · 2025 report, page 5 | 16.1 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 alpha (radioactivity)
What removes it: Reverse osmosis.
Bacteria and viruses
Found: Total coliform bacteria
What removes it: UV purification (and tell your utility).
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