We read 6 results from Vista Irrigation District’s 2025 water quality report. No results over a legal limit; 3 above a health goal or guideline.
Serves about 132,430 people · Water system ID CA3710027 · 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 |
|---|---|---|---|---|
| Copper90th percentile of 51 homes tested, 0 over the action level · sampled 2024 · Customer taps (51 samples) · 2025 report, page 5 | 0.54 ppm | 0.3 ppm | 1.3 ppm (action level) | Above the health goal1.8x the health goal |
| Lead90th percentile of 51 homes tested, 0 over the action level · sampled 2024 · Customer taps (51 samples) · 2025 report, page 5 | 4.2 ppb | 0.2 ppb | 15 ppb (action level) | Above the health goal21x the health goal |
| Total coliform bacteriahighest month · Distribution system · 2025 report, page 4 | 0.65 % positive | 0 % positive | 5 % positive | Above the health goalThe health goal is zero |
| Chloramineaverage · range 0.3 to 3.98 · Distribution system · 2025 report, page 4 | 2.53 ppm | None set | 4 ppm | Below the legal limit |
| Disinfection byproducts (HAA5)highest running annual average · range 4.1 to 31.8 · Distribution system · 2025 report, page 4 | 19.9 ppb | None set | 60 ppb | Below the legal limit |
| Disinfection byproducts (TTHM)highest running annual average · range 14.4 to 60.2 · Distribution system · 2025 report, page 4 | 45.8 ppb | None set | 80 ppb | Below the legal 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 Vista Irrigation District’s water between Mar 2023 and Dec 2023. These are EPA lab results, separate from the district’s report. Anything not listed was not detected.
- Lithium52 ppbFound in 8 of 8 samples · highest resultAbove EPA’s health reference level of 10 ppb (a guide, not a legal limit)
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.
Lead
Found: Copper, Lead
What removes it: Reverse osmosis or Certified carbon block or RO.
Bacteria and viruses
Found: Total coliform bacteria
What removes it: UV purification (and tell your utility).
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