We read 7 results from Nas North Island & Nab Coronado’s 2025 water quality report. No results over a legal limit; 2 above a health goal or guideline.
Serves about 36,990 people · Water system ID CA3710750 · Read the district’s 2025 report (opens in a new tab)
Open this district in the water lookupCompare with your own test results, see the district map and get matched filters.
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 20 homes tested, 0 over the action level · sampled 2023 · Customer taps · 2025 report | 0.73 ppm | 0.3 ppm | 1.3 ppm (action level) | Above the health goal2.4x the health goal |
| Lead90th percentile of 20 homes tested, 0 over the action level · sampled 2023 · Customer taps · 2025 report | 2.6 ppb | 0.2 ppb | 15 ppb (action level) | Above the health goal13x the health goal |
| Chlorinehighest running annual average · range 0.04 to 3.4 · Naval Amphibious Base distribution, highest of 2 sources · 2025 report | 0.99 ppm | None set | 4 ppm | Below the legal limit |
| Disinfection byproducts (HAA5)highest running annual average · range 6.9 to 17 · Naval Amphibious Base distribution, highest of 2 sources · 2025 report | 11.5 ppb | None set | 60 ppb | Below the legal limit |
| Disinfection byproducts (TTHM)highest running annual average · range 25 to 38 · Naval Amphibious Base distribution, highest of 2 sources · 2025 report | 30 ppb | None set | 80 ppb | Below the legal limit |
| Nitrite (as N)average · range ND to 0.38 · NAS North Island distribution, highest of 2 sources · 2025 report | 0.38 ppm | 1 ppm | 1 ppm | Below the health goal |
| Lithiumaverage · range 25.2 to 28.8 · Distribution system · 2025 report | 27 ppb | 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 Nas North Island & Nab Coronado’s water between Feb 2025 and Nov 2025. These are EPA lab results, separate from the district’s report. Anything not listed was not detected.
- Lithium28.8 ppbFound in 4 of 4 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.
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