We read 9 results from Nogales City of’s 2024 water quality report. No results over a legal limit; 4 above a health goal or guideline.
Serves about 22,000 people · Water system ID AZ0412004 · Read the district’s 2024 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 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 |
|---|---|---|---|---|
| Arsenichighest measured · range 0.001 to 5.4 · Wells · 2024 report, page 3 | 5.4 ppb | 0.004 ppb | 10 ppb | Above the health goal1,350x the health goal |
| Fluoridehighest measured · range 3.3 to 3.3 · Wells · 2024 report, page 4 | 3.3 ppm | 1 ppm | 4 ppm | Above the 2 ppm secondary standard1.7x the 2 ppm secondary standard (EPA's level to prevent tooth discoloration, also used as health guidance); below the 4 ppm legal limit |
| Gross alpha (radioactivity)highest measured · range 4.7 to 4.7 · sampled 2022 · Wells · 2024 report, page 3 | 4.7 pCi/L | 0 pCi/L | 15 pCi/L | Above the health goalThe health goal is zero |
| Radium (combined 226 + 228)highest measured · range 0.8 to 0.9 · Wells · 2024 report, page 3 | 0.85 pCi/L | 0 pCi/L | 5 pCi/L | Above the health goalThe health goal is zero |
| Bariumhighest measured · range 0.04 to 0.06 · Wells · 2024 report, page 4 | 0.04 ppm | 2 ppm | 2 ppm | Below the health goal |
| Chlorinehighest running annual average · range 0.35 to 0.6 · Distribution system · 2024 report, page 3 | 0.48 ppm | None set | 4 ppm | Below the legal limit |
| Copper90th percentile of homes tested, 0 over the action level · Customer taps · 2024 report, page 3 | 0.04 ppm | 0.3 ppm | 1.3 ppm (action level) | Below the health goal |
| Nitrate (as N)highest measured · Wells · 2024 report, page 4 | 1.9 ppm | 10 ppm | 10 ppm | Below the health goal |
| Sodiumhighest measured · Wells · 2024 report, page 4 | 24 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 Nogales City of’s water between Sep 2023 and Jun 2025. These are EPA lab results, separate from the district’s report. Anything not listed was not detected.
- Lithium57.4 ppbFound in 9 of 10 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.
Fluoride
Found: Fluoride
What removes it: Reverse osmosis.
Radium and uranium
Found: Gross alpha (radioactivity), Radium (combined 226 + 228)
What removes it: Reverse osmosis.
More districts: Arizona water quality · All states · Something look wrong? Tell us