We read 8 results from Clay Rural Water System’s 2025 water quality report. No results over a legal limit; 2 above a health goal or guideline.
Serves about 4,900 people · Water system ID SD4600626 · 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 |
|---|---|---|---|---|
| Arsenichighest measured · range 1 to 1 · sampled 2021 · Wholesale supplier · 2025 report, page 4 | 1 ppb | 0.004 ppb | 10 ppb | Above the health goal250x the health goal |
| Lead90th percentile of homes tested, 0 over the action level · sampled 2024 · Customer taps · 2025 report, page 4 | 1 ppb | 0.2 ppb | 15 ppb (action level) | Above the health goal5x the health goal |
| Bariumhighest measured · range 0.0055 to 0.0055 · sampled 2021 · highest of 2 sources · 2025 report, page 4 | 0.0055 ppm | 2 ppm | 2 ppm | Below the health goal |
| Chromium (total)highest measured · range 0.9 to 0.9 · sampled 2021 · highest of 2 sources · 2025 report, page 4 | 0.9 ppb | None set | 100 ppb | Below the legal limit |
| Copper90th percentile of homes tested, 0 over the action level · sampled 2024 · Customer taps · 2025 report, page 4 | Not detected | 0.3 ppm | 1.3 ppm (action level) | Not detected |
| Fluoridehighest measured · range 0.49 to 0.76 · highest of 2 sources · 2025 report, page 4 | 0.76 ppm | 1 ppm | 4 ppm | Below the health goal |
| Nitrate (as N)highest measured · Wholesale supplier · 2025 report, page 4 | 1.1 ppm | 10 ppm | 10 ppm | Below the health goal |
| Lithiumhighest measured · 2025 report, page 5 | 52.5 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 Clay Rural Water System’s water between Mar 2025 and Sep 2025. These are EPA lab results, separate from the district’s report. Anything not listed was not detected.
- Lithium52.5 ppbFound in 2 of 2 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: Lead
What removes it: Certified carbon block or RO.
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