We read 16 results from Herculaneum Pws’s 2025 water quality report. No results over a legal limit; 2 above a health goal or guideline.
Serves about 4,227 people · Water system ID MO6010359 · 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 |
|---|---|---|---|---|
| Lead90th percentile of homes tested, 0 over the action level · sampled 2023 · Customer taps · 2025 report, page 2 | 1.43 ppb | 0.2 ppb | 15 ppb (action level) | Above the health goal7.2x the health goal |
| pHhighest measured · range 8.85 to 8.85 · Purchased water (wholesaler) · 2025 report, page 3 | 8.85 | — | — | Outside the normal rangeAlkaline water can leave scale |
| Chloridehighest measured · range 32 to 32 · Purchased water (wholesaler) · 2025 report, page 3 | 32 ppm | — | 250 ppm guideline | Within the guideline |
| Copper90th percentile of homes tested, 0 over the action level · sampled 2023 · Customer taps · 2025 report, page 2 | 0.25 ppm | 0.3 ppm | 1.3 ppm (action level) | Below the health goal |
| Disinfection byproducts (HAA5)highest running annual average · range 13.5 to 94.5 · DBPDUAL-02, highest of 3 sources · 2025 report, page 2 | 27 ppb | None set | 60 ppb | Below the legal limit |
| Disinfection byproducts (TTHM)highest running annual average · range 35.2 to 71.6 · DBPDUAL-01, highest of 3 sources · 2025 report, page 2 | 50 ppb | None set | 80 ppb | Below the legal limit |
| Sulfatehighest measured · range 70.9 to 70.9 · Purchased water (wholesaler) · 2025 report, page 3 | 70.9 ppm | — | 250 ppm guideline | Within the guideline |
| Total dissolved solidshighest measured · range 212 to 212 · Purchased water (wholesaler) · 2025 report, page 3 | 212 ppm | — | 500 ppm guideline | Within the guideline |
| Alkalinityhighest measured · range 202 to 260 · Purchased water (wholesaler) · 2025 report, page 3 | 260 ppm | None set | None | No health limit |
| Calciumhighest measured · range 13.8 to 13.8 · Purchased water (wholesaler) · 2025 report, page 3 | 13.8 ppm | None set | None | No health limit |
| Hardnesshighest measured · range 5.52 to 5.52 · Purchased water (wholesaler) · 2025 report, page 3 | 5.52 gpg (94.3 ppm) | — | — | Moderately hard |
| Lithiumhighest measured · range ND to 19.9 · sampled 2024 · UCMR 5 testing · 2025 report, page 2 | 19.9 ppb | None set | None | No health limit |
| Magnesiumhighest measured · range 14.5 to 14.5 · Purchased water (wholesaler) · 2025 report, page 3 | 14.5 ppm | None set | None | No health limit |
| Nickelhighest measured · range 1.14 to 1.14 · printed as 0.00114 MG/L · Purchased water (wholesaler) · 2025 report, page 3 | 1.14 ppb | None set | None | No health limit |
| Potassiumhighest measured · range 4.8 to 4.8 · Purchased water (wholesaler) · 2025 report, page 3 | 4.8 ppm | None set | None | No health limit |
| Sodiumhighest measured · range 28.6 to 28.6 · Purchased water (wholesaler) · 2025 report, page 3 | 28.6 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. 4 numbers we weren’t sure about are held back until a person checks.
EPA testing for PFAS and lithium
EPA’s own nationwide testing (UCMR 5) found these in Herculaneum Pws’s water between Mar 2024 and Dec 2024. These are EPA lab results, separate from the district’s report. Anything not listed was not detected.
- Lithium22 ppbFound in 7 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: Lead
What removes it: Certified carbon block or RO.
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