We read 10 results from City of Rockville’s 2025 water quality report. No results over a legal limit or above a health goal.
Serves about 52,000 people · Water system ID MD0150003 · 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 |
|---|---|---|---|---|
| Bariumhighest measured · range ND to 0.05 · listed as a violation in the report · Treatment plant · 2025 report, page 2 | 0.05 ppm | 2 ppm | 2 ppm | Below the health goal |
| Chlorineaverage · range 0.2 to 1.9 · listed as a violation in the report · Distribution system · 2025 report, page 2 | 1 ppm | None set | 4 ppm | Below the legal limit |
| Chromium (total)highest measured · range ND to 1.2 · listed as a violation in the report · Treatment plant · 2025 report, page 2 | 1.2 ppb | None set | 100 ppb | Below the legal limit |
| Copper90th percentile of homes tested, 0 over the action level · listed as a violation in the report · sampled 2024 · Customer taps · 2025 report, page 2 | 0.1 ppm | 0.3 ppm | 1.3 ppm (action level) | Below the health goal |
| Disinfection byproducts (HAA5)highest running annual average · range 7 to 30 · listed as a violation in the report · Distribution system · 2025 report, page 2 | 25 ppb | None set | 60 ppb | Below the legal limit |
| Disinfection byproducts (TTHM)highest running annual average · range 13 to 75.9 · listed as a violation in the report · Distribution system · 2025 report, page 2 | 74 ppb | None set | 80 ppb | Below the legal limit |
| Fluoridehighest measured · range 0.5 to 0.7 · listed as a violation in the report · Treatment plant · 2025 report, page 2 | 0.7 ppm | 1 ppm | 4 ppm | Below the health goal |
| Lead90th percentile of homes tested, 0 over the action level · listed as a violation in the report · sampled 2024 · Customer taps · 2025 report, page 2 | Not detected | 0.2 ppb | 15 ppb (action level) | Not detected |
| Nitrate (as N)highest measured · range ND to 2.4 · listed as a violation in the report · Treatment plant · 2025 report, page 2 | 2.4 ppm | 10 ppm | 10 ppm | Below the health goal |
| Turbidity (cloudiness)highest measured · range 0.03 to 0.12 · listed as a violation in the report · Treatment plant · 2025 report, page 2 | 0.12 NTU | None set | 1 NTU | 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 City of Rockville’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.
- PFBS3.6 pptFound in 1 of 4 samples · highest resultNo federal limit in force for this one
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 in this report is above a health goal or legal limit. If you’re bothered by taste, smell, hardness or spots, or your home has older pipes, the filter catalog and buyer questions can help you pick, and a test of your own tap shows what your plumbing adds.
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