We read 19 results from City of Mckinney’s 2025 water quality report. No results over a legal limit; 6 above a health goal or guideline.
Serves about 224,043 people · Water system ID TX0430039 · 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 · NTMWD Wylie plant · 2025 report, page 6 | 1 ppb | 0.004 ppb | 10 ppb | Above the health goal250x the health goal |
| Bromatehighest measured · range 2.5 to 2.5 · sampled 2024 · NTMWD Leonard plant · 2025 report, page 7 | 2.5 ppb | 0.1 ppb | 10 ppb | Above the health goal25x the health goal |
| Copper90th percentile of homes tested · Customer taps · 2025 report, page 8 | 0.79 ppm | 0.3 ppm | 1.3 ppm (action level) | Above the health goal2.6x the health goal |
| Gross beta (radioactivity)highest measured · range 5.3 to 5.3 · sampled 2024 · NTMWD Wylie plant · 2025 report, page 6 | 5.3 pCi/L | 0 pCi/L | 50 pCi/L | Above the health goalThe health goal is zero |
| Lead90th percentile of homes tested · Customer taps · 2025 report, page 8 | 0.9 ppb | 0.2 ppb | 15 ppb (action level) | Above the health goal4.5x the health goal |
| Total coliform bacteriahighest month · sampled 2024 · City of McKinney · 2025 report, page 9 | 1.33 % positive | 0 % positive | 5 % positive | Above the health goalThe health goal is zero |
| Atrazinehighest measured · range 0.1 to 0.2 · NTMWD plants · 2025 report, page 6 | 0.1 ppb | 0.15 ppb | 3 ppb | Below the health goal |
| Bariumhighest measured · range 0.04 to 0.06 · NTMWD Wylie plant · 2025 report, page 6 | 0.06 ppm | 2 ppm | 2 ppm | Below the health goal |
| Chloramineaverage · range 0.2 to 3.8 · City of McKinney · 2025 report, page 7 | 2.22 ppm | None set | 4 ppm | Below the legal limit |
| Cyanidehighest measured · range 47 to 56 · NTMWD Wylie plant · 2025 report, page 6 | 56 ppb | 150 ppb | 200 ppb | Below the health goal |
| Disinfection byproducts (HAA5)highest running annual average · range 6.5 to 25.6 · City of McKinney · 2025 report, page 8 | 20.5 ppb | None set | 60 ppb | Below the legal limit |
| Disinfection byproducts (TTHM)highest running annual average · range 9.4 to 46.9 · City of McKinney · 2025 report, page 8 | 35.4 ppb | None set | 80 ppb | Below the legal limit |
| Fluoridehighest measured · range 0.35 to 0.49 · NTMWD Wylie plant · 2025 report, page 6 | 0.49 ppm | 1 ppm | 4 ppm | Below the health goal |
| Nitrate (as N)highest measured · range 0.06 to 0.4 · City of McKinney · 2025 report, page 6 | 0.4 ppm | 10 ppm | 10 ppm | Below the health goal |
| Turbidity (cloudiness)highest measured · NTMWD Wylie plant · 2025 report, page 8 | 0.29 NTU | None set | 1 NTU | Below the legal limit |
| Bromodichloromethanehighest measured · range 3.81 to 17.1 · City of McKinney · 2025 report, page 7 | 17.1 ppb | None set | None | No health limit |
| Bromoformhighest measured · range ND to 3.02 · City of McKinney · 2025 report, page 7 | 3.02 ppb | None set | None | No health limit |
| Chloroformhighest measured · range 2.46 to 13.9 · City of McKinney · 2025 report, page 7 | 13.9 ppb | None set | None | No health limit |
| Dibromochloromethanehighest measured · range 3.14 to 14.1 · City of McKinney · 2025 report, page 7 | 14.1 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.
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.
Radium and uranium
Found: Gross beta (radioactivity)
What removes it: Reverse osmosis.
Bacteria and viruses
Found: Total coliform bacteria
What removes it: UV purification (and tell your utility).
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