We read 17 results from City of Houston’s 2025 water quality report. 1 result over a legal limit and 2 above a health goal or guideline.
Serves about 2,202,531 people · Water system ID TX1010013 · 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 |
|---|---|---|---|---|
| Turbidity (cloudiness)highest measured · listed as a violation in the report · Water plants · 2025 report, page 7 | 1.95 NTU | None set | 1 NTU | Over the legal limit2x the legal limit |
| Lead90th percentile of homes tested, 0 over the action level · Customer taps · 2025 report, page 8 | 5.1 ppb | 0.2 ppb | 15 ppb (action level) | Above the health goal25x the health goal |
| Total coliform bacteriahighest month · Distribution system · 2025 report, page 8 | 2.7 % positive | 0 % positive | 5 % positive | Above the health goalThe health goal is zero |
| Aluminumaverage · range ND to 2.86 · Main System · 2025 report, page 9 | 0.12 ppm | — | 0.2 ppm guideline | Within the guideline |
| Chlorideaverage · range 28 to 49 · Main System · 2025 report, page 9 | 38.4 ppm | — | 250 ppm guideline | Within the guideline |
| Copper90th percentile of homes tested, 0 over the action level · Customer taps · 2025 report, page 8 | 0.22 ppm | 0.3 ppm | 1.3 ppm (action level) | Below the health goal |
| Disinfection byproducts (HAA5)highest running annual average · range ND to 55.9 · Distribution system · 2025 report, page 8 | 40.8 ppb | None set | 60 ppb | Below the legal limit |
| Disinfection byproducts (TTHM)highest running annual average · range ND to 47.7 · Distribution system · 2025 report, page 8 | 43.6 ppb | None set | 80 ppb | Below the legal limit |
| Fluorideaverage · range ND to 0.71 · Main System · 2025 report, page 9 | 0.11 ppm | 1 ppm | 4 ppm | Below the health goal |
| Ironaverage · range ND to 1.02 · Main System · 2025 report, page 9 | 0.08 ppm | — | 0.3 ppm guideline | Within the guideline |
| Manganeseaverage · range ND to 0.06 · Main System · 2025 report, page 9 | 0.01 ppm | — | 0.05 ppm guideline | Within the guideline |
| pHaverage · range 7.3 to 8.3 · Main System · 2025 report, page 9 | 7.8 | — | — | Normal range |
| Sulfateaverage · range ND to 48 · Main System · 2025 report, page 9 | 20.8 ppm | — | 250 ppm guideline | Within the guideline |
| Total dissolved solidsaverage · range 146 to 331 · Main System · 2025 report, page 9 | 260 ppm | — | 500 ppm guideline | Within the guideline |
| Zincaverage · range ND to 0.03 · Main System · 2025 report, page 9 | 0.004 ppm | — | 5 ppm guideline | Within the guideline |
| Hardnessaverage · range 2.54 to 13.4 · Main System · 2025 report, page 9 | 7.92 gpg (136 ppm) | — | — | Hard |
| Lithiumaverage · range 13.7 to 33.9 · sampled 2024 · Main System · 2025 report, page 9 | 23.8 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. 1 number we weren’t sure about is held back until a person checks.
EPA testing for PFAS and lithium
EPA’s own nationwide testing (UCMR 5) found these in City of Houston’s water between Feb 2023 and Feb 2025. These are EPA lab results, separate from the district’s report. Anything not listed was not detected.
- Lithium33.9 ppbFound in 69 of 96 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.
Sediment or cloudy water
Found: Turbidity (cloudiness)
What removes it: Sediment filter.
Lead
Found: Lead
What removes it: Certified carbon block or RO.
Bacteria and viruses
Found: Total coliform bacteria
What removes it: UV purification (and tell your utility).
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