Community Water System (CWS) · TX1010013
Surface Water · serves an estimated 2,970,543 people · across Houston
Score withheld — not published
Evidence quality describes the record, not the water. A strong record can carry a poor assessment.
sampled 2024
f-houston-pfoa
src-ucmr5-2024 · released 2026-01-15
The original published file, referenced from the source record.
Not detected in the 2024 UCMR5 round.
Why it matters. Studies associate PFOA exposure with effects on the immune system, cholesterol, liver, and developmental outcomes, and with certain cancers. Because it accumulates, the EPA has set the enforceable limit near the lowest reliably measurable level.
Understand Perfluorooctanoic acid (PFOA) →Every measured value against its published reference, with the sampling date and a link to the underlying evidence. A missing measurement is shown as its own status, never as a non-detect.
| Substance | Result | Reference | Sampled | Status | Evidence |
|---|---|---|---|---|---|
| Perfluorooctanoic acid (PFOA) | < 4 ng/L | 4.0 ng/L federal MCL (2024) | 2024 | Not detected | View evidence |
| Perfluorooctane sulfonic acid (PFOS) | < 4 ng/L | 4.0 ng/L federal MCL (2024) | 2024 | Not detected | View evidence |
| Perfluorohexane sulfonic acid (PFHxS) | < 10 ng/L | 10.0 ng/L federal MCL (2024) | 2024 | Not detected | View evidence |
| Lead (90th percentile) | 3 µg/L | 15 µg/L federal action level | 2023-2023 | Below limit | View evidence |
| Water hardness | 7.9 gpg | Aesthetic — no federal health limit | 2025 | Above guideline | View evidence |
| Total trihalomethanes (TTHM) | 43.6 ppb | 80 ppb federal MCL | 2025 | Below limit | View evidence |
| Haloacetic acids (HAA5) | 40.8 ppb | 60 ppb federal MCL | 2025 | Below limit | View evidence |
A federal limit (an MCL or action level) is an enforceable legal cap. A health goal (an MCLG or health benchmark) is a non-enforceable target, often stricter — sometimes zero. A system meeting the legal limit is a compliance fact; it is not a guarantee of no health concern. PurityMap publishes no overall compliance verdict for a system — read each finding against its own reference below.
CITY OF HOUSTON (PWS ID TX1010013) is a public water system serving 2,970,543 people in Houston, Texas.
CITY OF HOUSTON is on record as drawing from surface water. The source shapes which contaminants matter most for this system.
PurityMap's record for CITY OF HOUSTON shows 1 finding measured above a benchmark and 6 within benchmark, from 7 evidence records. Every finding links to its source; a substance that was never monitored is shown as pending, not as a pass.
PurityMap does not issue a safety verdict. It publishes CITY OF HOUSTON's measured results against each contaminant's benchmark so you can read them in context — safety depends on the specific finding, your plumbing, and how the water reaches your tap.
The latest published record for CITY OF HOUSTON is dated 2026-09-16. Utilities report on regulatory cycles, so results reflect the monitoring period rather than a live reading.