Total Trihalomethanes (TTHM)
Unresolved Total Trihalomethanes Rule violation cited in 2025 (total trihalomethanes (tthm)).
Texas · drinking water · SDWIS through latest publish
Cinco Mud 5 Water Quality — Houston, Texas
PWSID TX0790291 · Purchased / wholesaleMunicipal
2,460 people served. 2 health-based SDWIS violations recorded in the past 5 years. 1 remains unresolved. Last cited 1 year ago.
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Total Trihalomethanes (TTHM)
Total Trihalomethanes Rule health-based violation cited in 2025 (total trihalomethanes (tthm)).
Most-cited contaminants
What This Utility Gets Cited For
- Total Trihalomethanes (TTHM)2 citations
- Contaminant 75001 citation
Violation history
What's On The SDWIS Record
Health-based violations exceed an MCL or treatment-technique standard. Monitoring violations are reporting failures with no measured exceedance — they tell you the system isn't fully transparent, not that the water is unsafe today.
HEALTH-BASED · TOTAL TRIHALOMETHANES (TTHM)
2025 · Total Trihalomethanes (TTHM) · Total Trihalomethanes Rule
Maximum contaminant level exceeded
HEALTH-BASED · TOTAL TRIHALOMETHANES (TTHM)
2025 · Total Trihalomethanes (TTHM) · Total Trihalomethanes Rule
Maximum contaminant level exceeded; returned to compliance
OTHER · CONTAMINANT 7500
2025 · Contaminant 7500 · Volatile Organic Chemical Rule
OTHER; returned to compliance
Equity context · ACS 2018-2022 · USEPA-clone EJ disparity
Who Drinks This Water
Houston, Texas (Census place; block-group disparity scores aggregated by centroid containment): a service population of 2,296,253. Local disparity score for pm2.5 (fine particulate) sits well above the reference burden (191). Why we surface this →
19.6%
Low-income
76.4%
People of color
6.5%
Under age 5
11.6%
Over age 64
- PM2.5 (fine particulate)Health riskFine inhalable particles 2.5 micrometers or smaller. They travel deep into the lungs and into the bloodstream — linked to asthma, heart disease, stroke, and premature death.88in the highest 20% nationally
- OzoneHealth riskGround-level ozone (smog) inflames the airways. Even short exposures trigger asthma attacks and worsen chronic lung and heart disease.70above the national median
- Nitrogen dioxide (NO₂)Health riskA tailpipe and combustion gas. Concentrates near busy roads and industrial sites; raises risk of airway inflammation, asthma, and lower respiratory infections in children.96in the highest 5% nationally
- Diesel particulateHealth riskSoot from diesel engines (trucks, trains, ports, construction). EPA classifies it as a likely human carcinogen and a major driver of childhood asthma near freight corridors.78above the national median
- Toxic releases (RSEI)Health riskEPA's Risk-Screening Environmental Indicators score — weights TRI chemical releases by toxicity, where they go, and how many people are nearby. Higher means greater modeled cancer and chronic-health risk.98in the highest 5% nationally
- Traffic proximityHealth riskPopulation-weighted distance to high-volume roads. Living close to heavy traffic raises exposure to PM2.5, NO₂, and diesel exhaust — and the cardiovascular and asthma risks that follow.81in the highest 20% nationally
- Lead-paint risk (pre-1960 housing)Health riskShare of housing built before 1960, when lead-based paint was common. Dust from deteriorating paint is the leading cause of childhood lead poisoning, which permanently impairs cognitive development.54near the national median
- Superfund site proximityHealth riskPopulation-weighted distance to NPL Superfund sites — the most contaminated waste sites in the country. Nearby groundwater, soil, and air can carry industrial solvents, metals, and other long-lived contaminants.79above the national median
- RMP-facility proximityHealth riskDistance to facilities holding chemicals at quantities large enough to require an EPA Risk Management Plan (refineries, fertilizer plants, etc.). These pose acute exposure risk during accidental releases.89in the highest 20% nationally
- Hazardous-waste site proximityHealth riskDistance to RCRA hazardous-waste handlers (treatment, storage, disposal facilities). Indicates potential exposure to industrial chemicals in air, soil, and groundwater.71above the national median
- Underground storage tanksHealth riskDensity of underground tanks (gasoline, heating oil, industrial fluids). Leaking tanks are a leading source of benzene and other volatile organic compounds in groundwater drinking-water supplies.79above the national median
- NPDES wastewater proximityHealth riskDistance to permitted industrial wastewater dischargers. Closer proximity raises exposure to pollutants released into surface waters used for fishing, recreation, and downstream drinking-water intakes.82in the highest 20% nationally
- Drinking-water non-complianceHealth riskEPA score for public water systems with health-based Safe Drinking Water Act violations. Higher means more residents on systems that recently exceeded safe limits for contaminants like lead, arsenic, or nitrate.76above the national median
| Indicator | Disparity score | Reading |
|---|---|---|
| PM2.5 (fine particulate) | 191 | well above the reference burden |
| Ozone | 53 | below the reference |
| Nitrogen dioxide (NO₂) | 198 | well above the reference burden |
| Diesel particulate | 160 | well above the reference burden |
| Toxic releases (RSEI) | 208 | severely above the reference burden |
| Traffic proximity | 164 | well above the reference burden |
| Lead-paint risk (pre-1960 housing) | 77 | below the reference |
| Superfund site proximity | 136 | moderately above the reference |
| RMP-facility proximity | 178 | well above the reference burden |
| Hazardous-waste site proximity | 143 | moderately above the reference |
| Underground storage tanks | 152 | well above the reference burden |
| NPDES wastewater proximity | 125 | moderately above the reference |
| Drinking-water non-compliance | 3 | well below the reference |
Source: Census ACS 2018-2022 (5-year) + USEPA-clone EJ blockgroup stats (raw indicators + EJ disparity mirror).
Source. EPA Safe Drinking Water Information System · retrieved 2026-05-07. Reporting period 2025-01-01 → 2026-05-07.
What this is not. SDWIS records compliance against federal MCLs — not a direct readout of tap-water concentrations. Active health-based violations are not the same as a current crisis; we link to the EPA record so you can verify return-to-compliance status before forming a conclusion.