Total Trihalomethanes (TTHM)
Unresolved Total Trihalomethanes Rule violation cited in 2023 (total trihalomethanes (tthm)).
PWSID LA1073003 · GroundwaterPrivate
2,160 people served. 23 health-based SDWIS violations recorded in the past 5 years. 10 remain unresolved. Last cited 2 years ago.
Unresolved Total Trihalomethanes Rule violation cited in 2023 (total trihalomethanes (tthm)).
Unresolved Total Trihalomethanes Rule violation cited in 2023 (total trihalomethanes (tthm)).
Unresolved Total Trihalomethanes Rule violation cited in 2022 (total trihalomethanes (tthm)).
Unresolved Total Trihalomethanes Rule violation cited in 2022 (total trihalomethanes (tthm)).
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.
Reporting failure; returned to compliance
Reporting failure; returned to compliance
Treatment technique violation; returned to compliance
Treatment technique violation; returned to compliance
Maximum contaminant level exceeded; returned to compliance
Maximum contaminant level exceeded; returned to compliance
Maximum contaminant level exceeded
Maximum contaminant level exceeded
Maximum contaminant level exceeded
Maximum contaminant level exceeded; returned to compliance
Maximum contaminant level exceeded; returned to compliance
Maximum contaminant level exceeded
Maximum contaminant level exceeded; returned to compliance
Maximum contaminant level exceeded; returned to compliance
Maximum contaminant level exceeded
Maximum contaminant level exceeded
Maximum contaminant level exceeded; returned to compliance
Maximum contaminant level exceeded; returned to compliance
Maximum contaminant level exceeded
Maximum contaminant level exceeded
Maximum contaminant level exceeded; returned to compliance
Maximum contaminant level exceeded; returned to compliance
Maximum contaminant level exceeded
Maximum contaminant level exceeded
Maximum contaminant level exceeded; returned to compliance
West Monroe, Louisiana (Census place; block-group disparity scores aggregated by centroid containment): a service population of 12,987. Local disparity score for pm2.5 (fine particulate) sits near the reference (96). Why we surface this →
Low-income
People of color
Under age 5
Over age 64
| Indicator | Disparity score | Reading |
|---|---|---|
| PM2.5 (fine particulate) | 96 | near the reference |
| Ozone | 28 | well below the reference |
| Nitrogen dioxide (NO₂) | 88 | below the reference |
| Diesel particulate | 76 | below the reference |
| Toxic releases (RSEI) | 150 | moderately above the reference |
| Traffic proximity | 57 | below the reference |
| Lead-paint risk (pre-1960 housing) | 76 | below the reference |
| Superfund site proximity | 0 | well below the reference |
| RMP-facility proximity | 106 | near the reference |
| Hazardous-waste site proximity | 85 | below the reference |
| Underground storage tanks | 127 | moderately above the reference |
| NPDES wastewater proximity | 61 | below the reference |
| Drinking-water non-compliance | 156 | well above the reference burden |
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 2021-01-01 → 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.