Total Trihalomethanes (TTHM)
Unresolved Total Trihalomethanes Rule violation cited in 2024 (total trihalomethanes (tthm)).
PWSID MS0170024 · GroundwaterMunicipal
729 people served. No health-based SDWIS violations recorded in the past 5 years. 6 remain unresolved. Last cited 2 years ago.
Unresolved Total Trihalomethanes Rule violation cited in 2024 (total trihalomethanes (tthm)).
Unresolved Total Trihalomethanes Rule violation cited in 2024 (total trihalomethanes (tthm)).
Unresolved Total Trihalomethanes Rule violation cited in 2024 (total trihalomethanes (tthm)).
Unresolved Total Trihalomethanes Rule violation cited in 2024 (haloacetic acids (haa5)).
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.
Failure to monitor as scheduled
Failure to monitor as scheduled
Failure to monitor as scheduled
Failure to monitor as scheduled
Failure to monitor as scheduled
Failure to monitor as scheduled
Horn Lake, Mississippi (Census place; block-group disparity scores aggregated by centroid containment): a service population of 26,652. Local disparity score for pm2.5 (fine particulate) sits moderately above the reference (140). Why we surface this →
Low-income
People of color
Under age 5
Over age 64
| Indicator | Disparity score | Reading |
|---|---|---|
| PM2.5 (fine particulate) | 140 | moderately above the reference |
| Ozone | 85 | below the reference |
| Nitrogen dioxide (NO₂) | 57 | below the reference |
| Diesel particulate | 91 | near the reference |
| Toxic releases (RSEI) | 158 | well above the reference burden |
| Traffic proximity | 73 | below the reference |
| Lead-paint risk (pre-1960 housing) | 40 | well below the reference |
| Superfund site proximity | 115 | moderately above the reference |
| RMP-facility proximity | 3 | well below the reference |
| Hazardous-waste site proximity | 72 | below the reference |
| Underground storage tanks | 111 | moderately above the reference |
| NPDES wastewater proximity | 66 | below the reference |
| Drinking-water non-compliance | 36 | 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 2024-01-01 → 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.