Total Trihalomethanes (TTHM)
Unresolved Total Trihalomethanes Rule violation cited in 2023 (total trihalomethanes (tthm)).
PWSID VA5590100 · Surface waterMunicipal
43,055 people served. 13 health-based SDWIS violations recorded in the past 5 years. 4 remain unresolved. Last cited 3 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 2023 (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.
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; 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; returned to compliance
Maximum contaminant level exceeded
Maximum contaminant level exceeded; returned to compliance
Danville, Virginia (Census place; block-group disparity scores aggregated by centroid containment): a service population of 42,507. Local disparity score for pm2.5 (fine particulate) sits well below the reference (50). Why we surface this →
Low-income
People of color
Under age 5
Over age 64
| Indicator | Disparity score | Reading |
|---|---|---|
| PM2.5 (fine particulate) | 50 | well below the reference |
| Ozone | 50 | well below the reference |
| Nitrogen dioxide (NO₂) | 88 | below the reference |
| Diesel particulate | 89 | below the reference |
| Toxic releases (RSEI) | 96 | near the reference |
| Traffic proximity | 78 | below the reference |
| Lead-paint risk (pre-1960 housing) | 150 | moderately above the reference |
| Superfund site proximity | 0 | well below the reference |
| RMP-facility proximity | 123 | moderately above the reference |
| Hazardous-waste site proximity | 98 | near the reference |
| Underground storage tanks | 142 | moderately above the reference |
| NPDES wastewater proximity | 120 | moderately above the reference |
| Drinking-water non-compliance | 0 | 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 2022-01-01 → 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.