Total Trihalomethanes (TTHM)
Unresolved Total Trihalomethanes Rule violation cited in 2025 (total trihalomethanes (tthm)).
PWSID IL0310210 · Purchased / wholesaleMunicipal
57,250 people served. No health-based SDWIS violations recorded in the past 5 years. 2 remain unresolved. Last cited 1 year ago.
Unresolved Total Trihalomethanes Rule violation cited in 2025 (total trihalomethanes (tthm)).
Unresolved Total Trihalomethanes Rule violation cited in 2025 (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; returned to compliance
Failure to monitor as scheduled
Failure to monitor as scheduled; returned to compliance
OTHER; returned to compliance
Berwyn, Illinois (Census place; block-group disparity scores aggregated by centroid containment): a service population of 56,556. Local disparity score for pm2.5 (fine particulate) sits well above the reference burden (158). Why we surface this →
Low-income
People of color
Under age 5
Over age 64
| Indicator | Disparity score | Reading |
|---|---|---|
| PM2.5 (fine particulate) | 158 | well above the reference burden |
| Ozone | 159 | well above the reference burden |
| Nitrogen dioxide (NO₂) | 183 | well above the reference burden |
| Diesel particulate | 171 | well above the reference burden |
| Toxic releases (RSEI) | 176 | well above the reference burden |
| Traffic proximity | 165 | well above the reference burden |
| Lead-paint risk (pre-1960 housing) | 178 | well above the reference burden |
| Superfund site proximity | 142 | moderately above the reference |
| RMP-facility proximity | 188 | well above the reference burden |
| Hazardous-waste site proximity | 173 | well above the reference burden |
| Underground storage tanks | 179 | well above the reference burden |
| NPDES wastewater proximity | 182 | well above the reference burden |
| 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 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.