Total Trihalomethanes (TTHM)
Unresolved Total Trihalomethanes Rule violation cited in 2021 (total trihalomethanes (tthm)).
PWSID IL1795345 · Purchased / wholesalePrivate
248 people served. No health-based SDWIS violations recorded in the past 5 years. 6 remain unresolved. Last cited 3 years ago.
Unresolved Total Trihalomethanes Rule violation cited in 2021 (total trihalomethanes (tthm)).
Unresolved Total Trihalomethanes Rule violation cited in 2021 (total trihalomethanes (tthm)).
Unresolved Total Trihalomethanes Rule violation cited in 2021 (total trihalomethanes (tthm)).
Unresolved Total Trihalomethanes Rule violation cited in 2021 (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.
OTHER; returned to compliance
OTHER; returned to compliance
OTHER; returned to compliance
OTHER; returned to compliance
Failure to monitor as scheduled; returned to compliance
Failure to monitor as scheduled; returned to compliance
Failure to monitor as scheduled; returned to compliance
Failure to monitor as scheduled; returned to compliance
Failure to monitor as scheduled; returned to compliance
Failure to monitor as scheduled; returned to compliance
Failure to monitor as scheduled
Failure to monitor as scheduled
Failure to monitor as scheduled
Failure to monitor as scheduled; returned to compliance
Failure to monitor as scheduled; returned to compliance
Failure to monitor as scheduled
Failure to monitor as scheduled
Failure to monitor as scheduled
Monitoring failure; returned to compliance
Monitoring failure; returned to compliance
Failure to monitor as scheduled; returned to compliance
Failure to monitor as scheduled; returned to compliance
Failure to monitor as scheduled; returned to compliance
Failure to monitor as scheduled; returned to compliance
Failure to monitor as scheduled; returned to compliance
Failure to monitor as scheduled; returned to compliance
Failure to monitor as scheduled; returned to compliance
Failure to monitor as scheduled; returned to compliance
Failure to monitor as scheduled; returned to compliance
Failure to monitor as scheduled; returned to compliance
Blue Island, Illinois (Census place; block-group disparity scores aggregated by centroid containment): a service population of 22,934. Local disparity score for pm2.5 (fine particulate) sits well above the reference burden (194). Why we surface this →
Low-income
People of color
Under age 5
Over age 64
| Indicator | Disparity score | Reading |
|---|---|---|
| PM2.5 (fine particulate) | 194 | well above the reference burden |
| Ozone | 191 | well above the reference burden |
| Nitrogen dioxide (NO₂) | 216 | severely above the reference burden |
| Diesel particulate | 200 | severely above the reference burden |
| Toxic releases (RSEI) | 195 | well above the reference burden |
| Traffic proximity | 181 | well above the reference burden |
| Lead-paint risk (pre-1960 housing) | 163 | well above the reference burden |
| Superfund site proximity | 155 | well above the reference burden |
| RMP-facility proximity | 201 | severely above the reference burden |
| Hazardous-waste site proximity | 179 | well above the reference burden |
| Underground storage tanks | 178 | well above the reference burden |
| NPDES wastewater proximity | 222 | severely above the reference burden |
| Drinking-water non-compliance | 12 | 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 2020-01-01 → 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.