Contaminant 4109
Unresolved Lead and Copper Rule violation cited in 2024 (contaminant 4109).
PWSID IL0970170 · GroundwaterPrivate
382 people served. No health-based SDWIS violations recorded in the past 5 years. 8 remain unresolved. Last cited 1 year ago.
Unresolved Lead and Copper Rule violation cited in 2024 (contaminant 4109).
Unresolved Lead and Copper Rule violation cited in 2024 (contaminant 4109).
Unresolved Lead and Copper Rule violation cited in 2024 (contaminant 4109).
Unresolved Lead and Copper Rule violation cited in 2024 (contaminant 4109).
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
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
Failure to monitor as scheduled
Failure to monitor as scheduled
Schaumburg, Illinois (Census place; block-group disparity scores aggregated by centroid containment): a service population of 77,571. Local disparity score for pm2.5 (fine particulate) sits below the reference (86). Why we surface this →
Low-income
People of color
Under age 5
Over age 64
| Indicator | Disparity score | Reading |
|---|---|---|
| PM2.5 (fine particulate) | 86 | below the reference |
| Ozone | 94 | near the reference |
| Nitrogen dioxide (NO₂) | 92 | near the reference |
| Diesel particulate | 86 | below the reference |
| Toxic releases (RSEI) | 106 | near the reference |
| Traffic proximity | 80 | below the reference |
| Lead-paint risk (pre-1960 housing) | 27 | well below the reference |
| Superfund site proximity | 3 | well below the reference |
| RMP-facility proximity | 68 | below the reference |
| Hazardous-waste site proximity | 85 | below the reference |
| Underground storage tanks | 67 | below the reference |
| NPDES wastewater proximity | 106 | near 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 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.