Cook County Drinking Water Report Card
Cook County scores 39 out of 100 on WaterViolations.org's Drinking Water Violation Exposure Score. The county has 132 active public water systems serving 2,419,792 people, with 114 health-based violations on record and 3 systems with active health-based violations.
This is a research signal, not an official safety grade. Contact the water utility or state drinking-water agency for current notices and guidance.
Quote-Ready Local Facts
- 132 active public water systems serve 2,419,792 people in Cook County.
- 114 health-based violations are on record, or 4.7 per 100,000 people served.
- 3 systems have active health-based violations in the current dataset.
Score Breakdown
| Factor | Value | Penalty |
|---|---|---|
| Health-based violations per 100,000 people | 4.7 | 56.5 / 60 |
| Systems with active health violations | 2.3% | 4.5 / 40 |
System to Review
The county system with the most health-based violations in this dataset is Lemont, with 10 health-based violations on record.
Reporter Story Kit
Use this section as a starting point for local reporting. These figures are screening signals from EPA SDWIS records, not a substitute for utility notices, state agency guidance, or direct water testing.
Fast local angles
- Ask which systems account for the active health-based violations and whether residents received required public notices.
- Compare older health-based violations with the latest Consumer Confidence Reports for affected systems.
- Ask the state drinking-water agency which violations are resolved, pending, or tied to monitoring/reporting gaps.
Contaminants Driving Health-Based Violations
| Contaminant | Health-Based Violations |
|---|---|
| Unknown | 115 |
Active Health-Violation Systems to Check First
| System | City | Population | Active Health Violations | Active Total |
|---|---|---|---|---|
| Bellwood | Bellwood | 19,156 | 1 | 3 |
| Cicero | Cicero | 83,000 | 1 | 5 |
| Calumet City | Calumet City | 37,000 | 1 | 2 |
Questions to Ask
- What contaminant or treatment requirement caused each active health-based violation?
- When did the utility notify customers, and where is that notice posted?
- Has follow-up sampling shown the issue is resolved?
- Are private well owners nearby being advised to test for related contaminants?
Download all county report-card scores · Download Illinois violation data
Copyable Reporter Summary
WaterViolations.org gives Cook County, Illinois a Drinking Water Violation Exposure Score of 39/100 (F). The county has 132 active public water systems serving 2,419,792 people, with 114 health-based violations on record and 3 systems with active health-based violations. The score is based on EPA SDWIS records and is not an official safety grade.