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Not health advice. Contact your local water utility for concerns.
Data from EPA Water Quality Reports. For official information, contact your water utility or health department.
Water quality data for 3 cities serving 260,458 residents
Will County in Illinois has an average water quality score of 83/100 (Grade B) based on analysis of 3 municipal water systems. The county's water systems serve approximately 260,458 residents.
Overall, Will County demonstrates good water quality standards. 2 of 3 cities exceed the county average, with Plainfield leading with a score of 99/100.
3 cities ranked by water quality score
| Rank | City | Score | Grade | Population |
|---|---|---|---|---|
| 1 | Plainfield Biggest deduction: 1 monitoring/reporting violation in the last 5 years (−1 pts) | 99 | A | 50,000 |
| 2 | Romeoville Biggest deduction: Other PFAS detected in UCMR5 sampling: PFBA 8.9 ppt, PFPeA 21.2 ppt, PFHxA 11.8 ppt (−6 pts) | 88 | B | 50,458 |
| 3 | Joliet Biggest deduction: 1 health-based violation (MCL/treatment-technique) in the last 5 years (−10 pts) | 61 | D | 160,000 |
Real EPA readings across county water systems (lead: latest 90th percentile; PFAS: UCMR5 2023–2026; others: 2012–2019 averages)
| Contaminant | Avg Level | Max Level | EPA Limit | % of Limit | Cities |
|---|---|---|---|---|---|
| Radium (2012–2019 avg) | 2.083 pCi/L | 2.758 pCi/L | 5 pCi/L | 41.7% | 2 |
| Lead (90th percentile) | 4.897 ppb | 8.22 ppb | 15 ppb | 32.6% | 3 |
| Fluoride (2012–2019 avg) | 1.03 mg/L | 1.119 mg/L | 4 mg/L | 25.7% | 2 |
| TTHM (2012–2019 avg) | 18.727 ug/L | 38.37 ug/L | 80 ug/L | 23.4% | 3 |
| HAA5 (2012–2019 avg) | 5.195 ug/L | 11.929 ug/L | 60 ug/L | 8.7% | 3 |
| Uranium (2012–2019 avg) | 0.457 ug/L | 0.457 ug/L | 30 ug/L | 1.5% | 1 |
| Arsenic (2012–2019 avg) | 0.118 ug/L | 0.217 ug/L | 10 ug/L | 1.2% | 2 |
| Nitrate (2012–2019 avg) | 0.119 mg/L | 0.236 mg/L | 10 mg/L | 1.2% | 2 |
Recent violations across county water systems
Other — Consumer Confidence Report Inadequate Reporting - Consumer Confidence Rule
6/30/2025
Monitoring & reporting — Monitoring, Regular - Total Polychlorinated Biphenyls (PCB)
12/31/2022
Monitoring & reporting — Monitoring, Regular - Total Polychlorinated Biphenyls (PCB)
12/31/2022
Monitoring & reporting — Monitoring, Regular - Total Polychlorinated Biphenyls (PCB)
12/31/2022
Monitoring & reporting — Monitoring, Regular - Total Polychlorinated Biphenyls (PCB)
12/31/2022
Showing 10 of 14 recent violations
Water quality in Will County, Illinois reflects the region's unique combination of water sources, treatment infrastructure, and environmental factors. Our comprehensive analysis examines 3 municipal water systems serving a combined population of over 260,458 residents.
The county shows strong water quality performance, with scores ranging from 61/100 in Joliet to 99/100 in Plainfield. This 38-point spread indicates significant variation in water quality across the county, suggesting different water sources or treatment approaches.
The most prevalent contaminants detected across Will County water systems include Radium (2012–2019 avg), Lead (90th percentile), Fluoride (2012–2019 avg). Every county-wide average sits below 50% of its EPA Maximum Contaminant Level (MCL).
Will County's water quality is generally good. Residents can feel confident in their tap water quality, though those with specific health concerns or sensitivity to certain contaminants may still benefit from filtration. Regular review of your city's annual Consumer Confidence Report is recommended.
Will County has an average water quality score of 83/100 (Grade B) based on analysis of 3 municipal water systems serving 260,458 residents.
Plainfield has the highest water quality score in Will County at 99/100. View the detailed report for Plainfield.
Most cities in Will County have water that meets EPA standards. However, a water filter can provide additional protection and improve taste. The need depends on your specific city and any personal health considerations.
Click on any city in the rankings table above to view its detailed water quality report, including contaminant levels, EPA compliance history, and filter recommendations.