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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 4 cities serving 368,883 residents
Kane County in Illinois has an average water quality score of 79/100 (Grade C) based on analysis of 4 municipal water systems. The county's water systems serve approximately 368,883 residents.
Water quality in Kane County is fair, with some cities showing room for improvement. 2 cities have scores below 70, indicating elevated contaminant levels that residents should be aware of. Carpentersville has the best water quality at 100/100.
4 cities ranked by water quality score
| Rank | City | Score | Grade | Population |
|---|---|---|---|---|
| 1 | Carpentersville | 100 | A | 37,983 |
| 2 | St. Charles Biggest deduction: Radium-226/228 (combined): 1 of 13 finished-water samples (2012–2019) above the 5 pci/l MCL (7.7% of samples); max 5.26 pci/l (−10 pts) | 83 | B | 33,103 |
| 3 | Aurora Biggest deduction: Lead 90th-percentile tap result 24 ppb for 2025-07-01–2025-12-31, above the 15 ppb federal action level (−25 pts) | 69 | D | 183,000 |
| 4 | Elgin Biggest deduction: Lead 90th-percentile tap result 53 ppb for 2025-07-01–2025-12-31, above the 15 ppb federal action level (−25 pts) | 63 | D | 114,797 |
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 |
|---|---|---|---|---|---|
| Lead (90th percentile) | 20.475 ppb | 53 ppb | 15 ppb | 136.5% | 4 |
| TTHM (2012–2019 avg) | 32.446 ug/L | 46.497 ug/L | 80 ug/L | 40.6% | 4 |
| Fluoride (2012–2019 avg) | 0.917 mg/L | 0.976 mg/L | 4 mg/L | 22.9% | 4 |
| Radium (2012–2019 avg) | 0.959 pCi/L | 2.072 pCi/L | 5 pCi/L | 19.2% | 3 |
| HAA5 (2012–2019 avg) | 10.674 ug/L | 22.171 ug/L | 60 ug/L | 17.8% | 4 |
| Nitrate (2012–2019 avg) | 0.538 mg/L | 1.25 mg/L | 10 mg/L | 5.4% | 4 |
| Arsenic (2012–2019 avg) | 0.254 ug/L | 0.5 ug/L | 10 ug/L | 2.5% | 4 |
| PFAS (PFOA/PFOS max, UCMR5) | 0 ppt | 0 ppt | 4 ppt | 0% | 4 |
Recent violations across county water systems
Monitoring & reporting — Follow-up Or Routine LCR Tap M/R - Lead and Copper Rule
12/31/2025
Other — Consumer Confidence Report Inadequate Reporting - Consumer Confidence Rule
6/30/2025
Other — Consumer Confidence Report Complete Failure to Report - Consumer Confidence Rule
6/30/2024
Showing 10 of 13 recent violations
Water quality in Kane County, Illinois reflects the region's unique combination of water sources, treatment infrastructure, and environmental factors. Our comprehensive analysis examines 4 municipal water systems serving a combined population of over 368,883 residents.
The county shows moderate water quality performance, with scores ranging from 63/100 in Elgin to 100/100 in Carpentersville. This 37-point spread indicates significant variation in water quality across the county, suggesting different water sources or treatment approaches.
The most prevalent contaminants detected across Kane County water systems include Lead (90th percentile), TTHM (2012–2019 avg), Fluoride (2012–2019 avg). At least one reading averages above 50% of its EPA limit across the county's systems, worth attention from residents and utilities.
Water quality in Kane County is fair but shows room for improvement. Residents in cities scoring below 70 should consider water filtration, particularly for drinking and cooking. Check your specific city's report above for personalized recommendations.
Kane County has an average water quality score of 79/100 (Grade C) based on analysis of 4 municipal water systems serving 368,883 residents.
Carpentersville has the highest water quality score in Kane County at 100/100. View the detailed report for Carpentersville.
Given the water quality variation across Kane County, we recommend reviewing your specific city's water quality report. 2 cities have scores below 70, where filtration is particularly recommended.
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.