Illinois
Water Quality Report
66 Fair
Average Score
66/100
Water Systems
856
Population
11.6M
Violations
1435 403 unresolved
Score Distribution
65 A
88 B
70 C
30 D
45 F
Top Contaminant Violations
| Contaminant | Violations |
|---|---|
| Copper (90th percentile) | 20 |
| Lead (90th percentile) | 8 |
Lowest Scoring Water Systems
0
Devils Kitchen Water District F
IL1995160 Carbondale, IL 1,428 served
0
Maywood F
IL0311830 Maywood, IL 24,090 served
0
Crest Hill F
IL1970250 Crest Hill, IL 21,169 served
0
Millstone Pwd F
IL1515050 Nashville, IL 5,565 served
0
Blue Diamond Rainbow Sw Plaza Water F
NV0000323 Chicago, IL 1,871 served
Counties in Illinois
Cities in Illinois
View all 631 cities →Popular City Comparisons in Illinois
Quickly compare major cities in Illinois by water quality score and grade.
Frequently Asked Questions
Is tap water in Illinois safe to drink?
Illinois has an average WaterQ score of 66/100 across 856 public water systems. Safety can vary by city and system, so check your local report for recent violations and contaminants.
How many water systems are in Illinois?
WaterQ currently tracks 856 public water systems in Illinois.
Where can I compare cities in Illinois?
Use the city list below to open detailed reports, or visit the compare tool to benchmark two cities side-by-side on score, grade, and system coverage.