CITY REPORT
IL
Naperville, IL Water Quality Report
1 ZIP code · 1 water system · Updated 2026-03-16
Data: EPA SDWIS Last verified: 2026-03-16
1
ZIP Codes
1
Water Systems
1
ZIPs with Violations
Zone 1
Radon Risk (High)
Overview
We track water quality and home safety data for 1 ZIP code in Naperville, Illinois, covering 1 community water system serving approximately 156,406 people.
1 of 1 ZIP code (100%) have recorded EPA violations. All violations are monitoring/reporting type.
Water Sources
Naperville water systems draw from: Surface water.
Lead & Copper
- Lead data: not yet available for Naperville
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 1 (High Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Top Contaminants
| Contaminant | Category | Violations | ZIPs Affected |
|---|---|---|---|
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 10 | 1 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 60540 | — | 5 | 0 | NAPERVILLE |
All ZIP Codes in Naperville
- 60540 — 5 violations
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- Radon: EPA Map of Radon Zones
Updated daily.