Lead in Wisconsin Drinking Water — 690 ZIPs Tested

Lead Contamination in Wisconsin

ZipCheckup analyzed drinking water data across 898 ZIP codes in Wisconsin for lead contamination. 690 ZIP codes have reported lead detections, and 388 have EPA violations on record.

The violation rate for lead in Wisconsin is 43.2% of all ZIP codes — higher than the national average.

EPA Standard for Lead

The EPA maximum contaminant level (MCL) for lead is 15 ppb (action level), governed by the Lead and Copper Rule (LCRR/LCRI). Water systems that exceed this limit must take corrective action and notify consumers.

Worst ZIP Codes for Lead in Wisconsin

These ZIP codes reported the highest lead levels in Wisconsin based on CCR reports and EPA data:

Lowest Lead Levels in Wisconsin

These ZIP codes had the lowest reported lead detections in Wisconsin:

Health Effects of Lead

Lead is a potent neurotoxin with no safe level of exposure. In children, lead causes developmental delays, reduced IQ, and behavioral problems. In adults, it causes high blood pressure, kidney damage, and cardiovascular effects. Pregnant women face increased risk of premature birth.

How to Remove Lead From Drinking Water

The most effective treatment for lead removal is Reverse Osmosis or NSF 53 Carbon Block. Look for filters certified under NSF 53 / NSF 58 standards.

Check Your ZIP Code

Use the ZipCheckup water quality search to see lead data for your specific water system in Wisconsin.