Copper in Wisconsin Drinking Water — 63 ZIPs Tested

Copper Contamination in Wisconsin

ZipCheckup analyzed drinking water data across 898 ZIP codes in Wisconsin for copper contamination. 63 ZIP codes have reported copper detections, and 57 have EPA violations on record.

The violation rate for copper in Wisconsin is 6.3% of all ZIP codes — higher than the national average.

EPA Standard for Copper

The EPA maximum contaminant level (MCL) for copper is 1.3 mg/L (action level), governed by the Lead and Copper Rule. Water systems that exceed this limit must take corrective action and notify consumers.

Worst ZIP Codes for Copper in Wisconsin

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

Lowest Copper Levels in Wisconsin

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

Health Effects of Copper

Short-term exposure to copper above the action level causes gastrointestinal distress (nausea, vomiting, diarrhea). Long-term exposure can cause liver and kidney damage. People with Wilson's disease are particularly sensitive.

How to Remove Copper From Drinking Water

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

Check Your ZIP Code

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