Nitrate in Wisconsin Drinking Water — 2 ZIPs Tested

Nitrate Contamination in Wisconsin

ZipCheckup analyzed drinking water data across 898 ZIP codes in Wisconsin for nitrate contamination. 2 ZIP codes have reported nitrate detections, and 15 have EPA violations on record.

The violation rate for nitrate in Wisconsin is 1.7% of all ZIP codes — roughly in line with the national average.

EPA Standard for Nitrate

The EPA maximum contaminant level (MCL) for nitrate is 10 mg/L (as nitrogen), governed by the National Primary Drinking Water Regulations. Water systems that exceed this limit must take corrective action and notify consumers.

Worst ZIP Codes for Nitrate in Wisconsin

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

Lowest Nitrate Levels in Wisconsin

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

Health Effects of Nitrate

How to Remove Nitrate From Drinking Water

The most effective treatment for nitrate removal is Reverse Osmosis or Ion Exchange. Look for filters certified under NSF 53 / NSF 58 standards.

Check Your ZIP Code

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