Copper in Washington Drinking Water — 33 ZIPs Tested

Copper Contamination in Washington

ZipCheckup analyzed drinking water data across 726 ZIP codes in Washington for copper contamination. 33 ZIP codes have reported copper detections, and 18 have EPA violations on record.

The violation rate for copper in Washington is 2.5% of all ZIP codes — roughly in line with 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 Washington

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

Lowest Copper Levels in Washington

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

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 Washington.