Nitrate in Washington Drinking Water — 1 ZIPs Tested
EPA data analysis for nitrate in Washington drinking water systems
Nitrate Contamination in Washington
ZipCheckup analyzed drinking water data across 726 ZIP codes in Washington for nitrate contamination. 1 ZIP codes have reported nitrate detections, and 0 have EPA violations on record.
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 Washington
These ZIP codes reported the highest nitrate levels in Washington based on CCR reports and EPA data:
Lowest Nitrate Levels in Washington
These ZIP codes had the lowest reported nitrate detections in Washington:
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 Washington.
Worst ZIP Codes for Nitrate in Washington
Ranked by highest nitrate detection level.
| Rank | ZIP Code | City | Level Detected | EPA Limit | Status |
|---|---|---|---|---|---|
| 1 | 99362 | Walla Walla | 5.95 mg/L | 10 mg/L | Within Limit |
Lowest Nitrate Levels in Washington
| ZIP Code | City | Level Detected |
|---|---|---|
| 99362 | Walla Walla | 5.95 mg/L |
Cities with Nitrate Data in Washington
4 cities in Washington have nitrate testing data available.