Manganese in Washington Drinking Water — 24 ZIPs Tested
EPA data analysis for manganese in Washington drinking water systems
Manganese Contamination in Washington
ZipCheckup analyzed drinking water data across 726 ZIP codes in Washington for manganese contamination. 24 ZIP codes have reported manganese detections, and 4 have EPA violations on record.
The violation rate for manganese in Washington is 0.6% of all ZIP codes — lower than the national average.
EPA Standard for Manganese
The EPA maximum contaminant level (MCL) for manganese is 50 µg/L (SMCL / health advisory), governed by the Secondary Drinking Water Standards. Water systems that exceed this limit must take corrective action and notify consumers.
Worst ZIP Codes for Manganese in Washington
These ZIP codes reported the highest manganese levels in Washington based on CCR reports and EPA data:
Lowest Manganese Levels in Washington
These ZIP codes had the lowest reported manganese detections in Washington:
Health Effects of Manganese
At elevated levels, manganese causes neurological effects similar to Parkinson's disease (tremors, difficulty walking). Infants and children are most vulnerable — studies link high manganese in water to lower IQ and behavioral problems.
How to Remove Manganese From Drinking Water
The most effective treatment for manganese removal is Oxidation Filter or Reverse Osmosis. Look for filters certified under NSF 42 / NSF 58 standards.
Check Your ZIP Code
Use the ZipCheckup water quality search to see manganese data for your specific water system in Washington.
Worst ZIP Codes for Manganese in Washington
Ranked by highest manganese detection level.
| Rank | ZIP Code | City | Level Detected | EPA Limit | Status |
|---|---|---|---|---|---|
| 1 | 98503 | Lacey | 61 ppb | 50 ppb | Exceeds |
| 2 | 98509 | Lacey | 61 ppb | 50 ppb | Exceeds |
| 3 | 98513 | Olympia | 61 ppb | 50 ppb | Exceeds |
| 4 | 98030 | Kent | 0.51 ppm | 0.05 ppm | Exceeds |
| 5 | 98031 | Kent | 0.51 ppm | 0.05 ppm | Exceeds |
| 6 | 98032 | Kent | 0.51 ppm | 0.05 ppm | Exceeds |
| 7 | 98035 | Kent | 0.51 ppm | 0.05 ppm | Exceeds |
| 8 | 98064 | Kent | 0.51 ppm | 0.05 ppm | Exceeds |
| 9 | 98089 | Kent | 0.51 ppm | 0.05 ppm | Exceeds |
| 10 | 98198 | Seattle | 0.51 ppm | 0.05 ppm | Exceeds |
| 11 | 98501 | Olympia | 0.176 ppm | 0.05 ppm | Exceeds |
| 12 | 98502 | Olympia | 0.176 ppm | 0.05 ppm | Exceeds |
| 13 | 98504 | Olympia | 0.176 ppm | 0.05 ppm | Exceeds |
| 14 | 98505 | Olympia | 0.176 ppm | 0.05 ppm | Exceeds |
| 15 | 98506 | Olympia | 0.176 ppm | 0.05 ppm | Exceeds |
| 16 | 98507 | Olympia | 0.176 ppm | 0.05 ppm | Exceeds |
| 17 | 98508 | Olympia | 0.176 ppm | 0.05 ppm | Exceeds |
| 18 | 98512 | Olympia | 0.176 ppm | 0.05 ppm | Exceeds |
| 19 | 98516 | Olympia | 0.176 ppm | 0.05 ppm | Exceeds |
| 20 | 98599 | Olympia | 0.176 ppm | 0.05 ppm | Exceeds |