Water Quality: Mattawa, WA

3 water systems • 5,361 people served

Multiple Health Violations
282
Total Violations
8
Health-Based Violations
3
Water Systems
5,361
Population Served

Water Quality Summary

Mattawa is served by 3 public water systems with a combined service population of 5,361 people, and has 282 EPA Safe Drinking Water Act violations on record. Critically, 8 of those are health-based violations, meaning one or more contaminants were detected above EPA-established safe levels — a serious public health concern. Mattawa's violation count is 74% above the national average for Washington. Contaminants associated with violations include E. coli, Selenium.

Contaminants Found

E. coli

Causes gastrointestinal illness; certain strains (e.g., O157:H7) can cause severe kidney failure and death.

Common source: Fecal contamination from humans or animals entering the water supply

EPA limit: Zero (no E. coli permitted in drinking water)

Selenium

Hair loss, nail brittleness, and nervous system damage at elevated concentrations.

Common source: Natural geological deposits, mining discharges, oil refinery waste

EPA limit: 0.05 mg/L (50 ppb)

Water Systems Serving Mattawa

System Name PWSID Source Population Violations
Mattawa City of WA5352000 Groundwater 5,015 166
SENTINEL GAP WATER ASSN WA5376620 Groundwater 226 9
BEVERLY WATER DISTRICT WA5306350 Groundwater 120 107

Concerned About Your Water?

A home water filter can remove common contaminants. NSF-certified filters are tested against EPA standards.

Consider a reverse osmosis system for comprehensive filtration or a carbon filter for basic improvement.

Other Cities in Washington

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Data Sources

Drinking water violation data from the EPA Safe Drinking Water Information System (SDWIS). Data includes all recorded violations for active community water systems.

Verify at epa.govSearch ECHO for WA