Water Quality: Issaquah, WA
4 water systems • 43,739 people served
Some ConcernsWater Quality Summary
Issaquah is served by 4 public water systems with a combined service population of 43,739 people, and has 142 EPA Safe Drinking Water Act violations on record. Critically, 1 of those are health-based violation, meaning one or more contaminants were detected above EPA-established safe levels — a serious public health concern. Issaquah's violation count is 12% below the national average for Washington. Contaminants associated with violations include E. coli.
Contaminants Found
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)
Water Systems Serving Issaquah
| System Name | PWSID | Source | Population | Violations |
|---|---|---|---|---|
| ISSAQUAH WATER SYSTEM | WA5336350 | Surface Water | 43,584 | 3 |
| ISSAQUAH VALLEY WATER ASSN #1 | WA5336300 | Groundwater | 80 | 10 |
| ALPINE MOBILE MANOR | WA5301830 | Groundwater | 45 | 12 |
| TIGER MTN TRACTS | WA5388315 | Groundwater | 30 | 117 |
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
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.