MERCER ISLAND CITY OF
Washington — Community Water System — PWSID: WA5353640
System Information
| PWSID | WA5353640 |
| System Name | MERCER ISLAND CITY OF |
| System Type | Community Water System |
| Water Source | Surface Water Purchased |
| Activity Status | Active |
| Owner Type | Local |
| EPA Region | 10 |
| Serves School | No |
| Wholesaler | No |
| First Reported | Feb 7, 1981 |
| Last Reported | Dec 11, 2025 |
Location & Contact
| State | Washington |
| City | Mercer Island |
| ZIP Code | 98040 |
| Address | 9601 SE 36th St |
| Organization | MERCER ISLAND CITY OF |
| Phone | — |
Population & Service
| Population Served | 30,689 |
| Service Connections | 9,769 |
Drinking Water Violations (5)
This water system has 5 violations recorded in the EPA SDWIS database.
| Begin Date | End Date | Contaminant | Category | Health-Based | Major | Measured | Federal MCL | State MCL | Status | Return to Compliance | Rule |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Dec 1, 1992 | Dec 31, 1992 | Coliform (TCR) | MR | No | No | — | 5% of samples | — | Archived | Dec 31, 1992 | Total Coliform Rule |
| Aug 1, 1992 | Aug 31, 1992 | Coliform (TCR) | MR | No | No | — | 5% of samples | — | Archived | Aug 31, 1992 | Total Coliform Rule |
| Jan 1, 1992 | Jan 31, 1992 | Coliform (TCR) | MCL | Yes | No | — | 5% of samples | — | Archived | Jan 31, 1992 | Total Coliform Rule |
| Jan 1, 1992 | Jan 31, 1992 | Coliform (TCR) | MCL | Yes | No | — | 5% of samples | — | Archived | Jan 31, 1992 | Total Coliform Rule |
| Jan 1, 1992 | Jan 31, 1992 | Coliform (TCR) | MCL | Yes | No | — | 5% of samples | — | Archived | Jan 31, 1992 | Total Coliform Rule |
About This Water System
Public water system data comes from the EPA Safe Drinking Water Information System (SDWIS). Systems with violations must notify customers. Contact your water utility for the latest annual water quality report.