County · Washington
Mason County, Washington: drinking water records
This overview covers 9 ZIP codes and 125 community water systems in Mason County. It also stands in for 1 ZIP codes whose utility has too little EPA data for a page of its own.
System population figures are summed from EPA registry records and can overlap where wholesalers and retail systems serve the same people. They are not a Census county-population estimate.
Water systems with the most complete records
| Water system | People served | PFAS survey results | PFAS found | Health-based violations | Lead, 9 in 10 homes at or below |
|---|---|---|---|---|---|
| Shelton City of WA5378170 | 15,089 | 180 | 0 | 0 | 1.8 ppb |
| Lake Cushman System 5 WA5303529 | 3,675 | 420 | 2 | 0 | 2 ppb |
| Squaxin Consolidated 105300146 | 1,500 | 0 | 0 | 4 | 8.1 ppb |
| Shoalwater Bay 105300019 | 898 | 60 | 0 | 0 | 2.9 ppb |
| Hartstene Pointe WA5331569 | 460 | 0 | 0 | 4 | 8.5 ppb |
| Emerald Lake WA5323294 | 331 | 60 | 0 | 0 | 0 ppb |
| Lakewood Heights WA5317999 | 170 | 0 | 0 | 1 | 1 ppb |
| Shadowood WA5313584 | 154 | 0 | 0 | 2 | 4.5 ppb |
| Bayshore WA5304900 | 130 | 60 | 0 | 0 | 4.5 ppb |
| Three Fingers WA5361129 | 78 | 0 | 0 | 1 | 0 ppb |
| Golf MHP OR4100588 | 60 | 0 | 0 | 23 | 1.9 ppb |
| Olympic Trails Water Supply WA5363448 | 44 | 0 | 0 | 2 | 22.5 ppb |
| River Village MHP OR4105854 | 40 | 0 | 0 | 14 | 10.9 ppb |
| Smith Cove WA5313651 | 30 | 0 | 0 | 1 | 0.7 ppb |
| Belfair Water District 1 WA5305350 | 4,432 | 0 | 0 | 0 | 0 ppb |
| Timberlake Community Club INC WA5388370 | 2,337 | 0 | 0 | 0 | 5 ppb |
| Washington Corrections Center WA5393063 | 2,223 | 0 | 0 | 0 | 1.6 ppb |
| Alderbrook Water Co WA5301050 | 2,154 | 0 | 0 | 0 | 0 ppb |
| Lake Limerick Water WA5344150 | 2,148 | 0 | 0 | 0 | 0 ppb |
| Lakeland Village Water WA5345090 | 2,120 | 0 | 0 | 0 | 0 ppb |
| Hoodsport WA5334100 | 1,853 | 0 | 0 | 0 | 2 ppb |
| Shorecrest Estates Water Co WA5378620 | 1,321 | 0 | 0 | 0 | 1 ppb |
| Skokomish 105300020 | 1,150 | 0 | 0 | 0 | 0 ppb |
| Beards Cove WA5305100 | 1,100 | 0 | 0 | 0 | 0 ppb |
| Fawn Lake Maintenance Comm WA5324713 | 1,044 | 0 | 0 | 0 | 5 ppb |
ZIP reports in Mason County
No ZIP report in this county is published yet.
These ZIP codes are covered by this overview because their utility has too little EPA data for a separate page: 98560.
Sources and scope
EPA UCMR 5 occurrence data, samples collected 2023-01-03 – 2026-06-17, final release, August 2026 (file dated Aug 28, 2026); EPA SDWIS via ECHO, 2026Q2 extract (file dated Jul 9, 2026); EPA service-area boundaries v3.0; Census 2020 ZCTAs. Page generated 2026-09-03.
Counts cover the systems that report this county to EPA. A water system may cross county lines. "Found" means at least one result at or above the laboratory reporting level; it is not a compliance finding.