Washington Water Quality
Health violation data for 2,397 community water systems in Washington. Based on EPA Safe Drinking Water Information System (SDWIS) data.
Water Systems
2,397
Total Violations
2,705
Systems with Violations
50
Cities with Issues
113
Water Systems with Most Violations
| # | Water System | Violations | Health |
|---|---|---|---|
| 1 | DELTA WATER ASSOCIATION Lynden | 124 | Yes |
| 2 | ORIENT WATER COMPANY Republic | 123 | Yes |
| 3 | WALLA WALLA WATER DIVISION Walla Walla | 105 | Yes |
| 4 | SUNRISE ESTATES WATER SYSTEM Moses Lake | 85 | Yes |
| 5 | COXVILLE WATER ASSN #1 Benton City | 81 | Yes |
| 6 | RED GATE MOBILE HOME PARK Port Orchard | 78 | Yes |
| 7 | SPRING POINT HOMEOWNERS ASSOCIATION Deer Harbor | 72 | Yes |
| 8 | MARTHA BOARDMAN Wellpinit | 67 | Yes |
| 9 | FORD-NEWHOUSE LANE Wellpinit | 59 | Yes |
| 10 | KAPOWSIN WATER DISTRICT Puyallup | 48 | Yes |
| 11 | MCNEIL ISLAND WATER Tumwater | 47 | Yes |
| 12 | COLUMBIA CREST ESTATES Napavine | 44 | Yes |
| 13 | MAKAH NEAH BAY Neah Bay | 42 | Yes |
| 14 | DEVRIES ROAD COMMUNITY ASSN Coupeville | 41 | Yes |
| 15 | ARROWHEAD BEACH COOP WATER ASSOC Mount Vernon | 35 | Yes |
| 16 | CALMOR COVE CLUB Lynden | 35 | Yes |
| 17 | BONNIE VIEW WATER Oak Harbor | 34 | Yes |
| 18 | BC WATER CO Kennewick | 34 | Yes |
| 19 | GOLF MHP Seattle | 32 | Yes |
| 20 | RIDGEVIEW ESTATES COMMUNITY ASSN. Freeland | 32 | Yes |
| 21 | HOT SPRINGS COURT Seattle | 30 | Yes |
| 22 | PENN COVE WATER AND SEWER DISTRICT Oak Harbor | 30 | Yes |
| 23 | SARATOGA WATER DISTRICT Coupeville | 30 | Yes |
| 24 | CAPE SAN JUAN WATER DISTRICT Friday Harbor | 29 | Yes |
| 25 | BEVERLY BEACH IMPROVEMENT CLUB Mount Vernon | 28 | Yes |
| 26 | PARKER SPRING ACRES WATER ASSOC Moses Lake | 27 | Yes |
| 27 | CAMPBELLS GLEN Coupeville | 26 | Yes |
| 28 | SIERRA COUNTRY CLUB Coupeville | 25 | Yes |
| 29 | SUNDANCE IMPROVEMENT ASSOCIATION Kennewick | 25 | Yes |
| 30 | RIVER VILLAGE MHP Seattle | 24 | Yes |
| 31 | COUNTRY CLUB ESTATES 521 Olympia | 24 | Yes |
| 32 | BADGER MOUNTAIN IRRIGATION DISTRICT Kennewick | 23 | Yes |
| 33 | TAMOSHAN Olympia | 23 | Yes |
| 34 | TOWNSHIP 29 WATER ASSOCIATION Mount Vernon | 22 | Yes |
| 35 | FAIRWAY NUMBER THREE WATER Friday Harbor | 22 | Yes |
| 36 | 5 CEDARS Deming | 21 | Yes |
| 37 | BEACHWOOD WATER COMPANY Coupeville | 21 | Yes |
| 38 | LISECC Lummi Island | 20 | Yes |
| 39 | GREATER BAR WATER DISTRICT Bridgeport | 19 | Yes |
| 40 | GOLDEN VALLEY WATER ASSN Quincy | 19 | Yes |
| 41 | TWO RIVERS RESORT Wellpinit | 18 | Yes |
| 42 | FALL CITY WATER DIST.(SPRING HILL) Fall City | 18 | Yes |
| 43 | OLYMPIC PARK TRAILER COURT Olympia | 17 | Yes |
| 44 | ROLLING HILLS-GLENCAIRN Oak Harbor | 17 | Yes |
| 45 | E.L.C. WATER SYSTEM Eastsound | 16 | Yes |
| 46 | EASTGATE Coupeville | 16 | Yes |
| 47 | CAMANO SUNSET WATER SYSTEM Mount Vernon | 16 | Yes |
| 48 | HIWAY TRAILER COURT Port Orchard | 16 | Yes |
| 49 | SURFSIDE HOMEOWNERS Ocean Park | 16 | Yes |
| 50 | RESERVATION ROAD Wellpinit | 15 | Yes |
Most Common Contaminants in Washington
| Contaminant | Violations | Systems Affected |
|---|---|---|
| Nitrate | 582 | 40 |
| Total Trihalomethanes (TTHM) | 427 | 37 |
| Barium | 415 | 32 |
| Arsenic | 403 | 37 |
| Fluoride | 266 | 43 |
| Haloacetic Acids (HAA5) | 218 | 17 |
| E. coli | 150 | 78 |
| Total Coliform (RTCR) | 60 | 18 |
| Combined Radium 226/228 | 48 | 26 |
| Manganese | 40 | 3 |
| Atrazine | 29 | 5 |
| Gross Alpha | 27 | 27 |
| Turbidity | 21 | 5 |
| Lead (Action Level) | 8 | 2 |
| Chloroform | 8 | 1 |
Cities with Water Quality Issues
Bothell Seattle Issaquah Kent Renton Vashon Arlington Bellingham Ferndale Lynden Monroe Mount Vernon Oak Harbor Silverdale Port Townsend Puyallup Poulsbo Tacoma Olympia Tumwater Chehalis Elma Shelton Westport Yelm Camas Longview Vancouver Woodland Moses Lake Quincy Yakima Selah Toppenish Colville Newport Northport Republic Usk Spokane +73 more
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About This Data
Water quality data is from the EPA Safe Drinking Water Information System (SDWIS). Health-based violations include Maximum Contaminant Level (MCL) and Treatment Technique (TT) violations. Only community water systems (CWS) in Washington are included.
Source: U.S. Environmental Protection Agency, SDWIS Federal Reporting Services U.S. Environmental Protection Agency, SDWIS Federal Reporting Services
Read our methodology - how this data is sourced, computed, and verified.