Seattle Water Quality
Washington
The tap water in Seattle, Washington is served by 15 EPA-regulated water systems covering approximately 1,161,399 people. 98 health-based violations are on record, most recently for 1040 in 2025. Data source: EPA Safe Drinking Water Information System.
Drinking water in Seattle, Washington is delivered through 15 EPA-regulated community water systems serving an estimated 1,161,399 people. Each system is tracked in the EPA Safe Drinking Water Information System (SDWIS) under the Safe Drinking Water Act, which requires testing for regulated contaminants, consumer notification of violations, and publication of an annual Consumer Confidence Report.
The SDWIS record for Seattle shows 98 total violations across all 15 systems, of which 98 are health-based, meaning either a Maximum Contaminant Level (MCL) was exceeded or a required treatment technique was not followed. Contaminants cited in health-based violations include 1040, 1025, 1005, 8000, 0700 and 2 others. 34 TRI-reporting industrial facilities are also located within the city limits.
A past EPA violation does not mean the water is currently unsafe, utilities are required to notify customers and remediate under state primacy oversight. For current water-quality status and treatment practices, review your local utility's most recent Consumer Confidence Report or contact the Washington drinking water program. All records above reflect federal EPA SDWIS data and are not independently verified against state databases.
Community Water Systems
| System Name | Pop. Served | Violations | Status |
|---|---|---|---|
| SEATTLE PUBLIC UTILITIES | 1,091,904 | 3 | Health |
| KING COUNTY WATER DISTRICT #20 | 38,974 | 0 | Clean |
| KING COUNTY WATER DISTRICT #125 | 17,546 | 0 | Clean |
| SKYWAY WATER & SEWER | 12,036 | 0 | Clean |
| Ravenwing Ranch | 250 | 0 | Clean |
| VALLEY MOBILE HOME PARK | 120 | 0 | Clean |
| CHERRYWOOD MOBILE HOME MANOR | 120 | 0 | Clean |
| COUNTRY HOMES MOBILE PARK | 90 | 0 | Clean |
| HIDDEN VILLAGE MHP, LLC | 66 | 2 | Health |
| MONTIPARK LLC | 60 | 6 | Health |
| GOLF MHP | 60 | 32 | Health |
| HOT SPRINGS COURT | 55 | 30 | Health |
| BRUNSWICK HILLS MHP | 50 | 1 | Health |
| RIVER VILLAGE MHP | 40 | 24 | Health |
| Majestic Oaks Water System | 28 | 0 | Clean |
Does this city have health-based water violations?
Health-based violations indicate contaminant levels that exceeded EPA maximum contaminant levels (MCLs). This does not necessarily mean water is currently unsafe.
| Contaminant | Begin Date |
|---|---|
| 1040 | 2025-09-01 |
| 1025 | 2025-07-01 |
| 1040 | 2025-06-01 |
| 1040 | 2025-06-01 |
| 1005 | 2025-04-01 |
| 1005 | 2025-04-01 |
| 1025 | 2025-04-01 |
| 1040 | 2025-03-01 |
| 1040 | 2025-03-01 |
| 1040 | 2025-02-01 |
| 1040 | 2025-02-01 |
| 1040 | 2025-01-01 |
| 1040 | 2025-01-01 |
| 1025 | 2025-01-01 |
| 1040 | 2024-12-01 |
| 1040 | 2024-12-01 |
| 1040 | 2024-11-01 |
| 1040 | 2024-11-01 |
| 1040 | 2024-10-01 |
| 1040 | 2024-10-01 |
| 1025 | 2024-10-01 |
| 1025 | 2024-10-01 |
| 1040 | 2024-09-01 |
| 1040 | 2024-09-01 |
| 1040 | 2024-09-01 |
| 1040 | 2024-09-01 |
| 8000 | 2024-07-01 |
| 8000 | 2024-07-01 |
| 8000 | 2024-07-01 |
| 1025 | 2024-07-01 |
| 1025 | 2024-07-01 |
| 1025 | 2024-04-01 |
| 1025 | 2024-04-01 |
| 1040 | 2024-02-01 |
| 1040 | 2024-02-01 |
| 1025 | 2024-01-01 |
| 1025 | 2024-01-01 |
| 1025 | 2023-10-01 |
| 1025 | 2023-10-01 |
| 1040 | 2023-08-01 |
| 1040 | 2023-08-01 |
| 1040 | 2023-08-01 |
| 8000 | 2023-07-28 |
| 8000 | 2023-07-28 |
| 1040 | 2023-04-01 |
| 1040 | 2023-04-01 |
| 1040 | 2023-04-01 |
| 1025 | 2023-01-01 |
| 1025 | 2023-01-01 |
| 0700 | 2022-12-24 |
TRI Facilities in Seattle
| Facility | Total Releases |
|---|---|
| Nucor Steel Seattle Inc | 2.4M lbs |
| Emerald Services Inc. | 1.7M lbs |
| Magnetic & Penetrant Services Co/mapsco | 136.0K lbs |
| Puget Sound Coatings | 117.4K lbs |
| Asko Processing Inc | 79.3K lbs |
| Sound Propeller Services Inc | 29.1K lbs |
| Boeing Commercial Airplane Group North Boeing Field | 24.3K lbs |
| Shell Seattle Distribution Terminal | 23.9K lbs |
| Rudd Co Inc | 20.5K lbs |
| Vigor Shipyards Inc-Seattle | 20.3K lbs |
Frequently Asked Questions
Is Seattle, Washington water safe to drink? ▼
How many water violations does Seattle have? ▼
What contaminants were found in Seattle water? ▼
How many water systems serve Seattle? ▼
Where does Seattle get its drinking water? ▼
Are there pollution sources near Seattle? ▼
About This Data
Water system data comes from the EPA's Safe Drinking Water Information System (SDWIS). Violations are reported by state agencies to EPA and include both health-based (MCL exceedances) and monitoring/reporting violations.
A reported violation does not necessarily mean water is currently unsafe to drink. Many violations are resolved quickly, and public water systems are required to notify customers of significant issues. For current water quality, contact your local water utility.
TRI facility data comes from the EPA Toxic Release Inventory. Facilities shown are those that self-report to the TRI program. PlainEnviro presents this data without advocacy framing.
Read our methodology - how this data is sourced, computed, and verified.