Seattle Water Quality
Washington
According to EPA SDWIS, Seattle, Washington is served by 16 community water systems covering about 1,245,539 people. The same extract lists 119 health-based violation records, most recently coded 8000 in 2025. Counts are historical EPA registry rows, not a current compliance or drinkability score.
Drinking water in Seattle, Washington is delivered through 16 EPA-regulated community water systems serving an estimated 1,245,539 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.
PlainEnviro's health-based SDWIS extract shows 119 violation records across the 16 active community systems shown here. Monitoring and reporting records are not present in the extract. The records carry 7 distinct EPA contaminant codes: Revised Total Coliform Rule, Nitrate, Arsenic, Fluoride, Groundwater Rule and 2 others. 34 TRI-reporting industrial facilities are also located within the city limits.
A past EPA health-based registry row does not describe water delivered today or current compliance status; utilities notify customers and remediate under state primacy oversight when required. 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 | 1,161,961 | 4 | Health |
| KING COUNTY WATER DISTRICT #20 | 48,469 | 0 | Clean |
| KING COUNTY WATER DISTRICT #125 | 21,904 | 0 | Clean |
| SKYWAY WATER & SEWER | 12,036 | 0 | Clean |
| Ravenwing Ranch | 250 | 0 | Clean |
| PCM ARIA MARION LLC | 230 | 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 | 41 | Health |
| HOT SPRINGS COURT | 55 | 40 | Health |
| BRUNSWICK HILLS MHP | 50 | 1 | Health |
| RIVER VILLAGE MHP | 40 | 25 | Health |
| Majestic Oaks Water System | 28 | 0 | Clean |
Does this city have health-based water violations?
These health-based records can represent Maximum Contaminant Level (MCL), Treatment Technique (TT), or Maximum Residual Disinfectant Level (MRDL) categories. A historical record does not establish that water is currently unsafe.
| Water system | Contaminant | Begin Date |
|---|---|---|
| RIVER VILLAGE MHP | Revised Total Coliform Rule | 2025-12-28 |
| GOLF MHP | Nitrate | 2025-12-01 |
| GOLF MHP | Nitrate | 2025-11-01 |
| GOLF MHP | Nitrate | 2025-10-01 |
| GOLF MHP | Arsenic | 2025-10-01 |
| HOT SPRINGS COURT | Fluoride | 2025-10-01 |
| GOLF MHP | Nitrate | 2025-09-01 |
| GOLF MHP | Nitrate | 2025-09-01 |
| GOLF MHP | Arsenic | 2025-07-01 |
| HOT SPRINGS COURT | Fluoride | 2025-07-01 |
| HOT SPRINGS COURT | Fluoride | 2025-07-01 |
| GOLF MHP | Nitrate | 2025-06-01 |
| GOLF MHP | Nitrate | 2025-06-01 |
| GOLF MHP | Arsenic | 2025-04-01 |
| GOLF MHP | Arsenic | 2025-04-01 |
| HOT SPRINGS COURT | Fluoride | 2025-04-01 |
| GOLF MHP | Nitrate | 2025-03-01 |
| GOLF MHP | Nitrate | 2025-03-01 |
| GOLF MHP | Nitrate | 2025-02-01 |
| GOLF MHP | Nitrate | 2025-02-01 |
| GOLF MHP | Nitrate | 2025-01-01 |
| GOLF MHP | Nitrate | 2025-01-01 |
| HOT SPRINGS COURT | Fluoride | 2025-01-01 |
| GOLF MHP | Nitrate | 2024-12-01 |
| GOLF MHP | Nitrate | 2024-12-01 |
| GOLF MHP | Nitrate | 2024-12-01 |
| GOLF MHP | Nitrate | 2024-11-01 |
| GOLF MHP | Nitrate | 2024-11-01 |
| GOLF MHP | Nitrate | 2024-11-01 |
| GOLF MHP | Nitrate | 2024-10-01 |
| GOLF MHP | Nitrate | 2024-10-01 |
| GOLF MHP | Nitrate | 2024-10-01 |
| HOT SPRINGS COURT | Fluoride | 2024-10-01 |
| HOT SPRINGS COURT | Fluoride | 2024-10-01 |
| HOT SPRINGS COURT | Fluoride | 2024-10-01 |
| GOLF MHP | Nitrate | 2024-09-01 |
| GOLF MHP | Nitrate | 2024-09-01 |
| GOLF MHP | Nitrate | 2024-09-01 |
| GOLF MHP | Nitrate | 2024-09-01 |
| RIVER VILLAGE MHP | Revised Total Coliform Rule | 2024-07-01 |
| RIVER VILLAGE MHP | Revised Total Coliform Rule | 2024-07-01 |
| RIVER VILLAGE MHP | Revised Total Coliform Rule | 2024-07-01 |
| HOT SPRINGS COURT | Fluoride | 2024-07-01 |
| HOT SPRINGS COURT | Fluoride | 2024-07-01 |
| HOT SPRINGS COURT | Fluoride | 2024-04-01 |
| HOT SPRINGS COURT | Fluoride | 2024-04-01 |
| GOLF MHP | Nitrate | 2024-02-01 |
| GOLF MHP | Nitrate | 2024-02-01 |
| HOT SPRINGS COURT | Fluoride | 2024-01-01 |
| HOT SPRINGS COURT | Fluoride | 2024-01-01 |
What are Seattle's health-based records for?
Seattle's health-based violation records carry 7 distinct EPA codes: some name a substance, others the drinking-water rule that was breached. Counts are records on file in the EPA SDWIS extract, not current test results.
| Contaminant | Records | Systems |
|---|---|---|
| Nitrate | 42 | 2 |
| Fluoride | 32 | 1 |
| Arsenic | 25 | 2 |
| Revised Total Coliform Rule | 10 | 3 |
| Groundwater Rule | 5 | 2 |
| Surface Water Treatment Rule | 4 | 1 |
| Lead and Copper Rule | 1 | 1 |
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
What does EPA SDWIS list for drinking water in Seattle, Washington? ▼
How many water violations does Seattle have in this EPA extract? ▼
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? ▼
How does Seattle compare in Washington?
Of the 365 Washington places with at least one community water system on file, Seattle ranks #33 by number of systems (16).
Either side of it: Stanwood (18), Woodland (18), Raymond (15), Walla Walla (15)
About This Data
Figures here are the current EPA SDWIS extract joined to the 16 community water systems whose service area lists Seattle, ranked against the 365 Washington places with at least one system on file. Data current as of 2026-08-25.
Water system data comes from the EPA's Safe Drinking Water Information System (SDWIS). PlainEnviro's violation fetch is restricted upstream to records EPA flags as health-based and then joined to active community water systems. Monitoring and reporting violations are not included.
A health-based violation row in this extract is a historical EPA registry entry. It does not describe water delivered today or current compliance status. Many records are later resolved, and public water systems notify customers when required. For current conditions, contact your local water utility or the state drinking water program.
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.