Skagit County, Washington: drinking water report. Skagit County in northwestern Washington has about 131,000 residents, with Mount Vernon and Burlington as…
Skagit County in northwestern Washington has about 131,000 residents, with Mount Vernon and Burlington as the main communities. The Skagit River – the largest river flowing into Puget Sound – provides the primary water source through the Skagit PUD and municipal systems. The county's agricultural Skagit Valley (tulip fields, berry farms, dairy) and the refineries at March Point create a dual industrial-agricultural water quality environment.
The Skagit River produces exceptionally clean water, fed by Cascade snowmelt and rainfall in a largely forested watershed. According to Washington DOE's 2024 water quality assessment, the river at the Mount Vernon intake meets all standards with wide margins. The river's volume and clean headwaters dilute any agricultural inputs from the valley floor.
The March Point refineries (Marathon and Shell Puget Sound Refinery) operate on the Fidalgo Bay shore. While refinery operations primarily affect marine water quality, the Skagit County airport at Burlington has documented AFFF use. Washington DOE's 2024 PFAS investigation found PFOS at 7 ppt in monitoring wells near the airport.
Skagit County benefits from one of the cleanest river water sources in the Puget Sound region. The mountain-fed Skagit River starts from a position of strength, and treatment adds to that foundation. Household filtration is beneficial but less urgent here than in many other counties.
Check your water for data at your address. A carbon filter addresses chlorine taste from treatment. For additional protection including trace PFAS, reverse osmosis goes further. Our water filter guide covers both approaches. Pull your detailed report for local data, and visit our Washington page for statewide data.
Drinking water is one exposure route. These federal datasets also cover Skagit County, WA.
The EPA places Skagit County, WA in Zone 3 - the EPA's lowest-risk category, with a predicted average indoor radon level below 2 pCi/L. Zone maps predict an area's radon potential from geology and existing indoor readings; they say nothing about a specific house. Testing is the only way to know your own level.
45% of homes in Skagit County, WA were built before 1980, and 17% before 1950. Residential lead paint was banned in 1978, so housing age is the strongest available proxy for lead-paint exposure. This describes the county's housing stock, not any one home.
Modelled annual fine-particle pollution (PM2.5) in Skagit County, WA averages 7.1 µg/m³, within the EPA's annual standard of 9 µg/m³. These are CDC modelled county estimates rather than readings from a specific monitor.
How radon zones work · Air quality by county · Lead exposure guide
Across 64 public water systems serving Skagit County, WA with EPA lead testing on record, 2 (3.1%) reported a 90th-percentile lead result above the EPA's 15 ppb action level, and the median is 2.9 ppb. 11 water systems serving Skagit County, WA carry a health-based EPA Safe Drinking Water Act violation.
| Most-cited violation type | Systems affected |
|---|---|
| Total Trihalomethanes (TTHM) | 5 |
| Revised Total Coliform Rule | 3 |
| Arsenic | 2 |
| Lead and Copper Rule | 1 |
| Haloacetic Acids (HAA5) | 1 |
Source: EPA Lead and Copper Rule 90th-percentile tap sampling and EPA SDWIS Safe Drinking Water Act enforcement records, aggregated from the public water systems serving this county. Figures are counts of water systems, not a test of any individual home or tap.