Kitsap County, Washington: drinking water report. Kitsap County occupies a peninsula in Puget Sound with a population of about 275,000.
Kitsap County occupies a peninsula in Puget Sound with a population of about 275,000. The county is defined by its military presence – Naval Base Kitsap (which includes the former Bremerton Naval Shipyard and Bangor submarine base) is one of the largest naval installations in the country. Water comes from a combination of local surface sources, groundwater wells, and the Tacoma-supplied system that crosses the Narrows. Multiple water districts serve different parts of the county.
Naval Base Kitsap is a confirmed PFAS contamination source. The Navy has documented AFFF use at both the Bremerton and Bangor facilities, and groundwater monitoring has detected PFAS compounds at concentrations exceeding EPA health advisory levels. According to the Washington Department of Ecology's 2024 PFAS investigation report, six groundwater monitoring wells near the Bremerton shipyard showed PFOS levels above 70 ppt.
Beyond PFAS, the shipyard's industrial history includes heavy metals, solvents, and petroleum products that have contaminated sediment and groundwater in the Sinclair Inlet area. Washington's PFAS action levels of 10 ppt for individual compounds are stricter than federal MCLs, meaning Kitsap County systems face earlier regulatory triggers than they would in most other states.
Military-adjacent communities in Kitsap County face PFAS exposure risk that varies with proximity and groundwater flow direction. The Navy has provided bottled water and treatment systems to some affected properties, but not all areas have been fully characterized.
Check your water to see monitoring data for your specific water district. For PFAS, reverse osmosis is the gold standard for household treatment. Our water filter guide identifies which systems meet the removal thresholds needed for military-grade contamination. Pull your detailed report for historical data, and visit our Washington page for statewide patterns.
Drinking water is one exposure route. These federal datasets also cover Kitsap County, WA.
The EPA places Kitsap 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.
41% of homes in Kitsap County, WA were built before 1980, and 13% 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 Kitsap County, WA averages 6.9 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