Stevens County, Washington: drinking water report. Stevens County stretches across northeastern Washington, where communities like Colville, Chewelah, and…
Stevens County stretches across northeastern Washington, where communities like Colville, Chewelah, and Kettle Falls draw water from a mix of sources including the Columbia River, the Colville River system, and numerous groundwater aquifers. This rural county relies heavily on smaller municipal systems and private wells, with many residents in unincorporated areas depending entirely on individual groundwater sources that may receive limited regulatory testing.
Northeastern Washington's geological conditions create specific water quality challenges that Stevens County shares with much of the region. The area's naturally occurring arsenic in groundwater affects multiple wells throughout the county, a pattern consistent across the Columbia Plateau and surrounding areas. Historic mining activity near communities like Colville and Northport adds legacy concerns about heavy metal contamination in localized water sources, though most municipal systems have implemented treatment to address these issues.
The county's reliance on small water systems presents monitoring challenges. Many of Stevens County's public water supplies serve fewer than 3,300 people, which means they fall outside the EPA's UCMR5 testing requirements for emerging contaminants like PFAS. While larger systems in places like Colville conduct regular testing under Safe Drinking Water Act standards, residents served by smaller utilities or private wells may lack recent data on their water quality. Washington State's voluntary PFAS testing program has identified detections in some eastern Washington communities, though comprehensive county-level data remains limited.
Seasonal variation affects water quality across Stevens County. Spring snowmelt can increase turbidity and pathogen risks in surface water sources, while summer drought conditions may concentrate contaminants in shallow wells. The county's agricultural areas, particularly around Chewelah and the Colville Valley, face typical rural concerns about nitrate contamination from fertilizer application and septic systems. Private well owners bear full responsibility for testing and treatment, yet many go years between water quality assessments.
If you receive water from a municipal system, request the most recent Consumer Confidence Report to understand what's been detected and at what levels. Private well owners should test annually for bacteria and nitrates at minimum, with periodic testing for arsenic and metals given the county's geology. Check your water to see current contamination data for your area, review our water filter guide to find treatment systems suited to Stevens County's specific contaminant profile, or get a detailed report with testing recommendations for your location. For broader context on Washington's water challenges, visit our state page.
Drinking water is one exposure route. These federal datasets also cover Stevens County, WA.
The EPA places Stevens County, WA in Zone 1 - the EPA's highest-risk category, where the predicted average indoor radon level is above 4 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.
44% of homes in Stevens County, WA were built before 1980, and 12% 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 Stevens County, WA averages 8.4 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
29 public water systems serving Stevens County, WA have EPA lead testing on record. The reported lead sample skews toward systems that already flagged a problem, so its exceedance rate is not directly comparable with other areas. 4 water systems serving Stevens County, WA carry a health-based EPA Safe Drinking Water Act violation.
| Most-cited violation type | Systems affected |
|---|---|
| Revised Total Coliform Rule | 2 |
| Arsenic | 1 |
| Nitrate | 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.