Tapcensus

Water quality in Dayton, Washington

Dayton is in Columbia County. 12 active public water systems serve the county; 5 had an EPA violation in the past three years.

Most likely your provider

Dayton Water Department WA5318250 · Community water system · Ground water
Serves 3,374 people Rules violated, past 3 years 0 Last sanitary survey Jul 7, 2021 Distance under 0.1 mi

Your location is within the outer bounds of this system's EPA service area.

Other community water systems in Columbia County

1 systems, nearest first
SystemServesStatusRules violated, 3 yrDistance
Starbuck City of
147 1 15.6 mi
Non-community systems in Columbia County (10: schools, campgrounds, workplaces, restaurants)

These systems serve places you visit rather than homes.

SystemServesStatusRules violated, 3 yrUnresolved
Shangri-La Ranch Park
6 2 0
Lewis & Clark Trail State Park
239 0 0
Tucannon River Retreat
7 0 0
Camp Wooten State Park
131 0 0
Last Resort
22 1 0
Lyons Ferry Marina
54 2 0
Bluewood Ski Area
532 1 0
Little Goose Dam
62 0 0
Touchet Valley Baptist Camp
40 0 0
Columbia Pulp I
25 0 0
About this data

Water systems are matched to Columbia County, nearest to Dayton first. Your exact provider depends on your address and connection; the largest community water system in a county is usually the city or town utility. Distances are measured to the centre of the service area EPA publishes for the system.

Town locations and ZIP code areas come from U.S. Census Bureau 2020 files.

Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The Washington records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet. Retrieved from ECHO on Oct 11, 2026.