Nitrate violations in Washington
452 active public water systems in Washington had a Nitrate violation in the past three years, 15 of them still unresolved. What Nitrate is and why it matters.
Systems with a Nitrate violation
Unresolved first, then largest first| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Basin City Water Sewer District Franklin County |
1,740 | 5 | 0 | |
|
Delta Water Association Whatcom County |
450 | 1 | 0 | |
|
Parker Spring Acres Water Assoc Grant County |
255 | 1 | 0 | |
|
Grove Terrace MHP Two LLC Grant County |
220 | 1 | 0 | |
|
Martell Mobile Manor Kitsap County |
143 | 2 | 0 | |
|
Sundance Improvement Association Benton County |
100 | 2 | 0 | |
|
Eddie Farms Dairy Site Benton County |
96 | 1 | 0 | |
|
Westbourne Acres Walla Walla County |
94 | 4 | 0 | |
|
Pro Pac Sales LLC Walla Walla County |
60 | 1 | 0 | |
|
Alamo Orchard CO Pateros Okanogan County |
48 | 2 | 0 | |
|
Afc Ranch 5 Douglas County |
40 | 1 | 0 | |
|
Badger Canyon Water Assn Benton County |
40 | 1 | 0 | |
|
Pepperfield Village Wapato · County |
40 | 3 | 1 | |
|
Grandview Farms Pasco Dodd Rd Walla Walla County |
32 | 1 | 0 | |
|
Four Seasons Campground Adams County |
15 | 2 | 0 | |
|
Pasco Water Department Franklin County |
115,102 | 2 | 0 | |
|
Auburn City of King County |
107,655 | 1 | 0 | |
|
Walla Walla Water Division Walla Walla County |
42,959 | 1 | 0 | |
|
Camas Municipal Water Sewer System Clark County |
31,794 | 2 | 0 | |
|
Pullman Water Department City of Whitman County |
31,315 | 3 | 0 | |
|
Whitworth Water District 2 Spokane County |
26,883 | 1 | 0 | |
|
Ellensburg Water Dept Kittitas County |
20,900 | 1 | 0 | |
|
Cheney City of Spokane County |
16,954 | 1 | 0 | |
|
Leavenworth City of Chelan County |
11,041 | 1 | 0 | |
|
Orting City of Pierce County |
10,332 | 2 | 0 | |
|
Yak CO Terrace Heights Yakima County |
8,410 | 3 | 0 | |
|
Prosser City of Benton County |
8,030 | 1 | 0 | |
|
Deer Park City of Spokane County |
5,435 | 3 | 0 | |
|
Spokane Business & Industrial Park Spokane County |
5,000 | 1 | 0 | |
|
Longmire Pierce County |
4,871 | 3 | 0 | |
|
Trentwood Irrigation District 3 Spokane County |
4,228 | 3 | 0 | |
|
White Salmon City of Klickitat County |
4,077 | 3 | 0 | |
|
Brewster City of Okanogan County |
3,843 | 1 | 0 | |
|
Lummi Tribal Water District Ferndale · County |
3,699 | 8 | 3 | |
|
Newport City of Pend Oreille County |
3,331 | 4 | 0 | |
|
Nisqually-Leschi & West Nisqually Olympia · County |
3,200 | 7 | 0 | |
|
Schrag Eb/wb Rest Areas Adams County |
3,096 | 1 | 0 | |
|
Stevens CO Pud Deer Lake Stevens County |
2,884 | 1 | 0 | |
|
Alpine Water District Chelan County |
2,255 | 3 | 1 | |
|
Darrington Town of Snohomish County |
2,246 | 1 | 0 | |
|
Hurricane Ridge Clallam County |
2,221 | 1 | 0 | |
|
Sunnyslope Kitsap County |
2,112 | 1 | 0 | |
|
Waitsburg City of Walla Walla County |
1,817 | 1 | 0 | |
|
Camano Island State Park Island County |
1,718 | 2 | 0 | |
|
Maxwelton Water System Island County |
1,700 | 3 | 0 | |
|
Scott Lake Thurston County |
1,604 | 1 | 0 | |
|
Tapps Island Water System Pierce County |
1,501 | 4 | 1 | |
|
Squaxin Consolidated Shelton · County |
1,500 | 6 | 1 | |
|
Winthrop Town of Okanogan County |
1,350 | 4 | 0 | |
|
Diamond Lake Water & Sewer District Pend Oreille County |
1,299 | 1 | 0 |
About this data
A system is counted once if any of its violations in the past three years involved Nitrate, including monitoring and reporting lapses. Rules violated and status in the table are for the whole system, not Nitrate alone.
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.