Nitrate violations in California
524 active public water systems in California had a Nitrate violation in the past three years, 41 of them in the latest quarter of EPA's data. What Nitrate is and why it matters.
Systems with a Nitrate violation
Latest quarter first, then largest first| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Hurkey Creek Riv. Co. Parks Riverside County |
756 | 1 | 0 | |
|
Kingdom Hall of Jehovah S Witnesses Fresno County |
720 | 1 | 0 | |
|
Cuyama Community Services District Santa Barbara County |
700 | 1 | 0 | |
|
MC Clellan MHP Sacramento County |
700 | 1 | 0 | |
|
Spartan Veterinary Services Riverside County |
700 | 1 | 0 | |
|
Edwards Afb Main Base Kern County |
661 | 2 | 0 | |
|
Del Oro Traver District Tulare County |
657 | 1 | 0 | |
|
Nepenthe WS Monterey County |
618 | 2 | 1 | |
|
Pleasant Valley Baptist Church Butte County |
600 | 2 | 1 | |
|
Stagecoach Trails RV Resort San Diego County |
600 | 2 | 0 | |
|
Usfs/vermillion Campground Fresno County |
575 | 1 | 0 | |
|
Bear River Lake Resort Amador County |
571 | 2 | 0 | |
|
Riverview Mobile Home Estates Stanislaus County |
540 | 2 | 0 | |
|
Deloro Valley Water System Tuolumne County |
528 | 2 | 0 | |
|
Santa Lucia Preserve WS Monterey County |
524 | 1 | 0 | |
|
Studios 6 Suites Madera County |
508 | 2 | 0 | |
|
Chico Eastside Little League Butte County |
500 | 1 | 0 | |
|
Crows Landing Comm Svc District Stanislaus County |
500 | 2 | 1 | |
|
Diaz Lake Campground Inyo County |
500 | 1 | 0 | |
|
Knoll Enterprises San Bernardino County |
500 | 6 | 2 | |
|
Lsid Tonyville Tulare County |
500 | 3 | 2 | |
|
Marysville Flea Market Yuba County |
500 | 1 | 0 | |
|
Millpond Recreation Area Inyo County |
500 | 1 | 0 | |
|
River Oak Grace-Water System Stanislaus County |
500 | 1 | 0 | |
|
Sierra Tahoe Grandview El Dorado County |
500 | 2 | 0 | |
|
Silver Lake Campground Amador County |
500 | 1 | 0 | |
|
Kennedy Grocery Riverside County |
458 | 1 | 0 | |
|
Cloverdale Mutual Water Co. Ventura County |
455 | 1 | 0 | |
|
Ceres Unified/westport School Stanislaus County |
450 | 2 | 0 | |
|
Son Shine Properties Kern County |
438 | 2 | 1 | |
|
Sunnyside Farms Mutual Water Company Los Angeles County |
436 | 3 | 1 | |
|
Usmc Housing Coleville Mono County |
424 | 3 | 0 | |
|
Round Valley Piner County |
409 | 5 | 1 | |
|
Forest Park Mwc San Bernardino County |
406 | 3 | 1 | |
|
Twin Lakes Resort San Diego County |
400 | 5 | 2 | |
|
Spring Creek Tract Association El Dorado County |
389 | 2 | 0 | |
|
Thomas Aquinas College Ventura County |
382 | 1 | 0 | |
|
Havasu Water Company County |
361 | 11 | 4 | |
|
Lake Morena Views Mwc San Diego County |
360 | 1 | 0 | |
|
Jehovah's Witnesses Church Reedley Fresno County |
330 | 2 | 0 | |
|
Washington Water District Nevada County |
330 | 3 | 1 | |
|
Twin Valley INC Santa Clara County |
317 | 1 | 0 | |
|
Aha Quin County |
315 | 3 | 2 | |
|
Shady Creek Outdoor School Nevada County |
315 | 2 | 0 | |
|
Toca Madera Winery Madera County |
310 | 1 | 0 | |
|
Newberry Springs Gas Station & Mini-Mart San Bernardino County |
306 | 1 | 0 | |
|
Huttopia Paradise Springs Los Angeles County |
302 | 1 | 0 | |
|
Lighthouse Trailer Resort San Bernardino County |
302 | 1 | 0 | |
|
Sun Pacific Tulare Tulare County |
301 | 4 | 2 | |
|
Barrett Lake MH and RV LLC San Diego County |
300 | 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 California 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.