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 |
|---|---|---|---|---|
|
Psmcsd Springfield WS Monterey County |
200 | 1 | 0 | |
|
USA Petro Super Stop Tulare County |
200 | 1 | 0 | |
|
Welcome Grange Hall Napa County |
200 | 1 | 0 | |
|
Colonial Oak WC INC Monterey County |
198 | 2 | 1 | |
|
Alpine Acres Mutual Water CO Tuolumne County |
195 | 3 | 0 | |
|
Monte Vista Farming Denair · Stanislaus County |
188 | 3 | 2 | |
|
Pauma Valley Water Company San Diego County |
185 | 5 | 2 | |
|
Marina Landfill WS Monterey County |
180 | 1 | 0 | |
|
Marble Quarry Resort Tuolumne County |
176 | 1 | 0 | |
|
Jesuit Retreat Center of the Sierra Placer County |
175 | 1 | 0 | |
|
Struve RD WS #02 Monterey County |
166 | 1 | 0 | |
|
San Joaquin Estates Mutual Water Company Kern County |
165 | 2 | 0 | |
|
Sugar Pine RV Resort Tuolumne County |
160 | 2 | 0 | |
|
MK Properties Fresno County |
156 | 1 | 0 | |
|
Shadow Hills RV Resort Riverside County |
156 | 1 | 0 | |
|
Kashia County |
153 | 7 | 0 | |
|
Donner Mine Camp INC Nevada County |
151 | 2 | 0 | |
|
Hidden Falls Girl Scout Camp Santa Cruz County |
151 | 1 | 0 | |
|
Baker Ranch Water Corp Placer County |
150 | 3 | 1 | |
|
Foster Road Mutual Water Company Santa Barbara County |
150 | 4 | 0 | |
|
Grindstone Rancheria County |
150 | 9 | 4 | |
|
Hines Nurseries Winters North Solano County |
150 | 2 | 1 | |
|
Jess Martin County Park San Diego County |
150 | 1 | 0 | |
|
Kingdom Hall of Jehovah's Witnesses, Ber Placer County |
150 | 1 | 0 | |
|
Lifebridge Community Church Madera County |
150 | 1 | 0 | |
|
Nelson's Grove Yolo County |
150 | 1 | 0 | |
|
Pipi Campground Water System El Dorado County |
150 | 1 | 0 | |
|
Skyline Park Napa County |
150 | 1 | 0 | |
|
Wolf Creek Campground El Dorado County |
150 | 1 | 0 | |
|
Vallecito County Park San Diego County |
145 | 1 | 0 | |
|
Northshore RV Resort INC San Bernardino County |
140 | 2 | 0 | |
|
Round Valley Hidden Oaks Casino and Restaurant County |
137 | 6 | 2 | |
|
Valley View Trailer Park Riverside County |
135 | 2 | 1 | |
|
Kern Valley Mutual Water Company Kern County |
132 | 4 | 3 | |
|
Old River Mutual Water Company Kern County |
130 | 3 | 0 | |
|
Valley Creek MHP WS Monterey County |
129 | 1 | 0 | |
|
Grover Landscape Water System Stanislaus County |
125 | 2 | 1 | |
|
Lazy B Mobilehome Park Stanislaus County |
125 | 1 | 0 | |
|
Legacy Packing and Cold Storage Tulare County |
125 | 3 | 0 | |
|
Madera Hispanic Church Madera · Madera County |
125 | 1 | 0 | |
|
Matsuda's by Green Acres, LLC Sacramento County |
125 | 3 | 0 | |
|
Peters Fruit Farms, INC Tulare County |
125 | 1 | 0 | |
|
Cdfa-Mountain Pass Jpoe Ais San Bernardino County |
123 | 1 | 0 | |
|
Oak Knolls Mutual Water Company Kern County |
123 | 2 | 1 | |
|
Sierra View JR Academy Tulare County |
121 | 2 | 0 | |
|
Cold Spring Tavern Santa Barbara County |
120 | 2 | 0 | |
|
Fort Independence Fort Independence Reservation · County |
120 | 5 | 3 | |
|
Madonna Inn Water Company San Luis Obispo County |
120 | 3 | 1 | |
|
New Auberry Water Association Fresno County |
120 | 3 | 1 | |
|
Pedrick Produce Solano County |
120 | 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.