zone priority map

Priority 1
Groundwater Basins for Nitrate Management
Kaweah Turlock
Chowchilla Tule
Modesto Kings

The Nitrate Problem

Many small communities in the Central Valley rely on groundwater for drinking water. Some communities can’t safely use groundwater for drinking water as nitrate levels present a potential for human health impacts. Learn more about the potential human health impacts from nitrate here.

The Nitrate Control Program has three goals:

1. Provide safe drinking water supplies.

2. Reduce nitrate impacts to water supplies.

3. Restore groundwater quality, where reasonable and feasible.

The Central Valley Regional Water Quality Control Board (Central Valley Water Board) will implement regulations to achieve these goals first in six Priority 1 groundwater basins (see table), beginning in 2020. Once the implementation schedule for the Priority 1 groundwater basins is developed, it will be added here.

A Notice to Comply will be issued within 2 to 4 years of approval of the Nitrate Control Program—between late 2022 and late 2024—for Priority 2 Groundwater Basins, which include Yolo, Merced, Kern County (west side south), Tulare Lake, Kern County (Peso), Delta Mendota, Eastern San Joaquin, and Madera.