The ILRP was initiated to prevent agricultural runoff from impairing surface waters, and later included the addition of groundwater regulations. Runoff from irrigated lands can contain pollutants, such as pesticides, fertilizers, salts, and sediment, which can harm aquatic life or make water unusable for drinking water or agricultural uses. Waste discharge requirements (WDRs) address irrigated agricultural discharges to protect water quality.
The Central Valley Water Board adopted waste discharge requirements (WDRs) for discharges from irrigated lands to protect both surface and groundwater. The ILRP regulates such discharges within the jurisdiction of the Central Valley Water Board, which extends from the Oregon border south to the northernmost tip of Los Angeles County.
Waste Discharge Order for Sacramento River Watershed adopted 2/23/2023
https://www.waterboards.ca.gov/centralvalley/board...