Groundwater Quality

Agricultural activities can affect ground water quality, especially in areas where the ground water is near the surface or where there are porous (sandy) soils. The issues include fertilizers, especially nitrates, as well as salinity leaching. A few particularly mobile pesticides have also been detected in ground water. It often takes years for a contaminant to find its way into ground water. Thus, care is necessary in vulnerable areas.

State regulations designate about 2.4 million acres across California where soil conditions make shallow ground water most vulnerable to contamination from leaching. As of June 2009, there are discussions underway to add ground water protection to the existing Irrigated Lands Program.  To determine the status of the ground water quality program by the Central Valley Regional Water Quality Control Board please click here. 

For some time California’s Department of Pesticide Regulation's has had a Groundwater Protection Program that limits the use of certain pesticides in more vulnerable regions of California. In 2009 DPR expanded the list of compounds included in the Ground water Protection Program. It is likely DPR’s efforts will be folded into the Regional Board’s program.