California has the largest agricultural economy in the nation, generating $34.8 billion in sales in 2009 [California Department of Food and Agriculture]. Nine of the top ten agricultural counties in the United States are located in California; six of them are in the 8-county San Joaquin Valley.

Our California program works with communities in the San Joaquin Valley that have contaminated drinking water. Most communities rely on groundwater for their drinking water supply. Throughout the Valley, extensive and ancient groundwater deposits are being depleted and contaminated with runoff from farms, dairies and other animal feeding operations, food processing plants, sewage and septic systems. In addition, naturally occurring contaminants like arsenic, manganese, and uranium also contaminate groundwater as a result of wasteful irrigation practices of agricultural operations.

Since World War II, chemicals (pesticides and fertilizer) have been heavily used to increase agricultural yield. As a result, the upper layers of the Valley's groundwater aquifers have become increasingly contaminated. Cities can afford to sink deep wells that pump older, clean groundwater; they can also blend different water sources, using dilution to reduce contamination. Smaller rural communities that often rely on just one or two wells for their entire supply are having more and more problems providing safe and affordable drinking water to their residents.