The exploding use of pesticides and synthetic fertilizer in post World War II agriculture generated an agricultural boom in California and throughout the US. Today seven of the top ten agricultural counties in the US are located in California and in 2010, California agriculture generated $37.5 billion in sales.
But that boom also created serious water quality problems that continue today. Runoff from agricultural fields washes pesticides, sediment and nutrients into our lakes, rivers and streams. DDT, Diedlrin, Diazonin, Malathion, Chlorpyrifos – many of these toxic chemicals have been banned for years, but are still present in our waterways. Small rural communities are disproportionately impacted because they lack the resources to treat or replace their water supply and because they are almost wholly dependent upon groundwater.
A report prepared for the State Water Board by the UC Davis Center for Watershed Sciences highlights the link between contaminated groundwater and agriculture. The report looks at two of the most impacted groundwater aquifers in the state and makes some troubling findings:
This is not the first report establishing the link between fertilizer use and groundwater contamination. However, little has been done to regulate agricultural pollution even though reported contamination has been increasing for decades. Agriculture is exempt from the federal Clean Water Act and, until recently, California agencies responsible for protecting water quality also gave agriculture pollution a pass.
That is about to change. In California, state and regional water boards are developing regulations that will reduce fertilizer use and protect both ground and surface water. The Central Coast Water Board adopted a program on March 15 that will require monitoring add protection of groundwater; the Central Valley will consider their first programs later this year.
It's time for a new agriculture, one that supports and sustains water quality for our communities
Best management practices need to be adopted on a large scale to protect community drinking water supplies. Regulation can help drive the technology and assistance programs needed to make these programs accessible to farmers.
Recent scientific reports show that applying current best management practices can reduce nitrogen pollution from farm and livestock operations by 30 percent to 50 percent. They include managing fertilizer timing, optimizing fertilizer use, and implementing wetlands, winter cover crops and streamside vegetation to soak up excess nitrogen.
State and Federal agencies need to resuscitate their assistance programs, including;