Thomas Harter, leading groundwater scientist at the University of California at Davis, believes nitrates may come from animal manure, but also suggests fertilizers as a contributor. Farmers are being blamed with no proof, Tulare County Supervisor Allen Ishida, a longtime citrus grower near Lindsay, told Grossi. "If it's my fertilizers that are causing this problem, then we'll adapt," Ishida said, welcoming a full investigation of nitrate sources.
California has regulations in place to prevent overloading the soil and crops with waste and Tulare County regulates the placement of dairies, Grossi reports. With only nine state inspectors overseeing 1,400 dairies in the San Joaquin and Sacramento valleys many dairy owners inspect and report on their own operations, making many activists question adequate enforcement of these rules. (Read more)