In March 2019, Clover Flat Land Fill spilled 40,000 gallons of leachate into nearby streams, which are tributaries of the Napa River, Haley said in a news release. Leachate is a liquid created when water runs through the waste in a landfill. Investigators looking into the spill also uncovered other alleged violations, including a road built through what had been a stream and the unauthorized removal of trees and other vegetation, according to prosecutors.