The battle in the Central Valley is just one of many happening against dairy farms and new manure digester projects in the state. Farmers say they are trying to be better neighbors.By Steven RodasPLANADA, Calif.—David Rodriguez learned to swim in the canals near his childhood home in the 1960s, back when orchards of figs, peaches and almonds encircled his neighborhood. Before the area around the small community of Planada exploded with dairy farms, he trusted the water that came out of his faucets.