Water is a currency in California, and the low-income farmworkers who pick the Central Valley’s crops know it better than anyone. They labor in the region’s endless orchards, made possible by sophisticated irrigation systems, but at home their faucets spew toxic water tainted by arsenic and fertilizer chemicals. “Clean water flows toward power and money,” said Susana De Anda, a longtime water-rights organizer in the region. She is the daughter of lechugueros who worked in lettuce fields and helped make California one of the agricultural capitals of the world. “Homes, schools and clinics are supposed to be the safest places to go. But not in our world.”