Hundreds of California’s municipal water supply systems rely on contaminated sources. Many such systems are in the San Joaquin Valley, home to over four million people – as well as some of the most productive farmland in the world. How is it possible that one of the richest states in the wealthiest and most powerful nation in the world, people still lack access to safe, clean and affordable drinking water in their homes? Meet activists, laborers, lawyers, and politicians all seeking solutions to the problem of this silent killer.