Across the U.S., drinking water systems serving millions of people fail to meet state and federal safety standards. Millions more Americans may be drinking unsafe water without anyone knowing because limits set by the U.S. Environmental Protection Agency (EPA) are too high, the contaminants it contains are unregulated, or their drinking water source is too small to fit under EPA regulations. The nitrate and disinfection by-products that worry Ramos represent a fraction of the many chemical and biological pollutants that find their way into drinking water systems through agricultural runoff, discharges from industry, aging pipes and all the stuff that flush down our toilets, sinks, showers and washing machines. From coast to coast, people are starting to recognize the pervasiveness of potential problems and rally around efforts to make drinking water safe for all.