Congress should consider revising the Clean Water Act to address nonpoint sources of pollution, such as runoff from farms and urban areas, a report by the Government Accountability Office concludes. The report also recommends that EPA issue new regulations requiring landowners to reduce nonpoint sources of pollution. Currently, such pollution is addressed through voluntary efforts. GAO, the investigative arm of Congress, found that water-quality targets for point source pollution, such as discharges from factories, were met 83% of the time, but targets for nonpoint source pollution were achieved only 20% of the time. More than 40 years after passage of the modern Clean Water Act, many U.S. waters remain impaired, the report states.