Dr. William Hsu, Imperial County's director of Environmental Health, erects a sign warning people to stay out of dangerously polluted water in New River, about 200 yards from the Mexican border in Calexico, Calif., Nov. 14, 1978. Raw sewage pumped from across the border in the city of Mexicali flows into the U.S. and is believed to be responsible for a serious type of dysentery contracted by a 9-year-old California boy who recently spent three days in a coma. (AP Photo)