"The high water and swift current carries raw sewage from overburdened treatment plants, animal waste and pesticides from farm fields, and spilled fuel," AP's Jim Salter reports. "Contaminated water can carry bacteria such as E. coli that can cause gastrointestinal illness, reproductive problems and neurological disorders, according to the Centers for Disease Control and Prevention. Infants, young children, pregnant women, elderly people, and people with compromised immune systems are particularly vulnerable."
According the National Ground Water Association, the 1.1 million private wells at risk span 300 counties in Illinois, Indiana, Iowa, Kansas, Kentucky, Missouri, Minnesota, Nebraska, Wisconsin, and South Dakota. The National Weather Service warned that the threat could persist well into spring because of upcoming snowmelt in northern states.
The flooding could also cause some Superfund sites to leach contaminants that could get into local water supplies. The Environmental Protection Agency is assessing two such sites for groundwater contamination: the Nebraska Ordnance Plant in Mead, and the Conservation Chemical Corp. in Kansas City, Mo. "The Mead site operated as a munitions plant from 1942 to 1956 and its disposal of radioactive waste and other chemicals led to groundwater contamination. The EPA says it has not found evidence that any hazardous contaminants were released by the flooding" but will "evaluate the sites further as floodwaters recede," AP reports.