Groundwater is a natural resource of enormous value. Three-quarters of U.S. cities get their water supplies totally or in part from groundwater and more than half of all Americans rely on it for drinking water. Ninety percent of rural households have no source other than groundwater for drinking water supplies. A number of recent studies have documented the actual or potential contamination of our nation's groundwater on a wide scale. The purpose of the paper is to discuss the status of DWRD's research activities and to provide a state-of-the-art summary on the removal of organic contaminants from groundwater.