The U.S. Geological Survey assembles baseline data.
Although select research has been conducted on OWC transport to ground water, no information, however, was previously available on a national scale in the United States. The U.S. Geological Survey, as part of a continuing effort to collect baseline information on the occurrence of pharmaceuticals, hormones and other OWCs in water resources of the United States, collected and analyzed 72 ground water samples derived from two separate studies across 24 states and Puerto Rico during 2000 and 2001.