The New York Times

By CHARLES DUHIGG and JANET ROBERTS

Published: February 28, 2010

"About 117 million Americans get their drinking water from sources fed by waters that are vulnerable to exclusion from the Clean Water Act, according to E.P.A. reports.

The E.P.A. said in a statement that it did not automatically concede that any significant water body was outside the authority of the Clean Water Act. “Jurisdictional determinations must be made on a case-by-case basis,” the agency wrote. Officials added that they believed that even many streams that go dry for long periods were within the act’s jurisdiction.

But midlevel E.P.A. officials said that internal studies indicated that as many as 45 percent of major polluters might be either outside regulatory reach or in areas where proving jurisdiction is overwhelmingly difficult." More>>>>