PHILADELPHIA -- The U.S. Environmental Protection Agency has ordered three companies to address contaminated groundwater, sediment and riparian soils at the Westinghouse Electric Superfund site in Sharon.

The order, effective today, requires Viacom Inc., Winner Development LLC and AK Steel Corp. to:

   » Clean about 600 feet of the Wishart Court sewer of debris contaminated by low levels of polychlorinated biphenols (PCBs).