CHICAGO -- Several environmental groups want the Illinois Pollution Control Board to order Midwest Generation to clean up groundwater pollution that allegedly leached from coal-ash ponds at four of the company's power plants.

The Environmental Integrity Project and the Environmental Law & Policy Center filed a legal complaint with the board Wednesday on behalf of several environmental groups, alleging that groundwater at the utility's Joliet, Pekin, Romeoville and Waukegan plants is contaminated with toxic pollutants _ such as arsenic, boron and selenium _ in levels that exceed state and federal standards.