A hazardous waste site in Indianapolis could be added to the federal Superfund program's priority list that speeds along investigations of contamination sources and eventual cleanups.
The U.S. Environmental Protection Agency proposed Wednesday adding the Riverside Ground Water Contamination site and seven other sites around the nation to its priority list.
The EPA said those sites have known or threatened hazardous wastes that could pose public health and environmental threats.
The Indianapolis site is a ground water plume at the northern end of the Fall Creek/White River confluence that's tainted with vinyl chloride and trichloroethene.
The exact boundaries of the area have not been defined by EPA, but are expected to include Citizens Energy Group's Riverside Wellfield on Riverside Drive and the White River Wellfield on 16th and Aqueduct Streets.
The plume has contaminated five wells in two municipal well fields. Water from those tainted wells is blended with other well sources to lower contamination levels. The contaminated well fields provide water to about 55,000 residents in Indianapolis.
Citizens Energy said it has 19 groundwater production wells in the Riverside and White River Wellfields that are used to supplement surface water supplied to the White River Treatment Plant. About 85 percent of water supplied annually to the White River Treatment Plant is surface water and the remaining 15 percent is groundwater.
The site's contamination's source hasn't been determined, but the Indiana Department of Environmental Management has identified more than 160 active and former facilities that could be contributing to the contamination, 12 of which are known to have chlorinated solvent releases in the area. An investigation into the origin of the contaminants is ongoing, the EPA said.
Citizens said it is treating the drinking water and has been meeting all EPA requirements under the Safe Drinking Water Act.
“Water produced by Citizens Energy Group meets all state and federal safety standards and the environmental work provided through the Superfund Program will help ensure continued water safety and quality,” IDEM said in a written statement.
Citizens and the IDEM also announced Wednesday that testing has confirmed that drinking water produced at all of the utility’s treatment plants is safe and in compliance with the rigorous standards of the Safe Water Drinking Act.