"The eight-state commission that sets water quality standards for the Ohio River wants a two-year delay on enforcement of a more stringent mercury standard while it considers relaxing those rules."

"The Ohio River Valley Water Sanitation Commission needs more time to look into the potential implications of its decision a decade ago to eliminate “mixing zones” for pollutants such as mercury that concentrate in the environment, said the commission’s executive director, Peter Tennant.

Mixing zones rely on dilution to minimize pollution’s effects."
 
James Bruggers reports for the Louisville Courier-Journal September 6, 2013. [2]