The mercury released from a DuPont plant in Waynesboro is front and center for federal officials.
Officials plan to study the effects of the mercury that was released for two decades.
That study will quantify environmental damage caused by the toxic substance, which was discharged into the South River.
The Waynesboro plant used mercury as a catalyst in manufacturing processes from 1929 to 1950.
The mercury was found in soil at the plant in 1976 during a construction project.
The Virginia Department of Health issued a fish consumption advisory for portions of the South River in the 1970s. It is still in effect.