INVESTIGATIONS BY THE EPA IN THE 1980'S AND 90'S ESTABLISHED THAT ELEVATED LEVELS OF CHROMIUM WERE PRESENT IN THE SOIL, GROUND WATER AND SURFACE WATER WITHIN AND ADJACENT TO THE SITE. IT WAS ALSO DETERMINED THAT A CONFIRMED PLUME WAS MOVING SOUTHEASTWARD TOWARD THE YELLOWSTONE RIVER. A THREAT TO THE PUBLIC HEALTH OR WELFARE OR THE ENVIRONMENT IS POSED BY THE SITE AND ADJACENT AREAS TO WHICH CHROMIUM CONTAMINATION HAS MIGRATED.