The Denver Post reports that Federal officials in Commerce City, Colorado are trying to contain contamination in the South Platte River near one of Suncor Energy's refineries.
What material is leaking and where it is actually coming from is still to be determined. The EPA has emergency response crew working on the scene.
Booms and barriers have been set up to contain the spill, which was first reported on Sunday.
Commerce City, Colorado is a 93,000-barrel-per-day refinery produces gasoline, diesel fuel and paving-grade asphalt.
Suncor Energy is an integrated energy company based in Calgary, Alberta, that specializes in production of synthetic crude from oil sands. On the Forbes Global 2000 list of top public companies in the world, Suncor ranks 159.