In the U.S. Justice Department’s largest environmental enforcement recovery ever, Kerr-McGee Corp. and its parent Anadarko Petroleum Corp. today agreed to pay $5.15 billion to settle charges that they fraudulently tried to duck responsibility to pay for environmental cleanup after decades of contamination.

“Kerr-McGee’s businesses all over this country left significant, lasting environmental damage in their wake,” Deputy Attorney General James Cole said in a written statement. “It tried to shed its responsibility for this environmental damage and stick the United States taxpayers with the huge cleanup bill.”