[for use IF KOCH SIGNS for ATC tonight at 5:20. I will write alternate version for use if Koch does NOT sign by 5:20.] The Koch Refining Company and officials of the Minnesota Pollution Control Agency have worked out final details of a 6.9 million dollar out-of-court- settlement. The agreement signed today requires Koch to begin agressive clean up of groundwater contamination at its Rosemount refinery south of the Twin Cities...but it comes years after the spills and leaks were first reported. Minnesota Public Radio's Mary Losure reports. HOST OUTCUE The signing of the new cleanup agreement removes one barrier to a new air