AMHERST, S.D. -- A South Dakota official says TransCanada Corp. plans to test water from a drainage ditch near the site of a 210,000-gallon oil spill from the Keystone pipeline to determine if it is polluted.

Brian Walsh, a manager at the South Dakota Department of Environment and Natural Resources, said Monday that officials don't believe the oil is polluting the ditch or leaving the spill site through it.

Walsh says there's no visible oil in the ditch. He says TransCanada environmental contractors will collect water for sampling Monday if ice in the ditch melts.

The state has said the buried pipeline leak was on agricultural land. Officials don't believe it has polluted any surface water bodies or drinking water systems.

The pipeline transports crude from Canada.