Keystone pipeline shut down after crude leak in South Dakota

TransCanada Corp. has shut down its Keystone crude oil pipeline indefinitely after a leak was detectedSaturday afternoon in South Dakota.

The company is investigating the incident near its Freeman pump station, ina remote area of Hutchinson County.

It is not clear how much oil was spilled but cleanupis underway.

"We've been given an early estimate, but until they actually dig down to the pipeline, I don't think they're going to have afirm number on the exact number of gallons that were involved," saidChris Nelson, chairman of the South Dakota Public Utilities Commission.

TransCanada is in the process of removing the oil and investigating the source of the leak,reported at 4p.m. Saturday.

"No significant impact to the environment has been observed and our investigation continues," Calgary-based TransCanada officials said in a statement.

The pipeline remains shut down fromHardisty, Alta., to Wood River, Ill., and from Steele City, Neb., to Cushing, Okla. However, theGulf Coast line, fromCushing to Nederland, Texas, remains operational.

TransCanada has advised affectedshippers the line will remain closed until at leastFriday.