The Minnesota Pollution Control Agency was investigating Tuesday after a Canadian Pacific Railway train dribbled about 12,000 gallons of crude oil along 68 miles of track between Winona and Red Wing in southeastern Minnesota.
MPCA spokeswoman Cathy Rofshus said no major cleanup was planned because the oil splattered between the rails onto the track bed as the train was moving Monday.
"It's like it spray-painted oil," she said, adding that emergency responders had not found any pools of oil or other concentrations that could be cleaned up. She said the area would be monitored for any runoff.
According to a duty officer's report from the state Department of Public Safety, the release started in Red Wing and continued through Winona, where somebody reported the leak around 9 a.m. The train crew stopped just past Winona and fixed the leak, which the report blamed on a missing valve or cap.
The spill involved less than half the contents of a typical tanker car, which holds about 26,000 gallons, the Winona Daily News reported.
Canadian Pacific spokesman Ed Greenberg told the newspaper the railroad was investigating the cause and cooperating with the MPCA's investigation, and would cooperate fully with any cleanup efforts if they're required.