By Edward McAllister
March 18 (Reuters) - Clean-up operations began on Tuesday after a major oil pipeline owned by Sunoco Logistics Partners LP leaked hundreds of barrels of crude oil into a nature preserve next to the Great Miami River in southwest Ohio.
Crews vacuumed oil that had leaked from the Mid-Valley pipeline into a wetland area of the Oak Glen Nature Preserve, 20 miles (32 km) north of Cincinnati, according to local officials.
The 240-barrel (10,000-gallons/38,000-liter) spill has been contained, Sunoco said in a statement.
The leak was discovered at 8:20 p.m. EDT on Monday (0020 GMT Tuesday) and the line was shut around 1 a.m. EDT on Tuesday, Sunoco said. It was unclear if any oil was still spewing from the pipe.
The spill did not appear to have reached the Great Miami River, about a quarter of a mile (400 meters) away, though tests were still being completed, said a spokeswoman for the Ohio Environmental Protection Agency.
"The extent of impact to the resource is currently unknown," said a statement from the Great Parks of Hamilton County, which oversees the Oak Glen preserve. "The EPA is assessing the situation to determine appropriate action."
The cause of the spill was unclear and under investigation, Sunoco said. It had no timeline for the restart of the line.
The Mid-Valley pipeline is part of the company's Midwest system that runs about 1,000 miles from Longview, Texas to Samaria, Michigan, providing crude oil to a number of refineries, primarily in the U.S. Midwest.
Flows along the line decreased overnight to around 163,000 barrels per day from an estimated 229,000 bpd, according to data provider Genscape. The pipeline has a capacity of 280,000 bpd, Genscape said.
The loss of a key supply route from the south hit physical crude oil prices in Texas, already pressured by ample supplies. West Texas Intermediate crude for delivery at Midland, Texas, fell $2.50 a barrel on Tuesday to $15 below U.S. oil futures. West Texas Sour fell $4.