A five-inch crack in a crude oil pipeline in southern Ohio, owned and operated by Sunoco Logistics Partners LP, was the source of a 10,000 gallon (240 bbl) leak discovered on Monday in a stream that contaminated part of a nature preserve in Colerain Township, just north of Cincinnati, local officials said.

The pipeline is part of Mid-Valley Pipeline Co.’s roughly 1,000-mile system that delivers crude from Texas to Michigan. Records from the U.S Department of Transportation’s Pipeline and Hazardous Materials Safety Administration (PHMSA), which oversees the interstate line, indicate that Monday’s incident is the 40th time since 2006 that either crude has leaked from the pipeline or other problems have been reported along it.

Clean-up operations got under way at the site of the leak on Tuesday after the oil was discovered in a stream and nearby wetland. The Oak Glenn Nature Preserve in Colerain was affected, and news media reports said wildlife had been affected in the spill.

A statement from Sunoco said the spill has been contained. Officials from PHMSA and the Ohio Environmental Protection Agency (EPA) were dispatched to the site. EPA officials said the spill did not reach a major river in the area, and they added that more than 4,000 gallons of oil had been recovered.

The pipeline has a capacity of 280,000 b/d, and clean-up efforts were continuing on Friday, with work expected to continue through the weekend.