Tests on soil and groundwater should determine the source of an oil leak at the Eagle Bluffs Conservation Area that was discovered last week, said Vic Bogosian, Missouri Department of Conservation wildlife biologist and Eagle Bluffs manager.

Once the results are back, he said, the Missouri Department of Natural Resources and Magellan Midstream Partners LP, the company that discovered the leak while it was replacing a natural gas pipeline, will be able to continue cleanup. The leak is suspected to be in excess of 50 gallons, according to a DNR incident report, but DNR spokeswoman Gena Terlizzi said the entire scope is not yet known.

At 12:28 p.m. Thursday, an employee of Magellan notified DNR�s Environmental Emergency Response Section that crude oil contamination was found during excavation of a pipeline under the Missouri River, but because of the age of the 12-inch pipeline, the source couldn�t be determined, according to an incident report.

The leak was found while Magellan crews were excavating the area underneath the river to connect the new pipeline to the existing one on the east side of the river, Bogosian said. Just the portion underneath the river had to be replaced.

Bogosian said the pipeline has been in place since the 1930s and used to carry oil but now carries natural gas. The oil could have come from the pipeline, he said, and could have been there for as long as 30 years or more, or from another source. The crude was found in groundwater and soil, Bogosian said.

�At this point, there�s a lot of questions, and the tests they�re doing will answer those questions,� Bogosian said.

Magellan has hired a contractor for the cleanup, and DNR will oversee the process, Terlizzi said.

A Magellan spokesman did not respond to requests for comment this morning.