Riverfront Park will be closed through early spring as officials with Vicksburg, Warren County and the Mississippi Department of Environmental Quality determine a plan to clean up oil contamination at the park.

The Board of Mayor and Aldermen Thursday approved a 60-day contract extension with Central Asphalt Co. of Vicksburg because of the problem. The park was closed for 90 days in December to allow the contractor to fix a slide area on the south end of the park that was discovered in 2017 and resurface the park’s three play areas.

The oil contamination was discovered Jan. 4 while Central Asphalt employees were working in the area and a track hoe dug up a scoop of oil believed to have been left from a former tank farm. The discovery shut down the repair project.

Lynn Chambers, division chief for DEQ’s groundwater assessment and remediation division, said at one time Midsouth Oil had a storage facility with nine above ground storage tanks that held various petroleum products on property south of the park.

The tank farm, she said, was located in an area between Ameristar and the park, and within 10 feet of the park’s access road off Washington Street. The former tank farm site is now part of the casino’s north parking area.

She said Friday DEQ officials working with the city’s environmental consultant are trying to determine the source of the oil and the extent of the contamination before a plan can be developed to resolve the problem.

“We don’t know if the contamination is coming from pipeline or a tank,” she said. “We need to find that out and determine the extent of the contamination before we can go any further with planning remediation. You need to know what you’re dealing with before you can develop a plan to resolve it.”

She said officials have been searching land records to see if they can find a responsible party for the problem, but no one has been found.