An investigation into the cause of a large fire last weekend at a Statoil ASA drilling site in Monroe County, OH, near the West Virginia state line continued on Thursday. Cleanup efforts were expected to last several days, said an Ohio Department of Natural Resources (ODNR) spokesman, Thursday.

"We've got folks down there right now and we're still trying to figure out the cause," said spokesman Mark Bruce. "I know they don't have an answer yet; it's still very early on."

An early morning fire was reported by Statoil last Saturday (see Shale Daily, June 30), prompting regulators and emergency management personnel to respond and issue a voluntary evacuation order that has since been lifted for those living nearby. ODNR said 20 pump and blender trucks, along with other surface equipment, were destroyed in the fire at the eight-well Eisenbarth pad in Ohio Township.

Statoil spokesman Bjorn Otto Sverdrup said crews, trucks and other equipment were at the site preparing for the hydraulic fracturing (fracking) of seven wells. The wells were shut-in before they could be damaged by the fire. 

The accident is thought to be the cause of a large fish kill in a nearby creek where crayfish, minnows and smallmouth bass were found dead miles away.

"There isn't an answer yet," Bruce said of the fish kill. "They've conducted tests of the water and the results have yet to come back. There's also speculation on how widespread the fish kill was. There's no definite connections -- I'm not saying this wasn't caused by the accident -- but we just don't have anything that concretely shows what killed the fish."

Bruce said Statoil has fully cooperated with regulators. A unified command center has also been established at the site for ODNR and Ohio Environmental Protection Agency personnel. Statoil officials are also on site "to get to the bottom of what happened," Bruce said.