A tanker truck driver was killed after a storage tank at an EQT Corp. natural gas well in West Virginia exploded on Friday morning.

Tom Aluise, spokesman for the West Virginia Department of Environmental Protection (DEP), told NGI’s Shale Daily that investigators believe the tanker truck arrived at the site of the producing well near Flemington, in Taylor County, at around 6:30 a.m. to offload material from the storage tank. The driver was an employee of one of EQT’s contractors, EQT said.

“They were offloading some water from the tank into the tanker truck, and something ignited and there was an explosion,” Aluise said Friday. “The storage tank blew up, killed the driver and also damaged his truck. His truck did not blow up. He was discovered at about 8:30 this morning, [probably] when EQT employees arrived.”

The well site, which EQT said is producing dry gas and does not contain any condensate, has been shut down.

Aluise said investigators from the DEP and the federal Occupational Safety and Health Administration (OSHA) visited the site on Friday, but were still trying to determine the tank’s size and contents, although it was more than likely to be wastewater or produced water. He said a secondary containment system appears to have captured most of the material that was spilled in the explosion.

Aluise did not identify the victim, but said he was an employee of Central Environmental Services, a trucking company based in the state.

“There were no witnesses,” Aluise said. “It was a site where they were producing gas. There really would be no reason for anybody to be around there, other than guys such as this who come in periodically to empty tanks. So no one really knows exactly what happened at this point.”

Details of the incident “are very limited, but what is known is that the incident was not related to drilling, as it occurred on a producing well site,” EQT said in a statement Friday.