Human error by an inexperienced natural gas well worker likely led to a February explosion that caused a fatal fire on a Marcellus Shale well site in Greene County, the Pennsylvania Department of Environmental Protection said.

The findings were part of a DEP report released Wednesday following a months-long investigation of the incident on the Chevron Corp. well site in Dunkard that resulted in the death of 27-year-old field service technician Ian McKee.

State investigators said a Cameron International Corp. contractor -- called a "greenhat" because of his inexperience -- was neither properly supervised nor trained when he was directed to loosen equipment on the wellhead in the process of bringing it into production. The greenhat was not named in the report. 

Several days later, one of the "lock pins" was ejected from the well, allowing gas to escape from the well and catch fire.

John Gismondi, a Pittsburgh attorney representing Mr. McKee’s parents, said the DEP was “rightfully critical” of the company.

“Obviously it’s disappointing that Chevron wasn’t doing a better job of watching what was going on at their own well,” he said. 

He noted that Mr. McKee, who had lived most recently in Morgantown, W.Va., but was originally from Warren, Pa., had worked at least two years with Houston, Texas-based Cameron International and was not the inexperienced worker in question. 

The report included Chevron’s and Cameron’s own recommendations for ensuring that wellhead equipment remains secure, including training, inspections and testing. Chevron has pledged to apply one measure, involving isolating equipment parts, at future Marcellus Shale wells drilled in the state, that would “completely eliminate the possibility of such a recurrence.”

The DEP review cited problems in Chevron’s communications with both the DEP and the media. The company “failed to continually provide meaningful update information” on the incident during scheduled briefings. Poor cell phone reception in the area and limited email and Internet access exacerbated those efforts.

For two days after the explosion, Chevron refused to allow state investigators onto the property, in violation of oil and gas laws, the DEP said earlier this year. The company received nine citations for that and other violations.

DEP spokesman John Poister said Chevron's behavior after the incident was "simply unacceptable."

"They were not forthright. They did not let us into strategy meetings," he said. "When they did brief us, it was very sparse. We had to develop some workarounds to get information from our emergency response people."

In a prepared statement, Chevron spokeswoman Lee Ann Wainwright said, "We are reviewing the DEP reports, and we look forward to the opportunity to discuss them with the DEP in the near future.

“Chevron is committed to safe operations. We look forward to continuing to work with the Pennsylvania DEP and [Occupational Safety and Health Administration] in order to fully understand what happened with this incident, and we are determined to prevent it from happening again."

Cameron spokeswoman Sharon Sloan said she had no knowledge of the report and could not comment.

Mr. McKee and one of the other 20 workers on site were walking toward the wellhead when they heard a hissing sound the morning of Feb. 11. The wellhead exploded, igniting natural gas that burned for five days before it finally extinguished itself.

Investigators said they still don’t know the source of ignition, but noted that ”resolving this question is far less critical than understanding how the assembly was loosened“ and not properly resecured. 

Mr. McKee’s remains were found at the site several days after the blast. His parents filed a wrongful death lawsuit against Chevron Corp.'s local subsidiary, Chevron Appalachia LLC, in June. His fiancee gave birth to the couple’s child last month. 

So far, no fines have been issued to Chevron. Mr. Poister said the DEP was awaiting this report to hash out the details of the entire incident with Chevron and begin negotiations over penalties.

The agency also has drafted new emergency protocols for its staff based on recommendations from the report and will be training DEP officials during the coming months.

"We're hoping the industry will look at these reports and use this as a framework for an emergency of a significant nature like this," he said.

First Published: August 7, 2014, 5:39 p.m.