Liquid gas products line eyed in Parachute-area leak
An investigation into a hydrocarbon leak northwest of Parachute is focusing on a valve box for a 4-inch-diameter natural gas liquids line, the director of the Colorado Oil and Gas Conservation Commission said Monday.
“The soil around that valve box is fairly saturated with hydrocarbons,” Matt Lepore told commissioner members at their meeting in Denver.
The line leaves Williams’ nearby Parachute Creek Gas Plant, which removes a mix of propane, butane, ethane and other liquids from raw natural gas produced in the region.
An investigation has been continuing into the source of some 6,000 gallons of an unidentified hydrocarbon liquid that Williams discovered after doing pipeline location work in preparation for building an additional plant at the same facility.
Lepore said when excavation began around the valve box as part of the continuing investigation, “they called a halt to the work because of the odors present in the area.”
“They wanted to bring in air monitoring equipment and/or respirators for the workers to be equipped with before they continued the investigation,” he said.
Michele Swaner, a Williams spokeswoman, said work around the valve box had resumed by Monday.
“It’s accurate to say that we’re certainly looking in that area as a potential source,” she said.
But she said the work is part of Williams’ plan to look at all potential sources.
Lepore said crews have excavated around a 30-inch-diameter raw gas pipeline in the area of the valve box but have found no signs of it having leaked. The pipeline leads to the gas plant.
Lepore also confirmed what WPX Energy has said — that testing of gas pressures involving the cement seals around wells it has in the area shows the wells appear to be sound.
Because both Williams and WPX have infrastructure near the leak site, COGCC staff have issued notices of alleged violation against each of them as the investigation into the leak’s cause continues.
The leak is just 50 feet from Parachute Creek, but authorities say there hasn’t been any sign of the creek having become contaminated. The leak has come in contact with shallow groundwater. Lepore said Williams has been installing groundwater monitoring wells between an interception trench and the creek, and test results are being awaited.
Leslie Robinson, chair of the Grand Valley Citizens Alliance, said she feels agencies still need to be more forthcoming about the investigation.
“We’ve got to have some lines of communication with the public and I just don’t see it there except for (through) the media,” she said.