Methane seep possible again for water wells south of Silt
The state is investigating the possibility that methane from natural gas development got into two domestic water wells in an area of controversy over drilling south of Silt.
The wells are within an area that the Colorado Oil and Gas Conservation Commission investigated in connection with the 2004 West Divide Creek gas seep.
EnCana Oil & Gas (USA) Inc. recently informed the state about concerns about methane buildup in a water well in the Dry Hollow area. EnCana has installed a bigger vent in a basement holding tank on the property in an effort to prevent accumulation of explosive levels of methane.
That well had been drilled to replace what was known as the Dietrich well, which the Colorado Oil and Gas Conservation Commission previously concluded had been contaminated by EnCana’s drilling operations in the area. EnCana also was held responsible and fined $371,200 for the gas that bubbled up into West Divide Creek.
Meanwhile, energy developer Bill Barrett Corp. has notified the state that gas possibly related to drilling has shown up in the Miller domestic well up Divide Creek.
“In both cases we’ve not been able to identify the specific source of the impact, and that remains under investigation,” said David Neslin, director of the oil and gas commission.
Lisa Bracken, who lives in the area of the gas seep, said gas development problems around the seep area have continued despite stricter drilling rules designed to better protect groundwater there.
“Unfortunately there’s nothing in place to really safeguard people,” she said.
Geoffrey Thyne, a geological consultant for Garfield County, believes methane levels in domestic water wells south of Silt have been increasing, at least partly because of drilling. But oil and gas regulators and the industry have disagreed with his conclusions.
Bill Barrett Corp. spokesman Jim Felton said the company will continue cooperating in the Miller well investigation, but it is “quite confident” there Is no link between its operations and the methane in the well.
EnCana spokesman Doug Hock said the gas in the Dry Hollow water well hasn’t been shown to contain benzene, toluene and other compounds normally found in the gas EnCana is developing in the area.
Neslin said the presence of heavier hydrocarbons in the methane in both water wells being investigated leads the state to believe the gas is related to energy development. But Hock said such gas is common even in shallow geological formations in the area, and its presence in water wells isn’t necessarily a result of drilling.
The state’s investigation includes evaluating the adequacy of cement sealing around some area gas well bores and comparing gas samples from those wells to what was found in the water wells.
Said Neslin, “We continue to view protection of the state’s water resources as a very important part of our mission.”