GarCo officials want tougher action against natural gas seep near Silt
GLENWOOD SPRINGS — Garfield County is pressing for answers from the state over a consultant’s concerns about a natural gas seep in West Divide Creek south of Silt.
Geoffrey Thyne, a geological consultant for the county, says the seep, discovered in 2004, is failing to subside. He questions whether it originated from just one gas well, as the state maintains. If the state is right, he wonders whether repairs to that well were adequate.
Commissioners voted Monday to follow Thyne’s recommendation of urging the state to either estimate how long the seep will last, if it’s coming only from one well, or identify other sources and address them.
Colorado Oil and Gas Conservation Commission staff on Monday said they don’t share Thyne’s concerns but will consider the county’s request.
County commissioners acted Monday at the urging of Lisa Bracken, who lives near the seep site.
The seep resulted in gas and benzene, a carcinogen, surfacing in the creek. The state blamed the problem on difficulties that EnCana Oil & Gas (USA) had sealing the outside of the well with cement. Officials said remedial cement work stopped the leak, although previously escaped gas is continuing to surface.
Thyne says that while benzene levels in groundwater monitoring wells are continuing to diminish, methane emissions, after initial reductions, have been occurring at a stable rate. He thinks the emissions could constitute a slow leak from a large source, or continued leaking from the well that was blamed in 2004, or could be coming from other sources.
Debbie Baldwin, environmental manager for the oil and gas commission, said the state is confident the remedial cement job was successful. She said data shows that not only benzene but methane concentrations are dropping.
“A very large quantity of gas was released, and it’s just taking time to work its way to the surface,” she said.
EnCana spokesman Doug Hock said EnCana doesn’t believe the residual leakage from the 2004 incident is more than expected, or that there is an ongoing problem with any wells in the area. But he said EnCana welcomes further study so that everyone has more certainty about when more gas dissipation might occur.
In an interview, Thyne said he was happy for the sake of area residents to hear of the county’s action.
“I think it’s just been tough to get attention focused on this. I think it’s always easier to say, ‘Ah, it looks OK,’ ” he said.