by Susan Simons
WALSENBURG- On Sat. Nov. 15, representatives from Petrogylph and the Colorado Oil and Gas Conservation Commission (COGCC) and a local geophysicist spoke to interested citizens at the Huerfano County Community Center. In each of the three talks the focus was on domestic water wells close to the Petroglyph coalbed methane (CBM) production site south of highway 160 which have been contaminated by methane or have gone dry. There appeared to be new cooperation and a new tone to the discussion with an emphasis on future solutions to problems.
First to speak was Paul Denney, a retired geophysicist with over 40 years in the field. Although Petroglyph and COGCC have both been researching why methane seeps are occurring in domestic water wells and why wells have dried up, neither feels they have a conclusive explanation. Denney presented an analysis of possible pathways through which fluids can move below the surface and to the surface. Based on his review of previous research and of coal mining records in the area, he demonstrated that there must be a pathway for fluids to move between Unfug and Walsen dikes. He further demonstrated using well logs that some of Petroglyph’s wells are drilled through fault lines. He also discussed how sand channels cutting across aquifers might transport fluids. Finally he recommended a method called passive seismic monitoring to study the movements of gases and fluids under the surface. Applied over time, this method might help resolve today’s problems and avoid future problems. The Chief Operating Officer of Petroglyph, Paul Powell, said that his specialists would consult with Denney.
Powell spoke next. He acknowledged that Petroglyph has been communicating with state agencies and local governments, but not with the people most affected and that Petroglyph wants solutions as much as people do. Petroglyph shut down its field operations a year and a half ago and has spent two and a half million dollars on the problems. They are monitoring 22 homes in River Ridge, Silver Spurs, City Ranch, and La Veta Pines. Powell addressed homeowners’ fears of explosion. He emphasized that the homes being monitored had around 340 parts per million (ppm) of methane and that methane combusts at around 50,000 ppm when in a closed system and mixed with oxygen. For example, if methane is venting at high levels in a closed pressurized system from well to house, there is danger. A short-term solution is to install a passive vent on the cistern.
In the afternoon, Peter Gintautas, Environmental Protection Specialist to COGCC spoke.
The Acting Director of COGCC was present as was the Environmental Supervisor for southeast Colorado, and an Environmental Protection Agency (EPA) representative. Petroglyph is near the end of Phase 1 of a Methane Mitigation Plan. They have done aerial and ground surveys to map methane seeps. They have drilled a monitoring well, extraction wells, and injection wells near the contaminated wells. The plan is to remove contaminated water, de-gas that water and reinject it into the Poison Canyon aquifer. They must have EPA approval to reinject the water. According to COGCC, the flow of water contaminated with methane has decreased and fewer wells are venting methane.
Gintautas also discussed the research COGCC has conducted since 2007 related to these problems.
The morning meeting was sponsored by Rural Property Owners Alliance (RPOA) and chaired by Al Tucker. The afternoon talk was organized by COGCC. The morning session drew an audience of about 65 persons and the afternoon session, about 85.