By Bill Knowles
WALSENBURG- The Environmental Protection Agency has issued a final permit allowing Petroglyph to inject treated groundwater pumped from the Vermejo Formation, into the Poison Canyon Formation. This process is designed to contain coal bed methane that has been leeching into private wells according to an EPA document dated May 26, 2010.
The final permit reflects the changes made by the EPA after taking public comments beginning July 9, 2009 and continuing through August 14, 2009.
“We are excited to move forward with this part of the the process,” Petroglyph Executive Vice President Paul Powell said. “This is a big step in the mitigation of coal bed methane in the Poison Canyon Aquifer.”
A previous permit dated November 2008, allowed Petroglyph to inject groundwater, taken from both the Poison Canyon Formation and the Vermejo Formation, into a ring of injection wells in the area of the River Ridge Ranch subdivison. That is where increased levels of methane have leeched into some of the area’s private wells.
The injection wells surround some recovery wells and Petroglyph hopes to stop the methane encroachment into private wells by forcing the coal bed methane into the two recovery wells after surrounding them with a type of water donut comprised of eight injection wells that should block the methane from getting into the private wells at River Ridge Ranch.
“However before we can begin the process by the end of June, there are some other things that still have to be finished,” Powell said.
Some of those things are the hookup of the water treatment facility which is a reverse osmosis plant. And Petroglyph is still putting a substitute water supply in place.
Concerns voiced in the public comment process brought about a requirement that ensures that if the reverse osmosis (R/O) treatment system shuts down, the injection of untreated injectate cannot occur.
The EPA documents made note that the water from the Vermejo Formation, after treatment, meets drinking water standards for all constituents with the exception of fluoride. Another addition to the permit requires that the waste stream from the R/O process would be disposed of in accordance with all applicable Federal, State and local regulations.
When Petroglyph fractured the strata in the Vermejo Formation part of the “fracking” fluid was comprised of borate which contains boron. The new permit calls for a year’s worth of testing by Petroglyph to determine if concentrations remain within the range of background levels of boron found in Vermejo Formation groundwater.
The EPA document also states that, “…two wells will potentially be used to pump groundwater from the Vermejo Formation.” These wells were formerly used to pump groundwater for the purpose of CBM production. However, in the current permit, the two wells will be used to pump Vermejo Formation water to supplement the ground water in the Poison Canyon Formation with the maximum daily volume pumped by the two wells estimated at 42,000 gallons.
The groundwater from the Vermejo Formation will be combined with the Poison Canyon water in order to increase the volume of injected water to provide enough pressure to create a hydraulic barrier around the area. The hydraulic barrier is intended to contain the methane within the ring of injection wells and increase the efficiency of methane removal from the Poison Canyon aquifer.
Petroglyph will also have to submit to the EPA a monitoring plan that the agency will review and approve before the initiation of phase two injection activities. This requirement looks at the total dissolved solids (TDS) in the injectate which will be at low concentrations after the R/O treatment. The injection of low TDS has the potential to dissolve minerals from the Poison Canyon Formations. These minerals include iron, manganese and fluoride. The plan will include, at a minimum, analyzing samples from private wells for these minerals.
The just-issued EPA permit allows for the injection of 42,000 gallons of treated water per day into eight injection wells using a mixture of Vermejo Formation and Poison Canyon Formation water to contain and extract coal bed methane that has been leeching into private wells located in the River Ridge Ranch subdivison.
“Right now there is no timeline on when phase three of the operation will begin,” Powell said. “That depends on the COGCC. But we do want phase two up and running before we go to phase three.”
The new permit does not allow for the surface water discharge of groundwater into the Cucharas River. Those permits are issued by the Colorado Department of Public Health and Environment, Water Quality Control Division. That phase calls for the discharge of 10.5 million gallons of water per day into the river.