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Spokesmen for a natural gas company and the state agency in charge of overseeing oil and gas operations in Colorado said this week that they are doing their best to investigate the five-year-old West Divide Seep case.
And, they pledged, they will continue to do so.
A representative of the EnCana Oil & Gas (USA) company, which was operating gas wells in the Divide Creek area when the seep occurred in 2004, said it has been continuously investigating the causes of the seep and the extent of the “plume” of contaminated water.
EnCana spokesman Doug Hock conceded that representatives of the company have met only once recently with West Divide Creek resident Lisa Bracken, who lives in the area of the seep and is worried it may poison her water well, among other effects.
Bracken has vocally demanded increased testing and monitoring of the water in the area. In 2008, she reported observing apparent surface seeps that were not detected in 2004. And on Nov. 16, she told the Garfield County Commissioners that EnCana had inspected her property only once since July, despite directions from state officials that EnCana should work diligently to get to the root of the matter.
“We did have just one face-to-face with her,” said Hock. But he added that company personnel have exchanged “multiple e-mails back and forth with her” about the seep, the investigation and other matters.
The company's researchers and consultants have taken samples from eight locations, installed 23 monitoring wells and sampled water on Bracken's property, much of it on a quarterly basis, he said.
Their findings are that the “plume” of chemicals has shrunk over the last couple of years, and that the seep has been closed off.
The seeps are detectable by the appearance of bubbling in standing water, oily slicks on the water's surface and other identifying factors. Investigations of the incident in 2004 lead to a moratorium on drilling in the immediate area, which was lifted after a year, although monitoring continues.
“We see zero evidence of further contamination,” Hock said.
The seep was discovered in the spring of 2004, around the time that a cement casing in an EnCana well was found to have come apart.
The company has consistently denied that its drilling operations, including the controversial procedure of hydraulic fracturing of the underground strata to get at trapped deposits, were the cause of the seep.
One explanation for the 2004 seep, according to company documents, is the existence of a lateral fault in the subterranean rocks that was breached by the drilling operation.
When the cement sheath applied to the inside of the bore hole failed at the intersection of the fault and the well bore, gases were released and began to migrate upward to the creek, according to this explanation.
By re-cementing the bore, the seep was closed off and the seepage of subsurface water and chemicals has been slowing ever since, the company maintains.
A study by geologist Geoffrey Thyne notes that, while “levels of methane and benzene [toxic chemicals associated with gas drilling operations] started to decline in early 2004,” they remain well above acceptable levels and probably will stay that way until 2012. His report stated that the gases were “thermogenic,” meaning they came from deep within the earth, rather than from biological reactions among plants and organisms near the surface, which is known as “biogenic.”
Colorado Oil and Gas Conservation Commission Environmental Protection Supervisor Margaret Ash found different results.
Based on a variety of data, including samples gathered during six visits to the area in 2007 and 2008, she concluded that the methane and other gases found in the bubbling waters were “of biogenic origin.”
In a telephone interview with the Post Independent, Ash added that her findings indicate that some of the gases from the 2004 seep may have been trapped in the soils and are only now finding their way to the surface.
Dave Neslin, executive director of the COGCC, disputed Bracken's assertions that the agency has not shared necessary data with her or with Garfield County.
A library of reports and data are all available on the COGCC website, he said, and the agency has not withheld information from anyone.
“We have tried to be transparent and informative in handling this matter,” Neslin declared.
Referring to a Nov. 17 story in the Post Independent about Bracken's concerns, and Garfield County's agreement to help her press for more action on the case, Neslin said, “The article suggested that we haven't shared any of this data. That's not the case.”
If the county or Bracken has any new data to submit, “We will be happy to consider that,” Neslin concluded.
“This was a serious event,” added Ash. “We can't minimize that.”
jcolson@postindependent.com
And, they pledged, they will continue to do so.
A representative of the EnCana Oil & Gas (USA) company, which was operating gas wells in the Divide Creek area when the seep occurred in 2004, said it has been continuously investigating the causes of the seep and the extent of the “plume” of contaminated water.
EnCana spokesman Doug Hock conceded that representatives of the company have met only once recently with West Divide Creek resident Lisa Bracken, who lives in the area of the seep and is worried it may poison her water well, among other effects.
Bracken has vocally demanded increased testing and monitoring of the water in the area. In 2008, she reported observing apparent surface seeps that were not detected in 2004. And on Nov. 16, she told the Garfield County Commissioners that EnCana had inspected her property only once since July, despite directions from state officials that EnCana should work diligently to get to the root of the matter.
“We did have just one face-to-face with her,” said Hock. But he added that company personnel have exchanged “multiple e-mails back and forth with her” about the seep, the investigation and other matters.
The company's researchers and consultants have taken samples from eight locations, installed 23 monitoring wells and sampled water on Bracken's property, much of it on a quarterly basis, he said.
Their findings are that the “plume” of chemicals has shrunk over the last couple of years, and that the seep has been closed off.
The seeps are detectable by the appearance of bubbling in standing water, oily slicks on the water's surface and other identifying factors. Investigations of the incident in 2004 lead to a moratorium on drilling in the immediate area, which was lifted after a year, although monitoring continues.
“We see zero evidence of further contamination,” Hock said.
The seep was discovered in the spring of 2004, around the time that a cement casing in an EnCana well was found to have come apart.
The company has consistently denied that its drilling operations, including the controversial procedure of hydraulic fracturing of the underground strata to get at trapped deposits, were the cause of the seep.
One explanation for the 2004 seep, according to company documents, is the existence of a lateral fault in the subterranean rocks that was breached by the drilling operation.
When the cement sheath applied to the inside of the bore hole failed at the intersection of the fault and the well bore, gases were released and began to migrate upward to the creek, according to this explanation.
By re-cementing the bore, the seep was closed off and the seepage of subsurface water and chemicals has been slowing ever since, the company maintains.
A study by geologist Geoffrey Thyne notes that, while “levels of methane and benzene [toxic chemicals associated with gas drilling operations] started to decline in early 2004,” they remain well above acceptable levels and probably will stay that way until 2012. His report stated that the gases were “thermogenic,” meaning they came from deep within the earth, rather than from biological reactions among plants and organisms near the surface, which is known as “biogenic.”
Colorado Oil and Gas Conservation Commission Environmental Protection Supervisor Margaret Ash found different results.
Based on a variety of data, including samples gathered during six visits to the area in 2007 and 2008, she concluded that the methane and other gases found in the bubbling waters were “of biogenic origin.”
In a telephone interview with the Post Independent, Ash added that her findings indicate that some of the gases from the 2004 seep may have been trapped in the soils and are only now finding their way to the surface.
Dave Neslin, executive director of the COGCC, disputed Bracken's assertions that the agency has not shared necessary data with her or with Garfield County.
A library of reports and data are all available on the COGCC website, he said, and the agency has not withheld information from anyone.
“We have tried to be transparent and informative in handling this matter,” Neslin declared.
Referring to a Nov. 17 story in the Post Independent about Bracken's concerns, and Garfield County's agreement to help her press for more action on the case, Neslin said, “The article suggested that we haven't shared any of this data. That's not the case.”
If the county or Bracken has any new data to submit, “We will be happy to consider that,” Neslin concluded.
“This was a serious event,” added Ash. “We can't minimize that.”
jcolson@postindependent.com
