Last Modified: Friday, June 22, 2012 7:55 PM
I’ve heard of concerns that fracking — a process that’s used for drilling for oil and gas — may be associated with causing earthquakes. Has the Environmental Protection Agency issued any warnings about its safety and the environment?
The EPA has issued no official warning about fracking and earthquakes. But it did mount an extensive investigation of allegations that the practice — formally called hydraulic fracturing — has contaminated groundwater around Pavillion, Wyo.
The town, with a population of 231, sits just west of the Pavillion Gas Field, site of 169 production wells and 33 surface pits used for drilling-fluid disposal and storage, according to a draft report on the EPA’s investigation.
The draft, released in December, says the agency, at the behest of residents, tested water from shallow wells and later drilled two monitoring wells to collect deep-groundwater samples for analysis.
The report says testing detected multiple synthetic chemicals related to hydraulic fracturing in samples from both the shallow and deep wells. Researchers said the contaminants in the shallow wells — including benzene and xylenes — likely came from the nearby storage and disposal pits.
The concentrations of chemicals found in the deep wells suggest the contaminants may have migrated upward from the gas field layer, according to the report.
“Alternative explanations were carefully considered to explain individual sets of data,” the report reads. “However, when considered together with other lines of evidence, the data indicates likely impact to ground water that can be explained by hydraulic fracturing.”
The EPA plans to open the study for peer review, but it has postponed the move until it finishes analyzing additional samples
from several wells. The agency will accept public comments on the report through October.
A National Research Council report released earlier this month — titled “Induced Seismicity Potential in Energy Technologies” — listed three major findings from a study of drilling operations’ and earthquakes:
Hydraulic fracturing “does not pose a high risk for inducing felt seismic events.”
Injection well operations “pose some risk for induced seismicity” — a fact The Informer pointed out in January.
Carbon capture and storage operations, “due to the large net volumes of injected fluids, may have potential for inducing larger seismic events.”
“Although induced seismic events have not resulted in loss of life or major damage in the United States, their effects have been felt locally, and they raise some concern about additional seismic activity and its consequences in areas where energy development is ongoing or planned,” the report reads.
“Further research is required to better understand and address the potential risks associated with induced seismicity.
The Informer recently addressed the questions of a couple readers who wrote to ask about what could have happened to the geckos they used to see regularly. The column offered several possible explanations, including predators, a lack of food and old age.
But The Informer also noted that it had noticed no shortage of geckos — an observation shared by reader Claude Beville. “Where have the geckos gone?” he wrote in an email Wednesday. “They are at my house ... on the window sills ... in my shop ... everywhere.”
The Informer answers questions from readers each Sunday, Monday and Wednesday. It is researched and written by Andrew Perzo, an American Press staff writer. To ask a question, call 494-4098, press 5 and leave voice mail, or email email@example.com