Two Separate Investigations:
UPDATED [April 2, 2012; see below]
A major review of hydraulic fracturing studies, completed last month by UT researchers, found “no direct evidence” that the natural gas drilling process known as ‘fracking’ contaminates groundwater.
A second investigation by the EPA of sites in Dimock, Penn., initial results of which were released last week, found only low levels of chemicals and that the water was “safe to drink.”
The University of Texas Review:
The 380,000.00 review* was conducted by a University of Texas (Austin) team lead by Charles Groat, former director of the U.S. Geological Survey, and results were released last month at the Annual Science/AAAS meeting in Vancouver, B.C.
The review suggested that the effects commonly attributed to fracking — contamination from methane and other chemicals — were occurring close to the surface and were the (probable) result of “poorly lined wells and storage ponds”. The team found no evidence of fracking fluids leaking deep underground.
“We found no direct evidence that fracking itself has contaminated groundwater,” said Groat in a press meeting, who also acknowledged “a lack of baseline information” which may have limited the accuracy of the review.
The presence of methane gas (CH4) in some areas probably derives from natural sources, according to the UT review. The team of some 16 researchers from various fields of expertise reviewed the scientific literature and regulatory documents focusing on three major U.S. fracking areas covering parts of Texas, Louisiana and New York and Pennsylvania.
The EPA Study:
In 2009, Following numerous residents’ reports of apparent water well contamination in the heavily fracked area around Dimock, Pennsylvania, State officials determined that methane gas had leaked underground from nearby drilling sites run by Cabot Oil and Gas. The company began providing drinking water to households in the Dimock area for a few months, but then stopped providing this service.
This past Jaunary, the EPA annouced it would take over the state’s investigation. The agency tested over 60 homes from the Dimock area (and resumed providing drinking water for some of the homes).
Last Thursday, the EPA released a short statement stating that the first eleven samples analyzed from the area “did not show levels of contamination that could present a health concern.” The agency did note that some traces of metals, methane gas and bacteria had been detected but at levels that did not exceed federal standards and were not considered threats to human health. However, in two samples, the analysis found levels of arsenic that did exceed federal safety levels for water.
So, is Fracking Relatively Safe? Many Doubts Remain
Based on their review, the UT team found no need for further regulation of the industry but did call for enforcement of existing drilling regulations, such as those governing well casings and waste water disposal (Note: in 2005, fracking was granted an exemption from chemical reporting compliance under the Clean Water Act).
This claim contradicts the findings of a Duke University team’s study from 2010 which found a distinct difference between the type of methane found in the local drinking water (thermogenic methane, created by deep heat and pressure, associated with drilling) in the studied areas (sites in New York and Pennsylvania States) and naturally occurring methane (or biogenic methane).
The UT review study acknowledged that all effects of the drilling process were not completely understood, including whether or not pumping wastewater into the ground triggers small earthquakes. Also, the cumulative and long-term impacts of the fracking process remain “unclear”.
As to the EPA tests, according to a recent Truthout report, residents are confused by what the EPA has said publicly and the data it has provided to residents, which appear to show different levels of one particular contaminant — bromide, which is often found in fracking fluid — but which the EPA has not explained, as of yet.
Additionally, low levels of hydrocarbon-derived chemicals were found, and include: anthracene, fluoranthene, pyrene and benzo(a)pyrene. The CDC has determined these chemicals to be carcinogenic even at small doses. Other metal elements, such as chromium, aluminum, and lead were found, as were other chemicals like chlorides, salts, bromide and strontium — all of which occur naturally but, found together in certain concentrations, are associated with natural gas drilling sites.
Additionally, ethane gas was also found in some samples, which may be an indication that the methane came from deep underground reservoirs. Methane and ethane in drinking water are not considered highly toxic (although this claim is disputed), but can accumulate to dangerous levels and become explosive.
Many of the chemicals found in the EPA tests have not yet been evaluated by federal scientists for exposure risks, making it difficult to determine if they present a health risk for humans.
Last December (2011), the EPA found a probable link between groundwater contamination and fracking in the central Wyoming area.
But so far, no clear causal relationship has be found between the presence of these chemicals and drilling in the Dimock area. The EPA plans on more sampling and testing.
* The funding source for this literature review/study came entirely from University of Texas at Austin funds.
UPDATE [April 2, 2012] EPA Drops Water Pollution Charges against Natural Gas Drillers in Texas