Monday, August 1, 2011

Fracking and Drinking Water Problems

On July 28th 2011 the EPA proposed standards that would require oil and gas well operators to cut emissions of volatile organic compounds, VOCs, (including methane) with fracking projects required to reduce VOC emissions by 95%. This is the second step EPA has taken in reexamining fracking. The documentary film “Gasland” created a groundswell of support for EPA to reexamine the impact of fracking on drinking water supplies and EPA announced in March 2010 that it will study the potential adverse impact that fracking may have on drinking water and developed a study plan with advise from their independent Science Advisory Board Environment Engineering Committee. Most of the Marcellus Shale hydraulic fracturing controversy has been focused on Pennsylvania and New York, but the Marcellus Shale runs through Maryland to Virginia.!OpenDocument&TableRow=2.1#2

Fracking or hydraulic fracturing as it is more properly known involves the pressurized injection of fluids commonly made up of mostly water and chemical additives into a geologic formation. The pressure used exceeds the rock strength and the fluid opens or enlarges fractures in the rock. As the formation is fractured, a “propping agent,” such as sand or ceramic beads, is pumped into the fractures to keep them from closing as the pumping pressure is released. The fracturing fluids (water and chemical additives) are partially recovered and returned to the surface or deep well injected. Natural gas will flow from pores and fractures in the rock into the wells allowing for enhanced access to the methane reserve.

Wells used for hydraulic fracturing are drilled vertically, vertically and horizontally, or directionally and may extend more than 8,000 feet below ground surface or less than 1,000 feet, and horizontal sections of a well may extend several thousands of feet away from the production pad on the surface. This allows potential impact to properties and water supplies far away from the well heads. Over the past few years, the use of hydraulic fracturing for gas extraction has increased and has expanded over a wider diversity of geographic regions and geologic formations beyond its original use in old oil and gas fields to revitalize them. It is projected that shale gas will comprise over 20% of the total U.S. gas supply in the next 20-35 years.

Given expansion in the use of fracking it seems appropriate to reexamine the potential consequences. The 2005 energy law exempts fracking from the Safe Drinking Water Act. It has been suggested by some that particular “loophole” was created for Halliburton, a company once headed by former Vice President Cheney and one of the companies that helped pioneer fracking and is a supplier of fracking fluids. A more likely explanation is that the energy industry managed once more to be exempted from regulation. The 2004 EPA study “Evaluation of Impacts to Underground Sources of Drinking Water by Hydraulic Fracturing of Coalbed Methane Reservoirs” states that EPA reviewed 11 major coal basins mined for coalbed methane and saw no conclusive evidence that water quality degradation on underground drinking water supplies had occurred as a direct result of the injection of hydraulic fracturing fluids.

The report goes on to state that “Although potentially hazardous chemicals may be introduced into USDW (underground source of drinking water) the risk posed to USDW by introduction of these chemicals is reduced significantly by groundwater production and injected fluid recovery, combined with the mitigation effects of dilution and dispersion, adsorption and potentially biodegradation. Additionally, EPA has reached an agreement with the major service companies to voluntarily eliminate diesel fuel from hydraulic fracturing fluids that are injected directly into USDW for coalbed methane production.”

However, the Marcellus Shale covers an area in Pennsylvania where the coal and gas rights were separated from the land title generations ago so that many people live on land where they do not own the gas and coal rights and fracking can occur adjacent to or beneath their homes. Much of the concern with fracking has been direct contamination of drinking water supplies with methane and the additives in the fracking water, but serious study should be given to the potential to impact groundwater flow and reservoirs through the fracking process.
Fracturing fluids can be up to 99% water. The volume of water needed for hydraulic fracturing varies by site and type of formation. Fifty thousand to 350,000 gallons of water may be required to fracture one well in a coalbed formation while two to five million gallons of water may be necessary to fracture one horizontal well in a shale formation. Water used for fracturing fluids is acquired from surface water or groundwater in the local area. Wastewaters from the hydraulic fracturing process may be disposed in several ways. The water that flows back after fracturing may be returned underground using injection well, discharged to surface waters after treatment to remove contaminants, or applied to land surfaces. Not all fracturing fluids injected into the geologic formation during hydraulic fracturing are recovered. The EPA estimates that the fluids recovered range from 15-80% of the volume injected depending on the site. No one has ever looked at what the long term implications are for the hydraulic balance when fracking occurs. The removal of millions of gallons of water, the fracturing of the geological formations, and the injection of contaminants even at low concentrations into the subsurface could cause significant changes in groundwater flow and quality. I jealously guard my groundwater supply and would be outraged if fracking or for that matter even massive pumping of that quantity of groundwater would occur anywhere within 5 miles of here (which covers the recharge zone up Bull Run mountain and the hydraulic barrier of the river. The water is a valuable resource and should be guarded and protected.

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