Monday, December 12, 2011

The Waste Pit Conundrum

New York State Department of Environmental Conservation will soon be working on its third version to the SGIES – the document that outlines how shale gas drilling will be permitted in New York State. The original draft, released in the fall of 2009, was roundly criticized by environmental advocates, and the DEC has since acknowledged its shortcomings. The executive summary of the second version, released in July, noted that the agency gained "a more detailed understanding of the potential impacts" of shale gas development since the first document. It attributed this understanding to events in Pennsylvania, reports and studies, and the public’s response, which amounted to more than 13,000 written comments.

One of the recurring problems in Pennsylvania has been pollution from waste pits that are dug beside wells pads to contain fluids and other byproducts that come up the well bore. They have been known to leak, or worse. In March 2010, a pit containing 400,000 gallons of wastewater ignited in balls of flame and black smoke in Washington County. The fire, fueled by a mixture of hydrocarbons that condense from natural gas, also consumed a tank containing fracking fluid and burned the plastic pit liner.

Those following the issue in New York have heard much about the proposal for closed loop drilling – the industry’s answer for spill-proof sites. The DEC is proposing metal tanks rather than open pits to contain “flow-back,” the mixture of fluids, brine, and other naturally occurring and manmade waste that comes from the hole after a well is stimulated by hydraulic fracturing. The agency would not eliminate pits, however.  Under certain circumstances, the operators would be allowed to stage and sometimes bury waste, such as cuttings, in on-site pits. Cuttings are pushed from the well bore prior to gas production with “drilling mud.” Although drilling mud looks like its name suggests, it’s not a benign product of nature. It’s engineered to precise chemical specifications to lubricate the drill bit, float cuttings to the surface, and to maintain hydrostatic pressure to prevent blowouts. It typically contains agents that are inert, such as clay, and many that are toxic, including barium. (For an analysis of the chemistry of drilling mud, see Jerry M. Neff, “Composition, Environmental Fates, and Biological Effects of Water Based Drilling Muds and Cuttings Discharged to the Marine Environment.”) In addition to mud, Marcellus drill cuttings also tend to contain natural occurring radioactive material (NORM) and pyrite. According to the SGEIS, pyrite can leach and produce an acidic discharge to groundwater referred to as acid rock drainage.

Pyrite is one of many factors that must be accounted for on a permit-by-permit basis, and these factors are highly variable. At certain points of the process, flow-back might mix with brine, brine might mix with drilling mud, and drilling mud might mix with cuttings. In addition to providing workable legal definitions – the foundation of regulatory enforcement -- of the various intermingled byproducts coming from a given bore hole, the DEC also faces the challenge of marshaling the resources to police, with a handful of inspectors, thousands of remote drilling sites spread over the countryside.

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