Most of us are familiar with hydraulic fracturing as a technique used for oil and natural gas drilling. The process uses a slurry of chemicals and sand to prop open rock fissures, allowing the release of fossil fuels. However, natural gas and oil are not the only constituents trapped in rock layers; these layers can also serve as a reservoir for contaminants. At Superfund sites and other polluted areas, the process of remediation, or cleanup, can be extended and expensive. Hydraulic fracturing has been utilized as an environmental cleanup method, where the same process is used to release trapped contaminants in rock layers. The EPA provides information on the process at
http://cluin.org/techfocus/default.focus/sec/Environmental_Fracturing/cat/Overview/
In fracking for environmental remediation just as in fracking for oil and gas drilling, a slurry of chemicals is pumped into the ground, typically containing a combination of water, sand to prop open fissures, detergent, and nutrients/amendments which stimulate the process of chemical breakdown. According to the EPA, “Environmental fracturing can be used to make primary treatment technologies…more efficient.” By enhancing the access of chemicals for pollution treatment to the rock layers where the pollutants are trapped, fracking has the possibility to decrease treatment times at polluted sites.
Fracking for fossil fuel extraction – specifically, horizontal drilling which uses a very large volume of chemicals- has been faulted for a number of high-profile instances of water contamination. When the process fails, the stakes are high for communities whose water supplies are in proximity to fracking wells. Through environmental hydraulic fracturing is intended to clean up already-polluted sites, the parallels between this process and fracking for natural gas are difficult to ignore. Is it possible for the process to further spread contamination in instances that pipelines or wells fail? The research is slim on this topic so far, but we do know that even with the best of intentions, remediation processes do not always go as planned. In my next post, I’ll explore the potential for unintended consequences from remediation.