Geologic sequestration of carbon dioxide (CO2) is an important tool for curbing the human-induced climate change caused by our addiction to burning fossil fuels. But a new paper from researchers at Princeton suggests that the very process of getting those fossil fuels out of the ground could ruin our ability to put CO2 back in. The culprit? The controversial practice known as “fracking,” a.k.a. hydraulic fracturing.
Despite posing similar risks to groundwater, regulation of CO2 sequestration is vastly different than regulation of hydraulic fracturing. CO2 sequestration is regulated through the Underground Injection Control (UIC) program under the authority of the Safe Drinking Water Act (SDWA). Hydraulic fracturing, on the other hand, is exempt from the SDWA, meaning that EPA has no authority to regulate it*. Doing away with the loophole that exempts hydraulic fracturing from the SDWA and ensuring that oil and gas wells are subject to rigorous construction, operation and maintenance standards under the UIC program will not only provide uniform federal standards to protect groundwater, it will also allow EPA to coordinate regulation of fracking and geologic sequestration under the same program and help avoid potential conflicts between these two activities.
In order to successfully store CO2 underground it needs to be injected into a container with a lid on it - a porous and permeable rock formation to receive the CO2, capped by an impermeable rock formation to keep it from escaping. These “caprocks” are often shale formations, because shale is essentially impermeable to CO2 and subsurface fluids. The Princeton study found that in 60% of places where we have a CO2 container (a formation with sufficient porosity and permeability to accommodate large volumes of injected CO2), there is the potential for hydraulic fracturing being employed in the overlying lid. If such fracturing impaired the trapping function of the lid it could potentially reduce available storage capacity significantly.
Read more... http://switchboard.nrdc.org/blogs/bmordick/federal_regulation_of_fracking.html