The U.S. Environmental Protection Agency (EPA) published its first report on the fluids used in hydraulic fracturing operations in the U.S.A. The purpose of the study was to compare chemicals and water used in hydraulic fracture stimulation in different regions of the country. The focus was on the assessment of the chemicals for toxicity.
The Report is a part of a comprehensive project: the study on potential fracturing impact on freshwater resources, which is to published in the months to come.
For two years the Environmental Protection Agency has analyzed data from FracFocus, which collects information about fracturing treatments across the U.S.A. Currently, the database contains information from 94 716 drilling wells. EPA specialists have analyzed data from over 39 000 fracturing operations made from January 2011 through February 2013.
According to the Report, fracturing companies use 692 chemicals in the process, of course not all of them simultaneously. On average, a fracturing fluid is composed of water (88%), proppant (10%) and various chemical additives that on average account for less than 2% of the total volume. Hydrochloric acid solutions, methanol and oil distillates are the most frequently used fracturing fluid additives, applied in 65% of all hydraulic fracture stimulation operations. The total water consumption per fracturing operation ranged substantially from 113 m3 to 27,500 m3. However, more than 50% of all treatments used in excess of 5,700 m3 of water per job.
The national FracFocus Registry has been maintained since 2011 by Ground Water Protection Council and Interstate Oil and Gas Compact Commission. Currently, more than 200 operators voluntarily disclose information about the volume and compositions of fracturing fluids they use in well stimulation jobs. However, some proprietary fluid composition data are not disclosed at the Registry website. The FracFocus Registry collect information from 16 states.
The Report is available at: www2.epa.gov
31.03.2015
source: EPA
