Hydraulic fracturing technology shale gas utilizes proppant high-pressure pump ground water and other chemicals mixed to form a fracturing fluid into the ground shale, shale after being fractured, releasing oil and gas contained therein. In recent years, the breakthrough of the technology and widespread use, promote a substantial increase in shale oil and gas production frac proppant the United States, but also caused American society concerns about the technology that may contaminate nearby drinking water wells shale oil and gas resources.
In 2009, the US Congress should request, EPA began the study, investigate all aspects of the hydraulic fracturing with water-related, including access to water, the drilling site was added chemicals injected underground fracturing fluid pressure wastewater treatment and discharge after the split is completed.