Hydraulic fracturing is a technique used to recover oil and natural gas from underground low permeability rock formations. Its use along with horizontal drilling has been responsible for an increase in estimated U.S. oil and natural gas reserves. Hydraulic fracturing and related oil and gas production activities have been controversial because of their potential effects on public health and the environment. Several environmental statutes have implications for the regulation of hydraulic fracturing by the federal government and states. An amendment to the Safe Drinking Water Act (SDWA) passed as a part of the Energy Policy Act of 2005 (EPAct 2005) clarified that the Underground Injection Control (UIC) requirements found in the SDWA do not apply to hydraulic fracturing, although the exclusion does not extend to the use of diesel fuel in hydraulic fracturing operations. The underground injection of wastewater generated during oil and gas production (including hydraulic fracturing) does require a UIC permit under the SDWA, as do injections for enhanced oil and gas recovery operations. Under the Clean Water Act (CWA), parties seeking to discharge produced water may have to apply for a permit under the National Pollutant Discharge Elimination System. Under the Clean Air Act (CAA), the Environmental Protection Agency (EPA) has issued new rules covering emissions of volatile organic compounds from hydraulic fracturing operations.