National Emission Standards for Hazardous Air Pollutants: Oil and Natural Gas Production and National Emission Standards for Hazardous Air Pollutants: Natural Gas Transmission and Storage

These promulgated national emission standards for hazardous air pollutants (NESHAP) limit emissions of hazardous air pollutants (HAP) from oil and natural gas production and natural gas transmission and storage facilities. These final rules implement section 112 of the Clean Air Act (Act) and are based on the Administrator's determination that oil and natural gas production and natural gas transmission and storage facilities emit HAP identified on the EPA's list of 188 HAP. The EPA estimates that approximately 69,000 megagrams per year (Mg/ yr) of HAP are emitted from facilities in these source categories. The primary HAP emitted by the facilities covered by these final standards include benzene, toluene, ethyl benzene, mixed xylenes (collectively referred to as BTEX), and n-hexane. Benzene is carcinogenic and has also been shown to cause various adverse health effects other than cancer (i.e., noncancer effects). The other four HAP are not classified as carcinogens based on available information; however, exposures to these four HAP have been shown to cause various noncancer effects. The EPA estimates that these promulgated NESHAP will reduce HAP emissions from major sources in the oil and natural gas production source category by 77 percent and from major sources in the natural gas transmission and storage source category by 95.0 percent.