Clean Air Act
The Clean Air Act is the law that defines EPA’s responsibilities for protecting and improving the nation’s air quality and the stratospheric ozone layer. The EPA sets limits on certain air pollutants and determines how much can be in the air anywhere in the United States. The EPA also has the authority to limit emissions of air pollutants coming from sources like chemical plants, utilities, and steel mills. Individual states or tribes may have stronger air pollution laws, but they may not have weaker pollution limits than those set by EPA.
National Ambient Air Quality Standards (NAAQS)
The Clean Air Act requires EPA to set National Ambient Air Quality Standards for pollutants considered harmful to public health and the environment. These standards set limits to protect public health, including the health of “sensitive” populations such as asthmatics, children, and the elderly. They also protect public welfare, including protection against decreased visibility, damage to animals, crops, vegetation, and buildings.
Acid Rain Program
Uses a combination of traditional requirements and a market-based cap and trade program to reduce power plant emissions of nitrogen oxides (NOx) and sulfur dioxide (SO2), which contribute both to acid rain and to fine particle formation.
National Emission Standards for Hazardous Air Pollutants From Coal- and Oil-Fired Electric Utility Steam Generating Units (“Utility MACT” or “MATS”)
More than 20 years after the 1990 Clean Air Act Amendments, some power plants still don’t control emissions of toxic air pollutants despite the wide availability of control technology. The Mercury and Air Toxics Standards (MATS)—finalized by the EPA in February 2012—set the first-ever power plant standards for mercury, acid gases and non-mercury metallic toxic pollutants. The MATS, assuming they survive a court challenge, cover about 1,400 coal- and oil-fired electric generating units at 600 power plants, which will have up to four years to comply.
Cross-State Air Pollution Rule (CSAPR)/Clean Air Interstate Rule (CAIR)
The Clean Air Act mandates that sources in one state cannot interfere with attaining pollution standards in another. To resolve this issue, on July 6, 2011, the U.S. EPA finalized the Cross-State Air Pollution Rule that requires 28 states—including Pennsylvania—to reduce power plant emissions of sulfur dioxide (SO2) and nitrogen oxide (NOx) that contribute to air pollution in states downwind. In August 2012, the U.S. Court of Appeals for the D.C. Circuit struck down CSAPR, leaving the Clean Air Interstate Rule (CAIR) in place while the EPA goes back to the drawing board. CAIR is a 2005 multi-state cap and trade program also intended to reduce interstate transport of SO2 and NOx, but would not result in as deep reductions in S02 in our region. The EPA filed a petition on October 5, 2012 seeking a rehearing of the CSAPR ruling.
Clean Air Standards for Harmful Soot Pollution
In response to a court order, the U.S EPA in December 2012 tightened its national air quality standards for harmful fine particle pollution, including soot (known as PM 2.5). These microscopic particles can penetrate deep into the lungs and have been linked to premature death, heart attacks, stroke, acute bronchitis and aggravated asthma. The new soot limit strengthens the annual health standard for PM2.5 to 12 micrograms per cubic meter; it replaced a 1997 annual standard of 15 micrograms per cubic meter.
Oil and Natural Gas Sector New Source Performance Standards, National Emission Standards for Hazardous Air Pollutants, and Control Techniques Guidelines (“Oil & Gas NESHAP/NSPS”)
This package of rules has been revised in light of the broad expansion of unconventional shale gas drilling. New performance standards restrict the amount of pollution oil and gas equipment is allowed to emit. New technology requirements were mandated for most aspects of oil and gas drilling and production, including drilling equipment, green completions for wells and compressor stations that move natural gas. These rules, if they survive challenges in court, promise to reduce air pollution from natural gas production in unconventional shale formations.
Source: David Presley, Staff Attorney, Clean Air Council