Air Pollution Laws: Breathing Easier

The Clean Air Act (CAA) is the primary federal law in the US that limits air pollution. It was enacted in 1963 and has been amended several times since, most notably in 1970, 1977, and 1990. The Clean Air Act authorizes the Environmental Protection Agency (EPA) to regulate air emissions from stationary and mobile sources, such as power plants, chemical plants, vehicles, and nonroad engines. The EPA sets National Ambient Air Quality Standards (NAAQS) and emission standards for hazardous air pollutants under the CAA. The law has been instrumental in reducing air pollution and protecting public health and the environment.

The Clean Air Act (CAA)

The Clean Air Act was initially enacted in 1963 and has been amended several times since, making it one of the country's first and most influential modern environmental laws. The Act was significantly amended in 1970, with the latest amendments being made in 1990. The 1970 amendments were passed unanimously in the U.S. Senate and were signed into law by President Richard Nixon. These amendments were passed in recognition of the right to healthy air quality, regardless of where one lives.

The Clean Air Act is a comprehensive law that regulates air emissions from stationary sources, such as factory buildings and power plants, and mobile sources, such as cars, planes, and lawnmowers. One of the goals of the Act was to set and achieve National Ambient Air Quality Standards (NAAQS) in every state by 1975 to address the health and welfare risks posed by widespread air pollutants. The Act also directs states to develop state implementation plans (SIPs) to achieve these standards.

Section 112 of the Clean Air Act specifically addresses emissions of hazardous air pollutants. The 1990 amendments to this section required the issuance of technology-based standards for major sources and certain area sources. Major sources are defined as stationary sources that emit or have the potential to emit 10 tons or more of a hazardous air pollutant per year. These standards are referred to as "maximum achievable control technology" or "MACT" standards.

The Clean Air Act has been instrumental in reducing air pollution in the United States and has had a positive impact on public health and the economy. It has helped to reduce healthcare costs and absences from work or school. The Act has also played a critical role in combating climate change by regulating and reducing greenhouse gas emissions.

Technology-based emissions standards

Under the CAA, the Environmental Protection Agency (EPA) is tasked with setting national emissions standards that target major sources of hazardous air pollutants. These standards, known as "Maximum Achievable Control Technology" (MACT) standards, are based on the emissions levels already achieved by the best-controlled and lowest-emitting sources in an industry. The CAA Amendments of 1990 introduced a shift, recognising the immediate public health benefits of implementing affordable and available control technologies. This resulted in the inclusion of economic costs and technological feasibility in determining the required level of pollution control.

The CAA requires emissions standards for various pollution sources, including motor vehicles, power plants, and industrial facilities. When setting these standards, the EPA considers the emissions performance and cost of technologies, allowing for flexibility in the methods used to comply with the standards. For instance, new gas power plants must not emit more than 1,000 pounds of CO2 per megawatt-hour of electricity produced, but the specific technology used to achieve this standard is left to the discretion of the industry.

Additionally, states play a crucial role in implementing technology-based emissions standards. They are responsible for setting emissions limits for pollution sources, considering technology performance and cost. States require "reasonably available" controls for existing stationary sources, such as factories, to meet air quality standards. The "best available control technology" requirement in permits for major new pollution sources is another example of how states regulate emissions.

EPA's role in limiting air pollution

Laws that limit air pollution include the Clean Air Act, which is a comprehensive federal law that regulates air emissions from stationary and mobile sources. The Clean Air Act also addresses emissions of hazardous air pollutants.

The Environmental Protection Agency (EPA) plays a crucial role in limiting air pollution and was founded in 1970 to protect human health and the environment by establishing and enforcing air quality regulations. The EPA enforces Clean Air Act laws to enhance air quality and safeguard public health.

The EPA sets National Ambient Air Quality Standards (NAAQS) for six major pollutants: ozone, particulate matter, carbon monoxide, sulfur dioxide, nitrogen dioxide, and lead. These standards are designed to protect public health and the environment. The EPA regulates emissions from cars, trucks, and buses, setting strict standards for new vehicles and controlling fuel sulfur content to minimize pollutants like nitrogen oxides and volatile organic compounds.

The EPA also implements the New Source Performance Rules (NSPS), which limit emissions from new or modified stationary sources, ensuring the use of the best available technology. In addition, the National Emission Standards for Hazardous Air Pollutants (NESHAPs) are employed to control emissions of hazardous air pollutants from specific industries, utilizing maximum achievable control technology to reduce toxic emissions.

Furthermore, the EPA works with states on State Implementation Plans (SIPs), which outline strategies to meet NAAQS through industrial and vehicle emissions regulations. The EPA conducts inspections and imposes penalties for non-compliance.

The EPA's efforts have significantly improved air quality, and they also provide guidelines for individuals to contribute to pollution reduction by conserving energy, limiting car use, and avoiding wood burning. Climate change adaptation and mitigation are also important aspects of the EPA's work, as they address the impacts of increased atmospheric greenhouse gases on pollution levels and vulnerable communities.

State implementation plans (SIPs)

SIPs are designed to outline how a state will achieve the NAAQS set by the EPA. They include narrative, rules, technical documentation, and agreements that a state will use to control and remediate polluted areas. For example, in Ohio between 1970 and 1977, a rule in the CAA required a reduction in the measured sulfur dioxide (SO2) emitted by coal-fired power plants. The SIP to achieve this was to increase the height of the smokestacks on the plants, so the SO2 was carried in the wind out of the state, resulting in reduced measured SO2 levels near the source.

SIPs are developed by state agencies and then approved by the EPA. The Lowest Achievable Emissions Rate (LAER) is a standard used by the EPA to determine if emissions from a new or modified major stationary source are acceptable under SIP guidelines. LAER standards are applied when a new stationary source is located in a region that has not met air quality standards. These standards are more stringent than the Best Available Control Technology (BACT) and Reasonably Available Control Technology (RACT) standards.

The CAA has undergone several amendments since its inception, with the 1990 amendments setting deadlines for states to attain NAAQS based on the severity of their air pollution problems. These amendments also revised Section 112, which addresses emissions of hazardous air pollutants. Section 112 now requires the EPA to establish technology-based standards for "major sources" and certain "area sources" of hazardous air pollutants. "Major sources" are stationary sources that emit or have the potential to emit 10 tons per year or more of a hazardous air pollutant, while "area sources" are any stationary sources that are not considered major.

Litigation and the Clean Air Act

The Clean Air Act (CAA) is a comprehensive federal law that regulates air emissions from stationary and mobile sources. The Act authorises the Environmental Protection Agency (EPA) to establish National Ambient Air Quality Standards (NAAQS) to protect public health and welfare and to regulate emissions of hazardous air pollutants. The CAA has been amended several times since its inception, with the most recent amendments in 1990 focusing on setting new goals and dates for achieving NAAQS.

The CAA has been the subject of numerous court cases and litigation over the years. One example is Massachusetts v. EPA, 549 U.S. 497 (2007), which upheld that gases causing global warming are considered pollutants under the CAA. Another case, Environmental Defense v. Duke Energy Corporation, 549 U.S. 561 (2007), ruled that industrial smokestacks and power plants must meet today's cost-effective pollution control standards when facilities are updated.

The Supreme Court has also played a significant role in shaping the CAA and its implementation. In one notable case, Ohio v. EPA, the Court put on hold an EPA air pollution regulation intended to prevent upwind states from harming downwind states and their residents. This decision was part of a string of rulings expressing hostility towards federal regulatory agencies and public health protections.

Another case, Corner Post Inc. v. Board of Governors of the Federal Reserve System, exposed even well-settled agency regulations to near-endless litigation. The Court's decision in this case interpreted the statute of limitations for civil actions against the United States as running separately for each individual starting when they are first injured by a regulation, allowing new entities to challenge regulations decades after they were published.

The CAA continues to be a critical tool in the fight against air pollution and climate change, and litigation surrounding the Act will likely continue to shape its implementation and impact.

Frequently asked questions