Best available technologies to reduce pollution

DEFINITION: The most efficient control and treatment techniques that are economically achievable by various industries to limit adverse environmental impacts

As concerns regarding all forms of pollution have increased around the world, many governments—including those of the United States and many European nations—have responded with environmental laws requiring industries to employ the best available techniques to reduce polluting emissions and discharges.

Major US industries receiving national permits, usually from the Environmental Protection Agency (EPA), for new or modified emissions and point source discharges regulated by the Clean Air Act and the Clean Water Act are required to use the best available technologies to reduce environmental pollution. Best available technologies, also known as best available control technologies and best available techniques, include state-of-the-art controls on emissions and discharges into environmental media such as air, water, and soil. The term “available” means that the technology exists or is capable of being developed. A best available technology, however, must be affordable based on a cost-benefit analysis.

In addition to best available technology standards, the environmental laws in the United States include requirements for best conventional technologies. The best available technology mandates generally apply to pollutants that are considered to be toxic or are labeled as nonconventional because no determination has yet been made concerning their toxicity. However, once the EPA determines that a pollutant is toxic, an industry has three years to meet the best available technology standards that apply to that pollutant. Conventional pollutants, such as agricultural chemicals that have the ability to accumulate in body fat but have not been deemed toxic, are governed by the best conventional technology standards.

The permitting agency reviews each major industrial application for a stationary source permit to allow emissions into the air or discharges into the water on a case-by-case basis. Environmental, energy, and economic impacts are all considered in determining which processes and techniques an industry can afford while still protecting the environment. A variance from a best available technology standard may be granted as part of the permitting process to an industry that has agreed to use the best technology that is financially achievable, even if the technology is not the latest available. The technology used, however, must not create further pollution. For example, an industry will not receive a waiver to the best available technology requirements under the Clean Water Act unless it can show that the discharge controls and techniques it will utilize will not interfere with the quality of public water supplies, recreational activities, or wildlife, fish, and shellfish populations.

Under the Clean Air Act, some of the best available technology standards include production and treatment techniques and fuel cleaning and combustion systems for various regulated air pollutants. Under the Clean Water Act, effluent guidelines are based on best available technologies to achieve the goal of eliminating the discharge of all pollutants into the waters of the United States. Some of the factors considered in the cost-benefit analysis to determine if the effluent technologies are economically feasible include assessment of existing equipment, facilities, and techniques used in effluence reduction; the cost to achieve further effluent reduction; and other environmental impacts that are not related to water quality but that may occur if new technologies are employed, such as increased energy requirements. In addition to effluent guidelines, the Clean Water Act requires the use of best available technologies to minimize environmental impacts for cooling water intake structures that might be used in industries that produce heated water, such as nuclear power plants and food and beverage manufacturing facilities employing pasteurization.

Into the mid-2020s, the best available technology standards have increasingly been applied to greenhouse gas emissions following the Supreme Court’s 2007 Massachusetts v. EPA ruling. Under President Joseph Biden's administration, the EPA issued stricter rules for industries, such as power generation, oil and gas, cement, and chemicals. These included updated effluent limitation guidelines, tighter cooling water intake requirements, and draft rules requiring carbon capture or equivalent controls for new fossil fuel plants. In 2023, the agency also set new discharge limits for PFAS (“forever chemicals”), expanding the scope of pollutants covered by best available technology standards.

Bibliography

Malone, Linda A. Emanuel Law Outlines: Environmental Law. 4th ed., Wolters Kluwer, 2014.

“Massachusetts v. EPA, 549 U.S. 497 (2007).” Justia, supreme.justia.com/cases/federal/us/549/497/. Accessed 21 Aug. 2025.

Morag-Levine, Noga. Chasing the Wind: Regulating Air Pollution in the Common Law State. Princeton UP, 2009.

Percival, Robert V., and Christopher H. Schroeder. Environmental Law: Statutory and Case Supplement 2023-2024. Aspen, 2023.

"Setting Emissions Standards Based on Technology Performance." Environmental Protection Agency, 17 July 2025, www.epa.gov/clean-air-act-overview/setting-emissions-standards-based-technology-performance. Accessed 21 Aug. 2025.