Audit, Compliance and Risk Blog

The federal Clean Air Act (CAA) requires the U.S. Environmental Protection Agency (EPA) to establish and maintain national air quality standards, including criteria for permits and other authorizations issued to (potential) emission sources by state or local air quality management agencies (with EPA itself as the default regulator if other agencies fail). Forms of authorization include permits for specified stationary emission sources, and equipment/emission standards for mobile sources and some components of stationary sources. Almost all requirements apply to “direct sources” – the equipment or activity that directly produces emissions.

The Clean Air Act (CAA) authorizes the Environmental Protection Agency (EPA) to set emission standards for motor vehicles and engines. Although the primary focus is on Corporate Average Fuel Economy (CAFÉ) standards for new vehicles, set jointly by EPA and the Department of Transportation’s (DOT’s) National Highway Traffic Safety Administration (NHTSA) (I’ve discussed ongoing disputes about the latest CAFÉ standards several times, including HERE), EPA and states also have authority over post-sale “aftermarket” equipment and modifications to vehicles.

The Environmental Protection Agency (EPA) has completed a long review, and reaffirmed the primary National Ambient Air Quality Standards (NAAQS) for particulate matter (PM), including those for PM-10 (particulates with an aerodynamic diameter less than or equal to 10 microns) and PM-2.5 (less than or equal to 2.5 microns; also call “fines”). On December 4, EPA announced it would retain the PM standards set in 2013, despite comments presenting recent scientific evidence – including evidence that higher pollution levels exacerbate harm from COVID-19 -- and seeking tighter standards.

During President Trump’s term, the Environmental Protection Agency (EPA) has taken a number of steps to narrow benefit-cost analyses (BCAs), reversing expansive approaches used during the Obama Administration and thereby reducing the calculated benefits of environmental and health regulations. EPA announced what will probably be the last such step on December 4, by adopting a new Part 83 in Title 40 of the Code of Federal Regulations (CFR) entitled “Increasing Consistency and Transparency in Considering Benefits and Costs in Clean Air Act Rulemaking Process.” (I wrote about less formal guidance in a May 2019 memorandum from EPA Administrator Wheeler to his Assistant Administrators HERE.)

The Clean Air Act (CAA) directs the Environmental Protection Agency (EPA) to define “hazardous air pollutants (HAPs)” that may pose acute health hazards, and to impose regulations to reduce those hazards. EPA requires permits for “major sources” of HAPs based on “Maximum Achievable Control Technologies (MACT),” and lesser controls for non-major “area sources.” During President Trump’s term, EPA has pursued several initiatives to make it easier for sources to reclassify from “major” to “area” in order to reduce their regulatory responsibilities.

When are changes to an existing system so extensive that they produce a “new” system? This question is conceptually important in any evolving organization, and can have important regulatory consequences if requirements for “existing” systems are substantially different than those for “new” systems. Emissions regulations under the Clean Air Act (CAA) contain many such situations, and on October 22 the US Environmental Protection Agency (EPA) adopted changes to the “project emissions accounting” it uses to decide whether modifications to an existing major source are so extensive as to trigger preconstruction New Source Review (NSR) requirements. This revision codifies into regulations a policy changed announced in 2018.

I’ve written numerous times in this space about specific efforts by the Trump administration to reduce environmental regulation and enforcement. A new study from the University of Michigan Law School quantifies reductions in the administration’s criminal enforcement levels. The report is part of the school’s “Environmental Crimes Project,” and includes the first two years of the Trump Administration as the latest in a 14-year series of federal environmental enforcement data. Readers should note that federal criminal environmental enforcement is brought by the US Department of Justice (DOJ) on behalf of the US Environmental Protection Agency (EPA); EPA and delegated state agencies bring their own civil cases, and most state criminal enforcement is brought by state prosecutors on behalf of state regulatory agencies (I summarized agency enforcement in the first year of the Trump administration HERE).

In 1987, California adopted the Air Toxics “Hot Spots” Information and Assessment Act, responding to increasing concern over toxics in the air (AB 2588 (Connelly, Sterling)).  This law complements California’s enforcement of national requirements governing stationary source emissions of air toxics. The federal Clean Air Act (CAA) required the U.S. Environmental Protection Agency (EPA) to establish and maintain a list of air toxics, named as Hazardous Air Pollutants (HAPs), and to set emissions standards (National Emissions Standards for Hazardous Air Pollutants (NESHAPs) for many HAP emission sources; California incorporates HAP/NESHAP requirements into the state’s Toxic Air Contaminant (TAC) / Airborne Toxic Control Measure (ATCM) program. (I discussed these requirements HERE).

The federal Clean Air Act (CAA) requires the U.S. Environmental Protection Agency (EPA) to establish and maintain a list of air toxics, named as Hazardous Air Pollutants (HAPs), and to set emissions standards for many sources of such pollutants. HAPs include heavy metals, organics, and other airborne pollutants that are not otherwise regulated as “criteria” air pollutants (such as carbon monoxide, particulate matter, and ground level ozone). This note summarizes requirements applicable to stationary sources.

Although a major focus of the Clean Air Act (CAA) is the definition, attainment and maintenance of national ambient air quality standards (NAAQSs), the statute doesn’t define the term “ambient air.” This gap leaves the Environmental Protection Agency (EPA) to develop regulatory and policy definitions that delimit the reach of CAA authority. Since 1971, EPA’s definition defines “ambient air” as “that portion of the atmosphere, external to buildings, to which the general public has access.” EPA also provides additional details in a series of policy documents, which have just been updated with a  memorandum from EPA Administrator Wheeler to expand the exclusions for onsite air.