By Robynn Andracsek, PE
Air permitting people love acronyms. And have you noticed that they all seem to sound the same? You're not imagining things. This article will help you understand the alphabet soup that regulates a facility's emissions. Learn a few. Sound like you know what you're talking about — because you will — and impress your boss and co-workers. Be a hit at the next conference. You, too, can speak in acronym code.
Table 1 lists the common regulations that can require a facility to control or limit emissions. Best available control technology (BACT) applies to criteria pollutants for which a source is subject to Prevention of Significant Deterioration (PSD). Similarly, lowest achievable emission rate (LAER) applies to pollutants for which a source is subject to Non-Attainment New Source Review (NNSR) and for which the source's location is out of attainment (Figure 1). Reasonably available control technology (RACT) addresses pollutants for which an area is out of attainment. Maximum achievable control technology (MACT) applies to hazardous air pollutants (HAPs). There were originally 188 HAPs, but some have been delisted, e.g., methyl ethyl ketone, and some are actually groups of chemicals, e.g., glycol ethers, (www.epa.gov/ttn/atw/188polls.html). Clean Air Interstate Rule (CAIR) and Cross-State Air Pollution Rule (CSPAR) were developed to address PM2.5 non-attainment through its precursors, SO2 and NOx. Finally, each New Source Performance Standard (NSPS) applies to specific criteria pollutants and sometimes to HAPs.
A Key to Understanding the Requirements
There are subtle differences in the names of these control requirements that give insight as to what level of control is required. Take for example the various uses of "available" versus "achievable." An available control technology is not necessarily the one with the lowest emission rate. You might be allowed to take into account the cost of the technology or if it is commercially available. Contrast "available" with "achievable," which can be taken to mean to lowest or strictest emission limit found anywhere. "Available" is usually less strict than "achievable."
Type of Sources
Another important difference is understanding which control requirements apply to which sources. BACT, NSPS and lowest achievable emission rate (LAER) only apply to newly constructed or modified major sources. In the case of NSPS, "new" is defined by a specific date in each NSPS. Some NSPSs have two sets of "new" sources, based on the date when the NSPS was modified. (See NSPS Subpart Da for an example.) BACT and LAER evolve over time and are redefined with each new construction permit application issued. RACT and best available retrofit technology (BART) apply to existing sources and require the retrofit of control devices. MACT, the Clean Air Interstate Rule (CAIR) and Clean Air Mercury Rule (CAMR) apply to both new and existing sources, but may have different requirements for each. (For now, we'll ignore the Clean Air Mercury Rule, which is in legal limbo and may go away entirely. Likewise, CAIR is under legal attack and its fate is uncertain.)
Location of Sources
The location of a source can also dictate if a control requirement applies. BACT applies only in attainment areas; LAER and RACT only in non-attainment areas. See Figure 1. BART addresses visibility and is only applicable to sources having an influence on the visibility in a Class I area. The BART applicable sources are usually located within 155 miles (250 km) of one of these areas. However the case-by-case applicability analysis can extend BART to 248 miles (400 km) or more away from a Class I area.
Each regulation controls a different subset of pollutants. There are seven criteria pollutants, as shown in Table 2, and a list of toxic chemicals known as HAPs.
Title IV and Title V
The end result of all of these abbreviations will be the permits in which the regulations are implemented, specifically the Title IV Acid Rain permit and the Title V Operating permit.
Title IV of the Clean Air Act (or Acid Rain Program) regulates electric utilities over 25 MW (with some exceptions) that sell electricity to the distribution grid. Title IV requires a designated representative, similar to the responsible official of the Title V program, who is personally responsible for compliance with the regulation.
Title V of the Clean Air Act establishes an operating permit program for major facilities, those with emissions of any criteria pollutant more than 100 tons per year (tpy) (100,000 tpy for CO2e) or HAP emissions more than 10 tpy for a single HAP or 25 tpy for all HAPs combined. A Title V permit should role up all of the construction permits for a facility into a single document, as well as add additional monitoring (such as compliance assurance monitoring) and regular certification of compliance. Title V requires a responsible official, a specific officer in the company or a person delegated by an officer to take personal responsibility for the plant's compliance. This person can in theory be fined or jailed for violations of the Clean Air Act.
Air permitting acronyms can be very easy, if you spend all day, every day, reading air pollution control regulations. And, remember, if it doesn't make sense, then you probably understand it correctly.
About the Author
Robynn Andracsek, PE, is an associate environmental engineer in the Burns & McDonnell Environmental Studies & Permitting. She specializes in
air quality regulations.