Regs serve up alphabet soup

To make sense of all the acronyms that find their way into air regulations, environmental professionals may need a crib sheet. Certain acronyms are basic to understanding both the ambient air quality and air toxics provisions of the federal Clean Air Act as amended in 1990 (CAAA). Foremost among these are acronyms that don't even appear in the Act such as BACT, LAER, RACT, MACT and GACT. These acronyms are classified by their relationships to the acronyms NAAQS and NESHAP. National Ambient Air Quality Standards (NAAQS) and National Environmental Standards for Hazardous Air pollutants (NESHAP) designate two separate types of air pollution standards. Under NAAQS, control technology requirements vary based on a source's geographic location. The United States is divided into attainment areas and non-attainment areas, depending on the level of criteria pollutants in the area's ambient air. NESHAP provisions, which regulate emissions of a hazardous air pollutant, base control technology requirements on the source category and quantity of toxic emissions.