What is an Area Source of Hazardous Air Pollutants? Why is it regulated?

Hazardous air pollutants (HAPs) are known or suspected to cause adverse environmental effects and/or serious health effects. The U.S. Environmental Protection Agency (EPA) has identified 187 air pollutants, for example, benzene, which is found in gasoline. EPA places standards, or requirements on categories of stationary sources that emit (or have the potential to emit) one or more hazardous air pollutants called national emission standards for hazardous air pollutants (NESHAP) standards. EPA lists these standards and which agency enforces the standards in tables published in the Federal Register.

Major source of hazardous air pollutants: The term "major source"  refers to any stationary source or group of stationary sources that emits or has the potential  to emit 10 tons per year of any of the 187 named pollutants, or 25 tons per year of a mixture of pollutants.

Area source of hazardous air pollutants: The term "area source" refers to facilities that release smaller quantities of toxic air pollutants. Although emission from one area source may be relatively small, multiple area sources concern environmental specialists, especially when they are in densely populated areas.

To reduce the hazardous area pollutants released by area sources, EPA places standards, or requirements, on area sources to minimize emissions. These requirements call for specific management practices and generally available control technologies (GACT). These technologies consist of methods, practices, and techniques applicable to area sources. When EPA developed these technologies, staff members considered the economic impact as well as the technical abilities of employees to operate and maintain systems for emission control.

What are Missouri's Area Source Requirements?

The following table gives area source requirements for which the Missouri Department of Natural Resources is conducting compliance-enforcement activities. Direct questions regarding standards, compliance, and reports about area sources to the agency listed as “Regulating Agency” in the table, below. The department's Air Pollution Control Program recommends that facilities submit notifications and other required reports about area sources to the air program and EPA Region 7 contacts. If you have questions regarding any of the area source regulations or need help navigating the requirements, contact the Air Pollution Control Program.

Dry Cleaners

Online Compliance Resources for Missouri Area Source Requirements

Regulating Agency Description 40 CFR 63 Subpart Title V Permit Sort descending Keywords Rule and Implementation Information Regulation Helpful Link
EPA Gasoline Dispensing Facilities (6C) - CCCCCC Exempt Gasoline Link Link Link
EPA Secondary Nonferrous Metals Processing (6T) - TTTTTT Exempt Nonferrous metals Link Link
EPA Gasoline Distribution (6B) - BBBBBB Exempt Gasoline Link Link Link
EPA Wood Preserving Industry (6Q) - QQQQQQ Exempt Wood Preserving Link Link
MoDNR Halogenated Solvent Cleaning (Major and area sources) (1T) - T Exempt Solvent Cleaning Link Link
MoDNR Hard and Decorative Chromium Electroplating and Chromium Anodizing Tanks (Major and area sources) (1N) - N Exempt Chromium Link Link
EPA Hospital Ethylene Oxide Sterilizers (5W) - WWWWW Exempt hospital Link Link
EPA Industrial, Commercial and Institutional Boilers (6J) - JJJJJJ Exempt Boilers Link Link Link
EPA Iron and Steel Foundries (5Z) - ZZZZZ Exempt Foundry Link Link
EPA Lead Acid Batteries Industry (6P) - PPPPPP Exempt lead Link Link
MoDNR Portland Cement Regulations (Major and area sources) (3L) - LLL Major Permit Cement Link Link
EPA Carbon Black Production (6M) MMMMMM Major Permit Carbon Black Link
EPA Primary Copper Smelting (6E) - EEEEEE Major Permit Copper Link
EPA Chemical Manufacturing Area Sources: Chromium Compounds (6N) - NNNNNN Major Permit Chromium, Chromium Manufacturing Link
MoDNR Primary Lead Smelting (3T) - TTT Major Permit lead Link Link
EPA Primary Nonferrous Metals Area Sources—Zinc, Cadmium, and Beryllium (6G) - GGGGGG Major Permit zinc, Cadmium, beryllium Link
MoDNR Printing and Publishing Industry (Some Major sources that can prove actuals below HAP limits) (2K) - KK Major Permit Printing Link Link
MoDNR Coke Oven Batteries (Reg refers to Sources, not area or major) (1L) - L Major Permit Coke Ovens Link Link
EPA Electric Arc Furnaces Steelmaking Facilities (5Y) - YYYYY Major Permit Steel Link Link Link
EPA Secondary Copper Smelting (6F) - FFFFFF Major Permit Copper Link