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Clean Air Act (CAA)

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The objective of the Clean Air Act is to protect human health, welfare, and the environment by maintaining and improving the quality of the air through the development of standards.

Summary of Clean Air Act and Amendments

Agriculture-Specific Requirements

More Information

Related topics
Air and Climate

Agricultural Burning
Risk Management Program

Related publications from the Ag Center
Air and Climate 
Climate Change
Risk Management Plan (RMP) Information 

Text of law and related regulations
Clean Air Act
Air Regulations 40 CFR Parts 50 - 97 (scroll down; select Parts 50-97)

More information from EPA 
Clean Air Act -- Plain English Guide
Office of Air and Radiation Home Page
Office of Air and Radiation Policy and Guidance

More information from states Exit EPA
National Association of State Departments of Agriculture (NASDA) - Representatives of the state departments of agriculture in the development, implementation, and communication of sound public policy and programs which support and promote the American agricultural industry, while protecting consumers and the environment.
EZregs - University of Illinois Extension Web site that identifies environmental regulations that pertain to specific agricultural and horticultural operations and practices in Illinois.

Clean Air Act enforcement
Clean Air Act: Agriculture-Related Enforcement
EPA's Air Enforcement Division
Clean Air Act Policy and Guidance

Telephone assistance from EPA 
General assistance on Clean Air Act: 919-541-0800
Stratospheric Ozone Information Hotline: 800-296-1996
Risk Management Program Hotline:  800-424-9346 or 703-412-9810

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Overview of Clean Air Act and Amendments

The Clean Air Act (CAA) and its amendments, including the Clean Air Act Amendments (CAAA) of 1990, are designed to "protect and enhance the nation's air resources so as to promote the public health and welfare and the productive capacity of the population." The CAA consists of six sections, known as Titles, that direct EPA to establish national standards for ambient air quality and provide for EPA and the states to implement, maintain, and enforce these standards through a variety of mechanisms. Under the CAA, many facilities will be required to obtain permits for the first time. State and local governments oversee, manage, and enforce many of the requirements of the CAA. CAA regulations appear at 40 CFR Parts 50 - 97 (scroll down; select Parts 50-97).

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Title I

Pursuant to Title I of the CAA, EPA has established national ambient air quality standards (NAAQSs) to limit levels of "criteria pollutants," including carbon monoxide, lead, nitrogen dioxide, particulate matter, ozone, and sulfur dioxide. Geographic areas that meet NAAQSs for a given pollutant are classified as attainment areas; those that do not meet NAAQSs are classified as non-attainment areas. Under Section110 of the CAA, each state must develop a State Implementation Plan (SIP) to identify sources of air pollution and to determine what reductions are required to meet federal air quality standards.

Title I also authorizes EPA to establish New Source Performance Standards (NSPSs), which are nationally uniform emission standards for new stationary sources falling within particular industrial categories. NSPSs are based on the pollution control technology available to that category of industrial source, but allow the affected industries the flexibility to devise a cost-effective means of reducing emissions.

Under Title I, EPA establishes and enforces National Emission Standards for Hazardous Air Pollutants (NESHAPs), nationally uniform standards oriented towards controlling particular hazardous air pollutants (HAPs). Title III of the CAAA further directed EPA to develop a list of sources that emit any of 188 HAPs, and to develop regulations for these categories of sources. To date, EPA has listed 174 categories and developed a schedule for the establishment of emission standards. The emission standards will be developed for both new and existing sources based on "maximum achievable control technology" (MACT). The MACT is defined as the control technology achieving the maximum degree of reduction in the emission of the HAPs, taking into account cost and other factors.

More information from EPA
Title I Fact Sheets for Hazardous Air Pollutants
Fact sheet: Final Air Toxics Standards for Reciprocating Internal Combustion Engines (02/17/2010) (PDF) (3 pp, 25K)
Fact sheet: Final Air Toxics Standards for Reciprocating Internal Combustion Engines (08/10/2010) (PDF) (3 pp, 32K)
Information for Irrigation Engine Owners
Fact sheet: Final Rule To Reduce Air Toxics Emissions from Area Source Prepared Feeds Manufacturing Facilities (PDF) (3 pp, 24K)
Fact sheet: Final Air Toxics Standards for Area Sources in the Chemical Manufacturing Industry (PDF) (4 pp, 37K)

Air emissions from farming practices
Under Section 110 of the CAA, each state must develop a State Implementation Plan (SIP) to identify the sources of air pollution and to determine what reductions are required to meet federal air quality standards. The degree to which ambient air emissions from farming practices -- such as prescribed burning -- are allowed are location-specific (specific to a geographic area) within each State Implementation Plan. Visibility standards may also apply through the State Implementation Plan. Locations that are in areas that have been classified as "nonattainment areas" under the National Ambient Air Quality Standards are subject to more restrictions.

For assistance in determining the potential to emit, please refer to EPA's Emissions Factors and Policy Applications Center or contact your EPA regional office or state permitting staff.

Related topics
Air and Climate

Text of applicable laws and regulations 
CAA Sec 109 National ambient air quality standards
CAA Sec 110 Implementation plans
Promulgation of each state's specific implementation plan (40 CFR Part 52)

More information from EPA
National Ambient Air Quality Standards
November 13, 2009 Federal Register Notice: Initial Air Quality Designations for the 2006 24-Hour Fine Particle (PM2.5) National Ambient Air Quality Standards
USA Air Quality Nonattainment Areas
Criteria Pollutants -- Particulate Matter 

Related publications
Clean Air Act -- Plain English Guide

Telephone assistance from EPA
General assistance on Clean Air Act: 919-541-0800

Grain terminal elevators
Grain terminal elevators having a permanent storage capacity of more than 2.5 million U.S. bushels (88,100 cubic meters) and grain storage elevators with a permanent storage capacity of more than 1.0 million U.S. bushels (35,200 cubic meters) including their loading and unloading facilities, may not discharge any gases which exhibit greater than 0 percent opacity and/or particulate matter in excess of 0.023 g/dscm. Regulations also address loading and unloading emissions.

Related topics
Air and Climate

Text of applicable laws and regulations
CAA Sec 109 National ambient air quality standards
CAA Sec 110 Implementation plans
40 CFR 60.300 (scroll down to 60.300) - Standards of Performance for Grain Elevators

More information from EPA
National Ambient Air Quality Standards
USA Air Quality Nonattainment Areas
Criteria Pollutants -- Particulate Matter

Related publications
Clean Air Act -- Plain English Guide

Telephone assistance from EPA
General assistance on Clean Air Act: 919-541-0800

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Title II

Title II of the CAA pertains to mobile sources, such as cars, trucks, buses, and planes. Reformulated gasoline, automobile pollution control devices, and vapor recovery nozzles on gas pumps are a few of the mechanisms EPA uses to regulate mobile air emission sources.

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Title IV

Title IV establishes a sulfur dioxide emissions program designed to reduce the formation of acid rain. Reduction of sulfur dioxide releases will be obtained by granting to certain sources limited emissions allowances, which, beginning in 1995, will be set below previous levels of sulfur dioxide releases.

Related topics
Air and Climate

Text of applicable laws and regulations
Clean Air Act Title IV - text
Acid Rain Regulations - 40 CFR Parts 72-80

More information from EPA
Acid Rain Program
US - Canada Air Quality Agreement and Progress Reports

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Title V

Title V of the CAA of 1990 created a permit program for all "major sources" (and certain other sources) regulated under the CAA. One purpose of the operating permit is to include in a single document all air emissions requirements that apply to a given facility. States are developing the permit programs in accordance with guidance and regulations from EPA. Once a state program is approved by EPA, permits will be issued and monitored by that state.

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Title VI

Title VI is intended to protect stratospheric ozone by phasing out the manufacture of ozone-depleting chemicals and restricting their use and distribution. Production of Class I substances, including 15 kinds of chlorofluorocarbons (CFCs), will be phased out entirely by the year 2000, while certain hydrochlorofluorocarbons (HCFCs) will be phased out by 2030.

Related topics
Air and Climate

Related publications from the Ag Center 
Air and Climate 
Climate Change

Text of applicable laws and regulations
Clean Air Act Title VI - text
List of Ozone-Depleting Substances
Substitutes for Ozone-Depleting Substances

More information from EPA
Ozone Depletion
Climate Change
Methyl Bromide
Stationary Refrigeration and Air Conditioning
Fact Sheet - Final Rule to Authorize Critical Use Exemptions of Methyl Bromide for the 2005 Supplemental Request

Telephone assistance from EPA
Stratospheric Ozone Information Hotline: 800-296-1996

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