1. Clean Air Act (CAA) Purpose
To control air pollution by instituting point source controls and establishing maximum pollutant levels for the ambient air
Scope
The main focus is stationary sources of air pollution, but the Act also provides some regulation for mobile sources
Who implements the program?
The EPA must establish national ambient air quality standards (NAAQS) for criteria pollutants
6 Criteria Pollutants: (i) total suspended particulates, (ii) sulfur dioxide, (iii) nitrogen oxides, (iv) carbon monoxide, (v) ozone, and (vi) lead
Each state is required to determine how to attain and maintain NAAQS by developing a State Implementation Plan (SIP)
If the EPA is not satisfied that a state’s SIP is adequate, the EPA may promulgate a Federal Implementation Plan (FIP)

2. Technology Standards
Usually require use of particular equipment that, in the EPA’s opinion, is appropriate for the applicable technology standard
Choices include:
Best Available Control Technology (BACT)
The maximum degree of reduction in pollutants that is achievable in light of economic, energy, and environmental factors
Generally Available Control Technology (GACT)
The technology that generally is available to reduce air emissions at a facility
Maximum Achievable Control Technology (MACT)
Standards based on existing technology as well as the level of control achieved by sources in each source category demonstrating the best results in eliminating pollutants
Reasonably Available Control Technology (RACT)
A technology standard pursuant to the CAA requiring facilities to use air cleaning technology reasonably available to facilities of that type and with the same type of emissions

3. Emission Standards
The CAA controls any emissions standards and the states may not usurp the authority to set those standards
The CAA is designed to set maximum levels of pollutants in “outside air” for areas typically accessible to the public
Ambient air, a key term used in the CAA, is the air outside the boundaries of one’s fence line

4. National Ambient Air Quality Standards (NAAQS)
NAAQS are the maximum levels of pollutants allowed in the ambient air (air outside the boundaries of one’s fence line)
Criteria Pollutants
6 pollutants NAAQS have been determined for
For each of these there are
Primary NAAQS
Designed to protect human health
Secondary NAAQS
Designed to promote the public welfare

5. State Implementation Plans (SIPs)
How are NAAQS implemented?
Each state is required to enact a State Implementation Plan (SIP)
Minimum standards for state SIPs are set by the CAA
If a state does not attain the NAAQS goals, the minimum requirements for its SIP will be more stringent than if it had attained the NAAQS goals
A SIP must change as federal requirements, technology, or conditions within a state change
Once approved by the EPA, a SIP may be enforced through state or federal law

6. SIP Requirements Adequate personnel/funding Air quality data
Air quality monitoring
Contingency plans
Enforceable emission limitations
Enforcement
Interstate air pollution
Local consultation
Monitoring and emission data
“Part D requirements”
Permit fees
Preconstruction review and notification
Revision

7. Federal Implementation Plan (FIP)
If the EPA is not satisfied that a state has successfully enacted a SIP for the preservation of air quality in that state, the federal government may enact its own plan (FIP) for that state

8. Attainment States v. Nonattainment States
States that are in compliance with (have attained) the NAAQS
Nonattainment States
States that do not meet the NAAQS
Additional SIP requirements are imposed on these states

9. Additional SIP Requirements for Nonattainment States
Annual incremental reductions in nonattainment pollutants
Automatic contingency measures to be implemented if the area does not make significant progress or obtain the NAAQS by the appropriate deadline
Identification and quantification of new emissions and a documentation that new emissions will not interfere with eventual attainment of the NAAQS
If permitted, the revised SIP may provide substitute equivalent techniques for modeling, inventory, and planning as long as the substituted techniques are at least as effective as the EPA’s suggested methods
Inventory of current emissions from all sources of the nonattainment pollutants
Permit requirements for any new or modified “major” or “minor” new sources
Provisions requiring that all existing sources and major sources (as soon as possible) comply with RACT technology

10. 1990 Amendments to the CAA
Added significant requirements for the following specific pollutants in nonattainment areas:
Carbon monoxide (CO)
Ozone (O3)
Particulate matter with an aerodynamic diameter of less than 10 microns (PM10)