1998 Year of the Ocean Perspectives on Marine Environmental Quality 



Clean Air Act , as amended, (CAA), 42 U.S.C. §§ 7401 et se^. 



The CAA is divided into six principal subchapters. Subchapter 1 addresses air pollution from 

 stationary sources and requirements for states to develop plans to meet health-based standards. 

 (Also, subchapters IV-A, V and VI deal with specific stationary source programs.) Part A of 

 subchapter I contains the basic provisions to control air pollution from stationary sources. Based on 

 statutor}' criteria, the Environmental Protection Agency (EPA) is required to list criteria pollutants 

 and for each such pollutant establish primary and secondary national ambient air quality standards 

 (NAAQSs). Each state (or EPA, if the state declines) must submit to EPA a state implementation 

 plan with individual emission limitations and procedures to ensure timely attainment of the 

 NAAQSs for each air quality region within the state. 



Part A also includes, among other things, key specialized stationary source programs. For example, 

 EPA must adopt emission standards for categories of hazardous air pollutants (HAPs) in 

 accordance with a specified schedule. (HAPs are listed in the statute.) Section 1 12(m) of the CAA 

 directs EPA. in cooperation with the National Oceanic and Atmospheric Administration, to assess 

 the extent of atmospheric deposition of HAPs (and, in the discretion of EPA, other air pollutants) to 

 the Great Lakes, Chesapeake Bay, Lake Champlain and coastal waters (defined, for purposes of the 

 subsection, as estuaries under the National Estuary Program and National Estuarine Research 

 Reserves). The assessment program is to, among other things, establish a monitoring network, 

 investigate sources and deposition rates, evaluate any adverse effects to public health or the 

 environment, and assess the contribution of such deposition to violations of water quality standards 

 established pursuant to the Clean Water Act. EPA is to submit biennial reports to Congress on the 

 matter and issue a determination as to whether the other provisions of section 1 1 2 are adequate to 

 prevent serious adverse effects to public health and serious or widespread environmental effects 

 associated with HAP deposition. If EPA determines that the authorities of section 1 12 are not 

 adequate, the agency is directed to promulgate such further emission standards or control measures 

 under section 1 12 as may be necessary and appropriate. 



Part B of Subchapter 1 is repealed; Part C addresses the "prevention of significant deterioration ' 

 program, designed to limit the deterioration of air quality in regions with air cleaner than the 

 minimum federal air quality standards. Part D addresses plan requirements for non-attaimnent 

 areas. 



Subchapter II addresses emission standards for moving sources. 



Subchapter III addresses administration and enforcement. Amendments to Subchapter 111 made in 

 1990 require EPA, following consultation with the Department of the Interior and the U.S. Coast 

 Guard, to establish regulatory requirements to control air pollution from Outer Continental Shelf 

 sources (except in the Gulf of Mexico, over which the Department of the Interior has jurisdiction). 



Subchapter IV-A addresses acid deposition. This subchapter was added in 1 990 to reduce emissions 

 of pollutants, primarily sulfur dioxide and nitrogen dioxide, leading to the formation of acid 

 precipitation. 



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