Abstract |
The Clean Air Act, as amended in 1970, provided that for each national ambient air quality standard (NAAQS) promulgated by the Administrator, a State Implementation Plan (SIP) for each Air Quality Control Region (AQCR) was to be developed which was to contain emission control measures that would provide for attainment and maintenance of the SIP. It is now believed that continued growth of nitrogen oxide (NOx) emissions from mobile and stationary sources in a number of cases will make it difficult to maintain national standards in some areas where they are not presently being exceeded. Thus, additional NOx emission control measures may be necessary in some areas to assure attainment and maintenance of national standards. This SIP Preparation Manual for NOx has been prepared to provide guidance to EPA Regional Offices and State and local control agencies on the development of an approvable control strategy for nitrogen oxides. |