Is Herculaneum the only area with a State Implementation Plan?
No. The Clean Air Act has been in existence since 1970. According to the EPA, areas of the country where air pollution levels persistently exceed the national ambient air quality standards may be designated “nonattainment.” Currently, there are more than 500 areas nationwide that are designated as such, all of these have SIPs in place that are designed to work toward attainment of the air quality standards. To maintain quality standards, air quality areas that have reached attainment keep a SIP in place, simply amending the plan as needed. For a list of areas designated nonattainment, visit www.epa.gov/oar/oaqps/greenbk/.
