Specific Elements for Each of the Major SIP Types for Sulfur Dioxide (SO2)
Infrastructure State Implementation Plan (SIP)
An infrastructure SIP, or i-SIP, is a requirement for all states, regardless of designation. Even areas in attainment must demonstrate what controls they will continue to use and regulate in order to remain in attainment.
Nonattainment New Source Review SIP
- EPA's New Source Review (NSR) program requires major stationary sources of air pollution in nonattainment areas to get permits before construction starts:
- Startup, shutdown, and malfunction (SSM) emissions
Nonattainment Area SIP
- If an area is designated as nonattainment, the state must develop an additional SIP detailing the path to attainment. The SIP will require different elements depending on how far the area is from being able to reach attainment.
Interstate transport SIP
- Interstate Air Pollution Transport: upwind transport of pollutants across state borders makes it difficult for downwind states to meet health-based air quality standards for SO2.
- Cross-State Air Pollution Rule (CSAPR) provides the regulatory basis for reducing interstate air pollution.