In its implementation of the Clean Air Act Amendments of 1990 (CAAA), the EPA is seeking ways to promote pollution prevention. The CAAAs Title V creates an Operating Permits program that requires facilities to have all of their federal and state air requirements and compliance schedules within one document, known as the operating permit. These permits do not contain new requirements beyond those already mandated by state and federal law. Permits are one of the primary vehicles by which environmental law and policy are applied to industry. To explore how pollution prevention (P2) can be integrated with the Title V program, EPAs Office of Air Quality Planning and Standards (OAQPS), which is responsible for developing regulations under the Acts Title V Operating Permits provisions, established two pilot projects. These projects explored how pollution prevention and operational flexibility could be integrated with permits issued to a pharmaceutical firm (Merck) and a semiconductor manufacturer (Intel). In addition to EPAs efforts, many states are examining ways of promoting pollution prevention and providing operational flexibility to facilities. In support of these pilot projects and its other efforts to investigate ways to integrate P2 with the Title V program, EPA tasked Research Triangle Institute (RTI) to review existing national, state and local efforts to integrate P2 into permits and to assess the effectiveness of these efforts. However, the scope of this report does not address how OAQPS could promote the promising efforts identified here and elsewhere.