The Office of Inspector General (OIG) performed six audits on EPA’s oversight of the states’ air enforcement data. The six states reviewed were located in four of EPA’s ten regions. The OIG identified national issues during these audits and have used that work as a basis for this report. The objective of this audit was to determine the functions that the Office of Enforcement and Compliance Assurance (OECA) needs to perform in order to resolve the deficiencies identified by the previous audits of state enforcement data.