Clean Air Act Applicability Determinations

Highlights

Applicability Determination Index

The general provisions to the New Source Performance Standards (NSPS) in 40 CFR Parts 60 and the National Emission Standards for Hazardous Air Pollutants (NESHAP) in 40 CFR Parts 61 and 63, under the Clean Air Act, provide that a source owner or operator may request a determination of whether certain intended actions constitute the commencement of construction, reconstruction, or modification. EPA's written responses to these inquiries are broadly termed applicability determinations.

The NSPS and NESHAP also allow sources to seek permission to use monitoring or recordkeeping which is different from the promulgated requirements. EPA's written responses to these inquiries are broadly termed alternative monitoring decisions.

Further, EPA responds to written inquiries about the broad range of NSPS and NESHAP regulatory requirements as they pertain to a specific source. These inquiries question whether a regulation applies to a specific source, or may relate to the testing, monitoring, recordkeeping or reporting requirements contained in the regulation as it applies to a specific source.

To ensure nationally consistent responses, the Agency currently compiles EPA-issued NSPS and NESHAP applicability determinations, alternative monitoring decisions, and regulatory interpretations, and posts them on the Applicability Determination Index (ADI) on a quarterly basis. In addition, the ADI contains EPA-issued responses to requests pursuant to the chlorofluorocarbons (CFC) regulations, cited in 40 CFR Part 82.

The ADI is a computerized database of such letters and memoranda that allows users to search by date, office of issuance, subpart, citation, control number, or string word searches. The Office of Enforcement and Compliance Assurance (OECA), Compliance Assessment and Media Programs Division (CAMPD) maintains the ADI database and provides guidance on how to review and issue CAA applicability determinations.