When the current LRTP was originally adopted, the MATS area was found to be conforming with all applicable National Ambient Air Quality Standards (NAAQS) as defined by the U.S. Environmental Protection Agency. Previously, the MATS area was designated an Air Quality Maintenance Area under the 1997 NAAQS for Ozone and Particulate Mater of less than 2.5 microns in diameter. The 1997 NAAQS standards revoked with the adoption of the new standards, and with that, the MATS designation as an Air Quality Maintenance area was lifted.
Subsequent to that Conformity designation, a decision by the Federal 3rd Circuit Court of Appeals (South Coast Air Quality Management District vs. U.S. EPA; 882 F.3rd 1138) reinstated the Maintenance Area designation for the MATS area under the 1997 NAAQS. As a result, MATS re-adopted air quality Transportation Conformity Determination protocols for amendments to the LRTP and TIP. These protocols, and procedures for compliance, can be found in the document embedded below.