Clean Air Act Approval and Promulgation of State Implementation Plan; Colorado; Prevention of Significant Deterioration; Designation of Areas for Air Quality Planning Purposes

In this document, EPA is approving revisions to Colorado's prevention of significant deterioration (PSD) permitting requirements in Regulation No. 3, which were submitted as revisions to the State Implementation Plan (SIP) by the Governor on August 1, 1996. The revisions were submitted mainly to address the replacement of the total suspended particulate (TSP) increments with increments for particulate matter with an aerodynamic diameter less than or equal to a nominal ten micrometers (PM-10). EPA is also deleting the TSP area designation table and revising the PM-10 area designation table in 40 CFR part 81 for Colorado. With the PM-10 increments becoming effective in these areas, the TSP area designations no longer serve any useful purpose relative to PSD. Also in this document, EPA is amending the language in 40 CFR 52.343(a)(3) to further clarify which sources EPA retains PSD permitting authority over in the State of Colorado.