Approval and Promulgation of Air Quality Implementation Plans; State of Utah; Salt Lake County-Trading of Emission Budgets for PM10 Transportation Conformity

EPA is finalizing approval of the State of Utah's revision to the Utah State Implementation Plan (SIP) that was submitted by the Governor on May 13, 2002. This SIP revision allows trading from the motor vehicle emissions budget for primary Particulate Matter of 10 microns or less in diameter (PM<INF>10</INF>) to the motor vehicle emissions budget for Nitrogen Oxides (NO<INF>X</INF>) which is a PM<INF>10</INF> precursor. EPA's approval of this SIP revision allows Salt Lake County to increase their NO<INF>X</INF> budget in the Salt Lake County PM<INF>10</INF> SIP by decreasing their PM<INF>10</INF> budget in the Salt Lake County PM<INF>10</INF> SIP by an equivalent amount, and use these adjusted motor vehicle emissions budgets for NO<INF>X</INF> and PM<INF>10</INF> to demonstrate transportation conformity with the Salt Lake County PM<INF>10</INF> SIP. Trading between emissions budgets for transportation conformity is allowable as long as a trading mechanism is approved into the SIP. On May 1, 2002, EPA published a notice of proposed rulemaking (NPR) that used EPA's parallel processing procedure to propose approval of this SIP revision (67 FR 21607). EPA's NPR was in response to a letter of March 15, 2002, in which the Governor asked that EPA parallel process a proposed revision to the Salt Lake County PM<INF>10</INF> SIP consisting of a new rule, R307-310 "Salt Lake County: Trading of Emission Budgets for Transportation Conformity." On May 13, 2002, the Governor submitted the final version of R307-310 for EPA's approval. EPA's 30-day comment period concluded on May 31, 2002. During this comment period, EPA received one comment letter in response to the May 1, 2002, NPR. In this final rule action, EPA summarizes all comments and EPA's responses, and approves the Governor's May 13, 2002, final SIP revision, involving Utah's new rule R307-310.