Options for PM2.5 and PM10 Hot-Spot Analyses in the Transportation Conformity Rule Amendments for the New PM2.5 and Existing PM10 National Ambient Air Quality Standards

This supplemental proposal follows EPA's recent final rule that includes most of the transportation conformity requirements for the new 8-hour ozone and fine particulate matter (PM<INF>2.5</INF>) national ambient air quality standards. In today's action, EPA is requesting further comment on options for consideration of localized emissions impacts of individual transportation projects in particulate matter (PM<INF>2.5</INF> and PM<INF>10</INF>) nonattainment and maintenance areas. The Clean Air Act requires federally supported highway and transit projects to be consistent with ("conform to") the purpose of a state air quality implementation plan. EPA has consulted with the Department of Transportation (DOT), and DOT concurs with this supplemental proposal.