Federal Rulemaking for the FMC Facility in the Fort Hall PM-10 Nonattainment Area

The Environmental Protection Agency (EPA) proposes to promulgate a Federal Implementation Plan (FIP) containing emission limits and work practice requirements that represent reasonably available control technology, along with related monitoring, recordkeeping, and reporting requirements, for particulate matter air pollution emitted from an elemental phosphorous facility owned and operated by FMC Corporation and located within the exterior boundaries of the Fort Hall Indian Reservation in southeastern Idaho (FMC or FMC facility). A portion of the Fort Hall Indian Reservation, known as the ``Fort Hall PM-10 nonattainment area,'' has been designated as a nonattainment area for the National Ambient Air Quality Standards (NAAQS) for particulate matter with an aerodynamic diameter less than or equal to a nominal ten micrometers (PM-10), which pre-date the new PM NAAQS that were promulgated in 1997. The FMC facility is the only major stationary source of PM-10 located in the Fort Hall PM-10 nonattainment area. Although there are other area sources and minor stationary sources of PM-10 in the Fort Hall PM-10 nonattainment area, EPA believes that these other sources have an insignificant impact on the violations of the pre-existing 24-hour PM-10 standard that have been recorded by the monitors located in the nonattainment area. EPA believes that the control strategy for FMC proposed by EPA in this rulemaking is necessary to ensure maintenance of air quality that protects public health during the transition period leading to implementation of the newly-promulgated PM standards and assist in bringing the Fort Hall PM- 10 nonattainment area into attainment with the recently-promulgated PM NAAQS as expeditiously as practicable. If EPA later determines that sources other than FMC contribute to PM violations in the area, the Shoshone-Bannock Tribes or EPA will develop and impose appropriate controls on these other sources in the Fort Hall PM-10 nonattainment area. EPA's 1997 PM NAAQS rulemaking established new standards for particulate matter with a diameter equal to or less than 2.5 microns and also revised the existing PM-10 standards. Today's proposal, however, does not directly address these new and revised standards. Rather, it addresses requirements under the pre-existing PM-10 standards, which are still in effect for a limited time, and the provisions of section 172(e) to which the Fort Hall PM-10 nonattainment area is subject during the transition toward implementation of the new and revised PM standards.