Approval and Promulgation of Implementation Plans; Washington: Spokane Second 10-Year Carbon Monoxide Limited Maintenance Plan

The Environmental Protection Agency (EPA) is approving the limited maintenance plan submitted on May 11, 2016, by the Washington Department of Ecology (Ecology), in cooperation with the Spokane Regional Clean Air Agency (SRCAA) for the Spokane carbon monoxide (CO) maintenance area (Spokane area or area). The Spokane area includes the cities of Spokane, Spokane Valley, Millwood, and surrounding urban areas in Spokane County, Washington. This plan addresses the second 10- year maintenance period for the National Ambient Air Quality Standards (NAAQS) promulgated for CO, as revised in 1985. The Spokane area has had no exceedances of the CO NAAQS since 1997 and monitored CO levels in the area continue to decline steadily. The EPA is also approving an alternative CO monitoring strategy for the Spokane area which was submitted as part of the limited maintenance plan.