Approval and Promulgation of Implementation Plans; Spokane, Washington: Second 10-Year PM10

The Environmental Protection Agency (EPA) is proposing to approve the limited maintenance plan submitted on January 4, 2016, by the State of Washington for the Spokane area, which includes the cities of Spokane, Spokane Valley, Millwood and surrounding unincorporated areas in Spokane County, Washington. This plan addresses the second 10- year maintenance period for particulate matter with an aerodynamic diameter less than or equal to a nominal 10 micrometers (PM10). A limited maintenance plan is used to meet Clean Air Act requirements for formerly designated nonattainment areas that meet certain qualification criteria. The EPA is proposing to determine Washington's submittal meets the limited maintenance plan criteria. The Spokane area currently has monitored PM10 levels well below the National Ambient Air Quality Standards (NAAQS) and levels have not increased since the area was redesignated to attainment in 2005. The EPA is also proposing to approve minor updates to the Spokane Regional Clean Air Agency (SRCAA) regulations controlling PM10 related to the maintenance plan.