Approval and Promulgation of Air Quality Implementation Plans; State of Montana; East Helena Lead Nonattainment Area Maintenance Plan and Redesignation Request

摘要

The Environmental Protection Agency (EPA) is approving the Maintenance Plan, submitted by the State of Montana to the EPA on October 28, 2018, for the East Helena Lead (Pb) nonattainment area (East Helena NAA) and concurrently redesignating the East Helena NAA to attainment of the 1978 Pb National Ambient Air Quality Standard (NAAQS). The EPA is taking this action pursuant to the Clean Air Act (CAA).