Energy & environment · 26/02/2010Updated: 10/17/2026 · 1 min read

EPA Approves Ohio and Indiana's Requests to Redesignate Cincinnati-Hamilton Area for Ozone Attainment

The US Environmental Protection Agency (EPA) is proposing to approve Ohio and Indiana's requests to redesignate the Cincinnati-Hamilton area to attainment for the 8-hour ozone National Ambient Air Quality Standard (NAAQS), following statutory requirements under the Clean Air Act (CAA). The redesignation is based on three years of complete ambient air quality monitoring data for the 2007-2009 ozone seasons.