Section 110(a)(2)(D)(i) of the federal Clean Air Act, known as the "good neighbor" provision, requires states to demonstrate to the U.S. Environmental Protection Agency (EPA) that emissions from one state do not adversely affect another state. Specifically, the act prohibits any source or other type of emissions activity within the state from emitting any air pollutant in amounts which will:

(I) contribute significantly to nonattainment in, or interfere with
maintenance by, any other state with respect to any ... national
primary or secondary air quality standard, or

(II) interfere with measures required to be included in the applicable
implementation plan for any other state ... to prevent significant
deterioration of air quality or to protect visibility.

DEQ has evaluated its existing State Implementation Plan (SIP) and the state's Rules for the Control of Air Pollution in Idaho and has determined that the SIP and rules meet the requirements of Section 110(a)(2)(D)(i) for the 8-Hour Ozone and PM2.5 National Ambient Air Quality Standards. An information document detailing Idaho's compliance has been developed and will be incorporated into Idaho's SIP.