Note: EPA no longer updates this information, but it may be useful as a reference or resource.
Please see www.epa.gov/nsr/ for the latest information on EPA's New Source Review program.
June 13, 1978 Impact of Secondary Emissions in New Source Reviews 24.5The revised emission offset policy defines "secondary emissions" as emissions from new or existing sources which occur as a result of the construction and/or operation of a major source or major modification, but do not come from the source itself. Secondary emissions must be specific and well defined, must be quantifiable, and must impact the same general nonattainment area as the major source which causes secondary emissions.
Secondary emissions need not be considered in determining whether the emission rate cutoff points would be exceeded. However, if a source is subject to the offset ruling on the basis of the direct emissions from the source, the applicable conditions of the ruling must also be met for secondary emissions.