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New Source Review


The purpose of the New Source Review (NSR) program is to provide methods to grant Authorities to Construct to new and modified stationary sources without interfering with the attainment or maintenance of ambient air quality standards. When a person applies for a permit for new equipment or to modify existing equipment, the source must go through a NSR review, which is conducted pursuant to Monterey Bay Air Resources District (MBARD) Rule 207. Although the nuances of NSR are intricate, there are two key elements; Best Available Control Technology and Emissions Offsets.

Best Available Control Technology

Best Available Control Technology (BACT) is the requirement for certain air pollution sources install equipment or employ administrative practices which will result in the lowest achievable emission rate. The lowest achievable emission rate is defined by state law as:

  • The most stringent emission limitation contained the State Implementation Plan for the particular class or category of source, unless the owner of the source demonstrates that the limitation is not achievable, or
  • The most stringent emission limitation that is achieved in practice by that class or category or source.

In no case can the lowest achievable emission rate be greater than the emissions allowed under a federal New Source Performance Standard.

For MBARD BACT requirements please see equipment specific pages.  If there are no BACT requirements listed by MABRD, per the District policy, the South Coast Air Quality Management District's (SCAQMD) BACT Guidelines are the preferred methods for determining BACT requirements.  Please see SCAQMD's "Part D: BACT Guidelines For Non-Major Polluting Facilities."

Emissions Offsets

An emissions offset is a reduction in pollution from an existing source of air pollution within MBARD's jurisdiction. It is an emission reduction credit that compensates for an emission increase of an affected pollutant from a new or modified source subject to the requirements of Rule 207. When emissions are offset, the total allowable emissions from existing sources and the proposed source will be less than the total emissions from existing sources.