Talk:Best available control technology

message: Regarding the content that is already there, several corrections and clarifications are in order.  First, BACT is one of several requirements of the Prevention of Significant Deterioration (PSD) preconstruction permit program under the Clean Air Act (CAA).  As such, the PSD permitting authority that has jurisdiction over the geographic area in which the stationary source is or would be located is responsible for making the BACT determination for a particular project when it issues a PSD permit. That may be EPA in some cases, but it may also be a state or local air quality control agency.  
Next, while it is true that BACT is often expressed in terms of a numeric emission limit, that may not always be the case.  In situations where the permitting authority can demonstrate that it is not possible to express a BACT requirement as a numeric emission limit, it may be acceptable to establish BACT as a work practice standard. 
The statement that BACT is the current EPA standard for all polluting sources that fall under the New Source Review guidelines is not entirely accurate.  The term "New Source Review" (NSR) is generally used to describe the overall preconstruction permit program under the CAA.  The major source NSR program consists of two components - the PSD program (which applies to sources located in attainment areas), and the Non-attainment NSR (NNSR) program (which applies to sources located in non-attainment areas).  The application of BACT is a requirement of the PSD program while the application of the Lowest Achievable Emission Rate (LAER) is a requirement of the NNSR program.  One or both of these requirements may apply to a given emission unit depending on factors such as the attainment status of the area in which the source is located and the amount of emissions from the facility.  
The statement that BACT is much less stringent than LAER is also not accurate.  BACT is established on a case-by-case basis following a five step "top-down" approach in which the most stringent control technology available should be selected unless it can be ruled out based on energy, economic, or environmental factors.  In evaluating BACT for an emission unit in a given source category, applicants and permitting authorities should use relevant LAER determinations as a starting point.  Thus, in some instances BACT may be just as stringent as LAER in cases where the top control option or most stringent emission limit can not be ruled out based on the factors previously mentioned.  Also, the comparison between the stringency of BACT and RACT is not very useful because they are arise in different contexts.  
In terms of expanding this article, it might be useful to start out by reciting the statutory definition of BACT or at least citing to the section of the CAA where BACT is defined.  It might also be be helpful to briefly describe the top-down process used to evaluate BACT.  Finally, people might find it helpful to review EPA's New Source Review Workshop Manual, which contains a detailed discussion of BACT and the top-down selection process.  It is available at http://www.epa.gov/region07/air/nsr/nsrmemos/1990wman.pdf.  
:JLapka (talk) 03:58, 15 February 2011 (UTC)
thread_title:  Suggestions for improving and enhancing this article