CAPCOA BACT Clearinghouse Resource Manual

This page last reviewed May 10, 2017

IX. Procedures for Determining BACT and LAER

Summarizing from the last section, most California LAER and BACT definitions (i.e., BACT definitions that incorporate federal LAER requirements) usually have two or three alternative minimum requirements, with the most stringent for the particular circumstance being applicable. Most definitions will have one provision that states that BACT cannot be less stringent than a control measure implemented by a district or state and incorporated into an SIP. A second alternative minimum requirement incorporated into most California BACT and LAER definitions is the most stringent control technology that has been required or achieved in practice for that category of stationary source. A third alternative minimum requirement defines BACT as a control device or technique which the APCO determines to be technologically feasible and cost effective. Finally, there are usually provisions in the rule to assure that the control technology requirement is no less stringent than federal NSPS or NESHAPS.

California BACT is often specified as a requirement other than control equipment, e.g., a performance standard. Most districts feel it is wise not to burden themselves with the liability of directly dictating the basic design of a project through specific equipment requirements. An exception might be control equipment exclusively proposed by the applicant. As a result, California BACT is often specified as a performance standard that is equivalent to the control level that is achievable with the "best available control technology." Others may require that alternative basic equipment be chosen which has a lower uncontrolled emission rate, or basic equipment that is more subject to the application of control equipment with higher efficiencies.

A district may be predisposed to a given level of control being acceptable as BACT or LAER. However, it is unwise for an applicant to assume that such a level is BACT or LAER until after the required public comment period. Until this time, the Air Pollution Control Officer cannot make a decision or commitment to approve the project or deny the application.

The applicant has the responsibility for conducting a survey of control technologies which are potential BACT candidates. Such a survey can be aided using the following resources in addition to this document:

  1. Air Pollution Control Districts: A good starting place when conducting a survey is to contact the district of jurisdiction where the source will be sited. Applicants should get an idea of what the district will require at a minimum as achieved in practice, and perhaps inquire about any special instructions for submitting a BACT analysis. District personnel may also be helpful in providing leads on new technologies used elsewhere that they wish to have evaluated in a BACT analysis. In addition, some districts, such as the Bay Area AQMD, South Coast AQMD, Ventura County APCD, and San Joaquin Valley Unified APCD have guidance documents for BACT requirements. But one should note that such guidelines are dynamic, and are not meant to be stable in the long-term.

  2. The South Coast AQMD BACT guideline: This document is a standard in some circles, especially in regard to the status of different control technologies. The contents of the document are available at the web address of In order to get a copy of this document, one should contact the South Coast AQMD public information office at (909) 396-3600.

  3. The EPA RACT/BACT/LAER Clearinghouse: The U.S. EPA tracks control technology decisions by local and state agencies referred to as the RACT/BACT/LAER Clearinghouse. Data is accessible as a hardcopy publication or through electronic database access by modem. More information on accessing information in this clearinghouse can be obtained by accessing the U.S. EPA TTN at, or calling (919) 541-2736.

Furthermore, new information received by the CAPCOA BACT clearinghouse after the publication of this document is available as quarterly summaries until the next edition of this volume. One may request addition to the mailing list by calling (916) 327-5601.

The amount of formality required in preparing a BACT or LAER analysis for an application will vary by district. It is wise, however, to separately address each alternative minimum requirement of the BACT or LAER definition. Systematic methods of analysis provide for clarity and may expedite evaluation of your application.

Best Available Control Technology (BACT) Clearinghouse Program