Abrasive Blast Cleaning
January 1995

The requirement to use Best Available Control Technology (BACT) is only for facilities which
require an air quality permit to construct and operate.  Therefore, if your facility meets the
conditions of Standard Exemption No. 106.451 or Standard Exemption No. 106.452 or is
grandfathered, then you are not required to propose BACT.  

However, if your facility requires an air quality permit, then you must propose BACT to reduce
emissions as much as possible.  In our review of your BACT proposal, we consider technical
practicability and economic reasonableness on a case-by-case basis.  You may choose a
combination of several methods to satisfy the BACT requirement such as process changes or add-on controls.  
For example, one method to reduce emissions from an outdoor blasting facility is the
use of shrouds.  The following proposals  have been successfully used for other blasting facilities
and have met our BACT requirements:

Enclosed Operations:

*(1) Use of dry fabric filters with 99% or better removal efficiencies.
*(2) Baghouses and cartridge filters with outlet grain loadings of 0.01 grains/ft3 or less.
*(3) Water wash spray booths with 99% or better removal efficiencies.
 (4) Proper storage of fresh media and proper disposal of spent media
     
BACT for Non-Enclosed Blast Cleaning Operations is currently undergoing evaluation.  To obtain
the most current BACT guidance, please contact a technical specialist with the Coatings Group 
of the New Source Review Permit Division at (512)-239-1000.
     
* Note:  Removal efficiencies and outlet grain loadings must correspond with particle matter 10
microns or less in size.

When you propose BACT, you need to provide a detailed description of how your facility will
implement BACT.  If you wish to propose a different BACT method than those listed above, you
will need to  provide detailed descriptions of the technical problems that would be encountered
and the costs associated with implementing and operating one or more of the equipment/methods
mentioned above.  This discussion needs to follow the TNRCC "three tier" method or the EPA
"top down" method.  Regardless of the method used, applicants must supply control equipment
cost estimates (amortized over the life of the equipment) and annualized operating costs.  The
EPA document OAQPS Control Cost Manual (EPA 450/3-90-006) describes how to perform the
analysis and provides the format to use for presentation of results.  This manual can be obtained
by writing the National Technical Information Service (NATS), 5285 Port Royal Road,
Springfield, Virginia 22161 or telephoning (703)-487-4650.  The TNRCC "three tier" method can
be obtained by writing TNRCC, OAQ/NSR, Coatings Section, P.O. Box 13087, Austin, Texas
78711-3087.