oldfac.txt

File contents

                  Texas Air Control Board
            Austin                       Texas
                        Interoffice

From:  Louis R. Roberts, Ph.D., P.E., Director of Permits and
       Source Evaluation Division
To:  Permits Engineering Staff
Date:  December 5, 1980
Subject:  Best Available Control Technology (BACT)
          determinations for modified old facilities

Construction permit 1651 was recently amended to delete the 
requirement that the asphalt batch plant meet twenty percent
opacity and the operating permit was issued accordingly.  I
wish to emphasize that this was a case-by-case BACT
determination, and is not intended to set precedent for if
modified grandfathered facilities.

The facility in question is an old small unit built prior to
1970.  The cost to bring the unit into compliance with the
twenty percent opacity requirement was judged to be
unreasonable, and this particular unit was permitted to
continue operating within the thirty percent opacity limit.

The Legal Division confirms that "modified" facilities, even
if they are only modified by changing location, are subject to
BACT requirements.  Each case is to be considered on its own
merits.  Economics continues to be a factor in BACT
determinations.