Control of Volatile Organic Compounds Emissions from Manufacturing

The 20 pprn level was judged to be attainable. All of the non L.A. I I
and the majority of the LA. units met this criteria. There was
concern over the. large number of L.A. tests that failid, i .e. 43 percent.
However, two factors outweighed this concern.
First, all of the non L.A. units met the criteria. This is
significant since, though the L.A. units represent many tests, they
represent the same basic design. They all are small units designed
over a decade ago to meet a ruie for 90 percent reduction. They are
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I did so due to common factors and do not represent a widespread inability I
Second, the difference between 65 percent failing 10 ppmv and
, 43 percent failing 20 ppm is larger than a direct comparison of the
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percentages would reveal. At 20 ppm, not only did fewer units fail,
but those that did miss the criteria did so by a smaller margin and
would require less adjustment. Dropping the criteria from 10 pprn to '
20 pprn drops the failure rate by 20 percent, but is judged to drop the
overall time and cost for adjustment by over 50 percent.
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adjustment effort for the worst case is considered. The crucial point
is how close a 10 pprn level pushes actual field unit efficiencies to
those of the lab unit. Lab unit results for complete backmixing
indicate that a 10 pprn level would force field units to almost match
lab unit mixing. A less stringent 20 pprn level i~ncreasesthe margin
allowed for nonideal incinerator operation, especially for the worst
improve mixing enough for field units to approach lab unit efficiencies,
a drop from 10 pprn to 20 pprn hay decrease costs .to improve mixing in
the worst case by an order of magnitude.
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The 30 pprn level was judged too lenient. The only data indicating
such a low efficiencv was from L.A. All other data shbwed 20 Dpm.
showed that moderate adjustment can increase efficiency. In addition, I
the L.A. units were judged to have poor mixing. The mixing deficienkies
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