Opinion ID: 519994
Heading Depth: 3
Heading Rank: 3

Heading: Computation of Variability Factors When Data Were

Text: Insufficient (Borrowed Data) 283 When the EPA had not obtained sufficient plant variability data to calculate the variability factor for a pollutant, it used the average of those variability factors that it had established for other similar pollutants or, if no such average had been calculated, for all of the pollutants subject to the BAT limitations. CMA contends that the EPA's use of this borrowed data to determine the variability factor for a pollutant when data were not otherwise available was sheer guesswork. 284 For the BAT 1 limitations, when data were not otherwise available, the EPA determined the variability factor by using data from pollutants exhibiting similar chemical structure and characteristics that bear on treatability. This was based on the reasonable assumption that similar compounds react similarly to similar treatment. For BAT 2 , when direct data were not available, the EPA computed variability factors by averaging the variability factors for all other pollutants that the EPA found to be treatable by the same technology. The EPA has established a reasonable basis for its use of borrowed data. 215 Its assumptions are logical and there is nothing in the record to establish that they led to scientifically inaccurate results. 285