Opinion ID: 519994
Heading Depth: 3
Heading Rank: 1

Heading: Diversity of the Data Base

Text: 176 The BPT regulations for the OCPSF industry are based upon a broad and geographically diverse population of plants. The EPA used data from 71 plants to establish the long-term averages, and data from 21 plants to establish the variability factors. Together, these data formed the basis for the BPT limitations. 118 The northern, southern, and middle latitude regions are all well represented in both sets of data. 119 Furthermore, the data from these plants were collected throughout the year and thus represent a level of treatment performance that may be obtained under all seasonal conditions. 120 Additionally, this large data base represents a wide range of production operations. The size and diversity of the data base ensures that the BPT limitations based upon this data can generally be achieved across the industry, regardless of climate. 121 This basis alone is sufficient to support the limitations. 122 177 Petitioners object to the EPA's exclusion of seven plants that had permits allowing compliance with less stringent limitations during the winter months from the set of 21 plants used to develop the variability factors. The EPA fully explained its decision to exclude these plants: 178 [B]ecause these plants were subject to meeting two different sets of permit limits, they had no incentive to attempt to achieve uniform limitations throughout the year. Not surprisingly, then, the daily data from these plants exhibit a two-tier pattern. These data can be characterized by two means, and the variability of these data over a 12 month period is fundamentally different from the data from plants required to meet only one set of permit limits. Consequently, the data generated during these periods is not representative of well-operated biological treatment, which as noted above is capable of uniform treatment throughout the year as demonstrated by a number of plants. 123 179 These plants were in fact included in the 71-plant data base used to develop long-term averages. They were excluded only from the variability analysis. 124 Therefore, their lower average performance during the winter is reflected in the BPT limitations. It is reasonable for the EPA to choose not to rely on plants that have no regulatory incentive to achieve uniform performance, particularly where an ample data base of plants meeting uniform year-round permit limitations was available. 125 The exclusion of the data from the seven plants operating under special permits was adequately explained and is a determination peculiarly within EPA's expertise. The decision is therefore entitled to judicial deference. 126 Moreover, the EPA did not selectively exclude from the variability data base those plants that performed worse in the winter than in the summer. 127 Thus, any difference between winter and summer variability at the best plants was incorporated into the variability factors used to develop the limitations. There is ample support in the record for the EPA's conclusion that lower removal efficiencies were the result primarily of factors other than cold temperature and that the BPT limitations are achievable in all climates on a year-round basis. 128 Goodyear's contentions to the contrary are therefore without merit.