Opinion ID: 768833
Heading Depth: 3
Heading Rank: 3

Heading: ingaa

Text: 129 Interstate Natural Gas Association of America (INGAA), a trade association that represents major interstate natural gas transmission companies in the United States, contends that EPA did not provide adequate notice and opportunity to comment on the control level assumed for large stationary internal combustion (IC) engines in its determination of state NOx budgets. We agree. 130 EPA's NPRM in November 1997 assumed a 70% control level for large IC engines, see Proposed Rule, 62 Fed. Reg. at 60,354, after considering and rejecting an 80% control level. See id. at 60,348. Then, in the supplemental notice in May 1998, EPA continued to assume the 70% control level. See Supplemental Notice of Proposed Rule, 63 Fed. Reg. at 25,908. EPA stated in the same notice that it intends to further analyze control approaches for IC engines and said that [a]s the above analyses are completed, EPA intends to place them in the docket. Id. at 25,909. EPA did not present a new analysis until September 4, 1998, when it concluded that a 90% control level was more appropriate for large IC engines. See Technical Support Document for Stationary International Combustion Engines 2 (September 4, 1998). When the rule was finally promulgated in October 1998, EPA stated that it was assuming a 90% control level. See Final Rule, 63 Fed. Reg. at 57,418. 131 INGAA contends that EPA's switch from 70% to 90% for large IC engines was unanticipated and that EPA should have allowed comments on the issue. Considering EPA's repeated affirmation of the 70% assumption throughout rulemaking and rejection of a higher, 80% assumption earlier, a 132 revision in its assumption less than one month before the final rule was promulgated hardly provided adequate notice, especially given the magnitude of the consequences of the proposed change on the regulated bodies. Therefore, we remand for further consideration on this issue. 8 133 In addition, INGAA challenges EPA's definition of large IC engines. EPA, in the final rule, distinguished between large and small sources by defining a cutoff level. 63 Fed. Reg. at 57,414. EPA assumed no control for sources below the cutoff level and defined small sources as units with a capacity less than or equal to 250 mmBtu/hr and with emissions less than or equal to one ton per day. See id. at 57,415. EPA added that EPA is relying on a capacity approach first and a tons per day approach second (where a capacity data is not available or appropriate) to define small sources. Id. at 57,416. Then, in the December correction notice, EPA largely repeated the same methodology for determining the cutoff level, but added that [a] stationary internal combustion engine and a cement plant were determined to be 'large' if its 1995 average daily ozone season emissions were greater than one ton. Correction Notice to Final Rule, 63 Fed. Reg. at 71,224. 134 INGAA contends that EPA did not follow its own standard in the correction notice and singled out IC engines and cement plants without explanation. Although EPA's various statements on this issue throughout rulemaking have not always been very clear or entirely consistent, EPA went through an extensive commentperiod on this issue, see Final Rule, 63 Fed. Reg. at 57,415-17, and we agree with EPA that the change that INGAA criticizes for being arbitrary is merely a minor clarification that satisfies the reasonableness standard.