Opinion ID: 1269179
Heading Depth: 4
Heading Rank: 2

Heading: Cumulative Cap on De Minimus Discharges

Text: Plaintiffs next argue that [a] second requirement for any de minimus exemption from Tier II antidegradation requirements is that such exemption be subject to a cumulative cap, so that individual discharges allowed to pass as trivial do not end up having a significant combined impact. Pl. Br. at 34. Again, I agree that such a cumulative cap is required in order for a discharge exemption to be permitted as de minimus. As already noted, in order to qualify as de minimus, any exemption to the strict requirements of Tier II review must only exempt pollution discharges whose combined effect does not lead to a significant degradation of a Tier II water body's quality. While the limit of ten percent destruction of assimilative capacity for individual exempted discharges helps to ensure that the exemptions have only a trivial impact on water quality, a cumulative cap is necessary to ensure that the combined effect of the many discharges allowed under the exemption is truly de minimus. See Shays v. FEC, 414 F.3d 76, 115 (D.C.Cir.2005) (rejecting the Federal Election Commission's approval of a de minimus exemption of $5000 from a campaign finance reform regulation because it was not an obviously trivial amount, considering that donors could give that amount to each and every state, district, and local party organization); Alabama Power, 636 F.2d at 360 (indicating that an agency's power to find categorical exemptions to statutory schemes is designed to overlook circumstances that in context may fairly be considered de minimus). Indeed, if a significant degradation of Tier II water quality were allowed to occur because of numerous individually exempted de minimus discharges, then the non-textual de minimus exception would be allowed to swallow the rule set forth in 40 C.F.R. § 131.12(a)'s plain language that a Tier II water's quality  shall be maintained and protected unless the State determines, after engaging in the Tier II review process, that allowing lower water quality is necessary to accommodate important economic or social development in the area in which the waters are located. (emphasis added). Accordingly, the only court to have considered this issue has found that a cumulative cap is necessary in order for an exemption to be permitted as de minimus. Ohio Valley, 279 F.Supp.2d at 770. The Ohio Valley court persuasively articulated the rationale for such a cap: From the perspective of maintaining the water quality of a Tier 2 water body (which is the focus of § 131.12(a)(2)), the de minimus standard for cumulative discharges is more important than the de minimus standard for individual discharges; it is the former that will dictate the total reduction in available assimilative capacity that a water body may undergo without any Tier 2 review. Without a cumulative cap on de minimus discharges, individual de minimus discharges could easily consume all of the available assimilative capacity for a given pollutant parameter, reducing water quality to the minimum level necessary to support existing uses without ever having undergone Tier 2 review. Id. at 770-771. Likewise, the EPA has indicated that in order to qualify as de minimus an exemption must have a cumulative cap on the reduction of assimilative capacity that may be caused by exempted discharges. See J.A. at 923 (King Memorandum) (noting that in defining a sufficiency threshold for discharges into the Great Lakes the EPA technical experts reached a consensus on a significance threshold value of ten percent (10%) of the available assimilative capacity, coupled with a cumulative cap  (emphasis added)). In light of the foregoing concerns, I would hold that a cumulative cap on the allowable reduction of assimilative capacity is required in order for a categorical exemption to Tier II review to be approved as de minimus. Neither party has suggested an appropriate limit for this cumulative cap. However, given the previous discussion regarding the significant negative impact on water quality caused by the loss of more than ten percent of a water body's assimilative capacity, I am convinced that an exemption that would allow for combined discharges to cause more than a ten percent loss of assimilative capacity, i.e., a significant loss of Tier II water quality, cannot, under the EPA's own scientific standards, be considered de minimus. As the EPA never even considered whether a cumulative cap is necessary when approving Kentucky's categorical exemptions, let alone whether the combined effect of the individual discharges allowed under such exemptions would fall below the requirements of such a cap, I would find that the EPA acted contrary to law in approving these exemptions as de minimus. Accordingly, I would reverse the district court's grant of summary judgment to Defendants on Plaintiffs' challenge to Kentucky's Tier II review exemptions and remand the matter to the EPA. On remand, in addition to considering whether Kentucky's categorical exemptions would permit individual discharges that would cause more than a ten percent loss of a Tier II water's assimilative capacity, I would also require the EPA to evaluate the potential cumulative effect of these individual discharges so as to ensure that they do not cause a combined loss of more than ten percent of the assimilative capacity of Kentucky's Tier II waters.