parties. This undermines the purpose of the shield provision, which the Supreme Court has stated is to “giv[e] permits finality,” E.I. du Pont de Nemours, 430 U.S. at 138 n. 28, 97 S.Ct. 965. Second, plaintiffs’ approach constitutes a collateral attack on Wisconsin’s WPDES program, specifically NR § 216.21(4)(a). Plaintiffs, claim to challenge only Flam-beau’s conduct; however, integral to this challenge is plaintiffs’ assertion that Flam-beau lacks a WPDES permit and that NR § 216.21(4)(a) is not, contrary to Wisconsin’s view and the section’s plain language, part of the WPDES program. Plaintiffs fault Flambeau for doing what its CWA administrator and Wisconsin law authorize it to do. This is impermissible. See Kelley v. Bd. of Trs., Univ. of Illinois, 35 F.3d 265, 272 (7th Cir.1994) (<HOLDING>); Milwaukee Cnty. Pavers Ass’n v. Fiedler, 922
holding that insofar as the university actions were taken in an attempt to comply with the requirements of title ix plaintiffs attack on those actions is merely a collateral attack on the statute and regulations and is therefore impermissible holding that an attempt to set aside a divorce decree constituted an impermissible collateral attack holding that dormant judgment is voidable and therefore not subject to collateral attack recognizing collateral attack on void order holding that a judgment as to the title in a prior litigation was not subject to collateral attack