On March 21, 2012, the Supreme Court resolved a long-simmering issue of federal environmental enforcement. The issue in Sackett v. Environmental Protection Agency involved the "administrative compliance order" (ACO), a device frequently used by the Environmental Protection Agency (EPA) to enforce statutes it administers. The Court held that the Administrative Procedure Act makes available "pre-enforcement review" of ACOs under Section 404 of the Clean Water Act (CWA), which establishes the federal wetlands permitting program. Simply put, recipients of Section 404 ACOs no longer have to wait until the EPA files a civil action to enforce the ACO before they can have jurisdictional objections to the order heard by a court. A second issue in the case, whether a bar on pre-enforcement review of Section 404 ACOs would comport with due process, did not have to be reached by the Court. The importance of this ruling is suggested by the fact that, combining all of EPA's statutes, the agency issues over 1,000 ACOs a year—1,302 in FY2010, for example. The EPA statutes under which the largest number of ACOs are issued each year are the CWA, Safe Drinking Water Act, Superfund Act, and Clean Air Act. As will be discussed, however, the applicability of Sackett beyond CWA Section 404 is an open question. In an ACO, EPA directs the recipient to comply with a specified statutory, regulatory, or permit requirement by a stated deadline, and recites the penalties that noncompliance may entail (the order itself imposes no penalties). It is often described as a quick, flexible enforcement tool that serves as an advance warning allowing the recipient to sit down with EPA to negotiate a reasonable settlement that generally avoids penalties. It is said to be less confrontational, and less expensive for all parties, than EPA's other enforcement options. Under the CWA, Clean Air Act, and Safe Drinking Water Act, those other options are three. First, the agency may assess a civil money penalty —in which case the alleged violator is entitled to be heard and present evidence to the agency, the public is entitled to comment, and any assessed penalty is subject to judicial review. Second, EPA can file a civil enforcement action in federal district court. And third, in limited circumstances the agency can seek criminal penalties in federal district court. For all their advantages, however, ACOs sometimes come with a distinct downside from the recipient's vantage point: for ACOs issued under Section 404, the lower courts had barred pre-enforcement review. Thus, if the recipient disagreed with the facts or legal conclusions on which the ACO is based, he/she/it faced a difficult dilemma. The recipient could do nothing, challenging the order only later when EPA filed an enforcement action in court. If so and the challenge failed, the recipient faced the prospect of large civil penalties—in the case of the CWA, up to $37,500 per day for each violation of the act and an additional $37,500 per day for violating the ACO. Alternatively, the recipient could comply with the order even though disagreeing with it, at sometimes substantial cost, then apply for a permit and challenge any denial thereof (or unacceptable conditions therein) in court. This dilemma—forcing the Section 404 ACO recipient, in the absence of pre-enforcement review, to risk large penalties or incur substantial compliance costs for an ACO the recipient disputes—has long attracted interest in the legal literature and in the lower courts. Very likely, it is also what prompted the Supreme Court to take the Sackett case. And while Sackett concerned ACOs under only Section 404 of the CWA, the implications of the holding for ACOs under other statutes have been lost on no one. Michael and Chantelle Sackett own a 0.63 acre undeveloped lot in Idaho near a lake. In the spring of 2007, they filled in most of the lot with dirt and rock to prepare it for house construction. Months later, EPA issued them an ACO alleging that the parcel was a "jurisdictional wetland"—that is, was within the coverage of CWA Section 404, which requires a permit to fill in wetlands constituting "waters of the United States." The ACO required the Sacketts to remove the fill material and restore the lot to its pre-fill condition, and set out a compliance schedule. The order also encouraged the Sacketts "to engage in informal discussion of the terms and requirements of this Order" and indicated that the order could be amended to provide for alternative methods of complying with the CWA. Finally, it stated that failure to comply with the order could trigger "(1) civil penalties of up to $32,500 per day of violation pursuant to section 309(d) of the [CWA] ... ; (2) administrative penalties of up to $11,000 per day for each violation pursuant to section 309(g) of the [CWA] ... or (3) civil action in federal court for injunctive relief pursuant to section 309(b) of the [CWA]." The Sacketts sought a hearing to challenge the jurisdictional finding, which EPA denied. They then sued in federal district court. Holding that the CWA precludes judicial review of ACOs before EPA has filed an enforcement action in court, the district court dismissed the case. In support, the court noted that all federal circuits to address that question (a total of four), and all district courts to do so ("over ten," the court said), have ruled against pre-enforcement review of CWA ACOs as well. On appeal, the Ninth Circuit affirmed, holding both that the CWA prohibits pre-enforcement review of ACOs, and that the Due Process Clause is not offended thereby. In granting certiorari, the Supreme Court posed a statutory question and a constitutional one: (1) whether pre-enforcement review of the ACO issued against the Sacketts is available under the Administrative Procedure Act (APA), and (2) if not, whether this inability to seek pre-enforcement review violates the Due Process Clause. Widely noted was the fact that while granting certiorari in Sackett , the Court denied a contemporaneous petition for certiorari raising the due process issue in connection with "unilateral administrative orders" under the Superfund Act. Though the Court's certiorari process is famously opaque, one may speculate that the Court's greater receptiveness to the Sackett petition may have stemmed from the opportunity it afforded the Court to resolve the ACO pre-enforcement issue statutorily rather than constitutionally. Some also surmise that the different treatment of the two petitions may have turned on the concerns of the Court's conservative wing as to what it seems to regard as an over-expansive definition of wetlands by the federal agencies that administer CWA Section 404. In resisting the ACO, the Sacketts had sued EPA under the APA provision making judicial review available for "final agency action for which there is no other adequate remedy in a court." The Supreme Court's holding was unambiguous and narrow, confined to CWA Section 404: "We conclude that the compliance order in this case is final agency action for which there is no adequate remedy other than APA review, and that the Clean Water Act does not preclude that review." Given this ruling, the Sacketts now may seek judicial review of EPA's jurisdictional determination underlying the ACO and need not await the agency's enforcing the order in a court. The decision shows every sign of having been an easy one for the Court: the questioning at oral argument tilted heavily against EPA's arguments, the decision came down only 10 weeks after oral argument, and most obviously, it was unanimous. The Court gave not even passing mention to the substantial lower-court precedent holding to the contrary of its ruling, other than the Ninth Circuit decision it reversed. The Court needed to resolve three issues to reach its holding, and had little difficulty with any of them. First, it held that the Section 404 ACO against the Sacketts was "final agency action," required by the APA for judicial review under that act. The ACO, said the Court, "has all of the hallmarks of APA finality that our opinions establish." It determines rights and remedies since it imposes a duty on the Sacketts to restore their property, requires them to give EPA access, exposes them to penalties, and limits their ability to obtain a Section 404 permit. Nor was the order's invitation to the Sacketts to "engage in informal discussion" of the order with EPA seen to undermine that finality, since "it confers no entitlement to formal agency review." Second, the Court determined that there is "no other adequate remedy in a court" for a Section 404 ACO, another prerequisite for APA review. EPA argued that there is indeed "adequate remedy in a court"—namely, when EPA enforces the ACO in federal district court. The Court saw it differently, pointing out that the Sacketts have no control over when the civil action is filed, while in the meantime civil penalties accrue at up to $75,000 per day. Nor is applying to the Corps of Engineers for a permit and then suing under the APA if the permit is denied or unacceptably conditioned an "adequate remedy." A remedy for a Corps action is not, said the Court, adequate to remedy an action by EPA, a different agency. Finally, the Court saw nothing in the CWA that precludes judicial review of Section 404 ACOs, the final prerequisite for APA review. Invoking the well-established presumption favoring judicial review of agency action, the Court found EPA's arguments against reviewability based on the structure of the CWA not to overcome this presumption.