Whether the Due Process Clause of the Fourteenth Amendment prohibits a state from imposing retroactive environmental liability for the discharge of a substance that was not regulated as hazardous at the time of the discharge and for which the regulated party received no fair notice of the state's regulatory position

No question identified. : conduct. This Court has long maintained that the Due Process Clause establishes a right to fair notice before being deprived of life, liberty, or property. FCC v. Fox Television Stations, Inc., 567 U.S. 239, 253 (2012). By protecting regulated parties from statutes and regulations that “‘fail[] to provide a person of ordinary intelligence fair notice of what is prohibited,’” this bedrock constitutional principle ensures that regulated parties have the ability to “know what is required of them so they may act accordingly.” Ibid. (citation omitted). With respect to legal rules administered by government agencies, this Court has declined to accept interpretations of statutes and regulations where the relevant conduct “occurred well before the interpretation was announced” and where the regulated entity “had little reason to suspect” that the agency’s “longstanding practice” of “never initiat[ing] any enforcement actions” or “otherwise suggest[ing] that it thought the industry was acting unlawfully” meant anything other than “acquiescence.” Christopher v. SmithKline Beecham Corp., 567 U.S. 142, 155-158 (2012). Of particular relevance here, courts have applied the foregoing principles to prohibit the imposition of retroactive liability under environmental statutes where the regulated party lacked fair notice that a particular substance was regulated. See Commonwealth of Massachusetts v. Blackstone Valley Electric Co., 67 F.3d 981, 991 (lst Cir. 1995); General Electric Co. v. EPA, 53 F.3d 1324, 1330-1332 (D.C. Cir. 1995). 2. Applicants are the former owners and operators of an oil refinery located in North Pole, Alaska. Respondents are the State of Alaska and the subsequent owner of the refinery, Flint Hills Resources Alaska, LLC, as well as its parent company, Flint Hills Resources, LLC (together, “Flint Hills”). Applicants operated the refinery from 1977 through March 2004, when Flint Hills took possession. In 1985, applicants began using a chemical called sulfolane in their refining process. Applicants recycled and reused the sulfolane, but some escaped into wastewater and then migrated into the surrounding groundwater. App., infra, 4a, 6a. Under Alaska law, the Alaska Department of Environmental Conservation (DEC) has the authority to regulate the discharge of “hazardous substances.” See Alaska Stat. 46.03.822. The relevant environmental statute defines a “hazardous substance” as oil; a substance defined as hazardous under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA), see 42 U.S.C. 9601(14); or “an element or compound which, when it enters into the atmosphere or in or upon the water or surface or subsurface land of the state, presents an imminent and substantial danger to the public health or welfare, including but not limited to fish, animals, vegetation, or any part of the natural habitat in which they are found,” Alaska Stat. 46.03.826(5). Sulfolane is not oil and is not listed as a hazardous substance under CERCLA. And when applicants began using sulfolane, DEC did not otherwise regulate the chemical as hazardous. In fact, in communications with applicants, DEC expressly stated that it was not regulating sulfolane. DEC did not provide notice that they considered sulfolane a “hazardous substance” until October 2004, after the refinery’s transition to Flint Hills. App., infra, 6a-7a, 60a-6la. 3. In 2014, the State of Alaska brought suit in state court against both applicants and Flint Hills for damages, injunctive relief, and declaratory relief as a result of the discharge of sulfolane at the North Pole refinery. Both applicants and Flint Hills denied liability and brought counterclaims against the State and each other. In 2016, the Alaska Supreme Court dismissed some of Flint Hills’ claims against applicants as time-barred. See Flint Hills Resources Alaska, LLC v. Williams Alaska Petroleum, Inc., 377 P.3d 959, 973 (2016). Flint Hills settled with the St