DUFFLY, J.
After a spill of hazardous materials within a specified radius of a public water supply, Department of Environmental Protection (DEP) regulations require that those deemed to be liable undertake cleanup and monitoring actions to ensure the spill does not pose a danger to that water supply. See 310 Code Mass. Regs. §§ 40.0801, 40.0810, 40.0993(3)(a) (2014); 40.1030(2)(e) (2015). An exemption promulgated in 2007, however, exempts "oil" from some of these requirements when other enumerated requirements are met. See 310 Code Mass. Regs. § 40.0924(2)(b)(3)(a) (2014) (oil exemption). The DEP's definition of the term "oil" in this "oil exemption" is at the heart of this lengthy litigation between DEP and Peterborough Oil Company, LLC (Peterborough).
Peterborough owns a property, now vacant, in Athol, where it operated a gasoline station for more than ten years.
Peterborough thereafter filed an action in the Superior Court seeking declaratory and injunctive relief, contending that DEP's interpretation of its regulation was incorrect. Concluding that DEP's interpretation was reasonable, a Superior Court judge
Discussion. A declaratory judgment may be sought in "any case in which an actual controversy has arisen." See G. L. c. 231A, § 1. The requirement that there be an "actual controversy" should be construed liberally. See Gay & Lesbian Advocates & Defenders v. Attorney Gen., 436 Mass. 132, 134 (2002). An "actual controversy" may exist without final agency action, on the basis of an allegation that an improper agency interpretation of a regulation will harm the plaintiff. See Santana v. Registrars of Voters of Worcester, 384 Mass. 487, 493 (1981), S.C., 390 Mass. 353 (1983), citing Massachusetts Ass'n of Indep. Ins. Agents & Brokers, Inc. v. Commissioner of Ins., 373 Mass. 290, 293 (1977). Because none of the material facts are disputed, and Peterborough challenges whether DEP's interpretation of its regulation is correct as a matter of law, declaratory relief is appropriate here.
1. Statutory and regulatory framework. The Massachusetts Oil and Hazardous Material Release Prevention and Response Act, G. L. c. 21E (act), was enacted in 1983 to ensure the proper cleanup of sites contaminated with oil and hazardous materials. See G. L. c. 21E, §§ 1, 3; St. 1983, c. 7, § 5. The act grants DEP broad authority over cleanup of these contaminated sites. See G. L. c. 21E, § 3. "Oil" is defined under the act as
G. L. c. 21E, § 2. In addition to excluding from the definition of "oil" "substances which are included in 42 U.S.C. [§] 9601(14)," "oil" is explicitly excluded from the definition of "hazardous material" under the act. The act provides that a "hazardous material" is a
G. L. c. 21E, § 2.
To implement the cleanup process required under the act, G. L. c. 21E, § 3, DEP promulgated regulations known as the Massachusetts Contingency Plan (MCP). See 310 Code Mass. Regs. § 40.0001 (2014). The definition of "oil" in the MCP is identical to the definition of oil in the act. See G. L. c. 21E, § 2; 310 Code Mass. Regs. § 40.0006 (2014).
The MCP creates a multiphased assessment and cleanup process whereby a contaminated site can reach either a "temporary" or a "permanent" solution, as determined by DEP. See 310 Code Mass. Regs. §§ 40.0006(2), 40.0006(12). A temporary solution means that the site has achieved a substantial elimination of hazardous material, but monitoring and mitigation efforts may remain ongoing indefinitely.
The MCP also establishes additional cleanup requirements for sites where discharges pose a risk to a public water supply. See 310 Code Mass. Regs. § 40.0924. These requirements apply within two distinct zones: Zone I establishes a narrow, protective radius immediately surrounding the water supply; Zone II encompasses a larger area to address the risk that, in extreme conditions, water from that location might enter the public water supply.
2. Statutory language. Peterborough contends that the act plainly and unambiguously includes leaded gasoline in its definition of "oil." See G. L. c. 21E, § 2. On this view, Peterborough maintains that DEP erred in rejecting Peterborough's revised remediation plan.
As with any statute, we review questions concerning the meaning of an agency's enabling statute de novo. See Commerce Ins. Co. v. Commissioner of Ins., 447 Mass. 478, 481 (2006). If the meaning of a term is clear in the plain language of a statute, we give effect to that language as the clearest expression of the Legislature's purpose. See Goldberg v. Board of Health of Granby, 444 Mass. 627, 632-633 (2005). If, however, the statutory language is "sufficiently ambiguous to support multiple, rational interpretations," Biogen IDEC MA, Inc. v. Treasurer & Receiver Gen., 454 Mass. 174, 186 (2009), citing Goldberg v. Board of Health of Granby, 444 Mass. 627, 633 (2005), we look to "the cause of [the statute's] enactment, the mischief or imperfection to be remedied and the main object to be accomplished, to the end that the purpose of its framers may be effectuated"
In support of its claim that DEP's understanding of the term "oil" is incorrect under the plain language of the act, Peterborough argues that the statutory definition of "oil" is broad, encompasses any type of fuel or crude oil, and explicitly defines gasoline as a "partially soluble" "fuel oil" derived from a "mineral" oil. This argument, however, does not take into account that the statute then excludes from the definition of "oil" a list of substances, identified as "hazardous" under § 9601(14) of the Federal Comprehensive Environmental Response, Compensation, and Liability Act, 42 U.S.C. §§ 9601-9675 (2012) (CERCLA). See G. L. c. 21E, § 2. Lead is included on one of the CERCLA lists of hazardous substances, see 40 C.F.R. § 302.4 (2015), and therefore is excluded from the act's definition of "oil." See G. L. c. 21E, § 2.
While it distinguishes between "oil" and "hazardous substances," the act does not explain how a hazardous substance intermixed with an oil should be treated. For our purposes, it does not specify how to treat the lead in leaded gasoline, where lead is "hazardous," but other parts of the mixture fall within the oil exemption. This ambiguity is not resolved by the reference in the act to CERCLA's definition of hazardous materials.
CERCLA's definition of hazardous materials contains a so-called "petroleum exclusion" explicitly providing that petroleum may be excluded from certain cleanup requirements. See 42 U.S.C. § 9601(14). Leaded gasoline has been understood to fall within this "petroleum exclusion," albeit that lead is a hazardous substance, because of CERCLA's use of the term "petroleum." See, e.g., Wilshire Westwood Assocs. v. Atlantic Richfield Corp., 881 F.2d 801, 803-804 (9th Cir. 1989). The act, however, does
The act as a whole also creates greater liability for cleanup of oil spills than does CERCLA. See Griffith v. New England Tel. & Tel. Co., 414 Mass. 824, 830 (1993). Nothing in the act's language suggests that its definition of "oil" is meant to be coextensive with that of CERCLA, or to include CERCLA's exclusions of certain hazardous substances. See id. at 829-830. We therefore do not agree that the act unambiguously incorporates CERCLA's "petroleum exclusion." See ACME Laundry Co. v. Secretary of Envtl. Affairs, 410 Mass. 760, 771 (1991), quoting Globe Newspaper Co. v. Boston Retirement Bd., 388 Mass. 427, 432-433 (1983) (declining to interpret act in light of CERCLA because differences in language represent "a decision to reject the legal standards embodied or implicit in" CERCLA). See also DaRosa v. New Bedford, 471 Mass. 446, 452 (2015); Martignetti v. Haigh-Farr Inc., 425 Mass. 294, 321 (1997) (differences in statutory language require differing applications of similar provisions in CERCLA and act). Accordingly, we are unable to read into the statutory language a plain indication that the Legislature meant to include leaded gasoline within the definition of "oil," where the definition also provides that lead is not an "oil."
3. Legislative intent. Because the statutory language is ambiguous, we turn to consideration of the legislative intent. See Entergy Nuclear Generation Co. v. Department of Envtl. Protection, supra at 329.
The act "was drafted in a comprehensive fashion to compel the prompt and efficient cleanup of hazardous material," Taygeta Corp. v. Varian Assocs., 436 Mass. 217, 223 (2002). "The purpose of the MCP is, among other things, to `provide for the protection of health, safety, public welfare and the environment. . . .'" Bank v. Thermo Elemental Inc., 451 Mass. 638, 653 (2008), quoting 310 Code Mass. Regs. § 40.0002 (1995).
The act requires DEP to promulgate regulations to identify, assess, and mitigate sites where there has been a release of hazardous
In light of the act's purpose to compel the cleanup of hazardous material, and the legislative mandate that DEP ensure compliance with that purpose, interpreting leaded gasoline entirely as an "oil" would stretch the meaning of the "oil exemption" to the point that it would become virtually a nullity. In particular, under such an expanded definition, any hazardous material mixed with oil would appear to qualify for less stringent treatment under the oil exemption. Such an interpretation would eviscerate the legislative purpose. See, e.g., Mullally v. Waste Mgt. of Mass., Inc., 452 Mass. 526, 531 (2008) (statutory construction should not "frustrate the general beneficial purposes of the legislation" [citations omitted]); Watros v. Greater Lynn Mental Health & Retardation Ass'n, 421 Mass. 106, 113 (1995) ("strictly literal reading" of statute should not be adopted if result would "thwart or hamper the accomplishment of the statute's obvious purpose").
4. Creation of the oil exemption. Furthermore, the history of DEP's drafting of the "oil exemption" is instructive as to its view, at the time the exemption was enacted, that the lead in leaded gasoline was not included within the definition of "oil." The DEP created the oil exemption based on concern that very few sites had achieved a permanent solution after gasoline spills. The DEP, therefore, conducted studies at contaminated sites to determine the reason for the low rate of permanent resolution. Through these studies, DEP determined that, in part, the reason for the low remediation rate was the manner in which the risk assessment to determine whether a temporary or a permanent solution was available at a particular site was conducted.
Under the MCP, DEP determines risk to a public water supply by assessing the concentrations of specific substances, defined by their chemical properties and composition, in the soil near a contaminated site. See 310 Code Mass. Regs. §§ 40.0902(2)(a), 40.0904, 40.0924(2)(b)(3)(a), 40.0996 (2014). Where concentrations of individual substances of particular concern exceed certain levels, a "permanent" solution at a given site is not achievable unless and until those concentrations can be reduced to
The DEP's studies showed that petroleum hydrocarbons had unique properties. For example, if spilled in soil within a specified area near a potential water supply, the petroleum hydrocarbons did not appear to seep into that water supply. The DEP concluded this was because they were biodegradable, tended to be relatively stationary, and did not move through soil toward groundwater. Therefore, DEP concluded, petroleum hydrocarbons were unlikely to contaminate the drinking supply if released within a distance equating to the Zone II radius of a possible water supply, if all other necessary site conditions were met.
As a result of these studies, DEP created the "oil exemption" as a narrow exemption limited to petroleum hydrocarbons. The exemption applied to Zone II sites (known as GW-1 areas) whose groundwater is located within a potential drinking water source area, but where spill contamination is limited to petroleum hydrocarbons. See 310 Code Mass. Regs. §§ 40.0924(2)(b)(3)(a); 40.0932(4) (a)-(b) (2014).
5. DEP's interpretation of the oil exemption. In DEP's view, limiting the oil exemption to petroleum hydrocarbons comports with the legislative mandate while providing flexibility in remediation efforts of hazardous spills. Only petroleum hydrocarbons have been shown not to present a "significant risk of harm to health, safety, public welfare, or the environment during any foreseeable period of time," assuming other required conditions for a "permanent" solution are met. See 310 Code Mass. Regs. § 40.0006. Expanding the definition to include contaminants either known to be hazardous, or whose properties are less understood, would contravene the legislative mandate. See 310 Code Mass. Regs. § 40.0007(1) (2014) (MCP "shall be construed to effectuate the purposes of" act).
"An agency's interpretation of its own regulation and statutory mandate will be disturbed only `if the "interpretation is patently wrong, unreasonable, arbitrary, whimsical, or capricious."'" Box Pond Ass'n v. Energy Facilities Siting Bd., 435 Mass. 408, 416 (2001), quoting TBI, Inc. v. Board of Health of N. Andover, 431 Mass. 9, 17 (2000).
Risk assessment under the MCP requires DEP to examine the concentrations of specific substances, defined by their chemical properties and composition, in the public water supply. See 310 Code Mass. Regs. §§ 40.0902(2)(a), 40.0904, 40.0924, 40.0996. The oil exemption appears in the portion of the regulatory scheme governing response actions to contamination on the basis of risks posed by specific chemicals. 310 Code Mass. Regs. § 40.0924(2)(b)(3)(a). Because the regulatory scheme relies on distinctions between substances on the basis of chemical composition, DEP's decision to interpret "oil" similarly, as defined with reference to its chemical composition, is reasonable.
The DEP's more narrow interpretation advances its mandate to ensure the cleanup of spills posing a threat to public health and
Judgment affirmed.