Opinion ID: 4538714
Heading Depth: 5
Heading Rank: 3

Heading: unreasonably interfere with the

Text: comfortable enjoyment of life and property or the conduct of business. 310 Mass. Code Regs. § 7.00 (second emphasis added). Second, the General Regulations to Prevent Air Pollution state: No person owning, leasing, or controlling the operation of any air contamination source shall willfully, negligently, or through failure to provide necessary equipment or to take necessary precautions, permit any emission for said air contamination source or - 33 - sources of such quantities of air contaminants which will cause, by themselves or in conjunction with other air contaminants, a condition of air pollution. Id. § 7.01(1) (emphasis added). Because these regulations contemplate combinations of air contaminants, or contaminants in conjunction with one another, petitioners say that DEP is mandated to consider background levels of air toxics. DEP responds that its longstanding policy is to compare only emissions from the new source to the applicable AAL and TEL, without regard to background levels. According to its 1989 policy statement, DEP requires new or modified sources of air contaminants to assess, through computer modeling, the ambient concentrations caused solely by that source's emissions, and [t]hese modelled concentrations are then compared to the AALs to determine whether there may be potentially unacceptable risks associated with that particular source. DEP Div. of Air Quality Control, Air Toxics Implementation Update 2 (1989) [hereinafter 1989 Air Toxics Update] (emphasis added). DEP calls the AAL and TEL screening guidelines, whereby new sources that exceed these values are subject to further evaluation and new sources below these values receive no further scrutiny. And, DEP points out, most states have a similar two-step approach to air toxics, whereby - 34 - step one (here AAL and TEL comparison) is for screening purposes only.18 Petitioners argue, in substance, that to interpret the regulation's in conjunction with language as not requiring an assessment of the cumulative level of background and proposed new emissions would be to adopt an irrational or absurd interpretation of the regulation. We disagree, finding it perfectly rational to use a low threshold to identify those instances in which additional, cumulative impacts need be examined. Consider, for the sake of analogy, a baking hobbyist who plans on making a pie for a family reunion. The baker knows he has sugar, but he is not certain how much, and he may not even have the full cup needed for the recipe. Before he can start baking, his neighbor knocks on his door and asks to borrow some sugar. And, to make this analogy more like this case, imagine that measuring the baker's current supply of sugar would be resource intensive for the baker and his neighbor at that particular moment when the neighbor needs the sugar. It would be a perfectly reasonable response in this scenario for the baker to ask his neighbor how much sugar he needs. If the neighbor wants only a teaspoon, the baker might simply give 18 In practice, it appears, that applicants regard surviving step-one screening as essential, given that DEP Air Quality Section Chief Thomas Cushing could recall no instance in which DEP received an application for a project that exceeded an AAL or TEL. - 35 - it to the neighbor without first measuring his own supply. A teaspoon is likely too little to make a difference between having and not having a cup, and even if it would, the practical effect will not be noticeable. But if the neighbor wants a quarter cup, then the baker might decide to spend the resources to measure his supply before agreeing to the neighbor's request. This is in essence the purpose of AAL and TEL. Before deciding whether to require that the resources be spent to measure the current cumulative amount of air toxics, DEP asks whether the amount to be produced by the new source is like the teaspoon or like the quarter cup. If it is like the teaspoon, DEP decides that it is unlikely to make a practical difference. And here DEP's case is perhaps even stronger than the pie example, because petitioners have not pointed us to any other cap on how much pollutant is too much cumulatively (other than NESHAP, see supra note 17, and petitioners do not allege that the Weymouth station is even close to violating that standard). In other words, it would be as if the pie recipe said roughly one cup, depending on how sweet you want it. Petitioners, for their own analogy, point us to California's rules for automobile tailpipe emissions. See Motor Vehicle Mfrs. Ass'n of U.S., Inc. v. N.Y. Dep't of Envtl. Conservation, 17 F.3d 521, 524–25 (2d Cir. 1994) (explaining California's unique exemption from federal preemption over mobile- - 36 - source regulations). [P]rior to the creation of California's stringent air pollution regulations, petitioners tell us, daily emissions from millions of . . . vehicles resulted in a chronic condition of air pollution -- smog -- in the City of Los Angeles . . . even though the incremental emissions from each of those individual vehicles undoubtedly represented a tiny contribution to the overall problem, and a de minimis risk to human health. The tailpipe example would be like our hypothetical example if the baker had twelve neighbors at his door all asking for sugar. In that case, he might want to measure his supply even if each neighbor wanted only a teaspoon. But surely there are not millions of proposed stationary sources of formaldehyde, benzene, and acrolein around Weymouth. It is completely rational for DEP to treat this limited number of sources differently for screening purposes than California treats personal automobiles. Cf. 310 Mass. Code Regs. § 7.02(2)(b)(7) (excluding stationary sources not capable of emitting one ton or more of any pollutant from the air-permit requirement). Moreover, there are plenty of other examples of air-pollution regulatory schemes that similarly screen out de minimis sources. In addition to other states' rules on air toxics, DEP points us to the Significant Impact Limits (SILs) used by EPA when assessing compliance with the National Ambient Air Quality Standards (NAAQS). See Sierra Club v. EPA, - 37 - 705 F.3d 458, 461 (D.C. Cir. 2013) (explaining SILs); see also Sierra Club v. EPA, 955 F.3d 56, 58–60 (D.C. Cir. 2020); 40 C.F.R. § 51.166(b)(23)(i) (setting net-emissions-increase levels deemed [s]ignficant for purposes of Prevention of Significant Deterioration (PSD)). The fact that some regulatory programs take a different approach does not make these programs irrational. Of course, the fact that DEP's two-step approach is rational does not dispense with petitioners' argument that the Massachusetts regulations compel consideration of background levels. Nevertheless, we defer to the agency's interpretation. The regulations to which petitioners point us, 310 Mass. Code Regs. §§ 7.00, 7.01(1), are broad regulations concerning all air pollution generally, not just air toxics. See Town of Brookline v. Comm'r of Dep't of Envtl. Quality Eng'g (Brookline I), 439 N.E.2d 792, 799 (Mass. 1982) (giving DEP discretion to interpret 310 Mass. Code Regs. § 7.01); see also Brookline II, 497 N.E.2d at 13 (The Legislature has granted [DEP] broad authority.). And we do not think that the language from those general regulations unambiguously forecloses DEP's approach to air toxics. The phrases in conjunction with other air contaminants, 310 Mass. Code Regs. §§ 7.01(1), and combinations thereof, id. § 7.00, might mean, as petitioners argue, that DEP should consider background levels of a given pollutant. Or they might reasonably be read as referring to situations where two different air pollutants produce a chemical - 38 - reaction in the air, as with ozone precursors, see Ill. State Chamber of Commerce v. EPA, 775 F.2d 1141, 1143 & n.3 (7th Cir. 1985), in which case the regulations do not compel petitioners' approach. Since the text is ambiguous, and traditional tools of construction do not resolve that ambiguity, we defer to DEP's reasonable interpretation. See Kisor, 139 S. Ct. at 2414–18; Brookline II, 497 N.E.2d at 15.