Opinion ID: 4527400
Heading Depth: 2
Heading Rank: 1

Heading: The Clean Air Act Amendments

Text: When Congress enacted the Clean Air Amendments of 1970, it directed EPA to identify and regulate hazardous air pollutants. Pub. L. No. 91-604, § 4(a), 84 Stat. 1676, 1678-80 (codified as amended at 42 U.S.C. §§ 7407-09). Two decades on, “[d]issatisfied with EPA’s progress in identifying hazardous air pollutants, Congress amended the Act in 1990 to name nearly 200 such pollutants” and “charged EPA with identifying sources of those pollutants and setting emission standards for them.” Nat’l Ass’n for Surface Finishing v. EPA, 795 F.3d 1, 4 (D.C. Cir. 2015); see Nat’l Lime Ass’n, 233 F.3d at 634 (“Congress added the list of pollutants to be regulated, regulation deadlines, and minimum stringency requirements to the Clean Air Act precisely because it believed EPA had failed to regulate enough HAPs [Hazardous Air Pollutants] under previous air toxics provisions.”). The initial list of air toxics that Congress compiled to make up for EPA’s slow start appears at section 112(b)(1). 42 U.S.C. § 7412(b)(1). Section 112 of the Act, added as part of the 1990 Amendments, mandates EPA’s regulation of those listed air toxics. See Clean Air Act Amendments, Pub. L. No. 101-549, § 301, 104 Stat. 2399, 2531-74 (1990) (1990 Amendments). Section 112(b) calls on EPA to build on the initial list Congress created to maintain an up-to-date list of air toxics. To that end, the Act requires EPA periodically to review and revise the list 6 by rule. Id. § 7412(b)(2). In addition, “any person” may petition EPA to add a hazardous air pollutant to the list or delete one from it, and Congress directed that EPA grant or deny such petition within 18 months. Id. § 7412(b)(3)(A). The listed air toxics include known carcinogens as well as substances causing serious non-cancer health effects to various bodily organs and systems—including nerves, heart, lungs, liver, skin, and reproductive systems—and to fetal development. Many of these toxics affect people’s health through multiple pathways (water, soil, food, air), are persistent (meaning that, once emitted, they linger in the environment), and bio-accumulative (such that small amounts inhaled or otherwise absorbed by bodily tissues build up over time, thereby intensifying associated health risks). To control emissions of the listed air toxics, EPA must “promulgate regulations establishing emission standards for each category or subcategory of major sources.” Id. § 7412(d)(1). The Clean Air Act currently lists 190 hazardous pollutants. More than a hundred pulp mill chemical recovery combustion sources operating in the United States collectively emit more than 23 million pounds of those air toxics annually. See Proposed Rule: National Emission Standards for Hazardous Air Pollutants for Chemical Recovery Combustion Sources at Kraft, Soda, Sulfite, and Stand-Alone Semichemical Pulp Mills, 81 Fed. Reg. 97,046, 97,082 (Dec. 30, 2016) (2016 Proposed Rule). Those chemical recovery combustion sources are an identified subset of the sources of hazardous emissions at pulp mills. Pulp mills work to mush, grind, or dissolve wood and other materials into pulp, typically used to make paper. The pulping process creates a chemical liquor byproduct that contains some of the original pulping chemicals. Pulp mills can recover these chemicals for reuse through a variety of chemical processes as well as generate energy through incinerating other residual organic matter. These “chemical 7 recovery combustion sources” are the only sources of emissions regulated by the 2001 and 2017 Rules. Id. at 97,05152. Each source category’s “emission standard” must specify the source’s maximum allowable emission “of hazardous air pollutants listed for regulation.” 42 U.S.C. § 7412(d)(1). In other words, each “emission standard” includes limits on emissions of air toxics from a particular kind of air polluter. An emission standard must contain limits for each listed air toxic the relevant category of source emits. Id. § 7412(d)(1)- (3); see also, e.g., Sierra Club v. EPA, 479 F.3d 875, 878, 883 (D.C. Cir. 2007) (reiterating EPA’s clear statutory obligation to set limits on all air toxics a source emits, and invalidating “no control” emission floors for brick and ceramics kilns); Mossville Envtl. Action Now v. EPA, 370 F.3d 1232, 1236, 1242 (D.C. Cir. 2004) (reading section 112(d)(1) clearly to require limits “for every HAP emitted from each category or subcategory of major sources” and invalidating standard governing polyvinyl chloride (PVC) manufacturers that controlled only vinyl chloride); Nat’l Lime Ass’n, 233 F.3d at 634 (recognizing EPA’s “clear statutory obligation to set emission standards for each listed HAP” and invalidating standard governing brick and ceramics kilns that placed “no control” floors on their emissions of hydrogen chloride, mercury, and hydrocarbons). The existing standard governing pulp mill combustion sources limits a handful of the listed air toxics those sources emit but sets no limit on many others. Section 112(d)(2)-(3) prescribes the method by which EPA, in promulgating an emission standard, must calibrate source-specific limits on emission of each air toxic. Specifically, for existing major sources, EPA must “require the maximum degree of reduction in emissions” by the particular source category that the Agency “determines is achievable.” 8 42 U.S.C. § 7412(d)(2). To that end, the Act directs EPA to calculate the average level of emissions of each air toxic achieved by the best-performing 12 percent of facilities in a given source category—those that emit the toxic at the lowest levels. Id. § 7412(d)(3)(A). That baseline emissions limit is referred to as the “maximum achievable control technology” floor or “MACT floor.” Sierra Club v. EPA, 895 F.3d 1, 7-8 (D.C. Cir. 2018). EPA must then determine, considering cost, health, and environmental effects, whether a more stringent limit is “achievable.” Id. § 7412(d)(2). If so, EPA must promulgate a “beyond-the-floor” limit at that more stringent level. Surface Finishing, 795 F.3d at 5. When Congress amended the Act in 1990 to jumpstart implementation, it set a stringent timeline for EPA’s hazardous air pollutant regulation. Congress required EPA to promulgate standards for every area source and major source category and subcategory in the United States “as expeditiously as practicable.” 42 U.S.C. § 7412(e)(1). It set an overall deadline for EPA to regulate all identified air toxics emitted by any covered source within 10 years of the Act’s effective date— i.e., by November 15, 2000. Id. § 7412(e)(1)(E). To propel EPA to act, Congress set interim milestones. It directed EPA to finalize standards for at least forty categories of sources within two years of the effective date, id. § 7412(e)(1)(A), each of which had to address all the listed pollutants the source category emits, id. § 7412(b)(1). Congress further specified that EPA must finalize standards for 25 percent of source categories and subcategories within four years, id. § 7412(e)(1)(C), and at least another 25 percent within seven years of the Act’s effective date, id. § 7412(e)(1)(D). The provision at issue here, section 112(d)(6), requires EPA, on an ongoing periodic basis, to revisit and update emission standards that it has already set for each source. No 9 less than every eight years, EPA must “review, and revise as necessary (taking into account developments in practices, processes, and control technologies), emission standards promulgated under this section.” Id. § 7412(d)(6). That review ensures that, over time, EPA maintains source standards compliant with the law and on pace with emerging developments that create opportunities to do even better. In addition to its section 112(d)(6) review, EPA under section 112(f)(2) must conduct a one-time review within 8 years of promulgating an emission standard to, among other things, evaluate the residual risk to the public from each source category’s emissions and promulgate more stringent limits as necessary “to provide an ample margin of safety to protect public health.” Id. § 7412(f)(2)(A). Petitioners do not here challenge EPA’s section 112(f)(2) risk assessment.