Ctr. for Biological Diversity v. Envtl. Prot. Agency & Gina Mccarthy

• Decision Date: 27 May 2014
• Docket Number: No. 12–1238.,12–1238.
• Citation: Ctr. for Biological Diversity v. Envtl. Prot. Agency , 749 F.3d 1079 (D.C. Cir. 2014)
• Parties: CENTER FOR BIOLOGICAL DIVERSITY, et al., Petitioners v. ENVIRONMENTAL PROTECTION AGENCY and Gina McCarthy, Respondents. American Petroleum Institute and Utility Air Regulatory Group, Intervenors.
• Court: U.S. Court of Appeals — District of Columbia Circuit

749 F.3d 1079

CENTER FOR BIOLOGICAL DIVERSITY, et al., Petitioners

v. ENVIRONMENTAL PROTECTION AGENCY and Gina McCarthy, Respondents.American Petroleum Institute and Utility Air Regulatory Group, Intervenors.

No. 12–1238.

United States Court of Appeals, District of Columbia Circuit.

Argued Oct. 10, 2013.

Decided May 27, 2014.

On Petition for Review of a Final Agency Action of the United States Environmental Protection Agency.

Kevin P. Bundy argued the cause for petitioners. With him on the briefs were Kassia R. Siegel, Charles McPhedran, and David S. Baron.

Daniel R. Dertke, Attorney, U.S. Department of Justice, argued the cause and filed the brief for respondents.

Andrea Bear Field, Lucinda Minton Langworthy, and Aaron M. Flynn were on the brief for intervenors American Petroleum Institute, et al. in support of respondents.

Before: KAVANAUGH, Circuit Judge, and SENTELLE and RANDOLPH, Senior Circuit Judges.

Opinion for the Court filed by Senior Circuit Judge RANDOLPH.

RANDOLPH, Senior Circuit Judge:

This petition for judicial review deals mainly with what is popularly known as “acid rain.”

The Environmental Protection Agency decided in 2012, after an exhaustive rulemaking proceeding, that it needed further studies before it could set a new, joint, “secondary” national ambient air quality standard for oxides of nitrogen and oxides of sulphur, and other related compounds found in the ambient air and considered precursors of acid deposits on the land and in the waters of the continental United States. Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Sulphur, 77 Fed.Reg. 20,218, 20,226 (Apr. 3, 2012) [Final Rule]. EPA's failure to issue a new multi-pollutant rule at that time, petitioners claim, violated the Clean Air Act.

I

We begin with a brief description of the subjects of EPA's rulemaking.

A

The ambient air—the air we breathe—is made up of approximately 80 percent non-reactive nitrogen (N2) and 20 percent oxygen (O2). Like oxygen, nitrogen is essential to what we think of as life. See Ag 101: Nitrogen,U.S. Envtl. Prot. Agency,, http:// www. epa. gov/ oecaagct/ ag 101/ impactnitrogen. html (last updated June 27, 2012). This is so both as a matter of biochemistry—nitrogen is “an essential nutrient required by all living organisms,” id.—and as a matter of global economics. The mass agriculture that feeds the world's population is reliant on nitrogen, which is “normally supplied in the form of organic or inorganic fertilizers.” Margaret Rosso Grossman, Nitrates from Agriculture in Europe: The EC Nitrates Directive and Its Implementation in England, 27 B.C. Envtl. Aff. L.Rev. 567, 567 (2000).

But nitrogen takes many forms, some of which are harmful to the environment. Oxides of nitrogen (NOy), ammonia (NH3), and ammonium (NH4), ¹ together with oxides of sulphur (SOx) in the ambient air, “undergo a complex mix of reactions in gaseous, liquid, and solid phases to form various acidic compounds.” Final Rule, 77 Fed.Reg. at 20,224–25. Those compounds are, in turn, “removed from the atmosphere through deposition.” Id. at 20,225. “Wet” deposition occurs when the compounds return to earth through rain, snow, sleet, hail, fog, and dew. “Dry” deposition occurs when gases and particles of these compounds drop onto Earth without mixing with water in the atmosphere. Id.

Wet deposition has attracted most popular attention, but EPA has estimated that “[d]ry deposition now accounts [for] 20–60%” of total acid deposition. Causes of Acid Rain,U.S. Envtl. Prot. Agency,, http:// www. epa. gov/ region 1/ eco/ acidrain/ causes. html (last visited May 2014). EPA's number is a very rough estimate because dry deposition is “not easily measured” and because “[v]ery little falls at one time or at one location.” Id.; see Final Rule, 77 Fed.Reg. at 20,249 (attributing the lack of data about dry deposition to “the lack of efficient measurement technologies”). The shorthand “acid rain,” coined in the 1800s,² refers to wet and dry deposition collectively.

The effects of acid rain vary depending upon where it lands. Deposition in water bodies—aquatic acidification—can affect the pH ³ of the water and affect its habitability for aquatic organisms. EPA's rulemaking focused on these effects, rather than those of terrestrial acidification (deposits on land), because more and better data were available for aquatic ecosystems.⁴ Final Rule, 77 Fed.Reg. at 20,242. Even so, the data, from many studies, indicated that the effects of acid rain on surface waters vary widely throughout the United States. See id. at 20,227.

Factors such as “biota, climate, geochemistry, and hydrology” have an impact. Id. at 20,229;see also id. at 20,225 (listing additional factors such as geology, topography, land use, and hydrologic flowpath). This short sentence, accurate as it is, masks an enormity of scientific complications because every body of water is unique. How large and how deep is it? Is it a still lake or a flowing stream? And if it is a stream, is it a freestone stream slowly winding down from a mountain meadow, or does it move as rapidly as Niagara? What is the water body's mineral content, its vegetative content, its altitude, its temperature, its location?

“Parts of the West are naturally less sensitive to acidification,” while other areas—for instance, “lakes in the Adirondacks and streams in Shenandoah National Park”—are considered “acid sensitive aquatic ecosytems.” Id. at 20,236. In such “acid sensitive” waters, acid rain's effect on the water's pH can make the water uninhabitable for some fish and aquatic organisms. The disappearance of species can disrupt delicate food chains. Id. at 20,233. Less aquatic life may also mean less recreational fishing. Id.

In other areas, or in water bodies within the same area, acid rain may have no measurable effect.⁵Id. at 20,235. The limestone streams ⁶ of the Cumberland Valley of Pennsylvania (Letort Spring Run, Falling Springs Run, Big Spring Creek)—the birthplace of modern American dry fly fishing—have produced stream-bred, trophy-size brown and rainbow trout for generations. See generallyVincent C. Marinaro, A Modern Dry–Fly Code (1950). Because of their mineral content, these spring creeks—rich in aquatic vegetation (watercress, elodea grass) and insect life (mayflies, stoneflies, caddis, cress bugs)—are nature's antacid, quickly neutralizing whatever acidic compounds the rain may bring. See Joe Kendall Neel, Interrelations of Certain Physical and Chemical Features in a Headwater Limestone Stream, 32 Ecology 368, 386 (1951); cf. Final Rule, 77 Fed.Reg. at 20,235 (“[T]he same levels of deposition falling on limestone dominated soils have a very different effect from those falling on shallow glaciated soils underlain with granite.”). The Firehole River in Yellowstone National Park provides another example, but a rather different one. The Firehole is a geothermal freestone stream rising out of the Park's geyser basins. Caldrons and mud pots and other thermal features along its banks emit vast quantities of sulphur gases as the stream winds its way to join the Gibbon River to form the Madison River. Along the Firehole the odor of rotten eggs (hydrogen sulfide) hangs in the air. Yet despite constant doses of these sulphur compounds, the Firehole River is one of the most productive trout streams in the world—and one of the most beautiful. See generally Aquatic Ecology of Yellowstone,Nat'l Park Serv., http:// www. nps. gov/ yell/ naturescience/ fishing_ ecology. htm (last visited May 2014).

B

The sources of atmospheric NOy and SOx are fairly well known. Small amounts of both types of oxides occur naturally. Volcanic eruptions and sea spray produce SOx. Causes of Acid Rain,U.S. Envtl. Prot. Agency,, http:// www. epa. gov/ region 1/ eco/ acidrain/ causes. html (last visited May 2014). Lightning strikes and rotting vegetation produce NOy. Id. The largest sources of SOx are “fossil fuel combustion at power plants (73%) and other industrial facilities (20%).” Sulfur Dioxide,U.S. Envtl. Prot. Agency,, http:// www. epa. gov/ airquality/ sulfurdioxide (last visited May 2014). The bulk of NOy in the atmosphere also comes from the combustion of fossil fuels, mostly by motor vehicles and, to a lesser extent, from industrial operations. Nitrogen Oxides,U.S. Envtl. Prot. Agency,, http:// www. epa. gov/ cgi- bin/ broker?_ service= data&_ debug= 0&_ program= dataprog. national_ 1. sas& polchoice = NOX (last visited May 2014). With respect to ammonia, agriculture—particularly livestock operations—represents by far the largest source of emissions to the atmosphere, by one estimate 85 percent, although this estimate and others “are characterized by a high degree of uncertainty.” Comm. on Env't & Nat. Resources Air Quality Research Subcomm., Nat'l Oceanographic & Atmospheric Admin., Atmospheric Ammonia: Sources & Fate 1 (2000), available at http:// www. esrl. noaa. gov/ csd/ AQRS/ reports/ ammonia. pdf.

This explanation, too, overlooks many complexities. As explained, emitted oxides of nitrogen and sulfur cause the formation of acid rain which, in turn, causes both aquatic and terrestrial acidification. But acid rain is not the only or even the largest source of nitrogen's total environmental impact. Today, the largest source of so-called “reactive nitrogen” ⁷ is agriculture—the manufacture and use of nitrogen—based fertilizers. Envtl. Prot. Agency Science Advisory Bd., Reactive Nitrogen in the United States,, at ES–4 (2011), available at http:// yosemite. epa. gov/ sab/ sabproduct. nsf/ Web BOARD/ INCSupplemental. Agriculture is responsible for some NOy emissions, see id. at 12 tbl.1, but, to a much greater extent, agriculture-related nitrogen compounds are surface-bound, affecting nearby land and water via leaching and runoff, id. at 15, 34; see also id. at 46 box 2 (estimating the varied impacts of Nr—from atmospheric, terrestrial, and water-based nitrogen—on the Chesapeake Bay watershed)....