Citizens Against Burlington, Inc. v. Busey

The city of Toledo decided to expand one of its airports, and the Federal Aviation Administration decided to approve the city's plan. In this petition for review of the FAA's order, an alliance of people who live near the airport contends that the FAA has violated several environmental statutes and regulations. We hold that the FAA has complied with all of the statutes and all but one of the regulations.

The Toledo Express Airport, object of the controversy in this case, lies about twenty-five miles to the west of downtown Toledo. Half a mile to the southwest of the airport, surrounded by four highways and intersected by three more, lies the Oak Openings Preserve Metropark, used by joggers, skiers, and birders, and site of one of the world's twelve communities of oak savannas. Within Oak Openings lies the Springbrook Group Camp, site of a primitive (tents only) campground, and used by hikers and campers, including Richard Van Landingham III, one of the petitioners in this lawsuit. Near the airport live Daniel Kasch, Carol Vaughan, and Professor William Reuter, three of the other petitioners. The Toledo-Lucas County Port Authority, one of the intervenors, wants to make the city of Toledo a cargo hub. Burlington Air Express, Inc., the other intervenor, wants to move its operations to Toledo. Kasch, Vaughan, Reuter, Van Landingham, and others have formed Citizens Against Burlington, Inc. to stop them.

Citizens Against Burlington first materialized about a year after the Port Authority first commissioned an "Airport Noise Compatibility Planning" study (known as a "Part 150 study," see generally 14 C.F.R. pt. 150 & apps. A & B) and began to consider the possibility of the airport's expansion. The Port Authority soon heard from Burlington Air Express, which had been flying its planes out of an old World War II hangar at Baer Field, an Air National Guard airport in Fort Wayne. After looking at seventeen sites in four midwestern states, Burlington chose the Toledo Express Airport. Among Burlington's reasons were the quality of Toledo's work force and the airport's prior operating record, zoning advantages, and location (near major highways and close to Detroit and Chicago). For its part, the Port Authority expects the new hub to create one thousand new jobs in metropolitan Toledo and to contribute almost $68 million per year to the local economy after three years of the hub's operation. The Port Authority plans to pay for the new hub with both private and public funds. Much of the money, however, will come from user fees and lease agreements, and more than half will come from local bonds issued to private investors. Grants from the city of Toledo and the state of Ohio will make up another, much smaller portion of the costs. The Port Authority has applied for some federal funds as well, but the FAA has reacted coolly to the Port Authority's feelers.

The Port Authority agreed to let Burlington move to Toledo when Burlington's lease at Baer Field expired, in October 1990. Burlington later extended its lease in Fort Wayne, and the Port Authority now expects Burlington to move to Toledo Express in January 1992. First, though, the Port Authority has to accommodate Burlington's operations. In the first stage of the airport's expansion, the Port Authority plans to build a concrete ramp for cargo planes, a warehouse for sorting freight, lighting for the warehouse and the area around it, a road to the warehouse, a fuel farm, a maintenance building, taxiway connections to one of the airport's runways and lighting for the new taxiways, an overrun area attached to one of the runways, new power outlets for parked airplanes, and storage areas for de-icing equipment. In the second stage of expansion, planned for the five years after Burlington's move, the Port Authority wants to extend one of the airport's primary runways, install a landing system nearby, and build a new taxiway parallel to the extended runway.

The Port Authority submitted its proposal to the FAA on February 2, 1989 and promptly hired Coffman Associates, Inc., a consulting firm, to prepare an environmental assessment, see 40 C.F.R. Secs. 1501.3, 1508.9, and then to convert the environmental assessment into an environmental impact statement (EIS), see id. Sec. 1501.4; 42 U.S.C. Sec. 4332(2)(C). In December 1989, the FAA sent a draft of the EIS to the Environmental Protection Agency and several state and local agencies. See id. Sec. 7609; 40 C.F.R. Secs. 1503.1, 1503.2. Early the next month, the FAA made the draft public and held a public hearing. See id. Sec. 1502.19. Over the following six weeks, Citizens Against Burlington sent the FAA twenty-five letters, commenting on virtually every aspect of the EIS. Individuals sent over three hundred more.

On May 11, 1990, the FAA published a final environmental impact statement. The first chapter of the statement explained that the Port Authority needed the FAA's approval for its plan to expand the Toledo Express Airport and described the role in that process that Congress meant for the agency to play. The second chapter of the EIS reviewed the particulars of the Port Authority's plan, listed the fourteen separate federal statutes and regulations that applied to the Port Authority's proposal, briefly described some alternatives to acting on the Port Authority's plan, and explained why the agency had decided not to discuss those possibilities more fully. The FAA then concluded that it had to consider in depth the environmental impacts of only two alternatives: the approval of the Port Authority's plan to expand the airport, and no action. The third chapter of the EIS described the environment affected by the proposal, and the fourth chapter detailed the environmental consequences of the two alternatives. After summarizing the environmental impacts in the fifth chapter, the agency listed in the sixth chapter the statement's preparers. Appendices to the statement collected scientific data and relevant inter-agency correspondence. In the second volume of the statement, the FAA compiled copies of the hundreds of letters concerning the draft EIS, a transcript of the public hearing, and written comments submitted after the hearing had ended.

Having approved the final EIS, the agency faced a final choice: whether to endorse the Port Authority's plan, which the agency preferred, or not to endorse the plan. In a record of decision dated July 12, 1990, the FAA approved the plan to expand the Toledo Express Airport. See 49 U.S.C. app. Secs. 1349(a), 2208(b). Five days later, Citizens petitioned this court for review of the FAA's order and for a stay of the order pending our decision. See id. app. Sec. 1486(a), (d). On August 1, we denied the latter request.

Citizens continues to press for wide-ranging declaratory and injunctive relief, asking this court to vacate the FAA's decision, to force the agency to prepare a new EIS, to enjoin the agency from approving the Port Authority's current plan, and to enjoin any further construction at Toledo Express until the FAA complies with the applicable laws. Citizens contends that the FAA has violated the National Environmental Policy Act, regulations promulgated by the Council on Environmental Quality, the Department of Transportation Act, and the Airport and Airway Improvement Act. We consider these arguments in turn.

In the National Environmental Policy Act of 1969 (NEPA), Pub.L. No. 91-190, 83 Stat. 852 (1970) (codified as amended at 42 U.S.C. Secs. 4321-4370b), Congress resolved "to create and maintain conditions under which man and nature can exist in productive harmony, and fulfill the social, economic, and other requirements of present and future generations of Americans." NEPA Sec. 101(a), 42 U.S.C. Sec. 4331(a).1 These sweeping policy goals have inspired some commentators to call NEPA an environmentalist Magna Carta. See, e.g., D. Mandelker, NEPA Law and Litigation Sec. 1:01, at 1 (1990); cf. 40 C.F.R. Sec. 1500.1(a) ("[NEPA] is our basic national charter for protection of the environment."). But instead of ordering, say, that deforested land be reforested, Congress chose to make NEPA procedural. NEPA commands agencies to imbue their decisionmaking, through the use of certain procedures, with our country's commitment to environmental salubrity. See Robertson v. Methow Valley Citizens Council, 490 U.S. 332, 348, 109 S.Ct. 1835, 1844-45, 104 L.Ed.2d 351 (1989); see also 40 C.F.R. Sec. 1502.1. NEPA does not mandate particular consequences.

Just as NEPA is not a green Magna Carta, federal judges are not the barons at Runnymede. Because the statute directs agencies only to look hard at the environmental effects of their decisions, and not to take one type of action or another, federal judges correspondingly enforce the statute by ensuring that agencies comply with NEPA's procedures, and not by trying to coax agency decisionmakers to reach certain results. See Baltimore Gas & Elec. Co. v. Natural Resources Defense Council, Inc., 462 U.S. 87, 97-98, 103 S.Ct. 2246, 2252, 76 L.Ed.2d 437 (1983). As the Supreme Court has warned, "once an agency has made a decision subject to [Nepa]'s procedural requirements, the only role for a court is to insure that the agency has considered the environmental consequences; it cannot ' "interject itself within the area of discretion of the executive as to the choice of the action to be taken." ' " Strycker's Bay Neighborhood Council, Inc. v. Karlen, 444 U.S. 223, 227-28, 100 S.Ct. 497, 500, 62 L.Ed.2d 433 (1980) (per curiam) (citation omitted); see Kleppe v. Sierra Club, 427 U.S. 390, 410 n. 21, 96 S.Ct. 2718, 2730 n. 21, 49 L.Ed.2d 576 (1976) ("Neither [NEPA] nor its legislative history contemplates that a court should substitute its judgment for that of the agency as to the environmental consequences of its actions.").

In short, the obligations that NEPA levies on agencies determine the role of the courts in the statute's enforcement. This case concerns the most important responsibility that NEPA demands--that an agency reviewing proposals for action prepare an environmental impact statement, and, more specifically, that the agency discuss in its statement alternatives to the action proposed. We consider here whether the FAA has complied with NEPA in publishing an environmental impact statement that discussed in depth two alternatives: approving the expansion of the Toledo Express Airport, and not approving the expansion of the Toledo Express Airport.

(1)

Federal agencies must prepare environmental impact statements when they contemplate "major Federal actions significantly affecting the quality of the human environment." NEPA Sec. 102(2)(C), 42 U.S.C. Sec. 4332(2)(C).2 An EIS must discuss, among other things, "alternatives to the proposed action," NEPA Sec. 102(2)(C)(iii), 42 U.S.C. Sec. 4332(2)(C)(iii), and the discussion of alternatives forms "the heart of the environmental impact statement." 40 C.F.R. Sec. 1502.14; see Alaska v. Andrus, 580 F.2d 465, 474 (D.C.Cir.), vacated in part as moot sub nom. Western Oil & Gas Ass'n v. Alaska, 439 U.S. 922, 99 S.Ct. 303, 58 L.Ed.2d 315 (1978).

The problem for agencies is that "the term 'alternatives' is not self-defining." Vermont Yankee Nuclear Power Corp. v. Natural Resources Defense Council, Inc., 435 U.S. 519, 551, 98 S.Ct. 1197, 1215, 55 L.Ed.2d 460 (1978). Suppose, for example, that a utility applies for permission to build a nuclear reactor in Vernon, Vermont. Free-floating "alternatives" to the proposal for federal action might conceivably include everything from licensing a reactor in Pecos, Texas, to promoting imports of hydropower from Quebec. If the Nuclear Regulatory Commission had to discuss these and other imaginable courses of action, its statement would wither into "frivolous boilerplate," id., if indeed the agency were to prepare an EIS at all and not instead just deny the utility a permit. If, therefore, the consideration of alternatives is to inform both the public and the agency decisionmaker,3 the discussion must be moored to "some notion of feasibility." Vermont Yankee, 435 U.S. at 551, 98 S.Ct. at 1215; seeid. ("Common sense also teaches us that the 'detailed statement of alternatives' cannot be found wanting simply because the agency failed to include every device and thought conceivable by the mind of man.").

Recognizing the harm that an unbounded understanding of alternatives might cause, see id. at 549-55, 98 S.Ct. at 1214-17, CEQ regulations oblige agencies to discuss only alternatives that are feasible, or (much the same thing) reasonable. 40 C.F.R. Secs. 1502.14(a)-(c), 1508.25(b)(2); see Forty Most Asked Questions Concerning CEQ's NEPA Regulations, 46 Fed.Reg. 18,026, 18,026 (1981) [hereinafter Forty Questions]. But the adjective "reasonable" is no more self-defining than the noun that it modifies. Consider two possible alternatives to our nuclear reactor in Vernon. Funding research in cold fusion might be an unreasonable alternative by virtue of the theory's scientific implausibility. But licensing a reactor in Lake Placid, New York might also be unreasonable, even though it passes some objective test of scientific worth. In either case, the proposed alternative is reasonable only if it will bring about the ends of the federal action--only if it will do what the licensing of the reactor in Vernon is meant to do. See City of New York v. Department of Transp., 715 F.2d 732, 742-43 (2d Cir.1983) (construing NEPA Sec. 102(2)(E), 42 U.S.C. Sec. 4332(2)(E) (discussion of alternatives in environmental assessments)), cert. denied, 465 U.S. 1055, 104 S.Ct. 1403, 79 L.Ed.2d 730 (1984); see also City of Angoon v. Hodel, 803 F.2d 1016, 1021 (9th Cir.1986) (per curiam) ("When the purpose is to accomplish one thing, it makes no sense to consider the alternative ways by which another thing might be achieved."), cert. denied, 484 U.S. 870, 108 S.Ct. 197, 98 L.Ed.2d 148 (1987).4 If licensing the Vernon reactor is meant to help supply energy to New England, licensing a reactor in northern New York might make equal sense. If licensing the Vernon reactor is meant as well to stimulate the Vernon job market, licensing a reactor in Lake Placid would be far less effective. The goals of an action delimit the universe of the action's reasonable alternatives.

We have held before that an agency bears the responsibility for deciding which alternatives to consider in an environmental impact statement. See North Slope Borough v. Andrus, 642 F.2d 589, 601 (D.C.Cir.1980). We have also held that an agency need follow only a "rule of reason" in preparing an EIS, see Natural Resources Defense Council, Inc. v. Morton, 458 F.2d 827, 834, 837 (D.C.Cir.1972), and that this rule of reason governs "both which alternatives the agency must discuss, and the extent to which it must discuss them," Alaska v. Andrus, 580 F.2d at 475; see Allison v. Department of Transp., 908 F.2d 1024, 1031 (D.C.Cir.1990). It follows that the agency thus bears the responsibility for defining at the outset the objectives of an action. See City of Angoon v. Hodel, 803 F.2d at 1021; cf. 40 C.F.R. Sec. 1502.13. As the phrase "rule of reason" suggests, we review an agency's compliance with NEPA's requirements deferentially. We uphold an agency's definition of objectives so long as the objectives that the agency chooses are reasonable, and we uphold its discussion of alternatives so long as the alternatives are reasonable and the agency discusses them in reasonable detail.

We realize, as we stated before, that the word "reasonable" is not self-defining. Deference, however, does not mean dormancy, and the rule of reason does not give agencies license to fulfill their own prophecies, whatever the parochial impulses that drive them. Environmental impact statements take time and cost money. Yet an agency may not define the objectives of its action in terms so unreasonably narrow that only one alternative from among the environmentally benign ones in the agency's power would accomplish the goals of the agency's action, and the EIS would become a foreordained formality. See City of New York v. Department of Transp., 715 F.2d at 743. Nor may an agency frame its goals in terms so unreasonably broad that an infinite number of alternatives would accomplish those goals and the project would collapse under the weight of the possibilities.

Instead, agencies must look hard at the factors relevant to the definition of purpose. When an agency is asked to sanction a specific plan, see 40 C.F.R. Sec. 1508.18(b)(4), the agency should take into account the needs and goals of the parties involved in the application. See, e.g., Louisiana Wildlife Fed'n v. York, 761 F.2d 1044, 1048 (5th Cir.1985) (per curiam); Roosevelt Campobello Int'l Park Comm'n v. EPA, 684 F.2d 1041, 1046-47 (1st Cir.1982). Perhaps more importantly, an agency should always consider the views of Congress, expressed, to the extent that the agency can determine them, in the agency's statutory authorization to act, as well as in other congressional directives. See City of New York v. Department of Transp., 715 F.2d at 743-45 (Congress instructed the Department of Transportation to create safety regulations for carrying nuclear fuel by interstate highway; the Department was not required to discuss the unreasonable alternative of carrying nuclear fuel around New York City by barge); cf. Izaak Walton League of Am. v. Marsh, 655 F.2d 346, 372 (D.C.Cir.) ("When Congress has enacted legislation approving a specific project, the implementing agency's obligation to discuss alternatives in its [EIS] is relatively narrow."), cert. denied, 454 U.S. 1092, 102 S.Ct. 657, 70 L.Ed.2d 630 (1981).

Once an agency has considered the relevant factors, it must define goals for its action that fall somewhere within the range of reasonable choices. We review that choice, like all agency decisions to which we owe deference, on the grounds that the agency itself has advanced. See SEC v. Chenery Corp., 332 U.S. 194, 196, 67 S.Ct. 1575, 1577, 91 L.Ed. 1995 (1947).

(2)

In the first chapter of its environmental impact statement, the FAA begins by noting that the Port Authority had requested the agency's approval of the plan to develop Toledo Express. The agency then explains that "[t]he purpose and need for this action lies in [the] FAA's responsibility to review the airport design and runway configuration with respect to its safety, efficiency and utility within the national airspace system and its environmental impact on the surrounding area." After surveying the engineering reasons that justify an extended runway and new facilities, the FAA concludes by stating that the agency "has a statutory mandate to facilitate the establishment of air cargo hubs under Section 502(a)(7) [of the Airport and Airway Improvement Act of 1982 (AAIA), 49 U.S.C. app. Sec. 2201(a)(7) ] and to undertake capacity enhancement projects under Section 502(a)(11) [of the AAIA, 49 U.S.C. app. Sec. 2201(a)(11) ]."

In the second chapter of the environmental impact statement, the FAA begins by stating:The scope of alternatives considered by the sponsoring Federal agency, where the Federal government acts as a proprietor, is wide ranging and comprehensive. Where the Federal government acts, not as a proprietor, but to approve and support a project being sponsored by a local government or private applicant, the Federal agency is necessarily more limited. In the latter instance, the Federal government's consideration of alternatives may accord substantial weight to the preferences of the applicant and/or sponsor in the siting and design of the project.

In the present system of federalism, the FAA does not determine where to build and develop civilian airports, as an owner/operator. Rather, the FAA facilitates airport development by providing Federal financial assistance, and reviews and approves or disapproves revisions to Airport Layout Plans at Federally funded airports.... Similarly, under the Airline Deregulation Act of 1978, the FAA does not regulate rates, routes, and services of air carriers or cargo operators. Airline managements are free to decide which cities to serve based on market forces.

The EIS then describes five alternatives: approving the Port Authority's plan for expanding Toledo Express, approving other geometric configurations for expanding Toledo Express, approving other ways of channelling airplane traffic at Toledo Express, no action by the agency at all, and approving plans for other airports both in the Toledo metropolitan area and out of it, including Baer Field in Fort Wayne. Finally, the EIS briefly explains why the agency eliminated all the alternatives but the first and the fourth. See 40 C.F.R. Sec. 1502.14(a).

The FAA's reasoning fully supports its decision to evaluate only the preferred and do-nothing alternatives. The agency first examined Congress's views on how this country is to build its civilian airports. As the agency explained, Congress has told the FAA to nurture aspiring cargo hubs. See AAIA Sec. 502(a)(7), (11), 49 U.S.C. app. Sec. 2201(a)(7), (11).5 At the same time, however, Congress has also said that the free market, not an ersatz Gosplan for aviation, should determine the siting of the nation's airports. See Airline Deregulation Act of 1978, Pub.L. No. 95-504, 92 Stat. 1705; see also 14 Weekly Comp.Pres. Doc. 1837, 1837-38 (Oct. 24, 1978) (remarks of Pres. Carter); Suburban O'Hare Comm'n v. Dole, 787 F.2d 186, 196 (7th Cir.) ("The decision to make O'Hare, or any other airport, a 'hub' airport belongs to the airlines and not to the government."), cert. denied, 479 U.S. 847, 107 S.Ct. 169, 93 L.Ed.2d 106 (1986). Congress has expressed its intent by statute, and the FAA took both of Congress's messages seriously.6

The FAA also took into account the Port Authority's reasons for wanting a cargo hub in Toledo. In recent years, more than fifty major companies have left the Toledo metropolitan area, and with them, over seven thousand jobs. The Port Authority expects the cargo hub at Toledo Express to create immediately more than two hundred permanent and six hundred part-time jobs with a total payroll value of more than $10 million. After three years, according to the Port Authority, the hub should create directly more than one thousand permanent jobs at the airport and one hundred and fifty other, airport-related jobs. The University of Toledo estimates that the new Toledo Express will contribute at least $42 million to the local economy after one full year of operation and nearly $68 million per year after three. In addition, the Port Authority expects the expanded airport, and Burlington's presence there, to attract other companies to Toledo. All of those factors, the Port Authority hopes, will lead to a renaissance in the Toledo metropolitan region.

Having thought hard about these appropriate factors, the FAA defined the goal for its action as helping to launch a new cargo hub in Toledo and thereby helping to fuel the Toledo economy. The agency then eliminated from detailed discussion the alternatives that would not accomplish this goal. Each of the different geometric configurations would mean technological problems and extravagant costs. So would plans to route traffic differently at Toledo Express, or to build a hub at one of the other airports in the city of Toledo. None of the airports outside of the Toledo area would serve the purpose of the agency's action. The FAA thus evaluated the environmental impacts of the only proposal that might reasonably accomplish that goal--approving the construction and operation of a cargo hub at Toledo Express. It did so with the thoroughness required by law. See 40 C.F.R. Sec. 1502.16.7

We conclude that the FAA acted reasonably in defining the purpose of its action, in eliminating alternatives that would not achieve it, and in discussing (with the required do-nothing option) the proposal that would. The agency has therefore complied with NEPA.

(3)

Citizens agrees that the FAA need only discuss reasonable, not all, alternatives to Toledo Express. Relying on Van Abbema v. Fornell, 807 F.2d 633 (7th Cir.1986), however, Citizens argues that "the evaluation of 'alternatives' mandated by NEPA is to be an evaluation of alternative means to accomplish the general goal of an action; it is not an evaluation of the alternative means by which a particular applicant can reach his goals." Id. at 638 (construing NEPA Sec. 102(2)(E), 42 U.S.C. Sec. 4332(2)(E)). According to Citizens, the "general goal" of the Port Authority's proposal is to build a permanent cargo hub for Burlington. Since, in Citizens' view, Fort Wayne (and perhaps Peoria) will accomplish this general goal just as well as Toledo, if not better, Baer Field is a reasonable alternative to Toledo Express, and the FAA should have discussed it in depth. Since it did not, this court should force the FAA to prepare a new (or supplemental) environmental impact statement.

We see two critical flaws in Van Abbema, and therefore in Citizens' argument. The first is that the Van Abbema court misconstrued the language of NEPA. Van Abbema involved a private businessman who had applied to the Army Corps of Engineers for permission to build a place to "transload" coal from trucks to barges. See 807 F.2d at 635. The panel decided that the Corps had to survey "feasible alternatives ... to the applicant's proposal," or alternative ways of accomplishing "the general goal [of] deliver[ing] coal from mine to utility." Id. at 638; see also Trout Unlimited v. Morton, 509 F.2d 1276, 1286 (9th Cir.1974). In commanding agencies to discuss "alternatives to the proposed action," however, NEPA plainly refers to alternatives to the "major Federal actions significantly affecting the quality of the human environment," and not to alternatives to the applicant's proposal. NEPA Sec. 102(2)(C), 42 U.S.C. Sec. 4332(2)(C) (emphasis added). An agency cannot redefine the goals of the proposal that arouses the call for action; it must evaluate alternative ways of achieving its goals, shaped by the application at issue and by the function that the agency plays in the decisional process. Congress did expect agencies to consider an applicant's wants when the agency formulates the goals of its own proposed action. Congress did not expect agencies to determine for the applicant what the goals of the applicant's proposal should be.

The second problem with Van Abbema lies in the court's assertion that an agency must evaluate "alternative means to accomplish the general goal of an action," 807 F.2d at 638 (emphasis deleted)--a statement that troubles us even if we assume that the panel was alluding to the general goals of the federal action instead of to the goals of the private proposal. Left unanswered in Van Abbema and Citizens' brief (and at oral argument) is why and how to distinguish general goals from specific ones and just who does the distinguishing. Someone has to define the purpose of the agency action. Implicit in Van Abbema is that the body responsible is the reviewing court. As we explained, however, NEPA and binding case law provide otherwise.

(4)

In chiding this court for having overreached in construing NEPA, a unanimous Supreme Court once wrote that Congress enacted NEPA "to ensure a fully informed and well-considered decision, not necessarily a decision the judges of the Court of Appeals or of this Court would have reached had they been members of the decisionmaking unit of the agency." Vermont Yankee, 435 U.S. at 558, 98 S.Ct. at 1219. We are forbidden from taking sides in the debate over the merits of developing the Toledo Express Airport; we are required instead only to confirm that the FAA has fulfilled its statutory obligations. Events may someday vindicate Citizens' belief that the FAA's judgment was unwise. See id. at 557-58, 98 S.Ct. at 1218-19. All that this court decides today is that the judgment was not uninformed. See Methow Valley, 490 U.S. at 351, 109 S.Ct. at 1846.

The regulations of the Council on Environmental Quality provide that an environmental impact statement "shall [contain] a full and fair discussion of significant environmental impacts" and that "[i]mpacts shall be discussed in proportion to their significance." 40 C.F.R. Secs. 1502.1, 1502.2(b); see NEPA Sec. 102(2)(C)(i), (ii), 42 U.S.C. Sec. 4332(2)(C)(i), (ii). The EIS in this case discusses more than twenty impacts that the expanded Toledo Express would have on the environment, including the airport's effects on people's homes and neighborhoods; on the quality of the air, the water, and the earth; on architectural, archeological, and cultural resources; on sewage disposal; on traffic patterns; on swamps, marshes, bogs, and rivers; and on bats, butterflies, grass, flowers, and trees.8 The EIS also states flatly that "[a]ircraft sound emissions"--noise, in a word--are "often the most noticeable environmental effect[s] an airport will produce on the surrounding community." In all, the FAA devotes about half of its discussion on environmental consequences to the effects of an increase in noise. Although Citizens does not argue that the FAA failed to discuss the impacts of noise in rough proportion to the effects' importance, it does argue that the discussion is incomplete and unfair. We disagree.

The FAA begins its discussion in the EIS by describing how it assesses the effects of more noise. Using the same methods that the EPA and the Department of Housing and Urban Development use, the FAA measures in decibels the average day-night sound levels (Ldn ) produced at particular sites during each twenty-four hour period, then corrects its measurement for variations in airplane speed and formation and the like, adds a ten-decibel penalty for planes that fly at night, and, under certain circumstances, modifies the result depending on the number of people affected. See 14 C.F.R. Sec. 150.7; id. app. A Sec. A150.205 (describing methodology). In response to the EPA's comments on the draft statement, the FAA applied a second method of study, analyzing the effects on noise levels of exposure at twenty-six places to a single event. The EIS thoroughly explains the social, psychological, physical, and structural impacts of noise from Toledo Express. The EIS also explains the resulting Ldn and the single-event analysis in both mathematical equations and readable English and illustrates the text and data in graphs, maps, charts, and tables.

Citizens concedes, if only implicitly, that the rule of reason guiding the FAA necessarily covers the agency's discussion of particular environmental impacts. See Natural Resources Defense Council v. Morton,