                                                           FILED
                                              United States Court of Appeals
                                                      Tenth Circuit

                                                  November 28, 2012
                                  PUBLISH         Elisabeth A. Shumaker
                                                      Clerk of Court
                UNITED STATES COURT OF APPEALS

                             TENTH CIRCUIT



HILLSDALE ENVIRONMENTAL
LOSS PREVENTION, INC.; KANSAS
NATURAL RESOURCE COUNCIL;
CHRIS AXE; SHELLY AXE; FRANK
SAUNDERS; NATURAL
RESOURCES DEFENSE COUNCIL,
INC.,

           Plaintiffs - Appellants,

     v.                                      No. 11-3210
UNITED STATES ARMY CORPS OF
ENGINEERS; LIEUTENANT
GENERAL ROBERT L. VAN
ANTWERP, in his official capacity;
COLONEL ROGER A. WILSON, JR.,
in his official capacity; BNSF
RAILWAY COMPANY,

           Defendants - Appellees.

_______________________________

STATE OF KANSAS; STATE OF
OKLAHOMA,

           Amici Curiae.



      APPEAL FROM THE UNITED STATES DISTRICT COURT
                FOR THE DISTRICT OF KANSAS
             (D.C. Nos. 2:10-CV-02008-CM-DJW and
                    2:10-CV-02068-CM-DJW)
Melissa C. Lin Perrella, Natural Resources Defense Council, Santa Monica,
California, and Mark V. Dugan, Dugan Schlozman LLC, Overland Park, Kansas,
for Appellants.

Douglas R. Dalgleish, Lathrop & Gage LLP, Kansas City, Missouri, (Matthew K.
Corbin, Lathrop & Gage LLP, Kansas City, Missouri, Gus B. Bauman and W.
Parker Moore, Beveridge & Diamond, P.C., Washington, District of Columbia,
and Kathryn F. Kusske and Jay C. Johnson, Dorsey & Whitney LLP, Washington,
District of Columbia, with him on the brief), for Appellee BNSF Railway
Company.

Maggie B. Smith, Attorney, United States Department of Justice, Environmental
& Natural Resources Division, Washington, District of Columbia (Ignacia S.
Moreno, Assistant Attorney General, and T. Monique Peoples and Kristofor R.
Swanson, Attorneys, United States Department of Justice, Environmental &
Natural Resources Division, Washington, District of Columbia, and Matthew P.
Jeppson, Of Counsel, Assistant District Counsel, United States Army Corps of
Engineers, Kansas City District, Kansas City, Missouri, for Federal Appellees.

Derek Schmidt, Attorney General of Kansas, and Jeffrey A. Chanay, Deputy
Attorney General, Christopher M. Grunewald, Assistant Attorney General, Office
of the Kansas Attorney General, Topeka, Kansas, on the brief for Amicus Curiae
State of Kansas, and E. Scott Pruitt, Attorney General of Oklahoma, Oklahoma
City, Oklahoma, for Amicus Curiae State of Oklahoma.


Before TYMKOVCH, McKAY, and HOLMES, Circuit Judges.


TYMKOVICH, Circuit Judge.


      This case concerns the construction of a new Burlington Northern Santa Fe

(BNSF) rail/truck terminal outside Kansas City, Kansas. Because the preferred

site contained streams and wetlands protected under federal law, several groups

(collectively, Hillsdale) brought challenges to a dredge and fill permit issued by

                                        -2-
the United States Army Corps of Engineers (Corps) under the Clean Water Act,

33 U.S.C. §§ 1251–1387, and the National Environmental Policy Act, 42 U.S.C.

§§ 4321–4370H. The district court denied Hillsdale’s motion for an injunction

and granted summary judgment for the Corps and BNSF.

      On appeal, Hillsdale requests we set aside the Corps’s decision to grant the

permit because the Corps inadequately considered alternatives to the selected site

under the Clean Water Act and violated the National Environmental Policy Act by

preparing an inadequate environmental assessment and failing to prepare a full

environmental impact statement. We conclude the Corps’s decision is supported

by the record, and was not an arbitrary and capricious exercise of its approval

powers under federal law.

                                 I. Background

      In 2007, BNSF applied for a permit from the Corps to dredge and fill

waters of the United States (§ 404 permit) as part of its plan to construct a new

intermodal facility in the Kansas City area. 1 BNSF operates a transcontinental

railroad, the Southern Mainline, that passes through Kansas City. BNSF sought

to construct the new intermodal facility near the Southern Mainline because its

current Kansas City facility, the Argentine Yard, is inadequate to handle the

current volume of freight shipped through Kansas City and lacks space to expand.


      1
       An intermodal facility is a facility where a railroad transfers cargo
between trains and other forms of transportation, usually trucks.

                                         -3-
      BNSF identified a site near Gardner, Kansas as its preferred location for the

new intermodal facility. The Gardner site consists of 490 acres of primarily

agricultural land, containing 28,000 linear feet of streams and nearly 8 acres of

wetlands. Construction of the intermodal facility would affect only a portion of

these. The unnamed and seasonally dry streams are tributaries of Big Bull Creek,

which flows into Hillsdale Lake, a Corps-operated reservoir. The Gardner site is

located roughly one-half mile from a residential subdivision, and two miles from

Interstate 35. BNSF anticipates businesses dependent on the intermodal facility

will use an adjacent 567 acres to construct a logistics center.

      After receiving BNSF’s application, the Corps issued a public notice

describing the application and solicited comments from the public. The Corps

worked with other federal, state, and local authorities regarding the proposal, and

asked the EPA to participate in its review as a cooperating agency. BNSF and its

consultants provided the Corps with information relevant to this analysis.

      The Corps then prepared a draft environmental assessment based on this

information and comments provided by other agencies. As part of its alternatives

analysis under the Clean Water Act (CWA), the Corps considered many options,

including modifications to existing BNSF facilities, seven alternative sites for a

new intermodal facility, alternative designs for the facility, and a no-action

alternative.




                                          -4-
      Based on this review, the Corps concluded modifications to BNSF’s

existing facilities were infeasible due to space limitations. The Corps also found

the no-action alternative would have detrimental impacts on regional traffic and

air quality because increased shipping by trucks would be necessary to handle all

growth in freight shipments in the area. In its analysis of alternative sites for the

intermodal facility, the Corps compared the proposed sites to criteria provided by

BNSF. For example, BNSF required the site to be close to existing rail tracks and

highways, large enough to handle the projected volume of freight, and within 30

miles of BNSF’s existing intermodal facility at the Argentine Yard.

      After applying BNSF’s criteria, the Corps eliminated all alternatives as

impracticable except for the Gardner site and a nearby location, Wellsville North. 2

Therefore, the Corps analyzed the potential environmental impacts only of the

Gardner and Wellsville North sites. The Corps determined construction at

Gardner would impact 17,302 linear feet of streams and 4.61 acres of wetlands,

whereas construction at Wellsville North would impact 19,594 linear feet of

streams and 15.83 acres of wetlands. It also determined the streams and wetlands

at Wellsville North were of a higher quality than those at Gardner. Based on this

comparison, the Corps concluded construction at Gardner was the least

environmentally damaging practicable alternative under the CWA.

      2
        Wellsville North was 34 miles from the Argentine Yard, but the Corps
concluded it met BNSF’s other criteria and was close enough to the Argentine
Yard to warrant a closer look.

                                          -5-
      The Corps also prepared an environmental assessment to consider the

impact of BNSF’s proposal on the human environment, as required by the

National Environmental Policy Act (NEPA). This analysis considered both direct

and reasonably foreseeable indirect impacts to land use, air quality, noise, traffic,

water quality, threatened and endangered species, and cultural resources.

      Its air quality analysis was based on a report developed by a BNSF

consultant in conjunction with the EPA, the Kansas Department of Health and the

Environment (KDHE), and the Mid-America Regional Council. This report went

through multiple rounds of review and analysis to incorporate feedback from

these agencies. The report modeled emissions from on-site trains, trucks,

miscellaneous heavy equipment used at the intermodal facility, and off-site trucks

traveling to the intermodal facility, as well as the health risks associated with

these emissions. The Corps determined air quality impacts from the project

would not be significant, with the possible exception of fugitive dust emissions.

Because BNSF and KDHE entered a binding agreement to monitor dust emissions

at the site and adopt mitigation measures should emissions exceed specified

levels, the Corps concluded the intermodal facility was unlikely to have any

significant impacts on air quality. The EPA and KDHE concurred with this

analysis.

      The Corps’s water quality analysis considered impacts to local streams and

wetlands, as well as water quality. The Corps concluded construction at Gardner

                                          -6-
would impact 17,302 linear feet of streams and 4.61 acres of wetlands. But it also

found BNSF would reroute 9,100 linear feet of streams, create 7.18 acres of

wetlands, and restore a large, degraded wetland on the site. And the Corps found

the intermodal facility was unlikely to significantly impact local groundwater.

The agency concluded the overall impacts to onsite waters would not be

significant.

      After the Corps released its final environmental assessment and finding of

no significant impact, it issued BNSF a § 404 permit. Soon after, Hillsdale filed a

complaint in federal district court challenging the Corps’s environmental analysis

under both NEPA and the CWA. 3 Hillsdale also moved for a preliminary

injunction to halt construction of the intermodal facility, which the district court

denied.

      The district court then granted summary judgment to the Corps. The court

upheld the Corps’s conclusion that the Gardner site was the least environmentally

damaging practicable alternative under the CWA. The court also affirmed the

Corps’s NEPA analysis of air and water impacts, concluding the Corps’s reliance

on KDHE’s mitigation agreement was reasonable, its air quality assessment

methodologies were also reasonable, and the project was not highly controversial.

This appeal followed.


      3
        Hillsdale Environmental Loss Prevention and the Natural Resources
Defense Council each filed separate complaints, but the cases were consolidated.

                                         -7-
                                 II. Discussion

      We review the district court’s grant of summary judgment de novo. New

Mexico ex rel. Richardson v. Bureau of Land Management, 565 F.3d 683, 704–05

(10th Cir. 2009) (New Mexico). Because suits alleging NEPA and CWA

violations are brought under the Administrative Procedure Act (APA), we review

the underlying agency decision to determine whether it was “arbitrary, capricious,

an abuse of discretion, or otherwise not in accordance with law.” 5 U.S.C.

§ 706(2)(A); Colo. Wild v. U.S. Forest Serv., 435 F.3d 1204, 1213 (10th Cir.

2006). An action is arbitrary and capricious if

      the agency (1) entirely failed to consider an important aspect of the
      problem, (2) offered an explanation for its decision that runs counter
      to the evidence before the agency, or is so implausible that it could
      not be ascribed to a difference in view or the product of agency
      expertise, (3) failed to base its decision on consideration of the
      relevant factors, or (4) made a clear error of judgment.

New Mexico, 565 F.3d at 704 (internal quotation omitted).

      Our inquiry under the APA must be thorough, but the standard of review is

very deferential to the agency. Forest Guardians v. U.S. Fish and Wildlife Serv.,

611 F.3d 692, 704 (10th Cir. 2010). “A presumption of validity attaches to the

agency action and the burden of proof rests with the parties who challenge such

action.” Morris v. U.S. Nuclear Regulatory Comm’n, 598 F.3d 677, 691 (10th

Cir.), cert. denied 131 S. Ct. 602 (2010) (internal quotation and alteration

omitted). We may set aside the agency’s decision “only for substantial


                                         -8-
procedural or substantive reasons.” Silverton Snowmobile Club v. U.S. Forest

Serv., 433 F.3d 772, 780 (10th Cir. 2006).

      “Deficiencies in an [environmental assessment] that are mere ‘flyspecks’

and do not defeat NEPA’s goals of informed decisionmaking and informed public

comment will not lead to reversal.” New Mexico, 565 F.3d at 704. “Furthermore,

even if an agency violates the APA, its error does not require reversal unless a

plaintiff demonstrates prejudice resulting from the error.” Prairie Band

Pottawatomie Nation v. Federal Highway Admin., 684 F.3d 1002, 1008 (10th Cir.

2012) (Prairie Band); 5 U.S.C. § 706(2)(F) (“[D]ue account shall be taken of the

rule of prejudicial error.”).

      A. Clean Water Act

      The CWA prohibits dredging or filling “waters of the United States”

without a permit from the Corps. 33 U.S.C. § 1344; Greater Yellowstone Coal. v.

Flowers, 359 F.3d 1257, 1269 (10th Cir. 2004). This permit, known as a § 404

permit, requires the Corps to review projects and ensure jurisdictional waters are

not disturbed without an adequate study of alternatives. Neither party disputes

that the streams and wetlands on the Gardner site are waters of the United States.

Before the Corps may issue a § 404 permit, it must determine there is “no

practicable alternative” to the proposed activity “which would have less adverse

impact on the aquatic ecosystem.” 40 C.F.R. § 230.10(a). A practicable

alternative is one that is “available and capable of being done after taking into

                                         -9-
consideration cost, existing technology, and logistics in light of overall project

purposes.” Id. § 230.10(a)(2).

      When a project is not water dependent, a presumption arises that there are

“practicable alternatives that do not involve special aquatic sites” and “have less

adverse impact on the aquatic ecosystem.” 4 Id. § 230.10(a)(3). In such cases, the

§ 404 applicant must rebut this presumption if an alternative involving the

destruction of U.S. waters is chosen. Greater Yellowstone Coal., 359 F.3d at

1269 (citing Utahns for Better Transp. v. U.S. Dep’t of Transp., 305 F.3d 1152,

1186–87 (10th Cir. 2002) (Utahns)). The intermodal facility is not water

dependent, so § 230.10(a)(3)’s presumption applies in this case.

      B. National Environmental Policy Act

      NEPA “requires federal agencies to pause before committing resources to a

project and consider the likely environmental impacts of the preferred course of

action as well as reasonable alternatives.” New Mexico, 565 F.3d at 703. NEPA

requires an agency to prepare an environmental assessment prior to undertaking

any “major federal action” to determine whether the proposed action is likely to

“significantly affect[] the quality of the human environment.” 42 U.S.C.

§ 4332(2)(C). The environmental assessment must discuss the need for the

proposal, alternatives to the proposal, and the environmental impacts of the

      4
        A “special aquatic site” is a geographic area protected by the CWA. 40
C.F.R. § 230.3(q-1). Wetlands are classified as special aquatic sites. 40 C.F.R.
§ 230.41.

                                         -10-
proposal and any alternatives. 40 C.F.R. § 1508.9(b). This includes not only

direct but also indirect and cumulative impacts. Id. §§ 1508.7, 1508.8.

      If the agency concludes the action is unlikely to have a significant impact,

it may issue a finding of no significant impact and proceed. 40 C.F.R. § 1508.13.

If the agency reaches the opposite conclusion, it must prepare an environmental

impact statement (EIS) to thoroughly analyze the action’s predicted

environmental impacts, including direct, indirect, and cumulative impacts. 42

U.S.C. § 4332(2)(C); 40 C.F.R. pt. 1502 & §§ 1508.11, 1508.25.

      The significance of an impact is determined by the action’s context and its

intensity. Middle Rio Grande Conservancy Dist. v. Norton, 294 F.3d 1220, 1224

(10th Cir. 2002) (Middle Rio Grande). Applicable regulations require agencies to

consider ten factors when assessing intensity, including the proposed action’s

effects on public health, the unique characteristics of the geographic area, the

uncertainty of potential effects, and the degree of controversy surrounding the

effects on the human environment. 40 C.F.R. § 1508.27(b).

      Unlike the Clean Water Act, NEPA requires no substantive result. New

Mexico, 565 F.3d at 704. NEPA imposes procedural, information-gathering

requirements on an agency, but is silent about the course of action the agency

should take. Id. “NEPA merely prohibits uninformed—rather than

unwise—agency action.” Robertson v. Methow Valley Citizens Council, 490 U.S.

332, 351 (1989)

                                         -11-
      C. Mootness

      Because we denied Hillsdale an injunction pending this appeal, BNSF has

proceeded with construction of the intermodal facility. In a motion filed July 27,

2012, the Corps informed us construction of the facility is now 65% complete,

95% of jurisdictional waters have been filled or rerouted, and 95% of the

associated mitigation is now complete. The Corps suggests this renders

Hillsdale’s appeal moot and asks us to dismiss the appeal.

      The Corps acknowledges the appeal is not constitutionally moot, as we still

have the ability to afford Hillsdale at least partial relief. See WildEarth

Guardians v. Pub. Serv. Co. of Colo., 690 F.3d 1174, 1182–83 (10th Cir. 2012).

But the Corps argues the appeal is prudentially moot because “the case is so

attenuated that considerations of prudence and comity for coordinate branches of

government counsel the court to stay its hand.” Rio Grande Silvery Minnow v.

Bureau of Reclamation, 601 F.3d 1096, 1121 (10th Cir. 2010) (internal quotation

omitted). The Corps argues the intermodal facility’s construction, particularly as

it affects the waters of the United States, is so far advanced that we should

decline to grant Hillsdale relief. Unsurprisingly, Hillsdale disagrees. BNSF, for

its part, suggests we avoid the question altogether and simply decide the appeal

on the merits.

      We are convinced, as the Corps acknowledges, that this appeal is not moot

in the Article III sense. As for prudential mootness, it is within the court’s

                                         -12-
discretion to decline to address an issue on prudential mootness grounds. See S.

Utah Wilderness Alliance v. Smith, 110 F.3d 724, 727 (10th Cir. 1997). We have

no trouble concluding that Hillsdale’s NEPA claims are not prudentially moot.

Because the intermodal facility is not yet complete, there is a reasonable

probability that if we find the Corps’s environmental assessment was defective

and remand for further analysis, new information revealed by that analysis could

motivate the Corps to revise its decision by, for example, requiring additional

mitigation. Marsh v. Or. Natural Res. Council, 490 U.S. 360, 371 (1989)

(holding preparation of a postdecision EIS may sometimes be necessary, so long

as an agency can still take environmentally significant action).

        The Corps does not lack authority to impose additional mitigation, as it

argues, because it may add conditions to permits even after they are granted when

those conditions are necessary to satisfy legal requirements or protect the public

interest. 33 C.F.R. §§ 325.4(a), 325.7. BNSF’s permit specifically states that the

Corps may reevaluate its decision to issue the permit at any time, and such

reevaluation may lead to the suspension, modification, or revocation of the

permit. Accordingly, we decline to find Hillsdale’s NEPA claims prudentially

moot.

        Whether Hillsdale’s CWA claim is prudentially moot is a closer question.

Nearly all of the jurisdictional waters on the Gardner site have been filled, and

nearly all of the associated mitigation is now complete. We still have the

                                         -13-
theoretical power to afford Hillsdale relief by enjoining further construction on

the Gardner site, or even ordering BNSF to restore the preexisting wetlands and

streams. But the progress in the intermodal facility’s construction undoubtedly

changes the balance of the equities. Nonetheless, whether this change is so

drastic as to render Hillsdale’s appeal prudentially moot is a question we need not

reach since Hillsdale’s CWA claim fails on the merits. See Winzler v. Toyota

Motor Sales U.S.A., Inc., 681 F.3d 1208, 1210 (10th Cir. 2012) (finding a claim is

prudentially moot when “the anticipated benefits of a remedial decree no longer

justify the trouble of deciding the case on the merits.”); see also 13B Charles A.

Wright, et al., Federal Practice and Procedure § 3533.1 (3d ed. 2008).

      D. Clean Water Act Alternatives Analysis

      Hillsdale contends the Corp did not properly apply Clean Water Act

regulations in concluding there was no practicable alternative to the Gardner site.

The thrust of its argument is that the Corps did not rebut the presumption that a

practicable alternative existed which did not involve the destruction of U.S.

waters. 40 C.F.R. § 230.10(a)(3).

      The Corps’s actions are presumptively valid under the APA, and Hillsdale

bears the burden of proving the agency acted arbitrarily and capriciously. Forest

Guardians, 611 F.3d at 704. But BNSF has a duty under the CWA to rebut the

presumption that a less environmentally damaging practicable alternative to the

Gardner site exists. 40 C.F.R. § 230.10(a)(3). Thus, if Hillsdale establishes

                                        -14-
BNSF did not rebut this presumption but the Corps issued BNSF a § 404 permit

anyway, Hillsdale can establish the Corps acted arbitrarily and capriciously, “or

otherwise not in accordance with law.” 5 U.S.C. § 706(2)(A). We review the

Corps’s practicability analysis and determination that the selected site was the

least environmentally damaging practicable alternative under this standard of

review.

      1. Practicability Analysis

      For an alternative to be selected under the Corps’s CWA regulations, it

must be practicable, as defined by 40 C.F.R. § 230.10(a)(2), and it must be less

environmentally damaging than all other practicable alternatives. Id.

§ 230.10(a)(3). Practicability is thus a threshold determination. “[A]n agency

need not analyze the environmental consequences of alternatives it has in good

faith rejected as too remote, speculative, or . . . impractical or ineffective.”

Prairie Band, 684 F.3d at 1011 (internal quotation omitted); see also Airport

Neighbors Alliance, Inc. v. United States, 90 F.3d 426, 432 (10th Cir. 1996). 5

The question, then, is what information the Corps must provide to support its

practicability determination.




      5
         These cases involved challenges to a NEPA analysis, rather than a CWA
analysis. But we see no principled reason why an agency should be forced to
analyze the environmental consequences of impracticable alternatives in either
context.

                                          -15-
      Hillsdale contends the Corps and BNSF failed to provide “detailed, clear

and convincing” information establishing the eliminated alternatives were not

practicable. 6 Utahns for Better Transp., 305 F.3d at 1186. The Corps’s

regulations state that “practicable alternatives . . . are presumed to be available,

unless clearly demonstrated otherwise.” 40 C.F.R. § 230.10(a)(3) (emphasis

added). This does not require a specific level of detail to rebut the presumption,

but only record evidence the agency took a hard look at the proposals and reached

a meaningful conclusion based on the evidence. Under this understanding of 40

C.F.R. § 230.10(a)(3)’s presumption, the Corps met this standard.

      The Corps’s environmental assessment discusses BNSF’s site selection

criteria in detail, and clearly indicates whether each proposed alternative met

those criteria. The environmental assessment does not explain in detail the

application of every criterion to every site, but it provides more explanation when

necessary. For example, the environmental assessment explains that a proposed

site near Olathe, Kansas, is close to an airport, and lighting at the site would

conflict with airport operations.

      Hillsdale does not clearly state what sort of additional information the

Corps should have provided in rejecting alternatives. For several criteria,

additional information or explanation would not be helpful. For example, one

      6
         Hillsdale’s citation to Utahns does not support its position, as the portion
of the opinion it quotes is a discussion of the appellant’s argument, not the court’s
holding. See 305 F.3d at 1186 (citing Aplt. Br. at 22).

                                         -16-
criterion states the site must have a minimum of 300 to 400 acres to accommodate

ten 8,000-foot stripping tracks. Two sites—Wellsville South and Olathe—simply

are not large enough to satisfy this criterion. Explaining in more detail why they

are not large enough is unnecessary.

      Similarly, BNSF mandated the site be within 30 miles of its existing

intermodal facility at the Argentine Yard because many of its customers have

facilities nearby. It would be too expensive for them to ship freight more than 30

miles from the new intermodal facility to their existing facilities. Again, several

of the sites were simply too far from the Argentine Yard to meet this criterion,

and explaining this in greater detail is also unnecessary.

      Finally, the Corps’s analysis was appropriate given the minor-to-moderate

anticipated impact of BNSF’s project. The Corps’s CWA regulations instruct it to

“recognize the different levels of effort that should be associated with varying

degrees of impact and require or prepare commensurate documentation. The level

of documentation should reflect the significance and complexity of the discharge

activity.” 40 C.F.R. § 230.6(b). In addition, “[a]lthough all requirements in

§ 230.10 must be met, the compliance evaluation procedures will vary to reflect

the seriousness of the potential for adverse impacts on the aquatic ecosystems

posed by specific dredged or fill material discharge activities.” Id. § 230.10.

      Our decision in Greater Yellowstone Coalition better explains this process.

There, we upheld the Corps’s approval of a project that would destroy 1.45 acres

                                         -17-
of wetlands but improve 32.65 acres of wetlands and add new wetlands, even

though the Corps failed to consider an obvious alternative: committing more of

the developer’s property to the project so more of the development could be

located away from wetlands and bald eagle habitat. 359 F.3d at 1270–71. We

noted the impacts to jurisdictional waters were minimal and possibly even

beneficial and held the Corps adequately supported its alternatives analysis in

light of the project’s anticipated impact. Id.

      Here, the impacts to U.S. waters also are projected to be minimal.

Construction of the intermodal facility at Gardner will affect 4.61 acres of “low-

quality” wetlands and 17,302 feet of similarly low-quality streams, which have

low or intermittent flows. App. Vol. XIV at 4577. The largest seasonal stream,

P-1, is now mostly dry, as the bulk of its flow came from a wastewater treatment

facility that shut down in 2008. Based on these conditions, the Corps estimated

the impact to onsite waters will be minor to moderate. In addition, BNSF’s

proposal includes a conservation corridor that will create 7.18 new acres of

wetlands, realign approximately 9,100 feet of the P-1 stream, and restore a large

existing wetland. Given the minor-to-moderate anticipated impact to U.S. waters,

the Corps was not required to extensively document why the eliminated

alternatives were impracticable.




                                         -18-
      2. Practicable Alternatives

      This leads to Hillsdale’s next argument: that the Corps had a duty under

§ 230.10(a)(3) to locate additional practicable sites that do not contain

jurisdictional waters. They contend it is “virtually certain” a suitable site for the

new intermodal facility that does not contain jurisdictional waters exists

somewhere along the Southern Mainline, and the Corps violated its duty under

§ 230.10(a)(3) by failing to locate such a site. Aplt. Br. at 35.

      To be practicable, an alternative site would have to satisfy BNSF’s site

selection criteria, including the requirement that the site be located within 30

miles of the Argentine Yard. The intermodal facility is needed to serve the

Kansas City area, so BNSF could not build the intermodal facility anywhere along

the “hundreds of miles” of the Southern Mainline in the Midwest, as Hillsdale

argues. Id. at 34.

      In addition, the Corps considered seven alternative sites within or near this

fairly limited geographical area. There is no magic number of alternatives the

Corps must consider for its analysis to be acceptable, but the agency must draw

the line somewhere, even when § 230.10(a)(3)’s presumption applies. “There will

always be more data that could be gathered; agencies must have some discretion

to decide when to draw the line and move forward with decisionmaking.” Habitat

Educ. Ctr., Inc. v. U.S. Forest Serv., 673 F.3d 518, 531 (7th Cir. 2012) (quoting

Town of Winthrop v. FAA, 535 F.3d 1, 11 (1st Cir. 2008)).

                                         -19-
      If Hillsdale had identified an obvious practicable alternative with no

jurisdictional waters that the Corps failed to consider, we might conclude the

Corps failed in its duty. But Hillsdale has not identified such a site, and even if it

had, it should have brought the site to the Corps’s attention. See River Rd.

Alliance, Inc. v. Corps of Eng’rs of U.S. Army, 764 F.2d 445, 452–53 (7th Cir.

1985). Hillsdale instead identified two sites, Le Loup and Ottawa, which the

Corps actually considered but found impracticable. 7 Thus Hillsdale has not

established the Corps acted arbitrarily and capriciously by failing to find an

alternative site that would not involve the destruction of jurisdictional waters.

      3. Duty to Evaluate

      Hillsdale’s final argument is that the Corps did not critically evaluate the

accuracy and necessity of BNSF’s site selection criteria. In particular, it argues

the 30-mile criterion was baseless and claims the Corps should have required

BNSF to consider sites farther from the Argentine Yard.

      The Corps has a duty to independently evaluate BNSF’s site selection

criteria. Greater Yellowstone Coal., 359 F.3d at 1270. In Utahns, we held the

Corps acted arbitrarily and capriciously by eliminating an alternative without

verifying the applicant’s claim that it was prohibitively expensive. 305 F.3d at

1187. Utahns did not state what sort of critical assessment was required, merely

      7
         The Le Loup and Ottawa sites met all of BNSF’s site-selection criteria
save for their distance from the Argentine Yard. These two sites were both more
distant than Wellsville North—40.2 and 44 miles, respectively.

                                         -20-
that the Corps failed to assert independent verification of the applicant’s cost

estimates and the record contained no evidence of such evaluation. Id. at 1165.

      In contrast, there was evidence here that the Corps questioned BNSF’s

criteria by requiring BNSF to seriously consider the Wellsville North site. In

addition, the environmental assessment discusses each criterion in some detail,

explaining the reasoning behind its application to the proposal. The 30-mile

criterion, in particular, is supported by a BNSF study of shipping costs at a

similar intermodal facility in Alliance, Texas. Based on this study, BNSF

estimated it would cost its customers more than $1 million in additional shipping

costs during the intermodal facility’s first year of operation if the facility were

located at Wellsville North (34.4 miles from the Argentine Yard) versus Gardner

(28.6 miles). Hillsdale contends this study only showed a de minimis difference

in shipping costs and the Corps should have rejected or discounted it.

      This argument fails for two reasons. First, the Corps’s CWA regulations

stipulate “it will generally be assumed that appropriate economic evaluations have

been completed, the proposal is economically viable, and is needed in the

marketplace.” 33 C.F.R. § 320.4.(q). The Corps is not entitled to reject an

applicant’s determination that a particular type of development is economically

advantageous. See Sylvester v. U.S. Army Corps of Eng’rs, 882 F.2d 407, 409

(9th Cir. 1989).




                                          -21-
      Further, the Corps is entitled to accept a project applicant’s criteria based

on information the applicant submits. Sierra Club v. Van Antwerp, 661 F.3d 1147

(D.C. Cir. 2011). In Van Antwerp, the plaintiff challenged the Corps’s acceptance

of an applicant’s claim that an 8% rate of return was necessary to secure

financing for its project, and that alternatives to its preferred site offered a lower

rate of return. Id. at 1152. Van Antwerp found a report submitted by the

applicant sufficiently supported the Corps’s acceptance of the 8% figure as the

minimum acceptable rate of return on the project. Id.

      Like the applicant in Van Antwerp, BNSF submitted a study showing its

customers’ costs increase the farther they have to transport goods from an

intermodal facility to their places of business. BNSF’s study establishes its

customers will experience real cost increases if BNSF builds its facility more than

30 miles from the Argentine Yard. The Corps was entitled to rely on this study.

Id.; see also Sylvester, 882 F.2d at 409 (“In evaluating whether a given alternative

site is practicable, the Corps may legitimately consider such facts as cost to the

applicant and logistics.”).

      As the Corps’s acceptance of the 30-mile criterion finds support in the

record, the Corps did not act arbitrarily and capriciously by failing to take

additional steps to verify BNSF’s claim that sites more than 30 miles from the

Argentine Yard were infeasible. See River Road Alliance, Inc. v. Corps of Eng’rs

of U.S. Army, 764 F.2d 445, 452–53 (7th Cir. 1985) (“The Corps is not a business

                                          -22-
consulting firm. It is in no position to conduct . . . a study that would have to . . .

evaluate [BNSF’s] business needs . . . .).”

      Second, the Corps’s analysis was appropriate in light of the anticipated

environmental impact. The Corps in Greater Yellowstone Coalition also failed to

“examine whether any commitment of Ranch property beyond the 359 acres”

allotted by the developer would compromise the viability of the developer’s

ranch. 8 359 F.3d at 1271. Despite a lack of “any evidentiary support for such a

conclusion” in the record, Greater Yellowstone Coalition held this was not

arbitrary and capricious in light of the project’s minor anticipated impact to

jurisdictional waters. Id. The project here is also anticipated to have a minor

impact on jurisdictional waters. And BNSF’s transportation cost study provides

significantly more support for the 30-mile criterion than the applicant in Greater

Yellowstone Coalition provided for the 359-acre limit. The Corps’s analysis of

this criterion was not arbitrary and capricious in light of this anticipated impact. 9




      8
         One of the applicant’s criteria in Greater Yellowstone Coalition was that
the proposed housing development be small enough to avoid compromising the
viability of his working ranch. 359 F.3d at 1271.
      9
        As for BNSF’s other site-selection criteria, Hillsdale does not explain
why they are flawed or why the Corps’s acceptance of them was arbitrary and
capricious. Thus it does not carry its burden with respect to these criteria.
Morris, 598 F.3d at 691.

                                          -23-
      4. Conclusion

      Because the Corps did not act arbitrarily and capriciously by excluding all

but two of the proposed alternative sites as impracticable, we affirm the Corps’s

determination that Gardner was the least environmentally damaging practicable

alternative of the two remaining sites. Both the Gardner and Wellsville North

sites contain wetlands. The Corps examined both sites and determined

construction at Wellsville North would impact more wetlands and streams than at

Gardner. It also determined the wetlands and streams at Wellsville North were of

a higher quality than the wetlands and streams at Gardner. Hillsdale does not

claim construction at Wellsville North would be less environmentally damaging

than at Gardner. Thus the Corps successfully rebutted the presumption that less

environmentally damaging practicable alternatives to the Gardner site existed, and

its CWA analysis was not arbitrary and capricious.

      E. Fugitive Dust Emissions

      Pursuant to NEPA, the Corps prepared an environmental assessment but

declined to prepare an EIS after finding the intermodal facility would not have a

significant environmental impact. As part of its analysis, the Corps considered

BNSF’s model of fugitive dust emissions at the intermodal facility, which

concluded such emissions would be insignificant. Fugitive dust is dust that

accumulates on hard surfaces like roads and is launched into the air by vehicle

traffic and other disturbances. The EPA designed its own model of dust

                                        -24-
emissions at the intermodal facility and concluded they had the localized potential

to exceed National Ambient Air Quality Standards (NAAQS) for particulate

emissions. As a result of the EPA’s analysis, the Corps determined the

intermodal facility had the potential for localized significant impacts.

      In response, BNSF entered a mitigation agreement with KDHE. The

agreement requires BNSF to monitor dust emissions at the intermodal facility for

two years after the facility opens, using a KDHE-operated sampling station. If

dust concentrations exceed specified levels—levels lower than the applicable

NAAQS—BNSF must work with KDHE to determine the cause of the elevated

dust emissions and must take concrete steps to reduce those emissions. KDHE

can require BNSF to implement one of the mitigation options listed in the

agreement, such as spraying for dust suppression, or it can require BNSF to adopt

any other mitigation practice it determines is appropriate. BNSF must submit a

written compliance plan to KDHE, which the agency must approve. The

agreement is enforceable under Kansas law. See Kan. Stat. Ann. § 65-3011.

KDHE may extend the agreement if dust emissions exceed the specified levels at

any time during the monitoring period.

      The Corps decided this agreement sufficiently mitigated the potential for

significant fugitive dust emissions at the site. The EPA agreed. The Corps then

issued a finding of no significant impact, concluding, based on this mitigation




                                         -25-
agreement, that the potential for fugitive dust emissions did not warrant

preparation of an EIS.

      The Corps can decline to prepare an EIS even if it finds a potentially

significant impact so long as it also finds “changes or safeguards in the project

sufficiently reduce the impact to a minimum.” Mich. Gambling Opposition v.

Kempthorne, 525 F.3d 23, 29 (D.C. Cir. 2008). Mitigation measures must be

supported by substantial evidence of some kind. Nat’l Audubon Soc’y v.

Hoffman, 132 F.3d 7, 17 (2d Cir. 1997); Nat’l Parks & Conservation Ass’n v.

Babbitt, 241 F.3d 722, 734–35 (9th Cir. 2001) (Nat’l Parks), abrogated on other

grounds by Monsanto v. Geertson Seed Farms, 130 S. Ct. 2743, 2757 (2010).

They also must be imposed by statute or regulation, or submitted as part of the

original proposal. Davis v. Mineta, 302 F.3d 1104, 1125 (10th Cir. 2002). In

general, agencies “should not rely on the possibility of mitigation as an excuse to

avoid the EIS requirement.” Id. (internal quotation omitted).

      Hillsdale claims the mitigation agreement here cannot support a finding of

no significant impact. First, Hillsdale argues the record contains no studies or

papers supporting the effectiveness of the mitigation options in the agreement.

But “mitigation measures have been found to be sufficiently supported when

based on studies conducted by the agency . . . or when they are likely to be

adequately policed.” Nat’l Audubon Soc’y, 132 F.3d at 17 (emphasis added); see

also Greater Yellowstone Coal., 359 F.3d at 1276; Wyoming Outdoor Council v.

                                        -26-
U.S. Army Corps of Eng’rs, 351 F. Supp. 2d 1232, 1252 (D. Wyo. 2005). Even in

the absence of studies supporting the effectiveness of the listed mitigation

measures, the Corps did not commit a clear error in judgment by basing its

finding of no significant impact on this agreement because the agreement contains

mandatory monitoring provisions and is enforceable under Kansas law.

         Second, Hillsdale claims the monitoring period is too brief because it does

not cover construction of the intermodal facility and will expire in two years,

whereas business at the intermodal facility is projected to increase for at least

twenty years, bringing with it the potential for increased dust emissions. The

intermodal facility is projected to handle roughly twice the business in its

twentieth year of operation as it will in its first, so it stands to reason fugitive

dust emissions will be greater at that time. But the action levels specified in the

mitigation agreement are below NAAQS levels. 10 EPA’s worst-case estimates are

that dust levels will exceed NAAQS by four to ten times. If dust emissions will

be a significant problem at the intermodal facility, they will likely trigger action

under the agreement even before the facility is operating at peak capacity.

         Even if dust levels during the monitoring period do not trigger extension of

the agreement, KDHE may continue monitoring air quality near the intermodal

facility after the agreement expires. To the extent Hillsdale insinuates KDHE

         10
         The agreement requires mitigation if PM 2.5 concentrations exceed 30
μg/m , while the NAAQS for PM 2.5 is 35 μg/m3. PM 10 concentrations over 100
     3

μg/m3 trigger mitigation, while the NAAQS for PM 10 is 150 μg/m3.

                                          -27-
may fail to perform such monitoring if circumstances warrant, or fail to extend

the agreement if dust emissions exceed the specified levels, their argument is

unpersuasive. KDHE has a legal duty under both the Clean Air Act and Kansas

law to protect air quality. 42 U.S.C. § 7410; Kan. Stat. Ann. § 65-3003. We

presume KDHE will perform that duty and either extend the mitigation agreement

or continue independent monitoring, as necessary. See Pit River Tribe v. U.S.

Forest Serv., 615 F.3d 1069, 1082 (9th Cir. 2010).

      Hillsdale also does not establish that the Corps’s failure to require fugitive

dust monitoring during the intermodal facility’s construction was arbitrary and

capricious. Hillsdale points to nothing in the record supporting its claim that

fugitive dust emissions during construction will cause a significant impact. The

intermodal facility’s construction likely will generate some dust, but the record

states fugitive dust emissions primarily occur when “vehicles traveling on paved

roads . . . cause resuspension of dust accumulated on the roads.” App., Vol. XIV

at 4636. The record contains no estimates of vehicle traffic generated by the

intermodal facility’s construction. Given Hillsdale’s failure to support its claim

that fugitive dust emissions during construction are likely to have a significant

impact, this argument is unconvincing. See Morris, 598 F.3d at 691.

      Finally, Hillsdale contends the agreement is insufficient because although it

specifies mitigation measures BNSF must consider, it does not specify measures

BNSF must adopt in the event mitigation is necessary. Hillsdale characterizes

                                        -28-
this as merely a commitment to do “something.” See Davis, 302 F.3d at 1125.

But “[a] mitigation plan need not be legally enforceable, funded or even in final

form to comply with NEPA’s procedural requirements.” Okanogan Highlands

Alliance v. Williams, 236 F.3d 468, 473 (9th Cir. 2000) (internal quotations

omitted). In Greater Yellowstone Coalition, we upheld a mitigation plan that did

not call for specific mitigation measures, other than requiring the applicant not to

build within 400 meters of a bald eagle nest. 359 F.3d at 1276. That plan merely

called for monitoring eagle activity and unspecified modifications to construction

activities if the eagles were disturbed. Id.

      Hillsdale tries to distinguish Greater Yellowstone Coalition by arguing

there was greater uncertainty over how bald eagles would react to construction

near their nests than there is over effective strategies to mitigate dust emissions.

359 F.3d at 1276. Hillsdale claims the mitigation plan here is like the one in

Davis, which was insufficient to support a finding of no significant impact

because it merely listed potential mitigation measures without any supporting data

or “any basis for concluding they will occur.” 302 F.3d at 1125.

      Hillsdale’s reliance on Davis is also misplaced. The plan in that case was

insufficient because it made “no firm commitment to any noise mitigation

measures.” Id. In other words, there was no “binding obligation to provide the

proposed mitigation.” Id. n.16. In addition, the environmental assessment in

Davis actually rejected a number of the proposed mitigation measures as

                                         -29-
incompatible with the project’s purpose. Id. The plan here, by contrast, is

enforceable. Hillsdale argues enforceability is insufficient without data on the

measures’ effectiveness, but as we discussed, mandatory monitoring can provide

such support.

      And though the potential sources of fugitive dust emissions might be less

uncertain than the reaction of bald eagles to construction near their nests, there is

disagreement in the record about whether excessive dust emissions will even

occur and, if they do, what their precise source will be. NEPA does not require a

finalized mitigation plan so long as the proposed plan is supported or monitored.

Okanogan Highlands Alliance, 236 F.3d at 473; Nat’l Audubon Soc’y, 132 F.3d at

17. Flexible mitigation plans are acceptable even when the harm they are

designed to avert is more predictable than the behavior of bald eagles.

      The Corps’s finding of no significant impact based on this plan was not

arbitrary and capricious. If dust emissions exceed levels specified in the

agreement, the plan requires BNSF to adopt mitigation measures, even if it does

not specify which ones. The plan’s mandatory monitoring provisions are

designed to ensure BNSF adopts effective mitigation measures if excessive

emissions occur.

      Thus, we affirm the Corps’s finding that there will be no significant impact

from fugitive dust emissions at the intermodal facility.




                                         -30-
      F. Other Air Emissions

      Hillsdale next raises a number of related claims concerning the adequacy of

the Corps’s treatment of other potential air emissions attributable to the

intermodal facility. Hillsdale contends the Corps failed to take a “hard look” at

(1) emissions from off-site locomotives and (2) non-truck vehicles, (3) the cancer

risks of diesel exhaust, and (4) emissions from increased traffic along Interstate

35 (I-35). Prairie Band, 684 F.3d at 1016.

      We address each of Hillsdale’s claims in turn.

      1. Off-Site Locomotive Emissions

      The Corps considered the impacts of on-site locomotive emissions, but did

not analyze locomotive emissions attributable to the intermodal facility outside

the facility boundaries. Hillsdale claims this was arbitrary and capricious because

train traffic will increase due to the intermodal facility, and the environmental

assessment states locomotive emissions are a significant source of particulate

matter (PM) and nitrous oxide (NO x) emissions. 11 Hillsdale contends increased

emissions likely will be significant and should have been analyzed.

      We disagree. Under NEPA, the Corps’s obligation is to take a “hard look”

at information relevant to its factual determination. Forest Guardians, 611 F.3d

at 710–11. The record shows the Corps reasonably considered off-site locomotive


      11
        PM and NO x are both criteria pollutants regulated under the Clean Air
Act. 42 U.S.C. § 7408.

                                        -31-
emissions in the background emissions levels. For its model, the Corps measured

background emissions levels at Gardner and other sites and then added them to

projected emissions at the intermodal facility, which included emissions from on-

site locomotives. The Corps determined total emissions would not exceed

applicable NAAQS. The Corps also noted large, EPA-mandated increases in

locomotive efficiency over the next 20 years will result in lower locomotive

emissions when the intermodal facility begins operations, even taking into

account rail traffic growth. Thus it concluded current emissions were a worst-

case scenario, and even these did not violate federal emissions limits.

      Hillsdale contends this entire process was flawed. Hillsdale argues it

“defies logic” to consider all off-site emissions part of existing conditions. Aplt.

Br. at 39. But the record reflects that locomotive emissions are expected to

decrease significantly over the next 20 years, even considering the expected

increases in rail traffic. 12 Based on information provided by the EPA, BNSF’s

consultant calculated that even if the number of locomotives moving through the

intermodal facility increases by 250% between its opening and 2030, the most

optimistic scenario in the record, locomotive emissions in the area will still

      12
         Based on these efficiency regulations, the EPA projects that, even
assuming a 50% increase in rail traffic between 2010 and 2030, nationwide NO x
emissions from locomotives will decrease by roughly 66%, and PM emissions will
decrease by about 80%. This means emissions from individual locomotives will
decrease by at least a factor of three. The Corps was required to consider the
likely impact of these regulations. Wyoming v. U.S. Dept. of Agriculture, 661
F.3d 1209, 1251 (10th Cir. 2011).

                                         -32-
decline. Thus it was not unreasonable for the Corps to conclude existing

conditions—which include current locomotive emissions—are a worst-case

scenario.

      The Corps and BNSF then added modeled emissions at the intermodal

facility—which included estimates of locomotive emissions—to the background

emissions levels. These totals were still below the applicable NAAQS. Thus the

Corps concluded locomotive emissions attributable to the intermodal facility—on-

or off-site—were unlikely to have a significant impact. This approach was

reasonable.

      Hillsdale also claims the Corps should have quantified what proportion of

future rail traffic—and emissions due to that traffic—is attributable to the

intermodal facility. Hillsdale argues the agency must consider all direct and

indirect impacts of its decision. But an agency must consider only “every

significant aspect” of a proposed action. Baltimore Gas and Elec. Co. v. Natural

Res. Def. Council, 462 U.S. 87, 97 (1983) (emphasis added). Although some

proportion of future rail traffic can logically be attributed to the intermodal

facility, this by itself does not establish significance. NEPA regulations direct the

Corps to consider both context and intensity when weighing the significance of an

impact. 40 C.F.R. § 1508.27. Hillsdale does not argue locomotive emissions

attributable to the intermodal facility implicate any of the intensity factors listed

in § 1508.27(b). As Hillsdale does not carry its burden of demonstrating these

                                          -33-
emissions are likely to be significant, it does not establish the Corps erred by

failing to quantify them.

      Nor do the cases Hillsdale cites convince us the Corps erred. Hillsdale

insists the Corps is attempting to excuse its analysis on the basis that increases in

rail traffic will occur with or without the intermodal facility, an argument we

rejected in Davis. 302 F.3d at 1123. This misstates the Corps’s position. 13 The

Corps did not conclude locomotive emissions would increase anyway, but that

emissions would not increase. This distinguishes this case from Ocean Advocates

v. U.S. Army Corps of Eng’rs, 402 F.3d 846, 867–68 (9th Cir. 2004), where the

Corps did not consider the potential environmental effects of increased shipping

traffic. Here, the Corps considered those impacts and concluded they would not

be significant even if rail traffic increased.

      In sum, although there will likely be some impact from offsite locomotive

emissions attributable to the intermodal facility, the Corps’s conclusion that this

impact was unlikely to be significant, and its decision not to quantify this impact,

was not arbitrary and capricious.

      2. Non-Truck Vehicle Emissions

      The Corps estimated that in the intermodal facility’s first year of operation,

it and nearby associated warehouse facilities are likely to generate an average of


      13
         BNSF makes this argument, but it does not accurately reflect the Corps’s
conclusions in the environmental assessment.

                                          -34-
2,185 one-way non-truck vehicle trips per weekday. By the fifth year of

operation, that number is expected to grow to 9,211 one-way non-truck trips per

weekday, primarily due to an increasing number of warehouse facilities. The

Corps did not model emissions from non-truck vehicles. Instead, the agency

determined automobile traffic in the Gardner area was projected to increase

substantially in the next twenty years due to other developments and non-truck

traffic attributable to the intermodal facility would be insignificant in comparison.

The Corps also noted EPA regulations are expected to decrease automobile

emissions significantly over the next twenty years. The Corps then declined to

include non-truck vehicle emissions in its air pollution model.

      Hillsdale contends this was arbitrary and capricious because non-truck

vehicle emissions are a significant source of regulated air pollutants, including

ozone precursors. Hillsdale points to several comments emphasizing that the

Kansas City area, including the county where the Gardner site is located, has

recently violated federal ozone standards and is in danger of being designated a

nonattainment zone for ozone. Accordingly, Hillsdale argues the Corps should

have considered these emissions per 40 C.F.R. § 1508.27(b)(10), which directs

the Corps to consider whether a proposed action threatens a violation of federal

environmental standards. 14

      14
       The Corps responds that Hillsdale did not raise this issue in its
comments to the draft environmental assessment, depriving it of its opportunity to
                                                                     (continued...)

                                         -35-
      The Corps decided not to include these emissions in its model, concluding

that, based on local land-use plans, traffic will increase substantially in the

Gardner area regardless of the intermodal facility. The Corps also found new

regulatory requirements will decrease vehicle emissions even as traffic increases.

As with locomotives, the Corps claims its background emissions sampling

adequately accounted for vehicle emissions because it sampled emissions in areas

with much more traffic, including downtown Kansas City and Overland Park,

Kansas. The Corps argues traffic near the intermodal facility will not exceed

traffic in these areas within the next twenty years.

      The Corps’s argument that new regulatory requirements will reduce non-

truck vehicle emissions over the next 20 years finds little support in the record.

In contrast to the detailed evidence discussing future decreases in locomotive

emissions, the evidence for future decreases of non-truck emissions is lacking,

amounting to little more than a statement that such decreases are likely to occur.


      14
         (...continued)
respond on the record. The Corps therefore argues we should not consider this
argument because Hillsdale did not exhaust its administrative remedies. Ark
Initiative v. U.S. Forest Serv., 660 F.3d 1256, 1261 (10th Cir. 2011).

       Hillsdale did not raise this claim, but several other comments discussed
Kansas City’s ozone problems, including two comments that mention concerns
with non-truck emissions. Claims not raised before an agency are not waived if
they are “obvious, or otherwise brought to the agency’s attention.” Id. at 1262
(internal quotation omitted). These comments make it clear that concerns about
non-truck emissions were otherwise brought to the agency’s attention, and so this
claim is not waived.

                                         -36-
And though traffic in the area may increase independently of the intermodal

facility, the record specifies the intermodal facility will create some non-truck

vehicle traffic. The environmental assessment even quantifies the estimated

number of vehicle trips to and from the intermodal facility.

      Despite this, the Corps’s decision to not analyze non-truck vehicle

emissions was not arbitrary and capricious. Traffic attributable to the intermodal

facility will be insignificant compared to overall traffic in the area. The record

reflects that the intermodal facility will generate 9,211 vehicle trips per day by its

fifth year of operation, estimated to be 2015. In contrast, total traffic in only one

nearby community—Olathe—is expected to be over 942,000 vehicle trips per day

by 2015. The record also reflects that ozone levels are affected by regional

emissions, indicating the proper point of comparison is not a single nearby

community or even Johnson County, but the entire Kansas City region.

      The Corps is only required to consider potential impacts relative to their

significance. 40 C.F.R. § 1502.2(b). The small number of non-truck vehicle trips

attributable to the intermodal facility is clearly insignificant in comparison to

regional traffic. The Corps did not “fail[] to consider an important aspect of the

problem” when it declined to model non-truck vehicle emissions. New Mexico,

565 F.3d at 704. Its decision to focus its analysis on fugitive dust emissions and

emissions from trucks, heavy equipment, and locomotives—anticipated to be the




                                         -37-
primary sources of air pollution at the intermodal facility—was not arbitrary and

capricious.

      3. Cancer Risk Methodology

      As part of its emissions analysis, the Corps considered potential cancer

risks associated with a wide variety of pollutants. The Corps did not specifically

analyze the cancer risks from diesel exhaust, although its cancer risk analysis

considered many of the toxic components of diesel exhaust. 15 Hillsdale complains

the Corps’s failure to separately analyze cancer risks from diesel exhaust,

particularly diesel particulate matter (DPM), was arbitrary and capricious.

      “Courts are not in a position to decide the propriety of competing

methodologies . . . but instead, should determine simply whether the challenged

method had a rational basis and took into consideration the relevant factors.”

Silverton Snowmobile Club, 433 F.3d at 782 (internal quotation omitted). This is

particularly true when the dispute involves a technical judgment within the

agency’s area of expertise. Envt’l Defense Fund v. U.S. Nuclear Regulatory

Comm’n, 902 F.2d 785, 789 (10th Cir. 1990) (internal quotation omitted).




      15
         The chemicals considered in the Corps’s analysis include acetaldehyde,
benzene, 1,3-butadiene, formaldehyde, and particulate matter. These are the
major toxic DPM components Hillsdale identifies. The record also reflects that
DPM can contain trace amounts of various heavy metals, as well as small amounts
of dioxins, although it notes diesel engines “are a minor contributor to overall
dioxin emissions.” App. Vol. XII at 3968.

                                        -38-
      We find the Corps adequately analyzed the cancer risks of DPM. Hillsdale

claims deference to an agency’s chosen methodology is due only when the impact

is agreed upon and the disagreement is over the appropriate methodology to

assess its significance. Hillsdale characterizes the disagreement here as over

whether DPM poses a cancer risk, not over the methodology to assess that risk.

      This misstates the Corps’s position. The Corps does not dispute that DPM

poses a cancer risk. It notes, as the EPA concluded, that DPM is a likely

carcinogen. It merely chose a methodology Hillsdale dislikes to analyze that risk.

The crux of Hillsdale’s claim, then, is that the Corps used the wrong

methodology. Hillsdale contends the Corps should have employed a DPM-

specific methodology, in particular one that has been adopted by the State of

California, which the Corps has used in NEPA analyses of California-based

projects.

      The Corps’s prior use of California’s DPM methodology for California

projects does not require it to use the same methodology here. An agency has

discretion to choose a methodology, so long as it explains why it is reliable.

Lands Council v. McNair, 629 F.3d 1070, 1078 (9th Cir. 2010). The Corps can

rationally choose to use California’s DPM methodology when conducting NEPA

analysis of a California project, and choose to use a different methodology here.

Hillsdale is correct that the Corps’s prior DPM assessments were conducted to




                                        -39-
comply with NEPA, not California law, but they fail to explain why this requires

the Corps to use this methodology for every future analysis of DPM emissions.

      As for the reliability of the Corps’s chosen methodology, Hillsdale argues

the methodology is likely to understate the cancer risk at the intermodal facility

because the combination of toxic chemicals in DPM likely creates a cancer risk

greater than the sum of the risks from individual toxic DPM components. But it

points to nothing in the record supporting this assertion, merely to a list of the

many toxic compounds in DPM.

      The Corps’s chosen methodology is entitled to deference. Silverton

Snowmobile Club, 433 F.3d at 782; Prairie Band, 684 F.3d at 1017. The Corps

considered California’s methodology and determined it was inappropriate. The

Corps based this decision on information provided by an expert agency, the EPA,

including the EPA’s conclusion that it cannot currently establish an accurate

dose-response relationship for DPM exposure and EPA’s concerns with

California’s methodology. The Corps instead relied on EPA standards. The EPA

signed off on the Corps’s air quality analysis.

      We conclude the Corps’s methodology had a rational basis and considered

the appropriate factors, including the carcinogenic components of DPM.

Silverton Snowmobile Club, 433 F.3d at 782; Northwest Envtl. Advocates v. Nat’l

Marine Fisheries Serv., 460 F.3d 1125, 1139 (9th Cir. 2006). The Corps did not

act arbitrarily and capriciously by utilizing its chosen methodology to assess the

                                         -40-
cancer risk from DPM and other air pollution attributable to the intermodal

facility, rather than a competing methodology proposed by Hillsdale.

      4. I-35 Emissions

      Finally, Hillsdale claims the Corp arbitrarily and capriciously failed to

analyze DPM emissions from increased truck traffic on portions of I-35 near the

intermodal facility. The Corps estimated 81% of the trucks traveling to the

intermodal facility will pass by the town of Gardner on I-35, coming within 122

feet of two residential areas. The Corps forecasts the intermodal facility will

generate 3,000 diesel truck trips per day by year five, and 7,600 per day at full

capacity. Based on these estimates, Hillsdale argues the intermodal facility will

subject the residential areas abutting I-35 to elevated DPM emissions. The Corps

did not analyze DPM or any other emissions along I-35. It analyzed emissions

only at the intermodal facility and along an access road. Hillsdale claims this

failure was arbitrary and capricious.

      The Corps’s conclusion is sufficiently supported by the record. The

Corps’s methodology involved sampling background air quality at numerous

stations in the Kansas City area. 16 The Corps then modeled emissions at or near

the intermodal facility, including diesel truck emissions, and added these

emissions to the background levels. Its model assumed 100% of truck emissions


      16
        The record states many sample stations were in areas more developed
than Gardner, although it does not quantify this disparity.

                                         -41-
would occur along the access road. The Corps found these emissions were well

below NAAQS levels and would quickly disperse. Consequently, the Corps

concluded emissions along I-35 would be even lower and would not be

significant.

      We agree. Hillsdale does not challenge the Corps’s conclusion that 100%

of truck emissions along the access road does not create a significant impact, and

it fails to demonstrate how 81% of the truck emissions farther from the

intermodal facility would be more significant. Nor does Hillsdale argue the

background emissions levels along I-35 are higher than the background emissions

levels the Corps used to model emissions closer to the intermodal facility.

Instead, Hillsdale mostly repeats its arguments regarding the health risks of DPM,

which we addressed previously.

      Thus the Corps did not “fail[] to consider an important aspect of the

problem,” and did not violate NEPA, when it declined to model truck emissions

along I-35. New Mexico, 565 F.3d at 704.

      G. Water Pollution

      The Gardner site sits in the watershed for Hillsdale Lake, a local reservoir

and drinking water source for roughly 30,000 people. 17 Hillsdale Lake does not

meet Kansas water quality standards for phosphorus and contains high levels of


      17
          The Corps constructed Hillsdale Lake and continues to operate the
reservoir.

                                        -42-
polycyclic aromatic hydrocarbons (PAHs). The Corps concluded the intermodal

facility would not have a significant impact on Hillsdale Lake or local

groundwater quality. The Corps relied on a BNSF study of potential impacts to

water resources to reach this conclusion.

       Hillsdale is correct that the environmental assessment and water quality

report indicate some potential adverse effects to both Hillsdale Lake and local

groundwater. The question is whether the Corps took a hard look at these

potential impacts in the environmental assessment and adequately supported its

conclusion that they are insignificant. Forest Guardians, 611 F.3d at 710–11. It

did.

       Hillsdale first argues Hillsdale Lake is “ecologically critical” under 40

C.F.R. § 1508.27(b)(3) because it is a drinking water source. Hillsdale contends

this required the Corps to prepare an EIS to examine the potential impacts to the

lake. It does not support its claim that all drinking water sources are ecologically

critical areas under 40 C.F.R. § 1508.27(b)(3), and we fail to see how this factor

is implicated. But Hillsdale also argues that because Hillsdale Lake is a drinking

water source, 40 C.F.R. § 1508.27(b)(2), which pertains to effects to public

health, requires preparation of an EIS. Hillsdale relies heavily on United States v.

27.09 Acres of Land, 760 F. Supp. 345, 353 (S.D.N.Y. 1991), which found “the

threatened introduction of contaminants into drinking water” required preparation

of an EIS even if it was not projected to violate federal drinking water standards.

                                         -43-
      Regardless of which § 1508.27(b) factor is implicated, a project’s potential

to affect one of these factors does not require an agency to prepare an EIS. The

relevant analysis is the degree to which the proposed action affects this interest,

not the fact it is affected. See Nat’l Parks, 241 F.3d at 731. Hillsdale’s attempt

to create a per se rule that any potential impact to drinking water, however minor,

requires preparation of an EIS is thus unconvincing. Instead, Hillsdale must show

the intermodal facility has the potential to significantly impact drinking water to

establish the Corps’s failure to prepare an EIS was arbitrary and capricious. It

does not.

      Some passages in the environmental assessment state, for example, that

sedimentation may occur during construction or that runoff from the intermodal

facility may contain some pollutants and could infiltrate shallow groundwater.

But Hillsdale cites nothing establishing that these are “clear and well-documented

threats” to local surface and groundwater, as it claims. Aplt. Br. at 55.

      On the contrary, the record shows the Corps thoroughly considered the

intermodal facility’s impacts to both surface and groundwater. The

environmental assessment and water quality report acknowledge runoff may occur

during construction and operation of the intermodal facility. Because BNSF plans

a number of mitigation and water-treatment measures and must obtain a KDHE

construction permit with requirements to reduce erosion and runoff, the Corps

found adverse impacts during construction will be minor.

                                         -44-
      The Corps’s conclusion is supported by a study of runoff at a similar

intermodal facility in Birmingham, Alabama. The study found negligible amounts

of phosphorus—the major pollutant of concern at Hillsdale Lake—and suspended

solids in the runoff. The only pollutants with elevated levels were oil and grease.

Based on this study, the Corps concluded the only likely impacts to surface and

ground water at the Gardner intermodal facility will be from oil and grease in

runoff, these would be minor, and planned mitigation measures would minimize

even this small risk.

      Hillsdale also argues the Corps should have prepared an EIS to examine

groundwater impacts because BNSF’s water quality report acknowledged a

potential for contaminated runoff to infiltrate groundwater. As with surface water

impacts, the Corps found “there is potential for some contaminated water to

infiltrate to shallow groundwater.” App. Vol. XV at 4827. But the Corps also

concluded groundwater risks are minimal for several reasons: the project area will

mostly be paved or impervious, there will be no underground storage tanks onsite,

and the project area consists of clay soil, which has low hydraulic conductivity.

Any groundwater contamination also would be limited to groundwater at the

facility, which is unlikely to be used for drinking water.

      Hillsdale again points to 40 C.F.R. § 1508.27(b)(2), effects to public

health, claiming there are numerous drinking water wells near the Gardner site

and the impact to those wells should have been examined. But Hillsdale

                                         -45-
identifies only one comment from a landowner with a well who resides over a

mile from the Gardner site. 18 Hillsdale also fails to undermine the Corps’s

conclusion that groundwater impacts will be minimal and localized.

      Hillsdale fails to carry its burden. The Corps’s decision is entitled to a

presumption of regularity, and it finds support in the record. Accordingly, we

affirm the Corps’s conclusion that water impacts from the intermodal facility are

insignificant.

      H. The Controversial Nature of the Intermodal Facility

      The Corps’s CWA regulations require it to gauge the intensity of

environmental impacts, including the extent to which these impacts are

controversial, in assessing the significance of a proposal. 40 C.F.R.

§ 1508.27(b)(4). Hillsdale claims the intermodal facility project is highly

controversial, and the Corps should have prepared an EIS on account of this

controversy. See Nat’l Parks, 241 F.3d at 736–37; Public Citizen v. Dept. of

Transp., 316 F.3d 1002, 1024 (9th Cir. 2003), rev’d on other grounds by Dept. of

Transp. v. Pub. Citizen, 541 U.S. 752 (2004). But Hillsdale overstates the

importance of this factor.

      Controversy is only one of ten factors the Corps must consider when

deciding whether to prepare an EIS. 40 C.F.R. § 1508.27(b)(4). Controversy in

      18
         Hillsdale cites to one other comment, from an environmental group, but
this comment merely states there are many drinking wells in the area without
specifying their number or location.

                                        -46-
this context does not mean opposition to a project, but rather “a substantial

dispute as to the size, nature, or effect of the action.” Middle Rio Grande, 294

F.3d at 1229. In addition, “controversy is not decisive but is merely to be

weighed in deciding what documents to prepare.” Town of Marshfield v. FAA,

552 F.3d 1, 5 (1st Cir. 2008). So even if a project is controversial, this does not

mean the Corps must prepare an EIS, although it would weigh in favor of an EIS.

      As support for their argument that the intermodal facility is controversial

within the meaning of 40 C.F.R. § 1508.27(b)(4), Hillsdale claims 90% of the

comments to the Corps’s environmental assessment either disapproved of the

project or asked the Corps to prepare an EIS. See Nat’l Parks, 241 F.3d at

736–37 (finding an “out-pouring of public protest” when 85% of comments

objected to the agency’s chosen alternative).

      This argument is without merit. When analyzing whether a proposal is

controversial, we consider the substance of the comments, not the number for or

against the project. Even if 90% of the comments to the environmental

assessment were negative, this merely demonstrates public opposition, not a

substantial dispute about the “size, nature, or effect” of the intermodal facility.

Middle Rio Grande, 294 F.3d at 1229. National Parks, which Hillsdale cites,

found controversy not because of the high number of negative comments but

because those comments “cast substantial doubt on the adequacy of the [agency’s]

methodology and data.” 241 F.3d at 736–37.

                                         -47-
      The comments here do not cast substantial doubt on the agency’s

methodology and data. Hillsdale is correct that many of the comments they cite

are more than mere statements of opposition; they question various aspects of the

Corps’s analysis, mostly its failure to analyze the cancer risks of DPM emissions

but also the intermodal facility’s impacts on water quality, regional air quality,

and so on.

      But all comments Hillsdale identifies raise the same issues it raised in this

appeal. As we have discussed, the Corps took the requisite “hard look” at every

one of these issues, which is all NEPA requires. Forest Guardians, 611 F.3d at

711. Hillsdale cannot overcome its failure on the merits simply by pointing to

comments expressing the same concerns. If Hillsdale cannot show there is some

merit to opposing opinions, they cannot demonstrate controversy. Town of Cave

Creek v. FAA, 325 F.3d 320, 331 (D.C. Cir. 2003); see also Bering Strait Citizens

v. U.S. Army Corps of Eng’rs, 524 F.3d 938, 957 (9th Cir. 2008).

      An additional point in the Corps’s favor is that none of the federal or state

agencies the Corps consulted opposed the project or the Corps’s analysis.

Although not dispositive, this is additional evidence of a lack of controversy. See

Nw. Envtl. Advocates, 460 F.3d at 1139; Nat’l Wildlife Fed’n v. Norton, 332 F.

Supp. 2d 170, 185 (D.D.C. 2004); cf. Friends of the Earth v. U.S. Army Corps of

Eng’rs, 109 F. Supp. 2d 30, 43 (D.D.C. 2000) (finding controversy where “three




                                         -48-
federal agencies and one state agency have all disputed the Corps evaluation . . .

and pleaded with the Corps to prepare an EIS”).

      In short, neither the nature nor the number of the comments Hillsdale cites

demonstrates the intermodal facility is controversial, let alone that the Corps’s

decision not to prepare an EIS was arbitrary and capricious in light of this

controversy.

                                 III. Conclusion

      Having considered the record and the parties’ arguments, we AFFIRM the

decision of the district court and uphold the Corps’s issuance of a § 404 permit.




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