                 FOR PUBLICATION

  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT


MICHELLE BARNES, an individual;           No. 14-71180
PATRICK CONRY, an individual;
BLAINE ACKLEY, an individual;
DAVID BARNES, an individual;               OPINION
JAMES LUBISCHER, an individual;
OREGON AVIATION WATCH, an
Oregon non-profit organization,
                         Petitioners,

                 v.

FEDERAL AVIATION
ADMINISTRATION,
                        Respondent;

PORT OF PORTLAND,
            Intervenor-Respondent.


        On Petition for Review of an Order of the
            Federal Aviation Administration

         Argued and Submitted October 5, 2016
                   Portland, Oregon

                  Filed August 3, 2017

Before: Sidney R. Thomas, Chief Judge, and Richard R.
   Clifton and Jacqueline H. Nguyen, Circuit Judges.
2                         BARNES V. FAA

                     Opinion by Judge Clifton


                            SUMMARY*


               Federal Aviation Administration

   The panel denied a petition for review of a decision of the
Federal Aviation Administration (“FAA”), finding that a new
runway project at Hillsboro Airport near Portland, Oregon,
would have no significant impact on the environment
(“FONSI”).

    The panel held that in adopting the supplemental
environmental assessment, issuing the FONSI, and
concluding that the project at Hillsboro Airport complied with
the requirements of the Airport and Airway Improvement
Act, the FAA did not act in a manner that was arbitrary,
capricious, an abuse of discretion, or otherwise not in
accordance of law.


                             COUNSEL

Sean Malone (argued), Eugene, Oregon, for Petitioners.

Robert Lundman (argued), Maggie B. Smith, and Andrew C.
Mergen, Attorneys, Appellate Section; Sam Hirsch, Acting
Assistant Attorney General; Environment and Natural


    *
      This summary constitutes no part of the opinion of the court. It has
been prepared by court staff for the convenience of the reader.
                      BARNES V. FAA                          3

Resources Division, United States Department of Justice,
Washington, D.C.; Patricia Deem, Office of Regional
Counsel, NW Mountain Division, Federal Aviation
Administration; Eric Elmore and Daphne Fuller, Office of the
Chief Counsel, Federal Aviation Administration, Washington,
D.C.; for Respondent.

Jason T. Morgan (argued) and Beth S. Ginsberg, Stoel Rives
LLP, Seattle, Washington, for Intervenor-Respondent.


                         OPINION

CLIFTON, Circuit Judge:

    This case involves a new runway at Hillsboro Airport, a
general aviation airport near Portland, Oregon. We
previously considered a challenge to the original
environmental assessment done for the new runway project
in Barnes v. United States Department of Transportation,
655 F.3d 1124 (9th Cir. 2011) (“Barnes I”). Although we
rejected many of the arguments raised in the prior petition for
review, we granted the petition and remanded for further
consideration based primarily on concern for the possibility
that the new runway would result in a larger number of
takeoffs and landings at the airport, a possibility we
concluded had not been adequately addressed.

    Following remand, a supplemental environmental
assessment was prepared. It concluded that the new runway
would cause at most a small increase in air traffic and also
determined that, even if the runway did induce a growth in
traffic, any impact on air quality would be immaterial. The
Federal Aviation Administration accepted that assessment
4                       BARNES V. FAA

and issued a finding that the new runway would have no
significant impact on the environment. Petitioners, five
individuals and a non-profit organization, oppose the new
runway and challenge the FAA’s conclusions. We have
jurisdiction pursuant to 49 U.S.C. § 46110(a), and we deny
their petition for review.

I. Background

    Hillsboro Airport (“HIO”) is located in the city of
Hillsboro in Washington County, Oregon, twelve miles west
of downtown Portland. It is owned by Intervenor-Respondent
Port of Portland. In terms of airport operations (the sum of
takeoffs and landings), it became the busiest airport in
Oregon in 2008, surpassing Portland International Airport.1

    In 2005 the Port undertook to develop a Master Plan for
HIO. Among other things, the Plan proposed construction of
a new third runway, which would run parallel to the existing
primary runway and would be used by small general aviation
aircraft. The Plan concluded that adding the new runway
would be “the best means available for reducing delays and
the undesirable conditions that occur due to delay.” The new
runway would also allow for separating small, single-engine
propeller planes from larger propeller planes and jet aircraft.
The modifications were to be funded in part by FAA grants.

    The use of FAA funds meant that the environmental
effects of the project had to be considered. See 40 C.F.R.
§ 1508.18(a). The Port produced an environmental


    1
      More background on HIO, its configuration, and the changes
proposed by the Port is provided in our prior opinion. See Barnes I,
655 F.3d at 1126–29.
                       BARNES V. FAA                          5

assessment (“EA”) for the FAA, and the FAA issued a
finding of no significant impact (“FONSI”) in 2010. See
40 C.F.R. § 1508.13. That finding relieved the FAA of the
obligation to have a more detailed environmental impact
statement prepared. See 40 C.F.R. § 1501.4(e).

    Opponents of the new runway, including three of the
petitioners in this action, petitioned this court for review,
arguing, among other things, that the EA did not meet the
requirements of the National Environmental Policy Act of
1969 (“NEPA”), 42 U.S.C. § 4321 et seq. Barnes I, 655 F.3d
at 1130–31. We rejected many of the opponents’ arguments,
but we granted the petition and remanded for further
consideration. Id. at 1143. Although the EA concluded that
the new runway would not increase air traffic at the airport,
our decision concluded that the EA was inadequate because
the FAA could not “point to any documents in the record that
actually discusse[d] the impact of a third runway on aviation
demand at HIO.” Id. at 1136. Accordingly, we determined
“that remand [was] necessary for the FAA to consider the
environmental impact of increased demand resulting from the
HIO expansion project, if any.” Id. at 1139.

    On remand, the Port produced a supplemental
environmental assessment (“SEA”), which included three
different forecasts for demand at HIO. The forecasts
predicted at most a small increase in air traffic operations due
to the new runway and concluded that pollution generated by
any increased traffic would be negligible. The FAA adopted
the SEA, concluded that it was unnecessary to prepare an
environmental impact statement, and, in 2014, issued a new
FONSI. See 40 C.F.R. §§ 1501.4, 1508.13; Morongo Band
of Mission Indians v. FAA, 161 F.3d 569, 575 (9th Cir. 1998)
(“If a FONSI is made, the agency need not prepare an EIS.”).
6                         BARNES V. FAA

Following the decision of a motions panel of this court to
deny Petitioners’ motion for an injunction pending
consideration of the petition, the Port constructed the runway,
and the runway is now completed and open for use.2

    Petitioners now contend that, on remand, the FAA did not
fulfill NEPA’s requirement to take a “hard look” at the
environmental impacts of additional air traffic generated by
the new runway. See Envtl. Prot. Info. Ctr. v. U.S. Forest
Serv., 451 F.3d 1005, 1009 (9th Cir. 2006). They also argue
that the circumstances of the project necessitated preparation
of an environmental impact statement. See 42 U.S.C.
§ 4332(2)(C); 40 C.F.R. § 1508.27. Finally, they contend that
the FAA did not comply with the Airport and Airway
Improvement Act’s requirement to ensure that the new
runway was consistent with the plans of the appropriate local
agencies. See 49 U.S.C. § 47106(a)(1).

II. Discussion

      “Judicial review of agency decisions under NEPA . . . is
provided by the [Administrative Procedure Act], which
maintains that an agency action may be overturned only when
it is ‘arbitrary, capricious, an abuse of discretion, or otherwise


    2
      The parties have not addressed whether this development rendered
the case moot. We conclude that it did not. In a similar context, we
previously held that a NEPA challenge to a completed and fully
operational freeway interchange was not moot because the court could
conceivably have ordered that the interchange be closed and dismantled.
West v. Sec’y of the Dep’t of Transp., 206 F.3d 920, 925 (9th Cir. 2000);
see also Feldman v. Bomar, 518 F.3d 637, 642–43 (9th Cir. 2008)
(collecting cases). Potential remedies available in the instant case,
including decommissioning the runway, are no less implausible than
dismantling a freeway interchange.
                      BARNES V. FAA                         7

not in accordance with law.’” Pit River Tribe v. U.S. Forest
Serv., 469 F.3d 768, 778 (9th Cir. 2006) (quoting 5 U.S.C.
§ 706(2)(A)). In the context of “reviewing an agency’s
decision not to prepare an EIS under NEPA,” we consider
“whether the agency has taken a ‘hard look’ at the
consequences of its actions, ‘based [its decision] on a
consideration of the relevant factors,’ and provided a
‘convincing statement of reasons to explain why a project’s
impacts are insignificant.’” Envtl. Prot. Info. Ctr., 451 F.3d
at 1009 (alteration in original) (quoting Nat’l Parks &
Conservation Ass’n v. Babbitt, 241 F.3d 722, 730 (9th Cir.
2001)). The FAA’s conclusion that a proposed project meets
the requirements specified in the Airport and Airway
Improvement Act, 49 U.S.C. § 47106, is also reviewed under
the arbitrary and capricious standard. See City of Dania
Beach v. FAA, 628 F.3d 581, 588 (D.C. Cir. 2010).

A. Petitioners’ Challenges         to   the    Supplemental
   Environmental Assessment

    Petitioners argue that the SEA was deficient in a number
of respects and that it therefore did not constitute the “hard
look” NEPA requires. We address each of Petitioners’
contentions in turn.

   1. Forecasting Methodologies

    On remand, the Port produced three forecasts for air
traffic growth at HIO: the Unconstrained Forecast, the
Constrained Forecast, and the Remand Forecast.

    The Unconstrained Forecast modeled air traffic based on
socio-economic data without limitations related to the
airport’s infrastructure. In other words, the Unconstrained
8                     BARNES V. FAA

Forecast predicted how much air traffic HIO would see if it
had limitless runways and other facilities. The Unconstrained
Forecast predicted that HIO would have 224,260 total aircraft
operations in 2016 and 242,680 total aircraft operations in
2021.

    The Constrained Forecast modeled air traffic while taking
account of HIO’s limited runways and assuming that the new
runway would not be built. The Constrained Forecast
assumed that, if HIO became so crowded that the wait time to
use its two then-existing runways became intolerable, then
pilots would begin using other airports, and growth at HIO
would taper off. The Constrained Forecast determined that,
even without the new runway, the delays at HIO would not
have reached an intolerable level by 2021, the end of the
forecasting period adopted by the SEA. Because a delay-
induced curb on operations growth was the only difference
between the Unconstrained and Constrained Forecasts, and
because such delays were not anticipated during the
forecasting period, the Constrained Forecast predicted the
same number of operations as the Unconstrained Forecast.

     In order to accommodate our direction in Barnes I to
consider demand induced by the new runway, the SEA also
included what it called a Remand Forecast, which
incorporated data derived from a survey. In the survey, pilots
with planes based at HIO and other airports around Portland
estimated whether and by how much they would increase
their operations at HIO due to the new runway, the associated
reduced delays at peak times, and the increased safety arising
from separating single-engine propeller planes from larger
planes. The SEA added the increase that the pilots projected
to the projections from the Unconstrained Forecast to arrive
at the Remand Forecast, which predicted that HIO would see
                       BARNES V. FAA                           9

235,610 operations in 2016 and 254,030 operations in 2021.
Accordingly, among the three forecasts, the Remand Forecast
predicted the largest air traffic volume. Specifically, the
Remand Forecast predicted that HIO would have 11,350
more takeoffs and landings each year with the new runway
than it would without the new runway.

    The SEA contended that the Unconstrained Forecast,
which took account of socio-economic conditions, adequately
predicted future demand at HIO assuming the new runway
were built. Additionally, the SEA provided extensive
analysis about the Remand Forecast. Our primary concern in
Barnes I was the original EA’s lack of a comparison of
projected air traffic with and without the new runway.
655 F.3d at 1134 (“The agencies are unable to point to
anything in the record showing that they in fact considered
the possibility that expanding HIO’s capacity would lead to
increased demand and increased aircraft operations . . . .”); id.
at 1136–37. By including, on the one hand, the Constrained
Forecast, and comparing it with, on the other hand, both the
Unconstrained and Remand Forecasts, the SEA addressed this
concern two times over.

    Petitioners contend that the Remand Forecast
underestimates growth. Specifically, Petitioners claim that
the survey used to generate the Remand Forecast did not
include a response from Hillsboro Aviation, a pilot training
school that Petitioners state is the largest aviation operator at
HIO. The FAA counters that Petitioners are mistaken and
that Hillsboro Aviation did in fact respond to the survey. The
record indicates that Hillsboro Aviation’s response was
10                          BARNES V. FAA

included in the survey. Accordingly, the challenge to the
Remand Forecast is without merit.3

    The SEA concluded that even the higher activity levels
reflected in the Remand Forecast would not have any
significant environmental effects. With regard to air quality,
for instance, it stated that “the proposed project would either
reduce emissions and be de minimis, or, if the Remand
Forecasts occurred, would slightly increase emissions but
remain well below the de minimis level.” Petitioners
challenge specific elements of that conclusion.

     2. Lead Pollution Baseline Measurements

     Petitioners argue that, because the SEA did not assess the
existing amount of lead in the soil and water in the area
surrounding HIO, it did not consider how any lead emissions
from increased air traffic might impact the accumulation of
lead in the soil and water. Unlike jet fuel used by commercial
airlines, fuel used in general aviation may contain lead.
Petitioners contend that the SEA therefore “ignore[d] an
important aspect” of the impacts of potentially increased air
traffic associated with the new runway in violation of
NEPA’s requirements.



     3
       In their reply brief, Petitioners contend that, even if Hillsboro
Aviation was included in the survey, the survey did not capture all of the
likely growth related to pilot training. Petitioners did not raise this
argument in their opening brief, and it is therefore waived. See McKay v.
Ingleson, 558 F.3d 888, 891 n.5 (9th Cir. 2009) (“Because this argument
was not raised clearly and distinctly in the opening brief, it has been
waived.”); Fed. R. App. P. 28(a)(8)(A) (“The appellant’s brief must
contain . . . appellant’s contentions and the reasons for them, with citations
to the authorities and parts of the record on which the appellant relies.”).
                          BARNES V. FAA                              11

     The SEA demonstrated that the new runway would have
little effect on lead in the area around HIO. The Remand
Forecast estimated that the new runway would result in the
annual emission of an additional 0.03 ton of lead in 2016
(from 0.83 ton under the Constrained Forecast to 0.86 ton
under the Remand Forecast) and the annual emission of an
additional 0.02 ton of lead in 2021 (from 0.90 ton under the
Constrained Forecast to 0.92 ton under the Remand
Forecast).4 These predictions represent an increase in lead
emissions of less than four percent. The data underlying
these forecasts were discussed in great detail in the “air
quality technical memorandum” attached to the SEA.

    To assess the significance of this increase in lead
emissions, the SEA referred to the Environmental Protection
Agency’s regulations on lead. In certain circumstances, when
a federal action would cause the annual emission of more
than 25 tons of lead, EPA regulations require a “conformity
determination” to evaluate the action’s impact on the relevant
region’s compliance with the national ambient air quality
standards (“NAAQS”). 40 C.F.R. § 93.153. The forecasted
increase in lead emissions due to the new runway was very
small in comparison to the levels of lead emissions that the
EPA considers sufficient to necessitate study.

    The SEA reasonably determined that any increased air
traffic would have virtually no effect on the lead levels in the
area around HIO. If a project will have virtually no effect on


    4
       The reduced amount of pollution attributable to the new runway
over the five year period is due to the model’s prediction that the new
runway will decrease delays and reduce emissions from idling aircraft,
thereby partially offsetting emissions from increased operations. The
difference in delays with and without the new runway increases with time.
12                        BARNES V. FAA

the presence of a pollutant, then it would be pointless to
measure or model the presence of that pollutant prior to
commencing the project. Therefore, it was not arbitrary or
capricious to refrain from conducting additional analyses
regarding baseline lead levels in the soil or water.5

     3. Impacts on Children

    Petitioners argue that the SEA failed to consider the
impact that increased lead emissions may have on children.
The SEA included a section titled “Children’s Health and
Safety Risk,” in which it explained that, even with the
increased air traffic projected by the Remand Forecast, the air
around HIO would remain “well below” the EPA’s NAAQS
lead limit of 0.15 µg/m3.

    Using the FAA’s Emission & Dispersion Modeling
System, the SEA concluded that the maximum lead
concentration in the air around HIO was 0.00405 µg/m3 prior
to the construction of the new runway. Using a “sensitivity
analysis” that assumed that all emissions occurred near

     5
      The SEA’s analysis in this case is distinguishable from a different
analysis we recently rejected on NEPA grounds, in which the Bureau of
Land Management analyzed the effects of a proposed open pit mine.
Great Basin Res. Watch v. Bureau of Land Mgmt., 844 F.3d 1095, 1104
(9th Cir. 2016). The BLM, citing only a completely conclusory statement
in an email from an “expert,” had “assumed” that the baseline levels for
a host of pollutants around the mine was “zero.” Id. at 1103. The BLM
provided no explanation whatsoever justifying its adoption of this
assumption. Unlike this case, the issue in the BLM case was not whether
the pollutants emanating from the mine would be so negligible that a
baseline analysis of pollutants was unnecessary. Moreover, the BLM
analysis was grounded in nothing but an unsupported assertion, whereas
the report on which the SEA based its conclusion regarding lead emissions
from HIO was thorough and rigorous.
                       BARNES V. FAA                         13

ground level, the SEA found a maximum lead concentration
in the air around HIO of 0.06567 µg/m3. Accordingly, even
assuming that all lead emissions from the airport occurred at
ground level, the projected lead level in the air around HIO
was less than half of the maximum allowed under the EPA’s
standards. Given these conditions, it was not arbitrary or
capricious for the SEA to conclude that an increase in lead
emissions of less than four percent would not cause the
ambient lead concentrations surrounding HIO to exceed the
EPA’s lead NAAQS.

    The SEA also concluded that the EPA’s NAAQS for lead
was set at an acceptable level to protect sensitive populations,
including children. When it issued its final rule, the EPA
explained that the NAAQS for lead was established “to
provide increased protection for children and other at-risk
populations against an array of adverse health effects, most
notably including neurological effects in children, including
neurocognitive and neurobehavioral effects.” Environmental
Protection Agency, National Ambient Air Quality Standards
for Lead, Final Rule, 73 Fed. Reg. 66964, 66965 (Nov. 12,
2008). The EPA further stated that the “standards include an
adequate margin of safety . . . to address uncertainties
associated with inconclusive scientific and technical
information [and] to provide a reasonable degree of
protection against hazards that research has not yet
identified.” Id. at 66966. When setting this standard, the
EPA considered the variety of ways in which people may be
exposed to lead, including through water, dust, soil, and food.
Id. at 66971. It was appropriate for the FAA to defer to the
EPA on the factual question of what level of airborne lead is
safe for children. See WildEarth Guardians v. Jewell,
738 F.3d 298, 311–12 (D.C. Cir. 2013) (approving of
agency’s use of NAAQS in completing NEPA analysis).
14                     BARNES V. FAA

     4. Flight Stage Components Included in Lead Emission
        Calculation

    Petitioners argue that the SEA did not adequately account
for the various components of a typical flight in its lead
emission calculations. First, Petitioners contend that the SEA
did not adequately support its estimate for the time it takes for
aircraft to taxi to and from the runway. The SEA stated that
the taxi times were forecast taking into account HIO’s
runway usage, aircraft mix, and weather conditions. This
explanation does not, as Petitioners contend, represent a
“void,” but rather it is a methodology selected by the FAA
and entitled to deference. Compare Or. Nat. Desert Ass’n v.
Bureau of Land Mgmt., 625 F.3d 1092, 1121 (9th Cir. 2010)
(“We cannot defer to a void.”) with Nat’l Parks &
Conservation Ass’n v. U.S. Dep’t of Transp., 222 F.3d 677,
682 (9th Cir. 2000) (“[T]he FAA’s determination is due
deference—especially in areas of agency expertise such as
aviation forecasting.”).

    Petitioners also argue that, when considering lead
emissions in the air surrounding HIO, the SEA did not
properly consider the altitude at which emissions were
released during the “cruise” phase of flights. Specifically,
Petitioners contend that the SEA should have applied a
mixing height (the height below which air particles will mix
to become homogeneous) of 3,000 feet. That is essentially
what the SEA did, as the FAA pointed out in its answering
brief. The FAA’s Emissions and Dispersion Modeling
System (“EDMS”), approved by the EPA, calls for emissions
released above 1,000 feet to be treated as being released
halfway between 1,000 feet and the mixing height. The SEA
treated those emissions as being released at a height of
619 meters (2,031 feet), which is approximately halfway
                       BARNES V. FAA                          15

between 1,000 feet and the mixing height of 3,000 feet that
Petitioners advocate. Petitioners did not say anything further
on the subject in their reply.

    Petitioners argue separately that the EDMS model did not
include lead emissions that occur during the “run-up” phase,
when pilots conduct pre-flight checks. The FAA confirmed
in its response to comments that it was developing a
methodology to measure emissions during the run-up phase
but had not yet completed that endeavor, so it continued
relying on the existing EDMS methodology in the interim.
The FAA is entitled to deference in its decision. See Nat’l
Parks & Conservation Ass’n, 222 F.3d at 682.

    5. Impacts on Water Quality

    Petitioners argue that the SEA did not account for
pollution in water and wetlands arising from potential
increased air operations. In fact, the SEA discussed the
project’s impact on water quality and wetlands in detail.
Although the section of the SEA discussing water did not
specifically address lead emissions, the NAAQS for lead
accounts for exposure to lead through water, 73 Fed. Reg. at
66971, and the SEA concluded that any increased lead
emissions would be de minimis under the NAAQS.
Accordingly, the SEA’s assessment of the impacts to lead
content in water arising from a potential increase in air traffic
was not arbitrary or capricious.

    6. Duration of Emissions Forecasting Period

    Petitioners argue that the SEA should have published
twenty years of emissions projections instead of the ten years
it provided. Petitioners contend that the FAA typically
16                      BARNES V. FAA

forecasts demand twenty years in advance for long-range
planning purposes and note that the FAA prepared such a
forecast for HIO. The SEA explained that, consistent with
the FAA’s typical practices for NEPA analyses, the SEA
would rely on forecasts for the period through 2021 because
the air traffic for that period was “reasonably foreseeable[,]
i.e.[,] . . . likely to occur or probable rather than . . . merely
possible.”

     “The selection of the [temporal] scope of an EIS is a
delicate choice and one that should be entrusted to the
expertise of the deciding agency.” Selkirk Conservation
Alliance v. Forsgren, 336 F.3d 944, 962 (9th Cir. 2003). In
that case we concluded that, although the Forest Service had
data that could have allowed it to forecast further into the
future, it was within the agency’s discretion to select a three-
year window for analyzing the future effects of its action. Id.
at 962–63. Similarly, it was not arbitrary or capricious for the
FAA to determine that, under NEPA, the reasonably
foreseeable emission forecasting time frame for this project
was five to ten years, even though it had (less precise)
demand estimates available in the twenty-year time frame.
That was especially true for lead emissions given that the
FAA and the EPA are working to create an unleaded aviation
fuel for existing piston engine aircraft by 2018. See Town of
Cave Creek v. FAA, 325 F.3d 320, 331 (D.C. Cir. 2003)
(concluding that, especially in light of evolving technologies,
it was permissible under NEPA for the FAA to model
environmental impacts five years in advance, even though the
agency possessed demand projections stretching further into
the future).

    Because the FAA “‘based [its decision] on a consideration
of the relevant factors,’ and provided a ‘convincing statement
                       BARNES V. FAA                          17

of reasons to explain why [the] project’s impacts are
insignificant,’” we conclude that the FAA took the requisite
“‘hard look’ at the consequences of its actions.” Envtl. Prot.
Info. Ctr., 451 F.3d at 1009 (first alteration in original)
(quoting Nat’l Parks & Conservation Ass’n, 241 F.3d at 730).

B. Petitioners’ Arguments Related to the Significance of the
   Project

    “An agency must prepare an EIS ‘if “substantial questions
are raised as to whether a project . . . may cause significant
degradation of some human environmental factor.”’” Ctr. for
Biological Diversity v. Nat’l Highway Traffic Safety Admin.,
538 F.3d 1172, 1219 (9th Cir. 2008) (omission in original)
(quoting Idaho Sporting Cong. v. Thomas, 137 F.3d 1146,
1149 (9th Cir.1998)).           Petitioners contend that the
significance of the new runway’s potential impacts requires
the agency to produce an EIS. Although we rejected many of
Petitioners’ arguments in support of this contention in Barnes
I, we left open the possibility that Petitioners might prevail on
their arguments related to demand induced by the new
runway. 655 F.3d at 1140.

    Petitioners contend that the new runway will result in
increased lead emissions “significantly” affecting public
health, especially children’s health.      See 40 C.F.R.
§ 1508.27(b)(2). However, the SEA concluded that any
increase in lead emissions would be “de minimis.” An
environmental impact statement is not required merely
because an analysis reveals a potential for a minor impact.
See Native Ecosystems Council v. U.S. Forest Serv., 428 F.3d
1233, 1240 (9th Cir. 2005) (“[I]t does not follow that the
presence of some negative effects necessarily rises to the
18                    BARNES V. FAA

level of demonstrating a significant effect on the
environment.”).

    Petitioners also contend that the new runway is significant
because it involves “unique . . . risks” to children. See
40 C.F.R. § 1508.27(b)(5). This is simply a reformulation of
the argument regarding children’s health discussed above,
and it is no more meritorious.

    Additionally, Petitioners contend that the new runway is
significant because it is near residences and therefore has
“unique geographical characteristics.” Petitioners refer to
40 C.F.R. § 1508.27(b)(3), which states that evaluating a
project’s significance includes considering “[u]nique
characteristics of the geographic area such as proximity to
historic or cultural resources, park lands, prime farmlands,
wetlands, wild and scenic rivers, or ecologically critical
areas.” Petitioners provided no reason to conclude that there
is anything unique about an airport near a residential area.
See Town of Cave Creek, 325 F.3d at 331 (rejecting challenge
to air traffic rerouting project by observing that “there is
nothing unique about Cave Creek or Carefree. Petitioners
concede that they are residential areas.”). Accordingly,
Petitioners have not identified any unique issues requiring an
EIS.

    Citing 40 C.F.R. § 1508.27(b)(4), Petitioners also contend
that the project’s effects are likely to be “highly
controversial” because of disputes about lead emissions from
the airport. Under that regulation, “‘controversial’ is ‘a
substantial dispute [about] the size, nature, or effect of the
major Federal action rather than the existence of opposition
to a use.’” Blue Mountains Biodiversity Project v.
Blackwood, 161 F.3d 1208, 1212 (9th Cir. 1998) (alteration
                       BARNES V. FAA                         19

in original) (quoting Sierra Club v. U.S. Forest Serv.,
843 F.2d 1190, 1193 (9th Cir. 1988)).

    In support of their argument, Petitioners point to another
airport, in San Carlos, California, that was responsible for
lead emissions lower than those attributed to HIO but had a
higher ambient lead level than the SEA ascribed to HIO.
Petitioners reason that this circumstance calls into question
the accuracy of the SEA’s assessment of the ambient lead
level at HIO. To the contrary, the study does not support
Petitioners’ position because ambient lead levels are the
result of emissions from all sources in a region. The non-
airport lead sources near HIO were not the same as the non-
airport lead sources near the other airport, and Petitioners do
not contend otherwise.

    Petitioners also claim controversy exists because different
analyses identified different levels of lead near HIO.
Contrary to Petitioners’ argument, the analysis that indicated
the highest levels of ambient lead was not the result of a
difference of opinion but rather was the result of an error that
was corrected in subsequent analyses. There was no
“substantial dispute” about the SEA’s conclusion that
ambient lead levels at HIO were well within the NAAQS.
See Blue Mountains, 161 F.3d at 1212. Therefore, there was
no controversy necessitating an EIS.

C. Petitioners’ Arguments Related to the Airport and Airway
   Improvement Act

    The Airport and Airway Improvement Act requires that,
before approving a project grant, the FAA must ensure that
“the project is consistent with plans (existing at the time the
project is approved) of public agencies authorized by the
20                     BARNES V. FAA

State in which the airport is located to plan for the
development of the area surrounding the airport.” 49 U.S.C.
§ 47106(a)(1). In assessing the plans of the city of Hillsboro,
the FONSI considered two city zoning ordinances that
established an Airport Use Zone and an Airport Safety and
Compatibility Overlay Zone. Petitioner Michelle Barnes
succeeded in an effort to invalidate those ordinances in a state
court lawsuit, arguing that the avigation easement they
included was an unconstitutional taking and that the
provisions governing one of the zones involved an
impermissible delegation of legislative authority. Barnes v.
City of Hillsboro, 243 P.3d 139, 141 (Or. Ct. App. 2010).

    The city indicated that it planned to resolve the zoning
ordinances’ infirmities and reinstate the relevant provisions
in substance. Accordingly, the zones represented the plans
“of public agencies authorized by the State in which the
airport is located,” 49 U.S.C. § 47106(a)(1), and it was not
arbitrary or capricious for the FONSI to consider them.

III.     Conclusion

    In adopting the SEA, issuing the FONSI, and concluding
that the project at Hillsboro Airport complied with the
requirements of the Airport and Airway Improvement Act,
the FAA did not act in a manner that was arbitrary,
capricious, an abuse of discretion, or otherwise not in
accordance with law. The petition for review is denied.

       PETITION FOR REVIEW DENIED.
