Sssr v. Cabrera

NOTICE: NOT FOR OFFICIAL PUBLICATION.
UNDER ARIZONA RULE OF THE SUPREME COURT 111(c), THIS DECISION IS NOT PRECEDENTIAL
AND MAY BE CITED ONLY AS AUTHORIZED BY RULE.

IN THE
ARIZONA COURT OF APPEALS
DIVISION ONE

SAVE THE SCENIC SANTA RITAS, Appellee,

v.

MISAEL CABRERA, Director, Arizona Department of Environmental
Quality; ROSEMONT COPPER COMPANY, Appellants.

No. 1 CA-CV 15-0226
FILED 7-12-2016

Appeal from the Superior Court in Maricopa County
No. LC2014-000262-001
The Honorable Crane McClennen, Judge

REVERSED

COUNSEL

Salmon Lewis & Weldon, PLC, Phoenix
By G. Van Velsor Wolf, Jr., Mark A. McGinnis, Scott M. Deeny,
Daniel B. Jones
Counsel for Appellee

Arizona Attorney General's Office, Phoenix
By James T. Skardon
Counsel for Appellant Cabrera

Jorden Bischoff & Hiser, PLC, Scottsdale
By Eric L. Hiser, Trevor Joseph Louis Burggraff
Co-Counsel for Appellant Rosemont
Lewis Roca Rothgerber Christie, LLP, Phoenix
By Kimberly A. Demarchi
Co-Counsel for Appellant Rosemont

MEMORANDUM DECISION

Presiding Judge Diane M. Johnsen delivered the decision of the Court, in
which Judge Randall M. Howe and Judge Andrew W. Gould joined.

J O H N S E N, Judge:

¶1 The Director of the Arizona Department of Environmental
Quality ("ADEQ") and Rosemont Copper Company appeal the superior
court's order reversing ADEQ's decision to grant an air-quality permit
allowing Rosemont to build and operate a new open-pit copper mine in
Southern Arizona. For the following reasons, we reverse the superior
court's order and affirm the decision to grant the permit.

FACTS AND PROCEDURAL BACKGROUND

¶2 Rosemont requires an air-quality permit to proceed with its
plan to build an open-pit copper mine and processing plant some 30 miles
southeast of Tucson, on the northeast face of the Santa Rita Mountains. The
pit is projected to be about 4,000 feet in diameter. At its peak over the mine's
projected 20-year life, Rosemont expects the mine to produce as much as
221 million pounds of copper and 4.7 million pounds of molybdenum a
year, along with smaller amounts of gold and silver. Rosemont applied for
a permit in November 2011. Its application described its planned mining
processes and included information about emissions expected from those
processes, along with control mechanisms it intended to install to reduce
those emissions. Rosemont also submitted the results of computer
modeling its consultants performed using a standard air-quality program
called AERMOD (short for American Meteorological
Society/Environmental Protection Agency Regulatory Model).1

¶3 After ADEQ reviewed Rosemont's application, it issued a
draft permit and took public comments for nearly three months. In
response to some of the comments, the Department modified the permit

1 The Environmental Protection Agency has adopted AERMOD as its
preferred air dispersion model. 40 C.F.R. pt. 51, App. W, App. A.1.

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conditions to require Rosemont to install a monitor to track particulate
matter smaller than ten microns.

¶4 In January 2013, ADEQ issued a Class II Air Quality Permit to
Rosemont, and an organization called Save the Scenic Santa Ritas ("SSSR")
and others appealed. An administrative law judge ("ALJ") heard 13 days of
testimony. Fourteen witnesses testified, including several ADEQ
employees who participated in reviewing Rosemont's application,
Rosemont employees and consultants who were involved in the proposed
mine project and in preparing the permit application, and expert witnesses
retained by SSSR. The evidence primarily focused on the adequacy of the
computer modeling Rosemont submitted with its permit application,
ADEQ's review of that modeling, and SSSR's critiques. The witnesses
included chemical, civil, mining, metallurgical and mechanical engineers,
meteorologists, geologists, and atmospheric and environmental scientists.

¶5 In April 2014, the ALJ issued a 49-page decision containing
detailed findings of fact and conclusions of law, recommending that the
Director dismiss the appeals and affirm the Department's decision to issue
the permit. After reviewing the ALJ's findings and conclusions, the
Director dismissed the appeals. SSSR appealed to the superior court
pursuant to Arizona Revised Statutes ("A.R.S.") sections 12-904(A) (2016)
and 49-443(A) (2016).2 After briefing and oral argument, the superior court
reversed the Department's decision to issue the permit. ADEQ and
Rosemont timely appealed. We have jurisdiction pursuant to A.R.S. §§ 49-
443(C) (2016) and 12-2101(A)(1) (2016).

DISCUSSION

A. Appeal of an Agency Decision: Legal Principles.

¶6 We review de novo a superior court order reviewing an agency
action. Carlson v. Ariz. State Pers. Bd., 214 Ariz. 426, 430, ¶ 13 (App. 2007).
The court must affirm the agency action "unless after reviewing the
administrative record and supplementing evidence . . . the court concludes
that the action is not supported by substantial evidence, is contrary to law,
is arbitrary and capricious or is an abuse of discretion." A.R.S. § 12-910(E)

2 Absent material revision after the relevant date, we cite a statute's
current version.

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(2016).3 Although this court applies its own independent judgment to
questions of law, we defer to the agency's factual findings and will not
substitute our judgment for that of the agency on matters of agency
expertise. Webb v. State ex rel. Ariz. Bd. of Med. Exam'rs, 202 Ariz. 555, 557, ¶
7 (App. 2002). We will not re-weigh the evidence to resolve any perceived
conflicts, but must affirm the agency's decision if it is supported by
substantial evidence. DeGroot v. Ariz. Racing Comm’n, 141 Ariz. 331, 335-36
(App. 1984).

B. ADEQ's Power to Deny the Permit.

¶7 By state law, a new mine may not start up without an air
permit from ADEQ:

It is further declared to be the policy of this state that no
further degradation of the air in the state of Arizona by any
industrial polluters shall be tolerated. . . . A new industry
hereinafter established shall not begin normal operation until
it has secured a permit attesting that its operation will not
cause pollution in excess of the standards set by the director
of environmental quality.

A.R.S. § 49-401(B) (2016).

¶8 In challenging ADEQ's decision to grant the Rosemont
permit, SSSR cited A.R.S. § 49-427(A) (2016), which provides:

The director shall deny a permit or revision if the applicant
does not show that every such source is so designed,
controlled or equipped with such air pollution control

3 The final agency action in this matter is the Director's decision
dismissing SSSR's appeal of the permit. SSSR argues that decision is not
entitled to deference because the Director did not make any findings of fact
and conclusions of law, as required by A.R.S. § 41-1063 (2016). But that
statute does not apply to the ADEQ Director's review of an ALJ's
recommended decision. See A.R.S. § 41-1067 (2016). The statute governing
the Director's review of such a decision is A.R.S. § 41-1092.08 (2016). Under
§ 41-1092.08(B), the Director may "accept, reject or modify" a decision by the
ALJ. If the Director decides to reject or modify the decision, he or she must
provide "a written justification setting forth the reasons for the rejection or
modification." Id. But § 41-1092.08(B) does not require the Director to
explain an acceptance of the decision.

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equipment that it may be expected to operate without
emitting or without causing to be emitted air contaminants in
violation of this article and the rules adopted by the director.

SSSR argued that in considering Rosemont's application, ADEQ needed to
apply the National Ambient Air Quality Standards ("NAAQS"), which are
established by the Environmental Protection Agency ("EPA") and which
ADEQ has adopted by rule. A.A.C. R18-2-201 et seq.4 SSSR contended
ADEQ should have rejected Rosemont's permit because the modeling
Rosemont submitted was flawed for a variety of reasons, and that a proper
model would have demonstrated a violation of the NAAQS.

¶9 On appeal, ADEQ argues that even if Rosemont's model had
predicted air-quality violations, another statute, A.R.S. § 41-1030 (2016),
deprived the Department of the power to reject the permit for that reason.
Subpart (B) of that statute provides:

An agency shall not base a licensing decision in whole or in
part on a licensing requirement or condition that is not
specifically authorized by statute, rule or state tribal gaming
compact. A general grant of authority in statute does not
constitute a basis for imposing a licensing requirement or
condition unless a rule is made pursuant to that general grant
of authority that specifically authorizes the requirement or
condition.

ADEQ argues that when Rosemont applied for its permit, no statute or rule
specifically authorized the Department to reject an application for failure to
demonstrate compliance with NAAQS.5 ADEQ argues that, without such
authority, under § 41-1030(B), it had to grant Rosemont the permit if the
company promised to install emission controls "designed to meet
applicable standards" and the Department's "experience or calculations
show[ed] that the proposed facility can meet" those standards.

4 The NAAQS specify limits on concentrations of air pollutants,
including ozone, carbon monoxide, nitrogen dioxide, sulfur dioxide,
particulate matter and lead. 42 U.S.C. § 7409; 40 C.F.R. pt. 50.

5 At oral argument, ADEQ counsel informed the court that a formal
rule, A.A.C. R18-2-334, authorizing it to deny a permit on that ground
became effective while this litigation was pending.

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¶10 SSSR vigorously argues in response that § 41-1030(B), a
statute generally referring to administrative licensing decisions, does not
limit the Department's power under § 49-427, a statute referring specifically
to ADEQ. We need not resolve whether a predicted air-quality violation by
Rosemont would have required the Department to deny its application,
however, because we conclude that substantial evidence supported the
Department's determination that the proposed Rosemont mine will not
exceed air-quality standards.

C. The Validity of Rosemont's Air-Dispersion Model.

1. Modeling and the effects of the Tucson airshed.

¶11 The customary way to assess whether emissions from a new
industrial source will degrade air quality is an air-dispersion model. Such
a model calculates emissions the new source is expected to generate and
predicts whether those emissions, when added to the reported background
levels of pollutants already existing in the area ("ambient conditions"), and
taking into account atmospheric and meteorological conditions, may
violate air-quality standards. When used for regulatory purposes, air-
dispersion models are designed to be conservative, meaning that they over-
predict the polluting effects of the new source on ambient air quality.

¶12 In its appeal of the Department's decision, SSSR mounted a
broad attack on the Rosemont model, arguing that in several key respects it
violated ADEQ and EPA guidelines by failing to use sufficiently
conservative calculated, estimated and reported data about emissions. As
Rosemont and the Department argue, however, EPA regulations do not
demand use of the most conservative data. The primary goal is accuracy:
"The model that most accurately estimates concentrations in the area of
interest is always sought." 40 C.F.R. pt. 51, App. W, at § 1.0(d). "In all cases,
the model applied to a given situation should be the one that provides the
most accurate representation of atmospheric transport, dispersion, and
chemical transformations in the area of interest." 40 C.F.R. pt. 51, App. W,
at § 1.0(e).

¶13 The validity of air-dispersion modeling hinges on, among
other things, the validity of the model's governing assumptions. One of the
principal issues SSSR raised in its appeal was whether the Rosemont model
used properly representative data about background conditions at the mine
site. SSSR argued the Rosemont model was invalid because it did not use
background data that reflected emissions from Tucson, 30 miles northwest
of the Rosemont site.

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¶14 The Department operates several monitoring stations around
the state that gather air-quality data that can be used to show ambient
background conditions for purposes of an air-dispersion model. In the
absence of historical data from monitor stations located near the Rosemont
site, the company used background data gathered at rural locations
elsewhere in the state. SSSR argued those data did not fairly represent
conditions at the planned mine site, asserting that conditions at the
Rosemont site are bound to be significantly influenced by emissions from
the Tucson urban area.

¶15 There is no dispute that the prevailing winds in the area of the
planned mine do not blow from the north to the southeast (in the direction
of the Rosemont mine from Tucson). SSSR argued, however, that Rosemont
should have performed more sophisticated analyses to confirm that winds
would not cause emissions from Tucson and the Interstate 10 corridor to be
"connected meteorologically at certain times of the day and on certain days
of the year" with the Rosemont location. SSSR's expert witness, Dr. Eric
Betterton, testified that a computer program called HYSPLIT showed a
connection between Tucson emissions and the Rosemont site.6 He testified
that a HYSPLIT model run for one day in July 2012 showed that a particle
released at the Saguaro National Park, located just east of Tucson, moved
toward the south, suggesting that winds sometimes may carry Tucson
emissions toward the Rosemont site. He urged the Department to require
Rosemont to further analyze whether air quality near the proposed mine
site is affected by emissions from Tucson.

¶16 David Strohm, a project manager at JBR Environmental,
testified on behalf of Rosemont that it was unlikely that Tucson emissions
would have a significant and consistent influence on the Rosemont site. He
testified the HYSPLIT program tracks the movement of a distinct "parcel"
of air from one place to another, but cannot be used to analyze the interplay
among air parcels and or to show the magnitude one "parcel" of air might
have on another.

¶17 Dr. Feng Mao, an environmental engineer with ADEQ who
reviewed Rosemont's model, testified that meteorological data Rosemont
collected from its site and from a nearby monitoring station indicated
Tucson pollution would not affect ambient conditions at the Rosemont site.
Although Tucson is northwest of the Rosemont site, data from the

6 HYSPLIT is an acronym for Hybrid Single Particle Lagrangian
Integrated Trajectory. The general purpose of HYSPLIT is to track the path
of a single particle or "parcel" of air over time.

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Rosemont monitor reflected three percent winds coming from the east and
18 percent coming from the west, while data from the other monitor
showed two percent of eastern winds and 20 percent of western winds.
Mao also testified that the Santa Rita Mountains create a barrier that further
reduces the likelihood that emissions from Tucson would significantly
affect the Rosemont site.

¶18 Mao also reviewed ozone data from a monitor in Green
Valley, located 15 miles west of the Rosemont site, but, like Rosemont,
about 30 miles south of Tucson. That monitor did not show ozone
concentrations coming from Tucson, from which Mao inferred that Tucson
emissions do not significantly affect the Rosemont site.

¶19 Despite Betterton's suggestion that emissions from Tucson
sometimes may affect ambient conditions near the Rosemont site, we
cannot say the Department abused its discretion or acted arbitrarily and
capriciously in accepting Rosemont's use of data from monitoring locations
that do not reflect emissions from in and around Tucson. See, e.g., United
States v. Alpine Land & Reservoir Co., 887 F.2d 207, 213 (9th Cir. 1989)
("Deference to an agency's technical expertise and experience is particularly
warranted with respect to questions involving engineering and scientific
matters.").

2. Use of ozone and particulate data from Chiricahua National
Monument.

¶20 Rosemont used data from a monitor in the Chiricahua
National Monument, about 100 miles south of the Rosemont site, to derive
estimated background concentrations of particulate matter and ozone near
the mine site.7 SSSR argued Rosemont should have used data from another
monitor located in the Saguaro National Monument, just east of Tucson and
32 miles north of the Rosemont site.

¶21 Although SSSR pointed out that the Saguaro monitor is much
closer to the Rosemont site than the Chiricahua monitor, under EPA rules,
proximity is not the sole basis on which to select a monitoring location.
Regulations explain that whether a location is "representative" of another
depends on whether the two are similar in terms of terrain, distance from

7 Background ozone concentrations are relevant because ozone in the
ambient air will promote conversion of emissions of nitric oxide from
Rosemont's trucks and other vehicles into nitrogen dioxide, a pollutant
subject to NAAQS.

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the source of the monitored pollutant, elevation and proximity to other
emission sources. EPA Guidance W, at § 8.3(a). When no background
monitors are "in the vicinity of the source," the rules allow use of data from
a monitor located elsewhere that is "impacted by similar natural and distant
man-made sources." 40 C.F.R. pt. 51, App. W, at § 8.2.2(c).

¶22 Mao, the ADEQ reviewer, testified Rosemont demonstrated
that the Chiricahua location and the Rosemont site share similar elevations
and are similarly removed from urban centers. Mao explained that
although the Saguaro monitor is closer to the proposed Rosemont site, the
Saguaro monitor is affected by emissions from Tucson that are not present
at the Rosemont location. Mao also testified that the Chiricahua monitor
showed higher concentrations of ozone than reflected at the Green Valley
monitor, which is closer to Rosemont than the Chiricahua monitor. Mao
concluded based on that comparison that, consistent with EPA guidance,
use of data from the Chiricahua monitor resulted in a conservative
modeling result, despite its more distant location.

¶23 Although two SSSR expert witnesses, Betterton and D.
Howard Gebhart, testified the Saguaro monitor would be more appropriate
because it is closer to Rosemont and more likely to reflect Tucson emissions,
given the evidence that Tucson emissions are unlikely to significantly affect
ambient conditions at the Rosemont site, and the similarities between
conditions at the Rosemont site and at the Chiricahua monitor, the
Department did not act arbitrarily or capriciously in accepting Rosemont's
decision to use background ozone and particulate-matter data from the
Chiricahua monitor.

3. Use of nitrogen dioxide data from Alamo Lake.

¶24 SSSR also argued Rosemont's modeling was flawed because
it used background nitrogen dioxide data gathered from a monitor located
at Alamo Lake, located near Wenden, in western Arizona, rather than data
from a monitor at Children's Park, located in downtown Tucson. SSSR
argued that Alamo Lake is not a representative background monitor
because it is 200 miles away from Rosemont, it sits at a lower elevation than
the Rosemont site, and some periods of time are missing from the data set
at that location. Rosemont argued Alamo Lake is the most appropriate
monitor for nitrogen dioxide because it is the only nitrogen dioxide monitor
located in a rural location in Arizona not influenced by a coal-fired power
plant.

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¶25 The Rosemont site ranges from 4500 to 6300 feet above sea
level; the elevation of Alamo Lake is between 1200 and 1300 feet. Moreover,
Rosemont is just 15 miles away from a traffic corridor; Alamo Lake sits 50
miles away from the nearest traffic corridor. Mao testified that
nevertheless, under the circumstances, Rosemont's use of Alamo Lake for
background levels of nitrogen dioxide was appropriately conservative. By
way of explanation, Mao testified ADEQ collects nitrogen dioxide data at
only two rural locations that are relatively unaffected by urban vehicle
emissions – Alamo Lake and Tonto National Monument, located about 60
miles east/northeast of Phoenix. Based on wind patterns flowing from
Phoenix to Tonto National Monument, Mao knew that the Tonto data
would be strongly affected by Phoenix's urban plume. Despite this
connection to Phoenix, concentrations of nitrogen dioxide at the Tonto
monitor were lower than those at Alamo Lake. From that, Mao concluded
that Rosemont's use of Alamo Lake's comparably higher nitrogen dioxide
background concentrations was appropriately conservative.

¶26 Although SSSR argued that the Alamo Lake data were
incomplete because they did not span a full three years, ADEQ guidelines
only say that three years of data are preferred, and EPA guidance does not
establish a minimum monitoring period. Ariz. Dep't of Envtl. Quality, Air
Dispersion Modeling Guidelines for Arizona Air Quality Permits ("ADEQ
Guidelines"), at § 3.9 (2004); 40 C.F.R. pt. 51, App. W, at § 8.22.

¶27 For reasons discussed above in connection with the use of the
Chiricahua monitor for ozone and particulate-matter data, substantial
evidence supported the Department's decision to accept use of Alamo Lake
as the background monitor for nitrogen dioxide concentrations. Although
SSSR argued Rosemont should have used a monitor located in Children's
Park in Tucson, that monitor showed higher concentrations of nitrogen
dioxide, precisely due to its proximity to Tucson vehicle emissions.
Evidence in the record supported the Department's determination that
Tucson emissions generally do not affect ambient conditions at the
Rosemont site. Because evidence in the record supported use of the Alamo
Lake monitor data, the Department did not abuse its discretion when it
declined to require Rosemont to use data from the Children's Park monitor.

4. The proper in-stack ratio.

¶28 SSSR also criticized the Rosemont model's assumptions
concerning emissions to be produced by the huge haulage trucks that will
transport ore from the Rosemont pit for processing. The Rosemont model

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used a calculation called the NO2:NOx ratio to estimate nitrogen dioxide
that will result from emissions from the "stack," or tailpipe, of the trucks.8

¶29 As planned, Rosemont will mine as much as 110,000,000 tons
a year of mineral ore and waste material. Working 24 hours a day, 365 days
a year, haulage trucks will carry ore to associated processing facilities and
waste to tailings piles. Accordingly, the Rosemont model results are very
sensitive to the choice of an emissions ratio (the "in-stack ratio") to apply to
those trucks. Rosemont's model used a ratio of five percent; SSSR pointed
out that EPA rules establish 50 percent as the default ratio to be used in the
absence of more precise calculations, and argued the Department should
have required Rosemont to use a ratio of 10-50 percent. See 40 C.F.R. pt. 51,
App. W, at ¶ 5.2.4(d); U.S. Envtl. Prot. Agency, memorandum, "Additional
Clarification Regarding Application of Appendix W Modeling Guidance
for the 1-hour NO2 National Ambient Air Quality Standard" (Mar. 1, 2011).

¶30 In support of its decision to use a ratio of only five percent,
Rosemont submitted a report created by Leonard Montenegro, an air-
quality modeling expert who reviewed literature concerning tests and
estimates of vehicle in-stack ratios. The report explained the difficulty of
obtaining direct (in-stack or in-pipe) measurements from mobile sources
(by contrast to measurements of emissions from industrial smoke-stacks,
for which EPA requires actual testing). The report summarized six studies
that reported ratios ranging from two percent to 15 percent. Although
Montenegro also cited estimated ratios ranging up to 30 percent, he stressed
the reliability of two studies that reflected ratios ranging from two percent
to six percent. The report also asserted that EPA tests, which take place
after exhaust has been allowed to mix and react with the ambient air, are
inappropriate for model input, which requires in-stack measurements
before combustion with the ambient air has occurred.

¶31 SSSR's expert, Gebhart, pointed to the studies described in the
Montenegro report that reflected ratios higher than five percent, including
a 30 percent ratio calculated from diesel vehicles fitted with after-treatment
devices. He also noted that under EPA guidance, in the absence of more

8 The trucks emit both nitrogen dioxide ("NO2"), a pollutant subject to
the NAAQS, and nitric oxide ("NO"), which, when combined with ozone
naturally occurring in the ambient air, converts to nitrogen dioxide. To
accurately account for vehicle emissions, an air-dispersion model must treat
each separately. (The other factor in the ratio, NOx, is the sum of NO and
NO2.)

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appropriate source-specific information on in-stack ratios, a permittee
should apply a default ratio of 50 percent.

¶32 Mao testified Rosemont's use of the five percent ratio for
haulage truck emissions was appropriate and reasonable. He testified
Rosemont was not required to use the EPA default ratio of 50 percent
because the Montenegro report provided more appropriate source-specific
information. Mao also testified that the diesel vehicle study that Gebhart
cited used data from ambient air, not from measurements taken in the
"stack." Although Gebhart also pointed to ratios of five to 15 percent in a
letter by a truck manufacturer cited in the Montenegro report, Montenegro
explained it was not clear if the manufacturer's "estimates are for engine-
out or tailpipe" concentrations of nitrogen dioxide.

¶33 SSSR also argued that Rosemont submitted modeling results
to the United States Forest Service pursuant to the National Environmental
Policy Act that used a ten percent in-stack ratio, and which as a result
predicted the new mine was likely to violate air-quality standards.
Rosemont argued to the ALJ that it performed a modeling run using the ten
percent ratio figure because the Forest Service required it, not because that
ratio figure is more accurate. Mao testified there were no test results
requiring use of ten percent rather than the five percent ratio Rosemont
used in the model it submitted to ADEQ. Because the Department's
approval of Rosemont's use of a ratio of five percent was supported by
substantial evidence, the agency did not act arbitrarily or capriciously in
accepting that figure.

5. Adequacy of on-site data.

¶34 SSSR also raised several issues with Rosemont's collection of
data to show ambient conditions at its mine site. It first argued the
Rosemont meteorological data were flawed because, due to an equipment
failure, three months of data were missing, out of three years collected. On-
site meteorological data is an air-dispersion model's source of information
about air flow at the source of the emissions. EPA guidelines suggest the
use of data from "consecutive years from the most recent," and SSSR argued
that because of the three-month gap, Rosemont's data were unacceptable.

¶35 ADEQ modeling guidelines require "one year of
meteorological parameters from a representative on-site location." ADEQ
Guidelines, at § 3.8. EPA guidelines likewise require one year of site-
specific data. 40 C.F.R. pt. 51, App. W at § 8.3.1.2(b). Mao testified he
reviewed and validated the site-specific meteorology data Rosemont

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submitted. To fill in the three-month gap, Rosemont substituted data
collected during the same season the following year. Mao reviewed the
data and found there were no substantial differences in the data from year
to year, which led him to believe that the use of the substituted data would
not undermine the representativeness of the meteorology data. Because
Rosemont only was required to submit one year of data, and because
sufficient evidence supported the use of the substituted data, ADEQ did not
act arbitrarily or capriciously in accepting Rosemont's meteorological data
for purposes of modeling.

¶36 SSSR also took issue with Rosemont's use of a single
meteorological monitoring site at its mine, arguing that, due to the site's
complex terrain, multiple monitors would have provided better
information.

¶37 EPA guidelines state:

The meteorological data used as input to a dispersion model
should be selected on the basis of spatial and climatological
(temporal) representativeness as well as the ability of the
individual parameters selected to characterize the transport
and dispersion conditions in the area of concern. . . .

* * *

Of paramount importance is the requirement that all
meteorological data used as input to AERMOD must be both
laterally and vertically representative of the transport and
dispersion within the analysis domain.

40 C.F.R. pt. 51, App. W, at § 8.3(a), (c). With respect to site-specific
meteorological data, EPA guidelines state, "Spatial or geographical
representativeness is best achieved by collection of all of the needed model
input data in close proximity to the actual site of the source(s)." Id. at §
8.3.3.1(a). ADEQ air dispersion modeling guidelines similarly accord
priority to the representativeness of meteorological data, requiring "one
year of meteorological parameters from a representative on-site location."
ADEQ Guidelines, at § 3.8.

¶38 Rosemont placed its meteorological station at the center of its
planned open pit. Michael Sundblom, who supervises the ADEQ
evaluation unit responsible for processing Rosemont's application, testified
that was an appropriate location because it is at the spot where the
emissions would originate. He explained that dispersion modeling

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performs best when the meteorology data are derived from the point where
maximum concentrations are expected. Mao testified his primary concern
in reviewing the model was with the maximum possible predicted
concentrations that might result. Mao explained that, based on the specific
topography of the Rosemont site, the most significant emissions effects
would be close to the ground and close to the emissions source, which is
where he focused his review.

¶39 Neither EPA nor ADEQ guidelines require the use of multiple
meteorological monitoring sites such as SSSR advocates. The AERMOD
model can use data from only one meteorological station at a time; multiple
model runs would have to be performed with additional meteorological
data. Based on this record, sufficient evidence existed on which ADEQ
could decide not to require Rosemont to collect meteorological data from
more than one location at the site.

¶40 Finally, SSSR took issue with Rosemont's placement of its
monitor for particulate matter at a location two miles away from its
meteorological monitor. SSSR admitted there is no requirement that the
monitors be placed near each other. Shantanu Kongara testified for
Rosemont that there was no reason why the monitors should be placed near
each other, because the particulate-matter monitor collected data
concerning background concentrations, while the meteorological monitor
collected data concerning wind patterns. Kongara testified that placement
of the particulate monitor conformed to EPA regulations.

¶41 Because SSSR showed no requirement that the monitors be
placed near one another, and because sufficient evidence supported
Rosemont's placement of the monitors, the Department did not abuse its
discretion or act arbitrarily in accepting Rosemont's decisions of where to
place its on-site monitor locations.

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CONCLUSION

¶42 For the foregoing reasons, sufficient evidence supported
ADEQ's decision to issue the permit to Rosemont. The record does not
demonstrate the Department's decision was contrary to law, arbitrary and
capricious or an abuse of discretion. Accordingly, we reverse the superior
court's order and affirm the Department's decision to issue the air-quality
permit.

:AA

15