Center Biological v. Dept Public Health

23CA2143 Center Biological v Dept Public Health 05-22-2025

COLORADO COURT OF APPEALS

Court of Appeals No. 23CA2143
City and County of Denver District Court Nos. 21CV30049 & 21CV30886
Honorable Sarah B. Wallace, Judge

Center for Biological Diversity, Colorado Latino Forum, and Sierra Club,

Plaintiffs-Appellants,

v.

Colorado Department of Public Health and Environment, Air Pollution Control
Division, and American Petroleum Institute Colorado,

Defendants-Appellees.

JUDGMENT AFFIRMED

Division I
Opinion by JUDGE BROWN
J. Jones and Yun, JJ., concur

NOT PUBLISHED PURSUANT TO C.A.R. 35(e)
Announced May 22, 2025

Allison N. Henderson, Crested Butte, Colorado; Jeremy McKay, Denver,
Colorado; Ryan Maher, Washington, D.C., for Plaintiffs-Appellants

Phillip J. Weiser, Attorney General, Laura Terlisner Mehew, Senior Assistant
Attorney General, Julia La Manna, Assistant Attorney General, Denver,
Colorado, for Defendant-Appellee Colorado Department of Public Health and
Environment, Air Pollution Control Division

Williams Weese Pepple & Ferguson PC, Jennifer L. Biever, John H. Bernetich,
Dale T. Ratliff, Denver, Colorado, for Defendant-Appellee American Petroleum
Institute Colorado
¶1 Center for Biological Diversity, Colorado Latino Forum, and

Sierra Club (collectively, the Public Interest Groups) appeal the

district court’s judgment affirming the decision of the Colorado Air

Pollution Control Division (Division) to issue a general construction

permit, General Permit 11 (GP11), to regulate routine or predictable

emissions (ROPE) from oil and gas operations. The Public Interest

Groups contend that the Division’s decision to issue GP11 was

arbitrary or capricious or contrary to law because (1) GP11’s

conditions are not practically enforceable, and (2) GP11 allows

sources to exceed the national ambient air quality standards

(NAAQS) set by the Environmental Protection Agency (EPA). We

affirm.

I. Regulatory Framework

¶2 The Clean Air Act (CAA) “establishes a cooperative-federalism

framework” to prevent and control air pollution. WildEarth

Guardians v. Extraction Oil & Gas, Inc., 457 F. Supp. 3d 936, 941

(D. Colo. 2020); 42 U.S.C. § 7402. One of the CAA’s primary goals

is “to protect and enhance the quality of the [n]ation’s air resources

so as to promote the public health and welfare.” 42 U.S.C.

§ 7401(b)(1). To that end, the CAA directs the EPA to publish a list

1
of air pollutants with emissions that “cause or contribute to air

pollution which may reasonably be anticipated to endanger public

health or welfare.” 42 U.S.C. § 7408(a)(1)(A). The CAA then

requires the EPA to promulgate NAAQS for such pollutants in

designated air quality control regions across the country. 42 U.S.C.

§§ 7409(a), 7410(a)(1).

¶3 Each state is responsible for “assuring air quality” within its

geographic boundaries by developing and submitting to the EPA a

state implementation plan (SIP) to achieve, maintain, and enforce

the NAAQS in each air quality control region within the state. 42

U.S.C. §§ 7407(a), 7410(a)(1). Among other things, the SIP must

include “enforceable emission limitations and other control

measures, means, or techniques . . . as may be necessary or

appropriate” and regulations addressing “the modification and

construction of any stationary source . . . as necessary to assure

that [NAAQS] are achieved.” § 7410(a)(2)(A), (C).

¶4 Within the Colorado Department of Public Health and

Environment (CDPHE), two sub-departments administer Colorado’s

EPA-approved SIP: the Air Quality Control Commission

(Commission) and the Air Pollution Control Division (Division). See

2
§§ 25-7-103(2), (7), -104(a), -114.4(1), -114.5, C.R.S. 2024; Dep’t of

Pub. Health & Env’t Reg. 3, 5 Code Colo. Regs. 1001-5 (Regulation

3); WildEarth Guardians, 457 F. Supp. 3d at 941. The Commission

is responsible for developing rules and regulations regarding the

construction, operation, and permitting of stationary sources of air

pollutants. § 25-7-114.4(1) (“The commission shall promulgate . . .

regulations . . .for the orderly and effective administration of

construction permits.”). The Division then implements the rules

and regulations promulgated by the Commission. See

§§ 25-7-114.2, -114.4(1)-(2), -114.5, C.R.S. 2024. A “[s]tationary

source” is defined as “any building, structure, facility, or

installation which emits or may emit any air pollutant.”

§ 25-7-103(23); accord Regulation 3, pt. A, § I.B.52; § 7411(a)(3).

¶5 As detailed in CDPHE Regulation 3, Colorado’s New Source

Review (NSR) program governs the permitting of stationary sources

of air pollutants. See Regulation 3, pt. D; WildEarth Guardians,

457 F. Supp. 3d at 941. The program requires a stationary source1

1 Regulation 3 applies to any source that did not commence

construction or operation before February 1, 1972. Dep’t of Pub.
Health & Env’t, 5 Code Colo. Regs. 1001-5, pt. B, § I.A.

3
to have or obtain a valid construction permit before (1) constructing

or substantially altering any building, facility, structure, or

installation (with exceptions not relevant here); (2) installing any

machine, equipment, or device; or (3) commencing the conduct,

performance, or operation of any such activity. § 25-7-114.2;

Regulation 3, pt. B, §§ II.A, III.I.2.

¶6 A stationary source can be classified as a “[m]ajor source,” a

“[m]inor source,” or a “[s]ynthetic minor source.” § 25-7-114(3), (6),

C.R.S. 2024; Regulation 3, pt. A, § I.B.30, I.B.31. A source’s

classification is determined by its potential to emit (PTE), defined as

“the maximum capacity of [the] stationary source to emit a

pollutant under its physical and operational design.” § 25-7-114(4);

Regulation 3, pt. A, § I.B.43; accord 40 C.F.R. § 51.166(b)(4) (2024).

¶7 A source is a “major source” if its PTE is above certain

thresholds. § 25-7-114(3)(a)-(c); Regulation 3, pt. A, § I.B.30;

accord 42 U.S.C. § 7479(1); 40 C.F.R. § 51.165(a)(1)(iv)(A) (2024). A

source is a “[m]inor source” if it “does not qualify as a major

source.” Regulation 3, pt. A, § I.B.31. Major sources are subject to

greater regulatory requirements, see generally 40 C.F.R. §§ 51.165,

51.166, while minor sources are subject to “only the barest of

4
requirements,” Sierra Club v. EPA, 964 F.3d 882, 886 (10th Cir.

2020) (citation omitted).

¶8 A “[s]ynthetic minor source” is “any source which would

otherwise meet the definition of major source for any pollutants but

for the existence of enforceable emission limitations contained in

the permit or regulation applicable to that source.” § 25-7-114(6).

In other words, a source may “voluntarily lower emissions to avoid

major-source requirements,” WildEarth Guardians, 457 F. Supp. 3d

at 942, by implementing physical or operational limitations on the

capacity of the source to emit pollutants, see 40 C.F.R.

§ 51.166(b)(4); Regulation 3, pt. B, § II.A.7. Such limitations can

include, for example, “air pollution control equipment and

restrictions on hours of operation or on the type or amount of

material combusted, stored, or processed.” Regulation 3, pt. A,

§ I.B.43; accord 40 C.F.R. § 51.166(b)(4).

¶9 The Division can issue two types of construction permits: an

individual construction permit, which is unique to a source and

requires analysis of that source’s particular operations and

emissions, or a general construction permit, which is issued to

cover numerous similar sources. § 25-7-114.2; Regulation 3, pt. A,

5
§ I.B.16, I.B.27, pt. B, § III.B, III.I. The EPA has approved the use of

general permits as they “provide for emission limitations in a

one-time permitting process, and thus avoid the need to issue

separate permits for each source.” Off. of Enf’t & Compliance

Assurance, EPA, Guidance on Enforceability Requirements for

Limiting Potential to Emit through SIP and § 112 Rules and General

Permits 3 (1995) (1995 EPA Guidance).

II. Procedural History

¶ 10 In 2019, the Commission decided that routine or predictable

emissions (ROPE) associated with certain maintenance and

processing activities at oil and gas facilities should no longer be

exempt from permitting requirements. Instead, these emissions

should be subject to permitting under Colorado’s SIP. See

Regulation 3, pt. F, § I.DDD. The Commission also determined that

the new ROPE permitting requirements would apply to existing

sources, not just newly constructed or modified sources. Id.

¶ 11 In August 2020, the Division proposed GP11 to regulate ROPE

and initiated a public comment period. The Center for Biological

Diversity timely submitted comments raising the same concerns it

raises on appeal. In December 2020, the Division issued GP11.

6
¶ 12 The following month, the Public Interest Groups filed a

complaint seeking judicial review of the Division’s decision to issue

GP11 under the State Administrative Procedure Act (APA). See

§§ 24-4-106(2), 25-7-120(1), C.R.S. 2024. The American Petroleum

Institute Colorado (API) intervened in the action as a defendant.

After a hearing, the district court issued a written order affirming

the Division’s decision to issue GP11.

III. Public Interest Groups’ Challenges to GP11

¶ 13 The Public Interest Groups contend that the Division’s

decision to issue GP11 was arbitrary or capricious or contrary to

law because (1) GP11’s conditions are not practically enforceable,

and (2) GP11 allows the construction of sources that cause an

exceedance of NAAQS. We conclude that the Division’s decision

was neither arbitrary or capricious nor contrary to law.

A. Standard of Review

¶ 14 “Our review of a district court’s decision in a proceeding under

the [APA] is de novo.” Farmer v. Colo. Parks & Wildlife Comm’n,

2016 COA 120, ¶ 12. We sit in the same position and apply the

same standard of review as the district court. Gessler v. Grossman,

2015 COA 62, ¶ 9, aff’d, 2018 CO 48. We must “hold unlawful and

7
set aside” an agency action if, as argued here, the action is arbitrary

or capricious or otherwise contrary to the law. § 24-4-106(7)(b)(I),

(VIII), (IX). If we perceive no such error, we must “affirm the agency

action.” § 24-4-106(7)(a).

¶ 15 “In applying this standard, we presume the validity and

regularity of administrative proceedings and resolve all reasonable

doubts as to the correctness of administrative rulings in favor of the

agency.” Grossman, ¶ 11. Ultimately, “[t]he burden is on the party

challenging the agency action to overcome the presumption that the

agency’s acts were proper.” Wildwood Child & Adult Care Program,

Inc. v. Colo. Dep’t of Pub. Health & Env’t, 985 P.2d 654, 655 (Colo.

App. 1999).

¶ 16 To conclude that an agency’s decision is arbitrary or

capricious, “we must determine that no substantial evidence exists

in the record to support the agency’s decision.” Grossman, ¶ 39.

“There must be a clear error of judgment, and we may not

substitute our judgment for that of the agency.” Id. Indeed, the

agency, not this court, “has the task of weighing the evidence and

resolving any conflicts.” Chostner v. Colo. Water Quality Control

Comm’n, 2013 COA 111, ¶ 24. “So long as the agency decision

8
reflects conscientious effort to reasonably apply legislative

standards to particular administrative proceedings, it is neither

arbitrary nor capricious.” Moya v. Colo. Ltd. Gaming Control

Comm’n, 870 P.2d 620, 624 (Colo. App. 1994).

¶ 17 We also review de novo the agency’s interpretations of law.

Citizens for Clean Air & Water in Pueblo & S. Colo. v. Colo. Dep’t of

Pub. Health & Env’t, 181 P.3d 393, 396 (Colo. App. 2008). But, “[a]s

part of our de novo review, ‘we may consider and defer to an

agency’s interpretation of its own enabling statute and [of]

regulations the agency has promulgated.’” Gessler v. Colo. Common

Cause, 2014 CO 44, ¶ 7 (quoting Bd. of Cnty. Comm’rs v. Colo. Pub.

Utils. Comm’n, 157 P.3d 1083, 1088 (Colo. 2007)); see Chostner,

¶ 24 (“[A]though we are not bound by an agency decision that

misapplies or misconstrues the law, we defer to an agency’s

interpretation of the statute or regulation it is charged with

administering.” (citing El Paso Cnty. Bd. of Equalization v. Craddock,

850 P.2d 702, 705 (Colo. 1993))). An agency’s interpretation is

“most useful to the court when the subject involved calls for the

exercise of technical expertise which the agency possesses.”

Craddock, 850 P.2d at 705.

9
B. General Permit 11 (GP11)

¶ 18 GP11 is a general minor source construction permit that

authorizes and regulates ROPE from discrete activities conducted at

certain oil and gas industry facilities. ROPE are only one

component of the entire set of emissions from oil and gas

operations. GP11 does not address non-ROPE emissions, which

must be permitted through other means. ROPE consist mostly of

volatile organic compounds (VOCs).

¶ 19 Because ROPE are produced by routine activities that are

generally short in duration, sources registered under GP11 need not

control ROPE. Instead, to comply with GP11’s emission limits,

operators can choose to minimize ROPE or reduce the frequency of

ROPE-producing activities. Still, a major source can register under

GP11 as a synthetic minor source by choosing to control ROPE —

that is, by reducing VOCs through air pollution control equipment

such as combustion devices (flares or enclosed combustion devices),

vapor recovery units, or catalysts. Either way, GP11 requires

sources to aggregate emissions from facility-wide ROPE activities to

determine whether they meet certain emission limits.

10
¶ 20 If an operator chooses to control ROPE with a combustion

device, GP11 allows the operator to claim a destruction and removal

efficiency (DRE) of 95%. A DRE of 95% means that 95% of the

VOCs from ROPE will be destroyed by the device before being

released into the atmosphere. However, the combustion of VOCs

creates nitrogen oxides (NOx) as a byproduct. NOx emissions are

measured as nitrogen dioxide (NO2) in NAAQS. 40 C.F.R.

§ 50.11(a)-(b) (2024). To ensure that sources using combustion

devices to control ROPE achieve 95% DRE, GP11 imposes certain

design, operation, monitoring, and recordkeeping requirements on

operators.

¶ 21 For design, GP11 requires that any pollution control

equipment used to comply with the permit’s emission limits be

“adequately designed and sized to achieve the control efficiency

rates and to handle reasonably foreseeable fluctuations in gas

quantity and/or composition during emitting activities.”

Combustion devices used to control ROPE must also “have a design

destruction efficiency of at least 98%” and “be equipped with and

operate an auto-igniter.”

11
¶ 22 For operations, GP11 requires that any pollution control

equipment “be operated and maintained consistent with

manufacturer specifications and good engineering and maintenance

practices.” It also requires that the manufacturer specifications be

kept on file for review by the Division.

¶ 23 For monitoring, GP11 requires that any combustion devices

“have no visible emissions during normal operation, and be

designed so that an observer can, by means of visual observation

from the outside of the enclosed combustion device, or by other

means approved by the [D]ivision, determine whether it is operating

properly.” It also requires the operator to “monitor proper operation

of the air pollution control equipment . . . at least once each day

that [such] equipment is in use to control the emitting activities

registered under” GP11 and identifies certain “[i]ndications of

improper operation.”

¶ 24 And for recordkeeping, GP11 requires that, “[f]or each separate

air pollution control equipment, the owner or operator must keep

an air pollution equipment maintenance log,” displaying the date,

time, and nature of any maintenance activity. It requires that any

“[i]mproper operation of air pollution control equipment” be

12
documented, including a description of the problem and its

resolution, the date range the equipment was inoperable, and the

“uncontrolled mass of emissions during the downtime.” GP11 also

requires operators to record “actual emissions from all emitting

activities” and, for synthetic minor sources that use equipment to

control emissions, to calculate such emissions on a “rolling twelve

(12) month” basis.

C. Practical Enforceability

¶ 25 The Public Interest Groups contend that the Division’s

decision to issue GP11 is arbitrary or capricious or contrary to law

because the conditions that allow a source to control ROPE through

combustion devices are not enforceable as a practical matter. In

particular, the Public Interest Groups argue that (1) GP11 allows

sources to assume 95% DRE despite evidence in the administrative

record showing that combustion control devices can have much

lower control efficiencies; (2) the Division did not account for

variables that affect control efficiency; (3) only testing can verify

that emissions remain below the permit’s limits; and (4) in crafting

GP11’s conditions, the Division relied on EPA guidance regarding

13
practical enforceability that has been undermined by recent EPA

decisions.

¶ 26 We begin by reviewing the requirement that permit conditions

allowing a source to limit PTE be “practically enforceable.” Next, we

conclude that substantial record evidence supports the Division’s

determination that GP11’s conditions — under which a major

source can elect to control ROPE through combustion devices in

order to register as a synthetic minor source — are practically

enforceable. See Grossman, ¶ 39. We then address and reject each

of the Public Interest Groups’ contentions because they effectively

ask us to reweigh the evidence and substitute our judgment for the

Division’s, something we cannot do. See id.

1. GP11’s Control Conditions Must Be Practically Enforceable

¶ 27 As an initial matter, the parties agree that permits allowing

sources to limit PTE must include “practically enforceable permit

conditions,” Regulation 3, pt. B, § II.A.4, that impose “physical or

operational limitation[s] on the capacity of the source to emit a

pollutant, including air pollution control equipment,” Regulation 3,

pt. A, § I.B.43. See also § 24-7-114(6) (defining synthetic minor

source as one constrained by “enforceable emission limitations

14
contained in the permit or regulation applicable to that source”);

WildEarth Guardians, 457 F. Supp. 3d at 959 (conditions must be

“legally and practicably enforceable by a state or local air pollution

control agency” (quoting EPA, Release of Interim Policy on Federal

Enforceability of Limitations on Potential to Emit 3 (1996))). Thus,

the conditions in GP11 that apply to “[c]ombustion devices, vapor

recovery units, catalysts, or other division-approved air pollution

control equipment used to reduce emissions (from the emitting

activities registered under this general permit) below” applicable

limits must be “practically enforceable.” Regulation 3, pt. B,

§ II.A.4.

¶ 28 Notably, “practically enforceable” is not defined by Regulation

3 or any relevant Colorado statute. To interpret the term, the

Division relies on the 1995 EPA Guidance regarding practical

enforceability. It provides that a general permit’s provisions must

“specify (1) a technically accurate limitation and the portions of the

source subject to the limitation; (2) the time period for the limitation

(hourly, daily, monthly, annually); and (3) the method to determine

compliance including appropriate monitoring, record keeping, and

reporting” and must “(4) identify the categories of sources that are

15
covered by the [permit]; (5) where coverage is optional, provide for

notice to the permitting authority of the source’s election to be

covered by the [permit]; and (6) recognize the enforcement

consequences relevant to the [permit].” 1995 EPA Guidance at 6.

¶ 29 The 1995 EPA Guidance clarifies that general permits must

identify and apply to categories of sources “specifically or narrowly

enough so that specific limits and compliance monitoring can be

identified and achieved by all sources.” Id. It further provides that

“monitoring” may refer to “many different types of data collection,

including continuous emission or opacity monitoring, and

measurements of various . . . [p]arameters of processes or control

devices (e.g. temperature, pressure drop, fuel usage) and record

keeping of parameters that [have] been limited.” Id. at 9. It notes

that “[c]ontinuous emissions monitoring, especially in the case of

smaller sources, is not required.” Id. And it provides that general

permits “can allow for generic control efficiencies where technically

sound and appropriate, depending on the extent of the application

and ability to monitor compliance with resultant emission limits.”

Id. at 6.

16
2. Division’s Determination that GP11’s Conditions are
Practically Enforceable Was Not Arbitrary or Capricious or
Contrary to Law

¶ 30 The Division’s determination that GP11’s conditions, allowing

sources to elect to control ROPE through combustion devices, are

practically enforceable is supported by the foregoing EPA guidance,

the unique characteristics of ROPE, and the technical evidence in

the administrative record.

¶ 31 Consistent with the 1995 EPA Guidance, GP11 identifies and

applies to a narrow category of sources, activities, and emissions; it

governs a limited number of specific ROPE-producing activities

conducted only at certain “oil and gas industry well production

facilit[ies] . . . and the associated . . . well(s).” GP11 also identifies a

narrower subcategory of sources that elect the permit’s option to

control ROPE through pollution control equipment such as

combustion devices. Only the latter subcategory must comply with

“practically enforceable” conditions to register as synthetic minor

sources under the permit.2

2 Because the focus of the Public Interest Groups’ arguments is on

GP11’s conditions related to combustion devices, ours is as well.

17
¶ 32 Given the unique characteristics of ROPE as discrete episodic

or sporadic emissions that occur in connection with routine

maintenance and processing activities at oil and gas facilities, the

Division determined that operators are unlikely to opt to control

ROPE at all. The Division also considered the types of devices an

operator might use to control ROPE and how to ensure proper

operation of those devices. Due to the short-term, variable nature

of ROPE and the types of devices used to control it, the Division

determined that performance testing was not a feasible means of

monitoring control efficiency. See, e.g., 40 C.F.R. § 60.5413(d)(2)

(2024) (requiring testing for combustion devices in “three one-hour

(or longer) test runs”). The Division reasoned that if operators were

required to conduct performance tests on combustion devices used

to control ROPE, they would likely need to supplement the material

being combusted and run the devices for longer periods than

necessary, which would lead to increased pollution.

¶ 33 Instead, to ensure that operators choosing to control ROPE

through combustion devices would meet emission limits, the

Division implemented the design, operation, monitoring, and

recordkeeping conditions set forth in GP11 and detailed above. The

18
Division concluded that, when these combustion devices are

operated and maintained properly, as required by GP11’s

conditions, they achieve DRE of 95% or higher. Therefore, allowing

sources to claim 95% DRE was “technically sound and

appropriate.” 1995 EPA Guidance at 6. And the Division’s

conclusion is supported by substantial evidence in the

administrative record, including reports, control device

manufacturer specifications, and dozens of performance test

results. See Grossman, ¶ 39.

¶ 34 We perceive no clear error in the Division’s judgment. See id.

Rather, the Division’s decision “reflects conscientious effort to

reasonably apply” the practical enforceability standard to a narrow

category of sources that elect to control a unique type of emissions

through combustion devices. Moya, 870 P.2d at 624. And given

the Division’s technical expertise, its decision is entitled to

substantial deference. See Citizens for Clean Air, 181 P.3d at 397.

Thus, we conclude that the Division’s decision was neither arbitrary

or capricious nor contrary to law.

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3. Public Interest Groups’ Arguments

a. Contrary Evidence in the Record

¶ 35 The Public Interest Groups contend that the Division’s

decision is arbitrary or capricious because GP11 allows sources to

assume 95% DRE, despite record evidence demonstrating that

combustion control devices can have significantly lower control

efficiencies. They argue that, without testing, GP11’s conditions are

not enforceable as a practical matter because there is no reliable

way to measure the pollution emitted by the permitted source.

¶ 36 To support this argument, the Public Interest Groups point to

a test of combustion flares at Bonanza Creek’s Wetco Farms A-4

well pad (hereinafter Wetco Farms Test). This test yielded DRE

results of 73.92%, 73.80%, and 73.85% for one flare and 91.21%,

90.06%, and 89.34% for another flare. The Division counters that it

is unclear whether the Wetco Farms Test involved ROPE or whether

the tested combustion devices were subject to GP11’s design,

operation, monitoring, or recordkeeping requirements. The Division

and the API also argue that the conditions of the Wetco Farms Test

were not representative of normal operating conditions. They point

20
to evidence that a follow-up test conducted at the same well pad

produced a DRE of over 99%.

¶ 37 The Public Interest Groups also emphasize findings from a

report involving EPA Region 8 and the Wyoming Department of

Environmental Quality (EPA-Wyoming Report), which found that

combustion flare efficiency varied dramatically “depending on the

operational setup.” Michael Stovern et al., EPA, Region 8,

Measuring Enclosed Combustion Device Emissions Using Portable

Analyzers – Phase 1: Test Summaries 9 (May 14, 2020),

https://perma.cc/RBT2-9547. But the Division notes that it is

unclear whether the emissions measured in the EPA-Wyoming

Report were ROPE or analogous to ROPE. The Division also argues

that some of the DRE results below 95% were due to insufficient or

variable gas flow rates and improper operation. The Division

explains that these issues are not relevant in this case because

ROPE are “manually-triggered bursts of gas over a short period of

time,” and GP11 requires that combustion devices be adequately

designed to handle fluctuations in gas and operated consistent with

manufacturer specifications.

21
¶ 38 Still, the Public Interest Groups argue that the Division has

failed to account for variables such as weather, altitude, damage

during shipping, equipment installation, improper construction,

wear and tear over time, fluctuations in fuel and waste streams,

and different temperatures needed to destroy different VOCs. They

cite a technical comment on a different permit to support their

position. See Ranajit Sahu, Technical Comments on the Proposed

CDPHE Permit No.20AD0062 for Haugen #1-30,

https://perma.cc/8MSV-ALT3. But, as the Division points out,

that permit involved a permanent emissions-generating activity (a

separator); it did not involve ROPE or consider the conditions in

GP11 that allow sources to opt to control ROPE.

¶ 39 Even if the parts of the record the Public Interest Groups

highlight support their claim, they do not negate the other

substantial evidence on which the Division based its decision. The

Division provides a rational explanation for discounting the Wetco

Farms Test, the EPA-Wyoming Report, and the technical comments

and, instead, relying on the dozens of other tests that show

combustion devices operating at or above 98% DRE. See FCC v. Fox

Television Stations, Inc., 556 U.S. 502, 513 (2009) (Under the

22
“narrow” arbitrary or capricious standard of review, “we insist that

an agency ‘examine the relevant data and articulate a satisfactory

explanation for its action.’”) (citation omitted). And we decline to

reweigh the evidence, as the Public Interest Groups essentially ask

us to do. See Chostner, ¶ 24. In the end, the Public Interest

Groups have not persuaded us that the design, operation,

monitoring, and reporting requirements in GP11 are inadequate.

See Wildwood Child & Adult Care Program, Inc., 985 P.2d at 655.

b. Recent EPA Decisions

¶ 40 The Public Interest Groups also argue that the Division’s

reliance on the 1995 EPA Guidance to conclude that GP11’s

conditions are practically enforceable has been undermined by two

recent EPA orders granting objections to specific operating permits.

See Bonanza Creek Energy Operating Co., Petition No. VIII-2023-11

(EPA Jan. 30 2024) (final order on petition) (Bonanza Creek Order);

DCP Operating Co. LP, Platteville Nat. Gas Processing Plant, Petition

No. VIII-2023-14 (EPA Apr. 2, 2024) (final order on petition)

(Platteville Order). In both cases, the petitioners (including two of

the Public Interest Groups) challenged the Division’s issuance of

permits before the EPA in part because the permits “[u]njustifiably

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[a]ssume” a 95% control efficiency for control devices, without

adequate testing, monitoring, and reporting “[d]espite [e]vidence to

the [c]ontrary.” Bonanza Creek Order at 9; see also Platteville

Order at 7. The petitioners made arguments similar to those raised

by the Public Interest Groups in this appeal, including that “only

site-specific, periodic testing” can ensure compliance. Bonanza

Creek Order at 9-10; see also Platteville Order at 8. The EPA

concluded that the existing permit records did not sufficiently

explain how the permit conditions “assure[d] compliance with the

requirements to achieve 95 percent VOC control efficiency”

applicable to the specific units, facilities, and activities at issue.

Bonanza Creek Order at 15; see also Platteville Order at 9. The EPA

directed CDPHE to revise the permit records to address the

petitioners’ arguments. Bonanza Creek Order at 15; see also

Platteville Order at 13.

¶ 41 The Division and the API argue that we should not consider

these EPA orders because they were not available to the Division

when it issued GP11 and are not part of the administrative record.

See Brighton Pharmacy, Inc. v. Colo. State Pharmacy Bd., 160 P.3d

412, 417 (Colo. App. 2007) (“Agency actions are to be reviewed

24
based solely upon the record made before the agency.”). But see

Sierra Club, 964 F.3d at 893 n.9 (taking judicial notice of

documents published on EPA’s website). To be sure, since the EPA

issued these two orders in 2024, the Division could not have been

aware of them or considered them when issuing GP11. They are

not part of the administrative record and were not available to the

district court when it affirmed the Division’s decision. For these

reasons, we hesitate to even review the EPA orders as part of this

APA judicial review proceeding. But even if we did consider them,

they fail to demonstrate how the Division’s reliance on the 1995

EPA Guidance is misguided or that the conditions in GP11 are not

practically enforceable to control ROPE generated from the limited

activities GP11 covers.

¶ 42 First, the Public Interest Groups have not established that the

standard the EPA applied to evaluate the major source permits in

those orders applies to evaluate the practical enforceability of

conditions in minor source permits like GP11. See Bonanza Creek

Order at 6-8 (identifying each source at issue as a “major source

under title V”); Platteville Order at 6 (same). As noted, major source

permits are subject to stricter regulation, while minor source

25
permits are not. See Sierra Club, 964 F.3d at 886; Luminant

Generation Co. v. EPA, 675 F.3d 917, 922 (5th Cir. 2012) (for minor

sources, the CAA requires only that the SIP regulate the

construction of a stationary source “as necessary to assure that

[NAAQS] are achieved” and “includes no specifics regarding the

structure or functioning of minor NSR programs” (first quoting

§ 7410(a)(2)(C); and then quoting Operating Permit Programs and

Flexible Air Permitting Rule, 74 Fed. Reg. 51418, 51421 (Oct. 6,

2009))). Indeed, the petitioners argued that “title V permits must

contain ‘sufficiently reliable’ procedures for determining compliance

and ‘periodic monitoring sufficient to yield reliable data from the

relevant time period that are representative of the source’s

compliance with the permit.’” Bonanza Creek Order at 10 (first

quoting 42 U.S.C. § 7661c(b); and then quoting 40 C.F.R.

§ 70.6(a)(3)(i)(B) (2024)); see also Platteville Order at 11. And part of

the EPA’s rationale for concluding that the permit records were

insufficient was that title V permits must “set forth . . .

monitoring . . . requirements to assure compliance with the permit

terms and conditions,” Bonanza Creek Order at 13 (first quoting

§ 7661c(c); and then citing 40 C.F.R. § 70.6(c)(1)), and that “[t]he

26
rationale for the selected monitoring requirements must be clear

and documented in the permit record,” id. (citing 40 C.F.R.

§ 70.7(a)(5) (2024)); see also Platteville Order at 11-12. It is not

clear how these standards relate to practical enforceability.

¶ 43 Second, in each case, the EPA did not conclude that the

permit conditions were not practically enforceable to “assure

compliance” with the presumed 95% control efficiency. Instead, the

EPA determined that the permit record was inadequate to explain

how the permit conditions assured compliance. See Bonanza Creek

Order at 14; see also Platteville Order at 12. In other words,

uncertainty remains about whether the conditions at issue in those

cases are, in fact, sufficient. And notably, the permit records are

not part of the administrative record before us, so we have no way

to compare what the EPA considered inadequate there with what

the Division relied on to issue GP11. Under these circumstances,

we are not persuaded that the EPA orders demonstrate that the

Division’s decision regarding the conditions in GP11 — a minor

source permit regulating limited ROPE-producing activities — is

arbitrary or capricious.

27
¶ 44 Because there is competent evidence supporting the Division’s

decision, see Grossman, ¶ 39, and because we defer to the

Division’s interpretation of its own regulations based on its

technical expertise, see Craddock, 850 P.2d at 705, we conclude

that the Public Interest Groups have not met their burden to show

the Division’s issuance of GP11 was arbitrary or capricious or

contrary to law, see Wildwood Child & Adult Care Program, Inc., 985

P.2d at 655.

D. Exceedance of NO2 NAAQS

¶ 45 The Public Interest Groups contend that the Division’s

decision to issue GP11 is contrary to law because (1) the

self-executing nature of GP11 allows a source to begin construction

once it has submitted an application, but before the Division has

determined that it will not exceed NO2 NAAQS; (2) the Division failed

to explain how it would determine whether a source is exceeding

emission limits; and (3) the public is unable to submit comments or

obtain judicial review as required under state and federal law when

a permit goes into effect upon registration. We are not persuaded.

28
1. Applicable Law

¶ 46 The EPA has approved the use of general permits broadly, see

40 C.F.R. § 49.156 (2024); 1995 EPA Guidance, and specifically as

part of Colorado’s SIP, see Approval and Promulgation of Air Quality

Implementation Plans; Colorado; New Source Review and

Prevention of Significant Deterioration, 59 Fed. Reg. 42500 (Aug.

18, 1994) (approving modifications to Colorado’s SIP). The EPA has

explained that “[t]he purpose of a general permit is to simplify the

permit issuance process for similar facilities so that a reviewing

authority’s limited resources need not be expended for site-specific

permit development for such facilities.” Review of New Sources and

Modifications in Indian Country, 76 Fed. Reg. 38748, 38767 (July

1, 2011). According to the EPA, “general permits offer a

cost-effective means of issuing permits and provide a quicker and

simpler alternative mechanism for permitting minor sources than

the site-specific permitting process.” Id.; see also Approval and

Promulgation of Air Quality Implementation Plans; North Dakota;

Revisions to Air Pollution Control Rules, 84 Fed. Reg. 11646, 11647

(Mar. 28, 2019) (“The EPA has a well-established, longstanding

position that the use of general permits for construction of . . .

29
minor sources[, including synthetic minor sources,] is appropriate

under the CAA.”).

¶ 47 To implement general permitting in Colorado, the Commission

was charged with promulgating “[p]rocedures for issuing general

permits after notice and an opportunity for hearing, covering

numerous similar sources.” § 25-7-114.4(1)(p). The regulations

authorize the Division to “issue a general construction permit

covering numerous similar sources to a source that would

otherwise be required to obtain a construction permit.” Regulation

3, pt. B, § III.I.1. General construction permits “shall comply with

all applicable requirements, including notice and opportunity for

public participation where warranted for such sources.” Id. Such

permits “shall undergo statewide public notice.” Regulation 3, pt.

B, § III.I.7.

¶ 48 The Division must also “enforce compliance with the . . . terms

and conditions of any permit” issued under Colorado’s SIP.

§ 25-7-115(1)(a), C.R.S. 2024. Enforcement mechanisms include

cease-and-desist orders, injunctions, and civil penalties. See

§§ 25-7-112(1), -113, -115, -121, -122, C.R.S. 2024.

30
2. Registration and Certification under GP11

¶ 49 Under GP11’s terms, a source initially receives conditional

certification that takes effect on the date the source submits a

complete registration request. This means a source can commence

construction and operation of ROPE-emitting activities as soon as

the Division receives its completed registration.

¶ 50 GP11 provides that, within ninety days of the date the Division

receives the complete registration, it must approve or deny the

registration request in writing. See Regulation 3, pt. B, § III.I.4

(requiring the Division to review and certify or deny each application

for coverage under a general permit). The Division may also deny or

revoke registration and require a source to apply for an individual

construction permit if either of the following occurs: (1) “[a] change

has occurred in the availability of control technology or practices for

the control or abatement of air pollutants applicable to the source,”

or (2) “[c]ircumstances have changed since the time of the request,”

and “the source is no longer appropriately controlled under the

general construction permit.” Regulation 3, pt. B, § III.I.3.c.(i).

GP11 also provides that, if a source improperly registers under it,

the operator “accepts the liability of commencing” construction and

31
emitting activities, and the Division may take enforcement action

against the operator.

¶ 51 For minor sources permitted under GP11, compliance with

emission limits is determined on an annual calendar-year basis.

Minor sources must keep a compliance record on site or at a local

office. A synthetic minor source’s emission limits compliance is

determined on a rolling twelve-month basis. A synthetic minor

source is required to calculate actual emissions each month and

keep a record on site or at a local office.

3. Division’s Determination that GP11 Sources Will Not Cause an
Exceedance of NAAQS

¶ 52 At the outset, we note that the Public Interest Groups argue

that the Division’s decision is contrary to law because “GP11 allows

the construction of sources of air pollution that cause or contribute

to violations of NAAQS set by EPA.” (Emphasis added.) But under

Regulation 3, the Division must grant a construction permit if it

finds that the “proposed source or activity will not cause an

exceedance of any [NAAQS].” Regulation 3, pt. B, § III.D.1.c

(emphasis added). That is the standard we apply. See

§ 25-7-114.5(7)(a)(III) (The Division shall grant a construction

32
permit if it finds that “the source or activity will meet any applicable

ambient air quality standards and all applicable regulations.”).

¶ 53 On the merits, the Public Interest Groups argue that, because

a source can begin construction and emitting activities once it

registers under GP11, the Division cannot determine whether the

source will cause an exceedance of NAAQS before construction

starts. They frame this issue as a “straightforward temporal

problem” resulting from the self-executing nature of GP11. And

they point to a computer modeling analysis of a well pad in

Bighorn, which they claim “is under the emission caps in GP11,

and yet the modeling demonstrates that the source will cause

violations of the NAAQS for nitrogen oxides.”

¶ 54 The Public Interest Groups’ argument overlooks the fact that

the Division already determined that the sources eligible to register

under GP11, categorically, will not exceed NAAQS by engaging in

the permitted emitting activities. The Division explains that,

because VOCs that occur from ROPE are intermittent and typically

of short duration and because operators are unlikely to opt to

control ROPE through combustion devices, it used a “qualitative

method” to analyze potential NO2 emissions rather than

33
quantitative “modeling.” Using its technical expertise and

judgment, the Division concluded,

While a small small amount of [NO2] may be
periodically generated where an operator
chooses to use a combustion device to control
emissions, the amount generated by control of
ROPE is currently expected to be well below
the levels at which the [D]ivision would require
a source to perform modeling to demonstrate
compliance.

The Division has cited information from the administrative record

that supports each step in its reasoning. Thus, we conclude that

the Division’s decision to issue GP11 is not contrary to law because

registration under GP11 is available to only those sources that the

Division predetermined would not cause an exceedance of the NO2

NAAQS.

¶ 55 Admittedly, the significance of the Bighorn well pad modeling

remains unclear to us. The Division asserts that the modeling is

not representative of NOx emissions from controlling ROPE. The

Division points out that the constant emission rate from that well

pad was significantly higher than the emissions the Division would

normally expect from sources controlling ROPE. The Division also

notes that monitoring data from 2016 to 2020 showed no

34
exceedance of NO2 NAAQS across the state. Given this lack of

clarity in the record, we defer to the Division’s technical expertise.

See Craddock, 850 P.2d at 705.

4. Enforcement

¶ 56 The Public Interest Groups contend that the Division has not

explained how it will identify sources that violate GP11 or exceed

NAAQS, arguing that the Division is obligated to prevent the

construction of violating sources rather than applying a “retroactive

fix” through post hoc enforcement mechanisms. But the Public

Interest Groups provide no authority requiring that the Division

individually preapprove every source that registers under GP11.

Indeed, such a requirement would undermine the purpose of

general permitting to simplify the permitting process and avoid the

need for the Division to conduct site-specific approval.

¶ 57 GP11 authorizes sources to register only if they meet all the

permit conditions. It sets emission limitations and requires sources

to maintain compliance records for Division review. For sources

that elect to control ROPE, the permit requires additional

recordkeeping. If a source violates the permit, the Division has

access to all mechanisms of enforcement available under the law.

35
See §§ 25-7-112, -113 (cease and desist orders); § 25-7-115 (general

enforcement authority); § 25-7-121 (injunctions); § 25-7-122 (civil

penalties). We are not convinced that the Division’s reliance on

these enforcement methods undermines its initial determination

that sources authorized to register under GP11 will not cause an

exceedance of NO2 NAAQS.

5. Public Comment

¶ 58 Finally, the Public Interest Groups contend that a member of

the public cannot submit comments or obtain judicial review, even

if they have evidence that a source permitted under GP11 caused

an exceedance of NAAQS. But the applicable statutes and

regulations require notice and an opportunity for the public to

participate before general permits are issued. See

§ 25-7-114.4(1)(p); Regulation 3, pt. B, § III.I.1. Indeed, the Center

for Biological Diversity participated and submitted comments for

the Division’s consideration before GP11 was issued.

6. Concerns with General Permitting

¶ 59 Although the Public Interest Groups acknowledge that general

permits are part of Colorado’s SIP and insist they are not

challenging general permitting broadly, the Division and the API

36
argue, and we tend to agree, that the Public Interest Groups attack

features common to all general permits. The “temporal problem[s]”

the Public Interest Groups highlight regarding when the Division

determines a permitted source will not cause an exceedance of

NAAQS, when the Division will enforce permit violations, and when

the public can participate, exist with any general permit and are not

unique to GP11.

¶ 60 On this record, we conclude the Public Interest Groups have

not met their burden to show that the Division acted contrary to

law. See Wildwood Child & Adult Care Program, Inc., 985 P.2d at

655.

IV. Disposition

¶ 61 We affirm the district court’s judgment affirming the Division’s

issuance of General Permit 11.

JUDGE J. JONES and JUDGE YUN concur.

37