Document ID: s3://data.kl3m.ai/documents/govinfo/USCOURTS/USCOURTS-caDC-07-01053/USCOURTS-caDC-07-01053-0/pdf.json

Parties Involved:
American Chemistry Council
Intervenor
Environmental Protection Agency
Respondent
Louisiana Environmental Action Network
Petitioner
Natural Resources Defense Council
Petitioner

Document Text:

United States Court of Appeals

FOR THE DISTRICT OF COLUMBIA CIRCUIT

Argued April 10, 2008 Decided June 6, 2008

No. 07-1053

NATURAL RESOURCES DEFENSE COUNCIL AND LOUISIANA

ENVIRONMENTAL ACTION NETWORK,

PETITIONERS

v.

ENVIRONMENTAL PROTECTION AGENCY,

RESPONDENT

AMERICAN CHEMISTRY COUNCIL,

INTERVENOR

On Petition for Review of an Order

of the Environmental Protection Agency

John D. Walke argued the cause for petitioners. With him

on the briefs were Aaron S. Colangelo, Patrice Simms, Adam

Babich, and Jill Witkowski.

David S. Gualtieri, Attorney, U.S. Department of Justice,

argued the cause for respondent. With him on the brief were

John C. Cruden, Deputy Assistant Attorney General, and

Michael W. Thrift, Counsel. Kent E. Hanson, Attorney, U.S.

Department of Justice, entered an appearance.

USCA Case #07-1053 Document #1120274 Filed: 06/06/2008 Page 1 of 18
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Leslie A. Hulse, Charles H. Knauss, Robert S. Taylor, and

Robert V. Zener were on the brief for intervenor.

Before: GRIFFITH and KAVANAUGH, Circuit Judges, and

SILBERMAN, Senior Circuit Judge.

Opinion for the court filed by Senior Circuit Judge

SILBERMAN.

SILBERMAN, Senior Circuit Judge: Synthetic organic

chemicals have few direct consumer uses, but they often serve

as raw materials in the production of plastics, rubbers, fibers,

protective coatings, and detergents. Petitioners, the Natural

Resources Defense Council and the Louisiana Environmental

Action Network, challenge EPA’s residual risk rulemaking

under subsection 112(f) of the Clean Air Act for facilities that

use or produce synthetic organic chemicals (“the industry”).

Petitioners also challenge EPA’s technology review under

subsection 112(d)(6). In a rather unusual bit of rulemaking, the

agency determined by rule not to change its previous rule, which

gave rise to petitioners’ challenge. We deny the petition.

I.

Section 112 of the Clean Air Act regulates hazardous air

pollutants. When the Act was passed in 1970, hazardous air

pollutant was defined as a substance “which may reasonably be

anticipated to result in an increase in mortality or an increase in

serious irreversible, or incapacitating irreversible, illness.”

Sierra Club v. EPA, 353 F.3d 976, 979 (D.C. Cir. 2004) (citation

omitted). The Administrator of the EPA was required to prepare

a list of air pollutants that fell within this definition, then

promulgate standards to protect the public health from these

substances with an “ample margin of safety.” Id.

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1

 The Act defines “major source” as “any stationary source or

group of stationary sources located within a contiguous area and under

common control that emits or has the potential to emit considering

controls, in the aggregate, 10 tons per year or more of any hazardous

air pollutant or 25 tons per year or more of any combination of

hazardous air pollutants.” 42 U.S.C. § 7412(a)(1).

As we have explained, this arrangement proved

problematic. Id. In light of unrealistic time frames and

scientific uncertainly over which substances posed a threat to

public health, EPA only listed eight pollutants as hazardous

between 1970 and 1990. Id. In 1990, Congress sought to hasten

the process by adopting a new regulatory approach for

hazardous air pollutants. Rather than have EPA list one-by-one

those substances likely to be harmful, the amended version of

section 112 provides a list of 191 substances that Congress

deemed to be hazardous. 42 U.S.C. § 7412(b)(1). EPA could

subsequently add to or subtract from this list. Id. § 7412(b)(2)-

(3).

Instead of basing its regulations on health risks (the “ample

margin of safety”), EPA was required by the 1990 amendments

to adopt technology-based standards in the first instance. That

is to say, in the first round of regulation, the agency was obliged

to look to the best available control technology to control

emissions for each category of major sources that emits one or

more of the listed hazardous air pollutants.1

 Id. § 7412(d)(2)-

(3). (The control technology used to meet this standard is

referred to as the “maximum achievable control technology” or

“MACT.”) Under this technology-based approach, standards for

new sources may not be less stringent than “the emission control

that is achieved in practice by the best controlled similar

source.” Id. § 7412(d)(3). And for existing sources, the

emission standards may not be less stringent than “the average

emission limitation achieved by the best performing 12 percent

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2

 Although EPA considered costs (as we discuss supra) in

setting its technology-based standards, we subsequently held that it

was not appropriate to consider costs in establishing the maximum

achievable control technology “floor” (although the agency is

permitted to consider cost in deciding whether to require further

“beyond the floor” reductions). See Nat’l Lime Ass’n v. EPA, 233

F.3d 625, 640 (D.C. Cir. 2000); see also NRDC v. EPA, 489 F.3d

1364, 1375-76 (D.C. Cir. 2007).

of the existing sources.” Id. After setting the “floor” – i.e., the

minimum required reduction in emissions for a new or existing

source – EPA has discretion to require an even greater reduction

in emissions, taking into account costs, health effects,

environmental effects, and energy requirements.2 Id. §

7412(d)(2).

In the second stage of regulation, EPA was obliged to

review any residual health risks that had not been eliminated by

the initial technology-based standards. Id. § 7412(f). This

second stage is described as “risk-based” or “health-based”

because it requires EPA to set a standard based on a medical

assessment of a given pollutant’s health risks (as was true of the

pre-1990 statute), rather than the current state of control

technology. See generally Percival, Schroeder, Miller & Leape,

ENVIRONMENTAL REGULATION: LAW, SCIENCE & POLICY 126

(4th ed. 2003). Within six years of promulgating the technologybased standards, EPA was required to prepare a report to

Congress analyzing any residual health risks. If Congress did

not act on the report, then EPA was to conduct residual risk

analysis under subsection 112(f)(2).

* * *

EPA initially promulgated technology-based emission

standards for the industry in 1994 (there are 238 facilities in the

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3

 See National Emission Standards for Organic Hazardous

Air Pollutants, 59 Fed. Reg. 19,402 (1994).

United States that produce or use synthetic organic chemicals).3

Those standards required the use of control technologies such as

recovery devices, thermal oxidizers, carbon absorbers, and

steam strippers. After submitting the required report to

Congress in 1999, the agency commenced residual risk

rulemaking, apparently because – as we discuss below – it read

the statute as requiring a rulemaking proceeding to consider

whether to revise the technology-based standards, since the

industry’s emissions pose lifetime excess cancer risks of greater

than one-in-one million.

In the notice of proposed rulemaking, EPA listed two

options for the residual risk rulemaking, one of which would

have imposed somewhat stricter standards. 71 Fed. Reg. 34,422,

34,438 (2006). But the other, which EPA adopted in the final

rule, 71 Fed Reg. 76,603 (2006), was a reaffirmation of the

existing rule. EPA determined that under the existing

technology-based standard, no individual would face an excess

lifetime cancer risk of greater than 100-in-one million, which

EPA regards as the “presumptively acceptable” level under its

precedents. In the same regulatory procedure, EPA sought to

satisfy another statutory requirement, subsection 112(d)(6),

which commands the Administrator to “review, and revise as

necessary” the technology-based standards in light of

technological developments at least every eight years. 42

U.S.C. § 7412(d)(6). It concluded there were no such

developments.

Petitioners challenge EPA’s actions on several grounds.

Their primary argument is one of statutory construction. They

contend that the statute obliged EPA, in the residual risk

rulemaking, to tighten the standards for the industry so that the

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lifetime excess cancer risk to exposed persons would be no

greater than one-in-one million. It is also argued that in

reviewing the technology-based standards, EPA violated

subsection 112(d)(6) by taking costs into account. Alternatively,

even if EPA complied with the statute, petitioners claim that the

rulemaking violated the APA, as arbitrary and capricious,

because it relied on faulty data and overlooked significant

sources of emission.

II.

A.

Petitioners contend that subsection 112(f)(2)(A) obliged

EPA to revise industry standards to reduce lifetime excess

cancer risk to one-in-one million. Petitioners rely primarily on

the last sentence of that subsection, whereas EPA looks to the

whole subsection. That provision states in full:

If Congress does not act on any recommendation submitted

under paragraph (1), the Administrator shall, within 8 years

after promulgation of standards for each category or

subcategory of sources pursuant to subsection (d) of this

section, promulgate standards for such category or

subcategory if promulgation of such standards is required

in order to provide an ample margin of safety to protect

public health in accordance with this section (as in effect

before November 15, 1990) or to prevent, taking into

consideration costs, energy, safety, and other relevant

factors, an adverse environmental effect. Emissions

standards promulgated under this subsection shall provide

an ample margin of safety to protect public health in

accordance with this section (as in effect before November

15, 1990), unless the Administrator determines that a more

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stringent standard is necessary to prevent, taking into

consideration costs, energy, safety, and other relevant

factors, an adverse environmental effect. If standards

promulgated pursuant to subsection (d) of this section and

applicable to a category or subcategory of sources emitting

a pollutant (or pollutants) classified as a known, probable or

possible human carcinogen do not reduce lifetime excess

cancer risks to the individual most exposed to emissions

from a source in the category or subcategory to less than

one in one million, the Administrator shall promulgate

standards under this subsection for such source category.

42 U.S.C. § 7412(f)(2)(A).

It is undisputed that facilities that produce or use synthetic

organic chemicals emit carcinogens and are, therefore, within

the reach of the last sentence. It is also undisputed that, in light

of the fact that existing technology-based standards do not

reduce the risk to less than one-in-one million, EPA was obliged

to “promulgate standards” under subsection 112(f). Petitioners

contend that the third sentence obviously means that residual

risk standards must meet the threshold test – i.e., EPA must

reduce such risks to one-in-one million. That may well be a

possible interpretation, but the sentence contains a glaring

omission; it does not say what petitioners would like us to infer.

Rather, that sentence instructs the Administrator to “promulgate

standards,” but it says nothing about the substantive content of

those standards. If Congress had wished to set a “bright line”

standard, it would have been rather easy for the draftsmen to say

just that. The failure to do so could not have been accidental.

In light of the rest of the subsection’s language (and other

provisions), it seems to us that the subsection was drafted as a

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4

 Congress rejected the Senate version of the bill – which

mandated a bright line standard for carcinogens – in favor of the

House version, which gave the Secretary more discretion under the

“ample margin of safety” standard. Compare A LEGISLATIVE

HISTORY OF THE CLEAN AIR ACT AMENDMENTS OF 1990, at 4445, with

id. at 2139-40.

5

 As one commentator has noted, subsection 112(f)(2) “does

not require that the residual risk standard for a category be set at a

level that would force the highest risk source in that category to

achieve the one-in-one-million benchmark, but merely mandates an

additional round of regulation.” Bradford C. Mank, What Comes After

Technology: Using an “Exceptions Process” to Improve Residual Risk

Regulation of Hazardous Air Pollutants, 13 STAN. ENVTL. L.J. 263,

276 (1994). The author continues: “By not requiring a one-in-amillion or any other residual risk standard in section 112(f), Congress

essentially left the difficult task of defining an ‘ample margin of

safety’ to the EPA’s discretion.” Id. at 277.

deliberately ambiguous compromise.4

We reach that conclusion because the second sentence,

which sets forth the substantive standard to be applied, simply

calls for standards that “provide an ample margin of safety to

protect public health” (unless the Administrator wishes to go

further to avoid adverse environmental effects). No distinction

is drawn between carcinogens and non-carcinogens. The third

sentence, on which petitioners rely, not only lacks the language

that petitioners ask us to infer; it also specifically states that if

the one-in-one million trigger is met, the Administrator must

promulgate standards “under this subsection,” which, perforce,

takes us back to the second sentence.5

EPA’s construction of the subsection is bolstered by another

paragraph, 112(f)(2)(B), which states:

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Nothing in subparagraph (A) or in any other provision of

this section shall be construed as affecting, or applying to

the Administrator’s interpretation of this section, as in

effect before November 15, 1990, and set forth in the

Federal Register of September 14, 1989 (54 Federal

Register 38044).

42 U.S.C. § 7412(f)(2)(B). The cited item in the Federal

Register is EPA’s emission standard for benzene, which is a

carcinogenic hazardous air pollutant. In the Benzene

rulemaking, EPA set forth its interpretation of “ample margin of

safety,” as that term was used in the 1970 version of the Clean

Air Act. It said that the “ample margin” was met if as many

people as possible faced excess lifetime cancer risks no greater

than one-in-one million, and that no person faced a risk greater

than 100-in-one million (one-in-ten thousand). 54 Fed. Reg. at

38,044-45. In other words, the Benzene standard established a

maximum excess risk of 100-in-one million, while adopting the

one-in-one million standard as an aspirational goal. This

standard, incorporated into the amended version of the Clean Air

Act, undermines petitioners’ assertion that EPA must reduce

residual risks to one-in-one million for all sources that emit

carcinogenic hazardous air pollutants.

Petitioners respond that subsection 112(f)(2)(B) is a savings

clause that only preserves EPA’s specific regulations regarding

benzene. But the text belies this contention. Subsection

112(f)(2)(B) makes clear that nothing in subparagraph (A) shall

be construed as “affecting, or applying to the Administrator’s

interpretation” of section 112, as set forth in the Benzene

standard. The word “interpretation” indicates that the savings

clause is not limited to EPA’s benzene-specific determinations,

but applies broadly to the agency’s construction of the Clean Air

Act in the Benzene standard. Petitioners also contend that

subsection (B) should only be read as applying to nonUSCA Case #07-1053 Document #1120274 Filed: 06/06/2008 Page 9 of 18
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carcinogens, but this is not persuasive. Subsection 112(f)(2)(B)

incorporates EPA’s “interpretation” of the Clean Air Act from

the Benzene standard, and the text of this provision draws no

distinction between carcinogens and non-carcinogens. Indeed,

benzene is itself a carcinogen, 54 Fed. Reg. at 38,048, so it

would make little sense for Congress to incorporate this standard

only for non-carcinogens.

The parenthetical clause in the second sentence of

subsection 112(f)(2)(A) lends further support to EPA’s position.

That sentence states “[e]missions standards promulgated under

this subsection shall provide an ample margin of safety to

protect public health in accordance with this section (as in effect

before November 15, 1990) . . . .” EPA interprets the

parenthetical as a “shorthand reference” to the Benzene standard,

given that subsection (B) uses almost identical language,

incorporating “the Administrator’s interpretation of this section,

as in effect before November 15, 1990, and set forth in the

Federal Register . . . .” The phrase “this section (as in effect

before November 15, 1990)” is certainly broad enough to

encompass EPA’s prior interpretations of “this section” as well

as the text itself. In fact, the operative provision of the pre-1990

version of section 112 uses the exact same “ample margin of

safety” language as subsection 112(f)(2)(A) currently uses. See

Sierra Club, 353 F.3d at 979-80. Thus, the parenthetical must

refer to something more than the bare text of “this section,” or

else it would be surplusage. 

Petitioners insist that EPA’s interpretation renders the third

sentence effectively meaningless. To be sure, the third sentence,

as EPA interprets it, seems relatively anodyne; it lacks

substantive force. But, at least as EPA reads it, the word

“promulgate” means the agency is obliged to conduct a

rulemaking to consider residual risks for sources that emit

carcinogens. That extra procedural step is not a trivial

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obligation. Congress often imposes procedural requirements

without dictating substantive outcomes. See, e.g., Strycker’s

Bay Neighborhood Council v. Karlen, 444 U.S. 223, 227-28

(1980) (discussing the National Environmental Policy Act). We

also disagree with petitioners’ argument that EPA did not

“promulgate standards” under subsection 112(f)(2) because it

simply readopted the initial standards. This position finds no

support in the text of the statute. Subsection 112(f)(2) only

mandates that residual risk standards “provide an ample margin

of safety to protect public health.” If EPA determines that the

existing technology-based standards already provide an “ample

margin of safety,” then the agency is free to readopt those

standards during a residual risk rulemaking.

Finally, petitioners argue that EPA unlawfully considered

cost while setting the “ample margin of safety” in the residual

risk standards. Petitioners are correct that the Supreme Court

has “refused to find implicit in ambiguous sections of the [Clean

Air Act] an authorization to consider costs that has elsewhere,

and so often, been expressly granted.” Whitman v. Am. Trucking

Ass’n, 531 U.S. 457, 467 (2001). In this case, however, we

believe the clear statement rule has been satisfied. As explained

above, subsection 112(f)(2)(B) expressly incorporates EPA’s

interpretation of the Clean Air Act from the Benzene standard,

complete with a citation to the Federal Register. In that

rulemaking, EPA set its standard for benzene “at a level that

provides ‘an ample margin of safety’ in consideration of all

health information . . . as well as other relevant factors including

costs and economic impacts, technological feasibility, and other

factors relevant to each particular decision.” 54 Fed. Reg. at

38,045 (emphasis added). EPA considered cost in Benzene, and

subsection 112(f)(2)(B) makes clear that nothing in the amended

version of the Clean Air Act shall “affect[]” the agency’s

interpretation of the statute from that rulemaking.

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In sum, we conclude that EPA’s interpretation of subsection

112(f)(2), although not an inevitable one, certainly is, at least, a

reasonable construction of the statute. See Chevron U.S.A., Inc.

v. NRDC, 467 U.S. 837, 843 (1984).

B.

Petitioners’ second statutory argument is based on

subsection 112(d)(6), which states:

The Administrator shall review, and revise as necessary

(taking into account developments in practices, processes,

and control technologies), emissions standards promulgated

under this section no less often than every 8 years.

42 U.S.C. § 7412(d)(6). It is argued that EPA was obliged to

completely recalculate the maximum achievable control

technology – in other words, to start from scratch. We do not

think the words “review, and revise as necessary” can be

construed reasonably as imposing any such obligation. Even if

the statute did impose such an obligation, petitioners have not

identified any post-1994 technological innovations that EPA has

overlooked.

More troublesome, however, is petitioners’ assertion that

the agency improperly considered costs in considering whether

to revise the standards. EPA did, in fact, state in its notice of

proposed rulemaking that “leakless components” should not be

considered the “maximum achievable control technology”

because of the high cost of replacing existing components. 71

Fed. Reg. at 34,438. That could be thought in tension with our

cases holding that EPA may not consider costs in setting the

maximum achievable control technology “floors,” but only in

determining whether to require “beyond the floor” reductions in

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6

 As we indicated, supra, costs may be considered in

appraising risk – i.e., the “ample margin of safety.” 42 U.S.C. §

7412(f)(2)(B); 54 Fed. Reg. at 38,045.

7

 In its brief, EPA asserts that it may consider “cost,” but the

agency draws no distinction between MACT floors and beyond-thefloor reductions. Nor does the agency address our decision in

National Lime. Petitioners, on the other hand, do not discuss the

significance of the fact that the initial MACT standards were

unchallenged.

8

 Even if petitioners did dispute this point, it involves a

factual finding; we would thus grant significant deference to the

agency’s conclusion. See NRDC v. EPA, 194 F.3d 130, 136 (D.C. Cir.

1999) .

emissions.6 See Nat’l Lime Ass’n v. EPA, 233 F.3d 625, 640

(D.C. Cir. 2000); see also NRDC v. EPA, 489 F.3d 1364, 1375-

76 (D.C. Cir. 2007). EPA may have done just that in setting the

initial floors. Yet the time period for challenging those

standards has long since passed, 42 U.S.C. § 7607(b)(1), which

raises the question whether EPA’s reaffirmation of its cost-based

reasoning in its technology review gives rise to a new

opportunity for petitioners to challenge this apparent defect.7

Fortunately, we do not have to decide this question because

in its final rule, EPA squarely found that there were no

“significant developments in practices, processes and control

technologies,” and petitioners do not challenge this conclusion.8

71 Fed. Reg. at 76,605. Since that is the core requirement of

subsection 112(d)(6) and EPA’s finding satisfies that

requirement, it is irrelevant whether EPA considered costs in

arriving at the initial MACT floor and reaffirming that standard

in the residual risk rulemaking. Petitioners argue that EPA’s

consideration of cost somehow “tainted” the entire technology

review. But under the deferential “arbitrary and capricious”

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standard, we may not set aside an agency’s factual finding based

on amorphous allegations of “taint.” 

III.

There remains petitioners’ claim that EPA’s analysis of the

residual health risks from facilities that use or produce synthetic

organic chemicals was arbitrary and capricious (unreasonable).

In conducting its risk assessment, EPA relied upon industrysupplied data – collected by the American Chemistry Council –

that was submitted on a questionnaire approved by the agency.

Based on this data, EPA determined that no source presented a

lifetime cancer risk of greater than 100-in-one million, and that

only two sources presented a risk equal to that threshold.

Petitioners argue that EPA should have handled the data

collection itself, and that the industry-supplied data was

defective in several respects.

Under section 114 of the Clean Air Act, EPA “may require”

the owner of an emissions source to keep records, make reports,

install monitoring equipment, take emissions samples, and

“provide such other information as the Administrator may

reasonably require.” 42 U.S.C. § 7414(a). Petitioners contend

that EPA’s risk analysis was flawed because the agency did not

exercise its authority under that section; instead, EPA relied

upon data voluntarily supplied by the industry. But section 114

is not a mandatory provision – it only states that EPA “may”

require sources to supply data. This wording gives the

Administrator discretion to decide what types of data should be

used for a risk assessment. Indeed, EPA has explained that

relying on data from industry sources is a well-established

practice. In its 1999 report to Congress on how the agency

planned to address residual risks, EPA stated that “source and

emissions data can be derived from broad-scale emissions

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inventories, specific data collection efforts with particular

industries, or information from regional, State, or local air toxics

agencies.” Residual Risk Report to Congress (Mar. 1999), at 35

(emphasis added). As EPA’s counsel explained at oral

argument, it is very costly and time-consuming – for both the

agency and the emissions sources – to issue information requests

under section 114. Tr. of Oral Arg. at 21-22. It was therefore

not unreasonable for the agency to decline to invoke its section

114 authority when more efficient data-collection methods were

available.

Nevertheless, petitioners assert that the industry-supplied

data was flawed. They contend that many of the questionnaires

were incomplete, and that the data will understate health risks

because high-emissions sources have an incentive to withhold

data from the agency. Although there were some gaps in the

data, EPA ultimately received responses from 44% of all

sources, including sources with both low and high emissions

levels. The agency also explained that when certain data points

were missing, EPA used “environmentally protective defaults”

in its models. (Petitioners do not dispute this point.) In other

words, EPA acknowledged that the data was not comprehensive,

but compensated for this uncertainty by erring on the side of

protecting public health. We think that is a reasonable position.

We also disagree with petitioners’ assertion that the

emissions data – which dated back to 1999 – was unreliable.

Although the risk assessment was completed in 2006, it

obviously began much earlier than that. Data from 1999 seems

a bit old, but EPA explained that a significant amount of time

was needed to collect the data, run the models, analyze the

results, and prepare the rulemaking. EPA persuasively argues

that by 1999, the technology-based standards had already been

in place for several years, so it was unlikely that there would be

a substantial increase in emissions between 1999 and 2006.

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9

 See http://www.epa.gov/ttn/chief/net/neiwhatis.html. 

Petitioners, moreover – and this is a key omission – do not assert

that emissions actually increased over this period.

EPA compared the industry-supplied data to the National

Emissions Inventory, which is a database of air emissions

information supplied by state and local air agencies, tribes, and

industry sources.9

 The agency determined that the two data sets

yield similar results in terms of maximum risk. Petitioners

challenge this conclusion, pointing to specific facilities in which

the Emissions Inventory data show higher risks than the

industry-supplied data. But EPA explained that the Emissions

Inventory data for each facility includes hazardous air pollutants

other than synthetic organic chemicals, which means that the

Emissions Inventory is likely to show higher risks than the

industry-supplied data. Intervenors further emphasize that in at

least one of the three “high risk” facilities in the Emissions

Inventory data, the emissions of synthetic organic chemicals

were less than half of the facility’s overall emissions. EPA

noted that the Emissions Inventory included conservative

assumptions that caused this data set to overstate the risks from

synthetic organic chemicals. And EPA never contended that the

two data sets perfectly overlapped; it only stated that “the

highest risks from using the [Emissions Inventory] data were of

the same order of magnitude as those using the industry data.”

71 Fed. Reg. at 76,607.

Be that as it may, EPA’s analysis of the Emissions

Inventory data was only used to check the agency’s risk analysis

based on the industry-supplied data. Even if the correlation

were not perfect, that would not necessarily show that EPA’s

use of industry-supplied data was unreasonable. Indeed, even

though the industry data does not include as many facilities as

the Emissions Inventory data, it is more detailed in other ways.

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For example, the industry data provides far greater detail on

emission point locations and release parameters than the

Emissions Inventory.

In sum, petitioners’ arguments boil down to one simple

point: EPA could have used better data in conducting its risk

analysis. Whether or not this is true, it misstates the inquiry

under the arbitrary and capricious standard. As we have

explained:

EPA typically has wide latitude in determining the extent of

data-gathering necessary to solve a problem. We generally

defer to an agency’s decision to proceed on the basis of

imperfect scientific information, rather than to invest the

resources to conduct the perfect study.

Sierra Club v. EPA, 167 F.3d 658, 662 (D.C. Cir. 1999) (citation

omitted). In other words, the sole question before us is whether

EPA has acted reasonably, not whether it has acted flawlessly.

On the record before us, EPA explained why it chose to rely on

industry-supplied data, and it reasonably responded to

petitioners’ objections to its data analysis.

* * *

Petitioners finally argue that EPA failed to address several

different types of emissions from synthetic organic chemical

manufacturing facilities, such as emissions from cooling towers,

emissions of inorganic hazardous air pollutants, and emissions

from “clusters” of nearby facilities. In making these arguments,

petitioners often reiterate their contentions that EPA relied upon

faulty data and did not reduce risks to one-in-one million. We

rejected those arguments above, and we need not address them

again here. With respect to the other arguments, we have

considered them and we find them to be without merit. EPA

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adequately responded to each of the alleged deficiencies in the

residual risk assessment.

IV.

For the aforementioned reasons, the petition for review is

denied.

 So ordered.

USCA Case #07-1053 Document #1120274 Filed: 06/06/2008 Page 18 of 18