PETITION FOR RECONSIDERATION OF EDISON MISSION ENERGY 

AND SUBSIDIARIES MIDWEST GENERATION EME, LLC AND EME 

HOMER CITY GENERATION, LP 

ON EPA’S FINAL RULE ON 

STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES 

AND EMISSION GUIDELINES FOR EXISTING SOURCES: 

COMMERCIAL AND INDUSTRIAL SOLID WASTE INCINERATION 

UNITS 76 FED. REG. 15,608 (MAR. 21, 2011) 

 

 Basil G. Constantelos 

 Managing Director, Environmental Services 

 Midwest Generation 

 Edison Mission Energy 

 235 Remington Blvd. 

 Suite A 

 Bolingbrook, IL 60440 

 Tel: 630-771-7829 

 Email: bconstantelos@mwgen.com 

May 20, 2011 
TABLE OF CONTENTS 

Page

I. INTRODUCTION & OVERVIEW..................................................................................1 

II. EXECUTIVE SUMMARY ...............................................................................................3 

III. EPA SHOULD ALLOW A DE MINIMIS EXEMPTION FROM 

TREATMENT AS AN INCINERATOR FOR UNITS BURNING 

MATERIALS GENERATED IN THE NORMAL COURSE OF BOILER 

OPERATION .....................................................................................................................5

A. EPA’s Frequent Application Of Its De Minimis Authority Has 

Withstood Judicial Challenge ...............................................................................6 

1. De Minimis Exemptions In EPA’s Transportation Conformity 

Regulations .................................................................................................6 

2. Exemption Of De Minimis Sources Of PM10 Under A Federal 

Implementation Plan .................................................................................7 

3. De Minimis Exceptions from New Source Review for Routine 

Maintenance, Repair and Replacement...................................................7 

4. De Minimis Exemption From CERCLA Requirements On The 

Basis Of No Appreciable Health Risk ......................................................8 

B. EPA Allows Similar De Minimis Exemptions Under the Solid Waste 

Rule and Other Rules Under RCRA....................................................................9 

C. An Exemption for Materials Generated in the Course of Normal 

Boiler Operations Would Fit Squarely Within the Scope of EPA’s De 

Minimis Authority................................................................................................10 

1. The Emissions Impacts of an Exemption Would Be Trivial................10 

2. NRDC V. EPA Does Not Address EPA’s De Minimis 

Authority...................................................................................................13 

3. Requiring Application of Section 129 to De Minimis Amounts 

of Secondary Materials Would Be a Mandate of Pointless 

Expenditure ..............................................................................................13 

4. The Text of Section 129 of the Clean Air Act is Not 

“Uncompromisingly Rigid”.....................................................................14 

IV. GRANTING EME’S RECONSIDERATION REQUEST WOULD SERVE 

THE GOALS OF EXECUTIVE ORDER 13,563 .........................................................15 

V. CONCLUSION ................................................................................................................16
Edisson Mission Energy 

Petition for Reconsideration on EPA’s 

CISWI Rule 

 

1

I. INTRODUCTION & OVERVIEW 

This petition is submitted pursuant to section 307(d)(7)(B) of the Clean Air Act 

(“CAA”).1

 Edison Mission Energy and its subsidiaries Midwest Generation EME, LLC and EME 

Homer City Generation, LP (collectively “EME”) respectfully request that EPA reconsider and 

revise one aspect of the final “Standards of Performance for New Stationary Sources and 

Emission Guidelines for Existing Sources: Commercial and Industrial Solid Waste Incineration 

Units” 76 Fed. Reg. 15,608 (Mar. 21, 2011) (“CISWI Rule”). EPA should exercise its de 

minimis authority to allow combustion in onsite boilers for materials generated in the normal 

course of boiler operations that do not significantly affect the level of contaminants emitted from 

the plant, without triggering the definition of “solid waste incineration unit” under Sec. 129 of 

the CAA. This petition also forms the basis for EME’s Petition for Review of the CISWI Rule, 

filed May 20, 2011, in the U.S. Court of Appeals for the District of Columbia Circuit. A copy of 

the Petition for Review is enclosed for your convenience. Given the important issues raised by 

this petition, EME would welcome an opportunity to discuss with EPA an appropriate schedule 

and process for reconsideration, as well as potential settlement of its Petition for Review. 

EME, through its subsidiaries and affiliates, is an independent power producer engaged in 

the business of developing, acquiring, owning or leasing, capacity to generate and sell electricity 

into the wholesale energy market.2

 EME owns or operates 39 operating assets that provide a 

total net generation capacity of approximately 10,979 megawatts (“MW”), including 7,133 

MW of coal-fired generation in Illinois, Pennsylvania and West Virginia, 1,934 MW of gasfired generation in California, 305 MW of oil-fired generation in Illinois, and more than 1,800 

MW of wind power from various projects throughout the country (making it one of the largest 

wind power generators in the United States). EME currently has five wind power projects under 

construction that will eventually provide an additional 630 MW of net generating capacity. 

EME’s largest electricity generating assets consist of one coal-fired power plant in western 

Pennsylvania and six coal-fired power plants in Illinois. EME also is a part owner and is the 

 

1

 42 U.S.C. § 7607(d)(7)(B). 

2

 EME is part of the Edison International family of companies. Based in Rosemead, California, Edison 

International is the parent company of Southern California Edison, EME, Edison Capital, Edison 

Enterprises and Edison O&M Services. 
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operator of the American Bituminous Grant Town Power Plant, a coal refuse-fired electric 

generation facility located in West Virginia with a combined output of 80 MW from two 

circulating fluidized bed boilers. The combined facilities can generate enough electricity to meet 

the needs of more than eight million homes. 

Under the CAA Section 129, 42 U.S.C. Section 7429, facilities combusting materials that 

are determined to be non-hazardous solid waste under the Resource Conservation and Recovery 

Act (“RCRA”) are regulated as incinerators and required to meet the emissions standards under 

Section 129 of the CAA. EPA had originally attempted to exempt energy recovery facilities 

from this requirement, but that approach was found to be invalid in NRDC v. EPA, 489 F. 3d 

1250 (D.C. Cir. 2007). In response to the NRDC decision, EPA promulgated a definition of nonhazardous solid waste under RCRA, which would be used to determine which facilities are 

classified as boilers and which are classified as incinerators. EPA released the new NonHazardous Secondary Materials Rule (“Solid Waste Rule”), 76 Fed. Reg. 15,456, along with the 

CISWI Rule and major source boiler standards (76 Fed. Reg. 15,608). All of these rules were 

published in the Federal Register on March 21, 2011. 

EME requests in this petition that EPA clarify that burning de minimis amounts of nonhazardous boiler cleaning wastes and other traditional byproducts of boiler operation (such as 

water treatment resins) does not transform a boiler into an incinerator, even if the byproducts 

have a low heat value. EPA has sufficient de minimis authority to prevent applications of the law 

which would have trifling benefits at extremely high cost. 

Additionally, reconsidering the CISWI Rule in the manner we seek will promote the 

principles of the recent regulatory Executive Order 13563, which was issued shortly before the 

final rules were signed. EPA should use the reconsideration of the CISWI Rule as an 

opportunity to apply the principles of the Executive Order. Specifically, EPA should allow 

regulatory flexibility in continuing existing utility practices by allowing de minimis exemptions 

from the definition of “solid waste incinerator unit” under the CAA. EME had originally 

submitted a request that EPA exercise its de minimis authority under RCRA in its comments to 

the proposed Solid Waste Rule; however EPA failed to address EME’s request in the final Solid 

Waste Rule. EME has submitted a request to reconsider the exemption under RCRA, but is also 
Edisson Mission Energy 

Petition for Reconsideration on EPA’s 

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submitting this request under the CAA for completeness. EPA’s authority to grant de minimis

exemptions under the CAA is supported by significant case law, and should be exercised here. 

II. EXECUTIVE SUMMARY 

EME supports EPA’s general goal of reducing risks to human health and the environment 

from emissions from combustion facilities; however it believes that regulation of the combustion 

of secondary materials under Section 129 of the CAA should be carefully applied so as to 

encourage the safe reuse of materials that were previously used for different purposes, and in a 

flexible manner that does not impose unnecessary regulatory burdens in exchange for trivial 

benefits. EME respectfully requests that EPA use its inherent de minimis authority to exempt 

boilers combusting small amounts of materials generated in the normal course of boiler operation 

from treatment as an incinerator when the materials are generated and combusted onsite. 

Combustion of these materials does not appreciably impact contaminant emissions, but the 

economic and environmental costs of alternative disposal are significant. 

 EPA granted a de minimis exemption in the related regulations under the RCRA Solid 

Waste definitions rule for contaminants in construction and demolition debris, and 

should do so under Section 129 of the CAA for boilers combusting materials generated 

in the course of normal boiler operation. 

o EPA has a long history of de minimis authority, and courts have allowed the 

exercise of that authority under statutory language analogous to that in the solid 

waste incineration unit definition under CAA Section 129. EPA is not required to 

apply the “literal terms of a statute to mandate pointless expenditures of effort.” 

Instead EPA should use its de minimis authority when the burden of the regulation 

would produce minimal or no benefit to the public. EPA can use its authority as long 

as the purpose of the statute is not frustrated, or it is prohibited by an extraordinarily 

inflexible statute, neither of which is the case under Section 129 of the CAA. 

o A de minimis exemption from treatment as an incinerator for boilers combusting 

materials generated in the course of normal boiler operations that do not 

appreciably increase emissions would fit squarely within the scope of EPA’s de 

minimis authority. The recorded impacts of combustion of boiler cleaning wastes 
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are less than that caused by the normal variations in the coal stream. Although NRDC 

v. EPA rejected EPA’s position that energy recovery facilities should be regulated 

under Boiler MACT (rather than CISWI) even if they burned solid wastes, that 

decision is not controlling as to EPA’s ability to exempt these small amounts of 

secondary materials with trivial to no emissions impacts from rendering a boiler 

subject to CISWI. EME estimates that alternate, off-site disposal costs for each boiler 

clean that it undertakes would be up to $1 million. That expense would provide no 

appreciable emissions reduction, and would further tax limited disposal resources, 

generate additional emissions from transportation, and increase safety hazards during 

transport. 

o While broad, the definition of solid waste incineration unit is not so restrictive as 

to prevent a de minimis exemption, and is similar to the provisions for which 

courts have allowed such exemptions under the CAA and CERCLA. Courts have 

held that de minimis authority was not restricted by language such as “any 

modification” or “any hazardous waste.” The purpose of the statute must not be 

frustrated, but that would not be the case for materials whose emissions increases are 

not appreciable.

 The exercise of EPA’s de minimis authority requested by EME would serve to further 

the goals of Executive Order 13653. By eliminating costs of approximately $50 million 

annually industry-wide, without reducing benefits, this flexibility from application of EPA’s 

de minimis authority could help increase the costs to benefits ratio of this expensive rule. By 

granting flexibility in dealing with these secondary materials, EPA can not only reduce the 

regulatory burden on EME and similarly situated companies, but also preserve the disposal 

options and capacity available for other uses. 

EME notes with approval EPA’s decision to reconsider and stay the CISWI rule and the 

related rule for boilers. However, the interaction with the Solid Waste Rule is an area which 

should also be addressed in the reconsideration process, as the Solid Waste Rule governs 

whether a facility could fall under CISWI or an alternate section of the CAA, including the 

existing boiler and forthcoming utility MACT standards. EME requests that EPA include the 
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CISWI Rule 

 

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issue of secondary materials in its reconsideration of the CISWI rule, particularly the de minimis 

issue raised in this petition. As EME outlines in more detail below, EPA should reconsider the 

Solid Waste Rule to incorporate greater flexibility and reduce regulatory burdens in ways that 

will advance the central purpose of the statutes at hand. 

III. EPA SHOULD ALLOW A DE MINIMIS EXEMPTION FROM TREATMENT AS 

AN INCINERATOR FOR UNITS BURNING MATERIALS GENERATED IN 

THE NORMAL COURSE OF BOILER OPERATION 

EPA has a long history of de minimis authority under the CAA, with the seminal case 

being Alabama Power Co. v. Costle.

3

 In Alabama Power the court held that the EPA has 

inherent de minimis authority to exempt small sources from all but the most rigidly prescribed 

statutes as long as the legislative intent of the statute is not frustrated. The D.C. Circuit expressly 

stated that: 

It is commonplace . . . that the law does not concern itself with 

trifling matters, and this principle has often found application in 

the administrative context. Courts should be reluctant to apply 

the literal terms of a statute to mandate pointless expenditure of 

effort . . . . The ability, which we describe here, to exempt de 

minimis situations from a statutory command is not an ability to 

depart from the statute, but rather a tool to be used in 

implementing the legislative design.4

 

This authority has been applied by EPA and upheld by the courts in a variety of different 

circumstances. Similar to the examples described below, EPA has the inherent authority under 

CAA Section 129 to limit the application of the incinerator standards in situations where the 

intent of the statute would not be frustrated, and imposing the regulation would produce no or 

trivial benefits.5

 It should do so here with respect to boiler cleaning wastes, water treatment 

residues, and other minor constituents generated in the normal course of boiler operations. 

 

3

 636 F.2d 323 (D.C. Cir. 1979). 

4

 Id. at 360 (emphasis added). 

5

 On the Senate floor prior to the vote to approve the CAA amendments including the CISWI provisions, 

Senator Baucus indicated that EPA was granted significant discretion in implementing the standards, and 
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Petition for Reconsideration on EPA’s 

CISWI Rule 

 

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A. EPA’s Frequent Application Of Its De Minimis Authority Has Withstood 

Judicial Challenge 

1. De Minimis Exemptions In EPA’s Transportation Conformity 

Regulations 

In Environmental Def. Fund, Inc., v. EPA (“EDF”), 82 F.3d 451 (D.C. Cir. 1996), the 

Court set forth the existing de minimis standard: 

As long as the Congress has not been extraordinarily rigid in 

drafting the statute . . . there is likely a basis for an implication of 

de minimis authority to provide an exemption when the burdens of 

regulation yield a gain of trivial or no value. 

Id. at 466 (quotations omitted and emphasis added). In EDF, the D.C. Circuit upheld EPA’s 

transportation conformity regulations promulgated under CAA Section 176.6

 CAA Section 

176(c)(1) contains a broad prohibition against any “department, agency, or instrumentality of the 

Federal Government . . . support[ing] in any way” or engaging in “any activity which does not 

conform to an implementation plan after it has been approved or promulgated[.]”7 

Notwithstanding this prohibition, EPA’s transportation conformity regulations presumptively 

exempted federal actions that resulted in emissions below certain tonnage thresholds, as well as 

certain other categories of government action, because the emissions increases they produced 

were presumed to be de minimis.

8

 EDF argued that these exemptions violated CAA § 176(c)(1), 

which (according to EDF) demonstrated congressional intent that the general conformity 

requirement should apply to every activity of the federal government, however minor a source of 

emissions. 

The D.C. Circuit rejected this challenge because EPA’s de minimis exemption did not 

hinder the accomplishment of the CAA’s goals: 

[I]t seems eminently reasonable for the EPA to interpret this provision to 

refer to ‘any activity’ that is likely to interfere with the attainment goals in 

 noted that the amendments recognize that some incinerators should not be regulated at all. See 136 Cong. 

Rec. 6402 (1990) (statement of Sen. Baucus). 

6

 See 82 F.2d at 469. 

7

 CAA § 176(c)(1), 42 U.S.C. § 7506(c)(1) (emphasis added). 

8

 Id. at 465. 
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a SIP – that is, to major federal actions and to lesser actions that could still 

produce a regionally significant level of emissions . . . we find nothing in 

the statute to preclude the EPA’s identification of categories of federal 

action that would produce either no or a trivial level of emissions.” 

Id. at 466-67 (emphasis added). Similarly an exercise of de minimis authority here for the 

combustion of boiler cleaning wastes and other materials, such as water treatment resins, with 

minimal impact on emissions levels would not be precluded by the statute. 

2. Exemption Of De Minimis Sources Of PM10 Under A Federal 

Implementation Plan 

In Ober v. Whitman, 243 F.3d 1190 (9th Cir. 2001), the Ninth Circuit upheld EPA’s 

authority to exempt de minimis sources of PM10 from control requirements under a federal 

implementation plan against a challenge that doing so was “arbitrary and capricious.” The 

Court acknowledged that the CAA makes no explicit provision for a de minimis exception, but 

it nonetheless upheld EPA’s de minimis authority because: 

“There is no explicit provision in the Clean Air Act prohibiting the 

exemption from controls for de minimis sources of PM-10 

pollution. Nor is the statutory language uncompromisingly 

rigid.”9

The Court’s reasoning is applicable to the CISWI context. No explicit provision of CAA 

Section 129 prohibits a de minimis exemption, and, as discussed below, the statutory language 

of CAA Section 129 is not “uncompromisingly rigid.” 

3. De Minimis Exceptions from New Source Review for Routine 

Maintenance, Repair and Replacement 

Following the reasoning of the Alabama Power decision, the D.C. Circuit recognized the 

continued validity of EPA’s de minimis authority in 2006 in New York v. EPA, although the case 

was decided on other grounds.10 EPA did not attempt to include its change in policy, the 

Equipment Replacement Provision (“ERP”), under de minimis authority, instead arguing that the 

 

9

 Id. at 1194 (emphasis added). 

10 See New York v. EPA, 443 F.3d 880 883-84 (D.C. Cir. 2006). 
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statutory term “any physical change” was ambiguous.11 Despite the use of the word “any,” the 

court noted the long history of EPA properly applying its de minimis authority beginning with 

Alabama Power, provided that the intent of the statute is not frustrated: “[r]eliance on the de 

minimis doctrine invokes congressional intent that agencies diverge from the plain meaning of a 

statue only so far as is necessary to avoid its futile application.”12 The final decision rested on 

emissions increases that the court found were significant, and although not evaluated under the 

de minimis standard, the court indicates that they would have exceeded its boundaries. The 

exemption EME requests from the CISWI rule application, by contrast, would not have any 

significant impact on emissions, resulting in statistically insignificant variations when compared 

to the baseline variation within the fuel stream.13

4. De Minimis Exemption From CERCLA Requirements On The Basis Of 

No Appreciable Health Risk 

De minimis exemptions have been applied – and upheld – in other environmental statutes 

as well. In Ohio v. EPA, the D.C. Circuit upheld EPA’s de minimis authority to exempt 

remediated hazardous waste sites that posed no appreciable health risk from a CERCLA 

requirement to review all remediated sites periodically.14 CERCLA provides that, “[i]f the 

President selects a remedial action that results in any hazardous substances ... remaining at the 

site, the President shall review such remedial action no less often than each 5 years after the 

initiation of such remedial action [.]”15 EPA interpreted this provision to require review only 

when remedial action “results in hazardous substances . . . remaining at the site above levels that 

allow for unlimited use and unrestricted exposure.” Notably, EPA exempted sites from review 

“when the initial remedial action renders the site safe, under the standard prevailing at the time 

of the determination,” notwithstanding the potential for the continued presence of “any

hazardous substances.”16

 

11 Id. at 888-89 (emphasis added). 

12 Id. at 888. 

13 See ELECTRIC POWER RESEARCH INSTITUTE, BOILER CHEMICAL CLEANING WASTE MANAGEMENT MANUAL

3-6 (1992). 

14 See Ohio v. EPA, 997 F.2d 1520, 1535 (D.C. Cir. 1993). 

15 42 U.S.C. § 9621(c) (emphasis added). 

16 Ohio at 1534 (emphasis added). 
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The D.C. Circuit upheld EPA’s implementation of the review provision, finding that the 

provision allowed the Agency to avoid having to undertake continuing regulatory action in the 

absence of risk: 

The legislative design is not being flouted by EPA’s reading of the 

five-year review provision because the statutory command is not 

so clear as to rule out EPA’s application of a de minimis exception 

. . . . The literal meaning of a statute need not be followed where 

the precise terms lead to absurd or futile results, or where failure to 

allow a de minimis exception is contrary to the primary legislative 

goal . . . . EPA’s interpretation, which requires review only where 

a hazardous substance is present in an amount appreciable 

enough to present some possibility of harm, squares with the 

health-protective purpose of the statute. To go beyond that is to 

adjudge Congress incompetent to fashion a rational legislative 

design.17

In the case of Section 129, an interpretation requiring treatment as an incinerator only 

where wastes are combusted in amounts appreciable enough to create a significant increase in 

emissions is squarely within the purpose of the CAA. 

On the whole, Courts have found broad authority for EPA to exempt minor sources of 

emissions when a strict legal application would provide little or no benefit. Given the limited 

emissions impacts from combusting materials generated in the regular operation of the boiler, 

EPA’s de minimis authority allows it to exempt units combusting those materials from 

application of Section 129. 

B. EPA Allows Similar De Minimis Exemptions Under the Solid Waste Rule and 

Other Rules Under RCRA 

EPA already uses its de minimis authority under RCRA, and, indeed, has applied it in the 

Solid Waste Rule. EPA allows a de minimis exemption for contaminants, including paper, 

 

17 Id. at 1534-35 (emphasis added). 
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insulation and other items which may be included in construction wastes demolition derived 

wood (“C&D wood”): 

C&D-derived wood can contain de minimis amounts of 

contaminants and other materials provided it meets the legitimacy 

criterion for contaminant levels.18 

EPA has also applied its de minimis authority under RCRA in the hazardous waste context, 

allowing listed wastes to be discharged to a wastewater treatment facility as long as the total 

concentration of the chemicals does not exceed a certain threshold.19 EPA allows similar 

exemptions from characterization as solid wastes for condensates derived from overhead gases 

from kraft mill steam strippers that are used to comply with 40 C.F.R. § 63.446(e) where the 

exemption applies only to combustion at the mill generating the condensates, 40 C.F.R. § 

262.4(a)(16), or pulping liquors that are reclaimed in a pulping liquor recovery furnace and then 

reused in the pulping process, 40 C.F.R. § 261.4(a)(6). One of the requirements under 40 C.F.R. 

§ 63.446(e) is for the condensate to be treated so it is either managed in specified equipment or 

in a manner that ensures the HAPs are destroyed to specified levels. Similar requirements could 

be used in a de minimis exemption under Section 129, limiting any exemption to onsite materials 

that do not significantly impact emissions. 

C. An Exemption for Materials Generated in the Course of Normal Boiler 

Operations Would Fit Squarely Within the Scope of EPA’s De Minimis

Authority 

1. The Emissions Impacts of an Exemption Would Be Trivial 

Combusting and evaporating boiler cleaning wastes and other materials generated in the 

course of normal boiler operations is standard practice, and currently part of most electrical 

generating units’ air permits in North America.20 Allowing this practice to continue would not 

increase emissions. Further, without a de minimis exemption, to maintain their status as 

generators, not incinerators, generating unit operators would be required to transport cleaning 

wastes and other materials to an offsite disposal site, incurring additional expenses, generating 

 

18 See Solid Waste Rule at 15,487. 

19 See 40 C.F.R. 261.3 (a)(2)(iv)(F) and (G). 

20 See ELECTRIC POWER RESEARCH INSTITUTE, GUIDELINES FOR CHEMICAL CLEANING OF CONVENTIONAL 

FOSSIL PLANT EQUIPMENT, 9-4 (2001). 
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more emissions in the process, creating potential safety issues associated with transportation of 

materials, and disposing of the wastes without necessarily destroying them. 

There is little to no environmental benefit to requiring alternate disposal of materials in 

control of the generator that have only a de minimis impact on emissions. The emissions impact 

from evaporating boiler cleaning materials, for example, is comparatively small and the resulting 

total variation in emission of pollutants from their combustion would likely be similar to that 

from normal variation resulting from differences in coal composition.21 Emissions tests of the 

electrostatic precipitator outlet flue gas conducted by the Electric Power Research Institute 

(“EPRI”) during evaporation of boiler cleaning wastes showed no statistically significant 

increases in metal concentrations over baseline data. In addition, the concentrations of NOx, 

HCl, and HF present in the flue gas were also not statistically affected.22 In monitoring studies 

conducted by EPRI on evaporation of boiler cleaning wastes in utility boilers, chromium levels 

in the stack gas were 0.076 lb/hr at baseline vs. 0.080 lb/hr during evaporation.23 Chromium is 

the metal typically of the highest concentration in boiler cleaning wastes and the boiler cleaning 

wastes are tested prior to combustion to ensure the concentrations are below the hazardous level. 

Results for other metals, PM, and trace organics were similarly low.24 

Water treatment resins are used to demineralize boiler feed water. Like home water 

softeners, utility-scale water treatment resins are used to remove minerals and other compounds 

that would lead to scaling and clogging of boiler equipment. Although resins can be reused 

multiple times, they eventually become spent and can no longer effectively cycle to capture 

minerals and release them, at which point they must be replaced. Resins typically have 

significant fuel value, and are relatively low in contaminants, as they are repeatedly flushed to 

remove mineral contents. Further, any contaminants they contain would be from the water 

supply, not the fuel supply, and thus with limited potential for hazardous materials to be 

included. 

 

21 See ELECTRIC POWER RESEARCH INSTITUTE, BOILER CHEMICAL CLEANING WASTE MANAGEMENT MANUAL

3-6 (1992). 

22 Id. at 8-15. 

23 Id. at 8-16. 

24 Id. 
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Indeed, boiler cleaning wastes and other non-hazardous materials have routinely been 

allowed to be evaporated in onsite utility boilers because they do not appreciably increase 

emissions and thus pose minimal risk to the environment. As an example, EME provides the 

following permit condition, included in its Illinois facility air operating permits: 

The permittee is allowed to burn boiler cleaning wastes only when 

the boiler is in a normal mode of operation and generating no less 

than 105 megawatts (gross). Burning of boiler cleaning wastes is 

not allowed during startup, shutdown, malfunction or breakdown.25 

Operating information submitted by the generating station to obtain the permit indicates that to 

ensure steady boiler operations, the maximum boiler cleaning waste feed rate to the boilers is up 

to 200 gpm depending on the size of the unit.26 

With respect to the volumes of onsite generated materials such as boiler cleaning wastes 

that would be evaporated in the boilers, EME’s experience is that the waste volumes range from 

approximately 250 to 1835 tons per boiler per boiler cleaning event, but would only be fed to the 

boiler at a rate of up to 0.8 tons per minute.27 This contrasts with a total amount of coal burned 

on average in each boiler of between 1,420 and 8,220 tons per day. The boiler cleaning 

frequency can vary from every two to ten years, depending on the type of boiler and the coal 

burned. Other materials generated include resins from water treatment; however, those materials 

are even more limited in amounts than the boiler cleaning wastes. Regardless, the annual 

amount of boiler cleaning wastes generated for each individual boiler is relatively small – a mere 

fraction of a percent on an annual basis – even assuming boilers are cleaned every year, which 

they are not. 

The application of de minimis authority where emissions impacts are trivial is consistent 

with how courts have addressed the authority in the context of similar situations. As in EDF, 

here a de minimis exemption for materials generated in the normal course of boiler operation 

 

25 EME’s IL station permits all include the same language, but this was taken from Crawford Unit 7’s permit. 

Crawford Unit 7, Crawford Electric Generating Station, Operating Permit, Special Condition 14 (June 25, 

2001). 

26 Id. 

27 Assuming boiler cleaning wastes have the same density as water. 
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would have minimal or no impact on the level of emissions. Since this does not affect the 

purpose of the CAA, i.e. reducing emissions, allowing such an exemption would be a proper 

exercise of EPA’s de minimis authority. 

2. NRDC V. EPA Does Not Address EPA’s De Minimis Authority. 

Although NRDC v. EPA rejected EPA’s position that energy recovery facilities should be 

regulated under Boiler MACT (rather than CISWI) even if they burned solid wastes, that 

decision is not controlling as to EPA’s ability to exempt these small amounts of secondary 

materials with trivial to no emissions impacts from rendering a boiler subject to CISWI. NRDC 

v. EPA did not address a de minimis argument, but was instead dealing with a significant 

regulatory interpretation exempting all energy recovery facilities from Section 129 of the CAA.28 

The court found that EPA’s interpretation of the unambiguous statute was invalid under Chevron 

Step 1.29 Although the court in NRDC found the term “any” in the “solid waste incineration 

unit” definition to be instructive to invalidate EPA’s interpretation exempting all generators of 

electricity from the Section 129 rules, no matter how much waste they burned, as noted above in 

numerous statutory and regulatory contexts, the term “any” does not restrict EPA’s de minimis 

authority.30 This is the same conclusion that the court reached in New York v. EPA, where the 

court overturned EPA’s statutory interpretation as a violation of an unambiguous statute, but 

upheld EPA’s de minimis authority.31

3. Requiring Application of Section 129 to De Minimis Amounts of 

Secondary Materials Would Be a Mandate of Pointless Expenditure 

While the volumes of solvents are minuscule compared to the overall volume of fuel 

burned, the costs of the disposal for a boiler cleaning event can exceed $1 million per event in 

EME’s experience, and as a result the costs to the industry may exceed $50 million per year. 

The amounts generated that would require offsite disposal are estimated at 125,100 tons per 

year.32 This compares to annual coal burned of over 1 trillion tons per year. EME questions 

 

28 See NRDC v. EPA, 489 F. 3d 1250 1257-60 (D.C. Cir. 2007). 

29 Id. at 1257-58. 

30 See id. 

31 See New York v. EPA, 443 F.3d 880 883-84 (D.C. Cir. 2006).

32 Again assuming the density of boiler cleaning wastes is identical to water. 
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whether there is sufficient treatment capacity for this volume of material, which EPA may not 

have considered because the volumes and frequency of occurrence per facility are relatively low. 

As in Alabama Power, the flexibility to prevent these kinds of needless expenditures and 

unnecessary burdens are exactly the reasons that the courts originally applied de minimis

exemptions. Given the trivial impact on emissions, the environmental and economic costs 

generated by treating generators as incinerators because of common utility practice is simply not 

justified. EME requests that EPA apply its de minimis authority to prevent this unnecessary 

regulatory burden. 

4. The Text of Section 129 of the Clean Air Act is Not “Uncompromisingly 

Rigid” 

In Section 129, the key term for application of the incinerator standards is the definition 

of “solid waste incineration unit”: 

“a distinct operating unit of any facility which combusts any solid 

waste material from commercial or industrial establishments or the 

general public (including single and multiple residences, hotels, 

and motels).”33 

While clearly broad, the definition is not so restrictive as to prevent a de minimis exemption, and 

is similar to the provisions for which courts have allowed exemptions under the CAA and 

CERCLA. Specifically, in New York v. EPA, the court recognized EPA’s inherent de minimis 

authority notwithstanding the language “any modification.”34 The D.C. Circuit in EDF also 

allowed an exemption from the broad “any activity which does not conform to an 

implementation plan after it has been approved or promulgated” when increases in emissions 

were trivial. 35 Finally, in Ohio v. EPA, the court upheld EPA’s de minimis authority to only 

monitor sites with minimal contamination despite the language of CERCLA that required 

monitoring of any sites with “any hazardous substances.”36 

 

33 CAA § 129 (g)(1) (portions omitted). 

34 See New York v. EPA, 443 F.3d 880 883-84 (D.C. Cir. 2006) (decided on other grounds) (emphasis added). 

35 See Environmental Def. Fund, Inc., v. EPA (“EDF”), 82 F.3d 451 (D.C. Cir. 1996)(quoting CAA § 

176(c)(1), 42 U.S.C. § 7506(c)(1)) (emphasis added). 

36 See Ohio v. EPA, 997 F.2d 1520, 1535 (D.C. Cir. 1993) (emphasis added). 
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The definition also includes several more general exemptions, such as for air curtain 

incinerators burning solely wood and yard wastes, qualifying cogeneration facilities, and 

materials recovery facilities, further supporting a conclusion that Congress did not intend an 

“uncompromisingly rigid” application of the provision.37 Rather, the intent of the section overall 

is to protect public health by limiting emissions, by means of numerical limits on particular 

facilities.38 Applying EPA’s de minimis authority will not frustrate, and has the potential to 

further, the goals of the statute. EME respectfully requests that EPA do so here. 

IV. GRANTING EME’S RECONSIDERATION REQUEST WOULD SERVE THE 

GOALS OF EXECUTIVE ORDER 13,563 

President Obama’s Executive Order 13563, “Improving Regulation and Regulatory 

Review,” 76 Fed. Reg. 3821 (Jan. 18, 2011), reaffirms and expands upon Executive Order 

12866, “Regulatory Planning and Review,” 58 Fed. Reg. 51,735 (Sept. 30, 1993). In the new 

Executive Order, President Obama ordered federal agencies to take several actions to improve 

the federal regulatory system. Among these, agencies must: 

 “propose or adopt a regulation only upon a reasoned determination that its 

benefits justify its costs (recognizing that some benefits and costs are difficult to 

quantify),” 

 “use the best available techniques to quantify anticipated present and future 

benefits and costs as accurately as possible,” 

 “tailor its regulations to impose the least burden on society ...,” 

 “identify and consider regulatory approaches that reduce burdens and maintain 

flexibility and freedom of choice for the public,” and 

 “consider how best to promote retrospective analysis of rules that may be 

outmoded, ineffective, insufficient, or excessively burdensome, and to modify, 

streamline, expand, or repeal them ....” 

Exec. Order 13563, 76 Fed. Reg. at 3821-22. 

 

37 Id. 

38 See CAA § 129 (a)(3) (directing the Administrator to set standards protective of the public health and the 

environment).
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In responding to this Executive Order, EPA focused its request for comments on the final 

bullet point above addressing the “retrospective analysis” of existing regulations. See 76 Fed. 

Reg. 9988. EME submitted comments addressing the CISWI Rule to EPA’s review docket 

requesting retrospective analysis and revision. The exercise of EPA’s de minimis authority 

requested by EME would serve to further the goals of the executive order in numerous ways. 

First, the costs of treating generators as incinerators as a result of de minimis amounts of 

secondary materials far outweigh the benefits to the public of such treatment. EME estimates 

that each boiler clean would generate up to $1 million in disposal costs, for an estimated $50 

million in annual disposal costs throughout the industry. The emissions impacts are minimal, 

and less than that caused by regular variation in the coal fuel stream.39 By eliminating costs of 

approximately $50 million annually, without reducing benefits, this flexibility could help 

increase the costs to benefits ratio of this expensive rule. 

Second, a de minimis exemption for the on-site combustion of boiler cleaning wastes and 

other materials generated in the course of normal boiler operation, such as water treatment resins, 

would “tailor[ the] regulations to impose the least burden.” By granting flexibility in dealing 

with these secondary materials, EPA can also preserve the disposal options and capacity 

available for other uses. As discussed above, exemption of these materials is squarely within the 

courts’ traditional interpretation of EPA’s de minimis authority, which is further buttressed by 

the Executive Order. As a result, EME requests that EPA should apply its regulatory flexibility 

and grant a de minimis exception here. 

V. CONCLUSION 

Consistent with the cases upholding EPA’s de minimis authority, and the reasons 

discussed above, EME respectfully requests that EPA reconsider the CISWI Rule and exercise its 

authority here to prevent the unnecessary expense of regulating electric generators as incinerators 

for combusting on-site materials generated in the course of normal boiler operations. 

 DC\1451424.5 

 

39 See ELECTRIC POWER RESEARCH INSTITUTE, BOILER CHEMICAL CLEANING WASTE MANAGEMENT MANUAL

3-6 (1992).