ENVIRONMENTAL PROTECTION AGENCY 

[EPA-HQ-RCRA-2008-0329] 

RIN 2050-AG44 

Advanced Notice of Proposed Rulemaking – Identification of Non-Hazardous 

Materials That Are Solid Waste 

AGENCY: Environmental Protection Agency (EPA). 

ACTION: Advanced Notice of Proposed Rulemaking (ANPRM). 

SUMMARY: The Environmental Protection Agency (EPA or Agency) is seeking 

comment on which non-hazardous materials are or are not solid waste under the Resource 

Conservation and Recovery Act (RCRA). The Agency is also seeking comment on a 

number of specific questions concerning the meaning of “solid waste” under RCRA, as it 

applies to non-hazardous waste programs. We are issuing this ANPRM to assist the 

Agency in developing certain standards under sections 112 and 129 of the Clean Air Act 

(CAA). The meaning of “solid waste” as defined under RCRA is of particular 

importance since CAA section 129 states that the term “solid waste” shall have the 

meaning “established by the Administrator pursuant to [RCRA].” 

DATES: Comments must be received on or before [Insert date 30 days from the date 

of publication of this notice in FR]. 

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-RCRA2008-0329, by one of the following methods: 

• http://www.regulations.gov: Follow the on-line instructions for submitting 

comments. 
2

• E-mail: Comments may be sent by electronic mail (e-mail) to: rcradocket@epa.gov, Attention Docket ID No.EPA-HQ-RCRA-2008-0329. In contrast to 

EPA's electronic public docket, EPA's e-mail system is not an “anonymous access'' 

system. If you send an e-mail comment directly to the docket without going through 

EPA's electronic public docket, EPA's e-mail system automatically captures your e-mail 

address. E-mail addresses that are automatically captured by EPA's e-mail system are 

included as part of the comment that is placed in the official public docket, and made 

available in EPA's electronic public docket. 

• Fax: Comments may be faxed to 202-566-9744, Attention Docket ID No.EPAHQ-RCRA-2008-0329. 

• Mail: Advanced Notice of Proposed Rulemaking - Identification of NonHazardous Materials That Are Solid Waste, Environmental Protection Agency, Mail 

code: 2822T, 1200 Pennsylvania Ave., NW. Washington, DC 20460. Please include a 

total of two copies. Attention Docket ID No. EPA-HQ-RCRA-2008-0329. 

• Hand Delivery: Deliver two copies of your comments to the Advanced Notice 

of Proposed Rulemaking - Identification of Non-Hazardous Materials That Are Solid 

Waste, EPA/DC, EPA West, Room 3334, and 1301 Constitution Ave., N.W., 

Washington, D.C. 20460. Attention Docket ID No. EPA-HQ-RCRA-2008-0329. Such 

deliveries are only accepted during the docket's normal hours of operation (8:30 a.m. to 

4:30 p.m., Monday through Friday, excluding legal holidays), and special arrangements 

should be made for deliveries of boxed information. 

Instructions: Direct your comments to Docket ID No. EPA-HQ-RCRA-2008-0329. 

EPA's policy is that all comments received will be included in the public docket without 
3

change and may be made available online at http://www.regulations.gov, including any 

personal information provided, unless the comment includes information claimed to be 

Confidential Business Information (CBI) or other information whose disclosure is 

restricted by statute. Do not submit information that you consider to be CBI or otherwise 

protected through http://www.regulations.gov or e-mail. The http://www.regulations.gov

website is an “anonymous access” system, which means EPA will not know your identity 

or contact information unless you provide it in the body of your comment. If you send an 

e-mail comment directly to EPA without going through http://www.regulations.gov, your 

e-mail address will be automatically captured and included as part of the comment that is 

placed in the public docket and made available on the Internet. If you submit an 

electronic comment, EPA recommends that you include your name and other contact 

information in the body of your comment and with any disk or CD-ROM you submit. If 

EPA cannot read your comment due to technical difficulties and cannot contact you for 

clarification, EPA may not be able to consider your comment. Electronic files should 

avoid the use of special characters, any form of encryption, and be free of any defects or 

viruses. For additional information about EPA's public docket, visit the EPA Docket 

Center homepage at http://www.epa.gov/epahome/dockets.htm. We also request that 

interested parties who would like information they previously submitted to EPA to be 

considered as part of this action, identify the relevant information by docket entry 

numbers and page numbers. 

Docket: All documents in the docket are listed in the www.regulations.gov index. 

Although listed in the index, some information is not publicly available, e.g., CBI or 

other information whose disclosure is restricted by statute. Certain other material, such 
4

as copyrighted material, will be publicly available only in hard copy. Publicly available 

docket materials are available either electronically in www.regulations.gov or in hard 

copy at the OSWER Docket, EPA/DC, EPA West, Room 3334, 1301 Constitution Ave., 

N.W., Washington DC. The Public Reading Room is open from 8:30 a.m. to 4:30 p.m., 

Monday through Friday, excluding legal holidays. The telephone number for the Public 

Reading Room is (202) 566-1744, and the telephone number for the OSWER Docket is 

202-566-0270. 

FOR FURTHER INFORMATION CONTACT: For questions regarding the 

development of this ANPRM, contact Michael Galbraith, Office of Solid Waste (5302P), 

U.S. Environmental Protection Agency, Ariel Rios Building, 1200 Pennsylvania Avenue, 

N.W., Washington, D.C. 20460-0002, telephone (703) 605-0567, e-mail address: 

galbraith.michael@epa.gov. 

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me? 

Categories and entities potentially affected by this action include: 
5

Generators Users 

Major Generator 

Category 

NAICS 

Major Boiler Type 

and Primary 

Industry Category 

NAICS 

Iron and Steel Mills 331111 Industrial Boilers:

 Food Manufacturing 311, 312, 

Scrap Tires Pulp and Paper Mills 322, 

Passenger cars and 

trucks N/A Chemicals and Allied Products 325, 

Other rubber product 

manufacturing 326290 Petroleum Refining 324 

 Metals 331, 332 

Logging 113310 Other Manufacturing 313, 339, 321, 333, 336, 

511, 326, 316, 327 

Sawmills and Wood 

Preservation 32111 

Veneer, Plywood, and 

Engineered Wood 

Product Manufacturing 

32121 Commercial Boilers:

Pulp, Paper, and 

Paperboard Mills 3221 Office 813,541,921 

Cattle Ranching and 

Farming 1121 Warehouse 421,422 

Hog and Pig Farming 1122 Retail 441, 445-454 

Poultry and Egg 

Production 1123 Education 611 

Sheep and Goat Farming 1124 Public Assembly 624, 

Horses and Other 

Equine Production 112920 Lodging, Restaurant 721, 722 

Crop Production 111 Health Care Facilities 621 

Support Activities for 

Crop Production 11511 Other 922140, others 

Food Manufacturing 311 

Beverage and Tobacco 

Product Manufacturing 312 Common Non- Manufacturing Boilers:

Construction of 

Buildings 236

Agriculture (crop & 

livestock production) 111,112,115 

Site Preparation 

Contractors 238910 All Mining 212,211 

Landscaping Services 561730 Construction 235 

Iron and Steel Mills. 

331111 

Fossil Fuel Electric 

Power Generation 221112 Other Boilers:

Cement Manufacturing 327310 Electric Utility Boilers 221100 

Bituminous Coal and 212111
6

Lignite Surface Mining 

Bituminous Coal 

Underground Mining 212112

Non HW Burning 

Cement Kilns 327310 

Anthracite Mining 212113 

Sewage Treatment 

Facilities 221320 

Solid Waste Landfill 562212 

metal-casting industry 3115

Glass and Glass Product 

Manufacturing 3272

Packaging 32611

Plastic manufacturers 325211 

Electrometallurgical 

Ferroalloy Product 

Manufacturing

331112 

Recycling services for 

degreasing solvents 

manufacturing

325998 

Solvent dyes 

manufacturing 325132 

Solvents made in 

petroleum refineries; and 324110 

Automotive repair and 

replacement shops. 811111 

This table is not intended to be exhaustive, but rather provides a guide for readers 

regarding entities likely to be impacted by this action. This table lists examples of the 

types of entities of which EPA is aware that could potentially be affected by this action. 

Other types of entities not listed could also be affected. To determine whether your 

facility, company, business, organization, etc., is affected by this action, you should 

examine the applicability criteria in this rule. If you have any questions regarding the 

applicability of this action to a particular entity, consult the person listed in the preceding 

FOR FURTHER INFORMATION CONTACT section. 

B. What Should I Consider as I Prepare My Comments for EPA?

 1. Submitting CBI. Do not submit this information to EPA through 

www.regulations.gov or e-mail. Clearly mark the part or all of the information that you 

claim to be CBI. For CBI information in a disk or CD ROM that you mail to EPA, mark 
7

the outside of the disk or CD ROM as CBI and then identify electronically within the disk 

or CD ROM the specific information that is claimed as CBI. In addition to one complete 

version of the comment that includes information claimed as CBI, a copy of the comment 

that does not contain the information claimed as CBI must be submitted for inclusion in 

the public docket. Information so marked will not be disclosed except in accordance with 

procedures set forth in 40 CFR part 2. 

2. Tips for Preparing Your Comments. When submitting comments, remember 

to: 

• Identify the rulemaking by docket number and other identifying 

information (subject heading, Federal Register date and page number). 

• Follow directions - The agency may ask you to respond to specific 

questions or organize comments by referencing a Code of Federal 

Regulations (CFR) part or section number. 

• Explain why you agree or disagree, suggest alternatives, and substitute 

language for your requested changes. 

• Describe any assumptions and provide any technical information and/or 

data that you used. 

• If you estimate potential costs or burdens, explain how you arrived at your 

estimate in sufficient detail to allow for it to be reproduced. 

• Provide specific examples to illustrate your concerns, and suggest 

alternatives. 

• Explain your views as clearly as possible, avoiding the use of profanity or 

personal threats. 
8

• Make sure to submit your comments by the comment period deadline 

identified. 

II. Background 

 The United States Court of Appeals for the District of Columbia Circuit vacated 

and remanded two Agency rules promulgated under the CAA — The Commercial and 

Industrial Solid Waste Incineration (CISWI) definitions rule (“CISWI Definitions Rule”), 

issued under CAA section 129, and the Industrial Boilers Maximum Achievable Control 

Technology (MACT) standards rule (“Boilers Rule”), issued under CAA section 112. 

The court concluded that EPA erred by excluding units that combust solid waste for the 

purposes of energy recovery from the Definitions Rule and including such units in the 

Boilers Rule. In response to the court’s decision, EPA is preparing to establish new 

standards under CAA sections 112 and 129 for the various units subject to each section. 

Congress added section 129 to the CAA in 1990 specifically to address emissions 

from solid waste combustion. CAA section 129 directs EPA to promulgate emission 

standards for “solid waste incineration units.” 42 U.S.C. § 7429(a)(1). The term “solid 

waste incineration unit” is defined, in pertinent part, to mean “any facility which 

combusts any solid waste material from commercial or industrial establishments...” Id. at 

§ 7429(g)(1). However, the CAA excludes the following types of units from 

classification as solid waste incineration units that are subject to the section 129 

standards: (1) incinerators or other units required to have a permit under section 3005 of 

RCRA; (2) materials recovery facilities (including primary and secondary smelters) 

which combust waste for the primary purpose of recovering metals; (3) qualifying small 

power production facilities, as defined in section 3(17)(C) of the Federal Power Act, or 
9

qualifying cogeneration facilities, as defined in section 3(18)(B) of the Federal Power 

Act, which burn homogeneous waste (such as units which burn tires or used oil, but not 

including refuse-derived fuel) for the production of electric energy or in the case of 

qualifying cogeneration facilities which burn homogeneous waste for the production of 

electric energy or steam or forms of useful energy (such as heat) which are used for 

industrial, commercial, heating or cooling purposes, or (4) air curtain incinerators, 

provided that such incinerators only burn wood wastes, yard wastes and clean lumber and 

that such air curtain incinerators comply with the opacity limitations to be established by 

the Administrator by rule. CAA section 129 also states that the term “solid waste” shall 

have the meaning “established by the Administrator pursuant to the Solid Waste Disposal 

Act” Id. at 7429(g)(6).1

 RCRA defines the term “solid waste” to mean “...any garbage, 

refuse, sludge from a waste treatment plant, water supply treatment plant, or air pollution 

control facility and other discarded material including solid, liquid, semisolid, or 

contained gaseous material resulting from industrial, commercial, mining, and 

agricultural operations, and from community activities, but does not include solid or 

dissolved material in domestic sewage, or solid or dissolved materials in irrigation return 

flows or industrial discharges which are point sources subject to permits under section 

402 of the Federal Water Pollution Control Act, as amended (86 Stat. 880), or source, 

special nuclear, or byproduct material as defined by the Atomic Energy Act of 1954, as 

amended (68 Stat. 923).” Section 1004 (27). 

A. CISWI Rule/CISWI Definitions Rule/Boiler Rule 

 

1 CAA section 129 refers to the Solid Waste Disposal Act (SWDA). However, this act, as amended is 

commonly referred to as RCRA. Thus, the term, "RCRA" is used in place of SWDA in this Notice. 
10

 EPA fulfilled its statutory obligation under CAA section 129 when it promulgated 

a final rule setting forth performance standards and emission guidelines (EG) for 

Commercial and Industrial Solid Waste Incineration Units (referred to as the “CISWI 

Rule”). 65 FR 75338 (December 1, 2000). Under CAA section 129, the New Source 

Performance Standards (NSPS) and EG adopted for CISWI units must reflect the 

maximum degree of reduction in emissions of air pollutants that the Administrator 

determines is achievable, taking into consideration the cost of achieving such emission 

reduction, and any non-air quality health and environmental impacts and energy 

requirements. This level of control is commonly referred to as MACT. The 

Administrator may also distinguish among classes, types (including mass-burn, refusederived fuel, modular and other types of units), and sizes of units within a category in 

establishing such standards. Id. at 7429(a)(2).

NSPS apply to new stationary sources-- that is, sources whose construction begins 

after the NSPS is proposed or sources that are reconstructed or modified on or after a 

specified date. The EG are similar to the NSPS, except that they apply to existing 

sources-- that is, sources whose construction begins on or before the date the EG are 

proposed, or sources that are reconstructed or modified before a specified date. Unlike 

NSPS, the EG are not enforceable until EPA approves a state plan or adopts a federal 

plan for implementing and enforcing them, and the state or federal plan becomes 

effective. 

The CISWI Rule established emission limitations for new and existing CISWI 

units for the following pollutants (or surrogates): cadmium, carbon monoxide, 

dioxins/furans, hydrogen chloride, lead, mercury, oxides of nitrogen (NOx), particulate 

Deleted: rule 
11

matter (PM), sulfur dioxide (SO2), and opacity. In addition, the rule established certain 

monitoring and operator training and certification requirements. See 65 FR 75338 for a 

more detailed discussion of the CISWI Rule. 

 The CISWI Rule was subject to judicial challenge in Sierra Club v. EPA (No. 01-

1048) (D.C. Cir.) and a separate petition for reconsideration of the final rule. The 

petition argued that the final rule was procedurally defective because EPA had failed to 

provide adequate notice and an opportunity to comment on the definitions adopted in the 

final rule. Also, after promulgation of the CISWI Rule, the court issued its decision in 

Cement Kiln Recycling Coalition v. EPA, 255 F.3d 855 (D.C. Cir. 2001) (“Cement 

Kiln”). In this decision, the court rejected certain common elements of EPA’s MACT 

methodology. As a result, EPA requested a voluntary remand of the CISWI Rule, in 

order to address concerns related to the issues that were raised by the court in Cement 

Kiln. The court granted the voluntary remand and remanded, without vacatur, the CISWI 

Rule back to EPA, thereby terminating the case (see Order dated September 6, 2001). 

Because the CISWI Rule was not vacated, its requirements remain in effect. See Sierra 

Club. v. EPA, 374 F. Supp.2d 30, 32-33 (D.D.C. 2005). In addition to taking a voluntary 

remand of the CISWI Rule, EPA also granted an administrative petition for 

reconsideration on February 17, 2004 related to the definitions of “solid waste,” 

“commercial or industrial waste” and “commercial and industrial solid waste incineration 

unit” in the CISWI Rule. 

 EPA responded to the petition for reconsideration on September 22, 2005, by repromulgating the definitions of “solid waste,” “commercial or industrial solid waste 

incineration unit” and “commercial or industrial waste” (the CISWI Definitions Rule). 

Deleted: (CISWI) 

Deleted: referred to as 

Deleted: “

Deleted: ”
12

See 70 FR 55568. In the CISWI Definitions Rule, EPA distinguished solid waste 

incinerators from boilers/furnaces based on the function of the units. Solid waste 

incinerators included units designed and operated to discard materials through high 

temperature combustion, but excluded units designed and operated to recover energy for 

a useful purpose. 

 The CISWI Definitions Rule was the subject of judicial challenge in NRDC v. 

EPA (489 F.3d 1250 (D.C. Cir. 2007)) where the court vacated the definitions of 

“commercial or industrial solid waste incineration unit” and “commercial or industrial 

waste.” The court observed that, although the functional distinction EPA drew between 

boilers/furnaces and incinerators “may well be reasonable,” the statute unambiguously 

requires any unit that combusts “any solid waste material at all” – regardless of whether 

the material is being burned as a fuel – to be regulated as a “solid waste incineration 

unit.” Id. at 1260. The court also vacated and remanded the Boilers Rule, concluding 

that EPA erred by excluding units that combust solid waste for the purposes of energy 

recovery from the CISWI Rule and including such units in the Boilers Rule. 

Therefore, the critical issue in responding to the court's decision is for EPA to 

establish, under RCRA, which non-hazardous secondary materials2

 constitute “solid 

waste.” This is necessary because, under the court’s decision, any unit combusting any 

“solid waste” at all must be regulated as a “solid waste incineration unit,” regardless of 

the function of the combustion device. If a non-hazardous material is not a “solid waste” 

under RCRA and such material is burned for fuel value or used as an ingredient in a 

 

2

 A secondary material is any material that is not the primary product of a manufacturing or commercial 

process, and can include post-consumer material, post-industrial material, and scrap. Many types of 

secondary materials have Btu or material value, and can be reclaimed or reused in industrial processes. For 

purposes of this notice, the term secondary materials include only non-hazardous secondary materials.

Deleted: that rule
13

manufacturing process, then under the court’s decision, the combustion unit would 

properly be regulated pursuant to CAA section 112. Alternatively, if such material is a 

“solid waste” under RCRA and is burned for fuel value or used as an ingredient in a 

manufacturing process and such ingredient is combusted, then the unit must be regulated 

under CAA section 129. 

B. Sections 112 and 129 of the CAA

CAA section 112 requires EPA to promulgate regulations to control emissions of 

1873

 hazardous air pollutants (HAP) from major sources4 in each source category listed 

by EPA under section 112(c). The statute requires the regulations to reflect the 

maximum degree of reduction in emissions of HAP that is achievable taking into 

consideration the cost of achieving the emission reduction, any non-air quality health and 

environmental impacts, and energy requirements. As noted previously, this level of 

control is commonly referred to as MACT. 

For new sources, MACT standards cannot be less stringent than the emission 

control achieved in practice by the best-controlled similar source (see CAA section 

112(d)(3)). The MACT standards for existing sources cannot be less stringent than the 

average emission limitation achieved by the best-performing 12 percent of existing 

sources for categories and subcategories with 30 or more sources, or the best-performing 

5 sources for categories or subcategories with fewer than 30 sources (Id). This level of 

control is usually referred to as the MACT ‘‘floor,’’ the term used in the Legislative 

History. 

 

3

 EPA has delisted 3 of the 190 HAP initially listed in section 112(b)(1): Methyl ethyl ketone, glycol 

ethers, and caprolactam. 

4

 A “major source” is any stationary source that emits or has the potential to emit considering controls, in 

the aggregate, 10 tons per year or more of any HAP or 25 tons per year or more of any combination of 

HAP. CAA section 112(a)(1). 

Deleted: 186
14

 Like the CAA section 112 standards, the CAA section 129 standards are based on 

a MACT floor. Also, as with the section 112 standards, above-the-floor standards may 

be established where EPA determines it is “achievable” taking into account costs and 

other factors. Although CAA section 129 “establishes emission requirements virtually 

identical to section [112’s],” Nat’l Lime Ass’n v. EPA, 233 F.3d at 631, the two sections 

differ in three primary respects. First, CAA section 112 requires that MACT standards be 

established for major sources of HAP emissions, but provides discretionary authority to 

establish MACT standards for area sources of HAP emissions.5

 On the other hand, the 

CAA section 129 MACT standards apply across the board to all solid waste incineration 

units in a given category regardless of size. Second, CAA section 129 requires that 

emission standards be set for specific HAP and certain pollutants that are not classified as 

CAA section 112 HAP.6

 Specifically, CAA section 129 requires numeric emission 

limitations for the following nine pollutants: cadmium, carbon monoxide, dioxins/furans, 

hydrogen chloride, lead, mercury, NOx, particulate matter (total and fine), opacity (as 

appropriate), and SO2.

7

 The CAA section 129 pollutants listed above represent the 

minimum that must be regulated; EPA has the discretion to establish standards for other 

pollutants as well. Third, CAA section 129 includes requirements for operator training, 

pre-construction site assessments, and monitoring that are not included in CAA section 

 

5

 An “area source” is any stationary source of HAP that is not a major source. CAA section 112(a)(2). 

Area sources may be regulated under CAA section 112(d)(2) standards if the Administrator finds that the 

sources “presen[t] a threat of adverse effects to human health or the environment (by such sources 

individually or in the aggregate) warranting regulation under this section.” Section 112(c)(3). Certain 

categories of area sources must be regulated in accordance with section 112(c)(3) and (k)(3)(B). 

6

 This is in reference to the initial list of 190 HAPs provided by Congress. 

7 Of these nine pollutants, cadmium, dioxins/furans, hydrogen chloride, lead, and mercury are also 

regulated HAP pursuant to CAA section 112, and particulate matter and carbon monoxide are commonly 

used as surrogate emission standards to control specific CAA section 112 HAP (e.g., CAA section 112 

HAP metal and organic emissions). 
15

112. See CAA section 129 (a)(3), (c) and (d). Rather, CAA section 112’s implicit 

authority and CAA sections 113 and 114’s explicit authority is relied upon to include 

provisions as necessary to assure compliance with and enforcement of the emission 

limitations. It is important to note that CAA section 129 (h)(2) specifies that no solid 

waste incineration unit subject to the performance standards under CAA sections 111 and 

129 shall be subject to the standards under CAA section 112(d). 

III. Beneficial Use of Secondary Materials 

A. Introduction 

 EPA supports exploring regulatory alternatives that achieve the following goals: 

maximizing the usefulness of secondary materials in production, reducing or eliminating

waste, conserving energy, and reducing harmful air emissions. Such alternatives should 

ensure protection of human health and the environment, and one alternative would be an 

integrated management approach that includes emissions and source reduction and 

recycling, as well as energy capture and resource recovery from secondary materials. For 

example, within the context of RCRA,8

 the Agency seeks to achieve these goals through 

promotion of the use or reuse of various secondary materials, provided such reuse activity 

is protective of human health and the environment. EPA seeks to accomplish this in 

conjunction with our state partners through research, analysis, communication, and 

outreach.

 To help put this discussion into context, the Agency notes that non-hazardous 

secondary materials are widely used today as fuels or ingredients in industrial processes. 

 

8

 RCRA Section 6901(c) – Materials: The Congress finds with respect to materials, that—(1) millions of 

tons of recoverable material which could be used are needlessly buried each year;(2) methods are available 

to separate usable materials from solid waste; and (3) the recovery and conservation of such materials can 

reduce the dependence of the United States on foreign resources and reduce the deficit in its balance of 

payments. 

Deleted: strongly 

Deleted: a sustainable materials 

management system

Deleted: maximizes

Deleted: reduces 

Deleted: eliminates

Deleted: conserves

Deleted: reduces 

Deleted: of greenhouse gas (GHG)

Deleted: a system must 

Deleted: while employing 

Deleted: help facilitate a sustainable 

management system
16

We expect this trend will continue with higher prices for energy and materials and 

advancing technology in secondary material use.

 The nature of what constitutes a legitimate fuel or ingredient reflects the 

availability of natural resources and technology development. The use of materials from a 

variety of non-traditional sources, including the use of energy-containing secondary 

materials, may have a significant role to play in our resource conservation efforts. 

The use of non-hazardous secondary materials as alternative fuels and ingredients 

in manufacturing processes using combustion has a long history, and is increasingly 

becoming an accepted characteristic of the modern industrial economy.

10 Under

conditions in the past, many secondary materials may have been managed as wastes—

that is, they were discarded. However, if the cost of fossil fuel increases and technology 

advances, such materials become comparatively more valuable as an energy source, 

ingredient, or both. Furthermore, the use of some of these materials is likely to contribute 

to certain emission reductions and may increase other emissions.11 

The reuse of secondary materials may result in other benefits. First, the use of 

secondary materials could result in reduction of imported fuel. Second, using secondary 

materials for fuel or ingredient value has an additional benefit of reducing the 

environmental impacts caused by the disposal of such materials, if such disposal has 

 

10 For example, use of tire-derived fuel in the cement industry began in Japan and Germany in the 1970s. 

See docket item titled “Scrap Tire Markets in the United States,” RMA, November 2006. Also, the market 

for woody biomass is strong in Europe, where this material sells for $100 to $125 per ton. See docket item 

titled “Biocycle, Advancing Composting, Organics Recycling and Renewable Energy,” July 2008.

11 See the Materials Characterization Papers in the docket established for this action for examples of 

emission comparisons. 

Deleted: Projections indicate that

Deleted: , 

Deleted: , and the potential for 

governments to impose costs for emitting 

GHGs. 

Deleted: Typical renewable energy 

sources, such as wind and solar energy, 

are clearly a crucial part of the solution. 

However, the

Deleted: alternative fuels

Deleted: should play 

Deleted: . The Agency suggests that 

the beneficial use of secondary materials 

should be strongly encouraged as an 

alternative to use of the world’s limited 

non-renewable virgin materials.9

Deleted: . This trend has been even 

more pronounced in the European Union 

(EU), where alternative industrial sources 

of fuel and ingredients are more 

aggressively promoted through economic 

and environmental policies. Clearly, 

under

Deleted: as

Deleted: . For example, reductions in 

GHG 

Deleted: and particulate matter have 

been identified

Deleted: There are several other policy 

considerations involved in the beneficial 

Deleted: that are germane and should 

be taken into consideration in the public 

debate.

Deleted: be one part of our effort to 

reduce the need for importing energy. 

Secondary materials generated in U.S. 

commerce are a “domestic” energy 

source that can be used/reused to help 

reduce the need to import fossil fuels.

Deleted: . 

Deleted: reductions
17

environmental impacts. For example, use of tires as a fuel source means that those tires 

are no longer accumulated in huge piles where there are known incidents of them 

catching fire and serving as breeding grounds for disease carrying mosquitoes. 13,14 

The remainder of this section first presents an overview of the secondary 

materials and their contribution to improved economic efficiency. Then, we briefly 

summarize selected materials management programs and successes. Finally, we discuss 

known use patterns for selected secondary materials and briefly summarize some 

economic and environmental benefits derived from the use of such materials. 

B. Overview of Secondary Materials and Their Contribution to Economic Efficiency 

There exists a wide and diverse range of secondary materials used as fuels and/or 

ingredients, or otherwise beneficially used. Although sometimes referred to as wastes, 

these secondary materials may, in most cases, be more appropriately defined as “byproducts,” 15 reflecting their inherent resource recovery value in the 

generation/production of heat, energy, and/or marketable products. This inherent value 

exists with or without processing, depending upon the material. These secondary 

materials commonly include, but are not limited to, the following: scrap tires; scrap 

plastics; the biomass group (pulp and paper residuals, forest derived biomass,16

agricultural residuals, food scraps, animal manure, gaseous fuels); the construction and 

 

13 Although this notice highlights the benefits of using secondary materials as fuels, EPA recognizes that 

there may be other uses of secondary materials that in some cases are preferable from an energy 

perspective. For example, re-refining used oil is reported to save more energy content of the used oil than 

burning for energy recovery. 

14 See docket entry titled “Scrap Tire Cleanup Guidebook, January 2006,” for more discussion on hazards 

associated with tire piles. 

15 For purposes of this action, we define by-product as a secondary or incidental material derived from the 

primary use or production process that has value in the marketplace, or value to the user. 16 More commonly referred to as scrap wood materials. 

Deleted: Some solid waste that is 

landfilled creates methane gas, some of 

which can be captured via gas collection 

and processing systems and used as fuel, 

although some escapes to the atmosphere 

and is a greenhouse gas. Significantly 

reducing landfilling through a combined 

strategy of recycling and energy capture12

could help reduce the methane generation 

rate.
18

demolition material group (building related, disaster debris, and land clearing debris); 

spent solvents; coal refuse; waste water treatment sludge; used oil; blast furnace slag; 

cement kiln dust (CKD); coal combustion products (e.g., fly ash, bottom, ash, boiler 

slag); foundry sand; silica fume; and secondary glass material. These secondary 

materials can provide significant and widespread environmental and economic benefits 

when legitimately used/reused as an effective substitute for, or supplement to, primary 

materials. 

As certain primary materials become costly, the use of secondary materials is 

likely to become more economical. Managers of manufacturing or energy-production 

units that use secondary materials as a substitute for primary fuels or ingredients are 

obviously doing so for their own interests, including short and/or long-term competitive 

advantage. In general, industry will use secondary materials so long as the final price to 

the user is equivalent or less than the price for comparable primary material(s), and the 

product(s) derived from these materials is of equal (or better) quality. Provided industry 

is able to continue to safely use secondary materials, economic efficiency may be 

improved. While the issue raised in this ANPRM is whether specific secondary materials 

are properly considered legitimate products, or RCRA solid wastes, EPA notes that the 

regulatory status of the fuel or ingredient may, as mentioned above, potentially affect 

choices made by industrial concerns in selecting raw materials. 

C. Materials Management Programs and Successes 

Deleted: more and more 

Deleted: reflecting increased 

worldwide demand combined with 

resource scarcity, 

Deleted: continue to 

Deleted: 

Deleted: is 

Deleted: This occurs because the use 

of these materials results in equivalent 

output at lower overall resource use (i.e., 

lower price), or in turn, more output 

could be generated using the same 

amount of resource inputs (i.e., the use of 

100 percent virgin/primary materials 

would force reduced output to maintain 

the same cost of production). When this 

occurs, monetary savings resulting from 

reduced resource usage are, theoretically, 

applied to a higher and better use in the 

economy. This promotes economic 

growth derived from improved industrial 

efficiency.17
19

EPA, like environmental agencies in other countries, is exploring approaches to 

waste management that employs the concepts of life cycle assessment19 and full cost 

accounting.20 The life cycle approach has been advanced in the EU where, for the past 

several years, the EU has been focused on developing a strategy designed to minimize 

and recycle secondary materials,21 while recognizing the importance of full life cycle 

analysis within a comprehensive materials management program. Japan has gone even 

further, passing ambitious laws and establishing an effective initiative22 focused on 

creating a “closed loop” economy. 

 EPA’s materials management approach is focused on the three R’s: reduce, reuse, 

and recycle.

23 This approach helps ensure more efficient resource and material use 

through the integration of both environmental and economic components in the 

management of materials. In 2002, EPA initiated the Resource Conservation Challenge 

(RCC). This program was designed to help implement the Agency’s approach to 

materials management. The RCC Program is currently focused on four specific material 

groups: municipal solid waste; green initiatives, such as electronics; industrial materials; 

and priority and toxic chemicals. The Agency also has materials management programs 

 

19 Note: The terms, “life cycle analysis” and “life cycle assessment” are commonly used interchangeably. 

Life cycle assessment is a system-wide analytical technique for assessing the environmental (and 

sometimes economic) effects of a product, process, or activity across all life stages. 

20 Full cost accounting is an accounting system that incorporates economic, environmental, health, and 

social costs of a product, action, or decision. 

21 For example, The Closed Substance Cycle and Waste Management Act of 1994 (Germany), the German 

Auto Recycling Law, Directive 2006/66/EC of the European Parliament (EU battery recycling law). 

22 The Japanese law Promoting the Utilization of Recyclable Resources, 1991, the Japanese Recycling 

Law, 2001 (the world’s first “take back” law), and The Ecofactory initiative (Ministry of International 

Trade and Industry). 

23 See: http://www.epa.gov/epawaste/rcc/basic.htm

Deleted: Similar to 

Deleted: Organization for Economic 

Co-operation and Development (OECD) 

nations, the U.S.

Deleted: pursuing a cradle-to-cradle18

approach to 

Deleted: The U.S. life cycle

Deleted: , as implemented through 

EPA,

Deleted: .

Deleted: life cycle system.
20

focused specifically on used oil and scrap tires.24 Other more broadly focused EPA 

programs include the Office of Solid Waste’s (OSW’s) Product Stewardship Program and 

the Comprehensive Procurement Guidelines. In addition, several states have also 

established life cycle approaches to materials management (e.g., California, Minnesota, 

Washington, and Vermont). 

 The Agency has an interest in understanding the environmental and economic 

tradeoffs associated with life cycle implications of our materials management programs. 

For example, we have conducted preliminary life-cycle analyses of beneficial impacts 

associated with recycling of foundry sand and selected coal combustion products.27 It is 

also one of our mandates under RCRA Subtitle F – Federal Responsibilities, which states 

the “Administrator shall provide information on the technical and economic aspects of 

developing integrated resource conservation or recovery systems...” (Sec.6003). For the 

examples cited above, the Agency used a rigorous analytical approach to evaluate the 

environmental and economic benefits associated with the management of those materials. 

This rigorous analytical approach to the development of materials management programs 

helps to ensure that we are not promoting economically or environmentally inefficient 

programs. Where we have evaluated the benefits of secondary materials management 

 

24 See: http://www.epa.gov/waste/conserve/materials/usedoil/index.htm, and, 

http://www.epa.gov/waste/conserve/materials/tires/index.htm 27 See docket items titled “Waste and Materials-Flow Benchmark Sector Report: Beneficial Use of 

Secondary Materials – Coal Combustion Products, Final Report,” USEPA, February 12, 2008 and “Waste 

and Materials-Flow Benchmark Sector Report: Beneficial Use of Secondary Materials – Foundry Sand, 

Final Report,” USEPA, February 12, 2008. 

Formatted: Font color: Auto

Deleted: The by-product synergies 

derived from the legitimate use of 

secondary materials under the guidance 

of federal and state programs is central to 

the concept of industrial ecology.25 

Progress in the field of Industrial Ecology 

and documented success

Deleted: by-product synergy programs 

confirm that EPA seeks to maintain and 

promote the beneficial use of nonhazardous secondary materials.26 

Furthermore, we believe that such 

programs make an important contribution 

in moving the country toward material 

sustainability, and energy self 

sufficiency, while maintaining protection 

to human health and the environment. ¶

Understanding and communicating

Deleted: is critical to ensuring longterm success.

Deleted: Depending upon

Deleted: material being assessed

Deleted: may employ one or more of 

several different life cycle analysis 

models, cost calculators, and economic 

assessment tools designed

Deleted: any materials

Deleted: program.

Deleted: ensures

Deleted: Our analyses to date indicate 

that all current
21

programs, such as the RCC’s Program as described above for uses of foundry sand and 

selected coal combustion products, our analyses have shown those programs provide 

benefits.

 We believe that it is critical to interpret which secondary materials are not “solid 

wastes” pursuant to RCRA to ensure the continued legitimate use of secondary materials 

in combustion processes. This, in turn, will maintain the continued environmental and 

economic benefits from these programs. 

D. Secondary Materials Use and Benefits 

 This part builds on the discussion in part “B” of this section and provides greater 

detail on some of the non-hazardous secondary materials that are commonly used by the 

industrial community. We summarize key information that is available on the known 

generation, use, and benefits of these secondary materials. The purpose of this part is to 

describe the Agency’s understanding regarding the wide-scale acceptance, use, and value 

of these secondary materials in U.S. industrial markets. More detailed information on a 

wide array of secondary materials potentially affected by this action is presented in the 

Materials Characterization Papers, which can be found in the Docket established for 

today’s action. 

 The Materials Characterization Papers outline publicly and readily available 

information concerning material characteristics relevant to this ANPRM. Specifically, 

for each material group, the papers endeavor to: (a) provide a clear definition of the 

material; (b) identify annual quantities generated and used; (c) outline current combustion 

and non-combustion uses, along with current quantities landfilled or otherwise stored; (d) 

discuss management and combustion processes utilized; and (e) summarize potential 

Deleted: to society. 
22

environmental and economic impacts from the use of each material. The available 

information across these components of each paper and the individual materials is often 

limited or uncertain. Thus, these papers represent our initial effort to gather and present 

relevant data. The Agency seeks comment on additional data sources that may enhance 

its understanding and knowledge of these materials. 

 Non-hazardous secondary materials are widely used as fuels and/or ingredients in 

virtually all types of boilers (e.g., industrial, commercial, institutional), cement kilns, 

lightweight aggregate kilns (LWAKs), and other industrial furnaces (e.g., glass furnaces). 

These facilities burn or otherwise use in the production process hundreds of millions of 

tons of secondary materials each year. The total number of facilities using secondary 

materials each year as a substitute for primary fuels and/or ingredients is unknown, but 

our best estimate indicates that approximately 200,000 units use secondary materials as a 

substitute for primary fuels and/or ingredients.29 

 The manner in which non-hazardous secondary materials are processed, the 

nature of the materials, and the ways in which they are used or recycled generally 

establishes whether such materials are wastes or “by-products.” Based on our research 

for the Materials Characterization Papers, we have identified eight non-hazardous 

secondary material fuels or fuel groups and six non-hazardous ingredients, or ingredient 

groups. The eight fuel source materials are: the biomass group (pulp and paper 

residuals, forest derived biomass, agricultural residues, food scraps, animal manure, 

gaseous fuels); construction and demolition materials (building related, disaster debris, 

 

29 Identification of Non-Hazardous Materials That Are Solid Waste. EPA Exhibit 1: Preliminary Estimate 

of Total Nonhazardous Secondary Materials Used Annually in Boilers and Kilns. Sept. 24, 2008. 

Deleted: believed to be significant (i.e., 

Deleted: 28).
23

and land clearing debris); scrap tires; scrap plastics; spent solvents; coal refuse; waste 

water treatment sludge, and used oil. The six secondary material ingredients are: blast 

furnace slag; CKD; coal combustion product group (fly ash, bottom ash, and boiler slag); 

foundry sand; silica fume; and secondary glass material. 

 Based on publicly available information, we believe that these materials account 

for the vast majority of all non-hazardous secondary materials used as fuels and/or 

ingredients in the U.S. However, the Agency solicits comment on whether there are 

other non-hazardous secondary materials that are also used as a fuel or ingredient that we 

have not identified, either in this notice or in the Materials Characterization Papers. If so, 

the Agency requests that commenters provide information on such materials, including 

the composition or characteristics of such materials, how much of the secondary material 

is produced and utilized, how it is utilized—that is, is it a fuel or an ingredient, and how 

is it generally handled. Detailed information will be the most useful as we move forward 

in the rulemaking effort. 

 The annual use patterns, quantities, and benefits associated with some of these 

secondary materials are well established, while less is known about other secondary 

materials. Presented below are brief summaries of the documented usage, trends in 

usage, and benefits associated with some of these widely used secondary materials. As 

mentioned above, the Materials Characterization Papers, available in the docket 

established for today’s action, present more detailed information on the quantities and use 

patterns, characteristics, composition, management and benefits associated with all eight 

secondary fuel materials/groups and the six secondary ingredient materials/groups we 

have identified. 

Deleted: Without such detailed

Deleted: , the Agency

Deleted: not be able to consider it
24

 Biomass30 - When used as a secondary material fuel, biomass consists primarily 

of pulp and paper mill residuals, forest derived biomass, agricultural residuals, food 

scraps, animal manure, and gaseous fuels. Sectors that generate and/or use these valuable 

biomass commodities include: crop production; support activities for crop production; 

food manufacturing; beverage and tobacco product manufacturing; logging; pulp, paper, 

and paperboard mills; sawmills and wood preservation; veneer, plywood, and engineered 

wood product manufacturing; cattle ranching and farming; hog and pig farming; poultry 

and egg production; sheep and goat farming; horses and other equine production; and, 

sewage treatment facilities. 

 Timber harvesting and the manufacture of lumber generate large amounts of 

forest-derived biomass used as secondary material fuels. These woody materials may 

originate directly from the forest as logging residues (e.g., tree limbs, tops, needles, 

leaves), or from timber processing mills (e.g., clean and unadulterated bark, sawdust, 

trim, screenings, tree harvesting residuals). Logging and other forest harvesting removal 

residues are estimated to range from 62 million tons per year (tpy) to 103 million tpy, 

with an estimated 42 to 93 million tpy available for recovery and beneficial use. Total 

primary mill31 residue production is estimated to range from 87 to 91 million tpy. 

Experts predict that by 2050, logging and other forest harvesting removal residues will 

increase by 23 million tpy and availability of secondary mill residues (i.e., residues such 

as board, trim and breakage from the manufacture of reconstituted wood/panel products) 

will increase by 16 million tpy. 

 

30 Source: Materials Characterization Paper in Support of the Advanced Notice of Proposed Rulemaking: 

Identification of Non-Hazardous Materials That Are Solid Waste – Biomass. 31 Lumber and veneer mills. 
25

 Available information indicates that logging residues, although a good potential 

source for secondary material fuel, are not currently collected for use as a fuel on any 

large scale. Primary mill residues, however, are highly valuable as feedstocks in 

combustion, as well as for non-combustion purposes.32 Approximately 42 percent of all 

primary mill residues are used as a fuel, including 76 percent of bark residues, 12 percent 

of coarse residues, and 56 percent of fine residues. These materials are burned in a 

variety of boilers, including Dutch ovens, fuel cell ovens, spreader stokers, suspensionfired boilers, and fluidized bed combustion boilers. Forest-derived materials may also be 

co-fired with other fuels, primarily solid fuels such as coal. Logging and primary milling 

residues may be chipped or sorted before being used, but otherwise generally undergo 

minimal processing. The use of forest-derived materials has been found to result in 

generally higher PM emissions than natural gas or distillate oil, but lower PM emissions 

than coal or residual oil systems. Estimated NOx emissions associated with the use of 

wood are similar to those associated with distillate and lower than the NOx emissions for 

other conventional fuels, while wood combustion results in lower SO2 emissions than 

most conventional fuels. Finally, the use of forest-derived materials results in reduced 

fuel costs to the user and may provide environmental benefits associated with avoided 

virgin material33 extraction and, in some cases, avoided transportation. 

 The forest products industry generates large quantities of secondary material 

biomass fuels in the form of pulp and paper residues, including sludges and black 

 

32 Primary mill residues tend to be clean, uniform, concentrated, and with a low-moisture content. As a 

result, these materials generally require little processing. 

33 The term “Virgin material,” as used in this Notice means resources extracted from nature in their raw 

form, such as timber, metal ore, coal, petroleum, etc.

Deleted: The Biomass Energy 

Resource Center indicates that the net 

long-term effect of burning wood-based 

materials as a secondary material fuel is 

that no new CO2 is added to the 

atmosphere, assuming that the forests 

from which the wood came are 

sustainably managed. 

Deleted: provides
26

liquor.34 However, black liquors that are reclaimed in a pulping liquor recovery furnace 

and then reused in the pulping process are excluded from the definition of solid waste 

under Subtitle C of RCRA, unless speculatively accumulated, as defined in 261.1(c), or 

reclaimed in another manner. Pulp and paper mills produce the dry biomass equivalent 

of between 4.2 and 5.8 million tons of wastewater treatment sludges. In 2002, 

approximately 22 percent of all pulp and paper mill sludges were used in hog fuel boilers 

as a supplementary or stand-alone fuel. An undetermined amount was used as a cement 

kiln feedstock and as a fuel pellet ingredient. Anaerobic sludge production also generates 

methane. Sludges typically undergo mechanical dewatering before being combusted. 

The use of mill sludges in onsite boilers results in reduced fuel costs for the facility, and 

may provide environmental benefits associated with avoided virgin material extraction 

and transportation. 

 Agricultural residuals include crop residues remaining in the fields after harvest 

(primary residues) and processing residues generated from the harvested portions of 

crops during food, feed, and fiber production (secondary residues). Current annual 

production of agricultural residues from major crops is estimated to be around 500 

million dry tpy. These primary biomass crops include barley, canola, corn, cotton, dry 

beans, flax, oats, peanuts, peas, potatoes, rice, rye, safflower, sorghum, soybeans, 

sugarcane, sunflowers, and wheat. Anywhere from 113 million tpy to 173 million tpy is 

estimated to be available for removal from the fields in a sustainable manner (i.e., while 

maintaining cropland fertility and quality). However, the total quantity of agricultural 

residues actually used for fuel on an annual basis is difficult to determine from the 

available literature. Total primary agricultural residue production fluctuates with the 

 

34 See 40 CFR 261.4(a)(6). 

Deleted: while providing
27

amount of U.S. land in crop production and the relative proportion of crops on this land. 

 In 2007, we estimate that approximately 6.0 million tons of agricultural residues 

were burned, 92 percent of which [on a British thermal unit (Btu) basis] provided useful 

thermal output. The remaining 8 percent was used to produce electricity. Around 71 

percent of total agricultural residues burned (Btu basis) were secondary residues used in 

the food processing industry, mostly sugarcane bagasse at sugar mills. The remaining 29 

percent was used in the Agriculture, Forestry, and Mining, and the Paper and Allied 

Products industries. Corn stover and other agricultural residues can be used as a heat and 

power source for the production of corn and cellulosic ethanol. Agricultural residues are

generally burned as fuel in fuel cells, horseshoe boilers, and spreader stoker boilers. 

Aside from occasionally drying, agricultural residues do not generally require processing 

prior to being utilized as a fuel. The use of agricultural residues as a substitute for coal in 

an existing power plant reduces SO2, NOX, and other emissions and eliminates the 

environmental impacts associated with the extraction and processing of the traditional 

fuels. 

 Food scraps are generated at all stages of the food production system, including 

farming, storage, processing, wholesaling, retail, and consumption. Food scraps, broadly 

defined, include both the portion of harvested crops and livestock that does not enter the 

retail market and the portion of food discarded by retailers and consumers. This ANPRM

is concerned only with industrial food scraps; food scraps generated by retailers and 

consumers are not considered because they enter the waste stream as municipal solid 

waste. The total quantity of industrial food scraps produced on an annual basis is not 

readily accessible from publically available information. Industrial food scraps are 

Deleted: Current trends suggest that 

higher food prices will drive additional 

land into crop production. 

Deleted: An emerging market for corn

Deleted: residue is for use

Deleted: residue is 

Deleted: action

Deleted: the

Deleted: literature.
28

known to be burned in lodging and restaurant boilers. However, the annual quantities 

burned and the distribution of this use is unknown. The use of food scraps with 

meaningful fuel value in lodging and restaurant boilers eliminates the environmental 

impacts associated with the extraction and processing of the traditional fuels. 

 Animal manure is the excrement of livestock reared in agricultural operations. 

Animal manure may also include straw, sawdust, and other residues used as animal 

bedding. Gaseous fuels may be derived from landfills (landfill gas) or from animal 

manure and solid biomass (biogas), such as crop silage. Biogas is generated via 

anaerobic digestion, a multi-stage process whereby bacteria convert carbohydrates, fats, 

and proteins to methane. Domestic livestock production generates over a billion tons of 

manure annually, which if used to produce biogas would yield approximately 19.4 

million tons of methane. Anaerobic digestion of current manure production managed in 

ponds, anaerobic lagoons, and holding tanks could yield a maximum of about 2.4 million 

tpy of methane. Current production, however, is about 0.07 million tons from 111 

operating digesters. 

We estimate that about 35 million dry tons of current manure production could be 

used for bioenergy purposes. Livestock production has become increasingly 

concentrated in recent years, facilitating the collection of manure for bioenergy purposes. 

As bioenergy conversion technologies improve, the opportunity for utilizing animal 

manure for bioenergy production may likely increase. Biogas produced on dairy farms is 

typically used to heat water for purposes of cleaning and sanitizing milking pipelines and 

equipment in dairy operations. Biogas generated on farms is typically burned on-site 

directly in boilers and, to a lesser extent, is burned in space heating. Biogas benefits 

Deleted: , and it eliminates emissions 

of the methane associated with food scrap 

disposal in landfills

Deleted: once sustainability concerns 

are met

Deleted: Opportunities

Deleted: are 

Deleted: to 

Deleted: in the coming years with 

higher fossil fuel prices and improved 

bioenergy conversion technologies

Deleted: In addition, we have 

identified an emerging market for animal 

manure for use in the direct production of 

heat and power.

Deleted: , with little processing 

(upgrading) necessary other than 

hydrogen sulfide and moisture removal. 

Carbon dioxide may also be removed for 

applications where high thermal values 

are needed
29

include displacement of fossil fuels, primarily natural gas. Furthermore, the use of biogas 

as a replacement for natural gas avoids the emissions associated with the extraction and 

processing of natural gas. 

Scrap tires35 - Scrap tires are used tires that are recycled when they can no 

longer be used as tires. This may occur because of normal tread wear, punctures, 

destruction in accidents, or any number of other reasons. Scrap tires are generated from 

the replacement of tires on passenger and commercial vehicles. Consumers and industry 

in the U.S. generated 299.6 million tires in 2005; this represents approximately 4.9 

million tons of tires, assuming an average of 33 pounds per tire. Approximately 52 

percent of the total number of scrap tires generated in 2005 went for tire-derived fuel 

(TDF).36 Although energy recovery is the most common use of scrap tires, there are 

many non-fuel uses for scrap tires, including: civil engineering (i.e., construction of 

landfills and roads); cut/punched/stamped into other products (i.e., floor mats); and, 

rubber modified asphalt. While some facilities are capable of burning whole tires, a large 

percentage of tires are sent to processors where they are shredded or chipped prior to 

being sent to plants for use as TDF. Facilities that burn whole tires often charge a tipping 

fee for acceptance of these tires, while chipped tires must be purchased. TDF is used in a 

variety of units, including boilers and industrial furnaces, such as kilns. It can be used to 

supplement and/or replace a wide range of fuels including coal, coke, fuel oil, natural gas, 

and wood. The use of tires for fuel has increased from 24.5 million tires in 1990 to 155.1 

million tires in 2005. During this same period, the number of tires in stockpiles declined 

by nearly 82 percent, going from approximately one billion tires to just under 200 

 

35 Source: Materials Characterization Paper in Support of the Advanced Notice of Proposed Rulemaking: 

Identification of Non-Hazardous Materials That Are Solid Waste - Scrap Tires.

36 TDF has a heating value of around 13,000 to 16,000 Btu/lb. 

Deleted: the use of methane, a GHG, 

thereby avoiding its release to the 

atmosphere and 
30

million, a significant environmental accomplishment. The majority of tires that have 

been removed from these piles have been used in industrial boilers and kilns for energy 

recovery. This trend may increase if the cost of conventional fossil fuels increases. 

Emissions test data compiled by EPA in 1997 suggest that substituting scrap tires 

for coal in electric utility boilers may lead to reductions in NOx and particulate matter 

emissions,37 but show no clear pattern for SOx and zinc emissions. 38 Studies indicate that 

there is an increase in zinc emissions when TDF is used at industrial boilers and pulp and 

paper mills, while zinc emission data are inconclusive for cement kilns and utility boilers. 

Finally, as referenced above, the use of TDF as a replacement for traditional primary 

fuels eliminates the environmental impacts associated with the extraction and processing 

of the traditional fuels. 

 Used Oil39 - Used oil is defined as petroleum-based or synthetic oil that has been 

used and has been contaminated from use (see 40 CFR 279.1 for the specific definition). 

To meet EPA's regulatory definition, contamination includes residues and contaminants 

generated from the handling, storing, use, and processing of oil.40 Physical contaminants 

from use include metal shavings, high water content, or dirt, while chemical 

contaminants from use include solvents, halogens, or lead. To meet EPA’s regulatory 

definition, used oil must have been refined from crude oil or made from synthetic 

 

37 United States Environmental Protection Agency (EPA). 1997, “Air Emissions from Scrap Tire 

Combustion”. 

38 See also the Nebraska Department of Environmental Quality, Applicability Determination for 

Combusting Tire Derived Fuel in Humboldt Wedag Kiln (Kiln #2), indicates that emissions of SO2, NOx, 

and CO decreased while TDF was used. (see: http://www.deq.state.ne.us/Press.nsf/pages/AGFactsheet1) 

39 Source: Materials Characterization Paper in Support of the Advanced Notice of Proposed Rulemaking: 

Identification of Non-Hazardous Materials That Are Solid Waste - Used Oil. 40 Used oil processing is defined as a chemical or physical operation designed to produce from used oil, or 

to make used oil more amenable for production of, fuel oils, lubricants, or other used oil-derived products. 

Processing includes, but is not limited to: blending used oil with primary petroleum products, blending used 

oils to meet the fuel specification, filtration, simple distillation, chemical or physical separation and rerefining. 

Deleted: is likely to 

Deleted: as 

Deleted: ¶

Data compiled by the Greenhouse Gas 

Protocol suggest that the GHG emissions 

rate associated with the combustion of 

scrap tires is approximately 0.081 metric 

tons of CO2 equivalents (MTCO2E) per 

million Btu (MMBtu) of scrap tires 

combusted. By comparison, based on 

emissions and energy data compiled by 

the Agency, the GHG emissions rates for 

coal, natural gas, distillate oil, and 

residual oil are approximately 0.094 

MTCO2E per MMBtu, 0.053 MTCO2E 

per MMBtu, 0.073 MTCO2E per MMBtu, 

and 0.079, respectively. These estimates 

do not include the upstream emissions 

impacts from the extraction and transport 

of virgin materials. These impacts are 

estimated to range anywhere from 0.01 

per MTCO2E per MMBtu for natural gas 

to 0.009 MTCO2E per MMBtu for 

residual fuel oil. The net TDF impact, 

therefore, may be derived by subtracting 

the extraction impact estimate from the 

TDF emissions impact. For example, if 

TDF is substituting for natural gas, the 

net TDF impact would be 0.071 MTCO2E 

per MMBtu (0.081–0.01 = 0.071). The 

100 percent virgin material impact would 

be the summation of the emissions impact 

plus the extraction impact, for the 

corresponding fuel. 
31

materials; animal and vegetable oils are excluded from EPA’s regulatory definition of 

used oil. Generators of used oil include businesses that handle oil through commercial or 

industrial operations or from the maintenance of vehicles and equipment. The oil may 

have been used as a lubricant, hydraulic fluid, heat transfer fluid, buoyant, and for other 

similar purposes. 

 Recent estimates indicate that approximately 1.35 billion gallons of used oil are 

collected each year. Depending upon the year, our estimates indicate that as much as 90 

percent of all collected used oil is burned for energy recovery. Both on-specification and 

off-specification41 used oil may be used as a source of fuel in combustion units. 

However, off-specification used oil may only be burned in the following types of boilers: 

industrial boilers located at facilities that are engaged in a manufacturing process where 

substances are transformed into new products; utility boilers used to produce electric 

power, steam, heated or cooled air or other gases or fluids for sale; used oil-fired space 

heaters provided that the burner meets the provisions of 40 CFR 279.23; and hazardous 

waste incinerators subject to regulation under 40 CFR subpart O of parts 264 or 265. 

National information on the distribution between on-specification and off-specification 

used oil used as a fuel is not readily available. However, asphalt plants appear to be the 

largest users of used oil, followed by space heaters, and industrial boilers. We estimate 

that approximately 73 percent of all used oil generated and used each year is onspecification. 

 

41 The Agency makes a distinction between on-specification and off-specification used oil. Only certain 

contaminants in used oil pose a significant threat to human health or the environment. As a result, EPA has 

established maximum concentration limits for these constituents of concern. These limits are set such that 

the emissions resulting from the burning of used oil containing these contaminants, at or below established 

“on-spec” limits, will pose no more threat to human health or the environment than the emissions resulting 

from the burning of virgin oil or diesel. See 68 FR 44662 (July 30, 2003). Also see Section V.A.4. for 

more discussion of used oil. 
32

The long-term trend in used oil generation is undetermined. However, during the 

1997-2005 time period, the recycling rate for used oil generated by service stations 

increased from 66 percent to almost 100 percent. 

The principal environmental benefits of burning used oil for energy recovery are 

associated with upstream production offsets and include substantial reductions of NOX

and carbon monoxide (CO) emissions. In terms of combustion-specific emissions, use of 

used oil results in notably lower NOX emissions, in particular when compared to residual 

fuel oil. However, PM and lead emissions may be higher than for primary fuel oil, 

depending upon the extent of processing. 

Coal Fly Ash42 - Exhaust gases leaving the combustion chamber of a power plant 

entrain particles during the coal combustion process. Fly ash is the finest of coal ash 

particles. To prevent this fly ash from entering the atmosphere, power plants use various 

collection devices to remove it from the gases that are leaving the stack. The coal-fired 

power industry is the largest generator of coal fly ash in the U.S and other industries that 

use coal as a fuel, such as commercial boilers and mineral and grain processors, also 

produce coal fly ash. In 2006, the coal-fueled electric power industry generated 

approximately 72.4 million tons of fly ash. This figure was estimated at 70.8 million tons 

for 2004 and 71.7 million tons for 2007.43 Electricity demand is projected to increase in 

coming years.44 Because coal is expected to continue to be an important fuel source, it is 

likely that the quantity of coal fly ash generated will also remain significant. 

 

42 Source (unless otherwise noted): Materials Characterization Paper in Support of the Advanced Notice of 

Proposed Rulemaking: Identification of Non-Hazardous Materials That Are Solid Waste - Coal 

Combustion Products - Includes Coal Fly Ash, Bottom Ash, and Boiler Slag. 43 ACAA. 2004 and 2007 Coal Combustion Product (CCP) Production and Use Survey Results (Revised 

for 2007). 

44 See United States Department of Energy, Energy Information Administration (EIA). 2008, “Annual 

Energy Outlook 2008 with Projections to 2030,” Publication DOE/EIA-0383 (2008), June 2008. 

Deleted: , 

Deleted: , and CO2

Deleted: The beneficial use of used oil 

also helps avoid illegal dumping. .

Deleted: Fly ash is the finest of coal 

ash particles. 

Deleted: . Other 

Deleted: ,

Deleted: that use coal as a fuel source

Deleted: by about 40 percent by 2020.
33

 Coal fly ash can be added to the raw material feed in clinker manufacturing to 

contribute specific required elements, such as silica, alumina, and calcium, in the final 

cement composition. Coal fly ash with relatively high unburned carbon content can also 

be re-burned in cement kilns for energy recovery at the same time as it provides 

ingredient value. The use of coal fly ash as an ingredient in cement kilns does not require 

processing. However, levels of key metals in coal fly ash must be carefully calibrated 

with other ingredients to ensure that the final cement product has the correct mineral and 

metal content. In clinker manufacture, coal fly ash partially offsets the need for raw 

materials, such as silica, iron, and alumina sources. Thus, using coal fly ash in the 

cement kiln can reduce the unit consumption of raw feed stock materials, which results in 

reduced emissions of certain pollutants.45 Furthermore, when coal fly ash with relatively 

high unburned carbon content is introduced to the cement kiln during clinker 

manufacture, the primary fuel supply may be reduced to accommodate the additional 

energy provided by the carbon in the fly ash. 

Cement Kiln Dust (CKD)46 - Generated by the cement manufacturing industry, 

CKD is a fine-grained, solid, highly alkaline low organic content material removed from 

the cement kiln exhaust gas by scrubbers. Much of the material comprising CKD is 

incompletely reacted raw material, including a raw mix at various stages of burning, and 

particles of clinker. There is an estimated 13 to 17 million short tons of CKD generated 

per year in the U.S. CKD can be directly reused in a closed-loop process back into the 

 

45 For more detailed information on the benefits of using coal fly ash and other recovered mineral 

components in manufacturing processes, please see: “Study on Increasing the Usage of Recovered Mineral 

Components in Federally Funded Projects Involving Procurement of Cement or Concrete to Address the 

Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users.” June 23, 2008. 

(EPA530-R-08-007) 

46 Source (unless otherwise noted): Materials Characterization Paper in Support of the Advanced Notice of 

Proposed Rulemaking: Identification of Non-Hazardous Materials That Are Solid Waste – Cement Kiln 

Dust (CKD). 
34

cement kiln as an ingredient for clinker manufacture. The cement industry is estimated to 

recycle more than 75 percent of its CKD each year. Significant increases in U.S. clinker 

capacity are expected over the 2008 to 2012 period resulting in an anticipated increase in 

CKD production and usage. In clinker manufacture, CKD partially offsets the need for 

raw material feed, such as limestone and natural constituents (rock), thus avoiding the 

energy usage and emissions related to their extraction and processing. 

Coal Refuse47 - Coal refuse refers to any by-product of coal mining or coal 

cleaning operations. Coal refuse is generally defined by a minimum ash content 

combined with a maximum heating value, measured on a dry basis. Coal refuse consists 

primarily of non-combustible rock with attached coal that could not be effectively 

separated in the era in which it was mined. Coal refuse includes mining rejects and 

recovered landfill ash. Coal mine rejects are generated by bituminous coal and lignite 

surface mining, bituminous coal underground mining, and anthracite mining. Recovered 

landfill ash is generated by fossil fuel electric power generation facilities. Specific data 

on the quantity of mining rejects generated is not available. However, we estimate that 

up to 1,145 million tons of coal refuse may have been generated48 in 2007. Generation of 

mining rejects, as well as the availability of recoverable landfill ash, correlates with the 

production and use of coal. Coal production is projected to increase in the coming 

decades in response to increased demand for electricity. Increasing coal use for 

electricity generation at existing plants and projected construction of new coal-fired 

plants is estimated to lead to coal production increases that average 1.1 percent per year 

 

47 Source (unless otherwise noted): Materials Characterization Paper in Support of the Advanced Notice of 

Proposed Rulemaking: Identification of Non-Hazardous Materials That Are Solid Waste – Coal Refuse. 

48 The term “generated” in this context refers to the quantity of coal mining rejects produced from the total 

quantity of U.S. coal mined in 2007. (Please see the coal refuse Materials Characterization Paper for a more 

detailed discussion.) 

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to the cement kiln can reduce

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material feed stock in the kiln, which then 

reduces the costs of such materials and 

the overall 

Deleted: of certain pollutants, most 

notably CO2 from cement manufacturin

Deleted: , mill rejects,

Deleted: Coal mill rejects and r

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Deleted: While aggregate data are not 

available, we found that the generation 

rate of mill rejects at coal fired power 

plants averages about 350 lbs/hr. 

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35

from 2005 to 2015, with 1.8 percent annual growth projected over the 2015 to 2030 

period. Based on our review of publicly available information, circulating fluidized bed 

(CFB) combustion units and pulverized coal power plants are currently the units that use 

coal refuse. 

 CFB is an integrated technology for reducing SO2 and NOx emissions during the 

combustion of coal. In addition to reduced SO2 and NOx emissions, use of coal refuse as 

a replacement for traditional primary fuels eliminates the environmental impacts 

associated with the extraction and processing of traditional fuels, and reduces the 

environmental impacts that may be associated with the piles of coal refuse (e.g., potential 

fire hazards and sources of surface and groundwater pollution). 

 The Agency seeks comment, with supporting data, on the secondary materials 

information provided in this ANPRM and in the Materials Characterization Papers. We 

also request comment, with supporting data, on any unidentified non-hazardous 

secondary fuel and/or ingredient materials used in combustion units. 

IV. What is the History of the Definition of Solid Waste Rules? 

A. Statutory Definition of Solid Waste 

RCRA defines “solid waste” as “...any garbage, refuse, sludge from a waste 

treatment plant, water supply treatment plant, or air pollution control facility and other 

discarded material... resulting from industrial, commercial, mining, and agricultural 

operations, and from community activities...” (RCRA section 1004 (27) (emphasis 

added)). The key concept is that of “discard” and, in fact, this definition turns on the 

meaning of the phrase, “other discarded material,” since this term encompasses all other 

examples provided in the definition. 

Deleted: Circulating

Deleted: only 

Deleted: any 

Deleted: and esthetic 
36

B. Solid Waste Program, RCRA Subtitle D 

The regulations that pertain to non-hazardous solid waste (RCRA Subtitle D) 

contain five definitions of the term “solid waste.” (See 40 CFR 240.101(y); 40 CFR 

243.101(y); 40 CFR 246.101(bb); 40 CFR 257.2; and 40 CFR 258.2.) These regulatory 

definitions largely mirror the statutory definition of solid waste with some clarifications 

applicable to the specific regulatory section. The RCRA statutory definition of solid 

waste has also been repeated in the CAA emission guidelines for other solid waste 

incineration units (e.g., see 40 CFR 60.2977 and 60.3078). 

EPA has not focused on the specific parameters of the definition of solid waste as 

it applies to non-hazardous solid waste programs under RCRA Subtitle D primarily 

because while, under RCRA Subtitle D, EPA promulgates criteria for municipal solid 

waste landfills and approves state solid waste landfill permitting programs, it is the states 

that fully implement those programs. EPA does not have the same role in these programs 

as it does in the hazardous waste programs established under RCRA Subtitle C. As a 

result, EPA has not promulgated detailed regulations of what is included in the definition 

of solid waste for the Subtitle D (non-hazardous) programs. States have promulgated 

their own laws and regulations regarding what constitutes solid waste and have 

interpreted those laws and regulations to determine what types of secondary materials 

management activities constitute discard (and therefore involve the management of a 

solid waste). However, EPA now needs to articulate which non-hazardous secondary 

materials constitute solid wastes under RCRA Subtitle D so that EPA can establish 

appropriate standards under CAA sections 112 and 129 for units that combust secondary 

materials for the purposes of energy recovery or when used as an ingredient. We 
37

envision that a Subtitle D definition of solid waste that could result from this rulemaking 

effort would not impact/affect any other types of management activities for these 

materials, such as landfilling, composting, etc., and as such, would have no impact at the 

Federal level on the Subtitle D program. 

C. Hazardous Waste Program, RCRA Subtitle C

The RCRA Subtitle C hazardous waste federal program has a long regulatory 

history in defining “solid waste” for purposes of the hazardous waste regulations. 

However, the 40 CFR 261.2 definition of solid waste explicitly applies only to wastes 

that also are hazardous for purposes of the Subtitle C regulations (see 40 CFR 

261.1(b)(1)). 

EPA emphasizes that it is not requesting comment on any of its Subtitle C 

regulations or on any of the issues involved in its hazardous waste regulations regarding 

whether secondary materials are hazardous wastes for purposes of its RCRA Subtitle C 

regulations. The Agency is not reopening its hazardous waste regulations in any way 

whatsoever; EPA does not intend to respond to any comments directed to its hazardous 

waste regulations. 

The following discussion provides the context in which EPA’s hazardous waste 

regulations exclude certain materials that would otherwise be hazardous waste from the 

definition of solid waste. In 40 CFR 261.2, EPA defines solid waste for purpose of the 

hazardous waste regulations as “any discarded material that is not excluded. . .” by other 

provisions of Part 261. 

For context, however, the Agency describes its hazardous waste regulations and 

the exclusions, themselves. First, a “discarded material” is defined in relevant part as a 
38

hazardous material which is abandoned, recycled, or considered inherently waste-like. A 

hazardous material is considered to be “abandoned” if it is disposed of, burned or 

incinerated, or accumulated, stored, or treated before or in lieu of being disposed of, 

burned, or incinerated. A hazardous material is considered to a be a solid waste when 

recycled (or when accumulated, stored or treated prior to recycling) if it is: (a) used in a 

manner constituting disposal (i.e., placed on the land or used to produce products that are 

placed on the land); (b) burned for energy recovery or used to produce a fuel49; (c) 

reclaimed; or (d) accumulated speculatively. 

While 40 CFR 261.2 sets out the basic regulatory definition of solid waste as it 

applies to hazardous waste, the regulations also exclude a number of specific hazardous 

secondary materials from the 40 CFR 261.2 definition of solid waste, and therefore, from 

the hazardous waste regulations. In general, these exclusions involve hazardous 

secondary materials that are products, co-products, or intermediates or other hazardous 

secondary materials that are reused/recycled/returned to the original process or hazardous 

secondary materials that meet fuel specifications. For example, hazardous secondary 

materials are not solid waste when used or reused as ingredients to make a product 

(provided the material is not reclaimed), used or reused as effective substitutes for 

commercial products, or are returned to the original process without first being reclaimed 

(40 CFR 261.2(e)(1)). In addition, EPA has developed many case-specific solid waste 

exclusions (see 40 CFR 261.4(a)). For example, hazardous secondary materials that are 

comparable fuels or comparable syngas fuels are excluded even when recycled by being 

burned for energy recovery. (See 40 CFR 261.4(a)(16).) Also, EPA has recently 

 

49 Commercial chemical products listed in 40 CFR 261.33 are not solid wastes if they themselves are fuels. 

Also, all commercial chemical products that are fuels are not solid waste, regardless of whether they are 

listed as a hazardous waste (see 50 FR 14219, April 11, 1985). 
39

finalized revisions to the definition of solid waste specifying that hazardous secondary 

materials being reclaimed under the control of the generator and hazardous secondary 

materials being transferred for reclamation are not solid wastes, provided certain 

restrictions and conditions are met.50 

D. Case Law on Definition of Solid Waste

Partly because the interpretation of the definition of solid waste is the foundation 

of the hazardous waste regulatory program, there has been a great deal of litigation over 

the meaning of “solid waste” under RCRA Subtitle C. From these cases, a few key 

principles emerge which guide our thinking on the definition of solid waste. 

First, the ordinary plain-English meaning of the term “discard” controls. See 

American Mining Congress v. EPA, 824 F.2d 1177 (D.C. Cir. 1987) (“AMC I”). The 

ordinary plain-English meaning of the term discarded means “disposed of,” “thrown 

away,” or “abandoned.” The court specifically rejected a more expansive meaning for 

discard that would encompass any materials “no longer useful in their original capacity” 

even if they were not destined for disposal. 824 F.2d at 1185-87. The Court further held 

that the term “discarded materials” could not include materials “...destined for beneficial 

reuse or recycling in a continuous process by the generating industry itself. (824 F.2d at 

1190). 

Subsequent to AMC I, the court discussed the meaning of discard in particular 

cases. In American Petroleum Institute v. EPA, 906 F.2d 729 (D.C. Cir. 1990) ("API I"), 

the court rejected EPA's decision not to regulate recycled air pollution control equipment 

slag based on an Agency determination that waste “ceases to be a ‘solid waste’ when it 

 

50 See “Revisions to the Definition of Solid Waste,” Final Rule, October 30, 2008, at 73 FR 64667.

Deleted: A more detailed discussion of 

these cases is provided in the Definition 

of Solid Waste Case Law support 

document contained in the administrative 

record for this ANPRM. 
40

arrives at a metals reclamation facility because at that point it is no longer ‘discarded 

material.’” 906 F.2d at 740. Instead, the materials were part of a mandatory waste 

treatment plan for hazardous wastes prescribed by EPA and continued to be wastes even 

if recycled. 906 F.2d at 741. Further, a material is a solid waste regardless of whether it 

“may” be reused at some time in the future. American Mining Congress v. EPA, 907 

F.2d 1179 (D.C. Cir. 1990) ("AMC II"). 

One of the more important holdings of a number of court decisions is that simply 

because a waste has, or may have, value does not mean the material loses its status as a 

solid waste. See API I, 906 F.2d at 741 n.16; United States v. ILCO Inc., 996 F.2d 1126, 

1131-32 (11th Cir. 1993); Owen Steel v. Browner, 37 F.3d 146, 150 (4th Cir. 1994). 

ILCO and Owen Steel, however, seem to recognize that products made from wastes are, 

themselves, products and not wastes. 

Association of Battery Recyclers v. EPA, 208 F.3d 1047 (D.C. Cir. 2000) 

(“ABR”) reiterated the concepts discussed in the previous cases. The Court held that it 

had already resolved the issue presented in ABR in its opinion in AMC I, where it found 

that “...Congress unambiguously expressed its intent that ‘solid waste’ (and therefore 

EPA’s regulatory authority) be limited to materials that are ‘discarded’ by virtue of being 

disposed of, abandoned, or thrown away” (208 F.2d at 1051). It repeated that materials 

reused within an ongoing industrial process are neither disposed of nor abandoned (208 

F.3d at 1051–52). It explained that the intervening API I and AMC II decisions had not 

narrowed the holding in AMC I (208 F.3d at 1054–1056). 

Notably, the Court did not hold that storage before reclamation automatically 

makes materials “discarded.” Rather, it held that “... at least some of the secondary 

Deleted: The court overturned an EPA 

rule that violated the principles expressed 

in AMC I because it allowed no storage 

on the ground whatsoever and would, 

therefore, result in regulating materials 

that were reclaimed within a continuous 

industrial process. 203 F.3d at 1053-4.
41

material EPA seeks to regulate as solid waste (in the mineral processing rule) is destined 

for reuse as part of a continuous industrial process and thus is not abandoned or thrown 

away” (208 F.3d at 1056). In this regard, the court criticized all parties in the case - 

industry as well as EPA - because they “presented this aspect of the case in broad 

abstraction, providing little detail about the many processes throughout the industry that 

generate residual material of the sort EPA is attempting to regulate . . .. ” (Ibid). 

American Petroleum Institute v. EPA, 216 F.3d 50, 55 (D.C. Cir. 2000) (“API 

II”), decided shortly after ABR and considered by the court at the same time, provides 

further guidance for defining solid waste, but in the context of two specific waste streams 

in the petroleum refining industry. The court overturned EPA’s determination that 

certain recycled oil bearing wastewaters are wastes (216 F.3d at 55-58) and upheld 

conditions imposed by the Agency in excluding petrochemical recovered oil from the 

definition of solid waste (216 F.3d at 58-59). In the case of oil-bearing wastewaters, EPA 

had determined that the first phase of treatment, primary treatment, results in a waste 

being created. 216 F.3d at 55. The court overturned this decision and remanded it to 

EPA for a better explanation, neither accepting EPA’s view nor the contrary industry 

view. The court noted that the ultimate determination that had to be made was whether 

primary treatment is simply a step in the act of discarding? Or is it the last step in a 

production process before discard? 213 F.3d at 57. In particular, the court rejected 

EPA’s argument that primary treatment was required by regulation, instead stating that 

the Agency needed to “set forth why it has concluded that the compliance motivation 

predominates over the reclamation motivation” and “why that conclusion, even if validly 

Deleted: . “ 203 F.3d at 1056
42

reached, compels the further conclusion that the wastewater has been discarded.” 213 

F.3d at 58. 

The court also considered whether material is discarded in Safe Food and 

Fertilizer v. EPA, 350 F.3d 1263 (D.C. Cir. 2003) (“Safe Food”). In that case, among 

other things, the court rejected the argument that, as a matter of plain meaning, recycled 

material destined for immediate reuse within an ongoing industrial process is never 

considered "discarded," whereas material that is transferred to another firm or industry 

for subsequent recycling must always be solid wastes. 350 F.3d at 1268. Instead, the 

court evaluated “whether the agency's interpretation of ... 'discarded' . . . is, reasonable 

and consistent with the statutory purpose. . . ." Id. Thus, EPA has the discretion to 

determine if material is not a solid waste, even if it is transferred between industries.

We also note that the Ninth Circuit has specifically found that non-hazardous 

secondary materials may, under certain circumstances, be burned and not constitute a 

solid waste under RCRA. See Safe Air For Everyone v. Waynemeyer (“Safe Air”), 373 

F.3d 1035 (9th Cir., 2004) (Kentucky bluegrass stubble may be burned to return nutrients 

to the soil and not be a solid waste). 

E. Regulatory Interpretations Regarding the Recycling of Hazardous Secondary 

Materials and the Concept of Legitimacy

As over twenty-five years of experience in implementing the hazardous waste 

regulations has demonstrated, drawing the line between materials that are part of a 

manufacturing process or are more commodity-like rather than waste-like (and therefore 

not discarded) from those that are discarded (and therefore are being disposed) is a 

Deleted: last time the 

Deleted: was 
43

difficult one and depends on a number of factors, including how the materials are 

managed. 

For example, it is clear that the distillation of hazardous waste solvents or the 

neutralization of contaminated acids (while the hazardous secondary material itself may 

be regulated under the RCRA hazardous waste regulations) can produce products which 

are not considered wastes. Similarly, under 40 CFR 260.31(c), EPA may grant a variance 

from classifying as a solid waste those hazardous secondary materials that have been 

reclaimed, but must be reclaimed further. In order for such a variance to be granted, the 

resulting material must be commodity-like (even though it may not be a commercial 

product) based on a series of specific factors. Under one such variance, World Resources 

Company (WRC) accepts shipments of metal bearing sludges (principally sludges from 

electroplating operations, a listed hazardous waste under RCRA), and then dries and 

blends the sludges with other shipments to achieve concentrates that meet the contractual 

specifications of its customers (smelters that recover metals contained in the 

concentrates). Under the variance, the incoming electroplating sludges are regulated as 

hazardous waste until they are processed, but the resulting product is no longer a solid 

waste, and it can be shipped to smelters for further reclamation as a product in commerce 

and not as a waste. EPA is aware that several authorized states have made comparable 

determinations, as part of the state authorized RCRA hazardous waste program. 

 An important element under the RCRA Subtitle C definition of solid waste is the 

concept of legitimate recycling, including the legitimate use of hazardous secondary 

materials. Under RCRA Subtitle C, some hazardous secondary materials that would 

otherwise be subject to regulation under RCRA’s “cradle to grave” system are not 
44

considered solid wastes if they are “legitimately recycled” or legitimately used as an 

ingredient or substitute for a commercial product. The principal reasoning behind this 

construct is that use or recycling of such materials often closely resembles normal 

industrial production, rather than waste management. However, since there can be 

considerable economic incentive to manage recyclable materials outside of the RCRA 

hazardous waste regulatory system, there is a clear potential for and historical evidence of 

some handlers claiming they are recycling, when in fact they are conducting waste 

treatment and/or disposal in the guise of recycling. EPA considers such “sham” recycling 

to be, in fact, discard and materials being sham recycled to be solid wastes. 

 To guard against hazardous secondary materials being discarded in the guise of 

recycling, EPA has long articulated the need to distinguish between “legitimate” (i.e., 

true) recycling and “sham” (i.e., fake) recycling, beginning with the preamble to the 1985 

hazardous waste regulations that first established the definition of solid waste under 

RCRA Subtitle C (50 FR 638; January 4, 1985). A similar discussion that addressed 

legitimacy as it pertains to burning hazardous secondary materials for energy recovery 

(considered a form of recycling under RCRA Subtitle C) was presented in the January 9, 

1988 proposed amendments to the definition of solid waste (53 FR 522). On April 26, 

1989, the Office of Solid Waste issued a memorandum that consolidated the various 

preamble and other statements concerning legitimate recycling into a list of questions to 

be considered in evaluating the legitimacy of a hazardous secondary materials recycling 

process (OSWER directive 9441.1989(19)). This memorandum (known to many as the 

“Lowrance Memo”) has been a primary source of information for the regulated 

community and for overseeing agencies in distinguishing between legitimate and sham 
45

recycling. 

 As discussed above, on October 30, 2008, EPA finalized several exclusions from 

the definition of solid waste for hazardous secondary materials being reclaimed and a 

non-waste determination process for persons to receive a formal determination that their 

hazardous secondary materials are not solid wastes when legitimately reclaimed. As part 

of that final rule, EPA codified a legitimate recycling provision specifically as a condition 

of these exclusions and the non-waste determination process. 

As discussed earlier, EPA emphasizes that it is not requesting comment on any 

Subtitle C regulation or any of the issues involved in its hazardous waste regulations. 

EPA does not intend to respond to any comments directed to its hazardous waste 

regulations. 

However, because the concept of legitimacy is a useful one in determining when a 

secondary material is genuinely recycled and not discarded under the guise of recycling, 

the Agency is including the following discussion in today’s preamble to provide the 

context in which EPA has integrated the concept of legitimacy into the latest hazardous 

waste exclusions from the definition of solid waste. 

The legitimacy provision in the October 2008 final rule, which applies 

specifically to the hazardous secondary materials excluded under the rule, has two parts. 

The first part includes two factors: 1) the hazardous secondary materials being recycled 

must provide a useful contribution to the recycling process or to the product or 

intermediate of the recycling process, and 2) the product or intermediate produced by the 

recycling process must be valuable. These two legitimacy factors make up the core of 

legitimacy, and, therefore, a process that does not conform to them cannot be a legitimate 
46

recycling process, but would be considered sham recycling. 

 The second part of the legitimacy provision consists of two factors that must be 

considered when determining if a particular hazardous secondary material recycling 

process is legitimate for the purposes of the exclusion. These two factors are: 1) the 

generator and the recycler should manage the hazardous secondary material as a valuable 

commodity, and 2) the product of the recycling process does not contain significant 

concentrations of hazardous constituents that are not in analogous products. EPA 

believes these two factors are important in determining legitimacy, but has not made 

them factors that must be met because the Agency is aware that a legitimate recycling 

process may not conform to one or both of these two factors. In making a determination 

that a hazardous secondary material is legitimately recycled, persons must evaluate all 

factors and consider legitimacy as a whole. If, after careful evaluation of these other 

considerations, one or both of the non-mandatory factors are not met, then this fact may 

be an indication that the material is not legitimately recycled. To evaluate the extent to 

which these factors are met and in determining the legitimacy of a recycling process that 

does not meet one or both of these factors, persons can consider the protectiveness of the 

storage methods, exposure from toxics in the product, the bioavailability of the toxics in 

the product, and other relevant considerations. 

 EPA stated in the preamble to the October 2008 final rule that, although the 

Agency was only codifying the legitimacy provision as part of the new hazardous 

secondary materials recycling exclusions and non-waste determination process, it was 

stressing that EPA retains its long-standing policy that all recycling of hazardous 

secondary materials must be legitimate and that the four legitimacy factors codified at 40 

Deleted: of some situations in which 

Deleted: does

Deleted: , yet the recycling process 

would still be considered legitimate.

Deleted: whether a 

Deleted: is still legitimate
47

CFR 260.43 are substantively the same as the existing legitimacy policy, as stated in the 

1989 Lowrance Memo and in various definitions of the solid waste rulemakings. 

 The same principle of “legitimacy” is likewise an important element in the 

recycling of non-hazardous secondary materials. That is, the concept of legitimate 

recycling is crucial to determining whether a non-hazardous secondary material being 

recycled is truly being recycled or is, in fact, being discarded through sham recycling. In 

this notice, the Agency is addressing the same basic concept of legitimate recycling by 

discussing when a non-hazardous secondary material that is not discarded is legitimately 

recycled or is a legitimate ingredient in an industrial process. Obviously, a secondary 

material that is not discarded and is combusted can only be a fuel or ingredient, and not a 

solid waste, if the material is being legitimately used as a fuel or ingredient. 

Consequently, the Agency is seeking comment on the appropriate construct for 

determining when non-hazardous secondary materials are legitimately burned as fuel or 

used as a legitimate ingredient in an industrial process. This is explained in detail in the 

following Section V: Preliminary EPA Approach to Determine if Materials Are 

Considered Solid Wastes. 

V. Preliminary EPA Approach to Determine if Materials Are Considered Solid 

Wastes 

A. Materials That Are Not Solid Wastes 

EPA is providing advanced notice of its intent to develop a definition of the term 

“solid waste” under RCRA for non-hazardous secondary materials that are used as a fuel 

or ingredient in a manufacturing process. As noted previously, the purpose of this notice 

is to assist EPA in developing emissions standards under sections 112 and 129 of the 

Deleted: Used 
48

CAA, because the CAA states that the term “solid waste” shall have the meaning 

“established by the Administrator pursuant to [RCRA].” 42 USC 7429(g)(6). The 

Agency is considering various usage of secondary materials (e.g., as fuels or ingredients) 

and whether these materials should be considered solid wastes under RCRA when used in 

combustion devices, such that units burning these materials would be subject to 

regulation under CAA section 129, rather than potentially subject to CAA section 112. 

EPA has identified several cases where we believe secondary materials are not solid 

wastes when combusted. These include: 

• Traditional fuels; 

• Secondary materials used as legitimate “alternative” fuels that have not been 

previously discarded; 

• Secondary materials used as legitimate “alternative fuels” resulting from 

processing of discarded secondary materials; 

• Secondary materials used as legitimate ingredients; and 

• Hazardous secondary materials that may be excluded from the definition of solid 

waste under RCRA Subtitle C because they are more like commodities than wastes. 

1. Traditional Fuels 

 Fossil fuels (e.g., coal, oil, natural gas), and their derivatives (e.g., petroleum 

coke, bituminous coke, coal tar oil, refinery gas, synthetic fuel, heavy recycle, asphalts, 

blast furnace gas, recovered gaseous butane, coke oven gas), as well as cellulosic biomass 

(e.g., wood) are traditional fuels which have been burned historically as fuels and have 

been managed as valuable products. These traditional fuels are unused products that have 

not been discarded and therefore are not solid wastes. (However, certain “alternative” 
49

fuels, such as coal refuse, have in some cases been abandoned, and therefore discarded - 

see discussion of coal refuse in section VI.A.) EPA also believes that wood collected 

from forest fire clearance activities and trees and uncontaminated wood found in 

hurricane debris is not discarded if managed properly and burned as a legitimate fuel, and 

therefore is not a solid waste. We request comment on whether there are other traditional 

fuels that would fall within this grouping. 

 It should be understood that cellulosic biomass, as described above, includes 

unadulterated or clean wood, but that other forms of wood, such as reconstituted 

wood/panel products (e.g., medium density fiberboard, particle board, and laminated 

lumber) or painted and chemically treated wood, would need to be evaluated as to 

whether they would qualify as a legitimate alternative fuel pursuant to the criteria 

described in the following section. 

2. Guiding Principles Used to Determine if Secondary Materials Used in Combustion 

Units are Solid Wastes 

For these various secondary materials that are used either as ingredients or 

alternative fuels, EPA is examining the principles expressed in the various court 

decisions on previous rulemakings. In addition, we are considering the overall principle 

in our hazardous waste regulations that materials treated as a commodity, rather than as a 

waste, are not discarded and are not solid wastes so long as they are legitimately 

recycled. We are soliciting comments on the appropriateness of the principles as applied 

to non-hazardous secondary materials and on how best to structure the criteria for when a 

non-hazardous secondary material is or is not a solid waste. To this end, the same 

secondary material could be a solid waste or not depending on how it has been handled 
50

and managed because handling and management factors into whether or not the 

secondary material has been discarded. Key factors in determining if these alternative 

fuels or ingredients are solid wastes under RCRA are: 1) whether they have been 

discarded, which includes how they are managed and whether they are being used as 

legitimate fuels and ingredients; and 2) if they have been discarded, whether they have 

been processed to produce a fuel or ingredient product that would not be considered a 

solid waste. 

 As noted above in the discussion of AMC I, as well as other consistent cases, the 

plain-English meaning of the term discard applies to the RCRA definition of solid waste. 

That is, a material is discarded if it is disposed of, thrown away, or abandoned. 

Moreover, the term “discarded materials” could not include materials “...destined for 

beneficial reuse or recycling in a continuous process by the generating industry itself.” 

Determining whether a secondary material is used in a continuous process is 

important because certain materials under consideration are produced and managed in a 

continuous process within an industry (e.g., bagasse and cement kiln dust that is recycled 

in cement kilns). In looking at the recently promulgated Subtitle C non-waste 

determination petition process under 40 CFR 260.34, to determine whether hazardous 

secondary materials are used in a continuous process, EPA would evaluate whether the 

hazardous secondary material is part of the continuous primary production process and is 

not waste treatment. If the hazardous secondary material is handled in a manner identical 

to virgin feedstock, then it would appear to be fully integrated into the production 

process. At the other end of the spectrum, however, hazardous secondary materials 

indisputably discarded prior to being reclaimed are not a part of the continuous primary 

Deleted: First, the ordinary plainEnglish meaning

Deleted: the term “discard” controls. 

See American Mining Congress v. EPA, 

824 F.2d 1177 (D.C. Cir. 1987) (“

Deleted: ”). The ordinary 

Deleted: means “

Deleted: ,” “

Deleted: ”

Deleted: “

Deleted: ” 825 F.2d at 1190. The court 

specifically rejected a more expansive 

meaning for discard that would 

encompass any

Deleted: “no longer useful in their 

original capacity” even if they were

Deleted: destined for disposal. 824 

F.2d at 1185-87. The result of this 

analysis is that EPA may not regulate as 

"discarded"

Deleted: . 824 F.2d at 1190.
51

production process. See API I, ILCO and Owen Steel, cited previously. Moreover, 

hazardous secondary materials are likely discarded in the case where industry may reuse 

materials in the future and it is not clear that reuse will occur. See AMC II, cited 

previously. By similar logic, EPA believes that non-hazardous alternative fuels or 

ingredients that are produced and used as a legitimate fuel or ingredient in a continuous 

process would not be considered to have been discarded. 

Furthermore, even if the material is not used in a continuous process, if it is used 

as a legitimate fuel or ingredient, these secondary materials are likely not solid wastes if 

they were not previously discarded. See API II and Safe Food, previously cited. Many 

materials, such as coal fly ash and biomass are intended for legitimate reuse and therefore 

are not discarded. EPA believes these materials, if used as legitimate fuels or ingredients 

(as discussed in more detail below) would likely not be solid wastes if they have not been 

previously discarded (however, as discussed later in this section, previously discarded 

materials that are processed into a legitimate fuel product or ingredient would also likely 

not be solid wastes). 

However, for alternative fuels or ingredients to not be considered discarded, and 

thus not solid wastes, they must be legitimate fuels or ingredients. Below we first discuss 

the legitimacy criteria for alternative fuels, followed by a discussion of the legitimacy 

criteria for materials used as ingredients. 

a. Legitimate Alternative Fuels. Specifically, the Agency generally considers 

secondary materials to be a legitimate fuel if they are handled as valuable commodities, 

have meaningful heating value, and contain contaminants that are not significantly higher 

in concentration than traditional fuel products. If these criteria are not met, sham 
52

recycling may be indicated and the secondary material might be a solid waste. EPA is 

interested in receiving comments on these principles. Specifically: 

• Handled as a Valuable Commodity. For hazardous secondary materials, EPA has 

previously said, with respect to whether something is managed as a valuable commodity, 

that where there is an analogous raw material, the hazardous secondary material should 

be managed, at a minimum, in a manner consistent with the management of the 

analogous raw material.51 Where there is no analogous raw material, the hazardous 

secondary material should be contained. Hazardous secondary materials that are released 

to the environment and are not recovered immediately are considered to be discarded. 

We request comment on whether similar criteria should be used to determine if nonhazardous secondary materials used as alternative fuels are being managed as valuable 

commodities and thus are not solid waste, or whether more tailored criteria are more 

appropriate for non-hazardous secondary materials. For example, in situations where 

there is no analogous raw material, the Agency is interested in what type of containment 

would be necessary for non-hazardous secondary materials, particularly whether 

materials that are physically solid, such as tires, require containment. 

• Meaningful Heating Value: EPA is seeking comment on how to define 

meaningful heating value for materials that are used as alternative fuels. Because of the 

wide variety of materials in question, and because of technology advances and the fact 

that fuel values vary, EPA questions whether it is possible or appropriate to establish a 

specific heating value cutoff for “legitimate” fuel. In the context of the hazardous waste 

regulations, EPA addressed the concept of whether a hazardous secondary material has 

an adequate, meaningful heating value in the so-called “comparable fuels” rule (63 FR 

 

51 See “Revisions to the Definition of Solid Waste,” Final Rule, October 30, 2008, at 73 FR 64667. 
53

33781) with a benchmark Btu content of 5,000 Btu/lb (see section V.A.6 for more on the 

comparable fuels rule).52 However, given improved combustion processes that have been 

developed that cost-effectively produce energy from lower rank materials (e.g., 

circulating fluidized bed combustion units), and given the fact that lower Btu content 

non-hazardous materials are frequently combusted for fuel value, EPA is requesting 

comment on whether a Btu content is needed, and if so whether a lower Btu content may 

be appropriate. Alternative fuel materials have a wide range of heating values that range 

from 2,600 Btu/lb for food; to 3,000 Btu/lb for yard trimmings; to 3,750 Btu/lb for 

sludge; to 5,000 Btu/lb for wood; and to 13,450 BTU/lb for rubber.

53 We request 

comment on whether we should develop a specific minimum Btu value on an “as-fired” 

basis that would qualify a secondary material as having meaningful heating content, or 

whether we should define meaningful heating value more qualitatively based on general 

principles. 

• Presence of Non-fuel Contaminants: In the hazardous waste comparable fuels 

rule, EPA established numerical specifications for toxic organics, toxic metals, sulfur, 

nitrogen, halogens, and polychlorinated biphenyls (PCBs). To address the possible 

presence of waste-like contaminants in non-hazardous secondary materials, EPA believes 

a qualitative approach is more appropriate and can be used to identify waste materials 

containing contaminants that are significantly higher in concentration than those 

contained in traditional fuel products to the degree that sham recycling is indicated. The 

 

52 In addition, EPA has previously stated that Subtitle C industrial furnaces (i.e., cement kilns and industrial 

boilers) burning wastes with energy value greater than 5,000 Btu may generally be said to be burning for 

energy recovery, however, lower energy wastes could conceivably be burned for energy recovery due to the 

devices’ general efficiency of combustion. “Thus, the 5,000 Btu level is not an absolute measure of 

burning for energy recovery...” (see 62 FR 24251, May 2, 1997). 

53 See background document titled “Methodology for Allocating Municipal Solid Waste to Biogenic and 

Non-Biogenic Energy, Energy Information Administration (U.S.DOE), May, 2007.

Deleted: 800

Deleted: (dry weight) 

Deleted: garden

Deleted: 800

Deleted: wood chips (45 percent 

moisture); to 4,000 

Deleted: green sawdust; to 8000 Btu/lb 

mean heating value for coal refuse

Deleted: 16,000 Btu

Deleted: pelletized 

Deleted: . (See 

http://msw.cecs.ucf.edu/EnergyProblem.p

pt#263,3Table1 and 

http://www.umass.edu/umext/floriculture/

fact_sheets/greenhouse_management/jb_f

uels.htm).
54

term “contaminants” refers to constituents in secondary materials that may be of a 

concern when burned as a fuel. For example, secondary materials that could contain 

contaminants that are significantly higher in concentration than those contained in 

traditional fuel products include chromium-, copper-, and arsenic (CCA)-treated lumber, 

secondary mill residues (i.e., residues such as board, trim and breakage from the 

manufacture of reconstituted wood/panel products), polyvinyl chloride (PVC) plastics 

which can contain 60 percent halogens (chlorine),54 lead-based painted wood, fluorinated 

plastics, and non-hazardous halogenated solvents. In determining whether the

concentration of contaminants in secondary materials is “significantly higher,” the 

Agency could include a qualitative evaluation of the potential human health and 

environmental risks posed. A contaminant concentration could be elevated without 

posing unacceptable risk, and therefore may not be considered “significant” for the 

purposes of determining whether the secondary material is a legitimate fuel. We request 

comment on whether a qualitative approach to defining fuels as solid waste because they 

are too contaminated (indicating sham recycling) is an appropriate option. In any case, 

given the multiplicity of fuel materials, we believe that numerical specifications are likely 

to be impractical. We also request comment on whether the contaminants evaluated for 

the comparable fuels rule,55 which mostly includes Appendix VIII constituents, should 

also be used for non-hazardous secondary materials used as fuels, or whether a different

of list contaminants is appropriate. 

b. Legitimate Alternative Ingredients. For non-hazardous secondary materials to 

be used as legitimate ingredients, the Agency would use a similar legitimacy analysis as 

 

54 Constituents, such as chlorine in PVC are relevant because of the potential for chlorinated combustion 

by-products to be emitted (e.g., dioxins, hydrogen chloride).

55 See RCRA Comparable Fuel Exclusion Final Rule, June 19, 1998 at 40 CFR 261.38.

Deleted: ),

Deleted: In addition, EPA would 

potentially consider asbestos-containing 

materials, including asbestos-containing 

ceiling and floor tiles, as a solid waste 

when combusted due to their relative 

contaminant levels, although it may be 

the case that other federal laws, most 

notably the National Emission Standards 

for Asbestos (40 CFR Part 61, Subpart 

M), prohibit the combustion of these 

materials.
55

was developed in the hazardous waste program. Specifically, the Agency would 

generally consider secondary materials to be a legitimate ingredient if the secondary 

material is handled as a valuable commodity, the secondary material provides a useful 

contribution, the recycling results in a valuable product, and the product does not contain 

contaminants that are significantly higher in concentration than traditional products. If 

these criteria are not met, sham recycling may be indicated and the secondary material 

may be a solid waste. For use as an ingredient, EPA would not be looking at fuel value 

since the secondary materials are being used as an ingredient and not a fuel. Instead, the 

Agency would look at useful contribution and valuable product, as described below. The 

Agency is interested in receiving comments on these principles, including whether the 

following principles are reasonable for non-hazardous secondary materials used as 

ingredients: 

• Handled as a Valuable Commodity. For hazardous secondary materials, EPA has 

previously said, with respect to whether a secondary material is managed as a valuable 

commodity, that where there is an analogous raw material, the hazardous secondary 

material should be managed, at a minimum, in a manner consistent with the management 

of the analogous raw material. Where there is no analogous raw material, the hazardous 

secondary material should be contained. Hazardous secondary materials that are released 

to the environment and are not recovered immediately are discarded, and thus would be 

regarded as a waste and not a commodity. We request comment on whether similar 

criteria should be used to determine if non-hazardous secondary materials used as 

ingredients are being managed as valuable commodities and thus are not solid waste, or 
56

whether more tailored criteria are more appropriate for non-hazardous secondary 

materials. 

• Useful Contribution: For hazardous secondary materials, EPA has previously 

stated that a secondary material must provide a useful contribution to the recycling 

process or to the product of the recycling process.56 The ways in which a secondary 

material can add value and usefully contribute to a recycling process are: (i) the 

secondary material contributes valuable ingredients to a product or intermediate; or (ii) 

replaces a catalyst or carrier in the recycling process; or (iii) is the source of a valuable 

constituent recovered in the recycling process; or (iv) is recovered or regenerated by the 

recycling process; or (v) is used as an effective substitute for a commercial product. We 

request comment on whether this description is applicable for non-hazardous secondary 

materials used as ingredients in a combustion process. 

• Valuable Product or Intermediate: Similarly, for hazardous secondary materials, 

EPA has stated that the recycling process must produce a valuable product or 

intermediate.57 The Agency believes a product or intermediate is valuable if it is (i) sold 

to a third party or (ii) used by the recycler or generator as an effective substitute for a 

commercial product or as an ingredient or intermediate in an industrial process. The 

Agency believes this description is broad enough to incorporate both products that are 

valuable from a monetary standpoint and products or intermediates that have intrinsic 

value to the generator or the recycler. We are seeking comment on whether this 

 

56 See “Revisions to the Definition of Solid Waste,” Final Rule, October 30, 2008, at 73 FR 64667. 

57 See “Revisions to the Definition of Solid Waste,” Final Rule, October 30, 2008, at 73 FR 64667. 
57

description of valuable product/intermediate is an appropriate way to consider this 

criterion in the context of non-hazardous secondary materials used as ingredients. 

• Presence of Contaminants: As mentioned above under legitimate fuel criteria, 

EPA is suggesting a qualitative approach may be more appropriate to use in identifying 

waste materials containing contaminants that are significantly higher in concentration

than those contained in traditional products to the degree that sham recycling is indicated. 

In the context of hazardous secondary materials, EPA expects those making a legitimate 

recycling determination to look at the concentrations of hazardous constituents found in 

the product made from hazardous secondary materials and compare them to the 

concentrations of hazardous constituents in analogous products to determine if the 

concentrations are significantly higher.58 In determining whether the concentration of 

contaminants in secondary materials is “significantly higher,” the Agency could include a 

qualitative evaluation of the potential human health and environmental risks posed. A 

contaminant concentration could be elevated without posing unacceptable risk, and 

therefore may not be considered “significant” for the purposes of determining whether 

the secondary material is a legitimate ingredient. EPA concluded in the most recent 

hazardous secondary material rulemaking that the complexities of defining “significant” 

via a bright-line quantitative test that would also still be appropriate for all industries, all 

recycling processes, and all recycled hazardous secondary materials were too great for 

the Agency to be able to design as a simple and straightforward system of tests to be used 

in making such determinations.

59 We request comment on whether a similar qualitative 

approach to defining ingredients used in a manufacturing process involving combustion

 

58 See “Revisions to the Definition of Solid Waste,” Final Rule, October 30, 2008, at 73 FR 64667.

59 See “Revisions to the Definition of Solid Waste,” Final Rule, October 30, 2008, 73 FR at 64745.

Deleted: at 

Deleted: 64667.¶
58

as solid waste because they are too contaminated (indicating sham recycling) is the 

preferred option or whether numerical specifications is a better approach. In addition, the 

Agency is requesting comment on whether the contaminants evaluated should be the 

hazardous constituents listed in Appendix VIII to 40 CFR Part 261 or whether a different 

list of contaminants is more appropriate for non-hazardous secondary materials used as 

ingredients. 

c. Discarded Secondary Materials That Have Been Processed. In many cases, 

the secondary material may have been discarded, but later processed to produce a 

legitimate fuel product or ingredient, ready for direct use in an industrial process. In such 

cases, the processed material that is extracted or reclaimed as a legitimate fuel or 

ingredient would not be a waste, but rather a product of the processing activity. In 

general, the products from the recycling of solid wastes are not themselves wastes - for 

example, paper that is made from recycling used paper and then sold in stores is a 

product, not a waste. EPA believes that if a secondary material is processed into a 

legitimate fuel or ingredient material, the processed material would not be a discarded 

material. Of course, these products still must qualify as legitimate fuels or ingredients, as 

previously discussed. Otherwise, sham recycling may be indicated and the materials may 

be a solid waste. For example, used oil that is processed to produce “on-spec fuel” and 

that meets the standards of 40 CFR 279.11 would be considered a product, not a waste. 

See section V.A.4 for more discussion of used oil. 

 In the following sections, we discuss three groupings (previously listed) where we 

believe secondary materials are not solid wastes, but rather are non-discarded products 
59

that are legitimate fuels or ingredients when used in combustion units. We are soliciting 

comment on our interpretation of these materials as not being solid wastes under RCRA. 

3. Secondary Materials Used as Legitimate “Alternative” Fuels That Have Not Been 

Previously Discarded 

 As we discussed previously, EPA believes that the question of what constitutes a 

legitimate “fuel” reflects the availability of fuel materials generally, the demand for fuel, 

and technology developments. Thus, in addition to traditional fuels, the Agency also 

believes that there is a category of secondary materials that are legitimate alternative 

fuels; that is, there are secondary materials that may not have been traditionally used as 

fuels, but that are nonetheless legitimate fuels today because of changes in technology 

and in the energy market. In cases where these legitimate alternative fuels have not been 

discarded, EPA would not consider them to be solid wastes. 

Alternative fuels consisting of biomass represent a large percentage of the 

alternative fuels in use today. We generally believe that much of the biomass currently 

used as alternative fuels are not solid waste since they have not been discarded in the first 

instance and are legitimate fuel products (i.e., they have been managed as valuable 

commodities, have meaningful heating value and do not contain contaminants that are 

significantly higher in concentration than those in traditional fuel products). Thus, when 

burned, it would not be considered “sham” combustion. See previous discussion in 

section V.A.2. Biomass can include a wide range of alternative fuels, and can be broken 

down into two different categories - cellulosic biomass and non-cellulosic biomass. 

Cellulosic biomass includes forest-derived biomass (e.g., green wood, forest thinnings, 

clean and unadulterated bark, sawdust, trim, and tree harvesting residuals from logging 
60

and sawmill materials), food scraps, and pulp and paper mill residuals (e.g., spent pulping 

liquors; hog fuel, such as clean and unadulterated bark, sawdust, trim screenings; and 

residuals from tree harvesting), and agricultural residues (e.g., straw, corn husks, peanut 

shells, and bagasse). Non-cellulosic biomass includes manures and gaseous fuels (e.g., 

from landfills and manures). 

EPA generally considers biomass as described above, especially cellulosic 

biomass, to have comparable composition when compared to traditional fuel products due 

to the nature of the plants and animals (i.e., they would not be considered to have 

additional “contaminants”). Thus, if they are managed as valuable commodities and have 

meaningful heating value, then we do not believe that they should be considered solid 

wastes. We request comment on whether biomass as described above contains 

contaminants that are significantly higher in concentration when compared to traditional 

fuel products. In determining whether the concentration of contaminants in biomass is 

“significantly higher,” the Agency could include a qualitative evaluation of the potential 

human health and environmental risks posed. A contaminant concentration could be 

elevated without posing unacceptable risk, and therefore may not be considered 

“significant” for the purposes of determining whether the secondary material is a 

legitimate fuel. We also request comment on the impact of a solid waste determination, 

one way or the other, on the inclusion of biomass materials in the many state-initiated 

renewable fuels specifications whereby such materials (e.g., manures, forest thinnings) 

are required to be used in the electric generation portfolio within the state. 

EPA also believes that tires used as TDF, which include whole or shredded tires, 

that have not been previously discarded, are legitimate fuels that meet our previous 
61

described criteria (i.e., they are handled as valuable commodities, have meaningful 

heating value, and do not contain contaminants that are significantly higher in 

concentration when compared to traditional fuel products). EPA's 1997 study on “Air 

Emissions from Scrap Tire Combustion”60 concluded that potential emissions from TDF 

are often less than and generally within the same range as, emissions from conventional 

fossil fuels. Thus, if the tires have not been abandoned and thrown away, we would not 

consider them to be solid wastes. For example, approximately 130 million tires per year 

are obtained from tire dealerships and used directly as a fuel. In many cases, these tires 

are collected pursuant to state tire programs and handled as valuable products, and, 

therefore, they have not been abandoned, disposed of, or thrown away.61 In other cases, 

they are transferred to brokers or directly to industrial operations through standard 

commercial transactions. In contrast, tires that have accumulated in tire piles over the 

years (i.e., those tires in tire piles that have been abandoned) have been discarded, and 

thus considered to be solid waste (although they may later be processed into a legitimate 

fuel product).62

Other non-traditional alternative fuels in use today that we are evaluating to 

determine whether they have not been discarded, and are legitimate alternative fuels 

include construction and demolition materials, scrap plastics, non-hazardous non-

 

60 This study was published by EPA’s Office of Research and Development and produced as part of EPA’s 

National Risk Management Research Laboratory strategic long-term research plan for the prevention and 

control of pollution to air, land, water, and subsurface resources; protection of water quality in public water 

systems; remediation of contaminated sites and groundwater; and prevention and control of indoor air 

pollution. 

61 States typically regulate these programs under their state solid waste authorities. It is not the Agency’s 

intent to undercut state authorities in this area. We request comment on whether tires collected pursuant to 

state tire programs have been discarded. We also request comment on whether an EPA designation 

specifying that used tires, for example, managed pursuant to state collection programs are not solid wastes, 

would adversely impact a states ability to manage such programs. This similarly would apply to used oil as 

well. 

62 For example, as noted below, whole tires can be processed (shredded) into fuel products after they have 

been discarded. 
62

halogenated solvents and lubricants, and wastewater treatment sludge. We request 

comment on whether these secondary materials are legitimate alternative fuels and thus 

would not be solid wastes if they have not been previously discarded. Commenters 

should provide data and/or information supporting whether these secondary materials are 

legitimate and whether they are or are not considered to have been discarded. 

Some secondary materials are questionable as to whether they are legitimate fuels 

because they lack adequate heating value, which could be the case for wet biomass that 

has insufficient as-fired heating content due to its moisture content. Another secondary 

material that may not be a legitimate fuel is biomass that has, for example, undergone 

chemical treatment, such that the material may contain contaminants that are significantly 

higher in concentration than those in traditional fuel products to the degree that sham 

recycling is indicated. Secondary materials that we think may contain contaminants that 

are significantly higher in concentration than those of traditional fuel products include 

PVC (which can contain 60 percent chlorine),63 halogenated plastics, chromated copper 

arsenate (CCA) lumber, creosote lumber, copper-based treated lumber, lead-based treated 

lumber, secondary mill residues (i.e., residues such as board, trim and breakage from the 

manufacture of reconstituted wood/panel products), and non-hazardous halogenated 

solvents. In determining whether the concentration of contaminants in secondary 

materials is “significantly higher,” the Agency could include a qualitative evaluation of 

the potential human health and environmental risks posed. A contaminant concentration 

could be elevated without posing unacceptable risk, and therefore may not be considered 

 

63 As previously discussed, the term “contaminants” refers to constituents in secondary materials that may 

be of a concern when burned as a fuel. Constituents, such as chlorine in PVC are relevant because of the 

potential for chlorinated combustion by-products to be emitted (e.g., dioxins, hydrogen chloride).

65 See Definition of Solid Waste Final Rule, January 4, 1985 at 50 FR 641-642, covering both black liquor 

and spent sulfuric acid. 

Deleted: ),

Deleted: , and asbestos-containing 

material.64
63

“significant” for the purposes of determining whether the secondary material is a 

legitimate fuel. We request comment on whether these secondary materials contain 

contaminants that are significantly higher in concentration compared to traditional fuel 

products, and whether there are other secondary materials not listed that should be 

considered to have contaminant concentrations that would result in them being 

disqualified as a legitimate fuel (i.e., a solid waste when burned). 

 We also request comment on whether there are other types of secondary materials 

that should be considered alternative fuels, assuming they have not been discarded and 

are legitimate (i.e., they meet the criteria discussed in section V.A.2). For example, as we 

discuss in more detail in section VI, biofuel production has increased dramatically in the 

past few years and is expected to continue increasing over the coming years. We later 

take specific comment on the extent to which biofuels are currently used in stationary 

combustion units, and the extent to which byproducts from the production of biofuels, as 

well as ingredients used to produce biofuels, such as fats, oils, and greases, are used 

directly in stationary combustion units as alternative fuel sources. Commenters should 

explain the circumstances under which these secondary materials would not be 

considered to have been discarded, and how these materials meet the criteria as legitimate 

fuels. See the Materials Characterization Papers in the docket established for this 

ANPRM for a complete description of the secondary materials EPA is assessing as part 

of this effort. 

4. Secondary Materials Used as Legitimate “Alternative Fuels” Resulting From the 

Processing of Discarded Secondary Materials 
64

 EPA also believes that legitimate fuel products may be extracted, processed, or 

reclaimed from non-hazardous secondary materials that have been discarded in the first 

instance and that such products would generally not be considered solid waste. Once 

processed to make a legitimate fuel product, such a product would not be discarded and 

therefore would not be a solid waste, provided it met the general principles previously 

discussed for being a legitimate fuel. (Note: Until a legitimate product has been 

extracted, processed or reclaimed, the secondary material that has been discarded is a 

solid waste.) The principle behind this idea of processing a waste to produce a product is 

common to industrial processes. 

Due to the nature of some materials (e.g., low Btu value, the presence of 

contaminants, or the need for certain physical characteristics to address handling issues 

associated with the combustion device), processing will be necessary for the secondary 

material to be used as a fuel. Such discarded materials generally would be solid wastes 

until the point that a fuel product is produced; however, the fuel itself would not be a 

solid waste as long as it met the legitimacy factors. Secondary materials that can be 

processed into fuel include discarded biomass, coal fines, used oil, tires, and landfill ash. 

The degree of processing necessarily will vary depending on the specific material, but the 

objective remains the same – the product from the processing must be a legitimate fuel 

(i.e., a material with meaningful heating value, with contaminants that are not present at 

significantly higher concentrations than those of traditional fuel products, and managed 

as a valuable commodity). Below are some examples of secondary materials that we 

believe may be processed to produce a legitimate non-waste fuel. 
65

• For biomass that has been previously discarded and has high moisture content, 

dewatering/drying techniques can be used to effectively increase the Btu/lb and 

produce a legitimate non-waste fuel, provided the biomass does not contain 

contaminants at significantly higher concentrations and is handled as a valuable 

commodity. 

• Wood with lead-based paint can be processed to remove the lead-based paint, 

leaving the underlying wood for use as a non-waste, traditional fuel, and the leadbased paint can then be safely disposed of or sent for lead recovery. 

• Tires that cannot be handled whole by some combustion devices (whether 

discarded or not) can be processed by shredding and removing dirt or other 

contaminants to produce TDF. Turning scrap tires into TDF can involve two 

physical processing steps: chipping/shredding and in some cases metal removal. 

TDF consists of chipped tires ranging in size from 1 to 4 inches; the amount of 

metal in TDF varies depending on how much of the tires have been processed. 

Some units, such as cement kilns use the metal in the wire as a valuable ingredient 

in the manufacturing process, and therefore do not require its removal. However, 

most other units benefit from TDF that has been processed to minimize the 

amount of metal and improve heating efficiency. At this point, EPA considers 

tire shredding/chipping alone (without metal recovery), as well as in combination 

with metal recovery, as legitimate processing activities sufficient to convert a 

discarded material into a fuel product. 

Deleted: significant levels of 
66

• Coal fines, biomass, and other materials can be mixed and processed into pellets 

(or other forms) that have the consistency and handling characteristics of coal 

(e.g., K-Fuel, N-Viro). 

In all of the examples above, we, at this point, view the secondary material to 

have been sufficiently processed to produce a fuel that would not be a solid waste if it 

met the general principles described earlier—that is, the fuel product is a legitimate fuel 

and “sham” combustion (i.e., discard rather than use) has not occurred. Of course, any 

waste generated in the “processing” of these materials would need to be managed 

properly. We seek comment on whether the processing described above is sufficient to 

convert discarded material into a fuel product. 

In addition to the examples above, we request comment on some additional 

operations that involve processing. Specifically, logging and primary milling residues 

may be chipped or sorted before combustion. Although we generally believe that this 

material would not be considered to have been discarded, we request comment on 

whether any forest-derived biomass that was determined to have been discarded and was 

subsequently processed by chipping or sorting prior to combustion would be considered 

to have undergone adequate processing to convert the discarded material into a fuel 

product. Mined landfill power plant ash can also be processed (e.g., crushed, screened, 

and/or separated into its fundamental components through density separation techniques) 

into a fuel. We also request comment on whether mined landfill ash is adequately 

processed to convert it into a fuel product or ingredient (under the assumption that it 

meets our previously described legitimacy criteria). 
67

Used oil is a special case since it is specifically addressed in the RCRA statute 

(RCRA section 3014). It is worth noting that the statute does not define used oil as a 

solid waste. Section 3014 provides that EPA is to make a determination whether used oil 

is a hazardous waste, but is silent on whether used oil per se is a solid waste. Thus, we 

must apply the previously described criteria to determine if used oil is in fact discarded. 

Pursuant to RCRA section 3014, the Agency has promulgated standards for used oil 

management. The Standards for the Management of Used Oil in 40 CFR part 279 set 

forth management requirements for used oil that include contaminant limits to identify 

when used oil is considered to be “on-specification” used oil as opposed to “offspecification,” and when it must be managed as a hazardous waste. 

Table 1 in section 279.11 provides contaminant limits for “on-specification” used 

oil. On-specification used oil can only be burned for energy recovery, and once used oil 

is shown to meet the specification limits, the only requirement is maintenance of records 

of shipment to on-specification burners. No requirements or limitations are imposed on 

the management or burning of the on-specification used oil. Other uses of onspecification used oil would continue to cause that use to be subject to the used oil 

regulations. Management of used oil that does not meet the specification limits (referred 

to as off-spec used oil) is subject to the management controls, including recordkeeping, 

storage standards, and burning requirements. With one exception, off-spec used oil may 

only be burned in Subtitle C hazardous waste incinerators, or in boilers and industrial 

furnaces specified by the regulations (see 40 CFR 279.61). The exception is generators 

may burn off-spec used oil in used oil-fired space heaters provided that the heater burns 

only used oil that the owner or operator generates or used oil received from household 
68

do-it-yourself used oil generators, the heater is designed to have a maximum capacity of 

not more than 0.5 million Btu per hour, and the combustion gases from the heater are 

vented to the ambient air. 

There also is an upper total halogen limit for used oil (known as the rebuttal 

presumption). If the used oil has halogens in excess of 1,000 ppm, the used oil is 

considered to have been mixed with halogenated hazardous wastes, and must be managed 

as a hazardous waste unless a demonstration can be made that the used oil does not in 

fact contain hazardous waste. 

We generally consider off-specification used oil that is collected from repair 

shops to have been originally discarded since this used oil contains both fossil fuel and 

contaminants picked up during use as a lubricant, and likely contains contaminants that 

are significantly higher in concentration than traditional fuels, and thus would not be 

considered a legitimate fuel per the criteria discussed in section V.A.2. However, if the 

fossil fuel component is extracted from the non-fuel contaminants through processing to 

meet the on-specification levels in 279.11, the resultant fossil fuel is not significantly 

different from traditional fossil fuels in every way and thus should be considered a 

product fuel, not a waste. We also consider used oil that is collected from repair shops 

that already meet the “on-spec” limits to be legitimate fuel products, not wastes. 

We request comment on whether off-specification used oil managed pursuant to 

the 40 CFR 279 used oil management standards which are burned for energy recovery is 

considered to be discarded, and thus solid waste. Although off-specification used oil may 

contain contaminant levels that are higher in concentration than traditional (virgin) fossil 
69

fuels, they still are managed within the constraints of the used oil management standards, 

and may only be burned in specific types of combustion devices. 

5. Secondary Materials Used as Legitimate Ingredients 

For secondary materials used as ingredients, we also must determine whether the 

alternative ingredients have been discarded, which includes assessing how they are 

managed, and whether they are being used as legitimate ingredients pursuant to the 

criteria described in section V.A.2. Secondary materials that the Agency is assessing as 

alternative ingredients include CKD, bottom ash, boiler slag, blast furnace slag, foundry 

sand, and secondary glass material. We request comment on whether these secondary 

materials are legitimate ingredients as previously described in section V.A.2 and thus 

would not be solid wastes if not previously discarded. Commenters should provide data 

and/or information supporting whether these secondary materials are legitimate 

ingredients and thus, whether they are or are not considered to have been discarded. For 

example, we believe that CKD is not a solid waste if it is recycled within the continuous 

clinker production process. We also believe that coal fly ash is handled as a commodity 

within continuous commerce when it is marketed to cement kilns as an alternative 

ingredient. As a result, if it is determined to be a legitimate ingredient pursuant to the 

criteria outlined in section V.A.2, we would not consider it to be a solid waste. 

 If the alternative ingredient was previously discarded, however, the Agency 

believes that such secondary materials are solid wastes, unless they were processed into a 

legitimate ingredient product. The Agency solicits comment on this situation (that is, the 

situation where a discarded material is recovered from the environment, and directly used 

as an ingredient) and, if comments are submitted that argue that such secondary materials 

Deleted: Further, it is unclear whether 

off-specification used oil that generators 

may burn in used oil-fired space heaters 

would not be considered to be discarded.
70

(once recovered from the environment) should not be considered solid waste, the 

commenters should provide the basis or rationale for such a position (including a 

demonstration of how the secondary materials meet the legitimacy criteria outlined in 

section V.A.2) in order for the Agency to evaluate the arguments that are presented by 

the commenters. The Agency specifically requests comments on the extent to which 

secondary materials that have already been discarded (e.g., coal ash that has been 

landfilled) are later processed and used as ingredients in combustion units. Commenters 

should provide a description of the types of processing that the secondary material 

undergoes. EPA is also soliciting comment on the level of processing that would be 

considered sufficient to transform a discarded material into an ingredient product. 

6. Hazardous Secondary Materials That May Be Excluded From the Definition of 

Solid Waste under RCRA Subtitle C Because They Are More Like Commodities Than 

Wastes 

Under the hazardous waste regulations, the Agency has evaluated a number of 

hazardous secondary materials that are recycled and determined that such materials, 

while they either met a listing description or exhibited one or more of the hazardous 

characteristics, were not “solid wastes” for purposes of the Subtitle C hazardous waste 

regulations. Specifically, the following materials may be burned under certain conditions 

and are not solid wastes, but only for purposes of the hazardous waste regulations--black 

liquor, spent sulfuric acid, and comparable fuels. EPA is interested in extending this 

determination so that these materials are not considered solid wastes under RCRA 

Subtitle D. 
71

The Agency believes that it has sufficient information in the rulemaking records 

that covered the determinations for black liquor, spent sulfuric acid,65 and comparable 

fuels66 to conclude that the exclusions are broadly applicable to the definition of solid 

waste; however, it solicits comment on whether it needs to develop additional 

information and provide new arguments. EPA emphasizes that it is not requesting 

comment on the solid waste definition for purposes of its hazardous waste regulation, but 

only on whether the exclusion conceptually applies to the definition of solid waste that is 

applicable to non-hazardous Subtitle D wastes, when these secondary materials are used 

as a fuel or ingredients. 

EPA provides the following summaries of its regulations and solicits any views 

from the public on these materials. Specifically, a determination was made that black 

liquor reclaimed in a pulping liquor recovery furnace and then reused in the pulping 

process and spent sulfuric acid used to produce virgin sulfuric acid were not solid wastes 

under the hazardous waste regulations. The reason that these hazardous secondary 

materials were determined not to be solid wastes was because these hazardous secondary 

materials were determined to be an integral part of the manufacturing process. With 

respect to comparable fuels, EPA determined that certain hazardous secondary materials 

that meet specific requirements to ensure the material’s toxic constituents and physical 

properties are similar to commercial (benchmark) fuels, are products, not solid wastes. 

See 63 FR 33781. The Agency has also recently finalized a rule that expands the 

Comparable Fuels Exclusion to encompass a new category of liquid hazardous secondary 

 

66 See “Expansion of the RCRA Comparable Fuels Exclusion (CFE)”, Final Rule, December 19, 2008, 73 

FR 77953. 
72

materials known as emission-comparable fuel (ECF).67 By expanding the Comparable 

Fuels Exclusion, ECF will be handled as a valuable commodity. ECF is subject to the 

same regulations that currently apply to the Comparable Fuels Exclusion, with the 

exception of certain oxygenates and hydrocarbons (constituents which contribute energy 

value to the fuel). The rule specifies conditions on burning ECF which assure that 

emissions from industrial boilers burning ECF are comparable to emissions from 

industrial boilers burning fuel oil. 

The Agency specifically states in the hazardous waste rules that such “solid 

waste” determinations are only with respect to the Subtitle C hazardous waste regulations 

(see 40 CFR 261.1(b)(1)). EPA, however, wishes to obtain comment on whether to 

extend these exclusions beyond the hazardous waste regulations and apply them to these 

materials when they are used as a fuel or ingredient, and they meet the general principles 

discussed in today’s notice. 

 VI. Additional Areas for Comment 

The Agency is also interested in receiving comments on the following four issues. 

A. Fuels or Materials That Have Been Discarded That Are Generally Considered to be 

Solid Wastes 

 The Agency considers materials that have been previously discarded and not 

subsequently processed into a legitimate fuel or ingredient products as solid wastes under 

RCRA. However, the question has been raised by certain industry groups and states68 as 

 

67 See “Expansion of the RCRA Comparable Fuels Exclusion (CFE)”, Final Rule, December 19, 2008, 73 

FR 77953. 

68 For example, see the Hybrid Regulatory Approach paper presented by the multi-industry coalition of 

stakeholders (PCA/CIBO/AF&PA/USWAG/RMA) in the docket established for this action entitled: 
73

to whether these discarded materials - once recovered from the environment – may no 

longer be considered solid waste (assuming they are in fact valuable fuels or ingredients 

and otherwise meet the legitimacy criteria once recovered). Therefore, the Agency 

solicits comment on whether there are any circumstances under which these secondary 

materials should not be considered solid wastes under RCRA. 

 EPA recognizes that waste can be burned for energy or material recovery, and 

such materials, once they have been discarded, generally are considered “solid wastes” 

and units that burn these materials would be subject to the CAA section 129 incineration 

standards if they have not been processed into a legitimate ingredient or fuel. However, 

as discussed in section III of this preamble, as prices for primary materials have 

increased, in many cases, the economics of using secondary materials as a substitute for 

primary materials has shifted, changing how the secondary materials are considered in 

commerce. In addition, new technologies can expand the universe of secondary materials 

that could be considered legitimate fuels. 

The Agency is therefore interested in taking comment on the situation where 

discarded materials can be directly used as a legitimate fuel or ingredient (as defined in 

section V.A.2) without processing because they are indistinguishable in all relevant 

aspects from a fuel or ingredient product. (Note that the Agency is only requesting 

comment on these secondary materials at the point they have been removed from their 

“discard” environment and are being managed as a valuable commodity. Materials that 

have been disposed of in abandoned piles or landfills are clearly discarded while they 

remain in those environments and are subject to the appropriate federal, state and local 

 “Outline of Regulatory Approach to Determine Materials Considered Fuels – not Solid Wastes - under 

RCRA,” June 12, 2008. We have had verbal discussions with the states on this issue as well. 
74

regulations.) As an example, based on the results of EPA's 1997 study on “Air Emissions 

from Scrap Tire Combustion,” it was concluded that potential emissions from TDF are 

often less than, but at least generally within the same range as, emissions from 

conventional fossil fuels, as long as combustion occurs in a well-designed, operated, and 

well-maintained combustion device. Other data supports this conclusion. See 

background document titled “Materials Characterization Paper; Scrap Tires,” for a more 

detailed discussion on comparing TDF emissions to traditional fossil fuel emissions. 

Coal refuse (i.e., mining rejects) is another secondary material that we believe 

falls within this category. Some of these materials were discarded by coal mining 

companies from the time mining first began in the Appalachians through the late 1970s. 

The materials had historically been piled through the Pennsylvania and West Virginia 

coal regions until laws were enacted in the late 1970s that required site reclamation. The 

advent of CFB combustion boilers, capable of efficiently burning fuels of lower calorific 

value, has resulted in the ability to use this material as a fuel (millions of tons of coal 

refuse have been burned as a fuel since the advent of CFBs). See background document 

titled “Materials Characterization Paper; Coal Refuse,” for more details. 

The Agency specifically solicits comment on whether there are circumstances 

under which materials that have been discarded and which are legitimate fuels or 

ingredients should or should not be considered a solid waste once they are removed or 

recovered from the “discard” environment and managed as a legitimate fuel or ingredient. 

B. Other Approaches for Determining Whether Secondary Materials Are Fuels and 

Not Solid Wastes 
75

The Agency is also interested in receiving comments on an approach, as presented 

to the Agency by industry representatives, for determining when secondary materials are 

fuels and thus, not solid waste, and how the process may be implemented.69 Many 

aspects of the approach presented have been discussed throughout this ANPRM, with the 

common principle that certain secondary materials are not solid waste when burned for 

energy if they meet established criteria or are specifically identified not to be solid waste. 

For example, industry representatives suggest that material should be evaluated, on a 

case-by-case basis, to identify which criteria have been satisfied and determine whether 

the material is legitimately handled as a fuel. Criteria identified by industry stakeholders 

may include: handling and storage of materials to minimize loss, use of materials within 

a reasonable period of time, material value (e.g., whether there is a market for the 

material as a fuel, internal or external to the company), material managed and treated as a 

commodity, and processing of material to enhance fuel value. Industry stakeholders also 

recommend that EPA should list by regulation specific materials as fuels, rather than 

solid wastes. Thus, under the industry recommended approach, it would not be necessary 

to evaluate whether the criteria have been satisfied in every instance. Specifically, listed 

materials that were recommended include: traditional/historical fuels (e.g., coal, fuel oil, 

pet coke, coal refuse, used oil regulated under 40 CFR Part 279, synfuel, TDF, biomass 

fuel, biofuel, and gas pipeline condensate), materials specifically excluded from RCRA 

Subtitle C that have beneficial fuel value, materials combusted for chemical recovery, 

materials that are modified or processed to produce a product of significant fuel or 

 

69 See the Hybrid Regulatory Approach paper presented by the multi-industry coalition of stakeholders 

(PCA/CIBO/AF&PA/USWAG/RMA) in the docket established for this action entitled: “Outline of 

Regulatory Approach to Determine Materials Considered Fuels – not Solid Wastes - under RCRA,” June 

12, 2008. 
76

feedstock value, biomass materials from agricultural and forest resources, tires reclaimed 

via state programs, materials that had been discarded, but can be processed for use as a 

fuel or feedstock, and materials that a state approves as a fuel or determines can be 

beneficially reused. 

To implement the aforementioned concepts for determining when or which 

secondary materials are fuels, industry presented two methods, which were not meant to 

be mutually exclusive. One method implements the criteria concept, by which an owner 

or operator of a combustion device must determine that the material meets the criteria set 

forth and maintain records to demonstrate that these criteria are met. (Presumably, the 

owner or operator would be subject to potential enforcement action if EPA determined 

that the criteria were misapplied.) The other method implements an extension of the 

listed materials concept, by allowing an owner or operator to petition EPA or the state to 

specifically list a material (in addition to a pre-established list of materials). In a petition, 

the owner or operator would use the criteria as the basis for proposing that EPA or the 

state list the material (although industry notes that not all criteria need to be satisfied to 

qualify as a fuel), or the owner or operator could submit additional information to 

demonstrate the environmental equivalence of the material to other listed fuels. 

The Agency solicits comments on whether the rules should include a petition 

process that would allow a person to submit a rulemaking petition and argue, on a caseby-case basis, that a secondary material is not a solid waste. This petition process would 

address situations where a material would otherwise be considered a solid waste under 

current regulations. As discussed in section V.A.6, the Agency has excluded certain 

materials from being a solid waste under the Subtitle C hazardous waste regulations. 
77

Should the Agency allow persons to petition the Agency to have a secondary material 

excluded from the definition of solid waste based on the legitimacy criteria discussed in 

section V.A.2? The Agency is interested in receiving comments on the validity and 

potential specific procedures of a case-by-case petition process by the owner or operator 

of a combustion device, including what criteria should be considered in evaluating such 

petitions. In addition, we also request comment on the concept of establishing a list of 

materials that are fuels. 

For more information, see the multi-industry coalition’s paper in the docket 

established for this action entitled: “Outline of Regulatory Approach to Determine 

Materials Considered Fuels – not Solid Wastes- under RCRA,” June 12, 2008. The 

Agency also has received several papers from industry groups which we have reviewed 

and considered in drafting this ANPRM that are also available for viewing and comment 

in the docket. 

C. Materials for Which State Beneficial Use Determinations Have Been Made70

States regulate the management of non-hazardous solid waste, typically including 

secondary industrial materials, but many have a process or promulgated regulations to 

determine when these materials are no longer wastes, because they can beneficially and 

safely be used as products in commerce. The Agency is also soliciting comments on state 

beneficial use determinations and how those determinations deal with solid wastes, and 

how those decisions should be considered by EPA in determining what is or is not a solid 

waste under RCRA, which in turn determines how it is regulated under the CAA 

standards. Many state determinations addressing a material’s beneficial use and solid 

 

70 This applies to state beneficial use determinations for secondary materials used as fuels or ingredients in 

combustion units that are not determined to be “non-wastes” pursuant to this rulemaking effort. 
78

waste status are consistent with the principles explained in this ANPRM, but some state 

determinations (as previously discussed, both wastes and non-wastes may be used 

beneficially) may be inconsistent. In order for state programs to qualify materials as not 

solid waste under federal law, under the terms suggested in this notice, secondary 

materials would need to be legitimate fuels or ingredients and otherwise meet the 

conditions of the federal regulations. 

As we have noted previously, states are the lead Agencies for implementing the 

non-hazardous waste programs and, as such, we want to make sure that state programs 

are not adversely affected by any decisions that are made by EPA. We see a benefit to 

deferring to state decisions, which are able to consider site specific information. The 

Association of State and Territorial Solid Waste Management Officials (ASTSWMO) 

reports that they receive requests from the regulated community to consider nonhazardous, industrial secondary materials as not being solid wastes when they are 

beneficially used. Most states (30 of 34 reporting) indicated they had either formal or 

informal decision-making processes or beneficial use programs relating to the use of solid 

wastes. Materials are no longer subject to the state’s solid waste regulations under the 

state rules when state determines that the secondary materials are no longer solid wastes 

when beneficially used. 

The Agency acknowledges state beneficial use determinations and seeks comment 

on whether to consider secondary materials that receive a state beneficial use 

determination for use as a fuel or as an ingredient as not a solid waste, should also not be 

considered a solid waste under federal law. Commenters who support such a position 

should provide the basis or rationale for this position. For example, would a 
79

determination be needed that shows the beneficial use determination was in-line with 

EPA’s principles as outlined in section V.A.2. (i.e., whether they were legitimate fuels or 

ingredients)? 

D. Biofuels

Biofuels and byproducts from the production of biofuels are non-traditional 

alternative fuels being offered for stakeholder consideration. Biofuels can be generally 

described as a gas or liquid fuel made from biological materials, including plants, animal 

manure, and other organic sources. Thus, biofuels produced from these materials, such 

as ethanol and biodiesel are not considered to be solid wastes themselves, but rather are 

viewed as legitimate fuel products. Biofuels production has increased dramatically in the 

past few years and is expected to continue increasing over the coming years. The Energy 

Policy Act of 2005 amended the CAA to establish a Renewable Fuel Standard (RFS) 

program which established a major new federal renewable fuel volume mandate. While 

market forces initially caused renewable fuel use to far exceed these mandates, this 

program provided certainty that at least a minimum amount of renewable fuel would be 

used in the U.S. transportation market, which in turn provided assurance for investment 

in production capacity. The Energy Independence and Security Act of 2007 (EISA) 

updated the RFS program to include a new definition of renewable fuels that accounted 

for the fuel life-cycle emissions of greenhouse gases (GHG)

71 and also increased the total 

renewable fuel volume mandate to 36 billion gallons per year by 2022; the statute also 

established four specific categories of renewable fuels, each with a separate volume 

 

71 A "renewable fuel" is defined in EISA as a fuel that is produced from renewable biomass and that is used 

to replace or reduce the quantity of fossil fuel present in transportation fuel. "Renewable biomass" is 

defined as 1) planted crops and crop residue, 2) planted trees and tree residue, 3) animal waste material and 

animal byproducts, 4) slash and commercial thinnings, 5) biomass from the immediate vicinity of 

buildings, 6) algae, and 7) separated yard waste or food waste, including recycled cooking and trap grease. 
80

mandate. These categories are renewable fuel, advanced biofuel, biomass-based diesel, 

and cellulosic biofuel. 

Biofuels production can be viewed as including both the feedstock materials that 

are used to produce biofuels, as well as the byproducts generated from the production of 

biofuels. EPA considers these materials to be legitimate alternative fuels when they have 

meaningful heating value, do not contain contaminants that are significantly higher in 

concentration than traditional fuels, and are handled as a valuable commodity. For 

example, a project completed by the University of Georgia (UGA) Engineering Outreach 

Service (EOS) demonstrated that biofuels processed from fats and grease (chicken fat, 

yellow grease, choice white grease, and beef tallow), either singly or blended with No. 2 

fuel oil, are technically and economically viable alternatives to No. 2 fuel oil in industrial 

boilers.72 We request additional data and comment on the extent to which fats, oils, and 

greases (FOGs) and related biomass materials that can be used as feedstocks to produce 

biofuels and that are not previously addressed in this ANPRM, are also used directly as 

fuels in stationary combustion sources. Further, the Agency requests comment on the 

extent to which FOGs and biomass materials are processed into biofuels for use in 

stationary combustion sources, such that their assessment as part of this rulemaking effort 

is warranted. For example, the U.S. Energy Information Administration estimated used 

cooking oil is produced at a rate of some 100 million gallons per day in the USA.73 

Literature suggests that biodiesel can be prepared from waste cooking oil. Although there 

are instances where such oil is used as a fuel for engines with only minimal processing 

 

72 FY 2005 FoodPAC Final Report; "Combustion of Poultry Fat for Plant Heat and Steam" University of 

Georgia. 

73 Radich, A. Biodiesel performance, costs, and use. US Energy Information Administration, 2006. 

http://www.eia.doe.gov/oiaf/analysispaper/biodiesel/index.html. 
81

(such as filtering), more intensive processing (such as the addition of ethyl alcohol with 

sodium hydroxide as a catalyst for the transesterification of vegetable oils and animal 

fats) is necessary to produce true biodiesel fuel.74 Finally, we request comment on 

whether non-hazardous byproducts generated from the production of biofuels, such as dry 

distiller's grain from corn ethanol and lignin from cellulosic ethanol, are being used as 

alternative fuels, which therefore should be assessed as part of this rulemaking effort. 

VII. Statutory and Executive Order Reviews 

 Under Executive Order (EO) 12866 (58 FR 51735, October 4, 1993), this action is 

a "significant regulatory action.” Accordingly, EPA submitted this action to the Office of 

Management and Budget (OMB) for review under EO 12866 and any changes made in 

response to OMB recommendations have been documented in the docket for this action. 

Generally, because this action is ‘‘advanced’’ in nature and does not, therefore, 

propose any requirements on any entities, the various administrative requirements EPA 

must address in the rulemaking process are not applicable. When EPA issues a notice of 

proposed rulemaking, EPA will address those requirements. EPA expects to prepare an 

Economic Assessment (EA) in support of the proposed action. We will submit this EA, 

along with the proposed rulemaking to OMB for review. 

 

74 Energies 2008, 1 , 3-18; DOI: 10.3390/en1010003, "Waste Cooking Oil as an Alternate Feedstock for 

Biodiesel," http://www.mdpi.com/1996-1073/1/1/3/pdf. 
82

List of Subjects in 40 CFR Part 257 

Environmental protection, waste treatment and disposal. 

Dated: ____________________________ 

 

 ____________________________ 

 Stephen L. Johnson, 

 Administrator.