***E.O. 12866 Review – Draft – Do No Cite, Quote, or Release During Review***

EO12866_CO2 RCRA Exclusion 2050-AG60 NPRM NPRM_20110303

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 260 and 261

[EPA-HQ-RCRA-2010-0695; FRL_XXXX-X]

RIN: 2050-AG60

Hazardous Waste Management System: Identification and Listing of Hazardous 

Waste: Carbon Dioxide (CO2) Streams in Geologic Sequestration Activities 

AGENCY: Environmental Protection Agency.

ACTION: Proposed Rule.

SUMMARY: The U.S. Environmental Protection Agency (EPA or the Agency) is 

proposing to revise the regulations for hazardous waste management under the Resource 

Conservation and Recovery Act (RCRA) to conditionally exclude carbon dioxide (CO2) 

streams that are hazardous from the definition of hazardous waste, provided these 

hazardous CO2 streams are captured from emission sources, are injected into Class VI 

Underground Injection Control (UIC) wells for purposes of geologic sequestration (GS), 

and meet certain other conditions. EPA is taking this action because the Agency believes

that the management of these CO2 streams under the proposed conditions does not 

present a substantial risk to human health or the environment, and therefore additional 

regulation pursuant to RCRA‟s hazardous waste regulations is unnecessary. EPA expects 

that this amendment will substantially reduce the uncertainty associated with identifying

these CO2 streams under RCRA subtitle C, and will also facilitate the deployment of GS 

by providing additional regulatory certainty. 

DATES: Comments must be received on or before [insert date 60 days after 
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publication in the Federal Register]. Under the Paperwork Reduction Act, comments 

on the information collection provisions must be received by the Office of Management 

and Budget (OMB) on or before [insert date 30 days after date of publication in the 

Federal Register].

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-RCRA2010-0695, by one of the following methods:

www.regulations.gov: Follow the on-line instructions for submitting comments.

Email: rcra-docket@epa.gov

Fax: 202-566-9744

Mail: RCRA Docket, Environmental Protection Agency, Mailcode: 2822T, 1200 

Pennsylvania Ave., NW., Washington, DC 20460. Please include a total of two 

copies. In addition, please mail a copy of your comments on the information 

collection provisions to the Office of Information and Regulatory Affairs, Office 

of Management and Budget, Attn: Desk Officer for EPA, 725 17th St. NW., 

Washington, DC 20503.

Hand Delivery: Deliver two copies of your comments to EPA West Building, 

Room 3334, 1301 Constitution Avenue, NW, Washington, DC 20460. Such 

deliveries are only accepted during the Docket‟s normal hours of operation, and 

special arrangements should be made for deliveries of boxed information.

Instructions: Direct your comments to Docket ID No. EPA-HQ-RCRA-2010-0695. 

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

change and may be made available online at www.regulations.gov, including any 
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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 www.regulations.gov or e-mail. The 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 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. For additional instructions on 

submitting comments, go to the SUPPLEMENTARY INFORMATION section of this 

document.

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 

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

NW, 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 RCRA Docket is 

(202) 566-0270.

FOR FURTHER INFORMATION CONTACT: Ross Elliott, Office of Resource 

Conservation and Recovery (5304P), Environmental Protection Agency, 1200 

Pennsylvania Avenue NW., Washington, DC 20460; telephone number: 703-308-8748; 

fax number: 703-308-0514; email address elliott.ross@epa.gov.

SUPPLEMENTARY INFORMATION: 

A. Does this Action Apply to Me?

This is a proposed regulation. If finalized, this rule may apply to generators, 

transporters, and owners or operators of treatment, storage, and disposal facilities 

engaged in the management of carbon dioxide streams that would otherwise be regulated 

as hazardous wastes under the RCRA subtitle C hazardous waste regulations as part of 

geologic sequestration activities. This includes entities in the following industries:

operators of carbon dioxide injection wells used for geologic sequestration; and certain 

industries identified by their North American Industry Classification System (NAICS) 

code: oil and gas extraction facilities (NAICS 211111); utilities (NAICS 22); 

transportation (NAICS 48-49); and manufacturing (NAICS 31-33). More detailed 

information on the potentially affected entities is presented in Section VI of this 

preamble. If you have questions regarding the applicability of this action to a particular 
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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 on a disk or CD ROM that you mail to EPA, mark 

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 

the 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 
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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.

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

identified.

3. Docket Copying Costs. The Docket Center no longer has hard copies of original 

OSWER documents. The documents were converted to PDF format. Oversized 

documents were retained and may be copied. Patrons are allowed 93 free copied-pages. 

Thereafter, they are charged 15 cents per page. When necessary, an invoice stating how 

many copies were made, the cost of the order, and where to send a check will be issued 

to the patron. There is also an administrative fee of $14.00 added to the cost of the 

order. 

Documents also are available on microfilm. The EPA/DC staff can help patrons locate 

needed documents and operate the microfilm machines. There is no fee for printing 

documents from microfilm or microfiche.

Patrons who are outside of the metropolitan Washington, DC, area can request 

documents by telephone, however, patrons are asked to submit requests by email to 

ensure accuracy. The photocopying fee is the same as for walk-in patrons. There is no 

charge for converting microfilm/microfiche to PDF format and sending it to a customer. 

If an invoice is necessary, EPA/DC staff can mail one with the order.

Preamble Outline
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I. Statutory Authority

II. Abbreviations, Acronyms, and Definitions

A. Abbreviations and Acronyms

B. Definitions Used in this Preamble

III. Background

A. What is Geologic Sequestration?

B. Why is Geologic Sequestration Being Considered as a Climate Change Mitigation 

Technology?

C. What Other Recent EPA Rulemakings are Related to CCS?

D. RCRA Applicability to GS Activities

E. CO2 Stream Characterization

IV. Detailed Discussion of This Proposed Rule

A. Authority for Conditional Exclusion from RCRA subtitle C requirements

B. CO2 Streams Managed Prior to Underground Injection

1. CO2 Streams Generated at Capture Sites

2. Transportation of CO2 Streams to UIC Class VI Injection Well

C. Underground Injection of CO2 Streams at UIC Class VI Wells

1. Development of UIC Class VI Wells Under SDWA

2. Key Elements of the UIC Class VI Well Requirements

3. RCRA Land Disposal Restrictions

4. Subtitle C Corrective Action

5. Conclusion

D. Prohibition on Introduction of Other RCRA Hazardous Wastes
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E. Loss of the Conditional Exclusion

F. Adaptive Approach

G. Definition of Carbon Dioxide Stream

V. State Authorization

A. Applicability of the Rule in Authorized States

B. Effect on State Authorization

VI. What are the Costs and Benefits of the Proposed Rule?

VII. Statutory and Executive Order (EO) Reviews

A. Executive Order 12866: Regulatory Planning and Review

B. Paperwork Reduction Act

C. Regulatory Flexibility Act

D. Unfunded Mandates Reform Act

E. Executive Order 13132: Federalism

F. Executive Order 13175: Consultation and Coordination with Indian Tribal 

Governments

G. Executive Order 13045: Protection of Children from Environmental Health and 

Safety Risks

H. Executive Order 13211: Actions that Significantly Affect Energy Supply, 

Distribution, or Usage

I. National Technology Transfer Advancement Act

J. Executive Order 12898: Federal Actions to Address Environmental Justice in 

Minority Populations and Low-Income Populations

I. Statutory Authority
Page 9 of 76

These regulations are proposed under the authority of sections 2002, 3001-3009 

and 3013 of the Solid Waste Disposal Act (SWDA) of 1970, as amended by the Resource 

Conservation and Recovery Act (RCRA) of 1976, and the Hazardous and Solid Waste 

Amendments of 1984 (HSWA), 42 U.S.C. 6912, 6921-6929, 6934.

II. Abbreviations, Acronyms, and Definitions

A. Abbreviations and Acronyms

AoR Area of Review

CAA Clean Air Act

CCS Carbon Capture and Storage

CERCLA Comprehensive Environmental Response, Compensation, and Liability Act

CO2 Carbon Dioxide

EOR Enhanced Oil and Natural Gas Recovery

EPA Environmental Protection Agency

GHG Greenhouse Gas

GS Geologic Sequestration

HSWA Hazardous and Solid Waste Amendments

RCRA Resource Conservation and Recovery Act

SDWA Safe Drinking Water Act

TC Toxicity Characteristic

TCLP Toxicity Characteristic Leaching Procedure

UIC Underground Injection Control

USDW Underground Source of Drinking Water

B. Definitions Used in this Preamble
Page 10 of 76

Authorized representative: The person responsible for the overall operation of a facility 

or an operational unit (i.e., part of a facility), e.g., the plant manager, superintendent or 

person of equivalent responsibility.

Carbon dioxide (CO2) stream: Carbon dioxide that has been captured from an emission 

source (e.g., power plant), plus incidental associated substances derived from the source 

materials and the capture process, and any substances added to the stream to enable or 

improve the injection process.

Enhanced Oil or Gas Recovery (EOR/EGR): Typically, the process of injecting a fluid 

(e.g., water, brine, or CO2) into an oil or gas bearing formation to recover residual oil or 

natural gas. The injected fluid thins (decreases the viscosity) or displaces small amounts 

of extractable oil and gas, which is then available for recovery. This is also known as 

secondary or tertiary recovery.

Supercritical CO2: Carbon dioxide that is above its critical temperature (31.1 oC, or 88oF) 

and pressure (73.8 bar, or 1070 psi). Supercritical substances have physical properties 

intermediate to those of gases and liquids.

III. Background

A. What is Geologic Sequestration?

Geologic Sequestration (GS) is the process of injecting carbon dioxide (CO2)

captured from an emission source (e.g., a power plant or industrial facility) into deep 

subsurface rock formations in order to isolate the CO2 permanently. GS is a key 

component of a set of climate change mitigation technologies referred to as “carbon 

capture and storage” or CCS. CCS can be described as a three-step process, beginning 
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with the capture and compression of the CO2 stream from fossil-fuel power plants or 

other industrial sources, after which the CO2 stream is transported (usually in pipelines) 

to an on-site or off-site location, where it is then injected underground for purposes of 

sequestration.1

To transport the captured CO2 stream for GS, the CO2 stream will typically be 

compressed into a supercritical fluid.

2

 CO2 exists as a supercritical fluid at approximately 

1,070 pounds per square inch (psi) and 88 o Fahrenheit (F), and in this state it exhibits 

physical properties intermediate to those of a liquid and a gas. As mentioned, the 

majority of CO2 is expected to be delivered to the sequestration site by dedicated 

pipeline;3however, transport by truck, rail, barge or supertanker may also occur, but 

these have been described as “logistically impractical” for large-scale CCS operations.4 

Whether by pipeline, or these other means, the transportation of supercritical CO2 is 

regulated by the U.S. Department of Transportation (DOT) under regulations found in 49 

CFR parts 171-180 (governing the transportation by air, rail, highway, and water) and 

parts 190 and 195-199 (governing the transportation of hazardous liquids and carbon 

dioxide by pipeline). The CO2 stream is then injected into deep subsurface rock 

formations via one or more wells, using technologies that have been developed and 

refined by the oil and gas and chemical manufacturing industries over the past several 

decades. To sequester the CO2 stream, EPA believes that many GS site owners or 

operators will inject the CO2 stream to depths of greater than 800 meters (or 2,625 feet), 

 

1 Report of the Interagency Task Force on Carbon Capture and Storage, August 2010, p. 8.

2 Carbon Dioxide Capture and Storage. Intergovernmental Panel on Climate Change (IPCC), 2005.

3 Guidelines for Carbon Dioxide Capture, Transport, and Storage. World Resources Institute, 2008.

4 CRS Report for Congress. Carbon Dioxide (CO2) Pipelines for Carbon Sequestration: Emerging Policy 

Issues. Paul W. Parfomak and Peter Folger. January 17, 2008.
Page 12 of 76

for the purpose of maximizing capacity and storage, and where ambient pressure and 

temperature are sufficient to maintain the CO2 stream in a supercritical state. December 

10, 2010 (75 FR at 77233).

When injected in an appropriate receiving formation, the CO2 stream is 

sequestered by a combination of trapping mechanisms, including physical and 

geochemical processes, as summarized below. 

o Physical trapping occurs when the relatively buoyant CO2 rises in the 

formation until it reaches a stratigraphic zone with low fluid permeability 

(i.e., geologic confining system) that inhibits further upward migration. 

Physical trapping can also occur as residual CO2 is immobilized in 

formation pore spaces. A portion of the CO2 will dissolve into the 

groundwater and hydrocarbons present in the receiving formation, and 

CO2 molecules can also attach onto the surfaces of coal and certain 

organic-rich shales (a process called preferential sorption), displacing 

other molecules, such as methane. The effectiveness of physical CO2 

trapping is demonstrated by natural analogs worldwide in a range of 

geologic settings, where CO2 has remained trapped for millions of years. 

For example, CO2 has been trapped for more than 65 million years under 

the Pisgah Anticline, northeast of the Jackson Dome in Mississippi and 

Louisiana, with no evidence of leakage from the confining formation.5

o Geochemical trapping occurs when chemical reactions between the 

dissolved CO2 and minerals in the receiving formation result in the 

 

5 Carbon Dioxide Capture and Storage. IPCC, 2005.
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precipitation of solid carbonate minerals.

6

 The timeframe over which CO2

will be trapped by these mechanisms depends on the properties of the 

receiving formation and the injected CO2 stream. Research is currently 

ongoing to further understand these mechanisms and the time required to 

trap CO2 under various conditions.

Additional background information on the GS of CO2 streams can also be found 

in the final rule and associated record for the final rule for UIC Class VI wells published 

on December 10, 2010 (75 FR 77230).

B. Why is Geologic Sequestration Being Considered as a Climate Change Mitigation 

Technology?

Climate change is happening now, and the effects can be seen on every continent 

and in every ocean. While certain effects of climate change can be beneficial, particularly 

in the short term, current and future effects of climate change pose considerable risks to 

human health and the environment. There is now clear evidence that the Earth‟s climate 

is warming:7 

o Global surface temperatures have risen by 1.3 oF over the last 100 years. 

o Worldwide, the last decade has been the warmest on record. 

o Ocean temperatures and sea levels are rising and glaciers are retreating 

around the world.

Most of this recent warming is very likely the result of human activities. Many human 

activities release greenhouse gases into the atmosphere (such as the combustion of fossil 

 

6

Ibid.

7 Climate Change Science Facts, U.S. EPA Office of Air and Radiation, April 2010, EPA-430-10-F-002.
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fuels). The levels of these gases are increasing at a faster rate than at any time in 

hundreds of thousands of years.

In addition, fossil fuels are expected to remain the main source of energy 

production well into the 21st century, and increased concentrations of CO2 are expected 

unless energy producers reduce CO2 emissions to the atmosphere. For example, CCS 

would enable the continued use of coal in a manner that greatly reduces the associated 

CO2 emissions, while other safe and affordable alternative energy sources are developed 

in the coming decades. CCS has the potential to be key to achieving domestic GHG 

emissions reductions, and as already mentioned, GS is a key component of CCS.8

GS is therefore one of a portfolio of options that could be deployed to reduce CO2

emissions to the atmosphere and help to mitigate climate change. Other options include, 

but are not limited to, energy conservation, efficiency improvements, and the use of 

alternative fuels and renewable energy sources, including solar and wind power.

C. What Other Recent EPA Rulemakings are Related to CCS?

In an effort to establish a regulatory framework that supports the future 

development and deployment of CCS technologies, EPA has set out a goal to provide the 

regulatory certainty needed to foster industry adoption of CCS. As mentioned above, 

EPA believes that GS is a key climate change mitigation technology. Therefore,

providing a consistent regulatory approach to GS will promote its future use in the United 

States. Two important EPA rulemakings that directly address GS activities are 

requirements under the Greenhouse Gas (GHG) Reporting Program; and Federal 

Requirements under the Underground Injection Control (UIC) Program for Carbon 

 

8

Report of the Interagency Task Force on Carbon Capture and Storage, August 2010, p. 14.
Page 15 of 76

Dioxide (CO2) Geologic Sequestration (GS) Wells. These are described in more detail 

below.

EPA Greenhouse Gas (GHG) Reporting Program: The GHG Reporting Program 

was established under authority of the Clean Air Act (CAA) and requires 

reporting of GHG emissions and other relevant information from certain source 

categories in the United States. On October 30, 2009, EPA issued a final rule (74 

FR 56260) that requires reporting by facilities with production process units that 

capture a CO2 stream under subpart PP of the program. These facilities are 

required to report the amount of CO2 in a stream captured, and provide 

information on the downstream CO2 end use (e.g., food and beverage, EOR, GS, 

etc.). On December 1, 2010, EPA issued a final rule (75 FR 75060) that requires 

reporting from facilities that inject CO2 underground for GS under subpart RR of 

the program. The rule requires facilities that inject CO2 underground for GS to 

report basic information on CO2 received for injection, develop and implement an 

EPA-approved site-specific monitoring, reporting and verification plan, and report 

the amount of CO2 sequestered using a mass balance approach and annual 

monitoring activities.

EPA Class VI Underground Injection Control (UIC) Rule: On July 25, 2008, 

EPA proposed to amend the UIC program (73 FR 43492) to establish a new class 

of injection well (Class VI) and to establish minimum federal requirements under 

the Safe Drinking Water Act (SDWA) for the underground injection of CO2 for 

the purpose of GS. The proposed requirements would ensure that GS is conducted 

in a manner that protects Underground Sources of Drinking Water (USDWs) from 
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endangerment, by tailoring existing components of the UIC program to address 

the unique nature of GS. On December 10, 2010, EPA finalized the new UIC 

Class VI injection well standards. These requirements are intended to provide 

certainty to industry and the public about the requirements that would apply to 

injection for purposes of GS, by providing consistency regarding the requirements 

across the U.S., and transparency about what requirements apply to permitted UIC 

Class VI facility owners or operators. For a more detailed discussion of these 

requirements, see the December 10, 2010 Federal Register (75 FR 77230).

D. RCRA Applicability to GS Activities

In response to the July 25, 2008 proposed rule for UIC Class VI wells, EPA 

received a number of comments regarding the potential applicability of RCRA subtitle C 

to CO2 streams being geologically sequestered. As a result of those comments, EPA 

decided to initiate work on today's proposal. EPA also considered those RCRA-related 

comments in the development of today‟s proposed rule. EPA notes, however, that all 

persons wishing to comment on the RCRA applicability issues raised by today‟s 

proposal, must submit comments to the docket established for today‟s proposed rule as 

described above in the ADDRESSES section of this Federal Register notice. EPA will 

not provide further responses to comments submitted on the UIC rule as part of this 

rulemaking. In addition, today's proposal is not reopening the UIC Class VI final rule, 

nor will EPA respond to comments related to that rule.

At this time, EPA has little information to conclude that CO2 streams would 

qualify as RCRA hazardous wastes, which would make them subject to EPA‟s 

comprehensive RCRA hazardous waste management regulations. However, commenters 
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have cited the potential for RCRA hazardous waste requirements to attach to some CO2

streams, as a significant impediment to widespread deployment of CCS technologies. 

Today‟s proposal seeks to address this concern and provide regulatory clarity through a 

unified RCRA regulatory regime for CO2 streams. Simultaneously, as discussed below, 

EPA expects that management in accordance with the conditions in today‟s proposal will 

provide no reduced protection to human health and the environment.

After issuance of the proposed UIC Class VI rule, EPA received public comments 

that the proposed requirements were unclear as to whether the CO2 stream would be a 

RCRA hazardous waste, and expressed concern that this created uncertainty regarding the 

type of permit needed for GS. Many commenters stated that a CO2 stream should not be 

treated as a RCRA hazardous waste on the grounds that it is neither a listed hazardous 

waste nor exhibits a hazardous characteristic, or even is a solid waste. Other 

commenters, however, asserted that CO2 in the presence of water could exhibit the 

RCRA corrosivity characteristic. Additionally, commenters argued that the analytic 

procedures used under RCRA (in particular, the toxicity characteristic leaching 

procedure, TCLP)9cannot be applied to supercritical CO2 streams, and that the UIC Class 

VI regulations would better ensure the proper management of CO2 streams than would 

the RCRA subtitle C hazardous waste requirements.

EPA believes that the RCRA hazardous waste regulations can apply to CO2

streams being geologically sequestered. Subtitle C of RCRA and its implementing 

regulations establish a “cradle to grave” regulatory scheme over certain “solid wastes” 

 

9

Toxicity Characteristic Leaching Procedure, or TCLP. See 40 CFR 261.24. A solid waste is defined as 

hazardous when a representative sample of that waste leaches a particular chemical or compound – for 

example, arsenic – above a specified regulatory concentration, using the TCLP.
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which are also “hazardous wastes.” 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, including solid, liquid, semisolid, or contained 

gaseous material . . .” See RCRA 1004(27), 42 U.S.C. § 6903(27). EPA has further 

defined the term “solid waste” for purposes of its RCRA hazardous waste regulations. 40 

CFR 261.2. To be considered a hazardous waste, a material first must be classified as a 

solid waste. Under EPA‟s regulations, generators of solid waste are required to 

determine whether their wastes are hazardous wastes. 40 CFR 262.11. A solid waste is a 

hazardous waste if it exhibits any of four characteristics (ignitability, corrosivity, 

reactivity, or toxicity), 40 CFR 261.20-.24, or is a listed waste, 40 CFR 261.30-.33 (these 

include wastes from non-specific sources, such as spent solvents; by-products from 

specific industries; and discarded, unused commercial chemical products). 

Some commenters for the UIC Class VI proposed rule asserted that a CO2 stream 

captured for sequestration is not a “contained gaseous material,” and therefore is not a 

solid waste as defined in the RCRA statute (see RCRA 1004(27), 42 U.S.C. § 6903(27)). 

One commenter specifically asked for clarification from EPA on whether or not captured 

CO2 would meet the definition of contained gas under RCRA.

EPA believes that CO2 streams that are the subject of today‟s proposed rule would 

be considered a contained gas, from the point of generation at the source, to injection into 

a UIC Class VI well for purposes of GS. A gas does not necessarily need to be in a 

container (which is defined under the RCRA regulations; see 40 CFR 260.10) to be 

considered a contained gas under the statute. While EPA generally does not regulate 

under RCRA gaseous emissions from non-waste management processes (for example, 
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gaseous emissions from a manufacturing process) that are released to the air, in the case 

of CO2 streams that are captured, transported, and injected into a UIC Class VI well for 

purposes of permanent isolation, the CO2 stream is contained throughout the entire 

process, and therefore, is a RCRA statutory solid waste.

A CO2 stream injected into a permitted UIC Class VI well for purposes of GS is a 

RCRA solid waste, as it is a “discarded material” within the plain meaning of the term in 

RCRA §1004(27). Courts have stated that the plain meaning of “discarded material” 

refers to materials that have been disposed of, abandoned or thrown away.

10

 This clearly 

applies to CO2 injected into Class VI wells, regardless of whether the material is a 

hazardous waste or not. An entity involved in the CCS process may generate CO2 that 

qualifies as a solid waste under the RCRA hazardous waste regulations by making the 

decision to discard the material through abandonment by disposing of the material (see 

40 CFR 261.2(a)(2)(i) and (b)(1)). This decision may be made well upstream of the 

injection well facility. As discussed above, EPA‟s regulations require that generators of a 

solid waste determine whether their wastes are hazardous wastes, and if so, manage them 

in accordance with EPA‟s RCRA hazardous waste regulations. 40 CFR 262.11.

One commenter to the UIC proposed rule suggested that the captured CO2 stream 

was exempt from the RCRA hazardous waste regulations under the exemption for “fly 

ash waste, bottom ash waste, slag waste, and flue gas emission control waste, generated 

primarily from the combustion of coal or other fossil fuels,” also referred to as the “Bevill 

exemption.” (See 40 CFR 261.4(b)(4).) 

 

10EPA is not addressing the status of CO2 that is injected into wells other than UIC Class VI wells in the 

discussion in this preamble. For example, CO2 that is used for enhanced oil or gas recovery (EOR/EGR) in 

other than UIC Class VI wells, where some sequestration may occur in the process of recovering gas or oil, 

is beyond the scope of this proposal.
Page 20 of 76

EPA studied the fossil fuel combustion wastes as directed by Congress, and 

published two Reports to Congress,11 and issued two Regulatory Determinations on the 

management and use of coal and other fossil fuel combustion products, one on August 9, 

1993 and a second one on May 22, 2000 (58 FR 42466 and 65 FR 32214, respectively). 

CO2 captured for purposes of GS was not included in either of these Regulatory 

Determinations, or in the underlying studies upon which these determinations were 

based. The Agency has consistently interpreted the §261.4(b)(4) exemption as only 

encompassing those wastes that were studied, and EPA did not study CO2 that has been 

captured for GS. Therefore, EPA believes that the CO2 streams discussed in today‟s 

proposed rule are not included within the Bevill exemption under §261.4(b)(4). (EPA 

notes that even if CO2 streams from the combustion of fossil fuels were exempt from 

regulation as hazardous waste under §261.4(b)(4) – which it does not believe to be the 

case – the Bevill exemption would only apply to CO2 generated from the combustion of 

materials in boilers to generate steam for the purpose of generating energy, and not to 

other CO2 streams generated from other sources.)

EPA notes that CO2 streams are not listed RCRA hazardous wastes (i.e., CO2

streams are not specifically identified as one of the hazardous wastes listed in 40 CFR 

part 261, subpart D). However, the CO2 stream would be a hazardous waste if it exhibits

any of the hazardous characteristics, or is mixed with a listed hazardous waste. Under the 

UIC Class VI final rule, injection site owners and operators must determine whether the 

CO2 stream is hazardous under the RCRA regulations, and if so, injection of the CO2

 

11 Report to Congress: Wastes from the Combustion of Coal by Electric Utility Power Plants, February 

1988, EPA-530-SW-88-002; and Report to Congress: Wastes from the Combustion of Fossil Fuels, Vol. 1 

& 2, U.S. EPA, March 1999, EPA-530-S-99-010 and EPA-530-R-99-010.
Page 21 of 76

stream may only occur in a UIC Class I hazardous waste injection well.12 Conversely, 

UIC Class VI wells cannot be used for the injection of RCRA hazardous wastes. Today‟s 

proposal, if finalized, would allow CO2 streams that would otherwise qualify as RCRA 

hazardous wastes to be managed in a Class VI well, provided that they meet the 

conditions of this proposed rule. 

As already noted, commenters to the UIC Class VI proposed rule also raised 

questions about the appropriateness and feasibility of applying the RCRA hazardous 

waste characteristics to CO2 streams and, in particular, the Toxicity Characteristic (TC). 

See §261.24. Some commenters stated that the TCLP test method associated with the TC 

could not be used on materials other than solids or liquids, and that EPA would have to 

develop new testing regulations and guidelines specifically for evaluating supercritical 

CO2. Commenters also stated that the TC regulation was inappropriate for CO2 streams 

because the TC was “...designed to assess the threat waste would have in a municipal 

landfill disposal scenario, a scenario that...is inherently inapplicable to uncontained 

supercritical CO2.” Many commenters also expressed concern over the uncertainty in 

determining how the RCRA hazardous waste regulations, including the hazardous waste 

identification issues described here, apply to CO2 streams being sequestered in UIC Class 

VI wells.

In light of these comments, EPA reiterates that no hazardous waste listings apply 

specifically to CO2 streams, therefore, a CO2 stream could only be defined as a hazardous 

 

12 As already mentioned, a hazardous waste determination must be made when a waste is first generated 

(§262.11); however, knowing whether a solid waste is a hazardous waste is necessary at any point during 

the management of that waste, in order for persons to ensure that they are in compliance with the hazardous 

waste requirements if and when they are managing hazardous waste. See 40 CFR §261.3(b)(3) and 45 Fed. 

Reg. 33096 (May 19, 1980).
Page 22 of 76

waste if it exhibits a hazardous waste characteristic as defined in 40 CFR part 261, 

subpart C.13 Regarding the feasibility of testing CO2 streams, EPA acknowledges the 

commenter‟s concern, but also notes that the hazardous waste regulations allow 

generators to apply their knowledge – in lieu of testing – of the hazard characteristic of a 

waste, in light of the materials or processes used, to determine whether that waste is a 

characteristic hazardous waste under RCRA.14 40 CFR 262.11(c)(2). EPA also notes 

that methods exist for sampling and analyzing gaseous emissions in order to identify and 

quantify hazardous constituents that may be present.15 Regarding whether a TCLP leach 

test can be applied to a supercritical CO2 stream, EPA notes that the TC regulation, and 

the TCLP test method, allow for measurement of total constituent concentrations in a 

waste, in lieu of running the leach test, and under certain circumstances even require it 

(such as where wastes are liquids that contain less than 0.5% solids).16 However, EPA 

acknowledges the commenters‟ underlying concerns related to RCRA characterization, 

and requests comment on this issue.

E. CO2 Stream Characterization

As noted above, EPA is proposing to conditionally exclude from the definition of 

hazardous waste CO2 streams captured, transported to, and injected into permitted UIC

Class VI wells for purposes of GS. At this time, EPA has little information to conclude 

 

13 It is also possible that a CO2 stream could become a hazardous waste if it is mixed with a listed 

hazardous waste, or, mixed with a characteristic hazardous waste and the resultant mixture exhibits a 

characteristic of hazardous waste. This is commonly referred to as the “mixture rule.” See 40 CFR 261.3. 

We note that today‟s proposed exemption includes the condition that prohibits the mixing of CO2 streams 

with hazardous waste.

14 Any persons claiming that a waste is non-hazardous, based on knowledge in lieu of testing, should be 

prepared to substantiate this claim.

15 E.g., EPA notes that existing analytical test methods, such as SW-846 Methods 0060, 0010, and 0031, 

are available to quantify the levels of various hazardous constituents in gaseous streams, although sampling 

a supercritical CO2 stream may require particular sampling protocols.

16 See SW-846, Method 1311, Section 2.1.
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that CO2 streams would qualify as RCRA hazardous wastes, which would make them 

subject to EPA‟s comprehensive RCRA hazardous waste management regulations. 

Today‟s proposal is intended to provide clarity for deployment of CCS under conditions 

that EPA believes would not present a substantial risk to human health and the 

environment. However, EPA acknowledges that at this time, it does not have full 

knowledge of the range of possible CO2 stream compositions. Today‟s proposed 

conditional exclusion is based upon EPA‟s existing knowledge of the composition of CO2

streams, and its analysis that compliance with the existing standards and regulations 

designed to prevent any exposure of CO2 (and any associated impurities) would render 

additional regulation under RCRA subtitle C unnecessary. Nevertheless, EPA is 

proceeding with this proposal, while at the same time seeking to collect additional data 

on the composition of captured CO2 streams. As CCS pilot projects move forward and 

continue to generate information, EPA expects the amount of available analytical data on 

captured CO2 to increase.

As described below, the final UIC Class VI rule requires physical and chemical 

characterization of the CO2 stream. While additional UIC Class VI permit guidance is 

still being developed regarding these requirements, at a minimum, the physical 

characteristics of the CO2 stream will include temperature and pressure, while the 

chemical characteristics will include pH, carbon dioxide purity (as a percent), as well as 

concentrations of non-CO2 constituents (in parts per million by volume, ppmv, or in 

percent). These non-CO2 constituents may include, but are not limited to, sulfur dioxide 

(SO2), hydrogen sulfide (H 2S), nitrous oxides (NOx), carbon monoxide (CO), methane 

(CH4), other hydrocarbons, water vapor (H2O), as well as certain contaminants, that are 
Page 24 of 76

also defined as hazardous contaminants in 40 CFR 261.24, such as arsenic (As), mercury 

(Hg), and selenium (Se).17

EPA has reviewed estimates of CO2 stream composition that were calculated 

using information, such as the composition of flue gas from the burning of fossil fuels 

and other likely sources, existing flue gas emission control technologies (e.g.,

electrostatic precipitators and scrubbers), and data from applied capture technology.

18

 

These estimates indicate that captured CO2 could contain (based upon the information 

used in developing those estimates) low concentrations of hazardous constituents, 

including those contaminants relevant to the TC regulation in §261.24 (e.g., arsenic, 

mercury, selenium) derived from the combustion flue gas. These estimates also indicate 

that the types of impurities and their concentrations would likely vary by facility, coal 

composition, plant operating conditions, and pollutant removal and carbon capture 

technologies. 

EPA did not receive any analytical data on the composition of captured CO2

streams in response to the July 25, 2008 proposed UIC Class VI rule. However, EPA 

expects that additional data will be generated with increasing research activity from

various domestic and global CCS pilot projects.19

In addition, EPA expects that data will become available under the recently 

promulgated UIC Class VI regulations. For example, the final UIC Class VI regulations 

 

17 Apps, J.A., A Review of Hazardous Chemical Species Associate with CO2 Capture from Coal-Fired 

Power Plants and Their Potential Fate in CO2 Geologic Storage, Lawrence Berkeley National Laboratory, 

March 2006.

18 Ibid.

19 See Exhibits 1 and 2 in EPA‟s analysis of the potential costs and benefits associated with this action, 

entitled Assessment of the Potential Costs, Benefits, and Other Impacts of the Conditional Exclusion from 

the RCRA Definition of Hazardous Waste for CO2 Streams Managed in UIC Class VI Wells for the 

Purposes of Geologic Sequestration, as Proposed. A copy of this document is available in the docket 

established for this action.
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require that prior to issuance of a permit, the owner or operator of the well must submit to 

the Director20 proposed operating data for the proposed GS site, including an analysis of 

the chemical and physical properties of the CO2 stream (40 CFR 146.82(a)(7)(iv)). The 

rule also requires that, throughout the operational life of the Class VI well, the injected 

CO2 stream be analyzed by owner/operators with sufficient frequency to yield data 

representative of its physical and chemical characteristics (§146.90(a)). In addition, 

owner/operators must submit semi-annual reports that include any changes to the 

physical, chemical, and other relevant characteristics of the CO2 stream from the 

proposed operating data (§146.91(a)(1)). EPA expects that these data will provide an 

indication of any impurities that may be present, their concentrations, and whether such 

impurities might alter the corrosivity or other properties of the CO2 stream after injection.

EPA today requests analytical data on the physical and chemical characteristics of 

captured CO2, including the concentrations of hazardous contaminants, CO2 content, 

information on the type of CO2 capture process used, and how the samples were collected 

and analyzed.

IV. Detailed Discussion of This Proposed Rule

EPA is proposing to revise the regulations for hazardous waste management 

under RCRA to exclude from the definition of hazardous waste certain CO2 streams that 

would otherwise be defined as hazardous, when these CO2 streams are managed under 

certain conditions. The Agency believes that this amendment to the RCRA hazardous 

 

20 As used here in the context of the UIC program, „Director‟ means the person responsible for permitting, 

implementation, and compliance of the UIC program. For UIC programs administered by EPA, the 

Director is the EPA Regional Administrator or his/her authorized representative; for UIC programs in 

Primacy States, the Director is the person responsible for permitting, implementation, and compliance of 

the State, Territorial, or Tribal UIC program. 40 CFR 144.3.
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waste rules, if finalized, will substantially reduce the uncertainty associated with defining 

and managing these CO2 streams under RCRA subtitle C. For the reasons discussed 

below, EPA believes that the management of these CO2 streams in accordance with the 

proposed conditions does not present a substantial risk to human health and the 

environment. These proposed conditions include, but are not limited to, compliance with 

the existing regulatory regimes governing the transportation of the CO2 stream, and its 

injection in a UIC Class VI permitted well.

A. Authority for Conditional Exclusion from RCRA Subtitle C requirements

EPA has previously interpreted RCRA section 3001(a) to authorize the issuance 

of “conditional exemptions” from the requirements of subtitle C, where it determines that 

“a waste might pose a hazard only under limited management scenarios, and other 

regulatory programs already address such scenarios.” 62 FR at 6636 (February 12, 

1997); 66 FR at 27222-27223 (May 16, 2001). Today‟s proposal takes a similar 

approach to those earlier rules.

Section 3001(a) provides the Agency with flexibility to consider the need for 

regulation in deciding whether to list or identify a waste as hazardous. Specifically, 

RCRA Section 3001(a) requires that EPA, in determining whether to list a waste as a 

hazardous waste, or to otherwise identify a waste as a hazardous waste, decide whether a 

waste "should be subject to” the requirements of subtitle C. Hence, RCRA Section 3001 

authorizes EPA to determine when subtitle C regulation is appropriate. EPA has 

consistently interpreted section 3001 of RCRA to give it broad flexibility in fashioning 

criteria for hazardous wastes to enter or exit the subtitle C regulatory system. EPA's 

longstanding regulatory criteria for determining whether wastes pose hazards that require 
Page 27 of 76

regulatory control incorporate the idea that a waste that is otherwise hazardous may not 

present a hazard if already subject to adequate regulation. (See, e.g., 40 CFR 

261.11(a)(3)(x), which requires EPA to consider action taken by other governmental 

agencies or regulatory programs based on the health or environmental hazard posed by 

the waste.)

EPA‟s interpretation is further supported by the text of RCRA sections 1004(5), 

and 3002-3004, and RCRA‟s legislative history. This interpretation has also been 

upheld upon judicial review. See, e.g., Military Toxics Project v. EPA, 146 F.3d 948 

(D.C. Cir. 1998) (upholding conditional exemption for storage of military munitions, 

based on EPA determination that such wastes are subject to binding standards that meet 

or exceed RCRA standards, in addition to an institutional oversight process).

The statutory definition of hazardous waste, section 1004(5)(B), informs EPA's 

interpretation that EPA may consider good management practices in determining the 

need to regulate waste as hazardous. That section defines a „hazardous waste‟ as “a solid 

waste, or combination of solid wastes, which because of its quantity, concentration, or 

physical, chemical or infectious characteristics may. . . (B) pose a substantial present or 

potential hazard to human health or the environment when improperly treated, stored, 

transported, or disposed of, or otherwise managed.” (Emphasis added.) EPA has 

interpreted the statutory definition as incorporating the idea that a waste that is otherwise 

hazardous does not require regulation so long as it is properly managed. For example, 

EPA‟s standards for listing hazardous wastes require consideration of a waste‟s potential 

for mismanagement. See 40 CFR 261.11(a)(3)(vii) (incorporating the language of RCRA 
Page 28 of 76

section 1004(5)(B) and requiring EPA to consider “plausible types of improper 

management”).

The statute also directs EPA to regulate hazardous waste generators (RCRA 

§3002(a)), transporters (RCRA §3003(a)) and treatment, storage and disposal facilities 

(RCRA §3004(a)) "as may be necessary to protect human health and the environment." 

By extension, the decision of when a waste should be subject to the regulatory 

requirements of subtitle C is a question of whether such regulatory controls are necessary 

to protect human health and the environment. 

Thus, where a waste might pose a hazard only under limited management 

scenarios, and other regulatory programs already address such scenarios, EPA is not 

required to classify a waste as hazardous waste subject to regulation under subtitle C. At 

least three decisions by the U.S. Court of Appeals for the D.C. Circuit provide support for 

this approach to regulating wastes as hazardous waste only where necessary to protect 

human health and the environment. In Military Toxics Project v. EPA, 146 F.3d 948 

(D.C. Cir. 1998), the court upheld a conditional exemption whereby the storage and 

transportation of certain military munitions are not considered hazardous waste subject to 

regulation under RCRA subtitle C, provided the munitions are stored and transported in 

compliance with regulations issued by the Department of Defense and the Department of 

Transportation, respectively. See 40 CFR 266.203, 266.205. The court ruled that EPA‟s 

interpretation of RCRA as authorizing a conditional exemption is “a permissible 

construction of the statute.” 146 F.3d at 958. The court cited its own precedent as 

recognizing “„that Congress intended the agency to have substantial room to exercise its 

expertise in determining the appropriate grounds for listing,‟” id. (citing NRDC v. EPA, 
Page 29 of 76

25 F.3d 1063, 1070 (D.C. Cir. 1994)), and concluded that, although the military 

munitions rule “does not involve the listing regulations at issue in NRDC v. EPA, we 

think the principle at work there also supports the conditional exemption at issue here.” 

Id.

In NRDC v. EPA, the court held that EPA appropriately used its discretion in 

relying on several existing regulatory frameworks governing used oil in determining not 

to list certain used oils as a hazardous waste. NRDC, 25 F.3d at 1071. Similarly, in 

Edison Electric Institute v. EPA, 2 F.3d 438 (D.C. Cir. 1993), the court upheld a 

temporary exemption from subtitle C for petroleum-contaminated media based on the 

fact that the potential hazards of such materials are already controlled under the 

underground storage tank regulations under RCRA subtitle I. In reaching its decision, the 

court considered the fact that the subtitle I standards could prevent threats to human 

health and the environment to be an important factor supporting the exemption. Id. at 

453. 

The legislative history of RCRA subtitle C also supports this interpretation, 

stating that "the basic thrust of this hazardous waste title is to identify what wastes are 

hazardous in what quantities, qualities, and concentrations, and the methods of disposal 

which may make such wastes hazardous." H. Rep. No.94-1491, 94th Cong., 2d Sess. 6 

(1976), reprinted in A Legislative History of the Solid Waste Disposal Act, as Amended, 

Congressional Research Service, Vol.1, 567 (1991) (emphasis added). Finally, as 

discussed above, in proposing this conditional exemption from RCRA, EPA is in part 

relying on the regulatory controls for Class VI wells, under the UIC program of the 

SDWA, 42 U.S.C. 300f et seq. EPA notes that such reliance is also consistent with the 
Page 30 of 76

direction provided in section 1006(b) of RCRA, which directs EPA to integrate the 

provisions of RCRA, for purposes of administration and enforcement and to avoid 

duplication, to the maximum extent practicable, with those of certain other statutes, 

including the SDWA, to the extent that it can be done in a manner that is consistent with 

the goals and policies of both RCRA and the other relevant statute(s).

B. CO2 Streams Managed Prior to Underground Injection

Under the subtitle C hazardous waste program, the generator requirements (40 

CFR part 262) contain provisions designed to ensure that hazardous wastes are properly

managed by persons who generate the wastes. This is accomplished through certain 

requirements governing the temporary storage (i.e., accumulation) of hazardous wastes, 

in units, such as tanks or containers, at the site of generation. These requirements include 

technical requirements for the tanks or containers, and time limits on hazardous waste 

storage, if the waste is to be sent off-site to a treatment, storage or disposal facility.21 

These requirements also include recordkeeping and reporting, and certain pre-transport 

requirements, such as packaging, labeling, and preparing a hazardous waste manifest to 

accompany the waste. Generators must also notify EPA of their hazardous waste 

management activity, and obtain an EPA identification (ID) number. Likewise, 

hazardous waste transporters (e.g., persons transporting waste, including over the 

highway or by rail) have certain requirements in 40 CFR part 263, to ensure that the 

hazardous wastes are properly transported to a hazardous waste treatment, storage, or 

 

21 The generator regulations in 40 CFR part 262 provide for limited, temporary on-site hazardous waste 

storage (accumulation) without a RCRA permit or being subject to the interim status standards, provided 

certain conditions are met (see §262.34). While generators are not required to send hazardous waste offsite for disposal, they often do so because they do not wish to engage in RCRA-permitted hazardous waste 

activity on-site.
Page 31 of 76

disposal facility. These transporter requirements include notifying EPA and obtaining an 

EPA ID number, recordkeeping, and compliance with the hazardous waste manifest. 

EPA notes that under the RCRA subtitle C regulations, a hazardous waste manifest is not 

required for hazardous wastes sent off-site via pipeline.22

For CO2 streams that are captured, compressed, and transported to a UIC Class VI

well, EPA believes that the full set of subtitle C generator and transporter requirements 

are not necessary, because they do not provide any additional protection over existing 

regulatory requirements. Regarding the generator requirements, EPA believes that the 

process of capturing and compressing CO2 prior to delivery to a UIC Class VI facility via 

a pipeline, as the Agency understands it, will not involve storage at the generator facility 

(i.e., at the CO2 source), but rather will occur in a continuous fashion (capture process → 

compression/dehydration → pipeline insertion). Once in the pipeline, EPA believes the 

applicable DOT requirements (which apply to supercritical CO2 streams regardless of 

whether or not these materials meet the definition of hazardous waste) will ensure that 

CO2 streams are managed in a manner that addresses the potential risks to human health 

and the environment that these materials may pose, prior to arrival at a Class VI injection

well facility.

1. CO2 Streams Generated at Capture Sites

While certain technologies for removing (capturing) CO2 have been in use 

commercially for over 60 years (e.g., natural gas processing, production of food-grade 

CO2), research has been underway to develop more cost-effective technologies to capture 

CO2 for purposes of CCS. Regardless of the capture technology that is ultimately 

 

22 This is because use of the hazardous waste manifest is triggered by the transport of hazardous waste (see 

discussion in Section IV.B.2. in this preamble, including Footnote 34).
Page 32 of 76

implemented, information currently available to EPA indicates that once the CO2 stream 

is captured at the source (e.g., coal-fired power plant), it will be dehydrated (to meet 

pipeline specifications preventing corrosion) and compressed (to match designated 

pipeline pressures) in preparation for transport, primarily via CO2 pipeline.23, 24

However, evaluating in more detail how CO2 streams will be managed at the CO2

source prior to GS in a UIC Class VI facility, and what regulations or other standards 

might apply to these activities in lieu of the RCRA generator standards, has proven 

somewhat difficult based on a review of the literature. This is either because many of the 

newer capture technologies are still in the developmental stages, or because the more 

established capture technologies used in commercial CO2 capture have not yet been 

scaled up to large facilities, such as coal-fired power plants. Nonetheless, EPA attempted 

to assess how captured CO2 streams would be managed in the context of the RCRA 

generator requirements identified above (e.g., EPA notification, standards for tanks or 

containers, time limits for on-site storage, recordkeeping and reporting, packaging, 

labeling, manifesting, etc.). 

First, it is unclear from existing information sources whether captured CO2 has 

been or will be stored at the generator site prior to insertion into a pipeline, so EPA 

examined the feasibility of storing captured CO2 streams at the source, since storage is a 

hazardous waste management activity of concern at RCRA generator sites generally.25 

EPA looked at estimates of CO2 capture rates both in the CCS projects currently 

 

23 DOE/NETL‟s Carbon Capture R&D Program for Existing Coal-Fired Power Plants, DOE/NETL-2009-

1356, February 2009.

24 Figueroa, Jose D. et al., 2008. Advances in CO2 capture technology – the U.S. Department of Energy’s 

Carbon Sequestration Program, International Journal of Greenhouse Gas Control 2, 2008 (9-20).

25 The term “store” or “storage” used throughout this preamble refers to the holding of waste for a 

temporary period above ground, and does not refer to the placement of CO2 streams in underground 

formations through the process of GS. See 40 CFR §260.10.
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underway, as well as future scenarios where CO2 capture is deployed at full scale. A 

review of commercially-available CO2 capture facilities in 2009 identified 17 facilities, 

with CO2 capture rates ranging from 50,000 metric tons/year to 3.63 million metric tons 

per year.26 According to the 2010 CCS Task Force Report, the largest of these capture 

rates (3.63 million metric tons/yr) is close to the volume of CO2 required for capture at 

electric utility generating plants. It is also estimated that a 500MW (megawatt) coal-fired 

power plant emits close to 3 million metric tons of CO2 per year.27 Similarly, the 

Mountaineer, West Virginia CCS project, which is currently capturing 100,000 metric 

tons CO2/year, will eventually scale up to 1.5 million metric tons of CO2 per year from an 

emission slipstream representing 235MW. See 75 FR 32171, June 7, 2010. An annual 

CO2 capture rate of 1.5 million metric tons translates to approximately 4,100 metric tons 

CO2 per day, or (at temperatures and pressures close to supercritical) 34,000 cubic 

meters, which is approximately 9 million gallons of CO2 per day. Even the smallest 

annual capture rate mentioned above (50,000 metric tons per year) equates to 

approximately 137 metric tons of CO2 per day, or 1,142 cubic meters, which is 

approximately 301,568 gallons per day.

Based on these estimates, the volume of CO2 streams either being captured, or 

anticipated to be captured, are quite large, and would require pressure vessels (i.e., tanks 

engineered for pressurized material) of inordinate size at the low end of these estimates, 

and are not likely to exist or be practicable at the upper end of these estimates. 

Therefore, EPA does not envision these large volumes of captured CO2 streams being 

stored on-site, and instead assumes that the CO2 streams will be dehydrated, compressed, 

 

26 CCS Task Force Study, August, 2010, Appendix A.

27 Carbon Dioxide Capture and Storage. Intergovernmental Panel on Climate Change (IPCC), 2005, p. 61.
Page 34 of 76

and either injected on-site, or sent off-site, in a continuous fashion. EPA believes that 

even if the CO2 were defined as a hazardous waste, under the scenario described above, 

where captured CO2 streams are delivered in a continuous fashion to either on-site 

injection wells, or to a pipeline for off-site injection (and presumably in a totally-enclosed 

manner, due to the need to maintain proper pressures) there would not be any 

substantive28 RCRA subtitle C requirements applicable to this activity. EPA notes that 

there are no RCRA hazardous waste standards for pipelines, unless the pipelines are 

ancillary to a regulated hazardous waste tank, which does not appear to be the case 

here.29

Regarding other generator requirements, such as notification to EPA of hazardous 

waste activity, and recordkeeping and reporting, EPA believes there will be equivalent 

notice and reporting for facilities engaged in CO2 capture for purposes of GS. The new 

GHG reporting requirements promulgated on October 30, 2009 (74 FR 56260) will 

provide information to the Agency regarding individual facilities engaged in CO2 capture 

activities. Under 40 CFR part 98, subpart PP, of the GHG rule, facilities with production 

process units that capture a CO2 stream must annually report certain information to EPA, 

such as the amount of CO2 in the stream captured, and information on the fate of the CO2

stream (i.e., the downstream „end use‟ of the CO2) including GS. See 40 CFR 98.426. 

The GHG rule also requires comprehensive recordkeeping, and records that must be 

retained for three years. See §98.3(g) and §98.427. EPA points out that these GHG 

 

28 “Substantive” as used here describes those requirements that are directly related to storage, 

transportation, treatment, or disposal, and not notification or biennial reporting.

29 EPA notes that there are no stand-alone RCRA hazardous waste standards for pipelines only; rather, EPA 

regulates hazardous waste “tank systems” which includes technical standards for piping where that piping 

is ancillary to hazardous waste tanks. See 40 CFR 260.10 for the definition of tank system; see also July 

14, 1986 Federal Register for discussion of ancillary equipment, 51 FR at 25441.
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requirements apply irrespective of whether a facility claims the RCRA exclusion being 

proposed today, if finalized.

Therefore, with respect to generators of CO2 streams, EPA believes there would 

not be any additional protection to human health or the environment through the RCRA 

hazardous waste regulations of these operations. Absent any storage, the regulation of 

the movement of captured CO2 streams from the point of capture to either an on-site UIC 

Class VI injection well, or to an off-site DOT-regulated pipeline (discussed below), 

would not be significantly different in the presence or absence of today‟s proposed 

conditional exclusion. While it is not clear what would be the procedure during 

maintenance or upset circumstances (such as if the capture process could not function), 

EPA assumes that the source emissions would be diverted for release under the facility‟s 

Clean Air Act permit. 

EPA requests information on whether EPA‟s estimates for captured CO2 volumes 

are accurate and reasonable, and whether the CO2 that is captured could be stored on-site 

prior to being sent elsewhere for GS or any other purpose; if so, EPA requests detailed 

information on the duration and method of storage, and what existing regulatory or 

voluntary controls and standards apply to such storage. EPA also requests information on 

the units and processes involved after the CO2 is captured, and before it is either injected 

on-site, or sent off-site. Finally, EPA requests comment and information on the 

procedures that have been or are expected to be used during maintenance and upset 

circumstances of the carbon capture system.

2. Transportation of CO2 Streams to UIC Class VI Injection Well

While there may be instances where captured CO2 streams are injected on-site, 
Page 36 of 76

most generators will likely transport their captured CO2 streams to UIC Class VI wells 

located off-site, and therefore EPA considered the transportation of CO2 streams under 

today‟s proposed conditional exclusion. Carbon dioxide itself is listed under the DOT 

regulations as a Class 2.2 hazardous material (non-flammable gas). See definitions in 49 

CFR 172.101 and 173.115(b). By this designation as a hazardous material, CO2 becomes 

subject to regulations established by DOT for the safe and secure transportation of 

hazardous materials in commerce. DOT‟s Pipeline Hazardous Materials Safety 

Administration (PHMSA) is charged with overseeing the movement of hazardous 

materials, including CO2, over all modes of transportation. For purposes of this proposal, 

EPA examined existing requirements for pipeline, and non-pipeline, modes of 

transportation.

Pipeline Transport - EPA presumes that pipeline transport of CO2 streams will be 

the principal mode of transport for CCS activities, either using existing or newly-built 

pipelines. For example, in 2008, a Congressional Research Service report stated that 

“[t]ransporting captured CO2 in relatively limited quantities is possible by truck, rail, and 

ship, but moving the enormous quantities of CO2 implied by a widespread 

implementation of CCS technologies would likely require a dedicated interstate pipeline 

network.”30 In the United States, CO2 pipelines as a whole are relatively modern, with 

approximately 91% of the nearly 4,000 miles of CO2 pipeline infrastructure being built 

after 1980.31 Also, industry knowledge gained from the oil and gas industry, which has

 

30 CRS Report for Congress. Carbon Dioxide (CO2) Pipelines for Carbon Sequestration: Emerging Policy 

Issues. Paul W. Parfomak and Peter Folger. January 17, 2008.

31 Oversight Hearing on Construction and Operation of Carbon Dioxide Pipelines. United State Senate‟s 

Committee on Energy and Natural Resources. Written statement of Krista L. Edwards, Deputy 

Administrator for DOT‟s PHMSA. January 31, 2008.
Page 37 of 76

used CO2 pipelines over the past 35 years to transport large volumes of CO2 to oil fields,

is directly applicable to carbon capture and GS operations and, thus, there is much 

experience with this activity.

Pipeline transportation of CO2 is subject to the PHMSA requirements in 49 CFR 

part 195, which apply to pipeline facilities used in the transportation of hazardous liquids 

or supercritical CO2.

32

 As defined in 49 CFR 195.2, carbon dioxide is “a fluid consisting 

of more than 90 percent carbon dioxide molecules compressed to a supercritical state,” 

which would include supercritical CO2 streams transported for purposes of CCS. The 

requirements in 49 CFR part 195 govern pipeline design, construction, operation and

maintenance, and emergency response planning, and EPA believes that by addressing 

these areas, the PHMSA requirements are consistent with the RCRA subtitle C goal of 

preventing releases in order to protect human health and the environment.

Additionally, PHMSA‟s goal is to improve the overall integrity of pipeline 

systems and reduce risks. See January 10, 2011 Federal Register (76 FR 1504). To 

evaluate risk adequately, the Hazardous Liquid and Gas Transmission Pipeline Integrity 

Management (IM) requirements were created (49 CFR 195.450 and §195.452), which 

supplement PHMSA‟s prescriptive safety regulations mentioned above. The goal of the 

IM requirements is to identify and evaluate the physical and operational characteristics of 

each individual pipeline system, in order to ensure the quality of pipeline integrity in 

areas with a higher potential for adverse consequences (high consequence areas or 

 

32 The pipeline transportation of carbon dioxide and hazardous liquids are both regulated under the same 

regulatory framework. “Hazardous liquids,” for purposes of 49 CFR part 195, are defined by DOT as

petroleum, petroleum products, and anhydrous ammonia, and are not the subject of this proposed rule. 49 

CFR 195.2. 
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HCAs).33 In addition, the PMHSA‟s IM requirements promote a more rigorous and 

systematic management of pipeline integrity and risk by operators; maintain the 

government‟s prominent role in the oversight of pipeline operator integrity plans and 

programs; and increase the public‟s confidence in the safe operation of the nation‟s 

pipeline network. EPA believes that these requirements, which focus on preventing 

releases that might affect human populations and ecologically-sensitive areas, further 

support the conclusion in today‟s proposal that additional regulation of pipeline 

transportation under RCRA subtitle C is not necessary in order to protect human health 

and the environment.

With respect to there being no requirement to use a hazardous waste manifest 

under today‟s proposal for CO2 streams that are conditionally excluded, it is important to 

note that under the RCRA subtitle C regulations, moving hazardous waste off-site 

through a pipeline does not trigger the use of a manifest, because pipelines are not 

included in the definition of “transportation” under RCRA subtitle C.34 With respect to 

the use of a manifest, because the applicable requirements would not change under either 

the existing RCRA subtitle C regulations, or when managed in accordance with today‟s

proposed conditional exclusion, there is no change in protection to human health and the 

environment under today‟s proposed rule. In fact, EPA notes that were CO2 streams to 

be subject to RCRA subtitle C as hazardous waste, they would not be regulated any 

differently under the part 195 regulations that are applicable to supercritical CO2 streams. 

 

33 HCAs include populated areas, and other areas particularly vulnerable to pipeline releases, such as 

drinking water resources or certain ecologically-sensitive areas. 49 CFR 195.450.

34 40 CFR 260.10, §262.20(a)(1), and §263.20(a)(1). See also Memorandum from Marcia Williams, 

Director, Office of Solid Waste, to Barry [sic] Seraydarian, Director, Toxics and Waste Management 

Division, EPA Region 9, April 30, 1986.
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Consultations with PHMSA staff indicate that whether a CO2 stream is defined as 

hazardous waste under RCRA subtitle C (in this instance, if it were to exhibit a RCRA 

characteristic) does not change the technical and other requirements applicable to the 

transportation of supercritical CO2 under PHMSA.35

Finally, EPA notes that it may be the case that some pipelines used to transport 

CO2 are not subject to the DOT requirements, because they are located on-site at the 

generator facility or at the UIC Class VI facility. See, e.g., 49 CFR 195.1(b)(8). EPA 

requests information on how these pipelines are currently regulated, including any design 

and operating standards that apply to such pipelines. As discussed earlier in today‟s 

preamble, EPA assumes that in the typical case, captured CO2 will not be stored at the 

generator facility, and will be transferred in a continuous manner either to an on-site or 

off-site UIC Class VI well. EPA is not proposing to apply RCRA subtitle C requirements 

to these pipelines as a condition of today‟s proposed rule (as stated earlier, absent storage 

of hazardous waste by generators, piping alone would not be subject to subtitle C 

regulation in any event); but EPA still requests comment on the appropriateness of 

applying the RCRA subtitle C standards to these non-DOT regulated pipelines.

Non-Pipeline Transport - While EPA expects that pipelines will be the most 

commonly used transportation method for moving supercritical CO2 from its source to a 

UIC Class VI injection well, other forms of transportation other than pipeline (e.g., 

highway, rail) are still possible. Supercritical CO2 streams being transported by means 

other than by pipeline must comply with applicable DOT hazardous materials 

transportation regulations, which address (for these modes of transportation) 

 

35 Electronic message from Vincent Holohan, Engineer, DOT/PHMSA, 7-21-2010.
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requirements, such as packaging, labeling, marking, placarding, emergency response, 

training, and shipping documentation. These regulations are found in 49 CFR parts 100-

180 (hazardous materials regulations). EPA believes that these DOT requirements will 

adequately address risks to human health and the environment from the transportation of 

CO2 and, therefore, additional RCRA subtitle C requirements specifically relating to 

transportation will not provide substantially more protection.

Where a hazardous waste manifest would otherwise be required for transporting

CO2 streams that meet the definition of hazardous waste, under today‟s proposed 

conditional exclusion, no hazardous waste manifest would be required. While the DOT 

hazardous materials shipping paper ensures that important information regarding the CO2

stream accompanies the shipment, and that persons offering the CO2 stream for transport 

must keep copies of the DOT shipping paper for two years, there is no tracking feature 

provided by the DOT shipping paper (as is the case for a hazardous waste manifest). 

EPA believes, however, that today‟s proposed rule will provide adequate incentive to 

ensure that the CO2 stream is delivered to a UIC Class VI facility (for example, as 

discussed later in today‟s preamble, EPA is proposing a condition requiring generators to 

certify that any CO2 stream, which they claim to be excluded from RCRA subtitle C, has 

been delivered to a UIC Class VI facility). EPA believes that this proposed certification 

statement, which must be signed by the generator, provides a strong incentive to ensure 

delivery to the designated UIC Class VI facility; this is because generators who claim the 

exclusion, but fail to ensure delivery of their CO2 stream that is hazardous to a Class VI 

facility, risk losing the exclusion and invoking the full hazardous waste requirements. 

Nonetheless, EPA notes that this certification statement does not provide the same type of 
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tracking as a hazardous waste manifest would provide. Therefore, EPA requests 

comment on the extent to which non-pipeline transportation will be used specifically for 

transporting CO2 streams to UIC Class VI facilities, and whether the use of the 

certification statement, together with compliance with applicable DOT hazardous 

material transportation requirements, are effective substitutes for the RCRA hazardous 

waste regulations that would apply to these specific circumstances.

C. Underground Injection of CO2 Streams at UIC Class VI Wells

The UIC Class VI regulations specifically preclude CO2 streams that are defined 

as RCRA hazardous waste from being injected into a UIC Class VI well. See 40 CFR 

146.81(d) (definition of Carbon Dioxide Stream in the UIC Class VI regulation). Instead, 

under the existing UIC and RCRA regulations, hazardous wastes (including CO2 streams 

that meet the definition of hazardous waste) – if injected – must be injected into a Class I 

hazardous waste well. As already discussed, EPA has little information about whether 

CO2 streams would exhibit a RCRA hazardous waste characteristic (in particular, the 

TC). However, because it is possible that captured CO2 streams could contain low 

concentrations of contaminants which could cause a waste to be identified as hazardous 

by the TC (e.g., arsenic, mercury, selenium),36 EPA considered whether the injection of 

captured CO2 streams into UIC Class VI wells would be properly managed, such that 

subtitle C regulation was duplicative and unnecessary.

The UIC Class VI well requirements are designed to ensure that the CO2 and any 

incidental associated substances will be isolated within the injection zone, and thus 

 

36 Apps, J.A., A Review of Hazardous Chemical Species Associate with CO2 Capture from Coal-Fired 

Power Plants and Their Potential Fate in CO2 Geologic Storage, Lawrence Berkeley National Laboratory, 

March 2006.
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protect USDWs from endangerment. The UIC Class VI requirements are designed for 

the unique characteristics of CO2, including its buoyancy relative to other fluids in the 

subsurface, which requirements account for the potential presence of impurities 

(including hazardous contaminants which could cause the waste to be identified as 

hazardous by the TC) in captured CO2. See 75 FR at 77234-5 (December 10, 2010).

Thus, EPA expects that compliance with the UIC Class VI requirements, which are 

designed to ensure isolation of supercritical CO2 streams, will also address the potential 

for effects on human health and the environment from the contaminants present in the 

stream. Below is a description of key elements of the UIC Class VI requirements that 

EPA believes will ensure protection of human health and the environment, such that 

RCRA subtitle C regulation would be duplicative and unnecessary.

1. Development of UIC Class VI Wells Under SDWA

Section 1421(d)(2) of the SDWA provides, “Underground injection endangers 

drinking water sources if such injection may result in the presence in underground water 

which supplies or can reasonably be expected to supply any public water system of any 

contaminant, and if the presence of such contaminant may result in such system‟s not 

complying with any national primary drinking water regulation or may otherwise 

adversely affect the health of persons.” Pursuant to §1421(d)(2), the UIC program 

requirements for all well classes, promulgated under the authority of the SDWA, are 

designed to comprehensively ensure that an injection well is appropriately sited, 

operated, tested, monitored, and closed in a manner that ensures USDW protection and 
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does not otherwise adversely affect the health of persons.37

In developing standards for CO2 injection for GS, the Agency evaluated the 

applicability of the existing UIC program requirements for Class I wells (hazardous and 

non-hazardous) through Class V wells, and determined that new, tailored regulations to 

address the injection of supercritical CO2 streams for GS, including any associated 

constituents that may be present in the CO2 streams, were warranted in order to protect 

USDWs from endangerment. In October 2007, EPA announced that it would develop 

tailored regulations for GS, by adapting the existing UIC program framework and by 

relying on that program‟s considerable experience – over 25 years – in regulating the 

injection of fluids, including CO2 injected for enhanced hydrocarbon recovery. The Class 

VI rule, finalized in December 2010, includes specific requirements designed to address 

the unique nature of CO2 injection for GS, including the large CO2 injection volumes 

anticipated at GS projects, the relative buoyancy of CO2, its mobility within subsurface 

geologic formations, and its corrosivity in the presence of water. In addition, EPA 

recognized that the CO2 stream could contain impurities, including those which could 

cause the waste to exhibit the TC under the RCRA subtitle C regulations.

Throughout the regulatory development process for the Class VI requirements, 

the UIC program, in coordination with other EPA program offices, stakeholders, and the 

public relied upon the existing UIC regulatory framework and applicable requirements of 

other well classes (i.e., Class II, Class I industrial, Class I hazardous), as appropriate. 

 

37 For example, the following general standard in the SDWA regulations applies to all classes of UIC wells: 

“No owner or operator shall construct, operate, maintain, convert, plug, abandon, or conduct any other 

injection activity in a manner that allows the movement of fluid containing any contaminant into 

underground sources of drinking water, if the presence of that contaminant may cause a violation of any 

primary drinking water regulation under 40 CFR part 142 or may otherwise adversely affect the health of 

persons. The applicant for a permit shall have the burden of showing that the requirements of this 

paragraph are met.” 40 CFR 144.12(a).
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However, the Agency recognized that these established programmatic requirements 

required certain modifications and enhancements with respect to CO2 injection for GS in 

order to ensure USDW protection.

2. Key Elements of the UIC Class VI Well Requirements

The UIC Class VI final regulations include specific requirements tailored to the 

particular nature of CO2 injection for GS. These program elements include site 

characterization, area of review (AoR) delineation, corrective action,38 well construction 

and operation, testing and monitoring, post-injection site care, site closure, and financial 

responsibility. Together, these program elements provide a comprehensive approach for 

verifiable isolation of the CO2 stream within the injection zone to ensure protection of 

USDWs from endangerment. Although not an exhaustive list, some requirements 

tailored for GS (Class VI) include:

o Class VI well owners or operators must conduct and submit, with the permit 

application, an extensive, detailed assessment of the geologic, hydrogeologic, 

geochemical, and geomechanical properties of the proposed GS site to ensure that 

GS wells are located in suitable geologic formations, and that the geology 

provides containment. The owner or operator must also select a site with an 

injection zone of sufficient areal extent, thickness, porosity and permeability to 

receive the total anticipated volume of the CO2 stream, and, confining zones free 

 

38 EPA notes that the term “corrective action” is used in both the SDWA and RCRA programs, but refers to 

different activities under each. Under the UIC Class VI rule, the phrase refers to actions taken to correct 

situations where artificial penetrations (e.g., wells) could serve as unwanted conduits for CO2 or other fluid 

movement into or between USDW within the AoR. See 40 CFR 144.55, §146.7, and §146.64. Under 

RCRA subtitle C, corrective action generally refers to actions taken to address releases of hazardous wastes 

or hazardous constituents from solid waste management units at a treatment, storage, or disposal facility. 

The RCRA corrective action aspects of this proposed rule are discussed in Section IV.C.4 of this preamble.
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of transmissive faults or fractures and of sufficient areal extent and integrity to 

contain the injected CO2 stream and displaced formation fluids. Class VI 

requirements also mandate a thorough process for the identification of features 

that might compromise the integrity of the containment system (e.g., abandoned 

wells) and remediation of those features through corrective action, within the 

AoR. Existing UIC regulations, including those for Class I hazardous wells, 

require that owners or operators define the AoR, within which they must identify 

artificial penetrations and determine whether they have been properly constructed 

or plugged; the Class VI regulations are consistent with this approach. 

o Class VI well owners or operators must delineate the AoR using a sophisticated 

computational model that incorporates available site characterization data and 

planned operational conditions. Throughout the life of the project, the AoR must 

be periodically reevaluated (at least once every 5 years) through the use of 

monitoring and operational data to verify that the CO2 plume and the associated 

area of elevated pressure are moving as predicted within the subsurface, and that 

the injected CO2 stream is isolated within the injection zone. With the exception 

of the UIC Class VI regulations, the existing UIC regulations (including Class I 

hazardous) do not include a requirement to reevaluate the AoR and corrective 

action plan. This reevaluation is an additional level of protection that has been 

added for Class VI wells in order to address the unique characteristics of the CO2

stream injectate. This reevaluation will provide an ongoing dialogue between the 

Director and the owners or operators, while ensuring that if a circumstance 

changes, the AoR will be updated to address those changes, while ensuring 
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protection of USDW. Because there will be inevitable plume movement, a 

reevaluation was deemed to be necessary to protect USDW for Class VI wells.

o Class VI well owners or operators must also identify and evaluate all artificial 

penetrations within the AoR, and based on this review, identify the wells that 

need corrective action to prevent the movement of CO2 or other fluids into or 

between USDWs. Owners or operators must perform corrective action to address 

deficiencies in any wells (regardless of ownership) that are identified as potential 

conduits for fluid movement into USDWs. The Director must approve the 

methods used to identify the wells and the corrective action selected by the 

owners or operators. This inventory and review process is similar to what is 

required of all Class I and Class II injection well owners or operators.

o Class VI wells must meet the same stringent injection well construction standards 

as Class I hazardous waste wells, in order to ensure that the well itself does not 

serve as a conduit for fluid movement. In addition, the Class VI rule requires that 

all well construction materials be compatible with the fluids with which the 

materials may come in contact (e.g., fluid formations; CO2 streams) over the life 

of the GS project. Class VI operating requirements also ensure that injection in a 

Class VI well will not propagate fractures within the injection and/or confining 

zones that could compromise containment.

o Class VI owners or operators must conduct robust monitoring to ensure the 

integrity of the injection well, detect any changes in groundwater geochemistry 

that may indicate leakage, and track the evolution of the CO2 stream and 

associated pressure front. Class VI monitoring requirements are generally more 
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detailed and rigorous than those for Class I hazardous waste injection wells, and 

are designed to verify isolation of the injected CO2 stream, and allow for earlywarning of any possible fluid leakage. 

o The Class VI rule contains tailored requirements for extended, comprehensive 

post-injection monitoring and site care of GS projects following cessation of 

injection, until it can be demonstrated that movement of the CO2 plume and 

pressure will not pose a risk of endangerment to USDWs. Owners or operators 

must also plug injection and monitoring wells in a manner that protects USDWs. 

Proper plugging of injection and monitoring wells is a long-standing requirement 

in the UIC Program to ensure that existing wells do not serve as conduits for fluid 

movement following cessation of injection and site closure. Post-injection site 

care (PISC), which is unique to GS and Class I hazardous wells in the UIC 

program, is a protective measure that requires site monitoring to continue in order 

to ensure the injectate and any mobilized fluids do not pose a risk to USDW.

o Class VI provisions require that owners or operators maintain financial 

responsibility obligations guaranteeing that funds will be available for all SDWA 

corrective action, injection well plugging, PISC, site closure, and emergency and 

remedial response.

These elements of the Class VI requirements are designed to provide verifiable 

control of the CO2 stream at the Class VI well, and containment of that stream within the 

injection zone, in order to ensure protection of USDW from endangerment. EPA 

believes that the elimination of exposure routes through these requirements will ensure 

protection of human health and the environment, and views this as determinative in its 
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evaluation of whether the RCRA subtitle C regulatory requirements for hazardous waste 

disposal provide any substantial, additional protection for CO2 streams which exhibit a 

characteristic of hazardous waste and are disposed in UIC Class VI wells. Thus, EPA 

concludes (subject to consideration of public comment) that a conditional exclusion from 

RCRA subtitle C requirements is warranted for CO2 streams that are injected into UIC 

Class VI wells for purposes of GS.

3. RCRA Land Disposal Restrictions

Under today‟s proposed rule, a CO2 stream that is conditionally excluded from the 

definition of hazardous waste would not be subject to the RCRA land disposal restriction 

(LDR) requirements in 40 CFR part 148 that apply to restricted hazardous wastes that are 

disposed of in UIC wells. EPA considered how the conditions proposed in today‟s rule 

compare to the protections afforded by the RCRA LDR requirements (that would 

otherwise apply to a CO2 stream that exhibits a RCRA characteristic and is disposed of in 

an injection well). As discussed below, EPA believes that with respect to CO2 streams 

that are conditionally excluded for purposes of GS, the LDR requirements would not 

provide more protection to human health and the environment than the UIC Class VI

requirements provide.

The LDR program ensures that hazardous waste cannot be placed on or under the 

land – i.e., land disposed – until the waste meets specific treatment standards to reduce 

the mobility or toxicity of the hazardous constituents in the waste. These treatment 

standards are waste-code specific, and either specify an allowable concentration of 

hazardous constituents or specify a method of treatment. These treatment standards must 

be satisfied before land disposal of the waste occurs. The alternative to meeting the 
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treatment standards is to make a successful demonstration to EPA that no hazardous 

constituents will migrate from the disposal unit (or, in the case of injection wells, the 

“injection zone” (see RCRA section 3004(d)(1)) for as long as the waste remains 

hazardous (a “no-migration” petition). See RCRA sections 3004(f) and (m). The LDR 

requirements are found in 40 CFR part 268, and the LDR requirements regarding 

injection wells are located in 40 CFR part 148.

LDR requirements attach to wastes that are hazardous at the point of generation. 

Chemical Waste Management v. EPA, 976 F. 2d 2, 13,14 (D.C. Cir. 1992), so that if a 

waste is conditionally excluded from being a hazardous waste, LDRs do not apply. EPA 

evaluated the protections afforded under the Class VI regulations and the LDR program 

to assure that this is an appropriate outcome here.

Class VI wells are required to demonstrate (through the initial permitting process, 

and periodically during the operational life of the well), on a well-by-well basis, that 

there are no features near an injection well that would allow injected fluid to move into a 

USDW or displace native fluids into USDWs resulting in their endangerment. EPA 

interprets the UIC Class VI isolation requirements as meeting the objectives of the RCRA

LDR requirements. This is because the same individualized determination, using the 

same or similar decision tools, with essentially the same ultimate determination (no 

migration of hazardous constituents from the injection zone of either a Class VI well or a 

Class I hazardous waste well) would apply in either instance. 

EPA thus believes (subject to consideration of public comment) that the Class VI 

well review process and isolation requirements will meet essentially the same 

requirements and objectives as the RCRA no-migration process, affords similar 
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procedural safeguards (individualized determinations in both instances), and will protect 

human health and the environment via proper management under the Class VI 

regulations. Thus, the proposed conditional exclusion appears reasonable with respect to 

otherwise-applicable LDR requirements.

In addition, we note that RCRA section 1006 (b) provides that EPA “shall 

integrate all provisions of this chapter for purposes of administration and enforcement 

and shall avoid duplication, to the maximum extent practicable, with the appropriate 

provisions of the...Safe Drinking Water Act.” For the reasons just discussed, it appears 

that the RCRA LDR provisions duplicate the requirements and procedures of the Class 

VI rules and that a conditional exclusion from being a hazardous waste avoids this 

duplication. See Chemical Waste Management v. EPA, 976 F. 2d 2, 23-24 (integration of 

RCRA LDR and Clean Water Act direct discharger requirements).

4. Subtitle C Corrective Action

EPA also reviewed the subtitle C corrective action requirements, which apply to 

any hazardous waste treatment, storage or disposal facility, including Class I UIC 

hazardous waste facilities. Under today‟s proposed conditional exclusion, CO2 streams 

that would otherwise be defined as RCRA hazardous waste (because they exhibit a 

RCRA characteristic) and meet the proposed conditions, would not be defined as 

hazardous waste. Therefore, the RCRA corrective action requirements would not be 

triggered at the Class VI UIC facility as a result of these activities. EPA does not believe, 

however, that the absence of RCRA corrective action authority at a Class VI UIC facility 

is of concern with respect to the management of excluded CO2 streams in the Class VI 

UIC well under a SDWA permit. In EPA‟s view, the comprehensive Class VI UIC 
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regulations provide multiple, enforceable mechanisms to correct permit violations and 

other situations that may pose a risk to USDW. These include enforceable requirements 

to develop, maintain, and update an emergency and remedial response plan and to 

undertake emergency or remedial response actions for any unauthorized releases from the 

well or injection zone. See 40 CFR 146.94.

5. Conclusion

In conclusion, consistent with SDWA and RCRA, the integrated application, 

implementation, and enforcement of UIC Class VI requirements will protect human 

health and the environment by ensuring that the CO2 streams (which may include low 

concentrations of hazardous constituents as discussed above) remain isolated in the 

injection zone and confined by confining zones in an appropriate, well-characterized 

geologic setting, that is continuously monitored to ensure that the CO2 streams remain in 

the injection zone. EPA believes that with respect to CO2 streams as discussed in today‟s 

proposed conditional exclusion, the existing UIC Class VI well requirements sufficiently 

address any potential risk to human health and the environment, such that subtitle C 

regulation is unwarranted. 

D. Prohibition on Introduction of Other RCRA Hazardous Wastes

The UIC Class VI well program was specifically developed for the unique 

purpose of GS of CO2 streams. Today‟s proposed conditional exclusion only applies to 

CO2 streams that have been captured for purposes of GS and are to be injected into a UIC 

Class VI well. EPA is proposing to limit the scope of this exclusion by including a 

condition that no other hazardous waste can be mixed with, or otherwise co-injected with, 

the CO2 streams as defined in today‟s proposed rule. Thus, if hazardous waste is mixed 
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with the CO2 stream, under today‟s proposal that stream would not be eligible for the 

conditional exclusion. That stream would need to be managed as a RCRA hazardous 

waste, and, if well injection is selected as the means of disposal, injected into a UIC Class 

I hazardous well. 

EPA expects that where facilities have made the significant economic 

commitment to capture and/or inject CO2 streams for purposes of GS, such facilities will 

not wish to jeopardize this arrangement by mixing hazardous waste into the CO2 stream

in violation of the explicit prohibition in the UIC Class VI rule, as well as the condition 

being proposed today in 40 CFR 261.4(h)(1)(iii). EPA seeks to safeguard the efforts of 

the CO2 sources and injection facilities that comply with the mixing prohibition by 

designing a regulatory scheme that is enforceable and is structured to ensure compliance, 

thus obtaining the full benefit of the regulation that the public expects. 

In order to better ensure that CO2 sources and UIC Class VI injection facilities 

choosing to use this conditional exclusion fully comply with the conditions of the 

exclusion, including the prohibition on mixing hazardous waste with the CO2 stream, 

EPA is proposing that a certification statement be executed by an authorized 

representative of the generator and the Class VI injection facility owner/operator. The 

term “authorized representative” is defined in the RCRA regulations to mean “the person 

responsible for the overall operation of a facility or an operational unit (i.e., part of a 

facility), e.g., the plant manager, superintendent or person of equivalent responsibility.” 

40 CFR 260.10.

Because the function of the certification statement is to ensure compliance with 

the conditions of the proposed conditional exclusion, EPA requests comment on whether 
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it should limit the categories of employees who would be required to sign this 

certification statement, to senior employees in the same manner as that which is required 

for RCRA permit applications under 40 CFR 270.11(a). Under this alternative approach, 

certification statements (for corporations) would need to be signed by a “responsible 

corporate officer” as defined in §270.11(a)(1)(i), or, plant managers for facilities over a 

certain size as defined in §270.11(a)(1)(ii); by a general partner or proprietor (for general 

partnerships or sole proprietorships, respectively) as specified in §270.11(a)(2); or, for 

public agencies, the chief executive officer, or certain other senior officers of that agency, 

as defined in §270.11(a)(3). Accountability and enforceability may be improved when 

signatories to these types of certifications are at the highest levels of an organization.

EPA is not requiring that these certifications be submitted to the Agency; rather, 

EPA is proposing that the signed certification statement be kept on-site for no less than 

three years, and that these signed certifications be made available within 72 hours of a 

written request from the Regional Administrator (or state Director, if located in a state 

implementing the conditional exclusion as part of their authorized RCRA program).39 

EPA believes the retention time of three years is reasonable and appropriate, and 

consistent with the existing subtitle C recordkeeping requirements (e.g., 40 CFR 262.40 

and §268.7(a)(8) for generators; §264.73 for TSDFs). Because EPA is not requiring the 

submittal of signed certification statements, today‟s proposed rule does not impose any 

new reporting requirements; however, EPA will be aware of the universe of generator 

and UIC Class VI facilities that may potentially claim this proposed conditional 

 

39 “Regional Administrator” as defined under RCRA subtitle C (40 CFR 260.10) includes any designee of 

the Regional Administrator; therefore, written requests may be made by a designee of the Regional 

Administrator or state Director. Today‟s proposed regulatory text reflects this.
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exclusion, because under the existing regulatory framework for GS, facilities that capture 

and sequester CO2 must identify themselves, and report specific information regarding 

their CO2 capture and GS activity, to the Agency.

40

 Therefore, EPA believes that it will 

have adequate opportunity to determine whether any particular facility is claiming the 

exclusion, as it anticipates a relatively gradual increase in the deployment of CCS 

activities in the near term. EPA is also proposing that these certifications shall be 

renewed every year that the generator or UIC Class VI well owner/operator claims the 

RCRA conditional exclusion, in order to ensure that the certification is kept current (e.g., 

facility personnel may change, etc.). This yearly renewal of the certification statement 

means that an authorized representative must annually prepare and sign a new copy of the 

certification statement, to be retained on-site for no less than three years.

The language for this certification is in proposed 40 CFR 261.4(h)(1)(iv), and 

reads as follows:

“I certify under penalty of law that the carbon dioxide stream that I am claiming 

to be excluded under 40 CFR 261.4(h)(1) meets all of the conditions set forth in 

that paragraph.”

While EPA is not currently aware of specific examples where hazardous wastes 

are being mixed into or with CO2 streams, particularly at this early stage of CCS 

deployment, well-designed rules are essential to the success of future enforcement 

efforts. EPA requests comment on the certification statement, and particularly seeks 

comment on whether this measure will appropriately ensure compliance with the 

 

40 Under subparts PP and RR of the GHG reporting program, facilities that capture CO2 and facilities that 

inject CO2 underground for GS (including UIC Class VI facilities) have certain reporting requirements. 

For more information, see Section III of this preamble.
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conditional exclusion, including the mixing prohibition. EPA also requests comment on 

how CO2 sources, who add excluded CO2 streams into an existing (or future) CO2

pipeline network, can ensure that the CO2 reaches a UIC Class VI facility. Finally, EPA 

requests comment on whether transporters, including pipeline owners and operators, 

should also sign such a certification statement. 

In addition to the conditions and requirements being proposed today, the Agency 

recognizes that other conditions or requirements could possibly improve EPA‟s and the 

states‟ ability to monitor compliance with the mixing prohibition. For example, there are 

certain existing requirements for the physical and chemical characterization of CO2

streams that apply at the UIC Class VI facility (discussed in Section III.E. of this 

preamble), and the prohibition that no hazardous waste be injected in the UIC Class VI 

well. However, there are no CO2 stream characterization requirements that EPA could 

identify upstream of the UIC Class VI well, such as at the CO2 source or in a pipeline, 

other than the general requirement that generators make a hazardous waste determination 

for any solid waste they generate (40 CFR 262.11), and the PHMSA requirement that 

supercritical CO2 streams be chemically compatible with the pipeline and any 

commodities in the pipeline (49 CFR 195.4), and will not corrode the pipeline and

pipeline system (49 CFR 195.579).41 EPA requests comment, including supporting 

information, on whether (and if so, what type of) additional monitoring, recordkeeping, 

and reporting of the CO2 composition by generators and transporters (including pipeline 

 

41 The Agency is also aware that supercritical CO2 pipeline owner/operators follow certain requirements 

and specifications related to monitoring supercritical CO2 composition, including water content, and the 

identification of any impurities or other inert materials, that might negatively affect CO2 transport, or 

otherwise take up needed space. Pers. comm., Doug McMurrey, V.P. for Marketing and Business 

Development, Kinder Morgan, 7-21-2010.
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operators), might aid EPA and the states in their ability to detect improper mixing of 

hazardous waste with CO2 streams. EPA also requests comment on whether there are 

other conditions, such as a minimum CO2 content, that could enhance compliance with 

the proposed “no mixture” condition. For example, EPA is aware that under the PHMSA 

requirements for the pipeline transportation of supercritical carbon dioxide, the definition 

of carbon dioxide specifies a CO2 content of greater than ninety percent. 49 CFR 195.2. 

EPA also requests comment on what commercial, operational, or regulatory requirements 

or specifications already exist regarding CO2 content in the management of supercritical 

CO2.

E. Loss of the Conditional Exclusion

The conditional exclusion being proposed today does not preclude regulation or 

enforcement by EPA or the states against generators, transporters, or treatment, storage, 

or disposal facilities who are not eligible for the conditional exclusion, or who do not 

meet the conditions of the exclusion. Because this hazardous waste exclusion is 

conditional, a claimant must meet the conditions to qualify for and maintain the exclusion

from the hazardous waste regulations. Failure to meet the conditions results in the loss of 

the exclusion. As proposed, a violation of a condition at any point in the management of 

a CO2 stream would result in that CO2 stream being subject to all applicable subtitle C 

regulatory requirements, from the point of generation. Thus, a violation of a condition at 

a UIC Class VI facility, for example, would mean that in addition to the UIC Class VI 

facility, the generator and transporter would also be considered to be managing (or to 

have managed) a hazardous waste. Moreover, imminent and substantial endangerment 

provisions under §7003 of RCRA will continue to apply to conditionally-excluded CO2
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streams as a safeguard in the unlikely event of a release which could pose a health or 

environmental threat. This is true even if the CO2 stream does not otherwise meet the 

regulatory definition of hazardous waste.42

F. Adaptive Approach

EPA is using an adaptive approach in the UIC Class VI final rule to allow it to 

consider making changes to the UIC Class VI program to incorporate new research, data, 

and information about GS and associated technologies. In the UIC final rule, EPA stated 

that the Agency plans, every six years, to review the rulemaking and data on GS projects 

to determine whether the appropriate amount and types of information and appropriate 

documentation are being collected, and to determine if modifications to the UIC Class VI

requirements are appropriate or necessary. See December 10, 2010 Federal Register (75 

FR at 77240-41, 77243, and 77257). This new information may increase protectiveness, 

streamline implementation, or otherwise inform the requirements for GS injection of 

CO2.

Consistent with EPA‟s stated intent in the UIC Class VI rule, EPA also plans to 

evaluate any new information related to the conditional exclusion being proposed today

at the same time as is planned for the UIC Class VI rule. EPA intends to use the 

information gathered by the UIC Class VI program described above, as well as additional 

information, such as data on the chemical and physical characteristics of the CO2 streams 

being injected, to inform its consideration of whether changes should be made to the 

 

42 EPA also notes that existing obligations to address corrective action at RCRA treatment, storage, and 

disposal facilities would not be affected by this proposed rule. In addition, today's proposed conditional 

exemption would not preclude RCRA corrective action requirements from applying to a Class VI UIC 

facility if the facility were to engage in the management of hazardous waste that would require a RCRA 

permit (e.g., if the conditions of today's proposed exemption were not met and the previously exempt CO2

streams were no longer exempt; or, if other hazardous wastes were treated, stored, or disposed of at the 

facility).
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conditional exclusion (such changes could require additional rulemaking). Thus, the 

Agency commits to reviewing, in coordination with the adaptive approach planned for 

the UIC Class VI rule, new research, data, and information related to today's proposed 

conditional exclusion (if finalized), particularly with respect to compliance with the 

conditions of the exclusion, and the nature and composition of the CO2 stream.

G. Definition of Carbon Dioxide Stream

Today, EPA is also proposing to add a definition for the term carbon dioxide 

(CO2) stream to the hazardous waste regulations in 40 CFR 260.10. Under today‟s 

proposed rule, carbon dioxide (CO2) stream is defined as “carbon dioxide that has been 

captured from an emission source (e.g., a power plant), plus incidental associated 

substances derived from the source materials and the capture process, and any substances 

added to the stream to enable or improve the injection process.” The same definition is 

used in the UIC Class VI regulations in 40 CFR 146.81(d), with one exception. The 

definition in §146.81(d) includes additional language that reads, “This subpart does not 

apply to any carbon dioxide stream that meets the definition of a hazardous waste under 

40 CFR part 261,” thus prohibiting the injection of hazardous waste into UIC Class VI 

wells. Because today‟s conditional exclusion would apply to CO2 streams that are 

otherwise RCRA hazardous wastes, EPA did not include similar language in today‟s 

proposed definition of carbon dioxide stream. EPA intends for the two definitions to 

work in concert, however, such that it is clear that both RCRA hazardous CO2 streams

(that are excluded when managed pursuant to the terms of today‟s proposed conditional 

exclusion) and non-hazardous CO2 streams may be injected into a UIC Class VI well. 

Finally, EPA notes that in today‟s proposed definition, “substances added to the stream to 
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enable or improve the injection process” refers to non-waste substances that serve the 

legitimate purpose as stated (i.e., to enable or improve the injection process), and does 

not include listed or characteristic hazardous wastes. EPA requests comment on the types 

and characteristics of substances that are added to CO2 streams to enable or improve the 

injection process.

V. State Authorization

A. Applicability of the Rule in Authorized States

Under Section 3006 of RCRA, EPA may authorize qualified states to administer 

their own hazardous waste programs in lieu of the federal program within the state. 

Following authorization, EPA retains enforcement authority under Sections 3008, 3013, 

and 7003 of RCRA, although authorized states have primary enforcement responsibility. 

The standards and requirements for state authorization are found at 40 CFR part 271.

Prior to enactment of the Hazardous and Solid Waste Amendments of 1984 

(HSWA), a state with final RCRA authorization administered its hazardous waste 

program entirely in lieu of EPA administering the federal program in that state. The 

federal requirements no longer applied in the authorized state, and EPA could not issue 

permits for any facilities in that state, since only the state was authorized to issue RCRA 

permits. When new, more stringent federal requirements were promulgated, the state was 

obligated to enact equivalent authorities within specified time frames. However, the new 

federal requirements did not take effect in an authorized state until the state adopted the 

federal requirements as state law.

In contrast, under RCRA Section 3006(g) (42 U.S.C. 6926(g)), which was added 

by HSWA, new requirements and prohibitions imposed under HSWA authority take 
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effect in authorized states at the same time that they take effect in unauthorized states. 

EPA is directed by the statute to implement these requirements and prohibitions in 

authorized states, including the issuance of permits, until the state is granted authorization 

to do so. While states must still adopt HSWA related provisions as state law to retain 

final authorization, EPA implements the HSWA provisions in authorized states until the 

states do so.

Authorized states are required to modify their programs only when EPA enacts 

federal requirements that are more stringent or broader in scope than existing federal 

requirements. RCRA Section 3009 allows the states to impose standards more stringent 

than those in the federal program (see also 40 CFR 271.1). Therefore, authorized states 

may, but are not required to, adopt federal regulations that are considered less stringent 

than previous federal regulations.

B. Effect on State Authorization

The provisions in today‟s notice are proposed pursuant to non-HSWA authority, 

and would eliminate the hazardous waste requirements for those CO2 streams that would 

otherwise meet the definition of hazardous waste, when these streams are managed in 

accordance with certain conditions. Therefore, this proposed exclusion is less stringent 

than the federal program, and states are not required to adopt this provision.43 

Nevertheless, while states do not have to adopt this provision, EPA strongly encourages 

them to do so, because this amendment will substantially reduce the uncertainty 

associated with defining and managing these CO2 streams under RCRA subtitle C, which 

 

43 EPA notes that decisions regarding whether a state rule is more stringent or broader in scope than the 

federal program are made when the Agency authorizes state programs.
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will remove the uncertainty regarding the type of permit needed for the GS of CO2

streams.

EPA notes that because the conditional exclusion is less stringent than the current 

RCRA program, states are not required to adopt this rule, if finalized.

44

 In situations 

involving the interstate transportation of conditionally-excluded waste, the exclusion

must be authorized in the state where the waste is generated, any states through which the 

waste passes, and the state where the UIC Class VI injection well is located, in order for 

that conditionally-excluded waste to be managed as excluded from subtitle C from point 

of generation to injection in a UIC Class VI well. A state that has not adopted the 

conditional exclusion may impose state requirements, including the uniform hazardous

waste manifest requirement, if characteristically-hazardous CO2 streams are being 

transported through that state.45 

VI. What are the Costs and Benefits of the Proposed Rule?

The economic assessment conducted in support of this action evaluated the costs, 

benefits, small entity impacts, environmental justice, and other impacts (e.g., children‟s 

health, unfunded mandates, federalism) of the proposal. As part of the evaluation of 

potential costs and benefits, EPA first prepared a baseline characterization of the 

potentially affected universe. We then assessed the “baseline” behavior that the affected 

entities could be expected to display in the absence of the proposed rule. This baseline 

 

44 Some states incorporate the federal regulations by reference, or have specific state statutory requirements 

that their state program can be no more stringent than the federal regulations. In those cases, EPA 

anticipates that the conditional exemption proposed today, if finalized, would be adopted by these states, 

consistent with state laws and administrative procedures (unless explicit action is taken by such a state to 

decline the revisions, as specified under that state‟s laws).

45 As discussed in Section IV.B.2. of this preamble, the off-site movement of hazardous waste through 

pipelines does not require the use of a hazardous waste manifest under the federal subtitle C hazardous 

waste regulations.
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provided a reference point from which the incremental costs and benefits of the proposed 

rule were measured. Finally, we estimated how the affected entities would likely change 

their behavior in response to the rule, as proposed. The analysis estimated incremental 

costs and benefits of the proposed rule over a 50-year period.

46

 

The universe of entities that may be directly affected by the proposed rule include 

CO2 generators, transporters, and sequestration facilities. CO2 generator facilities are 

likely to be entities that capture their CO2 byproducts and manage them in a manner other 

than releasing them into the atmosphere. We identified a total of 27 CO2 capture 

facilities47 that are expected to be affected by the rule, as proposed. EPA expects that 

captured CO2 will generally be transported by pipeline. As of 2008, there were 30 

operating CO2 pipelines in the U.S., operated by 29 separate entities. CO2 sequestration 

facilities inject the CO2 streams into UIC wells for the purposes of sequestration. This 

sequestration may be conducted either with or without concurrent enhanced oil recovery

(EOR). However, EOR itself is outside the scope of this rule, as proposed. EPA 

estimates that 29 planned sequestration facilities48 will be affected by the proposed rule.

In the baseline (absence of the proposed rule), generators of the captured CO2

streams would have to determine if their CO2 stream(s) is (are) a RCRA hazardous waste. 

Depending upon this determination, a capture facility is most likely to engage in one of 

four baseline management practices: 1) for CO2 streams that are nonhazardous waste, 

 

46 This 50-year time period is consistent with the Office of Water Analysis for the Final Geologic 

Sequestration Rule: Draft Cost Analysis for the Federal Requirements Under the Underground Injection 

Control Program for Carbon Dioxide Geologic Sequestration Wells (Final GS Rule), EPA 816-R-10-013, 

July 2010

47 This estimate includes ten facilities that currently capture CO2 plus 17 facilities expected to begin CO2

capture in the future, including 14 commercial projects, two non-commercial DOE pilot projects, and one 

other private/federal partnership project.

48 This estimate includes 15 planned commercial CO2 sequestration projects and 14 planned projects funded 

by DOE.
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transport the material to a sequestration facility for injection in a Class VI well; for CO2

streams that are hazardous waste, either 2) cease capturing the CO2 stream – that is, 

continue to allow the CO2 stream to be emitted into the atmosphere; or 3) transport the 

CO2 stream to a sequestration facility for injection in a Class I hazardous well; or 4) treat 

the CO2 stream so that it is no longer hazardous and transport it to a sequestration facility 

for injection in a Class VI well. A generator‟s determination as to how to manage a 

RCRA hazardous waste CO2 stream would depend on several factors. For our analysis, 

we assumed a reasonable worst-case scenario that 10 percent is nonhazardous49 and sent

to a Class VI well, while the remaining CO2 streams are assumed to be hazardous and 

managed in equivalent percentages (30% each), as described above. For all generators 

that capture CO2, we further assume the following: each facility would incur costs to 

determine if the CO2 stream is a RCRA hazardous waste; facilities that generate a CO2

stream that is characterized as a non-hazardous RCRA waste would face no further costs 

associated with the hazardous waste regulations, as would facilities who cease to capture

CO2; facilities that generate RCRA hazardous waste CO2 streams and do not cease 

capturing the CO2 would likely qualify as large quantity generators (LQGs) in the 

baseline and would be subject to applicable hazardous waste generator requirements; and, 

CO2 capture facilities that treat their RCRA hazardous waste CO2 streams would incur 

treatment costs, and may also incur RCRA permitting costs.

The baseline universe of CO2 sequestration facilities is assumed to include a mix 

of facilities with Class VI wells and facilities with Class I hazardous wells that will meet 

 

49 We employ this conservative assumption for analytical purposes only due to the absence of supporting 

data. This assumption should not be construed as an EPA determination of average CO2 stream status on a 

nationwide basis. The economic assessment document conducted in support of this action presents an 

alternative assumption of 90 percent non hazardous in order to derive a lower-level bounding estimate.
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the Class VI requirements. We further assume that 57 percent of the sequestration wells 

would manage non-hazardous CO2 streams and treated CO2 streams in Class VI wells

with the remaining sequestration wells managing RCRA hazardous CO2 streams in Class 

I hazardous wells. All CO2 streams are assumed to be transported via pipeline in the 

baseline and under the proposed rule.50

Under the proposed rule, CO2 streams that are captured, stored, transported, and 

injected into Class VI UIC wells in accordance with the conditions in the proposed rule 

would be excluded from the definition of hazardous waste and would therefore not be 

subject to EPA‟s RCRA hazardous waste requirements. The exclusion would not apply if 

the CO2 stream was mixed or co-injected with any other hazardous wastes.

Our analysis also assumes all affected states will adopt the conditional exclusion

and all generators that capture CO2 will claim the proposed conditional exclusion and 

send their CO2 streams to Class VI wells. These facilities would avoid the costs of 

determining whether their CO2 stream is RCRA hazardous or non-hazardous, and would 

also avoid possible RCRA permitting costs and generator requirements. They would 

only be required to submit an annual certification in accordance with the rule. These 

generators that capture CO2 would also be able to send their CO2 streams to Class VI 

wells without any additional cost of treating the CO2 stream. Under the proposed rule, all 

CO2 sequestration facilities are assumed to be permitted as Class VI wells, resulting in no 

need for a UIC Class I hazardous permit for those wells.

 

50 The bases or the assumptions presented in this paragraph are presented in the document: Assessment of 

the Potential Costs, Benefits, and Other Impacts of the Conditional Exclusion from the RCRA Definition of 

Hazardous Waste for CO2 Streams Managed in UIC Class VI Wells for the Purposes of Geologic 

Sequestration, as Proposed. This document is available in the docket established for this action.
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The CO2 stream exclusion, as proposed, would result in three areas of savings for 

generators of CO2 streams: exclusion from the hazardous waste determination, exclusion

from the need for hazardous waste treatment, and exclusion from compliance with any 

other hazardous waste-related requirements. CO2 sequestration facilities managing 

hazardous CO2 under a Class I hazardous well permit in the baseline would experience 

savings related to the hazardous waste determination and compliance with applicable 

hazardous waste regulations. Requirements and associated costs for pipeline 

transportation would be unchanged. In addition to industry impacts, we project 

negligible cost increases to EPA and state governments for rule implementation.

Our analysis indicates that the proposed rule is expected to result in undiscounted 

annualized net savings of approximately $56.6 million. Applying a 3 percent discount 

rate, the annualized net savings are approximately $44.9 million. Applying a 7 percent 

discount rate, the annualized net savings are approximately $32 million. The present 

value of the 50-year net savings ranges from $0.47 billion to $1.2 billion, depending upon 

the discount rate applied. These cost savings are expected to occur without any 

discernible increase in negative impacts to human health and the environment, as 

discussed above.

VII. Statutory and Executive Order (EO) Reviews

A. Executive Order 12866: Regulatory Planning and Review

Under Executive Order (EO) 12866 (58 FR 51735, October 4, 1993), this action is 

a "significant regulatory action.” Pursuant to the terms of Executive Order 12866, it has 

been determined that this rule is a “significant regulatory action” because it raises novel 

legal or policy issues. Accordingly, EPA submitted this action to the Office of 
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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.

In addition, EPA prepared an analysis of the potential costs and benefits 

associated with this action. This analysis is presented in the following support document: 

Assessment of the Potential Costs, Benefits, and Other Impacts of the Conditional 

Exclusion from the RCRA Definition of Hazardous Waste for CO2 Streams Managed in 

UIC Class VI Wells for the Purposes of Geologic Sequestration, as Proposed. A copy of 

this document is available in the docket established for this action. The methodology and 

findings from this analysis are briefly summarized in Section VI above. The reader is 

encouraged to review and comment on the full assessment document. 

B. Paperwork Reduction Act

The information collection requirements in this proposed rule have been 

submitted for approval to the Office of Management and Budget under the Paperwork 

Reduction Act, 44 U.S.C. 3501 et seq. The Information Collection Request (ICR) 

document prepared by EPA has been assigned EPA ICR number 2421.01.

The Agency believes that this proposal is an important part of its efforts to 

establish a regulatory framework for GS.51 

The certification included in the proposed rule would be required for entities 

wishing to take advantage of the flexibility provided by the conditional exclusion. The 

certification statements would be used by regulators to hold generators and Class VI well 

owner/operators accountable for knowing the conditions applicable to them (e.g., during 

 

51 See Section III of this preamble for a discussion of other recent EPA rules related to 

this strategy.
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an on-site inspection). The certification statements also would be used by generators and 

owner/operators to demonstrate that they are aware of, and complying with, the 

conditions. 

We believe that the certifications are a practical way to assure compliance 

because they hold a single person at each facility accountable for compliance (i.e., the 

authorized representative). Because of this, the representative has a personal incentive to 

make sure that the facility complies with the conditions. The proposed rule requires that 

the certification be renewed every year that the generator or UIC Class VI well 

owner/operator claims the RCRA conditional exclusion, in order to ensure that the 

certification is kept current.

EPA estimates the total annual burden to respondents under the new paperwork 

requirements to be 79 hours and $6,753. However, EPA also estimates an annual burden 

savings under the existing RCRA subtitle C paperwork requirements of 303 hours and 

$25,428. Thus, this would result in a net annual savings of 224 hours and $18,675. The 

bottom-line burden savings over three years is estimated to be 672 hours and $56,025. 

There are no capital costs associated with this burden requirement. Burden is defined at 5 

CFR 1320.3(b).

An agency may not conduct or sponsor, and a person is not required to respond to, 

a collection of information unless it displays a currently valid OMB control number. The 

OMB control numbers for EPA's regulations in 40 CFR are listed in 40 CFR part 9. 

To comment on the Agency's need for this information, the accuracy of the 

provided burden estimates, and any suggested methods for minimizing respondent 

burden, EPA has established a public docket for this rule, which includes this ICR, under 
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Docket ID number EPA-HQ-RCRA-2010-0695. Submit any comments related to the 

ICR to EPA and OMB. See ADDRESSES section at the beginning of this notice for 

where to submit comments to EPA. Send comments to OMB at the Office of Information 

and Regulatory Affairs, Office of Management and Budget, 725 17th Street, NW, 

Washington, DC 20503, Attention: Desk Officer for EPA. Since OMB is required to 

make a decision concerning the ICR between 30 and 60 days after [Insert date of 

publication in the Federal Register.], a comment to OMB is best assured of having its 

full effect if OMB receives it by [Insert date 30 days after publication in the Federal 

Register.]. The final rule will respond to any comments on the information collection 

requirements contained in this proposal.

C. Regulatory Flexibility Act 

The Regulatory Flexibility Act (RFA) generally requires an agency to prepare a 

regulatory flexibility analysis of any rule subject to notice and comment rulemaking 

requirements under the Administrative Procedure Act or any other statute unless the 

agency certifies that the rule will not have a significant economic impact on a substantial 

number of small entities. Small entities include small businesses, small organizations, 

and small governmental jurisdictions.

For purposes of assessing the impacts of today's rule on small entities, small 

entity is defined as: (1) a small business (based on Small Business Administration (SBA)

size standards), that is primarily engaged in the generation, capture, storage, 

transportation, and GS of excluded hazardous CO2 streams, as defined by NAICS codes 

211111, 221112, 322121, 324110, 324199, 325120, 325193, 325311, and 327310, with 
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total corporate employment ranging from 500 to 1,500 persons52 (based on SBA size 

standards); (2) a small governmental jurisdiction that is a government of a city, county, 

town, school district or special district with a population of less than 50,000; and (3) a 

small organization that is any not-for-profit enterprise which is independently owned and 

operated and is not dominant in its field.

After considering the economic impacts of today‟s proposed rule on small 

entities, I certify that this action will not have a significant economic impact on a 

substantial number of small entities. In determining whether a proposed rule has a 

significant economic impact on a substantial number of small entities, the impact of 

concern is any significant adverse economic impact on small entities, since the primary 

purpose of the regulatory flexibility analyses is to identify and address regulatory 

alternatives “which minimize any significant economic impact of the proposed rule on 

small entities” 5 USC 603 and 604. Thus, an agency may certify that a proposed rule will 

not have a significant economic impact on a substantial number of small entities if it 

relieves regulatory burden, or otherwise has a positive economic effect on all of the small 

entities subject to the proposed rule. This rule, as proposed, is projected to reduce the 

burden on regulated entities by conditionally exempting them from the RCRA subtitle C 

hazardous waste management requirements associated with CO2 streams captured, 

transported, and injected into Class VI wells. We have, therefore, concluded that today's 

proposed rule will relieve regulatory burden for all affected small entities. We continue 

 

52 211111 (500 persons), 221112 (500 persons), 322121 (750 persons), 324110 (1,500 persons), 324199 

(500 persons), 325120 (1,000 persons), 325193 (1,000 persons), 325311 (1,000 persons), and 327310 (750 

persons).
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to be interested in the potential impacts of the proposed rule on small entities and 

welcome comments on issues related to such impacts.

D. Unfunded Mandates Reform Act 

 This action contains no Federal mandates under the provisions of Title II of the 

Unfunded Mandates Reform Act of 1995 (UMRA), 2 U.S.C. 1531-1538 for State, local, or 

tribal governments or the private sector. As explained above, this proposed exclusion is 

less stringent than the current RCRA federal program, and states are therefore not required 

to adopt it. Moreover, the rule does not contain a federal mandate that may result in 

expenditures of $100 million or more for state, local, and tribal governments, in the 

aggregate, or the private sector in any one year. Our analysis indicates that the proposed 

rule is expected to result in undiscounted annualized net savings to the regulated 

community of approximately $56.6 million. Applying a 3 percent discount rate, the 

annualized net savings are approximately $44.9 million, while applying a 7 percent 

discount rate, the annualized net savings are approximately $32 million. Incorporated into 

these net saving estimates is a negligible total estimated annualized cost to states of $70 to 

nearly $565, depending on the discount rate. Thus, this proposed rule is not subject to the 

requirements of sections 202 or 205 of UMRA.

This proposed rule is also not subject to the requirements of section 203 of 

UMRA because it contains no regulatory requirements that might significantly or 

uniquely affect small governments. Occasional requests for and review of certification 

statements is the only potential impact on small governments. Furthermore, no small 

governments are known to be owners or operators of compressed CO2 facilities, storage 
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facilities, transporters, or sequestration facilities. We encourage comments on potential 

unfunded mandates associated with this proposed action.

E. Executive Order 13132: Federalism

This action does not have federalism implications. It will not have substantial 

direct effects on the states, on the relationship between the national government and the 

states, or on the distribution of power and responsibilities among the various levels of 

government, as specified in Executive Order 13132 (64 FR 43255, August 10, 1999),

because the rule will not impose any requirements on States or any other level of 

government. As explained above, today‟s proposed rule conditionally excludes CO2

streams that are hazardous from the definition of hazardous waste, where such streams, in 

accordance with the rule, are captured from emission sources and injected into UIC Class 

VI wells for purposes of GS, but States would not be required to adopt the rule. Thus, 

Executive Order 13132 does not apply to this action. 

In the spirit of Executive Order 13132, and consistent with EPA policy to promote 

communications between EPA and State and local governments, EPA specifically solicits 

comment on this proposed action from State and local officials. 

F. Executive Order 13175: Consultation and Coordination with Indian Tribal 

Governments

This action does not have tribal implications, as specified in Executive Order 

13175 (65 FR 67249, November 9, 2000). No tribal governments are known to generate 

CO2 streams or own or operate UIC Class VI wells subject to the proposed rule. 

Furthermore, we have identified no existing CO2 pipelines that cross tribal lands. Thus, 
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Executive Order 13175 does not apply to this action. EPA specifically solicits additional 

comment on this proposed action from tribal officials. 

G. Executive Order 13045: Protection of Children from Environmental Health 

and Safety Risks

This action is not subject to EO 13045 (62 FR 19885, April 23, 1997) because it is 

not economically significant as defined in EO 12866, and because the Agency does not 

believe the environmental health or safety risks addressed by this action presents a 

disproportionate risk to children. The public is invited to submit comments or identify 

peer-reviewed studies and data that are relevant to assessing the effects of early life 

exposure to CO2 streams captured from emission sources and transported to and injected 

into UIC Class VI wells for purposes of GS.

H. Executive Order 13211: Actions that Significantly Affect Energy Supply, 

Distribution, or Use

This action is not a “significant energy action” as defined in Executive Order 

13211 (66 FR 28355, May 22, 2001), because it is not likely to have a significant adverse 

effect on the supply, distribution, or use of energy. The only effect of this action will be 

to conditionally exclude CO2 streams that are hazardous from the definition of hazardous 

waste, where such streams are captured from emission sources and injected into UIC 

Class VI wells for purposes of GS. This conditional exclusion would allow for the GS of 

CO2, while maintaining protection of human health and the environment, and would not 

significantly disrupt the supply, distribution, or use of energy. 

I. National Technology Transfer and Advancement Act 

Section 12(d) of the National Technology Transfer and Advancement Act of 1995 
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(“NTTAA”), Public Law No. 104-113, 12(d) (15 U.S.C. 272 note) directs EPA to use 

voluntary consensus standards in its regulatory activities unless to do so would be 

inconsistent with applicable law or otherwise impractical. Voluntary consensus standards 

are technical standards (e.g., materials specifications, test methods, sampling procedures, 

and business practices) that are developed or adopted by voluntary consensus standards 

bodies. NTTAA directs EPA to provide Congress, through OMB, explanations when the 

Agency decides not to use available and applicable voluntary consensus standards. 

This proposed rulemaking does not involve technical standards. Therefore, EPA 

is not considering the use of any voluntary consensus standards. 

J. Executive Order 12898: Federal Actions to Address Environmental Justice in Minority 

Populations and Low-Income Populations

Executive Order (EO) 12898 (59 FR 7629, February 16, 1994)) establishes 

federal executive policy on environmental justice. Its main provision directs federal 

agencies, to the greatest extent practicable and permitted by law, to make environmental 

justice part of their mission by identifying and addressing, as appropriate, 

disproportionately high and adverse human health or environmental effects of their 

programs, policies, and activities on minority populations and low-income populations in 

the United States. 

EPA has determined that this proposed rule will not have disproportionately high 

and adverse human health or environmental effects on minority or low-income 

populations because it does not affect the level of protection provided to human health or 

the environment. The only effect of this action will be to conditionally exclude CO2

streams that are hazardous from the definition of hazardous waste, where such streams 
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are captured from emission sources and injected into UIC Class VI wells for purposes of 

GS, and meet other conditions. Existing regulations governing the generation, 

transportation, and injection of CO2 streams in UIC Class VI wells are expected to 

provide safety to human health and the environment, making additional regulation under 

RCRA subtitle C unnecessary (see discussion under Section IV).

LIST OF SUBJECTS

40 CFR Parts 260 and 261

Environmental protection, Hazardous waste, Recycling, Reporting and recordkeeping 

requirements

Dated:

___________________________________

Lisa P. Jackson,

Administrator.

For the reasons set out in the preamble, Parts 260 and 261 of title 40, Chapter I of 

the Code of Federal Regulations are proposed to be amended as follows:

PART 260 – HAZARDOUS WASTE MANAGEMENT SYSTEM: GENERAL

1. The authority citation for Part 260 continues to read as follows:

Authority: 42 U.S.C. 6905, 6912(a), 6921-6927, 6930, 6935, 6937-6939, and 6974.

Subpart B – Definitions

2. Section 260.10 is amended by adding in alphabetical order the definition of “Carbon 

dioxide stream” to read as follows:

§260.10 Definitions
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* * * * *

Carbon dioxide stream means carbon dioxide that has been captured from an emission 

source (e.g., power plant), plus incidental associated substances derived from the source 

materials and the capture process, and any substances added to the stream to enable or 

improve the injection process.

* * * * *

PART 261 - IDENTIFICATION AND LISTING OF HAZARDOUS WASTE

3. The authority citation for Part 261 continues to read as follows:

Authority: 42 U.S.C. 6905, 6912(a), 6921, 6922, 6924(y), and 6938

4. Section 261.4 is amended by adding a new paragraph (h) to read as follows:

§261.4 Exclusions.

* * * * *

(h) – Carbon Dioxide Stream Injected for Geologic Sequestration – Carbon dioxide 

streams that are captured and transported for purposes of injection into an underground 

injection well subject to the requirements for Class VI Underground Injection Control 

wells, including the requirements in 40 CFR parts 144 and 146 of the Underground 

Injection Control Program of the Safe Drinking Water Act, are not a hazardous waste, 

provided the following conditions are met.

(1) Carbon dioxide streams that meet all of the following conditions are excluded from 

the definition of hazardous waste:

(i) Transportation of the carbon dioxide stream must be in compliance with applicable 

Department of Transportation requirements;
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(ii) Injection of the carbon dioxide stream must be in compliance with the applicable 

requirements for Class VI Underground Injection Control wells, including the applicable 

requirements in 40 CFR parts 144 and 146; 

(iii) No other hazardous wastes may be mixed with, or otherwise co-injected with, the 

carbon dioxide stream; and

(iv) Any generator of a carbon dioxide stream, and any Class VI Underground Injection 

Control well owner or operator, who claims that a carbon dioxide stream is excluded

under paragraph (h)(1) of this section, must have an authorized representative (as defined 

in 40 CFR 260.10) sign a certification statement worded as follows:

I certify under penalty of law that the carbon dioxide stream that I am 

claiming to be excluded under 40 CFR 261.4(h)(1) meets all of the 

conditions set forth in that paragraph.

The signed certification statement must be kept on-site for no less than three years. The 

signed certification statement must be made available within 72 hours of a written request 

from the Regional Administrator or state Director (if located in an authorized state), or 

their designee, and shall be renewed every year by persons claiming the exclusion in 40 

CFR 261.4(h). The yearly renewal of a certification statement under this paragraph 

means that an authorized representative must annually prepare and sign a new copy of the 

certification statement.

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