Response to Comments Document

Hazardous Waste Management System: 

Conditional Exclusion for Carbon Dioxide (CO2) Streams in 

Geologic Sequestration Activities

Docket ID: EPA-HQ-RCRA-2010-0695

November 2013

This document was prepared with the support of The Cadmus Group, Inc., under subcontract to 

Eastern Research Group, Inc., Contract EP-W-10-055, Task Order #27.
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Table of Contents

1.0 Introduction____________________________________________________________ 1

1.1 Purpose & Organization of this Document ________________________________________ 1

1.2 Comment Analysis Procedures _________________________________________________ 1

2.0 List of Comments Submitted_______________________________________________ 3

3.0 Individual Comments and Agency Response __________________________________ 4

3.1 American Petroleum Institute (API) _____________________________________________ 4

3.2 Carbon Sequestration Council (CSC) ___________________________________________ 255

3.3 American Electric Power (AEP) _______________________________________________ 633

3.4 C12 Energy _________________________________________ Error! Bookmark not defined.4

3.5 Natural Resources Defense Council (NRDC) ______________________________________ 81

3.6 Clean Air Task Force __________________________________ Error! Bookmark not defined.8

3.7 Utility Solid Waste Activities Group (USWAG) _____________ Error! Bookmark not defined.7

3.8 CCS Alliance ________________________________________ Error! Bookmark not defined.8

3.9 State of Utah_____________________________________________________________ 1155

3.10 National Mining Association (NMA) __________________________________________ 1166

3.11 Texas Pipeline Association (TPA)____________________________________________ 12121

3.12 Western Business Roundtable_______________________________________________ 1244

3.13 Greater Houston Partnership (GHP) __________________________________________ 1299

3.14 North American Carbon Capture & Storage Association (NACCSA)_________________ 13030

3.15 Edison Electric Institute (EEI) ________________________________________________ 1422

3.16 Texas Carbon Capture & Storage Association (TxCCSA) __________________________ 15555

3.17 Tri-State Generation & Transmission Association, Inc. (Tri-State)__________________ 15858

3.18 Southern Company_______________________________________________________ 16363

3.19 Xcel Energy, Inc. _________________________________________________________ 16464

3.20 Basin Electric Power Cooperative (Basin Electric)_______________________________ 16565

3.21 Spectra Energy (Spectra) __________________________________________________ 17676

3.22 Western Environmental Trade Association (WETA) _____________________________ 18585

3.23 Chevron__________________________________________________________________ 188

3.24 Texas Oil and Gas Association (TxOGA)_________________________________________ 191

3.25 Florida Department of Environmental Protection (DEP) ___________________________ 192

3.26 Joyce Dillard ______________________________________________________________ 193
3.27 Anonymous 1 _____________________________________________________________ 194

3.28 Anonymous 2 _____________________________________________________________ 194

3.29 Anonymous 3 _____________________________________________________________ 195

Appendix A: Substantive Data Received from Commenters__________________________ 196
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1.0 Introduction

1.1 Purpose & Organization of this Document

On August 8, 2011, EPA published the proposed Hazardous Waste Management System: 

Identification and Listing of Hazardous Waste: Carbon Dioxide (CO2) Streams in Geologic Sequestration 

Activities (76 FR 48073, August 8, 2011). Following publication of the proposed rule, the Agency invited 

the public to comment over a 60-day comment period, which ended on October 7, 2011. EPA received 

29 unique comments on the proposed rule. These comments are available at: www.regulations.gov

(EPA-HQ-RCRA-2010-0695), under “Public Submissions.” This document presents extractions of each 

comment for each individual commenter. Agency responses are presented for each individual 

commenter. The document is organized as follows:

 Section 1.0, Introduction (this section), briefly describes the organization of this 

document and explains the procedures used to analyze and categorize the comments.

 Section 2.0, List of Comments Submitted, identifies the commenters.

 Section 3.0, Individual Comments and Agency Responses, includes the verbatim public 

comments, some of which are divided into shorter individual comments that address 

particular topics. Each individual comment is followed by the Agency response for that

comment letter or topic.

 Appendix A contains substantive data submitted by one commenter.

1.2 Comment Analysis Procedures

The following provides a brief overview of the procedures used to analyze and organize the 

public comments, prior to the development of our responses:

 Each comment letter was assigned an EPA Document ID that corresponds to the last 

four digits of the docket number of the original comment (as posted on 

www.regulations.gov).

 As necessary, comments were converted to text using Optical Character Recognition 

(OCR) software. As a result, there may be some typographical or formatting errors 

attributable to OCR issues.

 As necessary, special formatting was converted to plain text. Examples of these 

conversions include the following:

 Footnotes: Square parentheses were used to identify footnotes. Example: [FN1:

This is a footnote.].

 Tables and other Graphics: Square brackets are used to point the reader to the 

original text. Example: [Table 1. see PDF Docket ID EPA-HQ....].

 Bullets: Asterisks (*) replace bullets.

 Deletions: Deletions are marked with “<” and “>” on either side of the deletion.
 Additions: Some commenters recommended changes to the proposed 

regulatory text. Proposed additions are presented either as originally submitted 

(underlined) or in ALL CAPITAL LETTERS.

 The content of longer comments was divided into topic areas.
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2.0 List of Comments Submitted 

Table 1 identifies the EPA Document ID for each public comment (i.e., EPA-HQ-RCRA-2010-0695-

xxxx), the name of the organization or individual associated with each public comment, and the section 

number of Section 3.0 where each comment can be found.

Table 1

List of Commenters

EPA 

Document 

ID

Organization Name Section Number

-0077 American Petroleum Institute (API) 3.1

-0084 Carbon Sequestration Council (CSC) 3.2

-0063** American Electric Power (AEP) 3.3

-0073* C12 Energy 3.4

-0082 Natural Resources Defense Council (NRDC) 3.5

-0089* Clean Air Task Force 3.6

-0066 Utility Solid Waste Activities Group (USWAG) 3.7

-0083 CCS Alliance 3.8

-0086 State of Utah 3.9

-0065 National Mining Association (NMA) 3.10

-0068 Texas Pipeline Association (TPA) 3.11

-0071 Western Business Roundtable 3.12

-0074 Greater Houston Partnership (GHP) 3.13

-0078 North American Carbon Capture & Storage Assoc. (NACCSA) 3.14

-0080 Edison Electric Institute (EEI) 3.15

-0085 Texas Carbon Capture & Storage Association (TxCCSA) 3.16

-0055 Tri-State Generation &Transmission Association, Inc. (Tri-State) 3.17

-0061 Southern Company 3.18

-0072 Xcel Energy, Inc. 3.19

-0076 Basin Electric Power Cooperative (Basin Electric) 3.20

-0088* Spectra Energy (Spectra) 3.21

-0060 Western Environmental Trade Association (WETA) 3.22

-0064 Chevron 3.23

-0067 Texas Oil and Gas Association (TxOGA) 3.24

-0059 Florida Department of Environmental Protection 3.25

-0081 Joyce Dillard 3.26

-0058 Anonymous 1 3.27

-0069 Anonymous 2 3.28

-0070 Anonymous 3 3.29

* This comment letter was received after the close of the public comment period, and therefore, EPA does not have an 

obligation to respond. However, in the interest of completeness, EPA is choosing to provide the responses below.

** EPA’s response to this comment (EPA-HQ-RCRA-2010-0695-0063) is considered to be a response to comment EPA-HQ-RCRA2010-0695-0062 as well. These comments are identical except for a typographical error in Table 2-3 in EPA-HQ-RCRA-2010-

0695-0062, which was corrected by the commenter in comment EPA-HQ-RCRA-2010-0695-0063.
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3.0 Individual Comments and Agency Response

This section contains the verbatim text of the 29 unique public comments submitted on the 

proposed rule. Longer public comments were divided into smaller comments so that EPA could 

respond to one issue at a time. 

Note that, due to the nature of the comments and common themes in the submitted comments, 

there is a great deal of issue repetition. 

3.1 American Petroleum Institute (API)

Document ID: EPA-HQ-RCRA-2010-0695-0077

Comment 3.1.1:

The American Petroleum Institute (“API”), is pleased to provide the Environmental Protection 

Agency (“EPA” or the “Agency”) with these comments on the proposed rule entitled “Hazardous 

Waste Management System: Identification and Listing of Hazardous Waste: Carbon Dioxide (“CO2”) 

Streams in Geologic Sequestration Activities.” 76 Fed. Reg. 48073 (Aug. 8, 2011). [FN1: A technical 

correction was published on September 9, 2011. 75 Fed. Reg. 55846].

The American Petroleum Institute (API) represents more than 470 oil and natural gas companies, 

leaders of a technology-driven industry that supplies most of America’s energy, supports more than 

9.2 million U.S. jobs and 7.5 percent of the U.S. economy, and, since 2000, has invested nearly $2 

trillion in U.S. capital projects to advance all forms of energy, including alternatives. API has a 

strong interest in the development of the Underground Injection Control (UIC) program for 

Geologic Sequestration wells.

Adequate enforcement mechanisms currently exist to protect human health and the environment 

from CO2 streams under the Clean Air Act’s reporting requirements and to protect underground 

sources of drinking water, the primary route for any threats to human health and the environment 

from CO2 streams, under the UIC Class VI Rule. Additional RCRA regulation is redundant, not 

necessary, and will likely lead to unintended consequences that would undermine beneficial uses 

of CO2 streams for carbon capture and sequestration (“CCS”) and enhanced recovery (“ER”) of oil 

and gas. Therefore, EPA should enact a blanket exclusion of all CO2 streams from the Resource 

Conservation & Recovery Act’s (“RCRA”) definition of solid waste at this time. Under EPA’s 

“adaptive approach,” if evidence arises in the future that shows CO2 streams may be solid wastes 

or hazardous, then EPA may initiate another rulemaking based on those actual findings.

Response: The commenter cites both the Clean Air Act GHG reporting rules, and the UIC Class VI 

rule, in support of their statement that “additional RCRA regulation is redundant, not necessary, 

and will lead to unintended consequences.” In fact, in support of its proposed conditional 

exclusion, EPA evaluated these existing regulatory requirements, along with others (e.g., 

Department of Transportation, or DOT requirements) and concluded that management of CO2

streams under the terms of the conditional exclusion do not present a substantial risk to human 

health and the environment, and that therefore, under these conditions additional regulation 

pursuant to RCRA’s hazardous waste regulations is unnecessary. See Section V of the final rule 

preamble; see also the proposed rule, 76 FR at 48080-87. 
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However, EPA is not addressing the status of ‘all CO2 streams’ in this rulemaking; the scope of this 

rule is expressly limited to CO2 streams sent to a permitted UIC Class VI well for purposes of GS. 

EPA has also explained in its proposed and final rule preambles its view that a supercritical CO2

stream injected into a permitted UIC Class VI well for purposes of GS is a RCRA solid waste, because 

it is a “discarded material” within the plain meaning of the term in RCRA §1004(27). That is, a 

supercritical CO2 stream is a solid waste when it is to be discarded through abandonment by 

disposing of the material in a UIC Class VI well.

However, in the interest of public transparency and in light of the several public comments on this 

issue, EPA does note that (based on the limited information provided in the public comments),

should CO2 be used for its intended purpose as it is injected into UIC Class II wells for the purpose 

of EOR/EGR, it is EPA’s expectation that such an injection process would not generally be a waste 

management activity. EPA would encourage persons to consult with the appropriate regulatory 

authority to address any fact-specific questions they may have regarding the status of CO2 in 

situations that are beyond the scope of this final rule.

Finally, regarding the commenter’s references to “unintended consequences” of additional 

regulation under RCRA, the commenter did not provide specific information or examples of these, 

and therefore, while EPA acknowledges these comments it cannot provide more specific responses. 

Comment 3.1.2:

Alternatively, API supports a conditional exclusion of CO2 streams from the RCRA hazardous waste 

regulations definition of “solid waste” because of CO2’s unique properties and uses, coupled with 

the fact that these CO2 streams are not “discarded.” Failure of EPA to clarify that CO2 streams are 

not “solid wastes” will leave enhanced oil and gas recovery (“ER”) and carbon capture and 

sequestration (“CCS”) projects with unnecessary regulatory uncertainty while doing little to 

advance public health and environmental protection, given the rigorous requirements of the UIC 

Class VI rule under the Safe Drinking Water Act (“Class VI Rule”). Any potential that CO2 streams 

could be deemed solid wastes, with the enormous potential regulatory burdens associated with 

that designation, will discourage companies from handling CO2 streams, to the detriment of EPA’s 

efforts to remove CO2 emissions from the atmosphere. This discouragement is manifesting itself 

already in the dearth of states seeking Class VI primacy and industries attempting CO2 capture. 

If EPA elects to retain the proposed approach of a conditional exclusion for CO2 streams from 

RCRA’s hazardous waste regulations, we recommend that the proposed regulation be clarified to 

remove as much regulatory ambiguity as possible, including application of the conditional exclusion 

to concurrent ER/storage under the transition provisions of the Class VI Rule and declaration that 

CO2 streams used for non-geologic sequestration purposes are not solid wastes, as we set forth in 

detail below.

Response: See Response to Comments 3.1.1, 3.1.7, 3.1.8. 

EPA disagrees with the commenter that supercritical CO2 streams injected into Class VI wells for 

purposes of GS are not discarded, and that that should be the basis for the conditional exclusion. 

EPA bases its conditional exclusion on its analysis demonstrating that management of supercritical 

CO2 streams in accordance with the rule’s conditions does not present a substantial risk to human 

health or the environment. With respect to injection in other than UIC Class VI wells, as EPA noted 
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in the response to comment 3.1.1., this conditional exclusion is not intended to affect the 

regulatory status of CO2 streams that are injected into wells other than UIC Class VI wells, which is 

beyond the scope of this rule. Today’s rule only applies to CO2 injected into UIC Class VI wells, 

which would include any well that has transitioned to a UIC Class VI well under the provisions of 

the UIC Class VI rule. EPA would encourage persons to consult with the appropriate regulatory 

authority to address any fact-specific questions they may have regarding the status of CO2 in 

situations that are beyond the scope of this final rule.

The commenter did not provide any specific information to support its assertions regarding 

“enormous potential regulatory burdens” and negative impacts on industries attempting CO2 

capture and states seeking UIC Class VI primacy. 

Comment 3.1.3:

Specific Comments on the Proposed Rule Entitled “Hazardous Waste Management System: 

Identification and Listing of Hazardous Waste: Carbon Dioxide Streams in Geologic Sequestration 

Activities” 

EPA proposes to “conditionally” exclude “CO2 streams” [FN2: A “Carbon dioxide (CO2) stream” is 

defined at 40 CFR 146.81(d) as “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.” 76 Fed. Reg. at 48075.] that “are hazardous from the definition of hazardous waste, 

provided these hazardous CO2 streams are captured from air emission sources, are injected into 

Class VI *UIC+ wells for purposes of geologic sequestration ... and meet certain other conditions.” 

76 Fed. Reg. at 48074. EPA explains that it is taking this action because it “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.” Id. EPA notes that the conditional exclusion will 

provide additional regulatory certainty. 

API supports the proposed “conditional exclusion” - as far as it goes - because it endeavors, albeit 

incompletely, to clarify the regulatory regime for CCS while ensuring stringent protection of human 

health and the environment. API nonetheless believes that the “conditional exclusion” falls short of 

what is needed to provide adequate regulatory certainty for owners and operators in the ER and 

CCS industries for the following reasons.

Response: EPA thanks the commenter for its support of the conditional exclusion, and addresses 

any specific comments on how the rule ‘falls short’ of what is needed below in EPA’s responses 

below.

Comment 3.1.4:

A. CO2 Streams Are Appropriately Addressed under other Laws 

EPA’s proposal is premised on the notion that RCRA potentially applies to “CO2 streams” in the first 

instance. This premise is false for two reasons. 

First, Congress, in enacting RCRA, never envisioned regulation of a gas molecule such as CO2. In 

comparison to other materials regulated under RCRA, CO2 is unique. It performs a variety of 

beneficial and ubiquitous roles in a variety of natural (e.g., uptake by plants) and industrial (e.g., 
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ER) functions. Several states already have declared CO2 to be a “commodity” for these reasons. 

[FN3: See, e.g., Oklahoma SB 1610 (“Carbon dioxide is a valuable commodity to the citizens of the 

state”)]. It is currently regulated under both the Clean Air Act and Safe Drinking Water Act and 

should remain regulated this way without redundancy under RCRA. CO2 from natural sources and 

natural gas processing plants is widely used as a valuable product to enhance oil and gas 

production; captured CO2 has this same potential use and EPA’s evidence shows that it is 

substantially similar to existing streams of CO2. This rule has the potential to make beneficial 

products derived from captured CO2 into solid wastes, which would be a terrible disincentive for 

undertaking any climate control activities.

Response: See response to comments 3.1.1 and 3.1.2. Although, as the commenter pointed out, 

CO2 may be regulated under other environmental statutes (such as the CAA and SDWA), EPA 

disagrees that this means RCRA does not apply in the circumstances relevant to this rule. As 

already stated, the CO2 being injected into UIC Class VI wells for purposes of GS is discarded and a 

solid waste, therefore RCRA does apply. That CO2 may be useful (or a “commodity”) in other 

contexts has no bearing on the RCRA regulatory status of CO2 sent for GS in a Class VI well. 

Regarding the applicability of other statutory provisions to CO2, EPA did consider the effect of other 

statutory requirements – indeed, this conditional exclusion is based upon EPA’s determination that 

the management of hazardous CO2 streams under other requirements (e.g., the UIC Class VI rule) 

provides protection to human health and the environment and therefore, additional regulation 

pursuant to RCRA hazardous waste regulations is unnecessary. 

Comment 3.1.5:

Second, and similarly, RCRA was never meant to apply to air emissions or productive materials with 

beneficial uses, thus the statute provides a poor tool to regulate CCS activity. Nothing in RCRA or its 

regulations purports to apply to CCS generally or geologic sequestration specifically. Existing laws 

dealing with air and injection wells are appropriate vehicles to address any health and 

environmental concerns and there is no need for additional RCRA regulation. The RCRA model is 

prospective “cradle-to-grave” waste management and tracking of materials that pose a potential 

hazard to human health and the environment. CO2 is a common constituent of air, with no inherent 

hazard besides its ability to displace oxygen. The chief concern with CO2 according to the IPCC is its 

impacts on climate. Special identification of a gas with no toxic or hazardous impacts in a special 

rulemaking will have the result of additional misinformation and worry about CO2 in both 

operational and sequestration settings. 

CCS is regulated under the Safe Drinking Water Act with strict technical standards for the injection 

of CO2 for purposes of sequestration to ensuring environmental protection. That activity, 

moreover, is envisioned to involve mixed streams of CO2 from multiple sources, with injection of 

CO2 into multiple formations, especially saline or oil and gas, thereby defeating the notion of 

tracking wastes through manifests and the like. Trying to treat CO2 as a waste stream as it 

transitions between being contained in trucks or pipelines to uncontained in the subsurface will 

result in a chaotic regulatory situation that will not fit well into the RCRA framework. CO2 is handled 

as, and considered, a valuable product now and should continue to be so, regardless of its source. 

There also is no standardized test method to evaluate supercritical CO2. For these and other 

reasons, trying to specially treat CO2 streams and fit CCS under RCRA is unnecessary and a poor 

regulatory fit.

Response: EPA disagrees with the commenter’s broad statement that “RCRA was never meant to 
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apply to air emissions or productive materials with beneficial uses...” While not necessarily 

determinative in this conditional exclusion rulemaking, EPA clarifies that as a general matter RCRA 

subtitle C authorizes EPA to address air emissions in certain circumstances, such as emissions at 

hazardous waste treatment, storage, and disposal facilities. RCRA 3004(n). RCRA subtitle C also 

provides EPA with authority over recycling involving solid and hazardous wastes. With respect to

this rulemaking specifically, EPA has already explained why in its view supercritical CO2 streams 

being injected into Class VI wells for purposes of GS are solid wastes under RCRA. See Response to 

Comments 3.1.1, 3.1.7, 3.1.8. 

Regarding the comment that CO2 is “...a gas with no toxic or hazardous impacts...” EPA notes that 

the conditional exclusion applies to CO2 streams, which are not necessarily pure CO2 – in fact, “CO2

stream” as defined in the final rule includes “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”, see 40 CFR 260.10, and based on information EPA presented in the 

proposed rule (to which the comment does not provide information to the contrary), it is possible 

for these streams to contain hazardous constituents derived from the source materials and the 

capture process. See also response to comment 3.1.4.

Regarding the comment, “Trying to treat CO2 as a waste stream as it transitions between being 

contained in trucks or pipelines to uncontained in the subsurface will result in a chaotic regulatory 

situation...” while EPA agrees that a chaotic regulatory situations should be avoided, it is unclear 

from this specific comment how the commenter reaches this conclusion. Indeed, it is EPA’s intent 

through this rule to provide regularity to CCS management activities, by providing a straightforward 

framework for the regulated community to follow, should they determine (or are concerned) that 

their CO2 streams qualify as RCRA hazardous wastes. Regarding the possibility of CO2 from multiple 

sources being injected into different well classes or different formations, see Responses to 

Comments 3.2.3 and 3.2.4. 

How the CO2 streams are described in the subsurface is not relevant to the conditional exclusion 

rulemaking (i.e., CO2 streams that have been injected into the subsurface via a UIC Class VI well 

have already been disposed). EPA need not decide whether CO2 injected for purposes of GS is 

“uncontained” in the subsurface in this context. See Response to Comment 3.1.7.

Regarding the cited lack of a standardized test method, EPA notes that analytical methods do exist 

to analyze supercritical CO2 streams, and that generators may also use knowledge to determine 

whether a waste exhibits a RCRA characteristic. Also, EPA has indicated it could not unequivocally 

conclude that supercritical CO2 streams will never exhibit any RCRA hazardous waste characteristic. 

Comment 3.1.6:

B. CO2 Streams Are Not “Solid Wastes” 

The conditional exclusion is rooted on the unsupported premise that captured anthropogenic CO2

is a “solid waste.” EPA attempts to limit the scope of its erroneous premise by asserting that a 

“supercritical 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).” 

76 Fed. Reg. at 48077-78. [FN4: Relevant provisions of RCRA § 1004(27) define “solid waste” as 

“other discarded material, including solid, liquid, semisolid, or contained gaseous material resulting 

from ... industrial operations ....”]. While EPA’s attempt to narrow the scope is recognized, this 
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preamble language (including footnotes 16 and 54), and the proposed rule itself, leaves an 

inference that other CO2 streams are solid wastes. EPA states that “once a decision is made that 

the supercritical CO2 stream will be sent to a UIC Class VI well for discard, EPA considers this 

material to be a solid waste.” Id. at 48078. But this begs the question of what is the status of a 

“supercritical CO2 stream that is not injected into a Class VI well” or “a decision is made that the 

supercritical CO2 stream will be sent” elsewhere. EPA should flatly declare that no CO2 streams are 

solid wastes and avoid these ambiguities, as these streams are adequately addressed by existing 

law. If EPA refuses to make this flat declaration, it should at least clarify in its final rule that CO2

streams are not solid wastes when they are injected into Class II wells in connection with ER 

operations or used for any other beneficial purpose; in these cases they are commodities or 

products used in business processes that produce valuable end products, like oil and gas, and 

should not be regulated under RCRA.

Response: The commenter is correct that EPA has determined that a supercritical CO2 stream 

injected into a permitted UIC Class VI well for purposes of GS is a RCRA solid waste, because it is a 

“discarded material” within the plain meaning of the term in RCRA §1004(27). As EPA noted in the 

response to comment 3.1.1., this conditional exclusion is not intended to affect the regulatory 

status of CO2 streams that are injected into wells other than UIC Class VI wells, which is beyond the 

scope of this rule. Regarding the commenter’s request for clarification on the status of CO2

streams injected into UIC Class II wells for purposes of EOR, see Response to Comment 3.1.1. 

Today’s rule only applies to CO2 injected into UIC Class VI wells, which would include any well that 

has transitioned to a UIC Class VI well under the provisions of the UIC Class VI rule. EPA would 

encourage persons to consult with the appropriate regulatory authority to address any fact-specific 

questions they may have regarding the status of CO2 in situations that are beyond the scope of this 

final rule.

Comment 3.1.7:

To be regulated as a “solid waste,” a material must satisfy three criteria, two of which are relevant: 

(1) it must have the physical form of a solid waste; and (2) it must be “discarded.” [FN5: T. Garrett, 

ed., “The RCRA Practice Manual,” at 33]. Neither of these criteria is met here. 

CO2 Streams Do Not Have the Physical Form of a Solid Waste. In relevant part, RCRA defines “solid 

waste” as “other discarded material, including solid, liquid, semisolid, or contained gaseous 

material resulting from industrial, commercial, mining, and agricultural operations...” 42 U.S.C. § 

6903(27) (emphasis added). Supercritical states of material, such as is relevant for CO2, are not 

explicitly listed. Before it is compressed, at standard pressure and temperature, CO2 is a gas.

Response: As EPA noted in the proposed rule, the CO2 streams are delivered by pipeline and 

injected into UIC Class VI wells for GS in a supercritical state, which EPA stated at proposal was 

“...rather unique in that it has properties intermediate between a liquid and a gas.” 76 FR at 48078.

The scientific term used to describe or define this supercritical state (i.e., when a substance is at or 

above its critical temperature and critical pressure) is as a “supercritical fluid.” See Section V. A. in 

the preamble to the final rule. The RCRA statutory definition of solid waste specifically refers to 

“other discarded material, including solid, liquid, semisolid, or contained gaseous material resulting 

from industrial, commercial, mining, and agricultural operations, and from community activities . . 

.” While EPA has indeed interpreted the meaning of specific terms listed, including “contained 

gaseous material,” the RCRA definition of solid waste encompasses “other discarded material” and 

does not speak to materials such as supercritical fluids. Like the listed “solid, liquid, semisolid, or 
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contained gaseous material” specifically referenced, CO2 streams sequestered for purposes of GS 

are “other discarded material” from industrial and commercial operations and, therefore, are of a 

similar kind to the other types of wastes specifically referenced by the definition. They are, 

therefore, RCRA statutory solid wastes.

Comment 3.1.8:

Most CO2 Streams Are Not Discarded. EPA does not offer a detailed justification for its claim that 

CO2 streams are “discarded,” so we begin with an analysis of how RCRA and its regulations define 

that term. RCRA defines “solid waste” as “other discarded material, including solid, liquid, 

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

agricultural operations ....” 42 U.S.C. § 6903(27) (emphasis added). EPA’s regulations explain that a 

“solid waste” is any “discarded material” that is “not excluded under § 261.4(a) [FN6: 40 C.F.R. § 

261.4(a) excludes through numerous specific listings “[m]aterials which are not solid wastes.”] or 

that is not excluded by a variance granted under §§ 260.30 [FN7: 40 C.F.R. § 260.30 deals with nonwaste determinations and variances from classification as a solid waste] and 260.31 [FN8: 40 C.F.R. 

§ 260.31 sets forth standards and criteria for variances from classification as a solid waste.] or that 

is not excluded by a non-waste determination under §§ 260.30 [FN9: See note 8, supra.] and 

260.34 [FN10: 40 C.F.R. § 260.34 sets forth standards and criteria for non-waste determinations.].” 

[FN11: 40 C.F.R. § 261.2 (definition of “solid waste”) (emphasis and internal footnote references 

added)]. A “discarded material,” in turn, is “any material” that is: (1) abandoned; (2) recycled; or (3) 

considered inherently waste-like. [FN12: 40 C.F.R. § 261.2(a)(2)(i)]. 

Although they do not define the term “material,” EPA’s regulations set forth detailed criteria that 

must be met before a material is deemed to be “discarded” via the “abandoned,” “recycled,” or 

“inherently waste-like” regulatory paths: 

*Abandoned. Materials are “solid waste” if they are abandoned by being: (a) disposed of; (b) 

burned or incinerated; or (c) “[a]ccumulated, stored or treated (but not recycled) before or in lieu 

of being abandoned by being disposed of, burned, or incinerated.” [FN13: 40 C.F.R. § 261.2(b)]. 

*Recycled. Materials separately are “solid waste” if they are recycled – or accumulated, stored, or 

treated before recycling – if they fall into one of the following four categories: (a) used in a manner 

constituting disposal; (b) burned for energy recovery; (c) reclaimed; or (d) accumulated 

speculatively. [FN14: 40 C.F.R. § 261.2(c)]. 

*Inherently waste-like. Specifically identified materials, not including CO2, also are “solid waste” if 

they are recycled in any manner, and thus deemed to be “inherently waste-like materials.”[FN15: 

40 C.F.R. § 261.2(d)].

“CO2 streams” do not meet any of these three RCRA regulatory requirements. 

*CO2 streams are not abandoned. CO2 streams are not burned or incinerated, nor are they 

“disposed of.” “CCS” means “Carbon” is “Captured” from air emissions, transported in CO2 product 

pipelines, then “Stored” or “Sequestered” in secure geologic formations. “Capture” and either 

“Storage” or “Sequestration” do not contemplate “disposal.” The Merriam-Webster Dictionary 

defines “capture” as “to gain control over or take possession of” and “sequester” as “to set apart, 

segregate” or to “seclude, withdraw.”[FN16: http://www.merriamwebster.com/dictionary/sequestered?show=0&t=1315859974]. Synonyms for “sequestration”
11

include “isolation” and “seclusion.”[FN17: http://www.merriamwebster.com/dictionary/sequestration]. “Disposal,” on the other hand, is defined as the act of 

“disposing,” which means “to get rid of.”[FN18: http://www.merriamwebster.com/dictionary/disposing]. Based on a “plain meaning” analysis, CCS does not 

contemplate abandonment or “disposal.” In fact, CCS prevents air emissions from being abandoned 

or disposed into the environment. 

*CO2 streams are not recycled. RCRA’s provisions regarding “recycle” are detailed, and none of 

them apply to CO2 streams – nor has EPA claimed they do. [FN19: The fact that CO2 is recycled in 

EOR operations is not directly relevant for the RCRA regulatory concept of “recycle.”] In order for 

the recycle rules to apply, a material must first be deemed a secondary material. Among other 

things, secondary materials do not include “co-products.” Since in current commercial practice CO2

that is geologically injected is transacted as a valuable commodity as “co- products,” the recycle 

regulations do not apply. [FN20: T. Garrett, ed., “The RCRA Practice Manual,” at 36]. 

*CO2 streams are not “inherently waste-like.” RCRA’s provisions regarding “inherently waste-like” 

materials also are detailed, and none of them applies to CO2 streams – nor has EPA claimed they 

do. 

The concept of “disposal” is also inconsistent with the ways that most CO2 is currently being 

managed commercially. With the exception of demonstration and related projects, most if not all 

CO2 that is geologically injected today is used for ER. In that application, it is purchased and 

transacted as a valuable commodity, product, or co-product. When the oil and gas are produced, 

some CO2 comes to the surface as well, where the ER operator captures it again and returns it to 

the formation mixed with newly-purchased CO2. Some of this newly purchased CO2 comes from 

natural gas processing facilities that remove and capture CO2 from natural gas production in order 

to meet pipeline specifications. EPA’s proposed rule has the potential to erroneously deem both 

these sources of captured CO2 as generators of a solid waste, and force them into hazardous waste 

evaluations, which would create huge regulatory burdens for no environmental benefit. To avoid 

this unintended consequence, EPA must exclude all CO2 streams from the solid waste definition. As 

explained further below, EPA’s Class VI rule envisions that concurrent ER/storage may be 

conducted under Class II as either ER “business-as-usual” or as an ER transition to GS if it does not 

increase risk to underground sources of drinking water – usages that flatly contradict EPA’s 

assertion that injection is a “disposal activity.” 

CO2 that is injected in saline reservoirs under Class VI also is not “disposed of.” It is conceivable, for 

example, that such CO2 may be later withdrawn and put to a beneficial, but still non-atmosphericemitting, use. Such CO2 may also be used for reservoir maintenance as part of concurrent longterm storage/desalination operations, as explained by William Bourcier of Lawrence Livermore 

National Laboratory at the August 18, 2010 meeting of the California CCS Review Panel. 

[FN21:http://www.climatechange.ca.gov/carbon_capture_review_panel/meetings/2010-08-

18/presentations/01_Bourcier_Cal_CCS-Panel.pdf].

CCS-related offset credits are also transacted on various carbon registries, such as the American 

Carbon Registry. This activity is inconsistent with the notion of “disposal.” It is also worth noting 

that the terms “disposal” and “dispose” do not appear in any relevant portion of the Class VI rule or 

EPA’s preamble to the same. Because geologic sequestration/storage does not contemplate 

“disposal,” the regulatory “abandonment” provisions dealing with “[a]ccumulated, stored or 
12

treated” also are inapplicable. 

In the alternative - and despite the arguments above - if EPA concludes that a CO2 stream injected 

into a Class VI well for GS purposes is a solid waste, EPA should clarify in express language that CO2

streams intended for other purposes, such as ER, are not solid wastes and need not be evaluated 

for hazardous characteristics. Without this clarification, an inference could be made that all CO2 

streams are solid wastes and only those intended for Class VI injection wells are excluded from 

hazardous waste regulation, leaving all others to be tested for hazardous characteristics under 

RCRA. This cannot be EPA’s intent, therefore EPA should make it clear that this reading is not 

appropriate. As noted above, captured CO2 is a valuable product that is used beneficially; it should 

be clearly identified as such and not inferentially identified as a waste.

Response: EPA disagrees that CO2 streams sent to UIC Class VI wells for purposes of GS are not 

solid waste. As was stated in the preamble to the proposed rule, GS is an option to reduce CO2 

emissions to the atmosphere by injecting the CO2 streams into deep subsurface geologic 

formations, with the express purpose of isolating the CO2 so that it does not return to the 

atmosphere (August 8, 2011; 76 FR at 48075). Therefore, EPA views these CO2 streams as 

“discarded material” within the plain meaning of the term in RCRA §1004(27). That is, a 

supercritical CO2 stream is a solid waste when it is to be discarded through abandonment by 

disposing of the material in a UIC Class VI well (see 40 CFR 261.2(a)(2)(i) and (b)(1)). To use the 

commenter’s phrasing, injection of a CO2 stream into a Class VI well for purposes of GS is effectively 

“getting rid of” the CO2 stream by keeping it underground indefinitely. The fact that the 

sequestration of CO2 streams into deep geologic formations is at times labeled as “long-term 

containment” or “long-term storage,” or that offset credits may be transacted, does not change 

this view.

Regarding the comment that CO2 streams injected into saline formations under UIC Class VI wells 

are not disposal, because they can later be withdrawn, EPA disagrees and reiterates that CO2

streams injected into UIC Class VI wells are solid wastes. EPA adds that the RCRA conditional

exclusion does not preclude the removal of CO2 at a later date. How this activity is regulated would 

be a determination separate from the terms of the conditional exclusion in this rule. That EPA 

chose not to discuss the RCRA concepts of “disposal” or “dispose” in the UIC Class VI rulemaking, in 

the context of injection into UIC Class VI wells, is consistent with the facts that that rulemaking did 

not make any RCRA applicability determations for CO2 streams intended for Class VI GS, and that 

that rule was issued solely under the SDWA. This approach in no way implied an EPA 

determination on the RCRA status of CO2 streams at the time of the UIC Class VI rulemaking. 

Rather, EPA has discussed questions of whether CO2 streams can be a RCRA solid waste, in the 

appropriate context – that is, for the limited set of circumstances addressed through today’s final 

conditional exclusion.

EPA acknowledges that the underground injection of CO2 has largely been (and continues to be) for 

the purpose of EOR, and does not disagree that CO2 can and does have a variety of commercial and 

manufacturing uses (e.g., urea yield boosting, enhanced oil recovery, food processing and 

packaging, beverage carbonation, and wine making), but this does not affect the regulatory status 

of CO2 streams when they are to be injected into UIC Class VI wells for the purpose of GS, which is 

the focus of this final rule. Regarding the commenter’s request for clarification on the status of CO2

streams injected into UIC Class II wells for purposes of EOR, see Response to Comment 3.1.1. EPA 

would encourage persons to consult with the appropriate regulatory authority to address any fact-
13

specific questions they may have regarding the status of CO2 in situations that are beyond the 

scope of this final rule.

Regarding the comment that the CO2 streams injected into a UIC Class VI well are not abandoned or 

disposed because “CCS prevents air emissions from being abandoned or disposed into the 

environment” EPA notes that the RCRA program has historically addressed analogous situations, 

where materials that would otherwise be released to the air are instead captured and removed for 

subsequent disposal (e.g., contaminants captured by air pollution control devices).

Finally, the comment appears to raise questions relating to when a CO2 stream must be evaluated 

to determine whether a CO2 stream exhibits a RCRA hazardous waste characteristic. These issues 

are discussed in response to comment 3.1.9, below.

Comment 3.1.9:

C. CO2 Streams Are Not “Hazardous” 

Assuming arguendo that CO2 streams injected into Class VI wells for GS purposes are “solid wastes” 

– and they are not, as described above – they are definitely not “hazardous wastes.” Subtitle C of 

RCRA, which regulates hazardous wastes, applies only to “solid waste” that is “hazardous.” [FN22: 

T. Garrett, ed., “The RCRA Practice Manual,” at 2, 2nd ed. (ABA 2004)].

EPA states that it has “little information to conclude that CO2 streams would qualify as RCRA 

hazardous waste.” 76 Fed. Reg. at 48077. The Agency also acknowledges that “CO2 streams are not 

listed hazardous wastes” under subpart D of part 261. Id. [FN23: Accord 76 Fed. Reg. at 48078 

(“EPA reiterates that no hazardous waste listings apply specifically to CO2 streams”)]. The Agency 

nonetheless believes that the “RCRA hazardous waste regulations can apply to CO2 streams” based 

upon two hypothetical scenarios: (1) a CO2 stream exhibits hazardous characteristics [FN24: 40 

C.F.R. § 261.20(a)]; or (2) a CO2 stream is mixed with a listed hazardous waste, thus triggering 

application of the so-called “mixture rule.” Id.

Both of these hypothetical scenarios are already clearly covered by the current regulations, so 

there is no need for new regulatory action. However it is important to note that neither scenario is 

particularly plausible. With respect to whether a CO2 stream exhibits hazardous characteristics, EPA 

seems to grudgingly acknowledge that there is no available standardized analytical test method for 

supercritical materials such as CO2 or a “CO2 stream.” [FN25: 76 Fed. Reg. at 48078 n. 22 (“EPA 

notes that existing analytical test methods ... are available to quantify the levels of various 

hazardous constituents in gaseous streams, although sampling a supercritical CO2 stream may 

require particular sampling protocols”) (emphasis added)]. EPA may only define a characteristic of a 

hazardous waste if the characteristic can be: (1) measured by an “available standardized test 

method which is reasonably within the capability of generators or solid waste or private sector 

laboratories that are available to serve generators of solid waste,” or (2) “reasonably detected by 

generators of solid waste through their knowledge of their waste.” [FN26: 40 C.F.R. § 261.10(a)(2)]. 

This two-factor test simply cannot currently be met for supercritical CO2 streams based on available 

standards.

Even if a standardized analytical test method were available for supercritical CO2, API is not aware 

of any information which would suggest that supercritical CO2 meets any of EPA’s hazard 

characteristics. Supercritical CO2 is not: (1) ignitable under 40 C.F.R. § 261.21; (2) corrosive under 

40 C.F.R. § 261.22 [FN27: Supercritical CO2 is non-aqueous, so § 261.22(a)(1) does not apply, and § 
14

261.22(a)(2) only applies if the material is “liquid and corrodes steel.” Supercritical CO2 is not a 

“liquid” and does not corrode steel pipelines, through which it has been transported safely for 

several decades. EPA hints that corrosivity could be an issue down hole through interaction with insitu reservoir fluids, but that scenario is not contemplated by 40 C.F.R. §261.22 and would be an 

issue for only the owner or operator of the reservoir, not the generator or transporter. EPA’s 

remark at 76 Fed. Reg. 48087 that all actors in the product chain could be implicated if down-hole 

interactions convert a non-hazardous CO2 stream to hazardous waste should be withdrawn, as it 

creates an enormous expansion of RCRA liability and could chill CCS activity.]; (3) reactive under 40 

C.F.R. § 261.23; or (4) toxic under 40 C.F.R. § 261.24. [FN28: Toxicity is assessed under Test Method 

1311, the so-called Toxicity Characteristic Leaching Procedure (TCLP). 40 C.F.R. § 261.24(a). The 

TCLP is inapplicable to supercritical CO2 and CO2 streams, as the TCLP was “intended to reflect the 

potential for leaching to groundwater that results from the co-disposal of toxic wastes in an 

actively decomposing municipal landfill generating an acidic leachate.” T. Garrett, ed., “The RCRA 

Practice Manual,” at 52. With reference to a 2006 paper from Lawrence Livermore National 

Laboratory, EPA suggests that certain impurities are “relevant” for toxicity regulation under § 

261.24(a). However, all of the impurities referenced by EPA as potentially being present in certain 

CO2 streams are at levels that are orders of magnitude lower than the relevant regulatory levels set 

forth in the regulations]. In the preamble to the final Class VI rule, EPA stated that it had reviewed 

estimates of CO2 injectate quality, and based upon that assessment, “captured CO2 could contain 

some impurities.” [FN29: 75 Fed. Reg. 77230, 77260 (Dec. 10, 2010)]. The possible presence of 

“impurities” does not trigger any of EPA’s hazard characteristic tests.

In the absence of an available standardized analytical test method, the Agency asserts that the 

RCRA 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.” [FN30: 76 Fed. Reg. 48078]. Section 

262.11(c)(2) of the RCRA regulations provides that, in lieu of the use of a standardized analytical 

test method, the generator of a hazardous waste may determine whether a material is hazardous 

by “[a]pplying knowledge of the hazardous characteristic of the waste in light of the materials or 

processes used.” Based upon industry’s knowledge of CCS-related materials and processes, coupled 

with current uses of CO2, a capturing generator is unlikely to have a reasonable belief that its CO2

stream is hazardous.

EPA references the following March 2006 study by Lawrence Livermore National Laboratory to 

support an inference that certain “impurities” could be present in CO2 streams from coal-based 

facilities: Apps, J.A., “A Review of Hazardous Chemical Species Associated with CO2 Capture from 

Coal-Fired Power Plants and Their Potential Fate in Geologic Storage.”[FN31: 76 Fed. Reg. at 48079 

n. 24]. Contrary to EPA’s suggestion that the study supports the notion that regulators should be 

concerned about the inadvertent constituents of CO2 streams, the study proves just the opposite 

(id. at p. 44): 

“The preceding evaluation shows quite clearly that the concentrations of other 

chemical components accidentally incorporated in CO2, when captured from 

conventional coal fired power plants, or from advanced coal-fired IGCC plants, will 

be at most, relatively insignificant. For minor volatile species of S, N, F. and CL, the 

concentration of CO2 from conventional power plants is unlikely to exceed 5% of the 

base concentration in the original coal feed, i.e., between 0 and 250 ppmv. For 

potentially hazardous trace elements, such as As, B, Ba, Be, Cd, Co, Cr, Cu, Ge, Hg, 
15

Mn, Mo, Ni, P, Pb, Sb, Sc, Sn, Sr, U, V, and Zn, with the possible exception of Hg, the 

percentage concentrations are currently predicted to be at least two orders of 

magnitude less in concentration than was originally present in the coal. However, 

given that the concentrations of most of these elements were only in the ppm range 

in the original coal, accidentally incorporated concentrations are unlikely to exceed 

the range from 0.01 to 10 ppmv.” (emphasis added). 

Significantly, the paper ultimately concludes that “the concentrations of inadvertent contaminants 

in the injected CO2 would probably be comparable to the ambient concentrations in confining shales 

of the injection zone.” Id. at 1 (emphasis added). [FN32 : The rest of the Lawrence Livermore paper 

deals with the “mixture rule” scenario which, as noted above, is not relevant as that activity is 

already prohibited by the Class VI rule.]

With respect to the hypothetical scenario based on the mixture rule route of regulation, EPA has 

advanced no record evidence to support this case. Furthermore, the Class VI rule itself prohibits the 

co-injection of RCRA hazardous waste, so the mixture rule scenario is already prohibited.[FN33: 75 

Fed. Reg. at 77260 (“Class VI wells may not be used for the co-injection of RCRA hazardous 

wastes”)].

Response: First, regarding the commenter’s overall conclusion that EPA has not shown that CO2

streams are hazardous waste, EPA emphasizes that it is not required to affirmatively demonstrate, 

as part of this rulemaking, that a particular CO2 stream, or a portion of all CO2 streams, necessarily 

qualifies as RCRA hazardous waste. Rather, under the conditional exclusion concept, EPA considers 

whether RCRA subtitle C regulation is necessary to protect human health and the environment. As 

explained in the preamble to the final rule, after consideration of public comment, EPA has reached 

the conclusion that management of CO2 streams under existing standards, including the UIC 

requirements for Class VI wells, as well as DOT standards, will protect human health and the 

environment from potential risks associated with CO2 streams (including associated constituents 

that might be present). This conclusion is based on EPA’s analysis of those other regulatory 

programs directly. EPA’s analysis and conclusions are independent of, and thus unaffected by, the 

question of whether a stream is classified as a hazardous waste under EPA’s RCRA regulations.

Below, EPA addresses specific hazardous waste comments submitted by the commenter.

The commenter seems to suggest that if it is not “particularly plausible” for CO2 streams to either 

exhibit a RCRA characteristic, or become mixed with listed hazardous waste, that CO2 streams are 

not (or cannot be) hazardous waste. EPA disagrees with this logic – under the terms of the RCRA 

regulations generally, a solid waste is a hazardous waste if it exhibits a RCRA characteristic, or is (or 

is mixed with) a listed waste. The RCRA regulations do not require an evaluation of the plausibility 

of either occurring. 

Regarding the applicability of the RCRA characteristics, the commenter seems to suggest that the 

criteria in 40 CFR 261.10(a)(2)(i) or (ii) determine the applicability of the hazardous characteristics 

regulations to a solid waste. However, the introductory language at §261.10(a) clearly identifies 

that the requirements in subsequent paragraphs (a)(1) and (a)(2) apply to the EPA administrator 

when defining characteristics of hazardous waste. While EPA acknowledges that it may be difficult 

to determine whether CO2 streams exhibit a RCRA characteristic, EPA clarifies here that the 40 CFR 

261.10 criteria do not determine the applicability of the current hazardous waste characteristics 
16

regulations to a particular waste – the characteristics apply to solid wastes that are not otherwise 

excluded from the RCRA regulations, in accordance with the tests in §261.21-.24. 40 CFR 261.20(a). 

Any CO2 streams determined to be solid wastes under RCRA and not excluded from RCRA 

regulation are subject to a hazardous waste determination under 40 CFR 262.11 as to whether they 

are hazardous waste. 

The commenter also seems to suggest that in the absence of analytical test methods, “generator 

knowledge” would lead to the finding that CO2 streams are not characteristic hazardous waste. 

Specifically, they state that “based upon industry’s knowledge of CCS-related materials and 

processes, coupled with current uses of CO2, a capturing generator is unlikely to have a reasonable 

belief that its CO2 stream is hazardous.” The commenter also cites the March 2006 study by 

Lawrence Livermore National Laboratory as evidence that CO2 streams are not hazardous waste

because of the relatively low predicted concentrations of contaminants. First, the Lawrence 

Livermore study was cited by EPA to illustrate that, at a minimum, CO2 streams could contain TC 

contaminants and therefore EPA cannot unequivocally conclude that supercritical CO2 streams will 

never exhibit any RCRA hazardous waste characteristic – particularly in light of the early state of 

data development in this area. Regarding the comment that generators are unlikely to have a 

reasonable belief that their CO2 stream is hazardous, EPA notes that generators may make this 

determination under the existing RCRA regulations for any waste they generate, and if they 

determine they are not managing a hazardous waste, they need not avail themselves of this 

conditional exclusion. EPA sought to bring additional clarity to the regulatory regime through this 

rule, by establishing a conditional exclusion from the definition of hazardous waste that would 

apply in the event a generator determines that its CO2 streams exhibit a RCRA hazardous 

characteristic.

Regarding the commenter’s statement that “EPA’s remark at 76 Fed. Reg. 48087 that all actors in 

the product chain could be implicated if down-hole interactions convert a non-hazardous CO2

stream to hazardous waste should be withdrawn, as it creates an enormous expansion of RCRA 

liability and could chill CCS activity” the commenter is incorrectly interpreting EPA’s discussion in 

the cited preamble. EPA believes that the scenario described by the commenter regarding the 

potential behavior of CO2 streams after injection into a UIC Class VI well would not affect the 

availability of the conditional exclusion, because the exclusion requires injection into a UIC Class VI 

well (in compliance with all of the conditions), and any potential issues with the corrosiveness of 

the CO2 stream post-injection would be addressed as part of the site-specific UIC Class VI permit. 

EPA notes that corrosiveness is a consideration that is addressed in the UIC Class VI requirements 

(see, for example, injection well construction requirements in 40 CFR 146.86(b) and corrosion 

monitoring requirements in 146.90(c)).

In summary, EPA does not conclude that supercritical CO2 streams that are solid wastes would, as a 

class, exhibit a RCRA characteristic. However, EPA also indicated in the proposed rule that it could 

not unequivocally conclude that supercritical CO2 streams will never exhibit any RCRA hazardous 

waste characteristic. Generators of non-hazardous waste CO2 streams are not subject to the RCRA 

subtitle C regulations, and they are not obligated to make use of this conditional exclusion

(although they may still choose to do so in situations where, for example, the generator may be 

uncertain regarding the hazardous waste status of the CO2 stream). Moreover, because use of the 

conditional exclusion is voluntary, even those generators who characterize their streams as RCRA 

hazardous waste may continue to manage their streams as RCRA hazardous wastes from the point 

of generation. The only effect is upon those persons who choose to comply with the terms of the 
17

conditional exclusion.

Regarding the applicability of the RCRA listings, the commenter stated that EPA has provided no 

evidence that CO2 streams have been mixed with listed hazardous waste, and also pointed out that 

the UIC Class VI rule prohibits such mixing. The commenter then seems to suggest that therefore 

CO2 streams cannot ever be identified as a listed waste. EPA disagrees because the RCRA 

regulations provide that a solid waste is a hazardous waste if it is mixed with a listed hazardous 

waste, and do not require a showing of the plausibility of the mixing occurring. 

Comment 3.1.10:

D. API Otherwise Supports the Proposed Conditional Exclusion, But Believes That EPA Could Provide 

Further Regulatory Clarity 

EPA’s conditional exclusion is largely premised on the notion that CO2 streams already are subject 

to stringent regulation. API agrees. 

As to generators, in the vast majority of commercial scenarios, there will be no on-site storage of 

CO2. Instead, as EPA states, captured CO2 will be immediately transported offsite via pipeline. 

[FN34: 34 76 Fed. Reg. at 48081]. From a geologic sequestration point of view, the industrial 

source’s role is rather perfunctory, aside from complying with the terms and conditions of the 

relevant CO2 offtake contract. [FN35: A typical CO2 offtake contract obligates the source to deliver 

specified volumes or quantities of CO2 under minimum pressure and quality specifications at a 

nominated delivery point.] Subparts UU/RR to the GHG reporting rule also provide EPA with 

relevant information. [FN36 : 76 Fed. Reg. at 48082].

EPA also notes, and API agrees, the transportation of CO2 is also stringently and effectively 

regulated by the U.S. Department of Transportation (“DOT”). [FN37: We do not entirely agree with 

EPA’s characterization of DOT’s regulation, however. Although the RCRA proposal refers to “CO2

streams,” EPA shifts gear here and refers only to “CO2.” Also, supercritical CO2 does not appear in 

DOT’s hazmat table. The hazmat table instead lists three forms of CO2: (1) gas (UN 1013); (2) 

refrigerated liquid (UN 2187); and (3) solid or dry ice (UN 1845). 49 C.F.R. § 172.101. Finally, EPA 

should emphasize, as it already suggests, that DOT does not regulate the pipeline transportation of 

CO2 under the status of a “hazardous liquid.” 76 Fed. Reg. at 48082.] These regulations apply to all 

modes of transport, including but not limited to pipelines. DOT regulates the interstate pipeline of 

CO2 as a non-hazardous liquid, and relevant States apply comparable standards for intrastate 

pipelines. [FN38: Nordhaus, R., “Carbon Dioxide Pipeline Regulation,” Energy Law Journal, Vol. 

30:85 (2009).]

Response: EPA thanks the commenter for its support for the conditional exclusion, and the 

information provided. EPA notes that pipeline transportation of CO2 is subject to the DOT’s 

Pipeline Hazardous Materials Safety Administration (PHMSA) requirements in 49 CFR part 195, 

which apply to pipeline facilities used in the transportation of hazardous liquids or supercritical 

CO2. 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. This final rule does not change the status under DOT 

of supercritical CO2, nor does it change the manner in which supercritical CO2 is regulated under 

DOT. The points made by the commenter do not affect EPA’s assessment of applicable DOT 

regulations (as confirmed through discussions with DOT staff) for both pipelines and non-pipeline 
18

transportation for CO2 streams. Finally, EPA has noted in the final rule preamble (and by amending 

the relevant regulatory text in the final rule) the applicability of relevant state standards for 

intrastate pipelines.

Comment 3.1.11:

API agrees with the Agency that the Class VI and Class II provides a comprehensive management 

regime for CO2 streams that renders duplicative any potential additional regulation under RCRA. 

[FN39: 76 Fed. Reg. 48084-48085].

Response: EPA is not addressing the status of all CO2 streams in this rulemaking; the scope of this 

rule is limited to CO2 streams injected into a permitted UIC Class VI well for purposes of GS. EPA 

clarifies that the conditional exclusion only applies to carbon dioxide streams injected into Class VI 

wells, and only when the conditions of 40 CFR 261.4(h)(1) through (4) are met. While the 

requirements for each UIC injection well class address the specific practices and unique risks to 

USDWs posed by a specific well class, the Class VI requirements are tailored to the unique aspects 

of carbon dioxide injection for GS (e.g., large CO2 injection volumes, the buoyant and mobile nature 

of the Injectate, etc.) and EPA developed its RCRA conditional exclusion based upon injection in a 

UIC Class VI well. EPA’s analysis supporting the conditional exclusion did not include an evaluation 

of the UIC Class II well (or other well class) requirements, as those wells are beyond the scope of 

the rule as proposed. EPA does note that nothing in the conditional exclusion would prevent a Class 

VI well, that had previously transitioned from a Class II well, from being eligible for the RCRA 

conditional exclusion.

Comment 3.1.12:

API also agrees that CO2 streams subject to the conditional exclusion would not be subject to 

RCRA’s land disposal restrictions or separate provisions regarding corrective action. [FN40: 76 Fed. 

Reg. 48085-48086.]

Response: EPA acknowledges the comment.

Comment 3.1.13:

API does not understand why EPA proposes to make the conditional exclusion subject to the 

additional requirement that no hazardous wastes may be mixed with, or otherwise co-injected 

with, the CO2 stream, given that those activities are already barred under the Class VI rule. [FN41: 

76 Fed. Reg. at 48086.] 

EPA states that the conditional exclusion may be lost at any time, a situation which may serve to 

substantially weaken the exclusion’s salutary effects given that the Agency appears to be holding 

out the potential for down-hole formation of carbonic acid at some future date in a storage 

facility’s lifetime [FN42: 76 Fed. Reg. 48087]: 

“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 the CO2 stream being subject to all applicable subtitle C regulatory 

requirements, from the point of generation.”

This suggests that all entities involved in CCS – generator, transporter, and injector – could be held 

liable for RCRA violations if at some future date conditions down-hole, due to no fault of any party, 
19

could be deemed to have created or liberated a material that a future regulator or claimant 

considers to be of concern. This situation will increase, not decrease, regulatory certainty.

Response: EPA notes that the prohibition on mixing hazardous waste is a condition of the 

exclusion (and not an independent requirement). EPA also notes that the applicability of this final 

rule includes activities upstream of the UIC facility; therefore, EPA believes that the certification 

can help ensure compliance with the mixing prohibition by other entities (e.g., the CO2 stream 

generator). In EPA’s view, the mixing prohibition is entirely consistent with the prohibition in the 

UIC Class VI rule; and, given that this rule excludes certain materials from the definition of 

hazardous waste, it is entirely appropriate to prohibit mixing the excluded waste with other 

hazardous wastes from point of capture to injection in a UIC Class VI well, irrespective of the similar 

UIC Class VI provision. 

EPA is not clear on what is the commenter’s concern when they state the Agency is “holding out 

the potential for down-hole formation of carbonic acid at some future date...” As stated in 

response to comment number 3.1.9, EPA believes that the potential behavior of CO2 streams after 

injection into a UIC Class VI well would not affect the conditional exclusion (assuming the 

conditions are otherwise met). 

Comment 3.1.14:

EPA emphasizes that the generator is responsible for the initial, and perhaps sole, hazard 

determination, but this conflicts with the definition of “CO2 stream” which suggests that the 

injector may add materials to facilitate injection. What happens in the scenario where the 

industrial source effectively delivers pharmaceutical grade CO2 to a storage site via a pipeline 

transporter, and the site owner/operator thereafter adds incidental materials to facilitate 

injection? It would be unfair in that situation to hold the industrial source liable for the site 

owner/operator’s activities in the absence of an agreement to the contrary.

The conditional exclusion is premised on a linear model of CCS operations under which a single 

source delivers CO2 to a single transporter who in turn delivers the CO2 to a site owner/operator. 

While that scenario may apply in some circumstances, it is equally likely that one or more sources 

may be delivering CO2 into the same pipeline, which in turn will deliver the CO2 to a storage site 

that receives and stores CO2 from multiple sources. That storage site may also already hold, or 

accept for delivery, volumes of natural CO2. [FN43: This situation further supports our position that 

RCRA was never intended to apply to CCS.] Since CO2 streams will be intermingled, and CO2

molecules are identical, this sets up a “Superfund-esque” situation under which all parties, even 

the innocent, have the potential of being held liable. And unlike Superfund, where at least there is 

the hope of finding labels on drums to identify sources and parties, no such hope exists for 

intermingled CO2 molecules, particularly after they have already been injected into the subsurface. 

Furthermore, as Superfund is triggered by “hazardous substances,” regardless of concentration, 

released after an “arrangement for disposal,” there is an increased likelihood of Superfund liability 

if transmissions of CO2 streams are considered disposals of solid wastes.

Response: Regarding the comment that the generator is responsible for the initial and “perhaps 

sole” determination of whether any waste is a hazardous waste, as EPA noted in the proposed rule, 

while a hazardous waste determination must be made when a waste is first generated, knowing 

whether a solid waste is a hazardous waste is necessary at any point during the management of 
20

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 76 FR at 48078, Footnote 19. 

The commenter describes a hypothetical scenario where a generator sends a very clean CO2 stream

to a UIC Class VI owner or operator, who in turn adds “incidental materials to facilitate injection” to 

the CO2 stream. In this situation, the commenter suggests that the generator is “liable” for the well 

owner/operator actions. While EPA is at present unaware of actual examples of where substances 

are added to facilitate supercritical CO2 injection, because the definition of “CO2 stream” includes 

the possible addition of materials to facilitate injection, there does not appear to be any violation 

of the conditional exclusion in this hypothetical scenario (assuming that the addition of these 

materials is otherwise in compliance with the UIC Class VI permit, and that addition of these 

materials does not violate the prohibition on mixing or co-injecting hazardous wastes – assuming 

these materials are not hazardous wastes – with the CO2 stream). EPA has revised the certification 

statements such that the generator is certifying to activities that are under their control, namely, 

that they have not mixed their CO2 stream with hazardous waste, and that they have delivered (or 

arranged for delivery) of the stream to a UIC Class VI facility.

Nonetheless, EPA can appreciate the commenter’s concern over the loss of the conditional 

exclusion due to the actions of subsequent handlers of the CO2 stream (in this instance, mixing of 

hazardous waste into the CO2 stream downstream of the “...previous producer or manager of the 

CO2 stream.”). However, EPA maintains that the rule conditions, taken together, ensure that the 

excluded CO2 streams are being managed in a protective manner such that subtitle C regulations 

are not necessary. EPA’s Office of Enforcement and Compliance Assurance (OECA) is unable to 

provide definitive assurances outside the context of a formal enforcement proceeding that the 

government will not proceed with an enforcement response for a specific individual violation of an 

environmental protection statute, regulation, or legal requirement. However, EPA can (and has 

previously done so for other RCRA rules) exercise discretion to decide when and how to respond or 

not respond to a given violation, based on the Agency’s normal priorities. In RCRA penalty actions, 

the factors that EPA considers in assessing the gravity-based portion of the penalty are the 

potential for harm and the extent of deviation from a statutory or regulatory requirement. The 

penalty can be adjusted for numerous factors, including good faith efforts to comply, degree of 

willfulness and negligence, and history of noncompliance. Additional information can be found in 

the 2003 RCRA Civil Penalty Policy 

(http://www.epa.gov/compliance/resources/policies/civil/rcra/rcpp2003-fnl.pdf).

Regarding the comment which raises concerns about liability in a hypothetical situation where 

multiple sources of CO2 streams are delivered in a shared pipeline being injected into a single 

facility, this example illustrates why EPA is committed to an adaptive approach on CCS generally, so 

that the Agency may identify and address additional information and respond, including via

rulemaking, should that be necessary (see Response to Comment 3.2.3 and 3.2.4). However, in the 

example above, the terms of the conditional exclusion would not prevent an arrangement where a 

single UIC Class VI facility receiving both conditionally-excluded CO2 streams and other nonhazardous CO2 streams from multiple sources, through a shared pipeline. Issues surrounding 

potential Superfund liability related to GS are beyond the scope of this rulemaking.

Comment 3.1.15:

EPA states that the conditional exclusion only applies to “CO2 streams” that have been captured for 

purposes of “geologic sequestration.” [FN44: 76 Fed. Reg. at 48086.] There may be several 
21

destinations for the captured CO2, each with a different purpose. If there are different regulatory 

requirements for each purpose, there could be major complications for the shipper of the common 

stream. Again, this argues for a uniform, blanket exclusion of all CO2 streams from the solid waste 

definition. The Agency explains that [FN45: 76 Fed. Reg. at 48078 n. 16.]: 

“The proposed rule is not intended to affect the status of CO2 that is injected into 

wells other than UIC Class VI wells. 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.”

This limitation provides no regulatory clarity for Class II concurrent ER/storage projects that qualify 

for the risk-based factor test of 40 C.F.R. § 144.19 under the Class VI rule, which allows 

sequestration to occur under Class II if there is no increased risk to USDWs. [FN46: 75 Fed. Reg. at 

77245.] It is imperative that EPA make clear either that: (1) the conditional exclusion also applies to 

ER operators under 40 C.F.R. § 144.19, or (2) the RCRA status of ER operators under 40 C.F.R. § 

144.19 is identical to that of business-as-usual ER operators under Class II without claims of 

sequestration [FN47: “The agency has decided not to regulate oil and gas industry exploration and 

production wastes and mineral extraction and beneficiation and certain mineral processing under 

RCRA Subtitle C.” T. Garrett, ed., “The RCRA Practice Manual,” at 3].

Again, EPA needs to make clear that CO2 streams used for ER are not solid wastes. [FN48: Likewise, 

EPA needs to make clear that CO2 streams injected into experimental Class V wells are not solid 

wastes. Failing to do so would retard the research and development needed to advance 

understanding of storage.] ER operators using Class II wells may be the largest immediate 

customers of CO2 capturers and they currently handle their CO2 as a valuable product. If handled as 

a solid waste, CO2 injected into Class II wells would not receive the benefit of the conditional 

exclusion and the capturers would need to evaluate if those streams are hazardous before shipping 

them to ER customers. These same capturers would not need to determine if their CO2 streams are 

hazardous for Class VI well operator customers. This disparity will likely create regulatory confusion 

and administrative nightmares in dealing with two different customers for the same CO2 stream. As 

the regulatory burdens would be greater for ER customers, capturers may not deal with ER 

customers, who may not receive sufficient supplies, thereby undermining both ER and CCS 

operations. The best solution is to declare that all CO2 streams are not solid waste.

Response: EPA does note that (based on the limited information provided in the public 

comments), should CO2 be used for its intended purpose as it is injected into UIC Class II wells for 

the purpose of EOR/EGR, it is EPA’s expectation that such an injection process would not generally 

be a waste management activity. EPA would encourage persons to consult with the appropriate 

regulatory authority to address any fact-specific questions they may have regarding the status of 

CO2 in situations that are beyond the scope of this final rule. EPA also notes that nothing in the 

conditional exclusion would prevent a Class VI well, that had previously transitioned from a Class II 

well from being eligible for the RCRA conditional exclusion. See also responses to comment 3.1.2 

and 3.1.11.

Comment 3.1.16:

EPA states that RCRA’s § 7003 imminent hazard authorities would continue to apply under the 

conditional exclusion. [FN49: 76 Fed. Reg. at 48088.] For the reasons stated above, “CO2 streams” 
22

are neither solid nor hazardous wastes, so § 7003 – which only applies to solid or hazardous wastes 

-- should not apply to CO2 streams with the recommended changes. For the same reason, EPA 

should clarify that RCRA’s citizen suit provision -- § 7002 – also does not apply to CO2 streams.

Response: EPA disagrees with the commenter. For purposes of RCRA 7002 and 7003 imminent 

hazard authorities, the statutory, not regulatory, definitions of solid and hazardous waste are 

relevant. See, e.g., Connecticut Coastal Fishermen’s Ass’n v. Remington Arms Co., 989 F.2d 1305, 

1314-15 (2d Cir. 1993); Comite Pro Rescate De La Salud v. Puerto Rico Aqueduct and Sewer Auth., 

888 F.2d 180, 187 (1st Cir. 1989) (Breyer, J.). It is EPA’s position that a supercritical CO2 stream 

injected into a permitted UIC Class VI well for purposes of GS is a RCRA statutory solid waste, 

because it is a “discarded material” within the plain meaning of the term in RCRA §1004(27), and 

therefore RCRA §§ 7002 and 7003 are available. As explained in response to comment 3.1.11, EPA 

is not addressing the status of all CO2 streams in this rulemaking; the scope of this rule is limited to 

CO2 streams injected into a permitted UIC Class VI well for purposes of GS.

Comment 3.1.17:

API encourages EPA to clarify that CO2 streams subject to the conditional exclusion also are not 

subject to Superfund. [FN50: A CERCLA “hazardous substance” is defined to include all RCRA 

hazardous wastes, and because CO2 streams are not hazardous wastes, it is appropriate for EPA, in 

this rulemaking, to provide critical regulatory clarity for CCS under the Superfund statute, too]. 

Response: EPA is promulgating this rule under the authority of RCRA. To the extent the commenter 

is seeking interpretations of CERCLA, such interpretations are beyond the scope of this rulemaking.

Comment 3.1.18:

For the reasons stated above, EPA should exclude all CO2 streams as solid waste, by enacting the 

following section as a new § 261.4(a)(26) as follows [FN51: Suggested additions are {capitalized}.]: 

(a) Materials which are not solid wastes. 

* * *

(26) CARBON DIOXIDE (CO2) STREAMS. CARBON DIOXIDE STREAMS AS DEFINED IN 40 

CFR 146.81(D) ARE NOT A SOLID WASTE 

Alternatively, as API’s second preference, if this is rejected we recommend instead that EPA make 

clear that particular “CO2 streams” are neither solid nor hazardous wastes. The Agency could do so 

by promulgating a new § 261.4(a)(26) as follows [FN52: Suggested additions are {capitalized}]:

(a) Materials which are not solid wastes. * * *

(26) CARBON DIOXIDE (CO2) STREAMS. CARBON DIOXIDE STREAMS AS DEFINED IN 40 

CFR 146.81(D) THAT ARE CAPTURED AND TRANSPORTED FOR PURPOSES OF INJECTION 

INTO AN UNDERGROUND INJECTION WELL SUBJECT TO THE REQUIREMENTS FOR CLASS 

II, CLASS V, OR CLASS VI UNDERGROUND INJECTION CONTROL WELLS, INCLUDING THE 

REQUIREMENTS OF 40 CFR PARTS 144 (INCLUDING § 144.19) AND 146 OF THE 

UNDERGROUND INJECTION CONTROL PROGRAM OF THE SAFE DRINKING WATER ACT, 

ARE NOT A SOLID WASTE PROVIDED THAT THE GENERATOR ALSO COMPLIES WITH THE 

FOLLOWING REQUIREMENTS: 

(i) TRANSPORTATION OF THE CARBON DIOXIDE STREAM MUST BE IN COMPLIANCE 
23

WITH APPLICABLE DEPARTMENT OF TRANSPORTATION (OR ANALOGOUS STATE) 

REQUIREMENTS; 

(ii) INJECTION OF THE CARBON DIOXIDE STREAM MUST BE IN COMPLIANCE WITH 

THE APPLICABLE REQUIREMENTS FOR CLASS II, CLASS V, OR CLASS VI 

UNDERGROUND INJECTION CONTROL WELLS, INCLUDING THE APPLICABLE 

REQUIREMENTS IN 40 CFR PARTS 144 (INCLUDING § 144.19) AND 146; 

(iii) NO OTHER HAZARDOUS WASTE MAY BE MIXED WITH, OR OTHERWISE COINJECTED WITH, THE CARBON DIOXIDE STREAM AT THE GENERATOR’S FACILITY OR 

SITE; AND 

(iv) ANY GENERATOR OF A CARBON DIOXIDE STREAM, AND ANY CLASS II, CLASS V, 

OR CLASS VI UNDERGROUND INJECTION CONTROL WELL OWNER OR OPERATOR, 

WHO CLAIMS THAT A CARBON DIOXIDE STREAM IS EXCLUDED UNDER THIS 

PARAGRAPH, 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(A)(26) 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 (IF LOCATED IN AN AUTHORIZED STATE), OR THEIR DESIGNEE, 

ANDSHALL BE RENEWED EVERY YEAR. THIS YEARLY RENEWABLE OF A 

CERTIFICATION STATEMENT UNDER THIS PARAGRAPH MEANS THAT AN 

AUTHORIZED REPRESENTATIVE MUST ANNUALLY PREPARE AND SIGN A NEW COPY 

OF THE CERTIFICATION STATEMENT. 

As API’s third preference, if the first two are rejected and EPA elects to continue to pursue the 

conditional exclusion route, we suggest that the proposed exclusion in § 261.4(h) be revised to 

read as follows [FN53: The full text of EPA’s proposed conditional exclusion is shown, with 

suggested additions {capitalized}. We propose no textual deletions]. 

(h) Carbon Dioxide Stream Injected for Geologic Sequestration. Carbon dioxide streams 

that are captured and transported for purposes of GEOLOGIC SEQUESTRATION injection 

into an underground injection well subject to the requirements for Class II and Class V (as 

applicable) and Class VI Underground Injection Control wells, including the requirements of 

40 CFR parts 144 and 146 (AND § 144.19 FOR APPLICABLE CLASS II WELLS) 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 (OR ANALOGOUS STATE) requirements; 
24

(ii) Injection of the carbon dioxide stream for geologic sequestration purposes must 

be in compliance with the applicable requirements for Class II, Class V, or Class VI 

Underground Injection Control wells, including the applicable requirements in 40 

CFR parts 144 (INCLUDING § 144.19) and 146; 

(iii) No other hazardous waste may be mixed with, or otherwise co-injected with, 

the carbon dioxide stream AT THE GENERATOR’S FACILITY OR SITE; and 

(iv) Any generator of a carbon dioxide stream, and any Class II, Class V, or Class VI 

Underground Injection Control well owner or operator for geologic sequestration 

purposes, 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 (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). This 

yearly renewable of a certification statement under this paragraph means that an 

authorized representative must annually prepare and sign a new copy of the certification 

statement. 

In addition, as a necessary part of the foregoing changes, EPA should clarify that CO2 streams that 

are used for non-geologic sequestration purposes, or are not injected into Class VI wells (or 

applicable Class II wells under § 144.19), are not solid wastes by adding the following section as a 

new § 261.4(a)(26) as follows [FN54: Suggested additions are {capitalized}].

(b) Materials which are not solid wastes. 

* * *

(26) CARBON DIOXIDE (CO2) STREAMS. CARBON DIOXIDE STREAMS THAT ARE 

CAPTURED AND TRANSPORTED FOR A PRIMARY PURPOSE OTHER THAN GEOLOGIC 

SEQUESTRATION OR FOR PURPOSES OF INJECTION INTO AN UNDERGROUND 

INJECTION WELL THAT IS NOT SUBJECT TO THE REQUIREMENTS FOR CLASS VI 

UNDERGROUND INJECTION CONTROL WELLS, INCLUDING THE REQUIREMENTS OF 

40 CFR PARTS 144 AND 146 (AND § 144.19 FOR APPLICABLE CLASS II WELLS) OF 

THE UNDERGROUND INJECTION CONTROL PROGRAM OF THE SAFE DRINKING 

WATER ACT, ARE NOT A SOLID WASTE.

Response: See responses to comments 3.1.1 – 3.1.17. Regarding the commenter’s suggested 

language to include reference to ‘analogous state’ transportation requirements, EPA has addressed 

this in the regulatory text of the final rule, see Response to Comment 3.2.26. Regarding the 

commenter’s suggested language prohibiting mixing of hazardous waste only at the generator site, 

EPA disagrees, see response to comment 3.1.13.

Comment 3.1.19:
25

API appreciates the opportunity to submit comments. Any further requests by the Agency for 

additional information or comment should be directed to (see docket for contact information).

Response: EPA acknowledges the comment.

3.2 Carbon Sequestration Council (CSC) 

Document ID: EPA-HQ-RCRA-2010-0695-0084

Comment 3.2.1:

The Carbon Sequestration Council (the CSC) is pleased to submit these comments in response to 

the notice of proposed rulemaking (NPRM) entitled Hazardous Waste Management System: 

Identification and Listing of Hazardous Waste: Carbon Dioxide (CO2) Streams in Geologic 

Sequestration Activities, 76 Fed. Reg. 48073 (August 8, 2011), Docket ID No. EPA–HQ–RCRA–2010–

0695. The CSC is a multi-industry Association [FN1: Members of the Carbon Sequestration Council 

are American Electric Power, BHP Billiton, BP Alternative Energy North America Inc., 

ConocoPhillips, Denbury Resources Inc., Duke Energy, LG&E and KU Energy LLC, Occidental 

Petroleum Corporation, Shell Exploration and Production, and Southern Company] formed to 

provide a forum for inter-industry communication around key issues of carbon capture and 

sequestration or storage (CCS) including policy, funding, and messaging. CSC facilitates information 

sharing and consensus building to more effectively promote policies, legislation and regulatory 

frameworks that foster the use of anthropogenic CO2 for enhanced oil recovery (EOR) as well as the 

early use and commercial deployment of geologic sequestration (GS) as a means of addressing 

greenhouse gas mitigation. 

We appreciate the importance of this proposal, as many commenters on the proposed 

underground injection control (UIC) program rule for GS urged the Environmental Protection 

Agency (EPA) to provide clarification on the potential applicability to CCS of the Resource 

Conservation and Recovery Act (RCRA) regulations governing management of hazardous waste. 

EPA noted in the preamble to the proposal: “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.” 76 Fed. Reg. at 48077. 

As we will explain here and in our attached detailed comments, there are better ways to provide 

the regulatory certainty needed. The proposed conditional exclusion will not provide the necessary 

certainty because, in the form proposed, it will create additional unnecessary uncertainties.

The best way to provide the necessary certainty is to conclude—as we believe EPA must—that 

captured gaseous carbon dioxide emissions are not solid waste and are, therefore, outside of 

RCRA’s statutory purview under section 1004(27) because supercritical carbon dioxide is not 

“contained gaseous material”; it constitutes uncontained gaseous material and cannot be solid 

waste under both the statute and current EPA policy. 42 USC §6903(27) (2010). As explained in our 

attached detailed comments, EPA has already concluded that air emissions captured by an 

emissions control device fall outside the jurisdiction of RCRA, especially when that gaseous material 

is a gas at standard temperature and pressure. Since 1982 EPA has consistently adhered to the 

policy that “our authority to identify or list a waste as hazardous under RCRA is limited to 

containerized or condensed gases (i.e., section 1004(27) of RCRA excludes all other gases from the 

definition of solid wastes and thus cannot be considered hazardous wastes).” 54 Fed. Reg. 50968, 

50973 (December 11, 1989).
26

The carbon capture devices currently available and under development operate in a similar manner 

to capture a gaseous emission stream as air pollution control equipment. Accordingly, captured 

carbon dioxide streams could not be considered “discarded material”. The status of captured 

carbon dioxide streams was verified in the preamble to EPA’s final GS UIC rule, where EPA 

explained: “carbon dioxide is first captured from fossil-fueled power plants or other emission 

sources.” 75 Fed. Reg. 77230, 77233 (December 10, 2010) (emphasis added). As captured air 

emissions [FN2: See 76 Fed. Reg. at 48082: “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”], these carbon dioxide streams are uncontained gases and were statutorily excluded from 

RCRA by Congress.

Response: EPA agrees with the commenter that providing regulatory clarity is an important goal of 

this rule. However, EPA disagrees that CO2 streams sent to UIC Class VI wells for purposes of GS are 

not solid wastes, and therefore, disagrees that that is a basis to provide regulatory clarity. A 

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

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

§1004(27). That is, a supercritical CO2 stream is a solid waste when it is to be discarded through 

abandonment by disposing of the material in a UIC Class VI well (see 40 CFR 261.2(a)(2)(i) and 

(b)(1)). 

As EPA noted in the proposed rule, the CO2 streams are delivered by pipeline and injected into UIC 

Class VI wells for GS in a supercritical state, which EPA stated at proposal was “...rather unique in 

that it has properties intermediate between a liquid and a gas.” 76 FR at 48078. The scientific term 

used to describe or define this supercritical state (i.e., when a substance is at or above its critical 

temperature and critical pressure) is as a “supercritical fluid.” The RCRA statutory definition of solid 

waste specifically refers to “other discarded material, including solid, liquid, semisolid, or contained 

gaseous material resulting from industrial, commercial, mining, and agricultural operations, and 

from community activities . . .” While EPA has indeed interpreted the meaning of specific terms 

listed, including “contained gaseous material,” the RCRA definition of solid waste encompasses 

“other discarded material” and does not speak to materials such as supercritical fluids. Like the 

listed “solid, liquid, semisolid, or contained gaseous material” specifically referenced, CO2 streams 

sequestered for purposes of GS are “other discarded material” from industrial and commercial 

operations and, therefore, are of a similar kind to the other types of wastes specifically referenced 

by the definition. They are, therefore, RCRA statutory solid wastes. While the commenter points 

out that CO2 capture devices are similar to air pollution control equipment, as a basis for 

concluding that captured CO2 emissions should be defined as uncontained gases (and therefore not 

solid waste), EPA’s finding (as described above) is with respect to CO2 as a supercritical fluid, and 

does not view the comment as relevant to that determination. Finally, with regard to the 

commenter’s citation from the UIC Class VI final rule, that rulemaking did not make any RCRA 

applicability determinations for CO2 streams intended for Class VI GS, consistent with the fact that 

that rule was issued solely under the SDWA.

Comment 3.2.2:

Even if these captured carbon dioxide streams were not gaseous, the carbon dioxide is a 

commodity that has so many beneficial uses that it would be difficult to consider it to be discarded 

in any traditional sense because the carbon dioxide stored underground would be available for use 
27

in enhanced oil recovery (EOR), in support of geothermal operations and for numerous other 

beneficial activities. Indeed, captured carbon dioxide streams from some sources could even be 

used for food grade carbonation with little or no further purification.

Consistent with these considerations, if EPA were to proceed with promulgation of a regulatory 

exclusion from RCRA (notwithstanding the congressional exclusion already in the statute), it should 

be an exclusion from the definition of solid waste rather than an exclusion from the definition of 

hazardous waste. As noted in the preamble, “EPA has little information about whether carbon 

dioxide streams would exhibit a RCRA hazardous waste characteristic (in particular, the TC).” 76 

Fed. Reg. at 48083. Given the current status of the development of carbon capture technologies 

and the lack of knowledge about the specific characteristics of captured carbon dioxide emission

streams, EPA is not in the position to develop the full range of RCRA criteria and requirements that 

would be necessary to regulate these streams as potentially hazardous wastes particularly because 

such streams are quintessentially different from anything else currently managed under RCRA as 

hazardous waste.

Response: Regarding the comment that carbon dioxide is a commodity that has many beneficial 

uses, EPA acknowledges that CO2 can and does have a variety of commercial and manufacturing 

uses. That CO2 may be useful (or even a “commodity”) in other contexts has no bearing on the 

RCRA regulatory status of CO2 sent for GS in a UIC Class VI well. As was stated in the preamble to 

the proposed rule, GS is an option to reduce CO2 emissions to the atmosphere by injecting the CO2

streams into deep subsurface geologic formations, with the express purpose of isolating the CO2 so 

that it does not return to the atmosphere (August 8, 2011; 76 FR at 48075). This is the express 

purpose of the UIC Class VI well; therefore, EPA views these CO2 streams as “discarded material” 

within the plain meaning of the term in RCRA §1004(27). The fact that the sequestration of CO2

streams into deep geologic formations is at times labeled as “long-term containment” or “longterm storage” does not change this view. In addition, the RCRA conditional exclusion does not 

preclude the removal of CO2 from underground at a later time – how this activity is regulated, 

would be a determination separate from the terms of the conditional exclusion, and is thus outside 

the scope of this rulemaking. As already stated, EPA is not addressing the status of all CO2 streams 

in this rulemaking, as the scope of this rule is expressly limited to CO2 streams injected in a 

permitted UIC Class VI well for purposes of GS. 

Regarding the comment that EPA is not in the position to develop “...the full range of RCRA criteria 

and requirements that would be necessary to regulate these streams as potentially hazardous 

wastes...” EPA points out that it did not set out to do so. Instead, in the development of the 

conditional exclusion, EPA evaluated other applicable requirements, and reached the conclusion 

that additional regulation under RCRA subtitle C was not warranted for CO2 streams (that would 

otherwise be defined as hazardous waste) that are injected in a permitted UIC Class VI well for 

purposes of GS, when they are managed in accordance with the conditions in the final rule.

Regarding the comment that if EPA were to proceed with promulgation of a regulatory exclusion 

from RCRA, it should be an exclusion from the definition of solid waste rather than an exclusion 

from the definition of hazardous waste, EPA disagrees. A solid waste regulatory exclusion would 

need to be based upon a finding that CO2 streams sent to a UIC Class VI well for purposes of GS are 

not being discarded, and based on the information available to EPA, as explained elsewhere, EPA 

does not agree with such a conclusion.
28

Comment 3.2.3:

Moreover, any exclusion that EPA fashions needs to address carbon dioxide streams for the full 

range of scenarios under which the uses of captured anthropogenic carbon dioxide streams are 

likely to occur. In the proposal, EPA presumes a scenario where, “beginning 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”. 76 Fed. Reg. at 48076. But it is not 

appropriate to presume such a limited single source to single injector scenario. Because geologic 

sequestration without EOR is still very much in the experimental stage, it is not useful to simply 

consider current demonstration project scenarios. Instead, it is likely that each of the following 

scenarios would occur once the technology is implemented on more than an experimental 

developmental scale: 

*Capture of a carbon dioxide stream at a single emission source followed by transport via pipeline 

to an injection well or wells onsite or offsite through a dedicated pipeline [FN3: 76 Fed. Reg. at 

48076 (“[T]he majority of CO2 is expected to be delivered to the sequestration site by dedicated 

pipeline”)]. 

*Capture of carbon dioxide streams at multiple emission sources followed by delivery to a 

commercial interstate pipeline network [FN4: 76 Fed. Reg. at 48082 (“[M]oving the enormous 

quantities of CO2 implied by a widespread implementation of CCS technologies would likely require 

a dedicated interstate pipeline network”.), citing CRS Report for Congress. Carbon Dioxide (CO2) 

Pipelines for Carbon Sequestration: Emerging Policy Issues. Paul W. Parfomak and Peter Folger. 

January 17, 2008. Id., n. 37] for transport to multiple recipients, some of which will be using the 

carbon dioxide for enhanced recovery of oil and gas by injecting it through UIC Class II wells, and 

some of which will be operating UIC Class VI wells for geologic sequestration. 

*Capture of carbon dioxide streams at one or more emission sources followed by delivery to a 

commercial interstate pipeline network where those multiple anthropogenic streams are 

comingled with naturally sourced carbon dioxide from one or more sources for delivery to multiple 

recipients, some of which will be using the carbon dioxide for enhanced recovery of oil and gas by 

injecting it through UIC Class II wells, some of which will be operating UIC Class VI wells for geologic 

sequestration (and even to other recipients who will be using carbon dioxide for a variety of other 

activities, including in the production of foods and beverages or for agricultural and other uses). 

The scenarios can get more and more complicated, but the point we want to make is that it cannot 

be assumed that any producer of carbon dioxide through capture of emissions will always be 

sending that carbon dioxide stream to a single UIC Class VI injection well operation for geologic 

sequestration. Nor should any regulatory scheme be designed to force that type of singularity upon 

the nascent industry of carbon dioxide producers. To do so would stifle the potential use of EOR to 

provide incentives for the production of anthropogenic carbon dioxide streams by saddling both 

the producers and the operators of EOR projects with new barriers of uncertainty about the 

potential applicability of RCRA and related or derivative regulatory programs.

Response: EPA appreciates the commenter’s request, and notes that currently there is a lack of 

sufficient information to inform the agency on how to best address the “full range of scenarios” 

presented by the commenter because many of such scenarios are still under development. EPA 

notes that the purpose of developing this final rule was to provide for the option of a conditional 
29

hazardous waste exclusion that could be used, where necessary, to provide clarity as to the 

applicability of RCRA subtitle C, and in particular with respect to removing barriers to initiating 

near-term CCS projects. EPA does not wish to delay the issuance of the rule, until the types of 

situations outlined by the commenter already exist, because that would defeat EPA’s purpose, in 

particular with respect to removing barriers to initiating near-term CCS projects.1

These examples illustrate why EPA is committed to an adaptive approach on CCS generally, so that 

the Agency may identify and address additional information and respond, including via rulemaking, 

should that be necessary. EPA emphasizes that where additional information may increase 

protectiveness, streamline implementation, or otherwise inform the requirements for GS injection 

of CO2, EPA may need to evaluate whether changes are necessary. Thus, the Agency commits to 

reviewing, in a manner similar to the adaptive approach planned for the UIC Class VI rule, new 

research, data, and information related to today’s conditional exclusion.

In addition, EPA notes that the conditional exclusion as finalized is not as rigid as the comment 

suggests. For example, as described in section V.F. of the final rule preamble, the terms of the 

conditional exclusion would include CO2 streams generated from two or more independentlyproduced CO2 streams, provided that the conditions of the exclusion are met for all streams being 

for which it is claimed.

EPA acknowledges the commenter’s identification of other possible scenarios, but notes that the 

scope of this final conditional exclusion was developed to complement the UIC Class VI rulemaking, 

rules which were recently developed with geologic sequestration activities in mind. As EPA noted 

in the preamble to the proposed rule, this conditional exclusion is not intended to affect the 

regulatory status of CO2 streams that are injected into wells other than UIC Class VI wells, and EPA 

did not develop information for inclusion in the proposal on well classes other than UIC Class VI 

wells. 

Finally, EPA also notes that this conditional exclusion is voluntary, and generators are not obligated 

to make use of this conditional exclusion. For example, generators of non-hazardous waste CO2

streams are not subject to the RCRA subtitle C regulations, and they are not obligated to make use 

of this conditional exclusion (although they may still choose to do so in situations where, for 

example, the generator may be uncertain regarding the hazardous waste status of the CO2 stream). 

Even those generators who characterize their streams as RCRA hazardous waste may manage their 

streams as RCRA hazardous wastes from the point of generation. Finally, as noted in Response to 

Comment 3.2.2, EPA acknowledges that CO2 can and does have a variety of commercial and 

manufacturing uses. However, this does not affect the regulatory status of CO2 streams when they 

are to be injected into UIC Class VI wells for the purpose of GS. 

Comment 3.2.4:

Having declared that captured carbon dioxide emission streams are solid waste “when discarded”, 

EPA should not simply dismiss the potential use of such streams by UIC Class II enhanced 

production well operators [FN5: 76 Fed. Reg. at 48078, n. 16: “The proposed rule is not intended to 

affect the status of CO2 that is injected into wells other than UIC Class VI wells. 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.”] We know that the use of captured carbon dioxide emission streams as process inputs 

 

1

See Executive Summary, Report of the Interagency Task Force on Carbon Capture and Storage, August 2010.
30

for enhanced recovery will not be subject to the RCRA solid waste provisions because those 

materials are not being discarded, but we think EPA will not provide the intended “needed 

certainty” unless EPA states that the use of carbon dioxide streams for enhanced recovery does not 

subject those streams to RCRA now or in the future.

To understand the importance of providing this certainty, it is only necessary to consider the 

following potential scenarios:

*As noted, it is likely that once CCS becomes commercial, dedicated carbon dioxide interstate and 

intrastate commercial pipeline networks will accept carbon dioxide from both natural and 

anthropogenic sources for delivery to UIC Class II enhanced recovery operations.

*Some of these EOR operations will have begun years or decades before by receiving only naturally 

sources carbon dioxide streams and then will receive anthropogenic or mixed source streams.

*Other EOR projects will have already received anthropogenic carbon dioxide either alone or in 

combination with natural carbon dioxide.

*Some EOR operations can be expected to also operated co-located UIC Class VI wells for GS so 

that the project can receive constant streams of carbon dioxide from anthropogenic sources 

regardless of the quantities needed at any particular time exclusively for the EOR operations; any 

excess carbon dioxide received would be injected into the Class VI wells for GS.

*Some EOR operations may eventually transition to UIC Class VI GS operations under the UIC 

program and continue to operate inject carbon dioxide streams for GS.

*Some EOR operations may continue to operate as UIC Class II EOR projects and account for the 

mass of carbon dioxide sequestered in accordance with the provisions of 40 CFR Part 95, subpart 

RR.

*Still other EOR operations may cease operations as UIC Class II EOR projects while leaving in 

producing reservoirs substantial quantities of carbon dioxide (originally received from various 

natural and anthropogenic sources and then recycled through the EOR process for many years).

If EPA declares that captured gaseous carbon dioxide emission streams can be solid waste, then 

providing the necessary certainty will require a verification of the RCRA status of carbon dioxide 

streams under the full range of scenarios described in the preceding discussions. The producer who 

captures carbon dioxide emissions and compresses and then ships those supercritical carbon 

dioxide streams through pipelines in which those streams will be commingled with other streams 

before being delivered to the recipient(s) with whom that producer has contracts—and that 

producer’s investors, financiers, insurers, and other financial assurance providers—will need to 

know with certainty the circumstances, if any, under which those operations might be subject to 

RCRA solid and/or hazardous waste requirements.

Response: See response to comment 3.2.3. EPA did not have information to address these 

scenarios, such as information regarding the operation of extensive, shared CO2 pipeline networks, 

in terms of how CO2 streams might be distributed among different end users, or how separate CO2

streams might be accounted for, etc. EPA did not, therefore, attempt to address all scenarios, and 
31

EPA is committed to using an adaptive approach regarding CCS going forward.

As discussed, EPA did not develop information for inclusion in the proposal of well classes other 

than UIC Class VI wells. However, in the interest of public transparency and in light of the several 

public comments on this issue, EPA does note that (based on the limited information provided in 

the public comments), should CO2 be used for its intended purpose as it is injected into UIC Class II 

wells for the purpose of EOR/EGR, it is EPA’s expectation that such an injection process would not 

generally be a waste management activity. EPA would encourage persons to consult with the 

appropriate regulatory authority to address any fact-specific questions they may have regarding 

the status of CO2 in situations that are beyond the scope of this final rule.

Comment 3.2.5:

As we have noted, the best and—considering that Congress chose not to bring uncontained gases 

within the definition of solid waste—the only permissible approach would be to confirm that 

captured gaseous carbon dioxide emission streams are not solid waste. Failing that, EPA needs to 

consider and explain how its final action will affect the use of carbon dioxide streams under all of 

the likely scenarios described above. This could conceivably be done by confirming that the use of 

carbon dioxide streams for EOR and similar activities has not ever been subject to RCRA and then 

crafting an exclusion that fully addresses the circumstances under which carbon dioxide streams 

are managed and injected for GS.

Response: EPA disagrees with the commenter’s suggestion that CO2 streams sent to UIC Class VI

wells for purposes of GS are not solid waste, for reasons already explained in response to 

comments 3.2.1 and 3.2.2.

Regarding the commenter’s statement that EPA must explain how its final action will affect the use 

of CO2 streams under all of the scenarios described by the commenter, EPA refers to its responses 

to Comments 3.2.3 and 3.2.4. The commenter does describe one scenario that EPA points out is 

already covered by the UIC Class VI regulations at 40 CFR 144.19 – and EPA notes that nothing in 

the conditional exclusion would prevent a Class VI well that had previously transitioned from a 

Class II well from being eligible for the RCRA conditional exclusion. Otherwise, most of these 

scenarios do not yet exist, and many are clearly outside the scope of this rulemaking (because they 

deal with UIC Class II wells). With respect to the RCRA status of CO2 injected into a Class II well, EPA 

reiterates that this is beyond the scope of this final rule, and EPA did not develop information for 

inclusion in the proposal on well classes other than UIC Class VI wells. However, in the interest of 

public transparency and in light of the several public comments on this issue, EPA does note that 

(based on the limited information provided in the public comments), should CO2 be used for its 

intended purpose as it is injected into UIC Class II wells for the purpose of EOR/EGR, it is EPA’s 

expectation that such an injection process would not generally be a waste management activity.

EPA would encourage persons to consult with the appropriate regulatory authority to address any 

fact-specific questions they may have regarding the status of CO2 in situations that are beyond the 

scope of this final rule.

Again, as EPA has responded elsewhere to this commenter, these examples illustrate why EPA 

committed to an adaptive approach, so that the Agency may identify and address new information 

and respond, including via rulemaking should that be necessary.

Comment 3.2.6:
32

As explained in our detailed comments and as reflected in the scenarios described above, EPA’s 

proposed certification approach is unworkable because the producer of carbon dioxide streams will 

not always be able to state that its captured gaseous carbon dioxide emission streams are going 

exclusively to UIC Class VI wells. Instead, it should be sufficient for the producer to determine that 

the recipients with which the producer has contracted to take the carbon dioxide streams hold UIC 

permits for the underground injection of carbon dioxide.

Response: See responses to Comments 3.2.3 and 3.2.4. Under the conditions in this final 

rulemaking, if a generator decides to make use of the conditional exclusion, the excluded CO2

stream must be injected into a UIC Class VI well, which is the only class of UIC well EPA considered 

in its proposed conditional exclusion. EPA acknowledges that under the commenter’s scenarios, in 

particular where CO2 streams for which the conditional exclusion is being claimed are put into a 

CO2 pipeline that has the potential to deliver to both UIC Class II and UIC Class VI wells (a scenario 

that EPA notes does not exist at this time), a generator claiming the conditional exclusion might not 

be able to confirm with certainty that their CO2 stream was injected into a UIC Class VI well. 

However, this should not prevent EPA from proceeding with this final conditional exclusion rule, to 

provide certainty on near-term CCS projects by providing the option of a conditional exclusion 

specific to UIC Class VI well injection. Nonetheless, as EPA has responded elsewhere to this 

commenter, these examples illustrate why EPA committed to an adaptive approach, so that the 

Agency may identify and address new information and respond, including via rulemaking should 

that be necessary.

Comment 3.2.7:

Under EPA’s newly promulgated regulatory scheme, those UIC permits could be issued under Class 

I, Class II, Class V or Class VI. The assurances that EPA discusses in the preamble as being provided 

by the UIC Class VI program are provided as well by the other portions of the UIC program. In 

promulgating the final Class VI rule, EPA reviewed the operation of Class II EOR wells in comparison 

with Class VI wells and provided for the application of appropriate requirements, including 

requirements that govern the transition of Class II wells to Class VI wells as and when appropriate. 

EPA also considered and provided for the circumstances under which carbon dioxide streams could 

be injected into permitted Class I and Class V wells [FN6: 75 Fed. Reg. at 77234 (December 10, 

2010): “Today’s final rule provides minimum Federal requirements for the injection of CO2 to 

protect USDWs from endangerment as this key climate mitigation technology is developed and 

deployed. It clarifies requirements that apply to CO2 injection for GS, provides consistency in 

requirements across the US, and affords transparency about what requirements apply to owners or 

operators”]. As EPA stated in the preamble to the RCRA proposal, “[p]ursuant to § 1421(d)(2), the 

UIC program requirements for all well classes, promulgated under the authority of the [Safe 

Drinking Water Act], 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 

does not otherwise adversely affect the health of persons.” 76 Fed. Reg. at 48084 (emphasis 

added). Accordingly, EPA can conclude for all UIC classes “that the elimination of exposure routes 

through these requirements will ensure protection of human health and the environment” and that 

RCRA requirements would not “provide any substantial, additional protection for CO2 streams 

which . . . are disposed in UIC [Class II or] Class VI wells.” 76 Fed. Reg. 48085.

The development of CCS technologies and the completion of experiments to demonstrate the 

feasibility of GS in saline reservoirs stands at a critical point, and the future of these technologies is 

clouded by uncertainties—including primarily the lack of economic drivers. Nevertheless, progress 
33

can be made by completing the ongoing experiments involving GS in saline reservoirs as well as GS 

in combination with EOR. In addition, further development will be substantially aided by the 

incentives and opportunities provided for the anthropogenic production of carbon dioxide streams 

for EOR operations. Given the other uncertainties that hinder the progress of CCS and GS, EPA 

should avoid imposing new uncertainties that will undercut the use of anthropogenic carbon 

dioxide streams for EOR.

Response: EPA disagrees that it can conclude that the conditional exclusion should apply equally to 

CO2 streams to be injected into Class I, Class II, Class V and Class VI wells on the basis established by 

the commenter. While all classes of UIC wells are intended to protect USDWs from endangerment, 

EPA strongly emphasizes that the requirements for each UIC injection well class are designed to 

address the specific practices and unique risks to USDWs posed by each specific well class. Taken to 

its logical conclusion, the commenter’s reasoning would appear to eliminate the need for different 

well classes altogether. Instead, EPA developed the UIC Class VI requirements that are tailored to 

the unique aspects of carbon dioxide injection for GS (e.g., large CO2 injection volumes, the 

buoyant and mobile nature of the injectate, etc.); in turn, EPA developed its RCRA conditional 

exclusion based upon the condition that an owner or operator would inject the CO2 streams into a 

UIC Class VI well (among other conditions). EPA further explains its reasons for focusing on UIC 

Class VI wells in this rulemaking in response to comment 3.2.3. In the event that a Class II or Class 

V well transitions to a Class VI well pursuant to the requirements at 40 CFR 144.19, CO2 streams 

that are to be injected into the Class VI well may then be eligible for the RCRA conditional 

exclusion. Although outside the scope of this rulemaking, for the reader’s reference, EPA notes 

that a more detailed explanation of how existing classes of injection wells are affected by the 

promulgation of the new UIC Class VI requirements can be found in preamble to the final UIC Class 

VI rule (December 10, 2008 Federal Register; 75 FR at 77243-46).

Regarding the comment describing the conditional exclusion as imposing new uncertainties, EPA 

acknowledges the commenter’s concern regarding the uncertainties associated with CCS. EPA, 

through this rule, intends to address some of those uncertainties, specifically the uncertainty 

associated with managing these CO2 streams under RCRA subtitle C, for CO2 streams sent to a Class 

VI well for purposes of GS. 

Comment 3.2.8:

We have expressed serious concerns about the final geologic sequestration rules both separately in 

our comments on the proposed GS UIC and GHG reporting rules and in our comments on the draft 

guidance documents for the Class VI rule and together with other Multi-Stakeholder Discussion 

(MSD) participants in our letter to you on May 20, 2011. Nevertheless, if EPA adheres to its 

enunciated principles and implements the program consistent with its intended design and 

objectives, we believe that EPA’s final GS rules can provide a workable framework for the 

development and deployment of carbon capture and storage (CCS) as a key mitigation technology 

for achieving national greenhouse gas reduction goals while prevent endangerment of 

underground sources of drinking water (USDWs) and thereby protecting human health and the 

environment.

Response: Where these comments relate only to the UIC Class VI rulemaking and the greenhouse 

gas reporting rule, these comments are outside the scope of this rulemaking. If by “EPA’s final GS 

rules” the commenter is referring to this RCRA conditional exclusion, EPA acknowledges the 

commenter’s support for CCS.
34

Comment 3.2.9:

The Carbon Sequestration Council enthusiastically supports the following statement that EPA 

presented in the preamble to this RCRA proposal:

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. 76 Fed. Reg. at 48077.

This letter and the attached detailed comments present our ideas and recommendations for 

achieving this objective through the current proposed rulemaking, and we have provided additional 

comments and recommendations for achieving this important goal through the other “[t]wo 

important EPA rulemakings that directly address GS activities”—namely the GS UIC rule and the 

greenhouse gas reporting rule for injection of carbon dioxide. We have strived and stand ready to 

work with EPA and the other stakeholders interested in these rules to achieve this announced goal 

while prevent endangerment of underground sources of drinking water and protecting human 

health and the environment.

Thank you for the opportunity to comment on the RCRA GS proposal. If you have any questions or 

need any additional information about these comments, please contact me at (see docket for 

contact information).

Response: EPA agrees with the commenter that regulatory certainty is important to facilitate 

future deployment of CCS. To the extent these comments relate only to the UIC Class VI 

rulemaking and the greenhouse gas reporting rule, these comments are outside the scope of this 

rulemaking.

The remaining comments in this section (Section 3.2) were presented by the commenter in table 

format (Table 1, see Docket ID: EPA-HQ-RCRA-2010-0695-0084) and begin with a page number 

citation from the Federal Register proposed rule, followed by a line space and then the

commenter’s specific comment(s) to EPA.

Comment 3.2.10:

EPA NPRM Statements pg 48077

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

solid waste...

The Environmental Protection Agency (EPA) should not determine that a supercritical stream of 

captured gaseous carbon dioxide emissions is a solid waste. Instead, EPA should state in the final

notice that such streams are not solid waste. 

The determination that carbon dioxide (CO2) streams are solid waste is not supportable because 

captured CO2 streams are gaseous emission streams that are not subject to EPA’s authority under 

the Resource Conservation and Recovery Act (RCRA), RCRA §1004(27), 42 U.S.C. §6903(27). The 
35

decision not to include uncontained gases within RCRA section 1004(27) was made by Congress 

when it enacted RCRA. As noted in the preamble with respect to the streams at issue here, “CO2 is 

first captured from fossil-fueled power plants or other emission sources.” 75 Fed. Reg. 77230, 

77233 (December 10, 2010) (emphasis added). In 1982, EPA noted with respect to “fume 

incinerators” that “[f]ume incinerators which are used to destroy gaseous emissions from various 

industrial processes, for example, are not subject to regulation under RCRA.” 47 Fed. Reg. 27520, 

27530 (June 24, 1982). Clarifying, EPA went on to state: “In general, the RCRA standards do not 

apply to fume incinerators since the input is not identifiable as a solid waste, according to the 

definition set forth in § 261.2.” 47 Fed. Reg. at 27530. The point is that “gaseous emissions” do not 

constitute solid waste under RCRA. 

EPA reiterated and elucidated this point in 1987 in conjunction with its “listing of two generic 

categories of wastes generated during the manufacture of chlorinated aliphatic hydrocarbons as 

hazardous wastes”. 54 Fed. Reg. 50968 (December 11, 1989). In the preamble to the final rule, EPA 

explained that “[t]he proposed listing included light ends, spent filter and filter aids, and desiccant 

wastes (49 FR 5313-5315).” 54 Fed. Reg. at 50969. But the final rule did not include all of the “light 

ends” covered by the proposal. Instead, “[t]he category of light ends [was] narrowed in scope in 

this final rule to include only those light ends that have been condensed.” 54 Fed. Reg. at 50969 

(emphasis added). In explaining the reason for this change, EPA noted that “[s]everal commenters 

objected strongly to the Agency's proposal to list light ends which are in the gaseous state” even 

though these were “condensable by currently feasible technology to liquids at ambient 

temperature and pressure.” 54 Fed. Reg. at 50972. EPA elaborated, saying: “Several commenters 

stated that the Agency does not have authority under RCRA to regulate gaseous process emissions, 

since these are not solid wastes (i.e., they are not ‘contained gaseous material’) as stated in the 

definition of solid waste. See RCRA section 1004(27).” In the end, EPA concluded as follows: 

“Upon reconsideration of this issue (with the benefit of the comments received on the proposed 

rulemaking), EPA now believes our authority to identify or list a waste as hazardous under RCRA is 

limited to containerized or condensed gases (i.e., section 1004(27) of RCRA excludes all other gases 

from the definition of solid wastes and thus cannot be considered hazardous wastes).” 54 Fed. Reg. 

at 50973 (emphasis added). 

Thus, EPA did not follow through on its “proposal to list light ends which are in the gaseous state 

but condensable by currently feasible technology to liquids at ambient temperature and pressure” 

and only listed light ends actually condensed into liquid form. As noted by EPA, supercritical CO2

streams are not in liquid form. “EPA . . . decided not to regulate these uncondensed light ends.” 54 

Fed. Reg. at 50973.

Response: EPA disagrees that CO2 streams sent to UIC Class VI wells for purposes of GS are not 

solid waste. As EPA noted in the proposed rule, the CO2 streams are delivered by pipeline and 

injected into UIC Class VI wells for GS in a supercritical state, which EPA stated at proposal was 

“...rather unique in that it has properties intermediate between a liquid and a gas.” 76 FR at 48078.

The scientific term used to describe or define this supercritical state (i.e., when a substance is at or 

above its critical temperature and critical pressure) is as a “supercritical fluid.” The RCRA statutory 

definition of solid waste specifically refers to “other discarded material, including solid, liquid, 

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

agricultural operations, and from community activities . . .” While EPA has indeed interpreted the 

meaning of specific terms listed, including “contained gaseous material,” the RCRA definition of 
36

solid waste encompasses “other discarded material” and does not speak to materials such as 

supercritical fluids. Like the listed “solid, liquid, semisolid, or contained gaseous material” 

specifically referenced, CO2 streams sequestered for purposes of GS are “other discarded material” 

from industrial and commercial operations and, therefore, are of a similar kind to the other types 

of wastes specifically referenced by the definition. They are, therefore, RCRA statutory solid 

wastes.

Comment 3.2.11:

EPA NPRM Statements pg 48077-78

A supercritical 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.16 This clearly applies to supercritical CO2 stream 

(which, as already stated, is rather unique in that it has properties intermediate between a liquid 

and a gas) injected into UIC Class VI wells, regardless of whether the material is a hazardous waste 

or not.

EPA cannot universally consider captured CO2 gaseous emission streams to be discarded when sent 

for either geologic sequestration (GS) or for use in enhanced oil recovery (EOR) of hydrocarbons. 

CO2 is a commodity and is used as a process input for EOR projects. It is used to pressure up the 

target hydrocarbon reservoir and/or to reduce the miscibility of the hydrocarbons themselves to 

enhance recovery through the production wells. In addition, CO2 that is injected for long-term 

storage in saline reservoirs is also susceptible to future production. Moreover, CO2 storage in 

underground reservoirs is done with a definitive and beneficial purpose: to keep it from increasing 

atmospheric concentrations of CO2, incurring very high costs in the process – with commensurate 

benefits in mind. This is contrary to the plain meaning of the phrase discarded material. CO2 that is 

used for EOR and CO2 used for other industrial uses (such as freezing food/ carbonating beverages) 

and CO2 sequestered underground are indistinguishable from a producer’s standpoint. Therefore 

all CO2 should be treated the same. That is, CO2 is not “solid waste” and also not “hazardous” 

exhibiting none of the toxicity characteristics. Other uses of CO2 will also emerge from the 

numerous development efforts currently underway. Some of these efforts are detailed by the 

Department of Energy (DOE) with respect to its CO2 Use and Reuse research and development 

program:

“CO2 use and reuse efforts focus on pathways and novel approaches for reducing CO2 emissions by 

developing beneficial uses for the CO2, such as the conversion of CO2 to useable products and fuels, 

and other breakthrough concepts that will mitigate CO2 emissions in areas where geologic storage 

may not be an optimal solution. Applicable approaches include:

*“Use CO2 as one of the feedstocks to produce chemicals (including fuels and polymers) and find 

applications for the end products. 

*“Non-Geologic Storage of CO2 – Use CO2 from an effluent stream to immobilize the CO2

permanently by producing stable solid material that are either useful products with economic value 

or a low cost produced material. This approach could be viewed as an effective carbon storage 

method. 

*“Indirect Storage – Promote indirect carbon storage by removing CO2 in the air (such as enhanced 
37

photosynthesis) or by enhancing carbon intakes in terrestrial vegetations and soils. 

*“Beneficial Use of Produced Water – for produced water from CO2 storage in saline formations, 

develop novel methods to use CO2 to react with metallic ions to form less soluble carbonates that 

can be removed – and then find useful applications for the desalinated water. 

*“Breakthrough Concepts – Develop novel applications of CO2 that would limit its emissions into 

the air and novel approaches using microbes that consume CO2 and other materials to produce 

useful products or fuels. 

“Processes or concepts that undertake this CO2 reduction must take into account the life cycle of 

the processes to ensure that additional CO2 is not produced beyond what is already being removed 

from or going into the atmosphere. Several other challenges exist in using/reusing CO2. One 

involves determining how best to tap energy sources, since turning CO2 into fuels and chemicals 

would require energy input. In photosynthesis, solar energy is the obvious energy source. However, 

for solar applications as well as other approaches such as chemical processes or the use of 

microbes, consideration has to be given as to how best to tap solar or other energy sources. 

Another challenge is to find new reaction paths, including new catalysts and enzymes. This is 

important for many approaches in using CO2 to make new products, such as polymers. For some of 

these reactions, especially those involved in biological systems, the rate of reactions need to be 

improved.”[FN1: http://www.fossil.energy.gov/programs/sequestration/CO2_Use_and_Reuse.html 

(accessed on October 7, 2011)].

Response: See responses to Comments 3.2.2, 3.2.3 and 3.2.4. EPA is not addressing the status of 

all CO2 streams in this rulemaking. As stated above, EPA acknowledges that CO2 is used for EOR and 

does not disagree that CO2 can and does have a variety of commercial and manufacturing uses 

(e.g., urea yield boosting, enhanced oil recovery, food processing and packaging, beverage 

carbonation, and wine making). However, these activities are beyond the scope of this final rule

and do not affect the regulatory status of CO2 streams when they are to be injected into UIC Class 

VI wells for the purpose of GS.

The commenter is incorrect that the meaning of “discarded material” is contrary to the fact that 

there are benefits and costs to discarding material, including the sequestration of CO2 streams 

underground. That there may be benefits and costs does not change the fact that fundamentally, a 

decision to discard is being made when a CO2 stream is sent to a UIC Class VI well for geologic 

sequestration purposes, with the express purpose of isolating the CO2 so that it does not return to 

the atmosphere. That decision to discard brings the CO2 stream within the RCRA definition of solid 

waste.EPA acknowledges the commenter’s references to various DOE research projects related to reuse 

of CO2.

Comment 3.2.12:

EPA NPRM Statements pg 48078

[fn 16 The proposed rule is not intended to affect the status of CO2 that is injected into wells other 

than UIC Class VI wells. 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.]

EPA should not simply dismiss the use of CO2 for EOR/EGR with a footnote. It is important for EPA 
38

to clarify the status of captured CO2 emission streams in every context in which such streams might 

be used because the same streams may be used for multiple purposes and sent to diverse 

operations. Although it is probably not possible at this point to indicate exactly how all of the 

potential carbon capture, utilization and storage processes will ultimately evolve and work 

together, there are anticipated scenarios that would create complications for the proposed RCRA 

exclusion. It cannot be presumed that a single CO2 emission source will capture its CO2 stream and 

send it through a dedicated pipeline to a single injection well operator with a Class VI permitted GS 

project. It is anticipated that some operators of facilities that capture CO2 emission streams will 

send those streams to multiple operations, some of which may be GS operations while others will 

be using the CO2 stream for ER and still other recipients may be using the CO2 to produce various 

products. It is also anticipated that some producers of CO2 streams will be connecting into a 

common carrier CO2 pipeline where the streams will become commingled with other CO2 streams 

from various producers. In the near term, most of the recipients of the CO2 will likely either be EOR 

operations or GS operations, but eventually other uses of CO2 may emerge.

Response: See responses to Comments 3.2.3 and 3.2.4. 

EPA agrees that it is not possible at this point to know how all of the potential carbon capture, 

utilization, and storage processes will ultimately evolve and work together. EPA is committed to an 

adaptive approach on CCS generally, so that the Agency may identify and address additional 

information and respond, including via rulemaking, should that be necessary. EPA emphasizes that 

where additional information may increase protectiveness, streamline implementation, or 

otherwise inform the requirements for GS injection of CO2, EPA may need to evaluate whether 

changes are necessary. 

Comment 3.2.13:

EPA NPRM Statements pg 48078

[fn 16 The proposed rule is not intended to affect the status of CO2 that is injected into wells other 

than UIC Class VI wells. 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.]

It is also expected that some CO2 recipient projects will have both EOR Class II injection wells 

completed in oil and gas reservoirs into which CO2 is injected for EOR and Class VI GS wells 

completed in saline reservoirs that will be used for storage. In that case, the supplier of the CO2 is 

not likely to have much control over whether any particular CO2 stream or portion thereof is 

directed to Class II wells or Class VI wells or divided between them.

Response: See responses to Comments 3.2.3 and 3.2.4. Under the conditions in this final 

rulemaking, if a generator decides to make use of the conditional exclusion, the excluded CO2 

stream must be injected into a UIC Class VI well, which is the only class of UIC well EPA considered 

in its proposed conditional exclusion. EPA acknowledges that under the commenter’s hypothetical 

scenarios, in particular where CO2 streams for which the conditional exclusion is being claimed are 

put into a CO2 pipeline that has the potential to deliver to both UIC Class II and UIC Class VI wells (a 

scenario that EPA notes does not exist at this time), a generator claiming the conditional exclusion 

might not be able to confirm with certainty that their CO2 stream was injected into a UIC Class VI 
39

well. However, this should not prevent EPA from proceeding with this final conditional exclusion 

rule, which provides the option of a conditional exclusion specific to UIC Class VI well injection, and 

as EPA has responded elsewhere to this commenter, these examples illustrate why EPA is 

committed to an adaptive approach on CCS generally, so that the Agency may identify and address 

additional information and respond, including via rulemaking, should that be necessary. EPA 

emphasizes that where additional information may increase protectiveness, streamline 

implementation, or otherwise inform the requirements for GS injection of CO2, EPA may need to 

evaluate whether changes are necessary.

Comment 3.2.14:

EPA NPRM Statements pg 48078

[fn 16 The proposed rule is not intended to affect the status of CO2 that is injected into wells other 

than UIC Class VI wells. 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.]

To address the full range of utilization for captured CO2 emission streams, EPA should discuss the 

status of all CO2 streams to clarify whether those CO2 streams sent to EOR are subject to RCRA. 

These CO2 streams should not be subject to RCRA for the same reason that the streams are 

captured gaseous emissions and therefore cannot be solid waste. In addition, the CO2 used for 

enhanced recovery of any kind (ER) is a process input. The CO2 is used both to reduce the miscibility 

of the targeted hydrocarbons and to pressure up the reservoir. Furthermore, CO2 streams used for 

ER are not discarded, and this is certainly true for as long as the production field is in operation. 

(Captured CO2 streams used for food grade beverage carbonation and other purposes is also not 

discarded.)

Response: See responses to Comments 3.2.1, 3.2.3 and 3.2.4. . 

Comment 3.2.15:

EPA NPRM Statements pg 48078

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.

It will not be feasible for this determination to be made if a producer of a CO2 stream cannot apply 

any of the established tests or criteria for making the determination. For example, existing toxicity 

criteria are not directly applicable to concentrations that would be present in gaseous emissions. If 

EPA expects to require producers to make assessments and determinations of toxicity for gaseous 

emission streams of CO2, the Agency will need to develop an entire set of toxicity criteria at least 

for all of the constituents that might be present in CO2 streams. That might conceivably be done by 

reassessing each current toxicity criterion for each such constituent, but it would not be 

appropriate to simply presume that toxicity criteria based on ground water releases from landfills 

would also be applicable to gaseous emissions.

Response: The Agency recognizes that there are potential questions associated with applying the 

RCRA definition of hazardous waste to sequestered CO2 streams. EPA does not apply any significant 

technical limitations on sampling and analyzing a CO2 stream, even if it has been compressed to 
40

supercritical stage. Generators can conduct analyses to characterize the physical and chemical 

properties of their CO2 streams, e.g., whether the CO2 contains certain impurities, what the 

concentrations of the impurities are, and whether the CO2 stream may be corrosive, or apply their 

knowledge of the hazard characteristic of a waste, in light of the materials or processes used in 

order to determine whether a waste exhibits a RCRA characteristic. 

Comment 3.2.16:

EPA NPRM Statements pg 48078

EPA studied the fossil fuel combustion wastes as directed by Congress, and published two Reports to 

Congress, [17] 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.

It is not a mystery as to why CO2 was not considered by these studies. CO2 was not even a 

regulated air pollutant at the time of these studies. See EPA’s endangerment decision: 

“Under the Clean Air Act EPA is responsible for addressing air pollutants from motor vehicles. On 

April 2, 2007, the U.S. Supreme Court issued its opinion in Massachusetts v. EPA,12 a case involving 

a 2003 order of the Environmental Protection Agency (EPA) denying a petition for rulemaking to 

regulate greenhouse gas emissions from motor vehicles under section 202(a) of the Clean Air Act 

(CAA).13 The Court held that greenhouse gases were air pollutants for purposes of the Clean Air 

Act and further held that the Administrator must determine whether or not emissions from new 

motor vehicles cause or contribute to air pollution which may reasonably be anticipated to

endanger public health or welfare, or whether the science is too uncertain to make a reasoned 

decision. The Court further ruled that, in making these decisions, the EPA Administrator is required 

to follow the language of section 202(a) of the CAA. The Court rejected the argument that EPA 

cannot regulate CO2 from motor vehicles because to do so would de facto tighten fuel economy 

standards, authority over which has been assigned by Congress to DOT. The Court stated that 

‘‘[b]ut that DOT sets mileage standards in no way licenses EPA to shirk its environmental 

responsibilities. EPA has been charged with protecting the public‘s ‘health’ and ‘welfare’, a 

statutory obligation wholly independent of DOT’s mandate to promote energy efficiency.’’ The 

Court concluded that ‘‘[t]he two obligations may overlap, but there is no reason to think the two 

agencies cannot both administer their obligations and yet avoid inconsistency.’’ The Court 

remanded the case back to the Agency for reconsideration in light of its findings.”[FN2: Proposed 

Rulemaking To Establish Light-Duty Vehicle Greenhouse Gas Emission Standards and Corporate 

Average Fuel Economy Standards; Proposed Rule, 74 Fed. Reg. 49454, 49459 (September 28, 

2009).] 

In response to this decision, EPA has stated that “the Administrator exercised her judgement, 

based on an exhaustive review and analysis of the science, to conclude that ‘‘six greenhouse gases 

taken in combination endanger both the public health and the public welfare of current and future 

generations.’’ 74 FR 66496. The Administrator also found ‘‘that the combined emissions of these 

greenhouse gases from new motor vehicles and new motor vehicle engines contribute to the 

greenhouse gas air pollution that endangers public health and welfare under CAA section 202(a).’’ 

Id.[FN3: ‘‘Endangerment and Cause or Contribute Findings for Greenhouse Gases Under Section 

202(a) of the Clean Air Act.’’ 74 FR 66496 (December 15, 2009)] 
41

Prior to these developments, there would have been no reason for EPA to include CO2 captured for 

purposes of GS in either of its Regulatory Determinations on the management and use of coal and 

other fossil fuel combustion products, or in the underlying studies upon which those 

determinations were based.

Response: The exemption at 40 CFR 261.4(b)(4) does not apply to CO2 streams captured for 

purposes of GS, for the reasons given in the proposed rule preamble (76 FR at 48078), irrespective 

of why CO2 streams were not included in either of Regulatory Determinations related to wastes 

from the combustion of coal and fossil fuel.

Comment 3.2.17:

EPA NPRM Statements pg 48078

[fn 18] 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.

Notwithstanding the notation in footnote 18, it remains true that the Bevill exemption does apply 

to CO2 generated from the combustion of materials in boilers to generate steam for the purpose of 

generating energy. The assertion that some other CO2 streams might not be subject to the same 

exemption does not deprive the Bevill exemption of its validity as to those CO2 streams that clearly 

come within the ambit of that exemption. This provides yet another justification for excluding all 

captured gaseous emission streams of CO2. Given that some of these streams will be exempt 

anyway, it makes good sense to exclude all of the streams ab initio as not constituting solid wastes. 

EPA must at least recognize and reaffirm that CO2 streams from the combustion of fossil fuels are 

exempt from regulation as hazardous waste under § 261.4(b)(4).

Response: See response to comment 3.2.16.

Comment 3.2.18:

EPA NPRM Statements pg 48078

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 statement might conceivably raise potentially serious implications about CO2 streams used for 

EOR because CO2 will remain in the previously producing oil and gas formations when production is 

completed and the filed operator plugs and abandons all of the production and injection wells. 

Because the CO2 streams used as process input for EOR operations are not discarded and not solid 

waste, there should never be any question about the status of CO2 that remains contained in an oil 

and gas reservoir following plugging and abandonment of the production and injection wells for 

those operations. But EPA has not addressed the status of CO2 used for EOR. EPA should clarify that 

these streams would not ever be considered solid and hazardous waste either during EOR 

operations or after the close of those production operations. It is important for the producers of 

CO2 streams used for EOR to know that those streams will not be subjected to RCRA requirements 
42

at any time, including after EOR operations are completed. If CO2 streams sent to Class VI wells are 

excluded as proposed, these streams used for EOR and remaining contained in oil and gas 

reservoirs should also be addressed in EPA’s final action. Again, we urge EPA to conclude that none 

of these captured gaseous emission streams constitute solid waste. 

Placing this issue in another context, it is quite possible that an EOR operator will receive captured 

gaseous emission CO2 streams to use for EOR for a period of time, after which the operator will 

decide to convert that project from being primarily an EOR operation to become primarily a GS 

operation, transitioning the injection wells from Class II to Class VI and then continue to operate for 

many years as a GS operation. At the close of that operation, there should not be any question as 

to whether the CO2 streams used for EOR prior to conversion should be viewed any differently from 

the CO2 streams injected through many of the same wells following their conversion to Class VI. 

Uncertainties about how CO2 streams used for EOR will be treated under RCRA will have a chilling 

effect on the willingness of both CO2 producers and EOR operators to use captured gaseous 

emission streams for EOR. Instead, the overall program for the regulation of carbon capture, 

utilization and storage of CO2 emission streams should be encouraging and fostering the use and 

sequestration of those streams.

Response: As EPA noted in the preamble to the proposed rule, this conditional exclusion is not 

intended to affect the regulatory status of CO2 streams that are injected into wells other than UIC 

Class VI wells. EPA reiterates that these issues are beyond the scope of this final rule, and EPA did 

not develop information for inclusion in the proposal on well classes other than UIC Class VI wells. 

However, in the interest of public transparency and in light of the several public comments on this 

issue, EPA does note that (based on the limited information provided in the public comments) 

should CO2 be used for its intended purpose as it is injected into UIC Class II wells for the purpose of 

EOR/EGR, it is EPA’s expectation that such an injection process would not generally be a waste 

management activity. EPA would encourage persons to consult with the appropriate regulatory 

authority to address any fact-specific questions they may have regarding the status of CO2 in 

situations that are beyond the scope of this final rule.

 

Comment 3.2.19:

EPA NPRM Statements pg 48078

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. 40 CFR 262.11(c)(2). 

[fn 21 Any persons claiming that a waste is nonhazardous, based on knowledge in lieu of testing, 

should be prepared to substantiate this claim.] . . . EPA acknowledges the commenters’ underlying 

concerns related to RCRA characterization, and requests comment on this issue. 

EPA acknowledges that CO2 streams cannot be tested by any existing test to determine whether 

those streams – even if a solid waste – are hazardous. How is the capturer of a CO2 stream 

supposed to make this assessment if the existing tests cannot be used? If a CO2 producer were 

required to classify a material based on “knowledge” rather than testing, what standard can be 

used to substantiate this claim? How then can any claim be deemed valid or not in the absence of 

applicable criteria? This is particularly pertinent because CO2 is something we breathe day in and 

out without adverse effects, and we place large quantities of it in massively consumed beverages 

and other food products.
43

These streams are not going to demonstrate the characteristic of ignitability or reactivity. Captured 

gaseous CO2 streams will not meet either of the criteria set forth in section 261.22(a) of 40 CFR. 

Moreover, pipeline operators will not accept a CO2 stream that would prove corrosive to the 

pipelines used to transport these streams to either EOR or GS operators. Consequently, these 

streams could only potentially be considered to exhibit a toxicity characteristic. But captured 

gaseous CO2 emission streams cannot be tested with the Toxicity Characteristic Leaching 

Procedure, test Method 1311 in ‘‘Test Methods for Evaluating Solid Waste, Physical/Chemical 

Methods,’’ EPA Publication SW–846 as contemplated by section 261.24(a). Accordingly, the 

producers of CO2 streams are left by EPA to determine whether a CO2 stream is toxic – presumably 

by assessing whether the gaseous CO2 emission stream contains any of the forty section 261.24(b) 

contaminants at concentrations greater than those listed in that subsection. Nor are those 

concentration levels directly applicable to supercritical CO2 streams. EPA cannot expect CO2

producers to be able to do that without providing more detailed instructions on how that 

determination should be made. Again, we recommend that EPA dispense with the need for 

developing any such instructions by concluding that captured gaseous CO2 emission streams do not 

constitute solid waste.

Response: EPA appreciates these commenters’ concerns regarding the application of the 

hazardous waste regulations to supercritical CO2 streams being sequestered. EPA believes these 

concerns exist as a result of the unique circumstances associated with addressing the applicability 

of RCRA to CCS at such an early stage in the development of CCS. However, it is important to note 

that EPA did not set out in this rulemaking to conclude that those supercritical CO2 streams that are 

solid wastes would, as a class, exhibit a RCRA characteristic. Indeed, EPA indicated in the proposed 

rule that it could not unequivocally conclude that supercritical CO2 streams will never exhibit any 

RCRA hazardous waste characteristic and commenters provided no information to the contrary. 

Alternatively, EPA acknowledges that some RCRA hazardous characteristics are unlikely to apply to 

a waste composed of >90% CO2, such as ignitability (i.e., RCRA Waste Code D001). EPA 

acknowledges that additional guidance in determining when supercritical CO2 streams would be 

defined as hazardous under the Toxicity Characteristic may be useful, however EPA also notes that 

in light of the early state of data development in this area, EPA intends to bring additional clarity to 

the regulatory regime through this rule, by establishing a conditional exclusion from the definition 

of hazardous waste that would apply in the event a generator determines that its CO2 streams 

exhibit a RCRA hazardous characteristic, or, where a generator chooses to comply with the 

conditional exclusion as a precautionary matter, if they are unsure of the hazardous waste status of 

their CO2 stream. See also Responses to Comments 3.2.21 and 3.17.11.

With respect to the comment that EPA should conclude that captured gaseous CO2 emission 

streams do not constitute solid waste, see Response to Comment 3.2.2.

Comment 3.2.20:

EPA NPRM Statements pg 48079

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. The permit-issuing authority is also authorized under 

EPA’s UIC permit regulations to add any additional conditions to the permit, as necessary, to assure 

compliance with applicable SDWA requirements (40 CFR 146.52(b)). Under this authority, the UIC 
44

Program Director (EPA or a State permitting authority) may add specific testing or chemical/waste 

limitations to the permit to prevent endangerment of USDWs, or to assure that unauthorized 

wastes are not injected with the CO2 stream. 

It is certainly true that any further regulation of CO2 streams is completely unnecessary because the 

UIC regulations for all classes of wells that might receive CO2 streams provide for all of the 

necessary regulation. EPA has promulgated a comprehensive UIC program that addresses CO2

injected for EOR as well as GS. Because of the comprehensive scope of the UIC program, EPA’s 

RCRA requirements—to the extent that any exclusion is adopted—should provide an exclusion for 

any CO2 stream sent to any well that holds a valid UIC permit to inject CO2. That should be 

sufficient to provide that the recipient is covered within the UIC program, and EPA can rely on the 

UIC program Directors to enforce the applicable requirements to assure proper injection of those 

streams without trying to impose enforcement responsibilities on the CO2 producer. EPA need not 

add all of the CO2 stream producers to the enforcement personnel in the UIC program, thereby 

imposing on those producers all of the burdens and costs of UIC program implementation meant to 

be shouldered by the respective UIC program Directors and their agencies.

Response: See responses to Comments 3.2.7, 3.2.24 and 3.2.44.

Comment 3.2.21:

EPA NPRM Statements pg 48079

These non- CO2 constituents may include, but are not limited to, sulfur dioxide (SO2), hydrogen 

sulfide (H2S), nitrous oxides (NOX), carbon monoxide (CO), methane (CH4), other hydrocarbons, 

water vapor (H2O), as well as certain contaminants, that are also defined as hazardous 

contaminants in 40 CFR 261.24, such as arsenic, mercury, and selenium. 

The presence of “sulfur dioxide (SO2), hydrogen sulfide (H2S), nitrous oxides (NOX), carbon 

monoxide (CO), methane (CH4), other hydrocarbons, or water vapor (H2O)” will not render a CO2

stream hazardous for exhibiting the toxicity characteristic. Only the “hazardous contaminants in 40 

CFR 261.24, such as arsenic, mercury, and selenium” could do that, but it is not clear how CO2

producers should be assessing their captured gaseous emission streams for the presence of these 

contaminants.

Response: See response to 3.2.19. Also, the preamble language from the proposed rule cited by 

the commenter was part of a discussion on how the Agency expects to obtain additional data on 

CO2 streams, and was intended to describe the kinds of constituents that might be measured or 

identified as part of the UIC Class VI requirement to characterize CO2 streams, which would include 

constituents that are not part of the Toxicity Characteristic (as the commenter points out) as well 

as constituents that are. The point EPA was making was that these data will allow EPA to gain a 

better understanding of the nature and characteristics of captured CO2 streams generally, and not 

solely in the context of the Toxicity Characteristic. The Agency recognizes that there are potential 

questions associated with applying the RCRA definition of hazardous waste to sequestered CO2

streams. Generators can conduct analyses to characterize the physical and chemical properties of 

their CO2 streams, e.g., whether the CO2 contains certain impurities, and what the concentrations 

of the impuries are, or apply their knowledge of the hazard characteristic of a waste, in light of the 

materials or processes used in order to determine whether a waste exhibits a RCRA characteristic. 

Comment 3.2.22:
45

EPA NPRM Statements pg 48079

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.

Some of this type of information is provided in the IOGCC report on carbon dioxide pipelines. 

IOGCC, A Policy, Legal, and Regulatory Evaluation of the Feasibility of a National Pipeline 

Infrastructure for the Transport and Storage of Carbon Dioxide 21, Table 4 – “CO2 Stream 

Compositions from Various Processes” (September 2010) (Attachment A). We understand that 

American Electric Power (AEP) intends to submit data from its Mountaineer project [FN4: 

http://www.aep.com/environmental/climatechange/carboncapture/ (accessed on October 6, 

2011)] that has already been submitted to the West Virginia Department of Environmental 

Protection (DEP) and that Southern Company intends to submit data from its Plant Barry capture 

process..

Response: EPA thanks the commenter for its response.

Comment 3.2.23:

EPA NPRM Statements pg 48079

The Agency believes that this amendment to the RCRA hazardous waste rules, if finalized, will 

substantially reduce the uncertainty associated with defining and managing these CO2 streams 

under RCRA subtitle C.

That is not true because EPA does not address the situation where a CO2 stream is captured and 

sent for either EOR or GS. Moreover, EPA has proposed an illusory exclusion because the least

noncompliance with the DOT transportation requirements or the Class VI requirements could result 

not only in a violation of those regulatory provisions but also in a potential transformation of the 

CO2 stream into a hazardous waste by negating its exclusion.

Response: EPA disagrees with the commenter. Regarding the comment about CO2 streams “...sent 

for either EOR or GS...” EPA refers to its responses to Comments 3.2.3 and 3.2.4. 

Regarding the comment about loss of the conditional exclusion, EPA refers to its response to 

comments 3.2.24, 3.2.35, and 3.2.44.

Comment 3.2.24:

EPA NPRM Statements pg 48079

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.

It does not present a substantial risk, but the requirements for compliance impose a virtual 

impossibility. As described by the DC Circuit in its decision in Assn. of Battery Recyclers, Inc. v. EPA, 

208 F.3d 1047, (D.C. Cir. 2000), the proposed provision “describes what is not a solid waste, unless 

it complies with the other provision. But the other provision . . . is an exclusion, and the 

consequence of not complying with the provision is, of course, loss of exclusion. In other words, 

read together, the provisions seem to say that something is not a solid waste unless it is not 

excluded from being a solid waste. Lewis Carroll would be proud.” 208 F. 3d at 1051.
46

Response: EPA notes that the comment does not provide a basis for its conclusion that “the 

requirements for compliance impose a virtual impossibility.” EPA believes that it is possible for 

generators and UIC Class VI well owners or operators to comply with the conditions of the 

conditional exclusion. The conditions EPA is establishing for this conditional exclusion largely 

follow existing requirements with which persons must already comply – compliance with DOT 

provisions, and injection into UIC Class VI wells in compliance with UIC Class VI requirements 

(including a prohibition on mixing CO2 streams with hazardous waste). 

Comment 3.2.25:

EPA NPRM Statements pg 48082

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.

Storage of CO2 before injection is extremely unlikely given the large volumes we are talking about 

(multiple millions of tons per year for commercial operations). Temporary on site storage of such 

volumes is impractical. For example, the AEP Mountaineer project did not store CO2 after capture. 

It was either injected or sent back to the stack. The plans for the 235 MW scale-up of that project 

also did not include an option for storage of CO2 before injection.

Response: This comment (along with several others) supports EPA’s conclusion in the proposed 

rule (see 76 FR at 48081-82) that storage would not be expected to occur prior to delivery to a UIC 

Class VI facility, because storage would be technically infeasible.

Comment 3.2.26:

EPA NPRM Statements pg 48082

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. 

As further explained by IOGCC: “The federal Pipeline Safety Reauthorization Act of 1988 included a 

provision to regulate the safety of CO2 pipelines. Pipelines that both ‘start and stop’ within a state 

boundary are considered intrastate and would be regulated by the state authority if that authority 

has adopted regulations that are at least as stringent as the applicable federal safety regulations. 

Pipelines traversing more than one state are interstate pipelines and their safety is regulated by the 

Federal Pipeline and Hazardous Materials Safety Administration (PHMSA) within the DOT. PHMSA 

also would regulate those intrastate facilities within a state that has not adopted regulations as 

stringent as federal safety regulations.” IOGCC, A Policy, Legal, and Regulatory Evaluation of the 

Feasibility of a National Pipeline Infrastructure for the Transport and Storage of Carbon Dioxide 24 

(September 2010) (citations omitted) (Attachment A).

Response: EPA consulted with DOT and confirmed that with respect to the DOT regulations in 49 

CFR Part 195 (which apply to pipeline facilities used in the transportation of hazardous liquids or 

supercritical CO2), while some states have adopted regulations that apply to the transportation of 

supercritical CO2 and are certified by DOT to directly regulate these intrastate pipelines, many 

states do not have such a certification, and DOT remains the direct regulator of both interstate and 

intrastate pipelines in those states. EPA notes that state pipeline regulations are required to be at 
47

least as stringent as the federal DOT requirements; therefore, compliance with either the 

applicable DOT regulations or the applicable certified state regulations has the same effect under 

the proposed conditional exclusion. Because the proposed condition at §261.4(h)(1) only referred 

to compliance with applicable DOT regulations, EPA decided to modify the wording of the condition 

to add language that also refers to compliance with “pipeline safety regulations adopted and 

administered by a state authority pursuant to a certification under 49 U.S.C. § 60105” to reflect 

situations where a pipeline facility must comply with state, rather than federal, regulation. Again, 

EPA is making this change in order to more accurately describe how pipeline facilities are already 

regulated under applicable pipeline regulations (be they state or federal). EPA also made a 

conforming change to the related certification language so as to mirror the revised condition in 

§261.4(h)(1).

Comment 3.2.27:

EPA NPRM Statements pg 48082

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.

This statement also makes an important distinction that should be emphasized. Supercritical 

carbon dioxide is not considered or regulated as a hazardous liquid under the PHMSA regulations. 

That distinction is further emphasized in footnote 39: “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.” 76 

Fed. Reg. at 48082, n. 39.

It is important to emphasize this distinction to avoid the notion that supercritical CO2 is regulated 

as a hazardous liquid. This problem and solution are explained in a recent report from the 

Interstate Oil and Gas Compact Commission:

“Some confusion has arisen from the fact that regulations applicable to CO2 pipelines are included 

under the heading entitled "Transportation of Hazardous Liquids by Pipeline." 49 C.F.R. pt. 195. 

This led some commentators to assume, erroneously, that CO2 is a "hazardous liquid" under the 

regulations. This is not accurate. The Department of Transportation proposed safety regulations for 

CO2 pipelines in 1989 precisely because the regulations governing transportation of "hazardous 

liquids" did not apply to CO2. See Notice of Proposed Rulemaking, "Transportation of Carbon 

Dioxide by Pipeline", 54 Fed. Reg. 41912 (October 12, 1989). The term " ‘hazardous liquid’ is 

defined at 49 C.F.R. § 195.2, and does not include carbon dioxide. Commentators were concerned 

that including CO2 pipeline regulations under the section heading for "hazardous liquids" would 

lead to confusion. In response, the Office of Pipeline Safety said it had ‘no good reason to dispute’ 

this notion, and indeed it agreed that carbon dioxide ‘should not be included in the definition of 

“hazardous liquids”’. Id. Nevertheless, the Department said it would not change the title heading 

‘because it would result in an awkward title’ Id. The distinction between carbon dioxide and 

hazardous liquids is maintained at 49 C.F.R. § 195.0 which essentially provides that ‘[t]his part 

prescribes safety standards and reporting requirements for pipeline facilities used in the 

transportation of hazardous liquids or carbon dioxide.’ Id. (emphasis added) Although CO2 is listed 

as a Class 2.2 (non-flammable gas) hazardous material under DOE regulations (49 C.F.R. § 172.101), 

the agency applies nearly the same safety requirements to CO2 pipelines as it does to pipelines 

carrying hazardous liquids such as crude oil, gasoline, and anhydrous ammonia (49 C.F.R. § 195).’ 
48

IOGCC, A Policy, Legal, and Regulatory Evaluation of the Feasibility of a National Pipeline 

Infrastructure for the Transport and Storage of Carbon Dioxide 24-25, n.70 (September 2010).

Response: EPA acknowledges the comment, and does not believe that the factual descriptions and 

citations of the DOT regulations applicable to supercritical CO2 should result in any confusion as to 

how supercritical CO2 is regulated by DOT. EPA also notes that this final rule does not change the 

status under DOT regulations of supercritical CO2, nor does it change the manner in which 

supercritical CO2 is regulated by DOT. 

Comment 3.2.28:

EPA NPRM Statements pg 48082

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.

With CCS not required, the captured stream would be returned to the stack and vented. If and 

when CCS is required, this is an issue that will need to be addressed in regulations and/or permits. 

Temporary storage of volumes generated during full scale operations will not likely occur.

Response: EPA thanks the commenter for the information..

Comment 3.2.29:

EPA NPRM Statements pg 48083

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 onsite 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 detailed in an article by Philip Marston and Patricia Moore, the regulatory status of CO2

pipelines under existing law “was settled many years ago with respect to the Federal agencies 

charged with economic regulation under the Natural Gas Act and the Interstate Commerce Act, 

with findings that those statutes did not confer regulatory jurisdiction over CO2 pipelines. The 

Bureau of Land Management (BLM), on the other hand has been found to have the legal authority 

to impose common carrier obligations on certain CO2 pipelines that cross federal land. With regard 

to state law, the situation is more complex, with varying forms of carriage responsibilities being 

imposed on CO2 pipelines depending on a number of different factors.” P. Marston & P. Moore, 

From EOR to CCS: The Evolving Legal and Regulatory Framework for Carbon Capture and Storage, 

29 Energy L. J. 421, 451 (2008) [See Attachment PDF on policy, legal, and regulatory evaluation of 

feasibility of a national pipeline infrastructure for the transport and storage of CO2 Docket ID: EPAHQ-RCRA-2010-0695-0084].

Response: EPA thanks the commenter for the information.

Comment 3.2.30:

EPA NPRM Statements pg 48083

EPA still requests comment on the appropriateness of applying the RCRA subtitle C standards to 

these non-DOT regulated pipelines. 

EPA should not apply RCRA subtitle C standards to any pipelines associated with the transportation 
49

of captured CO2 emission streams because, as EPA has noted on numerous occasions, the pipeline 

transportation of uncontained gaseous emissions is outside the jurisdiction of RCRA. In addition, 

onsite piping will be covered by ASME B31.1, which is included in the engineering standards for the 

fabrication and installation of piping on-site. In accordance with ASME B31.1, these pipelines are 

built to conform to a very protective set of standards, and that additional regulation is not 

necessary. [FN4: “The B31.1 code prescribes minimum requirements for the design, materials, 

fabrication, erection, test, inspection, operation, and maintenance of piping systems typically found 

in electric power generating stations, industrial institutional plants, geothermal heating systems, 

and central and district heating and cooling systems. The code also covers boiler external piping for 

power boilers and high temperature, high pressure water boilers in which steam or vapor is 

generated at a pressure of more than 15 psig; and high temperature water is generated at 

pressures exceeding 160 psig and/or temperatures exceeding 250 degrees F.”]

Response: EPA agrees that RCRA subtitle C standards should not be applied to non-DOT regulated 

pipelines. While EPA acknowledges that ASME standards are not by themselves regulatory 

requirements,2these standards (e.g., ASME B31) are designed to ensure that the piping and 

associated equipment meet certain quality and safety criteria. In addition, that these ASME B31 

standards have been incorporated by reference in various federal and state regulatory programs 

illustrates the high degree of confidence and acceptance placed on these standards. Ultimately, 

EPA did not find a compelling reason to require RCRA subtitle C standards to on-site piping 

associated with supercritical CO2 streams. Regarding the statement that “as EPA has noted on 

numerous occasions, the pipeline transportation of uncontained gaseous emissions is outside the 

jurisdiction of RCRA[,]” see Response to Comment 3.2.1.

Comment 3.2.31:

EEPA NPRM Statements pg 48083

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.

We do not think that non-pipeline transportation will be feasible for any GS projects other than 

small scale pilot projects conducted for experimental purposes or test injections conducted to 

determine the appropriateness of a particular reservoir or formation to serve as an injection zone. 

In these cases, as in the case of pilot scale Phase II DOE Regional Carbon Sequestration Partnership 

projects, food grade CO2 will be trucked in for injection. The information on these projects is 

available at the DOE NETL website. [FN6: 

http://www.netl.doe.gov/technologies/carbon_seq/infrastructure/rcsp.html (accessed October 5, 

20110].

Response: EPA thanks the commenter for the information.

 

2

According to ASME, standards are considered voluntary and serve as guidelines. ASME publishes its 

standards, accredits users of standards to ensure that they are capable of manufacturing products that meet 

those standards, and provides stamps that accredited manufacturers place on their products, indicating that 

a product was manufactured according to a standard.
50

Comment 3.2.32:

EPA NPRM Statements pg 48084

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 does not otherwise adversely affect the health of persons. 

This statement reflects a fundamentally correct assessment of the UIC program and provides a 

strong foundation for reframing any exclusion that might be adopted to rely on the effectiveness of 

the UIC program in its entirety—and not just Class VI—as the basis for any exclusion. Thus, it 

should be sufficient to require that the producer of a CO2 stream send that stream to an injection 

well operator who holds a valid UIC permit to inject CO2. That permit may be a Class II EOR permit, 

a Class V experimental permit or a Class VI permit (or even conceivably a Class I permit if the CO2

stream is a hazardous waste through being combined with a listed hazardous waste stream). Under 

any of these circumstances, the injection well operator will be under the control of the UIC 

program and will hold a permit and be subject to requirements that can be enforced by the UIC 

program Director as necessary.

Response: EPA disagrees that the conditional exclusion should be extended to UIC well classes 

beyond Class VI, and refers to its response to comment 3.2.7.

Comment 3.2.33:

EPA NPRM Statements pg 48084

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.

This statement reflects the nature of the determinations that EPA made in promulgating the Class 

VI requirements. EPA also determined how these requirements should relate to the Class II 

requirements for EOR wells and established specific provisions for determining when the

requirements applicable to the operation of those wells should be changed in order to provide the 

necessary protections of USDWs. Accordingly, it is completely appropriate to rely on the UIC 

program provisions applicable to any injection of CO2 streams.

Response: See response to comment 3.2.7. 

Comment 3.2.34:

EPA NPRM Statements pg 48084

[T]he 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.

By the same token, EPA decided that it was not necessary to apply the same modifications to CO2

injection for EOR. There is no reason for EPA to question that determination at this point and in this 

regulatory provision.
51

Response: See response to comment 3.2.7.

Comment 3.2.35:

EPA NPRM Statements pg 48085

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.

This is a perfectly acceptable and completely justifiable requirement, but one that is already 

achieved by the Class VI UIC requirements. 40 CFR 146.81(d) (emphasis added): “Carbon dioxide 

stream means 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. This 

subpart does not apply to any carbon dioxide stream that meets the definition of a hazardous waste 

under 40 CFR part 261.” This definition effectively precludes the addition of a hazardous waste 

stream to a CO2 stream for injection into a Class VI well.

Nevertheless, we do not oppose inclusion of the provision if it is appropriately limited by 

recognizing that the hazardous waste resulting from such a mixture is generated at the time of 

mixture and by whoever does the mixing without eliminating the exclusion as applicable to any 

previous producer or manager of the CO2 stream. This is important because the CO2 producer 

cannot control the actions of subsequent handlers of the CO2 stream.

Response:

Regarding the comment that the UIC Class VI rule already prohibits the mixing of hazardous waste 

with CO2 streams, see Response to Comment 3.1.13.

EPA can appreciate the commenter’s concern over the loss of the conditional exclusion due to the 

actions of subsequent handlers of the CO2 stream (in this instance, mixing of hazardous waste into 

the CO2 stream downstream of the “...previous producer or manager of the CO2 stream.”). 

However, EPA maintains that the rule conditions, taken together, ensure that the excluded CO2 

streams are being managed in a protective manner such that subtitle C regulations are not 

necessary. EPA’s Office of Enforcement and Compliance Assurance (OECA) is unable to provide 

definitive assurances outside the context of a formal enforcement proceeding that the government 

will not proceed with an enforcement response for a specific individual violation of an 

environmental protection statute, regulation, or legal requirement. However, EPA can (and has 

previously done so for other RCRA rules) exercise discretion to decide when and how to respond or 

not respond to a given violation, based on the Agency’s normal priorities. In RCRA penalty actions, 

the factors that EPA considers in assessing the gravity-based portion of the penalty are the 

potential for harm and the extent of deviation from a statutory or regulatory requirement. The 

penalty can be adjusted for numerous factors, including good faith efforts to comply, degree of 

willfulness and negligence, and history of noncompliance. Additional information can be found in 

the 2003 RCRA Civil Penalty Policy 

(http://www.epa.gov/compliance/resources/policies/civil/rcra/rcpp2003-fnl.pdf).

EPA has also made revisions to the certification statement better reflect actions over which each 

party has control. EPA has modified the certification requirement in the final rule so that there are 
52

now two separate certification statements worded slightly differently – one for generators and 

another for UIC Class VI well owners or operators claiming this conditional exclusion. EPA is making 

these revisions to better reflect actions over which each party has control. See EPA response to 

comment 3.2.54.

Comment 3.2.36:

EPA NPRM Statements pg 48086

EPA is proposing that a certification statement be executed by an authorized representative of the 

generator and the Class VI injection facility owner/operator.

It is asking too much to expect these individuals or companies to assure compliance by others not 

within their control with every regulatory provision of each of these other regulatory regimes. It

should be sufficient for the capturer and injector to assure that the other links in the chain have the 

necessary permits. Further enforcement should come from the regulators implementing those

programs.

Response: EPA agrees that it may be difficult for generators and UIC Class VI well owners or 

operators to assure compliance by others not within their control. Therefore, EPA has made 

revisions to better reflect actions over which each party has control. EPA has modified the 

certification requirement in the final rule so that there are now two separate certification 

statements worded slightly differently – one for generators and another for UIC Class VI well 

owners or operators claiming this conditional exclusion. EPA is making these revisions to better 

reflect actions over which each party has control. See EPA response to comment 3.2.54

Comment 3.2.37:

EPA NPRM Statements pg 48087

EPA requests comment on the certification statement, and particularly seeks comment on whether 

this measure will appropriately ensure compliance with the conditional exclusion, including the 

mixing prohibition.

The certification statement goes too far in the extent of policing that is required of the certifying 

company. Producers of CO2 streams are not in a position to police the compliance of transporters 

with all of the applicable state or federal requirements. Nor can CO2 producers police the 

compliance of Class VI injection well operators with all of the individual requirements of Parts 144 

and 146 of the UIC program regulations. EPA has already undertaken extensive training to prepare 

state and federal UIC program officials to carry out enforcement [FN7: See 

http://water.epa.gov/type/groundwater/uic/class6/gsinformation.cfm “Rule Implementation 

Workshops”]. It would be expecting too much for CO2 producers to possess the same capabilities. 

Moreover, the imposition of such an exacting compliance restriction really renders the exclusion 

ephemeral. As worded, it could be argued that any instance of noncompliance with the recently 

delineated 57 pages of individual Class VI program requirements [FN8: Draft UIC Program Class VI 

Primacy Application and Implementation Manual for State Directors, EPA 816-D-11-001 at 

Appendix A-3 through A- 60 (June 2011).] would extinguish the exclusion and potentially expose 

the CO2 producer to the full range of RCRA liability.

Response: See EPA responses to Comment 3.2.24, 3.2.35 and 3.2.54.

Comment 3.2.38:
53

EPA NPRM Statements pg 48087

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.

As noted previously, it is unrealistic to expect the CO2 producer to be able to assure any more than 

that it has a contract for the operator of a UIC injection well to receive and inject a specific quantity 

of CO2 into a well covered by a valid UIC permit to inject CO2. The expectation that the type of 

assurance required by the proposed language could be provided is unrealistic because 

transportation is as likely—if not far more likely—to be through a common carrier pipeline as 

through a dedicated pipeline running from a single source to a single recipient.

Response: See responses to comments 3.2.3, 3.2.4, 3.2.6 and 3.2.7.

Comment 3.2.39:

EPA NPRM Statements pg 48087

Finally, EPA requests comment on whether transporters, as well as pipeline owners and operators, 

should also sign such a certification statement. 

It is neither reasonable nor necessary to have transporters, pipeline owners, or pipeline operators 

sign such a certification statement. It is sufficient to rely on the state or federal officials who have 

enforcement responsibility to police the transporters and pipeline operators. Indeed, it is most 

unlikely that these CO2 streams will be transported by means other than pipelines except when 

small quantities are used in experimental wells, and most of those CO2 streams have been food 

grade CO2 that will not be hazardous waste under any circumstances.

Response:

EPA agrees that a certification by the transporter is not necessary, and the final rule does not 

include a transporter/pipeline owner or operator certification. First, if EPA were to require such a 

certification, under the approach where EPA limits the scope of the certification to the conditions 

within the control of pipeline owners and operators or other transporters (the approach taken in 

the final rule for CO2 stream generators and UIC Class VI well owners and operators), the 

certification would essentially address: 1) compliance with applicable DOT requirements, and 2) to 

not mix hazardous waste into the CO2 streams. Regarding compliance with DOT requirements, EPA 

is persuaded by comments received on this issue that if persons transporting supercritical CO2 must 

comply with the applicable transportation requirements for all supercritical CO2 being moved, it 

seems unnecessary to require that they certify compliance with DOT requirements for a specific 

material (i.e., supercritical CO2 streams to be sequestered). Regarding mixing with hazardous waste, 

EPA does not have information, nor did commenters provide any new information, indicating that 

CO2 pipeline owners and operators or other transporters would mix hazardous waste into CO2

streams being delivered to UIC Class VI facilities. EPA expects that pipeline owners and operators 

engaged in delivering supercritical CO2 have strong disincentives to mix any hazardous waste into 

their pipeline system, both in order to honor their contractual arrangement with customers, and 

also to maintain their equipment. Also, as EPA stated in the proposed rule premable, PHMSA 

requires that pipeline owners and operators ensure that supercritical CO2 streams be chemically 

compatible with the pipeline and any commodities in the pipeline and will not corrode the pipeline 

and pipeline system. For these reasons, EPA does not see the need for a transporter certification, 

and is not changing its proposed approach and transporters and pipeline owners and operators will 

not be required to sign a certification statement as a condition of the exclusion.
54

Comment 3.2.40:

EPA NPRM Statements pg 48087

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 operators), might aid EPA and the states in their ability to detect 

improper mixing of hazardous waste with CO2 streams.

The extensive existing requirements of the UIC program are sufficient and will be further supported 

by the requirements that will be routinely imposed by pipeline operator specifications.

Response: As noted by this commenter, EPA had requested comment on what additional 

monitoring, recordkeeping, and reporting requirements on the CO2 stream composition would help 

ensure compliance with the condition that hazardous waste is not be mixed with excluded CO2

streams. EPA received several comments in response to this specific request, all stating that 

additional monitoring, recordkeeping, and reporting requirements were not necessary with respect 

to CO2 stream composition and the condition that hazardous waste not be mixed with excluded 

CO2 streams. Lacking any other information, EPA did not amend the final rule to include any 

additional monitoring, recordkeeping, and reporting requirements related to CO2 stream 

composition. See Response to Comment 3.2.55.

Comment 3.2.41:

EPA NPRM Statements pg 48087

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 should not use this means to impose any content restrictions.

Response: EPA received very little substantive comment on its specific request regarding whether 

adding a minimum CO2 content as an additional condition would enhance compliance with the no 

mixture condition. Therefore, lacking any other information, EPA did not amend the final rule to 

include a condition in the final rule related to a minimum CO2 content as an additional condition to 

enhance compliance with the no mixture condition. One commenter injecting on-site (AEP) did 

provide information on the monitoring of their CO2 streams, and stated that additional monitoring 

requirements were not necessary, but did not address the issue of setting a minimum CO2 content 

as part of the RCRA rulemaking. 

Comment 3.2.42:

EPA NPRM Statements pg 48087

EPA notes that it is requesting comment on whether persons engaged in the movement of 

conditionally excluded CO2 streams, including transporters, as well as pipeline owners or operators, 

should certify that they meet the conditions of today’s proposed conditional exclusion.

It is neither reasonable nor necessary to have transporters, pipeline owners, or pipeline operators 

sign such a certification statement. It is sufficient to rely on the state or federal officials who have 
55

enforcement responsibility to police the transporters and pipeline operators. Indeed, it is most 

unlikely that these CO2 streams will be transported by means other than pipelines except when 

small quantities are used in experimental wells, and most of those CO2 streams have been food 

grade CO2 that will not be hazardous waste under any circumstances.

Response:

EPA agrees that a certification by the transporter is not necessary, and the final rule does not 

include a transporter/pipeline owner or operator certification. First, if EPA were to require such 

a certification, under the approach where EPA limits the scope of the certification to the 

conditions within the control of pipeline owners and operators or other transporters (the 

approach taken in the final rule for CO2 stream generators and UIC Class VI well owners and 

operators), the certification would essentially address: 1) compliance with applicable DOT 

requirements, and 2) to not mix hazardous waste into the CO2 streams. Regarding compliance 

with DOT requirements, EPA is persuaded by comments received on this issue that if persons 

transporting supercritical CO2 must comply with the applicable transportation requirements for 

all supercritical CO2 being moved, it seems unnecessary to require that they certify compliance 

with DOT requirements for a specific material (i.e., supercritical CO2 streams to be 

sequestered). Regarding mixing with hazardous waste, EPA does not have information, nor did 

commenters provide any new information, indicating that CO2 pipeline owners and operators 

or other transporters would mix hazardous waste into CO2 streams being delivered to UIC Class 

VI facilities. EPA expects that pipeline owners and operators engaged in delivering supercritical 

CO2 have strong disincentives to mix any hazardous waste into their pipeline system, both in 

order to honor their contractual arrangement with customers, and also to maintain their 

equipment. Also, as EPA stated in the proposed rule premable, PHMSA requires that pipeline 

owners and operators ensure that supercritical CO2 streams be chemically compatible with the 

pipeline and any commodities in the pipeline and will not corrode the pipeline and pipeline 

system. For these reasons, EPA does not see the need for a transporter certification, and is not 

changing its proposed approach and transporters and pipeline owners and operators will not 

be required to sign a certification statement as a condition of the exclusion.

Comment 3.2.43:

EPA NPRM Statements pg 48087

EPA is also requesting comment on whether any new monitoring, recordkeeping or reporting 

requirements are necessary (including as those might apply to pipeline owners or operators) to 

ensure that the conditions of the proposed exclusion are met. EPA emphasizes that aside from 

seeking comment in these two areas, EPA is not proposing any new requirements applicable to 

pipelines or pipeline owner/operators. 

Such additional requirements are not necessary.

Response: While EPA agrees that new monitoring, recordkeeping or reporting requirements are 

not necessary for pipeline owners or operators, EPA has added a provision in the final rule for the 

signed certification statement to be posted prominently on the signatory’s publicly-available

website, as discussed further in EPA’s Response to Comment 3.2.55.

Comment 3.2.44:

EPA NPRM Statements pg 48087-88

Failure to meet the conditions results in the loss of the exclusion. As proposed, a violation of a 
56

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 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. 49 [fn 49 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). 

EPA is setting up precisely the situation that the United States Court of Appeals for the District of 

Columbia Circuit has forewarned would likely be viewed as untenable. Assn. of Battery Recyclers, 

Inc. v. EPA, 208 F.3d 1047, 1051 (D.C. Cir. 2000): “The new § 261.4(a)(17) gave a so-called 

‘conditional exclusion’: if the provision's criteria were met, reclaimed mineral processing secondary 

materials would not be classified as solid waste. We have trouble making sense of these two 

provisions. The first provision (§ 261.2(c)(3)) broadly describes what is not a solid waste, unless it 

complies with the other provision. But the other provision-§261.4(a)(17)-is an exclusion, and the 

consequence of not complying with the provision is, of course, loss of exclusion. In other words, 

read together, the provisions seem to say that something is not a solid waste unless it is not 

excluded from being a solid waste. Lewis Carroll would be proud.”

It is also worth noting that the exclusion under consideration in that case was far less demanding of 

regulatory perfection than the one proposed here. Assn. of Battery Recyclers, Inc. v. EPA, 208 F.3d 

1047, 1051-52 (D.C. Cir. 2000): As to the conditions set forth in § 261.4(a)(17), EPA's dividing line 

between “waste” and nonwaste is the manner of storage. If the mineral processor stores secondary 

material destined for recycling in tanks, containers, buildings, or on properly maintained pads, the 

materials are not considered “solid waste.” See id. § 261.4(a)(17)(iii), (iv). Given our assumption 

(and that of the parties), if by-products and sludges exhibiting a characteristic of hazardous waste 

are not stored in such a manner prior to being recycled, they may be regulated as hazardous 

“waste.”

Response: In the first place, EPA is not quite certain what this comment means. However, based 

on the EPA preamble text to which the comment refers, the Agency interprets this comment to 

mean that the conditions of the rule that would render a waste not hazardous are not appropriate. 

In addition, the comment appears to say that the CO2 should not be a hazardous waste for the 

generator if another person handling the waste violates one or more of the conditions. 

EPA disagrees with the comment as the Agency understands it. The straightforward response is 

that the rule conditions, taken together, ensure that the excluded CO2 streams are being managed 

in a protective manner such that subtitle C regulations are not necessary. Therefore, it follows that 

any management not in accordance with those conditions does not qualify for the exclusion.
57

Further, EPA’s Office of Enforcement and Compliance Assurance (OECA) is unable to provide 

definitive assurances outside the context of a formal enforcement proceeding that the government 

will not proceed with an enforcement response for a specific individual violation of an 

environmental protection statute, regulation, or legal requirement. However, EPA can (and has 

previously done so for other RCRA rules) exercise discretion to decide when and how to respond or 

not respond to a given violation, based on the Agency’s normal priorities. In RCRA penalty actions, 

the factors that EPA considers in assessing the gravity-based portion of the penalty are the 

potential for harm and the extent of deviation from a statutory or regulatory requirement. The 

penalty can be adjusted for numerous factors, including good faith efforts to comply, degree of 

willfulness and negligence, and history of noncompliance. Additional information can be found in 

the 2003 RCRA Civil Penalty Policy 

(http://www.epa.gov/compliance/resources/policies/civil/rcra/rcpp2003-fnl.pdf).

EPA fails to understand the relevance of this comment's rather vague reference to Association of 

Battery Recyclers, Inc., v. EPA, 208 F.3d 1047 (D.C. Cir. 2000) (“ABR”). First, ABR applies to whether 

the material in question is a waste or not. This rule applies to material that is a waste, but is not a 

hazardous waste. Thus, the case is not on point. Second, nothing in ABR addresses whether a 

waste may lose its non-hazardous designation (and become a hazardous waste), from the point at 

which it is generated if either the generator or another person who handles the material should 

violate one or more of the conditions. 

Comment 3.2.45:

EPA NPRM Statements pg 48088

EPA requests comment on the types and characteristics of substances that are added to CO2

streams to enable or improve the injection process.

There are not current examples of substances that have been added to CO2 streams to improve 

injectivity. The language contained in the Class VI rule has been included in recognition that 

substances have been added to improve the injection process under other UIC well classes. The 

rule preserves the ability to do this, subject to appropriate permit conditions. A number of pilot 

and other projects have added tracers not to improve injectivity, but to improve the monitoring 

and plume tracking processes.

Response: EPA acknowledges the comment. 

Comment: 3.2.46

EPA NPRM Statements pg 48090

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.

The economic analysis conducted in support of the proposal is inadequate and fails to consider the 

considerable costs that would be imposed on CO2 producers if they are saddled with the burden to 

determine on a regular basis the comprehensive compliance status of pipeline operators and of 

Class VI injection well operators. As noted in these comments, it is completely unrealistic and 

unreasonable to impose such burdens. But it is also inadequate to estimate that the only cost of 
58

providing a certification is the cost of typing and signing the forms. The current formulation of the 

conditions would impose substantial auditing requirements for anyone choosing to claim the 

proposed conditional exclusion. We have not attempted to estimate the costs of conducting such 

auditing, but we believe that the cost of requiring CO2 producers to essentially enforce the Class VI 

UIC requirements will be substantial and may run as high as 50 to 75 million dollars. The Ground 

Water Protection Agency (GWPC) has estimated that “UIC funding may need to be increased by as 

much as $75 million annually to effect full implementation” of the Class VI UIC program.[FN9: 

GWPC, An Assessment of State Needs for Regulating Geologic Sequestration of Carbon Dioxide 2-3 

(2011) (Attachment C): “Based on an analysis of expected staffing needs for states to implement 

the Class VI program, UIC funding may need to be increased by as much as $75 million annually to 

effect full implementation.”] As presently worded, the proposed exclusion would require CO2

producers to undertake the same level of compliance assessment, if not more.

Response: EPA disagrees with this comment. The Economic Assessment document does not 

attempt to assess costs associated with CO2 producers who may seek to determine the status of 

pipeline operators and Class VI UIC injection well owner/operators because this is not a 

requirement of the final rule. Moreover, this conditional exclusion is voluntary, and CO2 producers 

(generators) are not obligated to make use of this conditional exclusion. CO2 producers who 

choose to use the conditional exclusion may conduct whatever level of oversight they believe 

appropriate.

Comment 3.2.47:

pg 48092

Under existing RCRA statutory and regulatory requirements EPA must conclude that captured 

gaseous emission streams of CO2 are not solid waste for the reasons detailed throughout these 

comments.

Response: See EPA response to comments 3.2.1 and 3.2.2. 

Comment 3.2.48:

EPA NPRM Statements pg 48092

§ 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. 

If EPA insists instead on concluding that CO2 streams can be solid waste, we recommend for the 

reasons stated above that the exclusion be revised as follows:

§ 261.4 Exclusions.

(a) Materials which are not solid wastes. The following materials are not solid wastes for the 

purpose of this part:

* * * * *

(26) Carbon Dioxide Stream Injected for Geologic Sequestration.
59

Carbon dioxide streams that are captured and transported for purposes of injection into an 

underground injection well holding a valid permit for the injection of carbon dioxide under the 

Underground Injection Control Program of the Safe Drinking Water Act, are not solid waste,

provided the following conditions are met.

Response: EPA disagrees with the commenter’s suggested alternative regulatory approach to 

exclude these CO2 streams from the definition of solid waste, including when they are injected into 

any class of UIC well “holding a permit for the injection of carbon dioxide[,]” and EPA does not 

agree that an exclusion from the definition of solid waste for CO2 streams injected into UIC Class VI 

wells is appropriate, for the reasons EPA provides in response to comments 3.2.1, 3.2.2, 3.2.3, 

3.2.4, 3.2.5 and 3.2.7.

Comment 3.2.49:

pg 48093

Consistent with our comments, we recommend the following rewording:

(1) Carbon dioxide streams that meet all of the following conditions are excluded from the 

definition of solid waste:

Response: See response to comment 3.2.48.

Comment 3.2.50:

EPA NPRM Statements pg 48093

(i) Transportation of the carbon dioxide stream must be in compliance with applicable Department 

of Transportation requirements;

This is not something that the capturer of CO2 can assure because it is within the control of the 

pipeline operator. The capturer or producer can only assure that the pipeline is [permitted]. It is 

not reasonable to require the capturer or producer and the injection well operator to police the 

transporter or pipeline operator. 

Consistent with our comments, we recommend the following revision:

(i) Transportation of the carbon dioxide stream must be by means authorized in compliance with 

applicable Department of Transportation requirements or alternatively applicable state pipeline

requirements;

Response: With respect to the suggested alternative language addressing ‘applicable state pipeline 

requirements’ please see response to comment 3.2.26.

Regarding the comment that compliance with DOT regulations is “...not something that the 

capturer of CO2 can assure because it is within the control of the pipeline operator” and the parallel 

suggested regulatory language “by means authorized” EPA refers to its Responses to Comments 

3.2.35 and 3.2.54.

Comment 3.2.51:

EPA NPRM Statements pg 48093

(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;
60

This is not something that the capturer of CO2 can assure because it is within the control of the 

Class VI injection well operator to assure compliance with all of the requirements. The capturer or 

producer can only assure that the injection well operation has obtained the necessary Class VI 

permits. The assurance of compliance should reside with the operator and the enforcement 

mechanisms of the UIC program. 

Consistent with our comments, we recommend the following revised wording:

(ii) Injection of the carbon dioxide stream must be in a well permitted to inject carbon dioxide in 

compliance with the applicable requirements for Underground Injection Control wells, including 

the applicable requirements in 40 CFR parts 144 and 146;

Response:

EPA disagrees with the commenter’s suggested alternative regulatory approach to exclude these 

CO2 streams from the definition of solid waste, including when they are injected into any class of 

UIC well “permitted to inject carbon dioxide[,]” and EPA does not agree that an exclusion from the 

definition of solid waste for CO2 streams injected into UIC Class VI wells is appropriate, for the 

reasons EPA provides in response to comments 3.2.1, 3.2.2, 3.2.3, 3.2.4, 3.2.5 and 3.2.7.

Regarding the comment that compliance with applicable UIC Class VI requirements is the 

responsibility of the well owner/operator under the UIC program, and is “...not something that the 

capturer of CO2 can assure because it is within the control of the Class VI injection well operator...” 

EPA refers to its responses to Comments 3.2.35 and 3.2.54. 

Comment 3.2.52:

EPA NPRM Statements pg 48093

(iii) No other hazardous wastes may be mixed with, or otherwise co-injected with, the carbon 

dioxide stream; and

Why does the language say “other” when it excludes CO2 streams? We question whether “other” is 

appropriate. Otherwise, this is most appropriate to require of the capturer or producer but only 

insofar as the captured CO2 remains within the control of the producer. Accordingly, we request a 

clear explanation that whoever combines a CO2 stream with a hazardous waste is the generator of 

the waste and this does not cause the original producer of the CO2 stream to be subjected to RCRA 

hazardous waste provisions if the CO2 stream has passed out of the producer’s control.

Response:

With respect to the comment requesting a clear explanation as to who is the generator, under the 

approach described in the proposed rule for implementing this conditional exclusion, the addition 

of hazardous waste to a conditionally excluded CO2 stream at any point (including at a point after it 

leaves the control of the capture facility) would result in a loss of the exclusion back to the point of 

generation. EPA maintains that the rule conditions, taken together, ensure that the excluded CO2 

streams are being managed in a protective manner such that subtitle C regulations are not 

necessary. 

However, EPA can appreciate the commenter’s concern over the loss of the conditional exclusion 

due to actions outside the control of the generator. While EPA’s Office of Enforcement and 
61

Compliance Assurance (OECA) is unable to provide definitive assurances outside the context of a 

formal enforcement proceeding that the government will not proceed with an enforcement 

response for a specific individual violation of an environmental protection statute, regulation, or 

legal requirement, EPA can (and has previously done so for other RCRA rules) exercise discretion to 

decide when and how to respond or not respond to a given violation, based on the Agency’s 

normal priorities. In RCRA penalty actions, the factors that EPA considers in assessing the gravitybased portion of the penalty are the potential for harm and the extent of deviation from a 

statutory or regulatory requirement. The penalty can be adjusted for numerous factors, including 

good faith efforts to comply, degree of willfulness and negligence, and history of 

noncompliance. Additional information can be found in the 2003 RCRA Civil Penalty Policy 

(http://www.epa.gov/compliance/resources/policies/civil/rcra/rcpp2003-fnl.pdf).

Regarding the commenter’s issue with the term “other,” EPA notes that this comment appears to 

contradict the commenter’s opinion of this condition (provided with caveats not related to the use 

of the term “other” in Comment 3.2.35) (“This is a perfectly acceptable and completely justifiable 

requirement, but one that is already achieved by the Class VI UIC requirements.”). Nonetheless, for 

other reasons – primarily due to Agency concerns that the term ‘other’ may be confusing – EPA 

decided to revise the wording of the condition and is finalizing the following language: “No 

hazardous wastes shall be mixed with, or otherwise co-injected with, the carbon dioxide stream.”

Comment 3.2.53:

EPA NPRM Statements pg 48093

(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:

The injection well operator can be expected to provide such a certification for sole-sourced CO2

streams but not for integrated streams received through a common carrier pipeline.

Consistent with our comments, we recommend rewording the certification as follows:

(iv) Any generator of a carbon dioxide stream, and any Underground Injection Control well owner 

or operator, who claims that a carbon dioxide stream is excluded under paragraph (a)(26) of this 

section, must have an authorized representative (as defined in 40 CFR 260.10) sign a certification 

statement worded as follows:

Response: EPA disagrees with the commenter’s suggested alternative regulatory approach to 

exclude these CO2 streams from the definition of solid waste, including when they are injected into 

any class of UIC holding a permit for the injection of carbon dioxide. EPA does not agree that an 

exclusion from the definition of solid waste for CO2 streams injected into UIC Class VI wells is 

justified, for the reasons EPA provides in response to comments 3.2.1, 3.2.2, 3.2.3, 3.2.4, 3.2.5 and 

3.2.7.

Comment 3.2.54:

EPA NPRM Statements pg 48093

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.
62

This depends on how the language of the provision is revised. This is not an appropriate 

certification to expect under the proposed language because the assurances are beyond the 

capabilities of the responsible persons.

Response: EPA agrees that it may be difficult for generators and Class VI Underground Injection 

Control (UIC) well owners or operators to certify to actions beyond their control. Therefore, in the

final rule, the certification statement has been revised so that there are now two separate 

certification statements worded slightly differently – one for generators and another for UIC Class 

VI well owners or operators claiming this exclusion. As revised, the generator certification 

statement reads as follows:

I certify under penalty of law that the carbon dioxide stream that I am claiming to be 

excluded under 40 C.F.R. §261.4(h) has not been mixed with hazardous wastes, and I have 

transported the carbon dioxide stream in compliance with (or have contracted with a 

pipeline operator or transporter to transport the carbon dioxide stream in compliance 

with) Department of Transportation requirements, including the pipeline safety laws (49 

U.S.C. § 60101 et seq.) and regulations (49 C.F.R. Parts 190-199) of the U.S. Department of 

Transportation, and the pipeline safety regulations adopted and administered by a state 

authority pursuant to a certification under 49 U.S.C. § 60105, as applicable, for injection 

into a well subject to the requirements for the Class VI Underground Injection Control 

Program of the Safe Drinking Water Act.

As revised, the UIC Class VI well owner or operator certification reads as follows:

I certify under penalty of law that the carbon dioxide stream that I am claiming to be 

excluded under 40 C.F.R. §261.4(h) has not been mixed with, or otherwise co-injected with, 

hazardous waste at the Underground Injection Control (UIC) Class VI permitted facility, and 

that injection of the carbon dioxide stream is in compliance with the applicable 

requirements for UIC Class VI wells, including the applicable requirements in 40 CFR parts 

144 and 146.

EPA is making these revisions to better reflect actions over which each party has control. EPA 

emphasizes that these revisions do not change how the conditional exclusion is implemented – that 

a CO2 stream that is hazardous must meet all the conditions in 261.4(h)(1)-(4) to qualify for and 

maintain the exclusion from the hazardous waste regulations.

Comment 3.2.55:

EPA NPRM Statements pg 48093

The signed certification statement must be kept onsite 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.

Requiring production within 72 hours is too short. In addition, this requirement should reflect 

modern electronic filing systems where a paper copy may not be held in a file drawer. Making an 
63

electronic document available and submitting it electronically should both be allowed.

Response: EPA believes that 72 hours is sufficient time to provide a copy of the certification 

statement, since the generator and UIC Class VI well owner or operator should already have the 

statement on file. However, in the final rule, EPA has added a provision for the statement to be 

posted prominently on the signatory’s publicly-available website, if such website exists. As EPA 

made clear in the proposed rule, one of its key concerns with the certification statement was to 

ensure compliance with the terms of the conditional exclusion. Posting the signed certification 

statements on-line will promote compliance and accountability by providing efficient access by 

regulatory authorities and interested members of the public (consistent with the intent of the 

RCRA Enhanced Public Participation Rule cited by one commenter) to the exclusion certifications 

and the identities of the responsible officials. Moreover, EPA expects that posting the certifications 

on-line will simplify the reporting obligation for the regulated community because accessible 

internet posting obviates the need for a regulatory agency to request a hard copy.

EPA notes that it is not requiring the creation of any new corporate or other website. Entities 

without a website thus would not be required to post their certifications on-line. EPA expects, 

however, that most, if not all, affected entities already operate external websites to communicate 

to the public and, therefore, the posting requirement will be useful to regulators, the public, and 

the regulated community. The public disclosure of information is an increasingly common and 

important regulatory tool.3 In 2010, the Office of Management and Budget (OMB) issued guidance 

with principles to assist agencies in using information disclosure to achieve regulatory objectives, 4

and EPA believes that regulatory information disclosure can cost-effectively improve compliance 

and accountability.

3.3 American Electric Power (AEP)

Document ID: EPA-HQ-RCRA-2010-0695-0063

Comment 3.3.1:

American Electric Power (AEP) appreciates this opportunity to provide comments on the proposed 

regulation, “Hazardous Waste Management System: Identification and Listing of Hazardous Waste: 

Carbon Dioxide (CO2) Streams in Geologic Sequestration Activities,” which was issued by the agency 

on August 8, 2011, 76 Fed. Reg. 48073. The U.S. Environmental Protection Agency (EPA) is 

proposing to revise the regulations for hazardous waste management under RCRA to exclude from 

the definition of hazardous waste, CO2 streams that would otherwise be defined as hazardous, 

when these CO2 streams are managed under certain conditions. The agency believes, and AEP 

agrees, that this amendment to the RCRA hazardous waste rules, if finalized, will reduce the 

uncertainty associated with defining and managing these CO2 streams under RCRA Subtitle C. EPA 

has stated in the proposed rule that it has little information to conclude that CO2 streams would 

qualify as RCRA hazardous wastes; therefore, AEP would like to take this opportunity to provide the 

 

3

Cass R. Sunstein, Informational Regulation and Informational Standing: Akins and Beyond, 147 U. Pa. L. Rev. 

613, 613 (1999).

4 Memorandum for the Heads of Executive Departments and Agencies – Disclosure and Simplification as 

Regulatory Tools (Cass R. Sunstein, OMB; June 18, 2010). 

http://www.whitehouse.gov/sites/default/files/omb/assets/inforeg/disclosure_principles.pdf
64

agency with information obtained from AEP’s experience with sequestering and injecting CO2

streams, as well as comment on the proposed rule.

AEP appreciates the efforts EPA has made to engage and meet with stakeholders, not only during 

the Class VI rulemaking process, but also during the development of the guidance documents to 

date. As you know, AEP, along with its strategic partners, is a leader in the development of 

technology to capture CO2 from flue gas emissions and inject the resulting supercritical CO2 into 

deep subsurface formations for long term storage. AEP’s pilot project for this technology is located 

at the company’s Mountaineer Plant in New Haven, West Virginia. AEP is in a unique position with 

its developing expertise to provide comments on the proposed rule (attached) and hopes to 

continue this constructive dialogue as future rules and guidance documents are developed and 

issued.

If you have any questions or need any additional information regarding these comments, please 

contact (see docket for contact information).

Response: EPA acknowledges the comment.

Comment 3.3.2:

1. Comments to EPA’s Preliminary Statements Regarding the Nature of the Proposed Rulemaking

In EPA’s background to the proposed rule, EPA should consider adopting or referring to the 

definition of geologic sequestration (GS) found at 40 CFR § 144.3 to describe the process of GS. By 

referring to the UIC materials in the background information EPA can accurately characterize the 

sequestration process since these terms were vetted through the UIC rulemaking process.

Response: EPA does not see a need to define “geologic sequestration” in the final conditional 

exclusion because one of the conditions is that the excluded CO2 stream be sent to, and injected 

“incompliance with the applicable requirements for Class VI Underground Injection Control wells, 

including the applicable requirements in 40 CFR Parts 144 and 146” of the Underground Injection 

Control Program of the Safe Drinking Water Act.” 

Comment 3.3.3:

2. EPA’s Application of RCRA to CO2 Streams Injected into Permitted UIC Class VI Wells for Purposes 

of Geologic Sequestration is Inappropriate and Unnecessary

EPA proposes that injected CO2 may be considered a hazardous waste for RCRA purposes, if it 

exhibits any of the hazardous waste characteristics found in 40 CFR Part 261, Subpart C. 76 Fed. 

Reg. at 48078. While AEP believes that regulatory certainty in this area is critical to the successful 

deployment of the GS technology, AEP does not agree that the CO2 supercritical fluid should be 

assumed to be a hazardous waste.

Response: EPA disagrees with the commenter but notes that EPA does not assume all CO2

supercritical fluid is hazardous waste. In EPA’s view, CO2 streams that are sent to UIC Class VI wells 

for purposes of GS are RCRA solid wastes, and the RCRA hazardous waste regulations may apply to 

CO2 streams in the absence of the conditional exclusion. However, EPA does not conclude that 

supercritical CO2 streams that are solid wastes would, as a class, exhibit a RCRA characteristic. 

Indeed, EPA indicated in the proposed rule that it could not unequivocally conclude that 
65

supercritical CO2 streams will never exhibit any RCRA hazardous waste characteristic. Generators 

who are not managing a hazardous waste are not obligated to make use of this conditional 

exclusion and are not subject to the RCRA subtitle C regulations. 

Comment 3.3.4:

EPA notes “it has little information to conclude that CO2 streams would qualify as RCRA hazardous 

wastes” and EPA does not have full knowledge of the range of possible CO2 stream compositions 

(76 Fed. Reg. 48079). According to EPA, a supercritical CO2 stream injected into a permitted UIC 

Class VI well for purposes of geologic sequestration (GS) qualifies as a RCRA solid waste, as that 

term is defined in RCRA § 1004(27) by considering the stream to be a “discarded material” within 

the plain meaning of the term. EPA acknowledges that the CO2 streams under consideration are not 

specifically identified in 40 CFR Part 261, Subpart D as listed hazardous waste and the agency 

believes that the stream could be classified as hazardous if it exhibited any of the hazardous 

characteristics in 40 CFR Part 261, Subpart C. It is not known how a supercritical gas could be tested 

to determine if it had any of the hazardous characteristics, but EPA notes that the hazardous waste 

regulations allow generators to apply their knowledge, in lieu of testing, of the hazard 

characteristic of a waste, to determine whether that waste is a characteristic hazardous waste 

under RCRA. In light of the underlying concerns with characterizing this supercritical fluid, EPA 

specifically requests comments related to RCRA characterization.

The Carbon Sequestration Council (CSC), of which AEP is a member, addressed the issue of RCRA 

applicability for CO2 streams in its comments on the agency’s proposed rule for geologic 

sequestration of carbon dioxide under the Safe Drinking Water Act (SDWA) “Federal Requirements 

Under the Underground Injection Control (UIC) Program for Carbon Dioxide (CO2) Geologic 

Sequestration (GS)Wells,” 73 Fed. Reg. 4349 1-541 (July 25, 2008), Docket ID No. EPA–HQ–OW–

2008–0390 [See Attachment PDF on Comments of the Carbon Sequestration Council on Proposed 

UIC Program for Carbon Dioxide Geologic Sequestration Docket ID: EPA-HQ-RCRA-2010-0695-

0063].

The CSC noted that in light of the current uses and potential future uses of CO2 for enhanced 

oil/gas recovery, EPA had taken a sensible approach by proposing to create a new Class VI well 

category based on the injection of the CO2 stream as a fluid without characterizing that stream as a 

waste. It was neither necessary nor helpful to categorize CO2 as a pollutant or waste, and such a 

determination would have likely proved detrimental to the development of CCS technology. The 

CSC was concerned that EPA’s discussion of the potential for injected CO2 streams to be 

characterized as hazardous waste (or some type of hazardous release) was causing apprehension 

and possibly having a significant detrimental effect on any future deployment of carbon capture 

and sequestration technologies. Through the work of engineers and scientists familiar with capture 

technologies and the types of power plant flue gases likely to be sources of CO2 for sequestration, 

the CSC did not believe that captured CO2 streams should trigger the application of RCRA. 

Accordingly, it encouraged EPA to dispel concerns that geologic sequestration should be 

encumbered with those requirements.

AEP shares these concerns, agrees with the CSC position, reiterates those comments here and 

encourages EPA to consider them as well. While the agency is proposing an exemption from RCRA 

for injected CO2 streams, the very consideration of such an exemption unnecessarily suggests that 

these streams could be hazardous.
66

Response: In EPA’s view, a supercritical CO2 stream sent to a permitted UIC Class VI well for 

purposes of GS is a RCRA solid waste, because it is a “discarded material” within the plain meaning 

of the term in RCRA §1004(27). Also, it is important to note that EPA did not set out in this 

rulemaking to conclude that those supercritical CO2 streams that are solid wastes would, as a class, 

exhibit a RCRA characteristic. As EPA indicated in the proposed rule, EPA could not unequivocally 

conclude that supercritical CO2 streams will never exhibit any RCRA hazardous waste characteristic. 

In light of these circumstances, EPA thus seeks to bring additional clarity to the regulatory regime 

through this rule, by establishing a conditional exclusion from the definition of hazardous waste 

that would apply in the event a generator determines that its CO2 streams exhibit a RCRA 

hazardous characteristic. As EPA pointed out in the proposed rule, analytical methods are available 

to characterize CO2 streams (76 FR at 48078). EPA also notes that the Class VI Rule has several 

different CO2 stream characterization requirements, that require sampling and analysis (see 40 CFR 

146.82(a)(7)(iv) and 146.90(a)). EPA notes that generators who are not managing a hazardous 

waste are not obligated to make use of this conditional exclusion and are not subject to the RCRA 

subtitle C regulations. Finally, EPA made clear in the proposal that this final rule does not reopen 

the UIC Class VI rule, and that EPA would not respond to comments related only to that rule. To the 

extent that the Carbon Sequestration Council’s (CSC) comments discussed by the commenter relate 

to the UIC Class VI regulation, they are beyond the scope of this rule. Consistent with this, EPA will 

also not provide additional responses to the CSC’s comments on that rule, attached to the AEP 

comments.

Comment 3.3.5:

Further, in its comments, the CSC noted that there were important categorical determinations that 

EPA could and should make with respect to the RCRA status of CO2. The CSC urged, and AEP again 

asks, EPA to make these determinations as follows:

“First, EPA should clarify that gas-phase CO2 is not solid or hazardous waste for RCRA purposes and 

is not subject to any RCRA waste determination requirements. The RCRA definition of “solid waste” 

does not include gaseous material unless it is “contained.” RCRA 1004(27), 42 U.S.C. 6903(27). EPA 

has long taken the position that gasses do not qualify as “solid waste” under this definition unless 

they are “contained” in a cylinder or similar container. 54 Fed. Reg. 50968 at 50970, 50973 

(December 11, 1989). It follows that gas-phase CO2 streams are not solid waste, are not subject to 

the waste determination requirements of 40 C.F.R. 262.11, and cannot be considered hazardous 

waste for RCRA purposes. Second, EPA should clarify that supercritical CO2 is not solid or hazardous 

waste for RCRA purposes and is not subject to any RCRA waste determination requirements.”

Response:

EPA disagrees with the commenter. First, the commenter’s discussion of “contained gaseous 

material” is not on-point. Rather, as EPA noted in the proposed rule, the CO2 streams that are 

delivered by pipeline and injected into UIC Class VI wells for GS are in a supercritical state, which 

EPA stated at proposal was “...rather unique in that it has properties intermediate between a liquid 

and a gas.” 76 FR at 48078. The scientific term used to describe or define this supercritical state 

(i.e., when a substance is at or above its critical temperature and critical pressure) is as a 

“supercritical fluid.” The RCRA statutory definition of solid waste specifically refers to “other 

discarded material, including solid, liquid, semisolid, or contained gaseous material resulting from 

industrial, commercial, mining, and agricultural operations, and from community activities . . .” 

While EPA has indeed interpreted the meaning of specific terms listed, including “contained 

gaseous material,” the RCRA definition of solid waste encompasses “other discarded material” and 
67

does not speak to materials such as supercritical fluids. Like the listed “solid, liquid, semisolid, or 

contained gaseous material” specifically referenced, CO2 streams sequestered for purposes of GS 

are “other discarded material” from industrial and commercial operations and, therefore, are of a 

similar kind to the other types of wastes specifically referenced by the definition. They are, 

therefore, RCRA statutory solid wastes. Second, as was stated in the preamble to the proposed 

rule, GS is an option to reduce CO2 emissions to the atmosphere by injecting the CO2 streams into 

deep subsurface geologic formations, with the express purpose of isolating the CO2 so that it does 

not return to the atmosphere (August 8, 2011; 76 FR at 48075). Therefore, EPA views these CO2

streams as “discarded material” within the plain meaning of the term in RCRA §1004(27). That is, a 

supercritical CO2 stream is a solid waste when it is to be discarded through abandonment by 

disposing of the material in a UIC Class VI well (see 40 CFR 261.2(a)(2)(i) and (b)(1)). 

EPA does not conclude that supercritical CO2 streams that are solid wastes would, as a class, exhibit 

a RCRA characteristic. Indeed, EPA indicated in the proposed rule that it could not unequivocally 

conclude that supercritical CO2 streams will never exhibit any RCRA hazardous waste characteristic. 

Generators that are not managing a hazardous waste are not obligated to make use of this 

conditional exclusion and are not subject to the RCRA subtitle C regulations. Moreover, because 

use of the conditional exclusion is voluntary, even those generators who characterize their streams 

as RCRA hazardous waste may continue to manage their streams as RCRA hazardous wastes from 

the point of generation. The only effect is upon those persons who choose to comply with the 

terms of the conditional exclusion. Finally, EPA made clear in the proposal that this final rule does 

not reopen the UIC Class VI rule, and that EPA would not respond to comments related only to that 

rule. To the extent that the Carbon Sequestration Council’s (CSC) comments discussed by the 

commenter relate to the UIC Class VI regulation, they are beyond the scope of this rule.

Comment 3.3.6:

The CSC went on to explain, and AEP agrees, that,

“the RCRA definition of solid waste is limited to “solid, liquid, semi-solid, or contained gaseous 

material.” RCRA 1004(27). Because supercritical CO2 is none of these things; a plain reading of the 

statutory text suggests that supercritical CO2 should not be considered “solid waste.” This reading 

of the statute makes sense, because RCRA is primarily aimed at the kind of material that could end 

up being dumped into a landfill. Uncontained supercritical CO2 is not such a material. Instead, the 

physical properties of supercritical CO2 are such that it would immediately vaporize – becoming an 

uncontained gas – before it could contribute to the contents of a landfill. A related practical 

consideration is the fact that the hazardous characteristics – the broad waste determination 

criteria that provide a primary means for determining when solid waste is hazardous waste – are 

based largely on test methods that are inapplicable to materials such as supercritical CO2. In 

particular, the toxicity characteristic depends on test methods that can only be applied to materials 

that are solids or liquids at standard temperatures and pressures. This is unsurprising, because the 

toxicity characteristic was designed to assess the threat waste would have in a municipal landfill 

disposal scenario, a scenario that – as already discussed – is inherently inapplicable to uncontained 

supercritical CO2. Accordingly, it makes no legal, policy, or practical sense to treat uncontained 

supercritical CO2 as “solid waste” for RCRA purposes. EPA should therefore confirm that 

uncontained supercritical CO2 is not “solid waste” and is not subject to RCRA waste determination 

requirements.”
68

“It follows that a CO2 stream would only qualify as “solid waste” if it is actually in the form of a 

liquid (i.e., a liquid containing dissolved CO2). In such a case, the liquid would meet the statutory 

definition of “solid waste,” the requirement to perform a RCRA waste determination would be 

triggered, and the familiar test methods for waste determinations could be applied.”

AEP encourages the agency to reconsider the comments of CSC and to confirm that it is not 

necessary to apply RCRA hazardous waste determinations to CO2 streams intended for GS.

Response: See response to comment 3.3.5. As stated there, EPA noted in the proposed rule that 

the CO2 streams are delivered by pipeline and injected into UIC Class VI wells for GS in a 

supercritical state, which EPA stated at proposal was “...rather unique in that it has properties 

intermediate between a liquid and a gas.” 76 FR at 48078. The scientific term used to describe or 

define this supercritical state (i.e., when a substance is at or above its critical temperature and 

critical pressure) is as a “supercritical fluid.” The RCRA statutory definition of solid waste specifically 

refers to “other discarded material, including solid, liquid, semisolid, or contained gaseous material 

resulting from industrial, commercial, mining, and agricultural operations, and from community 

activities . . .” While EPA has indeed interpreted the meaning of specific terms listed, including 

“contained gaseous material,” the RCRA definition of solid waste encompasses “other discarded 

material” and does not speak to materials such as supercritical fluids. Like the listed “solid, liquid, 

semisolid, or contained gaseous material” specifically referenced, CO2 streams sequestered for 

purposes of GS are “other discarded material” from industrial and commercial operations and, 

therefore, are of a similar kind to the other types of wastes specifically referenced by the 

definition. They are, therefore, RCRA statutory solid wastes. 

EPA recognizes that there are potential questions regarding the application of the hazardous waste 

regulations to supercritical CO2 streams being sequestered. While EPA could develop a toxicity test 

tailored for supercritical CO2 streams, that is not necessary for the finalization of this rule. EPA does 

not apply any significant technical limitations on sampling and analyzing a CO2 stream, even if it has 

been compressed to supercritical stage. Generators can conduct analyses to characterize the 

physical and chemical properties of their CO2 streams, e.g., whether the CO2 contains certain 

impurities, what the concentrations of the impurities are, and whether the CO2 stream may be 

corrosive, or apply their knowledge of the hazard characteristic of a waste, in light of the materials 

or processes used in order to determine whether a waste exhibits a RCRA characteristic. EPA notes 

that the Class VI Rule has several different CO2 stream characterization requirements that require 

sampling and analysis (i.e., at 40 CFR 146.82(a)(7)(iv) and 146.90(a)), and EPA did not receive 

comments that indicated that meeting these requirements would not be possible. 

Finally, EPA made clear in the proposal that this final rule does not reopen the UIC Class VI rule, and 

that EPA would not respond to comments related only to that rule. To the extent that the Carbon 

Sequestration Council’s (CSC) comments discussed by the commenter relate to the UIC Class VI 

regulation, they are beyond the scope of this rule.

Comment 3.3.7:

3. Status of AEP Mountaineer CCS Project

The AEP Mountaineer CCS project in New Haven, West Virginia, is no longer in operation and plans 

for a 1.5 million metric tons per year scale-up from an emission slipstream representing 235 MW, 

have been cancelled. Because of AEP’s experience with the supercritical CO2 stream, we are 
69

providing the following information in response to EPA’s request for comments regarding CO2

stream analytical data.

Physical and Chemical Characteristics of Captured CO2

EPA is requesting 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. These data will allow 

EPA to gain a better understanding of the nature and characteristics of captured CO2 streams and 

support a determination by EPA that RCRA is inapplicable to these CO2 streams.

On September 30, 2009, prior to the start of CO2 injection at the AEP Mountaineer project, five 

samples of the CO2 injection gas stream were collected and analyzed for parameters of interest 

including CO2, oxygen (O2), moisture, and ammonia (NH3). Results are provided in Table 2-1 [See 

PDF Docket ID: EPA-HQ-RCRA-2010-0695-0063]. Procedures specified in United States 

Environmental Protection Agency (U.S. EPA) Method 3A (CO2 and O2), Method 4 (moisture), and 

CTM-027 (NH3) were used to determine these parameters. Analyses for CO2 and O2 were performed 

onsite by Shaw Environmental, Inc. using the MIDAC Fourier transform infrared analyzer. NH3

analyses were performed by an off-site laboratory (ALS Laboratory Group, Cincinnati, Ohio). 

Moisture is a calculated parameter.

Response: EPA acknowledges the comment. See Responses to Comments 3.3.9 through 3.3.16.

Comment 3.3.8:

Table 2-1 [See PDF Docket ID: EPA-HQ-RCRA-2010-0695-0063]

The chemical specification for the CO2 injection stream, as provided in the Testing and Monitoring 

Plan (Battelle, 2009), is provided in Table 2-2 [See PDF Docket ID: EPA-HQ-RCRA-2010-0695-0063]. 

During the baseline sampling event, all tested parameters were within their anticipated operating 

range and met their design specification. CO2 levels in all five samples exceeded the design 

specification of 99.7%, which is a minimum limit during normal operating conditions. Moisture was 

below its design specification of 0.2%, which is a maximum limit during normal operating 

conditions. NH3 was below its design specification of 50 parts per million by volume (ppmv), which 

is a maximum limit during normal operating conditions. All of these data have been provided to the 

West Virginia Department of Environmental Protection (WVDEP) through annual and semiannual 

monitoring reports.

Table 2-2 [See PDF Docket ID: EPA-HQ-RCRA-2010-0695-0063]

Response: EPA acknowledges the comment.

Comment 3.3.9:

Sampling After CO2 Injection Began

Since the beginning of CO2 injection in October 2009, the injectate stream has been sampled and 

analyzed on five occasions: January 27, 2010, April 6, 2010, June 16, 2010, December 21, 2010, and 

April 25, 2011. No testing/analysis of the CO2 stream was conducted during the three-month period 

from October 2009 through December 2009 due to the small amount of CO2 that was injected 

during this period. Similarly, a sampling event was not conducted during the period from 
70

September through November 2010 because the CO2 capture and injection system was shut down 

for the annual monitoring and well workover event.

During this period, the MIDAC Fourier transform infrared analyzer was not operating properly; 

therefore, analyses for O2 and CO2 were obtained by off-site laboratory analysis (Isotech) of CO2

stream samples. Results are reported on Table 2-3 [See PDF Docket ID: EPA-HQ-RCRA-2010-0695-

0063]. As indicated on Table 2-3, the CO2 content of the injection stream was within the expected 

operational range (97% to 99.7%) and above the design specification of 99.7%. Ammonia was 

below its design specification of 50 ppmv. The moisture content of the CO2 stream was below its 

design specification of 50 ppmv.

Table 2-3 [See PDF Docket ID: EPA-HQ-RCRA-2010-0695-0063]

Response: EPA acknowledges the comment.

Comment 3.3.10:

4. On-site Storage of Captured CO2 Prior to Injection

EPA is requesting information on whether the agency’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 is requesting detailed information on 

the duration and method of storage, and what existing regulatory or voluntary controls and 

standards apply to such storage. EPA is also requesting 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 is requesting comment and information on the procedures that have been or are expected to 

be used during maintenance and upset circumstances of a carbon capture system (76 Fed. Reg. 

48082).

During the operation of its CCS project in New Haven, WV, AEP did not “store” the CO2 after it was 

captured from the flue-gas slip stream. The CO2was sent directly from the compressor to the 

pipelines for injection or was vented back to the stack. In addition, plans for a 235 MW commercial 

scale project did not include a storage unit for CO2 after capture. Based on AEP’s experience, it is 

difficult to envision a storage unit for CO2 due to the large volumes involved. In cases of upsets or 

maintenance, it would be better to vent the CO2 back to the stack.

Response: EPA thanks the commenter for the information, and agrees (based on this and other 

public responses confirming EPA’s similar expectations as discussed in the proposal) that the 

process of capturing and compressing CO2 prior to delivery to a UIC Class VI facility, which would 

likely occur via a pipeline, will not involve on-site storage at the generator facility (i.e., at the CO2

source) but rather will occur in a continuous fashion.

Comment 3.3.11:

5. Regulation of Pipelines that are not subject to DOT requirements

EPA has requested information on pipelines that are not subject to DOT requirements, including 

any design and operating standards that apply to such pipelines. EPA is also requesting information 

on the appropriateness of applying RCRA subtitle C standards to these non-DOT regulated 

pipelines. For its CCS project, AEP used piping that met ANSI 31.3 chemical process piping 

standards. The CO2 did not leave the plant property, therefore DOT standards did not apply.
71

Response: EPA thanks the commenter for the information.

Comment 3.3.12:

6. Non-pipeline Transportation and Certification

EPA is requesting 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 a 

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 (76 Fed. Reg. 48083). EPA should determine the 

likelihood that supercritical CO2 will be a hazardous waste. AEP appreciates EPA’s recognition of 

other regulatory programs that govern CO2 activities and its efforts to avoid duplication, but 

requiring a certification amounts to a duplication of effort for the generator/operator. See AEP’s 

monitoring comments below.

Due to the large volumes of CO2 that are handled during GS operations, it would be preferable to 

use pipelines to transport the gas. The use of trucks for CO2 transportation was not considered for 

the AEP GS projects and pipelines are being constructed for Southern Company’s Plant Berry 

project in Alabama. Pipelines are also the primary mode of bulk transportation for EOR projects. 

Trucks can be used for small-scale CO2 test injections, but they are impractical for large scale 

projects involving millions of tons of CO2 per year.

Response: EPA thanks the commenter for the information.

EPA does not agree that the certification statement is a “duplication of effort” for the 

generator/operator, as there is no similar requirement of which EPA is aware, nor does the 

commenter describe specifically how the certification statement is duplicative. 

Regarding the comment that EPA should “determine the likelihood that supercritical CO2 will be a 

hazardous waste,” EPA notes that it is not required to affirmatively demonstrate, as part of this 

rulemaking, that a particular CO2 stream, or a portion of all CO2 streams, necessarily qualifies as 

RCRA hazardous waste. EPA acknowledges that some RCRA hazardous characteristics are unlikely 

to apply to a waste composed of >90% CO2, such as ignitability (i.e., RCRA Waste Code D001).

See also responses to comments 3.3.3 and 3.3.13.

Comment 3.3.13:

7. Signature Requirements for Certification Statements

Use of a certification statement is to ensure compliance with the conditions of the proposed 

conditional exclusion, EPA is requesting comment on whether 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 § 

270.1 1(a)(3). Accountability and enforceability may be improved when signatories to these types 

of certifications are at the highest levels of an organization.
72

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 is, therefore, requesting comment on 

the certification statement, and particularly seeks comment on whether this measure will 

appropriately ensure compliance with the conditional exclusion, including the mixing prohibition 

(76 Fed. Reg. 48087). Injected CO2 is not hazardous; therefore, a certification statement is not 

necessary. Current signatory requirements are sufficient. If CO2 were mixed with hazardous waste 

prior to injection, AEP would agree that RCRA requirements may be applicable, but EPA should 

evaluate the likelihood of this scenario occurring and whether existing regulations already apply to 

and discourage this practice.

Response: With respect to the signature requirements for certification statements, it appears the 

commenter is quoting from EPA’s preamble discussion on this issue, and then concludes (without 

explanation) that “Current signatory requirements are sufficient.” EPA received no other

comments specifically with respect to whether the certification should be signed by persons as 

described in 40 CFR 270.11 (as required for RCRA permit applications), rather than by “authorized 

representatives” as defined in 40 CFR 260.10. Lacking any other comments on this specific issue, 

EPA has decided to maintain the proposed approach that certifications must be signed by 

“authorized representatives” of the facility (in situations where the conditional exclusion is being 

used). Authorized representatives are defined as 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” and EPA believes that as defined, these “authorized 

representatives” will have both sufficient knowledge of, and responsibility for, the facility’s 

operations to be able to certify that the conditions are being met.

With respect to the commenter’s conclusion that “injected CO2 is not hazardous” EPA disagrees 

with the comment. The comment does not provide any basis for its conclusion, and as EPA has 

explained elsewhere, the RCRA hazardous waste regulations can apply to CO2 streams sent to UIC 

Class VI wells for geologic sequestration. Because of this possibility, EPA is providing the final 

conditional exclusion, and has included the certifications as a means to ensure compliance with the 

terms of the exclusion. Moreover, as the commenter states, the RCRA hazardous waste regulations 

could also apply as a result of mixing hazardous wastes with CO2 streams. For similar reasons, then, 

EPA also believes that a certification requirement is appropriate to ensure compliance with the 

mixing prohibition in today’s rule. Thus, these comments provide no reason for EPA to modify its 

approach.

While mixing hazardous wastes with CO2 streams is also prohibited by the UIC Class VI rules, EPA 

notes that this final rule applies upstream of the UIC facility; therefore, EPA believes that the 

certification can help ensure compliance with the mixing prohibition by other entities (e.g., the CO2

stream generator). This difference in scope exists regardless of the likelihood of hazardous wastes 

being mixed with CO2 streams.

Comment 3.3.14:

8. Monitoring of CO2 Composition

EPA is requesting 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 operators), might aid EPA and the states in their ability to detect 
73

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 (76 Fed. Reg. 48087).

Based on its experience with the Mountaineer CCS project in New Haven, West Virginia, AEP 

believes that the CO2 monitoring program, developed for the project, in conjunction with the West 

Virginia Department of Environmental Protection, was adequate to ensure the integrity of the 

injected CO2. This monitoring program required, among other analyses, quarterly analysis of the 

carbon dioxide stream, continuous recording of injection pressure, rate and volume, quarterly 

corrosion monitoring, quarterly groundwater monitoring and additional monitoring as required by 

the agency [See Attachment PDF on Appalachian Power Company Mountaineer Plant Underground 

Injection Control Permit Docket ID EPA-HQ-RCRA-2010-0695-0063]. Monitoring results were to be 

reported to the agency on a semiannual and annual basis and any changes to the physical, chemical 

or other relevant characteristics of the CO2 stream were to be noted [See Attachment PDF on 

Appalachian Power Company Mountaineer Plant Underground Injection Control Permit Docket ID 

EPA-HQ-RCRA-2010-0695-0063]. Procedures were also established to report any conditions which 

would have endangered underground sources of drinking water, public health or the environment.

This testing was adequate to ensure the quality and integrity of the CO2 stream, which met the 

design criteria of 99.7% CO2 (see Tables 2-1 and 2-3) [See PDF Docket ID: EPA-HQ-RCRA-2010-0695-

0063] and the PHMSA requirements for the pipeline transportation of supercritical carbon dioxide, 

which specifies a CO2 content of greater than ninety percent. Groundwater testing included 

analysis of inorganic parameters, such as calcium, magnesium and potassium, metals, such as 

aluminum, barium, iron, and manganese, as well as alkalinity, DOC and pH. All chemical analyses 

were to be performed by a West Virginia certified laboratory. Had injection of the CO2 created a 

potentially hazardous condition due to the leaching of metals, it would have been detected by the 

extensive monitoring program designed for the project.

Monitoring records for the project, including the nature and composition of all injected fluids, must 

be retained by AEP for the life of injection and after injection cessation, unless they are delivered to 

the agency. Permission for record disposal may be granted by the agency upon request, however, 

the agency may extend the period of record retention as its discretion [See Attachment PDF on 

Appalachian Power Company Mountaineer Plant Underground Injection Control Permit Docket ID 

EPA-HQ-RCRA- 2010-0695-0063]

Response: EPA thanks the commenter for the information. See Responses to Comments 3.2.40 

and 3.2.41.

Comment 3.3.15:

9. Types and Characteristics of Substances Added to CO2 Streams

EPA has requested comments on the types and characteristics of substances that are added to CO2

streams to enable or improve the injection process. During the operation of its CCS project, AEP did 

not add any substances to the CO2 stream to improve its injectivity.
74

Response: EPA thanks the commenter for the information.

Comment 3.3.16:

Conclusion

In addition to these comments, AEP also supports the comments submitted to EPA on this 

proposed rule by the Edison Electric Institute, the Carbon Sequestration Council, and the Utility 

Solid Waste Activities Group or USWAG. AEP appreciates EPA’s intent to provide regulatory 

certainty to the CO2 stream and GS technology. AEP requests that EPA recognize that while the GS 

technology is still in the demonstration phase there is analytical information available on the CO2

streams some of which AEP is providing as part of these comments. This data indicates that the CO2

streams do not pose the same risk as contemplated by RCRA. AEP urges EPA to consider the 

information submitted herein and determine whether the CO2 streams justify the imposition of 

management under RCRA. A sufficient regulatory and operational structure exists to ensure that 

hazardous wastes are not mixed with CO2 streams. AEP fears that further regulatory requirements 

put upon the generator could have the unintended effect of discouraging the deployment of these 

types of projects in the future. AEP urges EPA to exclude CO2 streams from RCRA hazardous waste 

regulations, but also recommends that the rule be revised as an exclusion of CO2 streams from the 

definition of “solid waste”. Due to their unique properties, coupled with the fact that they are not 

“discarded,” CO2 streams cannot be considered “solid waste”.

Response: With respect to the comments from Edison Electric Institute, the Carbon Sequestration 

Council, and the Utility Solid Waste Activities Group or USWAG, please see responses to comments 

3.15, 3.2, and 3.7, respectively. With respect to the comment regarding the mixing prohibition, see 

response to comment 3.3.13. EPA disagrees with the commenter’s suggested regulatory approach 

to exclude these CO2 streams from the definition of solid waste because CO2 streams that are 

injected for purposes of GS in Class VI UIC wells are solid wastes for the reasons stated in response 

to comment 3.3.5. With respect to the comment that this rule could discourage the deployment of 

GS, EPA disagrees. EPA notes that the conditional exclusion has a limited effect on the regulated 

community directly and the exclusion imposes no affirmative obligations upon them. The only 

effect is upon those persons who choose to comply with the terms of the conditional exclusion. 

Moreover, EPA believes this rule 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. Thus, EPA disagrees that it will have the effect of 

discouraging the deployment of GS.

Finally, the commenter asks EPA to “consider the information submitted...and determine whether 

the CO2 streams justify the imposition of management under RCRA.” The commenter states that 

the submitted analytical data on the composition of their CO2 streams “indicates that the CO2

streams do not pose the same risk as contemplated by RCRA.” While EPA acknowledges that the 

CO2 concentration in these CO2 streams is very high (97 to 99.7% CO2), EPA notes that these CO2

stream composition data are limited (e.g., they do not include information on potential 

concentrations of hazardous constituents). Regardless, if any particular CO2 stream is a hazardous 

waste, RCRA subtitle C would apply – but EPA has concluded that management of a hazardous CO2

stream under the conditions in today’s rule is protective such that RCRA subtitle C requirements 

are not necessary.

3.4 C12 Energy
75

Document ID: EPA-HQ-RCRA-2010-0695-0073

Comment 3.4.1:

C12 Energy firmly believes in thorough regulation of geologic carbon dioxide (CO2) sequestration. 

As leaders in this industry, we will take every step to ensure that CO2 is stored safely in geologic 

formations. [FN1: C12 Energy is the leading CO2 storage project developer in the United States. To 

date, we have secured CO2 storage rights to approximately 400,000 acres of privately-owned land 

with 13 projects in 10 different states, corresponding to approximately 10 billion tons of CO2

storage capacity distributed throughout the nation. To put this in context, our sites are currently 

sufficient to permanently store CO2 emissions from approximately 15% of the nation’s fleet of coal 

plants for the next 30 years, and we’re developing more capacity every day]. We consider the 

recently finalized UIC Class VI Rules to provide a thorough regulatory system for CO2 storage, and 

strongly support the proposed Hazardous Waste Management System: Identification and Listing of 

Hazardous Waste: Carbon Dioxide (CO2) Stream in Geologic Sequestration Activities (RCRA CO2

Conditional Exclusion or Conditional Exclusion). As outlined in the comments below, the potential 

for additional regulation of CO2 streams under the Resource Conservation and Recovery Act (RCRA) 

would not provide any additional protections for public health or the environment, but it would 

almost certainly create a serious impediment to aggressive implementation of carbon 

sequestration, which represents one of the most significant opportunities to reduce CO2 emissions 

in the United States. 

For the reasons outlined below, we strongly support the proposed CO2 Conditional Exclusion.

Response: EPA thanks the commenter for its support of the proposed rule.

Comment 3.4.2:

1 Introduction 

C12 Energy believes that risks associated with CO2 storage projects should be minimized, especially 

at the early stages of the industry. As a result of this view, we support the Class VI rules as they 

provide appropriate protections – in fact, more stringent protections than Class I rules – to prevent 

potential environmental harm associated with CO2 sequestration.

As leaders in this industry, we are concerned that the uncertainty surrounding whether CO2

streams would be subject to regulation under RCRA Subtitle C would create a serious impediment 

to widespread implementation of CO2 sequestration, which is essential to reduce U.S. CO2

emissions. As EPA notes in the Proposed Rule: [F]ossil 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 could enable 

the continued use of coal in a manner that greatly reduces the associated CO2 emissions, while 

other 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.[FN2: Proposed Rule, Section III.B, Why is Geologic Sequestration Being 

Considered as Climate Change Mitigation Technology?]

Commercial entities involved in the CCS industry, including utilities, equipment manufacturers, 

pipeline operators, and others, are very concerned about the potential for RCRA regulation of CO2

streams as it creates significant regulatory uncertainty. In the absence of the Conditional Exclusion, 

this uncertainty would act as a further barrier to widespread implementation of CO2 storage 
76

without creating any additional environmental benefit. However, as EPA recognizes in the 

proposed rule, Class VI rules provide appropriate environmental protections, and it is thus 

appropriate to conditionally exclude CO2 streams disposed of in injection wells permitted under the 

Class VI program from RCRA Subtitle C. We strongly support the proposed rule as it will accelerate 

the widespread deployment of CO2 sequestration and thus greatly reduce our CO2 emissions.

Response: EPA acknowledges the comment. EPA believes this rule 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. With respect to the 

commenter’s statement that “the Class VI rules...provide appropriate protections – in fact, more 

stringent protections than Class I rules – to prevent potential environmental harm associated with 

CO2 sequestration” EPA notes that each UIC well class is designed for particular purposes, see 

response to comment 3.2.7.

Comment 3.4.3:

2 Authority for Conditional Exclusion 

2.1.1 Description 

EPA cites the following as authority for the Conditional Exclusion: 

* RCRA §§3001(a), 3002(a), 3003(a), 3004(a), 1004(5)(B) 

* Military Toxics Project v. EPA, 146 F.3d 948 (D.C. Cir. 1998) 

* NRDC v. EPA, 25 F.3d 1063, (D.C. Cir 1994) 

* Edison Electric Institute v. EPA, 2F.3d 438 (D.C. Cir. 1993) 

* H. Rep. No. 94-1491, 94th Cong, 2d Sess. 6 (1976) [FN3: Proposed Rule, Section IV.A. Authority for 

Conditional Exclusion from RCRA Subtitle C Requirements].

We agree that these authorities and others provide EPA with the adequate authority to promulgate 

the Conditional Exclusion.

2.1.2 Requested Changes 

Fully support; no changes requested. 

Response: EPA agrees with the commenter that under its interpretation of RCRA, it has the 

authority to issue conditional exclusions from the hazardous waste regulations. EPA’s authority to 

issue the rule is described in section II.B. of the final rule preamble.

Comment 3.4.4:

3 CO2 Capture, Transportation, and Storage 

3.1.1 Description 

EPA requests further information on the process by which CO2 will be captured, transported, and 

stored, particularly with regard to whether CO2 will be stored at the point of capture and whether 

CO2 will be transported in trucks or by pipeline. EPA notes that: 

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 
77

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. [FN4: Proposed Rule, Section 

IV.B, CO2 Streams Managed Prior to Underground Injection]. 

EPA goes on to observe 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 substantive RCRA subtitle C requirements 

applicable to this activity. [FN5: Proposed Rule, Section IV.B, CO2 Streams Managed Prior to 

Underground Injection] 

* 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. 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. [FN6: Proposed Rule, Section IV.B, CO2 Streams Managed Prior to 

Underground Injection].

We make the following comments: 

* EPA is exactly right that the volumes involved in CO2 storage are simply too large to allow for 

anything other than direct pipeline transport. Commercial-scale CO2 storage volumes are too large 

for on-site storage or transport by truck. [FN7: See 

http://www.dakotagas.com/CO2_Capture_and_Storage/index.html].

* EPA is also right that any additional requirements for pipeline transport would not improve public 

health and safety as the existing PHMSA have proven effective in minimizing risks associated with 

CO2 pipelines, of which hundreds of miles of CO2 pipelines currently exist in the United States. 

[FN8: See http://petrolog.typepad.com/climate_change/2009/09/us-power-plant-emissions-andCO2-pipelines.html].

3.1.2 Requested Changes 

Fully support; no changes requested. 

Response: EPA acknowledges the comment and agrees (based on this and other public responses 

confirming EPA’s similar expectations as discussed in the proposal) that the process of capturing 

and compressing CO2 prior to delivery to a UIC Class VI facility, which would likely occur via a 

pipeline, will not involve on-site storage at the generator facility (i.e., at the CO2 source) but rather 

will occur in a continuous fashion. Regarding truck transportation, EPA notes that other 

commenters stated that truck transport was either not considered (3.3.12) or was used in a pilot or 

research (i.e., non-commercial) scale situations (e.g., 3.2.31, 3.20.12) or would be used under very 

limited occurrences (3.17.4). Finally, EPA agrees that additional RCRA requirements for pipeline 

transportation beyond the existing DOT requirements are not necessary. As explained in section VI 

of the final rule preamble, the changes EPA made to the condition on compliance with DOT 

regulations only focused upon adding a reference to state pipeline regulations that may apply in 

lieu of DOT regulations. 
78

Comment 3.4.5:

4 Class VI Rules Contain Appropriate Protections 

4.1 Description 

EPA notes that: 

[C]ompliance 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. [FN9: Proposed Rule, Section IV.C, 

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

EPA further states that: 

The Class VI rule ... 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. [FN10: Id.]. 

EPA finally notes that: 

[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, form 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. [FN11: Proposed Rule, Section IV.E., Loss of 

the Conditional Exemption].

EPA also proposes to add to the definition of CO2 stream “any substances added to the stream to 

enable or improve the injection process.” [FN12: Proposed Rule, Definition of “Carbon dioxide 

stream”]. 

We fully agree and make the following comments: 

*UIC Class I, which would be the alternative regulatory system if CO2 streams were classified as 

hazardous, does not include the same level of protection as Class VI particularly with regard to the 

Area of Review. Under the Class VI Rules, Area of Review is determined with regards to the 

maximum extent of the separate-phase plume or pressure front (MESPOP) [FN13: Area of Review 

Guidance, p. 31,

http://water.epa.gov/type/groundwater/uic/class6/upload/GS_AoR_CA_Guidance_DRAFT_FINAL_

031611.pdf]. The Class I Rules contain no such detailed description of Area of Review, and would 

likely result in an Area of Review being defined using the default quarter-mile radius Area of 

Review determination under Class I, which would be much less protective than the delineation 

required under the Class VI Rules.

* The Class VI Rules contain other provisions particular to CO2 injection that would provide greater 

protection than would be provided under the Class I program. For example, the Class VI rules 

provide protections particular to CO2 buoyancy, monitoring to ensure appropriate CO2 plume 

tracking, and potential corrective action associated with CO2 injection that would not be included 

were CO2 regulated under Class I.

Response: EPA thanks the commenter for its statements of support for the cited EPA statements.

The Class VI requirements are tailored to the unique aspects of carbon dioxide injection for GS 
79

(e.g., large CO2 injection volumes, the buoyant and mobile nature of the injectate) and EPA 

developed its RCRA conditional exclusion based upon injection in a UIC Class VI well. See section 

V.C. of the final rule preamble for a discussion of why EPA does not think it is appropriate to 

compare the UIC Class I and Class VI requirements point-by-point. However, if the carbon dioxide 

stream is considered to be hazardous and does not meet the requirements of the conditional 

exclusion, it would need to be disposed of in a manner appropriate for hazardous waste, such as 

injection into a Class I hazardous waste well. Regarding the comment’s citation to EPA’s discussion 

on the loss of the conditional exclusion, see response to comment 3.4.6. Regarding the phrase, 

“any substances added to the stream to enable or improve the injection process,” see response to 

comment 3.4.7. 

Comment 3.4.6:

* The Conditional Exclusion is predicated on appropriate management of the CO2 stream under 

Class VI, and we fully agree that a breach of the UIC permit – in particular, the migration of the CO2

beyond the Area of Review – should result in a loss of the exclusion. It may be difficult to manage a 

CO2 stream that migrates beyond the Area of Review, and in such a case, full regulatory authority, 

including RCRA, should apply to that stream. Consequently, we request that EPA expressly 

recognize the loss of the exclusion if a CO2 stream migrates beyond the Area of Review.

Response: A CO2 stream must meet all the conditions to qualify for and maintain the exclusion 

from the definition of hazardous waste, including the condition that 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.

Comment 3.4.7:

* It may be necessary to add substances to the CO2 stream to improve injectivity, including 

substances to reduce viscosity, inhibit reactions with brine or formation rocks, or otherwise 

improve permeability. Consequently, we fully support the addition of “substances added to the 

stream to enable or improve the injection process” to the CO2 stream definition.

Response: EPA clarifies that any addition of substances to CO2 streams to enable or improve the 

injection process would be occurring as part of the UIC Class VI permitted activity (subject to that 

program’s oversight) and thus ultimately implemented in a manner to prevent the endangerment 

of underground sources of drinking water. EPA notes that this rule’s definition of carbon dioxide 

stream is consistent with the one in the UIC Class VI final rule, in order to provide the regulatory 

clarity sought through this rule. It is from the UIC Class VI rule definition of “CO2 stream” that this 

phrase is drawn. 

Comment 3.4.8:

4.2 Requested Changes 

We request that the proposed rule expressly recognize that the Conditional Exclusion is revoked if a 

CO2 stream migrates beyond the Area of Review as determined under the Class VI permitting 

program.

Response: See response to comment 3.4.6.

Comment 3.4.9:

5 Necessary Changes 
80

We fully support the Conditional Exclusion for the reasons stated above. We, however, request the 

following necessary revisions to improve the Proposed Rule. 

5.1 Listed Wastes 

5.1.1 Description 

The Proposed Rule states in several places that the Conditional Exclusion applies to characteristic 

wastes. For example, EPA notes that: 

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. [FN14: Proposed Rule, Section IV.C.4, 

Underground Injection of CO2 Streams at UIC Class VI Wells, Subtitle C Corrective Action]. 

5.1.2 Necessary Changes 

The Conditional Exclusion should not only apply to CO2 streams that may meet the definition of a 

characteristic waste but also streams that include incidental substances that may be listed wastes. 

Consequently, the Proposed Rule should remove any reference to characteristic wastes unless also 

accompanied by a reference to listed wastes.

Response: EPA’s discussion in the preamble to the proposed rule does reference characteristic 

hazardous wastes because as EPA explained at proposal, there are no listed hazardous CO2 streams 

and the only way EPA can foresee a listing as applying to a CO2 stream is where prohibited mixing 

occurs, which would be a violation of one of the conditions (thus the exclusion would not apply). 

Based on the information EPA used in developing the proposed rule, as well as information 

obtained in public comments, EPA does not anticipate incidental associated substances that are 

derived from the source materials, which are captured together with the CO2, to be listed 

hazardous wastes. See also response to comment 3.28.1.

Comment 3.4.10:

5.2 Pipeline certification 

5.2.1 Description 

EPA proposes to require any generator of a CO2 stream who claims the Conditional Exclusion to 

certify that the stream meets the conditions of the exclusion, including “the prohibition on mixing 

hazardous wastes with the CO2 stream.” [FN15: Proposed Rule, Section IV.D, Prohibition on 

Introduction of Other RCRA Hazardous Wastes]. 

EPA further requests comment on “whether transporters, as well as pipeline owners and operators, 

should also sign such a certification statement.” [FN16: Id]. 

We fully support the certification requirement as it is necessary to ensure unscrupulous operators 

do not seek to sidestep appropriate regulation by purposefully mixing hazardous wastes into a CO2

stream. We further support a requirement that the pipeline operator, or other CO2 transporter, 

sign a similar statement as it is necessary to ensure that such wastes are not inappropriately mixed 

into the CO2 stream. Absent such certifications by both generators and pipeline operators, a CO2

storage operator would face an undue burden of demonstrating that hazardous wastes had not 

been inappropriately mixed into the CO2 stream. 

5.2.2 Necessary Changes
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Require the pipeline operator, or other transporter of the CO2 stream, to certify that hazardous 

wastes have not been purposefully mixed into the CO2 stream.

Response: The final rule maintains the condition that the generator and the UIC Class VI well owner 

or operator each sign a certification statement, which have been revised so that each party certifies 

to actions over which they have control. However, EPA disagrees that a certification by the 

transporter or pipeline owner or operator is necessary. First, if EPA were to require such a 

certification, under the approach where EPA limits the scope of the certification to the conditions 

within the control of pipeline owners and operators or other transporters (the approach taken in 

the final rule for CO2 stream generators and UIC Class VI well owners and operators), the 

certification would essentially address: 1) compliance with applicable DOT requirements, and 2) to 

not mix hazardous waste into the CO2 streams. Regarding compliance with DOT requirements, EPA 

is persuaded by comments received on this issue that if persons transporting supercritical CO2 must 

comply with the applicable transportation requirements for all supercritical CO2 being moved, it 

seems unnecessary to require that they certify compliance with DOT requirements for a specific 

material (i.e., supercritical CO2 streams to be sequestered). Regarding mixing with hazardous 

waste, EPA does not have information, nor did commenters provide any new information, 

indicating that CO2 pipeline owners and operators or other transporters would mix hazardous 

waste into CO2 streams being delivered to UIC Class VI facilities. EPA expects that pipeline owners 

and operators engaged in delivering supercritical CO2 have strong disincentives to mix any 

hazardous waste into their pipeline system, both in order to honor their contractual arrangement 

with customers, and also to maintain their equipment. Also, as EPA stated in the proposed rule 

premable, PHMSA requires that pipeline owners and operators ensure that supercritical CO2

streams be chemically compatible with the pipeline and any commodities in the pipeline and will 

not corrode the pipeline and pipeline system. For these reasons, EPA does not see the need for a 

transporter certification, and is not changing its proposed approach and transporters and pipeline 

owners and operators will not be required to sign a certification statement as a condition of the 

exclusion.

3.5 Natural Resources Defense Council (NRDC) 

Document ID: EPA-HQ-RCRA-2010-0695-0082

Comment 3.5.1:

A. Introduction

The Natural Resources Defense Council and Environmental Defense Fund thank the United States 

Environmental Protection Agency (EPA) for the opportunity to comment on the proposal 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.

The Natural Resources Defense Council (NRDC) is a national, nonprofit organization of scientists, 

lawyers and environmental specialists dedicated to protecting public health and the environment. 

Founded in 1970, NRDC has more than 1.2 million members and online activists nationwide, served 

from offices in New York, Washington D.C., San Francisco, Los Angeles, Chicago and Beijing.

The Environmental Defense Fund (EDF), founded in 1967, is a non-profit organization that 

represents more than 500,000 members. EDF links science, economics and law to create 
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innovative, equitable and cost-effective solutions to society’s most urgent environmental 

problems.

Response: EPA thanks the commenter for the information. 

Comment 3.5.2:

NRDC and EDF continue to believe strongly that geologic sequestration of CO2 (GS), correctly 

implemented, must be a component of the U.S. climate mitigation portfolio. We have supported 

deployment of CCS technologies and have shared the objective of establishing economic incentives 

for the technology.

Deployment of CCS must, however, take place safely and effectively without threatening human 

health or the environment. The governing regulatory framework is of primary importance to that 

effect. We have been actively working with EPA and other entities to ensure that the rules and 

regulations that govern CCS ensure that it is performed safely and effectively, without posing 

unacceptable risks. Ultimately, we believe that proper regulation is in the interests of CCS 

development, as it assures the public of adequate oversight and guards against sub-standard 

projects that could jeopardize further deployment.

Response: EPA agrees that the geologic sequestration of CO2 in Class VI UIC wells should be done 

safely and effectively without threatening human health or the environment and that a consistent 

regulatory approach to GS will help facilitate development and deployment of CCS technologies in 

the United States. EPA intends to bring additional clarity to the regulatory regime through this rule, 

by establishing a conditional exclusion from the definition of hazardous waste.

Comment 3.5.3:

Accordingly, we urge caution against using regulatory easements and exemptions in order to 

facilitate the deployment of CCS technologies. Unlike economic incentives that encourage 

deployment, regulatory relief approaches carry a real danger of adverse environmental 

consequences. Environmental statutes such as the Resource Recovery and Conservation Act (RCRA) 

offer important safeguards and exemptions should not be granted except in very specific 

situations.

Response: EPA agrees that RCRA provides safeguards to protect human health and the 

environment. However, after consideration of public comment, EPA has reached the conclusion 

that management of CO2 streams under existing standards, including the UIC requirements for 

Class VI wells, as well as DOT standards, will protect human health and the environment from 

potential risks associated with CO2 streams (including associated constituents that might be 

present). Additional RCRA subtitle C regulation is, therefore, unnecessary in these circumstances. 

EPA notes that this exclusion is specific to the terms outlined in the rule.

Comment 3.5.4:

B. General Comments

1. EPA correctly identifies supercritical CO2 as a solid waste.

EPA correctly identifies a supercritical CO2 stream injected in a Class VI well as a solid waste under 

RCRA. [FN1: Federal Register, Vol. 76, No. 152, Monday August 8, 2011, p. 48077 and p. 48079]. 
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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 [...]”. [FN2: RCRA 1004(27), 42 U.S.C. 6903(27)]. 

Supercritical CO2 is a fluid that behaves like a gas but has the density of a liquid. In addition, Class VI 

wells are defined as “[w]ells that are not experimental in nature that are used for geologic 

sequestration of carbon dioxide [...]” [FN3: 40 CFR §146.5 (f)], where geologic sequestration is in 

turn defined as “the long-term containment of a gaseous, liquid, or supercritical carbon dioxide 

stream in subsurface geologic formations” [FN4: 40 CFR §146.81(d).]. Thus, CO2 injected in Class VI 

wells clearly constitutes “discarded material”.

Response: EPA agrees that CO2 streams sent to UIC Class VI wells for purposes of GS are solid 

waste. 

Comment 3.5.5:

C. Specific Comments on the Proposed Conditional Exemption

1. Prohibiting the mixing or co-injection of other hazardous wastes in Class VI wells is appropriate, 

but also implies that subtitle C regulation offers a greater degree of protection compared to Class 

VI regulation.

If the proposed conditional exemption were to become final rule, EPA is correct in prohibiting the 

intentional co-mingling of hazardous waste. The purpose of Class VI regulations is not to permit the 

construction and operation of hazardous waste disposal wells, but specifically the injection of CO2

for geologic sequestration. However, in prohibiting the intentional co-mingling of hazardous 

wastes, EPA is implicitly accepting that regulation under subtitle C of RCRA and injection in Class I 

Hazardous wells is indeed more appropriate for hazardous wastes than regulation under Class VI of 

the UIC Program. This can only be the case by virtue of subtitle C and Class I hazardous regulation 

offering greater safeguards than Class VI. This becomes important in ways that we outline directly 

below.

Response: EPA does not agree that the hazardous waste mixing prohibition implies that UIC Class 

VI wells offer lesser safeguards than UIC Class I hazardous waste wells, for CO2 streams that are the 

subject of this conditional exclusion. This conditional exclusion is limited to a specific, unique waste 

– CO2 streams that are hazardous waste themselves (i.e., that exhibit a characteristic of hazardous 

waste due to the presence of impurities) – therefore, EPA needed to make clear that any other 

type of hazardous waste injection must continue to occur in UIC Class I hazardous waste wells.

EPA agrees that if the carbon dioxide stream is considered to be hazardous and does not meet the 

requirements of the conditional exclusion, it would need to be disposed of in a manner appropriate 

for hazardous waste, such as injection into a Class I hazardous waste well. 

Comment 3.5.6:

2. EPA’s clear admission that it “has little or no information to conclude that CO2 streams would 

qualify as RCRA hazardous wastes” [FN5: Federal Register, Vol. 76, No. 152, Monday August 8, 

2011, p. 48077-48078] renders the conditional exemption premature.

EPA does not argue that CO2 streams would likely qualify as RCRA hazardous wastes. Instead the 

Agency admits the lack of information that would enable it to conclude whether this is likely to 

happen or not. This directly calls in to question the need for the proposed conditional exemption. If 
84

there is no evidence that such streams would qualify, then the proposed exemption ranges from 

redundant, in that a clear need has not been identified, to unjustified, in that this very lack of 

knowledge may result in streams that do exhibit hazardous characteristics being exempt from 

RCRA subtitle C requirements.

Response: EPA disagrees that the conditional exclusion is premature or unjustified. As explained in 

response to comment 3.5.3, EPA has concluded that the injection of CO2 streams, including 

incidental associated substances derived from the source materials and the capture process, can be 

performed in a protective manner under the conditions identified in this rule. Nor is the exclusion 

redundant. Several commenters have stated concerns regarding the application of the hazardous 

waste regulations to supercritical CO2 streams being sequestered. In light of the early state of data 

development in this area, EPA intends to bring additional clarity to the regulatory regime through 

this rule, by establishing a conditional exclusion from the definition of hazardous waste that would 

apply in the event a generator determines that its CO2 streams exhibit a RCRA hazardous 

characteristic. Generators may also choose to make use of the conditional exclusion in situations 

where, for example, the generator may be uncertain regarding the hazardous waste status of the 

CO2 stream. 

Comment 3.5.7:

3. EPA should not exempt CO2 streams from subtitle C regulation without a better understanding of 

their composition, their potentially hazardous (or otherwise) characteristics in all plausible 

environments, and without identifying allowable contaminants and setting limits for their 

concentration in these streams.

Expanding on the point above, EPA’s admission clearly indicates a lack of knowledge of the 

probable composition of those CO2 streams, their exact properties (in terms of corrosivity, 

ignitability, toxicity and reactivity or other potentially hazardous characteristics). In fact, EPA 

admits that little published data exists on the likely composition of those streams, that a previous 

call for data during the Class VI rulemaking process yielded little additional information, and makes 

a renewed call for “analytical data on the physical and chemical characteristics of hazardous 

contaminants, CO2 content, information on the type of CO2 capture process used, and how the 

samples were collected and analyzed” [FN6: Federal Register, Vol. 76, No. 152, Monday August 8, 

2011, p. 48079] in order to “allow EPA to gain a better understanding of the nature and 

characteristics of captured CO2 streams” [FN7: Id.].

EPA should not grant an exemption from RCRA subtitle C regulations for streams that contain 

unknown concentrations of potentially hazardous contaminants, and without knowledge of the 

exact nature of their hazardous characteristics. The definition of a CO2 stream, which includes 

“incidental associated substances derived from the source materials and the capture process” is 

extremely broad and open ended, and may cover an unacceptably broad spectrum of substances 

and concentrations. These are likely to vary by facility depending on the particulars of the 

technology and plant layout, so it is especially important for EPA to be in possession of reliable 

information on the nature and concentration of these contaminants before it institutes an 

exemption from subtitle C regulation. Class VI regulations do require an analysis of the composition 

of the injected CO2 stream, but those regulations are new and there is no database or experience 

base yet. EPA should wait for the collection of a reliable data set before proceeding with the 

proposed conditional exemption.
85

If EPA proceeds with the conditional exemption, then it would provide a direct pathway for the cocontrol of pollutants that occur in capture plants (such as SOx, NOx and Hg) in Class VI injection 

wells. This would be a direct alternative to the conventional control of these substances through 

commonly established control methods. This would constitute a major policy shift which EPA 

should not undertake without a thorough review of the possible risks to the subsurface 

environment and groundwater, as well as to the air, land, and human health from their possible 

releases. The fact that control of some of these substances may be necessitated through pipeline 

regulations or by the nature of some CO2 capture processes [FN8: Some of today’s CO2 scrubbing 

solvents are sensitive to contamination by sulfur oxides and mercury, for example] does not 

constitute sufficient protection of human health and the environment, and in no way justifies EPA’s 

proposed exemption.

Response: While EPA agrees that obtaining more data on the composition of CO2 streams that will 

be injected into UIC Class VI wells is important overall, EPA disagrees with the commenter that the 

conditional exclusion should not be finalized without more information on the "...concentrations of 

potentially hazardous contaminants, and without knowledge of the exact nature of their hazardous 

characteristics." The particular inquiry before EPA in this rulemaking is whether RCRA subtitle C 

regulation is necessary to protect human health and the environment. EPA has concluded that the 

injection of CO2 streams, including incidental associated substances derived from the source 

materials and the capture process, can be excluded from the definition of hazardous waste under 

conditions that will ensure that CO2 streams are managed in a manner that addresses the potential 

risks to human health and the environment. This is the case regardless of the precise nature of the 

CO2 stream. EPA therefore has not altered its conclusion that the conditional exclusion is 

appropriate, and sees no need to delay further action on the conditional exclusion to gather 

additional data. EPA notes that the commenters did not identify the plausible environments to 

which they were referring. 

Comment 3.5.8:

Accordingly, if EPA were to finalize a conditional exemption of the nature contemplated in the 

proposal, it should identify a list of allowable contaminants that the CO2 stream may contain, and 

set maximum limits for them. The list of allowable contaminants must be derived from wellfounded science and data that clearly demonstrates that they will not pose undue risk to the 

subsurface environment, water, land, air and public health in their location of disposal or in the 

event of a release from Class VI wells or other potential leakage pathways in their vicinity. 

Appropriate tests and criteria must be identified to that effect. These may or may not be based on

the existing TCLP test, but must capture the potentially hazardous nature of contaminants in the 

CO2 stream in all possible environments where they may find themselves present intentionally or 

unintentionally.

Response: EPA disagrees it needs to identify a list of allowable contaminants that the CO2 stream 

may contain and set maximum limits for them. EPA has concluded that the injection of CO2 

streams, including incidental associated substances derived from the source materials and the 

capture process, can be performed in a protective manner at a permitted UIC Class VI well. This is 

the case regardless of the precise contaminants, and their concentrations, because the UIC Class VI 

permitting requirements will take into account the physical and chemical characteristics of the CO2 

streams before any injection may occur, as part of establishing the appropriate conditions for the 

successful confinement of CO2 in a manner that is protective of USDWs. EPA emphasizes that the 

UIC Class VI regulations themselves require that the chemical composition and physical 
86

characteristics of the CO2 streams be known as part of the initial permitting process, as well as 

during operation of the well, in order to ensure that these CO2 streams can be injected in a manner 

that is protective of human health and the environment. EPA expects that this will provide a full 

understanding of the properties of the CO2 streams being injected, including specific contaminants 

and their concentrations. EPA intends to monitor any data on the chemical composition and 

physical characteristics of the CO2 streams being injected by the UIC Class VI permitting program 

and to use that information to determine whether changes to the conditional exclusion may be 

appropriate.

Comment 3.5.9:

4. If EPA were to finalize the conditional exemption, it must provide further evidence and present a 

thorough analysis on a point-by-point basis showing that requirements for Class VI wells are at 

least as protective as those for Class I hazardous wells.

While Class VI is the appropriate class of well for geologic sequestration of CO2, EPA has not 

sufficiently demonstrated that it will be equally protective as Class I hazardous regulations if the 

CO2 stream also contains hazardous constituents. Class VI does not contemplate the injection of 

hazardous CO2 streams nor does it require operators to evaluate whether the presence of 

hazardous material in the CO2 stream could result in increased endangerment to USDWs, or to 

develop strategies to mitigate any increased endangerment. That is not to say, however, that some 

requirements of Class VI are not at least as, or more, protective that Class I requirements – but EPA 

has not provide adequate justification to that affect.

Although EPA provides a summary of key elements of the Class VI rule and its requirements [FN9: 

Federal Register, Vol. 76, No. 152, Monday August 8, 2011, p. 48084-44085], its description of Class 

I requirements is far more scant and does not enable a reliable enough comparison of 

requirements of the two well classes. In addition, it is not sufficient for EPA to use general 

descriptions of these requirements as support for the assertion that Class VI well regulations are as 

protective as those for Class I hazardous wells. For example, in asserting that “Class VI wells must 

meet the same stringent injection well construction standards as Class I hazardous waste wells”, 

EPA provides no references to these requirements or state what they are. In order for EPA to 

credibly claim an equivalent level of protection, it must provide a thorough, analytical comparison 

of rule requirements, ideally in tabulated manner, with references to and quoting the rule language 

verbatim. This may take place in the form of a comparison table in an appendix or in another form 

that enables the reader to compare requirements for the two injection well classes directly.

Response: EPA disagrees that it needs to compare the UIC Class I hazardous waste and Class VI 

requirements point-by-point in order to demonstrate that the requirements for UIC Class VI wells 

are at least as protective as UIC Class I hazardous waste wells for CO2 streams. Determining 

whether a conditional exclusion is appropriate includes consideration of whether a waste may not 

present a hazard because it is already subject to adequate regulation. In determining whether 

existing regulation is adequate, EPA does not necessarily need to show that each existing 

requirement has a corresponding analogue in the RCRA subtitle C regulations. While the Class VI 

requirements were not developed to address hazardous waste streams, EPA believes that the Class 

VI requirements provide the most appropriate and protective environmental management of 

carbon dioxide streams (including those streams that may be hazardous under RCRA subtitle C) by 

addressing each technical aspect of injection well siting, construction, operation, and closure. 
87

The Class I hazardous waste requirements, available at Subpart G of 40 CFR Part 146, were 

developed for certain types of hazardous wastes (typically liquid wastes, predominantly water), 

while the UIC Class VI requirements are designed to ensure that the CO2 streams (which may 

include low concentrations of hazardous constituents) 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 views the 

elimination of exposure routes through these requirements as determinative in its 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. See response to comment 3.5.8

Moreover, in some instances, a point-by-point comparison may not even be appropriate. For 

example, the UIC Class VI requirements are designed for the unique characteristics of CO2, 

including its large volume and its buoyancy relative to other fluids in the subsurface, unlike the 

typical fluids injected into UIC Class I hazardous waste wells. Finally, EPA also notes that the 

commenters, despite their general criticism that EPA did not undertake a particular enough analysis 

of the respective regulatory regimes, did not actually reject EPA’s ultimate conclusion that the UIC 

Class VI requirements are sufficiently protective, nor did they provide any evidence of gaps in 

protection or other deficiencies in the analysis that only a more particularized analysis would 

reveal.

Comment 3.5.10:

5. If EPA were to finalize the conditional exemption, the signed certification must be submitted to 

the UIC Program Director and be available publicly.

EPA’s current proposal only requires the signed certification to be kept on site. We believe that this 

requirement is not sufficient, especially given that requirements under RCRA’s Enhanced Public 

Participation Rule would not apply. The certification should be submitted to the UIC Program 

Director and be made publicly available on the regulator’s website.

Response: EPA agrees that provision should be made for public availability of the certification, and 

has added a provision for the statement to be posted prominently on the signatory’s publiclyavailable website, if such website exists. As EPA made clear in the proposed rule, one of its key 

concerns with the certification statement was to ensure compliance with the terms of the 

conditional exclusion. Posting the signed certification statements on-line will promote compliance 

and accountability by providing efficient access by regulatory authorities and interested members 

of the public (consistent with the intent of the RCRA Enhanced Public Participation Rule) to the 

exclusion certifications and the identities of the responsible officials. Moreover, EPA expects that 

posting the certifications on-line will simplify the reporting obligation for the regulated community 

because accessible internet posting obviates the need for a regulatory agency to request a hard 

copy. EPA notes that it is not requiring the creation of any new corporate or other website. 

In the final rule, EPA is not requiring that the signed certification statement be submitted to the UIC 

Program Director. EPA does not believe that an additional submission requirement will be 

necessary because the signed certification statement will in most circumstances be directly 

accessible on the injection facility’s website. EPA also notes that as part of the process of obtaining 

a UIC Class VI permit, owners and operators who plan to claim the conditional exclusion may 
88

choose to submit the certification to the UIC Program Director to provide the necessary clarity on 

the status of the CO2 streams under RCRA.

Comment 3.5.11:

D. Conclusion 

Due to the reasons listed above, we believe that EPA has not sufficiently demonstrated that 

conditionally excluding CO2 streams that are hazardous from the definition of hazardous waste is 

warranted or appropriate. Additional analysis is needed to determine whether CO2 streams may 

contain hazardous material, the exact nature of the hazard in different environments and the 

potential concentrations of such material in CO2 streams. In addition, EPA has not provided 

sufficient justification that disposing of such streams in Class VI wells will be as protective as those 

methods specifically designed for the disposal of hazardous waste under subtitle C of RCRA.

Response: See responses to comments 3.5.6 - 3.5.9. The Agency commits to reviewing, in a manner 

similar to the adaptive approach planned for the UIC Class VI rule, new research, data, and 

information related to this conditional exclusion, particularly with respect to compliance with the 

conditions of the exclusion and the nature and composition of CO2 streams.

3.6 Clean Air Task Force

Document ID: EPA-HQ-RCRA-2010-0695-0089

Comment 3.6.1:

The Clean Air Task Force (CATF) thanks the United States Environmental Protection Agency (EPA) 

for the opportunity to respond to EPA's proposed rules concerning Hazardous Waste Management 

System: Identification and Listing of Hazardous Waste: Carbon Dioxide (CO2) Streams in Geologic 

Sequestration Activities, 76 Fed. Reg. 48,073 (August 8, 2011). We appreciate your consideration of 

these comments.[FN1: Solite Corp. v. EPA, 952 F.2d 473, 485 (D.C. Cir. 1991), holds that the Agency 

can consider and rely on information received after the close of a public comment period on a rule, 

where the added information is used to check or confirm prior assessments]. 

Founded in 1996, CATF is a nonprofit organization dedicated to restoring clean air and healthy 

environments through scientific research, public education, and legal advocacy. CATF strongly 

believes that geologic sequestration of CO2 (GS), correctly implemented, must be a component of 

the U.S. climate change mitigation portfolio. CATF recognizes the important goal that this 

rulemaking seeks to foster, i.e. to "substantially reduce the uncertainty associated with identifying 

CO2 streams under RCRA Subtitle C, and will also facilitate the deployment of GS by providing 

additional regulatory certainty.” 76 Fed. Reg. at 48,074.

Response: EPA acknowledges the comment. 

Comment 3.6.2:

Specifically, CATF can support a conditional exclusion, for CO2 streams injected for the purpose of 

sequestration, from the RCRA definition of hazardous waste, and we recognize that EPA has 

provided with its proposal a good deal of support for many aspects of the conditional exclusion.

Response: EPA thanks the commenter for its support of the conditional exclusion.
89

Comment 3.6.3:

EPA asserts that Class VI well regulations under the Safe Drinking Water Act’s Underground 

Injection Control Program (UIC) provide more protection than Class I well regulations to which the 

CO2 streams would be subjected absent the exclusion; EPA asserts that the Class VI well 

regulations’ corrective action planning and enforcement program can take the place of the RCRA 

Land Disposal Regulatory Scheme (because Class VI rules are developed specifically for CO2 streams 

as defined in the Class VI rules).

Based on these assertions, EPA proposes to exclude CO2 injected for sequestration from RCRA 

Subtitle C requirements that would otherwise apply, provided that:

1) Transportation of the CO2 stream is in compliance with Department of Transportation (DOT) 

regulations;

2) Injection is in compliance with the Class VI well requirements;

3) No other hazardous wastes may be mixed with or co-injected with the CO2 stream; and

4) A certification statement is signed by the generator, and the well owner or operator that these 

conditions are met.

See 76 Fed. Reg. at 48,092-93 (proposed 40 C.F.R. § 261.4(h)).

Implicit in the first condition is the satisfaction of the DOT requirement in 49 CFR §195.2, that CO2

consists of “more than 90 percent carbon dioxide molecules compressed to a supercritical state ....” 

Id. at 48,082. This regulation addresses the need for sufficient CO2 purity levels to avoid pipeline 

corrosion. Class VI wells and reservoirs are, in turn designed to handle CO2 and “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.” Id. at 48,088, 48,092 

(proposed new RCRA definition, tracking class VI definition of “carbon dioxide stream”). Taken all 

together, CATF reads the proposed RCRA exclusion to be available to CO2 streams with a purity 

level of 90 percent CO2 commingled with incidental other substances up to 10%, but not 

commingled with or co-injected with other substances that are listed or characteristic hazardous 

wastes. CATF notes that this is not clear from the proposed regulatory text. CATF also notes that 

the Agency requests further information about “the types and characteristics of substances that 

are added to CO2 streams to enable or improve the injection process,” id. at 48,088, and about 

“whether there are other conditions, such as a minimum CO2 content, that could enhance 

compliance with the proposed “no mixture” condition. Id. at 48,087.

Response: The commenter summarizes how they generally interpret the conditional exclusion. 

With regard to the commenter’s statement that “EPA asserts that Class VI well regulations under 

the Safe Drinking Water Act’s Underground Injection Control Program (UIC) provide more 

protection than Class I well regulations to which the CO2 streams would be subjected absent the 

exclusion” EPA clarifies that the UIC Class VI requirements are more appropriate for CO2 streams 

than UIC Class I hazardous waste requirements, as the latter were developed for certain types of 

hazardous wastes (typically liquid wastes, predominantly water), while the UIC Class VI 

requirements are designed to ensure that the CO2 streams (which may include low concentrations 

of hazardous constituents) 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. See response to comment 3.5.9. 
90

EPA also clarifies that the proposed conditional exclusion did not specify an minimum CO2 content 

(nor does this final rule), rather, as EPA pointed out in the preamble to the proposed rule, the DOT 

requirements for supercritical CO2 streams sent via pipeline limits the CO2 content to 90 percent or 

greater. EPA believes the regulatory language finalized today is clear.

Comment 3.6.4:

CATF suggests that EPA can and should go further in demonstrating in its final rule that there is 

sufficient protection in the provisions of the UIC Class VI rules combined with the DOT regulation’s 

purity requirements, to replace the provisions of RCRA – specifically with respect to the question 

whether Class VI regulations governing CO2 streams as defined in the conditions precedent to the 

exclusion are as or more protective than the RCRA provisions which will no longer apply to these 

CO2 streams when the exclusion is finalized. To that end, CATF engaged in a preliminary review of 

the history of acid gas injection (AGI) in the US and Canada, which appears to support EPA's 

position that the proposed conditional exclusion is sufficient to replace RCRA protections. As 

described in more detail below, in the US, AGI projects can involve mixtures of CO2 and other 

materials where the CO2 is less than 90 percent of the injectate (by volume). These projects are 

permitted under UIC Class II wells, (which we believe are also less protective than Class VI wells and 

subpart RR requirements for sequestration). We understand that Canada has a similar regulatory 

scheme, although a comparative analysis of the US/Canadian permitting scheme was not 

undertaken by CATF. We note however, the existence of a body of Canadian technical research 

evaluating the 48 Alberta Basin AGI sites, which concludes that at no time during the three decades 

of AGI in Alberta was public safety at risk, including after over 2 million tons of injections.[FN2: 

Stefan Bachu & Theresa L. Watson, Review of Failures for Wells used for CO2 and Acid Gas Injection 

in Alberta, Canada, 1 Energy Procedia 3531 (2009), attached as Exhibit 1]. Therefore, CATF suggests 

that EPA more closely examine the AGI experience in the US and Canada and evaluate it, in the 

record of the rule finalizing the proposed RCRA exemption for CO2 streams in Class VI wells.

We describe the Canadian technical research below. Additionally, we suggest specific amendments 

to the proposed rule text in order to provide clarity to three specific aspects of the rule.

Response: Regarding the comment referencing Acid Gas Injection (AGI), EPA agrees that AGI 

experience can inform GS injection activities, and EPA examined AGI as part of its research to 

support options selection for the Class VI Rule. Many of the findings of this research supported 

EPA’s final requirements for the construction and testing of Class VI wells, including the use of 

carbon dioxide-compatible materials, corrosion monitoring, and continuous pressure, volume, and 

temperature monitoring to verify internal mechanical integrity. EPA notes that comments on the 

UIC Class VI rulemaking are beyond the scope of this final rule, and EPA did not consider AGI in 

developing the proposed hazardous waste exclusion. While the Agency acknowledges that AGI 

takes place in the energy industry, it takes place using UIC Class II wells, not UIC Class VI wells, 

which were the focus of EPA’s analysis in support of the conditional exclusion. Because AGI wells 

occur under well classes other than UIC Class VI wells, the protectiveness of those operations are 

beyond the scope of this rule.

Regarding the commenter’s reference to the protectiveness of UIC Class II wells and subpart RR 

requirements, EPA did not develop information for inclusion in the proposal on well classes other 

than UIC Class VI wells. EPA did not compare the UIC Class II well regulations with the UIC Class VI

well regulations, and such a comparison is irrelevant to this rulemaking. EPA notes that it did not 
91

propose to rely on, nor as part of the final rule did rely on, Clean Air Act controls as conditions. EPA 

does not believe this is necessary, as for reasons explained elsewhere, it believes the final rule 

conditions are appropriate in themselves.

Comment 3.6.5:

A. EPA authority to create conditional exclusions from RCRA hazardous waste requirements 

CATF recognizes that EPA has discretion under the Resource Conservation and Recovery Act (RCRA) 

to create regulatory exclusions for particular wastes that would otherwise be qualified as 

"hazardous waste" under RCRA. See e.g., Military Toxics Project., v. EPA 146 F.3d 948 (D.C. Cir. 

1998)(holding Agency has broad discretion to issue conditional exclusions that exempt waste 

streams from RCRA's definition of a hazardous waste). Additionally, CATF supports EPA's proposed 

reliance on DOT requirements, the Safe Drinking Water Act’s UIC Class VI well regulations, and the 

Clean Air Act’s Green House Gas Reporting Rule, Subpart RR (GHG) requirements to manage CO2

injected for the purpose of permanent sequestration, when utilizing such controls in conjunction 

with RCRA regulations would be repetitive and overly burdensome.[FN3: 40 CFR §261.11(a)(3)(x): 

After considering factors, including, action taken by other governmental agencies or regulatory 

programs based on the health or environmental hazard posed by the waste or waste constituent, 

the Administrator may create an exclusion.]. 

RCRA provides a "cradle-to-grave" approach to the treatment, storage, and disposal of hazardous 

waste. [FN4: 42 U.S.C. §6921]. Under 42 U.S.C. §6921(a), the Administrator of the EPA is charged to 

"develop and promulgate criteria for identifying the characteristics of hazardous waste, and for 

listing hazardous waste, which should be subject to provisions of Subtitle C." While CATF 

acknowledges that under RCRA Congress has left discretion to EPA to determine how and when 

substances are classified as a hazardous waste, that authority is, of course, not unbounded. [FN5: 

NRDC v. EPA, 25 F.3d 1063, 1070 (D.C.D.C. 1994)(stating, "of course, however reasonable the 

agency's interpretation of its regulations, we must not give those regulations effect if they conflict 

with the governing statute.")]. EPA must base its final exclusion on considerations of whether the 

rules that will effectively replace RCRA requirements when an exclusion is created will be sufficient 

to protect human health and the environment. 40 CFR §261.11(a)(3)(x).

Response: EPA has the authority to issue conditional exclusions from the hazardous waste 

regulations. EPA’s authority to issue the rule is described in section II.B. of the final rule preamble. 

EPA also believes that it appropriately concluded that management of CO2 streams under the terms 

of the final rule does not present a substantial risk to human health and the environment, making 

additional regulation under RCRA unnecessary. EPA notes that it did not propose to rely on, nor as 

part of the final rule did rely on, Clean Air Act controls as conditions. EPA does not believe this is 

necessary, as for reasons explained elsewhere, it believes the final rule conditions are appropriate 

in themselves. 

Comment 3.6.6:

B. CATF suggests that EPA consider and evaluate the AGI experience in finalizing the conditional 

exclusion. 

The experience to date with acid gas injections in Class II UIC wells, by the oil and gas industry in 

the US, as well as the acid gas injection experience in Canada, may provide a basis of support for 

EPA’s proposed conditional exclusion from RCRA’s hazardous waste definition for CO2 sequestered 
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in GS wells governed by the protections offered by Class VI, Subpart RR and DOT pipeline 

regulatory limits on CO2 quality.

CATF suggests that EPA should review the experience with AGI projects undertaken under Class II 

well regulations over the past two decades. Although EPA states, "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" 76 

Fed. Reg. at 48,077, 48,079, in fact AGI projects that have occurred in the United States and Canada 

for many years may provide EPA with evidence that the conditional exclusion is appropriate.

U.S. AGI activity involves injections of CO2 streams mixed with up to 76 percent hydrogen sulfide 

(H2S), has occurred for many years in Class II wells. [FN6: J. Kenneth Klewicki et al., Acid Gas 

Injection in the United States. Proceedings of the Fifth Annual Conference on Carbon Capture and 

Sequestration, DOE/NETL (2006) attached as Exhibit 2]. By comparison, as described above, CO2

streams injected for permanent subsurface containment in Class VI wells are governed by DOT 

standards requiring at least 90% CO2. Furthermore, EPA notes that UIC Class VI and CAA Subpart RR 

rules provide more regulatory protection for the sequestered CO2 than does the Class II regulatory 

scheme, alone. The Class VI/Subpart RR/DOT regulatory framework embodied in the conditions 

EPA proposes for the RCRA exclusion therefore should be sufficiently protective of human health 

and the environment to justify the proposed conditional exclusion from the RCRA regulatory 

scheme for hazardous waste for GS CO2 streams.

AGI operations in the United States are regulated under the Class II well standards of the Safe 

Drinking Water Act’s Underground Injection Control Program. Although EPA has classified H2S as a 

hazardous waste, [FN7: 40 CFR 261.33, Hydrogen sulfide is designated as Hazardous Waste No. 

U135]. Congress amended RCRA in 1980 to exempt drilling fluids, produced waters, and other 

wastes associated with oil and gas [FN8: 40 C.F.R. §261.4(b)(5), provides that "Drilling fluids, 

produced waters, and other wastes associated with the exploration, development, or production of 

crude oil, natural gas or geothermal energy" are solid wastes that are not hazardous wastes. 

Additionally, AGI is an activity that is characterized “underground injection for the secondary or 

tertiary recovery of oil and natural gas” or is associated with the “underground injection of brine or 

other fluids which are brought to the surface in connection with oil or natural gas production or 

natural gas storage operations,” and therefore in accordance with 42 U.S.C. §300h (b)(2), 

“Regulations of the Administrator under this section [the UIC program] ...may not prescribe 

requirements which interfere with or impede (A) The underground injection of brine or other fluids 

which are brought to the surface in connection with oil or natural gas production or natural gas 

storage operations, or (B) Any underground injection for the secondary or tertiary recovery of oil or 

natural gas, unless such requirements are essential to assure that underground sources of drinking 

water will not be endangered by such injection] from the RCRA definition of hazardous waste; 

[FN9: The Solid Waste Disposal Act Amendment of 1980 (SWDA), Pub. L. 96- 482, 94 Stat. 2334, 

added the Bevill amendment to §3001 of RCRA, "temporarily" suspending regulation of certain 

"special" wastes from oil and gas, mining, and utility industries] and therefore, AGI occurs in Class II 

rather than Class I wells, despite the hazardous characteristics of acid gas streams. As noted above, 

U.S. AGI activity involves injections of CO2 mixed with up to 80 percent H2S by volume.

For comparative purposes Table 1.1 provides compositions (by volume) of anthropogenic CO2

streams derived from carbon capture facilities. These capture stream compositions suggest that 

today’s pre- and post-combustion capture techniques yield CO2 streams that characterized by 
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purity levels on the order of 95% or greater CO2, and 5 percent or less (by volume) of other 

impurities. CATF’s literature search suggests CO2 purity levels for oxyfuel combustion occupy a 

broader range, from 85-99%, however, these streams are also characterized by several percent or 

more of the inert, non-reactive gas argon by volume, thereby increasing their effective purities.

TABLE 1.1[See PDF Docket ID EPA-HQ-RCRA-2010-0695-0089]

Additionally, CATF’s preliminary literature search uncovered several studies documenting AGI 

experience in the Alberta Basin in western Canada, where 48 AGI injection sites were active. [FN13: 

Stefan Bachu & Kristine Hague, In Situ Characteristics of Acid Gas Injection Operations in the 

Alberta Basin, Western Canada: Demonstration of Geological Storage, Vol. 2, Carbon Dioxide 

Capture for Storage in Deep Geologic Formations— Results From the CO2 Capture Project, 867 

(Sally M. Benson, et al., eds.) (2005), attached as Exhibit 4; see also Stefan Bachu et al., Evaluation 

of the Spread of Acid Gas Plumes Injected in Deep Saline Aquifers in Western Canada as an 

Analogue for CO2 Injection in Continental Sedimentary Basins, Published in: 1 Proceedings of 7th 

International Conference on Greenhouse Gas Control Technologies 479- 487 (E.S.Rubin, D.W.Keith 

and C.F.Gilboy, eds.,) (2005); available at: http://uregina.ca/ghgt7/PDF/papers/peer/012.pdf.], 

[FN14: H.L. Longworth et al., Underground Disposal of Acid Gas in Alberta, Canada. Regulatory 

Concerns and Case Histories, SPE 35584 (1996), attached as Exhibit 5], [FN15: Bachu, supra note 2.] 

Well over two million tons of acid gas have been injected in these wells, in accordance with 

Alberta’s regulatory requirements [FN16: See Alberta Canada ERCB Guide, G-51, available at: 

http://www.ercb.ca/docs/documents/directives/Directive051.pdf] assertedly without any reported 

safety or leakage incidents. [FN17: Bachu, supra note 2]. 

And, insofar as CATF has been able to determine, there have been no reported incidents of 

groundwater contamination associated with AGI in the United States over the past several decades. 

[FN18: Review of the available scientific literature and searches for published legal cases involving 

the release of AG from Class II injection wells did not result in information documenting such 

releases, or evidence of any litigation over damages from any such releases. CATF suggests that 

EPA closely review any reports of H2S releases, given the recent lifting of the administrative stay 

under EPCRA of §313 reporting requirements for hydrogen sulfide. See 76 Fed. Reg. 64,022 (Oct. 

17, 2011)]. CATF suggests that because injected CO2 streams have been commingled with volumes 

of H2S that are far greater – and therefore more corrosive – than would be characteristic of CO2

capture streams for Class VI wells (Table 1.1), and that because the Class II wells have apparently 

not experienced any harmful releases, the provisions of the proposed conditional exclusion may be 

sufficient. That is, the proposed Class VI/Subpart RR/DOT scheme can be shown to be sufficiently 

protective of human health and the environment by comparison, and this comparison offers 

further support for the conditional exclusion from RCRA regulation EPA has proposed. As we 

assume much of the data on AGI resides with the Agency, however, EPA will need to confirm this in 

the final rule.

Response: EPA thanks the commenter for the information. See responses to comments 3.6.3 –

3.6.5. Acid gas injection (AGI) has indeed been conducted through the Agency’s UIC Class II 

program. However, the scope of this rule is expressly limited to CO2 streams sent to a permitted 

UIC Class VI well for purposes of GS. Protections afforded by the GS-specific requirements of the 

UIC Class VI Rule include extensive site characterization, assessments of potential mineralization 

reactions between the carbon dioxide and subsurface rocks and fluids, identification of additional 

confining zones where needed, geomechanical assessment, and use of CO2-resistant well 
94

construction materials. The UIC Class VI requirements are designed for the unique characteristics of 

CO2, including its buoyancy relative to other fluids in the subsurface and potential presence of 

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

hazardous) in captured CO2.

EPA disagrees with the commenter’s statement that EPA has noted that “UIC Class VI and CAA 

Subpart RR rules provide more regulatory protection for the sequestered CO2 than does the Class II 

regulatory scheme, alone.” See specifically response to comment 3.6.4.

Comment 3.6.7:

C. CATF suggests specific revisions to the proposed regulatory text, to reference subpart RR, to 

clarify that the CO2 itself is not hazardous, under the exclusion, and to conform the certification 

requirements with other Class VI recordkeeping requirements

i. CATF suggests that the regulatory conditional exclusion should conform to the requirements of 

the UIC Rules and the Clean Air Rules that govern Class VI wells As written, the proposed 

conditional exclusion does not conform to or cross reference the language of the UIC or Clean Air 

Monitoring and Reporting Rules that govern Class VI wells. In an effort to promote clarity and 

consistency CATF suggests modifying the proposed conditional exclusion.

EPA's proposed rule now states that, "Carbon Dioxide streams that are captured and transported 

for purposes of injection into an underground injection well subject to the requirements of 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."

CATF suggests that this portion read as follows "Carbon Dioxide streams that are captured and 

transported for THE PRIMARY purposes of injection into an underground injection well subject to 

the requirements of 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, AND THE GREEN HOUSE GAS REPORTING PROGRAM CONTAINED IN 40 CFR PARTS 86, 87, 89, 

are not a hazardous waste, provided the following conditions are met."

CATF suggests inserting the word "primary" in this portion because this language would help mirror 

40 CFR §144.19 regarding Class II wells that transition into Class VI wells, [FN19: 40 CFR §144.19 

states that: Owners or operators that are injecting carbon dioxide for the primary purpose of 

carbon storage into an oil and gas reservoir must apply for and obtain Class VI geologic 

sequestration permit when there is an increased risk to USDWs compared to Class II operations. In 

determining if there is an increased risk to USDWs, the owner or operator must consider the 

factors specified in §144.19(b)] and therefore will help make it clear that it is the Class VI 

protections and other environmental regulations that will adequately address any risk posed by any 

plausible mismanagement of the CO2 after injection. Using "primary purpose" in the conditional 

exclusion will provide clarification and consistency for Class II operators, as well.

CATF also suggests inserting the reference to the Green House Gas Reporting Rule Subpart RR in 

this section because the preamble to the proposed rule states that the GHG Rule is an important 

rule that directly addresses GS, and provides additional protections for CO2 sequestered in Class VI 

wells. 76 Fed. Reg. at 48,077. The GHG Rule contains reporting requirements that are important to 
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GS activity in the context of the exclusion since they require analysis of the composition of the 

injectate.

Response: EPA has not included the commenter’s suggested edits into the rule. EPA clarifies that 

40 CFR 144.19 does not allow GS under the Class II requirements. Rather, it recognizes that 

construction of EOR/EGR wells could be grandfathered, but identifies criteria on which to base a 

determination that the project is no longer an EOR/EGR project and requires a Class VI permit. 

Injection projects that meet the criteria at 40 CFR 144.19 must be pre-permitted as Class VI. If a 

determination is made under 40 CFR 144.19 that there is increased risk to USDWs and the operator 

cannot demonstrate that large-scale injection for GS can be performed without endangering 

USDWs, the site cannot receive a Class VI permit and would not be eligible for the conditional 

exclusion.

Again, EPA did not develop information for inclusion in the proposal on well classes other than UIC 

Class VI wells. EPA notes that it did not propose to rely on, nor as part of the final rule did rely on, 

Clean Air Act controls as conditions. EPA does not believe this is necessary, as for reasons explained 

elsewhere, it believes the final rule conditions are appropriate in themselves.

Additionally, EPA points out that the UIC Class VI regulations themselves require that the chemical 

composition and physical characteristics of the CO2 streams be known as part of the initial 

permitting process, as well as during operation of the well, in order to ensure that these CO2 

streams can be injected in a manner that is protective of human health and the environment.

Comment 3.6.8:

ii. EPA must clarify that although no hazardous waste may be intentionally mixed with CO2

qualifying for the exclusion, that the CO2 itself is not “hazardous” under the exclusion 

The proposed conditional exclusion requires owner/operators and generators to sign a certification 

form that states their actions have conformed with all of the conditions, including the third 

condition that "no other hazardous wastes may be mixed with, or otherwise co-injected with, the 

carbon dioxide stream." This sentence has grammatical issues that should be modified to avoid 

confusion, and it also makes complying with the certification form problematic for generators, as 

explained below in part iii.

The use of the word "other" in this sentence is confusing because the purpose of the exclusion is to 

provide that the CO2 stream is classified as non-hazardous, provided all conditions are met. 

Including the word "other" indicates that a carbon dioxide stream is itself a hazardous waste and 

that no additional "other" hazardous wastes may be added to the hazardous carbon dioxide 

stream. Therefore, the word "other" should be removed from this sentence and the word "may" 

should be replaced with the word "shall." By using "may" rather than "shall" EPA is not, as it must, 

prohibiting knowingly commingling hazardous wastes with the CO2 stream. Therefore, the CATF 

suggests that the conditional exclusion should read, "NO HAZARDOUS WASTE SHALL BE MIXED 

WITH, OR OTHERWISE CO-INJECTED WITH, THE CARBON DIOXIDE STREAM."

Response: The Agency has concerns that the term ‘other’ may be confusing. EPA fails to see why 

the use of “may” instead of “shall” somehow makes the proposed mixing prohibition any less 

mandatory, since the proposed rule’s phrasing “No . . . hazardous wastes may be mixed with . . .” is 

clearly language of a prohibition. Nevertheless, to remove any doubt about this, EPA is changing 
96

the phrasing to “shall.” EPA does not understand this change to alter the meaning of the mixing 

prohibition, but merely to clarify it. Therefore, EPA decided to revise the wording of the condition 

and is finalizing the following language: “No hazardous wastes shall be mixed with, or otherwise coinjected with, the carbon dioxide stream.” 

Comment 3.6.9:

iii. CATF suggests that the certification statement for the exclusion be kept on-site during the 

relevant operating and post-closure period under UIC Class VI, and that the certification statement 

should be modified to promote clarity.

The proposed conditional exclusion only requires that the signed certification statement be kept 

on-site for a minimum of three years after the injection of a CO2 stream, and that it be made 

available within 72 hours of a written request from the Regional Administrator or state Director (if 

located in an authorized state). Additionally, the certification statement must be renewed every 

year that the exclusion is claimed. By contrast, Class VI rules require site closure records to be kept 

for 10 years. 40 C.F. R. § 146.93(f).

CATF suggests that EPA require owners/operators and generators to maintain certification forms 

for the same period for which Class VI well site closure records must be maintained. This will 

ensure that there is a complete record in the event that there is a release and questions regarding 

liability ensue. 40 CFR § 146.93(f) requires that post-closure site care records must be retained for 

10 years. CATF suggests that certification statements be kept for the full period of injection, and as 

well, remain for the 10 years post closure, or the amount of time that the Director determines is 

appropriate, consistent with class VI regulations.

Response: EPA is not entirely clear what type of release and resultant liability to which the 

commenter refers, however, EPA still believes that the 3-year recordkeeping requirement for the 

certification statement is sufficient for purposes of allowing access to these documents. EPA notes 

that the conditional exclusion certification is not a one-time requirement, but must be renewed 

annually, so that there is essentially a rolling 3-year record retention requirement (for as long as 

the conditional exclusion is being claimed).

The 3-year period is consistent with several other recordkeeping requirements under RCRA subtitle 

C. Generators and UIC Class VI well owners and operators can certainly maintain these records for 

a longer period if they wish to do so, to help document their efforts to comply with the exclusion. 

In addition, the final conditional exclusion also requires that the certification statement be posted 

prominently on the signatory’s publicly-available website, if such website exists. EPA believes 

makes this will make them more accessible to both the public and state directors. Finally, under 

the UIC Class VI regulations, UIC Directors have the option of requesting additional information 

from the permit applicant under 40 CFR 146.82(a)(21). Such information may include the 

certification (if the exclusion is being claimed at that time) and thus it would be maintained for a 

period of 10 years after site closure (see §146.91(f)(1)).

Comment 3.6.10:

Furthermore, the certification form in its current form is overly burdensome for generators. The 

purpose of the certification form is to ensure that both generators and owners/operators attest 

that they meet the all of the conditions required to obtain the exclusion. The proposed rule, 

however, requires generators not only to guarantee that they have met all of the conditions, but 
97

they must also to certify that the owner/operator that the generator contracts with has not 

comingled any hazardous waste with the generator's CO2 stream. But the generator has no way of 

determining whether an owner/operator has co-mingled its CO2 stream with hazardous waste. This 

creates an undue burden for generators to police owner/operators to ensure that 

owners/operators are complying with the conditions. For example an injection operator may add 

well stimulants to the CO2 stream. Generators should be required to determine that the 

owner/operator that accepts the generator's CO2 waste stream is properly permitted as a Class VI 

well; however, the generator should not be required to monitor all downstream owners/operators 

to ensure that the owner/operator does not co-injecting hazardous waste with the generator's CO2

stream. Therefore, CATF suggest EPA modify the certification form language to ensure that 

generators are not unfairly burdened by this rule.

Response: EPA agrees that it may be difficult for generators to certify compliance by the well 

owner or operator with the rule’s conditions. Therefore, EPA has modified the certification 

requirement in the final rule so that there are now two separate certification statements worded 

slightly differently – one for generators and another for UIC Class VI well owners or operators 

claiming this conditional exclusion. EPA has made these revisions to better reflect actions over 

which each party has control. Under the final rule, the certification statement that the generator 

would sign is specific to the activities within the generator’s control; likewise, the certification 

statement that the UIC Class VI well owner or operator would sign is specific to the activities within 

the owner or operator’s control. 

Comment 3.6.11:

Conclusion:

CATF supports EPA’s issuance of a final rule providing for a conditional exclusion of CO2 from the 

RCRA definition of a hazardous waste, as further supported by additional scientific data gleaned 

from experience with the successful implementation of AGI projects. CATF also suggests that EPA 

modify the rule language promulgating the final conditional exclusion to promote clarity.

Response: EPA believes it has brought additional clarity to the regulatory regime through this rule, 

by establishing a conditional exclusion from the RCRA subtitle C requirements that would apply in 

the event a generator determines that its CO2 streams are hazardous waste. See responses to 

comments 3.6.3-3.6.10.

3.7 Utility Solid Waste Activities Group (USWAG)

Document ID: EPA-HQ-RCRA-2010-0695-0066

Comment 3.7.1:

The Utility Solid Waste Activities Group (“USWAG”) submits these comments on EPA’s proposal to 

conditionally exclude carbon dioxide (“CO2”) streams that exhibit a hazardous characteristic from 

the definition of hazardous waste under the Resource Conservation and Recovery Act (“RCRA”), 

provided those streams are captured from emission sources, are injected into underground 

injection wells for the purposes of geologic sequestration (“GS”) under the Underground Injection 

Control (“UIC”) program, and meet certain other conditions. 76 Fed. Reg. 48073 (Aug. 8, 2011) 

(“the RCRA Proposal”). USWAG is an association of over one hundred and ten energy utilities, utility 

operating companies, energy companies and associations, including the Edison Electric Institute 

(“EEI”), the American Public Power Association (“APPA”), and the National Rural Electric 
98

Cooperative Association “NRECA”). [FN1: EEI is the principal national association of investor-owned 

electric power and light companies. APPA is the national association of publicly-owned electric 

utilities. NRECA is the national association of rural electric cooperatives. Together, USWAG 

members represent more than 73 percent of the total electric generating capacity of the United 

States and service more than 95 percent of the nation’s consumers of electricity and 91 percent of 

the nation’s consumers of natural gas. Throughout these comments, we refer to our industry as the 

“utility” or “electric utility” industry. This term is intended to include those portions of the industry 

and those USWAG members that generate electricity but do not directly provide electricity to the 

public and are technically not “utilities.”]. As the leading utility organization responsible for 

interacting with EPA and other federal and state agencies concerning the management of materials 

from the combustion of coal and other fossil fuels, USWAG submitted comments in 2008 on EPA’s 

proposal to regulate CO2 GS under the UIC program (see 73 Fed. Reg. 43492 (July 25, 2008)) and on 

the 2009 Notice of Data Availability (“NODA”) for CO2 GS (see 74 Fed. Reg. 44802)).

Response: EPA thanks the commenter for the information. 

Comment 3.7.2:

As expressed in our earlier comments on CO2 GS issues, USWAG recognizes that the development 

of a viable carbon capture and sequestration (“ CCS”) regulatory program has been cited by many 

as a prerequisite to the implementation of energy reform initiatives involving carbon reduction 

measures on both the federal and state level. EPA predicts that the electric power sector, including 

USWAG members, “will most likely be the largest potential market for [CCS] technologies,” and 

predicts that CCS technology could lead to CO2 reductions of approximately 80-90% at a single 

plant. 73 Fed. Reg. 44354, 44492 (July 30, 2008). USWAG’s decades of involvement with the 

management of fossil fuel combustion materials, as well as our members’ experiences in the field, 

provide us with a valuable knowledge base and perspective from which to provide meaningful 

input to EPA as the Agency continues to reassess and refine its UIC regulations for CO2 GS. We 

believe that the current RCRA Proposal to conditionally exclude CO2 streams captured and injected 

for GS from RCRA’s stringent hazardous waste controls is an important step in shaping more 

practicable – and therefore more effective – CCS regulations.

Response: EPA believes this rule 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.

Comment 3.7.3:

I. Background: USWAG Comments on the 2008 CO2 GS Proposal 

USWAG’s comments on the original CO2 GS proposal urged EPA to craft regulations that would 

prove flexible enough to be adapted as regulators and industry acquired data on, and experience 

with, large-scale CO2 GS projects. USWAG also emphasized the need for regulatory certainty on 

particular issues of concern, noting that the lack of such certainty could serve as a significant 

disincentive to industry implementation of CO2 GS projects. USWAG highlighted the need for 

Agency clarification of what application, if any, RCRA could have to CO2 streams injected for GS. 

USWAG noted that the proposal prematurely assumed that CO2 injected for GS is being “discarded” 

within the meaning of RCRA and is therefore a solid waste under RCRA. The USWAG comments 

added that, to the extent there is any possibility that CO2 GS injection operations could be subject 

to RCRA controls, EPA should either establish a conditional exclusion from the definition of solid 
99

waste for CO2 GS streams or should exempt such activities from RCRA hazardous waste regulation 

under the well-established contingent management concept since UIC permit conditions would 

provide adequate protection for injected CO2.

The portions of USWAG’s comments on the 2008 proposal relevant to RCRA applicability are 

attached hereto (Attachment A) and hereby incorporated by reference in these comments on the 

RCRA Proposal.

Response: EPA, through this rule, is establishing a conditional exclusion for CO2 streams sent to UIC 

Class VI wells for purposes of GS, under certain conditions. EPA believes this rule 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. The Agency 

commits to reviewing, in a manner similar to the adaptive approach planned for the UIC Class VI 

rule, new research, data, and information related to this conditional exclusion, particularly with 

respect to compliance with the conditions of the exclusion and the nature and composition of CO2

streams. See response to comment 3.2.3.

EPA notes that, despite the commenter’s statement that an Attachment A to their letter was 

submitted to EPA, EPA did not receive that attachment. EPA has provided extensive discussions of 

RCRA applicability questions in Section V of the final rule preamble, in response to USWAG’s other 

comments in this section 3.7, and in response to other commenters. 

Comment 3.7.4:

II. EPA Inappropriately Assumes that CO2 Captured and Injected for CO2 GS is a “Solid Waste” 

EPA incorrectly assumes in the preamble to the RCRA Proposal that supercritical CO2 injected for GS 

is “clearly” a “discarded material” within the meaning of RCRA [Section] 1004(27) and is therefore a 

RCRA solid waste. 76 Fed. Reg. at 48077-78. This statement is overly broad. As a threshold matter, 

supercritical CO2 is best described as an “uncontained gas,” and as such is not included within 

RCRA’s statutory definition of solid waste. See RCRA [Section] 1004(27) (including only “contained 

gaseous material” within the statute’s definition of a solid waste); see also, e.g., in re BP Chemicals 

America, Inc., RCRA Appeal No. 89-4, 1991 WL 208971, at *2 (EPA, Aug. 20, 1991) (explaining that 

only contained gaseous material is a solid waste under RCRA). [FN2: See also 47 Fed. Reg. 27520, 

27530 (fume incinerators “ used to destroy gaseous emissions from various industrial processes ... 

are not subject to regulation under RCRA” because “ the input [i.e., gaseous emissions to the fume 

incinerators] is not identifiable as a solid waste, according to the definition set forth in [Section] 

261.2.” (emphasis added).]. Therefore, supercritical CO2 is not subject to RCRA jurisdiction in the 

first instance.

Response: EPA disagrees that CO2 streams sent to UIC Class VI wells for purposes of GS are not 

solid waste. See response to comments 3.1.1 through 3.1.8.

Comment 3.7.5:

Assuming for the purposes of argument that CO2 can be viewed as a contained gas, and thus 

potentially subject to RCRA regulation, EPA mistakenly categorizes all CO2 captured, transported, 

and injected for sequestration in a Class VI well as a solid waste under the rationale that it has been 

discarded. As USWAG stated in its comments on the 2008 CO2 GS Proposal, CCS technology and 

implementation are still in a nascent stage; EPA should refrain from making categorical 
100

assumptions associated with this still-emerging technology, including with respect to the status 

(i.e., discarded or retaining value) of CO2 captured and injected for CO2 GS.

A series of relevant judicial decisions holds that Congress intended to extend EPA’s authority to 

regulate “solid waste” under RCRA “only to materials that are truly discarded, disposed of, thrown 

away, or abandoned.” American Mining Congress v. EPA, 824 F.2d 1177, 1190 (D.C. Cir. 1987) 

(emphasis added); see also, e.g., Assn. of Battery Recyclers, Inc. v. EPA, 208 F.3d 1047, 1051-52 

(D.C. Cir. 2000). As EPA is well aware, CO2 is a valuable commodity used in a variety of 

manufacturing operations, including in the enhanced oil recovery (“EOR”) and enhanced gas 

recovery (“EGR”) production process. When used in these commercial applications, CO2 is not 

“discarded” and therefore is not a solid waste. While large volumes of CO2 will be produced and 

captured for injection under the new UIC Class VI regulations, it is premature for EPA to presume 

that these additional volumes of CO2 will not retain commercial value and that their sequestration 

in Class VI wells automatically means that they have been “discarded” as that term has been 

defined under RCRA.

This flawed assumption, if incorporated into a final rule, could have far-reaching consequences for 

CCS, including opening the door for unfounded citizen suits under section 7002 of RCRA that would 

only serve to frustrate the successful implementation of CO2 sequestration technologies across the 

country. Indeed, it has been reported that citizen groups have already identified RCRA’s citizen suit 

provisions as a vehicle to hamper the future deployment of CO2 sequestration technologies. B. 

DiCosmo, “Activists Say EPA Plan for CCS Waiver Leaves Door Open to Citizen Suits,” InsideEPA 

(Aug. 10, 2011) (available online at www.insideepa.com). To avoid this counter-productive result, 

EPA should refrain from categorizing all sequestered CO2 as “discarded” and potentially subject to 

unwarranted and disruptive RCRA citizen suits.

Response: See Responses to Comments 3.1.1 through 3.1.8. Regarding the commenter’s 

statement about section 7002 of RCRA, EPA believes that the correct finding is that these CO2

streams injected into UIC Class VI wells for purposes of GS are discarded for the reasons EPA has 

explained throughout its responses to public comments, and any citizen suit will succeed or fail on 

its own merits.

Comment 3.7.6:

III. A Conditional Exclusion for CO2 Streams Captured and Injected for GS is Both Necessary and 

Justified 

Assuming that a CO2 stream captured, transported, and injected for GS is a “solid waste,” EPA has 

appropriately exercised its authority under RCRA to conclude that such a waste stream will not be 

mismanaged in manner that poses “a substantial present or potential hazard to human health or 

the environment” and, as such, does not warrant regulation as a hazardous waste under subtitle C. 

See 76 Fed. Reg. at 48080-81. Therefore, issuance of the conditional exclusion is fully authorized by 

the statute. [FN3: In fact, USWAG believes the conditional exclusion should exclude from the 

definition of solid waste, rather than from the definition of hazardous waste, CO2 streams 

captured, transported, and injected for GS. This is important to help protect against unwarranted 

and disrupted citizen suits as described in section II, above].

Response: See Responses to Comments 3.2.2. and 3.7.9.
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Comment 3.7.7:

EPA acknowledges that there is little evidence suggesting “that CO2 streams would even qualify as 

RCRA hazardous wastes.” Id. at 48077. [FN4: EPA emphasizes in the preamble to the Proposal that 

no hazardous waste listings apply specifically to CO2 streams; therefore, “ a CO2 stream could only 

be defined as a hazardous waste [if it has been discarded and] if it exhibits a hazardous waste 

characteristic as defined in 40 CFR Part 261, subtitle C.” 76 Fed. Reg. at 48078]. Regarding whether 

CO2 streams may exhibit the hazardous waste toxicity characteristic (“TC”), EPA considers in the 

preamble that it may be inappropriate to subject sequestered CO2 to the TC regulation “because 

the TC was designed to assess the threat waste would have in a municipal solid waste landfill 

(“MSWLF”) disposal scenario, a scenario that is inherently inapplicable to uncontained supercritical 

CO2.” Id. at 48078 (internal quotations omitted). Because there is no record evidence that 

sequestered CO2 is managed in a MSWLF – in fact, the conditional exclusion is premised on the 

material being managed in a UIC Class VI well – there is no basis for applying the TC to sequestered 

CO2. See Assn. of Battery Recyclers, 208 F.3d at 1064 (vacating the use of the Toxicity Characteristic 

Leaching Procedure (TCLP) as applied to MGP wastes because EPA failed to demonstrate that such 

wastes are likely to be disposed of in MSWLFs); see also EPA Memorandum from Elizabeth 

Cotsworth to EPA Regions, “Implication of Vacature of TCLP Use for Evaluating Manufactured Gas 

Plant (MGP) Wastes in the Battery Recyclers Case,” R.O. 14492. Therefore, subjecting CO2 that is 

captured, transported, and injected for GS to the TCLP for purposes of assessing whether it is a

hazardous waste would be contrary to law.

Response: EPA disagrees with the commenter. First, EPA notes that the commenter appears to 

have inaccurately quoted some of EPA’s statements, and misconstrued other statements, in the 

proposed rule preamble. For example, in the proposed rule preamble, EPA was summarizing the 

concerns of others when it when it stated, “[c]ommenters 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.’”. For its part, EPA noted in the preamble 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. 40 CFR 262.11(c)(2). 

EPA appreciates commenters’ concerns regarding the application of the hazardous waste 

regulations to supercritical CO2 streams being sequestered. EPA believes these concerns exist as a 

result of the unique circumstances associated with addressing the applicability of RCRA to CCS at 

such an early stage in the development of CCS. However, it is important to note that EPA did not 

set out in this rulemaking to conclude that those supercritical CO2 streams that are solid wastes 

would, as a class, exhibit a RCRA characteristic. Indeed, EPA indicated in the proposed rule that it 

could not unequivocally conclude that supercritical CO2 streams will never exhibit any RCRA 

hazardous waste characteristic and commenters provided no information to the contrary. 

Alternatively, EPA acknowledges that some RCRA hazardous characteristics are unlikely to apply to 

a waste composed of >90% CO2, such as ignitability (i.e., RCRA Waste Code D001). Thus, in light of 

the early state of data development in this area, EPA intends to bring additional clarity to the 

regulatory regime through this rule, by establishing a conditional exclusion from the definition of 

hazardous waste that would apply in the event a generator determines that its CO2 streams exhibit 

a RCRA hazardous characteristic.
102

EPA notes that it is not required to affirmatively demonstrate, as part of this rulemaking, that a 

particular CO2 stream, or a portion of all CO2 streams, necessarily qualifies as RCRA hazardous 

waste. Rather, under the conditional exclusion concept, EPA considers whether RCRA subtitle C 

regulation is necessary to protect human health and the environment. As explained in today’s rule, 

after consideration of public comment, EPA has reached the conclusion that management of CO2

streams under existing standards, including the UIC requirements for Class VI wells, as well as DOT 

standards, will protect human health and the environment from potential risks associated with CO2

streams (including associated constituents that might be present). This conclusion is based on EPA’s 

analysis of those other regulatory programs directly. EPA’s analysis and conclusions are 

independent of, and thus unaffected by, the question of whether a stream is classified as a 

hazardous waste under EPA’s RCRA regulations. 

Comment 3.7.8:

Moreover, as USWAG and others pointed out in 2008, and as EPA recognizes, uncertainty regarding 

the potential RCRA status of CO2 GS streams and the associated implications for the type of UIC 

permit required (i.e., Class I or Class VI) would be “a significant impediment to widespread 

deployment of CCS technologies.” 76 Fed. Reg. at 48077. Because the final UIC Class VI rules do not 

contain the requested clarification regarding applicability of RCRA to the injection of CO2, this 

regulatory uncertainty remains a significant concern to USWAG as it is likely to have a chilling effect 

on participation in CO2 GS projects. The proposed conditional exclusion is necessary to remove this 

regulatory uncertainty and remove an unnecessary impediment to the successful development and 

employment of CO2 sequestration technologies.

Response: See response to comment 3.7.3.

Comment 3.7.9:

EPA’s authority to issue conditional exemptions from the RCRA subtitle C requirements where “a 

waste might pose a hazard only under limited management scenarios, and [where] other 

regulatory programs already address such scenarios” derives from RCRA itself and is supported by 

case law. See id. at 48080. Section 3001(a) of RCRA requires EPA, prior to listing a waste as 

hazardous, to consider whether the waste “should be subject to” subtitle C’s hazardous waste 

requirements. RCRA [Section] 3001, 42 U.S.C. [Section] 6921 (emphasis added). RCRA’s statutory 

definition of “hazardous waste,” in turn, provides that “a solid waste ... which because of its 

quantity, concentration, or physical, chemical or infectious characteristics may ... pose a substantial 

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

transported, or disposed of, or otherwise managed.” RCRA [Section] 1004(5)(B), 42 U.S.C. [Section] 

6903(4)(B) (emphasis added); see also 76 Fed. Reg. at 48080. In other words, as EPA properly 

explains, “a waste that is otherwise hazardous does not require regulation [under subtitle C] so 

long as it is properly managed.” Id. at 48080. Put another way, if a waste is managed in a manner 

that ensures that it will not “be improperly treated, stored, transported, or disposed of, or 

otherwise mismanaged,” it does meet the statutory definition of “hazardous waste” and does not 

warrant regulation under RCRA subtitle C. See id. at 48081 (“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” (emphasis added)).

EPA’s longstanding practice in its administration of RCRA is based on this concept. As explained in 

the preamble, 
103

EPA has consistently interpreted section 3001 of RCRA to give [the Agency] 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 regulatory control incorporate the idea that a 

waste that is otherwise hazardous may not present a hazard if already subject to 

adequate regulation. 

Id. at 48080 (emphasis added). This interpretation of the statute has been repeatedly upheld by the 

courts in litigation involving other conditional exclusions from hazardous waste regulation. For 

example, the United States Court of Appeals for the District of Columbia Circuit held in Military 

Toxics Project v. EPA that EPA’s exemption from subtitle C of military munitions, where those 

munitions were transported and stored in compliance with DOT and Department of Defense 

regulations, was “a permissible construction of [RCRA].” 146 F.3d 948 (D.C. Cir. 1998); see also 76 

Fed. Reg. at 48080. The D.C. Circuit upheld similarly justified exemptions (i.e., based on existing 

regulatory controls independent from RCRA) in Natural Resources Defense Council v. EPA, 25 F.3d 

1063 (D.C. Cir. 1994), and Edison Electric Institute v. EPA, 2 F.3d 438 (D.C. Cir. 1993); see also 76 

Fed. Reg. at 48080.

In this case, EPA has established a rulemaking record demonstrating that CO2 (that is discarded and 

would otherwise exhibit a hazardous waste characteristic) managed in accordance with the 

proposed conditional exclusion will not be mismanaged and therefore should not be regulated 

under RCRA subtitle C. 76 Fed. Reg. at 48081. In the preamble, EPA provides an overview of the 

alternative regulatory controls that would be applicable to the transport and sequestration of CO2

that will ensure its proper management. These include comprehensive DOT regulations applicable 

to the transportation of the captured CO2 stream (id. at 48082-83) and imposition of the UIC 

requirements governing permitting, construction, operation, and closure of Class VI wells (id. at 

48083-85) on the CO2 stream. Moreover, as EPA correctly points out, the UIC regulations authorize 

the permit-issuing authority to attach “any additional conditions to the [Class VI UIC] permit, as 

necessary, to assure compliance with applicable SDWA requirements (40 CFR 146.52(b)).” Id. at 

48079. This broad permitting authority allows regulators to address, on a case-by-case basis, any 

additional concerns raised by the potential presence of hazardous constituents in individual CO2

streams intended for GS. In short, a full range of alternative, pre-existing regulatory controls apply 

to the management of CO2 that will ensure that this material is not mismanaged in a way that 

poses a threat to human health and the environment. As such, it does not warrant regulation as a 

hazardous waste.

Accordingly, because EPA has determined that CO2 streams will be properly managed under 

alternative regulatory regimes and will not be mismanaged, EPA has properly exercised its 

authority to exempt such streams from RCRA subtitle C and, in doing so, remove a significant 

barrier to this “key climate change mitigation technology.” Id. at 48077.

Response: EPA has the authority to issue conditional exclusions from the hazardous waste 

regulations. EPA’s authority to issue the rule is described in section II.B. of the final rule preamble. 

EPA also believes that it appropriately concluded that management of CO2 streams under the terms 

of the final rule does not present a substantial risk to human health and the environment, making 

additional regulation under RCRA unnecessary. 
104

Comment 3.7.10:

IV. EPA Should Clarify Certain Issues in Finalizing a Conditional Exclusion from RCRA’s Subtitle C 

Regulations for CO2 Streams Captured and Injected for GS 

If promulgated, the RCRA Proposal would exclude from RCRA hazardous waste regulation any CO2

GS streams that exhibit a hazardous characteristic from the definition of “hazardous waste” under 

RCRA, provided the following conditions are met:

(i) The CO2 stream is captured from emission sources and transported for purposes of injection into 

an underground injection well subject to the requirements for UIC Class VI wells;

(ii) Transportation of the CO2 GS stream is in compliance with applicable Department of 

Transportation (“DOT”) requirements;

(iii) Injection of the CO2 stream is in compliance with the applicable UIC requirements for Class VI 

wells, including the requirements set forth at 40 C.F.R. Parts 144 and 146;

(iv) No other hazardous wastes are mixed with, or otherwise co-injected with, the CO2 stream; and 

(v) Any generator of a CO2 stream, and any Class VI UIC well owner or operator who claims that a 

CO2 stream is excluded under the conditional exclusion, has an authorized representative sign a 

certification statement and keep that signed statement on-site for at least three years, to be made 

available within 72 hours of a written request from the regulating authority, and to be renewed 

every year by the person claiming the exclusion.

Id. at 48092-93 (proposed to be codified at 40 C.F.R. [Section] 261.4(h)).

USWAG supports a conditional exclusion from RCRA’s hazardous waste requirements for discarded 

CO2 GS streams, and believes that such an exclusion, provided it is crafted carefully, will provide 

much-needed regulatory certainty and promote participation in CO2 GS projects. However, certain 

issues raised in (or neglected by) the RCRA Proposal require attention and/or revision. These issues 

are raised below.

Response: EPA has made some changes to the proposed rule, as summarized in Section IV of the 

final rule preamble. EPA believes the rule as finalized 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. See responses to comments 3.7.11 

– 3.7.14.

Comment 3.7.11:

A. “Incidental Associated Substances”

The RCRA Proposal provides that CO2 GS streams are ineligible for the conditional exclusion if they 

have been “mixed with, or otherwise co-injected with,” any other hazardous waste stream. 76 Fed. 

Reg. at 48093. At the same time, the definition of “Carbon dioxide (CO2) stream” in the preamble 

mirrors that in the current Class VI UIC regulations in that it includes not only the captured CO2 but 

also “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.” Id. at 48075 

(emphasis added); see also 40 C.F.R. § 146.81(d). This component of the definition is critical to 
105

ensure that the conditional exclusion is practicable, as captured CO2 will necessarily include 

associated substances included in the stream from the capture process, as well as substances 

intentionally added to the stream to facilitate injection operations.

While the RCRA Proposal provides some information on estimated concentrations of certain 

constituents in the CO2 stream (76 Fed. Reg. 48079), it is important that EPA make clear in the final 

rule that these values are not intended to be regulatory limits or otherwise interpreted to identify 

the amount or scope of “incidental associated substances” that may be included in an excluded CO2

stream. Because the employment of CO2 capture operations is still in the formative stages and CO2

may be captured from a variety of industrial sources, EPA must be careful not to inadvertently 

restrict the scope of CO2 materials eligible for the conditional exclusion by inappropriately limiting 

the type of “incidental associated substances” and related substances that are legitimately 

included in a sequestered CO2 stream.

Response: The commenter makes the point that because of the condition that there can be no 

mixing of hazardous waste with the excluded CO2 stream, together with the fact that excluded CO2

streams may still contain (by definition) “incidental associated substances” and “substances added 

to the stream to enable the facilitate injection” EPA should clarify that the estimated constituent 

concentrations discussed in the preamble to the proposed rule (76 FR at 48079) are not intended 

to represent in some manner limits on allowable concentrations of incidental associated 

substances in excluded CO2 streams. EPA clarifies that this was not the purpose of presenting these 

constituent concentrations; rather, they were presented as part of the preamble discussion on the 

types of constituents that could be present in CO2 streams captured from coal-fired power plants.

EPA is not identifying the amount or scope of “incidental associated substances” that may be 

included in an excluded CO2 stream in this final rule. EPA has concluded that the injection of CO2 

streams, including incidental associated substances derived from the source materials and the 

capture process, can be performed in a protective manner at a permitted UIC Class VI well. This is 

the case regardless of the precise contaminants, and their concentrations, because the UIC Class VI 

permitting requirements will take into account the physical and chemical characteristics of the CO2 

streams before any injection may occur, as part of establishing the appropriate conditions for the 

successful confinement of CO2 in a manner that is protective of USDWs. EPA intends to monitor any 

data on the chemical composition and physical characteristics of the CO2 streams being injected by 

the UIC Class VI permitting program and to use that information to determine whether changes to 

the conditional exclusion may be appropriate.

Comment 3.7.12:

B. Prohibition on Mixing/Co-Injecting Other Hazardous Wastes with CO2 Stream

It is clear that substances naturally occurring underground would not be “discarded” and therefore 

could not be hazardous wastes under RCRA. Nonetheless, to avoid a scenario in which the 

applicability of the conditional exclusion might be jeopardized as the result of post-injection mixing 

of the CO2 stream and other underground substances, EPA should clarify that such a scenario 

would not run afoul of the exclusion’s condition that injected CO2 not be mixed or otherwise coinjected with other hazardous wastes.

Response: EPA believes that the scenario described by the commenter regarding the potential 

behavior of CO2 streams after injection into a UIC Class VI well would not affect the availability of 

the conditional exclusion, because the exclusion requires injection into a UIC Class VI well (in 
106

compliance with all of the conditions), and any potential issues with the CO2 stream post-injection 

would be addressed as part of the site-specific UIC Class VI permit. 

Comment 3.7.13:

C. Consequences of Minor/Technical Non-Compliance

As currently written, the terms of the proposed conditional exclusion would mean that noncompliance with any aspect of the conditional exclusion at any point in the management of the CO2

stream results in the material being subject to all applicable subtitle C requirements beginning at 

the point of generation. Id. at 48087. This would mean, for instance, if there is minor paperwork 

violation by the Class VI UIC well operator, the CO2 (assuming it is hazardous) would have been 

subject to all subtitle C generator and transportation requirements from the instant it was captured 

at the power facility, and that the well operator must be in immediate compliance with a different 

set of UIC Class I permit conditions. Clearly, this is not practical and, most importantly, not 

necessary.

Compliance with existing applicable regulatory programs is the foundation of this conditional 

exemption. However, both the DOT regulations and UIC regulations potentially applicable to CO2

streams captured for GS are complex, and contain a number of requirements that are 

administrative, rather than protective or risk-based, in nature (e.g., the recordkeeping 

requirements for Class VI wells set forth at 40 C.F.R. [Section] 146.91(f)). As noted above, it is 

possible that an owner/operator could be deemed ineligible for the conditional exclusion as the 

result of a mistake that has no bearing on risk or environmental safety but nonetheless results in an 

immediate conversion of the entire CO2 management stream to an entirely new set of controls that 

would be virtually impossible to meet.

To avoid this kind of scenario, EPA should, a minimum, make clear that any noncompliance 

occurring during a specific phase of the CCS process (i.e., capture, storage, transportation, or 

injection) would only implicate that specific phase of CCS management for purposes of determining 

applicability of the exclusion to a given CO2 stream. More generally, EPA should make clear that 

only a “material noncompliance” with applicable DOT and UIC regulations results in subjecting the 

CO2 stream to any applicable subtitle C requirements. In particular, EPA should amend the language 

of the proposed conditional exclusion to clarify that non-compliance that is administrative in nature 

and is not knowing or willful on the part of the owner/operator will not alone render the CO2

stream ineligible for the conditional exclusion. In addition, EPA should include in the conditional 

exclusion a provision granting the EPA (or, where applicable, state regulator) discretion to, on a 

case-by-case basis, apply the conditional exclusion even where some level of non-compliance with 

DOT or UIC regulations exists or has existed.

Response: In the final rule, EPA maintains that a CO2 stream must meet all the conditions to qualify 

for and maintain the exclusion from the hazardous waste regulations, and a violation of a condition 

at any point in the management of a CO2 stream (that is otherwise hazardous) would result in that 

CO2 stream being subject to all applicable subtitle C regulatory requirements, from the point of 

generation. The rule conditions, taken together, ensure that the excluded CO2 streams are being 

managed in a protective manner such that subtitle C regulations are not necessary. Therefore, it 

follows that any management not in accordance with those conditions does not qualify for the 

exclusion.
107

However, EPA can appreciate the commenter’s concern over the loss of the conditional exclusion 

due to, for example, small administrative or clerical errors. EPA’s Office of Enforcement and 

Compliance Assurance (OECA) is unable to provide definitive assurances outside the context of a 

formal enforcement proceeding that the government will not proceed with an enforcement 

response for a specific individual violation of an environmental protection statute, regulation, or 

legal requirement. However, EPA can (and has previously done so for other RCRA rules) exercise 

discretion to decide when and how to respond or not respond to a given violation, based on the 

Agency’s normal priorities. In RCRA penalty actions, the factors that EPA considers in assessing the 

gravity-based portion of the penalty are the potential for harm and the extent of deviation from a 

statutory or regulatory requirement. The penalty can be adjusted for numerous factors, including 

good faith efforts to comply, degree of willfulness and negligence, and history of noncompliance. 

Additional information can be found in the 2003 RCRA Civil Penalty Policy 

(http://www.epa.gov/compliance/resources/policies/civil/rcra/rcpp2003-fnl.pdf). 

Comment 3.7.14:

D. Certification Statement

One of the proposed conditions on which the exclusion would be based is that “[a]ny 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” the conditional exclusion, must have 

an authorized representative certify “ under penalty of law” that the CO2 stream “ meets all of the 

conditions set forth in [40 C.F.R. [Section] 261.4(h)(1)].” 76 Fed. Reg. at 48093 (proposed to be 

codified at 40 C.F.R. [Section] 261.4(h) (iv)). This certification statement is overly broad and 

impracticable.

As discussed above, compliance with [Section] 261.4(h)(iv) includes compliance with all applicable 

DOT and UIC regulations, including 40 C.F.R. Parts 144 and 146. Because a generator will in many 

cases not own or operate the Class VI well at which the CO2 stream is injected and sequestered, 

this certification provision would require an individual to attest, under penalty of law, to facts 

which are not readily known to him and/or which are not under his control. Similarly, a Class VI well 

owner or operator may not have access to information regarding any potential non-compliance 

with DOT regulations that occurred while the CO2 stream was in transit. It is fundamentally unfair 

and would create a regulatory disincentive to engage in CO2 sequestration to require persons 

engaged in these operations to certify under penalty of law compliance with obligations which are 

not applicable to their particular activities and for which they have no direct control. For these 

reasons, the certification statement should be amended to require parties to attest compliance 

with only those conditions for which they have responsibility under the proposed exclusion (e.g., in 

the case of generators, a certification that the CO2 stream was captured from an emission source 

and transported for purposes of injection into an underground injection well subject to the 

requirements for UIC Class VI wells).

Response: EPA agrees and has modified the certification requirement in the final rule so that there 

are now two separate certification statements worded slightly differently – one for generators and 

another for UIC Class VI well owners or operators claiming this conditional exclusion. EPA has made 

these revisions to better reflect actions over which each party has control. Under the final rule, the 

certification statement that the generator would sign is specific to the activities within the 

generator’s control; likewise, the certification statement that the UIC Class VI well owner or 

operator would sign is specific to the activities within the owner or operator’s control. 
108

Comment 3.7.15:

We appreciate the opportunity to comment on important proposal. If you have any questions 

regarding these comments, please contact USWAG counsel Douglas Green (see docket for contact 

information).

Response: EPA acknowledges the comment.

3.8 CCS Alliance

Document ID: EPA-HQ-RCRA-2010-0695-0083

Comment 3.8.1:

The CCS Alliance, a multi-industry group of entities whose mission is to address barriers to the 

potential deployment of carbon capture and sequestration, submits these comments in support of 

the Environmental Protection Agency's ("EPA" or "the Agency") proposed rule to conditionally 

exclude geologically sequestered CO2 from regulation under the Resource Conservation and 

Recovery Act's ("RCRA") hazardous waste program.

Response: EPA thanks the commenter for its support of the conditional exclusion.

Comment 3.8.2:

Introduction

The CCS Alliance favors a single, clear regulatory structure for geologic sequestration ("GS") of 

carbon dioxide, as opposed to a structure composed of multiple regulatory laws with overlapping 

enforcement regimes and penalty provisions. Unlike with other spheres of commercial activity, 

with GS the nation has the opportunity to establish a regulatory framework before the practice 

becomes widespread. Thus government may take into account the factors that specially 

characterize GS before regulating, as well as the public policy objectives surrounding it.

GS is a practice the government desires to encourage, or at least desires not to discourage, to 

reduce emission of CO2 into the atmosphere. We submit that a single, clear structure of regulation 

and enforcement suits this interest better than confusing requirements under multiple statutes. 

EPA already has established a detailed, comprehensive regulatory framework for GS through the 

Underground Injection Control ("UIC") program of the Safe Drinking Water Act. We agree with the 

Agency's commentary in the proposed rule that the UIC Class VI program for GS wells that EPA 

established in 2010 is sufficient to protect the environmental and safety interests that RCRA was 

enacted to protect. Applying burdensome RCRA hazardous waste regulation on top of the UIC 

regulations not only would not advance the interests served by RCRA, but could drive up costs for 

and discourage deployment of GS, frustrating EPA's carbon dioxide emission reduction goals.

Response: EPA agrees that management of CO2 streams under existing standards, including the UIC 

requirements for Class VI wells, as well as Department of Transportation (DOT) standards, will 

protect human health and the environment from potential risks associated with CO2 streams, 

making additional regulation pursuant to the Resource Conservation and Recovery Act’s (RCRA) 

hazardous waste regulations unnecessary.

Comment 3.8.3:
109

EPA itself has acknowledged the burden of RCRA and the fact that many of its requirements are 

poorly suited to at least some of the activities to which they apply. EPA initiated a rulemaking in 

2002 to reduce the burdens associated with the RCRA hazardous waste program. [FN1: Resource 

Conservation and Recovery Act Burden Reduction Initiative, 67 Fed. Reg. 2518 (proposed Jan. 

17,2002); see also RCRA Burden Initiative; Final Rule, 71 Fed. Reg. 16,862 (Apr. 4, 2006)]. The 

Agency noted, "[t]he existing hazardous waste regulations require the submittal of 334 

notifications, reports, certifications, demonstrations, and plans from generators and TSDFs to 

demonstrate compliance with the RCRA regulations." [FN2: RCRA Burden Reduction lnitiative; 

Notice of Data Availability, 68 Fed. Reg. 61,662, 61,644 (Oct. 29, 2003)].

Reporting requirements are just one example of RCRA' s burdens. Construction, permitting, 

operating, monitoring, and post-site closure requirements are much more burdensome for Class I 

hazardous wells than for the other types of injection wells. For instance, Class I hazardous wells 

have a requirement that there be no migration for 10,000 years. Such strict requirements may be 

appropriate to protect USDWs and the environment from certain hazardous wastes, but were not 

established with the circumstances of GS of CO2 in mind.

Furthermore, if a facility were required to obtain a Class I UIC hazardous waste injection permit, all 

other waste management units at the facility could be subject to the full extent of RCRA's Subtitle C 

corrective action program, which is an extremely costly and administratively complex program. 

Determining that CO2 constitutes a hazardous waste and subjecting CO2 injection and storage to 

the burdensome Class I well requirements would not promote underground injection and storage 

of CO2.

Imposing extensive, burdensome RCRA regulations likely to have little benefit for human health 

and the environment may result in larger atmospheric releases of CO2 if GS is not as widely 

deployed.

Response: See response to comment 3.8.2. Where these comments relate only to the general

burden of the RCRA requirements, as the commenter states, and the UIC Class I hazardous wells, 

these comments are outside the scope of this rulemaking. EPA agrees that while the requirements 

for each UIC injection well class address the specific practices and unique risks to USDWs posed by 

a specific well class, the Class VI requirements are tailored to the unique aspects of carbon dioxide 

injection for GS (e.g., large CO2 injection volumes, the buoyant and mobile nature of the injectate), 

and EPA developed its RCRA conditional exclusion based upon injection in a UIC Class VI well. EPA 

believes this rule will facilitate the deployment of GS by providing additional regulatory certainty.

Comment 3.8.4:

Issues with the Proposed Rule

The CCS Alliance supports a conditional exclusion from RCRA hazardous waste regulation for 

geologically sequestered CO2 streams. This is an appropriate regulatory approach that we and 

others recommended in comments on the UIC Class VI proposed rule in 2008. Nonetheless, there is 

one threshold issue the Agency needs to address, and there are several issues with the proposed 

exclusion that merit revision or clarification. 

Response: EPA thanks the commenter for its support of the conditional exclusion, and addresses 

the commenter’s further comments below.
110

Comment 3.8.5:

Applicability of RCRA

EPA has not clearly explained in this proposed rule why RCRA is applicable at all to GS. RCRA's 

detailed regulatory scheme applies to "solid wastes." However, RCRA's definition of "solid waste" 

includes a "contained gaseous material" but does not include an uncontained gaseous material. 

[FN3: 42 U.S.C. 6903(27)] Does the Agency assert that CO2 that is captured from a generation 

source - an electric generating facility, a gas processing facility, manufacturing facility, etc. - that is 

to be geologically sequestered is a contained gas?

Geologically sequestered CO2 should be considered an uncontained gaseous material and therefore 

not a solid waste, based on agency precedent. In In re BP Chemicals America, Inc., RCRA Appeal No. 

89-4, 1991 WL 208971 (Admin., Aug. 20, 1991), the Agency held that uncondensable hydrogen 

cyanide from an acrylonitrile manufacturing plant that is "contained" within piping and other 

equipment within the plant and thermally destroyed is not a solid waste subject to RCRA because it 

is not a contained gaseous material. Rejecting EPA Region V's argument for applying hazardous 

waste regulation, the Agency found:

[T]he Agency views gaseous material to be "solid waste" only when it is containerized. 

Region V argues that BP's HCN vapor is "contained" by the various process units 

through which it passes, by associated piping, and by the plant as a whole. The 

Region's reading of the term "contained," however, cannot be reconciled with the 

Agency's treatment of fume incinerators. Such incinerators are used to treat vapors 

that are "contained" in the broad sense of being bound or controlled and not being 

emitted to the atmosphere, but the Agency considers such vapors to be outside the 

scope of the "solid waste" definition because they are not containerized in the 

narrower sense of being in an individual container such that the gas is amenable to 

shipment. [FN4: In re BP Chemicals America. Inc., RCRA Appeal No. 89-4, 1991 WL 

208971 (Admin., Aug. 20, 1991), p.2-3]. 

Similarly, in the case of CO2 for GS, the CO2 will be "contained" only in the sense that it is within 

piping and associated equipment inside, and ultimately outside, the industrial facility where it is 

captured. It will be shipped via pipeline, and the Agency precedent makes clear that such 

containment does not render a material a contained gas. Once it is sequestered in a geologic 

formation, it is subject to regulations to ensure that it remains within that formation, but it will not 

be "containerized in the narrower sense of being in an individual container such that the gas is 

amenable to shipment."

We note that EPA earlier this year confirmed its interpretation of the "contained gaseous material" 

portion of the definition of "solid waste." In response to questions raised by industry about 

whether an Agency document issued earlier this year was reinterpreting the term, EPA 

acknowledged the document 

has created concerns among the regulated community that the [EPA] has changed a 

long-standing interpretation of what constitutes a "contained gaseous material" for 

purposes of defining the term "solid waste" under the Resource Conservation and 

Recovery Act (RCRA). We have not changed our prior interpretation. . .. We clarify 

here that the Agency's previous statements and interpretations remain effective. 
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[FN5: Letter from Suzanne Rudzinski, Director, Office of Resource Conservation and 

Recovery, to Tim Hunt, American Forest and Paper Association, May 13, 2011].

Response: EPA disagrees that CO2 streams sent to UIC Class VI wells for purposes of GS are not 

solid wastes. See Responses to Comments 3.2.1 and 3.2.10.

Comment 3.8.6:

Contours of Conditional Exclusion

Incidental Associated Substances

We note that the Agency did not consider it necessary to clarify in the proposed rule the term 

"incidental associated substances," which features in the definition of the term "carbon dioxide 

stream" in both the UIC Class VI regulation and the proposed rule. We believe that the context of 

the proposed rule makes clear that other substances captured together with the CO2 from a gas 

stream are "incidental associated substances." If this is not the Agency's intent, we recommend 

that this term be clarified. The proposed rule states:

[T]oday's conditional exclusion would apply to CO2 streams that are otherwise RCRA hazardous 

wastes .... EPA intends ... 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 

nonhazardous CO2 streams may be injected into a UIC Class VI well. [FN6: Proposed rule, 76 Fed. 

Reg. 48073, at 48088]. 

The motivation behind proposing the conditional exclusion is the fact that the presence of other 

substances in the CO2 stream could trigger the definition of hazardous waste. Thus it is essential in 

order for the exclusion to be effective that the scope of the non-CO2 substances that may be part of 

the CO2 stream is clear.

As the proposed rule notes, the purity of the CO2 stream will depend on a variety of factors, 

including the source material and the capture process employed. Furthermore, depending on the 

scope of future regulation, CO2 streams may be captured from a variety of industrial facilities. The 

proposed rule lists estimated concentrations of hazardous constituents, such as mercury and 

chromium, that may be expected to be present in the CO2 stream. EPA does not appear to suggest 

that these estimated concentrations are limits, and that higher concentrations or the presence of 

other incidentally captured materials would void the exclusion. They merely inform EPA's decision 

that the conditional exclusion is protective of the environment.

The type and amount of such substances that may be included in the stream is of critical 

importance, because the consequences of voiding the conditional exclusion could be severe. One 

might anticipate that a GS facility that inadvertently sequesters a CO2 stream that is not subject to 

the conditional exclusion could be forced to meet the more stringent Class I hazardous regulations, 

which could require the facility to shut down temporarily or perhaps permanently. This may have 

"upstream" effects, as discussed below.

Response: EPA confirms that “incidental associated substances derived from the source materials 

and the capture process” is intended to refer to those substances that are captured together with 

the CO2. EPA also confirms that it did not intend that the numerical concentrations of hazardous 

constituents described in the proposal’s discussion of RCRA characterization issues define what 

constitutes “incidental associated substances” in the proposed rule or in the final conditional 
112

exclusion. In the final rule, EPA is not identifying the type and amount of substances that may be 

included as "incidental associated substances" in the carbon dioxide stream. EPA has concluded 

that the injection of CO2 streams, including incidental associated substances derived from the 

source materials and the capture process, can be performed in a protective manner at a permitted 

UIC Class VI well. This is the case regardless of the precise contaminants, and their concentrations, 

because the UIC Class VI permitting requirements will take into account the physical and chemical 

characteristics of the CO2 streams before any injection may occur, as part of establishing the 

appropriate conditions for the successful confinement of CO2 in a manner that is protective of 

USDWs. EPA emphasizes that the UIC Class VI regulations themselves require that the chemical 

composition and physical characteristics of the CO2 streams be known as part of the initial 

permitting process, as well as during operation of the well, in order to ensure that these CO2

streams can be injected in a manner that is protective of human health and the environment. EPA 

intends to monitor any data on the chemical composition and physical characteristics of the CO2

streams being injected by the UIC Class VI permitting program and to use that information to 

determine whether changes to the conditional exclusion may be appropriate.

A RCRA hazardous CO2 stream that does not meet the conditions of this rule 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 acknowledges that there would be implications to 

changing the regulatory status of a UIC Class VI well to that of a UIC Class I hazardous well. See 

Responses to Comments 3.8.7 and 3.21.3.

Comment 3.8.7:

Paperwork and other Minor Violations

The proposed rule makes clear EPA's intention that the consequences of failing to maintain 

compliance with the conditions for the exclusion will end the exclusion: 

Failure to meet the conditions [of the proposed rule] 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 requirements, from the point of 

generation. [FN7: Id. at 48087].

Among the conditions that must be maintained is a requirement that "[i]njection 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 C.F.R. parts 144 and 146.” [FN8: 

Id. at 48093]. The requirements of these parts encompass dozens of pages of regulatory text and 

hundreds of individual requirements (many subject to interpretation of the EPA or the State, 

whichever may be implementing the program), including recordkeeping and reporting 

requirements, and others the violation of which may have no consequence to safety.

If violation of a regulatory requirements results in closure of a GS facility, and that closure means 

that electric generators must shut down because they would be unable to operate without 

violating Clean Air Act carbon emission regulations, there could be serious impacts to electric 

reliability, with potential impacts to public health. An affected power plant may be vital to 

reliability not only because of the power it generates, but for the voltage support it provides to the 

transmission grid in the region. Note that the fossil-fueled generating units that produce CO2

typically are baseload generating units that typically are the primary source of reactive power that 

provides voltage support. This concern about reliability would be attenuated if EPA were to choose 
113

another means to preclude the applicability of RCRA that could not result in the facility being 

potentially subject to hazardous waste regulation for minor violations.

It is understood that full compliance with Class VI UIC regulation is expected, in addition to being 

legally required. What is unclear is what enforcement discretion the Agency has and intends to be 

applied (by EPA and the States) in implementing the regulations. We recommend that EPA provide 

guidance that in considering enforcement options, UIC program directors should take into account 

the broad consequences of those options, such as electric reliability and operation of "upstream" 

CO2 generating facilities.

Response: It is unclear to EPA the extent to which these comments relate to terms of the RCRA 

conditional exclusion, or the UIC Class VI rules themselves. To the extent that these comments 

relate to the UIC program, they are beyond the scope of this rulemaking.

With respect to the comment regarding minor violations resulting in the loss of the conditional 

exclusion, EPA maintains that a CO2 stream must meet all the conditions to qualify for and maintain 

the exclusion from the hazardous waste regulations, and a violation of a condition at any point in 

the management of a CO2 stream (that is otherwise hazardous) would result in that CO2 stream 

being subject to all applicable subtitle C regulatory requirements, from the point of generation. The 

rule's conditions, taken together, ensure that the excluded CO2 streams are being managed in a 

protective manner such that subtitle C regulations are not necessary. Therefore, it follows that any 

management not in accordance with those conditions does not qualify for the exclusion.

However, EPA can appreciate the commenter’s concern over the loss of the conditional exclusion 

due to, for example, small administrative or clerical errors. EPA’s Office of Enforcement and 

Compliance Assurance (OECA) is unable to provide definitive assurances outside the context of a 

formal enforcement proceeding that the government will not proceed with an enforcement 

response for a specific individual violation of an environmental protection statute, regulation, or 

legal requirement. However, EPA can (and has previously done so for other RCRA rules) exercise 

discretion to decide when and how to respond or not respond to a given violation, based on the 

Agency’s normal priorities. In RCRA penalty actions, the factors that EPA considers in assessing the 

gravity-based portion of the penalty are the potential for harm and the extent of deviation from a 

statutory or regulatory requirement. The penalty can be adjusted for numerous factors, including 

good faith efforts to comply, degree of willfulness and negligence, and history of noncompliance. 

Additional information can be found in the 2003 RCRA Civil Penalty Policy 

(http://www.epa.gov/compliance/resources/policies/civil/rcra/rcpp2003-fnl.pdf). 

Comment 3.8.8:

Overbroad Certification Requirement

Among the conditions for being subject to the proposed conditional exclusion is the requirement 

that well owners and operators and CO2 stream generators have an authorized representative sign 

the following statement:

I certify under penalty of law that the carbon dioxide stream that I am claiming to be excluded 

under 40 C.F.R. 261.4(h)( 1) meets all of the conditions set forth in that paragraph. [FN9: Id.]. 

As noted above, one condition is that the sequestration well must be in compliance with 40 C.F.R. 

parts 144 and 146. It is broadly recognized that in many instances, perhaps even the majority of the 
114

time, a generator will not own or operate the GS facility at which the generator's CO2 stream is 

sequestered. One of many features in the regulatory structure that will contribute to safe 

operation of GS facilities is encouragement for generators to contract with competent, reputable 

GS facility operators. However, it is neither practicable nor appropriate for a generator to certify 

that a facility operator is in compliance with each UIC regulatory requirement. That should be the 

operator's obligation. Nor is it possible for a generator to certify to the compliance of other 

generators who send their CO2 streams to the facility.

The certification in proposed 40 C.F.R. 261.4(h)(1)(iv) should be limited to the regulatory 

obligations that are the responsibility of the party making the certification. For a generator, we 

believe there is only one such obligation, which is that the injectate be qualified as a CO2 stream. 

We recommend that the certification obligation for generators be amended to read as follows: 

I certify under penalty of law that the material being delivered is qualified as a carbon dioxide 

stream under 40 C.F.R. 146(d).

Response: EPA agrees that the certification statement should better reflect the activities within the 

signatory’s control. EPA has revised the certification statement in the final rule so that there are 

now two separate certification statements – one for CO2 stream generators and another for UIC 

Class VI well owners or operators. Under the final rule, the certification statement that the 

generator would sign is specific to the activities within the generator’s control; likewise, the 

certification statement that the UIC Class VI well owner or operator would sign is specific to the 

activities within the owner or operator’s control. The certification statement EPA is finalizing for 

generators includes the prohibition on hazardous waste mixing and delivery (or arranging for 

delivery) of the CO2 stream to a UIC Class VI facility in compliance with applicable DOT (or state) 

requirements, which EPA finds would be in the generator’s control. The commenter provides no 

reasons to conclude that these are not in the generator’s control. Therefore, EPA does not agree 

that the generator certification should be limited to certifying that the injectate qualifies as a CO2

stream. Note that these revisions do not change how the conditional exclusion is implemented –

that a CO2 stream that is hazardous must meet all the conditions in 261.4(h)(1)-(4) to qualify for 

and maintain the exclusion from the hazardous waste regulations. 

Comment 3.8.9:

Potential Applicability of CERCLA

We note that the issue of whether the CO2 stream is considered to be a hazardous waste not only 

determines whether RCRA would apply, but also would influence whether the Comprehensive 

Environmental Response, Compensation, and Liability Act ("CERCLA" or "Superfund") may apply. 

[FN10: 42 U.S.C. 9601 et seq.].

Under CERCLA, the President may compel cleanup actions "when the President determines that 

there may be an imminent and substantial threat to the public health or welfare or the 

environment because of an actual or threatened release of a hazardous substance from a facility 

....”[FN11: 42 U.S.C. 9606.]. In such cases, Superfund's joint, strict, several and retroactive liability 

scheme applies, a system that has been widely criticized for its expense, delay, and contentious 

legal wrangling. In fact, cleanups have been completed at fewer than one-quarter of the sites 

placed on Superfund's National Priorities List since its inception in 1983.
115

CERCLA defines a "hazardous substance" to include "any hazardous waste having the 

characteristics identified under or listed pursuant to Section 3001 of [RCRA].” [FN12: 1242 U.S.C. 

9601(14) [Emphasis added]].

The CCS Alliance and many others commented in response to the Class VI UIC proposed rule that 

the Superfund liability scheme would deter deployment of CCS. Furthermore, were an incident 

requiring remediation to occur at a Class VI facility, applicability of Superfund could doom the 

cleanup to delays. Only 350 of the nearly 1,700 sites placed on Superfund's National Priorities List 

since its inception in 1983 have been cleaned up sufficiently to be removed from the list. [FN13: 

http://www.epa.gov/superfund/sites/npl/, accessed September 23, 2011].

Response: EPA notes that CERCLA and its related provisions are beyond the scope of this 

rulemaking.

Comment 3.8.10:

Conclusion

We are pleased that the Agency has proposed this conditional exclusion from hazardous waste 

regulation. A legally justified and more effective means of precluding hazardous waste regulation 

would be to determine, consistent with Agency precedent, that CO2 streams that are geologically 

sequestered are an uncontained gas. If EPA persists with a conditional exclusion, it should provide 

clarification with respect to the points noted above.

Response: EPA thanks the commenter for its support of the conditional exclusion. For the reasons 

stated above, it is EPA’s position that a supercritical CO2 stream sent to a UIC Class VI well for 

purposes of GS is a RCRA solid waste. EPA is finalizing the conditional exclusion as described.

3.9 State of Utah

Document ID: EPA-HQ-RCRA-2010-0695-0086

Comment 3.9.1:

The State of Utah, through the Public Lands Policy Coordination Office (PLPCO), has reviewed this 

project. Utah Code (Section 63J-4-601, et. seq.) designates PLPCO as the entity responsible to 

coordinate the review of technical and policy actions that may affect the physical resources of the 

state, and to facilitate the exchange of information on those actions among federal, state, and local 

government agencies. As part of this process, PLPCO makes use of the Resource Development 

Coordinating Committee (RDCC). The RDCC includes representatives from the state agencies that 

are generally involved or impacted by public lands management.

Response: EPA acknowledges the comment.

Comment 3.9.2:

The Department of Environmental Quality, Division of Water Quality is supportive of the rule 

change and offers one singular comment for your consideration: The conditional exclusion should 

extend to Class V Experimental Technology CO2 wells for DOE's Phase III pilot projects. See foot 

note 54. Since EPA has made the following statement with regard to Class VI wells, "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 
116

therefore additional regulation pursuant to RCRA's hazardous waste regulations is unnecessary" 

(see Summary at the top of the Federal Register Notice), the statement must surely apply to Class V 

Experimental Technology CO2 wells.

Response: EPA disagrees that the conditional exclusion should be extended to experimental 

projects that have been issued Class V experimental technology well permits. EPA simply did not 

include UIC Class V wells in its evaluation. The Class VI requirements are tailored to the unique 

aspects of carbon dioxide injection for GS (e.g., large CO2 injection volumes, the buoyant and

mobile nature of the Injectate), and EPA developed its RCRA conditional exclusion based upon 

injection in a UIC Class VI well. EPA’s analysis supporting the conditional exclusion did not include 

an evaluation of the UIC Class V well requirements, as those wells are beyond the scope of the rule 

as proposed. 

Comment 3.9.3:

If you have any questions relative to this comment or requirement please contact William E.

Damery, P.G., NEPA Compliance Coordinator at [see docket for contact information].

The State of Utah appreciates the opportunity to review this proposal and we look forward to 

working with you on future projects. Please direct any other written questions regarding this 

correspondence to the Public Lands Policy Coordination Office at the address below, or call [see 

docket for contact information].

Response: EPA acknowledges the comment.

3.10National Mining Association (NMA)

Document ID: EPA-HQ-RCRA-2010-0695-0065

Comment 3.10.1:

The National Mining Association (NMA) appreciates the opportunity to provide comments on the 

U.S. Environmental Protection Agency’s (EPA) proposed rule that would conditionally exclude 

carbon dioxide (CO2) streams that are hazardous from comprehensive hazardous waste 

management regulations under the Resource Conservation and Recovery Act (RCRA). 76 Fed. Reg. 

48,073 (Aug. 8, 2011). Specifically, CO2 streams that are captured, transported and injected for 

geologic sequestration would not be treated as a hazardous waste under RCRA if the following 

requirements are met: (1) the transportation of the CO2 stream is in compliance with applicable 

Department of Transportation (DOT) requirements; (2) injection of the CO2 stream is in compliance 

with the requirements for Class VI Underground Injection Control (UIC) wells; (3) no other 

hazardous wastes are mixed with, or otherwise co-injected with, the CO2 stream; and (4) an 

authorized representative of the generator of the CO2 stream and the UIC Class VI well owner 

certify in writing that all the conditions are met. See Proposed § 261.4, 76 Fed. Reg. at 48,092-93. 

NMA is a national trade association representing the producers of most of America’s coal, metals, 

industrial and agricultural minerals; the manufacturers of mining and mineral processing 

machinery, equipment and supplies; and engineering, transportation, financial and other 

businesses that serve the mining industry. NMA strongly supports the development and use of 

carbon capture and storage (CCS) technologies given that they represent one of the most promising 

and effective long-term options for large-scale reductions in CO2 emissions from coal-based 
117

generation. NMA further believes that regulatory impediments must be removed to support 

investment in and development of CCS and thereby enable further development and deployment 

of this technology.

Response: EPA acknowledges the comment.

Comment 3.10.2:

NMA appreciates that the goal of EPA’s proposed rule is to address stakeholder concerns over the 

uncertainty that RCRA hazardous waste requirements would be applied to CO2 streams injected for 

geologic sequestration, which in turn would significantly obstruct the deployment of CCS 

technologies. See 76 Fed. Reg. at 48,077. NMA agrees with the agency that the proposed rule will 

reduce regulatory uncertainty and potentially help facilitate the deployment of CCS technologies. 

See id. at 48,074 (“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 [geologic sequestration] by providing additional regulatory certainty.”) Id. at 48,074. 

However, NMA is troubled by the agency’s characterization of supercritical CO2 streams injected 

into permitted UIC Class VI wells for geologic sequestration as being “clearly” within the plain 

meaning of “discarded material” and thus a “solid waste” under RCRA. See 76 Fed. Reg. at 48,077-

8. This characterization is unsupportable.

RCRA defines a “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 resulting from industrial, commercial, mining, and 

agricultural operations . . .” 42 U.S.C. § 6903(27) (emphasis added). As a threshold matter, 

supercritical CO2 streams are not a “contained gaseous material” and thus are not subject to RCRA 

jurisdiction. EPA recognizes that in a supercritical state CO2 “exhibits physical properties 

intermediate to those of a liquid and a gas.” 76 Fed. Reg. at 48,076. Yet, EPA fails to explain how 

this unique characteristic of supercritical CO2 streams translates into labeling the material as a form 

of “solid waste” as defined by the statute. Supercritical CO2 streams are best described as an 

“uncontained gas” and thus not subject to RCRA. 

Furthermore, even if supercritical CO2 streams could be classified as a “contained gaseous 

material,” EPA incorrectly characterizes all CO2 captured, transported, and injected for 

sequestration in a Class VI well as a solid waste under the rationale that it is “discarded material 

within the plain meaning of the term in RCRA § 1004(27).” 76 Fed. Reg. at 48,078. The pivotal term 

in this analysis is “discard.” As the D.C. Circuit recognized in 1987 and reaffirmed in 2000, 

“[C]ongress clearly and unambiguously expressed its intent that “solid waste” (and therefore EPA‟s 

regulatory authority) be limited to materials that are “discarded” by virtue of being disposed of, 

abandoned, or thrown away.” Association of Battery Recyclers v. EPA, 208 F.3d 1047, 1051-52 (D.C. 

Cir. 2000) (quoting American Mining Congress v. EPA, 824 F.2d 1177, 1190 (D.C. Cir. 1987)).

Response: EPA agrees with the commenter that conditional exclusion will reduce regulatory 

uncertainty for stakeholders and facilitate deployment of CCS technologies. EPA disagrees that CO2

streams sent to UIC Class VI wells for purposes of GS are not solid waste. Regarding the 

commenter’s statements that supercritical CO2 streams are not a ‘contained gaseous material,’ as 

EPA noted in the proposed rule, the CO2 streams are delivered by pipeline and injected into UIC 

Class VI wells for GS in a supercritical state, which EPA stated at proposal was “...rather unique in 

that it has properties intermediate between a liquid and a gas.” 76 FR at 48078. The scientific term 
118

used to describe or define this supercritical state (i.e., when a substance is at or above its critical 

temperature and critical pressure) is as a “supercritical fluid.” The RCRA statutory definition of solid 

waste specifically refers to “other discarded material, including solid, liquid, semisolid, or contained 

gaseous material resulting from industrial, commercial, mining, and agricultural operations, and 

from community activities . . .”

While EPA has indeed interpreted the meaning of specific terms listed, including “contained 

gaseous material,” the RCRA definition of solid waste encompasses “other discarded material” and 

does not speak to materials such as supercritical fluids. Like the listed “solid, liquid, semisolid, or 

contained gaseous material” specifically referenced, CO2 streams sequestered for purposes of GS 

are “other discarded material” from industrial and commercial operations and, therefore, are of a 

similar kind to the other types of wastes specifically referenced by the definition. They are, 

therefore, RCRA statutory solid wastes.

Regarding the question of whether or not these materials have been discarded, EPA disagrees that 

CO2 streams sent to UIC Class VI wells for purposes of GS are not solid waste. As was stated in the 

preamble to the proposed rule, GS is an option to reduce CO2 emissions to the atmosphere by 

injecting the CO2 streams into deep subsurface geologic formations, with the express purpose of 

isolating the CO2 so that it does not return to the atmosphere. August 8, 2011 (76 FR at 48075). 

Therefore, EPA views these CO2 streams as “discarded material” within the plain meaning of the 

term in RCRA §1004(27). The fact that the sequestration of CO2 streams into deep geologic 

formations is at times labeled as “long-term containment” or “long-term storage” does not change 

this view.

Comment 3.10.3:

EPA, however, simply declares that “[a]n 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.” 76 Fed. Reg. at 48,078. 

NMA believes it is premature and wrong to assume that the volumes of CO2 streams that will be 

produced and captured for injection under the new UIC Class VI regulations involves a final disposal 

decision. EPA wrongly assumes that these CO2 streams will not have commercial value and that 

their sequestration will automatically mean they have been “discarded” and thus subject to RCRA. 

To the contrary, CO2 is a valuable commodity used in enhanced oil or gas recovery production 

processes and other manufacturing operations. Additionally, CO2 injected in saline reservoirs under 

UIC Class VI regulations may later be withdrawn at least partially and used for reservoir 

maintenance as part of concurrent long-term storage/desalination operations. In these cases, and 

likely others in the future related to geologic sequestration, CO2 is used beneficially and is not 

“discarded” and not a “solid waste.”

Response: EPA acknowledges that the underground injection of CO2 has largely been (and 

continues to be) for the purpose of EOR, and does not disagree that CO2 can and does have a 

variety of commercial and manufacturing uses (e.g., urea yield boosting, enhanced oil recovery, 

food processing and packaging, beverage carbonation, and wine making), but this does not affect 

the regulatory status of CO2 streams when they are to be injected into UIC Class VI wells for the 

purpose of GS, which is the focus of this final rule. As EPA noted in the preamble to the proposed 

rule, this conditional exclusion is not intended to affect the regulatory status of CO2 streams that 

are injected into wells other than UIC Class VI wells. Regarding the comment that CO2 streams 

injected into UIC Class VI wells are not disposal, because they can later be withdrawn, EPA 

disagrees and reiterates that CO2 streams injected into UIC Class VI wells are solid wastes. As was 
119

stated in the preamble to the proposed rule, GS is an option to reduce CO2 emissions to the 

atmosphere by injecting the CO2 streams into deep subsurface geologic formations, with the 

express purpose of isolating the CO2 so that it does not return to the atmosphere (August 8, 2011; 

76 FR at 48075). Therefore, EPA views these CO2 streams as “discarded material” within the plain 

meaning of the term in RCRA §1004(27). That is, a supercritical CO2 stream is a solid waste when it 

is to be discarded through abandonment by disposing of the material in a UIC Class VI well (see 40 

CFR 261.2(a)(2)(i) and (b)(1)). EPA adds that the RCRA conditional exclusion does not preclude the 

removal of CO2 at a later date. How this activity is regulated would be a determination separate 

from the terms of the conditional exclusion in this rule.

Comment 3.10.4:

Assuming for purposes of argument that CO2 streams captured, transported and injected for 

geologic sequestration are a “solid waste,” the next step in the analysis is whether the CO2 streams 

are a “hazardous waste.” [FN1: EPA acknowledges that “no hazardous waste listings apply 

specifically to CO2 streams” and that “a CO2 stream could only be defined as a hazardous waste if it 

exhibits a hazardous waste characteristic as defined in 40 CFR part 261, subpart C.” 76 Fed. Reg. at 

48,078-79. EPA acknowledges that there are issues with testing CO2 streams to determine whether 

they exhibit the hazardous waste toxicity characteristic. Id. at 48,078]. EPA acknowledges that it 

“has little information to conclude that CO2 streams would qualify as RCRA hazardous wastes.” 76 

Fed. Reg. at 48,079. Despite this acknowledgment, EPA proposes to move forward with this 

conditional exclusion in order to “substantially reduce the uncertainty associated with defining and 

managing these CO2 streams under RCRA subtitle C.” Id.

Response: EPA did not set out in this rulemaking to conclude that those supercritical CO2 streams 

that are solid wastes would, as a class, exhibit a RCRA characteristic. Indeed, EPA indicated in the 

proposed rule that it could not unequivocally conclude that supercritical CO2 streams will never

exhibit any RCRA hazardous waste characteristic; alternatively, EPA acknowledges that some RCRA 

hazardous characteristics are unlikely to apply to a waste composed of >90% CO2, such as 

ignitability (i.e., RCRA Waste Code D001). This was confirmed in the public comment period, in 

which commenters did not provide EPA with evidence that CO2 streams could never qualify as RCRA 

hazardous wastes. Thus, in light of the early state of data development in this area, EPA intends to 

bring additional clarity to the regulatory regime through this rule, by establishing a conditional 

exclusion from the definition of hazardous waste that would apply in the event a generator 

determines that its CO2 streams exhibit a RCRA hazardous characteristic.

Regarding the commenter’s reference to testing CO2 streams, EPA notes that analytical methods do 

exist to analyze supercritical CO2 streams, and that generators may also use knowledge to 

determine whether a waste exhibits a RCRA characteristic. Should a generator determine that they 

are not managing a hazardous waste, they are not obligated to make use of this conditional 

exclusion and are not subject to the RCRA subtitle C regulations. Moreover, because use of the 

conditional exclusion is voluntary, even those generators who characterize their streams as RCRA 

hazardous waste may continue to manage their streams as RCRA hazardous wastes from the point 

of generation. The only effect is upon those persons who choose to comply with the terms of the 

conditional exclusion.

Comment 3.10.5:

As stated above, NMA supports EPA’s goal of the conditional exclusion. NMA also believes that EPA 

has properly executed its authority to conditionally exclude those CO2 streams injected for geologic 
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sequestration that may be deemed to be a “solid waste” and also exhibit a hazardous waste 

characteristic. As EPA correctly demonstrated in the proposed rule, “the existing UIC Class VI 

requirements sufficiently address any potential risk to human health and the environment, such 

that subtitle C regulation is unwarranted.” 76 Fed. Reg. at 48,086.

NMA, however, is concerned with two aspects of the conditional exclusion as proposed. First, NMA 

is concerned that the conditional exclusion could be lost and subtitle C requirements could apply at 

the point of generation if a minor paperwork violation occurs. The DOT and UIC regulations are 

complex and contain a number of administrative rather than risk-based requirements. An owner or 

operator should not lose the protections of the conditional exclusion simply because an 

administrative mistake is made somewhere in the CCS process (i.e., capture, storage, 

transportation or injection). NMA urges EPA to clarify in the final rule that only “material noncompliance” of the regulations would result in the loss of the conditional exclusion, and that 

“material non- compliance” does not include mistakes that are administrative in nature.

Response: While EPA maintains that the rule conditions, taken together, ensure that the excluded 

CO2 streams are being managed in a protective manner such that subtitle C regulations are not 

necessary, EPA can appreciate the commenter’s concern over the loss of the conditional exclusion 

due to, for example, small administrative or clerical errors. EPA’s Office of Enforcement and 

Compliance Assurance (OECA) is unable to provide definitive assurances outside the context of a 

formal enforcement proceeding that the government will not proceed with an enforcement 

response for a specific individual violation of an environmental protection statute, regulation, or 

legal requirement. However, EPA can (and has previously done so for other RCRA rules) exercise 

discretion to decide when and how to respond or not respond to a given violation, based on the 

Agency’s normal priorities. In RCRA penalty actions, the factors that EPA considers in assessing the 

gravity-based portion of the penalty are the potential for harm and the extent of deviation from a 

statutory or regulatory requirement. The penalty can be adjusted for numerous factors, including 

good faith efforts to comply, degree of willfulness and negligence, and history of noncompliance. 

Additional information can be found in the 2003 RCRA Civil Penalty Policy 

(http://www.epa.gov/compliance/resources/policies/civil/rcra/rcpp2003-fnl.pdf). 

Comment 3.10.6:

Second, NMA is concerned that the certification statement is overly broad and unworkable. 

Specifically, a generator may not own or operate the Class VI well at which the CO2 stream is 

injected and sequestered. In this case, the certification provision would require an individual to 

attest, under penalty of law, to facts which are not readily known to him/her and/or not under 

his/her control. Class VI well owners and operators also may not have access to certain information 

regarding any potential non-compliance with DOT regulations that occur before they take 

possession. To correct this problem, NMA urges EPA to amend the certification statement to 

require parties to attest to compliance with only those conditions for which they have 

responsibility under the proposed exclusion. Furthermore, NMA does not believe there is value in 

requiring transporters or pipeline owners or operators to sign a certification statement.

Response: EPA agrees and has modified the certification requirement in the final rule so that there 

are now two separate certification statements worded slightly differently – one for generators and 

another for UIC Class VI well owners or operators claiming this conditional exclusion. EPA has made 

these revisions to better reflect actions over which each party has control. Under the final rule, the 
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certification statement that the generator would sign is specific to the activities within the 

generator’s control; likewise, the certification statement that the UIC Class VI well owner or 

operator would sign is specific to the activities within the owner or operator’s control. 

EPA also agrees that there is no need for transporters or pipeline operators to be required to 

sign a certification statement as a condition of the exclusion. See response to comment 3.2.39. 

Therefore, EPA is not changing its proposed approach.

Comment 3.10.7:

NMA appreciates the opportunity to comment on this important proposed rule. If you have any 

questions regarding NMA’s position, please contact me at (see docket for contact information).

Response: EPA acknowledges the comment.

3.11Texas Pipeline Association (TPA)

Document ID: EPA-HQ-RCRA-2010-0695-0068

Comment 3.11.1:

The Texas Pipeline Association (TPA) submits the following comments on the proposed revision to 

the regulations for hazardous waste management under the Resource Conservation and Recovery 

Act (RCRA) to exclude carbon dioxide (CO2) streams from the definition of hazardous waste if they 

are injected into Class VI Underground Injection Control (UIC) wells for purposes of geologic 

sequestration and meet other specified conditions. TPA is an organization representing over 30 

members who gather, process, treat, and transport natural gas and hazardous liquids materials 

through intrastate pipelines in Texas.

Response: EPA acknowledges the comment.

Comment 3.11.2:

1. TPA supports the overall goal of this rulemaking. TPA generally supports this proposal and 

commends EPA on its efforts to ensure that geologic sequestration remains a viable option for the 

storage of captured CO2 streams. Excluding CO2 streams from the definition of hazardous waste for 

purposes of RCRA Subtitle C applicability is an important step in the right direction. As EPA 

recognizes, the imposition of Subtitle C requirements would be an undue burden on the 

implementation and use of geologic sequestration technology, given the protections that are 

already in place by virtue of the requirements governing the construction and maintenance of UIC 

Class VI wells.

Response: EPA acknowledges the comment. EPA notes that it based its conditional exclusion on its 

analysis demonstrating that management of supercritical CO2 streams in accordance with the rule’s 

conditions does not present a substantial risk to human health or the environment, and therefore 

that additional regulation pursuant to RCRA's hazardous waste regulations is unnecessary.

Comment 3.11.3:

2. The definition of "carbon dioxide stream" should be revised. EPA proposes to define "carbon 

dioxide stream" to mean CO2 that has been captured from "an emission source" plus "incidental 
122

associated substances derived from the source materials and the capture process .... " 76 Fed. Reg. 

48092. TPA believes that this definition would benefit from two revisions.

First, the term "an emission source" should be revised to make clear that a "carbon dioxide stream" 

could be derived from multiple sources and still qualify for the exemption provided by the rule. As 

currently written, the definition could be interpreted as requiring the CO2 stream to come from a 

single source to qualify for the exemption. CO2 streams often come from a number of different 

"sources" and there is no reason for the exemption to be withheld under such circumstances.

Second, the word "incidental" should be deleted. If a substance qualifies as an "associated

substance derived from the source materials and the capture process," then it should be within the 

exemption regardless of the quantity in which it exists in the stream. The word "incidental" 

connotes a volume limitation, and its use in the definition suggests that if such "associated 

substances" are present at sufficient volume, then they will no longer qualify as being "incidental," 

resulting in elimination of the exemption. The possibility of such a misinterpretation should be 

removed. 

Accordingly, TPA suggests the following revisions to implement the preceding comments: "Carbon 

dioxide stream means carbon dioxide that has been captured from an emission source OR 

SOURCES (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."

Response: Regarding the commenter’s request that EPA revise the term “emission source” to make 

it plural (“sources”), EPA never intended to limit the conditional exclusion to CO2 streams from a 

single source, and confirms that the existing language also would include CO2 streams generated 

from two or more independently-produced CO2 streams, and both would be excluded provided 

that the conditions of the exclusion are met for all streams for which it is being claimed. Thus, we 

are not making this suggested change. 

Regarding the request that EPA delete the term “incidental” from the proposed definition, EPA 

disagrees. In order to provide the regulatory clarity sought through this rule, it is critical that there 

be a consistent definition of carbon dioxide stream in both today’s final rule and the UIC Class VI 

final rule. This consistent definition is important because the applicability of the UIC Class VI 

requirements and the applicability of the conditional exclusion are linked in instances where the 

exclusion is being claimed. EPA is concerned that employing different definitions will result in 

confusion as to which streams are subject to both rules. In any event, EPA finds it unlikely that the 

applicability of the conditional exclusion will turn on how ‘incidental’ is interpreted; that is, in any 

instance where it has been determined that a “carbon dioxide stream” (as defined in either rule) 

can be safely and legally injected into a UIC Class VI well, the conditional exclusion is applicable, 

provided the other specified conditions are met.

Comment 3.11.4:

3. Certification and monitoring requirements should not apply to persons engaged in the 

movement of excluded CO2 streams. The rule being proposed by EPA would require any generator 

of a CO2 stream, and any Class VI DIC well owner or operator, to certify that the CO2 stream met all 

of the conditions set forth in 40 CFR 260.10. At 76 Fed. Reg. 48087, however, EPA raises the issue 

of whether certifications (and associated monitoring, recordkeeping, or reporting requirements) 
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should also be required of persons engaged in the movement of conditionally excluded CO2

streams, including transporters and pipeline owners or operators. TPA believes that no such 

additional requirement should be imposed. Under the rule as proposed, certifications as to content 

would already be obtained from the generator and from the well owner - the parties who should 

be expected to have the most knowledge of whether the CO2 stream at issue qualifies for the 

proposed exemption. It should be unnecessary to secure additional, duplicative certification from a 

pipeline owner or other transporter, who may handle the stream for only a brief period and whose 

knowledge of the details concerning the CO2 stream typically will be far inferior to that of the 

parties from whom certifications are already being obtained. TPA believes that requiring 

certifications as to content and other facts, under penalty of perjury, would result in a severely 

diminished willingness on the part of pipeline owners to transport CO2 streams for geologic 

sequestration in UIC wells. This would be contrary to the very point of the geologic sequestration 

regulations, which is to ensure that this promising technology is utilized to its fullest extent.

Response: EPA acknowledges the commenter’s comments regarding whether additional 

monitoring, reporting and recordkeeping requirements should be required, in this case with 

respect to transporters and pipeline owners and operators, and we note that the final rule is 

unchanged from the proposal with respect to requirements for transporters or pipeline owners 

and operators in this regard. See Responses to Comments 3.2.40 through3.2.43.

Regarding the commenter’s comments on requiring certification statements be signed by 

transporters or pipeline owners and operators, EPA agrees that a certification by the 

transporter is not necessary. First, if EPA were to require such a certification, under the 

approach where EPA limits the scope of the certification to the conditions within the control of 

pipeline owners and operators or other transporters (the approach taken in the final rule for 

CO2 stream generators and UIC Class VI well owners and operators), the certification would 

essentially address 1) compliance with applicable DOT requirements, and 2) to not mix 

hazardous waste into the CO2 streams. Regarding compliance with DOT requirements, EPA is 

persuaded by comments received on this issue that if persons transporting supercritical CO2

must comply with the applicable transportation requirements for all supercritical CO2 being 

moved, it seems unnecessary to require that they certify compliance with DOT requirements 

for a specific material (i.e., supercritical CO2 streams to be sequestered). Regarding mixing with 

hazardous waste, EPA does not have information, nor did commenters provide any new 

information, indicating that CO2 pipeline owners and operators or other transporters would mix 

hazardous waste into CO2 streams being delivered to UIC Class VI facilities. EPA expects that 

pipeline owners and operators engaged in delivering supercritical CO2 have strong disincentives 

to mix any hazardous waste into their pipeline system, both in order to honor their contractual 

arrangement with customers, and also to maintain their equipment. Also, as EPA stated in the 

proposed rule premable, PHMSA requires that pipeline owners and operators ensure that 

supercritical CO2 streams be chemically compatible with the pipeline and any commodities in 

the pipeline and will not corrode the pipeline and pipeline system. For these reasons, EPA does 

not see the need for a transporter certification, and is not changing its proposed approach and 

transporters and pipeline owners and operators will not be required to sign a certification 

statement as a condition of the exclusion.

Comment 3.11.5:

We appreciate the opportunity to submit these comments. Please let us know if you have any 

questions.
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Response: EPA acknowledges the comment.

3.12Western Business Roundtable

Document ID: EPA-HQ-RCRA-2010-0695-0071

Comment 3.12.1:

I am writing, on behalf of the multi-sector membership of the Western Business Roundtable

(“Roundtable”), in response to the Environmental Protection Agency’s (“EPA” or the “Agency”)

proposed rule entitled “Hazardous Waste Management System: Identification and Listing of

Hazardous Waste: Carbon Dioxide (“CO2”) Streams in Geologic Sequestration (“GS”) Activities.” 

[FN1: 76 Fed. Reg. 48073 (August 8, 2011)]. 

In this action, EPA proposes to revise the regulations for hazardous waste management under the

Resource Conservation and Recovery Act (”RCRA”) to “conditionally exclude” CO2 streams from the 

definition of hazardous waste, provided such streams meet certain capture and storage

requirements.

ABOUT THE ROUNDTABLE

The Roundtable is a broad-based coalition of companies doing business in the Western United

States. Our membership is comprised of a coalition of corporations and organizations representing 

a broad cross-section of Western business including, among others: manufacturing; mining; electric 

power generation/transmission/distribution; energy infrastructure development; energy supply 

exploration/development and transportation; energy services; and environmental engineering.

We work to defend the interests of the West and support policies that encourage economic growth 

and opportunity, freedom of enterprise and a sound approach to conservation and environmental 

stewardship.

Many of our members are centrally involved in the development, transportation and processing of 

a wide variety of energy resources -- fossil, renewable and nuclear -- as well as the generation and 

distribution of electricity across the West and technologies that facilitate greater energy

conservation and efficiency. Roundtable members also are on the cutting edge of technology

development related to the management of CO2 emissions.

I hope you will find the broad perspective and expertise reflected in these comments helpful as the 

Agency moves forward with its deliberations on this important policy issue.

Response: EPA acknowledges the comment.

Comment 3.12.2:

IMPORTANCE OF CCS

The Roundtable strongly supports the aggressive research and development efforts underway to

facilitate commercial-scale CO2 capture and sequestration (“CCS”) projects. We also believe that 

expansion of enhanced oil recovery (“EOR”) present a meaningful opportunity to utilize CO2 in a 

way that is beneficial to the global environment and both our nation’s economy and its energy 
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security.

Current research is moving America ever closer to technologies that can tap our domestic fossil

resources with less and less environmental impact. The goal of near-zero or zero-emission

technologies, capable of capturing CO2, is now foreseeable. Key to these technologies is the

assumption that effective sequestration/storage options will be available to dispose of the CO2

once captured.

The whole issue of CO2 management has tremendous macro-economic, consumer pocketbook,

environmental and national security implications. Extensive Congressional and regulatory reviews 

are underway regarding the efficacy of mandatory carbon regulations. A necessary predicate to any 

such regime must be a clear understanding of:

* The effectiveness of sequestration and storage options;

* Hurdles to the efficient implementation of those options;

* CO2 transportation system challenges; and

* Liability issues associated with both transportation and storage of CO2.

As policymakers and project developers work through the many nuances involved with large-scale 

CCS, we believe that it is important to keep focused on this central tenet: strong and early

investment in CCS technologies and infrastructure is a necessary foundation for any viable climate 

change regulatory regime.

One of the biggest impediments to commercial-scale CCS projects today is regulatory uncertainty. 

Meaningful investments will only occur in the presence of clear, carefully tailored regulatory 

constructs that help encourage early and robust development of projects and which aid in 

eliminating regulatory risk for such early investments.

In that regard, we believe EPA’s actions in this proposed rule are extremely important.

Response: EPA acknowledges the commenter’s support for CCS. The commenter raises several 

points regarding the importance of CCS and factors that can contribute to the successful 

development of CCS. EPA agrees with the overall conclusion that CCS is indeed an important tool in 

reducing GHG emissions and mitigating climate change. While many of the commenter’s specific 

points are beyond the scope of this instant rulemaking, EPA agrees with the commenter that 

regulatory certainty is important to facilitate future deployment of CCS. EPA believes this rule 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.

Comment 3.12.3:

We appreciate EPA’s statement that 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
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identifying these CO2 streams under RCRA subtitle C, and will also facilitate the deployment of GS 

by providing additional regulatory certainty.” [FN2: Id.].

Response: EPA acknowledges the comment. 

Comment 3.12.4:

The Roundtable has long been on record urging EPA to avoid utilizing risk management approaches 

that discourage CCS deployment. Regulatory certainty is absolutely crucial, if meaningful 

investment is going to flow to CCS technologies and implementation.

Public acceptance is also a crucial linchpin to any meaningful CCS program. This point was

emphasized in a 2007 National Academy of Sciences report, which noted that a large-scale CCS

program cannot be successful “if a significant fraction of the public views it as dangerous or

unacceptable.” [FN3: Prospective Evaluation of Applied Energy Research and Development of DOE 

(Phase Two), National Research Council (2007)].

Thus, we applaud the EPA for its clear sensitivity to the need for certainty in this arena. The

Agency’s approach here, and under the Safe Drinking Water Act (SDWA), will set the general tone 

for how other federal and state regulatory bodies, investors and the general the public will treat 

CCS going forward.

Response: See comment 3.12.2.

Comment 3.12.5:

RECOMMENDATIONS

With the shared goal of regulatory certainty in mind, we would offer the Agency the following

thoughts on how the proposed regulations might be clarified and strengthened:

Exclude CO2 Streams From the Definition of “Solid Waste”

As we have noted, we appreciate EPA’s recognition that CO2 streams captured from emission

sources and injected into Class VI (UIC) wells for purposes of geologic sequestration “do not

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

regulation pursuant to RCRA’s hazardous waste regulations are unnecessary.” [FN4: 76 Fed. Reg. at 

48075]. 

The Roundtable supports what EPA is attempting to achieve with the proposed “conditional

exclusion.” We do fear, however, that this approach does not fully meet the goals of regulatory

clarity and certainty. We believe the proposed rule would be strengthened if EPA simply excluded 

CCS CO2 streams from the definition of “solid waste” under RCRA.

Response: EPA disagrees that CO2 streams injected into UIC Class VI wells for purposes of GS are 

not solid waste. As was stated in the preamble to the proposed rule, GS is an option to reduce CO2 

emissions to the atmosphere by injecting the CO2 streams into deep subsurface geologic 

formations, with the express purpose of isolating the CO2 so that it does not return to the 

atmosphere (August 8, 2011; 76 FR at 48075). Therefore, EPA views these CO2 streams as 

“discarded material” within the plain meaning of the term in RCRA §1004(27). That is, a 
127

supercritical CO2 stream is a solid waste when it is to be discarded through abandonment by 

disposing of the material in a UIC Class VI well (see 40 CFR 261.2(a)(2)(i) and (b)(1)).

Comment 3.12.6:

Such an action is appropriate because:

* CO2 Provides Beneficial Uses

CO2 does not fit into the purposes of RCRA as a hazardous waste management regime.

It has all sorts of beneficial uses. Beyond its critical role in nature, it is a commodity used for a 

variety of industrial purposes (EOR being the most prevalent, but not the only, example).

Response: See response to comment 3.2.2.

Comment 3.12.7:

* RCRA is Poorly Suited to Regulate CCS CO2 Streams

RCRA’s structure is to provide “cradle-to-grave” tracking and management of hazardous wastes. It 

is not clear to us how that can ever be achieved for CO2 injected as part of CCS. In geologic 

sequestration, various streams of CO2 would be injected and mixed. There is no practical way to 

track one stream vs. another.

Response: It is not clear from the comment in what particular ways the commenter views mixed 

CO2 streams as “poorly suited” for RCRA. In any case, CO2 streams managed in accordance with the 

conditional exclusion would not be subject to other RCRA hazardous waste requirements, such as 

manifesting. Moreover, EPA believes that the applicable DOT requirements for pipelines and nonpipeline transport are sufficient to ensure proper handling and transport of CO2 streams. The UIC 

Class VI well requirements also provide sufficient protections where they apply. Regarding multiple 

sources of CO2 streams, shared pipelines, and similar issues see Responses to Comments 3.2.3 and 

3.2.4.

Comment:

* CO2 Streams Are Not “Solid Wastes”

The Roundtable shares the opinion of the North American Carbon Capture and Storage Association 

that CCS CO2 streams do not meet RCRA’s definition of solid waste.

RCRA defines “solid waste” as including “discarded material, including solid, liquid, semi-solid or 

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

operations...”[FN5: 42 USC Section 6903(27)]. CCS CO2 streams neither have the physical form of a 

solid waste (as defined under the Act), nor have they been “discarded.”

Response: See Responses to Comments 3.1.6 through 3.1.8. See also Responses to Comments 

3.14.6 through 3.14.8.

Comment 3.12.9:

While CCS CO2 streams are gases compressed to a supercritical state, they are not “contained.” 

RCRA regulations differentiate between those gases in non-flow-through containment systems 

(which are included in RCRA’s definition of solid waste) with those that are simply passing through 
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infrastructure for a specific purpose. That latter situation fits CCS CO2 streams, which are captured 

and then flow through a pipeline to a storage location. Under RCRA, such gases are considered 

“uncontained” and would be outside the definition of solid waste.

Response: See response to comment 3.1.7. Accordingly, the distinctions the commenter seeks to 

make between gases managed in “non-flow-through containment systems” and gases that are 

“passing through infrastructure” are not germane in this context. 

Comment 3.12.10:

We also are unclear how CCS CO2 streams can be considered “discarded” within the meaning 

defined in RCRA. They are not being disposed of or abandoned. The fact that these streams are 

being stored implies their availability for future use. The fact that there are economic uses for CO2, 

and that CO2 is currently being utilized as a commodity, refutes the suggestion that the materials 

are a waste without future beneficial use.

Response: See Responses to Comments 3.1.8, and 3.2.2.

Comment 3.12.11:

*CO2 Streams Are Not Hazardous

EPA acknowledges in the proposed rule that it has little information that would lead it to conclude 

that CO2 streams would qualify as RCRA hazardous wastes. [FN6: 76 Fed. Reg. at 48078]. The gases 

that are emitted in flue gas stream of coal-fired power plants would not generally contain 

constituents in sufficient concentrations to warrant concern. EPA appears to be asserting RCRA 

authority to provide “belts-and-suspenders” regulatory coverage.

Response: EPA appreciates commenters’ concerns regarding the application of the hazardous 

waste regulations to supercritical CO2 streams being sequestered. EPA believes these concerns 

exist as a result of the unique circumstances associated with addressing the applicability of RCRA to 

CCS at such an early stage in the development of CCS. However, it is important to note that EPA 

did not set out in this rulemaking to conclude that those supercritical CO2 streams that are solid 

wastes would, as a class, exhibit a RCRA characteristic. Indeed, EPA indicated in the proposed rule 

that it could not unequivocally conclude that supercritical CO2 streams will never exhibit any RCRA 

hazardous waste characteristic and commenters provided no information to the contrary. 

Alternatively, EPA acknowledges that some RCRA hazardous characteristics are unlikely to apply to 

a waste composed of >90% CO2, such as ignitability (i.e., RCRA Waste Code D001). Thus, in light of 

the early state of data development in this area, EPA intends to bring additional clarity to the 

regulatory regime through this rule, by establishing a conditional exclusion from the definition of 

hazardous waste that would apply in the event a generator determines that its CO2 streams exhibit 

a RCRA hazardous characteristic.

Comment 3.12.12:

While understanding EPA’s impulse to be cautious, we urge the Agency to be extremely careful in 

its characterization of CO2. As has been previously noted, a successful climate change control 

program will necessarily be predicated on development of -- and public support for -- CCS. EPA 

could inadvertently, and inappropriately, stigmatize CCS, if it veers into an unwarranted 

categorization of CO2 as a potential hazardous waste. That would put advancement of CCS 
129

commercialization into a deep freeze. Such an outcome would clearly be counter-productive.

Response: See response to comment 3.12.11. EPA believes a consistent regulatory approach to GS 

will help facilitate development and deployment of CCS technologies in the United States, rather 

than discourage deployment.

Comment 3.12.13:

Captured CO2 streams are already covered under federal pipeline transportation regulations and 

the Agency’s own recently finalized SDWA Underground Injection Control Class VI Rule.

Response: EPA acknowledges the comment. See response to comment 3.12.11. That management 

of CO2 streams is regulated by other federal programs does not affect the question of whether a 

particular CO2 stream may exhibit a RCRA hazardous waste characteristic.

Comment 3.12.14:

Avoid Duplicative Recordkeeping Requirements

In the proposed rule, EPA seeks comment on the need for additional monitoring record-keeping

and reporting requirements. We do not believe additional requirements should be placed on the

generators or the operators of CO2 sequestration wells. EPA already has established extensive

requirements for monitoring and documentation under its UIC Class VI well rulemaking.

This appears to us a perfect opportunity for EPA to demonstrate its commitment to the goals set

out in President Obama’s Executive 13563: Improving Regulation and Regulatory Review.

Response: See Responses to Comments 3.2.40 and 3.2.43. It is not clear to which goals in E.O. 

13563 the comment refers.

Comment 3.12.15:

CONCLUSION

On behalf of the many member organizations of the Western Business Roundtable, thank you for

the opportunity to provide our input on this crucially important public policy issue, the implications 

of which are so pivotal to the continued vitality of the West.

Response: EPA acknowledges the comment.

3.13Greater Houston Partnership (GHP)

Document ID: EPA-HQ-RCRA-2010-0695-0074

Comment 3.13.1:

The Greater Houston Partnership (GHP) appreciates the opportunity to provide comments on the 

Environmental Protection Agency’s (EPA) proposed rule entitled “Hazardous Waste Management 

System: Identification and Listing of Hazardous Waste: Carbon Dioxide (CO2) Streams in Geologic 

Sequestration Activities.” 
130

GHP represents the 10-county Houston region’s business interests to promote economic prosperity 

through the growth of high paying jobs, international trade and capital investment. As the primary 

advocate of Houston’s business community, GHP lobbies on behalf of its Members regarding the 

development of environmental regulation for our 10-county region. 

The proposed rule will have significant impact on the state of Texas. Texas has advantageous 

geologic formations for the storage of anthropogenic CO2. The state has one of the largest storage 

capacities in the country. The U.S. Department of Energy’s National Energy Technology Laboratory 

estimates Texas’ onshore storage capacity between 661 million and 2.4 billion tons of CO2.

GHP concurs and supports the comments submitted by the American Petroleum Institute (API) and 

the North American Carbon Capture & Storage Association (NACCSA).

Response: EPA acknowledges the comment and refers to the Agency’s Responses to Comments in 

Sections 3.1 (API) and 3.14 (NACCSA).

Comment 3.13.2:

GHP believes adequate enforcement mechanisms to protect human health and the environment 

from CO2 streams currently exist under the Clean Air Act’s reporting requirements and under the 

Underground Injection Control (UIC) Class VI Rule under the Safe Drinking Water Act to protect 

underground sources of drinking water. Additional regulation under the Resource Conservation and 

Recovery Act (RCRA) is redundant and could lead to unintended consequences that would 

undermine beneficial uses of CO2 streams for carbon capture and sequestration and enhanced oil 

and gas recovery. EPA should enact an exclusion of all carbon dioxide streams, with a conditional 

exclusion for supercritical CO2 streams, from the RCRA definition of solid waste at this time.

If CO2 streams were deemed solid wastes, the potential regulatory burdens associated with that 

designation will discourage companies from handling CO2 streams to the detriment of EPA’s efforts 

to remove CO2 emissions from the atmosphere.

Response: See Responses to Comments 3.1.1. and 3.1.2. Regarding the commenter’s statement 

that regulation under RCRA is not necessary because of adequate regulation under other statutes, 

EPA in fact considered the effect of other statutory requirements, and this conditional exclusion is 

based upon EPA’s determination that the management of these CO2 streams under other statutes 

provides protection to human health and the environment; therefore, additional regulation 

pursuant to RCRA hazardous waste regulations is unnecessary. 

Regarding the commenter’s references to “potential regulatory burdens” associated with CO2

streams that are deemed solid wastes (management of which may be outside the scope of this 

rule), and “unintended consequences” of additional regulation under RCRA, the commenter did not 

provide specific information or examples of these, and therefore, while EPA acknowledges these 

comments it cannot provide more specific responses. 

3.14 North American Carbon Capture & Storage Association (NACCSA)

Document ID: EPA-HQ-RCRA-2010-0695-0078

Comment 3.14.1:
131

On behalf of the North American Carbon Capture and Storage Association ("NACCSA"), we are 

pleased to provide the Environmental Protection Agency ("EPA" or the "Agency") with these 

comments on the proposed rule entitled "Hazardous Waste Management System: Identification 

and Listing of Hazardous Waste: Carbon Dioxide ("CO2") Streams in Geologic Sequestration 

Activities." 76 Fed. Reg. 48073 (Aug. 8, 2011).[FN1: A technical correction was published on 

September 9, 2011. 75 Fed. Reg. 55846.]

About NACCSA

NACCSA is a nonprofit organization of companies in North America that support the development 

of a sustainable carbon dioxide capture and storage ("CCS") industry in the United States and 

Canada. NACCSA members [FN2: NACCSA members are American Electric Power; American 

Petroleum Institute; Anadarko Petroleum Corporation; Arch Coal Inc.; Blue Source LLC; Denbury 

Resources, Inc.; Halliburton; Kinder Morgan; Occidental Petroleum Corporation; Peabody Energy; 

Sasol; Schlumberger Carbon Services; Shell; and Tenaska.] include companies involved in 

developing commercial processes to mitigate greenhouse gas emissions through CCS, and 

specialists engaged in the technical, commercial, financial and developmental aspects of CCS 

activities in both the U.S. and Canada.

Response: EPA acknowledges the comment.

Comment 3.14.2:

Executive Summary

NACCSA supports the conditional exclusion for CO2 streams from the Resource Conservation &

Recovery Act's ("RCRA") hazardous waste regulations but recommends that it be recast as an 

exclusion from the definition of "solid waste" because of CO2's unique properties and uses, coupled 

with the fact that CO2 streams are not "discarded." Failure of EPA to clarify that eligible CO2

streams are not "solid wastes" will leave CCS projects with unnecessary regulatory uncertainty 

while doing little to advance public health and environmental protection, given the rigorous 

requirements of the recently finalized Underground Injection Control ("UIC") Class VI rule.

If EPA elects to retain the proposed approach of a conditional exclusion for CO2 streams from 

RCRA's hazardous waste regulations, we recommend that the proposed regulation be clarified to 

remove as much regulatory ambiguity as possible, as we set forth in detail below.

Response: See response to comments 3.1.1 and 3.1.2.

Comment 3.14.3:

Specific Comments

EPA proposes to "conditionally" exclude “CO2 streams”, [FN3: EPA explains that a "Carbon dioxide 

(CO2) stream" is “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." 76 

Fed.Reg. at 48075.] that "are hazardous from the definition of hazardous waste, provided these 

hazardous CO2 streams are captured from emission sources, are injected into Class VI [UIC] wells 

for purposes of geologic sequestration ... and meet certain other conditions." 76 Fed. Reg. at 

48074. EPA explains that it is taking this action because it "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 
132

regulations is unnecessary." Id. EPA notes that the conditional exclusion will provide additional 

regulatory certainty.

NACCSA supports the proposed "conditional exclusion" as far as it goes because it endeavors, albeit 

incompletely, to clarify the regulatory regime for CCS while ensuring stringent protection of human 

health and the environment. We nonetheless believe that the "conditional exclusion" falls short of 

what is needed to provide adequate regulatory certainty for industry for the following reasons.

Response: See response to comment 3.1.3.

Comment 3.14.4:

A. CO2 Streams Are Not "Wastes"

EPA's proposal is premised on the notion that RCRA potentially applies to "CO2 streams" in the first 

instance. This premise is false for two reasons.

First, Congress, in enacting RCRA, never envisioned regulation of a molecule such as CO2. In 

comparison to other materials regulated under RCRA, CO2 is unique. It performs a variety of 

beneficial and ubiquitous roles in a variety of natural (e.g., uptake by plants) and industrial (i.e., 

enhanced oil recovery, or EOR) functions. Several states already have declared CO2 to be a 

"commodity" for these reasons. [FN4: See, e.g., Oklahoma SB 1610 ("Carbon dioxide is a valuable 

commodity to the citizens of the state").] If CO2 is subject to RCRA, perhaps water should be, too. A 

person can drown in water, but that doesn't mean that H2O is hazardous within the meaning of 

RCRA. [FN5: We do not believe that Massachusetts v. EPA, 549 U.S. 497 (2007), a Clean Air Act case, 

bears on the status of CO2 for purposes of geologic sequestration.]

Response: See Responses to Comments 3.1.4 and 3.1.5.

Comment 3.14.5:

Second, and similarly, RCRA was never meant to apply to CCS and thus the statute provides a poor 

tool to regulate the activity. Nothing in RCRA or its regulations purport to apply to CCS generally or 

geologic sequestration specifically. The RCRA model is prospective "cradle-to-grave" waste 

management and tracking. CCS, on the other hand, currently involves the injection of CO2 for 

beneficial purposes. That activity, moreover, is envisioned to involve mixed streams of CO2 from 

multiple sources, thereby frustrating the notion of tracking wastes through manifests and the like. 

There also is no standardized test method to evaluate supercritical CO2. For these and other 

reasons, trying to fit CCS under RCRA is the classic example of trying to wedge a square peg into a

round hole.

Response: See Responses to Comments 3.1.5 and 3.12.7.

Comment 3.14.6:

B. CO2 Streams Are Not "Solid Wastes"

The conditional exclusion is rooted on the unsupported premise that captured anthropogenic CO2

is a "solid waste." EPA asserts that a "supercritical CO2 stream ... is a RCRA solid waste, as it is a 

'discarded material' within the plain meaning of the term in RCRA § 1004(27)." 76 Fed. Reg. at 

48077-78. [FN6: Relevant provisions of RCRA § 1004(27) define "solid waste" as "other discarded 

material, including solid, liquid, semisolid, or contained gaseous material resulting from ... 

industrial operations .... "]
133

EPA does not offer a detailed justification for its claim that CO2 streams are "discarded," so we 

begin with an analysis of how RCRA and its regulations define that term.

Subtitle C of RCRA, which regulates hazardous wastes, applies only to a "solid waste" that is 

"hazardous.” [FN7: T. Garrett, ed., "The RCRA Practice Manual” at 2, 2nd ed. (ABA 2004).] To be 

regulated as a "solid waste," a material must satisfy three criteria, two of which are relevant: (1) it 

must have the physical form of a solid waste; and (2) it must be "discarded.” [FN8: Id. at 33.] 

Neither of these criteria is met here.

Response: See Responses to Comments 3.1.6 and 3.1.7.

Comment 3.14.7:

CO2 Streams Do Not Have the Physical Form of a Solid Waste. In relevant part, RCRA defines "solid 

waste" as "other discarded material, including solid, liquid, semisolid, or contained gaseous 

material resulting from industrial, commercial, mining, and agricultural operations .... " 42 U.S.C. § 

6903(27) (emphasis added). Supercritical states of material, such as is relevant for CO2, are not 

listed in this definition.

Before it is compressed to a supercritical state, moreover, CO2 is a gas. By "contained gas" in the 

definition above, EPA means [FN9: Id. at 33-34 (emphasis added).]:

“a gas that is contained in a cylinder or other non-flow-through containment 

system. In contrast, an uncontained gas, such as gas flowing through a pipe, column, 

or tank, is not a solid waste. Since uncontained gases are not solid wastes and 

therefore cannot be hazardous wastes, as a general matter, units that manage 

uncontained gases are not regulated under RCRA.”

Applying this relatively narrow concept of "contained gas” it is clear that a CO2 stream - - which at 

minimum spends part of its life "flowing through a pipe” is not a solid waste because it does not 

have the necessary form to be swept up under RCRA's jurisdiction. [FN10: The fact that a CO2

stream is not a "contained gas" should not be interpreted to suggest that geologic storage is not an 

effective means of long-term storage, as it is. "Contained gas" is a regulatory concept only.]

Response: See response to comment 3.1.7.

Comment 3.14.8:

CO2 Streams Are Not Discarded. RCRA defines "solid waste" as "other discarded material, including 

solid, liquid, semisolid, or contained gaseous material resulting from industrial, commercial, mining, 

and agricultural operations .... " 42 U.S.C. § 6903(27) (emphasis added). EPA's regulations explain 

that a "solid waste" is any "discarded material" that is "not excluded under § 261.4(a) [FN11: 40 

C.F.R. § 261.4(a) excludes through numerous specific listings "[m]aterials which are not solid 

wastes."] or that is not excluded by a variance granted under §§ 260.30 [FN12: 40 C.F.R. § 260.30 

deals with non-waste determinations and variances from classification as a solid waste.] and 

260.31[FN13: 40 C.F.R. § 260.31 sets forth standards and criteria for variances from classification as 

a solid waste.] or that is not excluded by a non-waste determination under §§ 260.30 [FN14: See 

note 12, supra.] and 260.34 [FN15: 40 C.F.R. § 260.34 sets forth standards and criteria for nonwaste determinations.]." [FN16: 40 CF.R. § 261.2 (definition of "solid waste") (emphasis and 
134

internal footnote references added).] A "discarded material," in turn, is "any material" that is: (1) 

abandoned; (2) recycled; or (3) considered inherently waste-like. [FN17: 40 C.F.R. § 261.2(a)(2)(i).]

Although they do not define the term "material," EPA's regulations set forth detailed criteria that 

must be met before a material is deemed to be "discarded" via the "abandoned," "recycled," or 

"inherently waste-like" regulatory paths:

*Abandoned. Materials are "solid waste" if they are abandoned by being: (a) disposed of; (b) 

burned or incinerated; or (c) “[a]ccumulated, stored or treated (but not recycled) before or in lieu 

of being abandoned by being disposed of, burned, or incinerated.” [FN18: 40 C.F.R. § 261.2(b).]

*Recycled. Materials separately are "solid waste" if they are recycled - or accumulated, stored, or 

treated before recycling - if they fall into one of the following four categories: (a) used in a manner 

constituting disposal; (b) burned for energy recovery; (c) reclaimed; or (d) accumulated 

speculatively. [FN19: 40 C.F.R. § 261.2(c).]

*Inherently waste-like. Specifically identified materials, not including CO2, also are "solid waste" if 

they are recycled in any manner, and thus deemed to be “inherently waste-like materials.” [FN20: 

40 C.F.R. § 261.2(d).]

"CO2 streams" do not meet any of these three RCRA regulatory requirements.

* CO2 streams are not abandoned. CO2 streams are not burned or incinerated, nor are they 

"disposed of." The "S" is CCS stands for either "storage" or "sequestration," neither of which 

contemplates "disposal." The Merriam Webster Dictionary defines "sequester" as "to set apart, 

segregate" or to "seclude, withdraw.” [FN21: http://www.merriamwebster.com/dictionary/seguestered?show=0&t=1315859974.] Synonyms for "sequestration" 

include "isolation" and "seclusion." [FN22: http://www.merriamwebster.com/dictionary/seguestration.] "Disposal," on the other hand, is defined as the act of 

"disposing," which means “to get rid of.” [FN23: http://www.merriamwebster.com/dictionary/disposing.] "Abandonment" also suggests that the material being 

abandoned is not thereafter managed; under the Class VI rule, injected CO2 will be - and is required 

to be - carefully managed. Based on a "plain meaning" analysis, CCS does not contemplate 

"disposal."

The concept of "disposal" is also inconsistent with how the bulk of CO2 is currently being managed 

commercially today. With the exception of demonstration and related projects, most if not all of 

the CO2 that is geologically injected today is used for EOR. In that application, it is purchased and 

transacted as a valuable commodity. As explained further below, EPA's Class VI rule envisions that 

concurrent EOR/storage may be conducted under Class II as long as certain conditions are met - a 

usage that flatly contradicts EPA's assertion here that injection is a “disposal activity."

CO2 that is injected in saline reservoirs under Class VI also is not "disposed of." It is conceivable, for 

example, that such CO2 may be later at least partially withdrawn and put to a beneficial, but still 

non-atmospheric-emitting, use. Such CO2 may also be used for reservoir maintenance as part of 

concurrent long-term storage/desalination operations, as explained by William Bourcier of 

Lawrence Livermore National Laboratory at the August 18, 2010 meeting of the California CCS 

Review Panel. [FN24: http://www.climatechange.ca.gov/carbon capture review 
135

panel/meetings/2010-08- 18/presentations/01 Bourcier Cal CCS-Panel.pdf.]

CCS-related offset credits are also transacted on various carbon registries, such as the American 

Carbon Registry. This activity is inconsistent with the notion of "disposal."

It is also worth noting that the terms "disposal" and "dispose" do not appear in any relevant 

portion of the Class VI rule or EPA's preamble to the same.

Because geologic sequestration/storage does not contemplate "disposal," the regulatory 

"abandonment" provisions dealing with "[a]ccumulated, stored or treated" also are inapplicable.

*CO2 streams are not recycled. RCRA's provisions regarding "recycle" are detailed, and none of 

them apply to CO2 streams - nor has EPA claimed the same.[FN25: The fact that CO2 is recycled in 

EOR operations is not directly relevant for the RCRA regulatory concept of "recycle."] In order for 

the recycle rules to apply, a material must first be deemed a secondary material. Among other 

things, secondary materials do not include "co-products." Since in current commercial practice CO2

that is geologically injected is transacted as a valuable commodity as "co-products," the recycle 

regulations do not apply. [FN26: T. Garrett, ed., "The RCRA Practice Manual," at 36.]

*CO2 streams are not "inherently waste-like." RCRA' s provisions regarding "inherently waste-like" 

materials also are detailed, and none of them applies to CO2 streams- nor has EPA claimed the 

same.

Response: See response to comment 3.1.8. In regards to the comment that careful management of 

the material would render material in a Class VI well not a waste and that ‘abandonment’ is not 

occurring because it is being managed, EPA disagrees. Whether the material is being managed, 

carefully or not, does not bear on whether injection into a Class VI well for purposes of GS is to 

discard a CO2 stream. Injection of a CO2 stream into a Class VI well for purposes of GS is effectively 

“getting rid of” the CO2 stream by keeping it underground indefinitely. Indeed, RCRA hazardous 

wastes are subject to controls after disposal (e.g., post-closure care at a RCRA hazardous waste 

landfill). It is thus very clear that CO2 streams managed in a Class VI well for purposes of GS are 

solid waste.

Comment 3.14.9:

C. CO2 Streams Are Not "Hazardous Wastes"

Assuming for the moment that CO2 streams are "solid wastes" - and they are not, as described

above - they also are not "hazardous wastes."

EPA states that it has "little information to conclude that CO2 streams would qualify as RCRA 

hazardous waste." 76 Fed. Reg. at 48077. The Agency also acknowledges that "CO2 streams are not 

listed hazardous wastes" under subpart D of part 261. Id.[FN27: Accord 76 Fed. Reg. at 48078 ("EPA 

reiterates that no hazardous waste listings apply specifically to CO2 streams").] The Agency 

nonetheless believes that the "RCRA hazardous waste regulations can apply to CO2 streams" based 

upon two hypothetical scenarios: (1) a CO2 stream exhibits hazardous characteristics [FN28: 40 

C.F.R. § 261.20(a).]; or (2) a CO2 stream is mixed with a listed hazardous waste, thus triggering 

application of the so-called "mixture rule." Id.
136

Neither of these hypothetical scenarios is plausible. With respect to whether a CO2 stream exhibits 

hazardous characteristics, EPA seems to acknowledge that there is no available standardized 

analytical test method for supercritical materials such as CO2 or a "CO2 stream.” [FN29: 76 Fed. Reg. 

at 48078 n. 22 ("EPA notes that existing analytical test methods ... are available to quantify the 

levels of various hazardous constituents in gaseous streams, although sampling a supercritical CO2

stream may require particular sampling protocols") (emphasis added).] EPA may only define a 

characteristic of a hazardous waste if the characteristic can be: (1) measured by an "available 

standardized test method which is reasonably within the capability of generators of solid waste or 

private sector laboratories that are available to serve generators of solid waste," or (2) "reasonably

detected by generators of solid waste through their knowledge of their waste.” [FN30: 40 C.F.R. § 

261.10(a)(2).] This two-factor test simply cannot currently be met for supercritical CO2 streams 

based on available standards.

Even if a standardized analytical test method were available for supercritical CO2, we are not aware 

of any information which would suggest that supercritical CO2 meets any of EPA's hazard 

characteristics. Supercritical CO2 is not: (1) ignitable under 40 C.F.R. § 261.21; (2) corrosive under 

40 C.F.R. § 261.22 [FN31: 31 Supercritical CO2 is non-aqueous, so § 261.22(a)(1) does not apply, and 

§ 261.22(a)(2) only applies if the material is "liquid and corrodes steel." Supercritical CO2 is not a 

"liquid" and does not corrode the steel pipelines through which it has been transported safely for 

several decades. EPA hints that corrosivity could be an issue down hole through interaction with insitu reservoir fluids, but that scenario is not contemplated by 40 C.F.R. § 261.22.]; (3) reactive 

under 40 C.F.R. § 261.23; or (4) toxic under 40 C.F.R. § 261.24. [FN32: Toxicity is assessed under 

Test Method 1311, the so-called Toxicity Characteristic Leaching Procedure ("TCLP"). 40 C.F.R. § 

261.24(a). The TCLP is inapplicable to supercritical CO2 and CO2 streams, as the TCLP was "intended 

to reflect the potential for leaching to groundwater that results from the codisposal of toxic wastes 

in an actively decomposing municipal landfill generating an acidic leachate." T. Garrett, ed., "The 

RCRA Practice Manual," at 52. With reference to a 2006 paper from Lawrence Livermore National 

Laboratory, EPA suggests that certain impurities are "relevant" for toxicity regulation under § 

261.24(a). However, all of the impurities referenced by EPA as potentially being present in certain 

CO2 streams are at levels which are orders of magnitude lower than the relevant regulatory levels 

set forth in the regulations.] In the preamble to the final Class VI rule, EPA stated that it had 

reviewed estimates of CO2 injectate quality, and based upon that assessment, "captured CO2 could 

contain some impurities.” [FN33:75 Fed. Reg. 77230, 77260 (Dec. 10, 2010).] The possible presence 

of "impurities" - the term used by EPA -- does not trigger any of EPA's hazard characteristic tests. 

[FN34: We believe that it would be helpful to have regulatory clarity over sour gas injections 

related to gasification facilities. It is conceivable that in a gasification facility, for example, costeffectiveness might dictate that a mixed stream of gaseous CO2 and H2S not be separated. If that 

combined stream were compressed to a supercritical state, and assuming that a standardized 

analytical test method were available to assess it, the combined stream could in theory trigger the 

toxicity threshold. Even here, however, describing the H2S as an "impurity" would have no 

regulatory significance.] The term "impurity" is irrelevant from a regulatory standpoint under 

RCRCA.

In the absence of an available standardized analytical test method, the Agency asserts that the 

RCRA 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.” [FN35: 76 Fed. Reg. 48078.] Section 

262.11(c)(2) of the RCRA regulations provides that, in lieu of the use of a standardized analytical 
137

test method, the generator of a hazardous waste may determine whether a material is hazardous 

by "[a]pplying knowledge of the hazardous characteristic of the waste in light of the materials or 

processes used." Based upon industry's knowledge of CCS-related materials and processes, coupled 

with current uses of CO2, a generator is unlikely to have a reasonable belief that its CO2 stream is

hazardous.

EPA references the following March 2006 study by Lawrence Livermore National laboratory to 

support an inference that certain "impurities" could be present in CO2 streams from coal-based 

facilities: Apps, J.A., "A Review of Hazardous Chemical Species Associated with CO2 Capture from 

Coal-Fired Power Plants and Their Potential Fate in Geologic Storage.” [FN36: Id. at 48079 n. 24.] 

Contrary to EPA's suggestion that this study supports the notion that regulators should be 

concerned about the inadvertent constituents of CO2 streams, the study proves just the opposite

(id. at p. 44):

“The preceding evaluation shows quite clearly that the concentrations of other 

chemical components accidentally incorporated in CO2, when captured from 

conventional coal fired power plants, or from advanced coal-fired IGCC plants, 

will be at most, relatively insignificant. For minor volatile species of S, N, F. and 

CL, the concentration of CO2 from conventional power plants is unlikely to 

exceed 5% of the base concentration in the original coal feed, i.e., between 0 

and 250 ppmv. For potentially hazardous trace elements, such as As, B, Ba, Be, 

Cd, Co, Cr, Cu, Ge, Hg, Mn, Mo, Ni, P, Pb, Sb, Sc, Sn, Sr, U, V, and Zn, with the

possible exception of Hg, the percentage concentrations are currently predicted 

to be at least two orders of magnitude less in concentration than was originally 

present in the coal. However, given that the concentrations of most of these 

elements were only in the ppm range in the original coal, accidentally 

incorporated concentrations are unlikely to exceed the range from 0.01 to 10 

ppmv.” (emphasis added).

Significantly, the paper ultimately concludes that "the concentrations of inadvertent contaminants 

in the injected CO2 would probably be comparable to the ambient concentrations in confining 

shales of the injection zone." Id. at 1 (emphasis added). [FN37: The rest of the Lawrence Livermore 

paper deals with the "mixture rule" scenario which, as noted above, is not relevant as that activity 

is already prohibited by the UIC Class VI rule.] In other words, according to this key reference cited 

by EPA, CO2 streams have a comparable concentration of naturally occurring materials in the 

subsurface environment.

With respect to the hypothetical scenario based on the mixture rule route of regulation, EPA has 

advanced no record evidence to support this case. Furthermore, the UIC Class VI rule itself 

prohibits the co-injection of RCRA hazardous waste, so the mixture rule scenario is 

inapplicable.[FN38: 75 Fed. Reg. at 77260 ("Class VI wells may not be used for the co-injection of 

RCRA hazardous wastes").]

Response: See response to comment 3.1.9. With respect to the commenter’s request for clarity 

over the status of mixed CO2 and H2S streams, see response to comments 3.6.4, 3.6.6, and 3.20.5

related to Acid Gas Injection (AGI).

Comment 3.14.10:
138

D. NACCSA Otherwise Supports the Proposed Conditional Exclusion, But Believes That EPA Could 

Provide Further Regulatory Clarity

EPA's conditional exclusion is largely premised on the notion that CO2 streams already are subject 

to stringent regulation. We agree.

As to generators, in the vast majority of commercial scenarios, there will be no on-site storage of 

CO2. Instead, as EPA states, captured CO2 will be immediately transported offsite via pipeline. 

[FN39: 76 Fed. Reg. at 48081.] From a geologic sequestration point of view, the industrial source's 

role is rather perfunctory, aside from complying with the terms and conditions of the relevant CO2

offtake contract.[FN40: A typical CO2 offtake contract obligates the source to deliver specified 

volumes or quantities of CO2 under minimum pressure and quality specifications at a nominated 

delivery point.] Subparts UU/RR to the GHG reporting rule also provide EPA with relevant 

information. [FN41: 76 Fed. Reg. at 48082.]

EPA also notes, and we agree, that the transportation of CO2 is also stringently and effectively 

regulated by the U.S. Department of Transportation ("DOT”). [FN42: We do not entirely agree with 

EPA's characterization of DOT's regulation, however. Although the RCRA proposal refers to "CO2

streams," EPA shifts gear here and refers only to "CO2." Also, supercritical CO2 does not appear in 

DOT's hazmat table. The hazmat table instead lists three forms of CO2: (1) gas (UN 1013); (2) 

refrigerated liquid (UN 2187); and (3) solid or dry ice (UN 1845). 49 C.F.R. § 172.101. Finally, EPA 

should emphasize, as it already suggests, that DOT does not regulate the pipeline transportation of 

CO2 under the status of a "hazardous liquid." 76 Fed. Reg. at 48082.] These regulations apply to all 

modes of transport, including but not limited to pipelines. DOT regulates the interstate pipeline of 

CO2 as a non-hazardous liquid, and relevant States apply comparable standards for intrastate 

pipelines. [FN43: Nordhaus, R., "Carbon Dioxide Pipeline Regulation," 30 Energy Law J. 85 (2009).]

Response: See Response to 3.1.10.

Comment 3.14.11:

We agree with the Agency that the UIC Class VI rule provides a comprehensive management 

regime for CO2 streams that renders duplicative any potential additional regulation under RCRA. 

[FN44: 76 Fed. Reg. 48084-48085.] We also agree that CO2 streams subject to the conditional 

exclusion would not be subject to RCRA's land disposal restrictions or separate provisions regarding 

corrective action. [FN45: Id. at 48085-48086.]

We do not understand why EPA proposes to make the conditional exclusion subject to the 

additional requirement that no hazardous wastes may be mixed with, or otherwise co-injected 

with, the CO2 stream, given that those activities are already barred under the UIC Class VI 

rule.[FN46: Id. at 48086.]

EPA states that the conditional exclusion may be lost at any time, a situation which may serve to 

substantially weaken the exclusion's salutary effects given that the Agency appears to be holding 

out the potential for down-hole formation of carbonic acid at some future date in a storage 

facility's lifetime [FN47: Id. at 48087.]:

“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 
139

result in the CO2 stream being subject to all applicable subtitle C regulatory 

requirements, from the point of generation.”

This suggests that all entities involved in CCS - generator, transporter, and injector - could be held 

liable for RCRA violations if at some future date conditions down-hole, due to no fault of any party, 

could be deemed to have created or liberated a material that a future regulator or claimant 

considers to be of concern. This situation will increase, not decrease, regulatory certainty.

Response: EPA acknowledges the commenter’s agreement with EPA’s finding that the UIC Class VI 

rule provides a comprehensive management regime for CO2 streams, such that management of CO2

streams in accordance with these requirements and other conditions, does not present a 

substantial risk to human health and the environment, therefore additional regulation under RCRA

is unnecessary, and that CO2 streams subject to the conditional exclusion would not be subject to 

RCRA's land disposal restrictions or separate provisions regarding corrective action. See Responses

to Comments 3.1.11 - 3.1.13.

Comment 3.14.12:

EPA emphasizes that the generator is responsible for the initial, and perhaps sole, hazard 

determination, but this conflicts with the definition of "CO2 stream" which suggests that the 

injector may add materials to facilitate injection. What happens in the scenario where the 

industrial source effectively delivers pharmaceutical grade CO2 to a storage site via a pipeline 

transporter, and the site owner/operator thereafter adds incidental materials to facilitate 

injection? It would be punitive in that situation to hold the industrial source liable for the site 

owner/operator's activities.

The conditional exclusion is premised on a linear model of CCS operations under which a single 

source delivers CO2 to a single transporter (expected to be a pipeline) who in turn delivers the CO2

to a site owner/operator. While that scenario may apply in some circumstances, it is equally likely 

that one or more sources may be delivering CO2 into the same pipeline, which in turn will deliver 

the CO2 to a storage site that receives and stores CO2 from multiple sources. That storage site may 

also already hold, or accept for delivery, volumes of natural CO2. [FN48: This situation further 

supports our position that RCRA was never intended to apply to CCS.] Since CO2 streams will be 

commingled, and CO2 molecules are identical, this sets up a “Superfund-esque" situation under 

which all parties, even the innocent, have the potential of being held liable. And unlike Superfund, 

where at least there is the hope of finding labels on drums to identify sources and parties, no such 

hope exists for commingled CO2 molecules, particularly after they have already been injected into 

the subsurface. [FN49: EPA's approach also assumes a simplistic, unitary model of pipeline 

operation and regulation that is unlikely to apply in initial projects. Experts have identified three

models of pipeline operation and regulation - one premised exclusively on deep saline injections, 

another premised exclusively on EOR, and a “hybrid" model that supports both (and potentially 

other) uses. Commercial operations under each model are expected to be unique, with deep saline 

pipelines having an “upstream" focus and EOR pipelines having a “downstream" focus. Marston P., 

"From EOR to CCS: The Evolving Legal and Regulatory Frame work for Carbon Capture and Storage," 

29 Energy Law J. 421,463-465 (2008). EPA's proposal adds to this already confusing framework a 

new consideration - is the material being transported and commingled with other CO2 a “solid 

waste" or "hazardous waste"?]
140

Response: See response to comments 3.1.14, 3.2.3 and 3.2.4.

Comment 3.14.13:

EPA states that the conditional exclusion only applies to "CO2 streams" that have been captured for 

purposes of “geologic sequestration."[FN50: 76 Fed. Reg. at 48086.] EPA never explains how that 

purpose is to be determined, an ambiguity that could negatively impact concurrent EOR/storage. 

The Agency explains that [FN51: Id. at 48078 n. 16.]: 

“The proposed rule is not intended to affect the status of CO2 that is injected into 

wells other than UIC Class VI wells. 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.”

This limitation provides no regulatory clarity for UIC Class II concurrent EOR/storage projects that 

qualify for the risk-based factor test of 40 C.F.R. § 144.19 under the UIC Class VI rule which allows 

sequestration to occur under Class II if there is no increased risk to USDWs. [FN52: 75 Fed. Reg. at 

77245.] It is imperative that EPA make clear either that: (1) the conditional exclusion also applies to 

EOR operators under 40 C.F.R. § 144.19, or (2) the RCRA status of EOR operators under 40 CF.R. § 

144.19 is identical to that of business-as-usual EOR operators under Class II without claims of 

sequestration. [FN53: “The agency has decided not to regulate oil and gas industry exploration and 

production wastes and mineral extraction and beneficiation and certain mineral processing under 

RCRA Subtitle C." T. Garrett, ed., “The RCRA Practice Manual," at 3.]

Response: See Responses to Comments 3.1.1, 3.1.11, 3.1.15 and 3.6.7.

Comment 3.14.14:

EPA erroneously states that RCRA's § 7003 imminent hazard authorities would continue to apply 

under the conditional exclusion.[FN54: 76 Fed. Reg. at 48088.] For the reasons stated above, "CO2

streams" are neither solid nor hazardous wastes, so § 7003 - which only applies to solid or 

hazardous wastes -- does not apply to CO2 streams. For the same reason, EPA should clarify that 

RCRA's citizen suit provision -- § 7002 - also does not apply to CO2 streams.

Response: See response to comment 3.1.16.

Comment 3.14.15:

We encourage EPA to clarify that CO2 streams subject to the conditional exclusion also are not 

subject to Superfund. [FN55: A CERCLA "hazardous substance" is defined to include all RCRA 

hazardous wastes, and because CO2 streams are not hazardous wastes, it is appropriate for EPA, in 

this rulemaking, to provide critical regulatory clarity for CCS under the Superfund statute, too.]

Response: See response to comment 3.1.17.

Comment 3.14.16:

Recommended Regulatory Changes

For the reasons stated above, if EPA elects to continue to pursue the conditional exclusion route, 

we suggest that the proposed exclusion in § 261.4(h) be revised to read as follows [FN56: The full 

text of EPA's proposed conditional exclusion is shown, with suggested additions underlined and 
141

deletions struck.]:

(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 of 

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 (OR ANALOGOUS STATE) requirements;

(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 (INCLUDING § 144.19) and 146;

(iii) No <other> hazardous waste may be mixed with, or otherwise co-injected with, the carbon 

dioxide stream AT THE GENERATOR'S FACILITY OR SITE; 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 (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). This yearly renewable of a 

certification statement under this paragraph means that an authorized representative must 

annually prepare and sign a new copy of the certification statement.

Response: See response to comment 3.1.18.

Comment 3.14.17:

In lieu of addressing the status of CO2 streams under proposed exclusion in § 261.4(h), even as 

modified above, which leaves "CO2 streams" as solid wastes, we recommend instead that EPA 

make clear that "CO2 streams" are neither solid nor hazardous wastes. The Agency could do so by 

promulgating a new § 261.4(a)(26) as follows [FN57: Suggested additions are {capitalized}.]:

(a) Materials which are not solid wastes.

* * *
142

(26) CARBON DIOXIDE (CO2) STREAMS. 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 OF 40 CFR PARTS 144 (INCLUDING § 144.19) AND 146 OF THE UNDERGROUND 

INJECTION CONTROL PROGRAM OF THE SAFE DRINKING WATER ACT, ARE NOT A SOLID WASTE 

PROVIDED THAT THE GENERATOR ALSO COMPLIES WITH THE FOLLOWING REQUIREMENTS:

(I) TRANSPORTATION OF THE CARBON DIOXIDE STREAM MUST BE IN COMPLIANCE WITH 

APPLICABLE DEPARTMENT OF TRANSPORTATION (OR ANALOGOUS STATE) REQUIREMENTS;

(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 (INCLUDING § 144.19) AND 146;

(III) NO HAZARDOUS WASTE MAY BE MIXED WITH, OR OTHERWISE CO-INJECTED WITH, THE 

CARBON DIOXIDE STREAM AT THE GENERATOR'S FACILITY OR SITE; 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 THIS PARAGRAPH, 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(A)(26) 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 (IF LOCATED IN AN AUTHORIZED 

STATE), OR THEIR DESIGNEE, AND SHALL BE RENEWED EVERY YEAR. THIS YEARLY RENEWABLE OF A 

CERTIFICATION STATEMENT UNDER THIS PARAGRAPH MEANS THAT AN AUTHORIZED 

REPRESENTATIVE MUST ANNUALLY PREPARE AND SIGN A NEW COPY OF THE CERTIFICATION 

STATEMENT.

Response: See response to comment 3.1.18.

Comment 3.14.18:

Conclusion

NACCSA appreciates the opportunity to submit these comments and welcomes any requests by the 

Agency for additional information or comment.

Response: EPA acknowledges the comment.

3.15Edison Electric Institute (EEI)

Document ID: EPA-HQ-RCRA-2010-0695-0080

Comment 3.15.1:
143

The Edison Electric Institute (EEl) submits the attached comments on Hazardous Waste 

Management System: Identification and Listing of Hazardous Waste: Carbon Dioxide (CO2) Streams 

in Geologic Sequestration Activities, which was recently proposed by the Environmental Protection 

Agency. See 76 Fed. Reg. 48074 (Aug. 8,2011). This proposal would revise regulations for hazardous 

waste management under the Resource Conservation and Recovery Act to conditionally exclude 

CO2 streams from the definition of hazardous waste, provided that they are injected into Class VI 

Underground Injection Control wells for the purpose of geologic sequestration. 

EEl is the association of shareholder-owned electric companies, international affiliates and industry 

associates worldwide. Our U.S. members serve 95 percent of the ultimate customers in the 

shareholder-owned segment of the industry, and represent approximately 70 percent of the U.S. 

electric power industry. Many of our members have been and are actively involved in the research, 

development, demonstration and deployment of technologies to capture CO2 from electricity 

production and inject it into geologic formations for long-term storage, activities covered by the 

draft guidance documents. Carbon capture and storage is a critical element in the full portfolio of 

technologies and measures to reduce greenhouse gas emissions.

EEl appreciates the opportunity to provide comments. Questions may be directed to (see docket 

for contact information).

Response: EPA acknowledges the comment. 

Comment 3.15.2:

COMMENTS OF THE EDISON ELECTRIC INSTITUTE ON THE ENVIRONMENTAL PROTECTION 

AGENCY’S PROPOSED RULE ENTITLED HAZARDOUS WASTE MANAGEMENT SYSTEM: 

IDENTIFICATION AND LISTING OF HAZARDOUS WASTE: CARBON DIOXIDE (CO2) STREAMS IN 

GEOLOGIC SEQUESTRATION ACTIVITIES

The Edison Electric Institute (EEI) [FN1: EEI is the national association of shareholder-owned electric 

utilities in the U.S. Our members represent about 70 percent of the U.S. electric power industry 

and serve 95 percent of the ultimate customers in the industry‘s investor-owned segment.] submits 

these comments on the proposed Environmental Protection Agency (EPA or Agency) rule entitled 

“Hazardous Waste Management System: Identification and Listing of Hazardous Waste: Carbon 

Dioxide (CO2) Streams in Geologic Sequestration Activities.” 76 Fed. Reg. 48073 (Aug. 8, 2011). 

[FN2: A technical correction was published on September 9, 2011. 75 Fed. Reg. 55846.]

This proposed rule complements EPA‘s final rule for the Federal Requirements under the

Underground Injection Control Program for Carbon Dioxide Geologic Sequestration (GS) Wells (the 

so-called “UIC Class VI rule”) and associated guidance issued (and still being issued) thereunder. 75 

Fed. Reg. 77230 (Dec. 10, 2010). EEI has actively participated in EPA‘s development of the UIC Class 

VI program under the Safe Drinking Water Act (SDWA). EEI recently submitted consolidated 

comments on the following four March 2011 UIC Class VI draft guidance documents: 1) Site 

Characterization (EPA 816-D-10-006), 2) Area of Review (AOR) (EPA 816-D-10-007), 3) Well 

Construction (EPA 816-D-10-008) and 4) Plan Development (EPA 816-D-10-012). On February 8, 

2011, EEI submitted comments on the draft guidance regarding financial responsibility for Class VI 

wells. EEI submitted comments to the Agency on October 15, 2009, on the Notice of Data

Availability (NODA) and Request for Comment related to the Agency‘s proposed regulations for 

injection and GS of CO2 under the authority of the SDWA UIC program, issued in July 2008 in Docket 
144

No. EPA-HQ-OW-2008-0290, 73 Fed. Reg. 43491 (July 25, 2008). EEI submitted pre-rulemaking 

comments to the Agency on May 15, 2008; provided oral and written testimony at EPA‘s 

September 30, 2008, public meeting on the proposed rules; and submitted written comments on 

December 24, 2008. EEI also provided testimony at the public hearing on the NODA on September 

17, 2009, and participated in the development of the proposed rule via webinars held in April and 

May 2009. These comments and testimony are incorporated by reference herein.

Response: EPA acknowledges the comment, but notes that EPA made clear in the proposal that this 

final rule does not reopen the UIC Class VI rule, and that EPA would not respond to comments 

related only to that rule. Consistent with this, EPA will not provide additional responses to the 

Edison Electric Institute’s comments on that rule, and that rule’s associated guidance. 

Comment 3.15.3:

I. Introduction

Carbon capture and storage (CCS) is a critical element in the full portfolio of options needed not 

only to reduce CO2 emissions, but also to ensure continued affordable and reliable electric service 

to customers throughout the U.S. EEI thus supports the development of clear, defensible and 

appropriately tailored regulatory regimes that will facilitate development of and investment in CCS 

technology and projects while protecting against potential environmental risks. Clarifying the 

treatment of geologically injected and sequestered CO2 under the Resource Conversation and 

Recovery Act (RCRA), which the Agency is addressing in the instant proposal, is a key element in the

development of this regulatory regime. EEI commends the Agency for establishing a CCS permitting 

regime through issuance of the UIC Class VI program, and appreciates the Agency‘s efforts to 

provide additional critical regulatory clarity under RCRA.

II. Executive Summary

EEI supports the conditional exclusion of CO2 streams from RCRA‘s hazardous waste regulations, 

but recommends that EPA‘s rule be recast as an exclusion of CO2 streams from the definition of 

“solid waste” because of CO2’s unique properties and uses, coupled with the fact that CO2 streams 

are not “discarded.” A failure to clarify that eligible CO2 streams are not “solid wastes” would leave 

CCS projects with unnecessary regulatory uncertainty while doing little to advance public health 

and environmental protection, given the rigorous requirements of the UIC Class VI rule.

If EPA elects to retain the proposed approach of a conditional exclusion for CO2 streams from 

RCRA’s hazardous waste regulations, the proposed regulation should be clarified to remove as 

much regulatory ambiguity as possible. In addition, EPA should explicitly address the applicability of 

RCRA to concurrent enhanced oil recovery (EOR)/storage under the provisions of the UIC Class VI 

rule.

Response: EPA thanks the commenter for its support of the conditional exclusion. Regarding the 

commenter’s suggestion that EPA promulgate a conditional exclusion from the definition of solid 

waste (rather than from the definition of hazardous waste), EPA disagrees and refers the 

commenter to response to comments 3.1.1 and 3.1.2. Regarding the commenter’s request for 

clarification on “the applicability of RCRA to concurrent enhanced oil recovery (EOR)/storage under 

the provisions of the UIC Class VI rule” EPA notes that status of CO2 streams injected into UIC Class 

II wells for purposes of EOR is discussed in response to comment 3.1.1. EPA also reiterates that 

today’s rule only applies to CO2 injected into UIC Class VI wells, which would include any well that 

has transitioned to a UIC Class VI well under the provisions of the UIC Class VI rule; that is, nothing 
145

in the conditional exclusion would prevent a Class VI well, that had previously transitioned from a 

Class II well, from being eligible for the RCRA conditional exclusion. EPA would encourage persons 

to consult with the appropriate regulatory authority to address any fact-specific questions they 

may have regarding the status of CO2 in situations that are beyond the scope of this final rule.

Comment 3.15.4:

III. Specific Comments

EPA proposes to “conditionally” exclude “CO2 stream” [FN3: EPA explains that a “carbon dioxide 

(CO2) stream” is “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” 76 

Fed. Reg. at 48075.] 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 ... and meet certain other

conditions” 76 Fed. Reg. at 48074. EPA explains that it is taking this action because it “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.” Id. EPA expects that the conditional 

exclusion will provide additional regulatory certainty, thereby facilitating CCS deployment. Id.

EEI supports the proposed “conditional exclusion” insofar as it endeavors, albeit incompletely, to 

clarify the regulatory regime for CCS while ensuring stringent protection of human health and the 

environment. Nonetheless, the “conditional exclusion” falls short of what is needed to provide 

adequate regulatory certainty for industry for the following reasons.

Response: EPA thanks the commenter for its support of the conditional exclusion, and addresses 

any specific comments on how the rule ‘falls short’ of what is needed below in EPA’s responses 

below.

Comment 3.15.5:

A. CO2 Streams Are Not "Wastes"

EPA's proposal is premised on the notion that RCRA potentially applies to "CO2 streams" in the first 

instance. This premise is false for two reasons.

First, in enacting RCRA, Congress never envisioned regulation of a molecule such as CO2. Compared 

to other substances or materials regulated under RCRA, CO2 is unique. It performs a variety of 

beneficial and ubiquitous roles in a variety of natural (e.g., uptake by plants) and industrial (i.e., 

EOR) functions. Several states already have declared CO2 to be a "commodity" for these reasons. 

[FN4: See, e.g., Oklahoma S.B. 1610 ("Carbon dioxide is a valuable commodity to the citizens of the 

state.").] 

Response: See response to comment 3.1.4.

Comment 3.15.6:

Second, and similarly, RCRA was never meant to apply to CCS, and thus the statute provides a poor 

tool to regulate the activity. Nothing in RCRA or its regulations purports to apply to CCS generally or 

geologic sequestration specifically. The RCRA model is prospective “cradle-to-grave” waste 

management and tracking. CCS, on the other hand, currently involves the injection of CO2 for 
146

beneficial purposes. Moreover, that activity is envisioned to involve mixed streams of CO2 from 

multiple sources, with injection of CO2 from multiple sources, thereby defeating the goal of tracking 

wastes through manifests and the like. There also is no standardized test method to evaluate 

supercritical CO2. For these and other reasons set forth below, trying to fit CCS under RCRA is 

inappropriate.

Response: See response to comments 3.1.5 and 3.12.7.

Comment 3.15.7:

B. CO2 Streams Are Not “Solid Wastes.”

The conditional exclusion is rooted on the unsupported premise that captured anthropogenic CO2

is a “solid waste.” EPA asserts that a “supercritical CO2 stream ... is a RCRA solid waste, as it is a 

‘discarded material’ within the plain meaning of the term in RCRA § 1004(27).” 76 Fed. Reg. at 

48077-78. [FN5: Relevant provisions of RCRA § 1004(27) define “solid waste” as “other discarded 

material, including solid, liquid, semisolid, or contained gaseous material resulting from ... industrial 

operations ....”] EPA does not offer a detailed justification for its claim that CO2 streams are 

“discarded.” An analysis of how RCRA and its regulations define that term demonstrates that CO2

streams injected for storage are not discarded with the meaning of RCRA.

Subtitle C of RCRA, which regulates hazardous wastes, applies only to “solid waste” that is 

“hazardous.” [FN6: The RCRA Practice Manual 2 (T. Garrett ed., ABA 2d ed. 2004).] To be regulated 

as a “solid waste,” a material must satisfy three criteria, two of which are relevant: 1) it must have 

the physical form of a solid waste, and 2) it must be “discarded.” [FN7: Id. at 33.] Neither of these 

criteria is met here.

Response: See response to comments 3.1.6, 3.1.7, and 3.1.8.

Comment 3.15.8:

1. CO2 streams do not have the physical form of a solid waste.

In relevant part, RCRA defines “solid waste” as “other discarded material, including solid, liquid, 

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

agricultural operations ....” 42 U.S.C. § 6903(27) (emphasis added). Supercritical states of material, 

such as is relevant for CO2, are not explicitly listed. Before it is compressed, CO2 is a gas. By 

“contained gas” in the definition above, EPA means:

“a gas that is contained in a cylinder or other non-flow-through containment 

system. In contrast, an uncontained gas, such as gas flowing through a pipe, column, 

or tank, is not a solid waste. Since uncontained gases are not solid wastes and 

therefore cannot be hazardous wastes, as a general matter, units that manage 

uncontained gases are not regulated under RCRA. [FN8: Id. at 33-34 (emphasis 

added).]”

Applying this relatively narrow concept of “contained gas,” it is clear that a CO2 stream– which at 

minimum spends part of its life “flowing through a pipe”—is not a solid waste” because it does not 

have the necessary form to be swept up under RCRA’s jurisdiction. [FN9: The fact that a CO2 stream 

is not a “contained gas” should not be interpreted to suggest that geologic storage is not an 

effective means of long-term storage, because it is. “Contained gas” is a regulatory concept only].
147

Response: See response to comment 3.1.7.

Comment 3.15.9:

2. CO2 streams are not discarded.

RCRA defines “solid waste” as “other discarded material, including solid, liquid, semisolid, or 

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

operations ....” 42 U.S.C. § 6903(27) (emphasis added). EPA‘s regulations explain that a “solid 

waste” is any “discarded material” that is “not excluded under § 261.4(a), [FN10: 40 C.F.R. § 

261.4(a) excludes through numerous specific listings “[m]aterials which are not solid wastes.”] or 

that is not excluded by a variance granted under §§ 260.30 [FN11: Id. at § 260.30 deals with nonwaste determinations and variances from classification as a solid waste.] and 260.31, [FN12: Id. at § 

260.31 sets forth standards and criteria for variances from classification as a solid waste.] or that is 

not excluded by a non-waste determination under §§ 260.30 [FN13: Id. at § 260.30.] and 260.34” 

[FN14: Id. at § 260.34 sets forth standards and criteria for non-waste determinations.], [FN15: Id. at 

§ 261.2 (definition of “solid waste”) (emphasis and internal footnote references added).] (emphasis 

added). A “discarded material,” in turn, is “any material” that is: 1) abandoned, 2) recycled or 3) 

considered inherently waste-like. [FN16: Id. at. § 261.2(a)(2)(i).]

Although they do not define the term “material,” EPA’s regulations set forth detailed criteria that 

must be met before a material is deemed to be “discarded” via the “abandoned,” “recycled” or 

“inherently waste-like” regulatory paths:

*Abandoned. Materials are “solid waste” if they are abandoned by being: a) disposed of; b) burned 

or incinerated; or c) “[a]ccumulated, stored or treated (but not recycled) before or in lieu of being 

abandoned by being disposed of, burned, or incinerated.” [FN17: Id. at § 261.2(b).]

* Recycled. Materials separately are “solid waste” if they are recycled–or accumulated, stored, or 

treated before recycling–if they fall into one of the following four categories: a) used in a manner 

constituting disposal, b) burned for energy recovery, c) reclaimed or d) accumulated speculatively. 

[FN18: Id. at § 261.2(c).]

*Inherently waste-like. Specifically identified materials, not including CO2, also are “solid waste” if 

they are recycled in any manner, and thus deemed to be “inherently waste-like materials.” [FN19: 

Id. at § 261.2(d).]

“CO2 streams” do not meet any of these three RCRA regulatory requirements.

Response: See response to comment 3.1.8.

Comment 3.15.10:

3. CO2 streams are not abandoned.

CO2 streams are not burned or incinerated, nor are they “disposed of.” The “S” in CCS stands for 

either “storage” or “sequestration,” neither of which contemplates “disposal.” The MerriamWebster Dictionary defines “sequester” as “to set apart, segregate” or to “seclude, withdraw.” 

[FN20: See http://www.merriamwebster. com/dictionary/sequestered?show=0&t=1315859974.] 

Synonyms for “sequestration” include “isolation” and “seclusion.” [FN21: See 

http://www.merriam- webster.com/dictionary/sequestration.] “Disposal,” on the other hand, is 

defined as the act of “disposing,” which means “to get rid of.”[FN22: See http://www.merriam-
148

webster.com/dictionary/disposing.]

The concept of “disposal” is inconsistent with how the bulk of CO2 is currently being managed 

commercially today. With the exception of demonstration and related projects, most if not all of 

the CO2 that is geologically injected today is used for EOR. In that application, it is purchased and 

transacted as a valuable commodity. As explained further below, EPA‘s Class VI rule envisions that 

concurrent EOR/storage may be conducted under Class II as long as certain conditions are met–a 

usage that flatly contradicts EPA‘s assertion here that injection is a “disposal activity.”

CO2 that is injected in saline reservoirs under Class VI also is not “disposed of.” For example, it is 

conceivable that such CO2 may be later withdrawn and put to a beneficial, but still nonatmospheric-emitting, use. Such CO2 also may be used for reservoir maintenance as part of 

concurrent long-term storage/desalination operations, as explained By William Bourcier of

Lawrence Livermore National Laboratory at the August 18, 2010, meeting of the California CCS 

Review Panel. [FN23: See 

http://www.climatechange.ca.gov/carbon_capture_review_panel/meetings/2010- 08-

18/presentations/01_Bourcier_Cal_CCS-Panel.pdf.] 

In addition, transactions of CCS-related offsets credits are made on various carbon registries, such 

as the American Carbon Registry. This activity is inconsistent with the notion of “disposal.”

Finally, it is worth noting that the terms “disposal” and “dispose” do not appear in any relevant 

portion of the Class VI rule or EPA’s preamble to the same.

Because geologic sequestration/storage does not contemplate “disposal,” the regulatory

“abandonment” provisions dealing with “[a]ccumulated, stored or treated” also are inapplicable.

4. CO2 streams are not recycled.

RCRA’s provisions regarding “recycle” are detailed, and none of them applies to CO2 streams–nor 

has EPA claimed that this is the case. [FN24: The fact that CO2 is recycled in EOR operations is not 

directly relevant for the RCRA regulatory concept of “recycle.”] In order for the recycle rules to 

apply, a material must first be deemed a secondary material. Among other things, secondary 

materials do not include “co-products.” Since in current commercial practice CO2 that is 

geologically injected is transacted as a valuable commodity as “co-products,” the recycle 

regulations do not apply. [FN25: Seen.6, supra, at 36.] 

CO2 streams are not “inherently waste-like.” RCRA’s provisions regarding “inherently waste-like” 

materials also are detailed, and none of them apply to CO2 streams – nor has EPA claimed the 

same.

Response: See response to comment 3.1.8.

Comment 3.15.11:

C. CO2 Streams Are Not “Hazardous Wastes.”

Assuming arguendo that CO2 streams are “solid wastes”–and they are not, as described above–they 

are not “hazardous wastes.”

EPA states that it has “little information to conclude that CO2 streams would qualify as RCRA 
149

hazardous waste.” 76 Fed. Reg. at 48077. The Agency also acknowledges that “CO2 streams are not 

listed hazardous wastes” under subpart D of part 261. Id. [FN26: Accord, 76 Fed. Reg. at 48078 

(“EPA reiterates that no hazardous waste listings apply specifically to CO2 streams.”).] The Agency 

nonetheless believes that the “RCRA hazardous waste regulations can apply to CO2 streams” based 

upon two hypothetical scenarios: 1) a CO2 stream exhibits hazardous characteristics; [FN27: 40 

C.F.R. § 261.20(a).] or 2) a CO2 stream is mixed with a listed hazardous waste, thus triggering 

application of the so-called “mixture rule.” Id.

Neither of these hypothetical scenarios is plausible. With respect to whether a CO2 stream exhibits 

hazardous characteristics, EPA seems to acknowledge that there is no available standardized 

analytical test method for supercritical materials such as CO2 or a “CO2 stream.” [FN28: 76 Fed. Reg. 

at 48078 n.22 (“EPA notes that existing analytical test methods ... are available to quantify the 

levels of various hazardous constituents in gaseous streams, although sampling a supercritical CO2

stream may require particular sampling protocols.”) (emphasis added).] EPA may only define a 

characteristic of a hazardous waste if the characteristic can be: 1) measured by an “available 

standardized test method which is reasonably within the capability of generators or solid waste or 

private sector laboratories that are available to serve generators of solid waste,” or 2) “reasonably 

detected by generators of solid waste through their knowledge of their waste.” [FN29: 40 C.F.R. § 

261.10(a)(2).] This two-factor test cannot currently be met for supercritical CO2 streams based on 

available standards.

Even if a standardized analytical test method were available for supercritical CO2, we are not aware 

of any information which would suggest that supercritical CO2 meets any of EPA‘s hazard 

characteristics. Supercritical CO2 is not: 1) ignitable under 40 C.F.R. § 261.21, 2) corrosive under 40 

C.F.R. § 261.22, [FN30: Supercritical CO2 is non-aqueous, so section 261.22(a)(1) does not apply, 

and section 261.22(a)(2) only applies if the material is “liquid and corrodes steel.” Supercritical CO2

is not a “liquid” and does not corrode the steel pipelines through which it has been transported 

safely for several decades. EPA hints that corrosivity could be an issue “down hole” through 

interaction with in-situ reservoir fluids, but that scenario is not contemplated by 40 C.F.R. § 

261.22.] 3) reactive under 40 C.F.R. § 261.23 or 4) toxic under 40 C.F.R. § 261.24. [FN31: Toxicity is 

assessed under Test Method 1311, the so-called Toxicity Characteristic Leaching Procedure (TCLP). 

40 C.F.R. § 261.24(a). The TCLP is inapplicable to supercritical CO2 and CO2 streams, as the TCLP was 

“intended to reflect the potential for leaching to groundwater that results from the codisposal of 

toxic wastes in an actively decomposing municipal landfill generating an acidic leachate.” See n.6, 

supra, at 52. Referring to a 2006 paper from Lawrence Livermore National Laboratory, EPA suggests

that certain impurities are “relevant” for toxicity regulation under § 261.24(a). However, all of the 

impurities referred to by EPA as potentially being present in certain CO2 streams are at levels that 

are several orders of magnitude lower than the relevant regulatory levels set forth in the 

regulations.] In the preamble to the final Class VI rule, EPA stated that it had reviewed estimates of 

CO2 injectate quality, and based upon that assessment, “captured CO2 could contain some 

impurities.”[FN32: 75 Fed. Reg. 77230, 77260 (2010).] The possible presence of “impurities” does 

not trigger any of EPA’s hazard characteristic tests.

In the absence of an available, standardized analytical test method, the Agency asserts that the 

RCRA 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.”[FN33: 76 Fed. Reg. 48078.] Section 

262.11(c)(2) of the RCRA regulations provides that in lieu of the use of a standardized analytical test 
150

method, the generator of a hazardous waste may determine whether a material is hazardous by 

“[a]pplying knowledge of the hazardous characteristic of the waste in light of the materials or 

processes used.” Based upon industry‘s knowledge of CCS-related materials and processes, coupled 

with current uses of CO2, a generator is unlikely to have a reasonable belief that its CO2 stream is 

hazardous.

EPA refer[s] to the following March 2006 study by Lawrence Livermore National Laboratory to 

support an inference that certain “impurities” could be present in CO2 streams from coal-based 

facilities: J.A. Apps, A Review of Hazardous Chemical Species Associated with CO2 Capture from 

Coal-Fired Power Plants and Their Potential Fate in Geologic Storage. [FN34: 76 Fed. Reg. at 48079 

n.24.] Contrary to EPA‘s suggestion that the study supports the notion that regulators should be 

concerned about the inadvertent constituents of CO2 streams, the study proves just the opposite:

“The preceding evaluation shows quite clearly that the concentrations of other 

chemical components accidentally incorporated in CO2, when captured from 

conventional coal fired power plants, or from advanced coal-fired IGCC plants, will 

be at most, relatively insignificant. For minor volatile species of S, N, F. and CL, the 

concentration of CO2 from conventional power plants is unlikely to exceed 5% of the 

base concentration in the original coal feed, i.e., between 0 and 250 ppmv. For 

potentially hazardous trace elements, such as As, B, Ba, Be, Cd, Co, Cr, Cu, Ge, Hg, 

Mn, Mo, Ni, P, Pb, Sb, Sc, Sn, Sr, U, V, and Zn, with the possible exception of Hg, the 

percentage concentrations are currently predicted to be at least two orders of 

magnitude less in concentration than was originally present in the coal. However, 

given that the concentrations of most of these elements were only in the ppm range 

in the original coal, accidentally incorporated concentrations are unlikely to exceed 

the range from 0.01 to 10 ppmv.” Id. at 44 (emphasis added). 

Significantly, the paper ultimately concludes that “the concentrations of inadvertent contaminants 

in the injected CO2 would probably be comparable to the ambient concentrations in confining 

shales of the injection zone.” Id. at 1. [FN35: The rest of the Lawrence Livermore paper deals with 

the mixture-rule scenario which, as noted below, is not relevant as that activity is already 

prohibited by the UIC Class VI rule.] In other words, CO2 streams have a comparable concentration 

of impurities already found in the natural subsurface environment.

With respect to the hypothetical scenario based on the mixture-rule route of regulation, EPA has 

advanced no evidence to support this case. Furthermore, the UIC Class VI rule itself prohibits the 

co-injection of RCRA hazardous waste, so the mixture-rule scenario is already prohibited. [FN36: 75 

Fed. Reg. at 77260 (“Class VI wells may not be used for the co-injection of RCRA hazardous 

wastes.”).]

Response: See response to comment 3.1.9.

Comment 3.15.15:

D. EEI Otherwise Supports the Proposed Conditional Exclusion, But EPA Could Provide Further 

Regulatory Clarity.

EPA‘s conditional exclusion is largely premised on the notion that CO2 streams already are subject 

to stringent regulation. We agree.
151

As to generators, in the vast majority of commercial scenarios, there will be no on-site storage of 

CO2. Instead, as EPA states, captured CO2 will be immediately transported offsite via pipeline. 

[FN37: 76 Fed. Reg. at 48081.] From a geologic sequestration point of view, the industrial source’s 

role is perfunctory, aside from complying with the terms and conditions of the relevant CO2 offtake contract. [FN38: A typical CO2 off-take contract obligates the source to deliver specified 

volumes or quantities of CO2 under minimum pressure and quality specifications at a designated 

delivery point.] EPA‘s Mandatory Reporting Rule of Greenhouse Gases: Injection and Geologic 

Sequestration of Carbon Dioxide rule also provides EPA with relevant information. [FN39: 76 Fed. 

Reg. at 48082.]

EPA notes, and we agree, that the transportation of CO2 also is stringently and effectively regulated 

by the Department of Transportation (DOT). [FN40: EPA’s characterization of DOT’s regulation is 

incorrect. Supercritical CO2 does not appear in DOT’s hazmat table. The hazmat table instead lists 

three forms of CO2: 1) gas (UN 1013), 2) refrigerated liquid (UN 2187) and 3) solid or dry ice (UN 

1845). 49 C.F.R. § 172.101. Finally, in the final rule EPA should emphasize, as the Agency already 

suggests in the proposed rule, that while DOT regulations impose “hazardous liquid” standards on 

CO2 pipelines, the CO2 transported in these pipelines itself has not been deemed hazardous by 

DOT. 76 Fed. Reg. at 48082; see also 49 C.F.R. § 195.0 (“[t]his part prescribes safety standards and 

reporting requirements for pipeline facilities used in the transportation of hazardous liquids or 

carbon dioxide.”) (emphasis added).] These regulations apply to all modes of transport, including 

pipelines. DOT regulates the transportation of CO2 in interstate pipelines as a non- hazardous 

liquid, and states apply comparable standards for intrastate pipelines. [FN41: Robert Nordhaus, 

“Carbon Dioxide Pipeline Regulation,” 30 Energy L.J. 85 (2009).]

Response: See Response to 3.1.10.

Comment 3.15.16:

We agree with the Agency that the UIC Class VI provides a comprehensive management regime for 

CO2 streams that renders duplicative any potential additional regulation under RCRA. [FN42: 42 76 

Fed. Reg. 48084-85.] We also agree that CO2 streams subject to the conditional exclusion would not 

be subject to RCRA’s land disposal restrictions or separate provisions regarding corrective action. 

[FN43: Id. at 48085-86.]

EPA proposes to make the conditional exclusion subject to the additional requirement that no 

hazardous wastes may be mixed with, or otherwise co-injected with, the CO2 stream. This is 

unnecessary, given that those activities are already barred under the UIC Class VI rule. [FN44: Id. at 

48086.]

Response: See response to comment 3.14.11.

Comment 3.15.17:

EPA asserts that the conditional exclusion may be lost at any time, a situation that arguably would 

weaken the exclusion’s salutary effects since the Agency appears to be holding out the potential for 

down-hole formation of carbonic acid at some future date in a storage facility’s lifetime.

However, we submit that the loss of the exclusion in this instance would impose greater regulatory 

burdens without any increase in environmental protection. As EPA notes, the UIC Class VI rule’s 

standards ensure environmental and health protections are in place in the event carbonic acid is 
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formed after injection into the storage formation. “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 contaminants in 

present in the stream.” 76 Fed. Reg. at 48084. This same logic holds true, even if carbonic acid is 

formed when the CO2 stream mixes with water in the storage formation. First, the UIC Class VI rules 

require that storage be sited to avoid any endangerment of underground sources of drinking water 

(USDW). Second, any endangerment to USDW would be addressed by the UIC Class VI rule, which 

holds storage operators liable for environmental remediation, if necessary. Imposing cradle-tograve handling requirements under RCRA would not stop carbon acid from being formed or ensure 

any greater protection for USDW.

More generally, EPA‘s approach to the exclusion suggests that all entities involved in CCS–

generator, transporter, and injector–could be held liable for RCRA violations if at some future date 

conditions down hole, due to the fault of no party, could be deemed to have created or liberated a 

material that a future regulator or claimant considers to be of concern. This situation would 

increase, not decrease, regulatory certainty.

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 the CO2 stream being 

subject to all applicable subtitle C regulatory requirements, from the point of generation. [FN45: Id. 

at 48087.]

As a general matter, EPA should state that minimal violations of the UIC Class VI rule, such as 

record-keeping errors, do not result in the loss of the exemption. Only substantive violations of the 

UIC Class VI rules should result in a loss of the RCRA exemption.

Response: See Responses to Comments 3.1.9, 3.1.13 and 3.10.5

Comment 3.15.18:

EPA emphasizes that the generator is responsible for the initial, and perhaps sole, hazard

determination, but this conflicts with the definition of “CO2 stream,” which suggests that the 

injector may add materials to facilitate injection. It is unclear what liability the generator would 

incur if it delivered food-grade CO2 to a storage site via a pipeline transporter and the site 

owner/operator thereafter adds incidental materials to facilitate injection that may change initial 

characterization of the CO2 stream. It would be punitive in that situation to hold the source liable 

for the site owner/operator’s activities.

The conditional exclusion is premised on a linear model of CCS operations under which a single 

source delivers CO2 to a single transporter who in turn delivers the CO2 to a site owner/operator. 

While that scenario may apply in some circumstances, it is equally likely that one or more sources 

may be delivering CO2 into the same pipeline, which in turn will deliver the CO2 to a storage site 

that receives and stores CO2 from multiple sources. That storage site may also already hold, or 

accept for delivery, volumes of natural CO2. [FN46: This situation further supports the proposition 

that RCRA was never intended to apply to CCS.] Since CO2 streams will be intermingled, and CO2

molecules are identical, under EPA’s construct this would set up a “Superfund-esque” situation 

under which all parties, even the innocent, have the potential of being held liable. And unlike the

Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), where at least 

there is the hope of finding labels on drums to identify sources and parties, no such hope exists for 
153

intermingled CO2 molecules, particularly after they have already been injected into the subsurface.

Response: See response to comment 3.1.14.

Comment 3.15.19:

EPA states that the conditional exclusion only applies to “CO2 streams” that have been captured for 

purposes of “geologic sequestration.”[FN47: 76 Fed. Reg. at 48086.] EPA never explains how that 

purpose is to be determined, an ambiguity that could negatively impact concurrent EOR/storage. 

The Agency explains that:

“The proposed rule is not intended to affect the status of CO2 that is injected into 

wells other than UIC Class VI wells. 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.” [FN48: Id. at 48078 n.16.]

This limitation provides no regulatory clarity for Class II concurrent EOR/storage projects that 

qualify for the risk-based factor test of 40 C.F.R. § 144.19 under the Class VI rule, which allows 

sequestration to occur under Class II if there is no increased risk to USDW. [FN49: Id. at 77245.] It is 

imperative that EPA clarify that either 1) the conditional exclusion also applies to EOR operators 

under 40 C.F.R. § 144.19, or 2) the RCRA status of EOR operators under 40 C.F.R. § 144.19 is 

identical to that of business-as-usual EOR operators under Class II without claims of sequestration. 

[FN50: “The agency has decided not to regulate oil and gas industry exploration and production 

wastes and mineral extraction and beneficiation and certain mineral processing under RCRA 

Subtitle C.” See n.6, supra, at 3.]

Response: See response to comment 3.1.15. Regarding the use of UIC Class II wells for EOR, see 

response to comment 3.1.1. Regarding concurrent EOR/storage and wells that transition to UIC 

Class VI wells, see response to comment 3.15.3.

Comment 3.15.20:

EPA erroneously states that RCRA’s section 7003 imminent hazard authorities would continue to 

apply under the conditional exclusion. [FN51: 76 Fed. Reg. at 48088.] For the reasons stated above, 

“CO2 streams” are neither solid nor hazardous wastes, so section 7003–which only applies to solid 

or hazardous wastes–does not apply to CO2 streams. For the same reason, EPA should clarify that 

RCRA’s citizen suit provision, section 7002, also does not apply to CO2 streams.

Response: See response to comment 3.1.16.

Comment 3.15.21:

EPA should clarify that CO2 streams subject to the conditional exclusion also are not subject to 

Superfund. A CERCLA “hazardous substance” is defined to include all RCRA hazardous wastes, and 

because CO2 streams are not hazardous wastes, it is appropriate in this rulemaking for EPA to 

provide critical regulatory clarity for CCS under the Superfund statute, too.

Response: See response to comment 3.1.17.

Comment 3.15.22:
154

For the reasons stated above, if EPA elects to continue to pursue the conditional exclusion route, 

the proposed exclusion in section 261.4(h) should be revised to read as follows:[FN 52: The full text 

of EPA’s proposed conditional exclusion is shown, with suggested additions underlined. No textual 

deletions are proposed.]

(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 of 

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 (or analogous state) requirements; 

(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 (including § 144.19) and 146; 

(iii) No other hazardous waste may be mixed with, or otherwise co-injected with, the carbon 

dioxide stream at the generator’s facility or site; 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 (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). This yearly renewable of a 

certification statement under this paragraph means that an authorized representative must 

annually prepare and sign a new copy of the certification statement.

Response: See Response to 3.1.18.

Comment 3.15.23:

In lieu of addressing the status of CO2 streams under proposed exclusion in section 261.4(h) (even 

as modified above), which leaves “CO2 streams” as solid wastes, we recommend instead that EPA 

clarify that “CO2 streams” are neither solid nor hazardous wastes. The Agency could do so by 

promulgating a new section 261.4(a)(26) as follows [FN53: Suggested additions are {capitalized}.]:

(a) Materials which are not solid wastes.
155

* * *

(26) Carbon dioxide (CO2) streams. 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 of 40 CFR parts 144 (including § 

144.19) and 146 of the Underground Injection Control program of the Safe Drinking Water Act, are 

not a solid waste provided that the generator also complies with the following requirements:

(i) Transportation of the carbon dioxide stream must be in compliance with applicable Department 

of Transportation (or analogous state) requirements;

(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 (including § 144.19) and 146;

(iii) No other hazardous waste may be mixed with, or otherwise co-injected with, the carbon 

dioxide stream at the generator’s facility or site; 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 this paragraph 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(a)(26) 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 (if located in an authorized state), or his designee, and shall be renewed 

every year. This yearly renewable of a certification statement under this paragraph means that an 

authorized representative must annually prepare and sign a new copy of the certification 

statement.

Response: See Response to Comment 3.1.18.

3.16Texas Carbon Capture & Storage Association (TxCCSA)

Document ID: EPA-HQ-RCRA-2010-0695-0085

Comment 3.16.1:

The Texas Carbon Capture & Storage Association (TxCCSA) is committed to promoting energy 

security and reducing greenhouse gas emissions through the advancement of carbon capture use 

and storage (CCUS) in Texas. The association provides education and outreach on behalf of 

industrial plants, utilities, the oil and gas industry and their service providers to promote the 

acceptance of CCS and advance market-based policies that encourage the development of a 

commercial CCUS industry in Texas.
156

TxCCSA recognizes the EPA’s effort to facilitate CCUS through this proposal. While TxCCSA supports 

the conditional exclusion for CO2 streams from the Resource Conservation & Recovery Act’s 

(“RCRA”) hazardous waste regulations we recommend that it be recast as an exclusion from the 

definition of “solid waste” because of CO2’s unique properties and uses, coupled with the fact that 

CO2 streams are not “discarded”, and as explained in more detail below.

We have reviewed and support the comments submitted by the North American Carbon Capture & 

Storage Association and those comments are provided as Attachment I. We also comment on a 

potential regulatory “gap” created by the exemption’s reliance on securing a Class VI permit which 

could leave federal offshore CCUS activity without access to the conditional exemption. These 

comments are discussed in Attachment II.

Response: Regarding this commenter’s support of comments submitted by the North American 

Carbon Capture & Storage Association (Attachment I), EPA refers the commenter to EPA’s 

responses in Section 3.14 of this document. These responses also address TxCCSA’s comment that 

EPA’s conditional hazardous waste exclusion should be ‘recast’ as an exclusion from the definition 

of solid waste.

Comment 3.16.2:

[Attachment II]

On August 8, 2011, EPA published a proposed rule in the Federal Register revising “the regulations 

for hazardous waste management under RCRA to exclude from the definition of hazardous waste 

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

under certain conditions.”[FN1: 76 Fed. Reg. at 48079]. These proposed conditions include 

compliance with existing regulatory regimes governing the transportation of the CO2 stream and its 

injection in a UIC Class VI permitted well [FN2: Id]. 

As currently proposed, it is unclear whether the RCRA conditional exemption will apply to CO2

storage in sub- seabed geological structures (CS-SSGS) on the Federal Outer Continental Shelf. As 

discussed above, the conditional exemption as currently proposed is largely based on compliance 

with SDWA UIC Class VI requirements. However, UIC Class VI permits are neither applicable nor 

required for geological storage under Federal offshore lands [FN3: 40 C.F.R. § 144.1(g)(2)(i)]. 

Application of the SDWA UIC Program is limited to lands located within the states’ territory, 

including state territorial waters, and including Federally-owned land [FN4: As codified at 42 U.S.C. 

300h (b)(1)(D)(ii), a state’s UIC program under that section cannot be approved by EPA unless it 

applies inter alia to underground injections “by any other person whether or not occurring on 

property owned or leased by the United States.” Where the state does not exercise primacy under 

the UIC program, the EPA administers the program directly] and Tribal lands, [FN5: See, e.g. Phillips 

Petroleum Company v. EPA, 803 F.2d 545 (10th Cir. 1986) (holding that SDWA applied to Tribal 

lands even before it was amended in 1986 to explicitly address Tribal lands)] but not to Federallyowned lands on the Outer Continental Shelf. 

The RCRA CCS exemption as proposed, however, presumes injection in a UIC Class VI well. To clarify 

coverage, the EPA must make clear its intent to expand the predicates for the conditional 

exemption to include additional Federal regulatory programs. We understand that currently, EPA 
157

and DOI are discussing applicable requirements for geological storage on Federal property 

including offshore waters. These discussions should result in regulations that complement the UIC 

Class VI requirements. The resulting regulations should therefore fall within the intent of the 

proposed RCRA exemption, providing a basis for coverage of Federal offshore CO2 storage under 

the RCRA conditional exemption.

Response: The issue of the scope of the UIC Class VI rules’ applicability identified by the 

commenter is outside the scope of this rulemaking. Today’s rule was not proposed or finalized 

under the SDWA, nor does it change how the UIC Class VI regulations apply. Likewise, EPA has 

made clear that the scope of this rule is expressly limited to CO2 streams sent to a permitted UIC 

Class VI well for purposes of GS, so this request is outside the scope of the rulemaking and EPA thus 

declines the commenter’s request to include additional federal programs. However, EPA has 

indicated that in the future, it would review any new information and consider whether changes 

should be made to the conditional exclusion. 

Comment 3.16.3:

For the reasons stated above, if EPA elects to pursue the conditional exclusion as proposed, in 

addition to the revisions suggested by NACCSA, we suggest that the proposed exclusion in § 

261.4(h) be revised to read as follows: 

(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 

AUTHORIZED UNDER FEDERAL REQUIREMENTS, INCLUDING <subject to the> requirements for Class 

VI Underground Injection Control wells, SPECIFIED <including the requirements> in 40 CFR parts 

144 and 146 of the Underground Injection Control Program of the Safe Drinking Water Act OR 

REQUIREMENTS UNDER AN APPLICABLE FEDERAL INJECTION WELL PROGRAM, are not a hazardous 

waste, provided the following conditions are met. 

(2) Carbon dioxide streams that meet all of the following conditions are excluded from the 

definition of hazardous waste: 

(v) Transportation of the carbon dioxide stream must be in compliance with applicable Department 

of Transportation requirements; 

(vi) Injection of the carbon dioxide stream must be in compliance with: A the applicable 

requirements for Class VI Underground Injection Control wells, including the applicable 

requirements in 40 CFR parts 144 and 146; OR 

B. REQUIREMENTS UNDER AN APPLICABLE FEDERAL INJECTION WELL PROGRAM; 

(vii) No hazardous waste may be mixed with, or otherwise coinjected with, the carbon dioxide 

stream; and 

(viii) 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: 
158

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 (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). This yearly renewable of a 

certification statement under this paragraph means that an authorized representative must 

annually prepare and sign a new copy of the certification statement.

Response: See Response to Comment 3.16.2. 

3.17Tri-State Generation & Transmission Association, Inc. (Tri-State)

Document ID: EPA-HQ-RCRA-2010-0695-00555

Comment 3.17.1:

Tri-State Generation & Transmission Association, Inc. (Tri-State) is a not-for-profit, wholesale 

electric power supply cooperative providing electric power to 44 member distribution systems that 

serve customers in a 250,000 square-mile territory including New Mexico, Colorado, Nebraska, and 

Wyoming. The mission of Tri-State is to provide our member-systems with a reliable, cost-based 

supply of electricity while maintaining high environmental standards. Tri-State provides electricity 

to members based on a diverse mix of generation sources including coal, natural gas, hydroelectric, 

wind, and solar power.

Tri-State owns and/or operates coal fired electric generation in four states, and is collaborating 

with Sunflower Electric who has been issued a permit to build a new coal fired unit at a facility in 

Holcomb, Kansas. Our facilities are heavily regulated by state and federal agencies which include: 

Colorado Department of Public Health and Environment, Arizona Department of Environmental 

Quality, New Mexico Environment Department, Wyoming Department of Environmental Quality, 

Kansas Department of Health and Environment, U.S. Environmental Protection Agency (EPA), Army 

Corps of Engineers, and Office of State Engineers. Tri-State is routinely inspected for environmental 

requirements and has consistently been determined to be in compliance with the broad array of 

rules and regulations that are already placed on coal fired electric generating units.

Response: EPA acknowledges the comment. EPA does not take a position here on Tri-State’s 

compliance status.

Comment 3.17.2:

In its proposed rule, EPA intends to conditionally exclude carbon dioxide (CO2) streams that meet 

the classification requirements of a hazardous waste from being defined as a hazardous waste, 

provided the CO2 waste streams are captured from the emission source and injected into a Class VI 

Underground Injection Control (UIC) Program well for the purposes of geologic sequestration. TriState appreciates EPAs recognition that there are several programs that will effectively manage 

carbon dioxide once it is captured from an emission source, and that it does not need to be further 

 

5

Identical to Docket ID EPA-HQ-RCRA-2010-0695-0056.
159

regulated under the Resource Conservation and Recovery Act as a hazardous waste if it is 

appropriately complying with other applicable regulatory programs implemented by the federal 

government.

Tri-State agrees with EPAs assertion that it is unlikely that most CO2 streams would meet the 

classification requirements to be identified as a hazardous waste. The gases that are emitted in the 

flue gas stream at a coal fired power plant would not generally contain constituents in sufficient 

concentrations that would exceed these requirements. However, the proposed exclusion will give 

CO2 stream generators a level of certainty in this area that they did not previously have. Tri-State 

agrees with and supports the EPA proposal to provide for the conditional exclusion of CO2 streams 

from the classification as a hazardous waste

Response: EPA thanks the commenter for its support of the conditional exclusion, and agrees with 

the commenter that management of CO2 streams under the terms of the conditional exclusion 

(including compliance with other regulatory programs) does not present a substantial risk to 

human health and the environment, and that therefore additional regulation pursuant to RCRA’s 

hazardous waste regulations is unnecessary. EPA also agrees that this conditional exclusion offers 

an option that provides a level of certainty regarding the potential applicability of RCRA subtitle C 

to CO2 streams being captured for injection into UIC Class VI wells for purposes of geologic 

sequestration.

Comment 3.17.3:

In the proposed rule, EPA suggests that generators seeking to sequester CO2 streams in the 

geologic subsurface would need to do so to a depth of at least 2600 feet below the surface in order 

for the CO2 to be maintained in a supercritical state. Tri-State believes that EPA is correct in its 

belief that geologic sequestration sites and site owners will generally look to inject CO2 streams at 

depths greater than 2600 feet below the surface, and that pressures and temperatures at this 

depth will maintain the injected CO2 in a supercritical state, however, Tri-State believes that

injection at shallower depths would still maintain the CO2 stream in the supercritical state. It should 

only take pressures achieved at about 850 feet below the surface with a temperature greater than 

88° Fahrenheit to achieve a supercritical state for the CO2 stream. Tri-State believes that EPA 

should simply state the requirement to ensure that the CO2 is maintained in the subsurface in a 

supercritical state for it to meet the conditions of the exclusion from the definition of being a 

hazardous waste.

Response: The information presented on injection depth was provided in the preamble to the 

proposed rule as background for the reader on geologic sequestration of CO2 streams generally. 

The final conditional exclusion does not include a minimum injection depth requirement, nor did 

EPA propose to include such a requirement in the proposed rule. The terms of the conditional 

exclusion require that injection of the CO2 stream that is claimed to be excluded be in compliance 

with the applicable requirements for UIC Class VI wells. 40 CFR 261.4(h)(2). EPA developed the 

conditional exclusion based on its analysis of the protectiveness of the UIC Class VI program, 

among other requirements. This analysis did not rely on a specific injection depth, which EPA 

expects will be determined on a case-by-case basis in the UIC Class VI permitting process. This 

process is separate from today’s RCRA conditional exclusion rule. 

Comment 3.17.4:
160

Tri-State believes that if it were to engage in the practice of carbon capture and sequestration, it 

would likely transport the captured CO2 to an underground injection well via a pipeline. Tri-State is 

currently involved with an interested group of organizations on a Department of Energy project to 

drill a geologic characterization well near Craig, Colorado. Tri-State believes that if the geologic 

structure and lithologic characteristics are determined to be suitable for commercial sequestration, 

Tri-State would likely use this well for injection of CO2 waste streams, if carbon capture and 

sequestration were adopted as a requirement to reduce emissions of carbon dioxide.

Tri-State believes that commercial scale geologic sequestration would likely need to be

accomplished through offsite transport via a pipeline, given the volume of material in question. TriState supports the EPA proposal to not require the development of a hazardous waste manifest for 

the off-site shipment of CO2 streams when the CO2 is transported offsite via a pipeline.

Tri-State also believes that EPA should not require the use of a manifest for those very limited 

occurrences where CO2 may be transported offsite via a tanker truck or other than pipeline means 

of conveyance.

Response: EPA had requested comment on the extent to which non-pipeline transportation will be 

used to transport CO2 streams; several commenters responded (including this commenter) and all 

agreed that pipelines would be the most likely way to move CO2 streams. Regarding the 

commenter’s support of EPA’s proposal to not require a hazardous waste manifest, EPA had 

discussed in the proposed rule its rationale for why a manifest was not needed for non-pipeline 

transportation (see 76 FR at 48083), and requested comment on whether the certification 

statement together with the DOT hazmat requirements are effective substitutes for RCRA subtitle C

requirements (which would include, in this context, the hazardous waste manifest). EPA did not 

receive any comments on this issue that caused it to alter its analysis, and the final rule will not 

require a manifest for conditionally-excluded CO2 streams transported via truck or other than 

pipeline, for the reasons set out in the proposed rule.

Comment 3.17.5:

Tri-State does not object to the proposed requirement that a certification statement by an

authorized official attesting to the fact that the CO2 stream was injected into a Class VI UIC program 

well be completed by an authorized representative of the generator, and retained on site for a 

period of no less than three years.

Response: In the final rule, in light of comments received from other commenters that the 

proposed certification would require signatories to attest to activities outside of their control, EPA 

has revised the certification statement so that there are now two separate certification statements 

– one for CO2 stream generators and another for UIC Class VI well owners or operators. EPA made 

these revisions to better reflect actions over which each party has control. Under the final rule, the 

certification statement that the generator would sign is specific to the activities within the 

generator’s control; likewise, the certification statement that the UIC Class VI well owner or 

operator would sign is specific to the activities within the owner or operator’s control. The 

certification statement EPA is finalizing for generators includes the prohibition on hazardous waste 

mixing, and transportation (or arranging for transport) of the CO2 stream in accordance with DOT 

(or certified state) for injection into a UIC Class VI facility, which EPA finds would be in the 

generator’s control. EPA acknowledges the commenter’s support of the three-year retention time 

for the certification statements; EPA agrees, and believes that the 3-year recordkeeping 
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requirement is sufficient. See 3.6.9.

Comment 3.17.6:

Tri-State does not believe that transporters of CO2 streams should need to complete such a 

certification. This certification statement should only be required from the generator.

Response: EPA agrees that a certification by the transporter is not necessary. See Response to 

Comment 3.2.39. However, EPA also notes that where the exclusion is being applied, a 

certification statement is also required for the UIC Class VI owner/operator, in response to 

commenters who expressed concern with the proposed certification language that would have 

persons certifying to activities beyond their control (see Response to Comment 3.2.36). 

Comment 3.17.7:

In the proposed rule, EPA seeks comment on the option that additional testing could be required to 

ensure that generators are not mixing other hazardous waste into the CO2 waste stream. Tri-State 

believes that testing of the CO2 waste streams can be done at any given time if there is a doubt or 

fear that the source is inappropriately mixing in other hazardous wastes. As the geologic 

sequestration program begins, it would be helpful to generators if there would be fewer 

requirements and if, over time, there were program abuse then EPA could move to add this type of 

requirement. If EPA believes this type of requirement is necessary, Tri-State believes that it should 

be implemented through the UIC program and not the RCRA hazardous waste program. Keeping 

the regulatory requirements in one place will be useful to future users of carbon capture and 

sequestration.

Response: EPA is not finalizing any new monitoring, recordkeeping, or reporting requirements 

related to the condition that no hazardous waste be mixed with excluded CO2 streams. See 

Responses to Comments 3.2.40 through 3.2.43.

Comment 3.17.8:

Tri-State supports the EPA proposed definition of CO2 stream to allow for the inclusion of incidental 

associated substances that result from the source materials, and from the inclusion of substances 

that will enable or improve the injection process. Tri -State believes that if EPA were to not allow 

the inclusion of these incidental substances it would negate the effect of the proposed rule, and 

make the effort of providing the exclusion meaningless. Tri-State believes that it will be technically 

impossible to obtain a pure CO2 stream from the combustion of coal or other fossil fuel, especially 

at the inception of this very important program.

Response: Based on the information EPA presented in the proposed rule, EPA agrees that sources 

would be unlikely to obtain a pure CO2 stream from the combustion of coal or other fossil fuel. 

Regarding the commenter’s support of EPA’s definition of CO2 stream to allow for the inclusion of 

incidental associated substances that result from the source materials, and from the inclusion of 

substances that will enable or improve the injection process, see Responses to Comments 3.7.11 

and 3.8.6.

Comment 3.17.9:

In the proposed rule, EPA intends to restrict the operation of Enhanced Oil Recovery (EOR) from 

using the proposed exclusion. Tri-State believes that EPA should reconsider the application of this 

exclusion for EOR. As EPA aptly notes in the preamble to the rule, there are very few CO2 streams 
162

that would be considered a hazardous waste pursuant to the requirements for classification 

anyway. Most CO2 injected into geologic formations today is for the purposes of EOR. Tri-State 

believes that the application of the exclusion of CO2 streams from the definition of hazardous 

waste would facilitate the injection of greater volumes of CO2 into geologic formations from actual 

emitting facilities. Also, many of the EOR operations in effect today would meet many of the 

requirements set forth in the proposed rule. This would facilitate a greater amount of CO2

sequestered into subsurface geologic formations and help grow the technology for sequestration.

Response: EPA is not addressing the status of all CO2 streams in this rulemaking; the scope of this 

rule is limited to CO2 streams injected into a permitted UIC Class VI well for purposes of GS.

However, in the interest of public transparency and in light of the several public comments on this 

issue, EPA does note that (based on the limited information provided in the public comments),

should CO2 be used for its intended purpose as it is injected into UIC Class II wells for the purpose 

of EOR/EGR, it is EPA’s expectation that such an injection process would not generally be a waste 

management activity. EPA would encourage persons to consult with the appropriate regulatory 

authority to address any fact-specific questions they may have regarding the status of CO2 in 

situations that are beyond the scope of this final rule.

Comment 3.17.10:

In the proposed rule, EPA seeks comment of the need for additional monitoring record keeping and 

reporting requirements. Tri-State does not believe that additional monitoring, recordkeeping, or 

reporting requirements should be placed on the generator or the operator of the CO2 sequestration 

well, in addition to the requirements that are set forth under the UIC program for Class VI wells, 

especially given EPA’s adaptive approach that it is taking with the implementation of the UIC Class 

VI well rulemaking. EPA will be able to re-evaluate the requirements in six years and should 

proceed in a step wise fashion with these requirements.

Response: See Responses to Comments 3.2.40 through 3.2.43.

Comment 3.17.11:

Tri-State supports EPAs inclusion in the final rule of a provision to allow generators of CO2 streams 

to submit those streams for hazardous waste testing and, if it is not determined to be a hazardous 

waste, waive any required compliance with the proposed rule. Some sources would find value in 

knowing that the CO2 stream being injected into the geologic formation is not a hazardous waste, 

and may desire to establish a non-hazardous waste classification for their CO2 stream prior to 

injection into a subsurface geologic formation. This approach would preserve any future liability 

exposure that may present itself were the CO2 stream determined to be a hazardous waste. EPA 

should focus greater discussion of this provision in the final rule.

Response: EPA’s proposal did not include any new provisions for making hazardous waste 

determinations beyond what the existing regulations specify. Under EPA’s existing hazardous 

waste regulations, all generators bear the obligation of determining whether or not their waste is 

hazardous, and for captured CO2 streams destined for injection into UIC Class VI wells, this would 

be no different. However, EPA appreciates the commenter’s concerns regarding the application of 

the hazardous waste regulations to supercritical CO2 streams being sequestered, and EPA believes 

these concerns exist as a result of the unique circumstances associated with addressing the

applicability of RCRA to CCS at such an early stage in the development of CCS. In the meantime, a 

generator may choose to comply with the conditional exclusion as a precautionary matter, if they 
163

are unsure of the hazardous waste status of their CO2 stream. It is not clear what it means to 

“preserve future liability exposure that may present itself were the CO2 stream determined to be a 

hazardous waste” as the commenter states. EPA does note that issues of potential CERCLA liability 

for GS are outside the scope of this rule, if that is to what the commenter is referring.

Comment 3.17.12:

Tri-State appreciates the opportunity to provide comment on this regulatory proposal from the 

EPA. Should you have any questions about these comments, or need additional information, please 

contact (see docket for contact information).

Response: EPA acknowledges the comment.

3.18Southern Company

Document ID: EPA-HQ-RCRA-2010-0695-0061

Comment 3.18.1:

Southern Company (“Southern” or “The Company”) appreciates the opportunity to provide 

comments on the U.S. Environmental Protection Agency’s (“EPA”) proposed rule to conditionally 

exclude geologically sequestered carbon dioxide (“CO2”) from regulation under the Resource 

Conservation and Recovery Act’s (“RCRA”) hazardous waste program.

As one of the largest generators of electricity in the nation, Southern serves both regulated and

competitive markets across the southeastern U.S. Southern participates in all phases of the electric 

utility business with more than 42,000 megawatts of electric generating capacity and more than 

27,000 miles of transmission lines. The Company provides electric service to over 4.4 million retail 

customers through its subsidiaries Alabama Power, Georgia Power, Gulf Power, and Mississippi 

Power. In addition, Southern Power, Southern's competitive wholesale generation business, is 

among the largest wholesale energy providers in the Southeast, meeting the electricity needs of 

municipalities, electric cooperatives, and investor-owned utilities.

Carbon capture and storage (“CCS”) is critical to the mitigation of greenhouse gases and Southern is 

working to help bring this important technology towards commercial viability. Southern manages 

the Department of Energy’s (DOE) National Carbon Capture Center in Alabama, testing the next 

generation of technologies to capture carbon dioxide emissions. Also, Mississippi Power’s Plant 

Daniel was the host site for a DOE carbon sequestration demonstration project where 3,000 tons of 

CO2 were injected and are being monitored. Beginning this year, Alabama Power's Plant Barry will 

capture up to 150,000 tons of CO2 per year for underground storage, and Southern Company is 

constructing a commercial-scale 582 MW integrated gasification combined cycle plant in Kemper 

County, Mississippi, with 65 percent CCS.

Response: EPA acknowledges the comment.

Comment 3.18.2:

Southern herby endorses and incorporates by reference the comments submitted to this docket on 

this proposed rule by the Utility Solid Waste Activities Group, the Edison Electric Institute, the 

Carbon Sequestration Council, and the CCS Alliance. 
164

Response: See Responses to Comments in Sections 3.7, 3.15, 3.2, and 3.8 of this document, 

respectively. 

Comment 3.18.3:

In sum: 1. While the conditional exclusion from hazardous waste regulation is helpful, EPA has not 

yet met the burden of explaining why a CO2 stream should be considered a solid waste. EPA has not 

explained how geologically sequestered CO2 qualifies as a discarded material that would result in it 

being considered a waste, nor has it explained why geologically sequestered CO2 should be 

considered a contained gas under RCRA's definition of solid waste.

Response: See Responses to Comments 3.1.1 through 3.1.8, and 3.2.1 and 3.2.2.

Comment 3.18.4:

2. Assuming geologically sequestered CO2 is a solid waste, the conditional exclusion should clarify 

that the exclusion will not be lost for minor administrative-type violations that do not bear on the 

safety of the sequestration facility.

Response: See Response to Comment 3.7.13.

Comment 3.18.5:

3. The certification statement required under the exclusion should be limited to matters properly 

within the control and knowledge of the party making the statement. Generators are not in a 

position to certify the behavior of the facility operator or other generators that send CO2 to the 

facility.

Response: See Response to Comment 3.2.54 and 3.8.8.

Comment 3.18.6:

Southern supports a single regulatory structure for geologic sequestration of CO2 as opposed to a 

structure composed of multiple regulatory laws with overlapping enforcement regimes and penalty 

provisions. The Company believes that the current RCRA proposal to conditionally exclude CO2

streams captured and injected for geologic storage from RCRA’s stringent hazardous waste controls 

is an important step in shaping practicable and effective CCS regulations. However, there are 

several issues that need to be addressed, and Southern Company requests that EPA take the 

recommendations summarized above, which are discussed in more detail in the groups’ comments 

listed above.

Response: EPA agrees that the final conditional exclusion is an important step in “shaping 

practicable and effective CCS regulations” which EPA believes includes addressing uncertainty with 

regard to RCRA subtitle C and CCS regulation. Regarding this commenter’s reference to other 

comments, see Responses to Comments in Sections 3.7, 3.15, 3.2, and 3.8 of this document.

3.19Xcel Energy, Inc.

Document ID: EPA-HQ-RCRA-2010-0695-0072
165

Comment 3.19.1:

Xcel Energy, Inc. (Xcel Energy) appreciates the opportunity to submit comments regarding the U.S. 

Environmental Protection Agency's (EPA) proposed Hazardous Waste Management System: 

Identification and Listing of Hazardous Waste: Carbon Dioxide (CO2) Streams in Geologic 

Sequestration Activities, which were published at 76 Fed. Reg. 48073 (Monday August 8, 2011) 

[FN1: Technical corrections published September 9, 2011, 75 Fed. Reg. 55846] hereafter referred to 

as the proposed rule. 

Xcel Energy owns and operates four electric and gas utilities: Northern States Power Company

Minnesota, Northern States Power Company Wisconsin, Public Service Company of Colorado, and 

Southwestern Public Service. Xcel Energy serves 3.4 million electric customers and 1.9 million 

natural gas customers in our service territories. Xcel Energy has over 16,000 megawatts of 

generation capacity including hydroelectric, natural gas, coal and nuclear facilities.

EPA's proposed rule provides a conditional exclusion of CO2 Streams Injected for Geologic

Sequestration (GS) from the Resource Conservation Recovery Act's (RCRA) definition of hazardous 

waste, provided the CO2 Streams meet certain conditions. Xcel Energy supports EPA's proposal for 

conditional exclusion of CO2 Streams from RCRA.

However, Xcel Energy believes that the Underground Injection Control (UIC) regulations for Class VI 

wells and Department of Transportation (DOT) regulations (including DOT Pipeline Hazardous 

materials Safety Administration (PHMSA) regulations) are more appropriate than RCRA for 

regulating for CO2 Streams Injected for Geologic Sequestration and are protective of human health 

and the environment. Inclusion of CO2 Streams Injected for Geologic Sequestration in RCRA does 

not provide any additional protection to human health or the environment, but may result in 

additional administrative burden by generators, transporters, UIC Class VI well owners or 

operators, and the EPA as well as potential duplicative enforcement actions.

Response: EPA thanks the commenter for their comment and agrees that finalization of the 

conditional exclusion is appropriate. EPA believes that management of CO2 streams under the 

terms of the conditional exclusion does not present a substantial risk to human health and the 

environment and that, therefore, under these conditions, additional regulation pursuant to RCRA’s 

hazardous waste regulations is unnecessary.

Comment 3.19.2:

In addition, Xcel Energy is in general agreement with comments on the proposed rule provided to 

the EPA by The Edison Electric Institute (EE1) dated October 7, 2011 and the Utility Solid Waste 

Activities Group (USWAG) dated October 7, 2011.

Xcel Energy appreciates the opportunity to submit these comments.

Response: See EPA’s responses to the Edison Electric Institute in Section 3.15 and to the Utility 

Solid Waste Activities Group in Section 3.7 of this document.

3.20Basin Electric Power Cooperative (Basin Electric)

Document ID: EPA-HQ-RCRA-2010-0695-0076
166

Comment 3.20.1:

Basin Electric Power Cooperative (Basin Electric) appreciates this opportunity to submit comments 

to the Environmental Protection Agency (EPA) in regard to the proposed rule for Hazardous Waste 

Management System: Identification and Listing of Hazardous Waste: Carbon Dioxide (CO2) Streams 

in Geological Sequestration Activities.

I. Importance of CCS to Basin Electric and its Members:

Executive Summary

Basin Electric agrees that CO2 should be considered non-hazardous for the purpose of storage in 

geological formations. Basin Electric also believes that coal needs to remain viable as a fuel source 

for electrical generation in the future. As EPA stated in the rule, carbon capture and storage (CCS) 

could enable the continual use of coal, and geological storage is a key component of CCS. The 

proposed rule will lessen the burden and provide more certainty for geological storage while still 

protecting human health and the environment.

Response: EPA thanks the commenter for its support of the proposed rule. EPA agrees with the 

commenter that the conditional exclusion for CO2 streams sent to a Class VI well for purposes of GS 

will reduce regulatory uncertainty for stakeholders with no reduced protection to human health 

and the environment. 

Comment 3.20.2:

Basin Electric understands that regulations need to be in place to safely handle CO2 sequestration 

in geological formations. However, the requirements for obtaining a Class VI well authorization for 

injection of CO2 in geological formations are unnecessarily onerous. For meaningful development 

of geological sequestration of CO2 to occur, a clear and consistent national regulatory structure 

must be developed. This regulatory structure must also allow for geologic-specific and site-specific 

differences to be considered. Basin Electric would urge that the States be given primacy for the 

Class VI portion of the Underground Injection Control (UIC) program as provided in EPA's UIC final 

rule, especially for those areas where geologic-specific and site-specific factors are to be weighed 

and considered.

Response: As a general matter, EPA agrees that a clear regulatory framework is important to 

facilitate development of GS, and to do so in a manner protective of human health and the 

environment. With respect to the commenter’s comments regarding the UIC Class VI regulations, 

as EPA stated in the proposed rule (76 FR 48077), the RCRA conditional exclusion rulemaking did 

not reopen the UIC Class VI rule, nor will EPA respond to comments related only to the UIC Class VI 

rulemaking, which are beyond the scope of this RCRA rulemaking.

Comment 3.20.3:

Basin Electric Power Cooperative

Basin Electric is a regional, consumer-owned, generation and transmission cooperative formed in 

1961 to supply supplemental power to a consortium of rural electric distribution cooperatives.

Basin Electric's core business is generating and delivering electricity to wholesale customers,

primarily our member systems. Basin Electric owns 3.437 megawatts (MW) and operates 4.424

MW of electric generating capacity. Basin Electric supplies 135 rural electric member cooperative 

systems with wholesale electric power who in turn serve approximately 2.8 million consumers in a 

nine-state area.
167

Basin Electric has extensive institutional knowledge of coal gasification, carbon capture and CO2

sequestration through its subsidiary, the Dakota Gasification Company (DGC). DGC owns and 

operates the Great Plains Synfuels Plant (Synfuels Plant), the only commercial-scale coal 

gasification plant in the United States that manufactures synthetic natural gas.

The $2.1 billion Synfuels Plant began operating in 1984. The Synfuels Plant uses the Lurgi

gasification process to gasify lignite coal to produce valuable gases and liquids. The average daily 

production is 160 million standard cubic feet of synthetic natural gas (SNG), the majority of which is 

piped to Ventura, Iowa, for distribution in the eastern United States. Many co-products are 

produced and marketed in the United States and Canada.

DGC captures CO2 from the gasification process and provides all the CO2 sequestered in the largest 

anthropogenic CO2 sequestration project in the world. Through 2010, DGC had successfully 

captured and marketed over 20 million tons of CO2 to two Canadian customers. The current total 

CO2 demand is 152.7 million standard cubic feet per day (MMscfd), which is approximately 8,800 

tons per day or 3 million tons per year. The CO2 is being used for enhanced oil recovery (EOR) in oil 

fields near Weyburn, Saskatchewan. The CO2 is expected to be permanently sequestered in the oil 

reservoir and is being monitored by the International Energy Agency (lEA) Weybum CO2 Monitoring 

and Storage Project. The 2000-2004 IEA GHG Weyburn CO2 Monitoring & Storage Project Summary 

Report states in the conclusion that "modeling predicts that there is a 95% probability that 98.7% 

to 99.5% of the initial CO2-in-place will remain in the geosphere for 5000 years."

Basin Electric also conducted a front-end engineering and design (FEED) study for a postcombustion CO2 capture demonstration project. The proposed project was to capture 90 percent of 

the CO2 from a 120 MW slipstream of flue gas at Basin Electric's Antelope Valley Station (AVS). AVS 

is a 900 MW pulverized coal power plant located adjacent to the Synfuels Plant near Beulah, North 

Dakota. After carefully analyzing the FEED study results, Basin Electric's Board of Directors put the 

project on hold. The reason was that a viable business plan could not be put in place to shield Basin 

Electric's members from undue financial burden. The FEED study was valuable. With the 

information from the FEED study in hand, Basin Electric knows what the impacts of the costs and 

the operational challenges a project like this will have on the consumers. Additionally, Basin Electric 

is better equipped to understand how all levels of the organization would be affected if a full-scale 

implementation of this capture technology were to be employed.

Response: EPA thanks the commenter for the information. EPA notes that uses of CO2 for purposes 

other than injection into a UIC Class VI well for GS are beyond the scope of this rulemaking.

Comment 3.20.4:

II. Importance of Developing Reasonable CO2 Storage Regulations

The energy needs of the United States are dependent upon carbon based fuels. The development 

of reasonable regulations, including reasonable regulations for CCS, is crucial for CCS to fulfill its 

potential as one of the important ways to mitigate greenhouse gas impacts. "While other climate 

mitigation options exist-such as energy efficiency improvements, a switch to less carbon-intensive 

fuels, nuclear power, and renewable energy sources-CCS is considered by many to be a crucial 

component of any U.S. approach or strategy for addressing the climate change issue, particularly 

given the United States' current reliance on coal for almost half of its electricity production." [FN1: 

GAO, Federal Actions Will Greatly Affect the Viability of Carbon Capture and Storage As a Key 
168

Mitigation Option, GAO-08-1080 at 1 (Washington, D.C. September 30, 2008)]. The use of CO2 for 

EOR is also generally recognized as important in developing geological storage data. The injection 

of CO2 in deep geological formations involves many of the same technologies that have been 

developed in the oil and gas exploration and production industry. Well-drilling technology, injection 

technology, computer simulation of storage reservoir dynamics and monitoring methods from 

existing applications are being developed further for design and operation of geological storage.

Response: EPA agrees with the commenter that CCS has the potential to be key to achieving

domestic greenhouse gas emissions reductions and that providing a consistent regulatory approach 

and regulatory certainty are important to facilitate future deployment of CCS. With respect to the 

commenter’s comments regarding the use of CO2 for EOR, EPA agrees that data from such 

operations can inform GS injection activities in Class VI wells. As part of the adaptive approach on 

CCS generally, the Agency will continue to identify and address additional information and respond, 

including via rulemaking, should that be necessary. EPA emphasizes that where additional 

information may increase protectiveness, streamline implementation, or otherwise inform the 

requirements for GS injection of CO2, EPA may need to evaluate whether changes are necessary. 

Thus, the Agency commits to reviewing, in a manner similar to the adaptive approach planned for 

the UIC Class VI rule, new research, data, and information related to today’s conditional exclusion.

Comment 3.20.5:

III. Comments on Identified Issues

The following comments are directed to the specific questions and comments that were raised in 

the proposed rule. Federal Register Vol. 76, No. 152/Monday, August 8, 2011/Proposed Rules

1. Page 48079 – “However, EPA acknowledges that at this time, it does not have knowledge of the 

range of possible CO2 stream compositions. While 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 (either in ppmv or in percent).

These non-CO2 constituents may include, but not limited to, sulfur dioxide (SO2), hydrogen sulfide 

(H2S), nitrous oxides (NOx), carbon monoxide (CO), methane (CH4), other hydrocarbons, water 

vapor (H20), as well as certain contaminants, that are also defined as hazardous contaminants in 40 

CFR 261.24, such as arsenic, mercury and selenium.”

Comment:

Basin Electric supports EPA's proposal to conditionally exclude from the definition of hazardous 

waste CO2 streams captured, transported, and injected into permitted underground injection 

control (UIC) Class VI wells.

The 40 CFR part 146 regulations have adequate protection for drinking water aquifers and address 

corrective action, financial assurance requirements, and long-term monitoring after closure. These 

requirements negate the need for any RCRA regulation.

Impurities, such as H2S or mercaptans, should not trigger a classification under RCRA. The success 

of existing acid gas injection operations into depleted oil and gas reservoirs conducted under the 

existing protective UIC regulations is further justification to exclude RCRA regulation. With the 

existing framework of RCRA, H2S is not part of the toxic list for toxicity characteristic leaching 

procedure (TCLP) testing, and U-listed wastes are only applicable to the listed chemical product in 
169

an essentially pure form. Also, historically, RCRA has been limited to containerized or condensed 

gases by the statute. Thus, the proposed exclusion of RCRA for injected CO2 streams including 

streams that have impurities such as H2S is warranted and makes sense.

As for corrosion concerns, the Synfuels Plant experience illustrates that corrosion has not been a 

problem when the captured and transported CO2 is maintained as dry. The Synfuels Plant has been 

successful in maintaining a dry CO2 gas (<10 ppm H20) and controlling a zero oxygen presence that 

is checked with lab results. 

DGC uses in line inspection tools capable of withstanding supercritical CO2 at 2700 psig. The tools 

travel down the inside of the pipeline while it is in operation to allow for assessment of the pipeline 

condition. It is one of the most important diagnostic tools available to maintain compliance with 

the integrity management portion of the hazardous liquid pipeline regulations. The Synfuels Plant

experience with CO2 pipeline transportation has indicated little corrosion concern with in line 

inspections verifying pipeline mechanical integrity.

Also, injected CO2 should be considered a product and not a solid waste, as stored CO2 in geologic 

storage could be retrieved in the future for industrial use. Any potential RCRA liability will be a 

deterrent to CO2 storage projects. Class VI CO2 injection operations should not be considered waste 

management activities.

Response: EPA thanks the commenter for their comment and for the information provided. EPA 

agrees that finalization of the conditional exclusion is appropriate. EPA believes that management 

of CO2 streams under the terms of the conditional exclusion do not present a substantial risk to 

human health and the environment, and that therefore, under these conditions, additional 

regulation pursuant to RCRA’s hazardous waste regulations is unnecessary.

Regarding the comment that injected CO2 “should be considered a product and not a solid waste,” 

EPA disagrees that CO2 streams sent to UIC Class VI wells for purposes of GS are not solid waste.

See Response to Comment 3.1.1 through 3.1.8, and 3.2.1 and 3.2.2. Regarding the comment 

stating that “historically, RCRA has been limited to containerized or condensed gases by the 

statute” please see EPA Response to Comment 3.1.7.

Regarding comment that UIC Class VI injection operations should not be considered waste 

management, because of the potential for retrieval of CO2 later, EPA disagrees that these 

operations do not involve solid waste (as described above) but adds that the RCRA conditional

exclusion does not preclude the removal of CO2 at a later date. How this activity is regulated would 

be a determination separate from the terms of the conditional exclusion in this rule. 

Regarding the comment referencing Acid Gas Injection, EPA did not consider the co-injection of H2S 

streams in developing the proposed hazardous waste exclusion. While the Agency acknowledges

that Acid Gas Injection takes place in the energy industry, it takes place using UIC Class II wells, not 

UIC Class VI wells, which were the focus of EPA’s analysis in support of the conditional exclusion. 

Because Acid Gas Injection wells occur under well classes other than UIC Class VI wells, the 

protectiveness of those operations as noted by the commenter are beyond the scope of this rule. 

EPA has indicated it may revisit the rule as part of the adaptive process, and any new information 

regarding, for example, the content of CO2 streams or co-injection of H2S could be part of that 

review. 
170

Also, EPA agrees that H2S would not cause a waste to be hazardous under the Toxicity 

Characteristic as H2S is not a TC contaminant; and EPA also agrees that as a waste generated from 

an industrial process, H2S would not be classified as a U-listed [commercial chemical product] 

waste. However, EPA notes that under the RCRA regulations, sulfide-bearing wastes that can 

produce “toxic gases, vapors or fumes in a quantity sufficient to present a danger to human health 

or the environment” are hazardous waste under the reactivity characteristic (40 CFR 261.23(a)(5)). 

EPA emphasizes that it is not making any finding on the hazardous waste status of captured 

supercritical CO2 streams as a class; these determinations are waste specific.

Comment 3.20.6:

2. Page 48081 – “For CO2 streams that are captured, compressed, and transported to a UIC Class VI 

well, EPA believes that the full set of subtitle generator and transporter retirements are not 

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

requirements.”

Comment:

Basin Electric agrees 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. The applicable Department of Transportation (DOT) requirements and 49 CFR part 

195 regulations will ensure that CO2 streams are managed in a safe and environmentally protective 

state.

Based on the Synfuels Plant's EOR experience, no on-site storage is necessary. The 

capture/compression/pipeline process occurs on a continuous basis. Basin Electric would not 

contemplate storage necessary for sequestration activities.

Response: EPA agrees with the commenter that additional requirements are not necessary when 

CO2 streams are managed in accordance with the terms of the conditional exclusion. EPA thanks 

the commenter for the information relating to its experience and plans regarding on-site storage of 

CO2.

Comment 3.20.7:

3. Page 48082 – “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.”

Comment:

Basin Electric does not believe that CO2 that is captured could be stored on-site. For example, at 

the Synfuels Plant, approximately 153 million standard feet per day of CO2 is captured and sent 

through a pipeline for EOR. This is approximately equal to the amount of CO2 that would be 

captured from a 400 MW power plant if fully controlled with a carbon capture system. Storing even

one week's worth of CO2 would require over 1,000 million standard cubic feet of capacity. Even 

after compressing to supercritical conditions, millions of cubic feet capacity would be required. 

Design for large quantities of pressurized CO2 is unprecedented. If such storage tanks could be 

designed and constructed to hold that pressure, the size and number of the tanks would be 

impractical to store on site.
171

Response: EPA thanks the commenter for the information provided regarding on-site storage of 

CO2. See Response to Comment 3.2.25.

Comment 3.20.8:

4. Page 48082 – “EPA also requests information on the units and process involved after the CO2 is 

captured, and before it is either injected on-site, or sent off-site.”

Comment:

The Synfuels Plant's EOR experience provides CO2 capture with a Rectisol cold methanol wash 

process. The compression process has three 20,000 HP compressors to provide supercritical CO2

suitable for transport by pipeline. The CO2 is compressed to an average of 2650 psi prior to 

metering to the CO2 pipeline.

Response: EPA thanks the commenter for the information.

Comment 3.20.9:

5. Page 48082 – “Finally, EPA requests comments and information on the procedures that have 

been or are expected to be used during maintenance and upset circumstances of the carbon 

capture system.”

Comment:

Appropriate seals are used in the compression process to avoid fugitive emissions and odors. Also, 

during plant upsets, CO2 may need to be flared for short periods due to H2S present in the product. 

Pipeline CO2 depressuring to the flare is much less frequent and flows are managed to avoid 

negative impacts and to allow proper operation of the flare.

The Synfuels Plant has numerous procedures for managing activities for operation and 

maintenance including purging the lines and mechanical integrity testing. Separate procedures also 

cover accident investigations, pipeline safety related conditions, abnormal operating conditions, 

and suspected pipeline leak detection. The pipeline is operated with on-line instrumentation and 

monitored with a leak detection system.

Supercritical CO2 pipelines are considered hazardous liquid pipelines, which are regulated by 49 

CFR Part 195 in the United States and the Canadian Standard Association Z662 in Canada. As a 

result, DGC must follow all of the same regulations as a pipeline operator transporting petroleum 

products. One of the requirements for operating a hazardous liquid pipeline on either side of the 

border is to have a dependable form of on-line leak detection. In addition, the Canadian National 

Energy Board specifically requires a computational leak detection system (LOS). The LOS in 

operation at the Synfuels Plant to monitor the CO2 pipeline is a sophisticated computer model that 

continuously queries pipeline operating data to identify potential leaks in the piping system. 

Pressure and temperature readings are taken at both ends of the pipeline and at each of the 12 

mainline valve stations. There is also a highly accurate mass flowmeter at each end of the pipeline 

to aid in the volume balance calculations of the LOS. The data is transmitted via microwave, hard 

wire, or radio communication to the control room at the Synfuels Plant, where it is automatically 

forwarded to the LOS computer. The software uses this information to identify a potential leak and

generate an audible and visual alarm on the pipeline control room screens. It can identify a 

potential leak location to within two miles, estimate the leak rate and report the total volume lost. 

A great deal of development work has gone into this system, by both the software vendor and OGC 
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personnel because it is the first of its kind on a supercritical CO2 pipeline.

There is also a reverse 911 system at the Synfuels Plant. If a leak is suspected due to a leak 

detection system alarm or any other means, plant supervision will trigger the reverse 911 

procedure. A computer at the Synfuels Plant is preprogrammed to call specific groups of residents 

and businesses that are determined by the supervisor to be in the vicinity of the potential leak. The 

recording gives them general instructions on the nature of the potential emergency and advises 

them of the appropriate response.

Response: EPA thanks the commenter for the information. The commenter’s description of the 

flaring during plant upsets at the Synfuels plant does not change EPA’s overall conclusion in the 

final conditional exclusion regarding the protectiveness of existing regulatory requirements. It is 

assumed that the flaring would be performed in compliance with applicable air pollution control 

reiquirements.

Comment 3.20.10:

6. Page 48083 – “EPA believes that these requirements, which focus on preventing release that 

might affect human populations and ecologically-sensitive areas, further support of the conclusion 

of today's proposal that additional regulations of pipeline transportation under RCRA subtitle C is 

not necessary in order to protect human health and the environment.”

Comment:

Basin Electric agrees with the analysis. Pipeline transportation of CO2 is subject to the 49 CFR Part 

195 Transportation of Liquids by Pipeline requirements. The requirements govern pipeline design, 

construction, operation and maintenance, and emergency response planning. The regulations also 

require pipeline integrity management systems to be in place including corrosion monitoring. 

These protective and detailed regulations and standards negate the need for further RCRA subtitle 

C regulation.

Response: EPA agrees that DOT’s PHMSA requirements in 49 CFR part 195 sufficiently protect 

human health and the environment. 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. 

Comment 3.20.11:

7. Page 48083 – “Finally, EPA notes 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 

pipelines are currently regulated, including any design and operating standards that apply to such 

pipelines. EPA still requests comment on the appropriateness of applying the RCRA subtitle C

standards to these non-DO T pipelines.”

Comment:

Basin Electric agrees with the EPA analysis in not proposing to apply RCRA subtitle C requirements 

to these on-site pipelines. At the Synfuels Plant, non-DOT regulated CO2 pipelines on-site are 

designed, constructed and maintained in accordance with the American Society of Mechanical 

Engineers Pipeline Transportation Systems for Liquid Hydrocarbons and Other Liquids (B31.4)

engineering standards, good engineering practice, and vendor mechanical and control 
173

requirements. The Synfuels Plant's CO2 is transferred on a continuous basis to a pipeline system to 

an EOR well injection site. The CO2 is not stored on-site. If there was any scenario of large storage 

on-site, the OSHA Process Safety Program regulation would apply at the Synfuels Plant due to H2S

thresholds. The Process Safety Management (PSM) regulation comprises 14 program elements 

including mechanical integrity, emergency response, and Process Hazard Analysis (PHA).

Response: See Response to Comment 3.2.30. EPA did not evaluate the OSHA PSM regulation as 

part of the conditional exclusion, but thanks the commenter for providing this information.

Comment 3.20.12:

8. Page 48083 – “Therefore, EPA requests comment on the extent to which non-pipeline

transportation will be used specifically for transporting CO2 stream 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.”

Comment:

Basin Electric would not anticipate using non-pipeline transportation in operations. It is Basin 

Electric's understanding that the Plains CO2 Reduction (PCOR) Partnership did use CO2

transportation by truck for a research project to demonstrate CO2 storage in an un-minable coal 

vein in North Dakota. It would be Basin Electric's belief that this "proof of concept" could be the 

type of projects where non-pipeline transportation could be utilized. Further in Basin Electric's 

estimation, the extent of using non-pipeline transportation would be very limited.

Response: EPA thanks the commenter for the information.

Comment 3.20.13:

9. Pages 48084-48085 – “Key Elements for the Class VI Well Requirements. Class VI provisions 

require that owners and 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.”

Comment:

There are essentially four stages to a CCS project:

*Siting and permitting;

*Construction and operation (including monitoring);

*Closure and Post-closure activities (including monitoring);

*Long-term responsibilities after the injected plume stabilizes.

The most important step is selection of a suitable geologic formation for long-term storage. That 

first step minimizes risks and potential liabilities for all subsequent stages, including long-term 

responsibilities after post-closure activities cease. Once a suitable geologic site has been identified, 

financial responsibility instruments should be affordable, because the high-risk projects will be 

eliminated during the permitting stage. Basin Electric supports consistent national regulations for 

financial responsibility requirements. But those regulations must consider site-specific conditions, 

including the key consideration of the suitability of the proposed geological formation, so that 
174

affordable financial responsibility instruments are available for low-risk projects built and operated 

according to the permit conditions. A critical aspect of the regulations should be to tie the cost of 

the financial responsibility instruments to the overall suitability and safety of the site. 

The division between federal and state authority should be divided along these lines:

 Consistent national regulations and oversight to eliminate higher-risk sites, and to minimize 

financial responsibility obligations on low-risk sites;

 Primacy to the states for permitting and making site-specific, case-by-case determinations 

based on rules that distinguish between high-risk and low-risk sites.

Basin Electric supports the state rights of primacy for the Class VI portion of the UIC program for 

making these site-specific determinations. The State of North Dakota has established rules for 

geological storage and is working to make them compatible with EPA's UIC program. But the States, 

in Basin Electric's opinion, are the regulatory bodies that should develop and administer the rules 

for permitting Class VI wells.

Basin Electric has many concerns relating to the requirements of permitting a Class VI well. One of 

Basin Electric's main concerns about obtaining a Class VI permit is the financial responsibility 

obligations. For the long-term responsibilities after post-closure activities are completed, the 

responsibility would be perpetual and would cause the geological sequestration costs to increase 

significantly. Basin Electric thinks the State of North Dakota has the right approach in addressing 

liability. A certificate of completion can be issued 10 years after the last injection of CO2 if the 

reservoir is determined to be stable as defined by the State of North Dakota. The State of North 

Dakota would then take ownership of the CO2 and assume all rights, responsibilities and interests in 

the CO2. The company injecting the CO2 in the geological formation would be released from all 

regulatory requirements. See N.D.C.C. § 38-22-17.

Basin Electric believes that the federal government should assume the liability of the CO2 in a 

similar fashion. Until the long-term responsibility issues after post-closure are addressed, it is 

unlikely that any company will consider CCS. It is critical that the rules be written so that high- risk 

and low-risk sites can be distinguished. This will allow affordable financial assurance instruments to 

be available for low-risk sites. This will also allow for some kind of affordable pool of financial 

responsibility monies to be accumulated through an appropriate fee structure or other legal 

mechanism so that after low-risk projects have gone through appropriate, rigorous post-closure 

certification, long-term responsibility may be transferred to the pool for those low-risk projects 

that qualify. Another option would be for the federal government to assume this responsibility 

after appropriate post-closure certifications are issued.

Response: The above comments relate to the UIC Class VI final regulation, and are beyond the 

scope of this rule. See response to comment 3.20.2. 
175

Comment 3.20.14:

10. Page 48087 – “Finally, EPA requests comment on whether transporters, as well as pipeline 

owners and operators, should also sign such a certification statement.”

Page 48087 – “EPA notes that it is requesting comment on whether persons engaged in the 

movement of conditionally-excluded CO2 streams, including transporters, as well as pipeline 

owners or operators, should certify that they meet the conditions of today's proposed conditional 

exclusion.”

Comment:

Basin Electric believes it is unnecessary and unwise to require transporters, pipeline owners and 

operators to certify that they meet the conditions of the proposed exclusion (FR 76 48087). Rather, 

Basin Electric supports each entity being responsible for the portions of the process that they have 

intimate knowledge of and that they control. Transportation through pipelines or by other means, 

must meet applicable transport requirements for all materials moved, and certification that they 

meet these requirements only for a specific material (i.e., CO2 to be sequestered) provides no 

additional protection and is unnecessary. In addition, in a manner similar to other existing rules 

associated with hazardous waste (40 CFR § 262.11 and §263) the generator is responsible for waste 

determination and characterization, not the transporter. The transporter must depend on the 

statements and characterizations made by the generator regarding the material being transported. 

In the proposed rule Basin Electric recommends the same approach be taken. If the transportation 

mechanism is a common carrier pipeline, the pipeline owner/operator much certify that the 

combination of CO2 streams from various sources in the pipeline meet the specifications to 

maintain the safe transport of CO2. The operator of the Class VI well should be responsible for 

certifying the characteristics of the CO2 that is actually being injected.

Response: EPA agrees that a certification by the transporter is not necessary, and the final rule 

does not include a transporter/pipeline owner or operator certification. First, if EPA were to require 

such a certification, under the approach where EPA limits the scope of the certification to the 

conditions within the control of pipeline owners and operators or other transporters (the approach 

taken in the final rule for CO2 stream generators and UIC Class VI well owners and operators), the 

certification would essentially address: 1) compliance with applicable DOT requirements, and 2) to 

not mix hazardous waste into the CO2 streams. Regarding compliance with DOT requirements, EPA 

is persuaded by comments received on this issue that if persons transporting supercritical CO2 must 

comply with the applicable transportation requirements for all supercritical CO2 being moved, it 

seems unnecessary to require that they certify compliance with DOT requirements for a specific 

material (i.e., supercritical CO2 streams to be sequestered). Regarding mixing with hazardous waste, 

EPA does not have information, nor did commenters provide any new information, indicating that 

CO2 pipeline owners and operators or other transporters would mix hazardous waste into CO2

streams being delivered to UIC Class VI facilities. EPA expects that pipeline owners and operators 

engaged in delivering supercritical CO2 have strong disincentives to mix any hazardous waste into 

their pipeline system, both in order to honor their contractual arrangement with customers, and 

also to maintain their equipment. Also, as EPA stated in the proposed rule premable, PHMSA 

requires that pipeline owners and operators ensure that supercritical CO2 streams be chemically 

compatible with the pipeline and any commodities in the pipeline and will not corrode the pipeline 

and pipeline system. For these reasons, EPA does not see the need for a transporter certification, 

and is not changing its proposed approach and transporters and pipeline owners and operators will 
176

not be required to sign a certification statement as a condition of the exclusion.

EPA also agrees that the UIC Class VI well owners or operators should be responsible for a 

certification statement as suggested by the commenter. EPA has modified the certification 

requirement in the final rule so that there are now two separate certification statements 

worded slightly differently – one for generators and another for UIC Class VI owner/operators

claiming this conditional exclusion. EPA has made these revisions to better reflect actions over 

which each party has control.

Comment 3.20.15:

11. Page 48087 – “EPA is also requesting comment on whether any new monitoring,

recordkeeping, or reporting requirements are necessary (including as those that might apply to 

pipeline owners and operators) to ensure that the conditions of the proposed exclusion are met.”

Comment:

The regulations for Class VI wells as well as the DOT regulations under 49 CFR 195 provide 

extensive requirements for monitoring, recordkeeping, and reporting. Basin Electric believes no 

new requirements are necessary other than the exclusion certification and compliance with the 

conditions set forth.

Response: See Responses to Comments 3.2.40 through 3.2.43.

Comment 3.20.16:

12. Page 48088 – “EPA requests comment on the types and characteristics of substances that are 

added to CO2 streams to enable or improve the injection process.”

Comment:

With the Synfuels Plant's EOR experience, no substances are added to the CO2 stream either at the 

Rectisol facility or the pipeline transport facility to improve the injection process.

Response: EPA thanks the commenter for the information.

Comment 3.20.17:

13. Page 48089 – “This sequestration may be conducted either with or without concurrent EOR. 

However, EOR itself is outside the scope of this rule, as proposed.”

Comment:

Basin Electric agrees that EOR is outside the scope of this rule. Basin Electric also believes that EOR 

will be the stepping stone for expanding more carbon dioxide capture in the United States. 

However, once EOR is completed, these formations could and should be used to store more CO2 if 

the need arises. EPA should give the States the primacy to determine how these EOR reservoirs 

could be recognized for acceptance of additional CO2 for geological sequestration in the future.

Thank you again for giving us the opportunity to file these comments.

Response: As the commenter notes, issues surrounding EOR itself are outside the scope of this 

rulemaking. With respect to the comments on UIC primacy, see Response to Comment 3.20.2.

3.21Spectra Energy (Spectra)
177

Document ID: EPA-HQ-RCRA-2010-0695-0088

Comment 3.21.1:

Spectra Energy (“Spectra”) submits the following comments in the above-referenced docket, 

relating to the U.S. Environmental Protection Agency’s (“EPA” or “the Agency”) proposed rule 

published at 76 Fed. Reg. 48073 (August 8, 2011) to conditionally exclude geologically sequestered 

CO2 from regulation as a hazardous waste under the Resource Conservation and Recovery Act 

(“RCRA”). We appreciate the Agency’s recognition that if RCRA’s applicability to geologic 

sequestration were left unclear, it could discourage deployment of geologic sequestration in the 

U.S. While we have a number of issues on which we request the Agency’s clarification, the 

proposed rule appears to be a reasonable and favorable means of addressing this issue. 

About Spectra Energy 

Headquartered in Houston, Texas, Spectra has one of the largest natural gas transportation 

systems in North America, encompassing more than 19,100 miles of transmission pipelines and 305 

billion cubic feet (Bcf) of storage capacity. Our U.S. operations include: 

*Texas Eastern Transmission which transports up to 6.7 Bcf per day from producing fields in the 

Gulf Coast region of Texas and Louisiana to high-demand markets primarily in the Northeastern 

U.S. The pipeline comprises 9,200 miles of onshore and offshore pipe into the Gulf of Mexico. 

*East Tennessee Natural Gas which transports up to 1.5 Bcf per day mainly through Tennessee and 

Virginia across 1,510 miles of pipeline. 

*Maritimes & Northeast which transports natural gas across the northeastern U.S. and Atlantic 

Canada. The U.S. portion, comprised of 343 miles of pipeline, currently transports up to 800 Mcf 

per day. 

*Algonquin Gas Transmission which plays a key role in servicing the New England region. Its 1,120

miles of pipeline transport up to 2.4 Bcf per day of natural gas. 

*Gulfstream Natural Gas in which Spectra has a 50% interest. Its 745 miles of pipeline transport 1.3 

Bcf per day of natural gas from the Mississippi and Alabama coast to Florida. 

*Southeast Supply Header in which Spectra has a 50% interest. Its 274 miles of pipeline transport 1 

Bcf per day of natural gas from northeast Louisiana to southwest Alabama. 

*Ozark Gas Transmission which transports up to 500 MMcf per day of natural gas from 

southeastern Oklahoma to southeastern Missouri. It is comprised of 565 miles of pipeline transport 

and 365 miles of a gas gathering system which accesses Fayetteville Shale and Arkoma production. 

*Market Hub Partners, Bobcat Gas Storage, Saltville Gas Storage and Steckman Ridge through 

which Spectra Energy has significant gas reservoir and salt cavern natural gas storage capabilities. 

Our storage assets are strategically located in both supply and market areas, including Texas, 

Louisiana, Virginia, and Pennsylvania. 

*DCP Midstream is one of the nation’s largest natural gas gatherers and processors, the largest 
178

NGL producer and one of the largest NGL marketers in the U.S. DCP Midstream is a 50-50 joint 

venture between Spectra Energy and ConocoPhillips. DCP operates processing plants, gas gathering 

systems, and other assets. 

Since the mid 1990s, Spectra Energy’s Western Canadian business unit (SET West) has incorporated 

carbon capture and sequestration (CCS) and acid gas re-injection (AGR) into our natural gas 

processing facilities in British Columbia and Alberta. Seven CCS facilities are in operation today at 

SET West. For example, our Kwoen facility is Spectra’s largest CCS/AGR operation in Canada, reinjecting approximately 100 Kt per year. Kwoen and SET West have been recognized by the 

Intergovernmental Panel on Climate Change (IPCC) as a leader in CCS. Further, a project at Spectra 

Energy’s Fort Nelson Gas Processing Plant, also in British Columbia, could result in the 

sequestration of up to 2.2 Mt CO2/year, once fully operational. The Fort Nelson CCS project is a 

multi-lateral partnership between Spectra Energy, the Province of British Columbia, Government of 

Canada (Natural Resources Canada), US Department of Energy/National Energy Technology 

Laboratory (Plains CO2 Reduction Partnership). Today, Spectra Energy’s CCS/AGR projects safely 

capture and store approximately 150 Kt CO2 per year. 

Imposition of excessive or unreasonable requirements could have negative implications for 

geologic sequestration activities in other jurisdictions such as Canada.

Response: EPA acknowledges the comment. EPA believes a consistent regulatory approach to GS 

will help facilitate development and deployment of CCS technologies in the United States, rather 

than discourage deployment. The comment does not elaborate on what “negative implications for 

geologic sequestration activities in other jurisdictions such as Canada” the commenter has in mind. 

In any event, EPA believes that, for the reasons explained in the preambles and elsewhere, that the 

requirements in the conditional exclusion are appropriate, and not excessive or unreasonable.

Comment 3.21.2:

General Commentary 

Subject to clarification of several issues discussed below, Spectra supports the proposed rule. As we 

stated in our comments to the proposed rule for UIC Class VI wells, RCRA’s hazardous waste 

regulatory regime is unnecessary and inappropriate for geologic sequestration of CO2. A CO2 waste 

stream is not a hazardous waste, as will be discussed further below. RCRA hazardous waste 

regulation is burdensome, and a Class VI geologic sequestration well cannot be converted into a 

Class I Hazardous well. 

Furthermore, as EPA amply describes in the proposed rule, hazardous waste regulation is 

unnecessary for CO2 streams being sequestered at Class VI wells, not only because CO2 streams do 

not meet the criteria to be deemed hazardous, but because a comprehensive and adequate multifaceted regulatory system already applies and serves the purposes for which hazardous waste 

regulation would be applied. 

A conditional exclusion is an appropriate mechanism to remove geologically sequestered CO2

streams from hazardous waste regulation. EPA has long interpreted Section 3001(a) of RCRA, which 

directs the Agency to develop criteria for identifying characteristics of hazardous wastes “which 

should be subject to the provisions of” the hazardous waste management requirements of RCRA 

Subtitle C, to authorize it to conditionally exclude from such regulation wastes for which those 

requirements are not justified. A conditional exclusion offers the opportunity to make clear the 
179

circumstances when hazardous regulation will or will not apply.

Response: EPA does agree that management of CO2 in accordance with the terms of the final 

conditional exclusion (which include management in accordance with existing regulations such as 

the UIC requirements for UIC Class VI wells as well as DOT requirements) protects human health 

and the environment. Therefore, EPA finds it is appropriate and justified to establish a conditional 

exclusion for hazardous CO2 streams injected for geologic sequestration. EPA agrees with the 

commenter that under its interpretation of RCRA (including RCRA section 3001(a)) it has the 

authority to issue conditional exclusions from the hazardous waste regulations. EPA’s authority to 

issue the rule is described in section II.B. of the final rule preamble. EPA responds to the 

commenter’s comments about the hazardous waste status of CO2 streams in Response to 

Comment 3.2.19.

Comment 3.21.3:

Specific Issues 

A. Minor Violations That Do Not Compromise Safety 

EPA should clarify that it does not intend that minor violations will void the exclusion, thereby 

triggering regulation of a facility as a hazardous waste facility. 

The exclusion for geologically sequestered CO2 requires, among other conditions, that: 

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. 

The exclusion also is conditioned upon the transportation of the CO2 stream being in compliance 

with applicable Department of Transportation requirements. Furthermore, the exclusion does not 

apply unless an authorized representative of the geologic sequestration facility owner or operator 

certifies under penalty of law that the injection of the carbon dioxide stream meets these and the 

other conditions set forth. 

EPA has a strong interest in promoting compliance discipline and not condoning noncompliant 

management. Industry shares this interest: violations at one facility could damage public 

perception of the safety of geologic sequestration. Nevertheless, the conditional exclusion should 

provide for flexibility in enforcement so that “paper” violations or non-compliance that has not 

compromised the ability of the geologic sequestration facility to meet the environmental, health, 

or safety protection objectives of the applicable statutes does not result in closure of the facility. At 

a minimum EPA should commit to implementation that will take into account the consequences of 

closing a sequestration facility. Considerable impacts could occur upstream of a geologic 

sequestration facility should the facility be closed. 

While there are not today federal standards that necessitate that natural gas processors capture 

and sequester the CO2 that is naturally commingled with raw natural gas streams in many natural 

gas fields, such requirements could be imposed in the future. Furthermore, some State greenhouse 

gas emissions limitations are stringent enough today that natural gas-fired electric generating 

facilities may be required to capture and sequester CO2. The availability of a suitable sequestration 

site within the vicinity of a gas processing facility, power plant, or other industrial operation may be 

indispensable to that industrial facility being able to continue to operate without violating 
180

greenhouse gas emission restrictions. The Agency must bear in mind that for a period of some 

years, there likely will be only a limited number of geologic sequestration facilities in operation. 

Even if another sequestration site is in the vicinity, it is unlikely to be a simple matter for a 

generator to switch CO2 deliveries to another facility. Bulk transportation of CO2 is likely to occur 

via pipeline, and a pipeline must be constructed and have available capacity in order for a 

generator to change delivery points.

It likely would be impossible or at least extremely difficult to reclassify a Class VI well as a Class I 

Hazardous well. Two differences in Class I Hazardous and Class VI regulations illustrate this. First, 

corrective action concerning a Class I Hazardous well effectively must be conducted up front. 

Regulations require that “No owner or operator of a new Class I hazardous waste injection well 

may begin injection until all corrective actions required under this section have been taken.” [40 

CFR 146.64(d)(2)]. This would include corrective action throughout all of the Area of Review, which 

could be very extensive in the case of a Class VI geologic sequestration well. Because the volumes 

for geologic sequestration are anticipated to be orders of magnitude larger than for other well 

classes, the plumes and Areas of Review also are expected to be much larger. This is why the 

Agency provided for phased corrective action for Class VI wells. [See 40 CFR 146.84(b)(iv)]. It may 

be impractical and prohibitively expensive to conduct corrective action all at once for a Class VI 

well, as EPA’s regulation has recognized. 

Second, Class I Hazardous wells are subject to the requirement of 40 CFR 148.20, subparagraph 

(a)(1) of which requires that “reliable predictions can be made that . . . [f]luid movement conditions 

are such that the injected fluids will not migrate within 10,000 years.” Supercritical CO2 injected for 

geologic sequestration is a mobile, buoyant injectate that is expected to migrate. EPA’s Class VI rule 

expressly stated that the Agency “determined that tailored requirements, modeled on the existing 

UIC framework, are necessary to manage the unique nature of CO2 injection for [geologic 

sequestration],” with those unique features including “the large volumes anticipated at geologic 

sequestration projects, the relative buoyancy of CO2, [and] its mobility within subsurface geologic 

formations. . . .”[FN1: “Federal Requirements Under the Underground Injection Control (UIC) 

Program for Carbon Dioxide (CO2) Geologic Sequestration (GS) Wells: Final Rule,” 75 Fed. Reg. 

77230 at 77233, Vol. 75, No. 237, December 10, 2010].

EPA’s conditional exclusion must be implemented broadly enough that minor violations that do not 

compromise the safe functioning of the geologic sequestration facility will not result in its being 

closed, thereby disrupting “upstream” activities.

Response: The commenter makes the point that minor violations (such as paperwork violations) 

should not void the conditional exclusion, which the commenter notes would require a 

“reclassification” of a UIC Class VI well to a UIC Class I hazardous well, and which the commenter 

states would be difficult or impossible. The commenter also states that the conditional exclusion 

should be implemented such that these minor violations do not result in the closing of that 

sequestration facility.

Regarding the comment that minor violations should not void the exclusion, it is EPA’s view that 

the rule conditions, taken together, ensure that the excluded CO2 streams are being managed in a 

protective manner such that subtitle C regulations are not necessary. Therefore, it follows that any 

management not in accordance with those conditions does not qualify for the exclusion. EPA 

nevertheless appreciates the commenter’s concern over the loss of the conditional exclusion due 
181

to, for example, small administrative or clerical errors. EPA’s Office of Enforcement and 

Compliance Assurance (OECA) is unable to provide definitive assurances outside the context of a 

formal enforcement proceeding that the government will not proceed with an enforcement 

response for a specific individual violation of an environmental protection statute, regulation, or 

legal requirement. However, EPA can (and has previously done so for other RCRA rules) exercise 

discretion to decide when and how to respond or not respond to a given violation, based on the 

Agency’s normal priorities. In RCRA penalty actions, the factors that EPA considers in assessing the 

gravity-based portion of the penalty are the potential for harm and the extent of deviation from a 

statutory or regulatory requirement. The penalty can be adjusted for numerous factors, including 

good faith efforts to comply, degree of willfulness and negligence, and history of noncompliance. 

Additional information can be found in the 2003 RCRA Civil Penalty Policy 

(http://www.epa.gov/compliance/resources/policies/civil/rcra/rcpp2003-fnl.pdf).

EPA agrees that there would very likely be significant logistical, regulatory and policy implications 

to changing the regulatory status of a UIC Class VI well to that of a UIC Class I hazardous well. EPA 

also notes that comments on existing UIC regulations are outside the scope of this rulemaking. 

Comment 3.21.4:

B. Substances Derived from the Capture Process 

The proposed rule excludes a “carbon dioxide stream” from regulation as a hazardous waste, 

subject to the proposed rule’s conditions. A carbon dioxide stream is defined as: 

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. 

This definition is identical to the definition of “carbon dioxide stream” in the Underground Injection 

Control program regulations for Class VI wells, with the exception that it does not exclude “any 

carbon dioxide stream that meets the definition of a hazardous waste under 40 CFR part 261.” 

[FN2: 40 CFR 146.81(d)].

EPA has not defined what constitutes an “incidental associated substance[] derived from the 

source materials and the capture process.” However, the proposed rule makes clear that such a 

material may be one the presence of which would make the CO2 stream a hazardous waste. EPA 

explains: 

Because today’s conditional exclusion would apply to CO2 streams that are otherwise RCRA 

hazardous wastes, EPA did not include [the language from the Class VI UIC rule excluding hazardous 

wastes] 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. [FN3: Proposed rule, 76 

Fed. Reg. 48073, at 48088].

The composition of the CO2 stream that results from the industrial process that produces it will be 

determined largely by chance of nature, because of the source material involved (natural gas, coal, 

oil, or other). Raw natural gas often contains a variety of contaminants, including (in addition to 

CO2) acid gases like hydrogen sulfide and mercaptans, and sometimes trace metals such as mercury 
182

in elemental or other forms. The percentage of CO2 and acid gases in raw natural gas vary. The 

methods of processing and capturing the CO2 stream may have some effect on the constituencies 

as well. 

We appreciate the clarity with which EPA is attempting to define the issue. If there is room for 

interpretive confusion in the definition, we recommend that EPA take steps to clarify it, as the 

scope of the CO2 streams covered is the essential feature of the conditional exclusion. We believe it 

is appropriate, given the Agency’s policy to pursue reductions in greenhouse gas emissions, for the 

Agency to interpret this term in a manner that encourages the capture and injection of CO2

streams. CO2 mixtures from natural gas operations have been safely injected for nearly two 

decades and represent a significant opportunity for further reductions in atmospheric CO2 emission 

through long-term geologic sequestration. 

As a final comment on this topic, we note that the proposed exclusion is consistent with other 

current regulation, as re-injection of carbon dioxide from gas processing is currently exempt from 

Subtitle C requirements of RCRA.

Response: While EPA acknowledges the commenter’s recommendation that EPA clarify the

definition of Carbon Dioxide Stream (CO2 Stream) “if there is room for interpretive confusion” or 

otherwise in a manner “that encourages the capture and injection of CO2 streams,” the commenter 

did not provide specific guidance on how EPA should revise the definition to provide this clarity. 

The proposed definition of CO2 Stream is being finalized as proposed, for the reasons EPA discusses 

in Section V.F. in the preamble to the final rule. EPA notes that the adaptive approach being taken

in the final rule (see response to comment 3.2.3) may provide future opportunity for clarifying the 

definition if necessary.

Regarding the comment on re-injection of CO2 from gas processing, EPA notes that that issue is 

beyond the scope of this rulemaking.

Comment 3.21.5:

C. Certification Is Based on Information Beyond Parties’ Control 

Proposed provision 40 CFR 261.4(h)(1)(iv) requires “[a]ny 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 [from hazardous waste regulation]” must sign a certification that states: 

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. 

This certification requires that generators of CO2 streams attest to information that is beyond their 

control and not reasonably possible for them to obtain. 

First, it requires that generators certify that the geologic sequestration facility, which is not under 

their control, meet all of the requirements of 40 CFR parts 144 and 146. Many geologic 

sequestration facilities are likely to be “merchant” facilities not under the control of the generator. 

Even where the generator insists upon one of its employees personally participating in an audit of 

the facility, which would be expensive, impractical, and have little benefit, generators who send 

materials to a merchant sequestration site cannot attest to ongoing compliance with these 

requirements. For example, information about plume movement, pressure calculations, and other 
183

operational, testing, and monitoring data are not under a generator’s control. 

Likewise, as drafted, the certification statement requires each generator to attest that the 

materials being injected by other generators are qualified as a carbon dioxide stream and do not 

void the hazardous waste exclusion.

Spectra does not believe it was the Agency’s intention to require parties to make a certification to 

facts pertaining to matters beyond their control. We recommend revising the certification 

requirement for generators to read as follows: 

I certify under penalty of law that the material being delivered is qualified as a carbon dioxide 

stream under 40 CFR 146(d).

Response: EPA agrees that the certification statement should better reflect the activities within the 

signatory’s control. EPA has revised the certification statement in the final rule so that there are 

now two separate certification statements – one for CO2 stream generators and another for UIC 

Class VI well owners or operators. Under the final rule, the certification statement that the 

generator would sign is specific to the activities within the generator’s control; likewise, the 

certification statement that the UIC Class VI well owner or operator would sign is specific to the 

activities within the owner or operator’s control. EPA did not use the language suggested by the 

commenter for generators, however, but instead developed language that includes the prohibition 

on hazardous waste mixing, and delivery (or arranging for delivery) of the CO2 stream to a UIC Class 

VI facility, which EPA finds would be in the generator’s control. See response to comment 3.8.8.

Comment 3.21.6:

D. EPA Has Not Sufficiently Clarified that CO2 for Geologic Sequestration is a Solid Waste In its 

comments to the proposed Underground Injection Control program rule for geologic sequestration 

wells, Spectra argued that there is a legitimate question whether CO2 is a solid waste based on the 

statutory definition of “solid waste” expressly including “contained gaseous material.” 42 U.S.C. § 

1004(27). EPA did not address this comment in the final rule, and it deserves clarification. If CO2 in 

the context of geologic sequestration is not a solid waste, RCRA does not apply and there is no 

reason for a conditional exclusion. 

For a waste to be a hazardous waste, it must first be a solid waste. Specifically, the term includes 

discarded material, including solid, liquid, semisolid, or contained gaseous material. . . .” 42 U.S.C. 

6903(27) [Emphasis added]. EPA has consistently interpreted this term as excluding uncontained 

gases from the definition of solid waste. [FN4: See, e.g., 47 Fed. Reg. 27530 (June 24, 1982) (gases 

from fume incinerators not subject to RCRA, because fumes are not a solid waste); 54 Fed. Reg. 

50973 (Dec. 11, 1989) (uncontainerized gases are excluded from RCRA)]. In In re BP Chemicals 

America, Inc., [FN5: RCRA Appeal No. 89-4, 1991 WL 208971, at *2 (Admin., Aug. 20, 1991) ] the 

Administrator rejected the argument that otherwise uncontained gas passing through piping or the 

facility made it “contained” and subject to RCRA. Specifically, the Agency determined: 

[T]he Agency views gaseous material to be “solid waste” only when it is containerized. Region V 

argues that BP’s HCN vapor is “contained” by the various process units through which it passes, by 

associated piping, and by the plant as a whole. The Region’s reading of the term “contained,” 

however, cannot be reconciled with the Agency’s treatment of fume incinerators. Such incinerators 

are used to treat vapors that are “contained” in the broad sense of being bound or controlled and 
184

not being emitted to the atmosphere, but the Agency considers such vapors to be outside the 

scope of the “solid waste” definition because they are not containerized in the narrower sense of 

being in an individual container such that the gas is amenable to shipment. [FN6: In re BP 

Chemicals America, Inc., RCRA Appeal No. 89-4, 1991 WL 208971 (Admin., Aug. 20, 1991), p. 2-3].

Just within the past several months the Agency had occasion to address the uncontained gas issue 

when guidance related to reinterpretation of the definition of “solid waste” created confusion 

about whether the meaning of “contained gaseous material” was being altered. EPA clarified that it 

was not. [FN7: See Letter from Suzanne Rudzinski, Director, Office of Resource Conservation and 

Recovery, to Tim Hunt, American Forest and Paper Association, May 13, 2011: “We clarify here that 

the Agency’s previous statements and interpretations remain effective.”]

Given this precedent and its very recent affirmation, CO2 streams captured from industrial 

processes and transported by pipeline are “uncontained” gases. That classification also should 

extend to CO2 that leaves the pipeline for injection into an underground formation. At no time is 

the gas “containerized in the narrower sense of being in an individual container such that the gas is 

amenable to shipment.” We believed in 2008 and believe now that CO2 streams should be 

exempted from RCRA on this basis and that this issue should be addressed by the Agency.

Response: EPA disagrees that CO2 streams sent to UIC Class VI wells for purposes of GS are not 

solid waste. As EPA noted in the proposed rule, the CO2 streams are delivered by pipeline and 

injected into UIC Class VI wells for GS in a supercritical state, which EPA stated at proposal was 

“...rather unique in that it has properties intermediate between a liquid and a gas.” 76 FR at 48078.

The scientific term used to describe or define this supercritical state (i.e., when a substance is at or 

above its critical temperature and critical pressure) is as a “supercritical fluid.” The RCRA statutory 

definition of solid waste specifically refers to “other discarded material, including solid, liquid, 

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

agricultural operations, and from community activities . . .” While EPA has indeed interpreted the 

meaning of specific terms listed, including “contained gaseous material,” the RCRA definition of 

solid waste encompasses “other discarded material” and does not speak to materials such as 

supercritical fluids. Like the listed “solid, liquid, semisolid, or contained gaseous material” 

specifically referenced, CO2 streams sequestered for purposes of GS are “other discarded material” 

from industrial and commercial operations and, therefore, are of a similar kind to the other types 

of wastes specifically referenced by the definition. They are, therefore, RCRA statutory solid 

wastes.

Comment 3.21.7:

E. Potential Applicability of Superfund 

Another benefit of the proposed rule is that it lessens the likelihood that the federal Superfund 

cleanup program will apply. The definition of “hazardous substance” includes RCRA hazardous 

wastes. [FN8: 42 U.S.C. 9601(14)]. The Superfund program, common parlance for the 

Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), is 

characterized by slow, overly expensive responses to releases and threatened releases of

hazardous substances. Superfund still may apply if the definition of “hazardous substance” is 

otherwise triggered. 

As we submitted in our comments to the proposed Class VI UIC rule in 2008, the threat of CERCLA 

litigation and the potential liability to a site owner or operator is significant and could discourage 
185

the deployment of geologic sequestration. The statute’s application is unnecessary, given the 

applicability of cleanup obligations and liability through other law.

Response: EPA thanks the commenter but notes that CERCLA and its related provisions are beyond 

the scope of this rulemaking.

Comment 3.21.8:

Conclusion 

In conclusion, we applaud EPA for its effort to clarify the applicability of RCRA’s hazardous waste 

requirements to geologic sequestration and believe that the commentary above will help make the

clarification more useful. We believe that removing uncertainty about the applicability of RCRA’s 

hazardous waste requirements will encourage deployment of geologic sequestration.

Response: EPA agrees with the commenter that the conditional exclusion will reduce regulatory 

uncertainty for stakeholders, and facilitate deployment of CCS technologies.

3.22Western Environmental Trade Association (WETA)

Document ID: EPA-HQ-RCRA-2010-0695-0060

Comment 3.22.1:

The Western Environmental Trade Association (WETA) and the Montana Petroleum Association

(MPA) appreciate this opportunity to submit comments to the Environmental Protection Agency 

(EPA) in regard to the proposed rule for Hazardous Waste Management System: Identification and 

Listing of Hazardous Waste: Carbon Dioxide (CO2) Streams in Geological Sequestration Activities.

WETA, organized in 1976, is a coalition of representatives of agriculture, labor, business, 

commercial industry, the scientific community, recreation, transportation and twenty-one other 

trade associations, with an interest in promoting the economic well being of the people of 

Montana while protecting the state’s environment. These member associations, companies and 

other organizations collectively employ or represent thousands of Montanans.

MPA is a voluntary, nonprofit trade association whose 169 members include oil and natural gas

producers, gathering and pipeline companies, petroleum refineries, service providers and

consultants. A majority of the oil and gas produced in Montana is produced by MPA members. Our 

mission is to MPA’s strives to maintain a positive business climate for the petroleum industry in 

Montana, and its education program fosters public awareness of the industry’s contributions to the 

state and nation.

We support EPA’s proposal to conditionally exclude from the definition of hazardous waste CO2

streams captured, transported, and injected into permitted Class VI wells.

Response: EPA thanks the commenter for its support of the proposed rule.

Comment 3.22.2:

The 40 CFR part 146 regulations has adequate protection for drinking water aquifers and addresses 

corrective action, financial assurance requirements, and long term monitoring after closure. These 

requirements negate the need for any RCRA regulation.
186

Response: EPA agrees that the management of these CO2 streams, when meeting certain 

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. 

Comment 3.22.3:

RCRA was never meant to apply to CCS and thus the statute provides a poor tool to regulate the

activity. Nothing in RCRA or its regulations purports to apply to CCS generally or geologic

sequestration specifically. The RCRA model is prospective “cradle-to-grave” waste management

and tracking. CCS, on the other hand, currently involves the injection of CO2 for beneficial purposes. 

That activity, moreover, is envisioned to involve mixed streams of CO2 from multiple sources, with 

injection of CO2 from multiple sources, thereby defeating the notion of tracking wastes through 

manifests and the like.

Response: See Responses to Comments 3.1.5 and 3.12.7.

Comment 3.22.4:

Impurities, such as H2S or mercaptans, should not trigger a classification under RCRA. The success 

of existing acid gas injection operations into depleted oil and gas reservoirs conducted under the 

existing protective underground injection control (UIC) regulations is further justification to exclude 

RCRA regulation.

Response: See Response to Comment 3.20.5.

Comment 3.22.5:

Corrosion has not been a problem when the captured and transported CO2 is maintained as dry.

Response: It is unclear to EPA how the comment is intended to relate to the proposed rule. To the 

extent the comment is referring to the RCRA hazardous characterization regulations, EPA discusses 

issues related to that topic in section V. B. of the final rule preamble.

Comment 3.22.6:

Also, injected CO2 should be considered a product and not a solid waste, as stored CO2 in geologic 

storage could be retrieved in the future for industrial use. Class VI CO2 injection operations should 

not be considered waste management activities.

The concept of “disposal” is also inconsistent with how the bulk of CO2 is currently being managed 

commercially today. With the exception of demonstration and related projects, most if not all of 

the CO2 that is geologically injected today is used for EOR. In that application, it is purchased and 

transacted as a valuable commodity.

Response: Regarding the subsequent retrieval of CO2 from UIC Class VI injection operations, see 

Response to Comment 3.20.5.

Regarding the comment that injected CO2 “should be considered a product and not a solid waste,”

and the use of CO2 for EOR, see Responses to Comments 3.1.8, 3.2.1, and 3.2.2.

Comment 3.22.7:
187

We agree 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. The 

applicable Department of Transportation (DOT) requirements and 49 CFR part 195 regulations will 

ensure that CO2 streams are managed in a safe and environmentally protective state.

Response: EPA acknowledges the comment. See responses to 3.22.9 and 3.22.10.

Comment 3.22.8:

We do not believe that CO2 that is captured could be stored on-site. Design for large quantities of 

pressurized CO2 is unprecedented. If such storage tanks could be designed and constructed to hold 

that pressure, the size and number of the tanks would be impractical to store on site.

Response: See response to 3.2.25.

Comment 3.22.9:

WETA and MPA agrees that additional regulations of pipeline transportation under RCRA subtitle C 

is not necessary in order to protect human health and the environment. Pipeline transportation of 

CO2 is subject to the 49 CFR Part 195 Transportation of Liquids by Pipeline requirements. The 

requirements govern pipeline design, construction, operation and maintenance, and emergency 

response planning. The regulations also require pipeline integrity management systems to be in 

place including corrosion monitoring. These protective and detailed regulations/standards negate 

the need for further RCRA subtitle C regulation.

Response: EPA thanks the commenter and notes that EPA does agree that management of CO2 in 

accordance with the terms of the final conditional exclusion (which include management in 

accordance with existing regulations such as the UIC requirements for UIC Class VI wells as well as 

DOT requirements) protect human health and the environment. Therefore, EPA finds it is 

appropriate and justified to establish a conditional exclusion for hazardous CO2 streams injected for 

geologic sequestration. 

Comment 3.22.10:

We agree with the EPA analysis in not proposing to apply RCRA subtitle C requirements to these 

on-site pipelines. Non-DOT regulated CO2 pipelines on-site are designed, constructed and

maintained in accordance with ASME.

Response: See Response to Comment 3.2.30.

Comment 3.22.11:

WETA and MPA support the state rights of primacy for the Class VI portion of the UIC program.

Response: Comments on existing UIC regulations, such as the Class VI requirements, are outside 

the scope of this rulemaking.

Comment 3.22.12:

We believe it is unnecessary to require transporters, pipeline owners and operators to certify that 

they meet the conditions of the proposed exclusion (FR 76 48087). Transport through pipelines or 

by other means, must meet applicable transport requirements for all materials moved, and 
188

certification that they meet these requirements only for a specific material (i.e., CO2 to be 

sequestered) provides no additional protection and is unnecessary.

We do not believe it is necessary to have transporters or pipeline operators certify that they

meet the conditions of the proposed exclusion for CO2. Only the operator for the Class VI well

should have to certify the conditions of the proposed conditional exclusion for CO2.

The regulations for Class VI wells as well as the DOT regulations under 49 CFR 195 provide

extensive requirements for monitoring, recordkeeping, and reporting. We believe no new

requirements are necessary other than the exclusion certification and compliance with the

conditions set forth.

Response: Regarding the comment that a certification is not necessary for transporters or pipeline 

owners, see Response to Comment 3.2.39.

EPA acknowledges the comment that additional monitoring, recordkeeping, and reporting 

requirements are not necessary under the final conditional exclusion because “regulations for Class 

VI wells as well as the DOT regulations...provide extensive requirements for monitoring, 

recordkeeping and reporting.” 

EPA disagrees with the commenter, however, that only the UIC Class VI well operator need sign a 

certification under the conditional exclusion, and EPA is retaining in the final rule that a

certification from the CO2 generator be signed (where they choose to use the conditional 

exclusion). This is because the generator plays a key role in the transaction of sending the CO2 

stream to the off-site UIC Class VI well (assuming the injection is not on-site). They are most 

knowledgeable about the characteristics of their CO2 stream, they are in the position to arrange for 

delivery of the CO2 stream to a UIC Class VI well, and are also in the position to know whether any 

hazardous waste has been mixed with the CO2 stream while at their facility. These are conditions 

of the exclusion that the generator would be able to confirm have been met, and therefore the 

certification is appropriate.

Comment 3.22.13:

We agree that EOR is outside the scope of this rule. Thanks again for the opportunity to forward 

these comments.

Response: As the commenter notes, issues surrounding EOR itself are outside the scope of this 

rulemaking. 

3.23Chevron

Document ID: EPA-HQ-RCRA-2010-0695-0064

Comment 3.23.1:

Chevron has been in operation for more than 130 years. We are vertically integrated with 

operations that range from oil and gas production to power generation to refining and marketing 

of transportation fuels. We believe that all feasible energy alternatives will be needed for the US 
189

economy to grow and prosper. As reduction of greenhouse gas emissions becomes a governmental 

priority, carbon capture and sequestration (CCS) is one part of a portfolio of emerging energy 

technologies that may help manage carbon in the future. Chevron supports continuing research 

and development of CCS and is participating in many joint industry-government partnerships aimed 

at reducing the cost of carbon dioxide (CO2) capture and doing so in a manner that is protective of 

human health and the environment. 

While we appreciate EPA’s efforts to provide regulatory clarity to the status of CCS under the 

Resource Conservation and Recovery Act (RCRA) by proposing to conditionally exclude CO2 streams 

destined for geologic sequestration from regulation as a “hazardous waste,” we believe that the 

proposal does not go far enough to reduce regulatory uncertainty. The proposed exclusion is 

predicated on a conclusion - which we believe to be inaccurate - that supercritical CO2 being 

sequestered in geologic formations is a “solid waste” because it is being “discarded,” as those 

terms are defined and interpreted under RCRA. We believe this conclusion deviates fundamentally 

from years of RCRA precedent and is at odds with Congressional intent underlying enactment of 

the law.

Response: With respect to the comment, “the proposal does not go far enough to reduce 

regulatory uncertainty” see Response to Comment 3.2.3. 

Regarding the comments that CO2 is not a solid waste, not discarded, and that this conclusion 

deviates from RCRA precedent and Congressional intent, see Responses to Comments 3.2.1, 3.2.2, 

and 3.1.1 through 3.1.8.

Comment 3.23.2:

RCRA was never intended to address continuously emitted gaseous streams such as CO2 even if 

they are captured, condensed and temporarily “contained” in pipelines or other transport 

mechanisms as part of a strategy to prevent their release to the atmosphere. The regulations that 

were developed under RCRA are alien to this technology, and we believe EPA’s attempt to “fit” CCS 

into that existing regulatory paradigm is tantamount to trying to fit a square peg into a round hole. 

For example, the analytical methods that were developed to identify characteristic hazardous 

wastes are not suitable for analysis of gaseous materials, including gases that exist for some 

transient period of time in a supercritical state. Similarly, the RCRA management requirements 

contemplate tangible wastes that can be physically picked up, moved around, placed on the 

ground, treated in treatment systems, or disposed of in landfills. None of these attributes is directly 

applicable to the processing and injection of bulk CO2 streams.

Response: EPA disagrees with the comment; RCRA expressly applies to “solid wastes,” which EPA 

has explained elsewhere includes CO2 streams sent to a UIC Class VI well for purposes of GS. 

EPA also disagrees that the “attributes” of the RCRA regulations cited by the commenter 

necessarily lead to the conclusion that supercritical CO2 cannot be defined as a RCRA statutory solid 

waste or that it cannot be defined as a RCRA hazardous waste. The RCRA regulations apply by their 

terms. As already discussed elsewhere in this comment response document and in the final rule 

preamble, EPA finds that supercritical CO2 streams, when sent to UIC Class VI wells for purposes of 

GS, are not only RCRA “solid wastes,” but also may be RCRA hazardous wastes.

See also Responses to Comments in Section 3.1 of this document.
190

Comment 3.23.3:

In addition, the general custody concepts underlying RCRA are ill-suited to supercritical CO2

transport by pipeline. In this regard, we note that the proposed exclusion would apply at the point 

where a decision is made to send the CO2 to a UIC Class VI well.” [FN1: 76 Fed. Reg. at 48086.] 

However, CO2 streams have multiple purposes including, most notably, use as an enhanced 

recovery fluid in oil and gas operations. Thus, streams from multiple sources, with different 

intended end uses, can be and often are co-managed in a single pipeline system. These gases from 

different sources and with different end uses are miscible, resulting in a regulatory morass if any 

component of the combined stream is viewed as a “solid waste” simply because it is destined for 

geologic sequestration as opposed to enhanced recovery or some other use as a product. EPA’s 

own preamble is replete with examples of the types of problems and uncertainties that will 

inevitably arise.

Response: See responses to comments 3.2.3, 3.2.4., and 3.2.6. 

Comment 3.23.4:

We do not believe that EPA’s offhand comment in Footnote 16 that “the proposed rule is not 

intended to affect the status of CO2 that is injected into wells other than UIC Class VI wells . . . [such 

as] CO2 that is used for enhanced oil or gas recovery,”[FN2: 76 Fed. Reg. at 48078 n. 16.] provides 

the necessary level of assurance to enhanced recovery (ER) [FN3: Enhanced recovery means 

enhanced recovery of hydrocarbons such as oil or natural gas.] operators or other segments of the 

business community that may be using CO2 streams for industrial purposes. In short, Footnote 16 

begs the question as to the regulatory status of CO2 used for purposes other than geologic 

sequestration. Today, ER operators using Class II wells are the largest immediate customers of CO2

capturers and they currently handle CO2 as a valuable product. If CO2 streams are generically 

classified as “solid wastes,”CO2 destined for ER operations would need to be evaluated to 

determine whether it exhibits a characteristic of hazardous waste before it could be shipped to ER 

customers. Conversely, these same capturers would have no such obligation if their CO2 streams 

were destined for Class VI injection well customers. This disparity will surely create regulatory 

confusion and administrative nightmares. And, as the regulatory burdens would be greater for ER

customers, the result may be that capturers would be unwilling to sell to ER customers, adversely 

impacting CO2 supplies to ER customers and thereby undermining both ER and CCS operations.

Response: EPA does not, through this RCRA rulemaking, generically classify as solid wastes CO2

streams destined for EOR/EGR operations. See response to comment 3.2.4.

Comment 3.23.5:

There is a much more straightforward solution to this problem. In our view, EPA should exercise its 

statutory authority to exclude all CO2 streams from classification as a “solid waste” under RCRA. 

Over the years, EPA has adopted many conditional exclusions from the definition of “solid waste” 

where such exclusions make good policy sense and can be implemented without significant risk to 

human health or the environment. This is exactly such a case. Each of EPA’s stated reasons for 

proposing to exclude CO2 streams destined for geological sequestration from regulation as a 

“hazardous waste” is equally applicable to an exclusion from regulation as a “solid waste.” And, the 

same conditions that EPA proposes to attach to the hazardous waste exclusion can be attached to 

the solid waste exclusion and will adequately protect human health and the environment. We 

believe this alternative approach is warranted for the following reasons:
191

*Regulation of CO2 streams, whether in an ambient gaseous or supercritical state, was never 

intended to fall under RCRA and the regulatory framework applicable to management of hazardous 

wastes is not germane to these types of materials.

* Excluding CO2 streams from regulation as a “solid waste” under RCRA will eliminate all 

uncertainty about the potential applicability of RCRA to CCS activities or other uses of CO2 (for 

example, as an enhanced recovery fluid in oil and gas operations), without sacrificing any 

protection of human health and the environment

*For the reasons stated above, we believe that EPA should exclude all CO2 streams as solid waste, 

by enacting the following section as a new § 261.4(a)(26): [FN4: Suggested additions are 

{capitalized}.]

(a) Materials which are not solid wastes.

* * *

(26) CARBON DIOXIDE STREAMS INJECTED FOR ENHANCED RECOVERY OR GEOLOGIC 

SEQUESTRATION. CARBON DIOXIDE STREAMS AS DEFINED IN 40 CFR § 146.81(D) ARE NOT SOLID 

WASTE WHEN CAPTURED AND TRANSPORTED FOR PURPOSES OF INJECTION INTO AN 

UNDERGROUND INJECTION WELL SUBJECT TO THE REQUIREMENTS FOR CLASS II OR 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, PROVIDED THAT THE CO2 STREAM HAS NOT BEEN INTENTIONALLY MIXED WITH 

HAZARDOUS WASTE REGULATED UNDER THIS PART OR OTHERWISE COINJECTED WITH 

HAZARDOUS WASTE UNLESS SPECIFICALLY AUTHORIZED UNDER THE UIC PROGRAM.

We wish to point out that we have purposefully limited the scope of our proposed solid waste 

exclusion to CO2 streams that are used for ER or geologic sequestration, both of which involve 

underground injection. We have limited the exclusion in this manner because we believe CO2

streams that are manufactured and used as products in a myriad of industrial or commercial 

applications cannot be viewed as “solid waste” under any reasonable interpretation of the law. 

Accordingly, we do not believe it is necessary to establish an all-encompassing, generic exclusion 

for CO2 streams, and are focusing on those that are destined for underground injection.

Thank you for this opportunity to provide comments, if you have any questions regarding our 

comments please contact us.

Response: Please see Response to Comment 3.1.1, 3.1.5, 3.1.18 and 3.2.2.

3.24Texas Oil and Gas Association (TxOGA)

Document ID: EPA-HQ-RCRA-2010-0695-0067

Comment 3.24.1:

Texas Oil and Gas Association (TxOGA) is the largest and oldest petroleum organization in Texas, 

representing over 4,500 members. The membership of TxOGA produces in excess of 90 percent of 
192

Texas' crude oil and natural gas, operates nearly 100 percent of the state's refining capacity, and is 

responsible for the vast majority of the state's pipelines. According to the most recent data, the oil 

and gas industry employs 315,000 Texans, providing payroll and benefits of over $30 billion in 

Texas alone. In addition, large associated capital investments by the oil and gas industry generates 

significant secondary economic benefits for Texas. TxOGA member companies produce a quarter of 

the nation's oil, a third of its natural gas and account for one-fourth of the U.S. refining capacity.

We support the comments and recommendations submitted by the American Petroleum Institute 

(API) relating to the Proposed Rule on Hazardous Waste Management System: Identification and 

Listing of Hazardous Waste: Carbon Dioxide Streams in Geologic Sequestration Activities.

Response: EPA acknowledges the comment; please refer to EPA’s responses to API’s comments in 

Section 3.1 of this document.

Comment 3.24.2:

The Clean Air Act provides mechanisms to protect human health and the environment from carbon

dioxide (CO2) streams and the Class VI Underground Injection Control (UIC) rules protect 

underground sources of drinking water from CO2 streams.

As detailed in the API comments, additional Resource Conservation and Recovery Act (RCRA) 

regulation is redundant and we believe it will undermine beneficial uses of CO2 streams for carbon 

capture and sequestration and enhanced recovery. Therefore, we join API in recommending that 

EPA enact an exclusion of all CO2 streams from the RCRA definition of solid waste. Should you have 

any questions concerning these comments please contact me at (see docket for contact 

information).

Response: Please see Responses to Comments 3.1.1 through 3.1.18.

3.25Florida Department of Environmental Protection (DEP)

Document ID: EPA-HQ-RCRA-2010-0695-0059

Comment 3.25.1:

There are numerous wells permitted for carbon sequestration that are not going to be Class VI 

wells but will initiate or continue carbon sequestration under Class I, II, or V (experimental) status.

The only part of this proposed rule that addresses carbon sequestration through wells other than 

Class VI status is a footnote at the bottom of the middle column on p. 48089 of the notice. That 

footnote only states that wells permitted as Class II and Class V experimental can transition to Class 

VI wells. It is appropriate to include any class of well being used for carbon sequestration in this 

proposed rule and not limit it to only Class VI wells. Use of classes other than Class VI will achieve 

the same goal as Class VI wells, namely to remove carbon from potential air pollutants and instead 

sequester it underground. Failure to include other classes of wells leaves the well owner and the 

permitting authority open to legal challenges as to a hazardous waste determination of the carbon 

dioxide.

Response: See response to comment 3.1.11. As the commenter has correctly noted, this 

conditional exclusion only applies to carbon dioxide streams injected into Class VI wells for 

purposes of GS, and only when the conditions of 40 CFR 261.4(h)(1) through (4) are met. While the 
193

requirements for each UIC injection well class address the specific practices and unique risks to 

USDWs posed by a specific well class, the Class VI requirements are tailored to the unique aspects

of carbon dioxide injection for GS (e.g., large CO2 injection volumes, the buoyant and mobile nature 

of the Injectate, etc.) and EPA developed its RCRA conditional exclusion based upon injection in a 

UIC Class VI well. EPA does note that nothing in the conditional exclusion would prevent a Class VI 

well, that had previously transitioned from a Class II well, from being eligible for the RCRA 

conditional exclusion.

3.26Joyce Dillard

Document ID: EPA-HQ-RCRA-2010-0695-0081

Comment 3.26.1:

What are the criteria for Injection wells and related pipelines for solid waste carbon sequestration 

injection such as we have in the City of Los Angeles Terminal Island Renewable Energy Project-Class 

V Experimental?

Methane is a concern, if we are correct. You would want a manifest regarding its transportation 

movement, in case of an explosion.

How are this gas and its related dangerous gases considered without being defined as hazardous 

and appear to be exempt from regulations around the term “hazardous.”

There is a potential market for the gas created via delivery through a pipeline to a neighboring

refinery, as energy.

Dewatering may be a problem and how will that be addressed, if applicable.

Being sequestered in or around faults, what is the effect of an earthquake or natural disaster?

What consideration is being made for heavily populated areas?

As a citizen viewing this, we want that oversight to include our Public Health and Safety concerns.

Response: This commenter has identified the City of Los Angeles Terminal Island Class V 

Experimental Well, and all of their comments appear to be associated with this particular facility, 

which is a biosolids injection well. EPA notes that this well is a Class V Experimental well, and it is 

therefore outside the scope of this rulemaking. EPA further clarifies that while carbon (in situ) 

sequestration is identified in the Class V permit for this facility as an aspect that could be 

quantified, other in situ, quantifiable attributes specific to the permit are identified (e.g., slurry

placement, biodegradation rates, carbon dioxide and methane separation, carbon sequestration 

and saturation in formation brine, free gas migration, commercial methane production potential 

and timeframes). EPA refers this commenter to the appropriate website for regarding this facility, 

including a copy of the permit, related public comments and EPA’s responses, and additional 

information on this facility:

http://www.epa.gov/region9/water/groundwater/uic-permits.html#la. 
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Finally, EPA notes that the requisite Class V injection well requirements can be found at 40 CFR 144 

through 146. However, because of the unique experimental aspects of this permit, requirements 

specific to this permit also include requirements and standards found in Class I (non-hazardous) 

portions of these regulations.

3.27Anonymous 1

Document ID: EPA-HQ-RCRA-2010-0695-0058

Comment 3.27.1:

This proposal generally appears to further the goals of the EPA and promote efficiency within the 

Agency. The implementation of this rule would promote the ability of the EPA to promote human 

health and environmental cleanliness, while simultaneously ensuring that the EPA does not 

overstep its bounds by regulating and monitoring sources of CO2 that do not pose such risks. It thus 

seems beneficial for the EPA to adopt this rule.

Response: EPA acknowledges the comment and is finalizing the rule.

3.28Anonymous 2

Document ID: EPA-HQ-RCRA-2010-0695-0069

Comment 3.28.1:

Regarding the statements on p 48078 (2nd column) that: (1) “CO2 streams are not listed RCRA 

hazardous wastes” but that such streams would be so listed if “mixed with a listed hazardous 

waste” via 261.3(a)[2](iv), and (2) the CO2 streams addressed in this proposal “are not included 

within the Bevill exemption under 261.4(b)(4)”: My understanding of the 261.4(b)(4) “fly ash” 

exclusion is that it is permissible for fuel consisting of up to 50% listed hazardous waste to be 

burned in a qualifying boiler [as per 266.112(a)(1)]. It is also our understanding that, under EPA’s 

261.3(c)(2)(i) “derived-from” rule, any non-Bevill-exempt residuals derived from such burning must 

take on the same listed waste codes as that of the hazardous waste fuel. As a consequence, it 

would appear that condensed CO2 obtained from the burning of the listed hazardous waste fuel 

would be required, under these two EPA provisions, to take on the same listed waste codes as the 

hazardous waste fuel (unless the proposed exclusion were to apply). Am I correct in my analysis 

that, under EPA’s regulations, the condensed CO2 is in fact a “residual” for purposes of EPA’s 

261.3(c)(2)(i) “derived-from” rule? [FN1: Or potentially EPA does not consider the condensed CO2

to be a residual subject to the derived-from rule because it was briefly an uncontained and 

uncontainerized gas and therefore perhaps not a solid waste as defined in RCRA’s 1004-27 (p 

48077, 3rd col of the proposal). Or potentially EPA does not consider the hazardous waste fuel 

components to have partitioned to residuals, analogous to its position for products produced by 

industrial furnaces. (Aug 17, 1988, p 31127)].

Response: The most common CCS scenario contemplated as EPA developed the proposed rule was 

coal-fired power plants (e.g., “While CCS can be applied to a variety of stationary sources of CO2, its 

application to coal-fired power plant emissions offers the greatest potential for GHG reductions.” 

Executive Summary: Report of the Interagency Task Force on Carbon Capture and Storage, August 

2010, p.1). The commenter is requesting that EPA confirm whether any of several interpretations 

(offered by the commenter) of the RCRA hazardous waste regulations correctly apply to a 
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hypothetical scenario. While EPA notes generally that it has authority under RCRA subtitle C (e.g., 

RCRA 3004(n)) to regulate air emissions from the combustion of hazardous waste, EPA lacks 

sufficient information to conclude whether and if so at what point the captured CO2 may or may 

not be designated a listed hazardous waste when listed hazardous waste is part of the boiler fuel. 

The Agency emphasizes that it is not aware of any coal-fired power plants that burn listed 

hazardous waste, and such facilities would be required to have a RCRA hazardous waste boiler 

permit.

3.29Anonymous 3

Document ID: EPA-HQ-RCRA-2010-0695-0070

Comment 3.29.1:

Additional Comment on 8/8/2011 proposed Hazardous Waste Exclusion for sequestered carbon 

dioxide Regarding the statement on p 48078 (3rd col) that the TCLP test method requires the 

measurement of total constituents concentrations (as opposed to measurement of the extract) in 

situations “where wastes are liquids that contain less than 0.5% solids”: It is my understanding that 

such a “totals” analysis would require an analysis of the entire sample including the solids, whereas 

a TCLP analysis would require that the sample first be filtered -- with the filter residue discarded 

and not analyzed -- since the filtered waste “is defined as the TCLP extract.” (Method 1311 at 2.1 

and 7.2.5) This could lead to significantly different analytical results. For example, a sample 

consisting of water and 4999 mg/L silver metal flake would show a “totals” silver concentration of 

4999 ppm, but a TCLP concentration of near zero (depending on the solubility of silver metal in 

water). As a result, I would like to respectfully suggest that the above preamble statement be 

amended to state that a measurement of total constituent concentrations in a waste is required by 

the TCLP test method “WHERE WASTE ARE ENTIRELY LIQUIDS.” Without this amendment, 

generators and regulators could incorrectly classify wastes with less than 0.5% solids (but more 

than 0%) as hazardous waste when in fact they may not be.

Response: EPA clarifies that its description at 76 FR at 48078, cited by the commenter, could have 

been clearer (i.e., EPA should have more clearly indicated that where liquid samples contain less 

than 0.5% solids, the totals analysis is performed on the filtrate, not the unfiltered waste). 

However, EPA notes that this same preamble text contained a footnote to the correct analytical 

method (Part 2.1 of Method 1311), which clearly describes the procedure to which EPA was 

referring. EPA thus clarifies that the totals analysis referred to in the preamble is as described in 

Part 2.1 of the protocol, which calls for totals testing of the filtrate of wastes containing less than 

0.5% solids, and in these instances, the solids are not tested.
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Appendix A: Substantive Data Received from Commenters

Below are tables from Comment Letter EPA-HQ-RCRA-2010-0695-0063 from American 

Electric Power. AEP was the only commenter to provide CO2 stream data with its comment.
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