### This comment letter response contains two parts:

(1) The original submittal from the commenter.

(2) A data base printout of EPA’s response to each point raised by the commenter.

Notes about the response letters:

• The response letters were generated by a data base used to track the content of all public

comment submittals and ensure that the Agency responds to each. Each comment letter

was assigned a Letter ID that corresponds to the last four digits of the docket number of the

original comment (as posted on www.regulations.gov).

• Each response letter includes: comment text; an EPA

‐ assigned comment code; and an

individual response. These are described and explained below.

• The data base contains Comment text from the letters submitted by commenters.

Many hard copy letters were scanned into electronic format for inclusion in the data

base. As a result, there may be some typographical errors attributable to optical

character recognition issues. However, all original submittals were reviewed in the

process of drafting responses to ensure that the comment content was understood and

appropriately addressed.

• The content of each comment letter was divided into topic areas and assigned a unique

Comment ID. Additionally, one or more Comment Codes (i.e., unique topic area ID) was

assigned to each discrete point raised by a commenter. This information was added to

the data base. To inform final rulemaking decisions, all comments and information

received on a given topic were reviewed by technical experts in each rule area (e.g., on

construction requirements).

• Following decisions on the final rule requirements, Individual responses were drafted

by topic area to ensure completeness and consistency of the responses with the final

rule and other responses to similar comments. Each discrete point made by a

commenter was given a unique response.

• Upon completion of comment responses, all information was entered into the data base.

Each letter response is a compilation of each comment and its individual response,

compiled in the order of the original comment letter. As a result of this process, there is

repetition in the response text. The Agency believes this approach ensures completeness

and attention to each comment letter that was submitted.

• All comments in a topic area were reviewed, evaluated, and responded to concurrently.

Responses on each topic area are compiled and are also available in the rulemaking docket.

## BEFORE THE UNI TED STATES

ENVIRONMENTAL PROTECTION AGENCY

________________________________________ )

Federal Requirements Under the )

Underground Injection Control (U IC) Program ) EPA-HQ-OW-2008-0390

for Carbon Dioxide (CO 2 

### ) ) FRL-8951-3

Geologic Sequestration (GS) Wells; ) RIN 2040–AE98

Notice of Data Availability and )

Request for Comment )

)

)

74 Fed. Reg. 44802 (August 31, 2009) )

___________________________________________)



## Comments of:

Clean Air Task Force

Environmental Defense Fund

Natural Resources Defense Council

A. Introduction

The Clean Air Task Force, Environmental Defense Fund and the Natural Resources Defense

Council thank the United States Environmental Pr otection Agency (EPA) for the opportunity to

comment on the Notice of Data Availability under the Underg round Injection Control (UIC)

Program for Carbon Dioxide (CO 2 

### ) Geologic Sequestration Wells.

Founded in 1996, the Clean Air Task Force (CATF) is a nonprofit organization dedicated to

restoring clean air and healthy environments th rough scientific research, public education, and

legal advocacy

.

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

innovative, equitable and cost-e ffective solutions to society’ s most urgent environmental

problems.

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.

### Our organizations continue to believe str ongly that geologic sequestration of CO 2 

### (GS), correctly

implemented, must be a component of the U.S. climate mitigation portfolio. For that reason, we

continue to stress the importance of the curr ent rulemaking and the timely promulgation of a

sound rule, as we stated in our joint co mments of December 2008 and June 26, 2009. We

reiterate the need for EPA to (1) address the question of atmospheric emissions of CO 2 

### as well as

protection of underground sources of dr inking water related to underground CO 2 

### injection

without delaying promulgation of the pending rule, (2) create a regulatory framework for

geologic sequestration, governing not only geologic sequestration in saline reservoirs, but also in

oil & gas reservoirs, and (3) expeditiously deve lop airside accounting, m onitoring and reporting

provisions for injected CO 2



### . 1 

### We are somewhat encouraged by EPA’s statements in this NODA

that it is “evaluating the need for a more comp rehensive regulatory framework to provide legal

guidance,” and that it will take comment on and “endeavor to issue a more comprehensive rule in

the same time frame” as the final rule in this docket. 2 

### Our organizations anticipate the

opportunity to provide input to the Agency when such a rule is proposed. However, EPA’s good

intentions do not obviate the need for the Agen cy to add a clear statement of Clean Air Act

authority when it finalizes this rule, as we ha ve noted in our earlier comments is necessary.



## B. Definitions in the NODA

1. Definition of Class VI well as proposed doe s not “preclude” or prohibit injection into

basalts, coal seams, salt caverns and shal es, and GS in such formations should be

excluded from Class VI at this time

EPA mistakenly asserts that the definition of a Class VI well “[a]s proposed, ... would ...

preclude the injection of CO 2 

### into shallow formations such as coal seams and basalts.” 3 

### In fact,

the definition of a Class VI well as proposed only states that a Class VI well is one “used for

geologic sequestration of carbon dioxide beneath the lowermos t formation containing an

underground source of dr inking water (USDW).” 4 

### As basalts and coal seams can be found in

areas beneath the lowermost US DW, or in areas where there is no USDW, this definition

actually does not preclude or prohib it injection into basalts or coal seams, shallow or otherwise.

A more important point, however, and one raised in both our earlier comments and today’s

comments, is that an affirmative prohibition on th e inclusion of basalts, coal seams, salt caverns

and shales in Class VI is warr anted based on the state of the science at present. EPA should

adopt regulatory language containing such a prohibition. 5 

### Such language need not be added to

the definition of a Class VI well, but it is not su fficient simply to assert in a preamble that the

current language preclude such injection. Experime ntation with GS in basalts, coal seams, salt

caverns and shales should continue u nder Class V for the foreseeable future.

1 For further details, refer to our letter of Jun26, 2009 to Administrator Jackson.

2 74 Fed. Reg, at 44805; see also Final Rule, Mandatory Reporting of Greenhouse Gases,

EPA-HQ-OAR-2008-0508, RIN 2060-A079, as signed, at 480-481 (Sept. 23, 2009).

3 74 Fed. Reg. 44808.

4 73 Fed. Reg. at 43535.

5 Also refer to Multi-Stakeholder Group letter of May14. 20 09, which supported the exclusion of GS in basalts, coal

seams, salt caverns, and shales from Class VI.



### 2

### 2. Other “Definitions” in the NODA

EPA has not proposed changes, in the NODA, to any of the regulatory la nguage included in the

Notice of Proposed Rulemaking. Therefore, we a ssume that the “definitions” included in the

NODA are meant for clarity only, and do not indicate any intention by the Agency to change

those definitions. Unfortunately cl arity is not always achieved: we note particularly the new

definition of “carbon capture and storage” 6 

### which is not found in the proposed regulatory text

and confusingly includes the word “storage” rather than “sequestration” making it inconsistent

with the regulatory text as proposed, as we ll as other definitions set out in the NODA.

In addition, we refer EPA to our previous joint comments of December 2008 and the MultiStakeholder Group letter of May 14, 2009 for sp ecific recommendations on regulatory language

changes to the proposed definitions.

“ Carbon dioxide stream means carbon dioxide plus incidental associated

substances derived from the source of the CO 2 

### and/or the capture process, and any

substances added to the stream to enable or improve the injection process. This

subpart does not apply to a ny carbon dioxide stream that meets the definition of a

hazardous waste under 40 CFR part 261.”

“Confining zone means a geological formation, group of formations, or part of a

formation that is capable of limiting flui d movement from an injection zone.”

“ Sequestration project [...] It includes the subsurface three-dimensional extent of

the carbon dioxide plume, associated pr essure front, and displaced formation

fluids, as well as the surface area above that delineated region.”

“ Geologic sequestration project means an injection well or wells used to emplace

a carbon dioxide stream into an injec tion zone for geologic sequestration.

“ Transmissive fault or fracture means a fault or fracture that has sufficient

permeability and vertical extent to allow fluids to move beyond a confining

zone.”

“

Area of review means the subsurface three-dimensional extent of the carbon

dioxide stream plume and the associated pressure front, as well as the overlying

formations, any USDWs underlying an inj ection zone along with any intervening

formations, and the surface area above that delineated region.”



## C. Research, Data Analysis and Findings

We agree with EPA that the Agency should continue to make available the results of studies and

data coming out of the Department of Energy (DOE) Regional Carbon Sequestration

6 74 Fed. Reg. 44803.



### 3

### Partnerships, and other research efforts, and that this data can inform the Agency’s rulemaking

effort now, and going forward. The Safe Drinking Water Act as it a pplies to the proposed Class

VI expressly mandates the incorpor ation of any amendments to the federal regulations into state

programs. This process will allow the results of future study (including this research) to be

incorporated into state Class VI programs over time. 7 

### Such an adaptive approach to regulating

means the results of this research can be incor porated in a revised regulatory framework. This

consideration, combined with the abundant scientific evidence al ready considered by EPA in the

development of this proposal, means that EPA need not wait for the completion of the DOE

program before finalizing this rule.

We provide below specific thoughts about research results and progress described by the Agency

in the NODA.

1. Regional Partnerships Data

EPA notes that the DOE Southwestern Regi onal Partnership site at Pump Canyon, near

Archuleta, New Mexico, “will inform a determination on whether CO 2 

### can be effectively and

safely sequestered in coal seams.” 8 

### The results of this proj ect are pending and given the

quantities injected it is unclear to us that this particular project will determine the techniques, if

any, that might establish commercial-scale coal seam GS as a safe and effective option. We

reiterate our concern expressed in our original comments, that at this time coal seams and basalt

formations, wherever located, should not be co nsidered appropriate fo rmations for GS under

Class VI.

2. LBNL Study of Ground Water Quality Changes Related to the Mobilization of Trace

Elements, If CO 2 

### Leakage is Assumed to Occur

We agree with EPA that it is important to r ecognize that these studies describe what happens if

one assumes that CO 2 

### leaks. The studies do not describe or model the risks of actual CO 2 

### leakage, nor should their results be taken as sup porting the idea that there is high risk of such

leakage. The LBNL study described in the NODA investigated trace element geochemical

changes in “representative” potable aquifers under the assumption of leaked CO2, which does

not represent the expected result of CO 2 

### injection at large scale. We agree with EPA that the goal

of the UIC program and these regula tions is to ensure that the ri sk of such leakage into USDWs

is low.

The results of the LBNL study to date suggest that UIC Class VI permits must be based on

submitted information that is sufficient to esta blish whether the AOR contains a high or low

hazard trace element leaching environment. Sp ecifically, the LBNL study of the fate and

transport of trace elements highlights the need fo r geochemical screening of reservoir rock in

potential GS sites. In the case of forma tions characterized by hazardous trace element

mineralogy where brine leaching could result in pore water that contains trace elements

exceeding the maximum contaminant levels (MCLs) and Action Levels (ALs), EPA must ensure

that the rule language results in the issuance of permits that take into account the potentially

7 42 U.S.C. § 300h(b)(1)(B).

8 74 Fed. Reg. 44806.



### 4

### higher risks involved. In particular, the rule should ensure that perm its issued in th is context will

require both baseline geochemical studies and monitoring of any geochemical changes above and

below the confining zone.

3. LBNL Study of Basin-Scal e Hydrologic Impacts of CO 2 

### Sequestration

The results of the 2008 LBNL study of basin-scale hydrologic impacts of CO 2 

### sequestration 9



### highlighted in the NODA, 10 

### demonstrate the potential for interference of far-field pressures in

large-scale GS deployment. Although we do not in terpret the interference and pressure effects

described in the study as “significant” compared to injection or formation pressures, these results

underscore the importance of sound basin-scale ma nagement practices, and the need for a noninterference principle to be adhered to during the early years of GS activity, until greater

proficiency in basin-scale management is gained. 11



## D. CO 2 

## Injection Above the Lowermos t Formation Containing a USDW

and Other Issues

1. Injection into coal seams and basalts

As noted above, the currently pr oposed definition of a Class VI well confines GS to geologic

formations located below the lowermost USDW. 12 

### While EPA asserts that “as proposed, the

definition would also preclude injection of CO 2 

### into shallow formations such as coal seams and

basalts,” in fact that is not the case. First, USDWs do not exist everywhere, and there may be

shallow coal seams and basalts in areas where there is not USDW. Sec ond, shallow basalts and

coal seams may be located below the lowermost USDW. We continue to a ssert that the Agency

should prohibit Class VI wells in basalts, coal seams, salt ca verns and shales regardless of

injection depth.

As we noted in our December comments: 13 

### there is no significant prior experience or consensus

on how to assess and manage risks, what data is needed to characte rize sites, how to select sites,

how to conduct and manage injection opera tions, how to model the behavior of CO 2 

### , and how to

monitor project performance of CO 2 

### sequestration in basalts, coal seams, salt caverns and shales.

The trapping mechanisms of CO 2 

### and/or the operationa l engineering involved in such operations

is significantly different from those in deep saline formations and hydrocarbon reservoirs. We

simply do not know at this time whether sequestra tion (or even injection in some cases) can even

be done at scale in such formations.

Due to this fundamentally different nature of GS in these formations, if EPA decides not to

explicitly prohibit Class VI wells in such format ions, it must provide subs tantial evidence of the

scientific basis on which it bases its belief that the physical processes, operational engineering,

9 Not “storage” – LBNL did not assume that the CO 2 could or will be released in the future.

10 74 Fed. Reg. 44808.

11 Also refer to Multi-Stakeholder Group letter of May14. 2009, which supported the incl usion of a non-interference

principle.

12 See proposed 40 C.F.R. §§ 144.6(f), 144.80(f) 146.5(f). at 73 Fed. Reg. 43534-43535.

13 Joint Environmental Group Comments at 11 (Dec. 24, 2008).



### 5

### and risks involved are similar to and/or equally mature as those in saline formations or oil/gas

reservoirs. We believe that such a demonstratio n is important both as a policy matter and a legal

matter.

We reassert that until there is better unders tanding of whether and how sequestration can be

safely accomplished in basalts, coal seams, salt caverns and shales, wells in these formations

should be treated as experimental and regulated under UIC Class V.

2. CO 2 

### Sequestration Should be Allowed Above the Lowermost USDW, But Only Where

the Geology is Sufficiently Protective, and the Permit Contains Adequate Requirements

EPA seeks comment on the alternative idea of a “w aiver” process, wherei n the Director might

grant site-specific exemptions from the gene ral prohibition on injection above the lowermost

USDW. We support this idea generally. As we describe d in our comments on the NOPR, 14 

### GS

reservoirs located above lowermost USDWs may or may not present additional risks than sites

located below the lowermost USDWs, and estab lishing safe and effective siting and operations

should be based on additional consid erations. At the same time, we recognize that there are many

potentially excellent sequestratio n sites above USDWs, and that in some areas of the country,

these may be the only sites available.

For that reason, we continue to assert that if CO 2 

### injection is permitted above the lowermost

USDW, the regulations allo wing such injection must require (in addition to the information EPA

asserts the Director would consider in evaluating a waiver application): 15



### • confirmation that there are laterally continuous, impermeable confining units above and

below the injection zone adequate to pr event fluid movement and pressure buildup

• identification of other wells in the area; and

• monitoring for changes in groundwater ch emistry above the upper confining zone and

below the lower confining zone.

EPA should also require, in appropriate circum stances, prior to permit issuance, completion of

regional hydrogeologic studies th at are conducted with sufficient accuracy to simulate regional

hydrologic flows and demonstrate th at USDWs would not be endangered if injected or formation

fluids were to move beyond either th e higher or the lower confining zone.

Before finalizing regulatory language on a waiv er process to allow injection above the

lowermost USDW, EPA should inves tigate and address the potential need for protection against

water wells, or wells of any other type th at may bisect pressurized GS reservoirs.

3. Distinction between Class VI and other wells

We commend EPA for recognizing that in the NODA th at “it is necessary to address the specific,

unique characteristics of Class VI injection (e.g., large injection volumes, viscosity, and

buoyancy) and the Agency does not have informati on or data indicating that Class II operations

14 Id. at 12.

15 74 Fed. Reg. at 44811.



### 6

### 7 are entirely analogous to Class VI, large-scale injection, this alternative allows Class VI injection

depth considerations to be tailored for GS. A number of dominant differences between Class II

and Class VI operations indicat e that these well classes warra nt different treatment. These

differences include: the risk profiles for these op erations; the greater total injection volumes (of

CO 2 

### ) for Class VI GS; and, differences in forma tion pressures (potentially higher for GS),

greater opportunities for mobilization of constituents, and injection rates and operating

conditions.” 16 

### This is of significance as the Agency considers how to regulate GS in oil/gas

reservoirs.

In addition, however, given the relative similarity between GS in saline formations and oil/gas

reservoirs in comparison to GS in coal seams, basalts, salt caverns and sh ales, we are puzzled by

the Agency’s omission in including a similar co mparison of risk profiles between saline and

basalts, coal seams, salt caverns and shales. We therefore reitera te our points above regarding GS

in such formations.



## E. Conclusion

Our organizations appreciate the opportunity to provide comments to EPA on this most

important rulemaking effort. A final rule will re present a significant step forward in combating

global climate change, and the time is more than ri pe for the U.S. to take such steps. When EPA

issues its final rule, we feel it must be both te chnically sound and adaptiv e to reflect learning

from experience with GS projects in as seamless a manner as is possible. We very much look

forward to continuing to work w ith the Agency on this rule, as well as other efforts under the

Agency’s existing authority to address the signif icant problem of climate change in the near

term.

Respectfully submitted on Oct15, 2009,

Scott Anderson, Environmental Defense Fund

44 East Ave, Suite 304, Austin, TX 78701, 512-691-3410, sanderson@edf.org

Ann Brewster Weeks, Clean Air Task Force

18 Tremont St, Suite 530, Boston, MA 02108, 617-624-0234, aweeks@catf.us

George Peridas, Natural Resources Defense Council

111 Sutter St, 20 th 

### Floor, San Francisco, CA 94104, 415-875-6181, gperidas@nrdc.org

16 74 Fed.Reg. 44810.Letter ID: 0376

Commenter: Scott Anderson

Organization: Environmental Defense Fund (EDF)

Letter ID: 0376 Comment ID: 28164 Letter Lines: 46 to 57

Comment Code: 6000 6. Other Comments that are Out of Scope for the NODA

Comment: Our organizations continue to believe strongly that geologic sequestration of

CO2 (GS), correctly implemented, must be a component of the U.S. climate

mitigation portfolio. For that reason, we continue to stress the importance of

the current rulemaking and the timely promulgation of a sound rule, as we stated

in our joint comments of December 2008 and June 26, 2009. We reiterate the need

for EPA to (1) address the question of atmospheric emissions of CO2 as well as

protection of underground sources of drinking water related to underground CO2

injection without delaying promulgation of the pending rule, (2) create a

regulatory framework for geologic sequestration, governing not only geologic

sequestration in saline reservoirs, but also in oil & gas reservoirs, and (3)

expeditiously develop airside accounting, monitoring and reporting provisions

for injected CO2 [FOOTNOTE 1]. We are somewhat encouraged by EPA’s statements

Individual Response: This comment pertains to EPA’s proposed GS rule (73 FR 43492) and is outside the

scope of the Notice of Data Availability. Please see responses to comments on the proposed rule for

EPA’s response to similar comments.

In addition, portions of this comment are outside the scope of the Notice of Data Availability and the UIC

Program’s authority under the GS rulemaking.

Letter ID: 0376 Comment ID: 28165 Letter Lines: 57 to 72

Comment Code: 1100 1.1 Comments on the Comprehensive Approach

Comment: for injected CO2 [FOOTNOTE 1]. We are somewhat encouraged by EPA’s statements

in this NODA that it is "evaluating the need for a more comprehensive regulatory

framework to provide legal guidance," and that it will take comment on and

"endeavor to issue a more comprehensive rule in the same time frame" as the

final rule in this docket. [FOOTNOTE 2] Our organizations anticipate the

opportunity to provide input to the Agency when such a rule is proposed.However, EPA’s good intentions do not obviate the need for the Agency to add a

clear statement of Clean Air Act authority when it finalizes this rule, as we

have noted in our earlier comments is necessary.

FOOTNOTE 1

‐ For further details, refer to our letter of Jun 26, 2009 to

Administrator Jackson.

FOOTNOTE 2

‐ 74 Fed. Reg, at 44805; see also Final Rule, Mandatory Reporting of

Greenhouse Gases, EPA

‐ HQ

‐ OAR

‐ 2008

‐ 0508, RIN 2060

‐ A079, as signed, at 480

‐ 481

(Sept. 23, 2009).

Individual Response: EPA acknowledges that GS falls within the broader context of CCS and the need for

regulatory clarity to ensure that USDWs are protected from endangerment. In developing the final GS

rule, the Office of Water coordinated with other Agency program offices and across federal agencies

(e.g., with the Department of Energy; United States Geological Survey; Bureau of Ocean Energy

Management, Regulation, and Enforcement, formerly the Minerals Management Service; Bureau of

Land Management). The Agency continues to evaluate areas of potential applicability of other Federal

environmental statutes including, but not limited to: the Clean Air Act; the Resource Conservation and

Recovery Act; the Comprehensive Environmental Response, Compensation, and Liability Act; and the

Marine Protection, Research and Sanctuaries Act to various aspects of GS and CCS. The Agency will

continue to coordinate on GS and CCS related issues to minimize redundancy and maximize efficiencies

for owners or operators. For additional information, please see the discussion entitled "How Does This

Rulemaking Relate to Other Federal Authorities and GS and CCS Activities?" in the preamble to the final

GS rule.

The Agency further clarifies that comments on the Greenhouse Gas Reporting Rule for CO2 Injection and

Geologic Sequestration (40 CFR 98), issued under the authority of the CAA in a separate rulemaking

action are out of the scope of the GS NODA. For additional information, see the responses to comments

on the proposed GHG rule in the rulemaking docket for that rule.

Letter ID: 0376 Comment ID: 28166 Letter Lines: 74 to 92

Comment Code: 3410 3.4.1. Applicability of Waiver Process to Deep Saline and Other Types of

Formations (seeking comment)

Comment: B. Definitions in the NODA

1. Definition of Class VI well as proposed does not "preclude" or prohibit

injection into basalts, coal seams, salt caverns and shales, and GS in such

formations should be excluded from Class VI at this timeEPA mistakenly asserts that the definition of a Class VI well }[a]s proposed,

... would

... preclude the injection of CO2 into shallow formations such as coal

seams and basalts." [FOOTNOTE 3] In fact, the definition of a Class VI well as

proposed only states that a Class VI well is one “used for geologic

sequestration of carbon dioxide beneath the lowermost formation containing an

underground source of drinking water (USDW). [FOOTNOTE 4] As basalts and coal

seams can be found in areas beneath the lowermost USDW, or in areas where there

is no USDW, this definition actually does not preclude or prohibit injection

into basalts or coal seams, shallow or otherwise.

FOOTNOTE 3

‐ 74 Fed. Reg. 44808.

FOOTNOTE 4

‐ 73 Fed. Reg. at 43535.

Individual Response: EPA agrees and clarifies that the rule does not preclude injection into coal seams

or basalts. EPA believes that the requirements that allow owners or operators to seek waivers from the

injection depth requirements at §146.95, along with proper siting, well construction, operation,

monitoring, and post

‐ injection site care pursuant to the GS rule requirements will ensure USDW

protection.

Letter ID: 0376 Comment ID: 28167 Letter Lines: 94 to 106

Comment Code: 3410 3.4.1. Applicability of Waiver Process to Deep Saline and Other Types of

Formations (seeking comment)

Comment: A more important point, however, and one raised in both our earlier comments and

today’s comments, is that an affirmative prohibition on the inclusion of

basalts, coal seams, salt caverns and shales in Class VI is warranted based on

the state of the science at present. EPA should adopt regulatory language

containing such a prohibition. [FOOTNOTE 5] Such language need not be added to the

definition of a Class VI well, but it is not sufficient simply to assert in a

preamble that the current language preclude such injection. Experimentation

with GS in basalts, coal seams, salt caverns and shales should continue under

Class V for the foreseeable future.

FOOTNOTE 5

‐ Also refer to Multi

‐ Stakeholder Group letter of May 14. 2009, which

supported the exclusion of GS in basalts, coal seams, salt caverns, and shales

from Class VI.Individual Response: EPA disagrees that categorically precluding or prohibiting injection into any type of

formation is appropriate. Instead, construction and operation of a Class VI well for injection into

shallower formations can be permitted if an owner or operator can demonstrate, pursuant to the

requirements at §146.95, that injection can be performed in a manner that protects USDWs and if the

owner or operator meets the other protective requirements at §146.82 through §146.94. EPA believes

that the injection depth waiver requirements at §146.95, along with proper siting, well construction,

operation, monitoring, and post

‐ injection site care pursuant to the GS rule requirements will ensure

USDW protection.

EPA recognizes that some types of formations, such as coal seams and basalts, are typically shallow and

above the lowermost USDW. The Agency expects that injection for GS into these shallow formations can

be issued waivers and permitted as Class VI wells, provided their owners or operators can meet all of the

requirements at §146.95 and demonstrate that such injection can be performed in a manner that

protects USDWs.

EPA recognizes that it may be appropriate to conduct injection into certain formation types (e.g., in

basalts, coal seams, salt caverns, and shales) on a small scale as experimental projects; such wells could

be permitted as Class V experimental technology wells. To facilitate experimental injection for GS and to

increase global understanding of injection into these formation types, the Agency is preparing an

addendum to the Class V experimental technology guidance on wells that meet the criteria. The decision

about whether a well should be permitted as a Class V experimental technology well or a Class VI well

will be site

‐ specific and depend on the nature of the project.

Letter ID: 0376 Comment ID: 28168 Letter Lines: 110 to 149

Comment Code: 1000 1. General Comments on the Notice of Data Availability

Comment: EPA has not proposed changes, in the NODA, to any of the regulatory language

included in the Notice of Proposed Rulemaking. Therefore, we assume that the

"definitions' included in the NODA are meant for clarity only, and do not

indicate any intention by the Agency to change those definitions. Unfortunately

clarity is not always achieved: we note particularly the new definition of

"carbon capture and storage" [FOOTNOTE 6] which is not found in the proposed

regulatory text and confusingly includes the word "storage" rather than

"sequestration" making it inconsistent with the regulatory text as proposed, as

well as other definitions set out in the NODA.

FOOTNOTE 6

‐ 74 Fed. Reg. 44803.

In addition, we refer EPA to our previous joint comments of December 2008 andthe Multi

‐ Stakeholder Group letter of May 14, 2009 for specific recommendations

on regulatory language changes to the proposed definitions.

"Carbon dioxide stream means carbon dioxide plus incidental associated

substances derived from the source of the CO2 and/or 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."

"Confining zone means a geological formation, group of formations, or part of a

formation that is capable of limiting fluid movement from an injection zone."

"Sequestration project [...] It includes the subsurface three

‐ dimensional extent of

the carbon dioxide plume, associated pressure front, and displaced formation

fluids, as well as the surface area above that delineated region."

"Geologic sequestration project means an injection well or wells used to emplace

a carbon dioxide stream into an injection zone for geologic sequestration."

"Transmissive fault or fracture means a fault or fracture that has sufficient

permeability and vertical extent to allow fluids to move beyond a confining

zone."

"Area of review means the subsurface three

‐ dimensional extent of the carbon

dioxide stream plume and the associated pressure front, as well as the overlying

formations, any USDWs underlying an injection zone along with any intervening

formations, and the surface area above that delineated region."

Individual Response: EPA did not include a definition for carbon capture and storage in the proposed or

final GS rule, although, the final GS rule includes some revised definitions in response to public

comments. The definitions, including the definition of a GS project, can be found at 40 CFR 146.81(d).

For details on specific definitions, see the responses to comments on the proposed rule in the

rulemaking docket.

Letter ID: 0376 Comment ID: 28169 Letter Lines: 151 to 170

Comment Code: 2100 2.1 DOE Regional Carbon Sequestration Partnership Projects

Comment: C. Research, Data Analysis and FindingsWe agree with EPA that the Agency should continue to make available the results

of studies and data coming out of the Department of Energy (DOE) Regional Carbon

Sequestration Partnerships, and other research efforts, and that this data can

inform the Agency’s rulemaking effort now, and going forward. The Safe Drinking

Water Act as it applies to the proposed Class VI expressly mandates the

incorporation of any amendments to the federal regulations into state programs.

This process will allow the results of future study (including this research) to

be incorporated into state Class VI programs over time. [FOOTNOTE 7] Such an

adaptive approach to regulating means the results of this research can be

incorporated in a revised regulatory framework. This consideration, combined

with the abundant scientific evidence already considered by EPA in the

development of this proposal, means that EPA need not wait for the completion of

the DOE program before finalizing this rule.

FOOTNOTE 7

‐ 42 U.S.C. §300h(b)(1)(B).

We provide below specific thoughts about research results and progress described

by the Agency in the NODA.

Individual Response: EPA agrees that the monitoring and publication of results of the RCSP projects in

combination with an adaptive approach to the rule is the best way to ensure protection of USDWs while

keeping up with ongoing research developments. EPA believes that the projects have provided new and

beneficial information. The state of knowledge regarding site characterization, plume monitoring, leak

detection, and plume modeling have all been advanced because of these studies; as such they have

informed the GS rule development.

EPA is using an adaptive approach to regulating CO2 injection for GS. EPA plans, every six years, to

collect and review data on GS projects to determine whether the appropriate amount and types of

information and appropriate documentation are being collected, and to determine if modifications to

the requirements are appropriate or necessary.

Letter ID: 0376 Comment ID: 28170 Letter Lines: 172 to 184

Comment Code: 2130 2.1.3. SWP (Pump Canyon, NM)

Comment: 1. Regional Partnerships Data

EPA notes that the DOE Southwestern Regional Partnership site at Pump Canyon,

near Archuleta, New Mexico, "will inform a determination on whether CO2 can be

effectively and safely sequestered in coal seams." [FOOTNOTE 8] The results ofthis project are pending and given the quantities injected it is unclear to us

that this particular project will determine the techniques, if any, that might

establish commercial

‐ scale coal seam GS as a safe and effective option. We

reiterate our concern expressed in our original comments, that at this time coal

seams and basalt formations, wherever located, should not be considered

appropriate formations for GS under Class VI.

FOOTNOTE 8

‐ 74 Fed. Reg. 44806.

Individual Response: EPA acknowledges concerns with ECBM and basalt projects but believes that it

may be possible to safely utilize these types of formations for GS. The RCSP projects have contributed to

the state of knowledge about injection into coal seams and basalts for GS, e.g., to determine under what

conditions such projects can be achieved safely. While the Archuleta project is a small volume

demonstration, other projects will use larger volumes if this project succeeds.

EPA does not intend to ban ECBM projects. In the final GS rule, GS into unmineable coal seams will be

allowed, provided the owner or operator can demonstrate that GS at the site can be performed without

endangering USDWs. Owners or operators of unmineable coal seam projects will be subject to the same

site characterization requirements (at §146.82) as those required of other projects.

Letter ID: 0376 Comment ID: 28171 Letter Lines: 186 to 210

Comment Code: 2210 2.2.1. Groundwater Quality and Mobilization of Trace Elements (seeking

comment)

Comment: 2. LBNL Study of Ground Water Quality Changes Related to the Mobilization of

Trace Elements, If CO2 Leakage is Assumed to Occur

We agree with EPA that it is important to recognize that these studies describe

what happens if one assumes that CO2 leaks. The studies do not describe or

model the risks of actual CO2 leakage, nor should their results be taken as

supporting the idea that there is high risk of such leakage. The LBNL study

described in the NODA investigated trace element geochemical changes in

"representative" potable aquifers under the assumption of leaked CO2, which does

not represent the expected result of CO2 injection at large scale. We agree with

EPA that the goal of the UIC program and these regulations is to ensure that the

risk of such leakage into USDWs is low.

The results of the LBNL study to date suggest that UIC Class VI permits must be

based on submitted information that is sufficient to establish whether the AORcontains a high or low hazard trace element leaching environment. Specifically,

the LBNL study of the fate and transport of trace elements highlights the need

for geochemical screening of reservoir rock in potential GS sites. In the case

of formations characterized by hazardous trace element mineralogy where brine

leaching could result in pore water that contains trace elements exceeding the

maximum contaminant levels (MCLs) and Action Levels (ALs), EPA must ensure that

the rule language results in the issuance of permits that take into account the

potentially higher risks involved. In particular, the rule should ensure that

permits issued in this context will require both baseline geochemical studies

and monitoring of any geochemical changes above and below the confining zone.

Individual Response: EPA agrees that LBNL’s study should not be taken as supporting the idea that there

is high risk of leakage and contamination of USDWs from GS activities. It is mentioned in the NODA that

the risk of fluids leaking from deep storage is low for properly managed GS projects, but it may not be

completely ruled out. Site specific risk analyses should be undertaken in order to determine the

probability of CO2 (and associated formation fluids) leaking from the storage reservoir.

EPA agrees that geochemical screening of reservoir rock in potential GS sites, as well as screening of

overlying USDW geochemistry, should be part of GS site characterization. For this reason, all GS project

owner or operators must submit detailed, site

‐ specific information about a proposed GS site, including

information on the porosity, permeability, mineralogy, and geochemistry of the targeted injection and

confining zones as well as all USDWs within the AoR. Operators must also present information on the

compatibility of the CO2 stream with fluids in the injection zone and minerals in the injection and

confining zones (§146.82(c)(3)). The data can help the Director determine the potential for geochemical

reactions between the injectate (CO2) and the host geologic formations. For additional information on

EPA’s approach to site characterization for GS wells, see the responses to comments on the proposed

rule in the rulemaking docket.

Letter ID: 0376 Comment ID: 28172 Letter Lines: 212 to 230

Comment Code: 2220 2.2.2. Basin

‐ Scale Hydrologic Impacts of CO2 Storage (seeking comment)

Comment: 3. LBNL Study of Basin

‐ Scale Hydrologic Impacts of CO2 Sequestration

The results of the 2008 LBNL study of basin

‐ scale hydrologic impacts of CO2

sequestration [FOOTNOTE 9] highlighted in the NODA, [FOOTNOTE 10] demonstrate

the potential for interference of far

‐ field pressures in large

‐ scale GS

deployment. Although we do not interpret the interference and pressure effects

described in the study as "significant" compared to injection or formation

pressures, these results underscore the importance of sound basin

‐ scalemanagement practices, and the need for a non ‐ interference principle to be

adhered to during the early years of GS activity, until greater proficiency in

basin

‐ scale management is gained. [FOOTNOTE 11]

FOOTNOTE 9

‐ Not "storage"

‐ LBNL did not assume that the CO2 could or will be

released in the future.

FOOTNOTE 10

‐ 74 Fed. Reg. 44808.

FOOTNOTE 11

‐ Also refer to Multi

‐ Stakeholder Group letter of May14. 2009, which

supported the inclusion of a non

‐ interference principle.

Individual Response: The final GS rule focuses on permitting of individual GS wells and therefore does

not include requirements for basin

‐ scale evaluations. However, EPA agrees that proactive management

of basin scale concerns to maintain pressures within acceptable ranges is important, and encourages

owners or operators and permitting authorities to communicate planned GS activities to maximize

coordination and minimize pressure interference. If a permit applicant (or the permitting authority) is

aware of pending GS projects near a proposed well, the AoR delineation performed pursuant to §146.84

should account for the impacts of multiple owners and operators injecting within a single basin. EPA

anticipates that, where multiple operators are involved, the Director would not approve modeling that

does not account for changes that may result from all injection operations. The proximity of injection

sites to each other and the relative timing of each injection operation might indicate a possible increase

in risk for the containment of the total CO2 and/or the effects of hydraulic perturbations and brine

displacement.

EPA adds that if any new GS projects are permitted within the AoR of a GS project between AoR

evaluations, the AoR reevaluation would need to address such projects. EPA also expects that the

permitting of the newer GS project would have considered the presence of an project. For additional

information regarding EPA’s requirements for AoR delineation for GS projects, see the responses to

comments on the proposed rule in the rulemaking docket.

Letter ID: 0376 Comment ID: 28173 Letter Lines: 232 to 273

Comment Code: 3410 3.4.1. Applicability of Waiver Process to Deep Saline and Other Types of

Formations (seeking comment)

Comment: D. CO2 Injection Above the Lowermost Formation Containing a USDW and Other Issues

1. Injection into coal seams and basaltsAs noted above, the currently proposed definition of a Class VI well confines GS

to geologic formations located below the lowermost USDW. [FOOTNOTE 12] While

EPA asserts that "as proposed, the definition would also preclude injection of

CO2 into shallow formations such as coal seams and basalts," in fact that is

not the case. First, USDWs do not exist everywhere, and there may be shallow

coal seams and basalts in areas where there is not USDW. Second, shallow basalts

and coal seams may be located below the lowermost USDW. We continue to assert

that the Agency should prohibit Class VI wells in basalts, coal seams, salt

caverns and shales regardless of injection depth.

FOOTNOTE 12

‐ See proposed 40 C.F.R. §§ 144.6(f), 144.80(f) 146.5(f). at 73 Fed.

Reg. 43534

‐ 43535.

As we noted in our December comments: [FOOTNOTE 13] there is no significant

prior experience or consensus on how to assess and manage risks, what data is

needed to characterize sites, how to select sites, how to conduct and manage

injection operations, how to model the behavior of CO2, and how to monitor

project performance of CO2 sequestration in basalts, coal seams, salt caverns

and shales. The trapping mechanisms of CO2 and/or the operational engineering

involved in such operations is significantly different from those in deep saline

formations and hydrocarbon reservoirs. We simply do not know at this time

whether sequestration (or even injection in some cases) can even be done at

scale in such formations.

FOOTNOTE 13

‐ Joint Environmental Group Comments at 11 (Dec. 24, 2008).

Due to this fundamentally different nature of GS in these formations, if EPA

decides not to explicitly prohibit Class VI wells in such formations, it must

provide substantial evidence of the scientific basis on which it bases its

belief that the physical processes, operational engineering, and risks involved

are similar to and/or equally mature as those in saline formations or oil/gas

reservoirs. We believe that such a demonstration is important both as a policy

matter and a legal matter.

We reassert that until there is better understanding of whether and how

sequestration can be safely accomplished in basalts, coal seams, salt caverns

and shales, wells in these formations should be treated as experimental and

regulated under UIC Class V.

Individual Response: As described above, EPA disagrees that categorically prohibiting injection into any

type of formation is appropriate. EPA recognizes that injection into basalts, coal seams, salt caverns, and

shales have been the subject of limited experimental projects in the past. However, EPA believes thatthe GS rule provides safeguards to allow, on a site

‐ specific basis, GS in other formation types, provided

the owner or operator demonstrates to the Director's satisfaction that the formations are suitable for

receiving and confining injected CO2 as specified at §146.83. The siting, well construction, operational,

and other requirements in the GS rule are designed to ensure that injected CO2 remains within the

target formation.

As described above, small

‐ scale, experimental injection into shallow basalts, coal seams, salt caverns

and shales; such wells would be permitted as Class V experimental technology wells. See the preamble

to the final rule and the responses to comments on the proposed GS rule for additional information on

EPA's approach to injection into various formation types.

Letter ID: 0376 Comment ID: 28174 Letter Lines: 275 to 289

Comment Code: 3210 3.2.1. Comments Generally in Support of the Approach

Comment: 2. CO2 Sequestration Should be Allowed Above the Lowermost USDW, But Only Where

the Geology is Sufficiently Protective, and the Permit Contains Adequate

Requirements

EPA seeks comment on the alternative idea of a "waiver" process, wherein the

Director might grant site

‐ specific exemptions from the general prohibition on

injection above the lowermost USDW. We support this idea generally. As we

described in our comments on the NOPR, [FOOTNOTE 14] GS reservoirs located above

lowermost USDWs may or may not present additional risks than sites located below

the lowermost USDWs, and establishing safe and effective siting and operations

should be based on additional considerations. At the same time, we recognize

that there are many potentially excellent sequestration sites above USDWs, and

that in some areas of the country, these may be the only sites available.

FOOTNOTE 14

‐ Id. at 12.

Individual Response: EPA acknowledges the commenter's support of the waiver approach and site

‐

specific flexibility in regulatory development and permitting as described in the NODA and Request for

Comment. The Agency acknowledges that there are some situations where injection into non

‐ USDW

formations above the lowermost USDW can be performed in a manner that protects USDWs. The final

GS rule at §146.95 establishes a process by which owners and operators can seek a waiver of the Class

VI injection depth requirements. The Agency believes the waiver approach: 1) responds to concerns

about local and regional geologic storage capacity limitations imposed by the proposed injection depth

requirements; 2) allows for a more site

‐ specific assessment of injection depth for GS projects; 3)

accommodates injection into different formation types; 4) allows for injection of CO2 for GS into non

‐USDWs above and/or between USDWs when appropriate and where it can be demonstrated that

USDWs will be protected; and 5) responds to concerns about the use of aquifer exemptions for GS.

Finally, EPA's approach to addressing injection depth variability through a waiver process responds to

concerns about future drinking water resource availability and the need to ensure that high quality

water remains available in sufficient quantities to supply drinking water needs.

EPA believes that that injection for the purpose of GS into non

‐ USDW formations above the lowermost

USDW warrants tailored requirements to address the unique challenges and risks relative to injection

below the lowermost USDW. For example, there is a risk of downward migration of fluids if there is no

lower confining layer or inadequate confinement. In addition, there is potential that wells will be drilled

through the injection zone in the future to reach USDWs. EPA believes that the additional requirements

that apply to owners or operators of Class VI wells granted a waiver of the injection depth requirements

at §146.95 will provide additional considerations for the owner or operator and Director when

permitting such wells to ensure protection of all USDWs.

Letter ID: 0376 Comment ID: 28175 Letter Lines: 291 to 314

Comment Code: 3230 3.2.3. Comments that Additional Submissions are Needed (seeking comment)

Comment: For that reason, we continue to assert that if CO2 injection is permitted above

the lowermost USDW, the regulations allowing such injection must require (in

addition to the information EPA asserts the Director would consider in

evaluating a waiver application): [FOOTNOTE 15]

‐ confirmation that there are laterally continuous, impermeable confining units

above and below the injection zone adequate to prevent fluid movement and

pressure buildup

‐ identification of other wells in the area; and

‐ monitoring for changes in groundwater chemistry above the upper confining zone

and below the lower confining zone.

FOOTNOTE 15

‐ 74 Fed. Reg. at 44811.

EPA should also require, in appropriate circumstances, prior to permit issuance,

completion of regional hydrogeologic studies that are conducted with sufficient

accuracy to simulate regional hydrologic flows and demonstrate that USDWs would

not be endangered if injected or formation fluids were to move beyond either the

higher or the lower confining zone.

Before finalizing regulatory language on a waiver process to allow injectionabove the lowermost USDW, EPA should investigate and address the potential need

for protection against water wells, or wells of any other type that may bisect

pressurized GS reservoirs.

Individual Response: EPA agrees that protecting drinking water resources is vital and is the purpose of

the UIC requirements. The waiver approach establishes extensive site

‐ specific information related to

injecting above or between USDWs that the owner or operator must submit and the Director must

consider, in consultation with PWSS Directors, to ensure that water supplies in the area and all USDWs

are protected. This includes site

‐ specific geologic and hydrologic data as the commenter suggests,

including a demonstration that the injection zone is bounded by laterally continuous, impermeable

confining units above and below it that are adequate to prevent fluid movement and pressure buildup

outside of the injection zone; and, that the confining units are free of transmissive faults and fractures

per §146.95(a)(2). The owner or operator must also describe how the monitoring and testing and any

additional plans will be tailored to the GS project to ensure protection of USDWs above and below the

injection zone as specified in §146.95(a)(5).

In making a determination regarding whether to grant a waiver, the Director must also consider the

suitability of the injection zone, including current or planned artificial penetrations into the injection

zone or formations below it as specified in §146.95(b)(ii).

Many of these additional requirements specifically address water resources, as the commenter

suggests. The requirement at §146.95(b) establishes considerations that the UIC Director must assess

when evaluating a waiver application to ensure that USDW protection, site

‐ specific drinking water

resource issues, and the use and impact of GS technologies are considered and documented.

Considerations associated with water resources include: community needs, demands, and supply from

drinking water resources; planned needs, potential, and/or future use of USDWs and non

‐ USDWs in the

area; planned or permitted water, hydrocarbon, or mineral resource exploitation potential of the

proposed injection formation and other formations both above and below the injection zone to

determine if there are any plans to drill through the formation to access resources in or beneath the

proposed injection zone/formation; and a proposed plan for securing alternative resources or treating

USDW formation waters in the event of contamination related to the Class VI injection activity.

EPA adds that owners or operators granted injection depth waivers are subject to additional

requirements at §146.95(f) ensuring protection of USDWs above and below an injection zone.

Letter ID: 0376 Comment ID: 28176 Letter Lines: 316 to 332

Comment Code: 3130 3.1.3. Addressing the Differences Between Class II and Class VI Wells

Comment: 3. Distinction between Class VI and other wellsWe commend EPA for recognizing that in the NODA that "it is necessary to address

the specific, unique characteristics of Class VI injection (e.g., large

injection volumes, viscosity, and buoyancy) and the Agency does not have

information or data indicating that Class II operations are entirely analogous

to Class VI, large

‐ scale injection, this alternative allows Class VI injection

depth considerations to be tailored for GS. A number of dominant differences

between Class II and Class VI operations indicate that these well classes

warrant different treatment. These differences include: the risk profiles for

these operations; the greater total injection volumes (of CO2) for Class VI GS;

and, differences in formation pressures (potentially higher for GS), greater

opportunities for mobilization of constituents, and injection rates and

operating conditions." [FOOTNOTE 16] This is of significance as the Agency

considers how to regulate GS in oil/gas reservoirs.

FOOTNOTE 16

‐ 74 Fed.Reg. 44810

Individual Response: EPA agrees that ER is different than GS, and clarifies that the final GS rule

requirements are designed to address these unique attributes of GS.

Letter ID: 0376 Comment ID: 28177 Letter Lines: 334 to 339

Comment Code: 3120 3.1.2. Allowing GS in All Formation Types

Comment: In addition, however, given the relative similarity between GS in saline

formations and oil/gas reservoirs in comparison to GS in coal seams, basalts,

salt caverns and shales, we are puzzled by the Agency’s omission in including a

similar comparison of risk profiles between saline and basalts, coal seams, salt

caverns and shales. We therefore reiterate our points above regarding GS in such

formations.

Individual Response: EPA recognizes that some types of formations, such as coal seams and basalts, are

typically shallow and above the lowermost USDW. The Agency expects that injection for GS into these

shallow formations can be issued waivers and permitted as Class VI wells, provided their owners or

operators can meet all of the requirements at §146.95 and demonstrate that such injection can be

performed in a manner that protects USDWs.

EPA believes that if site characterization is properly conducted, confinement is demonstrated, and wells

are properly constructed, operated, monitored, and closed then formations such as coal seams and

basalts can be safely used for GS. The final GS rule does not categorically preclude or prohibit injectioninto any type of formation. EPA believes that the requirements that allow owners or operators to seek

waivers from the injection depth requirements at §146.95, along with proper siting, well construction,

operation, monitoring, and post

‐ injection site care pursuant to the GS rule requirements will ensure

USDW protection.

Letter ID: 0376 Comment ID: 28178 Letter Lines: 341 to 351

Comment Code: 1000 1. General Comments on the Notice of Data Availability

Comment: E. Conclusion

Our organizations appreciate the opportunity to provide comments to EPA on this

most important rulemaking effort. A final rule will represent a significant step

forward in combating global climate change, and the time is more than ripe for

the U.S. to take such steps. When EPA issues its final rule, we feel it must be

both technically sound and adaptive to reflect learning from experience with GS

projects in as seamless a manner as is possible. We very much look forward to

continuing to work with the Agency on this rule, as well as other efforts under

the Agency’s existing authority to address the significant problem of climate

change in the near term.

Individual Response: EPA believes that the final GS rule is technically sound and that the adaptive

approach to the GS rulemaking will allow for the incorporation of new research, data, and information

about GS as it becomes available in the future. For more information on the adaptive approach, see the

responses to comments on the proposed rule in the rulemaking docket.