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.
Chris M. Hobson

Senior Vice President

Research and

Environmental Affairs

600 North 18th Street

Birmingham, AL 35203

Tel 205.257.2812

Fax 205.257.7938

SOUTHERNÂ.

COMPANY

December 23, 2008

Energy to ServeYtmr Worlt~

VIA MESSENGER AND ELECTRONIC SUBMISSION

Water Docket

EPA Docket Center (EPNDC)

EPA West

Room 3334

1301 Constitution Avenue NW

Washington, DC

Re: Proposal for Federal Requirements Under the Underground Injection

Control Program for Geologic Sequestration of Carbon Dioxide

Docket No.: EPA-HQ-OW-2008-0390

Dear Sir or Madam:

Enclosed please find the comments of Southern Company on the Environmental

Protection Agency's Proposed Rule for Geologic Sequestration ("GS") of Carbon Dioxide

("C02") under the Underground Injection Control ("UIC") Program.

Southern Company believes that carbon capture and storage has the potential to

lead to substantial environmental benefits in terms of avoided CO2 emissions. Therefore, a

workable CCS program, including a regulatory framework for long-term CO2 sequestration as

anticipated by this rulemaking, is an essential element in the full portfolio of options needed

to ensure continued affordable and reliable electric service to customers throughout the

United States while reducing CO2 emissions.

We appreciate the opportunity to comment on this important rulemaking and look

forward to continuing to work with EPA on this issue.

Sincerely,

Ck; M ~çEnclosures
COMMENTS OF SOUTHERN COMPANY

on the Environmental Protection Agency's Proposal for

FEDERAL REQUIREMENTS UNDER THE

UNDERGROUND INJECTION CONTROL PROGRAM FOR

GEOLOGIC SEQUESTRA nON OF CARBON DIOXIDE

Docket No. EPA-HQ-OW-2008-0390

73 Fed. Reg. 43492 (July 25, 2008)

INTRODUCTION

Southern Company submits these comments on the Proposal of the Environmental

Protection Agency ("EPA" or "the Agency") to establish a regulatory framework for geologic

sequestration ("GS") of carbon dioxide ("C02") under the Underground Injection Control

("UIC") Program pursuant to the Safe Drinking Water Act ("SDWA"). 73 Fed. Reg. 43492

(July 25, 2008).1 Southern Company (NYSE: SO) is a super-regional energy company with

more than 42,000 megawatts of electric generating capacity in the Southeast. Southern

Company is one of the largest producers of electricity in the country, supplying energy to a

120,000-square mile service territory spanning most of Georgia and Alabama, southeastern

Mississippi, and the panhandle region of Florida and serving nearly 4.4 milion customers.

Southern Company is ranked number 166 on the latest Fortune 500 listing of the largest United

States corporations, with approximately 26,000 employees and reported earnings in 2007 of

$1.73 bilion. Southern Company owns four regulated retail electric utilities: Georgia Power,

Alabama Power, Gulf Power, and Mississippi Power.

In addition, Southern Company is a leader in environmental research. Through 2007,

Southern Company has invested approximately $4.6 bilion in environmental controls and plans

¡ Southern Company also endorses the comments fied on this Proposal by the Utility Solid Waste Activities Group,

Edison Electric Institute, and the Carbon Sequestration Council Carbon Capture and Sequestration Contact Group.
to spend an additional $3.9 bilion through 2010 to further reduce emissions. Southern Company

is committed to the deployment of a variety of energy sources including renewable energy.

Southern Company has already begun a CO2 injection project at a deep saline-filled geologic

formation in Mississippi as part of the Southeast Carbon Sequestration Regional Partnership.

We believe that carbon capture and storage ("CCS") is critical to the likely federal goal of

reducing greenhouse gas emissions and to the implementation of a number of federal and state

energy reform initiatives; we are proud of our efforts to help bring this important technology

towards commercial viability and generally support EPA's efforts in this rulemaking.

Carbon capture and storage has the potential to lead to substantial environmental benefits

in terms of avoided CO2 emissions. Therefore, a workable CCS program, including a regulatory

framework for long-term carbon dioxide sequestration as anticipated by this rulemaking, is an

essential element in the full portfolio of options needed to ensure continued affordable and

reliable electric service to customers throughout the United States while reducing CO2 emissions.

It is critical, therefore, that EPA promulgate flexible regulations that can develop as industry and

regulators alike gain experience with large-scale CO2 sequestration. These regulations should be

built around performance-based standards that encourage tailoring of the Program's requirements

to the geologic and technical needs of a given CO2 GS site.

Southern Company agrees that the appropriate standard underlying the technical

requirements to be applied to Class VI wells should be the protection of underground sources of

drinking water ("USDWs"). See id. at 43497. With this standard in mind, it is imperative that

EP A fashion the Final Rule with sufficient flexibility to meet two primary goals: first, adequately

addressing the varied geologic conditions of different CO2 GS sites; second, ensuring

adaptabilty as industry and regulators gain experience with and information regarding CO2 GS.

-2-
It is important that the Final Rule not exclude the existing experience and knowledge gained

from current CO2 injection and GS demonstration projects. To encourage use of this

information, Southern Company supports faciltated GS in oil and gas reservoirs with the

protection of USD W s and the transition of Class II and Class V C02 inj ection operations to GS.

The Final Rule should establish a regulatory framework built around the standard of protecting

USDWs while allowing Directors to issue permits with site-specific requirements. An emphasis

on site selection, site characterization, and careful permit-writing wil further strengthen a

regulatory scheme that wil provide protection ofUSDWs while maximizing the beneficial

environmental and economic impacts of carbon sequestration.

The Proposal includes many provisions for directorial discretion that will help ensure that

the C02 GS program has the flexibility it needs to succeed. While EPA must take care to clearly

define the circumstances in which directorial discretion may be exercised and to limit the scope

of that discretion, in many cases this discretion wil allow Directors to consider the unique

characteristics of a given CO2 GS project and adopt a site-specific approach that wil meet the

Final Rule's performance-based standards.

Classification of CO2 GS Wells and Interaction with Other Regulatory Regimes

Southern Company supports EPA's approach of creating a new category of wells under

the UIC program for the long-term sequestration of C02. ¡d. at 43502. The new Class VI

designation is appropriate for the injection of CO2 streams captured from an emission source,

including incidental associated substances derived from source materials and the capture process,

as well as substances added to the stream to facilitate the injection process. As EPA observes,

the addition of such substances may sometimes prove a necessary step in the injection process.

-3-
See id. at 43493. Accordingly, the removal of these incidental associated substances should only

be required as necessary to avoid interference with capture, transportation, injection and

containment of CO2 streams.

Potential interaction with RCRA - Southern Company commends EPA for avoiding

characterization of the CO2 stream to be injected into Class VI wells. See id. at 43503. We,

however, are concerned with the Preamble's vague reference to potential interaction with the

Resource Conservation and Recovery Act ("RCRA"). ¡d. EPA should pursue all available

regulatory and legislative avenues to preclude applicabilty of RCRA to Class VI well

operations. For example, EPA could make use of the established "contingent management"

concept, which allows for the exclusion of certain materials from RCRA hazardous waste

regulation when those materials are' adequately regulated under another environmental regime.

The contingent management approach would allow EPA to sidestep any chiling effect that

potential RCRA liability would have on CO2 GS operations under the UIC Program without

jeopardizing protection ofUSDWs.

Potential interaction with CERCLA - EPA also raises the potential for liability under the

Comprehensive Environmental Response, Compensation, and Liability Act ("CERCLA")

stemming from CO2 GS operations. 73 Fed. Reg. at 43504. The potential for liability under

CERCLA wil have similar adverse implications as the potential for RCRA applicability _

specifically, potential CERCLA liabilty wil act as a significant deterrent to participation or

investment in CO2 GS projects. Southern Company again encourages EPA to pursue whatever

regulatory and/or legislative avenues are available to remove this obstacle without jeopardizing

the Program's standard of protection ofUSDWs.

-4-
Permit Application

Southern Company opposes EPA's proposed requirements for Class VI permit

applications to the extent that those requirements are more burdensome than current permit

application requirements for other classes ofUIC wells. ¡d. at 43517. C02 GS does not pose

unique risks warranting many of the Proposal's additional requirements for detailed information.

EP A should craft the Final Rule to require in the initial permit application information

that the Director will need to determine whether issuance of a Class VI permit is appropriate.

EP A could require submission of supplemental information as it becomes available through

driling, construction, and reevaluation of the welL. This wil not only prevent against the

chiling effect that overly burdensome permit application requirements would have on the CO2

GS program, but wil simultaneously ensure the ultimate collection of more thorough and

reliable data.

Duration oj permit - Southern Company supports EPA's proposal to issue Class VI

injection well permits for the operating life of the GS project. ¡d. at 43523. EPA correctly

observes that the requirements for periodic reevaluation of site data, corrective action status,

monitoring results, and operating parameter modifications would render mandatory five- and tenyear permit reviews unnecessary and duplicative. ¡d. Issuance of permits extending through the

operating life of the GS project, including the post-injection site care period, wil provide

Owners or Operators and investors with certainty and wil encourage investment in CO2 GS

projects.

-5-
Area of Review ("AoR") and Corrective Action

Southern Company encourages EPA to avoid arbitrary absolutes or blanket prohibitions

in the Final Rule and to instead craft regulations allowing Class VI permit applicants and

Directors to focus on scientific data and technical demonstrations in characterizing potential

geologic sequestration sites. It is premature to categorically preclude injection in certain types of

formations as CO2 injection and sequestration technology may develop to make injection in

those formations feasible while stil protecting against endangerment ofUSDWs. A recent

report by the Government Accountability Offce ("GAO") predicts a demand for thousands, if

not tens of thousands, ofUIC permits to accommodate the volumes of CO2 to be captured once

CCS is deployed on a commercial scale. Climate Change - Federal Actions Wil Greatly Affect

the Viabilty oJCarbon Capture and Storage as a Key Mitigation Option, GAO-08-1080 at 40

(September 2008) ("GAO Report"). Given the likelihood for such demand, EPA should

encourage the identification and utilzation of as many injection zones as possible, provided that

the Director determines that injection in a given site would be protective ofUSDWs before

issuing a permit for injection at that site.

To maximize capacity for CO2 injection that is protective ofUSDWs, the Final Rule

should avoid arbitrary exclusions of whole categories of injection zones. For example, a

requirement that all injection zones be located below the lowermost USDW is unnecessary; there

may be situations in which injection can occur above the lowermost USDW without endangering

USDWs - for example, in current oil and gas reservoirs with demonstrated trapping capabilties.

¡d. at 43512. In situations where the Owner or Operator could not demonstrate that injection

above the lowermost USDW could occur without endangering USDWs, the permit could

preclude injection into such formations.

-6-
The same logic argues against blanket prohibitions on injection in coal seams or other

formations such as basalts, salt domes, or shales: if a scientific and technical demonstration can

be made showing that the injection of CO2 into one of these formations wil be protective of

USDWs, then that formation should remain an available option under the Class VI UIC Program.

See id. at 43503. There is also no need for a minimum injection depth requirement for CO2 GS

projects, provided that protection ofUSDWs can be demonstrated. ¡d. at 43512. For similar

reasons, Southern Company opposes an absolute prohibition on use of exempt aquifers for Class

VI injection (including sole source aquifers); use of exempt aquifers should be permitted where

the specific aquifer exemption criteria are satisfied. ¡d. The Final Rule should give Directors

latitude to approve injection plans for a range of sites based on scientific data and technical

demonstrations that the site wil contain the injected CO2 streams, thereby preventing

endangerment ofUSDWs.

EP A also seeks comment on whether the Final Rule should require, or allow the Director

to require at his discretion, the identification and characterization of additional confining and

containment zones above the primary confining zone that could further impede vertical fluid

movement and allow for pressure dissipation. ¡d. at 43505-06. As a general matter, Southern

Company opposes the inclusion of any sort of "secondary containment" requirement - even at

the Director's discretion - as it would unnecessarily burden Owners or Operators of Class VI

wells while providing litte or no benefit in terms ofUSDW protection. An emphasis on proper

site selection and characterization combined with performance-based standards wil ensure that

Class VI permits are only issued for CO2 GS projects where the primary containment zone wil

protect against endangerment ofUSDWs in the first instance. Identification of redundant

-7-
confining and containment zones would only serve to confuse the permit application and

approval process and unduly restrict siting of CO2 GS projects.

Modeling- Southern Company supports EPA's suggestion to allow for use of proprietary

models with CO2 GS sites, provided that the permit applicant discloses the code assumptions,

relevant equations, and scientific basis of the modeL. ¡d. at 43507. Based on the valuable

experience Southern Company has gained through our C02 GS pilot project, we also support the

use of computational fluid flow models for AoR delineation, provided that these models are

available for use at the option of the Owner or Operator and are not required for all CO2 GS

projects. See id.

Corrective action - As the GAO Report observes, public perception of carbon

sequestration wil likely playa determinative role in the success of any CO2 GS regulatory

scheme. GAO Report at 49. The use of the phrase "corrective action" to describe plugging and

repair of Class VI wells risks confusion and possibly negative associations with the concept of

corrective action under RCRA and CERCLA. We encourage EPA to replace the phrase

"corrective action" with more appropriate terminology in the Final Rule.

Operating and Monitoring Requirements

It is important to reiterate that, because CO2 GS technology is stil developing, additional

information wil be gained and technological advancements made that wil allow Owners or

Operators to make use of a broader range of tools and methods in Class VI well operation while

being fully protective ofUSDWs. For example, our pilot projects as part of the Southeast

Carbon Sequestration Regional Partnership will lead to greater technical expertise related to CO2

injection. In addition, the geologic characteristics and limitations of Class VI wells wil vary

-8-
significantly from site to site. For these reasons, the Final Rule should be flexible enough to

incorporate new information and technological advancements which, in turn, will help promote a

more robust and environmentally protective CO2 injection program. To achieve this result, the

Final Rule should establish performance-based standards and allow permit applicants and

Directors to work together to fashion a plan that wil best suit the needs of a particular Class VI

site and any associated USDWs.

While some requirements are appropriate for all Class VI wells, as a general matter

operating and monitoring requirements for individual Class VI projects should be set forth in a

Director-approved plan as part of the permit application and approval process. For example,

while Southern Company supports a default requirement for automatic shut-off mechanisms for

Class VI wells, we oppose a uniform requirement for down-hole shut-off valves. ¡d. at 34511.

These valves are designed to meet unique offshore risks and are, in many instances, il-suited to

UIC operations, including C02 GS. A requirement for down-hole shut-off valves would provide

little benefit but would come at a significant cost and would preclude the use of some tools that

are critical to operation, monitoring, and repair of CO2 GS wells.

Southern Company also opposes a requirement for Owners or Operators to use tracers in

CO2 GS operations. As EPA observes, there are many adverse technical and environmental

consequences associated with the use of tracers, including the possibility of false positives and

the release of per fluorocarbon ("PFC") to the atmosphere. ¡d. at 43512-13. Southern Company

supports the use of tracers in the CO2 GS program only if at the option of the Owner or Operator.

Finally, Southern Company urges EPA to focus operating and monitoring requirements

on containment and preventive measures rather than to impose requirements that wil not

indicate C02 migration until potentially damaging migration has occurred. In particular, we

-9-
encourage containment monitoring only, such as one or at most two above-zone monitoring wells

that measure pressure to detect non-containment. ¡d. at 43514. The Final Rule should encourage

Owners or Operators to invest monitoring resources towards detecting subsurface movement of

CO2 or other substances at a point when action may be taken to address any potential problems

and prevent further migration, whether below or to the surface.

Financial Responsibility

As GAO observed in its recent report, there is a great deal of uncertainty regarding the

type of financial instruments that wil be available to meet the financial responsibility

requirements of the Final Rule. GAO Report at 39-40. This uncertainty has the potential to slow

development on CO2 GS programs; EPA can ease stakeholders' fears and facilitate commercial

deployment of the CO2 GS UIC Program by providing further clarity regarding these

requirements in the Final Rule where possible. In some situations, it may be more appropriate to

provide further clarification at a later date in the form of guidance, as EPA suggests in the

Preamble to the Proposal. ¡d. at 43520-22. Such guidance, however, must be issued in

accordance with the Good Guidance Practices Bulletin issued by the Offce of Management and

Budget ("OMB"), including provision of public notice and opportunities for comment before

issuance of any final guidance. 72 Fed. Reg. 3432, 3438 (Jan. 25, 2007).

The continued availabilty of self-insurance instruments as methods of financial

assurance for Class VI CO2 GS projects is crucial to the viabilty of the CO2 GS regulatory

scheme set forth in the Final Rule. Self-insurance instruments, including the corporate financial

test and the corporate guarantee, have been used successfully under the RCRA program for more

than two decades and wil be important elements of a full menu of options for meeting financial

-10-
responsibilty mechanisms under the Final Rule. Given the likelihood that many Class VI

Owners or Operators wil use a combination of approaches and instruments to meet the

Program's financial assurance requirements, EPA should take care not to constrain the

development of any otherwise acceptable means of achieving financial assurance. We urge EPA

to craft flexible requirements that allow Owners or Operators to use multiple instruments and

adjust their methods as necessary as industry, regulators, and markets gain experience with the

financial aspects of CO2 GS projects.

Post-Injection Site Care and Closure

Southern Company opposes a default fifty-year timeframe - or any fixed default length

of time - for the post-injection site care period. ¡d. at 43519. A default post-injection site care

period is of little value given the widely varied characteristics of future CO2 GS sites, and the

significant discrepancy between the appropriate post-injection site care period for various Class

VI wells. As EPA itself recognizes, the actual time required for plume stabilization following

cessation of injection wil be "very site specific." ¡d. A site-specific determination, based on

conditions at a particular Class VI well, wil be necessary in the case of every CO2 GS project

under the UIC Program. The Final Rule should define a performance-based standard for site

closure and leave the site-specific analysis and determination of appropriate post-injection site

care period to the Director. Potential Owners or Operators are likely to shy away from

undertaking a CO2 GS project if the Program's requirements may extend decades into the future

even when those requirements are no longer necessary. A performance-based standard allowing

for site-specific closure period determinations wil avoid the chiling effect that any default fixed

timeframe for post-injection site care and closure wil have on participation and investment in

-11-
C02 GS projects. Moreover, the site-specific approach wil ensure that an appropriate postinjection site care period is identified to meet the needs of each individual Class VI operation.

Public Perception and Participation

Southern Company encourages EPA to take steps to ensure that the public fully

understands that it is extremely unlikely that C02 GS projects wil harm USDWs or human

health. Effective dissemination of information regarding the limited risks posed by CO2 GS wil

lead to more informed and meaningful public participation in the permitting process. One step

EP A can take to adequately inform the public is to tie the requirements of the Final Rule more

closely to actual risks. The Class VI requirements are unprecedented in the UIC Program in

terms of their stringency; this wil create unnecessary public apprehension without improving

protection ofUSDWs.

Southern Company supports EPA's suggestion to modify existing public notice and

comment requirements under the UIC Program to reflect the availability of new tools and

technology, particularly web-based technology, for gathering and disseminating information. ¡d.

at 43523. Use of internet-based tools can playa key role in connecting regulators, permit

applicants, and the public through all stages of the comment period. Southern Company

understands that the public must be kept informed and allowed an opportunity to provide input

on potential Class VI projects; however, we urge EPA to establish requirements in the Final Rule

that call for public notice after submission of a Class VI permit application, but not before that

application has been deemed complete.

* * * * *

-12-
Southern Company applauds the EPA's initial efforts to create a clear and flexible

regulatory scheme that wil promote carbon capture and storage technology and projects while

protecting underground sources of drinking water. We appreciate the opportunity to comment on

this rulemaking and look forward to continuing to work with EPA on this important issue.

-13-
Letter ID: 0201 

Commenter: Chris M. Hobson 

Organization: Southern Company 

Letter ID: 0201 Comment ID: 22151 Letter Lines: 33 to 45 

Comment Code: 1420 1.2.1.1 Support the GS rulemaking 

Comment: Enclosed please find the comments of Southern Company on the Environmental 

Protection Agency's Proposed Rule for Geologic Sequestration ("GS") of Carbon 

Dioxide ("C02") under the Underground Injection Control ("UIC") Program. 

Southern Company believes that carbon capture and storage has the potential to 

lead to substantial environmental benefits in terms of avoided CO2 emissions. 

Therefore, a workable CCS program, including a regulatory framework for longterm CO2 sequestration as anticipated by this rulemaking, is an essential 

element in the full portfolio of options needed to ensure continued affordable 

and reliable electric service to customers throughout the United States while 

reducing CO2 emissions. 

We appreciate the opportunity to comment on this important rulemaking and look 

forward to continuing to work with EPA on this issue. 

Individual Response: EPA believes that the creation of a new injection well class (VI) under the 

existing UIC Program is necessary to enable the use of GS as a climate change mitigation 

technology in a manner that protects USDWs from endangerment. EPA agrees that the UIC 

Program, under the authority of the SDWA, provides a strong framework for regulating injection 

of CO2 for GS and adds that the GS regulation tailors the UIC requirements to address the 

unique issues associated with large-scale GS including large injection volumes, the relative 

buoyancy of CO2, its corrosivity in the presence of water, the potential presence of impurities in 

captured CO2, and its mobility within subsurface geologic formations. 

Letter ID: 0201 Comment ID: 22152 Letter Lines: 61 to 84 

Comment Code: 1000 1. General and Administrative Comments 

Comment: Southern Company submits these comments on the Proposal of the Environmental 

Protection Agency ("EPA" or "the Agency") to establish a regulatory framework 

for geologic sequestration ("GS") of carbon dioxide ("C02") under the 

Underground Injection Control ("UIC") Program pursuant to the Safe Drinking 

Water Act ("SDWA"). 73 Fed. Reg. 43492 (July 25, 2008). [FN1 Southern Company 

also endorses the comments filed on this Proposal by the Utility Solid Waste 

Activities Group, Edison Electric Institute, and the Carbon Sequestration 

Council Carbon Capture and Sequestration Contact Group.] Southern Company (NYSE: 

SO) is a super-regional energy company with more than 42,000 megawatts of 

electric generating capacity in the Southeast. Southern Company is one of the 

1
largest producers of electricity in the country, supplying energy to a 120,000- 

square mile service territory spanning most of Georgia and Alabama, southeastern 

Mississippi, and the panhandle region of Florida and serving nearly 4.4 million 

customers. Southern Company is ranked number 166 on the latest Fortune 500 

listing of the largest United States corporations, with approximately 26,000 

employees and reported earnings in 2007 of $1.73 billion. Southern Company owns 

four regulated retail electric utilities: Georgia Power, Alabama Power, Gulf 

Power, and Mississippi Power. 

In addition, Southern Company is a leader in environmental research. Through 

2007, Southern Company has invested approximately $4.6 billion in environmental 

controls and plans to spend an additional $3.9 billion through 2010 to further 

reduce emissions. Southern Company is committed to the deployment of a variety 

of energy sources including renewable energy. Southern Company has already begun 

Individual Response: EPA acknowledges the comment. Please see the remainder of EPA's 

responses to this letter for further details. For additional information on EPA's final regulatory 

approach, please see the final rule and preamble as well as the rulemaking docket. 

Letter ID: 0201 Comment ID: 22153 Letter Lines: 84 to 98 

Comment Code: 1330 1.1.3.1 Support use of GS in general 

Comment Code: 1420 1.2.1.1 Support the GS rulemaking 

Comment: of energy sources including renewable energy. Southern Company has already begun 

a CO2 injection project at a deep saline-filled geologic formation in 

Mississippi as part of the Southeast Carbon Sequestration Regional Partnership. 

We believe that carbon capture and storage ("CCS") is critical to the likely 

federal goal of reducing greenhouse gas emissions and to the implementation of a 

number of federal and state energy reform initiatives; we are proud of our 

efforts to help bring this important technology towards commercial viability and 

generally support EPA's efforts in this rulemaking. 

Carbon capture and storage has the potential to lead to substantial 

environmental benefits in terms of avoided CO2 emissions. Therefore, a workable 

CCS program, including a regulatory framework for long-term carbon dioxide 

sequestration as anticipated by this rulemaking, is an essential element in the 

full portfolio of options needed to ensure continued affordable and reliable 

electric service to customers throughout the United States while reducing CO2 

Individual Response: EPA believes that the creation of a new injection well class (VI) under the 

existing UIC Program is necessary to enable the use of GS as a climate change mitigation 

technology in a manner that protects USDWs from endangerment. EPA agrees that the UIC 

Program, under the authority of the SDWA, provides a strong framework for regulating injection 

of CO2 for GS and adds that the GS regulation tailors the UIC requirements to address the 

unique issues associated with large-scale GS including large injection volumes, the relative 

2
buoyancy of CO2, its corrosivity in the presence of water, the potential presence of impurities in 

captured CO2, and its mobility within subsurface geologic formations. 

Letter ID: 0201 Comment ID: 22154 Letter Lines: 99 to 103 

Comment Code: 1250 1.1.1.4 Flexibility is needed (performance-based standards) 

Comment: emissions. It is critical, therefore, that EPA promulgate flexible regulations 

that can develop as industry and regulators alike gain experience with largescale CO2 sequestration. These regulations should be built around performancebased standards that encourage tailoring of the Program's requirements to the 

geologic and technical needs of a given CO2 GS site. 

Individual Response: The Agency believes that the Class VI requirements balance site-specific 

flexibility with USDW protection. Rather than setting performance or technology-based 

standards for GS projects, EPA is adopting a flexible approach, where operators of GS projects 

would develop and implement site-specific plans for delineating the AoR, testing and monitoring 

the site, performing corrective action, and post-injection site care. EPA believes that the plans—

which would be reviewed and approved by the Director and periodically updated throughout the 

life of the project—promote an ongoing dialogue between the operator and the Director that will 

encourage use of the most appropriate technologies for a particular project. 

EPA adds that it is using an adaptive approach to regulating GS under the UIC Program. Even 

after finalization of the GS regulation, EPA plans, every six years, to collect and review project 

data on GS research 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: 0201 Comment ID: 22155 Letter Lines: 105 to 122 

Comment Code: 1250 1.1.1.4 Flexibility is needed (performance-based standards) 

Comment Code: 1610 1.3.1 Risks to USDWs 

Comment: Southern Company agrees that the appropriate standard underlying the technical 

requirements to be applied to Class VI wells should be the protection of 

underground sources of drinking water ("USDWs"). See id. at 43497. With this 

standard in mind, it is imperative that EPA fashion the Final Rule with 

sufficient flexibility to meet two primary goals: first, adequately addressing 

the varied geologic conditions of different CO2 GS sites; second, ensuring 

adaptability as industry and regulators gain experience with and information 

regarding CO2 GS. It is important that the Final Rule not exclude the existing 

experience and knowledge gained from current CO2 injection and GS demonstration 

projects. To encourage use of this information, Southern Company supports 

facilitated GS in oil and gas reservoirs with the protection of USDWs and the 

transition of Class II and Class V C02 injection operations to GS. The Final 

3
Rule should establish a regulatory framework built around the standard of 

protecting USDWs while allowing Directors to issue permits with site-specific 

requirements. An emphasis on site selection, site characterization, and careful 

permit-writing will further strengthen a regulatory scheme that will provide 

protection of USDWs while maximizing the beneficial environmental and economic 

impacts of carbon sequestration. 

Individual Response: EPA notes that the final rule does allow owners or operators flexibility. 

EPA has taken a regulatory approach that promotes USDW protection, incorporates flexibility or 

the discretion of the permitting authority when appropriate, seeks to limit burden on owners or 

operators and permitting agencies, and provides a foundation for national consistency in 

permitting of GS projects. Many Class VI permit requirements must be established through sitespecific plans developed by the owner or operator and approved by the Director. Consequently, 

EPA anticipates that owners or operators will consult with the Director as they develop, 

implement, and update these plans. In addition, the final rule affords the Director flexibility to 

approve alternatives to the requirements in some cases. For example, the Director may in certain 

situations modify the length of the post-injection site care period or approve an alternative postinjection site care timeframe as part of the permitting process under §146.93, allow the use of 

alternate methods for mechanical integrity testing (if approved by EPA), and waive the 

requirement that wells be designed to inject below the lowermost USDW. 

EPA recognizes that technologies will evolve and improve over time, and for these reasons, the 

Agency is using an adaptive approach to regulate GS injection. The Agency 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. 

EPA is allowing the construction of Class II and V wells to be re-permitted as Class VI wells 

pursuant to §146.81(c), provided the owner or operator can demonstrate to the Director that the 

wells were engineered and constructed to meet the requirements at §146.86(a) and ensure 

protection of USDWs, in lieu of requirements at §146.86(b) and §146.87(a). EPA believes that 

allowing for grandfathering of select construction requirements, if approved by the Director, will 

ease the transition to Class VI from an existing ER project while protecting USDWs from 

endangerment. 

EPA clarifies that the GS rule does not promote GS in specific settings, nor does it limit injection 

activities to any specific type of formation, geographic region, or depth. The focus of the GS rule 

is to ensure that, where GS is deployed, it is conducted in a manner that is protective of USDWs. 

Letter ID: 0201 Comment ID: 22156 Letter Lines: 124 to 130 

Comment Code: 1250 1.1.1.4 Flexibility is needed (performance-based standards) 

Comment: The Proposal includes many provisions for directorial discretion that will help 

ensure that the C02 GS program has the flexibility it needs to succeed. While 

EPA must take care to clearly define the circumstances in which directorial 

4
discretion may be exercised and to limit the scope of that discretion, in many 

cases this discretion will allow Directors to consider the unique 

characteristics of a given CO2 GS project and adopt a site-specific approach 

that will meet the Final Rule's performance-based standards. 

Individual Response: EPA is developing guidances for States that describe the process of 

applying for and receiving primary enforcement authority (primacy) for GS Class VI wells under 

Section 1422 of SDWA, as well as the technical and administrative issues on developing GS 

regulations that are the equivalent of minimum federal criteria and requirements. The guidance 

will describe areas of Directorial discretion and considerations for how that discretion would be 

exercised. This guidance will be available on EPA’s website at 

http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm. 

Letter ID: 0201 Comment ID: 22157 Letter Lines: 132 to 144 

Comment Code: 1614 1.3.1.2 Impurities in captured CO2; purity standards for CO2 

Comment Code: 2020 1.5.1 Support Class VI designation 

Comment: Classification of CO2 GS Wells and Interaction with Other Regulatory Regimes 

Southern Company supports EPA's approach of creating a new category of wells 

under the UIC program for the long-term sequestration of C02. Id. at 43502. The 

new Class VI designation is appropriate for the injection of CO2 streams 

captured from an emission source, including incidental associated substances 

derived from source materials and the capture process, as well as substances 

added to the stream to facilitate the injection process. As EPA observes, the 

addition of such substances may sometimes prove a necessary step in the 

injection process. See id. at 43493. Accordingly, the removal of these 

incidental associated substances should only be required as necessary to avoid 

interference with capture, transportation, injection and containment of CO2 

streams. 

Individual Response: EPA agrees that tailored requirements for Class VI wells are necessary to 

address the unique nature of injecting large volumes of CO2 and to ensure that USDWs are 

protected from endangerment. The GS rule contains tailored requirements for the permitting, 

geologic site characterization, AoR and corrective action, well construction, operation, 

mechanical integrity testing, monitoring, well plugging, post-injection site care, and site closure 

of GS wells that directly address issues unique to the nature of large-scale CO2 injection for GS. 

Letter ID: 0201 Comment ID: 22158 Letter Lines: 146 to 157 

Comment Code: 1630 1.3.3 RCRA/hazardous waste issues (seeking comment) 

Comment: Potential interaction with RCRA - Southern Company commends EPA for avoiding 

characterization of the CO2 stream to be injected into Class VI wells. See id. 

5
at 43503. We, however, are concerned with the Preamble's vague reference to 

potential interaction with the Resource Conservation and Recovery Act ("RCRA"). 

Id. EPA should pursue all available regulatory and legislative avenues to 

preclude applicability of RCRA to Class VI well operations. For example, EPA 

could make use of the established "contingent management" concept, which allows 

for the exclusion of certain materials from RCRA hazardous waste regulation when 

those materials are' adequately regulated under another environmental regime. 

The contingent management approach would allow EPA to sidestep any chilling 

effect that potential RCRA liability would have on CO2 GS operations under the 

UIC Program without jeopardizing protection of USDWs. 

Individual Response: EPA agrees that any requirements for the CO2 stream should be clearly 

identified. With respect to providing clarity on RCRA, EPA has decided to initiate a separate 

proposed rulemaking specifically to examine the issue of RCRA applicability to CO2 streams 

being geologically sequestered, including the possible option of a conditional exemption from 

the RCRA requirements for CO2 GS in Class VI wells. EPA will consider these comments as 

part of its development of that proposal. The Agency will consider issues particular to RCRA in 

the context of that separate rulemaking, and recommends that the commenter read that proposed 

rule when it is published. The Agency notes that commenters who wish to submit comments on 

the RCRA proposal will need to do so during the comment period for that rule. Finally, EPA also 

notes that the final GS rule, which adds new regulations for Class VI wells under the Safe 

Drinking Water Act (SDWA), is not making any changes to the RCRA regulations. 

EPA clarifies that the GS rule requires owner or operators of Class VI wells to characterize their 

injection stream prior to injection, and throughout the operational life of the injection facility. 

Since the GS rule, at §146.81(d), prohibits CO2 streams that meet the definition of a hazardous 

waste under 40 CFR part 261, owners or operators will need to characterize their CO2 stream as 

part of their permit application to determine if the injectate is a RCRA hazardous waste. If so, 

injection may only occur in a Class I hazardous waste injection well. 

EPA adds that promoting the use of GS is outside the scope of the GS rule. Rather, the purpose 

of the GS regulation is to ensure that, where deployed, GS is conducted in a manner that protects 

USDWs from endangerment. 

Letter ID: 0201 Comment ID: 22159 Letter Lines: 159 to 167 

Comment Code: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: Potential interaction with CERCLA - EPA also raises the potential for liability 

under the Comprehensive Environmental Response, Compensation, and Liability Act 

("CERCLA") stemming from CO2 GS operations. 73 Fed. Reg. at 43504. The potential 

for liability under CERCLA will have similar adverse implications as the 

potential for RCRA applicability _ specifically, potential CERCLA liability will 

act as a significant deterrent to participation or investment in CO2 GS 

projects. Southern Company again encourages EPA to pursue whatever regulatory 

and/or legislative avenues are available to remove this obstacle without 

6
jeopardizing the Program's standard of protection of USDWs. 

Individual Response: CO2 itself is not listed as a hazardous substance under CERCLA; 

however, the CO2 stream may contain a listed hazardous substance (such as mercury) or may 

mobilize substances in the subsurface that could react with ground water to produce listed 

hazardous substances (such as sulfuric acid). Whether such substances may result in CERCLA 

liability from a sequestration facility depends entirely on the composition of the specific CO2 

stream and the environmental media in which it is stored (e.g., soil or ground water). CERCLA 

exempts from liability, under CERCLA section 107, 42 U.S.C. 9607, certain “federally permitted 

releases” (FPR) as defined in CERCLA, 42 U.S.C. 9601(10). Class VI permits will need to be 

carefully structured to ensure that they prevent potential releases from the well which are outside 

the scope of the Class VI permit. Furthermore, EPA is promulgating the GS rule under the 

authority of the SDWA. To the extent the commenter is seeking interpretations of CERCLA and 

its related provisions, such as the definition of a federally permitted release, such interpretations 

are beyond the scope of this rulemaking. 

EPA adds that promoting the use of GS is outside the scope of the GS rule. Rather, the purpose 

of the GS regulation is to ensure that, where deployed, GS is conducted in a manner that protects 

USDWs from endangerment. 

Letter ID: 0201 Comment ID: 22160 Letter Lines: 169 to 184 

Comment Code: 4710 2.7.1 Proposed submissions required for permit applications (seeking 

comment) 

Comment Code: 4720 2.7.2 Operational recordkeeping and reporting 

Comment: Permit Application 

Southern Company opposes EPA's proposed requirements for Class VI permit 

applications to the extent that those requirements are more burdensome than 

current permit application requirements for other classes of UIC wells. id. at 

43517. C02 GS does not pose unique risks warranting many of the Proposal's 

additional requirements for detailed information. 

EPA should craft the Final Rule to require in the initial permit application 

information that the Director will need to determine whether issuance of a Class 

VI permit is appropriate. EPA could require submission of supplemental 

information as it becomes available through drilling, construction, and 

reevaluation of the well. This will not only prevent against the chilling effect 

that overly burdensome permit application requirements would have on the CO2 GS 

program, but will simultaneously ensure the ultimate collection of more thorough 

and reliable data. 

Individual Response: EPA believes that the unique characteristics of CO2 injection (e.g., its 

relative buoyancy, the large volume that may be injected, or the potential for chemical 

interaction with the subsurface) warrant the additional information required to be submitted by 

7
Class VI operators under §146.82. EPA disagrees that Directors should have the authority to 

waive some of the application requirements. In order to protect USDWs from endangerment, 

Directors must have all the data necessary to make well-informed decisions on establishing 

permit conditions and granting permits. 

In response to concerns that some data will not be available until the well has been drilled, EPA 

acknowledges that not all of the information listed at §146.82 of the proposed regulation will be 

available at the time the owner or operator develops their Class VI permit application. Based on 

comments and evaluation of the proposed requirements, EPA revised this subpart so that the 

final regulation specifies separate requirements for information to be submitted for approval with 

the permit application before well construction, as required at §146.82(a), and information to be 

submitted after the well is constructed; however, all data must be provided before injection is 

authorized, as required at §146.82(c). 

Letter ID: 0201 Comment ID: 22161 Letter Lines: 186 to 194 

Comment Code: 5700 2.12 Comments on the proposed duration of Class VI permits (seeking 

comment) 

Comment: Duration of permit - Southern Company supports EPA's proposal to issue Class VI 

injection well permits for the operating life of the GS project. Id. at 43523. 

EPA correctly observes that the requirements for periodic reevaluation of site 

data, corrective action status, monitoring results, and operating parameter 

modifications would render mandatory five- and ten year permit reviews 

unnecessary and duplicative. Id. Issuance of permits extending through the 

operating life of the GS project, including the post-injection site care period, 

will provide Owners or Operators and investors with certainty and will encourage 

investment in CO2 GS projects. 

Individual Response: EPA agrees with commenters that Class VI permits should be issued for 

the operating life of the GS project. EPA clarifies that the final GS rule specifies that Class VI 

permits will be issued for the operating life of the facility and the post-injection site care period 

(144.36(a)). The final rule also adds a requirement that the Director review each Class VI permit 

at least every five years to determine whether it should be modified, revoked and reissued, 

terminated, or a minor modification made as provided in §§144.39, 144.40, or 144.41. The 

Director’s review will be informed by the owners’ or operators’ iterative reevaluation of the 

project. Specifically, the final rule includes a requirement that the AoR be reevaluated at least 

every five years, and also requires owners or operators to review and update the AoR and 

corrective action plan, the testing and monitoring plan, and the emergency and remedial response 

plan throughout the life of the project (146.84(e), 146.90(j), and 146.94(d)). Owners or operators 

must review each plan and identify necessary amendments or demonstrate to the Director that no 

amendment is needed. In no case can reviews occur less often than once every five years. 

EPA adds that the required reviews of the AoR and corrective action plan, the testing and 

monitoring plan, and the emergency and remedial response plan throughout the life of the project 

are preferable to a periodic permit reapplication. The iterative process and subsequent plan 

8
reevaluations ensure that time and resources are committed to the most critical aspects of the 

permit in preventing endangerment to USDWs. 

Letter ID: 0201 Comment ID: 22162 Letter Lines: 196 to 223 

Comment Code: 4324 2.4.4.1.2 Comments opposed to requiring injection below the lowermost 

USDW 

Comment: Area of Review ("AoR") and Corrective Action 

Southern Company encourages EPA to avoid arbitrary absolutes or blanket 

prohibitions in the Final Rule and to instead craft regulations allowing Class 

VI permit applicants and Directors to focus on scientific data and technical 

demonstrations in characterizing potential geologic sequestration sites. It is 

premature to categorically preclude injection in certain types of formations as 

CO2 injection and sequestration technology may develop to make injection in 

those formations feasible while still protecting against endangerment of USDWs. 

A recent report by the Government Accountability Office ("GAO") predicts a 

demand for thousands, if not tens of thousands, of UIC permits to accommodate 

the volumes of CO2 to be captured once CCS is deployed on a commercial scale. 

Climate Change - Federal Actions Will Greatly Affect the Viability of Carbon 

Capture and Storage as a Key Mitigation Option, GAO-08-1080 at 40 (September 

2008) ("GAO Report"). Given the likelihood for such demand, EPA should encourage 

the identification and utilization of as many injection zones as possible, 

provided that the Director determines that injection in a given site would be 

protective of USDWs before issuing a permit for injection at that site. 

To maximize capacity for CO2 injection that is protective of USDWs, the Final 

Rule should avoid arbitrary exclusions of whole categories of injection zones. 

For example, a requirement that all injection zones be located below the 

lowermost USDW is unnecessary; there may be situations in which injection can 

occur above the lowermost USDW without endangering USDWs - for example, in 

current oil and gas reservoirs with demonstrated trapping capabilities. ¡d. at 

43512. In situations where the Owner or Operator could not demonstrate that 

injection above the lowermost USDW could occur without endangering USDWs, the 

permit could preclude injection into such formations. 

Individual Response: EPA acknowledges that there are limited circumstances where injection 

above the lowermost USDW can be performed in a manner that protects USDWs from 

endangerment, as long as appropriate protections are in place. The final GS rule at §146.95 

establishes a process by which owners or operators can seek a waiver of the Class VI injection 

depth requirements for injection into non-USDW formations above and/or between USDWs. 

Additionally, the final GS rule does not categorically preclude or prohibit injection into any type 

of formation. 

EPA believes that these requirements will ensure USDW protection while providing flexibility to 

9
UIC program Directors and owners or operators who undertake CO2 injection for GS. The 

Agency believes this 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. 

For additional information on the waiver approach, please see the final rule and preamble, as 

well as EPA's responses to comments on the Notice of Data Availability and Request for 

Comment. 

Letter ID: 0201 Comment ID: 22163 Letter Lines: 225 to 229 

Comment Code: 2163 1.6.3.1 Comments in favor of injection into unmineable coal seams 

Comment Code: 2200 1.6.4 Other formation types 

Comment: The same logic argues against blanket prohibitions on injection in coal seams or 

other formations such as basalts, salt domes, or shales: if a scientific and 

technical demonstration can be made showing that the injection of CO2 into one 

of these formations will be protective of USDWs, then that formation should 

remain an available option under the Class VI UIC Program. See id. at 43503. 

Individual Response: The final GS rule does not preclude injection into any non-USDW 

formations, such as basalts, salt domes, or shales, provided the site-suitability requirements in the 

GS rule are met, and owners or operators can demonstrate that GS can be performed in a manner 

that protects USDWs from endangerment. 

EPA acknowledges that there are unknowns associated with GS, particularly regarding GS into 

formations such as coal seams, basalts, salt domes, or shales, which have been the subject of 

limited experimental projects in the past. For this reason, the Agency is using an adaptive 

approach to regulate GS injection. EPA will collect and review project data on early GS projects, 

including those that inject into various formation types, to determine whether the appropriate 

amount and types of information and documentation are being collected. 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. 

EPA clarifies that the final rule requires that injection for GS be into non-USDWs below the 

lowermost USDW; however, owners or operators may apply for a waiver from this requirement, 

as described in §146.95. For more information, see the discussion of waivers in the preamble to 

the final rule. 

10
Letter ID: 0201 Comment ID: 22164 Letter Lines: 230 to 231 

Comment Code: 4344 2.4.4.2.2 Comments opposed to setting a minimum injection depth 

Comment: There is also no need for a minimum injection depth requirement for CO2 GS 

projects, provided that protection of USDWs can be demonstrated. ¡d. at 43512. 

Individual Response: EPA agrees that it is not appropriate to set a minimum injection depth for 

GS projects and the Agency believes that a determination of site-suitability for GS (i.e., that 

subsurface formations will receive and confine injected CO2) should be made on a site-specific 

basis. The GS rule, at §146.82, requires the owner or operator to provide extensive site- and 

project-specific information to the Director to demonstrate that the site meets the minimum site 

criteria at §146.83, that the CO2 will be contained within the injection formation, and that 

USDWs will be protected from endangerment. 

EPA acknowledges that there are limited circumstances where injection above the lowermost 

USDW can be performed in a manner that protects USDWs, as long as appropriate protections 

are in place. The final GS rule at §146.95 establishes a process by which owners or operators can 

seek a waiver of the Class VI injection depth requirements for injection into non-USDW 

formations above and/or between USDWs. The waiver approach requires the submission of 

extensive, site-specific information (in conjunction with the permit application submission) to 

demonstrate that injection of CO2 into a non-USDW that is above or between USDWs can be 

done in a manner that is protective of USDWs. The requirements are designed to ensure that the 

owner or operator, the Director, and the Regional Administrator consider, on a site-specific 

basis, the implications, benefits, and challenges associated with GS and ensuring water 

availability and USDW protection. For additional information on the waiver approach, please see 

the final rule and preamble, as well as EPA's responses to comments on the Notice of Data 

Availability and Request for Comment. 

Letter ID: 0201 Comment ID: 22165 Letter Lines: 232 to 238 

Comment Code: 4460 2.4.4.4.1 Comments in favor of allowing aquifer exemptions in certain 

circumstances 

Comment: For similar reasons, Southern Company opposes an absolute prohibition on use of 

exempt aquifers for Class VI injection (including sole source aquifers); use of 

exempt aquifers should be permitted where the specific aquifer exemption 

criteria are satisfied. Id. The Final Rule should give Directors latitude to 

approve injection plans for a range of sites based on scientific data and 

technical demonstrations that the site will contain the injected CO2 streams, 

thereby preventing endangerment of USDWs. 

Individual Response: EPA acknowledges that there are limited circumstances where aquifer 

exemptions for GS may be warranted. The final rule allows for the expansion of the areal extent 

of existing aquifer exemptions for Class II EOR/EGR wells transitioning to Class VI injection 

11
for GS pursuant to requirements at §§146.4 and 144.7(d). Class VI owners or operators granted 

expansions of existing Class II EOR/EGR aquifer exemptions for GS projects must meet all of 

the tailored requirements for GS wells in the final GS rule. 

However, the final rule precludes the issuance of new aquifer exemptions for Class VI GS wells; 

that is, aquifer exemptions will only be granted for projects that are transitioning from Class II 

EOR/EGR wells to Class VI. 

EPA clarifies that all decisions regarding whether expansion of existing aquifer exemptions will 

be at the Director's discretion and based on site-specific information. If an owner or operator 

applies for a Class VI permit to inject CO2 into a previously exempted aquifer (non-USDW) that 

is located above and/or between USDWs, the permit applicant must also apply for a waiver of 

the injection depth requirements pursuant to §146.95 to ensure that if a waiver is granted, 

USDWs above and below the injection zone are protected from endangerment. 

For additional information on aquifer exemptions for Class VI wells, please see the final rule and 

preamble, as well as EPA's responses to comments on the Notice of Data Availability and 

Request for Comment. 

Letter ID: 0201 Comment ID: 22166 Letter Lines: 240 to 253 

Comment Code: 3120 2.1.2 Need to identify additional confining and containment zones 

(seeking comment) 

Comment: EPA also seeks comment on whether the Final Rule should require, or allow the 

Director to require at his discretion, the identification and characterization 

of additional confining and containment zones above the primary confining zone 

that could further impede vertical fluid movement and allow for pressure 

dissipation. Id. at 43505-06. As a general matter, Southern Company opposes the 

inclusion of any sort of "secondary containment" requirement - even at the 

Director's discretion - as it would unnecessarily burden Owners or Operators of 

Class VI wells while providing little or no benefit in terms of USDW protection. 

An emphasis on proper site selection and characterization combined with 

performance-based standards will ensure that Class VI permits are only issued 

for CO2 GS projects where the primary containment zone will protect against 

endangerment of USDWs in the first instance. Identification of redundant 

confining and containment zones would only serve to confuse the permit 

application and approval process and unduly restrict siting of CO2 GS projects. 

Individual Response: EPA believes that the Class VI requirements, including the level of site 

characterization required under §§146.82 and 146.83, appropriately address the unique 

challenges posed by large-scale GS including large injection volumes, the relative buoyancy of 

CO2, its corrosivity in the presence of water, the potential presence of impurities in captured 

CO2, and its mobility within subsurface geologic formations. 

EPA retains the requirement to identify additional containment/confining zones, if required by 

12
the Director, as proposed (§146.83(b)). The Agency believes that in some geologic settings, the 

presence and identification of additional confining and containment zones above the primary 

(i.e., lowermost) confining zone can improve USDW protection. These formations could further 

impede vertical fluid movement, allow for pressure dissipation, and provide additional sites for 

monitoring, mitigation, and remediation, while also affording the greatest protection of USDWs 

from endangerment. 

Letter ID: 0201 Comment ID: 22167 Letter Lines: 255 to 258 

Comment Code: 3350 2.2.1.5 Use of proprietary models for GS sites (seeking comment) 

Comment: Modeling- Southern Company supports EPA's suggestion to allow for use of 

proprietary models with CO2 GS sites, provided that the permit applicant 

discloses the code assumptions, relevant equations, and scientific basis of the 

model. Id. at 43507. Based on the valuable experience Southern Company has 

Individual Response: EPA agrees with commenters that available proprietary models may meet 

the complex needs for calculating the AoRs of GS sites, and shares their concern about the need 

to evaluate the inputs and assumptions used. EPA will allow the use of proprietary models in 

meeting the requirements for the GS regulation, as long as GS well operators using a proprietary 

model clearly disclose, to the Director's satisfaction, the code assumptions, relevant equations, 

and scientific basis. EPA adds that its Confidential Business Information requirements at 40 CFR 

144.5 will apply to the use of proprietary models. 

Letter ID: 0201 Comment ID: 22168 Letter Lines: 258 to 262 

Comment Code: 3320 2.2.1.2 Comments opposed to requiring computational models to 

delineate the AoR 

Comment: model. Id. at 43507. Based on the valuable experience Southern Company has 

gained through our C02 GS pilot project, we also support the use of 

computational fluid flow models for AoR delineation, provided that these models 

are available for use at the option of the Owner or Operator and are not 

required for all CO2 GS projects. See id. 

Individual Response: EPA clarifies that the final rule requires the use of computational 

modeling at 146.84(c)(1). EPA believes that the use of computational modeling, rather than 

reliance on a fixed radius or simple computation, is necessary to account for the complexity of 

GS projects. EPA believes that predicting the complex multiphase, buoyant flow of the CO2, coinjectates, and compounds that may be mobilized due to injection requires the sophistication of 

computational models. Models can predict CO2 fate and transport, as well as changes in 

formation pressure, in three dimensions, as a function of time in order to delineate the subsurface 

storage site and the AoR. Models can account for site-specific and predicted operating conditions 

13
as well as geologic heterogeneities and potential migration through faults, fractures, and artificial 

penetrations. 

Letter ID: 0201 Comment ID: 22169 Letter Lines: 264 to 270 

Comment Code: 1220 1.1.1.1 Terminology and definitions 

Comment: Corrective action - As the GAO Report observes, public perception of carbon 

sequestration will likely play a determinative role in the success of any CO2 GS 

regulatory scheme. GAO Report at 49. The use of the phrase "corrective action" 

to describe plugging and repair of Class VI wells risks confusion and possibly 

negative associations with the concept of corrective action under RCRA and 

CERCLA. We encourage EPA to replace the phrase "corrective action" with more 

appropriate terminology in the Final Rule. 

Individual Response: EPA notes that the term "corrective action" at §146.84(d) has been used 

to describe the process of addressing improperly plugged wells in the AoR of injection wells 

since the inception of the UIC program, e.g., at §§146.7 and 146.64. While EPA is aware that the 

term has a different meaning under the UIC regulations than it does under RCRA and CERCLA, 

this has not caused confusion in the past. An alternative term, "well plugging," suggested by 

another commenter is reserved for injection well plugging, as indicated at §146.92. 

Based on its evaluation of all public comments and input on the proposed rule and the NODA 

and Request for Comment, EPA has made many revisions to the Class VI GS rule. Please see the 

final rule and preamble for additional information. 

Letter ID: 0201 Comment ID: 22170 Letter Lines: 272 to 287 

Comment Code: 1250 1.1.1.4 Flexibility is needed (performance-based standards) 

Comment: Operating and Monitoring Requirements 

It is important to reiterate that, because CO2 GS technology is still 

developing, additional information will be gained and technological advancements 

made that will allow Owners or Operators to make use of a broader range of tools 

and methods in Class VI well operation while being fully protective of USDWs. 

For example, our pilot projects as part of the Southeast Carbon Sequestration 

Regional Partnership will lead to greater technical expertise related to CO2 

injection. In addition, the geologic characteristics and limitations of Class VI 

wells will vary significantly from site to site. For these reasons, the Final 

Rule should be flexible enough to incorporate new information and technological 

advancements which, in turn, will help promote a more robust and environmentally 

protective CO2 injection program. To achieve this result, the Final Rule should 

establish performance-based standards and allow permit applicants and Directors 

to work together to fashion a plan that will best suit the needs of a particular 

14
Class VI site and any associated USDWs. 

Individual Response: The Agency believes that the Class VI requirements balance site-specific 

flexibility with USDW protection. Rather than setting performance or technology-based 

standards for GS projects, EPA is adopting a flexible approach, where operators of GS projects 

would develop and implement site-specific plans for delineating the AoR, testing and monitoring 

the site, performing corrective action, and post-injection site care. EPA believes that the plans—

which would be reviewed and approved by the Director and periodically updated throughout the 

life of the project—promote an ongoing dialogue between the operator and the Director that will 

encourage use of the most appropriate technologies for a particular project. 

EPA adds that it is using an adaptive approach to regulating GS under the UIC Program. Even 

after finalization of the GS regulation, EPA plans, every six years, to collect and review project 

data on GS research 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: 0201 Comment ID: 22171 Letter Lines: 289 to 299 

Comment Code: 4200 2.4.2 Down-hole shut-off valves in GS wells (seeking comment) 

Comment Code: 4710 2.7.1 Proposed submissions required for permit applications (seeking 

comment) 

Comment: While some requirements are appropriate for all Class VI wells, as a general 

matter operating and monitoring requirements for individual Class VI projects 

should be set forth in a Director-approved plan as part of the permit 

application and approval process. For example, while Southern Company supports a 

default requirement for automatic shut-off mechanisms for Class VI wells, we 

oppose a uniform requirement for down-hole shut-off valves. ¡d. at 34511. These 

valves are designed to meet unique offshore risks and are, in many instances, 

ill-suited to UIC operations, including C02 GS. A requirement for down-hole 

shut-off valves would provide little benefit but would come at a significant 

cost and would preclude the use of some tools that are critical to operation, 

monitoring, and repair of CO2 GS wells. 

Individual Response: After evaluating the risks and benefits of down-hole shut-off systems and 

considering additional research, EPA will not require automatic down-hole shut-off devices for 

onshore Class VI wells since it is not necessary in all cases to ensure protection of USDWs from 

endangerment. Instead, the final rule, at §146.88(e)(2), requires that owners or operators of 

onshore Class VI wells install automatic surface shut-off devices. The rule affords Director's 

discretion to mandate automatic down-hole shut-off devices in onshore situations that may 

warrant their use. 

The GS rule, at §146.88(e)(3), requires the installation of down-hole shut-off devices for Class 

VI wells located in the offshore submerged lands within the jurisdiction of a State UIC program. 

The Agency agrees that offshore Class VI wells present unique construction and operational 

15
conditions, including isolation from shorelines and the need to construct wells through the water 

column and the subsurface, which may delay response time in the event of well difficulties. 

These conditions merit requiring automatic down-hole shut-off devices for offshore wells in the 

submerged lands of a State. 

While EPA acknowledges that the likelihood of damage to onshore facilities is lower than that 

for off-shore facilities, down-hole shut-off valves are still commonly used in onshore facilities 

such as acid gas injection wells and high pressure, high-temperature wells. While valve failure is 

a concern, EPA believes that technology has advanced sufficiently to make valve failure a rare 

occurrence and to appropriately handle such failure if it occurs. For example, wireline retrievable 

devices can allow repair or replacement of damaged devices without necessitating pulling the 

tubing. 

EPA believes that requiring the installation of automatic surface shut-off devices for onshore 

wells (and affording Director's discretion to require down-hole devices where necessary) and 

automatic down-hole shut-off devices for offshore wells in submerged lands within the 

jurisdiction of a State ensures that proper precautions are taken to prevent subsurface fluid 

movement and ensure protection of USDWs. 

Letter ID: 0201 Comment ID: 22172 Letter Lines: 301 to 306 

Comment Code: 4490 2.4.5 Use of tracers and potential impact on human health or ecosystems 

(seeking comment) 

Comment: Southern Company also opposes a requirement for Owners or Operators to use 

tracers in CO2 GS operations. As EPA observes, there are many adverse technical 

and environmental consequences associated with the use of tracers, including the 

possibility of false positives and the release of per fluorocarbon ("PFC") to 

the atmosphere. ¡d. at 43512-13. Southern Company supports the use of tracers in 

the CO2 GS program only if at the option of the Owner or Operator. 

Individual Response: EPA agrees that tracer use is not appropriate in all situations. Some 

tracers may have the potential to cause harm to people or the environment. Nevertheless, there 

are many different types of tracers and not all are problematic; research is being done to 

overcome problems with existing tracers. EPA believes that tracers have been used safely and 

successfully in other applications. For this reason, EPA does not require the use of tracers at all 

GS sites; rather, the Director has discretion to require their use if he/she determines that the use 

of tracers could improve monitoring of the site and enhance USDW protection from 

endangerment. The rule will also allow their use if proposed by the owner or operator and 

approved by the Director. 

EPA has been following new and ongoing research on the safety and efficacy of tracers, and 

believes that, in some circumstances, tracers can be an effective part of monitoring GS projects. 

EPA will continue to track research related to tracer use and plans to, every six years, collect and 

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

16
information and appropriate documentation are being collected, and to determine if 

modifications to the requirements are appropriate or necessary. 

Letter ID: 0201 Comment ID: 22173 Letter Lines: 308 to 317 

Comment Code: 4610 2.6.1 Testing and monitoring plan requirement (seeking comment) 

Comment: Finally, Southern Company urges EPA to focus operating and monitoring 

requirements on containment and preventive measures rather than to impose 

requirements that will not indicate C02 migration until potentially damaging 

migration has occurred. In particular, we encourage containment monitoring only, 

such as one or at most two above-zone monitoring wells that measure pressure to 

detect non-containment. ¡d. at 43514. The Final Rule should encourage Owners or 

Operators to invest monitoring resources towards detecting subsurface movement 

of CO2 or other substances at a point when action may be taken to address any 

potential problems and prevent further migration, whether below or to the 

surface. 

Individual Response: EPA disagrees that pressure monitoring above the confining zone is 

appropriate. Instead, the final GS regulation, at §146.90(g)(1), requires all GS project operators 

to monitor for pressure changes in the injection zone. EPA believes that pressure monitoring in 

the injection zone is necessary to track the development and movement of the pressure front and 

CO2 plume. Pressure monitoring within the injection zone is necessary because any such 

monitoring above the confining zone would not detect movement of the pressure front unless a 

breach of the confining zone occurs. EPA believes that monitoring using wells in the injection 

zone (i.e., that penetrate the confining zone) can be safely performed if the wells are constructed 

to prevent flow between the injection zone and USDWs or other layers above the confining zone. 

Such construction technologies exist and have been used in the oil and gas industry for years. 

EPA believes that the benefits of monitoring in the injection formation outweigh the manageable 

risk of those monitoring wells serving as conduits for fluid movement. EPA adds that owners or 

operators may consider performing additional pressure monitoring in wells that are above the 

confining zone (e.g., in the same wells used to perform ground water quality monitoring required 

at §146.90(d)) to provide additional verification that no pressure changes are occurring above the 

confining zone due to CO2 leakage. 

In addition, EPA believes that shallow monitoring above the confining layer is an important part 

of a rigorous monitoring program. The final rule, at §146.90(d) requires periodic monitoring of 

the ground water quality and geochemical changes above the confining zone(s). Monitoring in 

additional formations, e.g., the injection zone, may also be necessary, and if the Director believes 

such monitoring is warranted he/she has the authority to require that it be included in the testing 

and monitoring plan. 

Letter ID: 0201 Comment ID: 22174 Letter Lines: 319 to 348 

Comment Code: 5432 2.9.1.1 Need to adjust financial responsibility mechanisms (seeking 

17
comment) 

Comment Code: 5434 2.9.1.2 Need for additional instruments (seeking comment) 

Comment: Financial Responsibility 

As GAO observed in its recent report, there is a great deal of uncertainty 

regarding the type of financial instruments that will be available to meet the 

financial responsibility requirements of the Final Rule. GAO Report at 39-40. 

This uncertainty has the potential to slow development on CO2 GS programs; EPA 

can ease stakeholders' fears and facilitate commercial deployment of the CO2 GS 

UIC Program by providing further clarity regarding these requirements in the 

Final Rule where possible. In some situations, it may be more appropriate to 

provide further clarification at a later date in the form of guidance, as EPA 

suggests in the Preamble to the Proposal. ¡d. at 43520-22. Such guidance, 

however, must be issued in accordance with the Good Guidance Practices Bulletin 

issued by the Office of Management and Budget ("OMB"), including provision of 

public notice and opportunities for comment before issuance of any final 

guidance. 72 Fed. Reg. 3432, 3438 (Jan. 25, 2007). 

The continued availability of self-insurance instruments as methods of financial 

assurance for Class VI CO2 GS projects is crucial to the viability of the CO2 GS 

regulatory scheme set forth in the Final Rule. Self-insurance instruments, 

including the corporate financial test and the corporate guarantee, have been 

used successfully under the RCRA program for more than two decades and will be 

important elements of a full menu of options for meeting financial 

responsibility mechanisms under the Final Rule. Given the likelihood that many 

Class VI Owners or Operators will use a combination of approaches and 

instruments to meet the Program's financial assurance requirements, EPA should 

take care not to constrain the development of any otherwise acceptable means of 

achieving financial assurance. We urge EPA to craft flexible requirements that 

allow Owners or Operators to use multiple instruments and adjust their methods 

as necessary as industry, regulators, and markets gain experience with the 

financial aspects of CO2 GS projects. 

Individual Response: Owners or operators may choose from a variety of financial instruments 

to meet their financial responsibility obligations under the rule, provided the Director determines 

that the operator's proposed financial responsibility demonstration is adequate to protect USDWs 

from endangerment, which means the ability of the owner or operator to pay for each activity for 

which financial responsibility must be demonstrated, including corrective action on wells in the 

AoR, injection well plugging, PISC and site closure, and emergency and remedial response 

throughout the life of the project. The final GS rule specifies at §146.85(a)(1) the permitted types 

of financial responsibility instruments. See the final rule and preamble for further discussion of 

EPA's final approach to financial responsibility. 

EPA will retain self insurance as an option for financial responsibility for Class VI wells. EPA 

believes that if properly used, the financial test can be an appropriate option for some owners or 

18
operators. EPA recognizes that it is important for self-insurers to be credit-worthy, otherwise 

USDWs may not be adequately protected. Owners or operators who choose to self-insure and 

use the financial test must be able to demonstrate profitability, with a margin sufficient to cover 

contingencies and unknown obligations, and stability. If the owner or operator meets corporate 

financial test criteria, this is an indication that the owner or operator can guarantee its ability to 

satisfy financial obligations based solely on the strength of the company’s financial condition. If 

an owner or operator is not able to meet the corporate financial test criteria, they may arrange a 

corporate guarantee by demonstrating that its corporate parent meets the financial requirements 

on its behalf. 

Additionally, EPA is developing guidance (available on EPA's website at 

http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm) that describes the types of 

financial instruments that owners or operators can use to meet financial responsibility 

requirements for GS wells. EPA plans to take OMB's Good Guidance Manual into consideration 

as financial responsibility guidance is developed. OMB's Good Guidance Manual establishes 

policies and procedures for the development, issuance, and use of significant guidance 

documents by Executive Branch departments and agencies. 

Letter ID: 0201 Comment ID: 22175 Letter Lines: 350 to 371 

Comment Code: 5240 2.8.2.2 Post injection timeframe (seeking comment) 

Comment Code: 5300 2.8.3 Site closure activities (40 CFR 146.93) 

Comment: Post-Injection Site Care and Closure 

Southern Company opposes a default fifty-year timeframe - or any fixed default 

length of time - for the post-injection site care period. ¡d. at 43519. A 

default post-injection site care period is of little value given the widely 

varied characteristics of future CO2 GS sites, and the significant discrepancy 

between the appropriate post-injection site care period for various Class VI 

wells. As EPA itself recognizes, the actual time required for plume 

stabilization following cessation of injection will be "very site specific." ¡d. 

A site-specific determination, based on conditions at a particular Class VI 

well, will be necessary in the case of every CO2 GS project under the UIC 

Program. The Final Rule should define a performance-based standard for site 

closure and leave the site-specific analysis and determination of appropriate 

post-injection site care period to the Director. Potential Owners or Operators 

are likely to shy away from undertaking a CO2 GS project if the Program's 

requirements may extend decades into the future even when those requirements are 

no longer necessary. A performance-based standard allowing for site-specific 

closure period determinations will avoid the chilling effect that any default 

fixed timeframe for post-injection site care and closure will have on 

participation and investment in C02 GS projects. Moreover, the site-specific 

approach will ensure that an appropriate post-injection site care period is 

identified to meet the needs of each individual Class VI operation. 

19
Individual Response: EPA agrees with commenters that there will be circumstances where it 

can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk 

of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility 

regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten 

or lengthen the PISC timeframe during the post-injection period based on site-specific data, 

pursuant to requirements at §146.93(b); or (2) affording the Director discretion to allow a Class 

VI well owner or operator to demonstrate, during the permitting process based on substantial 

data, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of 

USDWs pursuant to requirements at §146.93(c). 

EPA believes however, that to ensure USDW protection from endangerment, a default timeframe 

for post-injection site care will be necessary in all but a limited number of cases. This default 50 

year post-injection site care timeframe represents a reasonable and protective monitoring period 

based on a review of research studies, industry reports, and existing environmental programs, 

and evaluation of public comments. 

EPA believes that a default post-injection site care timeframe of 50 years, with flexibility to 

adjust the timeframe for a limited number of GS projects during the permitting process where 

substantial data exists to demonstrate that an alternative timeframe would be protective of 

USDWs, or based on data collected during the PISC period, is appropriate to address the range of 

sites where GS is anticipated to occur, to accommodate site-specific circumstances and various 

geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. 

Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW 

impacts. 

Letter ID: 0201 Comment ID: 22176 Letter Lines: 373 to 394 

Comment Code: 5540 2.10.2 Need for additional public participation requirements/ use of new 

information technology (seeking comment) 

Comment: Public Perception and Participation 

Southern Company encourages EPA to take steps to ensure that the public fully 

understands that it is extremely unlikely that C02 GS projects will harm USDWs 

or human health. Effective dissemination of information regarding the limited 

risks posed by CO2 GS will lead to more informed and meaningful public 

participation in the permitting process. One step EPA can take to adequately 

inform the public is to tie the requirements of the Final Rule more closely to 

actual risks. The Class VI requirements are unprecedented in the UIC Program in 

terms of their stringency; this will create unnecessary public apprehension 

without improving protection of USDWs. 

Southern Company supports EPA's suggestion to modify existing public notice and 

comment requirements under the UIC Program to reflect the availability of new 

tools and technology, particularly web-based technology, for gathering and 

disseminating information. ¡d. at 43523. Use of internet-based tools can playa 

20
key role in connecting regulators, permit applicants, and the public through all 

stages of the comment period. Southern Company understands that the public must 

be kept informed and allowed an opportunity to provide input on potential Class 

VI projects; however, we urge EPA to establish requirements in the Final Rule 

that call for public notice after submission of a Class VI permit application, 

but not before that application has been deemed complete. 

Individual Response: EPA agrees that informing the public on all aspects of GS projects is 

important. GS permitting authorities must follow the existing public participation requirements 

for UIC permits as specified in 40 CFR Part 124. These regulations lay out the procedures for 

decision-making and include requirements such as requiring the Director to notify the public 

regarding the availability of the draft permit and allow him or her to require a public hearing on 

the draft permit. 

The Agency encourages permitting authorities and GS operators to provide the public, including 

residents near the project, with as much project-specific information as possible. This 

information may include, but is not limited to, specific technologies used at the GS injection site, 

potential/new GS projects, and opportunities for public involvement. In addition to requiring 

public notice of all draft permits under §124.10(a)(1)(ii), stakeholders can request that they be 

notified about draft permits. In addition, §124.10(d) requires that the public notice state how 

stakeholders can obtain a copy of the permit application and draft permit. GS operators and 

permitting authorities are also encouraged to make this information available on the Internet. 

EPA is not requiring the use of new information technologies. EPA encourages GS operators to 

use new information technologies whenever possible to keep the public informed of GS projects. 

The Agency believes that flexibility is important and does not want to limit use of public 

participation and notification technologies developed in the future. 

Letter ID: 0201 Comment ID: 22177 Letter Lines: 396 to 400 

Comment Code: 1250 1.1.1.4 Flexibility is needed (performance-based standards) 

Comment Code: 1420 1.2.1.1 Support the GS rulemaking 

Comment: Southern Company applauds the EPA's initial efforts to create a clear and 

flexible regulatory scheme that will promote carbon capture and storage 

technology and projects while protecting underground sources of drinking water. 

We appreciate the opportunity to comment on this rulemaking and look forward to 

continuing to work with EPA on this important issue. 

Individual Response: As described above, EPA agrees that the UIC Program, under the 

authority of the SDWA, provides a strong framework for regulating injection of CO2 for GS. 

21