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.
DUKE ENERGY CORPORATION

526 South Church Street.

Charlotte, NC 28202

Mailing Address:

PO Box 1006

Charlotte, NC 28201-1006

COMMENTS OF DUKE ENERGY

ON THE ENVIRONMENTAL PROTECTION AGENCY’S

FEDERAL REQUIREMENTS UNDER THE UNDERGROUND INJECTION CONTROL 

(UIC) PROGRAM FOR CARBON DIOXIDE (CO2) GEOLOGIC SEQUESTRATION 

(GS) WELLS; NOTICE OF DATA AVAILABILITY AND REQUEST FOR COMMENT

DOCKET ID NO. EPA-HQ-OW-2008-0390

October 15, 2009

Duke Energy Shared Services (“Duke Energy”), on behalf of Duke Energy Carolinas, 

LLC., Duke Energy Indiana, Inc., Duke Energy Ohio Inc., and Duke Energy Kentucky Inc. 

submits these comments in response to the above-referenced Notice of Data Availability

(“NODA”) and request for comment from the Environmental Protection Agency (“EPA”). Duke 

Energy, one of the largest electric power companies in the United States, supplies and delivers 

electricity to approximately 4 million U.S. customers and natural gas service to approximately 

520,000 customers in its regulated jurisdictions. The company has approximately 35,000 net 

megawatts of electric generating capacity in the Midwest and the Carolinas, and natural gas 

distribution services in Ohio and Kentucky.

Duke Energy supports EPA’s efforts to develop a regulatory framework for geologic 

sequestration (“GS”) of carbon dioxide (“CO2”). Coal, the nation’s most abundant natural 

energy resource, accounts for approximately 50% of the electricity consumed in the U.S. today. 

Having a workable GS regulatory program that will facilitate the deployment of carbon capture 

and storage projects is critical to this country’s ability to make substantial reductions in CO2

emissions while keeping coal as a viable energy resource that contributes to the nation’s energy 

independence.

In addition to the following remarks, Duke Energy supports the comments submitted by 

the Edison Electric Institute and the Carbon Sequestration Council on the subject NODA.

As one of the largest coal-fired generators of electricity in the U.S., and as a likely user of 

GS to reduce CO2 emissions, this rulemaking will have a direct impact on Duke Energy and its 

customers. In its December 22, 2008 comments on EPA’s July 25, 2008 proposed “Federal 

Requirements Under the Underground Injection Control (UIC) Program for Carbon Dioxide 

(CO2) Geologic Sequestration (GS) Wells,” Duke Energy encouraged EPA to provide flexibility 

and avoid a one-size-fits-all approach by incorporating performance-based standards into the 

final rule that would allow for site-specific project design, monitoring and closure. Duke Energy 

further stated in its comments that because the technology associated with large scale injection 
2

and storage of CO2 associated with electricity generation is still developing, EPA should provide 

flexibility by designing the UIC program for GS of CO2 so the program requirements can evolve 

along with the technology over time rather than lock-in regulatory requirements that will likely 

become obsolete.

In its July 25, 2008 proposal, EPA proposed a blanket prohibition on injecting CO2 into 

formations which were either not far enough below an Underground Source of Drinking Water 

(“USDW”), or above a very deep USDW. In its August 31, 2009 NODA, EPA indicates that it is 

now considering an injection depth waiver process to allow GS injection above and between 

USDWs under specific conditions in lieu of a blanket prohibition. Duke Energy views EPA’s

consideration of new information and data from comments received, and its resulting proposal to 

consider an injection depth waiver process as a positive step and Duke Energy commends EPA 

for its action. A blanket prohibition related to injection depth would be problematic and 

unnecessary. An appropriately designed injection depth waiver process1 will add flexibility to a 

GS regulatory program by allowing site-specific factors to inform project siting and design 

decisions, thus avoiding unnecessary regulatory burdens, but still ensuring that potentially 

undesirable impacts to UDWS are avoided.

As EPA works to complete the subject rulemaking, Duke Energy urges the Agency to 

incorporate an appropriately designed injection depth waiver process in its final rule, rather than 

leaving the adoption of an injection depth waiver process to the discretion of the individual UIC 

Program Directors. Inclusion of a waiver provision would still leave UIC Program Directors free 

to decline to grant any waivers where they were not necessary or appropriate. Duke Energy 

further encourages EPA to consider and incorporate additional flexibility measures that will 

enhance the workability of the program while ensuring that potentially undesirable impacts to 

UDWS are avoided. Having a workable regulatory program in place for the GS of CO2 is 

absolutely essential to this country’s ability to make significant reductions in greenhouse gas 

emissions at a reasonable cost and without eliminating coal as a viable energy resource.

 

1 The waiver process itself must be workable to be of any practical value in providing flexibility to the GS program 

and to GS project developers. While the waiver process must ensure that potentially undesirable impacts to UDSW 

are avoided, the process must also avoid being so complex that it becomes too burdensome for project developers to 

use and as a result provide no flexibility to the GS program.
Letter ID: 0368  

Commenter: Mike Stroben  

Organization: Duke Energy Corporation  

Letter ID: 0368 Comment ID: 27927 Letter Lines: 50 to 63  

Comment Code: 5000 5. Comments on the Proposed Rule (out of NODA Scope)  

Comment: As one of the largest coal‐fired generators of electricity in the U.S., and as a  

likely user of GS to reduce CO2 emissions, this rulemaking will have a direct  

impact on Duke Energy and its customers. In its December 22, 2008 comments on  

EPA's July 25, 2008 proposed "Federal Requirements Under the Underground  

Injection Control (UIC) Program for Carbon Dioxide (CO2) Geologic Sequestration  

(GS) Wells," Duke Energy encouraged EPA to provide flexibility and avoid a one‐  

size‐fits‐all approach by incorporating performance‐based standards into the  

final rule that would allow for site‐specific project design, monitoring and  

closure. Duke Energy further stated in its comments that because the technology  

associated with large scale injection and storage of CO2 associated with  

electricity generation is still developing, EPA should provide flexibility by  

designing the UIC program for GS of CO2 so the program requirements can evolve  

along with the technology over time rather than lock‐in regulatory requirements  

that will likely become obsolete.  

Individual Response: The final rule is based on the most recent GS‐related data, information, and

scientific research available. EPA intends to continue to collect data on GS and to incorporate such data

as it implements its adaptive approach to GS rulemaking. EPA plans to, every six years, 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.  

For additional information on the adaptive approach and site specific requirements, see the responses

to comments on the proposed rule in the rulemaking docket.  

Letter ID: 0368 Comment ID: 27928 Letter Lines: 65 to 85  

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

Comment: In its July 25, 2008 proposal, EPA proposed a blanket prohibition on injecting  
CO2 into formations which were either not far enough below an Underground Source  

of Drinking Water (USDW), or above a very deep USDW. In its August 31, 2009  

NODA, EPA indicates that it is now considering an injection depth waiver process  

to allow GS injection above and between USDWs under specific conditions in lieu  

of a blanket prohibition. Duke Energy views EPA's consideration of new  

information and data from comments received, and its resulting proposal to  

consider an injection depth waiver process as a positive step and Duke Energy  

commends EPA for its action. A blanket prohibition related to injection depth  

would be problematic and unnecessary. An appropriately designed injection depth  

waiver process [FOOTNOTE 1] will add flexibility to a GS regulatory program by allowing  

site‐specific factors to inform project siting and design decisions, thus  

avoiding unnecessary regulatory burdens, but still ensuring that potentially  

undesirable impacts to UDWS are avoided.  

FOOTNOTE 1 ‐ The waiver process itself must be workable to be of any practical  

value in providing flexibility to the GS program and to GS project developers.  

While the waiver process must ensure that potentially undesirable impacts to  

UDSW are avoided, the process must also avoid being so complex that it becomes  

too burdensome for project developers to use and as a result provide no  

flexibility to the GS program.  

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. EPA agrees that a flexible, site‐specific approach to waiver

determinations (and all Class VI permitting decisions) is appropriate. Site‐specific demonstrations of

injection zone integrity along with proper well construction, operation, monitoring, and post closure site

care are the best way to ensure USDW safety while allowing flexibility for GS above or between 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 will provide additional considerations for the

owner or operator and Director when permitting such wells to ensure protection of all USDWs.  

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.  

Letter ID: 0368 Comment ID: 27929 Letter Lines: 87 to 98  

Comment Code: 3390 3.3.9. Comments Regarding State Discretion to Adopt the Waiver Approach  

Comment: As EPA works to complete the subject rulemaking, Duke Energy urges the Agency to  

incorporate an appropriately designed injection depth waiver process in its  

final rule, rather than leaving the adoption of an injection depth waiver  

process to the discretion of the individual UIC Program Directors. Inclusion of  

a waiver provision would still leave UIC Program Directors free to decline to  

grant any waivers where they were not necessary or appropriate. Duke Energy  

further encourages EPA to consider and incorporate additional flexibility  

measures that will enhance the workability of the program while ensuring that  

potentially undesirable impacts to UDWS are avoided. Having a workable  

regulatory program in place for the GS of CO2 is absolutely essential to this  

country's ability to make significant reductions in greenhouse gas emissions at  

a reasonable cost and without eliminating coal as a viable energy resource.  

Individual Response: EPA clarifies that adoption of the waiver process remains at the discretion of

individual UIC programs. Therefore, States, Territories, and Tribes seeking primacy for Class VI wells are

not required to provide for injection depth waivers in their UIC regulations and may choose not to make

this process available to Class VI wells under their jurisdiction. Although some commenters asked EPA to

require that waivers be applied nationally, the Agency believes that the decision about whether a waiver

program is appropriate in a specific State, Tribe, or Territory should be made by each program. This

approach allows flexibility for individual program Directors to determine the appropriateness of allowing

for waivers based on regional or state‐specific conditions, such as the predominant geologic settings

anticipated to be used for GS or other land uses in the state while ensuring maximum protection of

USDWs. The final approach for injection depth waivers represents minimum Federal requirements. UIC

program Directors may adopt GS requirements that do not allow injection above or between USDWs if

they determine this to be appropriate (for conditions in their State, territory, Tribe, or Region) and

protective.