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.Document ID: EPA

- HQ

- OW

- 2008

- 0390

- 0247

Last Name: Wrotenbery

First Name: Lori

Title: Director, Oil and Gas Conservation Division

Organization: Oklahoma Corporation Commission

City: Oklahoma

State: OK

Zip Code: 73152

Phone Number: 405.521.2211

Fax Number:

Country Code:

Email Address:

Current Category Code: 250

Comment:

Water Docket

Environmental Protection Agency

Mailcode: 2822T

1200 Pennsylvania Ave., NW

Washington, D.C. 20460

Re: Docket ID No. EPA

- HQ

- OW

- 2008

- 0390 (Proposed Federal Requirements Under the

Underground Injection Control Program for Carbon Dioxide Geologic Sequestration

Wells)

The Oil and Gas Conservation Division of the Oklahoma Corporation Commission

regulates oil and gas exploration and production activities and administers the

Class I I Underground Injection Control (UIC) program in the State of Oklahoma.

The division has followed the stakeholder discussions concerning the referenced

proposal with keen interest, particularly regarding those portions of the

proposal that may affect the management and regulation of the states oil and

gas resources.

The division supports the efforts of various groups filing comments on the

proposal to ensure that enhanced oil and gas recovery projects continue to

operate under the current, well

- established and highly effective Class II UIC

regulatory program. The division also supports efforts to develop a regulatory

framework for long

- term storage of carbon dioxide in depleted oil and gas

reservoirs that not only protects unde rground sources of drinking water, but

also prevents waste of oil and gas resources and protects the rights of mineral

interest owners.

The division encourages EPA to continue to work with the various stakeholders to

develop an appropriate regulatory fram ework for carbon dioxide storage in

depleted oil and gas reservoirs. In developing this framework, EPA should use

the existing Class II UIC regulatory program as a starting point and modify that

program as necessary to address any risks uniquely associated with carbondioxide storage operations. The resulting framework should be flexible enough to

accommodate regional variations in geological structures and engineering

parameters and incorporate the knowledge and experience of the state oil and gas

agencies in regulating enhanced oil and gas recovery operations and natural gas

storage operations.

Thank you for your consideration of these comments.

Sincerely yours,

Lori Wrotenbery, Director

Oil and Gas Conservation Division

Oklahoma Corporation CommissionLetter ID: 0247

Commenter: Lori Wrotenbery

Organization: Oklahoma Co rporation Commission

Letter ID: 0247 Comment ID: 22233 Letter Lines: 22 to 33

Comment Code: 1000 1. General and Administrative Comments

Comment: Re: Docket ID No. EPA-HQ-OW-2008- 0390 (Proposed Federal Requirements

Under the

Underground Injection Control Program fo r Carbon Dioxide Geologic Sequestration

Wells)

The Oil and Gas Conservation Division of the Oklahoma Corporation Commission

regulates oil and gas expl oration and production activiti es and administers the

Class II Underground Injection Control (UIC ) program in the State of Oklahoma.

The division has followed the stakeholder discussions concerning the referenced

proposal with keen interest, particular ly regarding those portions of the

proposal that may affect the management and regulation of the states oil and

gas resources.

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

responses to this comment letter for further de tails. For additional information on EPA's final

regulatory approach, please see the final rule and preamble, including the discussion of the

repermitting of Class II EOR wells for GS , as well as the rulemaking docket.

Letter ID: 0247 Comment ID: 22234 Letter Lines: 35 to 38

Comment Code: 2046 1.5.2.3 Continuing to classify CO2 in jection for EOR/EGR as Class II/

dividing line between Class II and Class VI (seeking comment)

Comment: The division supports the efforts of various groups filing comments on the

proposal to ensure that e nhanced oil and gas recovery projects continue to

operate under the current, well-establis hed and highly effective Class II UIC

regulatory program. The divi sion also supports efforts to develop a regulatory

Individual Response: EPA agrees that injection of CO2 for the primary purpose of enhancing

oil and gas recovery should remain under the Cl ass II Program. The Agen cy believes that the

nature and risks of CO2 inject ion for the primary purpose of l ong term storage poses different

risks than injection for the primary purpose of EOR, and therefore has developed new Class VI

regulations to address these unique risks. For example, the volu me of CO2 anticipated to be

injected for long term storage is significan tly greater than for EO R operations. Reservoir

pressure conditions will also be different, with Class VI injection ope rations involving large

1volumes of CO2 and likely having higher pressures w ithin their storage formations than Class II

EOR projects.

Letter ID: 0247 Comment ID: 22235 Letter Lines: 38 to 42

Comment Code: 2143 1.6.2.1 Comments in favor of inject ion into depleted reservoirs

Comment: regulatory program. The divi sion also supports efforts to develop a regulatory

framework for long-term storage of car bon dioxide in deplet ed oil and gas

reservoirs that not only protects unde rground sources of drinking water, but

also prevents waste of oil and gas resour ces and protects the rights of mineral

interest owners.

Individual Response: EPA agrees that depleted oil and gas fields are promising formations for

GS, provided the Class VI siting, AoR and corr ective action, well construction and operation,

monitoring and testing, and post-inj ection site care and site clos ure requirements are met. The

final GS rule does not preclude injection into oil and gas fields provided ow ners or operators can

demonstrate that GS can be performed in a mann er that protects USDWs from endangerment.

EPA further clarifies that the GS rule is not intended to promote a preference for GS in any

particular formation type, to addr ess use of resources, or to reduce costs associated with GS into

various formations. The focus of the GS rule is to ensure that, where GS is deployed, it is

conducted in a manner that protects USDWs from endangerment. Comments related to the

protection of rights of minera l interests are outside the scope of this rulemaking.

Letter ID: 0247 Comment ID: 22236 Letter Lines: 44 to 53

Comment Code: 2143 1.6.2.1 Comments in favor of inject ion into depleted reservoirs

Comment: The division encourages EPA to continue to work with the various stakeholders to

develop an appropriate re gulatory framework for car bon dioxide storage in

depleted oil and gas reservoirs. In de veloping this framework, EPA should use

the existing Class II UIC regulatory program as a starting point and modify that

program as necessary to address any ri sks uniquely associated with carbon

dioxide storage operations. The resulting fr amework should be flexible enough to

accommodate regional variations in ge ological structures and engineering

parameters and incorporate the knowledge a nd experience of the state oil and gas

agencies in regulating enhanced oil and gas recovery operations and natural gas

storage operations.

Individual Response: EPA believes that building upon th e existing UIC requirements (e.g.,

Class I well requirements) to develop the Class VI GS regulation provides a foundation for

protecting USDWs based on success, field experien ce, and lessons learned about CO2 injection

in other applications. However, EPA also believes that large-scal e GS presents unique technical

23 challenges, including large injection volumes, the relative buoyancy of CO2, its corrosivity in the

presence of water, the potential presence of impu rities in captured CO2, and its mobility within

subsurface geologic formations. For this reason, EP A has finalized the tailored requirements in

the GS rule.