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.
March 17, 2009 

Cynthia C. Dougherty 

Director 

Office of Ground Water and Drinking Water 

U. S. Environmental Protection Agency 

1200 Pennsylvania Ave., NW. 

Washington, DC 20460 

Re: Proposed Rule for Geologic Sequestration of Carbon Dioxide 

Dear Director Dougherty: 

The organizations identified by the signatures at the end of this letter are writing to advise 

you of our further progress in addressing through a multi-stakeholder process issues raised 

by the Environmental Protection Agency (EPA) proposed rule for geologic sequestration of 

carbon dioxide under the Safe Drinking Water Act (SDWA). "Federal Requirements Under 

the Underground Injection Control (UIC) Program for Carbon Dioxide (CO2) Geologic 

Sequestration (GS) Wells," 73 Fed. Reg. 43491-541 (July 25, 2008), Docket ID No. EPA–

HQ–OW–2008–0390. As indicated in the December 23, 2008 letter that we signed along 

with a number of other organizations, we have continued the multi-stakeholder discussions 

and have made great progress toward developing additional recommendations reflecting 

common views on a number of the issues in this rulemaking, including specifically: whether 

GS should be restricted to formations below the lowermost underground source of drinking 

water (USDW); GS in basalts, coal seams, salt caverns, and shales; potential for interference 

between GS projects; coverage for area of review and corrective action requirements; well 

construction requirements, cement bond assessments; annulus pressure; shut-off valves; 

emergency response requirements, and definitions for transmissive faults and fractures, 

carbon dioxide stream, confining zone, and area of review. We are working diligently toward 

submitting consensus recommendations on these issues that should help the Agency develop 

a rule that will allow GS technology to be permitted under appropriate injection well classes 

while also ensuring protection of underground sources of drinking water as well as human 

health and the environment. 

Following the December 23, 2008 submission, the stakeholders have focused in part on the 

potential publication of a Notice of Data Availability (NODA) that your Office has 

included—albeit with the qualifier “if appropriate”—on a rulemaking schedule discussed at 

various meetings of organizations over the past year. In the December 23 letter, the 

stakeholders described the agreement to include in Class II a classification (b)(4) that 

establishes a “bright line” definition for wells that inject CO2 for EOR/EGR and GS. The 

participating stakeholders agree that this approach is preferable to the approach in the 

proposed rule and recommended, consistent with EPA’s intent, that these wells should 

remain in Class II and be subject to the current requirements of Class II. We also agreed that 

wells used for GS in oil and gas reservoirs that do not meet the criteria of (b)(4) should be 

subject to additional requirements beyond current Class II requirements. That letter noted 
Cynthia C. Dougherty, Director 

March 17, 2009 

Page 2

agreement to define such wells as wells used “for geologic sequestration in oil and gas 

formations and where the criteria of paragraph (b)(4) are not met.” In our discussions since 

December, we have agreed that these wells should be regulated in a separate class or 

subclass, and we recommend that the Agency include in its plans for both publication of a 

NODA and the final rule the approach of regulating these wells used for GS in oil and gas 

reservoirs under a separate classification. We are still committed to and making progress in 

our multi-stakeholder discussions toward developing recommendations on the specific 

requirements that should be applied to this category of wells. 

Sincerely, 

Kyle Isakower 

Director, of Policy Analysis 

American Petroleum Institute 

William L. Fang 

Deputy General Counsel 

Edison Electric Institute 

Robert F. Van Voorhees 

Counsel to Carbon Sequestration Council (CCS Contact Group) 
Letter ID: 0289 

Commenter: Kyle Isakower 

Organization: American Petroleum Institute 

Letter ID: 0289 Comment ID: 25276 Letter Lines: 57 to 74 

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

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

Comment: year. In the December 23 letter, the stakeholders described the agreement to 

include in Class II a classification (b)(4) that establishes a "bright line" 

definition for wells that inject CO2 for EOR/EGR and GS. The participating 

stakeholders agree that this approach is preferable to the approach in the 

proposed rule and recommended, consistent with EPA’s intent, that these wells 

should remain in Class II and be subject to the current requirements of Class 

II. We also agreed that wells used for GS in oil and gas reservoirs that do not 

meet the criteria of (b)(4) should be subject to additional requirements beyond 

current Class II requirements. That letter noted agreement to define such wells 

as wells used "for geologic sequestration in oil and gas formations and where 

the criteria of paragraph (b)(4) are not met." In our discussions since 

December, we have agreed that these wells should be regulated in a separate 

class or subclass, and we recommend that the Agency include in its plans for 

both publication of a NODA and the final rule the approach of regulating these 

wells used for GS in oil and gas reservoirs under a separate classification. We 

are still committed to and making progress in our multi-stakeholder discussions 

toward developing recommendations on the specific requirements that should be 

applied to this category of wells. 

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

oil and gas recovery should remain under the Class II Program. However, EPA believes that 

there are significant differences between how EOR and GS projects are operated, as well as the 

different risks posed by these different injection activities. The new tailored approach of the GS 

rule was designed to address the general risks deep injection may pose to USDWs and was 

tailored specifically to address the risks posed by long term storage of CO2 (i.e., very large 

volumes, very long time-periods, and reservoir pressure conditions). 

The final Class VI regulations require that any owner or operator injecting CO2 for the primary 

purpose of long term storage obtain a Class VI permit with some special consideration for the 

fact that they are transitioning from a well not originally designed to meet Class VI requirements. 

The Director has the authority to determine at what point a Class VI permit is required for those 

projects that are transitioning from the primary purpose of EOR to long term storage of CO2. 

The final regulation provides a set of technical factors for the Director to evaluate in making this 

determination, at §144.19. EPA believes that this approach provides sufficient protection of 

USDWs when there is an increased risk to USDWs as compared to traditional Class II operations 

while allowing for site-specific flexibility. 

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EPA is developing guidance on transitioning permits from Class II to Class VI. The guidance 

will assist Directors in determining whether an injection project should be transitioned from 

Class II where the primary purpose is oil and gas production to Class VI where the primary 

purpose is long-term storage of large volumes of CO2. The guidance describes recommended 

methods the Director may use to evaluate changes in risk to USDWs from projects, and how the 

Director may determine whether a project should be regulated within the Class II or Class VI 

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

http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm. For more information, please 

see the discussion on transition of Class II wells in the preamble to the final GS rule.