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.Cynthia C. Dongherty

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

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

Dear Director Dougherty: March 27, 2009

On March 17,2009, Environmental Defense Fund (EDF) and Clean Air Task Force (CATF) wrote separate

letters to you reaffirming the importance of suggestions we submitted on December 23, 2008 as part of the

group generally known as the Multi-Stakeholder Group (MSG). We hoped that you would distribute copies

of our March 17 letters to the EPA workgroup convened for this docket if yon thought that distributing the

letters would be appropriate.

One of the subjects discussed in both the December 23 MSG letter and the March 17 ED F and CA TF

letters is the importance, for Safe Drinking Water Act purposes, of: (1) drawing a "bright line" between two

different types of C02 injection projects in oil and gas fields; and (2) more clearly distinguishing injection

projects in oil and gas fields from injection projects in brine formations. As explained in the letters, we

believe there are three different types of C02 injection activity that present three different risk profiles and

ought to be regulated in three different ways. We asked that the Agency solicit public comment on this

subject as part of a NODA process.

While the December 23 and March 17 letters discussed in a general way this three-fold approach to

managing the risks of C02 injection, and while the December 23 letter suggested "bright line" language we

believe should be used to distinguish between the two types of injection projects in oil and gas fields, none

of these letters set forth language that might be used to regulate the type of oilfield project that poses higher

risk to the environment. We are aware that other MSG participants arc forwarding to you today language

that might be used for this purpose in Class II or in a new Class VII. We expect to support portions of this

language and recommend changes in other portions. In order to move the process forward, however, we

urge you to publish the language for public comment as part of the contemplated NODA. EDF and CATF

will continue to work with other MSG participants on the issue and look forward to the opportunity to

make detailed comments on this subject in the future.

Sincerely,

A. Scott Anderson

Senior Policy Advisor

Environmental Defense Fund Kurt Waltzer

CCS Development Coordinator

Clean Air Task ForceLetter ID: 0296

Commenter: A. Scott Anderson

Organization: Environmental Defense Fund

Letter ID: 0296 Comment ID: 29476 Letter Lines: 29 to 58

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: On March 17,2009, Environmental Defense F und (EDF) and Clean Air Task Force

(CATF) wrote separate letters to you r eaffirming the importance of suggestions

we submitted on December 23, 2008 as part of the group generally known as the

Multi-Stakeholder Group (MSG). We hoped th at you would distribute copies of our

March 17 letters to the EPA workgroup c onvened for this docket if you thought

that distributing the letter s would be appropriate.

One of the subjects discussed in both th e December 23 MSG letter and the March

17 EDF and CATF letters is the importance , for Safe Drinking Water Act purposes,

of: (1) drawing a "b right line" between two differe nt types of CO2 injection

projects in oil and gas fields; and (2) more clearly disti nguishing injection

projects in oil and gas fields from inj ection projects in brine formations. As

explained in the letters, we believe th ere are three different types of CO2

injection activity that present three di fferent risk profile s and ought to be

regulated in three different ways. We asked that the Agency solicit public

comment on this subject as part of a NODA process.

While the December 23 and March 17 letters discussed in a general way this

three-fold approach to managing the risks of CO2 injection, and while the

December 23 letter suggested "bright line" language we believe should be used to

distinguish between the two types of injection projects in oil and gas fields,

none of these letters set forth language that might be used to regulate the type

of oilfield project that po ses higher risk to the envir onment. We are aware that

other MSG participants are forwarding to you today language that might be used

for this purpose in Class II or in a new Class VII. We expect to support

portions of this language and recommend chan ges in other portions. In order to

move the process forward, however, we urge you to publish the language for

public comment as part of the contemplated NODA. EDF and CATF w ill continue to

work with other MSG participants on the issue and look forward to the

opportunity to make detailed comments on this subject in the future.

Individual Response: EPA clarifies that the GS rule doe s not change the requirements or

address Class II EOR operations. EPA believes that injection of CO2 for the primary purpose of

enhancing oil and gas recovery should remain under the Class II Program. EPA 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

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

injected for long term storage is significantly gr eater than for ER operatio ns. Reservoir pressure

conditions will also be different, with Class VI injection operations involving large volumes of

CO2 and likely having higher pressures within th eir storage formations than Class II EOR

projects.

The final Class VI regulations re quire that any owner or operato r injecting CO2 for the primary

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

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

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

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

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

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

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

while allowing for site-specific flexibility. For more information, please see the discussion on

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