### 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.

# QIIEST~R

October 15, 2009

Water Docket

Environmental Protection Agency

Mailcode: 4101 T

1200 Pennsylvania Ave., N.W.

Washington DC 20460

Attention: Docket ID No. EPA-HQ-OW-2008-0390 R0StHYfC02, 10(;.

V'n:nhtcticm CMnpwny

Re: Comments on Federal Requirements Under the Underground Injection Control (UIC)

Program for Carbon Dioxide (C02) Geologic Sequestration (GS) Wells.

Questar Exploration & Production Company appreciates the opportunity to comment on

EPA's proposed rule for Carbon Dioxide Geologic Sequestration (GS) Wells under the

Underground Injection Control Program, and the associated Notice of Data Availability.

Questar Corporation is a natural gas-focused energy company headquartered in Salt Lake City,

Utah. Questar Exploration & Production Company (Questar) is one of Questar Corporation's

subsidiaries that explores for, develops and produces natural gas and oil in the Rockies and

Midcontinent regions of the United States.

The preliminary field data from DOE-sponsored projects, GS-related research and

changes EPA is proposing for injection depth requirements for Class VI wells demonstrate that

while there is much to be learned about long-term sequestration of Carbon Dioxide, there is a

lot we already know about the safe injection of Carbon Dioxide for enhanced oil and gas

recovery. Given that, it is important to draft the upcoming rules in a way that recognizes the

continuation and appropriateness of the existing enhanced oil and gas recovery Class II permit

while providing enough flexibility in the new Class VI permit to allow GS to move forward in a

safe and economic way. In this regard, Questar adopts and incorporates herein the various

documents that make up the comments on the underlying rule submitted by API on December

23,2008.

Questar appreciates EPA's Willingness to reassess its initial prohibition of injection to

formations below the lowermost USDW. As stated in the API comments, that proposal was"not necessary for the protection of USDWs and would remove a significant number of viable

formations from consideration as GS sites," using the Salt Creek EOR project in Wyoming as an

example. Therefore, Questar supports the availability of a waiver provision so long as it is

workable and available in practice. Including the Public Water Supply Supervision (PWSS)

Program Director in the approval process, like many of the underlying proposed regulations, is

unnecessary and only has the potential of slowing down the implementation of GS in

appropriate areas. Along those lines, Questar wishes to reinforce that the general well

construction and operation requirements set forth in the proposed rules do not incorporate the

lessons learned from industry's long-term implementation of enhanced oil and gas recovery,

and will ultimately make it more difficult to employ GS without providing the additional safety

benefits one would expect from adopting the more onerous Class I hazardous well construction

and operating requirements that EPA is proposing. The lessons we have learned from EOR

activities can and should be applied as EPA moves forward with its rulemaking.

Thank you for the opportunity to comment on the proposed rules and NODA. Please

feel free to contact me if you have any questions.

Sincerely,

ALetter ID: 0374

Commenter: Mike Smith

Organization: Questar Exploration & Production Company

Letter ID: 0374 Comment ID: 28117 Letter Lines: 39 to 49

Comment Code: 1000 1. General Comments on the Notice of Data Availability

Comment: The preliminary field data from DOE

‐ sponsored projects, GS

‐ related research and

changes EPA is proposing for injection depth requirements for Class VI wells

demonstrate that while there is much to be learned about long

‐ term sequestration

of Carbon Dioxide, there is a lot we already know about the safe injection of

Carbon Dioxide for enhanced oil and gas recovery. Given that, it is important to

draft the upcoming rules in a way that recognizes the continuation and

appropriateness of the existing enhanced oil and gas recovery Class II permit

while providing enough flexibility in the new Class VI permit to allow GS to

move forward in a safe and economic way. In this regard, Questar adopts and

incorporates herein the various documents that make up the comments on the

underlying rule submitted by API on December 23,2008.

Individual Response: EPA recognizes that the oil and gas industry has decades of experience injecting

CO2 for the purpose of ER. The GS rulemaking builds upon existing experience and knowledge about

safe injection practices in ER and other injection industries, with tailored requirements that address the

unique nature of CO2 injection for GS.

The final rule does not preclude CO2 injection for ER under Class II permits. However, the rule requires

re

‐ permitting of Class II wells (as Class VI) if the primary purpose of the injection transitions from ER to

long

‐ term storage, and establishes specific, risk

‐ based criteria to be considered by the Director in

making this determination (§144.19). For more information on the transition from Class II to Class VI,

see the responses to comments on the proposed rule in the rulemaking docket.

Letter ID: 0374 Comment ID: 28118 Letter Lines: 51 to 57

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

Comment: Questar appreciates EPA's Willingness to reassess its initial prohibition of

injection to formations below the lowermost USDW. As stated in the API comments,

that proposal was "not necessary for the protection of USDWs and would remove asignificant number of viable formations from consideration as GS sites," using

the Salt Creek EOR project in Wyoming as an example. Therefore, Questar supports

the availability of a waiver provision so long as it is workable and available

in practice. Including the Public Water Supply Supervision (PWSS) 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. 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.

EPA is developing guidance on the injection depth waiver process. The guidance describes the

recommended approach an owner or operator may follow when submitting a waiver application,

processing waiver applications by the UIC and PWSS Program Directors, and additional considerations

that may apply to projects that have been issued waivers. This guidance will be available on EPA’s

website at water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Letter ID: 0374 Comment ID: 28119 Letter Lines: 57 to 60

Comment Code: 3350 3.3.5. Requirement to Submit Waiver Application to UIC and PWSS Program

Directors

Comment: in practice. Including the Public Water Supply Supervision (PWSS) Program

Director in the approval process, like many of the underlying proposed

regulations, is unnecessary and only has the potential of slowing down the

implementation of GS in appropriate areas. Along those lines, Questar wishes to

Individual Response: EPA believes the consultation with the PWSS Director process is necessary and

appropriate to ensure that water system concerns are considered when evaluating a waiver application.

The final GS rule includes a requirement that the UIC Program Director consult with the PWSS Directors

of all states, Territories, and Tribes having jurisdiction within the AoR of a well for which a waiver issought as specified in §146.95(b)(2). EPA clarifies that the communication with the PWSS Director is

consultative and does not constitute a final decision making.

Letter ID: 0374 Comment ID: 28120 Letter Lines: 60 to 68

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

Comment: implementation of GS in appropriate areas. Along those lines, Questar wishes to

reinforce that the general well construction and operation requirements set

forth in the proposed rules do not incorporate the lessons learned from

industry's long

‐ term implementation of enhanced oil and gas recovery, and will

ultimately make it more difficult to employ GS without providing the additional

safety benefits one would expect from adopting the more onerous Class I

hazardous well construction and operating requirements that EPA is proposing.

The lessons we have learned from EOR activities can and should be applied as EPA

moves forward with its rulemaking.

Individual Response: This comment pertains to EPA’s proposed GS rule (73 FR 43492) and is outside the

scope of the Notice of Data Availability. Please see responses to comments on the proposed rule for

EPA’s response to similar comments.