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.
TRI-STATE GENERATION AND TRANSMISSION ASSOCIATION, INC. 

HEADQUARTERS: P,O. BOX 33695 

Water Docket 

Environmental Protection Agency 

Mailcode: 4101 T 

1200 Pennsylvania Ave., NW 

Washington, DC 20460 

Submitted also via www.regulations.gov 

Re: Docket ID EPA-HQ-OW-2008-0390 

74 Fed. Reg. 44802, Aug. 31, 2009 

DENVER, COLORADO 80233-0695 303-452-6111 

October 15, 2009 

Comments on Notice of Data Availability for Federal Requirements Under the 

Underground Injection Control (UIC) Program for Carbon Dioxide (C02) Geologic 

Sequestration (GS) Wells 

Tri-State Generation and Transmission Association, Inc. (Tri-State) transmits this letter to 

provide further comment about the Environmental Protection Agency's (EPA) proposed Federal 

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

(C02) Geologic Sequestration Wells; Notice of Data Availability and Request for Comment 

(NODA) [74 Fed. Reg. 44802 (Aug. 31, 2009)]. These comments supplement Tri-State's 

December 22,2008 letter about EPA's proposal to regulate CO2 GS under the UIC program. 

[See 73 Fed. Reg. 43492 (July 25, 2008)]. 

Tri-State is a not-for-profit, wholesale electric power supply cooperative providing power 

to 44 member distribution systems serving customers throughout a 250,000 square-mile territory 

in Colorado, Nebraska, New Mexico, and Wyoming. Tri-State provides electricity to members 

based on a diverse mix of generation sources including coal, natural gas, hydroelectric, and wind 

power. Tri-State is a member ofthe National Rural Electric Cooperative Association (NRECA) 

and the Utilities Solid Waste Activities Group (USWAG). Tri-State incorporates here by 

reference NRECA's and USW AG's written comments. 

Tri-State recognizes that the development of a viable carbon capture and sequestration 

(CCS) regulatory program has been cited by many as a prerequisite to the implementation of 

energy reform initiatives involving carbon reduction measures. Indeed, earlier this week United 

States Secretary of Energy Stephen Chu wrote to an international audience that 

Coal accounts for 25 percent of the world's energy supply and 40 percent of carbon 

emissions, and is likely to be a major and growing source of electricity generation for the 

foreseeable future. 

AN EQUAL OPPORTUNITY / AFFIRMATIVE ACTION EMPLOYER 

A Touchstone Energy' Cooperative ..)r( 

--

CRAIG STATION 

P.O. BOX 1307 

CRAIG, co 81626-1307 

970·824-4411 

ESCALANTE STATION NUCLA STATION 

P.O . BOX 577 P.O. BOX 698 

PREWJIT. NM 87045 NUClA, CO 81424 ·0698 

505-876-2271 970-864-7316 
Water Docket 

October IS, 2009 

Page 2 

For this reason. I believe that we must make it our goal to advance carbon capture and 

storage technology to the point where widespread. affordable deployment can begin in 8 

to 10 years. (emphasis original) 

The Secretary of Energy's October 12 letter goes on to itemize the several billion dollars 

that the U.S. Department of Energy is currently investing in CCS technologies and 

demonstration projects. 

EPA predicts that the electric power sector "will most likely be the largest potential 

market for [CCS] technologies," and predicts that CCS technology could lead to C02 reductions 

of approximately 80-90% at a single plant [73 Fed. Reg. 44354, 44492 (July 30, 2008)]. TriState believes that decades of involvement with the management of fossil fuel combustion 

materials provides our organization with a valuable knowledge base and perspective from which 

to provide meaningful input on the development of EPA's UIC regulations for C02 OS. 

Tri-State applauds EPA's careful approach to the development of C02 OS regulations, 

including this most recent release of additional data. Because the technology contemplated in 

the C02 OS proposal is not currently commercially deployed, it is essential a Final Rule be 

flexible enough to accommodate developments in information and technology related to carbon 

sequestration. It is critical that EPA develop a regulatory regime in order to allow for sitetailored requirements that will reflect the vast differences among various potential C02 OS sites. 

Tri-State supports EPA's suggestion to adopt a flexible waiver process to allow for C02 

OS injection above and between underground sources of drinking water (USDWs) [74 Fed. Reg. 

at 44810]. As stated in the NODA, EPA's original proposal to define Class VI injection wells as 

those used for injection of C02 beneath the lowermost formation containing a USDW (73 Fed. 

Reg. at 43511) would preclude injection of C02 into zones between and above USDWs, thereby 

restricting or rendering impossible C02 OS sites in large areas of the country with deep USDWs 

[74 Fed. Reg. at 44808]. The original proposal would also prohibit C02 injection into many 

shallow formations such as coal seams and basalts [73 Fed. Reg. at 43512]. As the NODA 

observes, a number of states have indicated that regions with very deep and layered USDWs 

could not undertake C02 OS projects because injectors could not comply with the proposed 

injection depth and well construction requirements [74 Fed. Reg. at 44809]. 

EPA addresses these concems by the proposal set forth in the NODA to keep the 

originally proposed injection depth requirement, but allow owners or operators to apply for a 

site-specific waiver from those injection depth requirements upon making a demonstration that 

such injection can be undertaken in a manner that protects public health and USDWs [Id. at 

44810]. Tri-State believes that such a flexible approach would ensure adequate protection of 

USDWs while recognizing the vast geographic and topographic differences between potential 

AN EQUAL OPPORTUNITY I AFFIRMATIVE ACTION EMPLOYER 

A Touchstone EnergY- Cooperative -t".)r( 

--
Water Docket 

October 15, 2009 

Page 3 

C02 GS sites throughout the country, allowing for maximization of safe C02 storage capacity 

nationwide. 

Tri-State urges EPA to consider requiring the inclusion of such a waiver provision, rather 

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

UIC Program Directors [Id. at 44811]. Inclusion of a waiver provision would retain for UIC 

Program Directors prerogative to decline to grant any waivers where not necessary or 

appropriate. See id. Since C02 GS technology is rapidly developing, it is prudent to structure a 

regulatory framework that is flexible enough to respond to developments in the field. 

Tri-State appreciates the opportunity to comment on this new data and EPA's new 

proposal for an injection depth waiver process. If you have questions regarding these comments, 

please contact Andy Berger at 303-254-3171. 

BAW:AB:pvt 

AN EQUAL OPPORTUNITY / AFFIRMATIVE ACTION EMPLOYER 

A Touchstone EnergY-Cooperative 1-.Jrr( 

--

Sincerely, 

Barbara A. Walz 

Vice President 

Environmental 
Letter ID: 0346  

Commenter: Barbara A. Walz  

Organization: Tri‐State Generation and Transmission Association, Inc. (Tri‐State)  

Letter ID: 0346 Comment ID: 27886 Letter Lines: 51 to 65  

Comment Code: 6000 6. Other Comments that are Out of Scope for the NODA  

Comment: Tri‐State recognizes that the development of a viable carbon capture and  

sequestration (CCS) regulatory program has been cited by many as a prerequisite  

to the implementation of energy reform initiatives involving carbon reduction  

measures. Indeed, earlier this week United States Secretary of Energy Stephen Chu  

wrote to an international audience that coal accounts for 25 percent of the world's energy supply and 40

percent of  

carbon emissions, and is likely to be a major and growing source of electricity  

generation for the foreseeable future.  

For this reason. I believe that we must make it our goal to advance carbon  

capture and storage technology to the point where widespread. affordable  

deployment can begin in 8 to 10 years. (emphasis original)  

The Secretary of Energy's October 12 letter goes on to itemize the several  

billion dollars that the U.S. Department of Energy is currently investing in CCS  

technologies and demonstration projects.  

Individual Response: This comment is outside the scope of the Notice of Data Availability and the UIC

Program’s authority under the GS rulemaking.  

Letter ID: 0346 Comment ID: 27887 Letter Lines: 67 to 73  

Comment Code: 6000 6. Other Comments that are Out of Scope for the NODA  

Comment: EPA predicts that the electric power sector "will most likely be the largest  

potential market for [CCS] technologies," and predicts that CCS technology could  

lead to C02 reductions of approximately 80‐90% at a single plant [73 Fed. Reg.  

44354, 44492 (July 30, 2008)]. TriState believes that decades of involvement  

with the management of fossil fuel combustion materials provides our  

organization with a valuable knowledge base and perspective from which to  
provide meaningful input on the development of EPA's VIC regulations for CO2 GS.  

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.  

Letter ID: 0346 Comment ID: 27888 Letter Lines: 75 to 82  

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

Comment: Tri‐State applauds EPA's careful approach to the development of CO2 GS  

regulations, including this most recent release of additional data. Because the  

technology contemplated in the CO2 GS proposal is not currently commercially  

deployed, it is essential a Final Rule be flexible enough to accommodate  

developments in information and technology related to carbon sequestration. It  

is critical that EPA develop a regulatory regime in order to allow for  

site tailored requirements that will reflect the vast differences among various  

potential CO2 GS sites.  

Individual Response: EPA believes that 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 to incorporate new

research, data, and information about GS. The Agency believes that an adaptive approach provides Class

VI owners or operators the flexibility to use and apply newly developed technologies for GS as they

become available in the future.  

EPA agrees with the commenter that a site‐specific approach to permitting GS sites is important. The

final rule provides Class VI owners or operators the flexibility to select technologies appropriate for a

specific site and affords the Director flexibility to establish permit requirements on the basis of site‐

specific characteristics. 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: 0346 Comment ID: 27889 Letter Lines: 84 to 106  

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

Comment: Tri‐State supports EPA's suggestion to adopt a flexible waiver process to allow  

for CO2 GS injection above and between underground sources of drinking water  

(USDWs) [74 Fed. Reg. at 44810). As stated in the NODA, EPA's original proposal  
to define Class VI injection wells as those used for injection of C02 beneath  

the lowermost formation containing a USDW (73 Fed. Reg. at 43511) would preclude  

injection of CO2 into zones between and above USDWs, thereby restricting or  

rendering impossible CO2 GS sites in large areas of the country with deep USDWs  

[74 Fed. Reg. at 44808). The original proposal would also prohibit CO2 injection  

into many shallow formations such as coal seams and basalts [73 Fed. Reg. at  

43512). As the NODA observes, a number of states have indicated that regions  

with very deep and layered USDWs could not undertake CO2 GS projects because  

injectors could not comply with the proposed injection depth and well  

construction requirements [74 Fed. Reg. at 44809).  

EPA addresses these concerns by the proposal set forth in the NODA to keep the  

originally proposed injection depth requirement, but allow owners or operators  

to apply for a site‐specific waiver from those injection depth requirements upon  

making a demonstration that such injection can be undertaken in a manner that  

protects public health and USDWs [Id. at 44810). Tri‐State believes that such a  

flexible approach would ensure adequate protection of USDWs while recognizing  

the vast geographic and topographic differences between potential CO2 GS sites  

throughout the country, allowing for maximization of safe CO2 storage capacity  

nationwide.  

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.  

Letter ID: 0346 Comment ID: 27890 Letter Lines: 108 to 115  

Comment Code: 3390 3.3.9. Comments Regarding State Discretion to Adopt the Waiver Approach  
Comment: Tri‐State urges EPA to consider requiring the inclusion of such a waiver  

provision, rather than leaving the adoption of an injection depth waiver process  

to the discretion of the individual UIC Program Directors [Id. at 44811].  

Inclusion of a waiver provision would retain for UIC Program Directors  

prerogative to decline to grant any waivers where not necessary or appropriate.  

See id. Since CO2 GS technology is rapidly developing, it is prudent to  

structure a regulatory framework that is flexible enough to respond to  

developments in the field.  

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.

EPA recognizes that GS technologies are rapidly developing. For this reason, the Agency is adopting an

adaptive rulemaking approach. EPA plans, every six years, to collect and review data on GS projects,

including information on any Class VI wells granted a waiver of the injection depth requirements, 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.