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.These comments have been prepared by Battelle researchers as part of their work for MRCSP. They do not necessarily reflect the official view of Battelle, the U.S. DOE, or sponsors and members entities of MRCSP. 24 December 2008

Water Docket U.S. Environmental Protection Agency

Mailcode: 2822T 1200 Pennsylvania Ave NW Washington, DC 20460 Email address: OW-Docket@epa.gov

Subject: Docket ID No. EPA-HQ-OW-2008-390 Underground Injection Control (UIC ) Class VI well rule proposed 25 July 2008 at 73 FR 43492-43541

Enclosed please find some comments prepared by th e Battelle geologic storage researchers working on the Midwest Regional Carbon Sequ estration Partnership (MRCSP) on USEPA Proposed Rule - Federal Requirements under UIC Program for CO 2 Geologic Sequestration Wells (Docket ID No. EPA-HQ-OW2008-390). We appreciate the opportunity to participate in formulation of these requirements for geologic sequestration. These comments reflect MRCSP experi ence in permitting and implementing three Phase II

CO 2 injection tests and the MRCSP Phase III project . While the MRCSP includes over 30 different members, the comments expressed herein do not necessar ily reflect opinions of the individual members of

the MRCSP.

If you have any questions or require additional information, please contact Neeraj Gupta (614) 424-3820, e-mail gupta@battelle.org or Joel Sminchak ( 614) 424-7392, e-mail Sminchak@battelle.org.

Sincerely,

Dr. Neeraj Gupta

Senior Research Leader Geologic Storage Battelle Energy TechnologyComments on EPA-HQ-OW-2008-390 Neeraj Gupta and Joel Sminchak 12/24/2008, Page 2 Battelle

These comments have been prepared by Battelle researchers as part of their work for MRCSP. They do not necessarily reflect the official view of Battelle, the U.S. DOE, or sponsors and members entities of MRCSP. Review and Comments on Proposed Rule - Federal Requirements under UIC Program for

CO 2 Geologic Sequestration Wells Docket ID No. EPA-HQ-OW-2008-390

Prepared by Neeraj Gupta and Jo el Sminchak for Battelle/MRCSP December 24, 2008

Introduction and Background

This document summarizes review and comments from Ba ttelle researchers’ under the regulatory work of Midwest Regional Carbon Sequestrati on Partnership’s (MRCSP) on the USEPA Proposed Rule- Federal Requirements under UIC Program for CO 2 Geologic Sequestration Wells (Docket ID No. EPA-HQ-OW2008-390). These comments reflect our experience in permitting and implementing three Phase II CO 2 injection tests and the MRCSP Phase III project, as we ll as work on several other research projects during last 12 years of CCS research at Battelle:

Site Location Agency P ermit Status Test Status

Appalachian Basin Shadyside,

OH Ohio EPA UIC Program Complete Injectivity testing completed

Cincinnati Arch Rabbit Hash,

KY USEPA Region 4 Draft permit in public comment phase Pending permit

Michigan Basin Otsego Co.,

MI USEPA Region 5 Complete 10,241 tons CO 2 injected Feb-Mar

2008. Additional injection under planning.

Phase III TAME Greenville,

OH Ohio EPA UIC Program Permit application in preparation Planning stages

The analysis also reflects Battelle experience w ith the UIC permitting of the AEP Mountaineer CO 2 storage project, which is targeting 4 years of injection of over 100,000 metric tons CO 2 /yr at the AEP Mountaineer plant in New Haven, WV. While the MRCSP includes over 30 different members, the comments expressed herein do not n ecessarily reflect opinions of the individual members of the

MRCSP.

The MRCSP is one of seven partnerships in a nationwide effort to determine regionally-appropriate carbon sequestrati on options and opportunities. These partnerships are part of an overall effort by the U.S. Department of Energy’s National Energy Technology Laborat ory (DOE/NETL) to develop robust strategies for mitigating carbon dioxide emissions. The MRCSP was formed to assess the technical potential, economic viability, and public acceptability of carbon sequestration within its Region.

The MRCSP region consists of eight contiguous states: Indiana, Kentucky, Maryland, Michigan, New York, Ohio, Pennsylvania, and West Virginia. The MRCSP includes over 30 organizations from the research community, energy industry, universities, non-government, and gove rnment organizations. In the first phase of research, which took place over a two year period ending in September 2005, the MRCSP characterized carbon sequestration opportunities in the region. MRCSP is now involved in a four yearComments on EPA-HQ-OW-2008-390 Neeraj Gupta and Joel Sminchak 12/24/2008, Page 3 Battelle

These comments have been prepared by Battelle researchers as part of their work for MRCSP. They do not necessarily reflect the official view of Battelle, the U.S. DOE, or sponsors and members entities of MRCSP. Phase II effort that began in October 2005. This phase will conduct several small-scale field tests of sequestration in different locations around the region to evaluate various sequestration options in realworld settings. The MRCSP Phase III project will involve sequestration of more than 1 million metric

tons CO 2

.

General and Specific Comments on Proposed Regulations

Adaptive Approach - Overall the proposed policy presents a comprehensive framework for geologic sequestration (GS). The adaptive a pproach seems especially useful fo r enabling early adopters to pursue GS while allowing flexibility for adjustments in the future based on technology development and lessons

learned at individual sites.

Permit Organization - The proposed regulation presents a large amount of material spread throughout the document. In general, it has been easier to co mplete the permit process with the basic UIC form with the simplified list of attachments (this procedure was used for Region 4 and Region 5). Thus, the MRCSP would encourage EPA to prepare suggested fo rmats and a systematically organized list of information and documents required for the permit.

Encouraging Innovation and Experimental Projects – We believe that USEPA recognizes that many facets of GS site selection, implementation, and m onitoring are still under technological assessment and innovation phase. Many of the concepts and technolog ical options are being evaluated under current field demonstration programs by Regional Partnerships a nd other projects across the world. The success of these existing and future experimental projects is heavily dependent on permitting process being as simple as possible. USEPA UIC Guidance 83 allowing the use of Class V experimental wells has been a very useful mechanism for facilitating experimental projects . In fact, if the proposed Class Vi framework was to be applied to smaller-scale t ests currently underway, it is our belief that many projects would have financial, logistical, or technical difficulties in moving to field stage. With the proposed regulation in the public comment phase, MRCSP has already observed th at the permit regulations for even small-scale field tests (such as MRCSP East Bend site and AEP Mountaineer Project) are becoming too onerous compared to similar projects permitted prior to the issuance of draft regulations. For example, the postinjection monitoring durations have become much l onger with the regulators citing the draft regulation as a basis for requirements. Such a trend will certainly adversely affect future experimental projects and lead to less new data being available to all stakeholders. We strongly encourage EPA to 1) continue the existing option for using Class V experimental well permits option and/or speci fically allow for a more simplified and less onerous permitting requirements for such project.

Complexity and Consistency of Regulations – We recognize that EPA has attempted to provide a great deal of flexibility in most aspects of the regulations, while incorporating most of currently known concepts and technologies in permitting, operation, an d monitoring of the sites. The flexibility has primarily been incorporated through making the requirements subject to “directors” decision. Our concern is that some directors may choose to require all of the numerous requirements mentioned in the permit, rather then selectively requir ing an appropriate portfolio of safe guards. Such an approach could deter operators from considering the GS as an option for CO 2 mitigation. Another concern is that the requirements will be applied with in consistent level of flexibility in various regions and states, making some regions more or less favorable for GS. We encourage EPA’s continuing oversight and guidance in ensuring that the regulations are applied consisten tly and with a reasonable selection of requirements.

Page 48 “Grandfather” Status - It is unclear how this would affect existing MRCSP Phase II Test sites. These host sites have been very accommodating in suppor ting these small scale tests and it is unclear if they would be subject to long term monitoring or a llowed to be closed out under the original Class V CO 2Comments on EPA-HQ-OW-2008-390 Neeraj Gupta and Joel Sminchak 12/24/2008, Page 4 Battelle

These comments have been prepared by Battelle researchers as part of their work for MRCSP. They do not necessarily reflect the official view of Battelle, the U.S. DOE, or sponsors and members entities of MRCSP. experimental policy the wells were permitted under. Clarification that the small scale tests would be allowed to continue injection under their original permit conditions be closed out under their original permits would be helpful to the pioneers of this tech nology, unless of course the site hosts wish to convert to a Class VI well under new regulations for longer-term..

Page 54 CO 2 Composition Requirements and Hazardous Waste under RCRA - While we agree some chemical impurities may cause CO 2 to be designated hazardous waste, there must be more clear guidance on this issue. In the MRCSP tests, each regulator y agency had different requirements on this issue injectate composition and analysis, even for commercial CO 2 . One agency required injection to cease if the injectate was above any maximum contaminant level (MCL) for groundwater, which is a large list of chemicals. Another state agency asked for some technically infeasible analyses on the CO 2 stream (pH, Fluouride, Mercury). Some impurities like H 2 S and hydrocarbons are naturally occurring in most deep saline formations anyway, so we would discourage setting limits on these items. Another significant aspect is the composition of CO 2 derived from various industrial, power generation, and capture processes. All of these are likely to result in minor differences in chemical compositions. In most cases the concentration of hazardous impurities is likely to be very low. The incremental environmental impact of these minor or trace impurities in deep forma tions that already have brine and will have CO 2 must be

demonstrated before these are excluded from the Class VI injection wells. EPA is encouraged to evaluate the range of potential impurities from various streams, their environmental impact if any, and provide more specific guidance on this topic. The evaluation should also assess how many of the GS projects could become infeasible due to this requireme nt. Finally, EPA should clarify whether CO 2 streams with RCRA level of impurities can be injected under Class I permits.

Page 61

, Injection Zone and Confining Layer - Conditions under which “director” may require a secondary containment/buffer zone should be more clear ly defined to provide regulatory certainty. In addition, in definition of what constitutes a secondary containment or buffer zone is highly subjective and a matter of individual opinions. Therefore, more clarity on how these zones should be selected is requested.

Page 63

, Geochemical Data - The proposed requirements ask for geochemical data on injection zone, confining zone, any underground source of drinking water, and any other important zone. This may be a

burdensome amount of information for GS sites. Wh ile some indication of geochemical parameters may

be obtained from wireline methods, it can be a ch allenge to collect representative brine samples, especially from low permeability caprock s and deep saline formations. It is very unlikely we would even be able to collect samples from many low permeability confining layers. In addition, no guidance on the list of analytes (i.e. cations, anions, metals, physical pa rameters) is provided. We would suggest that data from regional studies and other deep wells also be a llowed as an alternative for defining the geochemical setting.

Page 64, Area of Review Determination/Modeling

- We agree that multiphase numerical models are the best option for determining area of review (AOR) for complex, full-scale injection sites. Simpler analytical models may be used for smaller-scale, short-term tests. Multiphase computer simulations, supported with field data, should be primary tool for managing the storage sites through out the life cycle from site selection, permitting, characterization, opera tions, to post operational monitoring and closure. However, modeling should not be restricted to a single code or type of code. This will stifle innovation, because many more modeling codes are likely to be developed and existing commercial, academic, and national laboratory codes are incorporating new processes and improvements based on lessons learned from field projects. The incorporation of multiphase processes is likely to be a key requirement for

models. However, we do not believe that fully coupled model with CO 2 flow, transport, geochemical, geomechanical, and other processes in a single simulati on for the entire facility and life cycle is currentlyComments on EPA-HQ-OW-2008-390 Neeraj Gupta and Joel Sminchak 12/24/2008, Page 5 Battelle

These comments have been prepared by Battelle researchers as part of their work for MRCSP. They do not necessarily reflect the official view of Battelle, the U.S. DOE, or sponsors and members entities of MRCSP. feasible. Such fully-coupled cod es require extensive computational pow er and are more applicable to evaluating basic science questions.

Page 64, Area of Review Determination

- More clarity on determining the AOR is requested. Currently

it is not clear whether AOR will be based on CO 2 phase spreading, dissolved CO 2 plume, or pressure footprint. Models provide a large amount of information such as CO 2 gas saturation, pressure, and aqueous concentrations. They also involve a fair am ount of uncertainty. Our experience is that small portion of the CO 2 may extend or “finger” much furthe r than the bulk of the injected CO 2 . For example would EPA accept an AOR with a radius containing 90% of the CO 2 as supercritical gas saturation, so that the applicants do not have to account for small-scale fingering or heterogeneities?

Page 72, Corrective Action/Abandoned Wells - We would appreciate more clarity on whether it will be required to plug and abandon wells in zones above confining layers. At our sites, it appears the regulators have expected all inactive wells in the AOR to be plu gged, even if they are not penetrating the injection

zones.

Page 82, Cement and Casing Materials - We suggest that if acid resistant cement and casing are to be required, they should be required only in the injectio n interval and immediate confining layer, which are most likely to be affected by the CO 2 storage zone. The shallower drill strings may use more common materials. This seems a typical practice in most CO 2 applications.

Page 84, Fracture Pressures - We would suggest using a defined equation rather than 90% fracture pressure for injection pressure limits. Michigan and Ohio sites have permitted us ing a general equation to determine maximum allowable surface injection pressure:

Maximum Allowable Surface Injection Pressure =

depth x [(FG – 0.433 x (S.G. + safety factor)] – 14.7

Depth = depth at top of storage interval FG = fracture gradient S.G. (average specific gravity of CO2 in borehole) Safety factor = 0.05 14.7 = general friction factor

We have seen different fracture gradients: Region 5 EPA specifies 0.8 psi/ft, but Ohio specifies 0.75 psi/ft. They also permit determination of higher fract ure pressures with field tests. Also, this equation allows 95% of fracture pressure. Why would CO 2 require adjusting to 90% of fracture pressure?

Page 86, Downhole Shut-off valves - We would be interested in more detail on the downhole shut-off valves, their use in on-shore conditions in other injec tion wells, and suggested criteria for shut-down. It appears that so far such valves have mainly been a pplied in offshore wells. We are not aware of these in any of the injection wells or EOR operations we ha ve encountered. None of the MRCSP Phase II test permits have required this or mentioned it. This would seem to be somewhat redundant with annular

pressure system.

Page 88, Corrosion Coupons - We would appreciate more clarity on where corrosion coupons would be necessary (i.e. only within the injection zone or space d within the tubing). Woul d it be sufficient to use place coupons above-ground in the CO 2 pipeline near the well?Comments on EPA-HQ-OW-2008-390 Neeraj Gupta and Joel Sminchak 12/24/2008, Page 6 Battelle

These comments have been prepared by Battelle researchers as part of their work for MRCSP. They do not necessarily reflect the official view of Battelle, the U.S. DOE, or sponsors and members entities of MRCSP. Page 98, External MIT Testing - We suggest review of the experience with temperature logs, radioactive tracer logs, and noise logs to determine which method is best for evaluating external MIT. For example, in our experience temperature logs do not provide much indication of corrosion. In general, we have found wireline cement bond logs to be the best evaluator of external mechanical integrity. However, most

assessment of these is needed before firm conclusions can be made.

Page 102, Pressure monitoring in overlying zones - Implicit in this monitoring requirement is that network of deep monitoring wells w ill be required with the injection we ll. We know of no other method to accurately measure deep pressures. As such, this requirement will be costly to implement and should be spelled out clearly for planning pur poses. It may also be pertinent to make this optional depending on

identified risks.

Page 103, Monitoring within the confining zone - In our experience it is very difficult to measure parameters in confining layers like pH, salinity, mi nerals, heavy metals, and organic contaminants on a routine basis. Confining zones typically consist of very low permeability carbonates that do not produce water or unstable shale not suitable for sampling due to borehole stability concerns.

Page 103, Pressure fall-off tests - In our experience, pressure fall-off tests offer more information in initial injection testing. After longer term injection, we’ve seen basically the same, muted response. In addition, the fall-off response tended to take much l onger after sustained injection. A concern may be that you need to monitor pressure fall off for several weeks, months, or years after 5 years of continuous injection to obtain useful data. This would lead to the need for standby wells or emitting CO 2 to the atmosphere during fall-off tests. We think these shou ld be part of the initial testing sequence for new injection wells, but they might be a more optional rather than a mandatory part of testing.

Page 105, Tracers- We share some of EPA’s concerns about uncertainties in the use of Tracers such as

PFTs. At the same time these and other tracers have been used successfully in many applications in hydrogeology and petroleum geology. The current la nguage appears to go too far towards discouraging use of tracers. Tracers should not be required for every site however, at the same time their use under site-specific situations should not be discouraged.

Page 108, Seismic Monitoring - Seismic and other indirect geophysical monitoring has been used to

evaluate CO 2 movement at some sites. However, it is also well known that all of these options (threedimensional, cross well, vertical seismic profile etc) may not work in every settings where rocks are too thin, have unsuitable sonic properties, and/or ther e is too much surface infrastructure or overburden present. Therefore, these options should be required on ly based on their feasibility at individual locations. In addition, these technologies may be fairly cost proh ibitive on a routine basis. Finally, it must be recognized that none of these technologies can provide a complete mass balance or accounting to CO 2 movement in subsurface.

Page 111-118, Reporting - More streamlined permit application st ructure and clearly defined information requirements should be provided in regulatory guida nce. We request streamlined reporting (Monitoring and testing plan, AOR/Corrective action review pl an, post-injection plan, annual report, monthly operating reports).

Page 111, Semi-Annual Reporting - Some of our sites have required monthly operating reports. Would this reduce reporting to semi-annual? We would appreciate additional clarification.Comments on EPA-HQ-OW-2008-390 Neeraj Gupta and Joel Sminchak 12/24/2008, Page 7 Battelle

These comments have been prepared by Battelle researchers as part of their work for MRCSP. They do not necessarily reflect the official view of Battelle, the U.S. DOE, or sponsors and members entities of MRCSP. Page 112, Reporting - The policy suggests monitoring and testing plan, AOR/corrective action plan, and Post-Injection plan. We’d recommend these documents be included as supporting attachments the permit application. This level of reporting may result in delays to the permitting process.

Page 115, Annual Report - Another annual report is mentioned. The overall reporting requirements are confusing. We would recommend monthly or quarter ly operating reports and a single annual report.

Page 118, Post-injection Site Care Plan - The post injection site care plan would seem to require monitoring of pressures, plume extent , and other items after injection st ops. However, this would prevent plugging and abandoning wells. It is recommended that the post-injection site care requirements allow for the plugging and abandoning of wells that are not being used for monitoring.

Page 123- 50 year Post Injection Period - We strongly encourage EPA to not include a recommendation for 50 years of monitoring. We are concerned that most directors will choose to apply this as a default value, even for shorter duration projects or at low risk sites. Instead a site-specific post injection monitoring plan with clearly defined performance crit eria such as pressure reduction, plume stabilization, lack of leakage, or stable parameter values over a peri od of time, should be used. This approach will give EPA the flexibility to design site-specific requirement but will also provide a level of certainty to the operators in terms of performance expectations.

Page 138, Primacy/Jurisdiction - Given the size and location of potential GS projects, many storage areas are likely to cross state lines. For example almost all of the major sources of CO 2 emissions in the MRCSP region are at or near state boundaries, along Ohio River. For example, a geologic storage facility located near Wheeling West Virginia could have a CO 2 plume and injection well locations in Ohio, West Virginia, and Pennsylvania. It is unclear how these projects would be implemented regarding who has primacy in permitting the site under a single permit, rather than three separate permits. Additional guidance permitting sites with multiple jurisdictions is highly desirable to prevent confusion or legal challenges.

Page 193, AOR Map - It will be difficult to provide the numerous site features on a single map as required in the regulation. Multiple maps should be allowed. Otherwise, the map must show the number, or name and location of all injection wells , producing wells, abandoned wells, plugged wells or dry holes, deep stratigraphic boreholes, State or EPA approved subsu rface cleanup sites, surface bodies of water, springs, mines (surface and subsurface), quarries, water we lls and other pertinent surface features including

structures intended for human occ upancy and roads, and faults.

Cost Estimates - In general most of the estimates for hour s, hourly rates, and costs required for implementing the requirements appear to be too low compared to our experience and the complexity of proposed regulatory requirements. It is recommended th at EPA obtain more realistic cost estimates for all aspects of the regulations, deep well drilling, monitori ng, expert delivery of geosciences and engineering professionals.Letter ID: 0229 Commenter: Neeraj Gupta Organization: Battelle Energy Technology (BET)

Letter ID: 0229 Comment ID: 21809 Letter Lines: 57 to 93

Comment Code: 1000 1. General and Administrative Comments

Comment Code: 1852 1.4.2.1 DOE Regional Carbon Seque stration Partnerships

Comment: Introduction and Background

This document summarizes review and co mments from Battelle researchers’ under he regulatory work of Midwest Regiona l Carbon Sequestration Partnership’s (MRCSP) on the USEPA Proposed Rule- Fede ral Requirements under UIC Program for CO2 Geologic Sequestration Wells (Doc ket ID No. EPA-HQ-OW2008-390). These comments reflect our experience in permitting and implementing three Phase II CO2 injection tests and the MRCSP Phase III project, as well as work on several other research projects during last 12 years of CCS research at Battelle:

Table [see PDF Docket ID EPA-HQ-OW-2008-390-0229.1]

The analysis also reflects Battelle experience with the UIC permitting of the AEP Mountaineer CO2 storage project, which is targeting 4 years of injection of over 100,000 metric tons CO2/yr at the AEP Mountaineer plant in New Haven, WV.

While the MRCSP includes over 30 different members, the comments expressed herein do not necessarily reflect opini ons of the individual members of the

MRCSP.

The MRCSP is one of seven partnerships in a nationwide effort to determine regionally-appropriate car bon sequestration options a nd opportunities. These partnerships are part of an overall effo rt by the U.S. Department of Energy’s National Energy Technology Laboratory (DOE /NETL) to develop robust strategies for mitigating carbon dioxide emissions. The MRCSP was formed to assess the technical potential, economic viabil ity, and public acceptability of carbon sequestration within its Region.

The MRCSP region consists of eight c ontiguous states: Indiana, Kentucky, Maryland, Michigan, New York, Ohio, Pennsyl vania, and West Virginia. The MRCSP includes over 30 organizations from the research community, energy industry, universities, non-government, and government organizations. In the first phase of research, which took place over a two year period ending in September 2005, the MRCSP characterized carbon sequestrati on opportunities in th e region. MRCSP is now involved in a four year Phase II effort that began in October 2005. This phase will conduct several small-scale fiel d tests of sequestra tion in different locations around the region to evaluate va rious sequestration options in realworld settings. The MRCSP Phase III projec t will involve sequestration of more

1than 1 million metric tons CO2.

Individual Response: EPA acknowledges the value of the DOE pilot projects a nd resultant data and information generated by such projects. EPA has evaluated permits and reviewed operational

data and information associated with the seve n RCSPs funded by the U.S. Department of Energy and coordinated through the National Energy Te chnology Laboratory (NETL). In addition to the information cited in the preamble to the pr oposed rule, EPA published a Notice of Data Availability and Request for Comment on A ugust 31, 2009 (74 FR 44802), in which the Agency

described the results of research at three DOE partnership sites: the Escatawpa, Mississippi project; the Aneth Field project in Paradox Basin, Southeast Ut ah; and the Pump Canyon Site, New Mexico. The Agency will continue to track GS project developments and evaluate new and ongoing research and information to ensure USDW protection, in cluding those performed by the

MRCSP.

EPA is using an adaptive approach to re gulating GS under the UIC Program. Even after finalizing the rule, the Agency plans to collect and review data every si x years on GS projects, including data generated by the partnerships, to determine whet her the appropriate amount and types of information and appropriate documenta tion are being collected, and to determine if modifications to the requirements are appropriate or necessary.

Letter ID: 0229 Comment ID: 21810 Letter Lines: 95 to 101

Comment Code: 2400 1.8 Comments on EPA's adaptive rulemaking process

Comment: General and Specific Comment s on Proposed Regulations

Adaptive Approach - Overall the proposed policy presents a comprehensive framework for geologic sequestration (GS). The adaptive approach seems especially useful for enabling early a dopters to pursue GS while allowing flexibility for adjustments in the future based on technology development and

lessons learned at individual sites.

Individual Response: EPA agrees that an adaptive approach to the UIC GS rulemaking is appropriate. The Agency plans to use such an appr oach to ensure that USDWs are protected from endangerment and meet the potentially fast p ace of GS deployment. EPA believes that an adaptive approach will allow regulatory developmen t to proceed in time to meet the current and future demand for Class VI permits while recognizi ng the need to: continue to gather data from pilot projects and other research as it becomes available; and to enhanc e understanding of the technical and administrative asp ects of GS deployment, operati on, and technology developments.

EPA plans, every six years, to collect and review data on GS projects to determine whether the appropriate amount and types of information a nd appropriate documentation are being collected,

and to determine if modifications to the re quirements are appropr iate or necessary.

2Letter ID: 0229 Comment ID: 21811 Letter Lines: 103 to 108

Comment Code: 3150 2.1.5 Comments on required permit information (40 CFR 146.82)

Comment Code: 4710 2.7.1 Proposed submissions required for permit applications (seeking comment)

Comment: Permit Organization - The proposed regul ation presents a large amount of material spread throughout the document. In general, it ha s been easier to complete the permit process with the basi c UIC form with the simplified list of attachments (this procedure was used for Region 4 and Region 5). Thus, the MRCSP would encourage EPA to prepare s uggested formats and a systematically organized list of information and documents required for the permit.

Individual Response: EPA is developing guidance on site ch aracterization for GS projects to assist owners or operators and Directors in evaluating permit requirements and applications under §146.82. The guidance provides recommendati ons regarding charac terizing the regional geology and hydrogeology of a proposed GS site as well as performing the necessary geochemical, geomechanical, and ge ophysical analyses of the inj ection and confining zone. EPA is also developing a number of technical guida nces and implementation materials to assist owners or operators and Directors in the perm itting process. EPA expects that these guidances will assist permit writers in performing many of the activities necessary for applying for a permit, including developing all required plans and conducting site charact erizations that meet the requirements of §146.82. The guidance can be found on EPA’s website at http://water.epa.gov/type/groundwater /uic/wells_sequestration.cfm.

Letter ID: 0229 Comment ID: 21812 Letter Lines: 110 to 132

Comment Code: 1850 1.4.2 CO2 GS Field Research

Comment Code: 2048 1.5.2.4 Oppose Class VI/ Support Class V experimental technology well

Comment: Encouraging Innovation and Experimental Projects - We believe that USEPA recognizes that many facets of GS site selection, implementation, and monitoring

are still under tec hnological assessment and inno vation phase. Many of the concepts and technological options are being evaluated under current field demonstration programs by Regional Partners hips and other projects across the world. The success of these existing and future experimental projects is heavily dependent on permitting process bei ng as simple as possible. USEPA UIC Guidance 83 allowing the use of Class V experimental wells has been a very

useful mechanism for faci litating experimental proj ects. In fact, if the proposed Class Vi framework was to be a pplied to smaller-scale tests currently underway, it is our belief that many projec ts would have financ ial, logistical, or technical difficulties in moving to field stage. With the proposed regulation in the public comment phase, MRCSP has already observed that the permit regulations for even small-scale field tests (such as MRCSP East Bend site and AEP Mountaineer Project) are beco ming too onerous compared to similar projects permitted prior to the issuance of draft regulations. For example, the

3post-injection monitoring durat ions have become much l onger with the regulators citing the draft regulation as a basis for requirements. Such a trend will certainly adversely affect future experi mental projects and lead to less new data being available to all stakeholde rs. We strongly encourage EPA to 1) continue the existing option for using Cl ass V experimental well permits option and/or specifically allow for a more simplified and less onerous permitting requirements for such project.

Individual Response: EPA acknowledges the value of the DOE pilot projects a nd resultant data and information generated by such projects. EPA has evaluated permits and reviewed operational

data and information associated with the seve n RCSPs funded by the U.S. Department of Energy and coordinated through the National Energy Te chnology Laboratory (NETL). In addition to the information cited in the preamble to the pr oposed rule, EPA published a Notice of Data Availability and Request for Comment on A ugust 31, 2009 (74 FR 44802), in which the Agency

described the results of research at three DOE partnership sites: the Escatawpa, Mississippi project; the Aneth Field project in Paradox Basin, Southeast Ut ah; and the Pump Canyon Site,

New Mexico.

The GS final rule does not affect an owner or operator’s ability to apply for a Class V experimental technology well permit for projects that are of an expe rimental nature, i.e., to test GS technologies.

The Agency is also tracking operation and techni cal developments of more than three dozen small- and large-scale GS injection projects in the United States and abroad. EPA meets regularly with DOE to discuss its research initiatives, project deve lopments, and "best practices."

EPA agrees with commenters that flexibility to address new research is important. Even after finalizing the rule, the Agency plans to collect an d review data every six years on GS projects to determine whether the appropriate amount a nd types of information and appropriate documentation are being collected, and to determ ine if modifications to the requirements are appropriate or necessary.

Letter ID: 0229 Comment ID: 21813 Letter Lines: 134 to 147

Comment Code: 1250 1.1.1.4 Flexibility is needed (p erformance-based standards)

Comment: Complexity and Consistency of Regulations - We recognize that EPA has attempted to provide a great deal of flexibility in most aspects of the regulations, while incorporating most of currently known c oncepts and technologies in permitting, operation, and monitoring of the sites. The flexibility has primarily been incorporated through making the requiremen ts subject to "dir ectors" decision. Our concern is that some directors may choose to require all of the numerous requirements mentioned in the permit, ra ther then selectively requiring an appropriate portfolio of safeguards. Such an approach could deter operators from considering the GS as an option for CO2 mitigation. An other concern is that the requirements will be applied with inconsistent level of flexibility in

4various regions and states, making some re gions more or less favorable for GS. We encourage EPA’s continuing oversight and guidance in ensuring that the regulations are applied consistently and with a reasonable selection of requirements.

Individual Response: EPA is developing guidances for Stat es that describe the process of applying for and receiving primary enforcement au thority (primacy) for GS Class VI wells under Section 1422 of SDWA, as well as the technical and administrative issues on developing GS regulations that are the equivalent of minimum federal criteria and re quirements. The guidance

will describe areas of Directorial discretion and considerations for how that discretion would be exercised. This guidance will be available on EPA’s website at http://water.epa.gov/type/groundwater /uic/wells_sequestration.cfm.

Letter ID: 0229 Comment ID: 21814 Letter Lines: 149 to 157

Comment Code: 2066 1.5.3.3 Grandfathering construction of Class V wells (seeking comment)

Comment: Page 48 "Grandfather" Status - It is un clear how this would affect existing

MRCSP Phase II Test sites. These host si tes have been very accommodating in supporting these small scale te sts and it is unclear if th ey would be subject to long term monitoring or allowed to be cl osed out under the original Class V CO2 experimental policy the wells were pe rmitted under. Clarification that the

small scale tests would be allowed to c ontinue injection under their original permit conditions be closed out under their original permits would be helpful to the pioneers of this technology, unless of c ourse the site hosts wish to convert to a Class VI well under new regulations for longer-term..

Individual Response: EPA agrees that, when the Regiona l Carbon Sequestration Partnership projects are no longer of an expe rimental nature, they should be re-permitted as Class VI wells and subject to the Class VI requirements if th ey are to be used for commercial-scale GS.

EPA is providing for the construction of Cla ss V experimental technology wells to be grandfathered per §146.81(c), provid ed the owner or operator can demonstrate to the Director that the wells were engineered and constructed to meet th e requirements at §146.86(a) and ensure protection of USDWs, in lieu of requirements at §146.86(b) and §146.87(a). EPA

understands based on reviews of several Class V pilot project permits, that many Class V experimental technology wells, including those used in the RCSP projects, are specifically designed for injection of CO2 and are being built to Class I non-hazardous well specifications, which should facilitate re-permitting as Class VI wells. EPA adds that, following re-permitting as Class VI wells, these projects must be subject to the opera tional, MIT, monitoring, reporting, plugging, and post-injection site care and site closure requirements in the final GS rule. See the discussion of EPA's final regulatory approach in the preamble to th e GS rule for additional detail on these requirements.

EPA is preparing an addendum to UICPG #83 that describes the use of th e Class V experimental technology well classification to clarify perm itting for Class V wells. This addendum will

5address shifting of Class V experi mental projects to full-scale GS projects and the future use of the Class V experimental technology well s ubclass for research a nd testing of new GS technologies.

Letter ID: 0229 Comment ID: 21827 Letter Lines: 159 to 180

Comment Code: 1614 1.3.1.2 Impurities in captured CO 2; purity standards for CO2

Comment Code: 1630 1.3.3 RCRA/hazardous waste i ssues (seeking comment)

Comment: Page 54 CO2 Composition Requirements and Hazardous Waste under RCRA- While

we agree some chemical impurities may cause CO 2 to be designated hazardous waste, there must be more clear guidance on th is issue. In the MRCSP tests, each regulatory agency had different requireme nts on this issue injectate composition and analysis, even for commercial CO2. One agency required injection to cease if the injectate was above any maximum c ontaminant level (MCL) for groundwater, which is a large list of chemicals. Another state agency asked for some technically infeasible anal yses on the CO2 stream (p H, Fluouride, Mercury). Some impurities like H2S and hydrocarbons are naturally occurring in most deep saline formations anyway, so we would di scourage setting limits on these items. Another significant aspect is the com position of CO2 derived from various industrial, power generation, and capture processes. All of th ese are likely to

result in minor differences in chemi cal compositions. In most cases the concentration of hazardous impurities is like ly to be very low. The incremental environmental impact of these minor or tr ace impurities in deep formations that already have brine and will have CO2 must be demonstrated before these are excluded from the Class VI injection wells . EPA is encouraged to evaluate the range of potential impurities from various streams, their environmental impact if any, and provide more specific guidan ce on this topic. The evaluation should also assess how many of the GS projects could become infeasible due to this requirement. Finally, EPA should clarify whether CO2 streams with RCRA level of impurities can be injected under Class I permits.

Individual Response: EPA received many comments regardi ng the applicability of the RCRA regulations and statute to CO2 st reams that are geologically seque stered under the final Class VI UIC well requirements. As a result, EPA has deci ded to initiate a sepa rate proposed rulemaking specifically to examine the issue of RCRA appl icability to CO2 streams being geologically sequestered, including the possible option of a conditional exemption from the RCRA requirements for CO2 GS in Class VI wells. EPA will consider these comments as part of its development of that proposal. The Agency will consider issues pa rticular to RCRA in the context of that separate rulemaking, and recommends that the commenter read that proposed rule when it is published. The Agency notes that comment ers who wish to submit comments on the RCRA proposal will need to do so during the comment pe riod for that rule. Finall y, EPA also notes that the final GS rule, which adds ne w regulations for Class VI wells under the Safe Drinking Water Act (SDWA), is not making any ch anges to the RCRA regulations

6EPA recognizes that many CO2 streams may be rela tively pure, and research indicates that the estimated amounts of impurities in a CO2 stream are likely to be low. However, these estimates are based on limited information, and uncertainties remain about the expected concentrations of impurities from the various types of CO2 stream s. The concentrations of minor and trace

elements in CO2 streams for GS projects are likely to vary by facility, coal composition, plant operating conditions, and pollu tion removal technologies.

The GS rule does not set generic purity standa rds for CO2 injectate streams (e.g., a percent CO2). Instead, the GS rule addresses the quality and quantity of impurities by requiring owners or operators to submit information on the sour ce of the CO2 and its physical and chemical properties. Specifically, the GS rule requires the owner or operator to subm it data about the site, including an analysis of the chemical and physical characteristics of the CO2 stream, as required at §146.82(a)(7)(iv), and information on the compatib ility of the CO2 stream with fluids in the injection zone and minerals in both the injection and the confini ng zones and the materials used to construct the well, per §146.82(c)(3). This info rmation can help the Director determine the potential for geochemical reactions between the injectate (CO2) and the host geologic formations, which could result in the plugging of pore spaces or the dissolution of formation

minerals.

Since the GS rule, at §146.81(d), prohibits the inj ection of CO2 streams that meet the definition of a hazardous waste under 40 CFR part 261, injection of a CO2 stream that is determined to be a hazardous waste may only occur in a Cla ss I hazardous waste injection well.

Letter ID: 0229 Comment ID: 21828 Letter Lines: 182 to 187

Comment Code: 3120 2.1.2 Need to identify additional confining and containment zones (seeking comment)

Comment: Page 61, Injection Zone and Confining Laye r - Conditions under which "director" may require a secondary containment/buffer zone should be more clearly defined to provide regulatory certainty. In add ition, in definition of what constitutes a secondary containment or buffer zone is highly subjectiv e and a matter of individual opinions. Therefore, more clarity on how these zones should be selected is requested.

Individual Response: EPA retains the requirement to iden tify additional containment/confining zones, if required by the Di rector, as proposed (e.g., §146.83(b)). The Agency's decision is supported by commenters representing states, wate r associations, and an electric utility who assert that these requirements (at §146.83(b)) pr omote a flexible, risk-based, site-specific approach to characterizing and perm itting a site for GS projects.

The Agency believes that providing the Director di scretion will allow consideration of a range of sites for GS, based on site-specific conditions and ensure USDW protection. EPA believes that requiring appropriate site ch aracterization by the owner or operator (under §146.82) and providing an appropriate de gree of flexibility to the Director to evaluate site-specific geologic data will afford the greatest protec tion of USDWs from endangerment.

7EPA is developing guidance on site characterization for GS projects to assist owners or operators and Directors in evaluating permit requirements and applications under §146.82. The guidance provides recommendations regard ing characterizing the region al geology and hydrogeology of a proposed GS site as well as performing th e necessary geochemical, geomechanical, and geophysical analyses of the injection and confin ing zone. EPA expects that this guidance will assist permit writers in making an objective deci sion about requiring additional confining layers. The guidance can be found on EPA’s website at http://water.epa.gov/type/groundwater /uic/wells_sequestration.cfm.

Letter ID: 0229 Comment ID: 21829 Letter Lines: 189 to 199

Comment Code: 3140 2.1.4 Comments that the proposed ge ologic data requirements are too stringent

Comment: Page 63, Geochemical Data- The proposed re quirements ask for geochemical data on injection zone, confining zone, any underground source of drinking water, and any other important zone. This may be a burdensome amount of information for GS sites. While some indication of geochemi cal parameters may be obtained from wireline methods, it can be a challenge to collect representative brine samples, especially from low permeability caprocks and deep saline formations. It is very unlikely we would even be able to collect samples from many low permeability confining layers. In addition, no guidance on the list of analytes (i.e. cations, anions, metals, physical parameters) is provided. We would suggest that data from regional studies a nd other deep wells also be allowed as an alternative for defining the geochemical setting.

Individual Response: The Agency believes that the re quirement at §146.82(a)(6) to submit baseline geochemical data on subsurface geologic formations, including all USDWs in the AoR is appropriate and protective of USDWs. EPA believes that this data will support monitoring plan development, inform injectate fate a nd transport model development (e.g., by providing appropriate input parameters), a nd provide information needed to respond to any unexpected and unpermitted leaks outside of the injection zone. Th e baseline geochemical information will allow the owner or operator and permitting authority to evaluate monitoring data and identify any changes in subsurface geochemistry that may indicate fluid movement.

The rule requires geochemical analysis of, at a minimum, the injection zone, confining zone, and all USDWs (§146.82(a)(6)). These geochemical tests ar e necessary to ensure the adequacy of the confining system and to serve as a baseline for future monitoring. The Director has the discretion to require geochemical analysis of additional s ubsurface zones if in the Director's opinion they are necessary for the protection of USDWs from endangerment.

EPA agrees that site characterizati on should be site-specific, particul arly in light of the variety of geologic settings in which GS may be employe d. EPA believes that, while there is a large amount of required information, the owner or operat or is given flexibility in determining what methods are used to demonstrate the suitability of a potential site. EPA envisions an ongoing

8dialogue between the Director and the owner or operator during the permitting process (as well as throughout the operation of the site). EPA clar ifies that if recent information about the site exists (e.g., from other geologic st udies of the area), th e Director may, at his/her discretion, allow

its use in the site characte rization for the GS project.

Letter ID: 0229 Comment ID: 21830 Letter Lines: 201 to 217

Comment Code: 3310 2.2.1.1 Comments in favor of requiring computational models to delineate the AoR (seeking comment)

Comment: Page 64, Area of Review Determination/ Modeling - We agree that multiphase numerical models are the best option for determining area of review (AOR) for complex, full-scale injection sites. Simple r analytical models may be used for smaller-scale, short-term tests. Multi phase computer simulations, supported with field data, should be primary tool for managing the storage sites through out the life cycle from site sele ction, permitting, characterization, operations, to post operational monitoring and closure. However, modeling should not be restricted to a single code or type of code. This will stifle innovation, because many more modeling code s are likely to be developed and existing commercial, academic, and nationa l laboratory codes ar e incorporating new processes and improvements based on lessons learned from field projects. The incorporation of multiphase processes is likely to be a key requirement for models. However, we do not believe that fully coupled model with CO2 flow, transport, geochemical, geomechanical , and other processes in a single simulation for the entire facility and li fe cycle is currently feasible. Such fully-coupled codes require extensive computational power and are more applicable to evaluating basic science questions.

Individual Response: EPA acknowledges the commenter’s s upport and agrees that predicting the complex multiphase, buoyant flow of the CO 2, co-injectates, and compounds that may be mobilized due to injection requires the sophistica tion of computational models, as required at §146.84(c)(1). Models can predict CO2 fate and tr ansport, as well as changes in formation pressure, in three dimensions, as a function of ti me in order to delineate the subsurface storage site and the AoR. Models can account for site-specific and predicted operating conditions as well as geologic heterogeneities a nd potential migration through fau lts, fractures, and artificial penetrations.

EPA agrees that operators should have the flexib ility to select models with which they are familiar and that are most appropriate to the site conditions and available data types and

amounts. EPA has evaluated technical documents regarding several computational models that may be used for GS sites. Based on this review (as documented in the preamble to the proposed GS regulation and the background document "Computational Modeli ng of Underground Injection of Carbon Dioxide for Determinati on of Area-of-Review and Potential Risk to Underground Sources of Drinking Water"), EPA be lieves that several models meet the minimum requirements for models in the GS regulation.

9Letter ID: 0229 Comment ID: 21831 Letter Lines: 219 to 227

Comment Code: 3300 2.2.1 Delineating the AoR/M odeling CO2 movement

Comment: Page 64, Area of Review Determination -M ore clarity on determ ining the AOR is requested. Currently it is not clear wh ether AOR will be based on CO2 phase spreading, dissolved CO2 plume, or pressu re footprint. Models provide a large amount of information such as CO2 ga s saturation, pressure, and aqueous concentrations. They also involve a fair amount of uncertain ty. Our experience is that small portion of the CO2 may exte nd or "finger" much further than the bulk of the injected CO2. For example w ould EPA accept an AOR with a radius containing 90% of the CO2 as supercri tical gas saturation, so that the applicants do not have to account for sm all-scale fingering or heterogeneities?

Individual Response: EPA disagrees with defining the AoR re lative to the percentage of CO2 saturation. The UIC regulations, including the Cl ass VI regulations, are designed to ensure protection of USDWs from endangerment. The Agency believes that the AoR needs to incorporate not only the CO2 itsel f—regardless of saturation or phase—but also the area of increased pressure ahead of the CO2 plume, which can potentially displace saline, native fluids (i.e., naturally occurring salty water) into USDWs. This pr essure front would typically encompass an area larger than the plume itself, including any areas of small scale fingering or heterogeneities or where CO2 saturation is le ss than 100 percent. The Agency has carefully

considered all comments on the AoR definition at 146.84(a) and modified it to read as follows: The region surrounding the geologi c sequestration project where USDWs may be endangered by the injection activity. The area of review is delineated using computational modeling that accounts for the physical and chemical properties of all phases of the injected CO2 stream and is

based on available site characteriza tion, monitoring, and operational data.

EPA clarifies that the definition of AoR includes all areas that may poten tially be endangered by the injection activity. EPA recognizes that mode led AoRs may involve some uncertainty or “fingering,” as the commenter mentions. Any need ed corrective action must be done on wells in the modeled AoR, which would include these areas to ensure that they address any area that would be impacted by the CO2 plume and pressure front.

Letter ID: 0229 Comment ID: 21832 Letter Lines: 229 to 233

Comment Code: 3200 2.2 Proposed Area of Review and Corrective Action Requirements (40 CFR 146.84)

Comment: Page 72, Corrective Action/Abandoned Wells - We would appreciate more clarity on whether it will be required to plug and abandon wells in zones above confining layers. At our sites, it appears the re gulators have expected all inactive wells in the AOR to be plugged, even if they are not penetrating the injection

zones.

10Individual Response: EPA clarifies that wells requiring co rrective action are those in the AoR and wells that may penetrate the confining zone per 146.84(c)(2). Any well that penetrates the confining zone, even if it does not extend all the way through the confining formation, is to be included in the tabulation. EPA is issuing guidan ce on how to identify all wells that require corrective action. The guidance describes EPA's r ecommended approaches for the data to be

considered in an initial AoR delineation, how to apply computat ional modeling to delineate the AoR, performing corrective action at GS sites, and, when appropriate, completing AoR reevaluations. The guidance will be available on EPA's web site, at http://water.epa.gov/type/groundwat er/uic/wells_se questration.cfm.

Corrective action must be performed on wells dete rmined to need corrective action in order to prevent movement of fluid into or between US DWs, therefore some we lls above the confining zone may not be required to undergo corrective action; however, such a determination will be based on site-specific information.

Letter ID: 0229 Comment ID: 21845 Letter Lines: 235 to 239

Comment Code: 3862 2.3.3.1 Use of corrosion-resistant construction materials (seeking comment)

Comment Code: 3864 2.3.3.2 Use of corrosion-resistant cements (seeking comment)

Comment: Page 82, Cement and Casing Materials- We s uggest that if acid resistant cement and casing are to be required, they shoul d be required only in the injection interval and immediate confining layer, wh ich are most likely to be affected by the CO2 storage zone. The shallower drill strings may use more common materials. This seems a typical practice in most CO2 applications.

Individual Response: EPA clarifies that acid-resistant ce ment and casing are not specifically required in a Class VI injection well. Rather, as stated in §146.86(b)(1), ca sings and cement used must have sufficient strength and be designed for the life of the sequestration project. Further,

materials must meet standards listed in the rule and be compatible with fluids with which the materials may be expected to come into contact. Therefore, some well materials may need to be acid-resistant and some may not if they do not co me in contact with the CO2 stream or other

corrosive fluids and if approved by the Director.

See the discussion of Class VI well construction requirements in the preamble to the final GS rule for additional information. Additionally, EPA is developing guidance on the construction of Class VI wells. This guidance will be available on EPA’s website at http://water.epa.gov/type/groundwater /uic/wells_sequestration.cfm.

Letter ID: 0229 Comment ID: 21846 Letter Lines: 241 to 259

Comment Code: 4110 2.4.1.1 Injection pressure limitations

Comment: Page 84, Fracture Pressures- We would s uggest using a define d equation rather

11than 90% fracture pressure for injection pressure limits. Michigan and Ohio sites have permitted using a general equation to determine maximum allowable surface injection pressure:

Maximum Allowable Surface Injection Pressure =

depth x [(FG - 0.433 x (S.G. + safety factor)] - 14.7

Depth = depth at top of storage interval FG = fracture gradient S.G. (average specific gravity of CO2 in borehole) Safety factor = 0.05 14.7 = general friction factor

We have seen different fracture gradient s: Region 5 EPA specifies 0.8 psi/ft, but Ohio specifies 0.75 psi/ft. They al so permit determination of higher fracture pressures with field tests. Als o, this equation allows 95% of fracture pressure. Why would CO2 require adjus ting to 90% of fracture pressure?

Individual Response: EPA believes that injection pressures that are based on 90 percent of the fracture pressure are an appropriate maximum for the federal requirements. However, the determination of the injection pressure for a sp ecific project must be approved by the Director. Additionally, the Agency clarifies that if, in pr eparing any permit, if the Director determines, based on site-specific information, that a lower injection pressure is appropriate to ensure protection of USDWs from endangerment, he or she has the authority to set a lower injection pressure limit in the permit. The Agency clarifie s that if a permitting authority wants to use an equation to set the injection pressure limit in a GS permit, this is acceptable. However, the safety factor must be based on 90 percent of the fract ure pressure in order to protect USDWs from endangerment.

Letter ID: 0229 Comment ID: 21847 Letter Lines: 261 to 267

Comment Code: 4200 2.4.2 Down-hole shut-off valves in GS wells (seeking comment)

Comment: Page 86, Downhole Shut-off valves - We woul d be interested in more detail on the downhole shut-off valves, their use in on- shore conditions in other injection wells, and suggested criteria for shut-down. It appears that so far such valves have mainly been applied in offshore wells . We are not aware of these in any of the injection wells or EOR operations we have encountered. None of the MRCSP Phase II test permits have required this or mentioned it. This would seem to be

somewhat redundant with a nnular pressure system.

Individual Response: Down-hole shut-off systems are typica lly installed below the packer on a

well and are used to stem uncontrolled flow of fl uids out of the well. The devices default to the closed position and are opened by application of force from the surface. Pressure can be applied by the fluid itself or through a hydr aulic signal from the surface. They are typically set to close

12when the pressure in the tubing drops below a pre-de termined level. It is possible to set them to deploy based on other triggers. The devices can either be deployed on the tubing or by wire line. Tubing-deployed devices have the advantage of not constricting the flow in the tubing, but replacing them requires removal of the tubing. Wire line devices constrict the flow in the tubing, causing reduced pressure in the we ll, but these are easier to depl oy and retrieve. Down-hole shut off valves are required in offshore oil and gas we lls; however, they are considered standard on other wells where well damage is likely or where well failure could result in the release of toxic chemicals. Several types of Class II wells comm only use down-hole shut-off systems and include high pressure/high temperature wells , acid gas injection, and wells lo cated in permafrost regions.

After evaluating the risk s and benefits of down-hole shut-off systems and considering additional research, EPA will not require automatic down-ho le shut-off devices for onshore Class VI wells since it is not necessary in all cases to ensure protection of USDWs from endangerment. Instead, the final rule, at §146.88(e)(2), re quires that owners or operato rs of onshore Class VI wells

install automatic surface shut-off devices. The ru le affords Director's discretion to mandate

automatic down-hole shut-off devices in onshore situ ations that may warrant their use. However, the Agency believes that offshore Class VI we lls present unique construction and operational conditions, including isolation from shorelines and the need to c onstruct wells th rough the water column and the subsurface, which may delay res ponse time in the event of well difficulties. The rule requires, at §146.88(e)(3), that owners or oper ators of offshore wells w ithin State territorial waters install automatic down-hole shut-off system s. EPA believes that these requirements at §146.88(e) ensure that proper precautions are take n to prevent subsurface fluid movement and ensure protection of USDWs.

Letter ID: 0229 Comment ID: 21848 Letter Lines: 269 to 272

Comment Code: 4630 2.6.3 Corrosion monitoring

Comment: Page 88, Corrosion Coupons- We would apprec iate more clarity on where corrosion coupons would be necessary (i.e. only within the injection zone or spaced within the tubing). Would it be sufficient to use place coupons above-ground in the CO2 pipeline near the well?

Individual Response: EPA clarifies that the requirement to monitor corrosion by placing the coupons in the well would provide a more accura te analogue of the conditions to which well materials are exposed than would surface testing (i.e ., in the pipeline). Pleas e note that the use of coupons is one out three methods that an owne r or operator may use to monitor corrosion under §146.90(c). EPA adds that, under SDWA authority, the Agency cannot prescribe any testing methods that involve the pipeline.

Several options are available for monitoring corrosion using coupons. For example, corrosion coupons may be placed in a side stream loop so they are exposed to the injectate. Valves on either end of the side stream loop allow the ow ner or operator to shut off the injectate flow, extract the coupons, and measure any change in th ickness. Another monitori ng option is to insert the coupons through a "T" in the flowline and direc tly lower this into th e injection flow. The coupons can then be retracted into the side pipe , extracted, and measure d. Finally, spool pieces

13of the construction material can be installed either in the injectate flow line or in a side stream; flanges and valves allow the spool pieces to be isolated from the injectate so they can be

evaluated for corrosion.

EPA is developing guidance on testing and mon itoring to assist owne rs or operators and Directors in evaluating requi rements under §146.90, including pr oposed monitoring plans. The guidance describes available technologies a nd recommended approaches for implementing a testing and monitoring plan, including pre-ope rational geophysical l ogging and testing of injection wells, MITs, injecti on well testing during operation, groundwater quality monitoring, tracking the CO2 plume and pressure front, a nd soil gas and surface air monitoring which may be required by the UIC Director for specific GS projects. Th e guidance can be found on EPA’s website at http://water.epa.gov/type/gr oundwater/uic/wells_se questration.cfm.

Letter ID: 0229 Comment ID: 21849 Letter Lines: 274 to 280

Comment Code: 4540 2.5.2 Proposed external MIT requirements

Comment: Page 98, External MIT Testing- We suggest review of the experience with temperature logs, radioactive tracer logs , and noise logs to determine which method is best for evaluating external MIT. For example, in our experience temperature logs do not provide much indi cation of corrosion. In general, we have found wireline cement bond logs to be the best evaluator of external mechanical integrity. However, most assessment of these is needed before firm

conclusions can be made.

Individual Response: EPA believes that the MITs describe d in §146.89(c) of the rule (e.g., an approved tracer log or temperat ure or noise logs) are effec tive methods for demonstrating external MI. They are currently used by owners or operators of Class I and Class II wells. The Agency notes that the regulations do provide the Direct or flexibility at §146.89(e) to approve the use of alternative MIT methods. They have been used successfully by injection well operators for decades and provide an important early warni ng of potential problems in the injection well system. For additional information, please see the discussion of MITs in the final rule preamble.

EPA is using an adaptive approach to regulati ng GS. The Agency plans to collect and review data every six years on GS projects to determ ine whether the appropria te amount and types of information and appropriate documentation are being collected, and to determine if modifications to the requirements are appropriate or necessary.

Letter ID: 0229 Comment ID: 21850 Letter Lines: 282 to 287

Comment Code: 4600 2.6 Proposed Plume and Pressure Front Monitoring Requirements (40 CFR 146.90)

Comment Code: 4610 2.6.1 Testing and monitoring plan requirement (seeking comment)

Comment: Page 102, Pressure monitoring in overlyi ng zones- Implicit in this monitoring

14requirement is that network of deep mon itoring wells will be required with the injection well. We know of no other method to accurately measure deep pressures. As such, this requirement will be costly to implement and should be spelled out clearly for planning purposes. It may also be pertinent to make this optional depending on identified risks.

Individual Response: EPA acknowledges the commenters' concern about the cost of monitoring. However, EPA believes that monitoring is essential for protection of USDWs at GS sites. Although a significant cost in absolute te rms, monitoring costs are expected to be a small fraction of site operating costs, according to EPA' s cost analysis for the GS rulemaking (which is available in the docket).

EPA believes that monitoring using wells in the injection zone, e.g., for pressure monitoring as required at §146.90(g)(1), can be safely performed if the wells are constructed to prevent flow between the injection zone a nd USDWs or other layers above the confining zone. Such construction technologies exist and have been us ed in the oil and gas industry for years. EPA believes that properly constructed monitoring wells will be a safe way to obtain the data that is essential to ensure that the inje cted CO2 remains confined in the injection zone and that pressure changes are not causing movement of formation or other fluids. To mitigate the risk of fluid movement, EPA requires owners and operators to submit a testing and monitoring plan that describes how the owner or operator plans to site and construct monitoring wells. EPA is developing guidance on well constr uction that will include reco mmendations for monitoring well construction. The guidance will be available on EPA’s website at http://water.epa.gov/type/groundwat er/uic/wells_se questration.cfm.

EPA is developing guidance on testing and mon itoring to assist owne rs or operators and Directors in evaluating requi rements under §146.90, including pr oposed monitoring plans. The guidance describes available technologies a nd recommended approaches for implementing a testing and monitoring plan, including pre-ope rational geophysical l ogging and testing of injection wells, MITs, injecti on well testing during operation, groundwater quality monitoring, and tracking the CO2 plume and pressure front . The guidance can be found on EPA’s website at http://water.epa.gov/type/groundwat er/uic/wells_sequestration.cfm. In addition, in January 2009, DOE published a best practices manual entitled "Monitoring, Verificat ion, and Accounting of CO2 Stored in Deep Geologic Formations" (DOE/NETL-311/081508); this manual is included in

the docket for the final GS rule.

Letter ID: 0229 Comment ID: 21857 Letter Lines: 289 to 293

Comment Code: 4600 2.6 Proposed Plume and Pressure Front Monitoring Requirements (40 CFR 146.90)

Comment: Page 103, Monitoring within the confining zone- In our experience it is very difficult to measure parameters in confin ing layers like pH, salinity, minerals, heavy metals, and organic contaminants on a routine basis. Confining zones typically consist of very low permeability carbonates that do not produce water or unstable shale not suitable for sampli ng due to borehole stability concerns.

15Individual Response: EPA recognizes that the collecti on of representative ground water samples from depth poses challenges and that speci al methods, such as U-tubes, will be needed to preserve the integrity of such samples. EP A is developing guidance on testing and monitoring to assist owners or operators and Directors in evaluating requiremen ts under §146.90, including proposed monitoring plans. The guidance descri bes available technol ogies and recommended approaches for implementing a testing a nd monitoring plan, including pre-operational geophysical logging and testing of injection wells, MITs, injecti on well testing during operation, groundwater quality monitoring, tracking the CO2 plume and pressure front, and soil gas and surface air monitoring which may be required by the UIC Director for specific GS projects. The guidance can be found on EPA’s website at http://water.epa.gov/type/groundwat er/uic/wells_se questration.cfm.

Regarding the comment about the difficulty of sa mpling within the confin ing zone, EPA clarifies that §146.90(d) requires owners a nd operators to monitor ground water quality and geochemical changes above the confining zone(s), rath er than within the confining zone.

Letter ID: 0229 Comment ID: 21858 Letter Lines: 295 to 304

Comment Code: 4640 2.6.4 Pressure fall-off testing (seeking comment)

Comment: Page 103, Pressure fall-off tests- In ou r experience, pressure fall-off tests

offer more information in initial in jection testing. After longer term injection, we’ve seen basi cally the same, muted res ponse. In addition, the fall-off response tended to take much longer after sustained injection. A concern may be that you need to monitor pressure fall off for several weeks, months, or years after 5 y ears of continuous injection to obtain useful data. This would lead to the need for standby wells or emitting CO2 to the atmosphere during fall-off tests. We think these s hould be part of the initial testing sequence for new injection wells, but they might be a more optional rather than a mandatory part of testing.

Individual Response: EPA believes that a frequency of at least once every five years, as specified at §146.90(f), is an appropr iate interval for pressure fall- off testing (particularly given the suite of tests operators will perform on the well and the site). EPA clarifies that the Director may require more frequent pressure fall-off tests at a specific proj ect, if necessary based on sitespecific circumstances. Pressure fall-off tests ma y be conducted in conjunction with other well performance tests (i.e., mechanical integrity testing) to ensure sa fe and effective operations. All monitoring data collected, including information from pressure fall-off tests, will be incorporated in AoR reevaluations, at l east every five years.

Letter ID: 0229 Comment ID: 21859 Letter Lines: 306 to 311

Comment Code: 4490 2.4.5 Use of tracers and potential im pact on human health or ecosystems (seeking comment)

16Comment: Page 105, Tracers- We share some of EPA’s concerns about uncertainties in the

use of Tracers such as PFTs. At the same time these and other tracers have been used successfully in many applications in hydrogeology and petroleum geology. The current language appears to go too fa r towards discouraging use of tracers. Tracers should not be required for every si te however, at the same time their use under site-specific situations should not be discouraged.

Individual Response: EPA agrees that tracers can be useful tools for monitoring GS projects. However, EPA believes that tracer use is not appropriate in all situations. For this reason, EPA does not require the use of tracers at all GS sites; however, the Dire ctor has discretion to require

their use if he/she determines that the use of tracers could improve monitoring of the site and enhance USDW protection from endangerment. The rule will also allow their use if proposed by the owner or operator and approve d by the Director. The Director would assess the use of tracers in the context of site-specific information, in cluding risks to USDWs and other environmental

and health risks.

EPA will continue to track research related to tr acer use, and plans to, every six years, collect and review data on GS projects to determin e 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.

Letter ID: 0229 Comment ID: 21860 Letter Lines: 313 to 322

Comment Code: 4655 2.6.5.1 Plume tracking techniques/ geophysical methods (seeking comment)

Comment: Page 108, Seismic Monitoring- Seismic and other indirect geophysical monitoring

has been used to evaluate CO2 movement at some sites. However, it is also well known that all of these options (threedime nsional, cross well, vertical seismic profile etc) may not work in every settings where rocks are too thin, have unsuitable sonic properties, and/or there is too much surface infrastructure or overburden present. Therefore, these opti ons should be required only based on their feasibility at individual locations . In addition, these technologies may be fairly cost prohibitive on a routine basis. Finally, it must be recognized that none of these technologies can provide a complete mass balance or accounting to CO2 movement in subsurface.

Individual Response: EPA agrees that seismic monitoring ma y not be applicable or appropriate for all sites. The final rule (a t §146.90(g)) requires owne rs or operators to perform monitoring to track the extent of the CO2 plume and pressure front. The owner or operator must use direct methods to monitor for pressure changes in the injection zone. Indirect methods (e.g., seismic, electrical, gravity, or electromagnetic surveys an d/or down-hole CO2 det ection tools) are also required unless the Director determines, based on site-specific geology, that such methods are not appropriate.

17EPA is affording Director's disc retion regarding the use of geophys ical techniques at some sites because the Agency recognizes that geophysical methods are not appropriate in all geologic settings. For example, geophysical methods are diffi cult to execute in areas that are structurally and topographically complex or where lithologies have limited contrast in density, porosity, permeability, and other physical properties. EPA clarifies that this determination will be made by the Director based on the site-specific geologi c information submitted by the owner or operator with their permit application.

There may also be interference from urban and re sidential infrastructure, and sites with loose materials such as glacial deposits may produce poor or inaccurate seismic images. But the laterally continuous, confined formations that that make many sites appropriate for GS will also render many of them suitable for seismic survey ing. In fact, seismic and other geophysical and remote sensing methods have been used with suc cess at GS pilot projects and are likely to be useful for plume tracking at many GS sites. St atOilHydro has used both time-lapse seismic and gravity methods to track the CO2 plume at the Slei pner site. Seismic surveys have also been used successfully at the Weyburn pilot project site in Saskatchewan. Although resolution on seismic surveys is generally accepted to be the best of the geophysical methods, gravity monitoring at Sleipner has also imaged the plume, and results have agreed with seismic surveys. At InSalah, PSInSAR satellite monitoring has been used in co mbination with tiltmeter data and was able to detect otherwise imperceptible ground displacement (i.e., at the millimeter scale) that indicates the presence of CO2.

EPA acknowledges the commenters' concern about th e cost of geophysical techniques. However, EPA believes that tracking of the plume is essential for protection of USDWs from endangerment at GS sites and that geophysical methods are necessary for such tracking.

EPA is developing guidance on testing and mon itoring to assist owne rs or operators and Directors in evaluating requi rements under §146.90, including pr oposed monitoring plans. The guidance describes available technologies a nd recommended approaches for implementing a testing and monitoring plan, including pre-ope rational geophysical l ogging and testing of injection wells, MITs, injecti on well testing during operation, groundwater quality monitoring, tracking the CO2 plume and pressure front, a nd soil gas and surface air monitoring which may be required by the UIC Director for specific GS projects. Th e guidance can be found on EPA’s website at http://water.epa.gov/type/gr oundwater/uic/wells_se questration.cfm.

Letter ID: 0229 Comment ID: 21861 Letter Lines: 324 to 328

Comment Code: 4700 2.7 Proposed Recordkeeping and Reporting Requirements (40 CFR 146.91)

Comment: Page 111-118, Reporting- More streamlined permit applicatio n structure and clearly defined information requirement s should be provided in regulatory guidance. We request streamlined re porting (Monitoring and testing plan, AOR/Corrective action review plan, post-in jection plan, annual report, monthly operating reports).

18Individual Response: EPA disagrees with the s uggestion that the permit application structure be more streamlined and information requirements be more clearly defined. EPA believes that information required to be submitted with the permit application under §146.82 is necessary and appropriate to provide permitting authorities sufficient basis for informed decisions about establishing permit conditions a nd granting permits. The purpose of these requirements is to protect USDWs from endangerment, and all operations must be permitted and operated in manner that is protective of USDWs.

Furthermore, EPA’s GS Rule provides for a streamlined approach to reporting under §146.91. EPA is retaining the semi-annual reporting requireme nt in the final rule at §146.91(a) in order to ensure that permitting authorities can maintain pr oper oversight of GS projects, particularly in the early stages of rule implementation and deployment of GS technologies. The Agency also clarifies that permitting authorities may choose to require more frequent reporting, at the

discretion of the Director.

Letter ID: 0229 Comment ID: 21862 Letter Lines: 330 to 332

Comment Code: 4720 2.7.2 Operational record keeping and reporting

Comment: Page 111, Semi-Annual Reporting- Some of our sites have required monthly operating reports. Would this reduce reporting to semi-annual? We would appreciate additiona l clarification.

Individual Response: Existing pilot projects will continue to be regulated under their Class V experimental well permits and must meet the re porting requirements set forth in the individual permit. EPA expects that, as the permits for th ese Class V projects expi re or if owners or operators of Class V projects seek to apply for a Class VI permit (provided construction components are grandfathered), they would be re-permitted as Class VI wells (subject to reporting requirements at §146.91). If th e projects continue to be of an experimental nature, the wells may continue to be permitted as Class V experimental technology wells (subject to the reporting requirements in the permit).

Letter ID: 0229 Comment ID: 21863 Letter Lines: 334 to 337

Comment Code: 3150 2.1.5 Comments on required permit information (40 CFR 146.82)

Comment Code: 4710 2.7.1 Proposed submissions required for permit applications (seeking comment)

Comment: Page 112, Reporting - The policy suggest s monitoring and testing plan, AOR/corrective action plan, and Post-In jection plan. We’d recommend these documents be included as supporting a ttachments the permit application. This level of reporting may result in delays to the permitting process.

Individual Response: EPA believes that the requirement that owners and operators develop an area of review (AoR) and correctiv e action plan, a testing and mon itoring plan, an injection well

19plugging plan, a post-injection site care and site closure plan, and an emergency and remedial response plan are necessary to protecting USDW s from endangerment and does not believe they will result in delays to the permitting process. EPA anticipates that these plans will be attachments to the permit application and also ac knowledges that not all in formation necessary to develop full plans will be availa ble at the time of the initial permit application. For this reason, EPA envisions an iterative process where the owne r or operator and the Dir ector will discuss the site data being collected and how it will inform all aspects of the project, including the plans under §146.82. EPA is developing guidances to assi st the owner or operator in preparing the project plans and meeting the financial responsibility requirements for GS wells. The guidances

can be found on EPA’s website at http://water.epa.gov/type/groundwater /uic/wells_sequestration.cfm.

Letter ID: 0229 Comment ID: 21864 Letter Lines: 339 to 341

Comment Code: 4750 2.7.5 Comments on the merit of a nnual reports (seeking comment)

Comment: Page 115, Annual Report- Another annual report is mentioned. The overall reporting requirements are confusing. We w ould recommend monthly or quarterly operating reports and a si ngle annual report.

Individual Response: The final rule remains unchanged from the proposal and requires semiannual reporting of monthly average, maximum and minimum values for injection pressure, flow rate and volume, annular pressure, and monthl y annulus fluid volume added at §146.91(a). EPA believes that monthly reporting of routine operational data and monitoring results would provide no additional protection of USDW s from endangerment. EPA adds , at §146.91(c), that it has included in the final rule a requirement that ope rators must report with in 24 hours of any event that may endanger USDWs. EPA notes that states seeking primacy for Class VI wells are free to require more frequent reporting.

Letter ID: 0229 Comment ID: 21865 Letter Lines: 343 to 347

Comment Code: 5200 2.8.2 Post injection site care (seeking comment) (40 CFR 146.93)

Comment: Page 118, Post-injection Site Care Plan- Th e post injection site care plan would seem to require monitoring of pressures, plume extent, and other items after injection stops. However, this would pr event plugging and abandoning wells. It is recommended that the post-injection site care requirements allow for the plugging and abandoning of wells that are not being used for monitoring.

Individual Response: EPA acknowledges that owners or operators may wish to use injection wells for monitoring purposes to meet the post-injection monitoring requirements. Nothing in the GS rule precludes this. EPA clarifies that Cla ss VI injection wells must be plugged in a manner that protects USDWs from endangerment, as specified in 146.92(b). These requirements apply whether the well is plugged upon ce ssation of injection or at th e time of site closure.

20Letter ID: 0229 Comment ID: 21866 Letter Lines: 349 to 357

Comment Code: 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: Page 123- 50 year Post In jection Period- We strongly encourage EPA to not include a recommendation for 50 years of m onitoring. We are concerned that most directors will choose to apply this as a default value, even for shorter duration projects or at low risk sites. Instead a site-specific post injection monitoring plan with clearly defined pe rformance criteria such as pressure reduction, plume stabilization, lack of leak age, or stable parameter values over a period of time, should be used. This a pproach will give EPA the flexibility to design site-specific requirement but w ill also provide a level of certainty to the operators in terms of performance expectations.

Individual Response: EPA agrees with commenters that th ere will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the pos t-injection period based on site-specific data, pursuant to requirements at §146.93(b) ; or (2) affording the Director discretion to allow a Class VI well owner or operator to demonstrate, during the permitting process based on substantial data, that an alternative PISC timeframe may be appropriate if it ensu res non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from enda ngerment, a default timeframe for post-injection site care will be necessary in al l but a limited number of cases. This default 50 year post-injection site care ti meframe represents a reasonable and protective monitoring period based on a review of research studies, industr y reports, and existing environmental programs, and evaluation of public comments.

EPA believes that a default post-injection site car e timeframe of 50 years, with flexibility to adjust the timeframe for a limited number of GS projects during the permitting process where

substantial data exists to demonstrate that an alternative timeframe would be protective of USDWs, or based on data collected during the PISC period, is appropriate to address the range of sites where GS is anticipated to occur, to ac commodate site-specific circumstances and various geologic conditions, and addre sses commenters’ concerns, wh ile ensuring USDW protection. Both approaches will utilize si te-specific data, and be based on pressure monitoring and USDW impacts.

EPA is developing guidance to assist owners or operators in evaluating well plugging, postinjection site care, and site closure requi rements of §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstr ate the appropriateness of an alternative postinjection site care time frame; demonstrate non endangerment; and perform site closure activities. Additionally, the guidance will assist Directors in evalua ting proposed well plugging

21plans and post-injection s ite care and site closure plans under §146.92 and §146.93. This guidance will be available at h ttp://water.epa.gov/type /groundwater/uic/wells_sequestration.cfm.

Letter ID: 0229 Comment ID: 21867 Letter Lines: 359 to 368

Comment Code: 1310 1.1.2.4 Comments on other "out of scope" issues, e.g., pore space ownership

Comment: Page 138, Primacy/Jurisdiction- Given th e size and location of potential GS projects, many storage areas are likely to cross state lines. For example almost all of the major sources of CO2 em issions in the MRCSP region are at or near state boundaries, along Ohio River. For example, a geologic storage facility located near Wheeling West Virginia could have a CO2 plume and injection well locations in Ohio, West Virginia, and Pennsylvania. It is unclear how these projects would be impl emented regarding who has primacy in permitting the site under a single permit, rather than three separate permits. Additional guidance permitting sites with multiple jurisdictions is highly desirable to prevent confus ion or legal challenges.

Individual Response: EPA acknowledges that CO2 plumes may cross jurisdictional boundaries and encourages cooperation and coordination am ong permitting authorities. The final Class VI GS rule, at §146.82(a)(2), requires the owner or operator to identify al l State, Tribal, and

Territorial boundaries within the AoR. Based on this information, the Director must provide written notification to all States, Tribes, and Territories to inform them of the permit application and ensure that they are involve d in any necessary processes; th is new requirement was added to the final rule at §146.82(b). The Agency encourag es transparency in the permitting process and anticipates that State-State/State-Tribal communication on Class VI permitting will facilitate information sharing and encourag e safe, protective projects.

Letter ID: 0229 Comment ID: 21868 Letter Lines: 370 to 377

Comment Code: 3150 2.1.5 Comments on required permit information (40 CFR 146.82)

Comment: Page 193, AOR Map- It will be difficult to provide the numerous site features on a single map as required in the regulation. Multiple ma ps should be allowed. Otherwise, the map must show the number, or name and location of all injection wells, producing wells, abandoned wells, plugged wells or dr y holes, deep stratigraphic boreholes, State or EPA approved subsurface cleanup sites, surface bodies of water, springs, mines (surface and subsurface), quarries, water wells and other pertinent surface features in cluding structures intended for human occupancy and roads, and faults.

Individual Response: EPA acknowledges the comments and agrees that multiple maps may be necessary to present all of the data needed to support a determ ination of the suitability of a site for GS. Nothing in the GS rule prohibits this.

22Letter ID: 0229 Comment ID: 21869 Letter Lines: 379 to 384

Comment Code: 6100 3.1 Comments on the cost estimates

Comment: Cost Estimates- In general most of the estimates for hours, hourly rates, and costs required for implementing the requireme nts appear to be too low compared to our experience and the complexity of proposed regulatory requi rements. It is

recommended that EPA obtain more realistic cost estimates for all aspects of the regulations, deep well drilling, monitoring, expert delivery of geosciences and engineering professionals.

Individual Response: The Agency increased some unit costs (e.g., for labor rates, seismic analysis, pipeline, etc.) for the final rule, as desc ribed in the cost analys is, to address commenter concerns that they were underestimated. All un it costs were reviewed and updated commensurate with inflation, as explained in the Geologic CO2 Sequestration Technology and Cost Analysis document, which is in the rulemaking docket. In addition, EPA incorpor ated a site selection factor into the final cost analysis based on the assumption that site selection will be successful between 25 and 100 percent of the time, depending on project type; this fact or increased costs for geologic site characterization.

For additional information on the final costing ap proach, please see the final cost analysis and technology and cost document in the final rule docket.

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