### 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.COMMENTS OF THE INTERSTATE OIL AND GAS COMPACT COMMISSION ON THE U .S

. ENVIRONMENTAL PROTECTION AGENCY'S

PROPOSED FEDERAL REQUIREMENTS UNDER THE UNDERGROUND INJECTION CONTROL PROGRAM FOR CARBON DIOXIDE GEOLOGIC SEQUESTRATION WELLS

DOCKET ID NO

. EPA-HQ-OW-2008-0390

December 23, 2005 

# ~

: :- r DEC 2 3 2008

The Interstate Oil and Gas Compact Commission, representing the U .S

. states that produce oil and natural gas, submits the following comments to Docket ID No

. EPA-HQOW-2008-0390 on the Environmental Protection Agency's Proposed Federal Requirements for Carbon Dioxide (COZ) Geologic Sequestration (GS) Wells under the Underground Injection Control (UIC) Program of the Safe Drinking Water Act (SWDA)

.

1

. General Comments

A

. Funding : It is essential that EPA provide adequate funding to states assuming primacy jurisdiction under the UIC program to administer C02 storage regulatory activities

.

2

. IOGCC Response to EPA Narrative Proposal

II

. C

. Who Implements the UIC Program?

A

. EPA seeks comment on any aspects of the ongoing State efforts to regulate the GS of COZ and how these efforts might be used to better inform a final Federal rulemaking

.

IOGCC Response : Many states currently have primacy jurisdiction under the UIC program

and administer Class II and other wells

. Primacy should be allowed for Class VI and should be structured to allow flexibility in the primacy process and defer to the state rule where it effectively meets the intent of the federal requirements

.

II

. G

. How Would This Proposal Affect Existing Injection Wells Under the UIC Program?



# DEC 2 3 2008B

. EPA seeks comment on the merits of this approach since owners or operators of some Class II EOR/EGR wells may wish to use wells for the purposes of production and GS prior to the field being completely depleted

.

IOGCC Response : The IOGCC agrees with EPA's proposed approach as long as the project is an EOR project under Class II and the operator has been able to demonstrate viable production

. EPA should consider a separate classification other than the proposed Class VI, as well as requisite requirements, for wells that are transitioned from Class 11 EOR to Class II related storage

.

11

. G

. How Would This Proposal Affect Existing Injection Wells Under the UIC Program?

C

. EPA is proposing to give the Director discretion to carry over or "grandfather" the construction requirements (e .g ., permanent, cemented well components) for existing Class I and Class II wells seeking a permit for GS of CO2, provided he/she is able to make a determination that these wells would not endanger USDWs

.

IOGCC Response : The IOGCC agrees that discretion is appropriate and necessary when reviewing other UIC class wells for use as UIC Class VI wells or another class of well as suggested in the response to II

. G (B) above

.

II

. G

. How Would This Proposal Affect Existing Injection Wells Under the UIC Program?

D

. Accordingly, EPA is proposing that the Director have the discretion to "grandfather" the construction requirements for Class V experimental wells when they are converted to full-scale GS Class VI wells

. As with converted Class I and Class II wells, these grandfathered wells would be required to meet the other requirements of today's proposed rule (e .g ., operating, monitoring, MIT, well plugging, post-injection site

care and site closure)

.

IOGCC Response : The IOGCC agrees that discretion is appropriate and necessary when reviewing other UIC class wells for use as UIC Class VI wells or another class of well as suggested in the response to II

. G (B) above

.

11

. G

. How Would This Proposal Affect Existing Injection Wells Under the UIC Program?E

. EPA seeks comment on the approach to grandfather construction requirements at the Director's discretion for existing Class I, Class II, and Class V wells seeking to convert to Class VI wells, and whether additional construction requirements would be necessary to prevent endangerment to USDWs from the GS of CO2

.

IOGCC Response : As part of the primacy package negotiated with the state, when an operator submits an application to reclassify any existing injection well to Class VI or other storage well classification, the Director should have the flexibility to determine whether the well meets the federal Class VI or another storage well classification which incorporates protective standards and requires the operator to adhere to the permitting process

.

II

. G

. How Would This Proposal Affect Existing Injection Wells Under the UIC Program?

F

. Additionally, EPA seeks comment on how the grandfathering approach for existing wells may affect compliance with the requirements in this proposal

.

IOGCC Response : As part of the primacy package negotiated with the state, when an operator submits an application to reclassify any existing injection well to Class VI or other storage well classification, the Director should have the flexibility to determine whether the well meets the federal Class VI or another storage well classification which incorporates protective standards and requires the operator to adhere to the permitting process

.

II

. H

. What Are the Target Geologic Formations for GS of COZ?

G

. As with unmineable coal seams, EPA seeks comment on prohibiting injection into such formations if they are above the lowermost USDW

.
IOGCC Response : There should be no blanket prohibition against injection into any approved geologic zone even if above the lowermost USDW

. There may be circumstances where this is perfectly appropriate and safe

. The decision needs to be site-specific and based on evaluation of local geology

.

II

. I

. Is Injected COZ Considered a Hazardous Waste Under RCRA?

H

. EPA seeks comment on this approach and other considerations associated with the presence of impurities in the COZ stream

.IOGCC Response : Injected COZ is not and should not be considered a hazardous waste or regulated under RCRA or CERCLA

. It is assumed that RCRA or CERCLA wastes would be removed from the COZ stream prior to storage

.

Il

. J

. Is Injected COZ Considered a Hazardous Substance Under CERCLA?

1

. EPA requests comment on particular situations where this might occur

. EPA also requests comment on other considerations associated with the presence of impurities in the C02 stream related to CERCLA

.

IOGCC Response : Injected COZ is not and should not be considered a hazardous waste or regulated under RCRA or CERCLA

. It is assumed that RCRA or CERCLA wastes would be removed from the COZ stream prior to storage

.

III

. Proposed Regulatory Alternatives

J

. EPA is proposing Regulatory Alternative 3, the Tailored Requirements Approach

. EPA did not select alternative 1 (Non-Specific Requirements Approach) because it does not provide enough specificity to ensure that permitting authorities manage GS wells appropriately to prevent endangerment of USDWs

. In addition, this alternative may be burdensome for owners or operators because of the potential for inconsistency across States and burdensome for permitting authorities who will likely be faced with developing their

own technical approaches to regulating GS

.

IOGCC Response : The IOGCC strongly believes that Alternative lI is the better approach with some additional strengthening

. This would allow necessary discretion and flexibility on the part of the Director

. The alternative proposed by EPA, Alternative III, although described as "giving permitting authorities discretion in how to permit certain elements" appears to offer very limited discretion and flexibility to the Director

. Alternative III is unnecessarily prescriptive

.

III A

. 1 Proposed Geologic Siting Requirements

K

. EPA specifically seeks comment on the merits of identifying these additional zones

.

IOGCC Response : Secondary confinement should not be a requirement

. Such a requirement would eliminate good and sound storage sites and reduce ultimate capacity of the country to store anthropogenic CO2

. The determination as to whether secondary confinement should be required should be made on a project by project basis and be site specific

. It ispossible to hypothesize a circumstance where secondary confinement is not necessary with the addition of stronger monitoring requirements

.
III A

. 2 Proposed Area of Review and Corrective Action Requirements

IOGCC General Comment for Section lIl

. A

. 2 : The IOGCC believes use of traditional well specific AoR is problematic for comprehensive site characterization and licensing

. The IOGCC has recommended in its report a site characterization and licensing process that includes elements such as geologic and engineering evaluation, modeling, amalgamation of property rights and other appropriate elements that we believe exceeds the capacity of the traditional AoR to accomplish

.

III A

. 2 Proposed Area of Review and Corrective Action Requirements

L

. EPA seeks comment on the use of modeling for AoR delineation

.
IOGCC Response : See General Comment for Section III

. A

. 2 above

. The collection of physical data (i .e

. well bore data) may be necessary to fully utilize modeling to determine the ultimate extent of the proposed COZ storage volume

. Models should only be used when they are appropriate

. The Director needs the flexibility to be able to supplement or substitute other data elements as appropriate

.

III A

. 2 Proposed Area of Review and Corrective Action Requirements

M

. EPA seeks comment on allowing the use of proprietary models for GS sites

.

IOGCC Response : Proprietary models should be allowed provided the Director has discretion to evaluate the accuracy of the modeling methodology

. It should be noted that confidentiality of proprietary models will be subject to statutory limitation in various jurisdictions

.
III A

. 2 Proposed Area of Review and Corrective Action Requirements

N

. EPA seeks comment on the applicability of computational fluid flow models for delineating the AoR of GS sites

.

IOGCC Response : See General Comment for Section III

. A

. 2 above

. The collection of physical data (i .e

. well bore data) may be necessary to fully utilize modeling to determine the ultimate extent of the proposed C02 storage volume

. Models should only be used when they are appropriate

. The regulator of a GS project should not be required to relyfully on models

. As noted above, states need the flexibility to be able to go beyond models

.

III A

. 2 Proposed Area of Review and Corrective Action Requirements

O

. EPA seeks comment on requiring the reevaluation of the site AoR on a periodic basis, under what conditions the AoR should be reevaluated, and the appropriateness of a 10 year minimum fixed frequency for AoR reevaluation

.

IOGCC Response : Note : This comment is based on the traditional AoR requirement

. Most states do an annual project review with the operator not only to evaluate the project's performance but to determine if additional measures are needed

. Setting a frequency should be performance based and should be left to the Director's discretion, but in
no event less than every two years

. Only if the review determines that remodeling, further study or additional down-hole monitoring is necessary, should such work be done

. Additionally, such additional work should be done as needed, not at a set time interval

.

III A

. 2 Proposed Area of Review and Corrective Action Requirements

P

. EPA invites public comment on the merits and frequency of reevaluation of the AoR as well as the phased corrective action approach for GS wells

.

IOGCC Response : Same as the two comments above, however, the IOGCC reiterates the inappropriateness of using a wellbore-focused AoR methodology for evaluating the entire project

.

III A

. 3 Proposed Injection Well Construction Requirements

Q

. EPA seeks comment on the proposed GS well requirements for depth of surface casing, the cementing of long-string casing, and construction with a packer set opposite a cemented interval

.

IOGCC Response : IOGCC agrees with the need for adequate protection of USDWs and the proposed measures

. However, Director discretion is necessary to address site-specific conditions

. Well construction should be evaluated so as to insure necessary protections of the USDWs, and should not be overly prescriptive

.

III A

. 3 Proposed Injection Well Construction RequirementsR

. EPA also seeks comment on how the proposed grandfathering provisions for existing wells (construction requirements) may affect compliance with the above, proposed construction requirements

.
IOGCC Response : The IOGCC believes that Director discretion is appropriate and necessary when reviewing other UIC Class wells for use as UIC Class VI wells

. Overly prescriptive well construction requirements will limit the use of existing UIC wells and possible sequestration zones

.

III A

. 3 Proposed Injection Well Construction Requirements

S

. EPA seeks comment on the merits of horizontal well drilling techniques for GS wells and the applicability of well construction requirements discussed in this proposal

.

IOGCC Response : With Director discretion horizontal well drilling techniques may be appropriate for GS application

.

III A

. 3 Proposed Injection Well Construction Requirements

T

. EPA seeks comment regarding requirements for degradation-resistant well construction materials, such as acid-resistant cements and corrosion resistant casing

.

IOGCC Response : Concerning degradation-resistant well construction materials, the EPA rule should not be overly prescriptive but instead set a performance standard that would allow on a case by case basis the cementing materials necessary to meet the standard

.
III A

. 4 Proposed Injection Well Operating Requirements

U

. EPA is requesting comment on the extent and scope to which hydraulic fracturing should be allowed during GS injection, and whether the use of fracturing for the purposes of well stimulation is appropriate

.

IOGCC Response : While hydraulic fracturing may be necessary in some cases to complete an injection well, it should not be allowed during GS injection

. Any fracturing during well completion stimulation should be engineered so as to eliminate any risk of damage to confining zones

.

III A

. 4 Proposed Injection Well Operating RequirementsV

. EPA is also requesting information to better qualify the use of fracturing for GS injection in specific geologic settings and rock formation lithologies

.

IOGCC Response : As indicated above, hydraulic fracturing should only be allowed during the initial completion or recompletion of a well to enhance reservoir permeability

. However, once the completion phase has ended and the operational or injection phase has begun, fracturing during injection should never be permitted

. It is important to keep separate the concept of operational injection pressure limits and episodic well stimulation activities

.

In this respect, there should be no injection above the allowable permitted pressure

. Additionally, hydraulic fracturing of the cap rock should never be allowed nor should pressure testing of the confining layer

.

III A

. 4 Proposed Injection Well Operating Requirements

W

. EPA seeks comment on the merits of requiring down-hole shut-off valves in GS wells

.

IOGCC Response : There should be no hard and fast requirement for a down-hole shut-off valve in a GS well

. Down-hole shut-off valves may, however, at Director discretion provide a necessary extra level of protection in more sensitive settings

.

III A

. 4 Proposed Injection Well Operating Requirements

X

. As a result, the Agency is considering and requesting comment on alternative approaches that would allow injection between and/or above the lowermost USDW, and thus potentially allow for more areas to be available for GS while preventing USDW endangerment

.

IOGCC Response : There should be no blanket prohibition against injection into a zone even if above the lowermost USDW

. There may be circumstances where it is perfectly appropriate and safe

. The decision needs to be site specific based on local geologic conditions

.

III A

. 4 Proposed Injection Well Operating Requirements

Y

. In summary, EPA is soliciting comment on whether COZ injection should be allowed into an injection zone above the lowermost USDW, when the Director determines that geologic conditions (e .g ., thousands of feet of intervening formations between the injection zone and the overlying and/or underlying USDWs) exist that will prevent fluid movement into adjacent USDWs

.IOGCC Response : Injection criteria on which zones to use should be site specific based on local geologic conditions

.

III A

. 4 Proposed Injection Well Operating Requirements

Z

. EPA is also requesting comments on whether aquifer exemptions should be allowed for the purpose of Class VI injection, and under what conditions should such aquifer exemptions be approved

.

IOGCC Response : Aquifer exemptions under Class VI should be allowed

on the same basis as for other classes

. Each exemption should be considered on its own merits based on local geologic conditions and the likelihood of use of the zone for future public water supply

.

III A

. 4 Proposed Injection Well Operating Requirements

AA

. Finally, EPA seeks comment on whether the Agency should set a minimum

injection depth requirement for COZ GS, rather than require that such injection take place below the lowermost USDW

.

IOGCC Response : EPA should not set a minimum injection depth requirement for COZ GS as it is unnecessary

. The rule needs to allow site specific flexibility

.

III A

. 4 Proposed Injection Well Operating Requirements

BB

. EPA seeks comment on the use of tracers in COZ GS operations, and any potential impact of tracers on human health or ecosystems as they relate to USDWs

.

IOGCC Response : Adequate down hole monitoring above the containment zone should in most cases eliminate the need for tracer systems to detect the presence of injected COz at the surface

. Use of such tracers should not be required although should be an optional methodology for use at Director discretion

.

III A

. 5 Proposed Mechanical Integrity Testing Requirements

CC

. EPA requests comment on the practicability of this requirement

.

IOGCC Response : The IOGCC believes that the methodologies and requirements under Class II would be sufficient for Class VI wells and that applying Class I requirements is too stringent

.

III A

. 5 Proposed Mechanical Integrity Testing RequirementsDD

. EPA seeks comment on the appropriate frequency of internal and external MITs for GS injection wells, the appropriate types of MITs, and how

to optimize MIT methods for GS

.

IOGCC Response : For internal MITs for GS injection wells, 5 years would be a sufficient frequency

. For external MITs, the frequency should generally be annual depending upon the specific circumstances

. The types of test should be those which are most appropriate under the specific circumstances

.

III A

. 6 Proposed Plume and Pressure Front Monitoring Requirements

EE

. EPA seeks comment on the requirement for monitoring of GS sites for the purpose of tracking the location of the COZ plume and associated pressure front over time

.

IOGCC Response : The IOGCC suggests that the operator be required to conduct ongoing monitoring

. The frequency of reporting to the regulatory
agency should be flexible depending upon site characteristics

.

III A

. 6 Proposed Plume and Pressure Front Monitoring Requirements

FF

. EPA seeks comment on the use and frequency of pressure fall-off testing for GS wells

.

IOGCC Response : The IOGCC does not see the necessity of pressure falloff testing for GS wells

. It should be used as necessary but not mandated

.

III A

. 6 Proposed Plume and Pressure Front Monitoring Requirements

GG

. Based on information evaluated to date, EPA believes that tracking the plume and pressure front is an important companion step to address any uncertainties associated with initial AoR modeling and requests comment on this approach and more efficient alternatives that may be used to track the plume and pressure front

.

IOGCC Response : Tracking of the COz plume and pressure front should be required

. The methodology, however, should not be specified but determined on a site specific basis

. The IOGCC agrees with the following EPA statement : "As such, allowing flexibility in choosing the plume tracking methods and other monitoring technologies may provide an appropriate balance between the protective nature of indirect monitoring and cost considerations, as well as allowing for the adoption of continuously advancing technology ."

III A

. 6 Proposed Plume and Pressure Front Monitoring RequirementsHH

. EPA seeks comment on the appropriate amount and types of monitoring that should be conducted at a GS site

.

IOGCC Response : The IOGCC agrees that owners and operators should report semi-annually on the characteristics of injection fluids, injection pressure, flow rate, temperature, volume and annular pressure, and on the results of MITs, ground water monitoring, and any required atmospheric/soil gas monitoring

. The amount and types of monitoring to be required, however, should be site specific

.

III A

. 6 Proposed Plume and Pressure Front Monitoring Requirements

11

. Specifically, EPA seeks comment regarding the usefulness of indirect geophysical monitoring and surface air and soil gas monitoring

.

IOGCC Response : The IOGCC agrees that owners and operators should report semi-annually on the characteristics of injection fluids, injection pressure, flow

rate, temperature, volume and annular pressure, and on the results of MITs, ground water monitoring, and any required atmospheric/soil gas monitoring

. The amount and types of monitoring to be required, however, should be site specific

.

III A

. 6 Proposed Plume and Pressure Front Monitoring Requirements

JJ

. In addition, EPA seeks comment regarding the use of a Directorapproved monitoring plan for GS sites

.

IOGCC Response : The Director should be given flexibility to approve site specific monitoring plans as proposed in the IOGCC model regulations

.

III A

. 7 Proposed Recordkeeping and Reporting Requirements

KK

. EPA seeks comment on the merits of requiring plans for monitoring, AoR, and post-injection site care as part of a permit application

.

IOGCC Response : Yes, there should be detailed monitoring, AoR, and post-injection site care plans as a part of the permit consistent with the recommendations of the IOGCC model regulations

.

III A

. 7 Proposed Recordkeeping and Reporting Requirements

LL

. EPA seeks comment on the frequency of all proposed reporting requirements

.IOGCC Response : As concerns the frequency of reporting for the physical and chemical characteristics of the injected fluids in a Class VI well, IOGCC model regulations specified annual reporting although semiannual reporting (as proposed by EPA in the rule) would be acceptable

.

III A

. 7 Proposed Recordkeeping and Reporting Requirements

MM

. EPA seeks comment on the requirement for electronic reporting in today's proposed rule

.

IOGCC Response : The IOGCC agrees with electronic submittal in principle as long as there is sufficient flexibility to allow states to utilize existing or preferred state data processing systems or software

. Electronic reporting should be an option but not a requirement

.

III A

. 7 Proposed Recordkeeping and Reporting Requirements

NN

. Although EPA has not included a requirement for this report in today's proposal, EPA seeks comment regarding the necessity for such

an annual report

.

IOGCC Response : The IOGCC suggests that there be only one frequency of reporting, either annual or semi-annual

. Thus, this requirement should be incorporated into the semi-annual reporting requirement enunciated by EPA in the rule for the physical and chemical characteristics of the injected fluids in a Class VI well

. There should not be two different data reporting timeframes

.

III A

. 8 Proposed Well Plugging, Post-Injection site Care, and Site Closure Requirements

00

. EPA requests comment on the proposed use of a tentative 50-year fixed timeframe that could be modified at the Director's discretion based on monitoring and modeling data

.

IOGCC Response : Given that current injection and reservoir behavior data demonstrates a decreasing risk of leakage after injection ceases, the IOGCC has concluded that a 50 year fixed timeframe is both unnecessary and too long

. What is absolutely critical here is that the Director has discretion to increase or decrease the period based on the specifics of a particular project

. In the view of the IOGCC, it would be better to prescribe a shorter period with discretion to go longer, rather than vice versa, as such would better facilitate project planning

.III A

. 8 Proposed Well Plugging, Post-Injection site Care, and Site Closure Requirements

PP

. EPA is requesting comments on the proposed requirements for well plugging, post-injection site care, and site closure, including the proposed requirements for the post-injection time period

.

IOGCC Response : Given documented evidence to date that there is a decreasing risk of leakage after injection ceases, The IOGCC has concluded that a 50 year fixed timeframe is both unnecessary and too long

. What is absolutely critical here is that there be Director discretion to increase or decrease the period based on the specifics of a particular project

. In the view

of the IOGCC, it would be better to prescribe a shorter period with discretion to go longer, rather than vice versa, as such would better facilitate project planning

.

III A

. 8 Proposed Well Plugging, Post-Injection site Care, and Site Closure Requirements

QQ

. In addition, EPA seeks comment on whether the Director should be allowed to shorten the timeframe based on performance information, and whether EPA should require a shorter or longer postinjection period if data suggests the time frame should be adjusted

.

IOGCC Response : Given documented evidence to date that there is a decreasing risk of leakage after injection ceases, The IOGCC has concluded that a 50 year fixed timeframe is both unnecessary and too long

. What is absolutely critical here is that there be Director discretion to increase or decrease the period based on the specifics of a particular project

. In the view of the IOGCC, it would be better to prescribe a shorter period with discretion to go longer, rather than vice versa, as such would better facilitate project planning

.

III A

. 9 Proposed Financial Responsibility and Long-Term Care Requirements

RR

. EPA is requesting comments on whether financial responsibility mechanisms to be recommended in EPA guidance should be adjusted in the manner described, whether additional instruments should be included, and whether other adjustments to the financial responsibility mechanisms should be considered, all subject to EPA's authority under the SDWA

.

IOGCC Response : The EPA proposed rule for well financial assurance appears comprehensive enough

. However, the proposed two-tier bond system of pre and post plugging of the well would be administratively cumbersome and the IOGCC would recommend one bond that coversoperational, eventual plugging and post site remediation until the release date

.
The IOGCC model regulations proposed that in addition to well bonds that there also be an overall facility bond

. The purpose of the facility bond would be to insure financial responsibility to address and mitigate nonwell specific issues

. What EPA is suggesting in the rule needs to be supplemented by the states via mechanisms such as a facility bond

.
III A

. 9 Proposed Financial Responsibility and Long-Term Care Requirements

SS

. The Agency is also requesting comment on allowing separate financial demonstrations to be submitted for the plugging of the injection well and for the post-injection site care requirements

.
IOGCC Response : The IOGCC model regulations proposed that in addition to well bonds that there also be an overall facility bond

. The purpose of the facility bond would be to insure financial responsibility to address and mitigate non-well specific issues

. What EPA is suggesting in the rule needs to be supplemented by the states via mechanisms such as a facility bond

.

IV

. How

Should UIC Program Directors Involve the Public In Permitting Decisions for GS Projects?

TT

. EPA requests comment on adopting the existing requirements for public participation at 40 CFR Part 25 and 40 CFR Part 124 and whether additional requirements should be included to reflect the availability of new

tools for disseminating and gathering information

. Such tools include cable networks, the Internet, and other new technology

.

IOGCC Response : All states have public notice laws and regulations that cover most regulatory and permitting functions

. These laws and regulations would extend to the permitting and the regulation of GS that require public notice, hearings and due process to all affected parties

. This should be adequate for public involvement purposes

.
IV

. How

Should UIC Program Directors Involve the Public In Permitting Decisions for GS Projects?

UU

. EPA also requests comment on ways to enhance the public participation process, including engaging communities in the site characterization process as soon as candidate locations are identified

.
IOGCC Response : All states have public notice laws and regulations that cover most regulatory and permitting functions

. These laws andregulations would extend to the permitting and the regulation of GS that require public notice, hearings and due process to all affected parties

. This should be adequate for public involvement purposes

.

V

. How Will States, Territories, and Tribes Obtain UIC Program Primacy for Class VI Wells?

VV

. EPA is seeking comment on the merits and possible disadvantages of allowing primacy approval for Class VI wells independent of other well classes

.

IOGCC Response : The IOGCC strongly supports independent state primacy for Class VI

. States should have the authority to designate which
agency in the state can apply for and be granted primacy

.

VI

. What Is the Proposed Duration of a Class VI Injection Permit?

WW

. Therefore, EPA proposes that Class VI injection well permits would be issued for the operating life of the GS project including the post-injection site care period

. EPA seeks comment on the merits of this approach

.

IOGCC Response : The IOGCC agrees with the EPA proposal

.

VI

. Cost Analysis

XX

. Therefore EPA proposes that Class VI injection well permits would be issued for the operating life of the GS project including the post-injection site care period

. EPA seeks comment on the merits of this approach

.

IOGCC Response : No comment

.

### Letter ID: 0263 Organization: Interstate Oil & Gas Compact Commission

Letter ID: 0263 Comment ID: 22788 Letter Lines: 38 to 40

Comment Code: 5600 2.11 Comments related to UIC Program primacy for Class VI wells

Comment: A. Funding: It is essential that EPA provi de adequate funding to states assuming primacy jurisdiction under the UIC program to administer CO2 storage regulatory activities.

Individual Response: EPA acknowledges that there may be technical and administrative challenges including resource concerns , and will work closely with the states to assist them in resolving funding issues or acquiri ng the resources, personnel, and training needed to address the unique technical challenges associated with GS.

EPA will also incorporate Class VI wells into the UIC Program's grant allocation process. The States/Tribes/Territories must also demonstrate th at they have adequate resources to implement the program through matching resources against those allocated by the UIC Program's grant allocation formula. Currently, primacy programs ar e required to meet a minimum of 25 percent matching requirement.

Letter ID: 0263 Comment ID: 22789 Letter Lines: 46 to 54

Comment Code: 5610 2.11.1 Allowing partial primacy for Class VI wells (seeking comment)

Comment: A. EPA seeks comment on any aspects of th e ongoing State effort s to regulate the GS of CO2 and how these efforts might be used to better inform a final Federal rulemaking.

IOGCC Response: Many states currently have primacy jurisdiction under the UIC program and administer Class II and other wells. Primacy should be allowed for Class VI and should be stru ctured to allow flexibility in the primacy process and defer to the state rule where it effectively meets th e intent of the federal requirements.

Individual Response: EPA clarifies that the primacy approva l processes for Class II and Class VI differ. Section 1421 of SDWA directs EPA to grant primary enforcem ent responsibility (or primacy) to the States through two statutory pr ovisions. The first provision, under Section 1422, provides for a State to demonstrat e that its proposed UIC program is at least as stringent as the minimum Federal requirements in order to prevent endangerment of USDWs. The second provision, under Section 1425, allows a State to subm it an alternative demonstration for its Class II program (oil and gas), where the State only has to demonstrate that its proposed Class II program is an effective program to prevent underground injection that endangers USDWs.

1

### EPA clarifies that Class VI we lls are regulated under Section 1422 of SDWA, and adds that states should be able to obtain primacy for Class VI wells inde pendent of other well classes provided they develop regulations that are at least as stringent as the minimum Federal requirements (e.g., permitting, inspection, operation, monitoring, and recordkeeping requirements) provided in the final GS rule.

EPA acknowledges the expertise of state oil and gas agencies that have been regulating Class II wells for decades under secti on 1425 of SDWA. These agencies already understand CO2 injection, subsurface operations, and pipeline tr ansport, and they are familiar with public interests and the SDWA. EPA believes that this experience, along with the agencies' familiarity with UIC permitting requirements, will help facilitate the adoption of Class VI primacy
programs.

Letter ID: 0263 Comment ID: 22790 Letter Lines: 56 to 66

Comment Code: 2046 1.5.2.3 Continuing to classify CO2 in jection for EOR/EGR as Class II/ dividing line between Class II and Class VI (seeking comment)

Comment: II. G. How Would This Proposal Affect Existing Injection Wells Under the UIC Program?

B. EPA seeks comment on the merits of th is approach since ow ners or operators of some Class II EOR/EGR wells may wish to use wells for the purposes of production and GS prior to the field being completely depleted.

IOGCC Response: The IOGCC agrees with EP A's proposed approach as long as the project is an EOR project under Class II and the opera tor has been able to demonstrate viable production. EPA should consider a separate classification other than the proposed Class VI, as well as requisite requirements, for wells that are transitioned from Class II EOR to Class II related storage.

Individual Response: EPA agrees that injection of CO2 for the primary purpose of enhancing oil and gas recovery should remain under the Cl ass II Program. However, the Agency believes that the nature and risks of CO2 injection fo r the primary purpose of long term storage poses different risks than injection for the primary purpose of ER, and theref ore has developed new Class VI regulations to address these unique risks. For example, the volume of CO2 anticipated to be injected for long term storage is significa ntly greater than for ER operations. Reservoir pressure conditions will also be different, with Class VI injection ope rations involving large volumes of CO2 and likely having higher pressures w ithin their storage formations than Class II ER projects.

EPA is developing guidance on transitioning perm its from Class II to Class VI. The guidance will assist Directors in determining whether an injection project should be transitioned from Class II where the primary purpose is oil and gas production to Class VI where the primary

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### purpose is long-term storage of large volumes of CO2. The gu idance describes the recommended methods the Director may use to evaluate change s in risk to USDWs from projects, and how the Director may determine whether a project should be regulated within th e Class II or Class VI UIC program. This guidance will be available on EPA’s website at http://water.epa.gov/type/groundwat er/uic/wells_sequest ration.cfm. For more information, please see the discussion on transition of Class II well s in the preamble to the final GS rule.

Letter ID: 0263 Comment ID: 22791 Letter Lines: 68 to 118

Comment Code: 2060 1.5.3 Comments on grandfathering of existing wells (seeking comment)

Comment: II . G. How Would This Proposal Affect Existing Injection Wells Under the UIC Program?

C. EPA is proposing to give the Dire ctor discretion to carry over or "grandfather" the construction require ments (e.g., permanent, cemented well components) for existing Class I and Class II wells seeking a perm it for GS of CO2, provided he/she is able to make a dete rmination that these wells would not endanger USDWs.

IOGCC Response: The IOGCC ag rees that discretion is a ppropriate and necessary when reviewing other UIC class wells for use as UIC Class VI wells or another class of well as suggested in the response to II.G(B) above.

II . G. How Would This Proposal Affect Existi ng Injection Wells Under the UIC Program?

D. Accordingly, EPA is proposing that th e Director have th e discretion to "grandfather" the constructi on requirements for Class Experimental wells when they are converted to full-scale GS Cla ss VI wells. As with converted Class I and Class II wells, these gr andfathered wells would be required to meet the other requirements of today's proposed rule (e.g., operating, monitoring, MIT, well plugging, post-injection site care and site closure).

IOGCC Response: The IOGCC ag rees that discretion is a ppropriate and necessary when reviewing other UIC class wells for use as UIC Class VI wells or another class of well as suggested in the response to II. G(B) above.

11. G. How Would This Proposal Affect Existi ng Injection Wells Under the UIC Program?

E. EPA seeks comment on the approach to grandfather construction requirements at the Director's discretion for existing Cl ass I, Class II, and Class V wells seeking to convert to Class VI wells , and whether additional construction requirements would be necessary to preven t endangerment to USDWs from the GS of CO2.

IOGCC Response: As part of the primacy pack age negotiated with the state, when an

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### operator submits an application to reclassi fy any existing injection well to Class VI or other storage well classificat ion, the Director should have the flexibility to determine whether the well meets the federal Class VI or another storage well classification which incorpor ates protective stan dards and requires the operator to adhere to the permitting process.

II. G. How Would This Proposal Affect Existi ng Injection Wells Under the UIC Program?

F. Additionally, EPA seeks comment on how the grandfathering approach for existing wells may affect compliance with the requirements in this proposal.

IOGCC Response: As part of the primacy pack age negotiated with the state, when an operator submits an application to reclassi fy any existing injection well to Class VI or other storage well cl assification, the Director s hould have the flexibility to determine whether the well meets the fe deral Class VI or another storage well classification which incorporates protectiv e standards and requires the operator to adhere to the permitting process.

Individual Response: EPA agrees that many Class I, Cl ass II, and Class V experimental technology wells are designed and constructed to withstand exposure to CO2. The final GS rule provides for the construction of these wells to be grandfathered per §146.81(c), provided the owner or operator can demonstrate to the Director that the wells were en gineered and constructed to meet the requirements at §146.86(a) and ensure protection of USDWs, in lieu of requirements at §146.86(b) and §146.87(a). EPA clarifies that only the construction requirements are grandfathered and that all other Class VI requirements (reporting, monitoring, mechnical integrity testing, etc.) must be met fo llowing a determination under §146.81(c).

The final Class VI regulations re quire that any owner or operato r injecting CO2 for the primary purpose of long term storage obtain a Class VI pe rmit with some special consideration for the fact that they are transitioning from a well not or iginally designed to meet Class VI requirements. The Director has the authority to determine at wh at point a Class VI permit is required for those projects that are transitioning from the primar y purpose of EOR to long term storage of CO2. The final regulation provides a set of technical factors for the Direct or to evaluate in making this determination, at §144.19. EPA believes that this approach provides su fficient protection of USDWs when there is an increased risk to USDWs as compared to traditi onal Class II operations while allowing for site-specific flexibility.

EPA is developing guidance on transitioning perm its from Class II to Class VI. The guidance will assist Directors in evaluating when and whet her an injection projec t should be transitioned from Class II where the primary purpose is oil a nd gas production to Cla ss VI where the primary purpose is long-term storage of CO2. The guidance describes recommended methods for the Director to evaluate when determining changes in risk to USDWs from projects, and how the Director may determine whether a project should be regulated within th e Class II or Class VI UIC program. This guidance will be available on EPA’s website at http://water.epa.gov/type/groundwater /uic/wells_sequestration.cfm.

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### Letter ID: 0263 Comment ID: 22792 Letter Lines: 120 to 128

Comment Code: 4324 2.4.4.1.2 Comments opposed to requiring injection below the lowermost USDW

Comment: II. H. What Are the Target Geologi c Formations for GS of CO2?

G. As with unmineable coal seams, EPA seeks comment on prohibi ting injection into such formations if they are above the lowermost USDW.

IOGCC Response: There should be no blanket prohibition against injection into any approved geologic zone even if abov e the lowermost USDW. There maybe circumstances where this is perfectly appropr iate and safe. The decision needs to be site-specific and based on evaluation of local geology.

Individual Response: EPA acknowledges that there are lim ited circumstances where injection above the lowermost USDW can be performe d in a manner that protects USDWs from endangerment, as long as appropriate protections are in place. The final GS rule at §146.95 establishes a process by which owne rs or operators can seek a waiv er of the Class VI injection depth requirements for inject ion into non-USDW formations above and/or between USDWs. Additionally, the final GS rule doe s not categorically preclude or prohibit injection into any type of formation.

EPA believes that these requirements will ensure USDW protection while providing flexibility to UIC program Directors and owne rs or operators who undertak e CO2 injection for GS. The Agency believes this approach: 1) responds to co ncerns about local and re gional geologic storage capacity limitations imposed by th e proposed injection depth require ments; 2) allows for a more site-specific assessment of injection depth for GS projects; 3) accommodates injection into different formation types; 4) a llows for injection of CO2 for GS into non-USDWs above and/or between USDWs when appropriate and where it can be demonstrated that USDWs will be protected; and 5) responds to concerns about the use of aqui fer exemptions for GS. Finally, EPA’s approach to addressing injection depth va riability through a waiver process responds to concerns about future drinking wa ter resource availability and the need to ensure that high quality water remains available in sufficient qua ntities to supply drinking water needs. For additional information on the waiver approach, pleas e see the final rule and preamble, as well as EPA's responses to comments on the Notice of Data Availability and Request for Comment.

Letter ID: 0263 Comment ID: 22793

Comment: Individual Response:

Letter ID: 0263 Comment ID: 22794 Letter Lines: 149 to 165

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### Comment Code: 2300 1.7 Comments on the Alternatives Considered

Comment: III . Proposed Regulatory Alternatives

J. EPA is proposing Regulatory Alternativ e 3, the Tailored Requirements Approach. EPA did not select alternative 1 (Non-Sp ecific Requirements Approach) because it does not provide enough specificity to ensu re that permitting authorities manage GS wells appropriately to prevent enda ngerment of USDWs. In addition, this alternative maybe burdensome for owners or operators because of the potential for inconsistency across States and burdens ome for permitting authorities who will likely be faced with developing their own technical approaches to regulating GS.

IOGCC Response: The IOGCC st rongly believes that Alte rnative II is the better approach with some additional streng thening. This would allow necessary discretion and flexibility on the part of the Director. The alternative proposed by EPA, Alternative III, although describe d as "giving permitting authorities discretion in how to permit certain elem ents" appears to offer very limited discretion and flexibility to the Direct or. Alternative III is unnecessarily prescriptive.

Individual Response: Although Alternative 2 (General Re quirements Approach) provides standards for siting, construction, operation, and monitoring associated with basic deep well design and operation, EPA does not believe that this alternative is approp riate for GS because it does not contain requirements tailored to meet the unique challenges of long-term CO2 GS, including the potentially large injection volumes, buoyancy, corrosi vity in the pres ence of water, and viscosity and therefore canno t ensure protection USDWs. EPA believes that the GS rule offers states th e flexibility and discretion desired by commenters preferring Alternative 2 while ensuring the protec tion of USDWs. The final GS regulation gives the Director discretion to set permit criteria that are approp riate to site-specific conditions. The regulation provides flexibility to select approp riate sites and target formations (under §146.82), well construction specifics (under §146.86), and testing and monitoring regimes (under §146.90), provided the owner or operator can demonstrate that the injection and storage will not endanger USDWs and that minimum requirements for the site are met. Commenters representing electric utilities, water associations, and states supporte d Alternative 3 and the fl exibility it provides to permitting authorities to make case-by-case permitt ing decisions while ensuring the protection of USDWs.

Letter ID: 0263 Comment ID: 22795 Letter Lines: 167 to 177

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

Comment: III A. 1 Proposed Geologic Siting Requirements

K. EPA specifically seeks comment on the merits of identifying these additional zones.

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### IOGCC Response: Secondary confinement should not be a requirement. Such a requirement would eliminate good and sound storage sites and reduce ultimate capacity of the country to store anthr opogenic CO2. The determination as to whether secondary confinement should be re quired should be made on a project by project basis and be site specific. It is possible to hypothesize a circumstance where secondary confinement is not nece ssary with the addi tion of stronger monitoring requirements.

Individual Response: EPA clarifies that secondary confini ng zones are not required for all GS sites. Rather, secondary confini ng zones are required when the Di rector determines that these zones are needed to maximize the protection of USDWs from endangerment. EPA retains the requirement to identify additional containment/confining zones, if required by the Director, as proposed (e.g., §146.83(b)). EPA believes that, in some situations, the presence of additional confining and containment zones above the pr imary (i.e., lowermost) confining zone can improve USDW protection. These layers could fu rther impede vertical fluid movement and allow for pressure dissipation, and also provide additional sites for monitoring, mitigation, and remediation. EPA disagrees that the requirement would reduce the number of sites available for GS. The intent of this requirement is to ensure that a proposed site pr ovides adequate protection of USDWs from endangerment; if this protection cannot be demonstrated, the Director would not issue a permit for GS at the site.

Letter ID: 0263 Comment ID: 22796 Letter Lines: 179 to 186

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

Comment: III A. 2 Proposed Area of Review and Corrective Action Requirements

IOGCC General Comment for Section lIl. A. 2: The IOGCC believes use of traditional well specific AoR is problematic for co mprehensive site characterization and licensing. The IOGCC has recommended in its report a site characterization and licensing process that includes elements such as geologic and engineering evaluation, modeling, amalgamation of pr operty rights and other appropriate elements that we believe exceeds the capacity of the traditional AoR to accomplish.

Individual Response: EPA agrees that the AoR for a GS project should incorporate site characterization include elements such as ge ologic and engineering evaluation, modeling, and other appropriate elements, EPA clarifies that the area of review must be delineated using computational modeling that is based on avai lable site characteri zation, monitoring, and operational data. EPA is developi ng guidance on AoR and corrective action at GS Class VI sites to assist owners/operators and Directors in evaluating requirements and proposed AoR and corrective action plans under 146.84. The guidan ce describes EPA's recommended approaches for the data to be considered in an initial Ao R delineation, how to apply computational 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

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### http://water.epa.gov/type/groundwat er/uic/wells_se questration.cfm.

EPA clarifies that the pu rpose of the GS regulation is to ensu re the safe injection of CO2 through GS wells in order to protect USDWs from endangerment. Property, water, or mineral rights possibly affected by a GS project are outside th e scope of this rule and therefore are not incorporated into the AoR definition at 146.84(a).

Letter ID: 0263 Comment ID: 22797 Letter Lines: 188 to 196

Comment Code: 3320 2.2.1.2 Comments opposed to requiring computational models to delineate the AoR

Comment: III A. 2 Proposed Area of Review and Corrective Action Requirements

L. EPA seeks comment on the use of modeling for AoR delineation.

IOGCC Response: See General Comment for S ection III. A. 2 above. The collection of physical data (i.e. well bore data) maybe necessary to fully utilize modeling to determine the ultimate exte nt of the proposed CO2 stor age volume. Models should only be used when they are appropriate. The Director needs the flexibility to be able to supplement or substitute othe r data elements as appropriate.

Individual Response: EPA agrees that it is appropriate to al low operators the flexibility to select modeling, site characterization, a nd monitoring techniques that ar e most appropriate to site conditions and available types and amounts of data. However, EPA believes that modeling is necessary to delineate the AoR fo r GS projects, and the final rule retains this requirement. EPA notes that the final rule at 146.84(c)(1) requires the AoR to be predicted using existing site characterization, monitoring, and operational data , along with computational modeling, but that it does not specify the particular data inputs. EPA adds that the final rule at 146.82(c)(1) requires the owner or operator to revise the proposed AoR submitted under 146.82(a)(2) as necessary to address new data collected during logging and testing.

Letter ID: 0263 Comment ID: 22798 Letter Lines: 198 to 205

Comment Code: 3350 2.2.1.5 Use of proprietary models for GS sites (seeking comment)

Comment: III A. 2 Proposed Area ofReview and Corrective Action Requirements

M. EPA seeks comment on allowing the use of proprietary models for GS sites.

IOGCC Response: Proprietary models should be allowed provided the Director has discretion to evaluate th e accuracy of the modeling methodology. It should be noted that confidentiality of proprietary models will be subject to statutory limitation in various jurisdictions.

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### Individual Response: EPA will allow the use of proprietary models in meeting the requirements for the GS regulation, but clarifies that GS well operators using proprietary models are required to disclose, to the Director's sa tisfaction, the code assumptions, re levant equations, and scientific basis.

EPA adds that its Confidential Business Inform ation requirements at 40 CFR 144.5 will apply to the use of proprietary models. Information including model assumptions and equations are used by the Director to inform his/her decision to issu e the permit and ensure that the requirements are met and the GS well will not endanger USDWs.

The Agency plans, every six years, to collect and review data on GS projects to determine whether the appropriate amount and types of information and appropriate documentation are being collected, and to determine if modificatio ns to the requirements are appropriate or
necessary.

Letter ID: 0263 Comment ID: 22799 Letter Lines: 207 to 217

Comment Code: 3330 2.2.1.3 Applicability /adequacy of computational models (seeking comment)

Comment: III A. 2 Proposed Area of Review and Corrective Action Requirements

N. EPA seeks comment on the applicability of computational fluid flow models for delineating the AoR ofGS sites.

IOGCC Response: See General Comment for S ection III. A. 2 above. The collection of physical data (i.e. well bore data) maybe necessary to fully utilize modeling to determine the ultimate exte nt of the proposed CO2 stor age volume. Models should only be used when they are appropriate. The regulator of a GS project should not be required to rely fully on models. As not ed above, states need the flexibility to be able to go beyond models.

Individual Response: EPA agrees that a detailed geologic a ssessment is essential to evaluating the presence and adequacy of a proposed site to receive and confin e the CO2. The AoR and corrective action plan required at §146.84(b) must describe the site ch aracterization data on which the model will be based. The Director has discretion to require the use of existing data if it is not initially included.

EPA clarifies that the model i nputs must include act ual geologic information, data collected during the site characterization process (e.g., information about artificial penetrations), and anticipated operating parameters (e.g., injection rates) submitted with the permit application under §146.82. Models will be revised and recalibr ated during subsequent AoR reevaluations, which must account for all avai lable monitoring and operational data, as required at §146.84(e).

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### The Agency believes that predicting the comp lex multiphase buoyant flow of the CO2, coinjectates, and compounds that may be mobilized due to injection require s the sophistication of computational models. Models can predict CO2 fate and transport, as well as changes in formation pressure, in three dimens ions, as a function of time in or der to delineate the subsurface storage site and the AoR. Models can account fo r site-specific and pred icted operating conditions as well as geologic heterogeneities and potential migration through faults, fr actures, and artificial penetrations.

EPA agrees that it is appropriate to allow opera tors the flexibility to select modeling, site characterization, and monitoring techniques that are most appropr iate to site conditions and available types and amounts of data. The owner or operator must demonstrate, in the proposed AoR and corrective action plan at §146.84(b), to the satisf action of the Director that the modeled AoR will be based on detailed geolog ic data collected on the site.

Letter ID: 0263 Comment ID: 22800 Letter Lines: 219 to 232

Comment Code: 3530 2.2.3.1 AoR reevaluation fre quency (seeking comment)

Comment: III A. 2 Proposed Area ofReview and Corrective Action Requirements

O. EPA seeks comment on requiring the reev aluation of the site AoR on a periodic basis, under what conditions the Ao R should be reevaluated, and the appropriateness of a 10 year minimum fi xed frequency for AoR reevaluation.

IOGCC Response: Note: This comment is based on the trad itional AoR requirement. Most states do an annual project review with the operator not only to evaluate the project's performance but to determin e if additional measures are needed. Setting a frequency should be performan ce based and should be left to the Director's discretion, but in no event less than every two years. Only if the review determines that remodeling, further study or additional downhole monitoring is necessary, should such work be done. Additionally, such additional work should be done as ne eded, not at a set time interval.

Individual Response: EPA believes that periodic AoR reevalua tion at a set frequency of at least every 5 years is necessary to ensure protecti on of USDWs from endangerment and address the uncertainties inherent in predictive modeling. Periodic AoR reevaluations at §146.84(e) ensure that a deliberate effort is made to verify, base d on monitoring and operational data, that the CO2 plume is moving within the subsurface as predicted. EPA believes that less frequent reevaluations may not be sufficient to appropria tely model plume and pressure front movement, establish conditions for corrective action, and ensure protec tion of USDWs from endangerment.

EPA adds that the AoR and corrective action plan must specify the site-specific monitoring and operational conditions that warrant reevaluation, as specified in §146.84(b)(2)(ii). In addition,

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### the Director has discretion to re quire more frequent AoR reevalua tion if he or she has reason to believe, based on site-specific information, th at a five-year reeval uation schedule is not sufficiently protective of USDWs.

Letter ID: 0263 Comment ID: 22802 Letter Lines: 243 to 252

Comment Code: 1250 1.1.1.4 Flexibility is needed (p erformance-based standards) Comment Code: 3820 2.3.1 Well construction procedures

Comment: III A. 3 Proposed Injection Well Construction Requirements

Q. EPA seeks comment on the proposed GS well requirements for depth of surface casing, the cementing of long-string casing, and construction with a packer set opposite a cemented interval.

IOGCC Response: IOGCC agrees with the need for adequate protection of USDWs and the proposed measures. However, Director disc retion is necessary to address sitespecific conditions. Well construction shoul d be evaluated so as to insure necessary protections of the USDWs, a nd should not be overly prescriptive.

Individual Response: EPA agrees that, given the continuing evolution of material design and the numerous variables possible in a long-term GS project, listing specific requirements for casing and cement would not be appropriate. Ra ther, requiring that materials must have sufficient structural strength and be compatible w ith fluids with which they may come in contact, in §146.86(b)(1), allows the owner or operator to determine the be st casing and cementing design for each project based on information about th e site and the planned injection and for the Director to appr ove that design.

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: 0263 Comment ID: 22803 Letter Lines: 254 to 263

Comment Code: 2060 1.5.3 Comments on grandfathering of existing wells (seeking comment)

Comment: III A. 3 Proposed Injection Well Construction Requirements

R. EPA also seeks comment on how the pr oposed grandfathering provisions for existing wells (construction requirements) may affect compliance with the above, proposed construction requirements.

IOGCC Response: The IOGCC be lieves that Director discre tion is appropriate and

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### necessary when reviewing other UIC Class wells for use as UIC Class VI wells. Overly prescriptive well construction requirements will limit the use of existing UIC wells and possible se questration zones.

Individual Response: As described above, EPA agrees that many Class I, Class II, and Class V experimental technology wells are designed and constructed to withstand exposure to CO2. The final GS rule provides for the construction of these wells to be grandfathered per §146.81(c), provided the owner or operator can demonstrate to the Director that the wells were engineered and constructed to meet the requirements at §146. 86(a) and ensure protec tion of USDWs, in lieu of requirements at §146. 86(b) and §146.87(a).

Letter ID: 0263 Comment ID: 22804 Letter Lines: 265 to 272

Comment Code: 3840 2.3.2 Horizontal well drilling techniques (seeking comment)

Comment: III A. 3 Proposed Injection Well Construction Requirements

S. EPA seeks comment on the merits of hor izontal well drilling t echniques for GS wells and the applicability of well constructi on requirements discussed in this proposal.

IOGCC Response: With Dir ector discretion horizontal well drilling techniques maybe appropriate for GS application.

Individual Response: In this final rule, EPA allows the use of horizontal wells at GS projects. In the proposed rule, EPA sought comment on the appr opriateness of horizontal drilling techniques for Class VI wells, and commenters representing energy companies, el ectric utilities, the oil and gas industry, CCS associations, states, and the public, unanimously suppo rted the concept and provided many reasons why horizonta l wells could be beneficial at GS sites. Based on an evaluation of these comments and additional research by EPA, the Agency has concluded that horizontal wells that are properly constructed, logged, and tested for mechanical integrity (i.e., to meet the requirements of the GS rule) can ensu re the protection of US DWs from endangerment. EPA adds that all proposed construction, including the use of horizontal wells, must be approved by the Director.

Letter ID: 0263 Comment ID: 22805 Letter Lines: 274 to 283

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: III A. 3 Proposed Injection Well Construction Requirements

T. EPA seeks comment regarding requirements for degradation-resistant well construction materials, such as acid-res istant cements and co rrosion resistant

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### casing.

IOGCC Response: Concerning de gradation-resistant well cons truction materials, the EPA rule should not be overly prescriptive but instead se t a performance standard that would allow on a case by case basis the cementing materials necessary to meet the standard.

Individual Response: EPA clarifies that corrosion-resistan t materials are not specifically required in a Class VI injection well. Rather, as stated in §146.86(b)(1), casings and cement and other materials used must have sufficient st rength and be designe d for the life of the sequestration project. Further, materials must meet standards establishe d in the rule and be compatible with fluids with which the material s may be expected to come into contact. EPA believes the rule provides an appropriate amount of flexibility. The cons truction requirements at §146.86 provide flexibility by listing the basic com ponents a Class VI well must have to prevent endangerment of USDWs, and allow owners or operators to choose appropriate materials in meeting these requirements.

The Director will evaluate the appropriateness of the proposed well construction based on sitespecific information about the injection project, including injection pressures, injection and confining zone lithology, and information a bout the carbon dioxide stream as provided in §146.86(b)(1). In addition to the flexibility given to the owner and operator, Director's discretion is specifically provided in §146.86(b)(1) for ca sing and cementing and §146.86(c)(2 and 3) for tubing and packer location and t ype. EPA is developing guidance on the construction of Class VI wells. This guidance will be av ailable on EPA’s website at http://water.epa.gov/type/groundwater /uic/wells_sequestration.cfm.

Letter ID: 0263 Comment ID: 22806 Letter Lines: 285 to 294

Comment Code: 4120 2.4.1.2 Allowing hydraulic fracturing during GS (seeking comment) Comment Code: 4130 2.4.1.3 Appropriateness of using fractur ing for well stimulation (seeking comment)

Comment: III A. 4 Proposed Injection Well Operating Requirements

U. EPA is requesting comment on the extent and scope to which hydraulic fracturing should be allowed during GS injection, and whether the use of fracturing for the purposes of well stimula tion is appropriate.

IOGCC Response: While hydraulic fracturing maybe necessary in some cases to complete an injection well, it should not be allowed during GS injection. Any fracturing during well completion stimulat ion should be engineered so as to eliminate any risk of damage to confining zones.

Individual Response: EPA emphasizes that fracturing of th e confining zone during injection and/or stimulation is prohibited, as specified at §146.88(a). However, EPA believes there are some circumstances where fracturing of the in jection zone may be acceptable, provided the

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### integrity of the confining system remains unaffected and maintains USDW protection. EPA clarifies that §146.88(a) permits inje ction pressure to exceed 90 percent of the fracture pressure only during well stimulation. The final rule allows the use of hydraulic fracturing at GS sites, where approved by the Director. Hydraulic fracturing is one of several stimulation technologies available to improve wellbore and formation injectivity.

EPA clarifies that all stimula tion, including hydraulic fracturing, must be approved by the Director. Owners or operators must submit a propos ed stimulation program as part of the permit application under §146.82(a)(9); the plan must demonstrate that a ny stimulation act ivities will not compromise the integrity of the confining zone. The Director will evaluate the owner or operator's proposed stimulation plan in the cont ext of all information about the site, and the owner or operator must perform stimulation only as approved.

The final rule at §146.91(d)(2) also requires that the owner or operator notify the Director 30 days before performing stimulation during the operational phase of a GS project; this will provide an additional opportunity for the Director to review the owner or operator's plans for stimulation and add other requirements as needed.

Letter ID: 0263 Comment ID: 22807 Letter Lines: 296 to 310

Comment Code: 4140 2.4.1.4 Use of fracturing for GS in specific geologic settings (seeking comment)

Comment: III A. 4 Proposed Injection Well Operating Requirements

V. EPA is also requesting information to better qualify the use of fracturing for GS injection in specific geologic se ttings and rock formation lithologies.

IOGCC Response: As indicated above, hydr aulic fracturing shoul d only be allowed during the initial completion or recomple tion of a well to enhance reservoir permeability. However, once the completion phase has ended and the operational or injection phase has begun, fracturing during injection should never be permitted. It is important to keep separate the concept of operational injection pressure limits and episodic well stimulation activities.

In this respect, there should be no injection above the allowable permitted pressure. Additionally, hydraulic fracturing of the caprock should never be allowed nor should pressure tes ting of the confining layer.

Individual Response: As described above, the final GS re gulation allows hydraulic fracturing only during Class VI well stimulation, as speci fied at §146.88(a). EPA acknowledges that in some circumstances hydraulic fracturing during a well workover may be appropriate. The final rule at §146.91(d)(2) includes a re quirement that the owner or operator notify the Director 30 days before performing stimulation during the operational phase of a GS project; this will provide an additional opportunity for the Director to review the owner or operator's plans for stimulation and add other requirements as neede d. EPA clarifies that UIC regulations prohibit

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### fracturing of the confining zone at any time during injection or s timulation in order to protect USDWs from endangerment.

Letter ID: 0263 Comment ID: 22808 Letter Lines: 312 to 320

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

Comment: III A. 4 Proposed Injection Well Operating Requirements

W. EPA seeks comment on the merits of re quiring down-hole shut-off valves in GS wells.

IOGCC Response: There should be no hard and fast requirement for a down-hole shut-off valve in a GS well. Down-hole shut -off valves may, however, at Director discretion provide a necessa ry extra level of protec tion in more sensitive settings.

Individual Response: After evaluating the risks and benefi ts of down-hole shut-off systems and considering additional research, EPA will not re quire automatic down-hole 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 ), requires that owne rs or operators of onshore Class VI wells install automatic surface shut-off devices. The rule affords Director's discretion to mandate automatic down-hole shut -off devices in onshore situations that may warrant their use. However, the Agency believ es that offshore Class VI wells present unique construction and operational conditi ons, including isolation from shorelines and the need to construct wells through the water column and the subsurface, which may delay response time in the event of well difficulties. Th e rule requires, at §146.88(e)(3), that owners or operators of offshore wells within State territorial waters install automatic down-hole shut-off systems. EPA believes that these requirements at §146.88(e) ensure that proper precautions are taken to prevent subsurface fluid movement and ensure protection of USDWs.

Letter ID: 0263 Comment ID: 22809 Letter Lines: 322 to 332

Comment Code: 4324 2.4.4.1.2 Comments opposed to requiring injection below the lowermost USDW

Comment: III A. 4 Proposed Injection Well Operating Requirements

X. As a result, the Agency is consider ing and requesting comme nt on alternative approaches that would allow injection be tween and/or above the lowermost USDW, and thus potentially allow for more areas to be available for GS while preventing USDW endangerment.

IOGCC Response: There should be no blanke t prohibition against injection into a zone even if above the lowermost USDW. There maybe circumstances where it is

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### perfectly appropriate and safe. The decision needs to be site specific based on local geologic conditions.

Individual Response: As described above, EPA acknowledges that there are limited circumstances where injection above the lowerm ost USDW can be performed in a manner that protects USDWs from endangerment, as long as appropriate protections are in place. The final GS rule at §146.95 establishes a pr ocess by which owners or operato rs can seek a waiver of the Class VI injection depth requirements for inje ction into non-USDW form ations above and/or between USDWs. Additionally, the final GS rule does not categorically preclude or prohibit injection into any type of formation.

Letter ID: 0263 Comment ID: 22810 Letter Lines: 334 to 343

Comment Code: 4324 2.4.4.1.2 Comments opposed to requiring injection below the lowermost USDW

Comment: III A. 4 Proposed Injection Well Operating Requirements

Y. In summary, EPA is soliciting comment on whether CO2 injection should be allowed into an injection zone above th e lowermost USDW, when the Director determines that geologic conditions (e .g., thousands of feet of intervening formations between the injection zone and the overlying and/or underlying USDWs) exist that will prevent fluid move ment into adjacent USDWs.

IOGCC Response: Injection crit eria on which zones to use should be site specific based on local geologic conditions.

Individual Response: As described above, EPA acknowledges that there are limited circumstances where injection above the lowerm ost USDW can be performed in a manner that protects USDWs from endangerment, as long as appropriate protections are in place. The final GS rule at §146.95 establishes a pr ocess by which owners or operato rs can seek a waiver of the Class VI injection depth requirements for inje ction into non-USDW form ations above and/or between USDWs. Additionally, the final GS rule does not categorically preclude or prohibit injection into any type of formation.

Letter ID: 0263 Comment ID: 22811 Letter Lines: 345 to 354

Comment Code: 4460 2.4.4.4.1 Comments in favor of allowing aquifer exemptions in certain circumstances

Comment: III A. 4 Proposed Injection Well Operating Requirements

Z. EPA is also requesting comments on wh ether aquifer exemptions should be allowed for the purpose of Class VI inj ection, and under what conditions should such aquifer exemptions be approved.

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### IOGCC Response: Aquifer exemptions unde r Class VI should be allowed on the same basis as for other classes. Each ex emption should be considered on its own merits based on local geologic conditions and the likelihood of use of the zone for future public water supply.

Individual Response: EPA acknowledges that there are lim ited circumstances where aquifer exemptions for GS may be warranted. The final rule allows for the expansion of the areal extent of existing aquifer exemptions for Class II EOR/ EGR wells transitioning to Class VI injection for GS pursuant to requirements at §§146.4 and 144.7( d). Class VI owners or operators granted expansions of existing Class II EO R/EGR aquifer exemptions for GS projects must meet all of the tailored requirements for GS wells in the final GS rule.

However, the final rule precludes the issuance of new aquifer exemptions for Class VI GS wells; that is, aquifer exemptions will only be granted for projects that are transitioning from Class II EOR/EGR wells to Class VI.

EPA clarifies that all decisions regarding whethe r expansion of existing aquifer exemptions will be at the Director's discretion and based on site -specific information. If an owner or operator applies for a Class VI permit to inject CO2 into a previously exempted aquifer (non-USDW) that is located above and/or between USDWs, the perm it applicant must also apply for a waiver of the injection depth requirements pursuant to §146 .95 to ensure that if a waiver is granted, USDWs above and below the injection z one are protected from endangerment.

This approach is designed to ensure that th e differences between traditional Class II EOR/EGR operations and Class VI operati ons are considered during the aquifer exemption application process and the Class VI permitting process. Thes e differences include the anticipated large CO2 injection volumes associated with GS, the buoyant and mobile nature of the injectate, and its corrosivity in the presence of water. The Agen cy believes that this process will encourage owners or operators and Directors to consider the use of alterna tive formations for GS, including non-USDW formations through the waiver process, prior to applying for or approving aquifer exemption expansions for Class II EOR/EGR we lls transitioning to Cl ass VI GS operations.

For additional information on aquifer exemptions for Class VI wells, please see the final rule and preamble, as well as EPA's responses to comments on the Notice of Da ta Availability and Request for Comment

Letter ID: 0263 Comment ID: 22812 Letter Lines: 356 to 363

Comment Code: 4344 2.4.4.2.2 Comments opposed to setting a minimum injection depth

Comment: III A. 4 Proposed Injection Well Operating Requirements

AA. Finally, EPA seeks comment on wh ether the Agency should set a minimum injection depth requirement for CO 2 GS,rather than re quire that such injection take place below the lowermost USDW.

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### IOGCC Response: EPA should not set a minimum injection dept h requirement for CO2 GS as it is unnecessary. The rule needs to allow site specific flexibility.

Individual Response: EPA agrees that it is not appropriate to set a mi nimum injection depth for GS projects and the Agency believes that a determ ination of site-suitabili ty for GS (i.e., that subsurface formations will receiv e and confine injected CO2) s hould be made on a site-specific basis. The GS rule, at §146.82, requires the owne r or operator to provide extensive site- and project-specific information to the Director to demonstrate that the site meets the minimum site criteria at §146.83, that the CO2 will be contai ned within the injection formation, and that USDWs will be protected from endangerment.

EPA acknowledges that there are limited circum stances where injectio n above the lowermost USDW can be performed in a manner that protec ts USDWs, as long as appropriate protections are in place. The final GS rule at §146.95 establis hes a process by which owners or operators can seek a waiver of the Class VI injection de pth requirements for in jection into non-USDW formations above and/or between USDWs. The waiver approach requires the submission of extensive, site-specific information (in conjunc tion with the permit appl ication submission) to demonstrate that injection of CO2 into a non-US DW that is above or between USDWs can be done in a manner that is protective of USDWs. Th e requirements are designed to ensure that the owner or operator, the Director, and the Regional Administrator cons ider, on a site specific basis, the implications, benefits, and challenges associat ed with GS and ensuring water availability and USDW protection. For additional information on the waiver approach, please see the final rule and preamble, as well as EPA's responses to comments on the Notice of Data Availability and Request for Comment.

Letter ID: 0263 Comment ID: 22813 Letter Lines: 365 to 374

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

Comment: III A. 4 Proposed Injection Well Operating Requirements

BB. EPA seeks comment on the use of tr acers in CO2 GS operations, and any potential impact of tracers on human health or ecosystems as they relate to USDWs.

IOGCC Response: Adequate down hole monitori ng above the containment zone should in most cases eliminate the need for tracer systems to de tect the presence of injected CO2 at the surface. Use of such tracers should not be required although should be an optional methodology for use at Director discretion.

Individual Response: EPA agrees that the use of tracers shoul d not be required at all GS sites, but should be available as an option. For this reason, EPA does not require the use of tracers at all GS sites; however, the Director has discretion to require their us e if he/she determines that the use of tracers could improve monitoring of the site and enhance USDW protection from

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### endangerment. The rule will also allow their use if proposed by the owner or operator and approved by the Director.

While the intent of the GS regulations is to prevent leaks of CO2 to USDWs, EPA clarifies that all of the protective components of the regulation, includin g a comprehensive monitoring program per §146.90 (which includes testing of th e well, ground water quality monitoring, and tracking of the CO2 plume and pressure front) support a multi-barrier approach to protecting USDWs. Additionally, some studies (e.g., Phel ps and Cole, 2008; Hovorka et al., 2004; McCallum et al., 2005) found that tracers can pr ovide useful CO2 monitoring information at injection wells both at depth and at near-surface locations. At Fr io, tracers enabled quantification of CO2 plume behavior and provided a techniqu e for model validity tes ting (McCallum et al., 2005). EPA will continue to track research related to tracer use. The Agency plans to, every six years, collect and review data on GS projects to determine whether 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: 0263 Comment ID: 22814 Letter Lines: 376 to 382

Comment Code: 4500 2.5 Proposed Mechanical Integrity Testing (MIT) Requirements (40 CFR 146.89)

Comment: III A. 5 Proposed Mechanical Integrity Testing Requirements

CC. EPA requests comment on the practicability of this requirement.

IOGCC Response: The IOGCC believes that the methodologies and requirements under Class II would be sufficient for Class VI wells and that applying Class I requirements is too stringent.

Individual Response: EPA disagrees that the MIT requi rements for Class VI wells are excessive. MITs are a long-stan ding and proven method of provi ding early warning of potential problems in the injection well system before th ey lead to leakage and/or endangerment of USDWs. Given the unique nature of CO2 injection for GS (i.e., the potential corr osivity of CO2 in the presence of water and impurities on well material s, the potential geomechanical impacts to well integrity due to CO2 phase changes, the temper ature and pressure effects associated with injecting supercritical CO2, and the buoyant nature of CO2 and the potential for its movement up a wellbore), EPA believes it is important to protect USDWs from endangerment by adopting MIT requirements that are tailo red to CO2 injection for GS.

A comprehensive review conducted by EPA of MIT results from 1993 to 1998 found that Class I wells injecting corrosive fluids fa il MITs at rates two to three times higher than those that inject non-corrosive fluids (USEPA 1999). Given the pote ntial for CO2 to be corrosive (when in the presence of water or aqueous formation fluids), there is a potential risk factor for MIT failure and, for this reason, EPA believes that the ta ilored MIT requirement s are appropriate. For additional information, please s ee the discussion of MITs in the final rule preamble.

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### EPA acknowledges and agrees with the commenter th at Class II well operators have decades of experience injecting CO2. However, EPA believe s that significant op erational differences between Class II wells and Class VI wells indi cate that the Class II requirements are not sufficient to address the differences and that Class VI MIT requirements are, therefore, appropriate. For example, the volume of CO2 anticip ated to be injected in Class VI wells is significantly greater than for Class II wells. Also, reservoir pressure conditions will be different with ER production (extraction) se rving to reduce reservoir pressure for Class II operations while Class VI injection operations will have no compar able de-pressuring activiti es. For these reasons, EPA believes that injection of CO2 for GS projects differs significantly from that of Class II ER operations and warrants more freque nt MITs to provide sufficient early warning of the potential for MI failures due to the corrosivity of the CO2 or reservoir pressure co nditions associated with CO2 GS.

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

Letter ID: 0263 Comment ID: 22815 Letter Lines: 384 to 393

Comment Code: 4546 2.5.2.2 MIT frequency (seeking comment)

Comment: III A. 5 Proposed Mechanical Integrity Testing Requirements

DD. EPA seeks comment on the appropriate freq uency of internal and external MITs for GS injection wells, the appropriate types of MITs, and how to optimize MIT methods for GS.

IOGCC Response: For internal MITs for GS injection wells, 5 years would be a sufficient frequency. For external MITs, th e frequency should generally be annual depending upon the specific circumstances . The types softest should be those which are most appropriate unde r the specific circumstances.

Individual Response: EPA disagrees that a five-year extern al MIT is appropriate. The final GS regulation retains the requirement that owners or operators of Class VI wells must demonstrate injection well external mech anical integrity at least once annually under §146.89(c). EPA believes this is justifiable for the protecti on of USDWs from endangerment given the unique nature of CO2 GS relative to other injection operations, including the pote ntial corrosive impact of CO2 in the presence of water and impurities on well materials, the potential geomechanical impacts to well integrity due to CO2 phase ch anges, the temperature and pressure effects associated with injecting supercritical CO2, and the buoyant nature of th e injected CO2. Because of the unknown long-term effects of CO2 GS, EPA chose a more cons ervative initial approach in the early stages of deployment for GS..

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### In addition, a comprehensive review conducte d by EPA of MIT results from 1993 to 1998 found that Class I wells injecting corrosi ve fluids fail MITs at rates two to three times higher than those that inject non-corrosive fluids (USEPA 1999). Given the potentia l for CO2 to be corrosive (e.g., in the presence of water or aqueous formation flui ds), there is a potential risk factor for MIT failure and, for this reason, EPA be lieves that the tailored MIT requi rements in the final GS rule are appropriate.

EPA believes that the MITs described in §146.89(c) of the rule (e.g., an approved tracer log or temperature or noise logs) are effective methods to demonstr ate external MI, provide an important early warning of pot ential problems in the injectio n well system, and represent standard techniques that have been used succes sfully by the drilling industry and for the UIC Program for decades. EPA adds that the GS rule affords owners or operators the flexibility to choose appropriate MITs by requiring the owner or operator to prepare and gain approval for a project-specific tes ting and monitoring plan that includes MITs under §146.90. Owners or operators should develop a plan th at is appropriate to the well ’s design and construction; the Director will evaluate the plan based on construction plans submitted with the permit application.

EPA clarifies that the regulations provides the Director discreti on to require additional methods or, with the Administrator's approval, to appr ove the use of alterna tive MIT methods based on specific information about the s ite or the well. See §146.89(e).

EPA adds that it is using an ad aptive approach to regulating GS. The Agency plans to collect and review data every six years on GS projects, including MIT da ta, to determine whether the appropriate amount and types of information a nd appropriate documentation are being collected, and to determine if modifications to the requirements are appropriate or necessary.

Letter ID: 0263 Comment ID: 22816 Letter Lines: 395 to 402

Comment Code: 4650 2.6.5 CO2 plume and pressure fr ont tracking (seeking comment)

Comment: III A. 6 Proposed Plume and Pressu re Front Monitoring Requirements

EE. EPA seeks comment on the requirement for monitoring of GS sites for the purpose of tracking the location of th e CO2 plume and associated pressure front over time.

IOGCC Response: The IOGCC suggests that the operator be required to conduct ongoing monitoring. The frequency of reporting to the regulatory agency should be flexible depending upon s ite characteristics.

Individual Response: The final rule (at §146.90(g)) requires owners or operators to perform monitoring to track the extent of the CO2 plume and pressure fr ont. The owner or operator must use direct methods to monitor for pressure chan ges in the injection zone. Indirect methods (e.g., seismic, electrical, gravity, or electromagnetic surveys and/or down-hol e CO2 detection tools) are required unless the Director de termines, based on site-specific geology that such methods are not appropriate.

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### EPA clarifies that the specifics of this monitori ng must be described in the site-specific testing and monitoring plan, which must be approved by the Director. EPA believes that this approach provides flexibility to develop a site-specific monitoring plan, ensu res that direct monitoring is available to track the movement of the CO2 and validate models , and recognizes that indirect techniques are not appropriate in all situations. The owner or operator's approved testing and monitoring plan will include th e site-specific details, techno logies, testing and monitoring frequencies, and other pertinent information.

Letter ID: 0263 Comment ID: 22817 Letter Lines: 404 to 410

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

Comment: III A. 6 Proposed Plume and Pressu re Front Monitoring Requirements

FF. EPA seeks comment on the use and frequenc y of pressure fall-off testing for GS wells.

IOGCC Response: The IOGCC does not see the n ecessity of pressure fall off testing for GS wells. It should be used as necessary but not mandated.

Individual Response: EPA disagrees and believes that pressu re fall-off testing is necessary for GS wells to ensure the protecti on of USDWs. Pressure fall-off te sts are designed to verify that modeled projections of reservoir pressure decline agree with measured pressure decline profiles. These tests can be useful in AoR calculations and reevaluations and may also indicate mischaracterization of site geology and the presence of leakage pa thways. EPA therefore believes that pressure fall-off te sting must be conducted at leas t once every five years, and the final GS regulation includes this requiremen t at §146.90(f). Pressure fall-off tests may be conducted in conjunction with othe r well performance tests (i.e., mech anical integrity testing) to ensure safe and effective operations.

Letter ID: 0263 Comment ID: 22818 Letter Lines: 412 to 426

Comment Code: 4650 2.6.5 CO2 plume and pressure fr ont tracking (seeking comment) Comment Code: 4655 2.6.5.1 Plume tracking techniques/ geophysical methods (seeking comment)

Comment: III A. 6 Proposed Plume andPressure Front Monitoring Requirements

GG. Based on information evaluated to date , EPA believes that tracking the plume and pressure front is an important companion step to address any uncertainties associated with initial AoR modeling a nd requests comment on this approach and more efficient alternatives that maybe used to track the plume and pressure front.

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### IOGCC Response: Tracking of the CO2 plume and pressure front should be required. The methodology, however, should not be sp ecified but determined on a site specific basis. The IOGCC agrees with the following EPA statement: "As such, allowing flexibility in choosing the plum e tracking methods and other monitoring technologies may provide an appropriate balance between the protective nature of indirect monitoring and cost consid erations, as well as allowing for the adoption of continuously advancing technology."

Individual Response: EPA agrees with the comment and th e final rule (at §146.90(g)) requires owners or operators to perform monitoring to tr ack the extent of the CO2 plume and pressure front. The owner or operator must use direct me thods to monitor for pressure changes in the injection zone. Indirect methods (e.g., seismic, electrical, gravity, or electromagnetic surveys and/or down-hole CO2 detection to ols) are also required unless the Director determines, based on site-specific geology, that such methods are not appropriate. EPA cl arifies that the specifics of this monitoring must be described in the site-spe cific testing and monitoring plan, which must be approved by the Director.

EPA believes that this approach provides flexibility to develop a site-specific monitoring plan, ensures that direct monitoring is available to track the movement of the CO2 and validate models, and recognizes that indirect techniques are not appropriate in all situations. The owner or operator's approved testing and monitoring pl an will include the site-specific details, technologies, testing and monitoring freque ncies, and other pertinent information.

Letter ID: 0263 Comment ID: 22819 Letter Lines: 428 to 437

Comment Code: 4660 2.6.6 Geochemical monitoring

Comment: III A. 6 Proposed Plume and Pressu re Front Monitoring Requirements

HH. EPA seeks comment on the appropriate amount and types of monitoring that should be conducted at a GS site.

IOGCC Response: The IOGCC ag rees that owners and operators should report semiannually on the characteristics of injec tion fluids, injecti on pressure, flow rate, temperature, volume and annular pressure, and on the results of MITs, ground water monitoring, and any required atmospheric/soil gas monitoring. The amount and types of monitoring to be require d, however, should be site specific.

Individual Response: EPA agrees that monitoring plans and methods need to be site-specific and believes that the monitoring requirements for GS sites at §146.90 provide an appropriate level of flexibility in structuring a testing and monitoring plan that protects USDWs from endangerment. The final regulation provides for fl exibility in: 1) methodol ogies used to collect these data, 2) the spatial resolution at which the data should be collected, and 3) how often thedata should be collected. The number and placement of monitoring wells will be based on sitespecific information such as the calculated AoR, injection rate and volume, site geology, baseline data, and the presence of artificial penetrations within the AoR.

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### EPA adds that the final rule, at §146.91(a) re quires that owners and operators report semiannually on operating data and some monitoring da ta. See the preamble to the final rule for additional information.

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: 0263 Comment ID: 22820 Letter Lines: 450 to 456

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

Comment: III A. 6 Proposed Plume andPressure Front Monitoring Requirements

JJ. In addition, EPA seeks comment regard ing the use of a Director-approved monitoring plan for GS sites.

IOGCC Response: The Direct or should be given fl exibility to approve site specific monitoring plan s as proposed in the I OGCC model regulations.

Individual Response: EPA agrees with commenters that developing and following testing and monitoring plans and giving Directors flexibility to approve the plans based on site-specific criteria are important parts of assuring that a GS project is operating prop erly and is crucial for the early detection of potentia l endangerment to USDWs.

The testing and monitoring plan is developed by the owner or operator in consultation with the Director and is designed to ensure that a de tailed, Director-approve d document describing how monitoring will be conducted during the lifetime of the project exists. EPA is developing guidance on testing and monitoring to assist owners or operators and Directors in evaluating requirements under §146.90, including proposed monitoring plans. The guidance describes available technologies and reco mmended approaches for implem enting a testing and monitoring plan, including pre-operational geophysical logging and testin g of injection wells, MITs, injection well testing during ope ration, groundwater quali ty monitoring, tracking the CO2 plume and pressure front, and soil gas and surface ai r 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/groundwater /uic/wells_sequestration.cfm.

Letter ID: 0263 Comment ID: 22821 Letter Lines: 458 to 465

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

Comment: III A. 7 Proposed Recordkeeping and Reporting Requirements

KK. EPA seeks comment on the merits of requiring plans for monitoring, AoR, and post-injection site care as part of a permit application.

IOGCC Response: Yes, there should be de tailed monitoring, AoR, and post-injection site care plans as a part of the permit cons istent with the recommendations of the IOGCC modelregulations.

Individual Response: EPA agrees that incorporating the plans into the permit rather than establishing specific requirements for correctiv e action, monitoring, inje ction well plugging, and post-injection site care in the regulation provide th e appropriate flexibility to address the variety of site-specific conditions that ma y be encountered at GS sites.

EPA also believes that it is appropriate to re quire owners and operators to submit all plans, including the injection well pluggin g and post-injection site care a nd site closure plans, at the time of permit application. The owne r or operator must demonstrate to the Director a satisfactory level of assurance that the they have planned for these events before injection commences and that they have ensured that a ppropriate financial resources ar e available to fund all required activities, as required at §146.85. The final rule retains requirements for submitting these plans with the permit application at §146.82(a). EPA exp ects that the requirement for this and other plans associated with GS projects will pr omote an ongoing dialogue between the owner or operator and the Director to ensure USDWs are protected from endangerment. Please see the final rule and the discussion of GS project plan s in the preamble for additional information.

Letter ID: 0263 Comment ID: 22822 Letter Lines: 467 to 474

Comment Code: 4760 2.7.6 Proposed reporting frequency (seeking comment)

Comment: III A. 7 Proposed Recordkeeping and Reporting Requirements

LL. EPA seeks comment on the frequency of all proposed reporting requirements.

IOGCC Response: As concerns the freque ncy of reporting for the physical and chemical characteristics of the injected fluids in a Class VI well, IOGCC model regulations specified annual repor ting although semiannual reporting (as proposed by EPA in the rule) would be acceptable.

Individual Response: EPA is retaining the semi-annual repo rting requirements as proposed at §146.91(a). These requirements ensure the Direct or has the information needed to take preventive action in a timely manner to prot ect USDWs from endangerment. For additional information, please see the final rule and the prea mble for a discussion of EPA's final approach to recordkeeping and reporting.

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### Letter ID: 0263 Comment ID: 22823 Letter Lines: 476 to 484

Comment Code: 4740 2.7.4 Electronic reporting (seeking comment)

Comment: III A. 7 Proposed Recordkeeping andReporting Requirements

MM. EPA seeks comment on the requirement for electronic reporting in today's proposed rule.

IOGCC Response: The IOGCC agrees with elect ronic submittal in pr inciple as long as there is sufficient flexibility to allow st ates to utilize existing or preferred state data processing systems or softwa re. Electronic reporting should be an option but not a requirement.

Individual Response: EPA believes that electronic formatting is the most appropriate format for submitting Class VI project information to the Director, and based on comments received on the proposed rule, the majority of Class VI well owners or operators will have the capability to report electronically, and re quires this at §146.91(e).

Acknowledging that some States may have to develop electronic data systems to receive electronic information from the owner or operator, and that many States which already have electronic data systems will have to make ch anges to accommodate a new class of UIC well (Class VI), EPA believes that it is prudent to provide assi stance by develo ping a central framework for the electronic system that will be used by States to gather and track owner or operator data. This will enable owners or opera tors to submit data without having to wait for a State to develop a system. It will also provide for standardized submissions across the country and enable States to focus State resources on re viewing and approving permit applications rather than building or upgrading separate, inde pendent databases for GS information.

EPA is developing guidance for states that describes the recordkeeping, reporting, and additional data management needs associated with GS act ivities and provides recommended guidelines on the types of data to be collected for tracki ng GS projects, reporti ng to EPA for compliance tracking, and transfer of data to EPA's GS data system. The recordkeeping and reporting guidance will be available on EPA's web site, at http://water.epa.gov/type/groundwater /uic/wells_sequestration.cfm.

Letter ID: 0263 Comment ID: 22824 Letter Lines: 486 to 495

Comment Code: 4750 2.7.5 Comments on the merit of a nnual reports (seeking comment) Comment Code: 4760 2.7.6 Proposed reporting frequency (seeking comment)

Comment: III A. 7 Proposed Recordkeeping and Reporting Requirements

NN. Although EPA has not included a require ment for this report in today's proposal, EPA seeks comment regarding the necessity for such an annual report.

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### IOGCC Response: The IOGCC s uggests that there be only on e frequency of reporting, either annual or semi-annual. Thus, this requirement should be incorporated into the semi-annual reporting requirement e nunciated by EPA in the rule for the physical and chemical characteristics of th e injected fluids ina Class VI well. There should not be two different data reporti ng timeframe.

Individual Response: EPA is retaining the semi-annual repo rting requirements as proposed at §146.91(a). These requirements ensure the Direct or has the information needed to take preventive action in a timely manner to protect USDWs from endangerment.

The final GS regulation does not include a re quirement for an annual report. Instead, EPA believes that periodic reevaluation of the AoR, as required at §146.84(e), along with any revisions to the required plans that may be re quired based on the AoR reevaluation, will promote an ongoing relationship between the permitting aut hority and the owner or operator. The final GS rule, at §§146.84(c), 146.90(j), and 146.94(d), requi res owners or operators to review and update the AoR and corrective act ion plan, the testing and monitoring plan, and the emergency and remedial response plan thr oughout the life of the project. Own ers or operators must review each plan and identify necessary amendments to th e plan or demonstrate to the Director that no amendment is needed. These reviews must be performed within one year of an AoR reevaluation, following any significa nt changes to the facility (e .g., the addition of monitoring or injection wells), or when requi red by the Director. In no case ca n reviews occur less often than once every five years.

For additional information, please see the final rule and the preamble fo r a discussion of EPA's final approach to reco rdkeeping and reporting.

As described above, EPA is retaining the semi -annual reporting requirements as proposed at §146.91(a). These requirements ensure the Direct or has the information needed to take preventive action in a timely manner to protec t USDWs from endangerment. EPA notes that operators who want to streamline their reporting schedules can negotiate with the permitting authority to establish a schedule that allows repo rting on all wells in a GS project at the same time; however, data for each well must be report ed separately and at least as frequently as required at §146.91. For additional information, pleas e see the final rule and the preamble for a discussion of EPA's final approach to recordkeeping and reporting.

Letter ID: 0263 Comment ID: 22825 Letter Lines: 497 to 542

Comment Code: 5240 2.8.2.2 Post injection timeframe (seeking comment) Comment Code: 5260 2.8.2.3 Adjusting the post-injecti on timeframe (seeking comment)

Comment: III A. 8 Proposed Well Plugging, Post-Inject ion site Care, and Site Closure Requirements

00. EPA requests comment on the proposed use of a tentative 50-year fixed timeframe that could be modified at the Director 's discretion based on monitoring and

27

### modeling data.

IOGCC Response: Given that current inj ection and reservoir behavior data demonstrates a decreasing risk of leakag e after injection ceases, the IOGCC has concluded that a 50 year fixed timeframe is both unnecessary and too long. What is absolutely critical here is that the Director has discretion to increase or decrease the period based on the specifics of a particular project. In the view of the IOGCC, it would be better to prescr ibe a shorter period with discretion to go longer, rather than vice versa, as such would better facilitate project planning.

III A. 8 Proposed Well Plugging, Post-Inject ion site Care, and Site Closure Requirements

PP. EPA is requesting comments on the proposed requirements for well plugging, post-injection site care, a nd site closure, including the proposed requirements for the post-injection time period.

IOGCC Response: Given documented evidence to date that there is a decreasing risk of leakage after injection ceases, The IOG CC has concluded that a 50 year fixed timeframe is both unnecessary and too long. Wh at is absolutely critical here is that there be Director discretion to increase or decrease the period based on the specifics of a particular project. In the view of the IOGCC, it would be better to prescribe a shorte r period with discretion to go longer, rather than vice versa, as such would bette r facilitate project planning.

III A. 8 Proposed Well Plugging, Post-Inject ion site Care, and Site Closure Requirements

QQ. In addition, EPA seeks comment on whethe r the Director should be allowed to shorten the timeframe based on performan ce information, and whether EPA should require a shorter or longer post-injecti on period if data suggests the time frame should be adjusted.

IOGCC Response: Given documented evidence to date that there is a decreasing risk of leakage after injection ceases, The IOG CC has concluded that a 50 year fixed timeframe is both unnecessary and too long. Wh at is absolutely critical here is that there be Director discretion to increase or decrease the period based on the specifics of a particular project. In the view of the IOGCC, it would be better to prescribe a shorte r period with discretion to go longer, rather than vice versa, as such would bette r facilitate project planning.

Individual Response: EPA disagrees that a post-injection si te care timeframe of 50 years is excessive or unnecessary for most GS sites. EP A proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was in cluded in an EPA-prepared background document

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### that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area- of-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed vari ous default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a ch ange in the proposed timeframe. While the 10- or 30-year timeframe suggested by some of thes e commenters may be within the timeframe suggested in some studies, EPA believes that the potential risks of endangering USDWs will likely not decline within these timeframes a nd available data, including data submitted by commenters, do not support a different defau lt timeframe. However, EPA recognizes that alternative timeframes may be appropri ate under limited, specific circumstances.

For this reason, the GS rule offers owners or op erators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-injecti on period based on site-specific da ta, 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 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 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.

Letter ID: 0263 Comment ID: 22826 Letter Lines: 544 to 562

Comment Code: 5432 2.9.1.1 Need to adjust financial responsibility mechanisms (seeking comment)

Comment: III A. 9 Proposed Financial Responsibili ty and Long-Term Care Requirements

RR. EPA is requesting comments on whether fi nancial responsibility mechanisms to be recommended in EPA guidance should be ad justed in the manner described, whether additional instruments should be included, and whether other adjustments to the financial responsibility mechanisms should be considered, all subject to EPA's

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### authority under the SDWA.

IOGCC Response: The EPA proposed rule for well financial assurance appears comprehensive enough. However, the proposed two-tier bond system of pre and post plugging of the well would be administrati vely cumbersome and the IOGCC would recommend one bond that cove rs operational, eventual plugging and post site remediation until the release date.

The IOGCC model regulations proposed that in addition to well bonds that there also be an overall facility bond. The purpose of the facility bond would be to insure financial responsibility to address and mitigate non-well specific issues. What EPA is suggesting in the rule needs to be supplemented by the states via mechanisms such as a facility bond.

Individual Response: EPA will allow owners or operators to demonstrate that §146.85(a) is met by using separate and multiple financial responsibility instruments for different GS activities. However, owners or operators must demonstrate ad equate financial responsibility for all required activities with their permit a pplication per §146.82(a)(14).

EPA is developing guidance on financial responsibili ty for Class VI wells to assist owners or operators in evaluating the financial responsib ility requirements for Class VI wells. EPA will describe the types of financial in struments that owners or operator s can use to meet the financial responsibility requirements for GS wells. This guidance will be availabl e on EPA's website at http://water.epa.gov/type/groundwater /uic/wells_sequestration.cfm.

To the suggestion that EPA require an overall "facility bond," EPA clarifies that the financial responsibility requirements are limit ed to covering activities associat ed with the injection. If the commenter refers to USDW endangerment that is related to the project but not necessarily the injection well, EPA notes that sufficient financia l resources must be set aside to address the possibility of an emergency or remedial respons e in order to prevent endangerment of USDWs. Financial responsibility to addres s activities not associated with the endangermen t of USDWs is outside of the scope of this rulemaking.

EPA clarifies that the financial instrument the owner or operator provided to meet the requirements under §146.85 will be released when the phase of the project for which the instrument was required is complete and all financ ial obligations for that instrument have been met, pursuant to §146.85(b)(2) and §146.93.

Letter ID: 0263 Comment ID: 22827 Letter Lines: 564 to 574

Comment Code: 5432 2.9.1.1 Need to adjust financial responsibility mechanisms (seeking comment)

Comment: III A. 9 Proposed Financial Responsibili ty and Long-Term Care Requirements

SS. The Agency is also requesting co mment on allowing separate financial

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### demonstrations to be submitted for the pl ugging of the injection well and for the post-injection site care requirements.

IOGCC Response: The IOGCC mo del regulations proposed that in addition to well bonds that there also be an overall faci lity bond. The purpose of the facility bond would be to insure financial respons ibility to address and mitigate nonwell specific issues. What EPA is suggesti ng in the rule needs to be supplemented by the states via mechanisms such as a facility bond.

Individual Response: To the suggestion that EPA require an overall "facility bond," EPA clarifies that the financial res ponsibility requirements are limited to covering activities associated with the injection. If the commenter refers to USDW endangerment that is related to the project but not necessarily the injection well, EPA notes that sufficient fi nancial resources must be set aside to address the pos sibility of an emergency or reme dial response in order to prevent endangerment of USDWs. Financia l responsibility to a ddress activitie s not associated with the endangerment of USDWs is outside of the scope of this rulemaking scope.

Letter ID: 0263 Comment ID: 22828 Letter Lines: 576 to 589

Comment Code: 5520 2.10.1 Appropriateness of existing p ublic participation requirements (Part 25 and Part 124) for GS (seeking comment)

Comment: IV. How Should UIC Program Di rectors Involve the Public In Permitting Decisions for GS Projects?

TT. EPA requests comment on adopting th e existing requirements for public participation at 40 CFRPart 25 and 40 CFRPart 124 and whether additional requirements should be included to reflect the availability of new tools for disseminating and gathering information. Su ch tools include cable networks, the Internet, and other new technology.

IOGCC Response: All states have public notice laws and regulations that cover most regulatory and permitting functions. These laws and regulations would extend to the permitting and the regulation of GS that require public notice, hearings and due process to all affected parties. This should be adequate for public involvement purposes.

Individual Response: EPA does not require the use of a ny new information technologies to inform the public, but encourages GS project operators and permitting authorities to use the Internet as well as both new and established tools to explain and post information on the latest developments. This information may include schedules for hearings, briefings, and other opportunities for involvement. EPA plans to conduct outreach on the GS rule, and provides GS related information on its website at http://water.epa.gov/type/groundwat er/uic/wells_sequest ration.cfm. EPA currently uses social networking applications for important in formation (e.g., Facebook and Twitter), and will encourage GS operators and permitting authorities to use similar technologies to keep the public

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### informed of GS projects. If states have appli cable public participation requirements, these would need to be met as well.

EPA believes that the existing UIC public partic ipation requirements as specified in 40 CFR 25 and 40 CFR 124 are appropriate for GS projects. In addition, because of the unique nature of GS projects, and the anticipated level of public intere st in GS projects, EPA encourages early public involvement in GS projects. Providing the public with accurate, project specific information in the early stages of each GS project can he lp clarify project details and avoid public misperceptions about the nature and safety of GS projects, and will allo w a potential GS owner or operator and the permitting agency to addres s the public's concerns before the permitting process is complete.

EPA understands that public notice laws and regula tions vary from state to state. EPA would like to clarify that in order for a state to receive primacy for Cla ss VI GS wells their public notice requirements for permits must be at least as stringent as those required under 40 CFR Part 124. This requirement should provide a level uniform ity between primacy states for purposes of providing public notice for GS wells.

Letter ID: 0263 Comment ID: 22829 Letter Lines: 591 to 602

Comment Code: 5560 2.10.3 Enhancing the public particip ation process (seeking comment)

Comment: IV. How Should UIC Program Directors Involve the Public In Permitting Decisions for GS Projects?

UU. EPA also requests comment on ways to enhance the public partic ipation process, including engaging communities in the site characterization process as soon as candidate locations are identified.

IOGCC Response: All states have public notice laws and regulations that cover most regulatory and permitting functions. These laws and regulations would extend to the permitting and the regulation of GS that require public notice, hearings and due process to all affected parties. This should be adequate for public involvement purposes.

Individual Response: EPA disagrees with the commenter and believes that the existing UIC public participation requirements as specified in 40 CFR 25 an d 40 CFR 124 are appropriate for GS projects. GS permitting authorities must follo w the existing public participation requirements for UIC permits as specified in 40 CFR Part 124. These regulations lay ou t the procedures for decision making and include requirements such as requiring the Director to notify the public regarding the availability of th e draft permit and allow him or he r to require a public hearing on the draft permit.

EPA notes that administrative procedure laws va ry by state. States wi ll describe their public

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### participation activities in their primacy applicatio ns and must be at leas t as stringent as those provided under Parts 145 and 146.

In addition, because of the unique nature of GS projects, and the anticipated level of public interest in GS projects, EPA encourages early pu blic involvement in GS projects. Providing the public with accurate, project specifi c information in the early stages of each GS project can help clarify project details and avoid public misper ceptions about the nature and safety of GS projects, and will allow a potential GS owner or operator and the permitting agency to address the public's concerns before the permitting process is complete.

Letter ID: 0263 Comment ID: 22830 Letter Lines: 604 to 612

Comment Code: 5610 2.11.1 Allowing partial primacy for Class VI wells (seeking comment)

Comment: V. How Will States, Territories, and Tribes Obtain UIC Program Primacy for Class VI Wells?

VV. EPA is seeking comment on the merits and possible disadvantages of allowing primacy approval for Class VI wells i ndependent of other well classes.

IOGCC Response: The IOGCC st rongly supports independent state primacy for Class VI. States should have the authority to designate which agency in the state can apply for and be granted primacy.

Individual Response: EPA agrees with commenters that states should be allowed to obtain primacy for Class VI wells independently of other well classes, and will allow independent primacy for Class VI wells under §145.1(i) of th e final GS rule. Given the potential for CCS (encompassing capture, transportation, and geologic sequestration) to be an important part of a national priority to address clim ate change, EPA believes that provi ding states the flexibility to obtain primacy for Class VI wells independently of other well cla sses can help foster effective management of CCS. EPA believes that allowing independent Class VI primacy may encourage states to take responsibility for implementation of Class VI regulations and provide for a more comprehensive approach to managing CCS projects by promoting the integrat ion of GS activities under SDWA into a broader framework for mana ging CCS. Furthermore, GS operations involve ancillary activities (e.g., pipeline operations, pore space ownership, land use rights, and surface access) for which states can call upon other authorit ies that exist at the state level (but outside UIC authority) to provide a more comp rehensive CCS management approach.

EPA also believes that allowing states to apply only for Class VI primacy will shorten the primacy approval process for states. It is very im portant to note that this shift in policy allowing for Class VI primacy does not apply to a ny other well Class under Section 1422. EPA will continue to discourage applica tions for partial primacy for a ll other well types under Section 1422.

EPA clarifies that states should be able to obtain primacy for Cla ss VI wells independent of other

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### well classes provided they devel op regulations that are at leas t as stringent as the minimum Federal requirements (e.g., permitting, inspec tion, operation, monitoring, and recordkeeping requirements) in the final GS rule. EPA believes that existing programs can adapt their expertise to the new requirements for Class VI wells and w ill be able to develop a primacy application for Class VI wells under section 1422 of SDWA and en sure that their GS pr ograms integrate into national climate change priorities an d protect USDWs from endangerment.

EPA also clarifies that primacy is granted to a state, not to any agency within that state, and states are free to choose which agency will im plement the Class VI program—for instance, an environmental quality protection agency (non-Cl ass II) or the state's traditional oil and gas regulatory agency (Class II)—as long as the program meets the minimum Federal requirements for Class VI wells as required under section 1422 of SDWA. Some stat es administer their program for all injection well classes through a single agency, whereas other States elect to divide the program between agencies. For example, in most States, the Class II program is run by an oil and gas agency and other well classes are run by a State envir onmental agency (e.g., the Oklahoma Corporation Commission oversees Class II wells in the State, and the Oklahoma Department of Environmental Quality oversees other well classes). Additionally, several States allow their oil and gas agencies to administer their UIC program for specific well classes or subclasses provided they meet all Federal requirements (e.g., the Texas Railroad Commission oversees Class III brine-mining we lls and Class V geothermal well s in Texas). EPA believes that retaining this flexibility for States to identify the appropriate agency to oversee Class VI wells will address commenters’ concerns that States should be afforded the opportunity to determine which agency should oversee Class VI wells, and recognizes the existing e xpertise of both State oil and gas agencies and environmental agencies.

Letter ID: 0263 Comment ID: 22831 Letter Lines: 614 to 620

Comment Code: 5700 2.12 Comments on the proposed durati on of Class VI permits (seeking comment)

Comment: VI. What Is the Proposed Duration of a Class VI Injection Permit?

WW. Therefore, EPA proposes that Class VI injection well permits would be issued for the operating life of the GS projec t including the post-injection site care period. EPA seeks comment on the merits of this approach.

IOGCC Response: The IOGCC agr ees with the EPA proposal.

Individual Response: The final rule maintains the lifetime permit provision and clarifies that the permit extends through the post-inje ction site care period (144.36(a)). It also adds a requirement that the Director review each Class VI permit at least once every 5 years to determine whether it should be modified, revoked and reissued, termin ated or a minor modification made as provided in §§144.39, 144.40, or 144.41. The Director’s review will be informed by the owners’ or operators’ iterative reevaluation of the project. Specifically, the fi nal rule includes a requirement that the AoR be reevaluated at l east every five years, and also requires owners or operators to

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### review and update the AoR and co rrective action plan, the testi ng and monitoring plan, and the emergency and remedial response plan throughou t the life of the proj ect (146.84(e), 146.90(j), and 146.94(d)). Owners or operators must review each plan and identify necessary amendments or demonstrate to the Director that no amendm ent is needed. In no case can reviews occur less often than once every five years. The iterative pr ocess and subsequent plan reevaluations ensure that time and resources are committed to the most critical aspects of the permit in preventing endangerment to USDWs. EPA believes that the iterative process of developing and executing the various plans required of GS well operators in the final rule (e.g., for AoR and corrective action, testing and monitoring, in jection well plugging, post-inject ion site care, and emergency and remedial response) is tailor ed to the unique aspects of—and is more appropriate for–GS than establishing a finite permit dur ation (e.g., ten years as sugge sted by some commenters).

Letter ID: 0263 Comment ID: 24960 Letter Lines: 130 to 136

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

Comment: II . I. Is Injected CO2 Consider ed a Hazardous Waste Under RCRA?

H. EPA seeks comment on this approach and other considerations associated with the presence of impurities in the CO2 stream.

IOGCC Response: Injected CO2 is not a nd should not be considered a hazardous waste or regulated under RCRA or CERCLA. It is assumed that RCRA or CERCLA wastes

Individual Response: EPA recognizes that many CO2 str eams may be relatively 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 in formation, and uncertainties remain about the expected concentrations of impurities from the various types of CO2 streams.

With respect to RCRA, EPA received many commen ts regarding 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.

Letter ID: 0263 Comment ID: 24961 Letter Lines: 139 to 147

Comment Code: 1640 1.3.4 CERCLA issues (seeking comment)

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### Comment: II. J. Is Injected CO2 Considered a Hazardous Substance Under CERCLA?

1. EPA requests comment on particular situatio ns where this might occur. EPA also requests comment on other considerati ons associated with the presence of impurities in the CO2 stream related to CERCLA.

IOGCC Response: Injected CO2 is not and should not be considered a hazardous waste or regulated under RCRAor CERCLA. It is assumed that RCRA or CERCLA wastes would be removed from the CO2 stream prior to storage.

Individual Response: CO2 itself is not listed as a hazardous substance under CERCLA however, the CO2 stream may contain a listed hazardous substance (such as mercury) or may mobilize substances in the subsurface that could react with ground water to produce listed hazardous substances (such as sulf uric acid). Whether such subs tances may result in CERCLA liability from a sequestration f acility depends entirely on the composition of the specific CO2 stream and the environmental media in which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42 U.S.C. 9607, certain “federally permitted releases” as defined in CERCLA, 42 U.S.C. 9601(10). Class VI perm its will need to be carefully structured to ensure that they prevent potential releases from the well which are outside the scope of the Class VI permit.

With respect to the commenter’s reference to RCRA, EPA received many comments regarding the applicability of the RCRA re gulations and statute to CO2 st reams that are geologically sequestered under the final Class VI UIC well requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specificall y to examine the issue of RCRA applicability to CO2 streams being geologically sequestere d, 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 propos al. The Agency will consider issues particular to RCRA in the context of that separate rulemaking, and recommends that the commenter read that proposed rule when it is published. The Ag ency notes that commenters who wish to submit comments on the RCRA proposal will need to do so during the comment pe riod for that rule.

Letter ID: 0263 Comment ID: 24962 Letter Lines: 439 to 448

Comment Code: 4670 2.6.7 Surface air monitoring and/or soil gas monitoring (seeking comment)

Comment: III A. 6 Proposed Plume and Pressu re Front Monitoring Requirements

11. Specifically, EPA seeks comment regard ing the usefulness of indirect geophysical monitoring and surface air and soil gas monitoring.

IOGCC Response: The IOGCC ag rees that owners and operators should report semiannually on the characteristics of injec tion fluids, injecti on pressure, flow rate, temperature, volume and annular pr essure, and on the resu lts of MITs, ground

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### 37 water monitoring, and any required atmos pheric/soil gas monitoring. The amount and types of monitoring to be require d, however, should be site specific.

Individual Response: EPA agrees that monitoring plans and methods need to be site-specific and believes that the monitoring requirements for GS sites at §146.90 provide an appropriate level of flexibility in structuring a testing and monitoring plan that protects USDWs from endangerment. The final regulation provides for fl exibility in: 1) methodol ogies used to collect these data, 2) the spatial resolution at which the data should be collected, and 3) how often thedata should be collected. The number and placement of monitoring wells will be based on sitespecific information such as the calculated AoR, injection rate and volume, site geology, baseline data, and the presence of artificial penetrations within the AoR.

EPA adds that the final rule, at §146.91(a) re quires that owners and operators report semiannually on operating data and some monitoring da ta. See the preamble to the final rule for additional information.

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.