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(1) The original submittal from the commenter. (2) A data base printout of EPA’s response to each point raised by the commenter.

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comment submittals and ensure that the Agency responds to each. Each comment letter

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‐ assigned comment code; and an

individual response. These are described and explained below.

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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

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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

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• 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

NEW YORK STATE DEPARTMENT OF ENVIRONMENTAL CONSERVATION

DIVISION OF MINERAL RESOURCES

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, 2008

The New York State Department of Environmental Conservation (NYS DEC) Division of Mineral Resources (DMN) submits the followi ng comments to Docket ID No. EPA-HQOW-2008-0390 on the Environmental Protection Agency’s Proposed Federal Requirements for Carbon Dioxide (CO 2 ) Geologic Sequestration (GS) Wells under the Underground Injection Contro l (UIC) Program of the Safe Drinking Water Act (SDWA).

Submitter Information: Bradley J. Field, Director, Di vision of Mineral Resources, New York State Department of Environmen tal Conservation, 625 Broadway, Albany, New

York 12233-6500

Contact Information: If any additional information is needed regarding these comments, please contact Peter S. Briggs, Mineral Resources Specialist, Division of Mineral Resources, New York State Departme nt of Environmenta l Conservation, (518) 402-8056, psbriggs@gw.dec.state.ny.us

1. General Comments

A. Funding: It is essential that EPA provi de adequate funding to states assuming primacy jurisdiction under the UIC program to administer CO 2 storage regulatory activities.

2. NYSDEC-DMN 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 CO 2 and how these efforts might be used to better inform a final Federal rulemaking.NYSDEC-DMN Response : While the UIC program in New York State is directly implemented at this time , many other states currently have primacy jurisdiction and administer Class II and other wells. Primacy should be allowed solely for Class VI, and such should be structured to allow flexibility in the primacy proce ss and defer to the state rule when it effectively meets the intent of the federal requirements.

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

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

NYSDEC-DMN Response : NYSDEC-DMN agrees with EPA’s proposed approach provided the project is an EOR project under Class II and the operator is able to demonstrate it as an ongoing viable EOR project. Operators should not be allo wed to inject and store CO 2 under the guise of a Class II EOR project to avoid Class VI permitting requirements.

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

C. EPA is proposing to give the Direct or 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 CO 2 , provided he/she is able to make a

determination that these wells would not endanger USDWs.

NYSDEC-DMN Response : NYSDEC-DMN agrees that this discretion is appropriate and necessary when revi ewing other UIC Class wells for use

as UIC Class VI wells.

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

D. Accordingly, EPA is proposing that th e 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 requi rements of today’s proposed rule (e.g., operating, monitoring, MIT, we ll plugging, post-in jection site care and site closure)

.

2NYSDEC-DMN Response : NYSDEC-DMN agrees that this discretion is appropriate and necessary when revi ewing other UIC Class wells for use

as UIC Class VI wells.

II. 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 discre tion 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 CO 2

.

NYSDEC-DMN Response : The Director should have the flexibility to

determine whether a well meets federa l Class VI protective standards on a well-by-well basis, and require the op erator 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

.

NYSDEC-DMN Response : The Director should have the flexibility to

determine whether a well meets federa l Class VI protective standards on a well-by-well basis, and require the op erator to adhere to the permitting

process.

II. H. What Are the Target Ge ologic Formations for GS of CO 2 ?

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

NYSDEC-DMN Response : While not a likelihood in New York due to the absence of coal in the state and ty pical depths to lowermost USDWs,

NYSDEC-DMN believes there should not be any blanket prohibition against injection into any potentially approvable geologic zo ne even if it is

above the lowermost USDW. There ma y be circumstances where this is appropriate and safe. The decision to permit a project should be made on a site-specific basis and evaluation.

III. Proposed Regulatory Alternatives

3H. EPA is proposing Regulatory Altern ative 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 endangerm ent of USDWs. In addition, this alternative may be burdensome for ow ners or operators because of the potential for inconsistency across states and burdensome for permitting authorities who will likely be f aced with developing their own technical approaches to regulating GS.

NYSDEC-DMN Response : NYSDEC-DMN agrees that Regulatory Alternative 3, Tailored Requirements A pproach is appropriate provided it allows discretion and flexibility on the part of the Director.

III A. 1 Proposed Geologic Siting Requirements

I. EPA specifically seeks comment on the merits of identifying these

additional zones.

NYSDEC-DMN Response : It is NYSDEC-DMN’s opinion that

identification and characterization of secondary confinement should not be a requirement unless the unit identified as the primary confining zone isquestionable. This determination should be made on a project and sitespecific basis.

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

NYSDEC-DMN General Comment for Section III. A. 2 : NYSDEC-DMN

believes use of traditional well-s pecific AoR is problematic for comprehensive and adequate site characterization, and that EPA’s proposed approach is appropriate.

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

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

.

NYSDEC-DMN Response : See General Comment for Section III. A. 2

above. AoR delineation should be ba sed on best available technology and available data. The collection of phy sical data (i.e., well bore data) may be necessary to fully use modeling to determine the ultimate extent of the proposed CO 2 storage volume and reservoir pressures. The Director should have the flexibility to be able to supplement or substitute other data elements as appropriate ahead of su ch drilling and data gathering with

confirmation of the model once addi tional information is available.

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

4K. EPA seeks comment on allowing the use of proprietary models for GS

sites.

NYSDEC-DMN Response : NYSDEC-DMN believes proprietary models should be allowed provided the Direct or has discretion to evaluate the accuracy of the modeling methodology. It should be noted that confidentiality of proprietary models will be subject to various jurisdictions and st atutory limitations.

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

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

NYSDEC-DMN Response : See General Comment for Section III. A. 2

above. AoR delineation should be ba sed on best available technology and available data. The collection of phy sical data (i.e., well bore data) may be necessary to fully use modeling to determine the ultimate extent of the proposed CO 2 storage volume and reservoir pressures. The Director should have the flexibility to be able to supplement or substitute other data elements as appropriate ahead of su ch drilling and data gathering with

confirmation of the model once addi tional information is available.

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

M. EPA seeks comment on requiring the r eevaluation of the site AoR on a periodic basis, under what conditio ns the AoR should be reevaluated, and the appropriateness of a 10 y ear minimum fixed frequency for

AoR reevaluation.

NYSDEC-DMN Response : AoR reevaluation frequency could be based

on the amount of CO 2 injected relative to th e total proposed injection

volume of CO 2 . For example, reevaluation of AoR could be required for every 20% injected but in no event le ss than every five years or at any

other time at the discretion of the Dir ector. Such a frequency would allow an operator to gather sufficient opera ting history and monitoring data for subsequent reevaluation.

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

N. 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.

5NYSDEC-DMN Response : Same as the two comments above for frequency of AoR reevaluation. With respect to the proposed phased corrective action approach for wells, NYSDEC-DMN agrees with the stated approach for the reasons give n provided a permit can be suspended or revoked for failure to perform the co rrective actions in a timely manner. However, NYSDEC-DMN believes all wells potentially impacted within the first five years of operation should be addressed prior to first injection

of CO 2

.

III A. 3 Proposed Injection Well Construction Requirements

O. EPA seeks comment on the proposed GS well requirements for depth of surface casing, the cementi ng of long-string casing, and construction with a packer se t opposite a cemented interval.

NYSDEC-DMN Response : NYSDEC-DMN agrees with the need for adequate protection of USDWs and the proposed measures. However, Director discretion may be necessary to address site-specific conditions

and the Director should be able to grant waivers to any requirement provided it can be demonstrated that such will not endanger USDWs.

III A. 3 Proposed Injection Well Construction Requirements

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

NYSDEC-DMN Response : NYSDEC-DMN believes that Director discretion is appropriate and necessa ry when reviewing other UIC Class wells for use as UIC Class VI wells. Overly prescriptive well construction requirements without any mechanism for deviation may limit the use of existing UIC wells a nd possible sequest ration sites.

III A. 3 Proposed Injection Well Construction Requirements

Q. 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.

NYSDEC-DMN Response : NYSDEC-DMN believes the decision to use

vertical, directional or horizontal wells should be left up to the operator.

Horizontal wells shoul d not be mandated.

III A. 3 Proposed Injection Well Construction Requirements

6R. EPA seeks comment regarding requirements for degradation-resistant

well construction materials, such as acid-resistant cements and corrosion resistant casing.

NYSDEC-DMN Response : With regard to degradation-resistant well

construction materials, the EPA rule should not be overly prescriptive but instead set performance standards th at would allow case-by-case basis evaluation of casing and cementing ma terials necessary to meet the

standards.

III A. 4 Proposed Injection Well Operating Requirements

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

NYSDEC-DMN Response : Hydraulic fracturing of wells in New York may be necessary in some cases to complete or recomplete an injection well. Any fracturing during well completion stimulation should be engineered so as to eliminate any risk of damage to confining zone(s). Other stimulation techniques should also be allowed provi ded there is no endangerment to USDWs. In addition, NYSDEC-DMN agrees with EPA’s position that an injection pressure safety factor be included in that the maximum allowable injection pressu re during operational injection be limited to 90 percent of the fractur e pressure of the injection zone.

III A. 4 Proposed Injection Well Operating Requirements

T. EPA is also requesting informati on to better qualify the use of fracturing for GS injection in spec ific geologic settings and rock formation lithologies.

NYSDEC-DMN Response : As indicated above, engineered hydraulic fracturing of the injection zone shoul d only be allowed during the initial completion or recompletion of a well.

III A. 4 Proposed Injection Well Operating Requirements

U. EPA seeks comment on the merits of requiring down-hole shut-off

valves in GS wells.

NYSDEC-DMN Response : Downhole shut-off valves, sometimes referred

to as surface-controlled subsurface sa fety valves (SCSSV), should not be mandated in GS wells without further assessing the risk of wells without such (i.e., failure rate) and possible maintenance problems. It is

7NYSDEC-DMN’s understanding that SCSSV s are used in the offshore oil and gas industry primarily due to risk s associated with maritime collision and hurricane events (i.e., ability to shut wells in downhole before platform evacuation). SCSSV are also part of an offshore facility’s emergency shutdown system. Nevert heless, at Director discretion, SCSSVs may provide an extr a level of protect ion in sensitiv e settings but should not be required for all projects without additional study.

III A. 4 Proposed Injection Well Operating Requirements

V. As a result, the Agency is considering and requesting comment on alternative approaches that woul d 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.

NYSDEC-DMN Response : While not a likelihood in New York State due to typical depths to lowermost USDWs, NYSDEC-DMN believes there should not be any blanket prohibition ag ainst injection into any potentially approvable geologic zone, even if it is above the lowermost USDW. There may be circumstances where this is appropriate and safe. The decision to permit a project should be made on a site-specific basis and

evaluation.

III A. 4 Proposed Injection Well Operating Requirements

W. In summary, EPA is soliciting comment on whether CO 2 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

.

NYSDEC-DMN Response : Injection criteria and the decision to permit a project should be made on a si te-specific basis and evaluation.

III A. 4 Proposed Injection Well Operating Requirements

X. 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 aqui fer exemptions be approved.

NYSDEC-DMN 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.

8III A. 4 Proposed Injection Well Operating Requirements

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

NYSDEC-DMN Response : It is NYSDEC-DMN’s opinion that the EPA should not set a minimum injection depth requirement for CO 2 GS operations. The decision to permit a project should be made on a sitespecific basis and evaluation.

III A. 4 Proposed Injection Well Operating Requirements

Z. EPA seeks comment on the use of tracers in CO 2 GS operations, and any potential impact of tracers on human health or ecosystems as they

relate to USDWs.

NYSDEC-DMN Response : Use of tracers in CO 2 GS operations should not be routinely requ ired although such should be an optional methodology for use at Director discre tion. The shortcomings of routine use of tracers for GS operations were discussed at length at the February 2008 EPA stakeholder workshop.

III A. 5 Proposed Mechanical Integrity Testing Requirements

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

NYSDEC-DMN Response : NYSDEC-DMN supports EPA’s proposal to require operators of GS projects to monitor internal mechanical integrity by continuously monitoring injection pressure, flow rate, and injected volumes, as well as annular pressure and fluid volume to provide early detection of anomalies that may indicat e an internal leak. However, an

“alarm” should shut in the well at the surface rather than requiring the

installation and use of a downhole shut-off valve.

III A. 5 Proposed Mechanical Integrity Testing Requirements

BB. EPA seeks comment on the appropriate frequency of internal and external MITs for GS injection well s, the appropriate types of MITs, and how to optimize MIT methods for GS.

NYSDEC-DMN Response : As stated above, NYSDEC-DMN supports continuous monitoring of internal mech anical integrity for GS injection wells. For external MITs, the frequency should be more or less annually depending upon the specific circumstan ces. The types of tests allowed should be those appropriate unde r the specific circumstances.

9III A. 6 Proposed Plume and Pressure Front Monitoring Requirements

CC. EPA seeks comment on the requirement for monitoring of GS sites for the purpose of tracking the location of the CO 2 plume and associated pressure front over time.

NYSDEC-DMN Response : NYSDEC-DMN is in favor of the EPA requiring an operator to conduct ongo ing and sufficient monitoring to allow the tracking the CO 2 plume and associated pressure front. In addition to any regular reporting freque ncy, an operator should be required to provide notification whenever actual conditions vary significantly from modeled predictions.

III A. 6 Proposed Plume and Pressure Front Monitoring Requirements

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

NYSDEC-DMN Response : NYSDEC-DMN is unclear as to the actual utility of pressure fall-off testing for operational GS wells. Instead of being mandated at least once every fi ve years, the Director should have the discretion to require such testing as deemed appropriate.

III A. 6 Proposed Plume and Pressure Front Monitoring Requirements

EE. Based on information evaluated to date, EPA believes that tracking the plume and pressure front is an important companion step to address any uncertainties associat ed 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.

NYSDEC-DMN Response : NYSDEC-DMN agrees that tracking of the

CO 2 plume and pressure front is important and should be required. However, the exact methodology should not be specified but determined on a site-specific basi s. NYSDEC-DMN also agrees with EPA’s statement “As such, allowing flexibili ty in choosing the plume tracking methods and other monitoring technol ogies 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 Requirements

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

10NYSDEC-DMN Response : NYSDEC-DMN agrees with EPA’s proposal to require operators to report semi-annually on the characteristics of injection fluids, injection pressure, flow rate, temperature, volume and annular pressure, and on the result s of MITs, ground water monitoring, and any required atmospheric/soil gas monitoring. However, the amount and types of monitoring to be re quired should be site specific.

III A. 6 Proposed Plume and Pressure Front Monitoring Requirements

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

NYSDEC-DMN Response : NYSDEC-DMN agrees with EPA’s proposal to require operators to report semi-annually on the characteristics of injection fluids, injection pressure, flow rate, temperature, volume and annular pressure, and on the result s of MITs, ground water monitoring, and any required atmospheric/soil gas monitoring. However, the amount and types of monitoring that are required should be site specific. Certain geophysical monitoring techniques th at successfully monitor plume migration in the southern states may not have any monitoring capability in

northern Paleozoic basins.

III A. 6 Proposed Plume and Pressure Front Monitoring Requirements

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

NYSDEC-DMN Response : The Director should be given flexibility to approve site-specific monitoring plans.

III A. 7 Proposed Recordkeeping and Reporting Requirements

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

NYSDEC-DMN Response : NYSDEC-DMN believes monitoring and testing plans, an AoR and corrective action plan, and a post-injection site care and site closure plan are integr al components of any GS application, and should be required by the EPA.

III A. 7 Proposed Recordkeeping and Reporting Requirements

11JJ. EPA seeks comment on the frequency of all proposed reporting requirements.

NYSDEC-DMN Response : NYSDEC-DMN supports all stated reporting frequencies and requirements.

III A. 7 Proposed Recordkeeping and Reporting Requirements

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

NYSDEC-DMN Response : NYSDEC-DMN agrees with electronic submittal in principle as long as ther e is sufficient flexibility to allow states to utilize existing or preferred state data processing systems or

software. At this time, electronic re porting should be an option but not a requirement.

III A. 7 Proposed Recordkeeping and Reporting Requirements

LL. Although EPA has not include d a requirement for this report in today’s proposal, EPA seeks comment regarding the necessity for such an annual report.

NYSDEC-DMN Response : NYSDEC-DMN agrees with the concept and sees the merits of requiring an annual report that provides a narrative analysis of GS operations in addition to requirin g semi-annual reporting of

data.

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

MM. EPA requests comment on the proposed use of a tentative 50-year

fixed timeframe that could be modi fied at the Director’s discretion based on monitoring and modeling data.

NYSDEC-DMN Response : Given that current in jection and reservoir

behavior data demonstrates a decrea sing risk of leakage after injection ceases, NYSDEC-DMN believes that a 50-year default time frame for post-injection site care is too long and that a 30 -year starting period may be more appropriate to allow GS proj ects to move forward. It would be better to prescribe a shorte r period with discretion to go longer, rather than

vice versa, as such would better facil itate project planning. Regardless, it

is critical that the Director have the discretion to increase or decrease the period based on the specifics of a particular project.

12III A. 8 Proposed Well Plugging, Post-Injection site Care, and Site Closure Requirements

NN. 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.

NYSDEC-DMN Response : Given that current in jection and reservoir

behavior data demonstrates a decrea sing risk of leakage after injection ceases, NYSDEC-DMN believes that a 50-year default time frame for post-injection site care is too long and that a 30 -year starting period may be more appropriate to allow GS proj ects to move forward. It would be better to prescribe a shorte r period with discretion to go longer, rather than

vice versa, as such would better facil itate project planning. Regardless, it

is critical that the Director have the discretion to increase or decrease the period based on the specifics of a particular project.

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

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

NYSDEC-DMN Response : Given that current in jection and reservoir

behavior data demonstrates a decrea sing risk of leakage after injection ceases, NYSDEC-DMN believes that a 50-year default time frame for post-injection site care is too long and that a 30 -year starting period may be more appropriate to allow GS proj ects to move forward. It would be better to prescribe a shorte r period with discretion to go longer, rather than

vice versa, as such would better facil itate project planning. Regardless, it

is critical that the Director have the discretion to increase or decrease the period based on the specifics of a particular project.

III A. 9 Proposed Financial Responsibility and Long-Term Care Requirements

PP. 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 adjustment s to the financial responsibility

mechanisms should be considered, al l subject to EPA’s authority under

the SDWA.

NYSDEC-DMN Response : The EPA proposed rule for financial assurance appears to be adequate with respect to wells and NYSDEC-DMN

13understands that any well plugging financ ial instrument would be released upon proper plugging and abandonment of th e well. It is also understood

that a second tier of financ ial assurance, that could be filed at a later date (i.e., closer to ceasing injection), is be ing considered for post-injection site care. However, according to the proposed rule, both forms of financial

assurance would be limited to SDWA authority which does not extend to financial responsibility for activities unrelated to protection of USDWs (e.g., coverage of risks to air, ecosys tems, or public health unrelated to USDW endangerment). Because of EPA’s focused authority under the SDWA for the UIC program, action by i ndividual states may be required to fill any financial assurance and regulatory gaps.

III A. 9 Proposed Financial Responsibility and Long-Term Care Requirements

QQ. 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-inje ction site care requirements.

NYSDEC-DMN Response : EPA’s proposal for financial assurance appears to be adequate with respect to wells and NYSDEC-DMN understands that any well plugging financ ial instrument would be released upon proper plugging and abandonment of th e well. It is also understood

that a second tier of financ ial assurance, that could be filed at a later date (i.e., closer to ceasing injection), is be ing considered for post-injection site

care. EPA states that it is consid ering requiring well plugging financial demonstration at permit issuance and post-injection site care financial security demonstration at a later time (e.g., within 180 days of notifying

the Director that the well will be plugged and abandoned). EPA also states “Trying to determ ine the cost for post-injection site care, possibly 30 to 50 years in the future, could be difficult, as could the approval of a financial demonstration.” It is NYSDEC-DMN’s opinion that some level of financial assurance for post-site inj ection care should be in place at first injection of CO 2 . If there are concerns with uncertainty and overly burdening an operator, perhaps the am ount of post-injec tion site care

assurance could start with a basic leve l of protection and be required to be increased as the potentially affected area grows over time with additional injection.

IV. How Should UIC Program Director s Involve the Public In Permitting Decisions for GS Projects?

RR. 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 disse minating and gathering information.

1415 Such tools include cable networ ks, the Internet, and other new technology.

NYSDEC-DMN 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 no tice, hearings and due pr ocess to all affected parties. This should be adequate for public involvement purposes.

V. How Will States, Territories, and Tr ibes Obtain UIC Program Primacy for

Class VI Wells?

SS. EPA is seeking comment on the merits and possible disadvantages of allowing primacy approval for Cla ss VI wells independent of other

well classes.

NYSDEC-DMN Response : NYSDEC-DMN supports the creation of a separate class VI for GS wells and strongly supports allowing state primacy solely for Class VI. In addition, 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?

TT. Therefore, EPA proposes that Class VI injection well permits would be issued for the operating li fe of the GS project including the post-injection site care period. EPA seeks comment on the merits of this approach.

NYSDEC-DMN Response : NYSDEC-DMN agrees with the EPA proposal.Letter ID: 0186 Commenter: Bradley J. Field Organization: New York State Dept. of Environm ental Conservation Div. of Mineral Resources

Letter ID: 0186 Comment ID: 25170 Letter Lines: 44 to 46

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: 0186 Comment ID: 25171 Letter Lines: 52 to 61

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.

NYSDEC-DMN Response: While the UIC program in New York State is directly implemented at this time, many other stat es currently have primacy jurisdiction

and administer Class II and other wells. Primacy should be allowed solely for Class VI, and such should be structured to allow flexibility in the primacy process and defer to the state rule when it effectively meets the intent of the federal requirements.

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

1management 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., pipeli ne 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.

The Agency believes that it is important for stat es to use their unique e fficiencies to promote adoption of this burgeoning and important tec hnology, while assuring that USDWs are protected from endangerment through the UIC regulatory framework. EPA believe s that, due to the importance of implementing an effective, comprehensive, and seamless CCS program, States should be provided the flexibility to obtain primacy for Class VI only.

EPA also believes that allowing states to apply only for Class VI primacy will shorten the primacy approval process for states. EPA's willingness to accept independent primacy applications for Class VI wells represents a shift in its longstandi ng policy of discouraging "partial primacy." It is very important to note that this shift in policy allowing for Class VI primacy does not apply to any other well Cl ass under Section 1422. EPA will continue to discourage applications for pa rtial primacy for all other well types under Section 1422.

EPA clarifies that states should be able to obtain primacy for Cla ss VI wells independent of other 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) provided in the final GS rule. EPA believes that existing programs can adapt their expertise to the new requirements for Class VI wells and will be able to develop a primacy application for Class VI wells under section 1422 of SDWA and en sure that their GS programs integrate into national climate change priori ties and protect USDWs from endangerment.

Letter ID: 0186 Comment ID: 25172 Letter Lines: 66 to 74

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: B. 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.

NYSDEC-DMN Response: NYS DEC-DMN agrees with EPA’s pr oposed approach provided the project is an EOR project under Class II and the operator is able to demonstrate it as an ongoing viable EOR project. Operat ors should not be a llowed to inject and store CO2 under the guise of a Cla ss II EOR project to avoid Class VI permitting requirements.

Individual Response: EPA agrees that injection of CO2 for the primary purpose of enhancing

2oil and gas recovery should remain under the Cla ss II Program. EPA agrees that the nature and risks of CO2 injection for long te rm storage is different from Cl ass II CO2 injection for ER, and that tailored requirements for GS wells are appropriate and n ecessary to protect USDWs from endangerment. For this reason, the Agency tailored UIC requirements for Class VI wells that address the general risks deep injection may pose to USDWs and specifically address the unique nature of CO2 GS (i.e., very large volumes, very long time-periods, and reservoir pressure conditions).

EPA agrees and clarifies that the final Class VI regulations require that any owner or operator injecting CO2 for the primary purpose of long term storage obtain a Class VI permit with some special consideration for the fact that they are transitioning from a well not originally designed to meet Class VI requirements. The Di rector has the authority to dete rmine at what point a Class VI permit is required for those projects that are transitioning from the primary purpose of EOR to long term storage of CO2. The fina l regulation provides a set of tec hnical factors for the Director to evaluate in making this determination, at §144.19. EPA believes that th is approach provides sufficient protection of USDWs when there is an increased risk to USDWs as compared to traditional 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 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 purpose is long-term storage of large volumes of CO2. The guidance describes 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: 0186 Comment ID: 25173 Letter Lines: 79 to 86

Comment Code: 2062 1.5.3.1 Grandfathering construction of Class I wells (seeking comment)

Comment Code: 2064 1.5.3.2 Grandfathering construction of Class II wells (seeking comment)

Comment: 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 Cla ss II wells seeking a permit for GS of CO2, provided he/she is able to make a de termination that these wells would not endanger USDWs.

NYSDEC-DMN Response: NYS DEC-DMN agrees that this di scretion is appropriate and necessary when reviewing other UIC Class wells for use as UIC Class VI wells.

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

3to 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).

Letter ID: 0186 Comment ID: 25174 Letter Lines: 91 to 99

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

Comment: D. Accordingly, EPA is proposing that th e Director have th e discretion to "grandfather" the construc tion 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).

NYSDEC-DMN Response: NYS DEC-DMN agrees that this di scretion is appropriate and necessary when reviewing other UIC Class wells for use as UIC Class VI wells.

Individual Response: EPA agrees that many 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 grandfathe red per §146.81(c), provided th e owner or operator

can demonstrate to the Director that the wells were engineered and constructed to meet the requirements at §146.86(a) and ensu re 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).

Letter ID: 0186 Comment ID: 25175 Letter Lines: 104 to 112

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

Comment: 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.

NYSDEC-DMN Response: The Director should have the flexibility to determine whether a well meets federal Class VI pr otective standards on a well-by-well basis, and require the operator to adhere to the permitting process.

Individual Response: EPA believes that a cautious approach to grandfathering is appropriate, particularly given that the convert ed well will be used for a substa ntially different process, which

4involves increased reservoir pre ssures associated with large volumes of stored CO2 and the corrosivity of CO2 in the presence of water. Th e final GS rule provides for the construction of these wells to be grandfathered (per 146.81(c)). EPA has included a requirement in the final GS rule that owners or operators seeking to c onvert existing wells for long term storage must demonstrate to the Director that the grandfathe red wells were engineered and constructed meet the requirements at §146.86(a) and ensure prot ection of USDWs, in lieu of requirements at §146.86(b) and §146.87(a). Conversion of the well is at the Director's discretion following an evaluation of all other site-specific informati on about the well and the project, e.g., modeling, monitoring, and other data. Any wells that have de teriorated due to contact with incompatible injected or formation fluids ma y not be approved for conversion.

Letter ID: 0186 Comment ID: 25176 Letter Lines: 117 to 122

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

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

NYSDEC-DMN Response: The Director should have the flexibility to determine whether a well meets federal Class VI pr otective standards on a well-by-well basis, and require the operator to adhere to the permitting process.

Individual Response: EPA believes that a cautious approach to grandfathering is appropriate, particularly given that the convert ed well will be used for a substa ntially different process, which involves increased reservoir pre ssures associated with large volumes of stored CO2 and the corrosivity of CO2 in the presence of water. Th e final GS rule provides for the construction of these wells to be grandfathered (per 146.81(c)). EPA has included a requirement in the final GS rule that owners or operators seeking to c onvert existing wells for long term storage must demonstrate to the Director that the grandfathe red wells were engineered and constructed meet the requirements at §146.86(a) and ensure prot ection of USDWs, in lieu of requirements at §146.86(b) and §146.87(a). Conversion of the well is at the Director's discretion following an evaluation of all other site-specific informati on about the well and the project, e.g., modeling, monitoring, and other data. Any wells that have de teriorated due to contact with incompatible injected or formation fluids ma y not be approved for conversion.

Letter ID: 0186 Comment ID: 25177 Letter Lines: 126 to 134

Comment Code: 2163 1.6.3.1 Comments in favor of injection into unmineable coal seams

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

USDW

Comment: G. As with unmineable coal seams, EP A seeks comment on prohibiting injection into such formations if they are above the lowermost USDW.

5NYSDEC-DMN Response: While not a likelihood in New York due to the absence of coal in the state and typical depths to lowermost USDWs, NY SDEC-DMN believes there should not be any blanket proh ibition against injection into any potentially approvable geologic zone even if it is above th e lowermost USDW. There may be circumstances where this is appropriate and safe. The decision to permit a project should be made on a site-specific basis and evaluation.

Individual Response: EPA agrees that GS into unmineable coal seams has the potential to allow sequestration while ensuring USDW protection fro m endangerment, as described by commenters citing the process of enhanced methane recovery. The final GS rule does not preclude injection into unmineable coal seams provided owners or operators can demonstrate that GS can be performed in a manner that protects USDWs from endangerment. The Agency clarifies that owners or operators of Class VI wells used fo r injecting CO2 into unmineable coal seams are subject to the same site char acterization, well construction, oper ation, monitoring, post-injection site care and site closure requirements that are re quired of projects injecting into other formation

types.

EPA clarifies that the final rule requires that injection for GS be into non-USDWs below the lowermost USDW; however, owners or operators may apply for a waiver from this requirement, as described in §146.95. For more information, see the discussion of waivers in the preamble to

the final rule.

Letter ID: 0186 Comment ID: 25178 Letter Lines: 138 to 149

Comment Code: 2300 1.7 Comments on the Alternatives Considered

Comment: H. EPA is proposing Regulatory Alternative 3, the Tailored Requirements Approach. EPA did not select Alternativ e 1 (Non-Specific Requirements Approach) because it does not provide enough speci ficity to ensure that permitting authorities manage GS wells appropriately to prevent endangermen t of USDWs. In addition, this alternative may be burdensom e 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.

NYSDEC-DMN Response: NYSDEC-DMN agrees that Regula tory Alternativ e 3, Tailored Requirements Approach is appropriate provided it allows discretion and flexibility on the part of the Director.

Individual Response: EPA agrees with the commenters that Regulatory Alternative 3 is appropriate. The technical requirements in Alte rnative 3 (and the final GS rule) build upon the long-standing UIC regulatory framework for deep we lls and are appropriately tailored to address the unique nature of full-scale CO2 GS, includi ng the volumes of CO2 to be injected, the buoyant and mobile nature of the injectate, and its corrosivity in the presence of water.

6Even though the Agency did not choose Alternatives 1 or 2, EP A agrees that flexibility is important to accommodate the varied conditions that may be encountered at GS sites while ensuring the protection of USDWs. The final GS regulation gives the Director discretion to set permit criteria that are appropria te to site-specific conditions. Th e regulation provides flexibility to select appropriate sites a nd target formations (under §146. 82), well construction specifics (under §146.86), and testing and monitoring re gimes (under §146.90), provided the owner or operator can demonstrate that the injection a nd storage will not endanger USDWs and that minimum requirements for the site are met. Comm enters representing electric utilities, water associations, and states supported Alternative 3 and the flexibility it provides to permitting authorities to make case-by-case permitting decisi ons while ensuring the protection of USDWs.

Letter ID: 0186 Comment ID: 25179 Letter Lines: 153 to 159

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

Comment: I. EPA specifically seeks comment on the me rits of identifying these additional

zones.

NYSDEC-DMN Response: It is NYSDEC-DM N’s opinion that id entification and characterization of secondary confinement should not be a requirement unless the unit identified as the primary confin ing zone is questionable. This determination should be made on a pr oject and site-specific basis.

Individual Response: EPA agrees with the commenter that, in some situations, the presence of additional confining and containment zones above the primary (i.e., lowermost) confining zone can improve USDW protection from endangerment. The final regulation re tains the requirement at §146.83(b) which affords the Director discretion to require owners or op erators to identify and

characterize additional zones.

Letter ID: 0186 Comment ID: 25180 Letter Lines: 161 to 165

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

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

NYSDEC-DMN General Comment for Section II I. A. 2: NYSDEC-DM N believes use of traditional well-specific AoR is problematic for comprehensive and adequate site characterization, and that EPA’s propos ed approach is appropriate.

Individual Response: EPA agrees that the unique aspects of GS merit the use of sophisticated computational modeling for delineation of the Ao R, based on site-specifi c features and geology, including the presence of faults, fractures, a nd artificial penetrations. EPA believes that computational modeling of the AoR prior to inje ction will provide the best obtainable estimates

7of the extent of the CO2 plume over several years of active inj ection. EPA has strengthened the minimum frequency for the AoR reevaluation from ten years to 5 years (146.84(e)). EPA believes that this revised frequency addresse s commenters' concerns about the inherent uncertainties in modeling CO2 movement, the emerging nature of GS technology, risk-based targeting of monitoring activities, and the unique nature of CO2 GS.

Letter ID: 0186 Comment ID: 25181 Letter Lines: 169 to 178

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

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

NYSDEC-DMN Response: See General Comment for Section III. A. 2 above. AoR

delineation should be based on best availa ble technology and available data. The collection of physical data (i.e., well bore data) may be necessary to fully use modeling to determine the ultimate extent of the proposed CO2 storage volume and reservoir pressures. The Director should have the flexibility to be able to supplement or substitute other data elem ents as appropriate ahead of such drilling and data gathering with conf irmation of the model once additional

information is available.

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 . The owner or operator must demonstrate, in the proposed AoR and corrective action plan requ ired at §146.84(b), to the satisfaction of the Director, that the modeled AoR will be based on detailed geologic data collected on the site. EPA anticipates that any model that does this in a satisfactory manner will be approved by the Director. EPA acknowledges that modeling technology is expected to continuously improve, and encourages and expects owners or operators to use the best av ailable multiphase computational models to determine the AoR. Reliance on improve d models will likely increase the accuracy and quality of the AoR characterization, resulting in better prot ection of USDWs from endangerment.

Letter ID: 0186 Comment ID: 25182 Letter Lines: 182 to 187

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

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

NYSDEC-DMN Response: NYSDEC- DMN believes proprietary models should be allowed provided the Director has di scretion to evaluate the accuracy of the modeling methodology. It should be noted that confid entiality of proprietary models will be subject to various jurisdicti ons and statutory limitations.

8Individual Response: EPA agrees that some of the availa ble proprietary models may meet the needs for calculating the AoRs of GS sites. EPA will allow their use 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. Information including model assumptions a nd equations are used by th e Director to inform his/her decision to issue the permit and ensure that the requirements are met and the GS well will not endanger USDWs. EPA adds that its Confidential Business Information requirements at 40 CFR 144.5 will apply to the use of proprietary models.

Letter ID: 0186 Comment ID: 25183 Letter Lines: 191 to 201

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

Comment: L. EPA seeks comment on the applicability of computational flui d flow models for delineating the AoR of GS sites.

NYSDEC-DMN Response: See General Comment for Section III. A. 2 above. AoR

delineation should be based on best availa ble technology and available data. The collection of physical data (i.e., well bore data) may be necessary to fully use modeling to determine the ultimate extent of the proposed CO2 storage volume and reservoir pressures. The Director should have the flexibility to be able to supplement or substitute other data elem ents as appropriate ahead of such drilling and data gathering with conf irmation of the model once additional

information is available.

Individual Response: As described above, EPA agrees that it is appropriate to allow operators the flexibility to select modeli ng, site characterization, and mon itoring techniques that are most appropriate to site conditions and available types and amounts of data. The owner or operator must demonstrate, in the proposed AoR and corr ective action plan requir ed at §146.84(b), to the satisfaction of the Director, that the modele d AoR will be based on detailed geologic data

collected on the site. EPA adds that the Dire ctor has authority to request supplemental

information if needed to ensure that the site will be protective of USDWs.

Letter ID: 0186 Comment ID: 25184 Letter Lines: 205 to 214

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

Comment Code: 3560 2.2.3.2 Conditions that merit reevalua tion of the AoR (seeking comment)

Comment: M. 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.

NYSDEC-DMN Response: AoR reev aluation frequency could be based on the amount of CO2 injected relative to the total pr oposed injection volume of CO2. For

9example, reevaluation of AoR could be required for every 20% injected but in no event less than every five years or at a ny other time at the discretion of the Director. Such a frequency would allo w an operator to gather sufficient operating history and monitoring data for subsequent reevaluation.

Individual Response: EPA disagrees with the commente r's suggestion to tie the AoR reevaluation frequency to the volume or percentage of CO2 injected. EPA believes that it is important to set an AoR reevaluation frequency (i.e ., at least every five year s) to ensure that the project is reviewed and any n ecessary updates to the project plans or the permit are made on a regular schedule, regardless of the pace at which the injection is completed.

EPA believes that the commenter's proposed ap proach has the potential to lead to AoR

reevaluation schedules that ar e not sufficiently frequent to en sure protection of USDWs from endangerment, if for some reason the variables (r ate or volume) are such that reevaluation based on percentages are not triggered within 5 years. In addition, EPA believes this approach may complicate the administrative process of determ ining and tracking the re evaluation schedule.

For this reason, EPA has, at §146.84(e), adopted the 5 year interval (an adjustment from the ten year interval in the proposed rule) recomm ended by many commenters. EPA adds that the

Director has discretion to require reevaluation more frequent ly, such as when monitoring data differ significantly from modeled predictions, or when there are appreciable operational changes (e.g., injection rates).

Letter ID: 0186 Comment ID: 25185 Letter Lines: 218 to 227

Comment Code: 3630 2.2.4.1 Comments in favor of allowing phased corrective action

Comment: N. EPA invites public comment on the merits and frequency of reevaluation of the AoR as well as the phased correctiv e action approach for GS wells.

NYSDEC-DMN Response: Same as the two co mments above for frequency of AoR reevaluation. With respect to the propos ed phased corrective ac tion approach for wells, NYSDEC-DMN agrees with the stated ap proach for the reasons given provided a permit can be suspended or revoked fo r failure to perform the corrective actions in a timely manner. However, NYS DEC-DMN believes all wells potentially impacted within the first five years of operation should be addressed prior to first injection of CO2.

Individual Response: EPA agrees that corrective action on wells should be completed several years in advance of the anticipat ed arrival of the CO 2 plume or pressure front. However, EPA does not believe that it is appropr iate to set a specific time for completing corrective action in the regulation due to uncertainty in delineating the CO2 plume movement during certain time frames. Instead, such decisions would be incorp orated into the AoR a nd corrective action plan for each project, as specified in §146.84(b)(2)(iv), which would be developed by the owner or operator and approved by the Director based on the geology of the site and th e wells in the AoR.

10All needed corrective action (whe ther phased or not) must be performed by the owner or operator as described in the approved AoR and corrective action plan and on the approved

schedule to ensure that deficient wells in the Ao R are addressed in a timely manner; failure to do so will either preclude authori zation to inject or, in the case of phased corrective action, be considered a violation of the pe rmit and subject to applicable civil, criminal, or administrative penalties under SDWA §1423.

Letter ID: 0186 Comment ID: 25186 Letter Lines: 231 to 239

Comment Code: 3800 2.3 Proposed Injection Well Construction Requirements (40 CFR 146.86)

Comment: O. 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.

NYSDEC-DMN Response: NYS DEC-DMN agrees with the need for adequate protection of USDWs and the proposed measures. However, Director discretion may be necessary to address site-specific c onditions and the Director s hould be able to grant waivers to any requirement provided it can be demonstrated that such will not endanger USDWs.

Individual Response: EPA agrees that a flexible approach to the construction of Class VI wells is appropriate, and believes the rule provi des an appropriate amount of flexibility. The construction requirements at §146.86 provide flexibility by listing the basic components a Class VI well must have to prevent endangerment of USDWs, and allow owners or operators to choose appropriate materials in meeting these requirement s. However, EPA notes that the Director may not waive any construction require ment unless the regulation specifi cally gives the Director such discretion for a particular requirement (e.g., §146.83(b)(4) allows the Director to approve

alternative methods of cementi ng in some circumstances).

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). EPA is developing guidance on the c onstruction 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: 0186 Comment ID: 25187 Letter Lines: 243 to 251

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

Comment Code: 3800 2.3 Proposed Injection Well Construction Requirements (40 CFR 146.86)

11Comment: P. EPA also seeks comment on how the proposed grandfathering provisions for existing wells (construction requirements) may affect compliance with the above, proposed construction requirements.

NYSDEC-DMN Response: NYS DEC-DMN believes that Director discretion is appropriate and necessary when reviewing other UIC Class wells for use as UIC Class VI wells. Overly prescriptive well construc tion requirements without any mechanism for deviation may limit the use of existi ng UIC wells and possi ble sequestration

sites.

Individual Response: As described above, conversion of th e well would be at the Director's discretion following an evaluation of all other s ite-specific information about the well and the project, e.g., modeling, monitori ng, and other data. Any wells that have deteriorated due to contact with incompatible injected or formati on fluids may not be approved for conversion.

EPA believes that, given the range of types of existing wells that may be candidates for conversion, flexibility is appropriate regarding conversion of Class I, II, or V wells for GS, provided it can be demonstrated to the Director's satisfaction th at the converted well can conduct GS operations in a manner that does not enda nger USDWs. The final GS rule, at §146.81(c),

allows the construction of these wells to be grandfathere d, provided the owner or operator can

demonstrate to the Director that the wells we re engineered and constructed to meet the requirements at §146.86(a) and ensu re protection of USDWs, in lieu of requirements at §146.86(b) and §146.87(a). Only the cemented-in-pla ce construction requirements would be grandfathered under the final GS rule; following conversion, these wells must be permitted as Class VI wells and be subject to the operational, MIT, monito ring, reporting, plugging, and postinjection site care and site closure requirements in the final GS rule.

Furthermore, EPA is developing guidance on transitioning from Class II to Class VI. The guidance will assist Directors and owner/operators in evaluating where a pr oject may fit within a Class II to Class VI transition. The guidance descri bes the methods available for the Director to determine the risk posed to USDWs from a GS/E R project, and how the Director may determine if a project should be regulated by a Class II or Class VI UIC program . The guidance will be available on EPA's web site, at http://water.epa.gov/type/groundwater /uic/wells_sequestration.cfm.

Letter ID: 0186 Comment ID: 25188 Letter Lines: 255 to 261

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

Comment: Q. EPA seeks comment on the merits of hor izontal well drilling techniques for GS wells and the applicability of well constructi on requirements discussed in this proposal.

NYSDEC-DMN Response: NYSDE C-DMN believes the decisi on to use vertical,

directional or horizon tal wells should be left up to the operator. Horizontal

12wells should not be mandated.

Individual Response: In the final rule, EPA allows the us e of but does not mandate horizontal wells at GS projects. In the proposed rule, EPA sought comment on the appropriateness of horizontal drilling techniques for Class VI wells, and commenters representing energy companies, electric utilities, the oil and gas industry, CCS asso ciations, states, and the public, unanimously supported the concept and provided many reasons why horizontal 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 ensure the protection of USDWs from endangerment.

Letter ID: 0186 Comment ID: 25189 Letter Lines: 265 to 272

Comment Code: 3860 2.3.3 Well component degradation

Comment: R. EPA seeks comment regarding requirem ents for degradation-resistant well construction materials, such as acid-res istant cements and co rrosion resistant casing.

NYSDEC-DMN Response: With regard to de gradation-resistant well construction materials, the EPA rule should not be overly prescriptive but instead set performance standards that would allow case-by-case basis evaluation of casing and cementing materials necessary to meet the standards.

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

must meet standards listed in the rule and be compatible with fluids with which the materials may be expected to come into contact. Therefor e, some well materials may need to be acidresistant and some may not if they do not come in contact with the CO2 stream or other corrosive fluids and if approved by the Director.

See the discussion of Class VI well construction requirements in the preamble to the final GS rule for additional information. Additionally, EP A 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: 0186 Comment ID: 25190 Letter Lines: 276 to 284

Comment Code: 4130 2.4.1.3 Appropriateness of using fractur ing for well stimulation (seeking comment)

Comment: S. EPA is requesting comment on the ex tent and scope to which hydraulic fracturing should be allowe d during GS injection, and whether the use of

13fracturing for the purposes of we ll stimulation is appropriate.

NYSDEC-DMN Response: Hydraulic fracturing of wells in Ne w York may be necessary in some cases to complete or recomplete an injection well. Any fracturing during well completion stimulation should be engineer ed so as to eliminate any risk of damage to confining zone(s). Other stimul ation techniques should also be allowed provided there is no endangerment to USDWs. In addition, NYSDEC-DMN agrees with

Individual Response: The final GS regulation allows hydrau lic fracturing only during Class VI well stimulation. Section 146.88(a) permits inject ion pressure to exceed 90 percent of the fracture pressure only during well stimulation. 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 requirement that the owner or operator notify the Dir ector 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. EPA clarifies that UIC regulations prohibit fract uring of the confining zone at any time during injecti on or stimulation in order to protect USDWs from endangerment.

Letter ID: 0186 Comment ID: 25191 Letter Lines: 284 to 287

Comment Code: 4110 2.4.1.1 Injection pressure limitations

Comment: provided there is no endangerment to US DWs. In addition, NYSDEC-DMN agrees

with EPA’s position that an injection pressure sa fety factor be included in that the maximum allowable injection pressure duri ng operational injection be limited to 90 percent of the fracture pressu re of the injection zone.

Individual Response: EPA agrees that the injection pressu re should not exceed 90 percent of the fracture pressure of the injection zone. The fina l rule retains this provision at §146.88(a). EPA believes that the 90 percent requirement, whic h was suggested by State representatives whom EPA consulted when writing the regulation, is a satisfactory margin of safety during well operation necessary to protect USDWs from endangerment.

Letter ID: 0186 Comment ID: 25192 Letter Lines: 291 to 296

Comment Code: 4130 2.4.1.3 Appropriateness of using fractur ing for well stimulation (seeking comment)

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

NYSDEC-DMN Response: As indicated above, engineered hydraulic fracturing of the injection zone should only be allowe d during the initial completion or recompletion of a well.

14Individual Response: The final GS regulation allows hydrau lic fracturing only during Class VI well stimulation. Section 146.88(a) permits inject ion pressure to exceed 90 percent of the fracture pressure only during well stimulation. 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 requirement that the owner or operator notify the Dir ector 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. EPA clarifies that UIC regulations prohibit fract uring of the confining zone at any time during in jection or stimulation.

Letter ID: 0186 Comment ID: 25193 Letter Lines: 300 to 312

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

Comment: U. EPA seeks comment on the merits of re quiring down-hole shut-off valves in GS

wells.

NYSDEC-DMN Response: Downhole shut-off valves , sometimes referred to as surfacecontrolled subsurface safety valves (SCSSV ), should not be mandated in GS wells without further assessing the risk of we lls without such (i.e., failure rate) and possible maintenance problems. It is NYSDEC-DMN’s understanding that SCSSVs are used in the offshore oil and gas indus try primarily due to risks associated

with maritime collision and hurricane even ts (i.e., ability to shut wells in downhole before platform evacuation). SC SSV are also part of an offshore facility’s emergency shutdown system. Ne vertheless, at Director discretion, SCSSVs may provide an extra level of protection in sens itive settings but should not be required for all proj ects without additional study.

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. The Agency agrees with the commenter that offshore Class VI wells present unique construction and operational conditions, including isolation fr om 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. The 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.

While EPA acknowledges that the likelihood of damage to onshore f acilities is lower than that for off-shore facilities, down-hole shut-off valv es are still commonly used in onshore facilities such as acid gas injection wells and high pressu re, high-temperature wells. While valve failure is a concern, EPA believes that technology has advanced sufficiently to make valve failure a rare occurrence and to appropriately hand le such failure if it occurs. Fo r example, wireline retrievable

15devices can allow repair or replacement of da maged devices without necessitating pulling the tubing.

EPA believes that requiring the in stallation of automatic surfa ce shut-off devices for onshore wells (and affording Director's discretion to requir e down-hole devices where necessary) and

automatic down-hole shut-off devices for offsho re wells in submerged lands within the jurisdiction of a State ensures that proper pre cautions are taken to prevent subsurface fluid movement and ensure pr otection of USDWs.

Letter ID: 0186 Comment ID: 25194 Letter Lines: 316 to 326

Comment Code: 4410 2.4.4.3.1 Comments in favor of allowing injection above/between

USDWs in certain circumstances

Comment: V. 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.

NYSDEC-DMN Response: While not a likelihoo d in New York State due to typical depths to lowermost USDWs, NYSDEC-DMN believes there should not be any blanket prohibition against injecti on into any potentially a pprovable geologic zone,

even if it is above the lowe rmost USDW. There may be circumstances where this is appropriate and safe. The decision to perm it a project should be made on a sitespecific basis and evaluation.

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 quantities to supply dr inking water needs.

16Determinations about the appropriateness of a wa iver would be made by the Director, based on evaluation of site-specific conditions. For additional informati on on the waiver approach and 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 Data Availability and Request for Comment.

Letter ID: 0186 Comment ID: 25195 Letter Lines: 330 to 337

Comment Code: 4410 2.4.4.3.1 Comments in favor of allowing injection above/between

USDWs in certain circumstances

Comment: W. 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.

NYSDEC-DMN Response: Injection criteria and the decision to permit a project should be made on a site-sp ecific basis and evaluation.

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, where approved by the Dire ctor, based on evaluati on of site-specific

conditions.

Letter ID: 0186 Comment ID: 25196 Letter Lines: 341 to 348

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

circumstances

Comment: X. 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.

NYSDEC-DMN 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 believes that there are limited 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

17expansions of existing Class II EOR/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.

All decisions regarding whether 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 permit 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 zone are pr otected from endangerment.

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: 0186 Comment ID: 25197 Letter Lines: 352 to 358

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

Comment: Y. Finally, EPA seeks comment on whether the Agency should set a minimum injection depth requirement for CO2 GS, rath er than require that such injection take place below the lowermost USDW.

NYSDEC-DMN Response: It is NYSDEC-DMN’s opinion that the EPA should not set a minimum injection depth requirement fo r CO2 GS operations. The decision to permit a project should be made on a s ite- specific basis and evaluation.

Individual Response: EPA agrees that it is not appropriate to set a mi nimum injection depth for GS projects. EPA believes that a determination of site-suitability for GS (i.e., that subsurface

formations will receive and confin e injected CO2) should be made on a site-specific basis. The GS rule, at §146.82, requires the ow ner or operator to pr ovide 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 contained within the injection formation, a nd 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

18owner 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: 0186 Comment ID: 25198 Letter Lines: 362 to 369

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

Comment: Z. 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.

NYSDEC-DMN Response: Use of tracers in CO2 GS operations should not be routinely required although such should be an opti onal methodology for use at Director discretion. The shortcomings of routine us e of tracers for GS operations were discussed at length at the Februa ry 2008 EPA stakeholder workshop.

Individual Response: EPA agrees that tracer use is not appropriate in all situations. Nevertheless, there are many differ ent types of tracers and not al l are problematic; research is being done to overcome problems with existing tracer s. EPA believes that tracers have been used safely and successfully in other applications. For this reason, EPA does not require the use of tracers at all GS sites. Rather, the Director has di scretion to require their us e if he/she determines

that the use of tracers could im prove monitoring of the site a nd enhance USDW protection from endangerment. The rule will also allow their use if proposed by the owner or operator and approved by the Director.

EPA has been following new and ongoing research on the safety and efficacy of tracers, and believes that, in some circumstances, tracers can be an effective part of monitoring GS projects.

EPA will continue to track research related to tra cer use and plans to, every six years, collect and review data on GS projects to determine wh ether the appropriate amount and types of information and appropriate documentation are being collected, and to determine if modifications to the requirements are appropriate or necessary.

Letter ID: 0186 Comment ID: 25199 Letter Lines: 371 to 380

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

Comment Code: 4520 2.5.1 Continuous internal mechani cal integrity monitoring (seeking comment)

Comment: III A. 5 Proposed Mechanical Integrity Testing Requirements

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

19NYSDEC-DMN Response: NYSDEC-DMN supports EPA’s proposal to require operators of GS projects to monitor internal mechanic al integrity by continuously monitoring injection pressure, flow rate, and injected volumes, as well as annular pressure and fluid volume to provide early detecti on of anomalies that may indicate an internal leak. However, an "alarm" should shut in the well at the surface rather than requiring the installation and use of a downhole shut-off valve.

Individual Response: EPA acknowledges the comment and be lieves that continuous pressure monitoring to demonstrate internal mechanical integrity of Cla ss VI wells required at §146.89(b), instead of periodic testing, which is required for most other types of deep injection wells is important given the potential corrosive impact of CO2 and impurities on well materials, the potential geomechanical impacts to well inte grity due to CO2 phase changes, and the temperature and pressure effects associated w ith injecting supercritical CO2. For additional information, please see the discussion of MITs in the final rule preamble.

To meet the requirements at §146.88(e), Class VI wells will be equipped with some type of continuous computer-based monito ring device that will be connect ed to alarms and the shut-off system. EPA does not believe it is necessary to speci fy what type of equipment is to be used to trigger the shut-off system. Instead, the regulation allows the owner or oper ator some flexibility in deciding what equipment and alarms should be inst alled to allow site spec ific flexibility and to make use of improvements in technology. The te chnology for continuous monitoring is available and is currently in fairly wide use. The comb ination of computer-dri ven continuous pressure monitoring linked to an automa tic injection shut-off provides maximum protection of USDWs from endangerment and provides the earliest warni ng to owners or operators that well repairs need to be performed.

Letter ID: 0186 Comment ID: 25200 Letter Lines: 384 to 392

Comment Code: 4520 2.5.1 Continuous internal mechani cal integrity monitoring (seeking comment)

Comment Code: 4546 2.5.2.2 MIT frequency (seeking comment)

Comment: BB. 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.

NYSDEC-DMN Response: As st ated above, NYSDEC-DMN suppor ts continuous monitoring of internal mechanical integrity for GS injection wells. For external MITs, the frequency should be more or less annually depending upon the specific circumstances. The types of tests allowe d should be those appropriate under the specific circumstances.

Individual Response: EPA agrees with commenter regarding the importance of demonstrating internal mechanical integrity (MI). The final GS rule retains the re quirement for continuous pressure monitoring of Class VI wells to demons trate internal mechani cal integrity and annual

20external MITs.

EPA believes that the annual external mechanical integrity testing is appropriate for GS wells. EPA retains the requirement that owners or operators of Class VI wells demonstrate injection well external mechanical integrity at least once annually. See §146.89(c). EPA believes this is justifiable for the protection of USDWs from endangerment given the unique nature of CO2 GS relative to other injection opera tions, including the potential co rrosive impact 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 natu re of the 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.

EPA believes that the MITs described in the ru le at 146.89 are effective methods and have been used successfully by injection well operators for decades and provide an important early warning of potential problems in the injection well system.

EPA clarifies that the regulati ons at §148.89(e) allow the Director 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 site or the we ll. For additional information, please see the discussion of MITs in the final rule preamble.

Letter ID: 0186 Comment ID: 25201 Letter Lines: 396 to 404

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

Comment: CC. EPA seeks comment on the requirement for monitoring of GS sites for the purpose of tracking the locati on of the CO2 plume and associated pressure front

over time.

NYSDEC-DMN Response: NYS DEC-DMN is in favor of the EPA requiring an operator to conduct ongoing and sufficient monitoring to allow the tracking the CO2 plume and associated pressure front. In addi tion to any regular reporting frequency, an operator should be required to provi de notification whenever actual conditions vary significantly from modeled predictions.

Individual Response: EPA agrees with commenters on the im portance of monitoring at GS sites and emphasizes that monitoring of injection activ ities will be an important component of every GS project. Monitoring associated with injecti on wells and the movement of the CO2 plume is necessary to verify that the injectate is confin ed in the target formations and does not endanger

USDWs.

EPA notes that the results of monitoring to track the plume a nd pressure front are to be incorporated into the reevaluation of the AoR, which must be conducted at least once every 5 years under §146.84(e). EPA expects the monitoring result s to be used to refine the AoR model.

21Letter ID: 0186 Comment ID: 25202 Letter Lines: 408 to 414

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

Comment: DD. EPA seeks comment on the use and freque ncy of pressure fall-off testing for

GS wells.

NYSDEC-DMN Response: NYS DEC-DMN is unclear as to the actual utility of pressure fall-off testing for operational GS wells. Instead of being mandated at least once every five years, the Director should have the discretion to require such testing as deemed appropriate.

Individual Response: EPA believes that pressure fall-off testing is necessary for GS wells. Pressure fall-off tests are designe d to verify that modeled proj ections of reservoir pressure decline agree with measured pressure decline profiles. These tests can be useful in AoR

calculations and reevaluations and may also indicate mischaracter ization of site geology and the presence of leakage pathways. EPA therefore believes that pressure fall-off testing must be conducted at least once every five years and the fi nal GS regulation includes this requirement at §146.90(f). Pressure fall-off tests may be conducted in conjunction with other well performance tests (i.e., mechanical integrity testing) to ensure safe and effective operations.

EPA believes that a frequency of at least once every five years, as specified at §146.90(f), is an appropriate interval for pressure fall-off testing (particularly gi ven the suite of tests operators will perform on the well and the site). EPA clarifies that the Director may require more frequent pressure fall-off tests at a sp ecific project, if necessary base d on site-specific circumstances. Pressure fall-off tests may be conducted in conj unction with other well performance tests (i.e., mechanical integrity testing) to ensure safe and effective operations . All monitoring data collected, including information from pressure fall-off tests, will be incorporated in AoR

reevaluations conducted at le ast every five years.

Letter ID: 0186 Comment ID: 25203 Letter Lines: 418 to 431

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

Comment: EE. 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.

NYSDEC-DMN Response: NYSDEC- DMN agrees that tracking of the CO2 plume and pressure front is important and shoul d be required. However, the exact methodology should not be specified but de termined on a site-specific basis. NYSDEC-DMN also agrees with EPA’s statem ent "As such, allowing flexibility in

22choosing 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."

Individual Response: EPA agrees with commenters that an effective monitoring plan will need to consider site-specific conditi ons. The final rule (at §146.90(g)) re quires owners or operators to perform monitoring to track the extent of the CO2 plume and pressure front. The owner or operator must use direct methods to monitor for pressure changes in the injection zone. Indirect methods (e.g., seismic, electrical, gravity, or electromagnetic surveys and/or down-hole CO2 detection tools) are required un less the Director determines, ba sed on site-specific geology that such methods are not appropriate.

EPA believes that this approach provides flexibility to develop a site-specific monitoring plan, ensures that direct monitoring is available to track movement of the CO2 and validate models, and recognizes that indirect techniques are no t appropriate in all s ituations. 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.

EPA believes that pressure monitoring in the injection zone is necessary to track the development and movement of the pressure front and CO2 plume, and, for this reason, all GS well owners or operators must use direct met hods to monitor for pressure changes in the injection zone, as requ ired at §146.90(g)(1).

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

Letter ID: 0186 Comment ID: 25204 Letter Lines: 435 to 443

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

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

Comment: FF. EPA seeks comment on the appropriate amount and types of monitoring that

should

be conducted at a GS site.

NYSDEC-DMN Response: NYS DEC-DMN agrees with EPA’s pr oposal to require operators to report semi- annually on the characteris tics of injection fluids, injection pressure, flow rate, temperature, vol ume and annular pressure, and on the results of MITs, ground water monitoring, and any required atmospheric/soil gas

23monitoring. However, the amount and types of monitoring to be required 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 flexibility in: 1) methodologies used to co llect these data, 2) the spatial resolution at which the data should be co llected, and 3) how often the data should be collected. The number and placement of monitoring wells will be based on site-specific information such as the calculated AoR, inject ion rate and volume, site geology, baseline data, and the presence of artificial penetrations within the AoR. In some instances, there may be a limited number of options for complying with EPA's minimum requirements. For example, monitoring for geochemical changes will require use of monitoring wells and collection of groundwater samples for chemical analysis. Many options currently exis t for complying with other requirements, such as tracking the positio n of the plume and pressure front within the injection zone.

Flexibility is also provided re garding how to monitor for the sp ecific data required by the final rule. The testing and monitoring plan is develope d by the owner or operato r in consultation with the Director and is designed to ensure that a detailed, Director-approved 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.

EPA is retaining the semi-annual reporting requirements as proposed at §146.91(a). These requirements ensure the Director has the informati on needed to take preventive action in a timely manner to protect 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 reporting on all wells in a GS project at the same time; however, data for each well must be reported separately and at least as frequently as required at §146.91. For additional information, please see the final rule and the prea mble for a discussion of EPA's final approach to recordkeeping and reporting.

EPA agrees that some monitoring types and fr equencies (e.g., associated with ground water monitoring and plume tracking) will be site-specific. These activities must be established in the approved testing and monitoring plan, which will be incorporated as a condition of the Class VI permit.

24Letter ID: 0186 Comment ID: 25205 Letter Lines: 447 to 457

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

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

Comment: GG. Specifically, EPA seeks comment rega rding the usefulness of indirect geophysical monitoring and surface air and soil gas monitoring.

NYSDEC-DMN Response: NYS DEC-DMN agrees with EPA’s pr oposal to require operators to report semi- annually on the characteris tics of injection fluids, injection pressure, flow rate, temperature, vol ume and annular pressure, and on the results of MITs, ground water monitoring, and any required atmospheric/soil gas monitoring. However, the amount and types of monitoring that ar e required should be site specific. Certain geophysical monitoring techni ques that successfully monitor plume migration in the southern states may not have any monitoring capability in northern Paleozoic basins.

Individual Response: EPA agrees with commenters and believ es that flexibility is important in developing and implementing a monitoring plan that is appropriately tailored for a specific GS site. The purpose of the requirement at §146.90 to develop site-specific testing and monitoring plans is to ensure that the monitoring performe d at a site is appropria te for site operational conditions and the geologic setting. EPA believes th at this is the best approach for addressing potential risks at GS sites. These flexible provisions in the monitoring requirements for Class VI wells enable the owner or operator to tailor monitoring programs to the specific needs of each project in consultation with the Director.

EPA clarifies that the final ru le, at §146.90(g)(2), requires owne rs or operators to track the position of the CO2 plume using indirect met hods (e.g., seismic, electrical, gravity, or electromagnetic surveys and/or down-hole CO2 detection tools), unl ess the Director determines based on site-specific geology, that such met hods are not appropriate. EPA is affording Director's discretion regarding the use of geophys ical techniques at some sites because the Agency recognizes that geophysical methods are not appropriate in all geologic settings. For example, geophysical methods are difficult to ex ecute in areas that are structurally and topographically complex or where lithologies have limited contrast in density, porosity, permeability, and other physical properties. EPA clarifies that this determination will be made by the Director based on the site-specific geologi c information submitted by the owner or operator with their permit application.

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 plan must include the site-specific details, technologies, testing and monitoring freque ncies, and other pertinent information.

As described above EPA is retaining the requ irement at §146.91(a) for semi-annual reporting of

25monitoring and operational data. 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: 0186 Comment ID: 25206 Letter Lines: 461 to 465

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

Comment: HH. In addition, EPA seeks comment regard ing the use of a Di rector-approved monitoring plan for GS sites.

NYSDEC-DMN Response: The Dire ctor should be given flex ibility to approve sitespecific monitoring plans.

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. The testing and monitoring plan must be approved by the Director. EPA is developing guidance on testing and monitoring to assist owners or operators and Director s in evaluating requirements under §146.90, including proposed monitoring plans. The guidance descri bes available technol ogies and recommended approaches for implementing a testing a nd monitoring plan, including pre-operational geophysical logging and testing of injection wells, MITs, injecti on well testing during operation, groundwater quality monitoring, tracking the CO2 plume and pressure front, and soil gas and surface air monitoring which may be required by the UIC Director fo r 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: 0186 Comment ID: 25207 Letter Lines: 469 to 475

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

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

NYSDEC-DMN Response: NYSDEC- DMN believes monitoring and testing plans, an AoR and corrective action plan, and a post-inject ion site care and site closure plan are integral components of any GS app lication, and should be required by the

EPA.

Individual Response: EPA agrees that incorporating the plans into the permit rather than

26establishing 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. EPA belie ves that the Director needs a satisfactory level of assurance that the owner or operator has pl anned for these events before injection commences and that the owner or operator has ensured that appropriate financial reso urces are 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 anticipates that the requirement for this and other plans associated with GS proj ects will promote an ongoing dialogue between the owner or operator and the Director to ensure USDWs are protected from endangerment and the owner or operator is complying the Class VI permit. In addition, these plans will support a demonstration that owners and operators have ad equate financial resources to meet well plugging and post-injection site care a nd site closure requirements. Pl ease see the final rule and the discussion of the GS project plans in the preamble fo r additional information.

Letter ID: 0186 Comment ID: 25208 Letter Lines: 479 to 482

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

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

NYSDEC-DMN Response: NYSDEC- DMN supports all stated re porting frequencies and requirements.

Individual Response: The final GS regulation retains the reporting requirements as outlined in the proposed rule and does not include a requ irement for an annual report. For additional information, please see the final rule and the prea mble for a discussion of EPA's final approach to recordkeeping and reporting.

The semi-annual reporting required at §146.91(a) includes both operational data and data required as part of the testing and monitoring pl an, satisfying many of the concerns expressed by commenters who supported the annual report.

Letter ID: 0186 Comment ID: 25209 Letter Lines: 486 to 492

Comment Code: 4740 2.7.4 Electronic reporting (seeking comment)

Comment: KK. EPA seeks comment on the requiremen t for electronic repor ting in today’s proposed rule.

NYSDEC-DMN Response: NYS DEC-DMN agrees with electronic submittal in principle as long as there is sufficient flexibility to allow states to utilize existing or

27preferred state data processing systems or software. At this time, 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: 0186 Comment ID: 25210 Letter Lines: 496 to 501

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

Comment: LL. 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.

NYSDEC-DMN Response: NYS DEC-DMN agrees with the concep t and sees the merits of requiring an annual report that provides a narrative analysis of GS operations in addition to requiring semi -annual reporting of data.

Individual Response: The final GS regulation retains the reporting requirements as outlined in the proposed rule and does not include a requir ement for an annual report. 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 necessary based on the AoR reevaluation or other data collected during well operations, will prom ote an ongoing relationship between the permitting authority and the owner or operator. The final GS rule, at §§146.84(c), 146.90(j), and 146.94(d), requires owners or operators to review and update the AoR and correc tive action plan, the testing and monitoring plan, and the emergency and remedial response plan thr oughout the life of the project. Owners or operators must review each plan and identify necessary amendments to the plan or demonstrate to the Di rector that no amendment is needed. These reviews must be

28performed within one year of an AoR reeval uation, following any significant changes to the facility (e.g., the additio n of monitoring or injection wells), or when required by the Director. In

no case can reviews occur less often than once ev ery five years. For additional information, please see the final rule and the preamble fo r a discussion of EPA's final approach to recordkeeping and reporting.

The semi-annual reporting required at §146.91(a) includes both operational data and data required as part of the testing and monitoring pl an, satisfying many of the concerns expressed commenters who supported the annual report.

Letter ID: 0186 Comment ID: 25211 Letter Lines: 503 to 518

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

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

MM. EPA requests comment on the proposed use of a tentative 50-year fixed

timeframe that could be modified at the Director’s disc retion based on monitoring and modeling data.

NYSDEC-DMN Response: Given th at current injection and re servoir behavior data demonstrates a decreasing risk of leakage after injection ceases, NYSDEC-DMN believes that a 50-year default time frame for post-injection site care is too long and that a 30-year starting period ma y be more appropri ate to allow GS projects to move forward. It would be bett er to prescribe a shorter period with discretion to go longer, rather than vice versa, as such would better facilitate project planning. Regardless, it is cr itical that the Dire ctor have the

discretion to increase or decrease the period base d on the specifics of a particular project.

Individual Response: EPA disagrees that a post-injection si te care timeframe of 50 years is excessive for most Class VI wells. EPA proposed a default post-injection s ite care timeframe of 50 years based on a review of research studies , industry reports, and existing environmental programs. This analysis was included in an EPA- prepared background document that is available in the federal docket, titled "Computationa l Modeling of Underground Injection of Carbon

Dioxide for Determination of Area-of-Review a nd Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public commen ts. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided suffi cient data or other evidence to warrant a change in the proposed timeframe. While the 10- or 30-year timeframe suggested by some of these commenters may be within the timeframe suggested in some studies, EPA believes that the potential risks of endange ring USDWs will likely no t decline within these timeframes and available data, including da ta submitted by commenters, do not support a different default timeframe. However, EPA r ecognizes that alternative timeframes may be appropriate under limited, specific circumstances.

29For 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 however, that to ensure USDW protection from enda ngerment, a default timeframe for post-injection site care will be necessary in al l but a limited number of cases. This default 50 year post-injection site care ti meframe represents a reasonable and protective monitoring period based on a review of research studies, industr y reports, and existing environmental programs, and evaluation of public comments.

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

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

Letter ID: 0186 Comment ID: 25212 Letter Lines: 523 to 535

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

Comment: NN. 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.

NYSDEC-DMN Response: Given th at current injection and re servoir behavior data demonstrates a decreasing risk of leakage after injection ceases, NYSDEC-DMN believes that a 50-year default time frame for post-injection site care is too long and that a 30-year starting period ma y be more appropri ate to allow GS projects to move forward. It would be bett er to prescribe a shorter period with discretion to go longer, rather than vice versa, as such would better facilitate project planning. Regardless, it is cr itical that the Dire ctor have the

discretion to increase or decrease the period base d on the specifics of a particular project.

Individual Response: EPA disagrees that a post-injection si te care timeframe of 50 years is excessive for most Class VI wells. EPA proposed a default post-injection s ite care timeframe of 50 years based on a review of research studies , industry reports, and existing environmental

30programs. This analysis was included in an EPA- prepared background document that is available in the federal docket, titled "Computationa l Modeling of Underground Injection of Carbon

Dioxide for Determination of Area-of-Review a nd Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public commen ts. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided suffi cient data or other evidence to warrant a change in the proposed timeframe. While the 10- or 30-year timeframe suggested by some of these commenters may be within the timeframe suggested in some studies, EPA believes that the potential risks of endange ring USDWs will likely no t decline within these timeframes and available data, including da ta submitted by commenters, do not support a different default timeframe. However, EPA r ecognizes that alternative timeframes may be appropriate 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 however, that to ensure USDW protection from enda ngerment, a default timeframe for post-injection site care will be necessary in al l but a limited number of cases. This default 50 year post-injection site care ti meframe represents a reasonable and protective monitoring period based on a review of research studies, industr y reports, and existing environmental programs, and evaluation of public comments.

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

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

Letter ID: 0186 Comment ID: 25213 Letter Lines: 540 to 553

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

Comment: OO. 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-injec tion period if data suggests the time frame should be adjusted.

31NYSDEC-DMN Response: Given th at current injection and re servoir behavior data demonstrates a decreasing risk of leakage after injection ceases, NYSDEC-DMN believes that a 50-year default time frame for post-injection site care is too long and that a 30-year starting period ma y be more appropri ate to allow GS projects to move forward. It would be bett er to prescribe a shorter period with discretion to go longer, rather than vice versa, as such would better facilitate project planning. Regardless, it is cr itical that the Dire ctor have the

discretion to increase or decrease the period base d on the specifics of a particular project.

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

EPA believes however, that to ensure USDW protection from enda ngerment, a default timeframe for post-injection site care will be necessary in most cases. The default 50 year post-injection site care timeframe represents a reasonable and prot ective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public

comments.

As described above, EPA disagrees that a post -injection site care timef rame of 50 years is excessive for most Class VI wells. EPA proposed a default post-injection s ite care timeframe of 50 years based on a review of research studies , industry reports, and existing environmental programs. While the 10- or 30-year timeframe suggested by some of these commenters may be within the timeframe suggested in some studies, there are circumstances (e.g., little development of mineral trapping of CO2) under which the po tential risks of endangering USDWs will likely

not decline within these timefra mes and available data, including data submitted by commenters, do not support a different default timeframe.

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.

Letter ID: 0186 Comment ID: 25214 Letter Lines: 557 to 574

32Comment Code: 5430 2.9.1 Comments on proposed financia l responsibility requirements (40 CFR 146.85)

Comment: PP. EPA is requesting comments on whether fi nancial 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 responsibili ty mechanisms should be considered, all subject to EPA’s authority under the SDWA.

NYSDEC-DMN Response: The EPA proposed rule for financial assurance appears to be adequate with respect to wells and NYSD EC-DMN understands that any well plugging

financial instrument would be released upon proper plugging and abandonment of

the well. It is also understood that a sec ond tier of financial assurance, that could be filed at a later date (i.e., cl oser to ceasing injection), is being considered for post-injection site care . However, according to the proposed rule, both forms of financia l assurance would be limited to SDWA authority which does not extend to financial responsib ility for activities unrelated to protection of USDWs (e.g., coverage of ri sks to air, ecosystems, or public health unrelated to USDW endangerment). Because of EPA’s focused authority under the SDWA for the UIC program, action by i ndividual states may be required to fill any financial assurance and regulatory gaps.

Individual Response: EPA agrees that assuring financial responsibility for co rrective action of Class VI wells in the AoR, injection well plugg ing, PISC and site clos ure, and emergency and remedial response at GS sites is an important component of ensuring that USDWs are protected.

EPA clarifies that financial assurance for post-inj ection site care and site closure can be obtained separately from that for well plugging; however, financial responsibility for post-injection site

care and site closure must be dem onstrated at the time the permit application is filed. Please note that the rule requires the owner or operator to adjust the cost estimates of the financial instrument to address any amendments to the AoR and co rrective action plan, th e injection well plugging plan. Within 60 days after the Director has appr oved any modification to the plan(s), the owner or operator must review and update the cost es timate for well plugging, PI SC and site closure, and emergency and remedial response to accoun t for any amendments to the permit plans listed above. See the final rule and preamble for further discussion of EPA's final approach to financial responsibility.

EPA confirms that its authority to require financial responsibility is limited to that allowed by the SDWA as part of the UIC program . Financial responsibility and lia bility for activities unrelated to the protection of USDWs is outsi de the scope of this rulemaking.

Letter ID: 0186 Comment ID: 25215 Letter Lines: 578 to 598

Comment Code: 5436 2.9.1.3 Allowing separate financial demonstrations for plugging and abandonment and post-injection si te care (seeking comment)

33Comment: QQ.The Agency is also re questing comment on allowi ng separate financial

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

NYSDEC-DMN Response: EPA’s proposal for financial assurance appears to be adequate with respect to wells and NYSD EC-DMN understands that any well plugging

financial instrument would be released upon proper plugging and abandonment of

the well. It is also understood that a sec ond tier of financial assurance, that could be filed at a later date (i.e., cl oser to ceasing injection), is being considered for post- injection site care. EPA states that it is considering requiring well plugging financial demonstr ation at permit issuance and postinjection site care financial security demonstration at a later time (e.g., within 180 days of notifying the Director that the well will be plugged and abandoned). EPA also states "Trying to determine the cost for post-injection site care, possibly 30 to 50 years in the future, could be difficult, as could the approval of a financial demonstration." It is NYSDEC-DMN’s opinion that some level of financial assurance for post-site injection care should be in place at first injection of CO2. If there are co ncerns with uncertainty and overly burdening an operator, perhaps the amount of post-injection site care assurance

could start with a basic leve l of protection and be requi red to be increased as the potentially affected area grows over time with additional injection.

Individual Response: EPA agrees that an initial financia l responsibility demonstration at the time of permitting is appropriate. In the final rule, owners or operators are required to demonstrate, with their permit applications, adequate financial responsibility for all GS activities that require financial responsibility, at §146.82(a )(14). This will ensure that resources are available to prevent the endangerment of USDW s in the event that the owner or operator experiences financial difficulties at any time during the life of the GS project.

The final GS rule, at §146.85(c), also requires the owner or operator to provide annual updates to the cost estimate to account for any amendments to the AoR and corre ctive action plan, the injection well plugging plan, the PISC and site closure plan, and the emergency and remedial response plan. Owners or operators must also ad just the estimates for inflation annually under §146.85(c)(2). EPA adds that the Director can also require the owner or operator to provide an adjustment of the cost estimate if the Director determines that the original demonstration is no longer adequate, as sp ecified at §146.85(e).

In order to assist owners or operators and financial instituti ons in achieving accurate cost estimates for all GS activities, EPA plans to i ssue financial responsibil ity guidance that will

include a discussion of how best to estimate cost s, including how to adjust cost estimates for inflation to account for the long- term nature of GS projects, in its guidance on meeting 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.

Letter ID: 0186 Comment ID: 25216 Letter Lines: 603 to 613

34Comment Code: 5520 2.10.1 Appropriateness of existing p ublic participation requirements (Part 25 and Part 124) for GS (seeking comment)

Comment: RR. EPA requests comment on adopting th e existing requirements for public participation at 40 CFR Part 25 and 40 CFR Part 124 and whet her 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.

NYSDEC-DMN Response: All states have publ ic 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 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 st ringent as those require d under Part 124. This requirement should provide a level uniformity be tween primacy states for purposes of providing public notice for GS wells.

Letter ID: 0186 Comment ID: 25217 Letter Lines: 618 to 624

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

35Comment: SS. EPA is seeking comment on the merits and possible disadvantages of allowing primacy approval for Class VI wells i ndependent of other well classes.

NYSDEC- DMN Response: NYSDEC- DMN supports the creation of a separate class VI for GS wells and strongly supports allowi ng state primacy solely for Class VI. In addition, states should have the author ity to designate which agency in the state can apply for and be granted primacy.

Individual Response: As described above, EPA agrees with commenters that states should be allowed to obtain primacy for Class VI wells inde pendently of other well classes, and will allow independent primacy for Class VI wells under §145.1(i) of the final GS rule.

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: 0186 Comment ID: 25218 Letter Lines: 628 to 632

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

Comment: TT. 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.

NYSDEC-DMN Response: NYS DEC-DMN agrees with the EPA proposal.

Individual Response: EPA agrees with commenters. The final rule maintains the lifetime permit provision and clarifies th at the permit extends through the pos t-injection site care period (144.36(a)). However, it also adds a requirement that the Director review each Class VI permit at

3637 least every 5 years to determine whether it should be modified, revoked and reissued, terminated 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’ itera tive reevaluation of the project. Specifically, the final rule includes a requirement that the AoR be reevaluated at least every five years, and also requires owners or operat ors to review and update the Ao R and corrective action plan, the testing and monitoring plan, and the emergency and remedial res ponse plan thr oughout the life of the project (146.84(e), 146.90(j), and 146.94(d)). Own ers or operators must review each plan and identify necessary amendments or demonstrate to the Director that no amendment is needed.

In no case can reviews occur less often than once every five years. The iterative process and subsequent plan reevaluations ensure that time and resources are committed to the most critical aspects of the permit in preven ting endangerment to USDWs.

EPA believes that the iterative process of develo ping and executing the va rious plans required of GS well operators in the final rule (e.g., for AoR and corrective action, testing and monitoring, well plugging, and post-injection site care, and emergency and remedi al response) is tailored to the unique aspects of—and is more appropriate fo r–GS than establishing a finite permit duration (e.g., five years as suggested by some commenters).