2.7

– 2.8

– Responses to Public Comments on Recordkeeping, Reporting, Injection
Well Plugging, Post Injection Site Care, and Site Closure

This file contains responses to public comments on recordkeeping, reporting, i njection

w ell plugging, p ost injection s ite care, and s ite c losure ( c omment co des 4700 to 5300 ).

This section i ncludes comments on submissions required for permit applications,
operational recordkeeping, and electronic reporting

. It also includes comments on
requirements for closing and maintaining the site after injection has ceased.

The table below presents all of the EPA

- assigned comment codes that are included in

this section of the comment and response summary . Use the book marks in the PDF to
move among the comment codes

.

Topics included in this summary and associated comment codes

Topic Code

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

2.7.1 Proposed submissions required for permit applications 4710

2.7.2 Operational recordkeeping and reporting 4720

2.7.3 Reporting associated with closure and post

- injection site care 4730

2.7.4 Electronic reporting 4740

2.7.5 Comments on the merit of annual reports 4750

2.7.6 Proposed reporting frequency 4760

2.8 Proposed Well Plugging and Post

- Injection Site Care Requirements 5000

2.8.1 Injection well plugging activities (40 CFR 146.92) 5100

2.8.2 Post injection s ite care (40 CFR 146.93) 5200

2.8.2.1 Post

- injection monitoring activities 5220

2.8.2.2 Post injection timeframe 5240

2.8.2.3 Adjusting the post

- injection timeframe 5260

2.8.2.4 USDW non

- endangerment demonstrations 5280

2.8.3 Site closure activities (40 CFR 146.93) 5300

Every comment on these topic areas and the associated response is included in this
summary; there is some repetition where multiple commenters made the same

comment.

R esponses to letters from individual commenters or organizations are also available in

the rulemaking docket.Comment Code: 4700 2.7 Proposed Recordkeeping and Reporting Requirements (40 CFR 146.91)



### Individual Comments

Commenter Name: Dwight Lockwood, PE, QEP Letter ID: 0141 Commenter Organization: Global Energy, Inc. Comment ID: 23121 Other EPA Comment Codes and Descriptions: 4546 2.5.2.2 MIT frequency (seeking comment)

Comment: 6.We support mechanical integrity testing and monitoring, in some respects (on a continuous basis). Sensors and data logging is readily available. Semi-annual reporting, along with other reporting requirements, is also quite reasonable.

Response: EPA agrees with the commenter regarding the importance of demonstrating internal mechanical integrity (MI). EPA agrees with the commenter that continuous pressure monitoring of GS wells, instead of periodic testing, which is required for most other types of deep injection wells is appropriate because the potentially corrosive nature of CO2 injectate streams in the presence of water enables the immediate identification of corrosion-related internal mechanical integrity problems that could lead to significant well problems and failure.

Continuous monitoring was found to be very important in an EPA study of UIC Class I internal MIT failure rates and causes (USEPA 1993). The study reviewed MIT results over a 5 year period and found 135 MIT failures in 428 wells (a single well can have more than one MIT failure). In all cases, the MIT failures were found through continuous annulus monitoring which served the important role of an early warning to prevent any well failure. Class VI injection wells will be equipped with dedicated computer-based continuous pressure monitoring devices in concert with the shut-off systems required for GS wells, which typically take readings several times per second and record them electronically in a computer system. §146.91(a)(2) requires that monthly averages of the continuous annulus monitoring be reported on a semiannual basis.

EPA is retaining the semi-annual reporting requirement in the final rule at §146.91(a) in order to ensure that permitting authorities can maintain proper oversight of GS projects, particularly in the early stages of rule implementation and deployment of GS technologies. The Agency also clarifies that permitting authorities may choose to require more frequent reporting, at the discretion of the

Director.

Commenter Name: James Dooley Letter ID: 0156 Commenter Organization: Joint Global Change Research Institute, Pacific Northwest National Laboratory Comment ID:

22654 Other EPA Comment Codes and Descriptions: 5500 2.1 Comments on Involving the Public in Permitting Decisions

Comment: Page 43528. The proposed Class VI rule states "The information gathered as a result of this proposed rule" allows the Agency to verify throughout the life of the injection project that UIC protective requirements are in place and that USDWs are protected. At the end of the day, this is indeed the figure of merit. Does this rule allow for sufficient exchange of information between the owners/operators of GS projects and regulators and stakeholders (?). This reviewer is not convinced that this metric is satisfied by the proposed rule.

Response: EPA agrees that interaction between the owner or operator and the Director is animportant part of ensuring that GS projects are operated in a manner that protects USDWs from endangerment. EPA believes that the site-specific GS project plans which will be reviewed and approved by the Director and periodically updated throughout the life of the project—promote an ongoing dialogue between the operator and the Director that will encourage use of the most appropriate technologies for a particular project.

EPA encourages (but does not require) operators and permitting agencies to begin involving the public by providing information as early in the GS project development process as possible. Involving the public in the permitting process is an important aspect of both UIC Program requirements and EPA's overall mission. The public will also have the opportunity to submit written comments and, in many cases, attend hearings on proposed GS projects during formal public comment periods. Although permit application information will not be made available as it is submitted, permitting authorities must follow the public participation requirements for UIC permits specified in 40 CFR Part 124 which require that owners or operators publish a public notice that includes information about where interested parties can obtain copies of the draft permit and application in addition to requesting a public hearing.

Furthermore, the Agency recognizes that the initial phases of site evaluation and site selection may begin in advance of permit application submission. The public may become aware of these activities and begin to have questions or concerns about the pending project. For this reason, outreach and education—which are outside of, but complementary to, the public notification process—can help clarify project details and avoid public misperceptions about the nature and safety of GS projects. This may also benefit the owner or operator by improving local acceptance of the site. EPA also notes that should changes to these plans require a permit modification under §144.39, the public must be notified according to the public comment procedures under 40 CFR 124.

In addition, EPA is evaluating options for a centralized data system through which the public could have access to public information on a GS project. EPA will also provide access to any required plan to the public upon request. Providing the public with information throughout the GS project will help clear up and avoid public misperceptions about the nature and safety of GS.

Commenter Name: Frederick R. Eames Letter ID: 0178 Commenter Organization: CCS Alliance Comment ID: 23844

Comment: A. GENERAL COMMENTS

The application and reporting requirements for Class VI wells should be balanced, placing as little burden as possible on owners and operators, while also achieving EPA's goals. Sufficient reporting requirements ensure the collection of information necessary for the protection of human health and the environment, and provide companies and investors with information to better manage and mitigate risks. A robust but not overly burdensome reporting regime is necessary to the success of CCS. as well as to achieving EPA's goals of protecting USDWs.

Response: EPA believes that all of the requirements for Class VI wells, including the reporting and recordkeeping requirements, are necessary to ensure that GS is conducted in a manner that protects USDWs from endangerment. The requirements for GS projects are tailored to address the unique issues associated with GS including large injection volumes, the relative buoyancy of CO2, its corrosivity in the presence of water, the potential presence of impurities in captured CO2, and itsmobility within subsurface geologic formations. Because these requirements are necessary to protect USDWs from endangerment, they are in effect not overly burdensome to the owner or operator.

The final GS rule affords flexibility to owners or operators. Many of the permit requirements will be established through site-specific plans developed by the owner or operator and approved by the

Director.

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

Commenter Name: John R. Baza Letter ID: 0193 Commenter Organization: Utah Division of Oil, Gas, and Mining Comment ID: 23915 Other EPA Comment Codes and Descriptions: 4600 2.6 Proposed Plume and Pressure Front Monitoring Requirements (40 CFR 146.90)

Comment: Monitoring

EPA seeks comments on proposed pressure plume and pressure front monitoring including issues such as the amount and type of monitoring, the usefulness of geophysical, air and soil monitoring, post-injection site monitoring, and frequency of reporting requirements. The IOGCC comments of December 23, 2008 have addressed all of these issues in great detail, and the Division concurs

with their recommendations.

Response: Based on its evaluation of all public comments and input on the proposed rule and NODA and Request for Comment, EPA has made many revisions to the GS Rule. See the final rule and preamble for further discussion on EPA's final approach.

EPA agrees with commenters that developing and following testing and monitoring plans is an important part of assuring that a GS project is operating properly and is crucial for the early detection of potential endangerment to USDWs. EPA also agrees that periodic updates to the plan are appropriate. EPA clarifies that the final GS regulation includes a requirement that the AoR be reevaluated at least every five years, and it specifies at §146.90(j) that the operator revise the testing and monitoring plan to incorporate the results of the most recent AoR reevaluation and recent operational and monitoring data.

EPA acknowledges the comment and the final rule retains the text as proposed. Please see the final rule and the discussion of testing and monitoring in the preamble for additional information.

Commenter Name: Neeraj Gupta Letter ID: 0229 Commenter Organization: Battelle Energy Technology (BET) Comment ID: 21861

Comment: Page 111-118, Reporting- More streamlined permit application structure and clearly defined information requirements should be provided in regulatory guidance. We request streamlined reporting (Monitoring and testing plan, AOR/Corrective action review plan, post-injection plan, annual report, monthly operating reports).Response: EPA disagrees with the suggestion that the permit application structure be more streamlined and information requirements be more clearly defined. EPA believes that information required to be submitted with the permit application under §146.82 is necessary and appropriate to provide permitting authorities sufficient basis for informed decisions about establishing permit conditions and granting permits. The purpose of these requirements is to protect USDWs from endangerment, and all operations must be permitted and operated in manner that is protective of

USDWs.

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

Director.

Commenter Name: Mark Bohrer Letter ID: 0241 Commenter Organization: North Dakota Industrial Commission Comment ID: 23303

Comment: 146.91(a) Injection volumes and pressures should be reported monthly.

Response: The final rule remains unchanged from the proposal and requires semi-annual reporting of monthly average, maximum and minimum values for injection pressure, flow rate and volume, annular pressure, and monthly annulus fluid volume added at §146.91(a). EPA believes that monthly reporting of routine operational data and monitoring results would provide no additional protection of USDWs from endangerment. EPA adds, at §146.91(c), that it has included in the final rule a requirement that operators must report within 24 hours of any event that may endanger USDWs; noncompliance with a permit condition or malfunction of injection system which triggers fluid movement; any triggering of a shut-off system; any failure to maintain mechanical integrity; or if anything is detected through surface/air monitoring, if its required. EPA notes that states seeking primacy for Class VI wells are free to require more frequent reporting.

Please see the final rule and the discussion of testing and monitoring in the preamble for additional

information.

Commenter Name: Walter L. Baker Letter ID: 0253 Commenter Organization: Utah Division of Water Quality Comment ID: 22353 Other EPA Comment Codes and Descriptions: 4740 2.7.4 Electronic reporting (seeking comment)

Comment: ELECTRONIC REPORTING

We agree with EPA that electronic reporting will reduce reporting burden and will facilitate tracking of CCGS projects. However, the "electronic format acceptable to the Director" should not constitute a financial or resource burden to the owner / operator or to the regulating agency required to report to EPA on UIC program activity. Until that time when the regulating agency has developed a data flow to the National UIC Database, we strongly urge EPA to develop an online service for submitting CCGS information such as is currently in place for submitting Program Activity Measures (PAMs) and UIC inventory.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 requires 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 changes to accommodate a new class of UIC well (Class VI), EPA believes that it is prudent to provide assistance by developing 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 operators 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 reviewing and approving permit applications rather than building or upgrading separate, independent

databases for GS information.

EPA is developing guidance for states that describes the recordkeeping, reporting, and additional data management needs associated with GS activities and provides recommended guidelines on the types of data to be collected for tracking GS projects, reporting 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.

Commenter Name: John McManus Letter ID: 0294 Commenter Organization: American Electric Power Comment ID: 25317 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3500 2.2.3 Area of Review Reevaluation (seeking comment)

Comment: In addition, we recommend the following new §146.95:

"146.95 Plan Maintenance and Update

"(a) Owners or operators must submit an annual statement, signed by an appropriate company official, confirming that the company has:

"(i) reviewed the monitoring and operational data that are relevant to a decision on whether to reevaluate the area of review and the monitoring and operational data that are relevant to a decision on whether to update a plan identified in §146.82(p) or (u) through (x) or the quality assurance plan for all testing and monitoring requirements; and

"(ii) determined whether any updates were warranted by material change in the monitoring and operational data or in the evaluation of the monitoring and operational data by the owner or operator.

"(b) Owners or operators must submit either the updated plan or a summary of the modifications for each plan for which an update was determined to be warranted pursuant to subsection (a) of this section. The Director may require submission of copies of any updated plans and/or additional information regarding whether or not updates of any particular plans are warranted.

"(c) The Director may require the revision of any required plan whenever theDirector determines that such a revision is necessary to comply with the requirements of this subchapter."

Response: EPA agrees with the commenter that review of the GS project plans is appropriate. The final rule includes provisions that owners or operators review and update the AoR and corrective action plan, the testing and monitoring plan, and the emergency and remedial response plan throughout the life of the project (these provisions are added at §146.84(c), §146.90(j), and §146.94(d)). Owners or operators must review each plan and identify necessary amendments to the plan or demonstrate to the Director that no amendment is needed. These reviews must be performed within one year of an AoR reevaluation, following any significant changes to the facility (e.g., the addition of monitoring or injection wells), or when required by the Director.

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



### Individual Comments

Commenter Name: George Holliday, PhD, PE, BCEE Letter ID: 0114 Commenter Organization: Holliday Environmental Services, Inc. Comment ID: 22518 Other EPA Comment Codes and Descriptions: 1670 1.3.7 Other/miscellaneous risks

Comment: required to see the project to completion. Further, the well designs and operations would be approved by Agency technically untrained employees, who are not Professional Engineers and supervised by a Regional Director who is neither an engineer nor a Professional Engineer.

The Agency proposes using untrained EPA employees who are not required to demonstrate their CO2 sequestration technical knowledge by completing and passing a written examination. Further, the Agency proposes to sequester

Response: As described above, EPA disagrees that the people designing and regulating wells lack technical training for effective oversight of Class VI wells. Most permitting authority staff have years of experience with the current UIC injection well classes and have relevant specialties in geology, engineering, and related disciplines. Injection well owners and operators represent industries with decades of experience injecting a variety of fluids, including CO2. EPA believes that this experience has led to the development of well materials and construction and operating procedures that are applicable to Class VI wells.

Commenter Name: George Holliday, PhD, PE, BCEE Letter ID: 0114 Commenter Organization: Holliday Environmental Services, Inc. Comment ID: 22521 Other EPA Comment Codes and Descriptions: 1670 1.3.7 Other/miscellaneous risks

Comment: The sequestration of CO2 represents a money-making scheme for a "political" pollutant, which will encourage unqualified organizations and speculators to seek Class VI injection permits. These unqualified organizations will find unqualified consultants to prepare documents supporting the permit applications. EPA, in the instant proposed rule, suggests several financial responsibility schemes to avoid unqualified organizations and speculators from creating a disaster, but EPA and states do not know how to assure financial responsibilityas demonstrated by the lack specificity within the proposed rule. Rules proposed with this lack of specificity, typically result in EPA selecting final rule wording, which received no comments during the proposal stage. This gives EPA free rein to select regulation wording not reviewed by the commenting public, and not alluded to during the proposal.

One of the most frightening aspects of the proposed rule is EPA imposes no technical qualification requirements on EPA review personnel. Thus, a well written, but inaccurate document, can easily be accepted by EPA, when technically unqualified reviewers are used. If qualified reviewers were used, the application would be rejected.

Response: As described above, EPA disagrees with the assertion that the staff reviewing permit applications does not have adequate technical knowledge to review and approve Class VI permits. EPA will be facilitating training on the GS rule requirements for states and Regional staff in addition to providing guidance on implementation of the Class VI UIC program.

EPA clarifies that the person who signs a permit application must certify that the application is accurate and that data was collected in accordance with a system designed to ensure that qualified personnel evaluate the data. EPA believes that assigning this responsibility to the signatories will ensure that the work has been properly supervised. Failure to meet this requirement would subject the owner or operator of the well to applicable civil, criminal, or administrative penalties under SDWA §1423.

EPA adds that owners or operators of Class VI wells must ensure that resources are available to prevent endangerment of USDWs from improper plugging, remediation, and management of wells. For this reason, the GS rule requires that owners or operators demonstrate and maintain financial responsibility for corrective action on wells in the AoR, injection well plugging, post-injection site care and site closure, and emergency and remedial response at GS sites as specified in §146.85. EPA has revised the requirements in the final rule to provide more specifics. In the event of contamination or other adverse event that endangers a USDW during the life of the GS project, the financial instrument(s), such as insurance, bonds, etc., rather than public monies, would cover necessary response actions.

EPA adds that Class VI well owners and operators must site, construct, operate, monitor, and close their wells in a manner that protects USDWs, and Class VI permits will set forth rigorous technical requirements to ensure careful planning, operation, and closure of GS projects.

EPA adds that the requirements in the final GS rule, including all changes from the proposed rule, are based on consideration of public comments received in response to the proposed rule and its subsequent Notice of data Availability and Request for Comment issued on August 31, 2009 (74 FR 44802).

Commenter Name: George Holliday, PhD, PE, BCEE Letter ID: 0114 Commenter Organization: Holliday Environmental Services, Inc. Comment ID: 22529 Other EPA Comment Codes and Descriptions: 1670 1.3.7 Other/miscellaneous risks

Comment: LACK OF QUALIFIED EPA PERSONNEL

EPA requests comments on many aspects of CO2. For example at 73 FR 43514, col.2, EPA request help learning to track CO2 underground plumes. I have worked

with the UIC rules as a commenter since 1979. At no time did EPA use an EPA Professional Engineer (P.E.) for developing the UIC rules. During the initial stages of writing the 1979 draft rules, EPA used an Ancient English graduate as the Agency lead technical supervisor. Ancient English is not considered a technical background.

I have not found any of the current EPA UIC Regional employees to be professional engineers. When I requested the information in writing from EPA, I was told privacy laws prohibited providing such information. Reviewing and understanding CO2 sequestration projects is a technically exacting task. Assigning an EPA non-Professional Engineer to this review task exposes the U.S. public to severe risk. Placing the final approval in the hands of a Regional Administrator, who traditionally is not an engineer, means the EPA is disregarding public safety. At a minimum, the reviewing engineer and Regional Administrator must be Professional Engineers. EPA at 40 CFR Part 112 requires a Professional Engineer certify a Spill Prevention, Control and Countermeasure (SPCC) Plan, which typically is intrinsically a simple non-technical document, but EPA does not rely on EPA Professional Engineers to review high pressure, corrosive fluid injection projects, that are highly technical and intrinsically

unsafe.

EPA has likened Class VI projects to Class I hazardous waste injection wells and Class II CO2 enhanced recovery wells. It is true Class I disposal wells sequester hazardous waste, but these wastes are not buoyant and typically are combined with other waste to make them non-corrosive. FURTHER, THE AGENCY HAS

BEEN REVIEWING CLASS II WELL PLANS SUBMITTED BY EXPERIENCED OIL AND GAS

COMPANY ENGINEERS. An anticipated shortage of trained oil and gas industry engineers (Bryant, 2007) and the political nature of CO2 sequestration projects ( www.wecansolveit.org) will attract spectators, who do not intend to see the project through to completion. Thus, the Agency may be forced to correct many problems caused by poor review and oversight on the part of the untrained EPA employees

Bryant, S., 2007. Geologic CO2 Storage - Can the Oil and Gas Industry Help Save the Planet? J Pet. Tech (JPT), p 98-105, September

Response: As described previously, most permitting authority staff have years of experience with the current UIC injection well classes and have relevant specialties in geology, engineering, and related disciplines. Additionally, EPA will coordinate with and assist states, e.g., through guidance and on-line and in-person training, to help them address problematic technical and policy issues.

Commenter Name: Leslie Savage Letter ID: 0122 Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24762 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3130 2.1.3 Comments that operators should submit more (or different) geologic data than proposed

Comment: (2) Location, orientation, and properties of known or suspected faults andfractures that may transect the confining zone (s)in the area of review and a determination that they would not interfere with containment;

(4) Data on the depth, areal extent, thickness, mineralogy, porosity, permeability and capillary pressure of the injection and confining zone (s) ; including geology/facies changes based on field data which may include geologic cores, outcrop data, seismic surveys, well logs, and names and lithologic descriptions;

Response: EPA believes that the plural for injection zone(s) should be retained in the Final Rule in recognition of the fact that more than one injection zone may be used at some GS sites. EPA believes that in some geologic settings, the presence and identification of additional confining and containment zones above the primary (i.e., lowermost) confining zone can improve USDW protection. These formations could further impede vertical fluid movement, allow for pressure dissipation, and provide additional sites for monitoring, mitigation, and remediation, while also affording the greatest protection of USDWs from endangerment. While other countries may not require such additional protection, EPA believes that providing the Director this additional discretion is an important element of assuring that GS activities will not endanger USDWs.

Please see the final rule and the discussion of geologic site characterization in the preamble for

additional information.

Commenter Name: Leslie Savage Letter ID: 0122 Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24764 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3100 2.1 Proposed Geologic Siting Requirements (40 CFR 146.83)

Comment: (f) Maps and stratigraphic cross sections indicating the general vertical and lateral limits of all USDWs, water wells and springs within the area of review, their positions relative to the injection zone (s)and the direction of water movement, where known;

{Consistency with definition and use of term in other areas of the rules.}

Response: EPA believes that the plural for injection zone(s) should be retained in the Final Rule in recognition of the fact that characterizing more than one injection zone may be necessary at some GS sites. EPA believes that in some geologic settings, the presence and identification of additional confining and containment zones above the primary (i.e., lowermost) confining zone can improve USDW protection. These formations could further impede vertical fluid movement, allow for pressure dissipation, and provide additional sites for monitoring, mitigation, and remediation, while also affording the greatest protection of USDWs from endangerment. EPA believes that providing the Director this additional discretion is an important element of assuring that GS activities will not endanger USDWs.

Please see the final rule and the discussion of geologic site characterization in the preamble for

additional information.

Commenter Name: Leslie Savage Letter ID: 0122 Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24765Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3150 2.1.5 Comments on required permit information (40 CFR 146.82)

Comment: (i) The compatibility of the CO2 stream with fluids in the injection zone and minerals in both the injection and the confining zone (s) , based on the results of the formation testing program, and with the materials used to construct the well;

{See comment above.}

Response: The final rule will allow the Director to require more than one confining zone; therefore, EPA did not make the suggested change.

Please see the final rule and the discussion of geologic site characterization in the preamble for

additional information.

Commenter Name: Leslie Savage Letter ID: 0122 Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24766 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3150 2.1.5 Comments on required permit information (40 CFR 146.82)

Comment: (m) Proposed procedure to outline steps necessary to conduct injection operation;

{"Proposed procedure to outline steps" does not make sense. Recommend "Outline of steps ...."}

Response: EPA disagrees that the suggested edit provides more clarity to the requirements and has retained the language as proposed. Additionally, similar language is used for other UIC well classes and the regulated community and permitting officials are familiar with the terms.

Please see the final rule and the discussion of geologic site characterization in the preamble for

additional information.

Commenter Name: George Holliday, PhD, PE, BCEE Letter ID: 0127 Commenter Organization: Holliday Environmental Services, Inc. Comment ID: 23057

Comment: D. EPA RULE DOES NOT IMPOSE ANY TECHNICAL QULIFICATIONS ON THE

EPA PERMIT

REVIEWER.

1. CO2 is injected in a supercritical phase, e.g., 2200± psia.

2. CO2 is buoyant and becomes a gas as the pressure decreases.

3. CO2 sequestration looks like a money making scheme, so speculators will be

attracted.

4. EPA likens CO2 sequestration wells (Class VI wells) to Class II Enhanced oil/gas well, water injector wells and Class I hazardous waste disposal wells.4. Class II well injected liquids are not corrosive. Special care is exercised to make injected water O2 free to avoid corrosion.

5. Class I injected fluids are blended to avoid corrosion.

6. Class II Enhanced oil recovery CO2 injection wells reservoirs are produced until abandonment, which lower the pressure to about the original pressure, Unlike Class II wells, sequestration well will be abandoned at the maximum injection pressure.

7. CO2 sequestration will attract many speculators, because of fast money during injection, but the speculators will fade away during the monitoring phase.

8. Speculators will write a good proposal without the technical expertise to conduct the drilling, completion and injection safely. Unqualified/untrained EPA reviewers will have difficulty recognizing a sound proposal from an unsatisfactory proposal. So unsafe projects will be approved.

9. Speculators will go out of business in 50 years, assuming they remain in business after the money making inject is completed.

10. EPA makes no provision in the rules for qualified EPA personnel to correct problem left by the speculators.

11. EPA says the Regional Administrators have the authority to make technical

decisions.

12. Regional Administrators typically are not technically trained

13. I requested under a FOI letter, the number of Permit writer/reviewers who were graduate engineers. EPA refuse to respond by saying such information was protected by the privacy laws.

14. At a minimum the proposed rule needs to require the EPA permit writer/reviewer be a Professional Engineer who stamps ever permit demonstrating the competency of the well project design and the Regional Administrator must be a graduate engineer..

15. EPA require a P.E. stamp SPCC Plans, a Plan of no real consequence, but, now, allows an EPA employee, who has not demonstrated competency to review and approve a massive vessel operating at 2200 psia.

Response: EPA disagrees that the people designing and regulating wells lack technical training for effective oversight of Class VI wells. Most permitting authority staff have years of experience with the current UIC injection well classes and have relevant specialties in geology, engineering, and related disciplines. Injection well owners and operators represent industries with decades of experience injecting a variety of fluids, including CO2. Regarding UIC requirements for staff qualifications, EPA clarifies that only the Class I hazardous waste injection well regulations at §§144.14(c)(9) and 144.63 (i) require that a professional engineer certify closure of the well.Commenter Name: Christine Reimer Letter ID: 0142 Commenter Organization: National Ground Water Association Comment ID: 22545 Other EPA Comment Codes and Descriptions: 2064 1.5.3.2 Grandfathering construction of Class II wells (seeking comment); 2066 1.5.3.3 Grandfathering construction of Class V wells (seeking comment); 3130 2.1.3 Comments that operators should submit more (or different) geologic data than proposed

Comment: The NGWA Carbon Sequestration Task Force recommends that the experimental phaseextend beyond the regional partnerships to each site proposed for productionscale injection of carbon dioxide. It is recommended that at least one well at each site be constructed under the Class V experimental category, and that testing of the adequacy of the geologic environment for geologic sequestration of carbon dioxide be conducted prior to permitting any well in the Class VI category at the site.

The transition of carbon dioxide injection wells from Class II (Enhanced Oil Recovery wells) to Class VI (carbon sequestration wells) will presumably be requested when production of the petroleum has ceased. Liquid carbon dioxide from a distant source, such as a power plant, can be stored in the depleted petroleum reservoir even after production has ceased, necessitating a change in classification of the injection well. The new use of the wells involves much longer storage time, and raises concerns about mechanical integrity and long term effects, including geochemical changes, on underground source of drinking water (USDWs). The reclassification should depend on a positive outcome from a Class V experimental program conducted in the depleted reservoir, as described

below.

The "grandfathering" of Class V carbon sequestration wells would mean allowing experimental wells to be permitted for operation after the testing period is over. The NGWA Carbon Sequestration Task Force recommends that each carbon sequestration system or wellfield have an experimental phase, and not rely on results from distant experimental locations. Thus, nearly every operational well would start as a Class V experimental well, or would go through a Class VI testing phase, before being permitted for long-term operation. The transition to Class VI operational status would require demonstrating that the minimum requirements are met at that location. Most wells would go through the following permitting phases:

- Class V experimental well construction permit: This permit would allow geologic and geophysical testing, aquifer testing, laboratory work, etc, but would not include injection of CO2 (only potable water injection testing would be allowed).

- Class VI experimental well operational testing permit: At this stage, the full monitoring facilities would need to be constructed. This permit would allow test injection of liquid CO2 at rates high enough to demonstrate that the location meets the minimum requirements for operation, for a period of up to two

years.

- Class VI operation permit: After demonstrating that the location and the well meet all the minimum requirements for injection of CO2, the operationpermit can be issued.

The goals of the experimental well Class V construction permit would be to make the following demonstrations:

- A receiving zone of sufficient depth, area extent, thickness, porosity, and permeability is present;

- Lithologic description, geological name, thickness and depth of each confining unit above the storage aquifer, and of each USDW.

- A trapping mechanism that is free of pathways for migration of injected fluids into a USDW. These pathways may include major non-sealing faults, porous beds within the confining unit, changes of facies trending toward more porous units and man-made structures such as wells or mine shafts. A trapping mechanism is defined as a geologic environment that prevents vertical and horizontal movement of fluids into a USDW; The volume of the trap shall exceed the proposed total volume of injected carbon dioxide for the life of the proposed facility

- Identification of all confining units between the primary injection/storage zone and the lowermost USDW, and their adequacy to contain the injected fluid. Unless the only feasible injection zone has only one confining unit separating it from the lowermost USDW, this demonstration includes adequacy of confinement for both the primary confining unit and a secondary containment system that extends to the base of the lowermost USDW and is completely redundant of the primary confining system and could confine the injected CO2 should the primary system fail. In locations where the secondary containment system is not possible, the applicant shall propose an alternative system of early warning of failure of the primary confining unit in order to avoid impacting any USDW should that confinement fail. This demonstration applies in the horizontal sense as well, demonstrating one or more mechanisms containing the fluid from horizontal movement into a USDW in the storage aquifer at a distant location.

- The construction of an operational monitoring system meeting all the requirements described in this document’s MMV section, and demonstration of the adequacy of this system to meet those requirements.

- Demonstration of mechanical integrity

Having made the foregoing demonstrations, a Class VI operational testing permit can be issued for a period of up to two years. The goals of the experimental well Class VI operational testing permit would be to make the following

demonstrations:

- A hydraulic demonstration of the adequacy (depth, area extent, thickness, porosity, and permeability) of the storage zone, using monitoring data and 4-D seismic monitoring of the extent of the CO2 plume. - Demonstration of the adequacy of the trap for 5/10 years of injection at the proposed rate. The volume of the trap shall exceed the proposed total volume of injected carbon dioxide for the 5/10 years of the first operation permit.- Demonstration of the adequacy of confinement under operational conditions using monitoring data and a method of detecting the extent of the CO2 plume in the storage aquifer, such as 4-D seismic monitoring or direct sampling. - Re- evaluation of the Area of Review and extent of the zone of endangering

influence. - Re-evaluation of mechanical integrity, using the buoyancy of the injected CO2 to better measure external mechanical integrity. The re-evaluation shall include the testing required during the initial MIT, as well as evaluation of the cement for carbonation, or chemical weathering by CO2

Under this permitting scenario, the vast majority of Class V experimental wells would be constructed after the Class VI standards had been published. The "grandfathering" of Class V wells that do not meet the Class VI construction standards would only be needed for DOE test sites established before rulemaking was complete. If these wells include the ongoing mechanical integrity monitoring of annular fluid pressure and composition, and they pass periodic mechanical integrity testing, they should be able to follow the same permitting procedures to become operational Class VI wells.

Response: EPA believes that submittal and review of monitoring data (as required at §146.90) and the AoR reevaluation process (§146.84(e)) will provide an opportunity for an ongoing review of the site and a dialogue between the Director and the owner or operator to ensure that the project is being operated in a manner that protects USDWs from endangerment. EPA notes that changes to these plans require a permit modification under §144.39, the public must be notified according to the public comment procedures under 40 CFR 124.

Please see the final rule and the discussion of geologic site characterization in the preamble for

additional information.

EPA disagrees that every GS well should initially be permitted as a Class V well. The Agency believes that the tailored Class VI requirements including extensive requirements for geologic site characterization at §146.82, AoR evaluation at §146.84, and testing of the well during drilling at §146.87 are appropriate to ensure that permitting authorities have the necessary information to evaluate whether a specific site will allow safe injection of CO2. EPA adds that submittal and review of monitoring data (as required at §146.90) and the AoR reevaluation process (§146.84(e)) will provide an opportunity for an ongoing review of the site and a dialogue between the Director and the owner or operator to ensure that the project is being operated in a manner that protects USDWs from endangerment. Given this approach to permitting Class VI projects, EPA believes that the requirements for grandfathering of construction at §146.81(c) are necessary and appropriate.

Commenter Name: Christine Reimer Letter ID: 0142 Commenter Organization: National Ground Water Association Comment ID: 22546 Other EPA Comment Codes and Descriptions: 3130 2.1.3 Comments that operators should submit more (or different) geologic data than proposed

Comment: Geologic Characterization

The UIC program is required under the Safe Drinking Water Act to protect USDWs from contamination from fluids injected into the subsurface. Part of this requirement is the demonstration that the injected fluids will not migrate,through buoyancy, ground-water flow or injection pressure, into USDWs. This demonstration is based on the characteristics of the geological environment where injection is to take place. The current UIC regulations require investigation of waste disposal sites through an application-phase data summary (Area of Review study) and geologic testing while drilling the pilot hole of the injection well. In general, the critical attributes of the injection and confining units are measured during pilot hole drilling, and the integrity and

extent of those units are addressed in the literature review and Area of Review study at the application phase. Because of the large volumes of carbon dioxide that are expected to be injected, and the vast extent of the storage zones, it is expected that more detailed information will be needed over a larger area for carbon sequestration than has been historically needed for injection of other

wastes.

The NGWA recommends that the adequacy and safety of injection of liquid carbon dioxide at each site be evaluated by multi-phase, variable density ground-water modeling, supported by extensive field investigations (see section General Comments on the Use of Modeling for Ground-Water Protection Related to CO2 Sequestration, below) These models should be included at the experimental well permit application phase as conceptual models, and progressively refined as data are collected during well construction and testing, and monitoring of operations.

The test injection well/operational testing permit application for a carbon sequestration injection well must address the geological characteristics of the site. The data presented at this stage should be adequate to make and calibrate an appropriate ground-water model. The necessary elements of the geologic system for carbon sequestration include:

- A receiving zone of sufficient depth that the injected carbon dioxide can be maintained in a supercritical state - Of sufficient areal extent that it includes the entire zone of endangering

influence - Of sufficient thickness and porosity to contain the volume of carbon dioxide injected over the life of the proposed system - Of sufficient permeability to accept the peak daily flow of injected carbon dioxide from the facility - A trapping mechanism (consisting of either impermeable barriers or geochemical/mixing barriers) that is free of vertical or horizontal pathways for migration of injected fluids into a USDW. The volume of the trap shall exceed the proposed total volume of injected carbon dioxide for the life of the proposed facility - A primary confining system of sufficient areal extent, thickness and competency to contain the injected fluid at proposed rates and volumes without initiating or propagating fractures in the confining zone - Unless the only feasible injection zone has only one confining unit separating it from the lowermost USDW, a secondary containment system that is completely redundant of the primary confining system and could confine the injected CO2 should the primary system fail. - The identification of a monitoring zone between the primary and secondaryconfining units. In locations where the secondary containment system is not possible, the applicant shall propose a monitoring formation to provide early warning of failure of the primary confining unit in order to avoid impacting any

USDW should that confinement fail. - Provide depth and completion information of all USDWs that may be affected by the injection if fluid movement does occur. - Provide geochemical information on subsurface aquifers, including all USDWs: Baseline geochemical data on water-rock- CO2 geochemistry and mineral reactions, maps and cross sections.

These elements should be identified in existing well records, in geologic literature, and by using the results of the exploratory program. The critical storage and confining units should be shown to exist over the entire area of review, or zone of endangering influence

The operation permit application should also include a preliminary multi-phase numerical transport model for CO2 and formation fluid, including all of the

elements listed above. This model should include at least one calibration scenario and will be used to provide a preliminary evaluation of the adequacy and safety of injection of carbon dioxide at the site, as well as a preliminary calculation of the potential storage volume of the geologic structure.

Each permit application for a carbon sequestration injection well must include an Area of Review study, which addresses the entire zone of endangering influence of the carbon sequestration operation, including the area impacted after cessation of injection due to buoyancy transport. The zone of endangering influence shall be determined by the ground-water model described above and illustrated with maps and cross sections.

Provide information on the geologic structure of the proposed site, including:

- Maps and cross sections of local geologic structure. Each cross section should include the location and depth of relevant data sources, including geophysical logs, that were used in developing the cross section - Geological name and lithologic description of each injection zone, primary and/or secondary confining unit, and USDW - Data on the receiving formation and the confining systems : 1. Size of the storage reservoir, and extent of the confining units in comparison to the area of endangering influence 2. Presence or absence of a secondary confining unit 3. Porosity, and permeability of the storage zone and confining units, including any geology/facies changes, based on field data which may include geologic cores, outcrop data, 3-dimensional seismic surveys, and well logs 4. Capacity of the storage zone in comparison to the proposed total volume of carbon dioxide to be stored, 5. Evaluation of the long-term effectiveness of the storage structure, including expected pathways of migration of injected carbon dioxide, and

the horizontal barriers to fluid movement - Geomechanical information on fractures, stress, rock strength, and in situfluid pressures within the primary and secondary containment units and confining

systems - Identification of potential pathways for migration of injected fluids and determination that they would not conduct a volume of fluid that would cause a violation of the prohibition of fluid movement as it applies to the class of

well that is to be constructed - Identification of potential risks within the zone of endangering influence, including degradation of water quality in USDWs, gas buildup in USDWs, reduction of porosity through geochemical changes in USDWs, and population that could be affected by gas releases. - List of penetrations into the injection zone and secondary containment system. - Information on seismic history and the presence/depth of seismic sources

Response: EPA agrees that extensive geological data collection and computational modeling, similar to what the commenter suggests, are important components of characterizing a potential GS site. For this reason, the GS regulation requires owners or operators to collect and submit extensive geological data (specified at §146.82) on the proposed GS site, including the injection and confining zones. Operators must also delineate the AoR using computational modeling that accounts for the multiphase flow of CO2 and native fluids (§146.84(c)), based on the geological data collected and proposed injection operations.

EPA disagrees with the comment that all sites should be evaluated by multi-phase, variable density groundwater modeling; instead, EPA believes that owners or operators should have the flexibility to select models that are most appropriate to site conditions and available data types and amounts. EPA is also requiring that the AoR be reevaluated at a frequency of every 5 years using monitoring and operating data to verify that the CO2 plume and pressure front are behaving as predicted in AoR calculation models (§146.84(e)).

Commenter Name: Christine Reimer Letter ID: 0142 Commenter Organization: National Ground Water Association Comment ID: 22590 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Proposed Rule: 146.82

Comment: NGWA raises the question of whether a requirement should be included that all applications for Class VI construction permits include a certification that the facility was designed by an appropriately qualified professional engineer with an option for an appropriate qualified professional geologist to certify the well design (taking into consideration confinement, injectivity, etc).

Proposed addition: (1) Class VI - Test/Injection Well Construction and Testing

Permit

Proposed addition: (a) The Director shall deny a construction permit if construction of the well itself may endanger the health of persons or the

environment

Proposed addition: (b) For construction permit approval, reasonable assurance isrequired that the project will function in compliance with this chapter. The Director shall require an exploratory well for those projects located in an area where available information is lacking concerning geologic or hydraulic confinement or existing information indicates that geologic or hydraulic confinement may be poor or lacking.

Proposed addition: (c ) For a Class VI well, issuance of a construction permit does not obligate the Director to authorize any operation of the well, unless reasonable assurance has been provided that the well can operate in compliance with this chapter.

Proposed addition: (d) Information required in 40 CFR 144.31 (e)(1) through (6)

Proposed addition: (e) A map showing the injection well(s) for which a permit is sought and the applicable area of review. Within the area of review, the map must show the number, or name and location of all injection wells, producing wells, abandoned wells, plugged wells or dry holes, deep stratigraphic boreholes, State or EPA approved subsurface cleanup sites, surface bodies of water, springs, mines (surface and subsurface), quarries, water wells and other pertinent surface features including structures intended for human occupancy and roads. The map should also show faults, if known or suspected. Only information of public record is required to be included on this map;

Proposed addition: (f) The area of review based on modeling, using data obtained during logging and testing of the well and the formation as required by paragraphs (l), (r ), and (s) of this section;

Proposed addition: (g) Information on the geologic structure and hydrogeologic properties of the proposed storage site and overlying formations, including

Proposed addition: (1) Maps and cross sections of the area of review;

roposed addition: (2) Location, orientation, and properties of known or suspected faults and fractures that may transect the confining zone(s) in the area of review and a determination that they would not interfere with containment;

Proposed addition: (3) Information on seismic history including the presence and depth of seismic sources and a determination that the seismicity would not interfere with containment;

Proposed addition: (4) Data on the depth, areal extent, thickness, mineralogy, porosity, permeability and capillary pressure of the injection and confining zone(s); including geology/facies changes based on field data which may include geologic cores, outcrop data, seismic surveys, well logs, and names and lithologic descriptions;

Proposed addition: (5) Geomechanical information on fractures, stress, ductility, rock strength, and in situ fluid pressures within the confining zone;

andProposed addition: (6) Geologic and topographic maps and cross sections illustrating regional geology, hydrogeology, and the geologic structure of the

local area

Proposed addition: (h) All wells within the AOR and whose total depth is greater than the depth to the bottom of the lowermost USDW should be compiled. However, preventive corrective action should be undertaken only for those wells that penetrate the injection and confining zone(s)

Rationale: A substantive risk analysis can be performed only if all the (known) wells within the AOR and between the injection formation and the bottom of the

USDW are described.

Proposed addition: (i) Maps and stratigraphic cross sections indicating the general vertical and lateral limits of all USDWs, water wells and springs within the area of review, their positions relative to the injection zone(s) and the direction of water movement, where known;

Proposed addition: (j) Baseline geochemical data on subsurface formations, including all USDWs in the area of review;

Proposed addition: (k) Proposed operating data:

Proposed addition: (1) Average and maximum daily rate and volume of the carbon dioxide stream;

Proposed addition: (2) Average and maximum injection pressure;

Proposed addition: (3) The source of the carbon dioxide stream; and

Proposed addition: (4) An analysis of the chemical and physical characteristics of the carbon dioxide stream;

Proposed addition: (l) The compatibility of the carbon dioxide stream with fluids in the injection zone and minerals in both the injection and the confining zone(s), based on the results of the formation testing program, and with the materials used to construct the well;

Proposed addition: (m) Proposed formation testing program to obtain an analysis of the chemical and physical characteristics of the injection zone and confining

zone;

Proposed addition: (n) Proposed stimulation program and a determination that stimulation will not interfere with containment;

Proposed addition: (o) Proposed formation testing program to obtain an analysis of the chemical, physical and radiological characteristics of and other information on the injection zone.Proposed addition: (p) Proposed procedure to outline steps necessary to conduct injection operation;

Proposed addition: (q) Engineering drawings of the surface and subsurface construction details of the system, including design features for surge control and water hammer protection;

Proposed addition: (r ) Injection well construction procedures that meet the requirements of Section 146.86;

Proposed addition: (s) Proposed area of review and corrective action plan that meets the requirements under Section 146.84;

Proposed addition: (t) The status of corrective action on wells in the area of review;

Proposed addition: (u) A demonstration, satisfactory to the Director, that the applicant has met the financial responsibility requirements under Section
146.85;

Proposed addition: (v) Proposed testing and monitoring plan required by Section

146.90

Proposed addition: (w) Proposed injection well plugging plan required by Section 146.92(b)

Proposed addition: (x) Proposed post-injection site care and site closure plan required by Section 146.93(a)

Proposed addition: (y) Proposed emergency and remedial response plan required by Section 146.94; and

Proposed addition: (z) Any other information requested by the Director.

Proposed addition: (2) Required Class VI operation permit information

Proposed Rule: 146.82(a) & (b)

Revision or Comment: Renumber 2(a) & (b)

Proposed Rule: 146.82(d) - (h)

Revision or Comment: Renumber 2(d) - 2(h)

Proposed Rule: 146.82(h)

Proposed addition: (5) Contingency plans to cope with all shut-ins or well failures, including emergency discharge provisions;

No rationale providedProposed Rule: 146.82(i)

Revision or Comment: Renumber 2(i)

Proposed Rule: 146.82(j)

Proposed revision: 2(j) Results of the formation testing program to obtain an analysis of the chemical, physical and radiological characteristics of and other information on the injection zone.

No rationale provided

Proposed Rule: 146.82(k) - (m)

Revision or Comment: Renumber 2(k) - 2(m)

No rationale provided

Proposed Rule: 146.82(n)

Proposed revision: 2 (n) Engineering drawings of the surface and subsurface construction details of the system, including design features for surge control and water hammer protection, including the following:

Proposed addition: (1) Record drawings, based upon inspections by the engineer of record or persons under his direct supervision, with all deviations noted;

Proposed addition: (2) Copies of the mill certificates of all casings used in the construction of the well;

Proposed addition: (3) Certification of completion submitted by the engineer of record;

Proposed addition: (4) An operation manual including emergency procedures;

Proposed addition: (5) Proposed monitoring program and data to be submitted;

Proposed addition: (6) Proof that the existence of the well and any associated monitoring wells have been recorded with the permanent warranty deed or other instrument of conveyance as a two page proviso or addendum that contains certification of the locations of the wells (by metes and bounds) and a detailed sketch of the parcel that shows the location of the well. The location shall be measured by a certified land surveyor, and shall contain the surveyor's signature, registration number, official seal, and the following statement: "I hereby certify that this survey was made under my responsible direction and supervision, and is a correct representation of the land surveyed."

No rationale providedProposed Rule: 146.82(o) - (y)

Revision or Comment: Renumber 2(o) - (y)

Proposed Rule: 146.82

Proposed addition: (3) Operational Testing

Proposed addition: (a) For Class VI wells, the construction permit includes a period of temporary injection operation for the purposes of long term testing. Prior to commencement of operational testing:

Proposed addition: 1. Construction of the injection well shall be complete and the permittee shall submit a notice of completion of construction to the

Director.

Proposed addition: 2. Each well shall first be tested for integrity of construction, and shall be followed by a short term injection test of such duration to allow for the prediction of the operating pressure.

Proposed addition: 3. The permittee shall submit the following information to the Director, as described in the permit.

Proposed addition: a. A copy of the borehole television survey(s) Proposed addition: b. Geophysical logs, Proposed addition: c. Mechanical integrity test data, Proposed addition: d. Data obtained during the short term injection testing conducted according to subparagraph 2. above. Proposed addition: e. Confining zone data, Proposed addition: f. Background water quality data for the injection and monitor zones; Proposed addition: g. Waste stream analysis, Proposed addition: h. As-built well construction specifications, and Proposed addition: i. Other data obtained during well construction which demonstrates that the well will operate in compliance with this chapter.

Proposed addition: 4. Any corrective action required under Section 146.84, shall be completed.

Proposed addition: 5. Prior to granting approval for operational testing of a Class VI well, the Director shall consider the following information:

Proposed addition: a. All available logging and testing program data on the well; Proposed addition: b. A demonstration of mechanical integrity Proposed addition: c. The anticipated maximum pressure and flow rate at which the permittee will operate; Proposed addition: d. The results of the formation testing program; Proposed addition: e. The actual injection procedure; Proposed addition: f. The compatibility of injected waste with fluids in theinjection zone and minerals in both the injection zone and the confining zone; Proposed addition: g. The status of corrective action on defective wells in the area of review; and

Proposed addition: (b) Written authorization for operational testing shall be obtained from the Director. Authorization shall be for up to two years or the expiration date of the construction permit, whichever is less, and is only renewable once as described in Section 146.91. The authorization shall specify the conditions under which operational testing is approved. The authorization

shall include:

Proposed addition: 1. Injection pressure limitation, Proposed addition: 2. Injection flow rate limitation, Proposed addition: 3. Injection well monitoring requirements, Proposed addition: 4. Effluent monitoring requirements, Proposed addition: 5. Weekly ground water sampling of monitor wells, Proposed addition: 6. Monthly specific injectivity testing, Proposed addition: 7. Reporting requirements, and Proposed addition: 8. An expiration date for the operational testing period not to exceed two years.

Proposed addition: (c ) Before authorizing operational testing, the Director shall conduct an inspection of the facility to determine if the conditions of the permit have been met.

Proposed addition: (d) A sampling frequency and reporting of less than once per

month shall not be allowed.

Proposed addition: (e) For Class VI wells, the duration of the operational testing period shall not exceed two years or the expiration date of the construction permit, whichever is less. If the Director has not issued an intent to issue an operation permit for the einjectionwell9s) by the end of the operational testing period, the permittee shall cease injection.

Proposed addition: (f) For a Class VI well, if an operation permit has not been obtained for the well within two years after the cessation of operational testing, the permittee shall submit an application to the Director to plug and

abandon the well in accordance with Section 146.92.

Proposed addition: (4) The Director shall conduct periodic inspections during

construction

No rationale provided

Response: Based on its evaluation of all public comments and input on the proposed rule and NODA and Request for Comment EPA has made many revisions to the GS Rule. Please see the final rule and the discussion of geologic site characterization in the preamble for additional

information.

EPA clarifies that the final rule does not require an owner or operator to obtain a separate Class VIoperational testing permit. However, EPA revised §146.82 so that the final regulation specifies separate requirements for information to be submitted with the permit application and before well construction is approved (at §146.82(a)) and information to be submitted before operation of the well is authorized (at §146.82(c)). Final information on injection zone pressures are required following drilling of the well, at §146.82(c)(4).

EPA disagrees that the rule needs to specify the qualifications of owner or operator staff creating the permit submittals. EPA is developing a number of technical guidances and implementation materials to assist owners or operators and Directors in the permitting process. These guidances will provide suggestions on how to perform many of the activities necessary for applying for a permit, including developing all required plans and conducting site characterizations under §146.82. Technical guidances and implementation materials will be available on EPA's web site, at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Christine Reimer Letter ID: 0142 Commenter Organization: National Ground Water Association Comment ID: 22591 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3560 2.2.3.2 Conditions that merit reevaluation of the AoR (seeking comment)

Comment: Proposed Rule: 146.82(c)

Revision or Comment: Proposed Revision: 2(c ) Re-evaluation of Area of Review. After completion of the operational testing period, the Area of Review shall be re-evaluated, using a calibrated, multi-phase fluid flow model. The data collection during operational testing must be adequate for calibration of the model. If a calibrated model cannot be prepared using data collected during operational testing, the owner or operator shall apply for a new period of operational testing of up to two years in order to collect the required data.

No rationale provided

Response: EPA agrees that AoR reevaluations should be based on the same type of modeling that is used to perform the initial delineation, but disagrees that the suggested change is necessary. EPA clarifies that all AoR modeling (including that which supports reevaluations) should be based on accepted, verified, and validated scientific methods. Under requirements at §146.84(b), the owner or operator must demonstrate in the proposed AoR and corrective action plan, to the satisfaction of the Director that the modeled AoR (and all updates) will be based on detailed geologic data collected on the site. EPA anticipates that any model that does this in a comprehensive and satisfactory manner would be approved by the Director.

Commenter Name: Christine Reimer Letter ID: 0142 Commenter Organization: National Ground Water Association Comment ID: 22610 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Proposed Rule: 146.91

Proposed addition: (1) Class VI Test/Injection Well Construction Permit

Proposed addition: (a) The Director shall require periodic data reports andprogress reports during construction that include:

Proposed addition: 1. Driller's log Proposed addition: 2. Geophysical surveys Proposed addition: 3. Core analyses Proposed addition: 4. Lithologic logs Proposed addition: 5. Drill stem tests Proposed addition: 6. Pump tests Proposed addition: 7. Daily job (construction) reports Proposed addition: 8. Water quality analyses

Proposed addition: (b) The frequency of reporting shall be specified in the individual permit

Proposed addition: (c ) Interpretation of data is required in the data reports or progress reports at the completion of each significant phase of construction, such as completion of test well construction and testing, completion of injection well construction, and completion of injection well testing.

Proposed addition: (d) The owner or operator shall submit final reports of all data collected from the test injection ell with interpretations to the Director with the application for a Class VI Test/Injection Well Construction and Testing Permit and a Class VI Injection Well Operation Permit shall include all information and data collected under Section 146.87, with appropriate interpretations

Proposed addition: (2) Class VI Operational Testing Permit

Proposed addition: (a) The owner or operator shall submit, as part of the permit application, the proposed methodology for collection and reporting of operational data, to ensure that the data is collected, correlated, and reported in a fashion that would enable the Director to evaluate well performance.

Proposed addition: (b) All Class VI wells shall report monthly the following:

Proposed addition: 1. Operating reports to the Director on:

Proposed addition: a. The physical, chemical, and other relevant characteristics of injection fluids;

Proposed addition: b. Daily reading of the pressure and flow for each well. For each Class VI sequestration well, a specific injectivity test shall be performed quarterly;

Proposed addition: c. Monthly average, maximum and minimum values for injection pressure, flow rate and volume, and annular pressure; and

Proposed addition: d. The results of monitoring prescribed under Section 146.90

Proposed addition: 2. Reporting the results, within three months after thecompletion of:

Proposed addition: a. Annular monitoring tests of mechanical integrity;

Proposed addition: b. Any other test of the injection ell conducted by the permittee if required by the Director; and

Proposed addition: c. Any well work over.

Proposed addition: (c ) Specific injectivity testing shall be performed while the pumping rate to the well(s) has been set at a predetermined level and reported as the specific injectivity index (gpm/specific pressure (psig)). As part of this test, the well shall be shut-in for a period of time necessary to conduct a valid observation of pressure fall-off. The owner or operator shall propose which pumping rate will be used based on the expected flow, the design of the pump station including the volume of the wet well and pump type(s), and the type of pump controls used. The pumping rate(s) shall be included as a condition of the operation permit.

Proposed addition: (d) Re-evaluation of Area of Review. After completion of the operatonal testing period, the Area of Review shall be re-evaluated, using a calibrated, multi-phase fluid flow model. The data collection during operational testing must be adequate for calibration of the model. If a calibrated model cannot be prepared using data collected during operational testing, the owner or operator shall apply for a new period of operational testing of up to two years in order to collect the required data. No more than two operational testing permits can be issued for any Class VI well. If the recalculated Area of Review includes any relevant wells or penetrations through the confining zone that were not reported in the permit application, a new tabulation of penetrations as required in Section 146.84(c)(2) and (3) shall be provided. Owners or operators must perform corrective action as required in Section 146.84(d).

Proposed addition: (e) If physical or geochemical data such as water quality, pressure changes, or mechanical integrity test results indicate that fluid movement into or between underground sources of drinking water may be occurring, the permittee shall submit additional data to provide reasonable assurance that the injection operation is in compliance with the requirements of this chapter. This additional data shall be submitted with the periodic operations reports, the content and frequency of which are specified in the individual permit.

Proposed addition: (f) A Class VI well permit shall be written to require that if CFR Section 146.14(a) is applicable, progress reports shall be submitted no later than thirty days following each interim date and the final date of compliance.

Proposed addition: (3) Class VI Injection Well Operation Permit.

Proposed addition: (a) The applicant shall submit, as part of the permit application, the proposed methodology for collection and reporting ofoperational data, to ensure that the data is collected, correlated, and reported in a fashion that would enable the Director to evaluate well performance.

Proposed addition: (b) All Class VI wells shall report monthly the following:

Proposed addition: 1. Operating reports to the Director on:

Proposed addition: a. The physical, chemical, and other relevant characteristics of injection fluids;

Proposed addition: b. Daily readings of the pressure and flow for each well. For each Class VI well, a specific injectivity test shall be performed quarterly;

Proposed addition: c. Monthly average, maximum and minimum values for injection pressure, flow rate and volume, and annular pressure; and

Proposed addition: d. The results of monitoring prescribed under Section 146.90

Proposed addition: 2. Reporting the results, within three months after the completion of:

Proposed addition: a. Periodic tests of mechanical integrity;

Proposed addition: b. Any other test of the injection well conducted by the permittee if required by the Director; and

Proposed addition: c. Any well work over.

Proposed addition: (c ) Specific injectivity testing shall be performed while the pumping rate to the well(s) has been set at a predetermined level and reported as the specific injectivity index (gpm/specific pressure (psig)). As part of this test, the well shall be shut-in for a period of time necessary to conduct a valid observation of pressure fall-off. The owner or operator shall propose which pumping rate will be used based on the expected flow, the design of the pump stations including the volume of the wet well and pump type(s), and the type of pump controls used. The pumping rate(s) shall be included as a condition of the operation permit.

(d) Re-evaluation of Area of Review. Every five years, the Area of Review shall be re-evaluated, using a calibrated, multi-phase fluid flow model. The data collection during operation must be adequate for calibration of the model. If a calibrated model cannot be prepared using data collected during operation, the owner or operator shall, within 90 days, apply for a new operation permit with a revised monitoring and testing plan designed to collect the required data. The re-issued Class VI operation permit shall be valid for a period of no more than two years. After two years of operation under a re-issued operating permit, theapplicant shall again re- evaluate the Area of Review using a calibrated, multiphase fluid flow model and re-apply for a five-year operating permit. If the recalculated Area of Review includes any relevant wells or penetrations whosetotal depth is greater than the depth to the bottom of the lowermost USDW that were not reported in the permit application, a new tabulation of penetrations as required in Section 146.84(c)(2) and (3) shall be provided. Owners or operators must perform corrective action as required in Section 146.84(d) must perform corrective action as required in Section 146.84(d).

No rationale provided

Proposed Rule: Introductory text to 146.91 and 146.91(a)(1)-(4)

Revision or comment: Proposed for deletion

Rationale: Covered in proposed Section 146.91(3) and subsections

Proposed Rule: 146.91(a)(5)

Revision or comment: Renumber 3(e)

Proposed Rule: 146.91(a)(6)

Revision or comment: Renumber 3(f); delete "and"

Proposed addition: (g) If physical or geochemical data such as water quality, pressure changes, or mechanical integrity test results indicate that fluid movement into or between underground sources of drinking water may be occurring, the permittee shall submit additional data to provide reasonable assurance that the injection operation is in compliance with the requirements of this chapter. This additional data shall be submitted with the periodic operations reports, the content and frequency of which are specified in the individual permit.

Proposed addition: (h) A Class VI well permit shall be written to require that if CFR Section 146.41(a) is applicable, progress reports shall be submitted no later than thirty days following each interim date and the final date of compliance.

No rationale provided

Proposed Rule: 146.91(a)(7); 146.91(b)(1)-(3)

Proposed for deletion

Rationale: Covered in proposed Section 146.91(3) and subsections

Proposed Rule: 146.91(c)

Renumber (4)

Response: Based on its evaluation of all public comments and input on the proposed rule and NODA and Request for Comment EPA has made many revisions to the GS Rule. See the final rule and preamble for further discussion on EPA's final approach. EPA is developing guidances oninjection well construction and on monitoring and testing that will assist owners or operators and Directors in performing the pre-operational logging and testing required at §146.86. This guidance

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

As described above, EPA clarifies that the final rule does not require an owner or operator to obtain a separate Class VI operational testing permit. However, EPA revised §146.82 so that the final regulation specifies separate requirements for information to be submitted with the permit application and before well construction is approved (at §146.82(a)) and information to be submitted before operation of the well is authorized (at §146.82(c)). Final information on injection zone pressures are required following drilling of the well, at §146.82(c)(4).

Commenter Name: Brianne Metzger Letter ID: 0151 Commenter Organization: Spectra Energy Corp Comment ID: 21823 Other EPA Comment Codes and Descriptions: 3150 2.1.5 Comments on required permit information (40 CFR 146.82)

Comment: E. EPA Should Not Make The Permitting Process Overly Burdensome By Requiring Unnecessary Or Unavailable Data.

Under the proposal, EPA is requiring the collection and submission of a significant amount of information and data. Although we understand and support the need for certain baseline data to support the determination that a particular project location is suitable, in certain cases, some of the data that EPA is requiring is irrelevant, excessive, or may even be unavailable. Therefore, we would recommend that the Agency include a provision in the Final GS Rule that would provide a waiver process and criteria, whereby the Director could waive certain data requirements, where such requirements are unnecessary.

Response: EPA disagrees that any of these protective requirements are unnecessary, and believes that waiving any of the requirements would not be acceptable. The GS regulation allows flexibility where appropriate. Certain requirements (e.g., the need to characterize additional confining layers) are at the Director's discretion (§146.83(b)), based on his or her understanding of a particular site.

EPA believes that a detailed geologic site characterization (required under §146.82) is essential to evaluating the presence and adequacy of the various geologic features necessary to receive and confine injected CO2 for GS. The requirements for geologic site characterization are based on a long-standing UIC regulatory framework developed to address specific risks to USDWs posed by injection. The Class VI GS requirements are tailored so that they are appropriate for the unique nature of injecting large volumes of CO2 into a variety of geologic formations for long-term storage.

EPA believes that a determination about whether or what information may be necessary (for a specific GS project) is outside of the public record will be site-specific and based on knowledge of the site, data availability, and data quality. For instance, in meeting the requirement to tabulate information on wells in the AoR, the Director has the discretion to require the owner or operator to supplement a data records search if there is reason to believe that the incompleteness of available information could compromise USDW protection from endangerment.Commenter Name: Bonnie Lovelace Letter ID: 0152 Commenter Organization: Montana Department of Environmental Quality (MDEQ) Comment ID:

22118 Other EPA Comment Codes and Descriptions: 3700 2.2.5 Comments on the requirement for an AoR and corrective action plan; 4610 2.6.1 Testing and monitoring plan requirement (seeking comment)

Comment: 17. EPA seeks comment on the merits of requiring plans for monitoring, area of review and post-injection site care as part of a permit application. MDEQ agrees that this is necessary and appropriate. A"cradle-to-grave" approach is wise in this instance and allows for updating the permit application materials as new technologies are forthcoming.

Response: EPA acknowledges the commenter’s support of the GS project plans. EPA believes that the requirement for the plans associated with GS projects will promote an ongoing dialogue between the owner or operator and the Director to ensure that USDWs are protected from endangerment. EPA is developing guidances for owners or operators describing recommended approaches to prepare the project plans. The guidances will be available on EPA's web site, at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

On the topic of monitoring and plan revision: EPA agrees with commenters on the importance of monitoring at GS sites and emphasizes that monitoring of injection activities will be an important component of every GS project. EPA also believes that periodic updates to the plans are appropriate. EPA clarifies that the final GS regulation includes a requirement that the AoR be reevaluated at least every 5 years, and it specifies at §146.90(j) that the operator revise the testing and monitoring plan to incorporate the results of the most recent AoR reevaluation and recent operational and monitoring

data.

EPA agrees that incorporating the plans into the permit rather than establishing specific requirements for corrective action, monitoring, injection well plugging, and post-injection site care in the regulation provide the appropriate flexibility to address the variety of site-specific conditions that may be encountered at GS sites. This approach is retained in the final rule. Please see the final rule and the discussion of the required GS project plans in the preamble for additional information.

EPA also believes that it is appropriate to require owners and operators to submit all plans, including the injection well plugging and post-injection site care and site closure plans, at the time of permit application. EPA believes that the Director needs a satisfactory level of assurance that the owner or operator has planned for these events before injection commences and that the owner or operator has ensured that appropriate financial resources 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 believes that the requirement for this and other plans associated with GS projects will promote an ongoing dialogue between the owner or operator and the Director to ensure USDWs are protected from endangerment. In addition, these plans will support a demonstration that owners and operators have adequate financial resources to meet well plugging and post-injection site care and site closure requirements.

Commenter Name: James Dooley Letter ID: 0156 Commenter Organization: Joint Global Change Research Institute, Pacific Northwest National Laboratory Comment ID:

22636 Other EPA Comment Codes and Descriptions: 3420 2.2.2.1 Scope of the inventory process (e.g.,reliance on publicly available information, depth of wells)

Comment: All Wells and "All Known Wells" are not the Same Page 43507 and 43517. The proposed Class VI rule needs to be much more precise in its use of language in a couple of key areas. The rule requires an applicant for a Class VI permit to "identify all artificial penetrations." What exactly does this mean? Is it all known artificial penetrations (the rule speaks to the operator "review(ing) available information")? What is the test for what is a known well or available information (does it require detailed field surveys or does one only need to do a quick search of a database of wells drilled in the area)? If on the other hand it means literally all human penetrations, then one must ask if this is technologically possible (e.g., are there technologies which would allow for the

identification of a small diameter non-steel walled well that has no visible surface features)? Is there a danger in asking for something that can not actually be delivered? One can guess what was likely meant by "identify all artificial penetrations" in terms of drafting this rule but it is not at all clear how this would be opperationalized at actual prospective GS sites.

More importantly on Page 43535 under "144.55 Corrective Action", the rule says that owners/operators need to identify the location of "all known wells" which seems to be a lesser standard. In the actual text of the rule (page 43526), the applicant is told "Only information of public record is required to be included on this map." Given how many times the rule and its preamble talk about old wells being a potential conduit for CO2 release from the storage formation, this seems like an overly lax threshold. It would seem appropriate to require the applicant survey the actual site itself for artificial penetrations that might not be in the public record (the survey could include a number of different methods / tools). Further on in this section, the applicant is asked to submit a "tabulation of all wells within the area of review which penetrate the injection or confining zones." Again, "all wells" and "all known wells" and how much work does one need to do to determine if they have tried to find "all the wells" must be better articulated in the final rule. This same kind of language shows up on page 43537 within the discussion of the Area of Review and

Corrective Action.

Lastly, given the large amounts of money involved in a commercial CO2 storage project, I would think that the electric production, oil and gas, or other large industrial company contemplating a large CCS-enabled facility would want (or be required) to go beyond simply collecting existing data as a way of decreasing risk and uncertainty. In this context, the proposed "requirement" for going beyond existing data could be imposed by entities other than state or federal environmental regulators and could be imposed by shareholders, a public utility commission, or a firm’s own board of directors. In terms of abandoned wells, it seems likely that commercial firms would see it to be in their own best interest to do some kind of physical search / assessment of whether there are any known or unknown wells within the area of review given the relatively minor cost associated with something like an aerial magnetic survey versus the costs associated with loss of CO2 and any fines, the cost associated with any required post-leakage activities, or simply the cost of litigation and or loss of good will associated with such sloppy management of a critical, capital intensive pollution abatement facility.Response: EPA believes that, for the most part, data base and other public records searches will be sufficient to identify artificial penetrations in the AoR. This inventory and review process is similar to what is required of Class I and Class II injection well operators, that that the AoR and corrective action process for these well types has been successful.

EPA is developing guidance on AoR and corrective action for GS sites. The guidance describes EPA's recommended approaches for the data to be considered in an initial AoR delineation, how to apply computational modeling to delineate the AoR, performing corrective action at GS sites, and, when appropriate, completing AoR reevaluations. The guidance will be available on EPA's web site, at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

EPA agrees with commenters that, for most GS sites, relying on database and other public records searches (i.e., of "known" artificial penetrations) will be sufficient to meet the requirements at §146.84(c)(2). However, the Agency recognizes that there may be situations where additional surveys or research to locate wells may be appropriate. For example, there may be cases where the Director may determine that ground or airborne surveys for wells are appropriate, e.g., if there is reason to believe, based on knowledge of the site or of available data, that the incompleteness of information on known wells could compromise USDW protection from endangerment. In order to preserve the Director's discretion to require an operator to supplement a records search, EPA did not make the suggested change. EPA encourages owners or operators to expand their searches, as the commenter suggests. EPA adds that all corrective action must be performed pursuant to the approved AoR and corrective action plan, which affords the Director the discretion to require any additional information needed (including information that is not publically available) to ensure that all necessary corrective action is performed.

Commenter Name: James Dooley Letter ID: 0156 Commenter Organization: Joint Global Change Research Institute, Pacific Northwest National Laboratory Comment ID:

22637

Comment: In this same section (page 43526), the applicant is asked to submit information on "the presence and depth of seismic sources" but this falls under a heading that is limited to the "proposed storage site and overlying formations." So if a proposed GS site sat 10 cm, 10m or 10km north of any aspect of the New Madrid Fault, that would not be noted in the application. Limiting the scope of data collection to the boundaries of the project site might not be appropriate for data related to "the presence and depth of seismic sources"

Response: EPA believes that consideration of local and regional seismicity is important and this type of review is relevant to every project. The site characterization provisions in the GS rule, including a review of the local and regional geology, and detailed review of any known or potential seismically active terrain in the vicinity of a proposed GS site, are necessary to minimize the potential for induced seismic events or the reactivation of faults, which are a known potential risk associated with underground injection and are addressed in all aspects of the UIC regulations.

Commenter Name: James Childress Letter ID: 0158 Commenter Organization: Gasification Technologies Council (GTC) Comment ID: 23787

Comment: EPA is proposing that permit applications for GS sites include several plans not currently required under existing UIC regulations. These plans include amonitoring and testing plan, an AoR and corrective action plan, and a postinjection site care and site closure plan. EPA seeks comment on the merits of requiring plans for monitoring, AoR, and post-injection site care as part of a permit application. EPA Notice 112.

We believe that requiring a monitoring plan is reasonable. However, the EPA should develop such requirements with recognition of a distinct end to operations and monitoring following closure, and consider specific representations and codicils that recognize an end of "in-perpetuity" responsibility for the operator or owner.

Response: EPA clarifies that the owner or operator's approved testing and monitoring plan and postinjection site care and site closure plan will be incorporated as a condition of the Class VI permit. Class VI well operators will be required to perform monitoring pursuant to the plans throughout the life of the facility (i.e., the duration of the Class VI permit). EPA adds that §146.93(b) requires operators to perform post-injection site monitoring until it can be demonstrated that the CO2 and pressure front no longer pose a risk of endangerment to USDWs. EPA notes that the post-injection monitoring may be different from monitoring that occurs during the operational phase. Once this demonstration is made, site closure may be authorized and monitoring is no longer required. EPA adds that owners or operators must maintain financial responsibility until site closure has been

authorized.

Please see the final rule and preamble, including the discussion of post-injection site care monitoring and financial responsibility for additional information.

Commenter Name: Michael J. Miller Letter ID: 0168 Commenter Organization: Electric Power Research Institute (EPRI) Comment ID: 22509

Comment: Preamble, page 43517: "EPA seeks comment on the merits of requiring plans for monitoring, AoR, and post-injection site care as part of a permit application."

EPRI COMMENT #15: Submitting a monitoring and AoR plan with the application seems practical since these activities will occur in the reasonably near futureafter the permit is issued. However, requiring too much specificity in a postinjection site care plan as part of the permit application may cement in methods that will be obsolete by the time the GS project enters the post-injection phase, 20-50 years from the permit date. EPA could instead require that a preliminary post-injection site care plan be submitted at the time of application outlining the general approach and parameters needed to demonstrate closure, and that a final detailed plan be prepared for approval a certain period of time prior to implementation of this phase.

Preamble, page 43518: "Today’s proposal would require owners or operators to submit a well plugging plan at the same time the permit application is submitted and to have this plan approved by the Director."

EPRI COMMENT #16: Again, well plugging and abandonment are activities that take place far in the future, perhaps several decades off. Therefore, submitting this plan at the time of permit application could render it obsolete when implementation is needed. EPA could instead require a preliminary planoutlining the general approach at the time of application and require that a final detailed plugging and abandonment plan be submitted for approval a certain period of time prior to implementation of this activity, allowing for the incorporation and use of new/better technologies.

Response: EPA believes that incorporating the plans into the permit rather than establishing specific requirements for corrective action, monitoring, injection well plugging, and post-injection site care in the regulation provide the appropriate flexibility to address the variety of site-specific conditions that may be encountered at GS sites.

EPA also believes that it is appropriate to require owners and operators to submit all plans, including the injection well plugging and post-injection site care and site closure plans, at the time of permit application. EPA believes that the Director needs a satisfactory level of assurance that the owner or operator has planned for these events before injection commences and that the owner or operator has ensured that appropriate financial resources 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 believes that the requirement for this and other plans associated with GS projects will promote an ongoing dialogue between the owner or operator and the Director to ensure USDWs are protected from endangerment. In addition, these plans will support a demonstration that owners and operators have adequate financial resources to meet well plugging and post-injection site care and site closure requirements.

EPA recognizes that the injection well plugging and post-injection site care and site closure plans may need to be modified when injection ceases, as well as prior to site closure, which is why §146.92(c) and §146.93(a) require review of these plans to ascertain whether the plan needs to be modified. EPA notes that §144.39 and §144.41 contain requirements regarding permit modifications that may be triggered as a result of these plan modifications.

Please see the final rule and the discussion of the Class VI project plans in the preamble for

additional information.

Commenter Name: Theresa Pugh Letter ID: 0169 Commenter Organization: American Public Power Association Comment ID: 23407 Other EPA Comment Codes and Descriptions: 3150 2.1.5 Comments on required permit information (40 CFR 146.82)

Comment: · The Final Rule must not make the application process overly burdensome or unrealistic by requiring detailed information that may not be available at the time of the initial application; instead, the Final Rule should allow for submission of updated information regarding a CO2 GS well and its AoR as that information becomes available through phased corrective action.

Response: EPA agrees that not all of the information listed at §146.82 of the proposed regulation will be available at the time the owner or operator develops their initial permit application. In response to comments and based on an evaluation of the proposed requirements at §146.82, the Agency revised this subpart so that the final regulation specifies separate requirements for information to be submitted with the permit application and before well construction is approved (at §146.82(a)) and information to be submitted before operation of the well is authorized (at §146.82(c)).EPA believes that this revision of §146.82 addresses commenters' concerns regarding the timing of information to be submitted. In addition, section §146.82 in the final rule is similar to the permit application requirements for other injection well classes, which could help avoid confusion about how to meet the permitting requirements for Class VI wells. The requirements at §146.82(c) for information to be submitted before operation of the well is authorized are very similar to those for Class I wells, with modifications and additions that address the unique challenges and types of data

collected for GS wells.

The final rule requires for the submission of updated information on the well and its AoR. The final GS rule, at §§146.84(c) and §146.90(j) requires owners or operators to review and update the AoR and corrective action plan and the testing and monitoring plan, at least once every 5 years, throughout the life of the project. Owners or operators must review each plan and identify necessary modifications to the plan or demonstrate to the Director that no amendment is needed. These reviews must be performed within one year of an AoR reevaluation, following any significant changes to the facility (e.g., the addition of monitoring or injection wells), or when required by the Director. While the rule does not specify that changes in phased corrective action warrant an update, the Director may determine that these types of modifications need to be incorporated into a plan update. EPA is developing guidance on developing and updating the GS project plans, which includes recommended considerations for developing and updating the plans. This guidance will be available on EPA’s website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24151 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3130 2.1.3 Comments that operators should submit more (or different) geologic data than proposed

Comment: Rule Provision: 146.82(b)

API Comments: (b) A surface map showing the PROPOSED LOCATIONS FOR the injection well(s) for which a permit is sought and the applicable area of review. Within the area of review, the map must show the number, or name and location of all KNOWN injection wells, producing wells, abandoned wells, plugged wells or dry holes, deep STRATAGRAPHIC boreholes, State or EPA approved subsurface cleanup sites, surface bodies of water, springs, mines (surface and subsurface), quarries, water wells and other pertinent surface features including structures intended for human occupancy and roads. The map should also show faults, if known or suspected. Only information of public record is required to be included on this map;

Rationale: Faults are not shown on maps unless there is a surface expression of the fault. Also, faults are detailed in (d) below and this language appears

redundant.

The word "known" needs to be added to remove any implication that an applicant has to conduct studies to determine the location of wells that are not currently

documented in some fashion.

Response: EPA did not delete “faults” from §146.82(b) because faults may have surface expressions that should be presented on submitted maps to complement the required cross section data. EPA isdeveloping guidance on site characterization for GS projects to assist owners or operators and Directors in evaluating permit requirements and applications under §146.82. The guidance provides recommendations regarding characterizing the regional geology and hydrogeology of a proposed GS site as well as performing the necessary geochemical, geomechanical, and geophysical analyses of the injection and confining zone. The guidance can be found on EPA’s website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Please see the final rule and the discussion of geologic site characterization in the preamble for

additional information.

EPA acknowledges that some smaller fractures may not be detectable during the site characterization process, and clarifies that §146.82(a)(3)(ii) requires the owner or operator to submit data on known or suspected faults and fractures (i.e., not all fractures). Other requirements for GS injection wells and sites can mitigate the potential impacts of unidentified fractures. These include limitations on injection pressures to avoid propagation of existing fractures in the confining zone (§146.88(a)), collection and assessments of CO2 monitoring data at the site, and AoR reevaluations (§146.84(e)) to assess possible CO2 movement through high-permeability regions (i.e., faults and/or fractures) not

detected in the initial site characterization.

EPA believes that a determination about whether or what information may be necessary (for a specific GS project) is outside of the public record and will be site-specific and based on knowledge of the site, data availability, and data quality. For instance, in meeting the requirement to tabulate information on wells in the AoR, the Director has the discretion to require the owner or operator to supplement a data records search if there is reason to believe that the incompleteness of available information could compromise USDW protection from endangerment.

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24152 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3100 2.1 Proposed Geologic Siting Requirements (40 CFR 146.83)

Comment: Rule Provision: 146.82(c)

API Comments: (c) A MAP DELINEATING the area of review based onUPON modeling, using ALL AVAILABLE data INCLUDING DATA obtained during logging and testing of the well and the formation as required by paragraphs (l), (r), and (s) of this sectionANY WELLS IN THE AREA OF REVIEW

Rationale: This appears to be related to a condition where a well is already drilled. This does not align with requesting information to receive a permit.

Response: EPA agrees that not all of the information listed at §146.82 of the proposed regulation will be available at the time the owner or operator develops their initial permit application. In response to comments and based on an evaluation of the proposed requirements at §146.82, the Agency revised this subpart so that the final regulation specifies separate requirements for information to be submitted with the permit application and before well construction is approved (at §146.82(a)) and information to be submitted before operation of the well is authorized (at §146.82(c)).

The requirement to provide the final area of review based on modeling and data obtained duringlogging and testing is in the final GS rule at §146.82(c)(1). Please see the final rule and the discussion of geologic site characterization in the preamble for additional information.

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24153 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3130 2.1.3 Comments that operators should submit more (or different) geologic data than proposed

Comment: Rule Provision: 146.82(d)(1) and (2)

API Comments: (d) KNOWN information on the geologic structure and hydrogeologic RESERVOIR properties of the proposed storage site and overlying formations, including:

(1) ISOPACH maps and OF THE PROPOSED INJECTION AND CONFINING ZONE(S), A STRUCTURAL CONTOUR MAP HUNG ON THE TOP OF THE PROPOSED

INJECTION ZONE, AND AT LEAST TWO GEOLOGIC cross sections of the area of review SHOWING THE

GEOLOGIC FORMATIONS FROM THE SURFACE TO TOTAL DEPTH.

(2) Location, orientation, and properties of known or suspected

SUBSURFACE faults and fracturesthat may transect the confining zone(s) in

the area of review and a determination that they would not interfere with containment;

Rationale: If the information is not known, it cannot be reported. "Reservoir" and changes to (1) and (2) are technical corrections.

Fractures generally can’t be identified until a well is drilled and evaluated. Even then, only fractures in the immediate vicinity of the wellbore

can be identified.

This responsibility is best left with EPA.

Rule Provision: 146.82(d)(3)

API Comments: (3) Information on seismic history THAT HAVE AFFECTED THE PROPOSED AREA OF REVIEW, INCLUDING KNOWLEDGE OF PREVIOUS SEISMIC EVENTS, including

the presence and depth of seismic sources and a determination that the seismicity would not interfere with containment;

Rationale: Information on seismic history should have some degree of relevance to the project. This responsibility is best left with EPA.

Rule Provision: 146.82(d)(4)

API Comments: (4) Data on the depth, areal extent, thickness, mineralogy, porosity, permeability and capillaryRESERVOIR pressure of the injection andconfining zone(s) WITHIN THE AREA OF REVIEW; including geologic /facies changes based on field data which may include geologic cores, outcrop data, seismic surveys, well logs, and names and lithologic descriptions;

Rationale: Deleted capillary pressure because it is too hard to measure outside of the lab. Using sidewall cores, it may be difficult to determine capillary pressure. Additionally, full cores are not available until after the well being permitted is drilled.

Rule Provision: 146.82(d)(5)

API Comments: (5) KNOWN geomechanical information on fractures, stress, ductility, rock strength, and in situ fluid pressures withinthe confining zone(s) WITHIN THE AREA OF REVIEW; and

Rationale not provided

Response: EPA acknowledges that some smaller fractures may not be detectable during the site characterization process, and clarifies that §146.82(a)(3)(ii) requires the owner or operator to submit data on known or suspected faults and fractures (i.e., not all fractures). Other requirements for GS injection wells and sites can mitigate the potential impacts of unidentified fractures. These include limitations on injection pressures to avoid propagation of existing fractures in the confining zone (§146.88(a)), collection and assessments of CO2 monitoring data at the site, and AoR reevaluations (§146.84(e)) to assess possible CO2 movement through high-permeability regions (i.e., faults and/or fractures) not detected in the initial site characterization. Regarding the requirement to determine capillary pressure, EPA recognizes that this information may not be available until after a well has been drilled. EPA revised §146.82 so that the final regulation specifies separate requirements for information to be submitted with the permit application and before well construction is approved (at §146.82(a)) and information to be submitted before operation of the well is authorized (at §146.82(c)). Final information on injection zone pressures would be required following drilling of the well, at §146.82(c)(4).

EPA disagrees that information submitted with Class VI permit applications should be limited to known (i.e., previously available) data. Site-specific conditions may affect the suitability of a proposed site. Therefore the owner or operator must provide to the Director the necessary preliminary information to support a permit decision.

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24154 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3100 2.1 Proposed Geologic Siting Requirements (40 CFR 146.83)

Comment: Rule Provision: 146.82(e)

API Comments: (e) A tabulationRECORD of all wellsARTIFICIAL

PENETRATIONS within the area of review which penetrateTHAT REACH the injection or confining zone(s). Such data AS AVAILABLE IN THE PUBLIC RECORD must include a description of each well’s PENETRATION’S type, construction, date drilled, location, depth, record of plugging and/ or completion, and any additional information the Director may require;Rationale: Artificial penetrations is a more inclusive term.

Rule Provision: 146.82(f)

API Comments: (f) Maps and stratigraphic cross sections indicating the general vertical and lateral limits of all USDWs, water wells and springs within the area of review, their positions relative to the injection zone(s) and the direction of water movement, where known;POTENTIOMETRIC (WATER LEVEL) SURFACE MAP(S) OF EXISTING AQUIFERS BEING UTILIZED AS PRIVATE OR PUBLIC WATER

SUPPLIES AND THE DIRECTION OF GROUNDWATER FLOW IN THESE AQUIFERS WITHIN THE

AREA OF

REVIEW. AT LEAST TWO GEOLOGIC CROSS SECTIONS SHOWING THE THICKNESS

AND GENERAL

VERTICAL AND LATERAL LIMITS OF ALL USDWS WITHIN THE AREA OF REVIEW.

No rationale provided

Rule Provision: 146.82(g)

API Comments: (g) Baseline geochemical data on subsurface formations, including all USDWs in the area of reviewCOMPILATION OF AVAILABLE GEOCHEMICAL

DATA ON THE PROPOSED INJECTION ZONE AND NEAREST POROUS AND PERMEABLE

FORMATION

ABOVE THE CONFINING ZONE.

Rationale: Limits the data to be submitted to available information and to the injection zone and the zone immediately above the confining zone which are the zones most likely to be monitored for potential CO2 leakage.

Response: As described above, EPA disagrees that the information that is submitted to support a Class VI permit application should be limited to known/available data.

EPA believes that a thorough understanding of the hydrogeologic conditions of all USDWs in the AoR is necessary, and disagrees with the suggested edits because the GS rule, as written, affords flexibility to owners or operators and Directors to tailor the site characterization process to the unique features of the site. EPA encourages owners or operators and Directors to collaborate and consult during site characterization to discuss information needs and ensure that all appropriate data to assess the suitability of the site are collected. The Director has the authority to request additional hydrogeologic data or other data on USDWs as well.

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

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

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24155 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3150 2.1.5 Comments on required permit information (40 CFR 146.82)

Comment: Rule Provision: 146.82(h)

API Comments: (h) Proposed operating data: (1) Average and maximum daily INJECTION rate and volume of the carbon dioxide stream; (2) Average and maximum SURFACE injection pressure;

Rationale: Technical clarifications.

Rule Provision: 146.82(k)

API Comments: (k) Proposed stimulation program and a determination that stimulation will not interfere with containment;

Rationale: This responsibility is best left with EPA.

Rule Provision: 146.82(n)

API Comments: (n) A WELLBORE schematic or other appropriate drawings of the

surface and of the subsurface construction details of the wellAND SURFACE

WELLHEAD CONSTRUCTION.

Rationale: Technical clarification.

Rule Provision: 146.82(q)

API Comments: q) TheANY status of corrective action on wells in the area of review;

Rationale: Clarifies that wells not needing corrective action will not have a

corrective action status.

Response: EPA acknowledges the commenter’s support for parts of the requirements under 146.82. EPA disagrees with suggested technical clarifications regarding proposed operating data, needs for the stimulation program, and the status of corrective action. EPA adds that it is developing guidance for owners or operators on the geologic site characterization, AoR, and corrective action processes. These guidances will provide recommendations and clarify the intent of all required elements of a permit application. The guidances can be found on EPA’s website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24251 Other EPA Comment Codes and Descriptions: 4610 2.6.1 Testing and monitoring plan requirement (seeking comment)

Comment: Rule Provisions: 146.90, 146.93(a), 146.94(a) EPA Preamble Question: 34. EPA is proposing that permit applications for GS sites include several plans not currently required under existing UIC regulations. These plans include a monitoring and testing plan, an AoR and corrective action plan, and a post-injection site care and site closure plan. EPA seeks comment on the merits of requiring plans for monitoring, AoR, and Post-injection site care as part of a permit application. EPA Notice 43517.

API Response: The development of such plans is a good idea because it negates prescriptive regulation of the process. API is concerned that every modification of a plan may trigger a major permit modification. Although actual monitoring of injection formation is most effective, there is still the unintended consequence of penetrating the confining zone to gain that data. The number of monitoring wells should not be established in advance. It is unclear how monitoring well construction, operation, and closure will be regulated since these are not actual injection wells.

Timing of development of plans should be linked to the actual activity being addressed (i.e. staged). It should not be necessary to prepare and submit a site closure plan or the post-closure monitoring plan at the start of the project, particularly considering that these activities will not occur for many years after the project starts.

Response: EPA agrees with commenters that developing and following testing and monitoring plans is an important part of assuring that a GS project is operating properly and is crucial for the early detection of potential endangerment to USDWs. EPA expects that the number of monitoring wells needed will be determined based on site-specific information. EPA also agrees that periodic updates to the plan are appropriate. EPA clarifies that the final GS regulation includes a requirement that the AoR be reevaluated at least every five years, and it specifies at §146.90(j) that the operator revise the testing and monitoring plan to incorporate the results of the most recent AoR reevaluation and recent operational and monitoring data.

EPA believes that monitoring using wells in the injection zone, e.g., for pressure monitoring as required at §146.90(g)(1), can be safely performed if the wells are constructed to prevent flow between the injection zone and USDWs or other layers above the confining zone. Such construction technologies exist and have been used in the oil and gas industry for years. The testing and monitoring plan must describe how the owner or operator plans to site and construct monitoring wells. EPA is developing guidance on well construction that will include recommendations for monitoring well construction. The guidance will be available on EPA’s website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

EPA clarifies that every revision to the testing and monitoring plan will not necessarily trigger a major permit modification. The existing regulation at 40 CFR 144.39(a) identifies causes for modification of permits that would invoke the public notification procedures at 40 CFR 124. In the final rule, EPA added text to §144.39(a)(5) that permit modifications would be required if theDirector determines that a modification is necessary based on an AoR reevaluation, amendments to any of the project plans, or a review of the testing and monitoring results.

In addition, 40 CFR Part 144.41 identifies causes for minor modifications of permits (which do not require following the procedures of Part 124). In the final rule, EPA added a subparagraph (h) to §144.41 that would include minor amendments (e.g., to clarify, correct, or update) to the testing and monitoring plan, plugging plan, post-injection site care and site closure plan, or emergency and remedial response plan for a GS well (i.e., amendments that are not included under 144.39(a)(5) and that do not require additional permit requirements).

EPA is developing guidance on testing and monitoring to assist owners or operators and Directors in evaluating requirements under §146.90. The guidance can be found on EPA’s website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm. In addition, in January 2009, DOE published a best practices manual entitled "Monitoring, Verification, and Accounting of CO2 Stored in Deep Geologic Formations" (DOE/NETL-311/081508); this manual is included in the docket for the final GS rule. EPA notes that closure of monitoring wells should be addressed in the post-injection site care and site closure plan.

EPA also believes that it is appropriate to require owners and operators to submit all plans, including the injection well plugging and post-injection site care and site closure plans, at the time of permit application. EPA believes that the Director needs a satisfactory level of assurance that the owner or operator has planned for these events before injection commences and that the owner or operator has ensured that appropriate financial resources 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).

Commenter Name: James Rower Letter ID: 0173 Commenter Organization: Utility Solid Waste Activities Group (USWAG) Comment ID: 23500

Comment: 11. Permit Application and Reporting Requirements

The Proposal would impose a number of requirements on Class VI permit applications that are not currently required under the existing UIC regulations, most notably the mandatory inclusion of a monitoring and testing plan, an AoR and corrective action plan, and a post-injection site care and site closure plan. Id. at 43517. For many of these requirements, there do not appear to be concrete risks particular to CO2 GS that would warrant these additional

measures.

USWAG is particularly concerned that the level of detail that would be required for Class VI permit applications is overly burdensome and unnecessary. A great deal of this information may be unavailable - or could be speculative at best - because of a lack of information at the early stages in the application process; an ongoing requirement for submission of this information over time, as it becomes available through drilling and operation of the well, would be of greater practical use and would lead to collection of more accurate data.

Response: EPA believes that the unique characteristics of CO2 injection (e.g., its relative buoyancy, the large volume that may be injected, or the potential for chemical interaction with the subsurface) warrant the additional information required to be submitted by GS operators under §146.82. All ofthe tailored requirements of the GS rule are necessary to protect USDWs from endangerment; therefore Directors must have all site-specific data listed under §146.82 to make well-informed decisions when establishing permit conditions and granting permits.

In response to concerns that some data will not be available until the well has been drilled, EPA acknowledges that not all of the information listed at §146.82 of the proposed regulation would be available at the time the owner or operator develops the permit application. Based on comments and evaluation of the proposed requirements, EPA revised this subpart so that the final regulation specifies separate requirements for information to be submitted for approval with the permit application before well construction, as required at §146.82(a), and information to be submitted after the well is constructed yet before injection is authorized, as required at §146.82(c).

Commenter Name: Frederick R. Eames Letter ID: 0178 Commenter Organization: CCS Alliance Comment ID: 23839 Other EPA Comment Codes and Descriptions: 5100 2.8.1 Injection well plugging activities (seeking comment) (40 CFR 146.92)

Comment: A. WELL PLUGGING PLAN

EPA's Proposed Rule would require owners and operators to develop a well plugging plan to be approved by the Director as part of each permit application. Such a plan would include: (1) a determination of bottom-hole reservoir pressure; (2) the identification of type and numbers of plugs to be used; (3) the placement of each plug; (4) testing methods to ensure mechanical integrity testing ("MIT"); (5) the method of plug placement; and (6) the type, grade and quantity of material to be used in plugging. By not mandating specific types, materials, or testing methods, EPA is giving applicants broad flexibility to accommodate the varying types of GS projects contemplated by this rulemaking. The CCS Alliance agrees with this approach. Such flexibility also accounts for the fact that supercritical CO2 has different properties than current injectants under the UIC program and, therefore. may require different plugging methods and materials. For instance, cement plugs can degrade over time from the build up of carbonic acid, which forms when CO2 is injected in subsurface formations containing brine. However. well integrity should be considered the function of well materials collectively in maintaining a fluid barrier (as opposed to individual components susceptibility, particularly from laboratory tests).

Response: EPA agrees with commenters that a flexible approach is appropriate for GS wells. The GS rule does not prescribe the specific cements to be used to plug injection wells because industry standards, such as those developed by API or ASTM International, reflect the current state of the science and the expertise of industrial users on CO2-compatible materials, as specified in §146.92(b). Providing flexibility to choose materials for plugging, provided they are compatible with the injected fluid, is consistent with requirements for other injection well classes and will allow operators to utilize improved well technologies as they become available in the future without a need to amend the regulation.

Commenter Name: Frederick R. Eames Letter ID: 0178 Commenter Organization: CCS Alliance Comment ID: 23840 Other EPA Comment Codes and Descriptions: 5200 2.8.2 Post injection site care (seekingcomment) (40 CFR 146.93)

Comment: B. POST-INJECTION SITE CARE PLAN

The Proposed Rule would require that owners or operators develop a postinjection site care and closure plan, submitted as part of the permit application and approved by the Director. The proposed regulation at 40 C.F.R. $ 146.93 would require the plan to describe: (1) the pressure differential between pre-injection and anticipated post-injection pressures in the injection zone; (2) predicted position of the plume and associated pressure front at the time the site is closed; (3) post-injection monitoring location(s), methods, andproposed frequency of monitoring; and (4) a schedule for submitting postinjection site care and monitoring results to the Director.

These requirements are reasonable given the long-term nature of GS projects. The CCS Alliance also supports the ability to amend the plan should the plan no longer reflect what is likely to occur upon closing the site. Likewise, the CCS Alliance agrees that, upon permanent cessation of injection, the owner or operator should be provided the opportunity to demonstrate that no amendment to the plan is necessary through monitoring and modeling results.

Response: EPA agrees that a post-injection site care monitoring plan is an important tool for GS, and retains this requirement in the final rule, at 146.93(a). Regarding updates to the plan, EPA isrequiring that upon the cessation of injection, the owner or operator submit an amended postinjection site care and site closure plan or demonstrate to the Director that no changes to the original post-injection site care and site closure plan are necessary, as specified in §146.93(a)(3). EPA is not requiring formal periodic review and updates to the PISC and site closure plan throughout the injection phase. EPA does not expect that changes to this plan would be implemented until injection operations cease.

Commenter Name: Thomas Curtis Letter ID: 0181 Commenter Organization: American Water Works Association (AWWA) Comment ID: 23654 Other EPA Comment Codes and Descriptions: 3150 2.1.5 Comments on required permit information (40 CFR 146.82)

Comment: In its comments, AWWA makes several recommendations for the following specific items to be included in the final regulation:

- A permit process for geologic sequestration (separate from the coal plant), with required monthly reporting similar to the NPDES permit/reporting process;

Response: EPA believes that permitting under the UIC Program is an essential element for ensuring that GS projects are operated in a manner that protects USDWs from endangerment. The UIC Program establishes minimum federal requirements for owners or operators of GS wells; and, States may choose to develop requirements that are as stringent as or more stringent than the minimum federal requirements. This affords states the flexibility to implement the program while ensuring that USDWs are protected from endangerment. If a State does not develop UIC Program requirements for Class VI wells, EPA implements the program in those states. The Agency clarifies that all owners or operators of Class VI wells must comply with the requirements under Subpart H of 146 in order to inject CO2 for GS through a Class VI well. A UIC injection well permit application is separate from other permitting activities (i.e., coal plant permitting).EPA believes that the extensive requirements for geologic site characterization (at §146.82), AoR evaluation (§146.84), and testing of the well during drilling (§146.87) are appropriate to ensure that permitting authorities have the necessary information to evaluate whether a specific site will allow safe injection of CO2. EPA adds that submittal and review of monitoring data (as required at §146.90) and the AoR reevaluation process (§146.84(e)) will provide an opportunity for an ongoing review of the site and a dialogue between the Director and the owner or operator to ensure that the project is being operated in a manner that protects USDWs from endangerment.

EPA is developing a number of technical guidances and implementation materials to assist owners or operators and Directors in the permitting process. These guidances will provide recommendations regarding performing many of the activities necessary for applying for a permit, including developing all required plans and conducting site characterizations that meet the requirements of §146.82. These guidances can be found on EPA’s website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

EPA clarifies that owners or operators of Class VI GS wells must comply with UIC semi-annual reporting requirements at 146.91(a). EPA believes that semi-annual reporting is appropriate to ensure that permitting authorities can maintain proper oversight of GS projects, particularly in the early stages of rule implementation and deployment of GS technologies. The Agency also clarifies that permitting authorities may choose to require more frequent reporting, at the discretion of the

Director.

EPA clarifies that it does not have the authority under the SDWA (and associated UIC requirements) to alter permitting requirements issued under other environmental statutes for coal plants or any CO2 sources. The UIC program's authority is limited to the injection operation and ensuring that USDWs are protected from endangerment.

Commenter Name: Thomas Curtis Letter ID: 0181 Commenter Organization: American Water Works Association (AWWA) Comment ID: 23656 Other EPA Comment Codes and Descriptions: 3150 2.1.5 Comments on required permit information (40 CFR 146.82)

Comment: In its comments, AWWA makes several recommendations for the following specific items to be included in the final regulation:

- Requirement for formal technical, managerial, and financial plans for GS owners/operators; and

Response: EPA agrees that requiring project plans for GS wells is appropriate. The final GS rulerequires owners and operators to develop, gain approval for, and implement a series of projectspecific plans, including: an area of review (AoR) and corrective action plan, a testing and monitoring plan, an injection well plugging plan, a post-injection site care and site closure plan, and an emergency and remedial response plan. All of these plans must be submitted at the time of permit application (§146.82(a)), along with a demonstration that appropriate financial resources are available, pursuant to requirements at §146.85, to fund all required activities. EPA believes that the requirement for the plans associated with GS projects will promote an ongoing dialogue between the owner or operator and the Director to ensure that USDWs are protected from endangerment. EPA is developing guidances to assist owners or operators in describing how to prepare the project plans and how to meet the financial responsibility requirements for GS wells. The guidances can be foundon EPA’s website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Thomas Curtis Letter ID: 0181 Commenter Organization: American Water Works Association (AWWA) Comment ID: 23708 Other EPA Comment Codes and Descriptions: 5430 2.9.1 Comments on proposed financial responsibility requirements (40 CFR 146.85)

Comment: AWWA questions whether it would be acceptable for energy companies and owner/operators to bond projects as a way to demonstrate financial assurance. AWWA recommends that EPA develop formal technical, managerial, and financial requirements for carbon sequestration projects that owner/operators must meet and maintain. This should be tied to the permitting process as these requirements must be demonstrated prior to the operating permit being issued. Demonstrating ongoing technical, managerial, and financial capabilities would be an important component of the five-year permitting review process that AWWA is recommending.

Response: EPA agrees that financial responsibility demonstrations should be part of the permitting process for Class VI wells. As a result, the rule requires owners or operators to demonstrate adequate financial responsibility for all required activities with their permit application, per §146.82(a)(14).

EPA is developing guidance on financial responsibility for Class VI wells. The guidance will include a discussion on how best to estimate costs to assist GS well owners or operators, third party insurers or providers of financial instruments, and permitting authorities in developing estimates of the costs associated with various GS activities. This guidance will be available on EPA's website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Bradley J. Field Letter ID: 0186 Commenter Organization: New York State Dept. of Environmental Conservation

Div. of Mineral Resources Comment ID:

25207

Comment: 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 integral components of any GS application, and should be required by the

EPA.

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

EPA also believes that it is appropriate to require owners and operators to submit all plans, including the injection well plugging and post-injection site care and site closure plans, at the time of permit application. EPA believes that the Director needs a satisfactory level of assurance that the owner or operator has planned for these events before injection commences and that the owner or operator has ensured that appropriate financial resources 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 projects 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 adequate financial resources to meet well plugging and post-injection site care and site closure requirements. Please see the final rule and the discussion of the GS project plans in the preamble for additional information.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24413 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3130 2.1.3 Comments that operators should submit more (or different) geologic data than proposed

Comment: Rule Provision: 146.82(b)

Proposed CCS Group Recommendations: (b) A SURFACE map showing the PROPOSED LOCATIONS FOR the injection well(s) for which a permit is sought and the applicable area of review. Within the area of review, the map must show the number, or name and location of all KNOWN injection wells, producing wells, abandoned wells, plugged wells or dry holes, deep stratigraphic boreholes, State or EPA approved subsurface cleanup sites, surface bodies of water, springs, mines (surface and subsurface), quarries, water wells and other pertinent surface features including structures intended for human occupancy and roads. The map should also show faults, if known or suspected. Only information of public record is required to be included on this map;

Basis for CCS Group Comments: Faults are not shown on maps unless there is a surface expression of the fault. Also, faults are detailed in (d) below and this language appears redundant.

The word "known" needs to be added to remove any implication that an applicant has to conduct studies to determine the location of wells that are not currently

documented in some fashion.

Response: EPA disagrees that information submitted with Class VI permit applications should be limited to known (i.e., previously available) data. Site-specific conditions may affect the suitability of a proposed site. Therefore the owner or operator must provide to the Director the necessary preliminary information to support a permit decision.

EPA did not delete “faults” from §146.82(b) because faults may have surface expressions, which should be presented on submitted maps in order to complement the required cross-section data. EPA is developing guidance on site characterization for GS projects to assist owners or operators and Directors in evaluating permit requirements and applications under §146.82. The guidance provides recommendations regarding characterizing the regional geology and hydrogeology of a proposed GS site as well as performing the necessary geochemical, geomechanical, and geophysical analyses of the injection and confining zone. The guidance can be found on EPA’s website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm. Please see the final rule and the discussion of geologic site characterization in the preamble for additional information.EPA believes that a determination about whether or what information may be necessary (for a specific GS project) is outside of the public record will be site-specific and based on knowledge of the site, data availability, and data quality. For instance, in meeting the requirement to tabulate information on wells in the AoR, the Director has the discretion to require the owner or operator to supplement a data records search if there is reason to believe that the incompleteness of available information could compromise USDW protection from endangerment. EPA acknowledges that some smaller fractures may not be detectable during the site characterization process, and clarifies that §146.82(a)(3)(ii) requires the owner or operator to submit data on known or suspected faults and fractures (i.e., not all fractures).

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24414 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3100 2.1 Proposed Geologic Siting Requirements (40 CFR 146.83)

Comment: Rule Provision: 146.82(c)

Proposed CCS Group Recommendations: (c) A MAP DELINEATING the area of review

based onUPON modeling, using ALL AVAILABLE data INCLUDING DATA obtained during logging and testing of the well and the formation as required by paragraphs (l), (r), and (s) of this sectionANY WELLS IN THE AREA OF REVIEW

Basis for CCS Group Comments: This appears to be related to a condition where a well is already drilled. This does not align with requesting information to receive a permit.

Response: EPA agrees that not all of the information listed at §146.82 of the proposed regulation will be available at the time the owner or operator develops their initial permit application. In response to comments and based on an evaluation of the proposed requirements at §146.82, the Agency revised this subpart so that the final regulation specifies separate requirements for information to be submitted with the permit application and before well construction is approved (at §146.82(a)) and information to be submitted before operation of the well is authorized (at §146.82(c)).

EPA believes that this revision of §146.82 addresses commenters' concerns regarding the timing of information to be submitted. In addition, section §146.82 in the final rule is similar to the permit application requirements for other injection well classes, which could help avoid confusion about how to meet the permitting requirements for Class VI wells. The requirements at §146.82(c) for information to be submitted before operation of the well is authorized are very similar to those for Class I wells, with modifications and additions that address the unique challenges and types of data

collected for GS wells.

The requirement to provide the final area of review based on modeling and data obtained during logging and testing is in the final GS rule at §146.82(c)(1). Please see the final rule and the discussion of geologic site characterization in the preamble for additional information.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24415 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rulelanguage; 3130 2.1.3 Comments that operators should submit more (or different) geologic data than proposed

Comment: Rule Provision: 146.82(d)

Proposed CCS Group Recommendations: (d) KNOWN information on the geologic

structure and hydrogeologic RESERVOIR properties of the proposed storage site and overlying formations, including:

(1) ISOPACH maps and OF THE PROPOSED INJECTION AND CONFINING ZONE(S), A

STRUCTURAL CONTOUR MAP HUNG ON THE TOP OF THE PROPOSED INJECTION
ZONE, AND AT

LEAST TWO GEOLOGIC cross sections of the area of review SHOWING THE GEOLOGIC

FORMATIONS FROM THE SURFACE TO TOTAL DEPTH.

(2) Location, orientation, and properties of known or suspected SUBSURFACE

faults and fracturesthat may transect the confining zone(s) in the area of review and a determination that they would not interfere with containment;

Basis for CCS Group Comments: If the information is not known, it cannot be reported.

"Reservoir" and changes to (1) and (2) are technical corrections.

Fractures generally can't be identified until a well is drilled and evaluated. Even then, only fractures in the immediate vicinity of the well bore can be

identified.

Response: EPA acknowledges that some smaller fractures may not be detectable during the site characterization process, and clarifies that §146.82(a)(3)(ii) requires the owner or operator to submit data on known or suspected faults and fractures (i.e., not all fractures). Other requirements for GS injection wells and sites can mitigate the potential impacts of unidentified fractures. These include limitations on injection pressures to avoid propagation of existing fractures in the confining zone (§146.88(a)), collection and assessments of CO2 monitoring data at the site, and AoR reevaluations (§146.84(e)) to assess possible CO2 movement through high-permeability regions (i.e., faults and/or fractures) not detected in the initial site characterization.

As described above, EPA disagrees that information submitted with Class VI permit applications should be limited to known (i.e., previously available) data. Site-specific conditions may affect the suitability of a proposed site. Therefore the owner or operator must provide to the Director the necessary preliminary information to support a permit decision. Please see the final rule and the discussion of geologic site characterization in the preamble for additional information.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24416 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3130 2.1.3 Comments that operators should submit more (or different) geologic data than proposed

Comment: Rule Provision: 146.82(d)(3)Proposed CCS Group Recommendations: (3) Information on seismic history THAT HAVE
AFFECTED THE PROPOSED AREA OF REVIEW, INCLUDING KNOWLEDGE OF PREVIOUS

SEISMIC EVENTS, including the presence and depth of seismic sources and a determination that the seismicity would not interfere with containment;

Basis for CCS Group Comments: Information on seismic history should have some degree of relevance to the project.

Response: EPA believes that consideration of local and regional seismicity is important and this type of review is relevant to every project. The site characterization provisions in the GS rule, including a review of the local and regional geology, and detailed review of any known or potential seismically active terrain in the vicinity of a proposed GS site, are necessary to minimize the potential for induced seismic events or the reactivation of faults, which are a known potential risk associated with underground injection and are addressed in all aspects of the UIC regulations.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24417 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3130 2.1.3 Comments that operators should submit more (or different) geologic data than proposed

Comment: Rule Provision: 146.82(d)(4)

Proposed CCS Group Recommendations: (4) Data SUFFICIENT TO DEMONSTRATE THE EFFECTIVENESS OF THE INJECTION AND CONFINING ZONE(S), INCLUDING DATA ON

THE DEPTH, AREAL EXTENT, THICKNESS, MINERALOGY, POROSITY, VERTICAL

PERMEABILITY RESERVOIR PRESSURE AND OF THE INJECTION AND CONFINING ZONE(S) WITHIN THE

AREA OF
REVIEW; INCLUDING GEOLOGIC CHANGES BASED ON FIELD DATA WHICH MAY

INCLUDE
GEOLOGIC CORES, OUTCROP DATA, SEISMIC SURVEYS, WELL LOGS, CAPILLARY

PRESSURE TESTS AND NAMES and lithologic descriptions;

Basis for CCS Group Comments: Capillary pressure is too hard to measure outside the lab; how comparable are lab results to what goes into the ground. Sidewall core may not be sufficient to do this, and it is difficult to core the whole of the confining and injection zones. Rewording keeps the usefulness of capillary pressure in the provision without making it a mandatory use.

Response: EPA acknowledges that laboratory methods are standard for determining capillary pressures regardless of formation permeability and that in situ measurements would require drilling of a well. However, EPA also anticipates that test wells will be drilled to support geologic site characterization of the proposed GS sites and can be used to collect subsurface samples (for laboratory determination of capillary pressure) and take other necessary measurements.

EPA recognizes that this information may not be available until after a well has been drilled. EPArevised §146.82 so that the final regulation specifies separate requirements for information to be submitted with the permit application and before well construction is approved (at §146.82(a)) and information to be submitted before operation of the well is authorized (at §146.82(c)). Final information on injection zone pressures would be required following drilling of the well, at §146.82(c)(4).

EPA believes that information on capillary entry pressure is necessary and appropriate. Capillary entry pressure measurements on core samples can quantify the amount of buoyant force the confining zone can maintain before failure (World Resources Institute, 2008).

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24418 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3130 2.1.3 Comments that operators should submit more (or different) geologic data than proposed

Comment: Rule Provision: 146.82(d)(5)

Proposed CCS Group Recommendations: (5) KNOWN geomechanical information on fractures, stress, ductility, rock strength, and in situ fluid pressures within the confining zone(s) WITHIN THE AREA OF REVIEW; and

Basis for CCS Group Comments: Clarification.

Rule Provision: 146.82(d)(6)

Proposed CCS Group Recommendations: Delete item 6 because this issue is covered under other sections such as (b).

Response: EPA acknowledges the comment but did not make the suggested edits. The Agency believes that the site characterization requirements at §146.82, including geomechanical information and geologic and topographic maps and cross sections, are essential to proper siting of a GS well and are the foundation for a detailed understanding of the local and regional geology, and that the owner or operator should collect this information, regardless of whether it is known in advance of the siting process. Collecting and evaluating this data supports important evaluations regarding the suitability of the site to receive and contain injected CO2.

EPA recognizes that this information may not be available until after a well has been drilled. EPA revised §146.82 so that the final regulation specifies separate requirements for information to be submitted with the permit application and before well construction is approved (at §146.82(a)) and information to be submitted before operation of the well is authorized (at §146.82(c)). Final information on injection zone pressures would be required following drilling of the well, at §146.82(c)(4).

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24419 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3100 2.1 Proposed Geologic Siting Requirements (40 CFR 146.83)

Comment: Rule Provision: 146.82(e)Proposed CCS Group Recommendations: (e) A tabulationRECORD of all wells

ARTIFICIAL PENETRATIONS within the area of review which penetrateTHAT REACH the injection or confining zone(s). Such data AS AVAILABLE IN THE PUBLIC RECORD must include a description of each well’s PENETRATION’S type, construction, date drilled, location, depth, record of plugging and/ or completion, and any additional information the Director may require;

Basis for CCS Group Comments: "Artificial penetrations" is a more inclusive

term.

Rule Provision: 146.82(f)

Proposed CCS Group Recommendations: (f) Maps and stratigraphic cross sections indicating the general vertical and lateral limits of all USDWs, water wells and springs within the area of review, their positions relative to the injection zone(s) and the direction of water movement, where known;POTENTIOMETRIC (WATER LEVEL) SURFACE MAP(S) OF EXISTING AQUIFERS BEING UTILIZED AS

PRIVATE OR

PUBLIC WATER SUPPLIES AND THE DIRECTION OF GROUNDWATER FLOW IN THESE AQUIFERS

WITHIN THE AREA OF REVIEW. AT LEAST TWO GEOLOGIC CROSS SECTIONS

SHOWING THE

THICKNESS AND GENERAL VERTICAL AND LATERAL LIMITS OF ALL USDWS WITHIN

THE AREA

OF REVIEW.

Basis for CCS Group Comments: This revision more accurately identifies the information that is needed and should be considered for permitting.

Rule Provision: 146.82(g)

Proposed CCS Group Recommendations: (g) Baseline geochemical data on subsurface formations, including all USDWs in the area of reviewCOMPILATION

OF AVAILABLE GEOCHEMICAL DATA ON THE PROPOSED INJECTION ZONE AND

NEAREST POROUS

AND PERMEABLE FORMATION ABOVE THE CONFINING ZONE.

Basis for CCS Group Comments: Limits the data to be submitted to available information and to the injection zone and the zone immediately above the confining zone which are the zones most likely to be monitored for potential CO2 leakage.

Response: EPA believes that a determination of what information may be necessary for a specific Class VI well and what information is available in the public record will be site-specific and based on data availability and data quality. For instance, in meeting the requirement to tabulate information on wells in the AoR, the Director has the discretion to require the owner or operator to supplement a data records search if there is reason to believe that the incompleteness of available information could compromise USDW protection from endangerment. Please see the final rule and the discussion of permitting and geologic site characterization in the preamble for additional information.EPA believes that a thorough understanding of the hydrogeologic conditions of all USDWs in the AoR is necessary, and disagrees with the suggested edits because the GS rule, as written, affords flexibility to owners or operators and Directors to tailor the site characterization process to the unique features of the site. EPA encourages owners or operators and Directors to collaborate and consult during site characterization to discuss information needs and ensure that all appropriate data to assess the suitability of the site are collected. The Director also has the authority to request additional hydrogeologic data or other data on USDWs.

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

indicate fluid movement.

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

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24420 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3150 2.1.5 Comments on required permit information (40 CFR 146.82)

Comment: Rule Provision: 146.82(h)

Proposed CCS Group Recommendations: (h) Proposed operating data: (1) Average and maximum daily INJECTION rate and volume of the carbon dioxide

stream; (2) Average and maximum SURFACE injection pressure;

Clarifications

Basis for CCS Group Comments: Technical clarifications.

Rule Provision: 146.82(i)

Proposed CCS Group Recommendations: Support the proposed language.

Basis for CCS Group Comments: Agree with EPA’s rationale.

Rule Provision: 146.82(j)

Proposed CCS Group Recommendations: Support the proposed language.Basis for CCS Group Comments: Agree with EPA’s rationale.

Rule Provision: 146.82(k)

Proposed CCS Group Recommendations: (k) Proposed stimulation program and a determination that stimulation will not compromise containment;

Basis for CCS Group Comments: "Interfere" is too ambiguous and should be replaced by "compromise" which limits concerns to situations where containment may be lost.

Rule Provision: 146.82(n)

Proposed CCS Group Recommendations: (n) A WELLBORE schematic or other appropriate drawings of the surface and of the subsurface construction details

of the well AND SURFACE WELLHEAD CONSTRUCTION.

Basis for CCS Group Comments: (n) Technical clarification.

Rule Provision: 146.82(q)

Proposed CCS Group Recommendations: (q) TheANY status of corrective action on wells in the area of review;

Basis for CCS Group Comments: Clarifies that wells not needing corrective action

will not have a corrective action status.

Response: EPA acknowledges the commenter’s support for portions of the subject requirements. EPA disagrees that the suggested technical clarifications are necessary. EPA adds that it is developing guidance for owners or operators on the geologic site characterization and AoR and corrective action processes. These guidances will provide recommendations and clarify the intent of all required elements of a permit application. The guidances can be found on EPA’s website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24543 Other EPA Comment Codes and Descriptions: 4610 2.6.1 Testing and monitoring plan requirement (seeking comment)

Comment: Rule Provisions or Federal Register Cite: 146.90, 146.93(a), 146.94(a) EPA Preamble Question: 34. EPA is proposing that permit applications for GS sites include several plans not currently required under existing UIC regulations. These plans include a monitoring and testing plan, an AoR and corrective action plan, and a post-injection site care and site closure plan. EPA seeks comment on the merits of requiring plans for monitoring, AoR, and post-injection site care as part of a permit application. EPA Notice 43517.

CSC Response: The development of such plans is a good idea because it negates prescriptive regulation of the process. CSC is concerned that every modification of a plan may trigger a major permit modification, although it does not appearthat current regulations would require that result. If major permit modifications were required, EPA would lose the adaptability desired for responding to experience gained from GS projects.

It is unclear how the construction, operation, and closure of any monitor wells would be regulated, since these are not actual injection wells.

Timing of development of plans should be linked to the actual activity being addressed (i.e. staged). It should not be necessary to prepare and submit a site closure plan or the post-closure monitoring plan at the start of the project, particularly considering that these activities will not occur for many years after the project starts.

Response: EPA agrees with commenters that developing and following testing and monitoring plans is an important part of assuring that a GS project is operating properly and is crucial for the early detection of potential endangerment to USDWs. EPA expects that the number of monitoring wells needed will be determined based on site-specific information. EPA also agrees that periodic updates to the plan are appropriate. EPA clarifies that the final GS regulation includes a requirement that the AoR be reevaluated at least every five years, and it specifies at §146.90(j) that the operator revise the testing and monitoring plan to incorporate the results of the most recent AoR reevaluation and recent operational and monitoring data.

EPA clarifies that every revision to the testing and monitoring plan will not necessarily trigger a major permit modification. The existing regulation at 40 CFR 144.39(a) identifies causes for modification of permits that would invoke the public notification procedures at 40 CFR 124. In the final rule, EPA added text to §144.39(a)(5) that permit modifications would be required if the Director determines that a modification is necessary based on an AoR reevaluation, amendments to any of the project plans, or a review of the testing and monitoring results.

In addition, 40 CFR Part 144.41 identifies causes for minor modifications of permits (which do not require following the procedures of Part 124). In the final rule, EPA added a subparagraph (h) to §144.41 that would include minor amendments (e.g., to clarify, correct, or update) to the testing and monitoring plan, plugging plan, post-injection site care and site closure plan, or emergency and remedial response plan for a GS well (i.e., amendments that are not included under 144.39(a)(5) and that do not require additional permit requirements).

EPA is developing guidance on testing and monitoring to assist owners or operators and Directors in evaluating requirements under §146.90. The guidance can be found on EPA’s website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm. In addition, in January 2009, DOE published a best practices manual entitled "Monitoring, Verification, and Accounting of CO2 Stored in Deep Geologic Formations" (DOE/NETL-311/081508); this manual is included in the docket for the final GS rule. EPA notes that closure of monitoring wells should be addressed in the post-injection site care and site closure plan.

EPA also believes that it is appropriate to require owners and operators to submit all plans, including the injection well plugging and post-injection site care and site closure plans, at the time of permit application. EPA believes that the Director needs a satisfactory level of assurance that the owner or operator has planned for these events before injection commences and that the owner or operator has ensured that appropriate financial resources 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).

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24604 Other EPA Comment Codes and Descriptions: 4610 2.6.1 Testing and monitoring plan requirement (seeking comment)

Comment: Rule Provisions: 146.90, 146.93(a), 146.94(a) EPA Rule Issue: 34. EPA is proposing that permit applications for GS sites include several plans not currently required under existing UIC regulations. These plans include a monitoring and testing plan, an AoR and corrective action plan, and a post-injection site care and site closure plan. EPA seeks comment on the merits of requiring plans for monitoring, AoR, and postinjection site care as part of a permit application. EPA Notice 43517.

Anadarko Petroleum Corporation (APC) Response: The development of plans is a good idea because it negates prescriptive regulation of the process. APC is concerned that every modification of a plan may trigger a major permit modification. Although actual monitoring of injection formation is most effective, there is still the unintended consequence of penetrating the confining zone to gain that data. The number of monitoring wells should not be established in advance. It is unclear how monitoring well construction, operation, and closure will be regulated since these are not actual injection

wells.

Timing of development of plans should be linked to the actual activity being addressed. It should not be necessary to prepare and submit a site closure plan or the post-closure monitoring plan at the start of the project, particularly considering that these activities will not occur for many years after the project starts.

Response: EPA agrees with commenters that developing and following testing and monitoring plans is an important part of assuring that a GS project is operating properly and is crucial for the early detection of potential endangerment to USDWs. EPA expects that the number of monitoring wells needed will be determined based on site-specific information. EPA also agrees that periodic updates to the plan are appropriate. EPA clarifies that the final GS regulation includes a requirement that the AoR be reevaluated at least every five years, and it specifies at §146.90(j) that the operator revise the testing and monitoring plan to incorporate the results of the most recent AoR reevaluation and recent operational and monitoring data.

EPA believes that monitoring using wells in the injection zone, e.g., for pressure monitoring as required at §146.90(g)(1), can be safely performed if the wells are constructed to prevent flow between the injection zone and USDWs or other layers above the confining zone. Such construction technologies exist and have been used in the oil and gas industry for years. The testing and monitoring plan must describe how the owner or operator plans to site and construct monitoring wells. EPA is developing guidance on well construction that will include recommendations for monitoring well construction. The guidance will be available on EPA’s website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

EPA clarifies that every revision to the testing and monitoring plan will not necessarily trigger amajor permit modification. The existing regulation at 40 CFR 144.39(a) identifies causes for modification of permits that would invoke the public notification procedures at 40 CFR 124. In the final rule, EPA added text to §144.39(a)(5) that permit modifications would be required if the Director determines that a modification is necessary based on an AoR reevaluation, amendments to any of the project plans, or a review of the testing and monitoring results.

In addition, 40 CFR Part 144.41 identifies causes for minor modifications of permits (which do not require following the procedures of Part 124). In the final rule, EPA added a subparagraph (h) to §144.41 that would include minor amendments (e.g., to clarify, correct, or update) to the testing and monitoring plan, plugging plan, post-injection site care and site closure plan, or emergency and remedial response plan for a GS well (i.e., amendments that are not included under 144.39(a)(5) and that do not require additional permit requirements).

EPA is developing guidance on testing and monitoring to assist owners or operators and Directors in evaluating requirements under §146.90. The guidance can be found on EPA’s website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm. In addition, in January 2009, DOE published a best practices manual entitled "Monitoring, Verification, and Accounting of CO2 Stored in Deep Geologic Formations" (DOE/NETL-311/081508); this manual is included in the docket for the final GS rule. EPA notes that closure of monitoring wells should be addressed in the post-injection site care and site closure plan.

EPA also believes that it is appropriate to require owners and operators to submit all plans, including the injection well plugging and post-injection site care and site closure plans, at the time of permit application. EPA believes that the Director needs a satisfactory level of assurance that the owner or operator has planned for these events before injection commences and that the owner or operator has ensured that appropriate financial resources 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).

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24641 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3130 2.1.3 Comments that operators should submit more (or different) geologic data than proposed

Comment: Rule Provision: 146.82(b)

Anadarko Petroleum Corporation (APC) Comments: (b) A surface map showing the PROPOSED LOCATIONS FOR the injection well(s) for which a permit is sought and the applicable area of review. Within the area of review, the map must show the number, or name and location of all KNOWN injection wells, producing wells, abandoned wells, plugged wells or dry holes, deep STRATAGRAPHIC boreholes, State or EPA approved subsurface cleanup sites, surface bodies of water, springs, mines (surface and subsurface), quarries, water wells and other pertinent surface features including structures intended for human occupancy and roads. The map should also show faults, if known or suspected. Only information of public record is required to be included on this map;

Rationale: Faults are not shown on maps unless there is a surface expression of the fault. Also, faults are detailed in (d) below and this language appearsredundant.

Known needs to be added to remove any implication that an applicant has to conduct stuides to determine wells that are not currently documented in some

fashion.

Response: Regarding the comment that EPA delete mention of faults on surface maps, EPA believes that if faults have surface expressions, they should be presented on maps submitted; this information would complement the required cross section data. EPA is developing guidance on site characterization for GS projects to assist owners or operators and Directors in evaluating permit requirements and applications under §146.82. The guidance provides recommendations regarding characterizing the regional geology and hydrogeology of a proposed GS site as well as performing the necessary geochemical, geomechanical, and geophysical analyses of the injection and confining zone. The guidance can be found on EPA’s website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

EPA disagrees that the information that is submitted to support a Class VI permit application should be limited to known/available data. The Agency believes that the site characterization requirements at §146.82, including geomechanical information and geologic and topographic maps and cross sections, are essential to proper siting of a GS well and are the foundation for a detailed understanding of the local and regional geology, and that the owner or operator should collect this information, regardless of whether it is known in advance of the siting process. Collecting and evaluating this data supports important evaluations regarding the suitability of the site to receive and contain injected CO2. Please see the final rule and the discussion of geologic site characterization in the preamble for additional information.

EPA acknowledges that some smaller fractures may not be detectable during the site characterization process, and clarifies that §146.82(a)(3)(ii) requires the owner or operator to submit data on known or suspected faults and fractures (i.e., not all fractures). Other requirements for GS injection wells and sites can mitigate the potential impacts of unidentified fractures. These include limitations on injection pressures to avoid propagation of existing fractures in the confining zone (§146.88(a)), collection and assessments of CO2 monitoring data at the site, and AoR reevaluations (§146.84(e)) to assess possible CO2 movement through high-permeability regions (i.e., faults and/or fractures) not

detected in the initial site characterization.

EPA also believes that a determination about whether or what information may be necessary (for a specific GS project) is outside of the public record will be site-specific and based on knowledge of the site, data availability, and data quality. For instance, in meeting the requirement to tabulate information on wells in the AoR, the Director has the discretion to require the owner or operator to supplement a data records search if there is reason to believe that the incompleteness of available information could compromise USDW protection from endangerment.

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24642 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3100 2.1 Proposed Geologic Siting Requirements (40 CFR 146.83)

Comment: Rule Provision: 146.82(c)

Anadarko Petroleum Corporation (APC) Comments: (c) A MAP DELINEATING the area ofreview based onUPON modeling, using ALL AVAILABLE data INCLUDING DATA obtained during logging and testing of the well and the formation as required by paragraphs (l), (r), and (s) of this sectionANY WELLS IN THE AREA OF

REVIEW

Rationale: This appears to be related to a condition where a well is already drilled. This does not align with requesting information to receive a permit.

Response: EPA recognizes that this information may not be available until after a well has been drilled. EPA revised §146.82 so that the final regulation specifies separate requirements for information to be submitted with the permit application and before well construction is approved (at §146.82(a)) and information to be submitted before operation of the well is authorized (at §146.82(c)).

Final information on injection zone pressures would be required. EPA recognizes that this information may not be available until after a well has been drilled. EPA revised §146.82 so that the final regulation specifies separate requirements for information to be submitted with the permit application and before well construction is approved (at §146.82(a)) and information to be submitted before operation of the well is authorized (at §146.82(c)). Final information on injection zone pressures would be required following drilling of the well, at §146.82(c)(4).

In the final rule, the requirement for the final AoR based on modeling, including data obtained during logging and testing, can be found at §146.82(c)(1). Please see the final rule and the discussion of geologic site characterization in the preamble for additional information.

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24643 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3130 2.1.3 Comments that operators should submit more (or different) geologic data than proposed

Comment: Rule Provision: 146.82(d)

Anadarko Petroleum Corporation (APC) Comments: (d) KNOWN information on the geologic structure and hydrogeologic RESERVOIR properties of the proposed storage site and overlying formations, including:

(1) ISOPACH maps and OF THE PROPOSED INJECTION AND CONFINING ZONE(S), A

STRUCTURAL CONTOUR MAP HUNG ON THE TOP OF THE PROPOSED INJECTION
ZONE, AND AT

LEAST TWO GEOLOGIC cross sections of the area of review SHOWING THE GEOLOGIC

FORMATIONS FROM THE SURFACE TO TOTAL DEPTH.

(2) Location, orientation, and properties of known or suspected SUBSURFACE

faults and fracturesthat may transect the confining zone(s) in the area of review and a determination that they would not interfere with containment;

Rationale: If the information is not known, it cannot be reported.

"Reservoir" and changes to (1) and (2) are technical corrections.Fractures generally can’t be identified until a well is drilled and evaluated. Even then, only fractures in the immediate vicinity of the wellbore can be

identified.

Response: EPA believes that all of the site characterization requirements at 146.82, including information on faults and fractures, are essential to proper siting of a GS well and are the foundation for a detailed understanding of the local and regional geology, and that the owner or operator should collect this information, regardless of whether it is known in advance of the siting process. Collecting and evaluating this data supports important evaluations regarding the suitability of the site to receive and contain injected CO2.

EPA recognizes that this information may not be available until after a well has been drilled. EPA revised §146.82 so that the final regulation specifies separate requirements for information to be submitted with the permit application and before well construction is approved (at §146.82(a)) and information to be submitted before operation of the well is authorized (at §146.82(c)). Final information on injection zone pressures would be required following drilling of the well, at §146.82(c)(4).

EPA acknowledges that some smaller fractures may not be detectable during the site characterization process, and clarifies that §146.82(a)(3)(ii) requires the owner or operator to submit data on known or suspected faults and fractures (i.e., not all fractures). Other requirements for GS injection wells and sites can mitigate the potential impacts of unidentified fractures. These include limitations on injection pressures to avoid propagation of existing fractures in the confining zone (§146.88(a)), collection and assessments of CO2 monitoring data at the site, and AoR reevaluations (§146.84(e)) to assess possible CO2 movement through high-permeability regions (i.e., faults and/or fractures) not

detected in the initial site characterization.

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24644 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3130 2.1.3 Comments that operators should submit more (or different) geologic data than proposed

Comment: Rule Provision:146.82(d)(3)

Anadarko Petroleum Corporation (APC) Comments: (3) Information on seismic history THAT HAVE AFFECTED THE PROPOSED AREA OF REVIEW INCLUDING

KNOWLEDGE OF PREVIOUS SEISMIC EVENTS AND HISTORY OF THESE EVENTS, including the presence and depth of seismic sources and a determination that the seismicity would not interfere with containment;

Rationale: Information on seismic history should have some degree of relevance to the project.

Response: EPA believes that consideration of local and regional seismicity is important and this type of review is relevant to every project. The site characterization provisions in the GS rule, including a review of the local and regional geology, and detailed review of any known or potential seismically active terrain in the vicinity of a proposed GS site are necessary to minimize thepotential for induced seismic events or the reactivation of faults, which are a known potential risk associated with injection and are addressed in all aspects of the UIC regulations.

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24645 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3130 2.1.3 Comments that operators should submit more (or different) geologic data than proposed

Comment: Rule Provision: 146.82(d)(4) & (5)

Anadarko Petroleum Corporation (APC) Comments: (4) Data on the depth, areal extent, thickness, mineralogy, porosity, permeability and capillary RESERVOIR pressure of the injection and confining zone(s) WITHIN THE AREA OF REVIEW; including geologic /facieschanges based on field data which may include geologic cores, outcrop data, seismic surveys, well logs, and names and lithologic descriptions;

(5) KNOWN geomechanical information on fractures, stress, ductility, rock strength, and in situ fluid pressures withinthe confining zone(s) WITHIN THE AREA OF REVIEW; and

Rationale: Deleted capillary pressure because it is too hard to measure outside of the lab. Using sidewall cores, it may be difficult to determine capillary pressure. Additionally, full cores are not available until after the well being permitted is drilled.

Response: EPA acknowledges the comment but did not make the suggested edits. The Agency believes that the site characterization requirements at §146.82, including geomechanical information and geologic and topographic maps and cross sections, are essential to proper siting of a GS well and are the foundation for a detailed understanding of the local and regional geology, and that the owner or operator should collect this information, regardless of whether it is known in advance of the siting process. Collecting and evaluating this data supports important evaluations regarding the suitability of the site to receive and contain injected CO2.

EPA acknowledges that laboratory methods are standard for determining capillary pressures regardless of formation permeability and that in situ measurements would require drilling of a well. However, EPA also anticipates that test wells will be drilled to support geologic site characterization of the proposed GS sites and can be used to collect subsurface samples (for laboratory determination of capillary pressure) and take other necessary measurements.

EPA recognizes that this information may not be available until after a well has been drilled. EPA revised §146.82 so that the final regulation specifies separate requirements for information to be submitted with the permit application and before well construction is approved (at §146.82(a)) and information to be submitted before operation of the well is authorized (at §146.82(c)). Final information on injection zone pressures would be required following drilling of the well, at §146.82(c)(4).

EPA believes that information on capillary entry pressure is necessary and appropriate. Capillary entry pressure measurements on core samples can quantify the amount of buoyant force theconfining zone can maintain before failure (World Resources Institute, 2008).

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24646 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3100 2.1 Proposed Geologic Siting Requirements (40 CFR 146.83)

Comment: Rule Provision: 146.82(e)

Anadarko Petroleum Corporation (APC) Comments: (e) A tabulation of all wells ARTIFICIAL PENETRATIONS within the area of review which penetrate the injection or confining zone(s). Such data must include a description of each well’s type, construction, date drilled, location, depth, record of plugging and/ or completion, and any additional information the Director may require;

Rationale: Artificial penetrations is a more inclusive term.

Response: EPA agrees that all artificial penetrations must be identified and evaluated during site characterization. However the final rule retains the proposed text to be consistent with similar requirements for other well classes and to support the corrective action requirements. EPA is developing guidance on AoR and corrective action at GS Class VI sites to assist owners or operators and Directors in evaluating requirements and proposed AoR and corrective action plans under §146.84. The guidance can be found on EPA’s website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24647 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3100 2.1 Proposed Geologic Siting Requirements (40 CFR 146.83)

Comment: Rule Provision: 146.82(f)

Anadarko Petroleum Corporation (APC) Comments: (f) Maps and stratigraphic cross sections indicating the general vertical and lateral limits of all USDWs, water wells and springs within the area of review, their positions relative to the injection zone(s) and the direction of water movement, where known; POTENTIOMETRIC (WATER LEVEL) SURFACE MAP(S) OF EXISTING AQUIFERS BEING

UTILIZED

AS PRIVATE OR PUBLIC WATER SUPPLIES AND THE DIRECTION OF GROUNDWATER

FLOW IN THESE AQUIFERS WITHIN THE AREA OF REVIEW. AT LEAST TWO GEOLOGIC CROSS

SECTIONS

SHOWING THE THICKNESS AND GENERAL VERTICAL AND LATERAL LIMITS OF ALL

USDWS

WITHIN THE AREA OF REVIEW.

No rationale provided

Response: The Agency acknowledges the suggested edits but has retained the language as proposed. EPA believes that a thorough understanding of the hydrogeologic conditions of all USDWs in theAoR is necessary to protect USDWs from endangerment, and disagrees with the suggested edits because the GS rule, as written, affords flexibility to owners or operators and Directors to tailor the site characterization process to the unique geologic features of the site. The final requirements will allow for submittal of information similar to or the same as that which was suggested by the commenter. EPA encourages owners or operators and Directors to consult during site characterization to discuss information needs and ensure that all appropriate data necessary to assess the suitability of the site are collected. The Director may request additional hydrogeologic data or other data on USDWs as well, as provided in §146.82(a)(21).

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24648 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3100 2.1 Proposed Geologic Siting Requirements (40 CFR 146.83)

Comment: Rule Provision: 146.82(g)

Anadarko Petroleum Corporation (APC) Comments: (g) Baseline geochemical data on subsurface formations, including all USDWs in the area of review

COMPILATION OF AVAILABLE GEOCHEMICAL DATA ON THE PROPOSED INJECTION

ZONE AND

NEAREST POROUS AND PERMEABLE FORMATION ABOVE THE CONFINING ZONE.

Rationale: Limits the data submitted to available information and to the injection zone and the zone immediately above the confining zone which is the zones most likely to be monitored for potential CO2 leakage.

Response: The Agency acknowledges the suggested edits but has retained the language as proposed. EPA believes that a thorough understanding of the hydrogeologic conditions of all USDWs in the AoR is necessary, and disagrees with the suggested edits because the GS rule, as written, affords flexibility to owners or operators and Directors to tailor the site characterization process to the unique features of the site. EPA encourages owners or operators and Directors to consult during site characterization to discuss information needs and ensure that all appropriate data necessary to assess the suitability of the site are collected. The Director has the authority to request additional hydrogeologic data or other data on USDWs as well.

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

indicate fluid movement.

The rule requires geochemical analysis of, at a minimum, the injection zone, confining zone, and all USDWs (§146.82(a)(6)). These geochemical tests are necessary to ensure the adequacy of the confining system and to serve as a baseline for future monitoring. The Director has the discretion to require geochemical analysis of additional subsurface zones if, in the Director's opinion, they are necessary for the protection of USDWs from endangerment.Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24649 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3150 2.1.5 Comments on required permit information (40 CFR 146.82)

Comment: Rule Provision: 146.82(h)

Anadarko Petroleum Corporation (APC) Comments: (h) Proposed operating data: (1) Average and maximum daily INJECTION rate and volume of the carbon dioxide

stream; (2) Average and maximum SURFACE injection pressure;

Rationale: Technical clarifications.

Response: EPA disagrees that the suggested technical clarifications are necessary. EPA adds that it is developing guidance for owners or operators on the geologic site characterization process. The guidance will provide recommendations for owners and operators to consider when completing a permit application. The guidance can be found on EPA’s website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24650 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3150 2.1.5 Comments on required permit information (40 CFR 146.82)

Comment: Rule Provision: 146.82(n)

Anadarko Petroleum Corporation (APC) Comments: (n) A WELLBORE schematic or other appropriate drawings of the surface and of the subsurface construction

details of the wellAND SURFACE WELLHEAD CONSTRUCTION.

Rationale: Technical clarification.

Response: EPA disagrees that the suggested technical clarifications are necessary. EPA adds that it is developing guidance for owners or operators on the geologic site characterization process. The guidance will provide recommendations for owners and operators to consider when completing a permit application. The guidance can be found on EPA’s website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24651 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3150 2.1.5 Comments on required permit information (40 CFR 146.82)

Comment: Rule Provision: 146.82(q)

Anadarko Petroleum Corporation (APC) Comments: q) TheANY status of corrective action on wells in the area of review;

Rationale: Clarifies that wells not needing corrective action will not have a

corrective action status.Response: EPA disagrees that the suggested technical clarifications are necessary. EPA adds that it is developing guidance for owners or operators on the geologic site characterization and AoR and corrective action process. The guidance documents will provide recommendations for owners and operators to consider when completing a permit application. The guidance can be found on EPA’s website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Chris M. Hobson Letter ID: 0201 Commenter Organization: Southern Company Comment ID: 22160 Other EPA Comment Codes and Descriptions: 4720 2.7.2 Operational recordkeeping and reporting

Comment: Permit Application

Southern Company opposes EPA's proposed requirements for Class VI permit applications to the extent that those requirements are more burdensome than current permit application requirements for other classes of UIC wells. id. at 43517. C02 GS does not pose unique risks warranting many of the Proposal's additional requirements for detailed information.

EPA should craft the Final Rule to require in the initial permit application

information that the Director will need to determine whether issuance of a Class VI permit is appropriate. EPA could require submission of supplemental information as it becomes available through drilling, construction, and reevaluation of the well. This will not only prevent against the chilling effect that overly burdensome permit application requirements would have on the CO2 GS program, but will simultaneously ensure the ultimate collection of more thorough

and reliable data.

Response: EPA believes that the unique characteristics of CO2 injection (e.g., its relative buoyancy, the large volume that may be injected, or the potential for chemical interaction with the subsurface) warrant the additional information required to be submitted by Class VI operators under §146.82. EPA disagrees that Directors should have the authority to waive some of the application requirements. In order to protect USDWs from endangerment, Directors must have all the data necessary to make well-informed decisions on establishing permit conditions and granting permits.

In response to concerns that some data will not be available until the well has been drilled, EPA acknowledges that not all of the information listed at §146.82 of the proposed regulation will be available at the time the owner or operator develops their Class VI permit application. Based on comments and evaluation of the proposed requirements, EPA revised this subpart so that the final regulation specifies separate requirements for information to be submitted for approval with the permit application before well construction, as required at §146.82(a), and information to be submitted after the well is constructed; however, all data must be provided before injection is authorized, as required at §146.82(c).

Commenter Name: Chris M. Hobson Letter ID: 0201 Commenter Organization: Southern Company Comment ID: 22171 Other EPA Comment Codes and Descriptions: 4200 2.4.2 Down-hole shut-off valves in GS wells (seeking comment)Comment: While some requirements are appropriate for all Class VI wells, as a general matter operating and monitoring requirements for individual Class VI projects should be set forth in a Director-approved plan as part of the permit application and approval process. For example, while Southern Company supports a default requirement for automatic shut-off mechanisms for Class VI wells, we oppose a uniform requirement for down-hole shut-off valves. ¡d. at 34511. These valves are designed to meet unique offshore risks and are, in many instances, ill-suited to UIC operations, including C02 GS. A requirement for down-hole shut-off valves would provide little benefit but would come at a significant cost and would preclude the use of some tools that are critical to operation, monitoring, and repair of CO2 GS wells.

Response: After evaluating the risks and benefits of down-hole shut-off systems and considering additional research, EPA will not require 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 owners 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 GS rule, at §146.88(e)(3), requires the installation of down-hole shut-off devices for Class VI wells located in the offshore submerged lands within the jurisdiction of a State UIC program. The Agency agrees that offshore Class VI wells present unique construction and operational conditions, including isolation from shorelines and the need to construct wells through the water column and the subsurface, which may delay response time in the event of well difficulties. These conditions merit requiring automatic down-hole shut-off devices for offshore wells in the submerged lands of a State.

While EPA acknowledges that the likelihood of damage to onshore facilities is lower than that for off-shore facilities, down-hole shut-off valves are still commonly used in onshore facilities such as acid gas injection wells and high pressure, 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 handle such failure if it occurs. For example, wireline retrievable devices can allow repair or replacement of damaged devices without necessitating pulling the tubing.

EPA believes that requiring the installation of automatic surface shut-off devices for onshore wells (and affording Director's discretion to require down-hole devices where necessary) and automatic down-hole shut-off devices for offshore wells in submerged lands within the jurisdiction of a State ensures that proper precautions are taken to prevent subsurface fluid movement and ensure protection

of USDWs.

Commenter Name: John Corra Letter ID: 0205 Commenter Organization: Wyoming Department of Environmental Quality (DEQ) Comment ID:

22204 Other EPA Comment Codes and Descriptions: 4610 2.6.1 Testing and monitoring plan requirement (seeking comment)

Comment: 7. Permit application content:

a. We agree with the US EPA that permit applications for GS sites should include several plans not currently required under existing UIC regulations. These plans include a monitoring and testing plan, an AoR and corrective action plan, and apost-injection site care and site closure plan.

Response: EPA agrees with commenters that developing and following testing and monitoring plans is an important part of assuring that a GS project is operating properly and is crucial for the early detection of potential endangerment to USDWs. The final rule retains this requirement.

EPA agrees that incorporating the plans into the permit rather than establishing specific requirements for corrective action, monitoring, injection well plugging, and post-injection site care in the regulation provide the appropriate flexibility to address the variety of site-specific conditions that may be encountered at GS sites.

EPA believes that it is appropriate and necessary to require owners and operators to submit all plans, including the injection well plugging and post-injection site care and site closure plans, at the time of permit application for the Director to make a proper permit decision. EPA believes that the Director needs a satisfactory level of assurance that the owner or operator has planned for these events before injection commences and that the owner or operator has ensured that appropriate financial resources 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 expects that the requirement for this and other plans associated with GS projects will promote an ongoing dialogue between the owner or operator and the Director to ensure USDWs are protected from endangerment. In addition, these plans will support a demonstration under §146.85 that owners and operators have adequate financial resources to meet well plugging and post-injection site care and site closure requirements. Please see the final rule and the discussion of the GS project plans for additional

information.

Commenter Name: Diane VanDe Hei Letter ID: 0206 Commenter Organization: Association of Metropolitan Water Agencies (AMWA) Comment ID:

22213 Other EPA Comment Codes and Descriptions: 5700 2.12 Comments on the proposed duration of Class VI permits (seeking comment)

Comment: have a plan to update the regulation on a regular basis as well. Having a permit

renewal schedule built into the rule will allow each state Director to ensure that updates to the regulation are included in permit renewals. AWWA and AMWA also suggest that the permit application process include a review of the site operations to see if any instances of unsafe operation or changes in regulation would require a change in the plant operation.

Response: The final rule maintains the lifetime permit provision and clarifies that the permit extends through the post-injection site care period (144.36(a)). However, it also adds a requirement that the Director review each Class VI permit at 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’ iterative 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 operators to review and update the AoR and corrective action plan, the testing and monitoring plan, and the emergency and remedial response plan throughout the life of the project (146.84(e), 146.90(j), and 146.94(d)). Owners or operators must review each plan and identify necessary amendments or demonstrate to the Director that no 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 tothe most critical aspects of the permit in preventing endangerment to USDWs.

EPA believes that the iterative process of developing and executing the various plans required of GS well operators in the final rule (e.g., for AoR and corrective action, testing and monitoring, well plugging, and post-injection site care, and emergency and remedial response) is tailored to the unique aspects of—and is more appropriate for–GS than establishing a finite permit duration (e.g., five years as suggested by some commenters). This is preferable to a periodic permit reapplication.

EPA adds that, in addition to the requirement that the Director review the permit every 5 years, as part of existing requirements at 40 CFR 144.39, the Director has the authority to revise the permit if project operations change, if the Director believes based on monitoring or operational data that the project may endanger USDWs, or if the regulations change. EPA has also added text to 144.39(a)(5) saying that permit modifications may be required if the Director determines that a modification is necessary based on an AoR reevaluation, amendments to any of the project plans, or a review of the testing and monitoring results. The Director may also choose to require minor permit modifications under 40 CFR 144.41, depending on the extent of the plan amendment. All permit modifications, except minor modifications under 40 CFR 144.41, require an opportunity for public comment on the portion of the permit that is being reopened.

Commenter Name: Michael Stroben Letter ID: 0209 Commenter Organization: Duke Energy Comment ID: 22679

Comment: The rule should not be made unnecessarily stringent by requiring detailed information for Class VI permit applications that may not be available during the early phases of the permit application process. A better approach would be to require the reporting of detailed information over time as it becomes available through operation of the well, site reevaluation, and corrective

action.

Response: EPA believes that the unique characteristics of CO2 injection (e.g., its relative buoyancy, the large volume that may be injected, or the potential for chemical interaction with the subsurface) warrant the additional information required to be submitted by GS operators under §146.82. These requirements are not unnecessarily stringent or burdensome. In order to protect USDWs from endangerment, Directors must have all the data they need to make well-informed decisions on establishing permit conditions and granting permits.

In response to concerns that some data will not be available until the well has been drilled, EPA acknowledges that not all of the information listed at §146.82 of the proposed regulation will be available at the time the owner or operator develops the permit application. Based on comments and evaluation of the proposed requirements, EPA revised this subpart so that the final regulation specifies separate requirements for information to be submitted for approval with the permit application before well construction, as required at §146.82(a), and information to be submitted after the well is constructed; however all information must be submitted before injection is authorized, as required at §146.82(c).

Commenter Name: Richard Guinn Letter ID: 0210 Commenter Organization: Eastman Chemical Company Comment ID: 22737

Comment: EPA is proposing that permit applications for GS sites include several plans not currently required under existing UIC regulations. These plans include amonitoring and testing plan, an AoR and corrective action plan, and a postinjection site care and site closure plan. EPA seeks comment on the merits of requiring plans for monitoring, AoR, and post-injection site care as part of a permit application. EPA Notice 112.

We believe that requiring a monitoring plan is reasonable. However, the EPA should develop such requirements with recognition of a distinct end to operations and monitoring following closure, and consider specific representations and codicils that recognize an end of "in-perpetuity" responsibility for the operator or owner.

Response: EPA clarifies that the owner or operator's approved testing and monitoring plan and postinjection site care and site closure plan will be incorporated as a condition of the UIC permit. GS well operators will be required to perform monitoring pursuant to the plans throughout the life of the facility (i.e., the duration of the Class VI permit). EPA adds that §146.93(b) requires operators to perform post-injection site monitoring until it can be demonstrated that the CO2 and pressure front no longer pose a risk of endangerment to USDWs. EPA notes that the post-injection monitoring may be different from monitoring that occurs during the operational phase (i.e., as required at §146.90). Once this demonstration is made, site closure may be authorized and monitoring is no longer required. EPA adds that owners or operators must maintain financial responsibility until site closure

has been authorized.

Please see the final rule and preamble, including the discussion of post-injection site care monitoring and financial responsibility for additional information.

Commenter Name: Paul L. Carpinone Letter ID: 0212 Commenter Organization: Tampa Electric Company Comment ID: 22909 Other EPA Comment Codes and Descriptions: 3150 2.1.5 Comments on required permit information (40 CFR 146.82)

Comment: - The Final Rule must not make the application process overly burdensome or unrealistic by requiring detailed information that may not be available at the time of the initial application; instead, the Final Rule should allow for submission of updated information regarding a CO2 GS well and its AoR as that

information becomes available.

Response: EPA disagrees that any of the protective requirements are unnecessary, and believes that the Class VI GS requirements for obtaining a permit are tailored so that they are appropriate for theunique nature of injecting large volumes of CO2 into a variety of geological formations for longterm storage.

EPA agrees that not all of the information listed at §146.82 of the proposed regulation will be available at the time the owner or operator develops their initial permit application. In response to comments and based on an evaluation of the proposed requirements at §146.82, the Agency revised this subpart so that the final regulation specifies separate requirements for information to be submitted with the permit application and before well construction is approved (at §146.82(a)) and information to be submitted before operation of the well is authorized (at §146.82(c)).

EPA believes that this revision of §146.82 addresses commenters' concerns regarding the timing of information to be submitted. In addition, section §146.82 in the final rule is similar to the permitapplication requirements for other injection well classes, which could help avoid confusion about how to meet the permitting requirements for Class VI wells. The requirements at §146.82(c) for information to be submitted before operation of the well is authorized are very similar to those for Class I wells, with modifications and additions that address the unique challenges and types of data

collected for GS wells.

Commenter Name: Diane VanDe Hei Letter ID: 0213 Commenter Organization: Association of Metropolitan Water Agencies (AMWA) Comment ID:

22926 Other EPA Comment Codes and Descriptions: 3150 2.1.5 Comments on required permit information (40 CFR 146.82)

Comment: Drinking water utilities must be consulted during the review of any CO2 sequestration permit application. AMWA recommends that as part of the process, all drinking water utilities that draw from an aquifer in the area of review (AoR) of a potential CO2 sequestration project should be informed and consulted.

Response: As part of the UIC permit review process in 40 CFR 124, the UIC program Director must notify certain stakeholders of any public hearings and the availability of the draft permit. EPA has added a requirement at §124.10(c)(1)(xi) that state and local oil and gas regulatory agencies and state agencies regulating mineral exploration and recovery, the PWSS program director, and all agencies that oversee injection wells in the state must be notified as part of the public notice process for a Class VI permit.

In addition, the existing public participation requirements for UIC permits at 40 CFR 124.10(c)(1)(x)(A) require notification "to any unit of local government having jurisdiction over the area where the facility is proposed to be located." EPA believes these requirements address the

commenter's concerns.

Commenter Name: Diane VanDe Hei Letter ID: 0213 Commenter Organization: Association of Metropolitan Water Agencies (AMWA) Comment ID:

22950

Comment: updates to the regulation are included in permit renewals. AMWA also suggests that the permit application process include a review of the site operations to see if any instances of unsafe operation or changes in regulation would require a change in the plant operation.

Response: EPA agrees that review of site operations is important and expects that the reevaluations of the site plans will provide such review. For example, the AoR reevaluations offer a good opportunity to promote a dialogue between the owner or operator and the permitting authority. 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 corrective action plan, the testing and monitoring plan, and the emergency and remedial response plan throughout the life of the project. Owners or operators must review each plan and identify necessary amendments to the plan or demonstrate to the Director that no amendment is needed. These reviews must be performed within one year of an AoR reevaluation, following any significant changes to the facility (e.g., the addition of monitoring or injection wells), or when required by the Director. In no case can reviews occur less often than once every five years. Please see the final rule and the discussion of AoR reevaluations in the preamble for additional information.Commenter Name: Barbara Walz Letter ID: 0216 Commenter Organization: Tri-State Generation and Transmission Association,

Inc. Comment ID:

22977

Comment: F. The final rule must not make the application process overly burdensome or unrealistic by requiring detailed information that may not be available at the time of the initial application. Instead, the final rule should allow for submission of updated information regarding a CO2 geologic sequestration well,

and its Area of Review as that information becomes available.

Response: The final rule permit application process is not overly burdensome or unrealistic. EPA acknowledges that not all of the information listed at §146.82 of the proposed regulation will be available at the time the owner or operator develops their initial permit application. In response to comments and based on an evaluation of the proposed requirements at §146.82, the Agency revised this subpart so that the final regulation specifies separate requirements for information to be submitted with the permit application and before well construction is approved (at §146.82(a)) and information to be submitted before operation of the well is authorized (at §146.82(c)). EPA believes that this revision of §146.82 addresses commenters' concerns regarding the timing of information to be submitted. Please see the final rule and the discussion of AoR reevaluations in the preamble for

additional information.

Commenter Name: Darrick Eugene Letter ID: 0223 Commenter Organization: Texas Carbon Capture and Storage Association Comment ID: 23969 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3150 2.1.5 Comments on required permit information (40 CFR 146.82)

Comment: 2. § 146.82 Required Class VI permit information

This section of the proposed rule sets forth the information which the owner or operator must submit to the Director in order to obtain a Class VI well permit. All of the information specified must be part of the permit application. But some data are not necessary in light of other provisions of the current proposal, and some are not attainable prior to well drilling (applicants will not drill the well until it has been approved, otherwise they risk drilling an unusable well). Still other data can only be obtained after injection activities have been initiated. Post drilling and post injection data should not be required as part of the application process but instead should be considered confirmatory data that may be submitted after they are obtained. In general, the proposed rule should be modified to require submission of only those data which are needed for consideration of the initial permit application, and only those data that may be reasonably obtained prior to commencement of installation and operation of the injection well.

EPA Proposed: §146.82 (f) Maps and stratigraphic cross sections indicating the general vertical and lateral limits of all USDWs, water wells and springs within the area of review, their positions relative to the injection zone(s) and the direction of water movement, where known;

So long as the Applicant proposes to inject CO2 below the lowermost USDW, as required by the proposed rule, there is no justification to require maps and stratigraphic cross sections for the entire extent of those USDWs above thelowermost USDW, although mapping and stratigraphic cross sections in the immediate vicinity of the proposed injection locations (e.g. where the injection wells will be drilled) should still be required. Data regarding all USDWs in the AoR will likely be costly and/or difficult to collect and, except as noted above, the usefulness of those data seems questionable.

Accordingly, TxCCSA suggests that subparagraph (f) should be modified as

follows:

(f) Maps and stratigraphic cross sections indicating the general

vertical and lateral limits of allTHE LOWERMOST USDWs, ALL USDWS IN THE IMMEDIATE VICINITY OF THE PROPOSED INJECTION WELL(S), water wells and springs within the area of review, their positions relative to the injection zone(s) and the direction of water movement, where known;

EPA Proposed : §146.82(l) The results of the formation testing program as required in paragraph (j) of this section; (r) All available logging and testing program data on the well required by § 146.87; (s) A demonstration of mechanical integrity pursuant to § 146.89;

The requirements of subparts (l), (r) and (s) of § 146.82 cannot be met until after the well is drilled. For example, subparagraph (l) references (j), formation testing. Clearly formation testing is a drilling or post completion operation. Similarly, logging and mechanical integrity testing also are drilling or post well completion operations. Because this information will be collected post application approval, it should not be required prior to the granting of the Class VI permit.

TxCCSA suggests that EPA modify § 146.82 to eliminate subparts (l), (r) and (s) because those data do not belong in and in fact may not be available as part of a permit application.

Response: EPA agrees that not all of the information listed at §146.82 of the proposed regulation will be available at the time the owner or operator develops their initial permit application. In response to comments and based on an evaluation of the proposed requirements at §146.82, the Agency revised this subpart so that the final regulation specifies separate requirements for information to be submitted with the permit application and before well construction is approved (at §146.82(a)) and information to be submitted before operation of the well is authorized (at §146.82(c)).

EPA believes that this revision of §146.82 addresses commenters' concerns regarding the timing of information to be submitted. In addition, section §146.82 in the final rule is similar to the permit application requirements for other injection well classes, which could help avoid confusion about how to meet the permitting requirements for Class VI wells. The requirements at §146.82(c) for information to be submitted before operation of the well is authorized are very similar to those for Class I wells, with modifications and additions that address the unique challenges and types of data

collected for GS wells.

Additionally, EPA disagrees with the commenter that there is no justification to require maps andstratigraphic cross sections for the entire extent of those USDWs above the lowermost USDW. EPA believes a thorough understanding of the hydrogeologic conditions of all USDWs in the AoR is necessary. EPA clarifies that §146.82(a)(5) requires, as part of the site characterization and permit application process, that operators submit maps and cross sections indicating the general vertical and

lateral limits of all USDWs within the area of review. This information will result in information on and a characterization of the number, location and depth of USDWs. The Director has the authority to request additional hydrogeologic data or other data on USDWs as well.

Commenter Name: Andrew Duguid Letter ID: 0226 Commenter Organization: Schlumberger Carbon Services Comment ID: 24066 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: §146.91 Reporting requirements.

Proposed Rule: (1) Any changes to the physical, chemical and other relevant characteristics of the carbon dioxide stream from the proposed operating data;

Schlumberger Suggested Revision: (1) Any significant changes to the physical,

chemical and other relevant characteristics of the carbon dioxide stream from the proposed operating data;

Schlumberger Rationale: Minor changes could just be due to uncertainty in

measurements or models

Response: EPA retained this provision as proposed. The final rule at §146.91(a)(3) requires reporting of all exceedances of operating parameters. EPA disagrees with the suggestion to report only "significant" exceedances. Making a determination as to whether an exceedance is "significant" is not the purpose of the requirement. EPA believes that the ability of an operator to consistently meet operating requirements and avoid exceedances provides evidence of a well-managed GS project that is in compliance with the Class VI permit. If multiple exceedances occur, the Director should be aware of such occurrences and determine whether these indicate non-compliance at the site, and require the appropriate course of action (e.g., a well workover, modification of operating parameters, or imposition of a penalty). Please see the final rule and the discussion of testing and monitoring in the preamble for additional information.

EPA clarifies that the rule, at §146.91(c), also requires operators to notify the Director, within 24 hours, of any event that may cause endangerment to a USDW. If such events occur outside of business hours (e.g., over night), operators must report to the Director within 24 hours, and permitting agencies have staff and procedures to respond to these types of calls 24 hours a day, 7 days a week.

Commenter Name: Neeraj Gupta Letter ID: 0229 Commenter Organization: Battelle Energy Technology (BET) Comment ID: 21811 Other EPA Comment Codes and Descriptions: 3150 2.1.5 Comments on required permit information (40 CFR 146.82)

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

Response: EPA is developing guidance on site characterization for GS projects to assist owners or operators and Directors in evaluating permit requirements and applications under §146.82. The guidance provides recommendations regarding characterizing the regional geology and hydrogeology of a proposed GS site as well as performing the necessary geochemical, geomechanical, and geophysical analyses of the injection and confining zone. EPA is also developing a number of technical guidances and implementation materials to assist owners or operators and Directors in the permitting process. EPA expects that these guidances will assist permit writers in performing many of the activities necessary for applying for a permit, including developing all required plans and conducting site characterizations that meet the requirements of §146.82. The guidance can be found on EPA’s website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Neeraj Gupta Letter ID: 0229 Commenter Organization: Battelle Energy Technology (BET) Comment ID: 21863 Other EPA Comment Codes and Descriptions: 3150 2.1.5 Comments on required permit information (40 CFR 146.82)

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

Response: EPA believes that the requirement that owners and operators develop an area of review (AoR) and corrective action plan, a testing and monitoring plan, an injection well plugging plan, a post-injection site care and site closure plan, and an emergency and remedial response plan are necessary to protecting USDWs from endangerment and does not believe they will result in delays to the permitting process. EPA anticipates that these plans will be attachments to the permit application and also acknowledges that not all information necessary to develop full plans will be available at the time of the initial permit application. For this reason, EPA envisions an iterative process where the owner or operator and the Director will discuss the site data being collected and how it will inform all aspects of the project, including the plans under §146.82. EPA is developing guidances to assist the owner or operator in preparing the project plans and meeting the financial responsibility requirements for GS wells. The guidances can be found on EPA’s website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Mark Bohrer Letter ID: 0241 Commenter Organization: North Dakota Industrial Commission Comment ID: 23256 Other EPA Comment Codes and Descriptions: 4610 2.6.1 Testing and monitoring plan requirement (seeking comment)

Comment: 34. EPA is proposing that permit applications for GS sites include several plans not currently required under existing UIC regulations. These plans include amonitoring and testing plan, an AoR and corrective action plan, and a postinjection site care and site closure plan. EPA seeks comment on the merits of requiring plans for monitoring, AoR, and post-injection site care as part of a permit application. EPA Notice 43517.Allowing for different plans would be much more effective than prescriptive regulations; however, a plan modification should not be considered a major permit modification. Caution needs to be taken when monitoring the injection formation due to the artificial penetration of the confining zone to gain data. The number of monitoring wells should be decided on a case-by case basis. It is unclear how monitoring wells will be regulated since they are not injection wells. The timing of plan submittal should be linked to the activity being

Response: EPA agrees with commenters that developing and following testing and monitoring plans is an important part of assuring that a GS project is operating properly and is crucial for the early detection of potential endangerment to USDWs.

EPA expects that the number of monitoring wells needed will be determined based on site-specific information as the testing and monitoring plan is developed. EPA believes that monitoring using wells in the injection zone (i.e., that penetrate the confining zone) can be safely performed if the wells are constructed to prevent flow between the injection zone and USDWs or other layers above the confining zone. Such construction technologies exist and have been used in the oil and gas industry for years. EPA believes that the benefits of monitoring in the injection formation outweigh the manageable risk of those monitoring wells serving as conduits for fluid movement.

EPA also agrees that periodic updates to the plan are appropriate. EPA clarifies that the final GS regulation includes a requirement that the AoR be reevaluated at least every 5 years, and it specifies at §146.90(j) that the operator revise the testing and monitoring plan to incorporate the results of the most recent AoR reevaluation and recent operational and monitoring data. EPA clarifies that every revision to the testing and monitoring plan will not necessarily trigger a major permit modification. The existing regulation at 40 CFR 144.39(a) identifies causes for modification of permits that would invoke the public notification procedures at 40 CFR 124, including: alterations or additions to the facility; availability of additional information; new regulations; and compliance schedule modifications. In the final rule, EPA added text to §144.39(a)(5) that permit modifications would be required if the Director determines that a modification is necessary based on an AoR reevaluation, amendments to any of the project plans, or a review of the testing and monitoring results.

In addition, 40 CFR Part 144.41 identifies causes for minor modifications of permits (which do not require following the procedures of Part 124). These include correction of typographical errors; more frequent monitoring or reporting; changes in an interim compliance date; changes in ownership or control of a facility; changes in the quantities or types of fluids injected which are within the capacity of the facility; changes in construction requirements; or amendments to a plugging and abandonment plan. In the final rule, EPA added a subparagraph (h) to §144.41 that would include minor amendments (e.g., to clarify, correct, or update) the testing and monitoring plan, plugging plan, post-injection site care and site closure plan, or emergency and remedial response plan for a GS well (i.e., amendments that are not included under 144.39(a)(5) and that do not require additional permit requirements).

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 recommended approaches for implementing a testing and monitoring plan, including pre-operational geophysical logging and testing of injection wells, MITs, injection well testing during operation, groundwater quality monitoring, tracking the CO2 plume and pressure front, and soil gas and surface air monitoring which may be required by the UIC Director for specific GS projects. The guidance can be found on EPA’s website athttp://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm. In addition, in January 2009, DOE published a best practices manual entitled "Monitoring, Verification, and Accounting of CO2 Stored in Deep Geologic Formations" (DOE/NETL-311/081508); this manual is included in the docket for the final GS rule. EPA notes that closure of monitoring wells should be addressed in the post-injection site care and site closure plan.

Commenter Name: Mark Bohrer Letter ID: 0241 Commenter Organization: North Dakota Industrial Commission Comment ID: 23257 Other EPA Comment Codes and Descriptions: 3150 2.1.5 Comments on required permit information (40 CFR 146.82)

Comment: wells. The timing of plan submittal should be linked to the activity being addressed. Site closure plans, post-closure plans, well plugging plans, etc., should not be required many years in advance since conditions, understanding of the sequestration zones, and technology change over time.

Response: EPA disagrees with the commenter's assertion that that the timing of plan submittals should be linked to the specific activity being addressed, and believes that submittal and review of each of the owner or operator's plans required at §146.82 at the time of the permit application is necessary for the Director to make a permit approval determination. While injection well plugging, post-injection site care and site closure will likely not occur for years after injection commences, the Director needs to have assurance that the owner or operator has planned for these events.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24869 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3130 2.1.3 Comments that operators should submit more (or different) geologic data than proposed

Comment: EPA Proposal: (b) A map showing the injection well(s) for which a permit is sought and the applicable area of review. Within the area of review, the map must show the number, or name and location of all injection wells, producing wells, abandoned wells, plugged wells or dry holes, deep stratigraphic boreholes, State or EPA approved subsurface cleanup sites, surface bodies of water, springs, mines (surface and subsurface), quarries, water wells and other pertinent surface features including structures intended for human occupancy and roads. [Highlighted text: The map should also show faults, if known or suspected.] Only information of public record is required to be included on this

map;

GWPC Recommendations: (b) A surface map showing the proposed locations for the injection well(s) for which a permit is sought and the applicable area of review. Within the area of review, the map must show the number, or name and location of all known injection wells, producing wells, abandoned wells, plugged wells or dry holes, deep stratigraphic boreholes, State or EPA approved subsurface cleanup sites, surface bodies of water, springs, mines (surface and subsurface), quarries, water wells and other pertinent surface features including structures intended for human occupancy and roads. Only information of public record is required to be included on this map;Rationale: Insert "known" before "injection"

Suggests removing highlighted text as faults are not shown on maps unless there is a surface expression of the fault. Also, faults are detailed in (d) below and this language appears redundant.

Response: Regarding the comment that EPA delete mention of faults on surface maps, EPA believes that if faults have surface expressions, they should be presented on maps submitted; this information would complement the required cross section data. EPA is developing guidance on site characterization for GS projects to assist owners or operators and Directors in evaluating permit requirements and applications under §146.82. The guidance provides recommendations regarding characterizing the regional geology and hydrogeology of a proposed GS site as well as performing the necessary geochemical, geomechanical, and geophysical analyses of the injection and confining zone. The guidance can be found on EPA’s website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm. Please see the final rule and the discussion of geologic site characterization in the preamble for additional information.

EPA acknowledges but did not make the suggested edits. EPA believes that all of the site characterization requirements at §146.82, including geomechanical information and geologic and topographic maps and cross sections, are essential to proper siting of a GS well and are the foundation for a detailed understanding of the local and regional geology, and that the owner or operator should collect this information, regardless of whether it is known in advance of the siting process. Collecting and evaluating this data supports important evaluations regarding the suitability of the site to receive and contain injected CO2.

EPA acknowledges that some smaller fractures may not be detectable during the site characterization process, and clarifies that §146.82(a)(3)(ii) requires the owner or operator to submit data on known or suspected faults and fractures (i.e., not all fractures). Other requirements for GS injection wells and sites can mitigate the potential impacts of unidentified fractures. These include limitations on injection pressures to avoid propagation of existing fractures in the confining zone (§146.88(a)), collection and assessments of CO2 monitoring data at the site, and AoR reevaluations (§146.84(e)) to assess possible CO2 movement through high-permeability regions (i.e., faults and/or fractures) not

detected in the initial site characterization.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24870 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3100 2.1 Proposed Geologic Siting Requirements (40 CFR 146.83)

Comment: EPA Proposal: (c) The area of review based on modeling, using data obtained during logging and testing of the well and the formation as required by paragraphs (l), (r), and (s) of this section;

GWPC Recommendations: (c) A map delineating the area of review based upon modeling, using all available data including data available from any logging and testing of wells within the area of review.

Rationale: Is this supposed to be a map, a tabular display, a cross section or series of cross sections etc... This appears to be related to a condition where a well is already drilled. This does not align with requesting information toreceive a permit.

Response: EPA recognizes that information necessary for an area of review may not be available until after a well has been drilled and formation testing can occur. EPA revised §146.82 so that the final regulation specifies separate requirements for information to be submitted with the permit application and before well construction is approved (at §146.82(a)) and information to be submitted before operation of the well is authorized (at §146.82(c)) including The final area of review based on modeling, using data obtained during logging and testing of the well and the formation §146.82(c)(1).

Based on its evaluation of all public comments and input on the proposed rule and NODA and Response to Comments EPA has made many revisions to the GS Rule. See the final rule and the site characterization discussion in the preamble for further discussion on EPA's final approach.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24871 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3130 2.1.3 Comments that operators should submit more (or different) geologic data than proposed

Comment: EPA Proposal: (d) Information on the geologic structure and hydrogeologic properties of the proposed storage site and overlying formations, including:

(1) Maps and cross sections of the area of review;

(2) Location, orientation, and properties of known or suspected faults and fractures that may transect the confining zone(s) in the area of review and a determination that they would not interfere with containment;

GWPC Recommendations: (d) Sufficient information on the geologic structure and reservoir properties of the proposed storage site and overlying formations, including:

(1) Isopach maps of the proposed injection and confining zone(s), a structural contour map aligned with the top of the proposed injection zone, and at least two geologic cross sections of the area of review reasonably perpendicular to each other showing the geologic formations from the surface to total depth.

(2) Location, orientation, and properties of known or suspected subsurface faults that may transect the confining zone(s) in the area of review and a determination that they would not interfere with containment;

Rationale: Fractures can be incredibly small and it is virtually impossible to

find all subsurface fractures. The GWPC also recommends addition of the term "Sufficient" before the information sought in (d) as this is more precise.

Response: EPA acknowledges that some smaller fractures may not be detectable during the site characterization process, and clarifies that §146.82(a)(3)(ii) requires the owner or operator to submit data on known or suspected faults and fractures (i.e., not all fractures). Other requirements for GS injection wells and sites can mitigate the potential impacts of unidentified fractures. These includelimitations on injection pressures to avoid propagation of existing fractures in the confining zone (§146.88(a)), collection and assessments of CO2 monitoring data at the site, and AoR reevaluations (§146.84(e)) to assess possible CO2 movement through high-permeability regions (i.e., faults and/or fractures) not detected in the initial site characterization.

EPA disagrees with the other suggested edits because the GS rule, as written, affords flexibility to owners or operators and Directors to tailor the site characterization process to the unique features of the site. Please see the final rule and the discussion of geologic site characterization in the preamble

for additional information.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24872 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3130 2.1.3 Comments that operators should submit more (or different) geologic data than proposed

Comment: EPA Proposal: (3) Information on seismic history including the presence and depth of seismic sources and a determination that the seismicity would not interfere with containment;

(4) Data on the depth, areal extent, thickness, mineralogy, porosity, permeability and capillary pressure of the injection and confining zone(s); including geology/facies changes based on field data which may include geologic cores, outcrop data, seismic surveys, well logs, and names and lithologic descriptions;

(5) Geomechanical information on fractures, stress, ductility, rock strength, and in situ fluid pressures within the confining zone; and

GWPC Recommendations: (3) Information on seismic history that have affected the proposed area of review including knowledge of previous seismic events and history of these events, including the presence and depth of seismic sources and a determination that the seismicity would not compromise containment;

(4) Data sufficient to demonstrate the effectiveness of the injection and confining zone(s), including data on the depth, areal extent, thickness, mineralogy, porosity, vertical permeability reservoir pressure and of the injection and confining zone(s) within the area of review; including geologic changes based on field data which may include geologic cores, outcrop data, seismic surveys, well logs, capillary pressure tests and names and lithologic descriptions;

(5) Geomechanical information on the confining zone(s) within the area of review; and

Rationale: Capillary pressure is too hard to measure outside the lab; how comparable are lab results to what goes into the ground. Sidewall core may not be sufficient to do this, and it is difficult to core the whole of the confining and injection zones. Rewording keeps the usefulness of capillary pressure in the provision without making it a mandatory use.Response: EPA acknowledges that laboratory methods are standard for determining capillary pressures regardless of formation permeability and that in situ measurements would require drilling of a well. However, EPA also anticipates that test wells will be drilled to support geologic site characterization of the proposed GS sites and can be used to collect subsurface samples (for laboratory determination of capillary pressure) and take other necessary measurements. EPA believes that information on capillary entry pressure is necessary and appropriate. Capillary entry pressure measurements on core samples can quantify the amount of buoyant force the confining zone can maintain before failure (World Resources Institute, 2008).

EPA recognizes that this information may not be available until after a well has been drilled. EPA revised §146.82 so that the final regulation specifies separate requirements for information to be submitted with the permit application and before well construction is approved (at §146.82(a)) and information to be submitted before operation of the well is authorized (at §146.82(c)). Final information on injection zone pressures would be required following drilling of the well, at §146.82(c)(4).

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24873 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3100 2.1 Proposed Geologic Siting Requirements (40 CFR 146.83)

Comment: EPA Proposal: (6) Geologic and topographic maps and cross sections illustrating regional geology, hydrogeology, and the geologic structure of the local area.

GWPC Recommendations: Support the EPA language.

Response: EPA acknowledges the comment and the final rule retains the text as proposed.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24874 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3100 2.1 Proposed Geologic Siting Requirements (40 CFR 146.83)

Comment: Rule Provision: 146.82(e)

EPA Proposal: (e) A tabulation of all wells within the area of review which penetrate the injection or confining zone(s). Such data must include a description of each well’s type, construction, date drilled, location, depth, record of plugging and/ or completion, and any additional information the Director may require;

GWPC Recommendations: (e) A compilation of all artificial penetrations within the area of review which penetrate the injection or confining zone(s). Such data must include a description of each well’s type, construction, date drilled, location, depth, record of plugging and/ or completion, and any additional information the Director may require;

Rationale: The GWPC felt that the term compilation was more appropriate than tabulation because tabulation as tabulation implies a spreadsheet whilecompilation can take numerous forms.

Response: EPA used the term tabulation in the final rule because it is the same term used in the same requirement for other well classes; and, the regulated community and permitting officials are familiar with existing terminology.

Based on its evaluation of all public comments and input on the proposed rule and NODA and Response to Comments EPA has made many revisions to the GS Rule. See the final rule and preamble for further discussion on EPA's final approach.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24875 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3100 2.1 Proposed Geologic Siting Requirements (40 CFR 146.83)

Comment: EPA Proposal: (f) Maps and stratigraphic cross sections indicating the general vertical and lateral limits of all USDWs, water wells and springs within the area of review, their positions relative to the injection zone(s) and the direction of water movement, where known;

GWPC Recommendations: (f) Maps and stratigraphic cross sections indicating the general vertical and lateral limits of all USDWs, the location of water wells and perennial springs within the area of review, their positions relative to the injection zone(s) and the direction of water movement, where known;

Rationale: Clarification: Use of the term perennial before springs will prevent a requirement to list very minor, intermittent springs which are not hydrologically significant.

Response: EPA acknowledges the comment; however, the final rule does not reflect the suggested edit. The Agency uses the term “springs” in the site characterization requirements for other classes of wells (see §146.70 (a)(2)) and the term is familiar to the regulated community and permitting officials. EPA adds that characterization will be site-specific, and owners or operators are encouraged to discuss the site with the Director as data are collected to identify thresholds for certain types of data.

Based on its evaluation of all public comments and input on the proposed rule and NODA and Response to Comments EPA has made many revisions to the GS Rule. See the final rule and preamble for further discussion on EPA's final approach.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24876 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3100 2.1 Proposed Geologic Siting Requirements (40 CFR 146.83)

Comment: EPA Proposal: (g) Baseline geochemical data on subsurface formations, including all USDWs in the area of review;

GWPC Recommendations: (g) Compilation of available baseline geochemical data on the proposed injection zone and nearest adjacent porous and permeable formationto the confining zone, existing utilized water supply aquifers and any other USDWs designated by the Director.

Rationale: It will be unduly burdensome to address "all USDWs" in some contexts. This revision allows for more appropriate focusing on those USDWs designated by

the Director.

Response: EPA believes that identifying and mapping all surrounding USDWs near an injection well, as specified at §146.82(a)(5), is necessary to ensure protection of all USDWs from endangerment. The purpose of the UIC requirements (including those for Class VI wells) is to ensure the protection of USDWs from endangerment, which are defined based on total dissolved solids (TDS) content, not their location or depth (40 CFR §144.3).

EPA adds that knowing the number, location and depth of USDWs near an injection well will generate baseline regional information, support development of an effective testing and monitoring plan, and enhance owner or operator and Director understanding of the site. This requirement is common to all injection well classes.

Based on its evaluation of all public comments and input on the proposed rule and NODA and Response to Comments EPA has made many revisions to the GS Rule. See the final rule and preamble for further discussion on EPA's final approach.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24877 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3150 2.1.5 Comments on required permit information (40 CFR 146.82)

Comment: EPA Proposal: (h) Proposed operating data:

(1) Average and maximum daily rate and volume of the carbon dioxide stream; (2) Average and maximum injection pressure; (3) The source of the carbon dioxide stream; and (4) An analysis of the chemical and physical characteristics of the carbon dioxide stream;

GWPC Recommendations: (h) Proposed operating data:

(1) Average and maximum daily injection rate and volume of the carbon dioxide

stream; (2) Average and maximum surface injection pressure; (3) The source of the carbon dioxide stream; and (4) An analysis of the chemical and physical characteristics of the carbon dioxide stream;

Rationale: Clarification: Addition of the term surface in (h)(d) will make it clear as to where the injection pressure is to measured.

Rule Provision: 146.82(i)

EPA Proposal: (i) The compatibility of the carbon dioxide stream with fluids inthe injection zone and minerals in both the injection and the confining zone(s), based on the results of the formation testing program, and with the materials used to construct the well;

(j) Proposed formation testing program to obtain an analysis of the chemical and physical characteristics of the injection zone and confining zone;

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

EPA Proposal: (k) Proposed stimulation program and a determination that stimulation will not interfere with containment;

(l) The results of the formation testing program as required in paragraph (j) of this section;

(m) Proposed procedure to outline steps necessary to conduct injection operation;

(n) Schematic or other appropriate drawings of the surface and subsurface construction details of the well;

(o) Injection well construction procedures that meet the requirements of §
146.86;

GWPC Recommendations: (k) Proposed stimulation program and a determination that stimulation will not compromise containment;

(l) The results of the formation testing program as required in paragraph (j) of this section;

(m) Proposed procedure to outline steps necessary to conduct injection operation;

(n) A wellbore schematic of the subsurface construction details and surface

wellhead construction.

(o) Injection well construction procedures that meet the requirements of §
146.86;

Rationale: "Interfere" is too ambiguous and should be replaced by "compromise" which limits concerns to situations where containment may be lost.

EPA Proposal: (p) Proposed area of review and corrective action plan that meets the requirements under § 146.84;

(q) The status of corrective action on wells in the area of review;

(r) All available logging and testing program data on the well required by §
146.87;(s) A demonstration of mechanical integrity pursuant to § 146.89;

(t) A demonstration, satisfactory to the Director, that the applicant has met the financial responsibility requirements under § 146.85;

GWPC Recommendations: (p) Proposed corrective action plan for artificial penetrations within the area of review, if necessary

(q) All available logging and testing program data on the well required by §
146.87;

(r) The proposed demonstration method for mechanical integrity pursuant to

(s) A demonstration, satisfactory to the Director, that the applicant has met the financial responsibility requirements under § 146.85;

Rationale: (q) Should be deleted because it is not part of an applicationprocess but, rather a post permitting activity. This would result in a renumbering of the subsections after the new (q).

Rule Provision: 146.82(u)

EPA Proposal: (u) Proposed testing and monitoring plan required by § 146.90;

(v) Proposed injection well plugging plan required by § 146.92(b);

(w) Proposed post-injection site care and site closure plan required by § 146.93(a);

(x) Proposed emergency and remedial response plan required by § 146.94; and

(y) Any other information requested by the Director.

GWPC Recommendations: (t) Proposed testing and monitoring plan required by §
146.90;

(u) Proposed injection and monitoring well(s) plugging plan required by § 146.92(b);

(v) Proposed post-injection site care and site closure plan required by § 146.93(a);

(w) Proposed emergency and remedial response plan required by § 146.94; and

(x) Any other information requested by the Director.

Rationale: Need to address the plugging of monitoring well(s), if any, included in the project.Response: EPA acknowledges the commenter’s support for portions of the subject requirements. EPA disagrees that the technical clarifications suggested are necessary. EPA adds that it is developing guidance for owners or operators on the geologic site characterization and AoR and corrective action processes. These guidances will provide recommendations and clarify the intent of all required elements of a permit application. The guidances can be found on EPA’s website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Craig Hart Letter ID: 0261 Commenter Organization: Alston & Bird LLP Comment ID: 22985

Comment: Experience in Phase II with SDWA Permitting

Based on interviews with the lead implementing organizations in each regional partnership, the time and cost associated with preparing SDWA permit applications, and the time required for agency review, have caused delays and can impose burdens on small-scale research projects due to limited financial and staff resources. EPA review of permit applications is generally expected to require between 6 to 9 months based on EPA estimates provided to certain of the partnerships in informal consultations. State agency review under Class II, where available, is expected to require less time, in some cases requiring only

1 to 2 months.

Response: EPA disagrees that it should streamline or provide a different approval process for smallvolume operators. To protect USDWs from endangerment the information required to be submitted with the permit application under §146.82 is necessary and appropriate to provide permitting authorities sufficient information on which to base informed decisions about establishing permit conditions and granting permits. The purpose of these requirements is to protect USDWs from endangerment, and like large-volume operations, small-volume operations must be permitted and operated in manner that is protective of USDWs.

EPA is preparing guidances to support permit application reviews for Class VI permits, including guidance for primacy authorities and an addendum to UICPG #83 that describes the use of the Class V experimental technology well classification following promulgation of the GS Class VI rule. The guidances will be available on EPA's web site, at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Craig Hart Letter ID: 0261 Commenter Organization: Alston & Bird LLP Comment ID: 22987 Other EPA Comment Codes and Descriptions: 1530 1.2.3.1 State regulatory efforts on GS (seeking comment)

Comment: Examples of Streamline Permitting in CCS Regimes and U.S. Environmental Law

The State of Washington's Underground Injection Control Program allows streamline permitting under Class V for small-scale pilot injections of under 1,000 metric tons or larger volumes by application.[FN5] Australia has adopted a phased permitting process, which includes an assessment permit.[FN6]

[FN5] Wash. Admin. Code, 173-218-115(4)(b).[FN6] Nigel Bankes and Jenette Poschwatta, Australian Legislation on Carbon Capture and Storage: A Canadian Perspective (June 2008), available at www.iseee.cajfilesjiseeejbankesJesearch_paper.pdf.

Response: EPA clarifies that, with the promulgation of the GS rule, it no longer considers it appropriate to permit CO2 injection wells that are testing the injectivity or appropriateness of an individual formation (e.g., as a prelude to a commercial-scale operation) as Class V experimental technology wells. Such wells should be permitted as Class VI wells. EPA clarifies that Class V experimental technology wells may be used for experimental projects designed to test new technologies.

EPA is preparing an addendum to UICPG #83 that describes the use of the Class V experimental technology well classification to clarify permitting for Class V wells. This addendum will address shifting of Class V experimental projects to full-scale GS projects and the future use of the Class V experimental technology well subclass for research and testing of new GS technologies.

Throughout the regulatory development process for the Class VI regulation, EPA monitored states' regulatory and legislative development efforts and approaches. In EPA's August 31, 2009, Notice of Data Availability (NODA) and Request for Comment, the Agency described its ongoing monitoring of states' regulatory efforts and approaches and how the Agency is considering this information as it develops guidance on the primacy application and approval process for Class VI wells. Information about these state activities may be found in the docket for the GS rule.

EPA disagrees with the suggestion that it should streamline or provide a different approval process for small-volume operators. To protect USDWs from endangerment, EPA believes that the information required to be submitted with the permit application under §146.82 is necessary and appropriate to provide permitting authorities sufficient information on which to base informed decisions about establishing permit conditions and granting permits. The purpose of theserequirements is to protect USDWs from endangerment, and like large-volume operations, smallvolume operations must be permitted and operated in manner that is protective of USDWs.

EPA clarifies that small scale, experimental research injection wells, such as those operated by the Regional Carbon Sequestration Partnerships, will continue to be regulated as Class V experimental wells as long as they remain small scale and of an experimental nature. Permitting of these wells is addressed in UIC Program Guidance #83: Using the Class V Experimental Technology Well Classification for Pilot Carbon Geologic Sequestration Projects.

Existing pilot projects will continue to be regulated under their Class V experimental well permits and must meet the reporting requirements set forth in their individual permit. EPA expects that, as the permits for these Class V projects expire, they will either be re-permitted as Class VI wells (subject to reporting requirements at §146.91) or, if they continue to be of an experimental nature, they may continue to be permitted as Class V experimental technology wells (subject to the reporting requirements in the permit). EPA is preparing an addendum to UICPG #83 that describes the use of the Class V experimental technology well classification following promulgation of the GS Class VI rule. The guidance will address shifting of Class V experimental projects to full-scale GS projects and the future use of the Class V experimental technology well subclass for research and testing of new GS technology. The guidance will be available on EPA's web site, at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.Commenter Name: Craig Hart Letter ID: 0261 Commenter Organization: Alston & Bird LLP Comment ID: 22988 Other EPA Comment Codes and Descriptions: 4000 2.4 Proposed Injection Well Operating Requirements (40 CFR 146.88)

Comment: Other U.S. environmental laws, such as the Toxic Substances Control Act, also provide precedent for a streamline permitting approach in other contexts.[FN7]

Options for a Streamline Review Procedure

A common feature of streamline permitting schemes is a quantified limit, which in the case of CCS, would likely be a volume limit. The advantages of quantified volume limit include that it provides greater certainty for research organizations and allows EPA to allocate resources to higher volume CCS injections that pose more significant risks.

While no specific volume limit is suggested here, EPA should consider several factors for setting such a limit. A volume limit should be differentiated base on type of formation, site pressure, and other site-specific conditions. Such a limit could change (likely increase) along with our knowledge of a particular formation and experience with CO2 injections for purposes of permanent sequestration generally. Finally, in addition to considerations relating to protection of drinking water sources, a volume limit should be based on the needs of advancing research and the risks to health and safety, including workers, the general population, flora and fauna. CCS assessment models have been developed by our national laboratories specifically to address these kinds of risks.[FN8]

[FN7] TSCA governs the manufacture, processing, use, distribution in commerce, and disposal of chemical substances and mixtures. It provides for varying levels of expedited review and exemption from regulations in qualifying research, low volume commercial production, and low release low exposure commercial production. See Elizabeth Brown et al., A Practitioner's Guide to the Toxic Substance Control Act, Environmental Law Institute, 1999.

[FN8] See Curtis M. Oldenburg and Steven L. Bryant, Certification Framework for Geologic CO2 Storage, Sixth Annual Conference on Carbon Capture and Sequestration, National Energy Technology Laboratory, Pittsburgh, PA, May 7-10, 2007 available at www.netl.doe.govjpublicationsjproceedingsj07jcarbonseqjdatajpapersjtue_062.pdf; Curtis M. Oldenburg, Steven L. Bryant, JeanPhilippe Nicot, and Ying Zhang, Certification Framework for Geologic Carbon Sequestration Based on Effective Trapping, Seventh Annual Conference on Carbon Capture and Sequestration, National Energy Technology Laboratory, Pittsburgh, PA, May 5-8, 2008; Curtis M. Oldenburg, Steven L. Bryant, Jean-Philippe Nicot, Certification Framework for Geologic Carbon Sequestration Based on Effective Trapping (forthcoming 2008).

Response: As described above, EPA disagrees with the suggestion that it should streamline the approval process for small-volume operators. EPA believes that the information required to be submitted with the permit application under §146.82 is necessary and appropriate to provide permitting authorities sufficient information on which to base informed decisions about establishingpermit conditions and granting permits. The purpose of these requirements is to protect USDWs from endangerment, and like large-volume operations, small-volume operations must be permitted and operated in manner that is protective of USDWs.

EPA disagrees with the suggestion to set a volume limit. EPA believes that the potentially widerrange of injection scenarios, formation types, and other site-specific factors necessitate a sitespecific approach, and permit limits that are based on the unique geology of the site. The injection pressure limit for each GS project will be based on site-specific conditions, and be informed by data on the injection zone.

Commenter Name: Craig Hart Letter ID: 0261 Commenter Organization: Alston & Bird LLP Comment ID: 22989 Other EPA Comment Codes and Descriptions: 1852 1.4.2.1 DOE Regional Carbon Sequestration Partnerships

Comment: As EPA considers its proposed rule for Class VI wells under the SDWA UIC program, we will have additional information about the CCS permitting process from the DOE RCSP Phases II and III projects. As part of its review of the proposed rules for Class VI injection wells, EPA should take account of this experience and consider providing an improved permitting regime for small-scale research projects in order to facilitate CCS research and development efforts.

Response: The final rule allows owners or operators to continue using the Class V experimental well permit process for small-scale projects that are experimental in nature. EPA believes that the Class V and Class VI permitting requirements are necessary to protect USDWs from endangerment, and are based on site-specific and project-specific information, including CO2 volume. EPA believes that the requirements for GS owners or operators are flexible enough to take into account plant operating data, including the volume to be injected.

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

EPA is using an adaptive approach to regulating GS under the UIC Program. Even after finalizing the rule, the Agency plans to collect and review data every six years on GS projects, including data generated by the partnerships, to determine whether the appropriate amount and types of information and appropriate documentation are being collected, and to determine if modifications to the requirements are appropriate or necessary.

As described above, EPA disagrees with the suggestion that it should streamline the approval process for small-volume operators. EPA believes that the information required to be submitted with the permit application under §146.82 is necessary and appropriate to provide permitting authorities sufficient information on which to base informed decisions about establishing permit conditions and granting permits. The purpose of these requirements is to protect USDWs from endangerment, and like large-volume operations, small-volume operations must be permitted and operated in manner that is protective of USDWs.

Letter ID: 0263 Commenter Organization: Interstate Oil & Gas Compact Commission Comment ID: 22821Comment: III A. 7 Proposed Recordkeeping and Reporting Requirements

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

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

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

EPA also believes that it is appropriate to require owners and operators to submit all plans, including the injection well plugging and post-injection site care and site closure plans, at the time of permit application. The owner or operator must demonstrate to the Director a satisfactory level of assurance that the they have planned for these events before injection commences and that they have ensured that appropriate financial resources 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 expects that the requirement for this and other plans associated with GS projects will promote an ongoing dialogue between the owner or operator and the Director to ensure USDWs are protected from endangerment. Please see the final rule and the discussion of GS project plans in the preamble for additional information.

Commenter Name: Scott Anderson Letter ID: 0520 Commenter Organization: Environmental Defense Fund Comment ID: 21431 Other EPA Comment Codes and Descriptions: 1620 1.3.2 Induced seismicity; 4110 2.4.1.1 Injection pressure limitations

Comment: Injection pressure limits. This is very important and we think EPA's about halfway toward addressing this properly. The half that seems to be well done is that the proposed rule requires quite a bit of geomechanical information to be submitted. The kind of information that could be used, should be used to determine whether or not there is a risk of induced seismicity and to determine whether or not there is risks of reopening otherwise closed faults and fractures making them, making what starts out as a non-transmissive fault into a transmissive fault. So the proposed rule calls for the information that enables that kind of stuff to be calculated, but it fails to require that information to be used as part of the permitting process to inform the injection pressure limits. Instead the rule uses the traditional sort of injection pressure limit from oil and gas regulation that says accepted as a percentage of fracture pressure. The problem with that is that these other problems I mentioned, induced seismicity and reopening of faults can occur in lower pressures than say 90% of fracture pressure, it is possible for one to comply with the 90% of fracture pressure requirement and yet still cause these other geomechanics related problems.

Response: EPA clarifies that all information about the site, including seismic history and data on rock mechanics, will be used to inform pressure limitations.In response to the concern about induced seismicity and reopening of faults at lower pressures than 90 percent of fracture pressure, EPA believes that the requirement for the owner or operator to submit data on known or suspected faults and fractures and information on the seismic history of the site, including the presence and depth of seismic sources and a determination that the seismicity would not interfere with containment per §146.82(a)(3)(v), will inform the determination of an appropriate pressure limitation in the permit. This investigation would also identify any sites with the potential for reopening or reactivation of faults or unacceptable seismic risk that could otherwise

interfere with containment.

The Director will also review geologic, hydrogeologic, and geomechanical information submitted by the owner or operator in setting permit conditions. If, based on this information, a lower pressure limitation is appropriate, the Director has the authority to set a lower limit in the operating permit. EPA clarifies that fracturing of the confining zone during injection and/or stimulation is also prohibited at §146.88(a).

Commenter Name: Kevin Frederick Letter ID: 0525 Commenter Organization: Wyoming Department of Environmental Quality Comment ID: 21396 Other EPA Comment Codes and Descriptions: 1420 1.2.1.1 Support the GS rulemaking

Comment: A few specific comments on issues where we agree with EPA's proposed rule. We believe that permit applications for GS sites should include several plans, not currently required under existing UIC regulations. These plans include a monitoring, a testing plan and an area of review and corrective action plan and a post injection site care and site closure plan.

Response: EPA believes that the GS requirements, which are based on the long-standing UIC regulatory framework and tailored to meet the unique nature of CO2 injection for GS, appropriately address endangerment risks to USDWs. The GS rule contains minimum technical criteria for the permitting, geologic site characterization, AoR and corrective action, well construction, operation,mechanical integrity testing, monitoring, financial responsibility, injection well plugging, postinjection site care, and site closure of GS wells, which will ensure that USDWs are protected from endangerment.

For additional information on testing and monitoring, corrective action, and post-injection site care requirements, please also see the discussion of EPA’s Final Regulatory Approach in the preamble to

the final GS rule.

EPA agrees that incorporating the plans into the permit rather than establishing specific requirements for corrective action, monitoring, injection well plugging, and post-injection site care in the regulation provide the appropriate flexibility to address the variety of site-specific conditions that may be encountered at GS sites.

EPA also believes that it is appropriate to require owners and operators to submit all plans, including the injection well plugging and post-injection site care and site closure plans, at the time of permit application. EPA believes that the Director needs a satisfactory level of assurance that the owner or operator has planned for these events before injection commences and that the owner or operator has ensured that appropriate financial resources 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 believes that the requirement for this and other plans associated with GS projectswill promote an ongoing dialogue between the owner or operator and the Director to ensure USDWs are protected from endangerment. In addition, these plans will support a demonstration that owners and operators have adequate financial resources to meet well plugging and post-injection site care and site closure requirements. Please see the final rule and the discussion of the GS project plans in the preamble for additional information.

Commenter Name: Paul Pike Letter ID: 0535 Commenter Organization: Ameren Corporation on behalf of Utility Solid Waste Activities Group (USWAG) Comment ID:

21441

Comment: A final rule must not make Class VI permit application process overly burdensome or unrealistic by requiring detailed information that may not be available at the time of the initial application. Instead the final rule should allow for submission of updated information regarding Class VI well and its area of review

as that information becomes available.

Response: EPA believes that the unique characteristics of CO2 injection (e.g., its relative buoyancy, the large volume that may be injected, or the potential for chemical interaction with the subsurface) warrant the additional information required to be submitted by GS operators under §146.82. EPA disagrees that Directors should be able to waive some of the application requirements. To protect USDWs from endangerment, Directors must have all the data they need to make well-informed decisions on establishing permit conditions and granting permits.

In response to concerns that some data will not be available until the well has been drilled, EPA acknowledges that not all of the information listed at §146.82 of the proposed regulation will be available at the time the owner or operator develops the permit application. Based on comments and evaluation of the proposed requirements, EPA revised this subpart so that the final regulation specifies separate requirements for information to be submitted for approval with the permit application before well construction, as required at §146.82(a), and information to be submitted after the well is constructed yet before injection is authorized, as required at §146.82(c). Please see the final rule and the discussion of permitting and geologic site characterization in the preamble for

additional information.

Commenter Name: Olon Plunk Letter ID: 0536 Commenter Organization: Xcel Energy Comment ID: 21377 Other EPA Comment Codes and Descriptions: 3100 2.1 Proposed Geologic Siting Requirements (40 CFR 146.83)

Comment: In the meantime, I would like to offer some general observations. Having been through this effort to locate and prove up the acceptability of a CO2 sequestration site for a large commercial scale project, Excel believes the topics EPA would require permit applicant to address in its proposed rules are appropriate and important. For example, we believe the best technical expertise should be brought to bear in the first studying and then submitting documentation concerning site and formation geology, hydro-geology, faults, fractures, injectivity, existing wells and so on.

Response: EPA acknowledges the comment and agrees on the importance of the required permit information set in §146.82. EPA believes that the extensive requirements for geologic site characterization at §146.82 are appropriate to ensure that permitting authorities have the necessaryinformation to evaluate whether a specific site will allow safe injection of CO2.

Comment Code: 4720 2.7.2 Operational recordkeeping and reporting



### Individual Comments

Commenter Name: Leslie Savage Letter ID: 0122 Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24793 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4520 2.5.1 Continuous internal mechanical integrity monitoring (seeking comment)

Comment: (b) To evaluate the absence of significant leaks under paragraph (a)(1) of this section, owners or operators must, following an initial annulus pressure test, continuously monitor injection pressure, rate, injected volumes, and pressure on the annulus between tubing and long stem casing and annulus fluid volume as specified in §146.88(e);

{Redundant language.}

Response: The final rule retains this text to provide clarity about requirements for demonstrating internal mechanical integrity and to specify the necessary monitoring. EPA believes that continuous pressure monitoring to demonstrate internal mechanical integrity of Class VI wells (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 integrity due to CO2 phase changes, and the temperature and pressure effects associated with injecting supercritical CO2.

For additional information, please see the discussion of MITs in the final rule preamble.

Commenter Name: John Hanger Letter ID: 0130 Commenter Organization: Pennsylvania Dept. of Env. Protection Comment ID: 21513

Comment: Proposed Recordkeeping and Reporting Requirements

-The chemistry of the gas stream will be affected by the fuel source and the operating conditions of the capture and purification systems. These data, while not the responsibility of the operator, can have significant impacts on the gas constituents. Semi-annual reports will not be timely in identifying these impacts. The operator should require reports from the gas source, which can be forwarded to EPA as part of the semi-annual report, or as an additional submittal between the semi-annual reports. Once parameters of operations are known, the reports could be waived or modified. A specific example of a potential concern: Power Plant A receives a modification to its air permit from a non-primacy state. The modification allows the burning of petcoke, which commonly has a high vanadium content. Vanadium oxides can form on operating surfaces, affecting capture system efficiencies, or possible modifying down-hole behavior. This type of change could greatly affect the overall system.

-Also, operating performance of the gas suppliers’ systems should be monitored.Changes in characteristics such as pressure drop, filter cloth efficiencies, increases or changes in dilution air, etc., can affect the quality of the CO2

stream.

Response: EPA is retaining the semi-annual reporting requirement in the final rule at §146.91(a) in order to ensure that permitting authorities can maintain proper oversight and track compliance of GS projects, particularly in the early stages of rule implementation and deployment of GS technologies. The Agency also clarifies that permitting authorities may choose to require more frequent reporting,

at the discretion of the Director.

EPA cannot reply specifically as to whether any change to the CO2 stream or the fuel source would warrant a change in the permit. However, it is possible that a permit may have to be modified for these reasons. Section 144.39(a) identifies causes for modification of permits that would invoke the public notification procedures at Part 124, including: alterations or additions to the facility; availability of additional information; new regulations; and compliance schedule modifications. EPA added text to §144.39(a)(5) that permit modifications would be required if the Director determines that a modification is necessary based on an AoR reevaluation, amendments to any of the project plans, or a review of the testing and monitoring results.

If the source of the injectate changes, the Director must evaluate whether this change warrants a modification of the permit or is a minor modification based on site-specific information about the injection project, including geologic information about the injection and confining zones, formation fluids, and the well's construction. If the injectate from the new source were within the capacity of the facility, this would be considered a minor modification per §144.41(h); otherwise the Director must initiate a public process regarding the change in the permit.

Please see the final rule and the discussion of testing and monitoring for GS projects in the preamble

for additional information.

Commenter Name: Bonnie Lovelace Letter ID: 0152 Commenter Organization: Montana Department of Environmental Quality (MDEQ) Comment ID:

22119 Other EPA Comment Codes and Descriptions: 4730 2.7.3 Reporting associated with closure and post-injection site care

Comment: 18. EPA seeks comment on frequency of all reporting requirements. MDEQ believes that the proposed timeframe for post-closure recordkeeping and reporting is too short (page 43517). These projects are major facilities that should require a longer period of monitoring at least similar to other major industries. A 10-year minimum would be consistent with, for example, many surface mining operations that allow for reclamation to meet requirements. EPA's discussion of other factors for post-closure site care suggests at least a 10-year period. Seismic and surface level carbon dioxide monitoring needs to be continued. Further, this requirement should include the annual reporting that EPA considered, including the content listed.

Response: EPA agrees and believes that data collected during the post-injection phase should be retained throughout the post-injection site care timeframe and for ten years following site closure. EPA agrees with commenters who suggested that well plugging reports be retained for longer than one year. EPA has clarified the recordkeeping requirements in the final GS rule, which includesrequirements that well plugging reports, as required at §146.92(d), post-injection site care data, as required at §146.93(f), and site closure reports, as required at §146.93(h), be kept for ten years after

site closure.

EPA believes that longer record retention requirements for Class VI wells are appropriate and necessary for the post-injection and site closure period to ensure that data are available to support non-endangerment demonstrations and to address any concerns that may arise following site closure. This data will also support EPA's review of project data as part of the adaptive rulemaking approach.

See the final rule and preamble for further discussion on EPA's final approach to post-injection site

care.

Commenter Name: James Dooley Letter ID: 0156 Commenter Organization: Joint Global Change Research Institute, Pacific Northwest National Laboratory Comment ID:

22644

Comment: Much Data Is Collected; But how is it used and who has access to the data?

o Page 43514 includes a requirement that mechanical integrity be demonstrated annually, but it does not say what is done with this information or what it is used for. How long is this data retained?

o Page 43514 includes a requirement that owners / operators report semi-annually on the injection pressure, flow rate, temperature, volume and annular pressure

and on MIT test results. What is the data collection method and who will have access to these data? Is it an open website like the Toxic Report Inventory (TRI) where any citizen could view this information, or is it a single hard copy report locked in a state or regional EPA office that can only be seen via a FOIA request by members of the public or other stakeholders?

Response: EPA has clarified the recordkeeping requirements in the final GS rule, which includes requirements that well plugging reports, as required at §146.92(d), post-injection site care data, as required at §146.93(f), and site closure reports, as required at §146.93(h), be kept for ten years aftersite closure. See the final rule and preamble for further discussion on EPA's final approach to postinjection site care.

EPA will use the data to verify that the well and the site are behaving as predicted and within permitted guidelines to ensure that USDWs are protected from endangerment. In addition, the data may be used as evidence of a violation of a permit requirement that may result in an enforcement action under SDWA. The Agency clarifies that owners or operators may claim confidential business information under existing UIC regulations at §144.5. These requirements are applicable to all well

classes.

Commenter Name: James Dooley Letter ID: 0156 Commenter Organization: Joint Global Change Research Institute, Pacific Northwest National Laboratory Comment ID:

22647

Comment: o Page 43517 contains a requirement to report various data on the performance of GS on a semi-annual basis, but again it is not clear how these data will be used, retained, or who has access to them.Response: EPA has clarified the recordkeeping requirements in the final GS rule, which includes requirements that well plugging reports, as required at §146.92(d), post-injection site care data, as required at §146.93(f), and site closure reports, as required at §146.93(h), be kept for ten years aftersite closure. See the final rule and preamble for further discussion on EPA's final approach to postinjection site care.

EPA will use the data to verify that the well and the site are behaving as predicted and within permitted guidelines to ensure that USDWs are protected from endangerment. In addition, the data may be used as evidence of a permit violation that would result into an enforcement action. The Agency clarifies that owners or operators may claim confidential business information under existing UIC regulations at §144.5. These requirements are applicable to all well classes.

Commenter Name: Theresa Pugh Letter ID: 0169 Commenter Organization: American Public Power Association Comment ID: 23418 Other EPA Comment Codes and Descriptions: 5800 2.13 Comments on emergency and remedial response (40 CFR 146.94)

Comment: data point. We also suggest that the EPA have some reasonable test for response to the state or Federal permitting agency in the event that a reporting event happens on a weekend or during nighttime hours. Some owner/operators will be on different time zones than the injection well operator. APPA suggests that a reasonable time be allowed for reporting to be sent in on routine data where there is no catastrophic reporting event.

Response: EPA clarifies that the requirement at §146.94(b)(3) is to notify the Director within 24 hours of an emergency. The Agency believes that the 24 hour timeframe for notifying the Director is a "reasonable" time period. Furthermore, permitting agency response personnel are typically "on call" 24 hours a day, 7 days a week.

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24186 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4520 2.5.1 Continuous internal mechanical integrity monitoring (seeking comment)

Comment: Rule Provision: 146.89(b)

API Comments: (b) To evaluate the absence of significant leaks under paragraph (a)(1) of this section, owners or operators must, following an initial annulus pressure test, continuously monitor AND RECORD AT LEAST DAILY, ANNULUS PRESSURE

AND VOLUMES OF PACKER FLUID INJECTED OR REMOVED FROM injection pressure, rate,

injected volumes, and pressure onthe annulus between THE tubing and long

stemSTRING casing and annulus fluid volume as specified in §146.88 (e);

Rationale: Technical clarification.

Response: EPA agrees with the commenter regarding the importance of demonstrating internal mechanical integrity (MI), but disagrees with the suggested changes. Class VI injection wells must be equipped with dedicated computer-based continuous pressure monitoring devices in concert withthe shut-off systems required for GS wells, which typically take readings several times per second (i.e., more frequently than daily) and record them electronically in a computer system. See §146.88. For additional information, please see the discussion of MITs in the final rule preamble.

EPA also disagrees that it is necessary to report volumes of packer fluid injected or removed. EPA agrees with the commenter that recording annulus fluid volume may not be appropriate. EPA believes that knowing annulus fluid volume (146.88(e)) is a necessary component of monitoring well mechanical integrity, but believes that knowing the annulus fluid volume added is sufficient to meet the intent of the requirement. The final GS rule requires that owners or operators use continuous recording devices to monitor injection pressure, rate, and volume, as well as the pressure on the annulus between the tubing and the long string casing. It also modifies the requirement in the proposed rule to continuously monitor annulus fluid volume; it now requires recording of annulus fluid volume added. See §§146.88(e); 146.89(b); and 146.90 (b).

The final rule includes the suggested change from “long-stem” to “long-string” casing.

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24198 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.91(a)

API Comments: (a) Semi-annual OR LESS FREQUENT AT THE DISCRETION OF THE

DIRECTOR reports containing: (1) Any SIGNIFICANT changes to the physical, chemical and other relevant characteristics of the carbon dioxide stream from the proposed operating data;

Rationale: Over the life of the project, the Director may decide that less reporting is acceptable

(1) Technical clarification. Significance can be determined by a statistical analysis of the data. Rules should recognize that there will be minor variations in many data sets over time.

Rule Provision: 146.91(a)

API Comments: (3) A description of any SIGNIFICANT event that exceeds operating parameters for annulus pressure or injection pressure as specified in the permit; (4) A description of any SIGNIFICANT event which triggers a shutdown device required pursuant to §146.88(e) and the response taken;

Rationale: EPA should consider some significance threshold on reporting these events to avoid reporting events that would be of limited interest or

consequence.

Response: EPA disagrees that less frequent than semi-annual reporting is appropriate to protect USDWs from endangerment. The Agency believes semi-annual reporting is appropriate andnecessary for Class VI wells during the operational phase of the project. EPA believes that the potentially large injection volumes and injection pressures associated with GS warrant more frequent reporting than for other well classes. See the final rule and preamble for further discussion on EPA's final approach to testing and monitoring.

EPA also retained the provision at §146.91(a)(3) as proposed. The final rule at §146.91(a)(3) requires reporting of all exceedances of operating parameters. EPA disagrees with the suggestion to report only "significant" exceedances. Making a determination as to whether an exceedance is "significant" is not the purpose of the requirement. EPA believes that the ability of an operator toconsistently meet operating requirements and avoid exceedances provides evidence of a wellmanaged GS project that is in compliance with the Class VI permit. If multiple exceedances occur, the Director should be aware of such occurrences, determine whether these indicate problems at the site, and determine the appropriate course of action (e.g., a well workover, modification of operating parameters, or imposition of a penalty).

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24475 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4520 2.5.1 Continuous internal mechanical integrity monitoring (seeking comment)

Comment: Rule Provision: 146.89(b)

Proposed CCS Group Recommendations: (b) To evaluate the absence of significant leaks under paragraph (a)(1) of this section, owners or operators must, following an initial annulus pressure test, continuously monitor AND RECORD AT
LEAST DAILY, ANNULUS PRESSURE AND VOLUMES OF FLUID ADDED TO OR

REMOVED FROM injection pressure, rate, injected volumes, and pressure onthe annulus between the tubing and long stem string casing and annulus fluid volume as specified in §146.88 (e);

Basis for CCS Group Comments: We recommend continuous monitoring, but do not find continuous recording necessary as Class II requirements have proven sufficient. The alternative of continuous monitoring, which will alert operator to any problems, and daily recording to allow for daily check of wells. This is consistent with successful Class II operating experience.

Response: EPA agrees with the commenter regarding the importance of demonstrating internal mechanical integrity (MI). Class VI injection wells will be equipped with dedicated computer-based continuous pressure monitoring devices, in concert with the shut-off systems required for GS wells, which typically take readings several times per second (i.e., more frequently than daily) and record them electronically in a computer system. 40 CFR §146.91(a)(2) requires that monthly averages of the continuous annulus monitoring be reported on a semiannual basis.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24487 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.91(a)(1)Proposed CCS Group Recommendations: (1) Any SIGNIFICANT changes to the physical,

chemical and other relevant characteristics of the carbon dioxide stream from the proposed operating data;

Basis for CCS Group Comments: (1) Technical clarification. Significance can be determined by a statistical analysis of the data. Rules should recognize that there will be minor variations in many data sets over time.

Response: EPA retained this provision as proposed. The final rule at §146.91(a)(3) requires reporting of all exceedances of operating parameters. EPA disagrees with the suggestion to report only "significant" exceedances. Making a determination as to whether an exceedance is "significant" is not the purpose of the requirement. EPA believes that the ability of an operator to consistently meet operating requirements and avoid exceedances provides evidence of a well-managed GS project that is in compliance with the Class VI permit. If multiple exceedances occur, the Director should be aware of such occurrences, and that information will aid in his/her determination of whether these indicate problems at the site, and what is the appropriate course of action (e.g., a well workover, modification of operating parameters, or imposition of a penalty) to remediate such problem(s).

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24488 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.91(a)(3) & (4)

Proposed CCS Group Recommendations: (3) A description of any SIGNIFICANT event that exceeds operating parameters for annulus pressure or injection pressure as specified in the permit;

(4) A description of any SIGNIFICANT event which triggers a shutdown device required pursuant to §146.88(e) and the response taken;

Basis for CCS Group Comments: EPA should consider some significance threshold on reporting these events to avoid reporting events that would be of limited interest or consequence.

Response: EPA retained this provision as proposed. The final rule at §146.91(a)(3) requires reporting of all exceedances of operating parameters. EPA disagrees with the suggestion to report only "significant" exceedances. Making a determination as to whether an exceedance is "significant" is not the purpose of the requirement. EPA believes that the ability of an operator to consistently meet operating requirements and avoid exceedances provides evidence of a well-managed GS project that is in compliance with the Class VI permit. If multiple exceedances occur, the Director should be aware of such occurrences, and that information will aid in his/her determination of whether these indicate problems at the site, and what is the appropriate course of action (e.g., a well workover, modification of operating parameters, or imposition of a penalty) to remediate such problem(s).Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24489 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4740 2.7.4 Electronic reporting (seeking comment)

Comment: Rule Provision: 146.91(b) & (c)

Proposed CCS Group Recommendations: Support the proposed language.

Basis for CCS Group Comments: Agree with EPA’s rationale.

Response: EPA acknowledges the comment and the final rule retains the text as proposed. See the final rule and preamble for further discussion on EPA's final approach to reporting and recordkeeping.

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24698 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4520 2.5.1 Continuous internal mechanical integrity monitoring (seeking comment)

Comment: Rule Provision: 146.89(b)

Anadarko Petroleum Corporation (APC) Comments: (b) To evaluate the absence of significant leaks under paragraph (a)(1) of this section, owners or operators must, following an initial annulus pressure test, continuously monitor AND
RECORD AT LEAST DAILY, ANNULUS PRESSURE AND VOLUMES OF PACKER FLUID

INJECTED OR

REMOVED FROM injection pressure, rate, injected volumes, and pressure onthe annulus between THE tubing and long stemSTRING casing and annulus fluid volume as specified in §146.88 (e);

Rationale: Technical clarification.

Response: EPA agrees with the commenter regarding the importance of demonstrating internal mechanical integrity (MI), but disagrees with the suggested changes. Class VI injection wells will be equipped with dedicated computer-based continuous pressure monitoring devices in concert with the shut-off systems required for GS wells, which typically take readings several times per second (i.e., more frequently than daily) and record them electronically in a computer system. 40 CFR §146.91(a)(2) requires that monthly averages of the continuous annulus monitoring be reported on a

semiannual basis.

40 CFR §146.91(a)(2) requires that monthly averages of the continuous annulus monitoring be reported on a semiannual basis. EPA agrees with the commenter that recording annulus fluid volume may not be appropriate. EPA believes that annulus fluid volume (146.88(e)) is a necessary component of monitoring well mechanical integrity, but believes that knowing the annulus fluid volume added is sufficient to meet the intent of the requirement. The final GS rule requires that owners or operators use continuous recording devices to monitor injection pressure, rate, and volume, as well as the pressure on the annulus between the tubing and the long string casing. It also modifies the requirement in the proposed rule to continuously monitor annulus fluid volume; it now requires recording of annulus fluid volume added. See §§146.88(e), 146.89(b), and 146.90 (b). The final rule implements the suggested change from “long-stem” to “long-string” casing.Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24711 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.91(a)

Anadarko Petroleum Corporation (APC) Comments: (a) Semi-annual OR LESS FREQUENT AT THE DISCRETION OF THE DIRECTOR reports containing:

(1) Any SIGNIFICANT changes to the physical, chemical and other relevant characteristics of the carbon dioxide stream from the proposed operating data;

Rationale: Over the life of the project, the Director may decide that less reporting is acceptable

(1) Technical clarification. Significance can be determined by a statistical analysis of the data. Rules should recognize that there will be minor variations in many data sets over time.

Response: EPA retained this provision as proposed. The final rule at §146.91(a)(3) requires reporting of all exceedances of operating parameters. EPA disagrees with the suggestion to report only "significant" exceedances. Making a determination as to whether an exceedance is "significant" is not the purpose of the requirement. EPA believes that the ability of an operator to consistently meet operating requirements and avoid exceedances provides evidence of a well-managed GS project that is in compliance with the Class VI permit. If multiple exceedances occur, the Director should be aware of such occurrences, and that information will aid in his/her determination of whether these indicate problems at the site, and what is the appropriate course of action (e.g., a well workover, modification of operating parameters, or imposition of a penalty) to remediate such problem(s).

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24712 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.91(3) & (4)

Anadarko Petroleum Corporation (APC) Comments: (3) A description of any SIGNIFICANT event that exceeds operating parameters for annulus pressure or injection pressure as specified in the permit;

(4) A description of any SIGNIFICANT event which triggers a shutdown device required pursuant to §146.88(e) and the response taken;

Rationale: EPA should consider some significance threshold on reporting these events to avoid reporting events that would be of limited interest or

consequence.

Response: EPA retained this provision as proposed. The final rule at §146.91(a)(3) requiresreporting of all exceedances of operating parameters. EPA disagrees with the suggestion to report only "significant" exceedances. Making a determination as to whether an exceedance is "significant" is not the purpose of the requirement. EPA believes that the ability of an operator to consistently meet operating requirements and avoid exceedances provides evidence of a well-managed GS project that is in compliance with the Class VI permit. If multiple exceedances occur, the Director should be aware of such occurrences, and that information will aid in his/her determination of whether these indicate problems at the site, and what is the appropriate course of action (e.g., a well workover, modification of operating parameters, or imposition of a penalty) to remediate such problem(s).

Commenter Name: Chris M. Hobson Letter ID: 0201 Commenter Organization: Southern Company Comment ID: 22160 Other EPA Comment Codes and Descriptions: 4710 2.7.1 Proposed submissions required for permit applications (seeking comment)

Comment: Permit Application

Southern Company opposes EPA's proposed requirements for Class VI permit applications to the extent that those requirements are more burdensome than current permit application requirements for other classes of UIC wells. id. at 43517. C02 GS does not pose unique risks warranting many of the Proposal's additional requirements for detailed information.

EPA should craft the Final Rule to require in the initial permit application

information that the Director will need to determine whether issuance of a Class VI permit is appropriate. EPA could require submission of supplemental information as it becomes available through drilling, construction, and reevaluation of the well. This will not only prevent against the chilling effect that overly burdensome permit application requirements would have on the CO2 GS program, but will simultaneously ensure the ultimate collection of more thorough

and reliable data.

Response: EPA believes that the unique characteristics of CO2 injection (e.g., its relative buoyancy, the large volume that may be injected, or the potential for chemical interaction with the subsurface) warrant the additional information required to be submitted by Class VI operators under §146.82. EPA disagrees that Directors should have the authority to waive some of the application requirements. In order to protect USDWs from endangerment, Directors must have all the data necessary to make well-informed decisions on establishing permit conditions and granting permits.

In response to concerns that some data will not be available until the well has been drilled, EPA acknowledges that not all of the information listed at §146.82 of the proposed regulation will be available at the time the owner or operator develops their Class VI permit application. Based on comments and evaluation of the proposed requirements, EPA revised this subpart so that the final regulation specifies separate requirements for information to be submitted for approval with the permit application before well construction, as required at §146.82(a), and information to be submitted after the well is constructed; however, all data must be provided before injection is authorized, as required at §146.82(c).

Commenter Name: Neeraj Gupta Letter ID: 0229Commenter Organization: Battelle Energy Technology (BET) Comment ID: 21862

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

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

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24916 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4520 2.5.1 Continuous internal mechanical integrity monitoring (seeking comment)

Comment: EPA Proposal: (b) To evaluate the absence of significant leaks under paragraph (a)(1) of this section, owners or operators must, following an initial annulus pressure test, continuously monitor injection pressure, rate, injected volumes, and pressure on the annulus between tubing and long stem casing and annulus fluid volume as specified in § 146.88(e);

GWPC Recommendations: (b) To evaluate the absence of significant leaks under paragraph (a)(1) of this section, owners or operators must, following an initial annulus pressure test, continuously monitor and record at least daily injection pressure, rate, injected volumes, and pressure on the annulus between tubing and long stem casing and annulus fluid volume as specified in §146.88 (e);

Rationale: We believe that injection parameters must not only be monitored but should be recorded at least daily. We further believe the use of monitoring with digital equipment which records readings on an appropriate frequency should be considered continuous for purposes of this section.

Response: EPA believes that continuous pressure monitoring to demonstrate internal mechanical integrity of Class VI wells required at §146.89(b) is important, given the potential corrosive impact of CO2 and impurities on well materials, the potential geomechanical impacts to well integrity due to CO2 phase changes, and the temperature and pressure effects associated with injecting supercritical CO2. EPA also believes that the technology for continuous monitoring is practicable, available, andis currently in fairly wide use. Class VI injection wells will be equipped with dedicated computerbased continuous pressure monitoring devices (in concert with the shut-off systems required for GS wells), which typically take readings several times per second (i.e., more frequently than daily) and record them electronically in a computer system. 40 CFR §146.91(a)(2) requires that monthly averages of the continuous annulus monitoring be reported on a semiannual basis. For additional information, please see the discussion of MITs in the final rule preamble.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24933Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.91(a)

EPA Proposal: (3) A description of any event that exceeds operating parameters for annulus pressure or injection pressure as specified in the permit; (4) A description of any event which triggers a shutdown device required pursuant to § 146.88(e) and the response taken; (5) The monthly volume of the carbon dioxide stream injected over the reporting period and project cumulatively; (6) Monthly annulus fluid volume added; and (7) The results of monitoring prescribed under § 146.90.

GWPC Recommendations: (3) A description of any event that significantly exceeds operating parameters for annulus pressure or injection pressure as specified in the permit; (4) A description of any event which triggers a shutdown device required pursuant to §146.88(e) and the response taken;

Rationale: EPA should consider some significance threshold on reporting these events, to avoid reporting events would be of limited interest or consequence.

Response: EPA retained this provision as proposed. The final rule at §146.91(a)(3) requires reporting of all exceedances of operating parameters. EPA disagrees with the suggestion to report only "significant" exceedances. Making a determination as to whether an exceedance is "significant" is not the purpose of the requirement. EPA believes that the ability of an operator to consistently meet operating requirements and avoid exceedances provides evidence of a well-managed GS project that is in compliance with the Class VI permit. If multiple exceedances occur, the Director should be aware of such occurrences, and that information will aid in his/her determination of whether these indicate problems at the site, and what is the appropriate course of action (e.g., a well workover, modification of operating parameters, or imposition of a penalty) to remediate such problem(s).

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24934 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4740 2.7.4 Electronic reporting (seeking comment)

Comment: EPA Proposal: (b) Report, within 30 days the results of:

(1) Periodic tests of mechanical integrity; (2) Any other test of the injection well conducted by the permittee if required by the Director; and (3) Any well workover.

(c) Owners or operators must submit reports in an electronic format acceptable to the Director. At the discretion of the Director, other formats may be accepted.

GWPC Recommendations: Support the proposed EPA language.Rationale: Agree with EPA’s rationale.

Response: EPA acknowledges the comment. Please see the final rule and the discussion of reporting preamble for additional information on EPA's final rulemaking approach.

EPA believes that electronic formatting is the most appropriate format for submitting Class VI project information to the Director, and that many GS well owners or operators will have the capability to report electronically.

Comment Code: 4730 2.7.3 Reporting associated with closure and post-injection site care



### Individual Comments

Commenter Name: Michael H. Cochran Letter ID:

0108 Commenter Organization: Bureau of Water, Division of Environment, Kansas Department of Health & Environment (KDHE) Comment

ID: 21988 Other EPA Comment Codes and Descriptions: 5300 2.8.3 Site closure activities (40 CFR 146.93)

Comment: 146.93 (f): This will be impractical for large sequestration projects due to the paperwork and legal work to deal with a significant number of parties.

Response: EPA disagrees that the owner or operator should not be responsible for record retention such as site closure reports. EPA believes that the requirements that the owner or operator retain for ten years following site closure, records collected during the post-injection site care period at §146.93(f) and §146.93(h) are appropriate for the post-injection and site closure period to ensure that data are available to support non-endangerment demonstrations and to address any concerns that may arise following site closure. This data will also support EPA's review of project data as part of the adaptive rulemaking approach.

Commenter Name: Leslie Savage Letter ID: 0122 Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24801 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5200 2.8.2 Post injection site care (seeking comment) (40 CFR 146.93)

Comment: (4) THE OWNER OR OPERATOR MAY May modify and resubmit the post-injection site care and site closure plan for the Director's approval within 30 days of such change.

Response: Based on its evaluation of all public comments and input on the proposed rule and NODA and Request for Comment EPA has made many revisions to the GS Rule. See the final rule and preamble for further discussion on EPA's final approach.

Commenter Name: Leslie Savage Letter ID: 0122 Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24805 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule languageComment: (c) Notice of intent for site closure. Must notify the Director at least 120 days before site closure. At this time, if any changes have been made to the original post-injection site care and site closure plan, THE OWNER OR OPERATOR must also provide the revised plan. At the discretion of the Director, a shorter notice period may be allowed.

Response: Based on its evaluation of all public comments and input on the proposed rule and NODA and Request for Comment EPA has made many revisions to the GS Rule. See the final rule and discussion of post-injection site care in the preamble to the rule for further discussion on EPA's final approach.

Commenter Name: Leslie Savage Letter ID: 0122 Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24807 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5300 2.8.3 Site closure activities (40 CFR 146.93)

Comment: (e) Once the Director has authorized site closure, THE OWNER OR OPERATOR must submit a site closure report within 90 days that must thereafter be retained at a location designated by the Director. The report must include:

(1) Documentation of appropriate injection and monitoring well plugging as specified in §146.92 and paragraph (c) of this section. Must provide a copy of a survey plat which has been submitted to the local zoning authority designated by the Director, which indicates the location of the injection well relative to permanently surveyed benchmarks. Must also submit a copy of the plat to the regional administrator of the appropriate EPA Regional Office ;

{Why is this necessary? The EPA regional office will have access to all records at the State. }

Response: The GS regulation at §146.93(g) requires the owner or operator to record a notation on the deed to the facility property or other similar document examined during a title search that the land has been used to sequester CO2 at the time of site closure.

Commenter Name: Leslie Savage Letter ID: 0122 Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24808 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5300 2.8.3 Site closure activities (40 CFR 146.93)

Comment: (f) THE OWNER OR OPERATOR MUST Mustrecord a notation on the deed to the facility property or any other document that is normally examined during title search that will in perpetuity provide any potential purchaser of the property the following information:

(1) The fact that land has been used to sequester carbon dioxide; (2) The name of the State agency, local authority, and/or tribe with which the survey plat was filed , as well as the address of the Regional EPA Office to

which it was submitted ; and (3) The volume of fluid injected, the injection

zone or zones into which it was injected, and the period over which injection occurred.Response: The GS regulation at §146.93(g) requires the owner or operator to record a notation that the land has been used to sequester CO2 on the deed to the facility property at the time of site

closure.

Commenter Name: Leslie Savage Letter ID: 0122 Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24809 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5300 2.8.3 Site closure activities (40 CFR 146.93)

Comment: (g) Must retain for three years following site closure, records collected during the post-injection site care period. THE OWNER OR OPERATOR MUST Must deliver the records to the Director at the conclusion of the retention period, and the records must thereafter be retained at a location designated by the Director for that purpose.

Response: EPA disagrees that the owner or operator should not be responsible for record retention such as site closure reports. EPA believes that the requirements that the owner or operator retain for ten years following site closure, records collected during the post-injection site care period at §146.93(f) and §146.93(h) are appropriate for the post-injection and site closure period to ensure that data are available to support non-endangerment demonstrations and to address any concerns that may arise following site closure. This data will also support EPA's review of project data as part of the adaptive rulemaking approach.

Commenter Name: Christine Reimer Letter ID: 0142 Commenter Organization: National Ground Water Association Comment ID: 22611 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Proposed Rule: 146.92(b)

Proposed revision: (b) Well Plugging Plan. The owner or operator of a Class VI well must prepare; maintain; including updating on the same schedule as the update to the Area of Review; and comply with a plan that is acceptable to the Director. The requirement to maintain and implement an approved plan is directly...

Rationale: The Area of Review re-evaluation should trigger a review and updating of all the plans (MMV, financial, plugging, emergency response...) on the same interval that the AOR is updated. NGWA suggests EPA check all timelines and make them compatible.

Response: EPA agrees that the AoR reevaluations offer a good opportunity to promote a dialogue between the owner or operator and the permitting authority. Additionally, EPA recognizes that the AoR reevaluation has the potential to change or add important data to the other project plans and therefore the Agency agrees that the other Class VI plans must be updated when an AoR reevaluation takes place. 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 corrective action plan, the testing and monitoring plan, and the emergency and remedial response plan throughout the life of the project. Owners or operators must review each plan and identify necessary amendments to the plan or demonstrate tothe Director that no amendment is needed. These reviews must be performed within one year of an AoR reevaluation, following any significant changes to the facility (e.g., the addition of monitoring or injection wells), or when required by the Director. In no case can reviews occur less often than once every five years. EPA is preparing guidance for owners or operators on developing and updating all of the required GS project plans. The guidance will be available on EPA's web site, at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm. See the final rule and preamble for further discussion on EPA's final approach regarding the GS project plans.

Commenter Name: Christine Reimer Letter ID: 0142 Commenter Organization: National Ground Water Association Comment ID: 22612 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5100 2.8.1 Injection well plugging activities (seeking comment) (40 CFR 146.92)

Comment: Proposed Rule: 146.92(d)

Proposed revision: (d) Plugging Reports for Class VI Wells. Within 60 days after completion of plugging and abandonment of a well or well field the permittee shall submit to the Director a final report which includes:

Proposed addition: (1) Certification of completion in accordance with approved plans and specifications by an appropriately qualified engineer of record or professional geologist.

Note: It is important that the engineer and/or geologist have expertise and training in injection well drilling technology, reservoir characterization and injection well construction and operation.

Proposed addition: (2) Evidence, such as a sealed copy or certification from the county clerk, that a surveyor's plot of the location of the abandoned well has been recorded in the county courthouse property records.

Response: EPA agrees that appropriately qualified personnel (e.g., engineers and geologists) should be involved in all aspects of the GS operation, including the well plugging process. When the owner or operator (and/or the person who performs the plugging operation) signs the plugging report and certifies it as accurate; they are attesting to the fact that all required activities were performed by qualified personnel. This is required under §146.92(d) and is a condition of the permit that is enforceable under §1423 of the SDWA. EPA clarifies that, in addition to requiring appropriate well plugging, the Director retains the option of witnessing any plugging activity or testing at the well.

EPA clarifies that §146.93(g) requires the owner or operator, as part of the closure process, to record a notation on the deed stating that the property was used for GS. In addition, §146.93(f)(1) requires submission of a survey plat indicating the location of the well to the local zoning authority, as well

as to the Director.

Commenter Name: Christine Reimer Letter ID: 0142 Commenter Organization: National Ground Water Association Comment ID: 22613 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5220 2.8.2.1 Post-injection monitoring activities

Comment: Proposed Rule: 146.93(a)Proposed revision: (a) The owner or operator of a Class VI well must prepare; maintain; including updating on the same schedule as the update to the Area of Review; and comply with a plan for post-injection site care and site closure that meets the requirements of paragraph (a)(2) of this section and is acceptable to the Director.

Rationale: The Area of Review re-evaluation should trigger a review and updating of the well plugging plan, and the post injection site care and closure plan. NGWA suggests EPA check all timelines and make them compatible.

Response: EPA agrees with the commenter that, in some cases, the appropriate post-injection monitoring strategy may end up being different than initially projected at the time of permit application and there may be a need to amend the post-injection site care and site closure plan. EPAis requiring that upon the cessation of injection, the owner or operator submit an amended postinjection site care and site closure plan or demonstrate to the Director that no changes to the original post-injection site care and site closure plan are necessary, as specified in §146.93(a)(3). EPA is not requiring formal periodic review and updates to the PISC and site closure plan throughout the injection phase. EPA does not expect that changes to this plan would be implemented until injection operations cease. EPA envisions that owners or operators will take into account similar considerations that guide updates to other project plans, e.g., monitoring and operational data and

results of AoR reevaluations.

EPA has also added a new provision at §144.39(a)(5) requiring a modification, revocation, or reissuance of a Class VI permit whenever the Director determines that a change in the permit is necessary based on an amended AoR and corrective action plan, testing and monitoring plan, injection well plugging plan, post-injection site care and site closure plan, or emergency and remedial response plan is necessary. This would invoke the public notification procedures of 40 CFR Part 124 and the modification would be incorporated into the permit. EPA adds that, if any monitoring or other site data indicate a need for amending the post-injection site care plan, the owner or operator is expected to amend the plan accordingly.

Commenter Name: Bonnie Lovelace Letter ID: 0152 Commenter Organization: Montana Department of Environmental Quality (MDEQ) Comment ID:

22119 Other EPA Comment Codes and Descriptions: 4720 2.7.2 Operational recordkeeping and reporting

Comment: 18. EPA seeks comment on frequency of all reporting requirements. MDEQ believes that the proposed timeframe for post-closure recordkeeping and reporting is too short (page 43517). These projects are major facilities that should require a longer period of monitoring at least similar to other major industries. A 10-year minimum would be consistent with, for example, many surface mining operations that allow for reclamation to meet requirements. EPA's discussion of other factors for post-closure site care suggests at least a 10-year period. Seismic and surface level carbon dioxide monitoring needs to be continued. Further, this requirement should include the annual reporting that EPA considered, including the content listed.

Response: EPA agrees and believes that data collected during the post-injection phase should beretained throughout the post-injection site care timeframe and for ten years following site closure. EPA agrees with commenters who suggested that well plugging reports be retained for longer than one year. EPA has clarified the recordkeeping requirements in the final GS rule, which includes requirements that well plugging reports, as required at §146.92(d), post-injection site care data, as required at §146.93(f), and site closure reports, as required at §146.93(h), be kept for ten years after

site closure.

EPA believes that longer record retention requirements for Class VI wells are appropriate and necessary for the post-injection and site closure period to ensure that data are available to support non-endangerment demonstrations and to address any concerns that may arise following site closure. This data will also support EPA's review of project data as part of the adaptive rulemaking approach.

See the final rule and preamble for further discussion on EPA's final approach to post-injection site

care.

Commenter Name: James Dooley Letter ID: 0156 Commenter Organization: Joint Global Change Research Institute, Pacific Northwest National Laboratory Comment ID:

22650 Other EPA Comment Codes and Descriptions: 5280 2.8.2.4 USDW non-endangerment

demonstrations

Comment: o Page 43517. Records retention of only 3 years after site closure. That seems incredibly short. Also it is not clear how this requirement to hold on to these data for three years after site closure is consistent with the owner operators requirement to discharge its responsibilities under the post closure period including establishing that non-endangerment continues to be the case. Wouldn’t access to baseline and data collected during the period of principal operations be needed to report out these findings during the period of post closure. This short record retention period also seems to undercut assertion of a open continuous dialogue being a center piece of how USEPA and any states that have Class VI primacy will ensure public safety.

Response: EPA has changed the recordkeeping requirement in the final rule to require that owners or operators retain records collected during the post-injection site care period for at least 10 years following site closure. EPA believes that the requirements that the owner or operator retain for ten years following site closure, records collected during the post-injection site care period at §146.93(f) and §146.93(h) are appropriate to ensure that data are available to support non-endangerment demonstrations and to address any concerns that may arise following site closure. This data will also support EPA's review of project data as part of the adaptive rulemaking approach.

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24202 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5100 2.8.1 Injection well plugging activities (seeking comment) (40 CFR 146.92)

Comment: Rule Provision: 146.92(d)

API Comments: (d) Plugging report. Within 60 days after plugging the owner or operator must submit a plugging report to the Director. If the semi-annual report is due less than 15 days after completion of plugging, then the reportmust be submitted within 60 days after plugging. The report must be certified as accurate by the owner or operator and by the person who performed the plugging operation (if other than the owner or operator.)

Rationale: The proposed changes are suggested to simplify and clarify a provision that API believes is needlessly complicated.

Response: EPA has revised the text at §146.92(d) to reduce confusion. The final rule text reads, "Within 60 days after plugging, the owner or operator must submit a plugging report to the

Director."

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24205 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5200 2.8.2 Post injection site care (seeking comment) (40 CFR 146.93)

Comment: Rule Provision: 146.93(a)(4)

API Comments: (4) AT ANY TIME DURING THE POST-INJECTION SITE CARE PHASE, The owner or operator may modify and resubmit the post-injection site care and site closure plan for the Director‘s approval within 30 days of such change.

Rationale: Technical Clarification.

Response: EPA agrees that a post-injection site care monitoring plan is an important tool for GS, and anticipates that, in some cases, the appropriate post-injection monitoring strategy may end up being different than initially projected, and there may be a need to amend the post-injection site care and site closure plan. EPA is requiring that upon the cessation of injection, the owner or operator submit an amended post-injection site care and site closure plan or demonstrate to the Director that no changes to the original post-injection site care and site closure plan are necessary (§146.93(a)(3)). EPA is not requiring formal periodic review and updates to the PISC and site closure plan throughout the injection phase. EPA does not expect that changes to this plan would be implemented until injection operations cease. EPA envisions that owners or operators would take into account similar considerations that guide updates to other project plans, e.g., monitoring and operational data and results of AoR reevaluations. EPA adds that, if any monitoring or other site data indicate a need for amending the post-injection site care plan, the owner or operator is expected to amend the plan accordingly.

EPA adds that, in the final rule, it has revised the text at §146.93(a)(4) as follows: "At any time during the life of the geologic sequestration project, the owner or operator may modify and resubmit the post-injection site care and site closure plan for the Director’s approval within 30 days of such change."

EPA is issuing guidance on development and updating of the GS project plans, including the postinjection site care and site closure plan. The guidance will be available on EPA's web site, at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24210Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5300 2.8.3 Site closure activities (40 CFR 146.93)

Comment: Rule Provision: 146.93(e)

API Comments: (e) Once the Director has authorizeS dsite closure, the owner or operator must submit a site closure report within 90 days that must thereafter be retained at a location designated by the Director. AFTER COMPLETION OF ALL CLOSURE OPERATIONS. The report must include:

(1) Documentation of appropriate injection and monitoring well plugging as specified in §146.92 and paragraph (c) of this section. The owner or operator must provide a copy of a survey plat which has been submitted to the local zoning authority designated by the Director. The plat must indicate the location of the injection well(S) relative to permanently surveyed benchmarks. The owner or operator must also submit a copy of the plat to the Regional Administrator of the appropriate EPA Regional Office;

Rationale: Once the site closure report is submitted to the Director, the operator cease to bear responsibility for any further record retention. At this point, EPA becomes the steward of information for the project.

Response: EPA disagrees that the owner or operator should not be responsible for record retention such as site closure reports. EPA believes that the requirements that the owner or operator retain, for ten years following site closure, records collected during the post-injection site care period at §146.93(f) and §146.93(h) are appropriate for the post-injection and site closure period to ensure that data are available to support non-endangerment demonstrations and to address any concerns that may arise following site closure. This data will also support EPA's review of project data as part of the adaptive rulemaking approach.

Commenter Name: Quinlan J. Shea Letter ID: 0177 Commenter Organization: Edison Electric Institute Comment ID: 25116

Comment: [FN15] The proposed regulations would also require the permittee to record a notice on the deed (or other relevant document) to the "facility property" containing certain information. While EEI is not opposed to the concept of a deed notice, more clarity is needed in the regulations regarding how "facility property" is to be defined in order to better understand the scope of the proposed requirement. EEI recommends limiting "facility property" to the area immediately surrounding the injection well.

Response: EPA believes the requirements for submitting of survey plats, as specified at §146.93(f), and recording a notation on the deed to the facility property that the land has been used to sequester CO2, as specified at §146.93(g) are sufficiently clear. Additionally, they are important to ensure that future land owners do not inadvertently drill wells or perform other activities that may compromise the injection zone and/or confining zone and cause CO2 or other fluids to migrate into USDWs or other formations or to the surface. While EPA recognizes that this may entail a large area at large GS sites, the Agency believes that this requirement is necessary to maximize protection of USDWs from endangerment and human health. Please note that “facility” is defined at §144.3. See the final rule and preamble for further discussion on EPA's final approach to site closure.Commenter Name: Frederick R. Eames Letter ID: 0178 Commenter Organization: CCS Alliance Comment ID: 23848

Comment: 2. Records Retention

Under the proposal, owners and operators would be required to maintain recordkeeping and reporting information for the duration of the project, as well as for three years after site closure (following the post-injection site care period). Owners and operators also would be required to keep their most recent plugging and abandonment report for one year following site closure. Under proposed requirement 40 C.F.R. $ 146.93(g), EPA would require that the owner or operator deliver to the Director records collected during the post-injection site care period at the conclusion of the 3-year retention period. The CCS Alliance is concerned that some of this information may be of a confidential financial or business operations nature and should be protected from public disclosure. Thus, the CCS Alliance recommends the inclusion of a "non-disclosure requirement" to protect certain sensitive and confidential business information from public disclosure. The CCS Alliance also requests EPA to consult with the U.S. Department of Homeland Security to determine whether CCS sites would constitute "critical infrastructure," thereby necessitating additional protection of sensitive information.

Response: The Agency clarifies that owners or operators may claim confidential business information under existing UIC regulations at 40 CFR 144.5. These requirements are applicable to

all well classes.

Commenter Name: Thomas Curtis Letter ID: 0181 Commenter Organization: American Water Works Association (AWWA) Comment ID: 23702

Comment: With respect to the requirement for recordkeeping, AWWA recommends that the oneyear holding requirement for the plugging and abandonment report be extended. This is an extremely important report, and the owner/operator must be required to keep this report on file for a minimum of 10 years following the closure of the project site.

Response: EPA is requiring that data collected during the post-injection phase be retained throughout the post-injection site care timeframe and for ten years following site closure. EPA agrees that well plugging reports should be retained for longer than one year. EPA has clarified the recordkeeping requirements in the final GS rule, which includes requirements that well plugging reports, as required at §146.92(d), post-injection site care data, as required at §146.93(f), and site closure reports, as required at §146.93(h), be kept for ten years after site closure.

EPA believes that longer record retention times for GS wells are appropriate for the post-injection and site closure period to ensure that data are available to support non-endangerment demonstrations and to address any concerns that may arise following site closure. This data will also support EPA's review of project data as part of the adaptive rulemaking approach.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24491 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rulelanguage; 5100 2.8.1 Injection well plugging activities (seeking comment) (40 CFR 146.92)

Comment: Rule Provision: 146.92(c)

Proposed CCS Group Recommendations: Support the proposed language.

Basis for CCS Group Comments: Agree with EPA’s rationale.

Response: EPA acknowledges the commenter’s support and the final rule retains this approach.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24492 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5100 2.8.1 Injection well plugging activities (seeking comment) (40 CFR 146.92)

Comment: Rule Provision: 146.92(d)

Proposed CCS Group Recommendations: (d) Plugging report. Within 60 days after plugging the owner or operator must submit a plugging report to the Director. If the semi-annual report is due less than 15 days after completion of plugging, then the report must be submitted within 60 days after plugging. The report must be certified as accurate by the owner or operator and by the person who performed the plugging operation (if other than the owner or operator.)

Basis for CCS Group Comments: The proposed change will simplify and clarify a provision that is unnecessarily complicated.

Response: EPA has revised the text at §146.92(d) to reduce confusion. The final rule text reads, "Within 60 days after plugging the owner or operator must submit a plugging report to the Director."

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24496 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5200 2.8.2 Post injection site care (seeking comment) (40 CFR 146.93)

Comment: Rule Provision: 146.93(a)(4)

Proposed CCS Group Recommendations: 4) AT ANY TIME DURING THE POST-INJECTIONSITE CARE PHASE, The owner or operator may modify and resubmit the postinjection site care and site closure plan for the Director’s approval within 30 days of such change.

Basis for CCS Group Comments: Technical Clarification.

Response: EPA agrees that a post-injection site care monitoring plan is an important tool for GS and anticipates that, in some cases, the appropriate post-injection monitoring strategy may end up being different than initially projected and there may be a need to amend the post-injection site care and site closure plan. EPA is requiring that upon the cessation of injection, the owner or operator submit an amended post-injection site care and site closure plan or demonstrate to the Director that no changes to the original post-injection site care and site closure plan are necessary (146.93(a)(3)). EPA is not requiring formal periodic review and updates to the PISC and site closure planthroughout the injection phase. EPA does not expect that changes to this plan would be implemented until injection operations cease. EPA envisions that owners or operators would take into account similar considerations that guide updates to other project plans, e.g., monitoring and operational data and results of AoR reevaluations. EPA adds that, if any monitoring or other site data indicate a need for amending the post-injection site care plan, the owner or operator is expected to amend the plan accordingly under §146.93(a)(3).

EPA adds that, in the final rule, it has revised the text at §146.93(a)(4) as follows: "At any time during the life of the geologic sequestration project, the owner or operator may modify and resubmit the post-injection site care and site closure plan for the Director’s approval within 30 days of such change."

EPA is issuing guidance on development and updating of the GS project plans, including the postinjection site care and site closure plan. The guidance will be available on EPA's web site at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24501 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.93(c)

Proposed CCS Group Recommendations: Support the proposed language.

Basis for CCS Group Comments: Agree with EPA’s rationale.

Response: EPA acknowledges the comment and the final rule retains the text as proposed.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24503 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5300 2.8.3 Site closure activities (40 CFR 146.93)

Comment: Rule Provision: 146.93(e)

Proposed CCS Group Recommendations: (e) Once the Director has

authorizeS dsite closure, the owner or operator must submit a site closure report within 90 days that must thereafter be retained at a location designated by the Director. AFTER COMPLETION OF ALL CLOSURE OPERATIONS. The report must include:

(1) Documentation of appropriate injection and monitoring well plugging as specified in §146.92 and paragraph (c) of this section. The owner or operator must provide a copy of a survey plat which has been submitted to the local zoning authority designated by the Director. The plat must indicate the location of the injection well(S) relative to permanently surveyed benchmarks. The owner or operator must also submit a copy of the plat to the Regional Administrator of the appropriate EPA Regional Office;Basis for CCS Group Comments: Once the site closure report is submitted to the Director, the operator cease to bear responsibility for any further record retention. At this point, EPA becomes the steward of information for the project.

Rule Provision: 146.93(e)(2)

Proposed CCS Group Recommendations: Support the proposed language.

Basis for CCS Group Comments: Agree with EPA’s rationale.

Rule Provision: 146.93(f)

Proposed CCS Group Recommendations: Support the proposed language.

Basis for CCS Group Comments: Agree with EPA’s rationale.

Rule Provision: 146.93(g)

Proposed CCS Group Recommendations: Support the proposed language.

Basis for CCS Group Comments: Agree with EPA’s rationale.

Response: EPA disagrees that the owner or operator should not be responsible for record retention such as site closure reports. EPA believes that the requirements that the owner or operator retain for ten years following site closure, records collected during the post-injection site care period at §146.93(f) and §146.93(h) are appropriate for the post-injection and site closure period to ensure that data are available to support non-endangerment demonstrations and to address any concerns that may arise following site closure. This data will also support EPA's review of project data as part of the adaptive rulemaking approach.

The GS regulation at §146.93(g) requires the owner or operator to record a notation on the deed to the facility property or other similar document examined during a title search that the land has been used to sequester CO2 at the time of site closure.

EPA acknowledges the commenter’s support of the other parts; the final rule retains these provisions.

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24715 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5100 2.8.1 Injection well plugging activities (seeking comment) (40 CFR 146.92)

Comment: Rule Provision: 146.92(d)

Anadarko Petroleum Corporation (APC) Comments: (d) Plugging report. Within 60 days after plugging the owner or operator must submit a plugging report to the

Director. If the semi-annual report is due less than 15 days after completion of plugging, then the report must be submitted within 60 days after plugging. The report must be certified as accurate by the owner or operator and by the person who performed the plugging operation (if other than the owner oroperator.)

Rationale: The proposed changes are suggested to simplify and clarify a provision that APC believes is needlessly complicated.

Response: EPA has revised the text at §146.92(d) to reduce confusion. The final rule text reads, "Within 60 days after plugging the owner or operator must submit a plugging report to the Director."

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24718 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5200 2.8.2 Post injection site care (seeking comment) (40 CFR 146.93)

Comment: Rule Provision: 146.93(a)(4)

Anadarko Petroleum Corporation (APC) Comments: (4) AT ANY TIME DURING THE POSTINJECTION SITE CARE PHASE, The owner or operator may modify and resubmit the post-injection site care and site closure plan for the Director’s approval within 30 days of such change.

Rationale: Technical Clarification.

Response: EPA agrees that a post-injection site care monitoring plan is an important tool for GS and anticipates that, in some cases, the appropriate post-injection monitoring strategy may end up being different than initially projected and there may be a need to amend the post-injection site care and site closure plan. EPA is requiring that upon the cessation of injection, the owner or operator submit an amended post-injection site care and site closure plan or demonstrate to the Director that no changes to the original post-injection site care and site closure plan are necessary (146.93(a)(3)). EPA is not requiring formal periodic review and updates to the PISC and site closure plan throughout the injection phase. EPA does not expect that changes to this plan would be implemented until injection operations cease. EPA envisions that owners or operators would take into account similar considerations that guide updates to other project plans, e.g., monitoring and operational data and results of AoR reevaluations. EPA adds that, if any monitoring or other site data indicate a need for amending the post-injection site care plan, the owner or operator is expected to amend the plan accordingly. EPA is issuing guidance with recommended approaches for development and updating of the GS project plans, including the post-injection site care and site closure plan. The guidance will be available on EPA's web site at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

EPA adds that, in the final rule, it has revised the text at §146.93(a)(4) as follows: "At any time during the life of the geologic sequestration project, the owner or operator may modify and resubmit the post-injection site care and site closure plan for the Director’s approval within 30 days of such change."

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24723 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5300 2.8.3 Site closure activities (40 CFR 146.93)

Comment: Rule Provision: 146.93(e)Anadarko Petroleum Corporation (APC) Comments: (e) Once the Director has authorized site closure, the owner or operator must submit a site closure report within 90 days that must thereafter be retained at a location designated by

the Director. AFTER COMPLETION OF ALL CLOSURE OPERATIONS. The report must

include:

(1) Documentation of appropriate injection and monitoring well plugging as specified in §146.92 and paragraph (c) of this section. The owner or operator must provide a copy of a survey plat which has been submitted to the local zoning authority designated by the Director. The plat must indicate the location of the injection well(S) relative to permanently surveyed benchmarks. The owner or operator must also submit a copy of the plat to the Regional Administrator of the appropriate EPA Regional Office;

Rationale: Once the site closure report is submitted to the Director, the operator cease to bear responsibility for any further record retention. At this point, EPA becomes the steward of information for the project.

Response: EPA disagrees that the owner or operator should not be responsible for record retention such as site closure reports. EPA believes that the requirements that the owner or operator retain for ten years following site closure, records collected during the post-injection site care period at §146.93(f) and §146.93(h) are appropriate for the post-injection and site closure period to ensure that data are available to support non-endangerment demonstrations and to address any concerns that may arise following site closure. This data will also support EPA's review of project data as part of the adaptive rulemaking approach.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24938 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5100 2.8.1 Injection well plugging activities (seeking comment) (40 CFR 146.92)

Comment: EPA Proposal: (c) Notice of intent to plug. The owner or operator must notify the Director at least 60 days before plugging of a well. At this time, if any changes have been made to the original well plugging plan, the owner or operator must also provide the revised well plugging plan. At the discretion of the Director, a shorter notice period may be allowed.

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

Response: EPA acknowledges the commenter’s support; the final rule retains this provision.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24939 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5100 2.8.1 Injection well plugging activities (seeking comment) (40 CFR 146.92)

Comment: Rule Provision: 146.92(d)EPA Proposal: (d) Plugging report. Within 60 days after plugging or at the time of the next semi-annual report (whichever occurs earlier) the owner or operator must submit a plugging report to the Director. If the semi-annual report is due less than 15 days after completion of plugging, then the report must be submitted within 60 days after plugging. The report must be certified as accurate by the owner or operator and by the person who performed the plugging operation (if other than the owner or operator.)

GWPC Recommendations: (d) Plugging report. Within 60 days after plugging the owner or operator must submit a plugging report to the Director. The report must be certified as accurate by the owner or operator and by the person who performed the plugging operation (if other than the owner or operator.)

Rationale: Simplification

Response: EPA has revised the text at §146.92(d) to reduce confusion. The final rule text reads, "Within 60 days after plugging the owner or operator must submit a plugging report to the Director."

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24951 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5300 2.8.3 Site closure activities (40 CFR 146.93)

Comment: EPA Proposal: (e) Once the Director has authorized site closure, the owner or operator must submit a site closure report within 90 days that must thereafter be retained at a location designated by the Director. The report must include:

(1) Documentation of appropriate injection and monitoring well plugging as specified in § 146.92 and paragraph (c) of this section. The owner or operator must provide a copy of a survey plat which has been submitted to the local zoning authority designated by the Director. The plat must indicate the location of the injection well relative to permanently surveyed benchmarks. The owner or operator must also submit a copy of the plat to the Regional Administrator of the appropriate EPA Regional Office;

GWPC Recommendations: (e) Once the Director has authorized site closure, the owner or operator must submit a site closure report within 90 days after completion of all closure operations. The report must include:

(1) Documentation of appropriate injection and monitoring well plugging as specified in §146.92 and paragraph (c) of this section. The owner or operator must provide a copy of a survey plat which has been submitted to the local zoning authority designated by the Director. The plat must indicate the location of the injection well(s) relative to permanently surveyed benchmarks. The owner or operator must also submit a copy of the plat to the Regional Administrator of the appropriate EPA Regional Office;

Rationale: What is the retention period? Many other programs have a three year limit for retention of records. EPA is the steward of information at this point of the project, not the owner or operator.Response: The GS regulation at §146.93(g) requires the owner or operator to record a notation on the deed to the facility property or other similar document examined during a title search that the land has been used to sequester CO2 on the deed to the facility property at the time of site closure.

Regarding record retention, EPA has clarified the recordkeeping requirements in the final GS rule, which includes requirements that well plugging reports, as required at §146.92(d), post-injection site care data, as required at §146.93(f), and site closure reports, as required at §146.93(h), must be kept by the owner or operator for ten years after site closure. EPA believes that longer record retention times for GS wells are appropriate and necessary for the post-injection and site closure period to ensure that data are available to support non-endangerment demonstrations and to address any concerns that may arise following site closure. This data will also support EPA's review of project data as part of the adaptive rulemaking approach.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24952 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5300 2.8.3 Site closure activities (40 CFR 146.93)

Comment: EPA Proposal: (2) Documentation of appropriate notification and information to such State, local and tribal authorities as have authority over drilling activities to enable such State and local authorities to impose appropriate conditions on subsequent drilling activities that may penetrate the injection and confining zone(s); and

(3) Records reflecting the nature, composition and volume of the carbon dioxide

stream.

GWPC Recommendations: No recommendation

Rationale: Need for site-specific considerations and use of data

Response: The GS regulation at §146.93(g) requires the owner or operator to record a notation on the deed to the facility property or other similar document examined during a title search that the land has been used to sequester CO2 on the deed to the facility property at the time of site closure.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24953 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5300 2.8.3 Site closure activities (40 CFR 146.93)

Comment: Rule Provision: 146.93

EPA Proposal: (f) Each owner or operator of a Class VI injection well must record a notation on the deed to the facility property or any other document that is normally examined during title search that will in perpetuity provide any potential purchaser of the property the following information:

(1) The fact that land has been used to sequester carbon dioxide; (2) The name of the State agency, local authority, and/or tribe with which thesurvey plat was filed, as well as the address of the Regional Environmental Protection Agency Office to which it was submitted; and

GWPC Recommendations: No recommendation

Rationale: Need for site-specific considerations and use of data

Response: The GS regulation at §146.93(g) requires the owner or operator to record a notation on the deed to the facility property or other similar document examined during a title search that the land has been used to sequester CO2 on the deed to the facility property at the time of site closure.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24954 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5300 2.8.3 Site closure activities (40 CFR 146.93)

Comment: EPA Proposal: (3) The volume of fluid injected, the injection zone or zones into which it was injected, and the period over which injection occurred.

(g) The owner or operator must retain for three years following site closure, records collected during the post-injection site care period. The owner or operator must deliver the records to the Director at the conclusion of the retention period, and the records must thereafter be retained at a location designated by the Director for that purpose.

GWPC Recommendations: No recommendation

Rationale: Need for site-specific considerations and use of data

Response: The GS regulation at §146.93(g) requires the owner or operator to record a notation on the deed to the facility property or other similar document examined during a title search that the land has been used to sequester CO2 on the deed to the facility property at the time of site closure.

Comment Code: 4740 2.7.4 Electronic reporting (seeking comment)



### Individual Comments

Commenter Name: James Dooley Letter ID: 0156 Commenter Organization: Joint Global Change Research Institute, Pacific Northwest National Laboratory Comment ID:

22645

Comment: o Page 43514. EPA asks for "comments on the requirements for monitoring" but it is not clear that there are any requirements articulated here. The USEPA should require that data on the areal extent of the CO2 plume and the pressure front aswell as any other relevant data from MMV be reported to EPA on an annual / semiannual basis. USEPA still must come to some consensus on how these data will be collected, who will have access to them, ect.Response: EPA clarifies that the monitoring requirements for Class VI well owners or operators are presented in the final rule at §146.90. EPA is retaining the requirement at §146.91(a) for semi-annual reporting of monitoring and operational data, including data on monitoring and tracking the CO2 plume and pressure front. For additional information about monitoring requirements and reporting requirements see the preamble to the final rule.

EPA is developing guidance for states that describes the recordkeeping, reporting, and additional data management needs associated with Class VI activities and provides recommended guidelines on the types of data to be collected for tracking Class VI projects, reporting 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.

Commenter Name: James Dooley Letter ID: 0156 Commenter Organization: Joint Global Change Research Institute, Pacific Northwest National Laboratory Comment ID:

22646

Comment: o Page 43514 under "Monitoring CO2 Movement and Reservoir Pressure", USEPA states that the owner/operator must compare the results of monitoring to baseline data but the text of the proposed rule does not require that this information be shared with the USEPA or state permitting agency. Isn’t this critically important information on how GS is working at a site? Isn’t that information needed by USEPA to understand whether the Class VI rule is effective in protecting USDWs and the other goals of the SDWA? There should be a requirement that this data and comparison be shared with regulators.

Response: EPA expects that CO2 plume and pressure front tracking data will be reviewed as part of the AoR reevaluation and plan update process. 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 corrective action plan, the testing and monitoring plan, and the emergency and remedial response plan throughout the life of the project. Owners or operators must review each plan and identify necessary amendments to the plan or demonstrate to the Director that no amendment is needed. These reviews must be performed within one year of an AoR reevaluation, following any significant changes to the facility (e.g., the addition of monitoring or injection wells), or when required by the Director. In no case can reviews occur less often than once every five years. Furthermore, §146.90(b) requires that the owner or operator continuously monitor injection pressure, rate and volume; the pressure on the annulus between the tubing and the long string casing; and the annulus fluid volume added.

EPA believes that by requiring periodic reevaluations of the AoR, as required at §146.84(e), along with any revisions to the required plans that may be required based on the AoR reevaluation or other data collected during well operations, will promote an ongoing relationship between the permitting authority and the owner or operator, including discussion of all monitoring results.

Commenter Name: James Dooley Letter ID: 0156 Commenter Organization: Joint Global Change Research Institute, Pacific Northwest National Laboratory Comment ID:

22651

Comment: o Page 43517. USEPA asks for comments on electronic reporting. Yes, electronic reporting should be mandatory. USEPA also needs to find a way to ensure that electronic reports are eventually consolidated at a national level. Having thereports be submitted to a state but not having the reporting go any further will frustrate efforts to improve our knowledge about how CCS works in practice and it will frustrate efforts to cost effectively include GS in to the structure of a national climate policy. Page 43529. The USEPA should consider whether a requirement of being granted primacy for Class VI wells would be a requirement

to share data collected at the state or Tribal area with the federal USEPA. EPA

Response: EPA retains the requirement that owners or operators submit data electronically to an EPA data system. EPA believes that it is prudent to provide assistance by developing 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 operators 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 resources on reviewing and approving permit applications rather than building or upgrading separate, independent databases for GS information. EPA believes that electronic formatting is the most appropriate format for submitting Class VI project information to the Director, and that many GS well owners or operators will have the capability to report electronically. In addition to minimizing redundancy and streamlining reporting for GS projects, EPA intends to use the data collected to support its evaluation associated with the adaptive process.

EPA is developing guidance for states that describes the record keeping, reporting, and additional data management needs associated with GS activities and provides recommended guidelines on the types of data to be collected for tracking GS projects, reporting 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.

Commenter Name: James Childress Letter ID: 0158 Commenter Organization: Gasification Technologies Council (GTC) Comment ID: 23788

Comment: EPA seeks comment on the requirement for electronic reporting in its proposed rule. EPA Notice 115,

We recommend that EPA allow electronic reporting as an alternative to hardcopy submittals. The benefits are speed, efficiency, reduced cost and burden of paperwork, ease of document retrieval, public access, search and storage.

Response: EPA believes that electronic formatting is the most appropriate format for submitting Class VI project information to the Director, and that, 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 requires this at §146.91(e).

EPA is developing guidance for states that describes the recordkeeping, reporting, and additional data management needs associated with GS activities and provides recommended guidelines on the types of data to be collected for tracking GS projects, reporting 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.

Commenter Name: Michael Mudd Letter ID: 0167 Commenter Organization: FutureGen Alliance (FGIA) Comment ID: 22474

Comment: To comply with a requirement for electronic record-keeping, new data storagetools will be required to deal with the diverse nature of information that will be generated during the course of a CCS project.

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 GS well owners or operators will have the capability to report electronically, and requires this at §146.91(e).

EPA believes that it is prudent to provide assistance by developing 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 operators 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 reviewing and approving permit applications rather than building or upgrading separate, independent databases for GS information. EPA believes that electronic formatting is the most appropriate format for submitting Class VI project information to the Director, and that many GS well owners or operators will have the capability to report electronically.

EPA is developing guidance for states that describes the record keeping, reporting, and additional data management needs associated with GS activities and provides recommended guidelines on the types of data to be collected for tracking GS projects, reporting 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.

Commenter Name: Theresa Pugh Letter ID: 0169 Commenter Organization: American Public Power Association Comment ID: 23366

Comment: Permit Application and Reporting Requirements -- Pg. 39

APPA believes that electronic reporting should not be absolute but should instead permit the Director to allow other methods of reporting when he deems such methods more appropriate. In addition, APPA believes that annual

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 GS well owners or operators will have the capability to report electronically, and requires this at §146.91(e).

EPA is developing guidance for states that describes the recordkeeping, reporting, and additional data management needs associated with GS activities and provides recommended guidelines on the types of data to be collected for tracking GS projects, reporting 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.

Commenter Name: Theresa Pugh Letter ID: 0169 Commenter Organization: American Public Power Association Comment ID: 23417

Comment: Permit Application and Reporting Requirements

The EPA asks for comments about electronic reporting. Any requirement contained in the Final Rule for electronic reporting should not be absolute but shouldinstead allow the Director to allow other methods of reporting when he deems such methods more appropriate. APPA imagines that by the time CCS is widely commercially viable, electronic filing (or whatever society considers "electronic filing of data" will be at that future date) will be the least of our cost or operational concerns. APPA would suggests that early projects, say in the first five years, have some modest leniency for ways to file effectively and responsibly without the presumption of real time data on every imaginable data point. We also suggest that the EPA have some reasonable test for response

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 requires this at §146.91(e).

EPA is developing guidance for states that describes the recordkeeping, reporting, and additional data management needs associated with GS activities and provides recommended guidelines on the types of data to be collected for tracking GS projects, reporting 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.

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24253

Comment: Rule Provisions: 146.91(c) EPA Preamble Question: 36. EPA seeks comment on the requirement for electronic reporting in its proposed rule. EPA Notice 43518.

API Response: API strongly supports the concept of electronic reporting. Industry’s objections to prior proposals for electronic reporting have been with the scope and breadth of information (incremental over written reports) that the Agency has previously proposed. Electronic reporting equivalent to existing written reports would be supported by API. Until these concerns related to electronic reporting are resolved, such reporting may be encouraged but should not be required.

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

EPA is developing guidance for states that describes the recordkeeping, reporting, and additional data management needs associated with GS activities and provides recommended guidelines on the types of data to be collected for tracking GS projects, reporting 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.

Commenter Name: James Rower Letter ID: 0173 Commenter Organization: Utility Solid Waste Activities Group (USWAG) Comment ID: 23502

Comment: Reporting - USWAG agrees that electronic reporting should be an option availableto all states for data exchange related to Class VI wells, but believes that the Director should have the discretion to allow other modes of reporting. Id. at 43517-18. We appreciate the important steps EPA has taken, including the awarding of grants, to ensure that all states will have the capability to exchange data electronically. Id. USWAG also realizes the benefits of electronic reporting, particularly in terms of facilitating the application process and streamlining review of CO2 GS projects. However, while it is likely that all states will eventually have the general capability to report electronically, some may not have that capacity yet. Additionally, it is foreseeable that extraordinary circumstances may arise that would preclude access to or limit availability of electronic resources. Accordingly, any requirement contained in the Final Rule for electronic reporting should not be absolute but should instead allow the Director to approve other methods of reporting when he deems such methods more appropriate.

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 requires this at §146.91(e).

EPA is developing guidance for states that describes the recordkeeping, reporting, and additional data management needs associated with GS activities and provides recommended guidelines on the types of data to be collected for tracking GS projects, reporting 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.

Commenter Name: Thomas Curtis Letter ID: 0181 Commenter Organization: American Water Works Association (AWWA) Comment ID: 23703

Comment: EPA Request for Comment: EPA seeks comment on the requirement for electronic reporting in its proposed rule. EPA Notice 43518.

AWWA Response: AWWA agrees with the electronic reporting requirements include as part of the proposed regulation. Electronic reporting allows for easier tracking of the operating data to observe any trends that might indicate potential

contamination of a USDW. EPA should consider the infrastructure that will be required to collect information prior to publishing the first report and develop a model reporting plan for owner/operators to use when submitting data to state agencies.

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 requires this at §146.91(e).

EPA is developing guidance for states that describes the recordkeeping, reporting, and additional data management needs associated with GS activities and provides recommended guidelines on the types of data to be collected for tracking GS projects, reporting 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.Commenter Name: Bradley J. Field Letter ID: 0186 Commenter Organization: New York State Dept. of Environmental Conservation

Div. of Mineral Resources Comment ID:

25209

Comment: 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 there is sufficient flexibility to allow states to utilize existing or preferred state data processing systems or software. At this time, electronic reporting should be an option but not a requirement.

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 requires 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 changes to accommodate a new class of UIC well (Class VI), EPA believes that it is prudent to provide assistance by developing 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 operators 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 reviewing and approving permit applications rather than building or upgrading separate, independent

databases for GS information.

EPA is developing guidance for states that describes the recordkeeping, reporting, and additional data management needs associated with GS activities and provides recommended guidelines on the types of data to be collected for tracking GS projects, reporting 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.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24489 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4720 2.7.2 Operational recordkeeping and reporting

Comment: Rule Provision: 146.91(b) & (c)

Proposed CCS Group Recommendations: Support the proposed language.

Basis for CCS Group Comments: Agree with EPA’s rationale.

Response: EPA acknowledges the comment and the final rule retains the text as proposed. See the final rule and preamble for further discussion on EPA's final approach to reporting and recordkeeping.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190Commenter Organization: Carbon Sequestration Council Comment ID: 24545

Comment: Rule Provisions or Federal Register Cite: 146.91(c) EPA Preamble Question: 36. EPA seeks comment on the requirement for electronic reporting in its proposed rule. EPA Notice 43518.

CSC Response: Industry’s objections to prior proposals for electronic reporting have been with the scope and breadth of information (incremental over written reports) that the Agency has previously proposed. Electronic reporting equivalent to existing written reports would be acceptable to CSC. Until these concerns related to electronic reporting are resolved, such reporting may be encouraged but should not be required.

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 requires this at §146.91(e).

EPA is developing guidance for states that describes the recordkeeping, reporting, and additional data management needs associated with GS activities and provides recommended guidelines on the types of data to be collected for tracking GS projects, reporting 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.

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24606

Comment: Rule Provisions: 146.91(c) EPA Rule Issue: 36. EPA seeks comment on the requirement for electronic reporting in its proposed rule. EPA Notice 43518.

Anadarko Petroleum Corporation (APC) Response: APC strongly supports the concept of electronic reporting. Industry’s objections to prior proposals for electronic reporting have been with the scope and breadth of information (incremental over written reports) that the Agency has previously proposed. Electronic reporting equivalent to existing written reports would be supported by APC. Until these concerns related to electronic reporting are resolved, such reporting may be encouraged but should not be required.

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

EPA is developing guidance for states that describes the recordkeeping, reporting, and additional data management needs associated with GS activities and provides recommended guidelines on the types of data to be collected for tracking GS projects, reporting to EPA for compliance tracking, and transfer of data to EPA's 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.Commenter Name: Richard Guinn Letter ID: 0210 Commenter Organization: Eastman Chemical Company Comment ID: 22738

Comment: EPA seeks comment on the requirement for electronic reporting in its proposed

rule. EPA Notice 115.

We recommend that EPA allow electronic reporting as an alternative to hardcopy submittals. The benefits are speed, efficiency, reduced cost and burden of paperwork, ease of document retrieval, public access, search and storage.

Response: EPA agrees and 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 requires this at §146.91(e).

EPA is developing guidance for states that describes the recordkeeping, reporting, and additional data management needs associated with GS activities and provides recommended guidelines on the types of data to be collected for tracking GS projects, reporting 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.

Commenter Name: Mark Bohrer Letter ID: 0241 Commenter Organization: North Dakota Industrial Commission Comment ID: 23259

Comment: 36. EPA seeks comment on the requirement for electronic reporting in its proposed rule. EPA Notice 43518.

Electronic reporting should not be required. State systems may already be in place to collect data but may not be compatible with sending or receiving

systems.

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 requires 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 changes to accommodate a new class of UIC well (Class VI), EPA believes that it is prudent to provide assistance by developing 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 operators 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 reviewing and approving permit applications rather than building or upgrading separate, independent

databases for GS information.

EPA is developing guidance for states that describes the recordkeeping, reporting, and additional data management needs associated with GS activities and provides recommended guidelines on the types of data to be collected for tracking GS projects, reporting 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.Commenter Name: Mark Bohrer Letter ID: 0241 Commenter Organization: North Dakota Industrial Commission Comment ID: 23304

Comment: 146.91(c) Electronic reporting should not be required. State systems may already be in place to collect data but may not be compatible with sending or receiving systems.

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 requires 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 changes to accommodate a new class of UIC well (Class VI), EPA believes that it is prudent to provide assistance by developing 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 operators 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 reviewing and approving permit applications rather than building or upgrading separate, independent

databases for GS information.

EPA is developing guidance for states that describes the recordkeeping, reporting, and additional data management needs associated with GS activities and provides recommended guidelines on the types of data to be collected for tracking GS projects, reporting 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.

Commenter Name: Walter L. Baker Letter ID: 0253 Commenter Organization: Utah Division of Water Quality Comment ID: 22353 Other EPA Comment Codes and Descriptions: 4700 2.7 Proposed Recordkeeping and Reporting Requirements (40 CFR 146.91)

Comment: ELECTRONIC REPORTING

We agree with EPA that electronic reporting will reduce reporting burden and will facilitate tracking of CCGS projects. However, the "electronic format acceptable to the Director" should not constitute a financial or resource burden to the owner / operator or to the regulating agency required to report to EPA on UIC program activity. Until that time when the regulating agency has developed a data flow to the National UIC Database, we strongly urge EPA to develop an online service for submitting CCGS information such as is currently in place for submitting Program Activity Measures (PAMs) and UIC inventory.

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 requires this at §146.91(e).

Acknowledging that some States may have to develop electronic data systems to receive electronicinformation from the owner or operator, and that many States which already have electronic data systems will have to make changes to accommodate a new class of UIC well (Class VI), EPA believes that it is prudent to provide assistance by developing 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 operators 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 reviewing and approving permit applications rather than building or upgrading separate, independent

databases for GS information.

EPA is developing guidance for states that describes the recordkeeping, reporting, and additional data management needs associated with GS activities and provides recommended guidelines on the types of data to be collected for tracking GS projects, reporting 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.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24934 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4720 2.7.2 Operational recordkeeping and reporting

Comment: EPA Proposal: (b) Report, within 30 days the results of:

(1) Periodic tests of mechanical integrity; (2) Any other test of the injection well conducted by the permittee if required by the Director; and (3) Any well workover.

(c) Owners or operators must submit reports in an electronic format acceptable to the Director. At the discretion of the Director, other formats may be accepted.

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

Response: EPA acknowledges the comment. Please see the final rule and the discussion of reporting preamble for additional information on EPA's final rulemaking approach.

EPA believes that electronic formatting is the most appropriate format for submitting Class VI project information to the Director, and that many GS well owners or operators will have the capability to report electronically.

Letter ID: 0263 Commenter Organization: Interstate Oil & Gas Compact Commission Comment ID: 22823

Comment: III A. 7 Proposed Recordkeeping andReporting Requirements

MM. EPA seeks comment on the requirement for electronic reporting in today's proposed rule.IOGCC Response: The IOGCC agrees with electronic submittal in principle as long as there is sufficient flexibility to allow states to utilize existing or preferred state data processing systems or software. Electronic reporting should be an option but not a requirement.

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 requires 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 changes to accommodate a new class of UIC well (Class VI), EPA believes that it is prudent to provide assistance by developing 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 operators 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 reviewing and approving permit applications rather than building or upgrading separate, independent

databases for GS information.

EPA is developing guidance for states that describes the recordkeeping, reporting, and additional data management needs associated with GS activities and provides recommended guidelines on the types of data to be collected for tracking GS projects, reporting 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.

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



### Individual Comments

Commenter Name: James Childress Letter ID: 0158 Commenter Organization: Gasification Technologies Council (GTC) Comment ID: 23789

Comment: Although EPA has not included a requirement for this report in its proposal, EPA seeks comment regarding the necessity for such an annual report. EPA Notice 115.

While reports on status are worthwhile, activity and changes in status are not going to be significant on an annual basis. Following a report after the first year of operation to ensure that requirements for later reporting are being met, once every 10 years coincident with the periods for AoR review should be adequate.

Response: The final GS regulation retains the reporting requirements as proposed, which does not include a requirement for an annual report. Instead, EPA believes that periodic reevaluation of the AoR, as required at §146.84(e), along with any revisions to the required plans that may be necessary based on the AoR reevaluation, will promote 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 corrective action plan, the testingand monitoring plan, and the emergency and remedial response plan throughout the life of the project. Owners or operators must review each plan and identify necessary amendments to the plan or demonstrate to the Director that no amendment is needed. These reviews must be performed within one year of an AoR reevaluation, following any significant changes to the facility (e.g., the addition of monitoring or injection wells), or when required by the Director. In no case can reviews occur less often than once every five years. For additional information, please see the final rule and the preamble for a discussion of EPA's final approach to recordkeeping and reporting.

While the Agency recognizes some concerns expressed by commenters about the burden associated with an annual report, the Agency's decision to retain the semi-annual reporting requirement at §146.91(a) is because the semi-annual report in conjunction with the continued dialogue associated with AoR reevaluations and periodic updates to the plans is a preferred approach to an annual report.

EPA encourages and expects owners and operators to share monitoring and operating data with the public voluntarily (e.g., through the Internet), however. Providing the public with information throughout the Class VI project will help clear up and avoid public misperceptions about the nature and safety of GS.

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24254

Comment: Rule Provisions: 73 FR 43518 EPA Preamble Question: 37. In addition to the above recordkeeping and reporting requirements, EPA considered a requirement for owners or operators of GS sites to provide an annual report during the lifetime of the project, including the post-injection period, regarding the GS operation. Although EPA has not included a requirement for this report in its proposal, EPA seeks comment regarding the necessity for such an annual report. EPA Notice 43518.

API Response: An Annual report is not necessary given the other reporting requirements in the Rule. Alternatively, if this report was to replace the other reporting requirements, there would be value to the proposal.

Response: The final GS regulation retains the reporting requirements as proposed, which does not include a requirement for an annual report. Instead, EPA believes that periodic reevaluation of the AoR, as required at §146.84(e), along with any revisions to the required plans that may be necessary based on the AoR reevaluation, will promote 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 corrective action plan, the testing and monitoring plan, and the emergency and remedial response plan throughout the life of the project. Owners or operators must review each plan and identify necessary amendments to the plan or demonstrate to the Director that no amendment is needed. These reviews must be performed within one year of an AoR reevaluation, following any significant changes to the facility (e.g., the addition of monitoring or injection wells), or when required by the Director. In no case can reviews occur less often than once every five years. See the final rule and preamble for further discussion on EPA's final approach to reporting and recordkeeping.

While the Agency recognizes some concerns expressed by commenters about the burden associated with an annual report, the Agency's decision to retain the semi-annual reporting requirement at §146.91(a) is because the semi-annual report in conjunction with the continued dialogue associatedwith AoR reevaluations and periodic updates to the plans is a preferred approach to an annual report.

EPA encourages and expects owners and operators to share monitoring and operating data with the public voluntarily, however (e.g., through the Internet). Providing the public with information throughout the GS project will help clear up and avoid public misperceptions about the nature and safety of GS.

Commenter Name: James Rower Letter ID: 0173 Commenter Organization: Utility Solid Waste Activities Group (USWAG) Comment ID: 23503

Comment: With respect to the Proposal's suggestion of an annual reporting requirement for CO2 GS projects, USWAG appreciates the importance of the information EPA seeks to gather but believes that annual reporting will not always be the best way to collect this information over the lifetime of the project. Id. at 43518. The Final Rule will require some form of periodic reevaluation of the AoR throughout the life of the project; much of the information sought through the proposed annual reporting requirement would be gathered and submitted to EPA through the AoR reevaluation process. Gathering this information through the AoR reevaluations alone, rather than imposing an unnecessary and duplicative annual reporting requirement, will provide a more cost-effective and manageable method of information exchange for regulators and Owners or Operators alike.

Response: The final GS regulation retains the reporting requirements as proposed, which does not include a requirement for an annual report. Instead, EPA believes that periodic reevaluation of the AoR, as required at §146.84(e), along with any revisions to the required plans that may be necessary based on the AoR reevaluation, will promote 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 corrective action plan, the testing and monitoring plan, and the emergency and remedial response plan throughout the life of the project. Owners or operators must review each plan and identify necessary amendments to the plan or demonstrate to the Director that no amendment is needed. These reviews must be performed within one year of an AoR reevaluation, following any significant changes to the facility (e.g., the addition of monitoring or injection wells), or when required by the Director. In no case can reviews occur less often than once every five years. For additional information, please see the final rule and the preamble for a discussion of EPA's final approach to recordkeeping and reporting.

EPA also encourages and expects owners and operators to share monitoring and operating data with the public voluntarily (e.g., through the Internet), however. Providing the public with information throughout the GS project will help clear up and avoid public misperceptions about the nature and safety of GS. The Agency plans to, every six years, evaluate the information and determine if modifications to the requirements are appropriate or necessary to ensure protection of USDWs from endangerment.

Commenter Name: Frederick R. Eames Letter ID: 0178 Commenter Organization: CCS Alliance Comment ID: 23847

Comment: EPA also seeks comment on whether owners or operators of GS sites should be required to provide an annual report on GS operation during the lifetime of the project, including the post-injection period. Such a report is not necessary inlight of the other proposed semi-annual reporting obligations.

Response: The final GS regulation retains the reporting requirements as proposed, which does not include a requirement for an annual report. Instead, EPA believes that periodic reevaluation of the AoR, as required at §146.84(e), along with any revisions to the required plans that may be necessary based on the AoR reevaluation, will promote 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 corrective action plan, the testing and monitoring plan, and the emergency and remedial response plan throughout the life of the project. Owners or operators must review each plan and identify necessary amendments to the plan or demonstrate to the Director that no amendment is needed. These reviews must be performed within one year of an AoR reevaluation, following any significant changes to the facility (e.g., the addition of monitoring or injection wells), or when required by the Director. In no case can reviews occur less often than once every five years. For additional information, please see the final rule and the preamble for a discussion of EPA's final approach to recordkeeping and reporting.

While the Agency recognizes some concerns expressed by commenters about the burden associated with an annual report, the Agency's decision to retain the semi-annual reporting requirement at §146.91(a) is because the semi-annual report in conjunction with the continued dialogue associated with AoR reevaluations and periodic updates to the plans is a preferred approach to an annual report.

Commenter Name: Thomas Curtis Letter ID: 0181 Commenter Organization: American Water Works Association (AWWA) Comment ID: 23704

Comment: EPA Request for Comment: In addition to the above recordkeeping and reporting requirements, EPA considered a requirement for owners or operators of GS sites to provide an annual report during the lifetime of the project, including the post-injection period, regarding the GS operation. Although EPA has not included a requirement for this report in its proposal, EPA seeks comment regarding the necessity for such an annual report. EPA Notice 43518.

AWWA Response: AWWA recommends that an annual reporting requirement be included n the proposed regulation. This report should summarize the operation of the system including standard operating criteria, information on well operation, details of plume movement, and any details on major changes in well operation. It should be similar to the Consumer Confidence Reports (CCR) that drinking water utilities must develop and it should be mailed or emailed to all relevant stakeholders. EPA should develop requirements for the report similar to those required for the CCR because the annual report should be developed by someone one of the team members involved in the operation of the geologic sequestration project.

Response: Individual Response: The final GS regulation retains the semi-annual reporting requirements as proposed and does not include a requirement for an annual report. Instead, EPA believes that periodic reevaluation of the AoR, as required at §146.84(e), along with any revisions to the required plans that may be necessary based on the AoR reevaluation, will promote 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 corrective action plan, the testing and monitoring plan, and the emergency and remedial response plan throughout the life of the project. Owners or operators must review each plan andidentify necessary amendments to the plan or demonstrate to the Director that no amendment is needed. These reviews must be performed within one year of an AoR reevaluation, following any significant changes to the facility (e.g., the addition of monitoring or injection wells), or when required by the Director. In no case can reviews occur less often than once every five years.

EPA also encourages and expects owners and operators to share monitoring and operating data with the public voluntarily (e.g., through the Internet. Providing the public with information throughout the GS project will help clear up and avoid public misperceptions about the nature and safety of GS. For additional information, please see the final rule and the preamble for a discussion of EPA's final approach to recordkeeping and reporting.

Commenter Name: Bradley J. Field Letter ID: 0186 Commenter Organization: New York State Dept. of Environmental Conservation

Div. of Mineral Resources Comment ID:

25210

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

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 requiring semi-annual reporting of data.

Response: The final GS regulation retains the reporting requirements as outlined in the proposed rule and does not include a requirement 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 promote 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 corrective action plan, the testing and monitoring plan, and the emergency and remedial response plan throughout the life of the project. Owners or operators must review each plan and identify necessary amendments to the plan or demonstrate to the Director that no amendment is needed. These reviews must be performed within one year of an AoR reevaluation, following any significant changes to the facility (e.g., the addition of monitoring or injection wells), or when required by the Director. In no case can reviews occur less often than once every five years. For additional information, please see the final rule and the preamble 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 plan, satisfying many of the concerns expressed commenters who supported the annual report.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24546

Comment: Rule Provisions or Federal Register Cite: 73 FR 43518 EPA Preamble Question: 37. In addition to the above recordkeeping and reporting requirements, EPA considered a requirement for owners or operators of GS sites to provide an annual report during the lifetime of the project, including the post-injection period, regarding the GS operation. Although EPA has not included a requirement for this report in its proposal, EPA seeks comment regarding thenecessity for such an annual report. EPA Notice 43518.

CSC Response: An additional annual report is not necessary given the other reporting requirements in the Rule. Alternatively, if this report was to replace the other reporting requirements, there would be value to the proposal.

Response: The final GS regulation retains the reporting requirements as proposed and does not include a requirement for an annual report. Instead, EPA believes that periodic reevaluation of the AoR, as required at §146.84(e), along with any revisions to the required plans that may be necessary based on the AoR reevaluation, will promote 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 corrective action plan, the testing and monitoring plan, and the emergency and remedial response plan throughout the life of the project. Owners or operators must review each plan and identify necessary amendments to the plan or demonstrate to the Director that no amendment is needed. These reviews must be performed within one year of an AoR reevaluation, following any significant changes to the facility (e.g., the addition of monitoring or injection wells), or when required by the Director. In no case can reviews occur less often than once every five years. For additional information, please see the final rule and the preamble for a discussion of EPA's final approach to recordkeeping and reporting.

While the Agency recognizes some concerns expressed by commenters about the burden associated with an annual report, the Agency's decision to retain the semi-annual reporting requirement at §146.91(a) is because the semi-annual report in conjunction with the continued dialogue associated with AoR reevaluations and periodic updates to the plans is a preferred approach to an annual report.

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24607

Comment: Rule Provisions: 73 FR 43518 EPA Rule Issue: 37. In addition to the above recordkeeping and reporting requirements, EPA considered a requirement for owners or operators of GS sites to provide an annual report during the lifetime of the project, including the post-injection period, regarding the GS operation. Although EPA has not included a requirement for this report in its proposal, EPA seeks comment regarding the necessity for such an annual report. EPA Notice 43518.

Anadarko Petroleum Corporation (APC) Response: An Annual report is not necessary given the other reporting requirements in the Rule. The addition of this report would not produce any new pertinent information to the regulating agency; and, therefore, only increases their administrative burden on the agency and requires the generation of needless documents. In keeping with the provisions of the Paperwork Reduction Act, EPA should not require an annual report. Alternatively, if this report was to replace the other reporting requirements, there would be value to the proposal.

Response: The final GS regulation retains the reporting requirements as proposed and does not include a requirement for an annual report. Instead, EPA believes that periodic reevaluation of the AoR, as required at §146.84(e), along with any revisions to the required plans that may be necessary based on the AoR reevaluation, will promote 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 corrective action plan, the testing and monitoring plan, and the emergency and remedial response plan throughout the life of the project. Owners or operators must review each plan and identify necessary amendments to the plan or demonstrate to the Director that no amendment is needed. These reviews must be performed within one year of an AoR reevaluation, following any significant changes to the facility (e.g., the addition of monitoring or injection wells), or when required by the Director. In no case can reviews occur less often than once every five years. For additional information, please see the final rule and the preamble for a discussion of EPA's final approach to recordkeeping and reporting.

While the Agency recognizes some concerns expressed by commenters about the burden associated with an annual report, the Agency's decision to retain the semi-annual reporting requirement at §146.91(a) is because the semi-annual report in conjunction with the continued dialogue associated with AoR reevaluations and periodic updates to the plans is a preferred approach to an annual report.

Commenter Name: Richard Guinn Letter ID: 0210 Commenter Organization: Eastman Chemical Company Comment ID: 22739

Comment: Although EPA has not included a requirement for this report in its proposal, EPA seeks comment regarding the necessity for such an annual report. EPA Notice 115.

While reports on status are worthwhile, activity and changes in status are not going to be significant on an annual basis. Following a report after the first year of operation to ensure that requirements for later reporting are being met, once every 10 years coincident with the periods for AoR review should be adequate.

Response: EPA is requiring semi-annual reporting in addition to periodic reevaluations of required Class VI projects plans. 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 corrective action plan, the testing and monitoring plan, and the emergency and remedial response plan throughout the life of the project. Owners or operators must review each plan and identify necessary amendments to the plan or demonstrate to the Director that no amendment is needed. These reviews must be performed within one year of an AoR reevaluation, following any significant changes to the facility (e.g., the addition of monitoring or injection wells), or when required by the Director. In no case can reviews occur less often than once every five years. EPA adds that it has modified the AoR reevaluation frequency in the final rule, from 10 years to 5 years. For additional information, please see the final rule and the preamble for a discussion of EPA's final approach to AoR and corrective action.

Commenter Name: Neeraj Gupta Letter ID: 0229 Commenter Organization: Battelle Energy Technology (BET) Comment ID: 21864

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

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

Commenter Name: Mark Bohrer Letter ID: 0241 Commenter Organization: North Dakota Industrial Commission Comment ID: 23260

Comment: 37. In addition to the above recordkeeping and reporting requirements, EPA considered a requirement for owners or operators of GS sites to provide an annual report during the lifetime of the project, including the post-injection period, regarding the GS operation. Although EPA has not included a requirement for this report in its proposal, EPA seeks comment regarding the necessity for such an annual report. EPA Notice 43518.

During the active injection phase of a project, reports and frequencies similar

to those which exist in other UIC classes should be sufficient. Once active injection ceases, an annual report may be appropriate.

Response: EPA clarifies that reporting requirements for existing injection wells vary by well class. The Agency believes semi-annual reporting is appropriate for Class VI GS wells during the operational phase of the project. EPA believes that the potentially large injection volumes and injection pressures associated with GS warrant more frequent reporting than for other well classes. EPA adds, at §146.93(a)(2)(iv), that reporting during the post-injection site care timeframe would be at the frequency described in the approved post-injection site care and site closure plan. For additional information, please see the final rule and the preamble for a discussion of EPA's final approach to recordkeeping and reporting.

Commenter Name: Kristin Henry Letter ID: 0242 Commenter Organization: Sierra Environmental Law Program, Sierra Club Comment ID: 23329 Other EPA Comment Codes and Descriptions: 3530 2.2.3.1 AoR reevaluation frequency (seeking comment)

Comment: An update or redefinition of the AOR at a minimum fixed frequency of ten years is not sufficient. The operator should be required to submit an annual assessment under stating whether they deem a revision of the AOR necessary, explaining their reasoning based on site-specific operational and other data. The Director should examine and approve or reject this submission, requiring a revision of the AOR as needed. The same updating procedure should apply to all other plans: monitoring, closure, etc. We believe that this arrangement encourages honest and truthful reporting of data and site performance without placing excessive burdens on redefining the AOR if such revision is not needed. It also leaves a clear accountability trail for both operator and Director in case of disputes.

Response: EPA agrees with commenters that reevaluations of the AoR every ten years may not be sufficient to appropriately model plume and pressure front movement, establish conditions for corrective action, and ensure protection of USDWs from endangerment. For these reasons, the Agency changed the minimum frequency for the AoR reevaluation at §146.84(e) from 10 years to at least every 5 years in the final GS rule. EPA believes that this revised frequency addresses 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 CO2GS. In addition, the Director has discretion to require more frequent AoR reevaluation if he or she has reason to believe, based on site-specific information, that a five-year reevaluation schedule is not sufficiently protective of USDWs.

EPA also agrees that periodic reviews of the other plans based on the AoR reevaluation is appropriate. The final GS rule includes provisions that owners or operators review and update the AoR and corrective action plan, the testing and monitoring plan, and the emergency and remedial response plan throughout the life of the project, as specified in §146.84(c), §146.90(j), and §146.94(d). Owners or operators must review each plan and identify necessary amendments to the plan or demonstrate to the Director that no amendment is needed. These reviews must be performed within one year of an AoR reevaluation, following any significant changes to the facility (e.g., the addition of monitoring or injection wells), or when required by the Director.

EPA agrees that the AoR reevaluations offer a good opportunity to promote a dialogue between the owner or operator and the permitting authority. 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 corrective action plan, the testing and monitoring plan, and the emergency and remedial response plan throughout the life of the project. Owners or operators must review each plan and identify necessary amendments to the plan or demonstrate to the Director that no amendment is needed. These reviews must be performed within one year of an AoR reevaluation, following any significant changes to the facility (e.g., the addition of monitoring or injection wells), or when required by the Director. In no case can reviews occur less often than once every five years. For additional information, please see the final rule and the preamble for a discussion of EPA's final approach to recordkeeping and reporting.

Commenter Name: Kurt Waltzer Letter ID: 0250 Commenter Organization: Clean Air Task Force Comment ID: 22309 Other EPA Comment Codes and Descriptions: 3700 2.2.5 Comments on the requirement for an AoR and corrective action plan

Comment: The rule should require updating when warranted of all of the proposed "plans" and should require an annual report that summarizes whether not updates have been warranted, and whether or not updates have been undertaken

We applaud EPA for proposing to require the creation, use, and updating of various "plans" during the operating life of a facility. By creating such an iterative process, and basing it on monitoring and other operational data that become available through time, EPA can assure that facilities are managed in a way that adapts to changing circumstances. This approach also has the potential to enable what the Preamble calls an "ongoing dialogue" between operators and regulators, especially if the rule is enhanced by the annual reporting requirement suggested below for inclusion in §146.91.

Perhaps inadvertently, the proposed rule does not explicitly require updating of several of the required plans. In most but not all cases, there is a rather ambiguous requirement to "maintain" a given plan. Explicit requirements to make updates as warranted appear to be missing from provisions relating to:

Response: EPA acknowledges the commenters' support of the AoR and corrective action plan, and retains the requirement in the final regulation §146.84(b). EPA believes that the iterative process by which monitoring and operational data are used to validate the original AoR calculation, along withthe combined knowledge and ongoing dialogue between the owner or operator and the Director on the local geologic conditions will be critical in developing and implementing plans that protect USDWs from endangerment.

EPA adds that the final rule includes provisions that owners or operators review and update the AoR and corrective action plan, the testing and monitoring plan, and the emergency and remedial response plan throughout the life of the project, as specified in §146.84(c), §146.90(j), and §146.94(d). Owners or operators must review each plan and identify necessary amendments to the plan or demonstrate to the Director that no amendment is needed. These reviews must be performed within one year of an AoR reevaluation, following any significant changes to the facility (e.g., the addition of monitoring or injection wells), or when required by the Director.

EPA clarifies that the final rule does not require an annual report.

Commenter Name: Kurt Waltzer Letter ID: 0250 Commenter Organization: Clean Air Task Force Comment ID: 22314

Comment: An additional annual reporting requirement will enhance the ability of both Director and operators to keep track of which plans require updating and whether or not plans that ought to be updated have in fact been revised. Such a shared understanding is essential if there is to be the "ongoing dialogue" between regulators and operators that EPA anticipates. Our Environmental NGO Group considered supporting the inclusion of an annual report as described in the preamble at 73 Fed. Reg. 43518, but concluded that the benefits of that particular report would be outweighed by the burden. The annual report we are suggesting here, however, would be much simpler. We believe that EPA should require a report, signed by the appropriate company official, that:

• lists all of the required plans; • confirms for each plan that the company has reviewed all monitoring and operational data since the previous annual report that is relevant to a decision on whether to update the plan; • states with regard to each plan whether an update was determined to be warranted; and • for those plans where the operator did decide that an update was appropriate, a statement that the update has or has not been completed and a summary of the

modifications that have been made.

The rule should further provide that the Director has authority to require submission of copies of updated plans and/or further information regarding the reasons why updates of particular plans have or have not been done.

Response: The final GS regulation retains the reporting requirements as proposed and does not include a requirement for an annual report. Instead, EPA believes that periodic reevaluation of the AoR, as required at §146.84(e), along with any revisions to the required plans that may be required based on the AoR reevaluation, will promote 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 corrective action plan, the testing and monitoring plan, and the emergency and remedial response plan throughout the life of the project.Regarding the content of the reports on the updates, owners or operators must review each plan and identify necessary amendments to the plan or demonstrate to the Director that no amendment is needed. These reviews must be performed within one year of an AoR reevaluation, following any significant changes to the facility (e.g., the addition of monitoring or injection wells), or when required by the Director. In no case can reviews occur less often than once every five years. For additional information, please see the final rule and the preamble for a discussion of EPA's final approach to recordkeeping and reporting.

While the Agency recognizes some concerns expressed by commenters about the burden associated with an annual report, the Agency's decision to retain the semi-annual reporting requirement at §146.91(a) is because the semi-annual report in conjunction with the continued dialogue associated with AoR reevaluations and periodic updates to the plans is a preferred approach to an annual report.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24820

Comment: EPA Notice Questions: 73 FR 43518

EPA Rule Issue: 37. In addition to the above recordkeeping and reporting requirements, EPA considered a requirement for owners or operators of GS sites to provide an annual report during the lifetime of the project, including the post-injection period, regarding the GS operation. Although EPA has not included a requirement for this report in its proposal, EPA seeks comment regarding the necessity for such an annual report. EPA Notice 43518.

GWPC CO2 Committee Response: See Workgroup recommendation 7.6 for further

details.

Report annually, or at a frequency acceptable to the Director, the characteristics and cumulative volumes (annual and total) of injected fluids, injection pressures, injection rates, annular pressures for each injection well, the results of any mechanical integrity tests conducted during this time period, available site integrity monitoring results, the extent of the injected CO2 and the pressure front based on current data.

Update site operations as appropriate and site modeling results annually, or at a frequency acceptable to the Director, to reflect current data.

Compare the updated results to the previous results. Identify and explain to the Director any discrepancies between the updated results and the previous

results.

Note: Technology transfer is a better forum for driving regulatory changes. Do not support annual reporting as outlined in the preamble.

Response: EPA is retaining the semi-annual reporting requirements as proposed at §146.91(a). These requirements ensure the Director has the information needed to take preventive action in a timely manner to protect USDWs from endangerment.The final GS regulation does not include a requirement for an annual report. Instead, EPA believes that periodic reevaluation of the AoR, as required at §146.84(e), along with any revisions to the required plans that may be necessary based on the AoR reevaluation, will promote 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 corrective action plan, the testing and monitoring plan, and the emergency and remedial response plan throughout the life of the project. Owners or operators must review each plan and identify necessary amendments to the plan or demonstrate to the Director that no amendment is needed. These reviews must be performed within one year of an AoR reevaluation, following any significant changes to the facility (e.g., the addition of monitoring or injection wells), or when required by the Director. In no case can reviews occur less often than once every five years.

For additional information, please see the final rule and the preamble for a discussion of EPA's final approach to recordkeeping and reporting.

Letter ID: 0263 Commenter Organization: Interstate Oil & Gas Compact Commission Comment ID: 22824 Other EPA Comment Codes and Descriptions: 4760 2.7.6 Proposed reporting frequency (seeking comment)

Comment: III A. 7 Proposed Recordkeeping and Reporting Requirements

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

IOGCC Response: The IOGCC suggests that there be only one frequency of reporting, either annual or semi-annual. Thus, this requirement should be incorporated into the semi-annual reporting requirement enunciated by EPA in the rule for the physical and chemical characteristics of the injected fluids in a Class VI well. There should not be two different data reporting timeframe.

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

The final GS regulation does not include a requirement for an annual report. Instead, EPA believes that periodic reevaluation of the AoR, as required at §146.84(e), along with any revisions to the required plans that may be required based on the AoR reevaluation, will promote 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 corrective action plan, the testing and monitoring plan, and the emergency and remedial response plan throughout the life of the project. Owners or operators must review each plan and identify necessary amendments to the plan or demonstrate to the Director that no amendment is needed. These reviews must be performed within one year of an AoR reevaluation, following any significant changes to the facility (e.g., the addition of monitoring or injection wells), or when required by the Director. In no case can reviews occur less often than once every five years.

For additional information, please see the final rule and the preamble for a discussion of EPA's final approach to recordkeeping and reporting.As described above, EPA is retaining the semi-annual reporting requirements as proposed at §146.91(a). These requirements ensure the Director has the information 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 preamble for a discussion of EPA's final approach to recordkeeping and reporting.

Commenter Name: Greg Shubel Letter ID: 0284 Commenter Organization: Inter-Tribal Council of Michigan, Inc Comment ID: 25302

Comment: requirements, EPA considered a requirement for owners or operators ofOS sites toprovide an annual report during the lifetime of the project, including the postinjection period, regarding the GS operation." (Page 28 of 51)

ITCMI ESD feels that this is a necessary requirement, and will provide

invaluable data for future studies.

Response: The final GS regulation retains the reporting requirements as outlined in the proposed rule and does not include a requirement 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 required based on the AoR reevaluation or other data collected during well operations, will promote 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 corrective action plan, the testing and monitoring plan, and the emergency and remedial response plan throughout the life of the project. Owners or operators must review each plan and identify necessary amendments to the plan or demonstrate to the Director that no amendment is needed. These reviews must be performed within one year of an AoR reevaluation, following any significant changes to the facility (e.g., the addition of monitoring or injection wells), or when required by the Director. In no case can reviews occur less often than once every five years.

The semi-annual reporting required at §146.91(a) includes both operational data and data required as part of the testing and monitoring plan, satisfying many of the concerns expressed by commenters who supported the annual report. EPA encourages and expects owners and operators to share monitoring and operating data with the public voluntarily (e.g., through the Internet. Providing the public with information throughout the GS project will help clear up and avoid public misperceptions about the nature and safety of GS.

For additional information, please see the final rule and the preamble for a discussion of EPA's final approach to recordkeeping and reporting.

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



### Individual Comments

Commenter Name: Michael H. Cochran Letter ID:0108 Commenter Organization: Bureau of Water, Division of Environment, Kansas Department of Health & Environment (KDHE) Comment

ID: 21984

Comment: 146.91: We believe this should be monthly reporting. This is information that is important and needs to be reviewed at a frequency by the regulatory agency to ensure problems are identified and addressed in a timely manner. Think about this for example - quarterly reporting for say the third calendar quarter results in data that is collected July 1, 2008, would not be seen by the regulatory agency before October 30, 2009, if the operator is allowed say 30 days after the end of the quarter to provide the report. Is that reasonable or appropriate?

The timeframe for submittal of the quarterly report should be stated.

Response: The final rule remains unchanged from the proposal and requires semi-annual reporting of monthly average, maximum, and minimum values for injection pressure, flow rate and volume, annular pressure, and monthly annulus fluid volume added at §146.91(a). EPA believes that monthly reporting of routine operational data and monitoring results would provide no additional protection of USDWs from endangerment. EPA adds that, at §146.91(c), it has included in the final rule a requirement that operators must report within 24 hours of any event that may endanger USDWs. EPA notes that states seeking primacy for Class VI wells are free to require more frequent reporting. For additional information, please see the final rule and the preamble for a discussion of EPA's final approach to recordkeeping and reporting.

Commenter Name: Christine Reimer Letter ID: 0142 Commenter Organization: National Ground Water Association Comment ID: 22573

Comment: regulations. The results of the MMV and modeling including the integrity of the wells, fluid properties and volumes, subsurface location of the plume, leakage monitoring, modeling, and size of the AoR should be reported at least annually or upon a sudden significant change.

Response: EPA is retaining the requirement at §146.91(a) for semi-annual reporting of monitoring and operational data. External mechanical integrity testing, which must be conducted annually, must be reported within 30 days of the test. EPA clarifies that some monitoring frequencies (e.g., associated with ground water monitoring and plume tracking) will be established in the approved testing and monitoring plan, which will be incorporated as a condition of the Class VI permit. The frequency of these tests will be determined based on site-specific information.

EPA clarifies the final rule includes a requirement at §146.91(c) that operators report within 24 hours of any event that may endanger USDWs; any leakage that endangers a USDW would be addressed in this requirement.

For additional information, please see the final rule and the preamble for a discussion of EPA's final approach to recordkeeping and reporting.

Commenter Name: Theresa Pugh Letter ID: 0169 Commenter Organization: American Public Power Association Comment ID: 23367

Comment: such methods more appropriate. In addition, APPA believes that annual reporting will not always be the best way to collect this information over thelifetime of the project.

Response: The final GS regulation retains the reporting requirements as proposed and does not include a requirement for an annual report. Instead, EPA believes that periodic reevaluation of the AoR, as required at §146.84(e), along with any revisions to the required plans that may be required based on the AoR reevaluation, will promote 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 corrective action plan, the testing and monitoring plan, and the emergency and remedial response plan throughout the life of the project. Owners or operators must review each plan and identify necessary amendments to the plan or demonstrate to the Director that no amendment is needed. These reviews must be performed within one year of an AoR reevaluation, following any significant changes to the facility (e.g., the addition of monitoring or injection wells), or when required by the Director. In no case can reviews occur less often than once every five years. See the final rule and preamble for further discussion on EPA's final approach to reporting and recordkeeping.

Commenter Name: Theresa Pugh Letter ID: 0169 Commenter Organization: American Public Power Association Comment ID: 23419

Comment: With respect to the Proposal’s suggestion of an annual reporting requirement for CO2 GS projects, APPA appreciates the importance of the information EPA seeks to gather but believes that annual reporting will not always be the best way to collect this information over the lifetime of the project. Id. at 43518. The Final Rule will require some form of periodic reevaluation of the AoR throughout the life of the project; much of the information sought through the proposed annual reporting requirement would be gathered and submitted to EPA through the AoR reevaluation process. Gathering this information through the AoR reevaluations alone, rather than imposing an unnecessary and duplicative annual reporting requirement, will provide a more cost-effective and manageable method of information exchange for regulators and Owners or Operators alike. APPA prefers the idea of reporting every five years in the first 20 years of operations.

Response: The final GS regulation retains the reporting requirements as proposed and does not include a requirement for an annual report. EPA agrees that the AoR reevaluations offer a good opportunity to promote a dialogue between the owner or operator and the permitting authority. 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 corrective action plan, the testing and monitoring plan, and the emergency and remedial response plan throughout the life of the project. Owners or operators must review each plan and identify necessary amendments to the plan or demonstrate to the Director that no amendment is needed. These reviews must be performed within one year of an AoR reevaluation, following any significant changes to the facility (e.g., the addition of monitoring or injection wells), or when required by the Director. In no case can reviews occur less often than once every five years.

EPA encourages and expects owners and operators to share monitoring and operating data with the public voluntarily (e.g., through the Internet), however. Providing the public with information throughout the GS project will help clear up and avoid public misperceptions about the nature and safety of GS. See the final rule and preamble for further discussion on EPA's final approach to reporting and recordkeeping.Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24252

Comment: Rule Provisions: 146.91 EPA Preamble Question: 35. EPA seeks comment on the frequency of all proposed reporting requirements. EPA Notice 43517

API Response: Frequency should reflect the level of risk associated with the activity. Semi-annual reporting is adequate. Reporting should be on a project basis as opposed to a well basis consistent with 146.23(c).

Response: EPA agrees and is retaining the requirement at §146.91(a) for semi-annual reporting of monitoring and operational data. External mechanical integrity testing, which must be conducted annually, must be reported within 30 days of the test. EPA clarifies that some monitoring frequencies (e.g., associated with ground water monitoring and plume tracking) will be established in the approved testing and monitoring plan, which will be incorporated as a condition of the Class VI permit. The frequency of these tests will be determined based on site-specific information. For additional information, please see the final rule and the preamble for a discussion of EPA's final approach to recordkeeping and reporting.

EPA disagrees that reporting should be on a project, rather than a per-well basis. 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.

Commenter Name: Frederick R. Eames Letter ID: 0178 Commenter Organization: CCS Alliance Comment ID: 23846

Comment: 1. Reporting Requirements

EPA proposes to require owners or operators of Class V1 wells to report semiannually to the permitting authority on: the physical and chemical characteristics of injection fluids; injection pressure, flow rate, temperature, volume and annular pressure; annulus fluid volume added; and the results of MITs, plume tracking, and atmospheric/soil gas monitoring. Additionally, owners and operators will be required to submit the results of AoR modeling revisions: any updates to the information on the type, number, and location of all wells within the site AoR; and information on additional corrective action performed or planned based on AoR reevaluations.

A semi-annual reporting obligation with respect to the above information is reasonable. The CCS Alliance requests, however, that EPA streamline the final reporting requirements to ensure simplicity and to avoid unnecessary confusion or duplication of reporting obligations. For instance, proposed section 146.91(b) requires a report within 30 days for certain tests or any well workover. These additional reports should be incorporated into the semi-annual report, as they are not so time-sensitive as to require a separate reporting obligation.

Response: EPA is retaining the semi-annual reporting requirements as proposed at §146.91(a).These requirements ensure the Director has the information 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 preamble for a discussion of EPA's final approach to recordkeeping and reporting.

Commenter Name: Thomas Curtis Letter ID: 0181 Commenter Organization: American Water Works Association (AWWA) Comment ID: 23701

Comment: EPA Request for Comment: EPA seeks comment on the frequency of all proposed reporting requirements. EPA Notice 43517

AWWA Response: AWWA recommends that the owner/operators of a Class VI well provide a monthly operating report to the Director instead of the semi-annual report as proposed. The operating information for the geologic sequestration project is extremely important and needs to be reviewed at a frequency by the regulatory agency to ensure problems are identified and addressed in a timely manner. For example, based on the proposed regulation, data collected on July 1, 2008 would not be seen by the regulatory agency before January 15, 2009, if the operator is allowed 15 days to submit the report. This would allow for very little time to correct any potential issues in the operation of the project. We have provided example monthly reporting sheets that were developed as part of the AwwaRF project in Section III of our comments, and these reports are similar to the monthly reporting sheets used by water and wastewater treatment plants. Given the potential scale of carbon sequestration and the need to protect groundwater resources, a requirement for monthly operating reports is

reasonable.

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

EPA reviewed the sample reporting forms submitted by AWWA (EPA-HQ-OW-2008-0390-0181). The Agency will refer to these as it prepares guidance for complying with the reporting requirements. However, EPA notes that most reporting will be done electronically.

Commenter Name: Thomas Curtis Letter ID: 0181 Commenter Organization: American Water Works Association (AWWA) Comment ID: 23746 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Part 146.91(11)(a) AWWA believes that the reporting frequency should be on a monthly basis, similar to what water and wastewater treatment plants have to do. The operating information for the geologic sequestration project is extremelyimportant and needs to be reviewed at a frequency by the regulatory agency to ensure problems are identified and addressed in a timely manner. For example, with the way the regulation is currently structured, data collected on July 1, 2008 would not be seen by the regulatory agency before January 15, 2009, if the operator is allowed 15 days to submit the report. This would allow for very little time to correct any potential issues in the operation of the project. As such, AWWA recommends revising this part to read:

Monthly reports, due on the 15th day of each month for the previous month’s activities, containing:

Response: As described above, the final rule remains unchanged from the proposal and requires semi-annual reporting of monthly average, maximum and minimum values for injection pressure, flow rate and volume, annular pressure, and monthly annulus fluid volume added at §146.91(a). EPA believes that monthly reporting of routine operational data and monitoring results would provide no additional protection of USDWs from endangerment.

For additional information, please see the final rule and the preamble for a discussion of EPA's final approach to recordkeeping and reporting.

Commenter Name: Bradley J. Field Letter ID: 0186 Commenter Organization: New York State Dept. of Environmental Conservation

Div. of Mineral Resources Comment ID:

25204 Other EPA Comment Codes and Descriptions: 4600 2.6 Proposed Plume and Pressure Front Monitoring Requirements (40 CFR 146.90)

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

be conducted at a GS site.

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 results of MITs, ground water monitoring, and any required atmospheric/soil gas monitoring. However, the amount and types of monitoring to be required should be site specific.

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 collect these data, 2) the spatial resolution at which the data should be collected, 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, injection 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 exist for complying with other requirements, such as tracking the position of the plume and pressure front within the injection zone.Flexibility is also provided regarding how to monitor for the specific data required by the final rule. The testing and monitoring plan is developed by the owner or operator 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 technologiesand recommended approaches for implementing a testing and monitoring plan, including preoperational geophysical logging and testing of injection wells, MITs, injection well testing during operation, groundwater quality monitoring, tracking the CO2 plume and pressure front, and soil gas and surface air monitoring which may be required by the UIC Director for specific GS projects.

EPA is retaining the semi-annual reporting requirements as proposed at §146.91(a). These requirements ensure the Director has the information 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 preamble for a discussion of EPA's final approach to recordkeeping and reporting.

EPA agrees that some monitoring types and frequencies (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.

Commenter Name: Bradley J. Field Letter ID: 0186 Commenter Organization: New York State Dept. of Environmental Conservation

Div. of Mineral Resources Comment ID:

25205 Other EPA Comment Codes and Descriptions: 4655 2.6.5.1 Plume tracking techniques/geophysical methods (seeking comment)

Comment: GG. Specifically, EPA seeks comment regarding the usefulness of indirect geophysical monitoring 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 results 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 that successfully monitor plume migration in the southern states may not have any monitoring capability in northern Paleozoic basins.

Response: EPA agrees with commenters and believes 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 performed at a site is appropriate for site operational conditions and the geologic setting. EPA believes that 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 rule, at §146.90(g)(2), requires owners or operators to track the position of the CO2 plume using indirect methods (e.g., seismic, electrical, gravity, or electromagnetic surveys and/or down-hole CO2 detection tools), unless the Director determines based on site-specific geology, that such methods are not appropriate. EPA is affording Director's discretion regarding the use of geophysical 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 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 geologic 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 frequencies, and other pertinent information.

As described above EPA is retaining the requirement at §146.91(a) for semi-annual reporting of monitoring and operational data. For additional information, please see the final rule and the preamble for a discussion of EPA's final approach to recordkeeping and reporting.

Commenter Name: Bradley J. Field Letter ID: 0186 Commenter Organization: New York State Dept. of Environmental Conservation

Div. of Mineral Resources Comment ID:

25208

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

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

Response: The final GS regulation retains the reporting requirements as outlined in the proposed rule and does not include a requirement for an annual report. For additional information, please see the final rule and the preamble 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 plan, satisfying many of the concerns expressed by commenters who supported the annual report.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24486 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.91(a)

Proposed CCS Group Recommendations: (a) Semi-annual OR LESS FREQUENT AT THE DISCRETION OF THE DIRECTOR reports containing:Basis for CCS Group Comments: Over the life of the project, the Director may decide that less reporting is acceptable

Response: EPA is retaining the semi-annual reporting requirement in the final rule at §146.91(a) in order to ensure that permitting authorities can maintain proper oversight of GS projects, particularly in the early stages of rule implementation and deployment of GS technologies. The Agency also clarifies that permitting authorities may choose to require more frequent reporting, at the discretion of the Director. See the final rule and preamble for further discussion on EPA's final approach to reporting and recordkeeping.

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

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24544

Comment: Rule Provisions or Federal Register Cite: 146.91 EPA Preamble Question: 35. EPA seeks comment on the frequency of all proposed reporting requirements. EPA Notice 43517

CSC Response: Frequency should reflect the level of risk associated with the activity. Semi-annual reporting is adequate. Reporting should be on a project basis as opposed to a well basis consistent with 146.23(c).

Response: EPA is retaining the semi-annual reporting requirements as proposed at §146.91(a). These requirements ensure the Director has the information needed to take preventive action in a timely manner to protect USDWs from endangerment. See the final rule and preamble for further discussion on EPA's final approach to reporting and recordkeeping.

EPA disagrees that reporting should be on a project, rather than a per well, basis. 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.

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

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24605

Comment: Rule Provisions: 146.91 EPA Rule Issue: 35. EPA seeks comment on the frequency of all proposed reporting requirements. EPA Notice 43517

Anadarko Petroleum Corporation (APC) Response: Frequency should reflect thelevel of risk associated with the activity. Semi- annual reporting is adequate. Reporting should be on a project basis as opposed to a well basis consistent with 146.23(c).

Response: EPA is retaining the semi-annual reporting requirements as proposed at §146.91(a). These requirements ensure the Director has the information 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 preamble for a discussion of EPA's final approach to recordkeeping and reporting.

EPA agrees that some monitoring types and frequencies (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.

Commenter Name: Mark Bohrer Letter ID: 0241 Commenter Organization: North Dakota Industrial Commission Comment ID: 23258

Comment: 35. EPA seeks comment on the frequency of all proposed reporting requirements.

EPA Notice 43517.

Reporting frequency should coincide with requirements for existing UIC injection well classes unless there is a need for more frequent reporting.

Response: EPA clarifies that reporting requirements for existing injection wells vary by well class. The Agency believes semi-annual reporting is appropriate for Class VI GS wells during the operational phase of the project. EPA believes that the potentially large injection volumes and injection pressures associated with GS warrant more frequent reporting than for other well classes. See the final rule and preamble for further discussion on EPA's final approach to reporting and recordkeeping.

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

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24932 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.91

11. Reporting requirements.

The owner or operator must, at a minimum, provide the following reports to the Director, for each permitted Class VI well:(a) Semi-annual reports containing:

(1) Any changes to the physical, chemical and other relevant characteristics of the carbon dioxide stream from the proposed operating data; (2) Monthly average, maximum and minimum values for injection pressure, flow rate and volume, and annular pressure;

GWPC Recommendations: (a) Semi-annual or at a frequency determined by the Director reports containing:

(1) Any significant changes to the physical, chemical and other relevant characteristics of the carbon dioxide stream from the proposed operating data;

Rationale: Should be semi-annual unless otherwise determined

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

Letter ID: 0263 Commenter Organization: Interstate Oil & Gas Compact Commission Comment ID: 22822

Comment: III A. 7 Proposed Recordkeeping and Reporting Requirements

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

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

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

Letter ID: 0263 Commenter Organization: Interstate Oil & Gas Compact Commission Comment ID: 22824 Other EPA Comment Codes and Descriptions: 4750 2.7.5 Comments on the merit of annual reports (seeking comment)

Comment: III A. 7 Proposed Recordkeeping and Reporting Requirements

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

IOGCC Response: The IOGCC suggests that there be only one frequency of reporting, either annual or semi-annual. Thus, this requirement should be incorporated intothe semi-annual reporting requirement enunciated by EPA in the rule for the physical and chemical characteristics of the injected fluids in a Class VI well. There should not be two different data reporting timeframe.

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

The final GS regulation does not include a requirement for an annual report. Instead, EPA believes that periodic reevaluation of the AoR, as required at §146.84(e), along with any revisions to the required plans that may be required based on the AoR reevaluation, will promote 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 corrective action plan, the testing and monitoring plan, and the emergency and remedial response plan throughout the life of the project. Owners or operators must review each plan and identify necessary amendments to the plan or demonstrate to the Director that no amendment is needed. These reviews must be performed within one year of an AoR reevaluation, following any significant changes to the facility (e.g., the addition of monitoring or injection wells), or when required by the Director. In no case can reviews occur less often than once every five years.

For additional information, please see the final rule and the preamble for a discussion of EPA's final approach to recordkeeping and reporting.

As described above, EPA is retaining the semi-annual reporting requirements as proposed at §146.91(a). These requirements ensure the Director has the information 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 preamble for a discussion of EPA's final approach to recordkeeping and reporting.

Comment Code: 5000 2.8 Proposed Well Plugging and Post-Injection Site Care Requirements



### Individual Comments

Commenter Name: Herbert Skolnick, Ph.D. Letter ID: 0110 Commenter Organization: Group Against Smog and Pollution, Inc. (GASP) Comment ID: 22038 Other EPA Comment Codes and Descriptions: 5400 2.9 Proposed Financial Responsibility and Long-Term Care Requirements

Comment: Finally, given the lower costs of CO2 sequestration in existing oil fields and the attendant increased oil production, sequestration in existing oil fields is also more likely to provide storage site operators with the financial resourcesnecessary to ensure proper site closure and post-closure care, and to meet longterm financial assurance requirements.

Response: EPA agrees with the commenter that depleted oil and gas reservoirs associated with ERoperations may be used for CO2 storage and that these sites may be some of the first sites where commercial-scale GS is deployed.

EPA clarifies that the goal of financial responsibility is to ensure that financial resources are available to prevent or remediate the endangerment of USDWs from improper plugging, remediation, and management of wells in the event that the owner or operator experiences financial difficulties. Assuring financial responsibility for corrective action on wells in the AoR, injection well plugging, PISC and site closure, and emergency and remedial response at GS sites is an important component of ensuring that USDWs are protected.

EPA is developing guidance on financial responsibility for Class VI wells (available on EPA's website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm) that describes the types of financial instruments that owners or operators may use to meet financial responsibility requirements for Class VI wells.

Commenter Name: Paul Pike Letter ID: 0111 Commenter Organization: Ameren Corporation on behalf of USWAG Comment ID: 22405 Other EPA Comment Codes and Descriptions: 1250 1.1.1.4 Flexibility is needed (performancebased standards); 3500 2.2.3 Area of Review Reevaluation (seeking comment)

Comment: 6. Because of the widely varied characteristics and limitations of different carbon dioxide sequestration projects, it is essential to incorporate performance-based standards into the Final Rule, leading to a site-specific approach to requirements for Area of Review reevaluation and post-injection site care and closure periods.

Response: The post-injection site care requirements in the final GS rule, as specified in §146.93(b), incorporate a combination of a fixed timeframe and a performance standard approach. 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 PISC 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, based on substantial data during thepermitting process, that an alternative PISC timeframe may be appropriate if it ensures nonendangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate the appropriateness of an alternative post-injection site care time frame; demonstrate non endangerment; and perform site closure activities. The guidance will be available on EPA's web site, at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.In response to comments about AoR evaluation, EPA disagrees that the GS regulation should includeperformance-based standards for AoR calculation. However, EPA believes that consideration of sitespecific conditions is appropriate for the AoR calculation and reevaluation process. EPA believes that the flexibility incorporated into the AoR and corrective action plans and the provision for AoR reevaluation as required at §146.84(e) provide for an ongoing review of the site and a dialogue between the Director and the owner or operator to ensure that the most appropriate modeling and corrective action technologies are used to protect USDWs from endangerment.

Commenter Name: George Holliday, PhD, PE, BCEE Letter ID: 0114 Commenter Organization: Holliday Environmental Services, Inc. Comment ID: 22519 Other EPA Comment Codes and Descriptions: 1340 1.1.3.2 Oppose use of GS in general; 3800 2.3 Proposed Injection Well Construction Requirements (40 CFR 146.86)

Comment: passing a written examination. Further, the Agency proposes to sequester buoyant CO2 until the end-of-time by only requiring 50 years of monitoring (40 CFR 146.93(b)(1)). In addition, EPA proposes using well completion materials not currently developed and proven corrosion-resistant under carbonic acid

corrosive conditions.

The proposed regulations are a formula for future disaster: 1) Dangerous to sequester CO2, a supercritical fluid stored at high pressure (2200± psi): 2)

Response: EPA does not believe that a properly managed GS site is dangerous. The Class VI GS regulation builds upon the long-standing protective framework of the UIC program, which has been regulating the injection of billions of gallons of liquids for decades. The Class VI GS regulation enhances this existing framework with requirements for Class VI wells that are tailored to the unique nature of large scale GS of CO2.

EPA believes that a 50 year post-injection site care timeframe represents a reasonable and protective post-injection site monitoring period for most GS projects and available data, including data submitted by commenters, do not support a different default timeframe. EPA bases this on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments. EPA adds that the GS regulation includes a provision that the Director may, at their lengthen the post-injection site care timeframe if the owner or operator cannot demonstrate that movement of the plume and pressure front have ceased and the injectate does not pose a risk to USDWs (146.93(b)(2)).

EPA disagrees that corrosion-resistant materials and cement do not exist. Industry experience of many decades in corrosive down-hole situations such as acid gas injection and production of natural gas with carbon dioxide and hydrogen sulfide impurities shows that materials are available that can resist corrosive environments. Meyer (2007) lists several types of cements that have been used under such corrosive conditions. EPA acknowledges that studies have likely not been performed to prove a 50-year life span for corrosion-resistant materials. However, there are two studies of wells that were exposed to CO2 for approximately 30 years by Carey et al. (2007) and Crow et al. (2008). Although these studies are limited in the number of well material samples and the number of wells examined, the casing and cement sampled indicate fairly good condition (i.e., fairly significant corrosion resistance) of well materials installed three decades ago. The best available corrosion-resistant materials suited for each GS project will be determined by the Director.

EPA adds that, to address potential risks associated with high pressures associated with CO2injection for GS, the final rule, at §146.88(e)(2), requires that owners or operators of onshore Class VI wells install automatic surface shut-off devices. Owners or operators must also monitor pressure in the injection zone, as required at §146.90(g).

EPA acknowledges that there are limited data on this subject, and believes that providing multiple barriers of protection is the most appropriate approach to protecting USDWs from endangerment. See the discussion of Class VI well construction requirements in the preamble to the final GS rule for additional information. Additionally, EPA is developing guidance on the construction of Class VI wells. This guidance will be available on EPA’s website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

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

necessary.

Commenter Name: Leslie Savage Letter ID: 0122 Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24810 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: §146.94 Emergency and remedial response.

(a) As part of the permit application, THE OWNER OR OPERATOR must provide the Director with an emergency and remedial response plan that describes actions to be taken to address movement of the injection or formation fluids that may causean endangerment to a USDW during construction, operation, closure and postclosure periods.

{Redundant - See 146.82(X)}

Response: Based on its evaluation of all public comments and input on the proposed rule and NODA and Request for Comment EPA has made many revisions to the GS Rule. See the final rule and preamble for further discussion on EPA's final approach.

Commenter Name: Emily Rochon Letter ID: 0129 Commenter Organization: Greenpeace International Comment ID: 23068 Other EPA Comment Codes and Descriptions: 5400 2.9 Proposed Financial Responsibility and Long-Term Care Requirements

Comment: It must be reiterated that monitoring and verification of CO2 storage sites is along-term task. It does not end when the storage reservoir is capped. Postoperational monitoring over hundreds of years is essential. Significant risks continue to exist and must be monitored both to prevent a catastrophic short term release as well as long-term slow leakage. Even if it is feasible to bury hundreds of thousands of gigatons of CO2, there is no way to guarantee that storage locations will be appropriately designed and managed over the timescales required.

Response: EPA agrees that post-injection monitoring should continue for an extended time, butdisagrees that hundreds of years of monitoring would be needed. EPA believes that a 50 year postinjection site care timeframe represents a reasonable and protective monitoring period. EPA bases this on a review of research studies, industry reports, existing environmental programs, and evaluation of public comments. Furthermore, EPA believes that a 50-year default post-injection site care timeframe is not overly burdensome, does not exaggerate the risks associated with GS, is consistent with other environmental programs, and sufficiently protects USDWs from endangerment. For this reason, the final GS regulation retains the 50 year post-injection site care timeframe, as specified in §146.93(b)(1).

The GS rule provides the Director with discretion to extend the timeframe (e.g., if, after 50 years, monitoring data indicates that the CO2 plume may endanger a USDW), or shorten the timeframe (if the owner or operator can demonstrate that the GS project does not pose an endangerment to USDWs), under 146.93(b)(2). Such a demonstration will be site-specific, and based on pressure monitoring and USDW impacts. EPA clarifies that in no cases will site closure be authorized until the owner or operator demonstrates to the satisfaction of the Director that the site no longer poses a risk of endangerment to USDWs.

Under SDWA authority, owners or operators of injection wells must ensure protection of USDWs from endangerment and are subject to liability for enforcement under the Act.

Once an owner or operator has met all regulatory requirements under Part 146 for Class VI wells and the Director has approved site closure pursuant to requirements at §146.93, the owner or operator will generally no longer be subject to enforcement for regulatory noncompliance. Furthermore, his or her financial instrument as required under §146.85 will be released if it was not used. However, even if a site closure is approved under §146.93, an owner or operator may be held liable for regulatory noncompliance (including violation of 40 CFR 144.12) in certain circumstances. For example, an owner or operator may be held liable for regulatory noncompliance even after site closure was approved if the Director relied on erroneous information (e.g., erroneous modeling data) provided by the owner or operator when approving site closure.

Additionally, an owner or operator may always be subject to any action, such as administrative orders or civil actions, the Administrator deems necessary to protect the health of persons under §1431 of the SDWA after site closure if there is unanticipated migration towards or into a USDW that causes or threatens imminent and substantial endangerment to public health. If the owner or operator fails to comply with the order, he or she may be subject to a civil penalty for each day in which such violation occurs or failure to comply continues.

The Agency clarifies that Class VI well permits may be transferred to another owner or operator pursuant to §144.38 whereby generally all other regulatory responsibilities are transferred to that new owner and operator, including all potential liabilities associated with meeting the requirements of that permit. Please see further clarification on the issue of long term liability in the preamble of the final

rule.

Furthermore, after site closure an owner or operator may remain liable under tort and other remedies, or under other federal statutes including, but not limited to, the Clean Air Act, 42 U.S.C. §§ 7401- 7671; CERCLA, 42 U.S.C. § 9601-9675; and RCRA, 42 U.S.C. § 6901-6992. EPA does not have authority to transfer SDWA or other legal liability for Class VI wells to the State or federal government or a third-party fund. See the final rule preamble for further discussion of EPA's final approach.Commenter Name: Brianne Metzger Letter ID: 0151 Commenter Organization: Spectra Energy Corp Comment ID: 21877 Other EPA Comment Codes and Descriptions: 1250 1.1.1.4 Flexibility is needed (performancebased standards); 5400 2.9 Proposed Financial Responsibility and Long-Term Care Requirements

Comment: IV. EPA MUST DEVELOP A FLEXIBLE FRAMEWORK TO ADDRESS POSTINJECTION SITE CARE,
FINANCIAL ASSURANCE, AND LONG TERM LIABILITY THAT ELIMINATES OBSTACLES

TO

COMMERCIAL-SCALE DEPLOYMENT OF CCS.

Numerous studies and commentators have recognized that the principle obstacle to commercial-scale deployment of CCS is regulatory uncertainty over the capture, transport, injection, and storage of CO2. As stated by a recent GAO

report:

The IPCC, two federal advisory committee reports, and many stakeholders we contacted agreed that key regulatory and legal issues will need to be addressed if CCS is to be deployed at commercial scale. Among these issues are (1) confusion over the rules for injecting large volumes of CO2, (2) long-term liability issues concerning CO2 storage and potential leakage, (3) how property ownership patterns may affect CO2 storage, and (4) how the Clean Air Act will apply to facilities that capture CO2. - EPA’s 2007 UIC workshop, attended by more than 200 stakeholders, revealed liability associated with unintended migration of injected CO2 to be a critical concern. Similarly, 19 of the 20 stakeholders we interviewed told us that liability related to CO2 storage was a large or very large barrier to deployment of CCS at a commercial scale, with some noting that liability concerns have already negatively impacted companies’ ability to initiate CCS projects. For example, two stakeholders reported that these concerns had already made it difficult to obtain insurance for CCS projects. They noted specifically that insurers have difficulty writing insurance policies because of uncertainties associated with and limited data available for CCS, while another added that investors will not support projects like CCS if they expose them to unlimited and undefined long-term liabilities, especially when future revenue streams are uncertain.[14]

The promise of CCS as a strategy to address climate change and promote national energy security hinges on resolving this regulatory uncertainty in a way that does not place an unreasonable burden on site owners and operators that would effectively prevent the development of commercial-scale CCS projects in the United States. The EPA has the authority under SDWA and the UIC Program to create a flexible framework to address issues such as post-injection site care, financial assurance, and long-term liability in a manner that places enough responsibility on owners and operators to ensure that all applicable best practices are followed, but not so much that it becomes virtually impossible to secure the requisite financing and insurance needed for CCS projects to be commercially viable.

The potentially unique challenge of resolving the regulatory uncertainty currently inhibiting the development of CCS projects, if done with inadequate attention to existing market dynamics and economic realities, likely willpreclude any commercial-scale deployment of CCS and undermine its effectiveness as a strategy to reduce greenhouse gas emissions. Addressing the regulatory uncertainty surrounding post-injection site care, financial assurance, and long-term liability effectively boils down to four overarching questions confronting entities involved in the capture, transport, injection, and storage of CO2: (1) length of the post-injection site care time period; (2) aspects of post-injection site care for which entities will be responsible; (3) availability and suitability of different risk management instruments for meeting financial assurance requirements; and (4) permanent transfer of all liability to the State. Spectra’s comments on post-injection site care, financial assurance, and long-term liability focus broadly on these issues.

14 GAO Report, Climate Change, Federal Actions Will Greatly Affect the Viability of Carbon Capture and Storage As a Key Mitigation Option, Report to the Chairman on the Select Committee on Energy Independence and Global Warming, House of Representatives, GAO-08-1080, September 2008, at 23, 25. See also Capturing King Coal: Deploying Carbon Capture and Storage Systems in the US at Scale, WORLD RESOURCES INSTITUTE (2008) at 24 ("In the event of an accident or damage years after the well is closed, who is financially and legally responsible? Current law and policy is unclear on this matter, and more generally on the matter of responsibility for long-term measuring and monitoring of the site. In particular, the degree to which private parties remain responsible, or the government assumes a measure of responsibility, is important.").

Response: EPA acknowledges the commenter¿s request for certainty regarding post-injection site care (PISC) requirements for GS wells. However, EPA believes that a certain amount of flexibility is appropriate for setting the PISC timeframe, given the variety of circumstances that may occur at GS sites. The PISC requirements in the final GS rule, as specified in §146.93(b), incorporate a combination of a fixed timeframe and a performance standard approach. The GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Directordiscretion to shorten or lengthen the PISC timeframe during the post-injection period based on sitespecific 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 onsubstantial data, that an alternative PISC timeframe may be appropriate if it ensures nonendangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters¿ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA recognizes that there are challenges associated with financial responsibility for GS projects. However, the Agency believes that in order to protect USDWs from endangerment under the SDWA operators must demonstrate under §146.85 that financial resources are available to plug the injection well and provide PISC when injection begins.Under the final GS rule owners or operators may choose from a variety of financial instruments to demonstrate that they meet the financial responsibility requirements under §146.85, provided the Director determines that the demonstration is adequate to pay for each activity for which financial responsibility is required. EPA is developing guidance (available on EPA¿s website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm) to help owners or operators, permitting authorities, and third parties choose and evaluate appropriate financial methods.

Under SDWA authority, owners or operators of injection wells must ensure protection of USDWs from endangerment and are subject to liability for enforcement under the Act. The final rule requires an owner or operator to conduct monitoring as specified in the Director-approved PISC and site closure plan following the cessation of injection until he or she can demonstrate that the GS project no longer poses an endangerment to USDWs.

Once an owner or operator has met all requirements under Part 146 for Class VI wells and the Director has approved site closure pursuant to §146.93, the owner or operator will generally no longer be subject to enforcement for regulatory noncompliance. Furthermore, the financial instrument required under §146.85 will be released if it was not used. However, even if site closure is approved, an owner or operator may be held liable for regulatory noncompliance (e.g., violation of 40 CFR 144.12) in certain circumstances. For example, an owner or operator may be held liable for noncompliance even after site closure if the Director relied on erroneous information (e.g., erroneous modeling data) provided by the owner or operator when approving site closure.

Additionally, an owner or operator may always be subject to any action, such as administrative orders or civil actions, the Administrator deems necessary under §1431 of the SDWA after site closure if there is unanticipated migration towards or into a USDW that causes or threatens imminent and substantial endangerment to public health. If the owner or operator fails to comply with the order, he or she may be subject to a civil penalty for each day such violation occurs or failure to comply continues.

The Agency clarifies that Class VI well permits may be transferred to another owner or operator pursuant to §144.38 whereby all potential liabilities associated with meeting the requirements of that permit are transferred to that new owner or operator.

Furthermore, after site closure an owner or operator may remain liable under tort and other remedies, or under other federal statutes including, but not limited to, the Clean Air Act, 42 U.S.C. §§ 7401- 7671; CERCLA, 42 U.S.C. § 9601-9675; and RCRA, 42 U.S.C. § 6901-6992. EPA does not have authority to transfer SDWA or other legal liability for Class VI wells to the State or federal government or a third-party fund. See the final rule preamble for further discussion of EPA's final approach.

Commenter Name: Bonnie Lovelace Letter ID: 0152 Commenter Organization: Montana Department of Environmental Quality (MDEQ) Comment ID:

22120

Comment: 19. EPA is seeking comments on the proposed requirements for well plugging, postinjection site care, and site closure, including the proposed requirements for the post-injection time period. MDEQ agrees with EPA's approach and with the discretion for the Director to shorten the period based upon performance

information.Response: EPA acknowledges the commenter’s support and agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Olon Plunk Letter ID: 0536 Commenter Organization: Xcel Energy Comment ID: 21378 Other EPA Comment Codes and Descriptions: 3100 2.1 Proposed Geologic Siting Requirements (40 CFR 146.83); 3800 2.3 Proposed Injection Well Construction Requirements (40 CFR 146.86); 4000 2.4 Proposed Injection Well Operating Requirements (40 CFR 146.88)

Comment: We believe there must be suitable CO2 injection plans backed by seismic surveys, multi dimensional modeling simulations and formation testing.

We recognize the overriding importance of well design and construction that assures well integrity. We believe there must be a sound operations management program including appropriate monitoring and corrective actions that are prepared and implemented by experts in the field.

We recognize both the local and national interest in providing effective post injection site care and closure and demonstrating adequate financial responsibility for these activities. While agreeing with supporting all of these important program elements, I would like to add a few words of caution.

Response: EPA acknowledges the comment. The GS requirements are designed to ensure protection of USDWs from endangerment by requiring that injection wells are permitted, sited, constructed, operated, monitored, and plugged in a manner that does not endanger USDWs. Appropriately designed and constructed wells are necessary to prevent endangerment to USDWs and maintain integrity of the well throughout the lifetime of a GS project. This is the foundation of the requirements for construction and pre-operational testing of Class VI wells at §§146.86 and 146.87.

EPA is developing guidance on site characterization for GS projects to assist owners or operators and Directors in evaluating permit requirements and applications under §146.82. The guidance provides recommendations characterizing the regional geology and hydrogeology of a proposed GS site as well as performing the necessary geochemical, geomechanical, and geophysical analyses of the injection and confining zone. EPA expects that this guidance will assist permit writers in evaluating this information. The guidance can be found on EPA’s website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.EPA is developing guidance on site characterization for GS projects to assist owners or operators and Directors in evaluating permit requirements and applications under §146.82. The guidance provides recommendations characterizing the regional geology and hydrogeology of a proposed GS site as well as performing the necessary geochemical, geomechanical, and geophysical analyses of the injection and confining zone. EPA expects that this guidance will assist permit writers in evaluating this information. The guidance can be found on EPA’s website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Comment Code: 5100 2.8.1 Injection well plugging activities (seeking comment) (40 CFR 146.92)



### Individual Comments

Commenter Name: Michael H. Cochran Letter ID:

0108 Commenter Organization: Bureau of Water, Division of Environment, Kansas Department of Health & Environment (KDHE) Comment

ID: 21985

Comment: 146.92 (a): We believe the sequence of work listed is not appropriate. The bottom hole pressure should be determined prior to flushing the well to obtain a more accurate reading. 146.93 (b) (3): Plume stabilization needs to be

Response: EPA is retaining the proposed approach to well plugging in the final rule at §146.92(a), including the requirement to determine bottomhole reservoir pressure. In addition, the injection well plugging plan must include an appropriate test or measure to determine bottomhole reservoir pressure. EPA believes that the plugging procedures in the GS rule are necessary to ensure the injection well does not become a conduit for future fluid movement that could result in endangerment to USDWs.

Commenter Name: Christine Reimer Letter ID: 0142 Commenter Organization: National Ground Water Association Comment ID: 22570

Comment: Once injection ceases permanently, the operational portion of MMV can also cease. This period, called the closure period, is the time in which the operator will plug and abandon all wells that will not be used for further monitoring. Environmental MMV operations should continue throughout this period using the same suite of techniques as in the operational phase.

Response: EPA clarifies that, following plugging of the injection well and until site closure is authorized, owners or operators of GS wells must perform monitoring and provide post-injection site care as specified in the post-injection site care and site closure plan for at least 50 years or for the duration of the alternative timeframe approved by the Director pursuant to requirements in §146.93(c), unless the owner or operator can make a demonstration earlier that the geologic sequestration project no longer poses a risk of endangerment to USDWs.

Commenter Name: Christine Reimer Letter ID: 0142 Commenter Organization: National Ground Water Association Comment ID: 22612 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4730 2.7.3 Reporting associated with closure and post-injection site careComment: Proposed Rule: 146.92(d)

Proposed revision: (d) Plugging Reports for Class VI Wells. Within 60 days after completion of plugging and abandonment of a well or well field the permittee shall submit to the Director a final report which includes:

Proposed addition: (1) Certification of completion in accordance with approved plans and specifications by an appropriately qualified engineer of record or professional geologist.

Note: It is important that the engineer and/or geologist have expertise and training in injection well drilling technology, reservoir characterization and injection well construction and operation.

Proposed addition: (2) Evidence, such as a sealed copy or certification from the county clerk, that a surveyor's plot of the location of the abandoned well has been recorded in the county courthouse property records.

Response: EPA agrees that appropriately qualified personnel (e.g., engineers and geologists) should be involved in all aspects of the GS operation, including the well plugging process. When the owner or operator (and/or the person who performs the plugging operation) signs the plugging report and certifies it as accurate; they are attesting to the fact that all required activities were performed by qualified personnel. This is required under §146.92(d) and is a condition of the permit that is enforceable under §1423 of the SDWA. EPA clarifies that, in addition to requiring appropriate well plugging, the Director retains the option of witnessing any plugging activity or testing at the well.

EPA clarifies that §146.93(g) requires the owner or operator, as part of the closure process, to record a notation on the deed stating that the property was used for GS. In addition, §146.93(f)(1) requires submission of a survey plat indicating the location of the well to the local zoning authority, as well

as to the Director.

Commenter Name: Michael J. Miller Letter ID: 0168 Commenter Organization: Electric Power Research Institute (EPRI) Comment ID: 22498 Other EPA Comment Codes and Descriptions: 3862 2.3.3.1 Use of corrosion-resistant construction materials (seeking comment); 3864 2.3.3.2 Use of corrosion-resistant cements (seeking comment)

Comment: Preamble, page 43507: "Today’s proposal does not prescribe the specific cements to be used to plug abandoned wells..."

Also, preamble, page 43510: "EPA seeks comment regarding requirements for degradation-resistant well construction materials, such as acid-resistant cements and corrosion resistant casing."

EPRI COMMENT #5: We question the adequacy of the evidence employed to justify requiring the use of corrosion resistant cements in all cases. The laboratory study performed by Duguid, et al. (2004) cited by EPA exposed portland cement samples to acidified waters in an aggressive flow configuration uncharacteristic of a borehole environment. In contrast, the field study by Crow, et al. (2008) performed on a 30 year old production well is characteristic of a boreholeenvironment. Side-wall cores of the casing, acoustic bond logs and well integrity tests did not show signs of casing corrosion, leakage or cement-bond degradation. While side-wall cores of the cement indicated that CO2-induced cement alteration had occurred, the hydraulic integrity of the cement seal was still highly effective. EPA states that the cement alteration found in the study demonstrates that CO2 migrated up the borehole. We question this conclusion and believe the study is not conclusive on this point. Given that the study was performed on a natural CO2 reservoir, free and dissolved CO2 are expected to be present throughout the stratigraphic column from the top of the reservoir through the confining unit to the surface. Therefore, an alternative hypothesis is that the native CO2 present in the confining unit or caprock adjacent to the

cement seal caused the observed alteration. Evidence that the cement underwent greater alteration at the cement-formation interface adjacent to the caprock compared to the cement-casing interface located further from the caprock helps support this hypothesis. Most importantly, the seal maintained its integrity, exhibiting very low cement matrix, and low interface permeabilities, as determined by laboratory and vertical interference tests in the field, respectively. However, should the EPA eventually adopt a requirement for corrosion-resistant materials, we believe EPA is taking the correct approach by not prescribing the type of corrosion-resistant cements and casing to be used in well completions and abandonments; a number of materials are available and selection of a given material may be driven by site-specific well

characteristics.

Duguid, A., M. Radonjic, R. Bruant, T. Mandecki, G. Scherer, and M. Celia. 2004. The Effect of CO2 Sequestration on Oil Well Cements. Presented at the Greenhouse Gas Technologies Conference (GHGT-7), September 5-9, 2004. Vancouver, Canada.

Crow, W., D.B. Williams., B. Carey, M. Celia, and S. Gasda. 2008. CO2 Capture Project Field Study of A Wellbore from a Natural CO2 Reservoir. Presented at the 7th Annual Conference on Carbon Capture and Sequestration, May 5-8, 2008. Pittsburgh, Pennsylvania.

Response: EPA considered both field and lab studies in developing the requirements for Class VI well construction. The Duguid study referenced by the commenter examined a CO2-saturated brine flux condition that may be found in some injection environments such as a saline aquifer. The Crow study mentioned was a well that produced gaseous CO2 from a natural CO2 deposit. In the studies examined, cement alteration and corrosion was found to occur at differing rates. Factors such as contact with brine, temperature, CO2 flux, and time between cement curing and CO2 exposure may all be relevant. See the discussion of Class VI well construction requirements in the preamble to the

final GS rule for additional information.

EPA clarifies that corrosion-resistant cement is not specifically required in a Class VI injection well. Rather, as stated in §146.86(b)(1), casings and cement used must have sufficient strength and be designed for the life of the sequestration project. Further, materials must meet standards listed in the rule and be compatible with fluids with which the materials may be expected to come into contact. Therefore, some well materials may need to be acid-resistant and some may not if they do not come in contact with the CO2 stream or other corrosive fluids and if approved by the Director.

EPA clarifies that the GS rule does not prescribe the specific cements to be used to plug abandonedwells in the AoR because industry standards, such as those developed by API or ASTM International, reflect the current state of the science and the expertise of industrial users on CO2- compatible materials, as specified in §146.92(b). Providing flexibility to choose materials for plugging, provided they are compatible with the injected fluid, is consistent with requirements for other injection well classes and will allow operators to utilize improved well technologies as they become available in the future without a need to amend the regulation.

EPA plans to, every six years, collect and review project data on early GS projects and continue to monitor field and laboratory research to determine whether the appropriate amount and types of information and appropriate documentation are being collected, and to determine if modifications to the requirements are appropriate or necessary.

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24199 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.92(a)

API Comments: (a) Prior to the well plugging, the owner or operator must flush each Class VI injection well with a buffer fluid, determine bottomhole reservoir pressure, and perform a final EXTERNAL mechanical integrity test OF ANY RELEVANT

WELLBORE MATERIALS REMAINING.

Rationale: Many of the components that would be tested by an internal MIT are removed or tested during the plugging process.

Response: EPA agrees that only an external MIT is required, and has modified the GS rule at §146.92(a) to require owners or operators to perform a final external mechanical integrity test prior to the well plugging.

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24200 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.92(b)(2)

API Comments: (2) Appropriate testing methods to ensure FINAL EXTERNAL mechanical integrity as specified in §146.89(C);

Rationale: Many of the components that would be tested by an internal MIT are removed or tested during the plugging process.

Response: EPA agrees that only an external MIT is required, and has modified the GS rule at §146.92(a) to require owners or operators to perform a final external mechanical integrity test prior to the well plugging.

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24201Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.92(b)(5)

API Comments: (5) The type and grade and quantity of material to be used in plugging. The material must be SUITABLE FOR USE with the carbon dioxide stream;

and

No rationale provided

Response: EPA believes, considering the potentially corrosive nature of CO2 when it is in contact with water, that the requirement that the material must be compatible with the CO2 stream is appropriate. The final rule retains this requirement.

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24202 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4730 2.7.3 Reporting associated with closure and post-injection site care

Comment: Rule Provision: 146.92(d)

API Comments: (d) Plugging report. Within 60 days after plugging the owner or operator must submit a plugging report to the Director. If the semi-annual report is due less than 15 days after completion of plugging, then the report must be submitted within 60 days after plugging. The report must be certified as accurate by the owner or operator and by the person who performed the plugging operation (if other than the owner or operator.)

Rationale: The proposed changes are suggested to simplify and clarify a provision that API believes is needlessly complicated.

Response: EPA has revised the text at §146.92(d) to reduce confusion. The final rule text reads, "Within 60 days after plugging, the owner or operator must submit a plugging report to the

Director."

Commenter Name: Frederick R. Eames Letter ID: 0178 Commenter Organization: CCS Alliance Comment ID: 23839 Other EPA Comment Codes and Descriptions: 4710 2.7.1 Proposed submissions required for permit applications (seeking comment)

Comment: A. WELL PLUGGING PLAN

EPA's Proposed Rule would require owners and operators to develop a well plugging plan to be approved by the Director as part of each permit application. Such a plan would include: (1) a determination of bottom-hole reservoir pressure; (2) the identification of type and numbers of plugs to be used; (3) the placement of each plug; (4) testing methods to ensure mechanical integrity testing ("MIT"); (5) the method of plug placement; and (6) the type, grade and quantity of material to be used in plugging. By not mandating specific types, materials, or testing methods, EPA is giving applicants broad flexibility toaccommodate the varying types of GS projects contemplated by this rulemaking. The CCS Alliance agrees with this approach. Such flexibility also accounts for the fact that supercritical CO2 has different properties than current injectants under the UIC program and, therefore. may require different plugging methods and materials. For instance, cement plugs can degrade over time from the build up of carbonic acid, which forms when CO2 is injected in subsurface formations containing brine. However. well integrity should be considered the function of well materials collectively in maintaining a fluid barrier (as opposed to individual components susceptibility, particularly from laboratory tests).

Response: EPA agrees with commenters that a flexible approach is appropriate for GS wells. The GS rule does not prescribe the specific cements to be used to plug injection wells because industry standards, such as those developed by API or ASTM International, reflect the current state of the science and the expertise of industrial users on CO2-compatible materials, as specified in §146.92(b). Providing flexibility to choose materials for plugging, provided they are compatible with the injected fluid, is consistent with requirements for other injection well classes and will allow operators to utilize improved well technologies as they become available in the future without a need to amend the regulation.

Commenter Name: Thomas Curtis Letter ID: 0181 Commenter Organization: American Water Works Association (AWWA) Comment ID: 23747 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Part 146.92(b) As previously stated AWWA believes that potential changes in the size of the area of review require that all site plans be reevaluated at the same frequency as the area of review. Therefore, AWWA recommends revising this part to read:

Well Plugging Plan. The owner or operator of a Class VI well must prepare, maintain, and comply with a plan that is acceptable to the Director. The plan must be reviewed and revised by the owner or operator, and submitted to the Director for approval, at the same frequency and time as the AOR reevaluation. The requirement to maintain and implement an approved plan is directly enforceable regardless of whether the requirement is a condition of the permit. The well plugging plan must be submitted as part of the permit application and must include the following information:

Response: EPA agrees that developing, maintaining, and implementing an injection well plugging plan is important to assuring that GS wells are plugged in a manner that will ensure that the well will not serve as a conduit for CO2 leakage preventing endangerment of USDWs.

EPA disagrees with the suggested change, however. The final rule requirement at §146.92(c) for the owner or operator to notify the Director of any changes to the injection well plugging plan at least 60 days before plugging the well will allow the owner or operator (through communication with the Director) to address any issues associated with the initial well plugging plan submitted with the permit application. EPA is not requiring formal periodic review and updates to the injection well plugging plan throughout the injection phase. EPA does not expect that changes to this plan would be implemented until injection operations cease. EPA envisions that owners or operators will take into account similar considerations that guide updates to other project plans, e.g., monitoring andoperational data and results of AoR reevaluations.

EPA clarifies that the owner or operator's injection well plugging plan will be incorporated as a condition of their UIC permit and is therefore enforceable; failure to follow the approved plan would be considered a violation of the permit and would be subject to applicable civil, criminal, or administrative penalties under §1423 of the SDWA.

Commenter Name: Thomas Curtis Letter ID: 0181 Commenter Organization: American Water Works Association (AWWA) Comment ID: 24371 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Part 146.92(b)(5) AWWA recommends revising this part to read:

The type and grade and quantity of material to be used in plugging. The material must be compatible with the carbon dioxide stream and pre-injection formation conditions; and

Response: EPA believes, considering the potentially corrosive nature of CO2 when it is in contact with water, that the requirement that the material must be compatible with the CO2 stream is appropriate. The final rule retains this requirement.

Commenter Name: Wendy Jacobs Letter ID: 0183 Commenter Organization: Harvard Law School Environmental Law and Policy

Center Comment ID:

25143

Comment: B. EPA Should Impose More Specific Well Plugging Standards

In the preamble, EPA states that the proposed regulation will ensure that injection wells are plugged at the end of an injection project so that the wells will not serve as conduits for CO2 movement into USDWs. See 73 Fed. Reg. at 43,499, 43,518. If an improperly plugged well allows CO2 to escape into the atmosphere, the climate change mitigation purpose underlying Class VI wells is undermined. See id. at 43,492 (discussing how improper well plugging of an abandoned oil exploration well allows a geyser of CO2 and water to erupt periodically from the well, releasing 12,000 gigatons per year of CO2 into the atmosphere). The proposed regulation, however, does not provide enough meaningful guidance for owners/operators regarding how to "plug wells in a manner that does not endanger USDWs." Id. at 43,518. Owners/operators are directed simply to "prepare, maintain, and comply with a [well plugging] plan that is acceptable to the Director." Id. at 43,540 (proposed 40 C.F.R. § 146.92(b)). EPA neglects to specify "the types of materials or tests that must be used during well plugging because there are a variety of methods that are appropriate and new materials and tests may become available in the future." Id. at 43,518. Its general outline for the well plugging plan is intended "to give owners or operators flexibility in . . . choos[ing] from available materials and tests to carry out the proposed requirements." Id. Allowing flexibility is certainly important. It does not, however, preclude EPA fromproviding specific performance requirements, preferred methods, or a nonexhaustive list of approved materials and techniques.EPA’s existing regulations for other UIC wells and surface impoundments and landfills under the Resource Conservation and Recovery Act, 42 U.S.C. § 6901, et. seq., ("RCRA"), provide good models in this regard. The existing regulations for Class I, II, and III wells require plugging in a manner to "prevent the movement of fluids" into a USDW. 40 C.F.R.

§ 146.10(a)(1). In addition, the existing regulation lists three accepted plugging techniques. 40 C.F.R. § 146.10(a)(2)(i)-(iii)). It builds in flexibility by allowing the Director to approve plugging techniques outside of the enumerated categories if the technique will "reliably provide a comparable level of protection to USDWs." 40 C.F.R. § 146.10(a)(2)(iv); see also 40 C.F.R. §§ 264.228(a)(2)(iii)(A)-(E), 264.310(a)(1)-(5) (plugging requirements for surface impoundments and landfills, respectively, which include specific targets to be met (permeability) as well as general performance goals (minimum maintenance and migration)).

By specifying a baseline of plugging techniques that EPA already knows will work for GS, EPA would provide valuable GS-specific guidance to owners/operators (and Directors). This may be especially valuable in this early stage of development for GS technology as it will give all involved parties a brighter line by which to measure compliance. Additionally, existing regulations demonstrate that more specificity need not, as EPA suggests in the preamble to the proposed regulation (73 Fed. Reg. at 43,518), constrain the use of future technologies. The proposed regulations can preserve flexibility by vesting the Director with the authority to consider and approve new plugging techniques. Accordingly, EPA should revise the proposed Class VI UIC program regulation to include a list of specific materials and tests that it deems suitable for plugging GS wells, in addition to providing the Director with the discretion to approve new techniques as they become available, provided they will perform at least as well.

Response: EPA believes that the required information required to be included in the injection well plugging plan, as specified in §146.92(b), provides a framework for acceptable well plugging procedures. EPA clarifies that the injection well plugging plan must include the following information: (1) appropriate test or measure to determine bottomhole reservoir pressure; (2) appropriate testing methods to ensure mechanical integrity as specified in §146.89; (3) the type and number of plugs to be used; (4) the placement of each plug including the elevation of the top and bottom of each plug; (5) the type and grade and quantity of material to be used in plugging (the material must be compatible with the CO2 stream); and (6) the method of placement of the plugs. EPA believes that these requirements in conjunction with Agency technical guidance provide sufficient information to the owner or operator and the Director to allow for the development of a well plugging plan and will help ensure protection of USDWs from endangerment.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans required under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate non-endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.Commenter Name: Daniel Plath Letter ID: 0188 Commenter Organization: NiSource, Inc. Comment ID: 25229 Other EPA Comment Codes and Descriptions: 1610 1.3.1 Risks to USDWs; 3400 2.2.2 Corrective Action; 3800 2.3 Proposed Injection Well Construction Requirements (40 CFR 146.86)

Comment: aspects. The following points summarize four primary lessons learned through operation of natural gas storage that would be applicable to GS:

1. History has shown that the one component in the system that has caused the most safety issues is the wells; specifically the operator's wells, plugged and abandoned (P&A) wells and third party operating wells (e.g. oil and gas production wells). The casing and cement in the storage well is the "first line of defense" in the containment of high pressure gas and a properly designed,

constructed and maintained well is critical. Even after several decades of operations over a four State area, NiSource subsidiaries have never experienced loss of containment from cap rock leakage, migration up faults, re-activation of faults, earthquakes, or the other potential leakage pathways that EPA discusses in the Proposed Rule. While history will ultimately reveal the root causes of future problems, if any, with GS, NiSource submits that the predominant cause will likely be identified as being related to an active well, abandoned well or third party well if not properly addressed in the Final Rule. This is based on the belief that the rigorous site selection process will preclude the other sites that would have had other issues, e.g. cap rock leakage, from even being activated in the first place.

Response: EPA agrees that proper site characterization should minimize leakage through faults, breaks in the seal of the confining layer, and other geologic pathways. EPA believes that the construction, operating, and monitoring requirements in the GS rule will prevent leakage from occurring through active wells. Appropriately designed and constructed wells are necessary to prevent endangerment to USDWs and maintain integrity of the well throughout the lifetime of a GS project. This is the foundation of the requirements for construction and pre-operational testing of Class VI wells at §§146.86 and 146.87.

EPA also agrees that the AoR and corrective action process should identify both abandoned wells and third party wells that could serve as leakage pathways. The UIC Program's long-standing approach to corrective action, tailored to the potential corrosivity of and impurities in the CO2 stream, can address the potential risk associated with improperly plugged wells in the AoR.

EPA notes that the final rule, at 40 CFR §124.10(c)(1)(xi), requires the notification of state oil and gas agencies, state mineral exploration agencies, and state public water supply supervision directors about the availability of the draft permit . EPA expects that such notification can help with further identifying wells in the area of review.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24490 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.92(a)Proposed CCS Group Recommendations: (a) Prior to the well plugging, the owner or operator must flush each Class VI injection well with a buffer fluid, determine bottomhole reservoir pressure, and perform a final EXTERNAL mechanical integrity

test OF ANY RELEVANT WELLBORE MATERIALS REMAINING.

Basis for CCS Group Comments: Many of the components that would be tested by an internal MIT are removed or tested during the plugging process.

Rule Provision: 146.92(b)

Proposed CCS Group Recommendations: Support the proposed language.

Basis for CCS Group Comments: Agree with EPA’s rationale.

Rule Provision: 146.192(b)(2) & (5)

Proposed CCS Group Recommendations: (2) Appropriate testing methods to ensure FINAL EXTERNAL mechanical integrity as specified in §146.89(C); ...

(5) The type and grade and quantity of material to be used in plugging. The material must be SUITABLE FOR USE with the carbon dioxide stream; and

Basis for CCS Group Comments: Many of the components that would be tested by an internal MIT are removed or tested during the plugging process.

Response: Regarding the suggested edit at 146.92(b)(2), EPA agrees that only an external MIT is required, and has modified the GS rule at §146.92(a) and 146.92(b) to require owners or operators to perform a final external mechanical integrity test prior to the well plugging.

Regarding the edit at 146.92(b)(5), EPA believes, considering the potentially corrosive nature of CO2 when it is in contact with water, that the requirement that the material must be compatible with the CO2 stream is appropriate. The final rule retains this requirement.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24491 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4730 2.7.3 Reporting associated with closure and post-injection site care

Comment: Rule Provision: 146.92(c)

Proposed CCS Group Recommendations: Support the proposed language.

Basis for CCS Group Comments: Agree with EPA’s rationale.

Response: EPA acknowledges the commenter’s support and the final rule retains this approach.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24492 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rulelanguage; 4730 2.7.3 Reporting associated with closure and post-injection site care

Comment: Rule Provision: 146.92(d)

Proposed CCS Group Recommendations: (d) Plugging report. Within 60 days after plugging the owner or operator must submit a plugging report to the Director. If the semi-annual report is due less than 15 days after completion of plugging, then the report must be submitted within 60 days after plugging. The report must be certified as accurate by the owner or operator and by the person who performed the plugging operation (if other than the owner or operator.)

Basis for CCS Group Comments: The proposed change will simplify and clarify a provision that is unnecessarily complicated.

Response: EPA has revised the text at §146.92(d) to reduce confusion. The final rule text reads, "Within 60 days after plugging the owner or operator must submit a plugging report to the Director."

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24713 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.92(a)

Anadarko Petroleum Corporation (APC) Comments: (a) Prior to the well plugging, the owner or operator must flush each Class VI injection well with a buffer fluid, determine bottomhole reservoir pressure, and perform a final EXTERNAL mechanical integrity test OF ANY RELEVANT WELLBORE MATERIALS REMAINING.

Rationale: Many of the components that would be tested by an internal MIT are removed or tested during the plugging process.

Response: EPA agrees that only an external MIT is required, and has modified the GS rule at §146.92(a) to require owners or operators to perform a final external mechanical integrity test prior to the well plugging.

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24714 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.92(b)(2)

Anadarko Petroleum Corporation (APC) Comments: (2) Appropriate testing methods to ensure FINAL EXTERNAL mechanical integrity as specified in §146.89(C); ...

(5) The type and grade and quantity of material to be used in plugging. The material must be SUITABLE FOR USE with the carbon dioxide stream; and

Rationale: Many of the components that would be tested by an internal MIT are removed or tested during the plugging process.Response: Regarding the suggested edit at 146.92(b)(2), EPA agrees that only an external MIT is required, and has modified the GS rule at §146.92(a) to require owners or operators to perform a final external mechanical integrity test prior to the well plugging.

Regarding the edit at 146.92(b)(5), EPA believes, considering the potentially corrosive nature of CO2 when it is in contact with water, that the requirement that the material must be compatible with the CO2 stream is appropriate. The final rule retains this requirement.

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24715 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4730 2.7.3 Reporting associated with closure and post-injection site care

Comment: Rule Provision: 146.92(d)

Anadarko Petroleum Corporation (APC) Comments: (d) Plugging report. Within 60 days after plugging the owner or operator must submit a plugging report to the

Director. If the semi-annual report is due less than 15 days after completion of plugging, then the report must be submitted within 60 days after plugging. The report must be certified as accurate by the owner or operator and by the person who performed the plugging operation (if other than the owner or operator.)

Rationale: The proposed changes are suggested to simplify and clarify a provision that APC believes is needlessly complicated.

Response: EPA has revised the text at §146.92(d) to reduce confusion. The final rule text reads, "Within 60 days after plugging the owner or operator must submit a plugging report to the Director."

Commenter Name: Ronald Evans Letter ID: 0215 Commenter Organization: Denbury Resources, Inc. (DRI) Comment ID: 24312 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: H. § 146.92 Injection well plugging.

1. EPA Proposed §146.92 (b) Well Plugging Plan. (5) The type and grade and quantity of material to be used in plugging. The material must be compatible with the carbon dioxide stream;

The proposed regulation requires the wellbore to be flushed prior to plugging and thus it is unnecessary to use cement "compatible with the carbon dioxide stream." In the absence of water, CO2 is non-corrosive and compatible with conventional cements (see discussion under Comment #G). Accordingly, the rule

should be revised as follows:

§146.92 (b) Well Plugging Plan. (5) The type and grade and quantity of material to be used in plugging. The material must be compatible with the carbon dioxide stream;Response: EPA believes, considering the potentially corrosive nature of CO2 when it is in contact with water, that the requirement that the material must be compatible with the CO2 stream is appropriate. The final rule retains this requirement because CO2 and water will be present in the

subsurface.

Commenter Name: Darrick Eugene Letter ID: 0223 Commenter Organization: Texas Carbon Capture and Storage Association Comment ID: 23992 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: 9. § 146.92 Injection well plugging.

EPA Proposed §146.92 (b) Well Plugging Plan. (5) The type and grade and quantity of material to be used in plugging. The material must be compatible with the carbon dioxide stream;

The proposed regulation requires the wellbore to be flushed prior to plugging and thus it is unnecessary to use cement "compatible with the carbon dioxide stream". In the absence of water, CO2 is non-corrosive and compatible with conventional cements (see discussion under Comment #7). Accordingly, the rule

should be revised as follows:

§146.92 (b) Well Plugging Plan. (5) The type and grade and quantity of material to be used in plugging. The material must be compatible with the carbon dioxide stream;

Response: EPA believes, considering the potentially corrosive nature of CO2 when it is in contact with water, that the requirement that the material must be compatible with the CO2 stream is appropriate. The final rule retains this requirement because CO2 and water will be present in the

subsurface.

Commenter Name: Andrew Duguid Letter ID: 0226 Commenter Organization: Schlumberger Carbon Services Comment ID: 24027 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 3400 2.2.2 Corrective Action

Comment: Proposed Rule: (3) Determine which abandoned wells in the area of review have been plugged (as required by §146.92) in a manner that prevents the movement of carbon dioxide or associated fluids that may endanger USDWs.

Schlumberger Suggested Revision: (3) Determine which abandoned wells identified in 146.84 (c) (2) have been plugged (as required by §146.92) in a manner that prevents the movement of carbon dioxide or formation fluids that may endanger

USDWs.

Schlumberger Rationale: -

Response: EPA acknowledges the comment. Based on its evaluation of all public comments and input on the proposed rule and NODA and Request for Comment, EPA has made many revisions tothe GS Rule. See the final rule and preamble for further discussion on EPA's final approach.

Commenter Name: Andrew Duguid Letter ID: 0226 Commenter Organization: Schlumberger Carbon Services Comment ID: 24067 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: §146.92 Injection well plugging.

Proposed Rule: (a) Prior to the well plugging, the owner or operator must flush each Class VI injection well with a buffer fluid, determine bottomhole reservoir pressure, and perform a final mechanical integrity test.

Schlumberger Suggested Revision: (a) Prior to the well plugging, the owner or operator must flush each Class VI injection well with a buffer fluid, determine bottomhole reservoir pressure, and perform a final external mechanical integrity

test.

Schlumberger Rationale: Many of the components that would be tested by an internal MIT are removed or tested during the plugging process.

Response: EPA agrees that only an external MIT is required, and has modified the GS rule at §146.92(a) to require owners or operators to perform a final external mechanical integrity test prior to the well plugging.

Commenter Name: Andrew Duguid Letter ID: 0226 Commenter Organization: Schlumberger Carbon Services Comment ID: 24068 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Proposed Rule: (2) Appropriate testing methods to ensure mechanical integrity as specified in §146.89;

Schlumberger Suggested Revision: (2) Appropriate testing methods to ensure final external mechanical integrity as specified in §146.89(c);

Schlumberger Rationale: Many of the components that would be tested by an internal MIT are removed or tested during the plugging process.

Response: EPA agrees that only an external MIT is required, and has modified the GS rule at §146.92(a) to require owners or operators to perform a final external mechanical integrity test prior to the well plugging.

Commenter Name: Andrew Duguid Letter ID: 0226 Commenter Organization: Schlumberger Carbon Services Comment ID: 24069 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Proposed Rule: (5) The type and grade and quantity of material to be used in plugging. The material must be compatible with the carbon dioxide stream; andSchlumberger Suggested Revision: (5) The type and grade and quantity of material to be used in plugging. The material must be suitable for use with the carbon dioxide stream; and

Schlumberger Rationale: -

Response: EPA believes, considering the potentially corrosive nature of CO2 when it is in contact with water, that the requirement that the material must be compatible with the CO2 stream is appropriate. The final rule retains this requirement.

Commenter Name: Andrew Duguid Letter ID: 0226 Commenter Organization: Schlumberger Carbon Services Comment ID: 24070 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Proposed Rule: (d) Plugging report. Within 60 days after plugging or at the time of the next semi-annual report (whichever occurs earlier) the owner or operator must submit a plugging report to the Director. If the semi-annual report is due less than 15 days after completion of plugging, then the report must be submitted within 60 days after plugging. The report must be certified as accurate by the owner or operator and by the person who performed the plugging operation (if other than the owner or operator.)

Schlumberger Suggested Revision: (d) Plugging report. Within 60 days after plugging the owner or operator must submit a plugging report to the Director. The report must be certified as accurate by the owner or operator and by the person who performed the plugging operation (if other than the owner or operator.)

Schlumberger Rationale: Simplification

Response: EPA has revised the text at §146.92(d) to reduce confusion. The final rule text reads, "Within 60 days after plugging the owner or operator must submit a plugging report to the Director."

Commenter Name: Mark Bohrer Letter ID: 0241 Commenter Organization: North Dakota Industrial Commission Comment ID: 23305

Comment: 146.92(d) Simplify. Plugging reports should be required within a consistent

time frame.

Response: EPA has revised the text at §146.92(d) to reduce confusion. The final rule text reads, "Within 60 days after plugging the owner or operator must submit a plugging report to the Director."

Commenter Name: Kurt Waltzer Letter ID: 0250 Commenter Organization: Clean Air Task Force Comment ID: 22311

Comment: Perhaps inadvertently, the proposed rule does not explicitly require updating of several of the required plans. In most but not all cases, there is a rather ambiguous requirement to "maintain" a given plan. Explicit requirements to make updates as warranted appear to be missing from provisions relating to:• the plugging plan required by §146.92 (again the ambiguous word "maintain" is used);

Response: EPA believes that developing and implementing an injection well plugging plan is important to assuring that GS wells are plugged in a manner that will ensure that the well will not serve as a conduit for CO2 leakage, preventing endangerment of USDWs.

EPA disagrees that explicit requirements to make updates to the injection plugging plan is necessary. The final rule at §146.92(c) requires the owner or operator to notify the Director of any changes to the injection well plugging plan at least 60 days before plugging the well. This will allow the owner or operator (through communication with the Director) to address any issues associated with the initial well plugging plan submitted with the permit application and will require the owner or operator to maintain the plugging plan in order to communicate such changes. EPA is not requiring formal periodic review and updates to the injection well plugging plan throughout the injection phase. EPA does not expect that changes to this plan would be implemented until injection operations cease.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24935 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.92

EPA Proposal: 12. Injection well plugging.

(a) Prior to the well plugging, the owner or operator must flush each Class VI injection well with a buffer fluid, determine bottomhole reservoir pressure, and perform a final mechanical integrity test.

GWPC Recommendations: (a) Prior to the well plugging, the owner or operator must flush each Class VI injection well with a buffer fluid, determine bottomhole reservoir pressure, and perform a final external mechanical integrity test.

Rationale: Many of the components that would be tested by an internal MIT are removed or tested during the plugging process. Consequently, the GWPC suggests including the term internal to the language for clarification.

Response: EPA agrees that only an external MIT is required, and has modified the GS rule at §146.92(a) to require owners or operators to perform a final external mechanical integrity test prior to the well plugging.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24936 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.92(b)

EPA Proposal: (b) Well Plugging Plan. The owner or operator of a Class VI wellmust prepare, maintain, and comply with a plan that is acceptable to the Director. The requirement to maintain and implement an approved plan is directly enforceable regardless of whether the requirement is a condition of the permit. The well plugging plan must be submitted as part of the permit application and must include the following information:

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

Response: EPA acknowledges the commenter’s support; the final rule retains this provision.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24937 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: EPA Proposal: (1) Appropriate test or measure to determine bottomhole reservoir

pressure; (2) Appropriate testing methods to ensure mechanical integrity as specified in §
146.89; (3) The type and number of plugs to be used; (4) The placement of each plug including the elevation of the top and bottom of each plug; (5) The type and grade and quantity of material to be used in plugging. The material must be compatible with the carbon dioxide stream; and (6) The method of placement of the plugs.

GWPC Recommendations: Support the proposed EPA language for (1), (3), (4) and (6)

(2) Appropriate testing methods to ensure final external mechanical integrity as specified in §146.89(c);

(5) The type and grade and quantity of material to be used in plugging. The material must be suitable for use with the carbon dioxide stream; and

Rationale: Many of the components that would be tested by an internal MIT are removed or tested during the plugging process. Consequently, the GWPC suggests adding the term external to the language for clarification.

Response: Regarding the suggested edit at 146.92(b)(2), EPA agrees that only an external MIT is required, and has modified the GS rule at §146.92(a) to require owners or operators to perform a final external mechanical integrity test prior to the well plugging.

Regarding the edit at 146.92(b)(5), EPA believes, considering the potentially corrosive nature of CO2 when it is in contact with water, that the requirement that the material must be compatible with the CO2 stream is appropriate. The final rule retains this requirement.Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24938 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4730 2.7.3 Reporting associated with closure and post-injection site care

Comment: EPA Proposal: (c) Notice of intent to plug. The owner or operator must notify the Director at least 60 days before plugging of a well. At this time, if any changes have been made to the original well plugging plan, the owner or operator must also provide the revised well plugging plan. At the discretion of the Director, a shorter notice period may be allowed.

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

Response: EPA acknowledges the commenter’s support; the final rule retains this provision.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24939 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4730 2.7.3 Reporting associated with closure and post-injection site care

Comment: Rule Provision: 146.92(d)

EPA Proposal: (d) Plugging report. Within 60 days after plugging or at the time of the next semi-annual report (whichever occurs earlier) the owner or operator must submit a plugging report to the Director. If the semi-annual report is due less than 15 days after completion of plugging, then the report must be submitted within 60 days after plugging. The report must be certified as accurate by the owner or operator and by the person who performed the plugging operation (if other than the owner or operator.)

GWPC Recommendations: (d) Plugging report. Within 60 days after plugging the owner or operator must submit a plugging report to the Director. The report must be certified as accurate by the owner or operator and by the person who performed the plugging operation (if other than the owner or operator.)

Rationale: Simplification

Response: EPA has revised the text at §146.92(d) to reduce confusion. The final rule text reads, "Within 60 days after plugging the owner or operator must submit a plugging report to the Director."

Commenter Name: Donn Miller Letter ID: 0270 Commenter Organization: State of Oregon, Water Resources Department Comment ID: 22890

Comment: 146.92 Injection Well Plugging.

The rules describe plugs as a way to abandon class VI wells.

In order to ensure that these wells are properly abandoned and that they don't

become a health hazard or a health threat in the future the abandonment of class VIwells should consist of completely filling them from the bottom up to land surface with an approved sealant (i.e. cement). This assumes that the well was properly constructed in the first place. If the well wasn't constructed properly in the first place then another abandonment method maybe necessary to properly protect the groundwater resource.

Response: EPA requires that, to protect USDWs from endangerment, injection wells must be plugged in a manner to ensure that the well will not serve as a conduit for future fluid movement into USDWs. This may be accomplished in a number of ways using a number of different types of materials. In the case of GS wells, the plugging materials must be compatible with CO2.

EPA disagrees that Class VI wells need to be completely filled from the bottom of the well to the land surface with an approved cement in order to protect USDWs from endangerment. Most experts agree that a series of plugs separated by adequate well bore fluid (e.g., drilling mud) is considered to be adequate protection, and that the time and expense of continuous cementing may not be practical or necessary to prevent fluid migration and in some cases, other methods are equally protective. (Source: Technical Assistance Document: Cementing for the Plugging and Abandonment of Injection Wells, 1989) The Class VI well plugging requirements at §146.92 are very similar to those for Class I wells, with additional considerations that the materials used are compatible with CO2.

EPA adds that the Director must approve the owner or operator's injection well plugging plan. Additionally, while EPA believes the requirements for well plugging are adequately protective of USDWs, if there is reason to believe that completely filling the well is necessary to protect USDWs from endangerment, nothing in the federal regulation precludes this.

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



### Individual Comments

Commenter Name: Leslie Savage Letter ID: 0122 Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24795 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: (e) A demonstration of external mechanical integrity pursuant to §146.89(c) at least once per year throughout the duration of INJECTION the geologic sequestration project;

{Demonstration of external mechanical integrity should not be necessary after cessation of injection and (relatively immediate) dissipation of pressure near the wellbore resulting from injection.}

Response: In the final rule, EPA has revised the text at §144.90(e) to specify that owners or operators must demonstrate internal MI at least once per year until the well is plugged.

Commenter Name: Leslie Savage Letter ID: 0122 Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24799 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rulelanguage

Comment: (i) The pressure differential between pre-injection and predicted post-injection pressures in the injection zone; (ii) The predicted position of the carbon dioxide plume and associated pressure front at site closure as demonstrated inthe AOR evaluation required under §146.84(b); (iii) A description of postinjection monitoring location, methods, and proposed frequency; and (iv) A proposed schedule for submitting post-injection site care monitoring results to

the Director.

{This should be referenced in 146.82(w).}

Response: EPA clarifies that the reference to the post-injection site care and site closure plan, in the final rule at §146.82(a)(17), is to require that the plan be included in the attachments to the Class VI permit application. The details of the plan contents are included in §146.93 and are enforceable permit conditions, along with other requirements related to post-injection site care and site closure.

Commenter Name: Leslie Savage Letter ID: 0122 Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24800 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: (3) Upon cessation of injection, THE OWNER OR OPERATOR MUST either submit an

amended post-injection site care and site closure plan or demonstrate to the Director through monitoring data and modeling results that no amendment to the plan is needed.

Response: Based on its evaluation of all public comments and input on the proposed rule and NODA and Request for Comment EPA has made many revisions to the GS Rule. See the final rule and preamble for further discussion on EPA's final approach.

Commenter Name: Leslie Savage Letter ID: 0122 Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24801 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4730 2.7.3 Reporting associated with closure and post-injection site care

Comment: (4) THE OWNER OR OPERATOR MAY May modify and resubmit the post-injection site care and site closure plan for the Director's approval within 30 days of such change.

Response: Based on its evaluation of all public comments and input on the proposed rule and NODA and Request for Comment EPA has made many revisions to the GS Rule. See the final rule and preamble for further discussion on EPA's final approach.

Commenter Name: Leslie Savage Letter ID: 0122 Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24806 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: (d) After the Director has authorized site closure, THE OWNER OR OPERATOR must plug all monitoring wells in a manner which will not allow movement of injectionor formation fluids that endangers a USDW.

Response: Based on its evaluation of all public comments and input on the proposed rule and NODA and Request for Comment EPA has made many revisions to the GS Rule. See the final rule and preamble for further discussion on EPA's final approach.

Commenter Name: Christine Reimer Letter ID: 0142 Commenter Organization: National Ground Water Association Comment ID: 22564

Comment: Closure

When all injection operations are finished the site will be closed and the post closure period will begin. At this juncture the injection wells will be plugged and abandoned. The plugging needs to be done such that the CO2 and formation fluids cannot use the wellbore as a conduit when it is complete. No wells should be abandoned until there has been a final round of measurements to verify the integrity of the well in case remedial action is needed prior to plugging. Wells plugged prior to the site closure phase should be plugged and abandoned following the same procedures as those in the closure phase. Any requirements need to ensure that all wells are properly plugged and abandoned using material

and methods that will allow the well to remain safe and not become an avenue for leakage.

Response: EPA agrees that Class VI injection wells must be plugged in a manner that protects USDWs from endangerment, and believes that the final rule requirements address the commenter’s concerns. EPA requires that, to protect human health as it relates to endangered USDWs, injection wells be plugged in a manner to ensure that the well will not serve as a conduit for future fluid movement into USDWs. In the case of GS wells, the plugging materials must be compatible with CO2, as specified at 146.92(b). EPA clarifies that the final GS rule at 146.92(a) requires owners or operators to perform a final external mechanical integrity test prior to the well plugging. These requirements apply whether the well is plugged upon cessation of injection or at the time of site

closure.

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24147 Other EPA Comment Codes and Descriptions: 1220 1.1.1.1 Terminology and definitions

Comment: Rule Provision: 146.81(d) [Definition - Post-injection site care]

API Comments: Post-injection site care means appropriatemonitoring and other actions (including corrective action) neededfollowing cessation of injection to assure that USDWs are not endangered , AS REQUIRED UNDER §146.93.

Rationale: Deleted "appropriate" because the definition of it is not clear. Deleted USDW phrase because it is incorporated in 146 requirements.

Response: Based on its evaluation of all public comments and input on the proposed rule and NODA and Request for Comment, EPA has made many revisions to the GS Rule. See the final rule and preamble for further discussion on EPA's final approach. EPA adds that the owner or operatormust monitor as specified in the post-injection site care and site closure plan for at least 50 years or for the duration of the alternative timeframe approved by the Director pursuant to requirements in §146.93(c), unless the owner or operator can make a demonstration earlier that the geologic sequestration project no longer poses a risk of endangerment to USDWs.

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24149 Other EPA Comment Codes and Descriptions: 1220 1.1.1.1 Terminology and definitions

Comment: Rule Provision: 146.81(d) [Definition - Site closure]

API Comments: Site closure MEANS the point/time, as determined by the Director following the requirements under §146.93, at which the owner or operator of a GS

site PROJECT is released from post-injection site care responsibilities.

Rationale: "GS project" is consistent with other definitions.

Response: Based on its evaluation of all public comments and input on the proposed rule and NODA and Request for Comment, EPA has made many revisions to the GS Rule. See the final rule and preamble for further discussion on EPA's final approach.

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24204 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.93(a)(2)

API Comments: (2) The post-injection site care and site closure plan must include the following information: (i) The pressure differential between preinjection and predicted post-injection pressures in the injection zone; (ii) The predicted position of the carbon dioxide plume and associated pressure front at site closure as demonstrated in the area of review evaluation required under § 146.84(b); (iii) A description of post-injection monitoring location, methods, and proposed frequency; and (iv) A proposed schedule for submitting post-injection site care monitoring

results to the Director.

Rationale: Revisions here reflect changes to §146.93(b)(3)

Response: Based on its evaluation of all public comments and input on the proposed rule and NODA and Request for Comment, EPA has made many revisions to the GS Rule. See the final rule and preamble for further discussion on EPA's final approach.

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24205 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4730 2.7.3 Reporting associated with closure and post-injection site careComment: Rule Provision: 146.93(a)(4)

API Comments: (4) AT ANY TIME DURING THE POST-INJECTION SITE CARE PHASE, The owner or operator may modify and resubmit the post-injection site care and site closure plan for the Director‘s approval within 30 days of such change.

Rationale: Technical Clarification.

Response: EPA agrees that a post-injection site care monitoring plan is an important tool for GS, and anticipates that, in some cases, the appropriate post-injection monitoring strategy may end up being different than initially projected, and there may be a need to amend the post-injection site care and site closure plan. EPA is requiring that upon the cessation of injection, the owner or operator submit an amended post-injection site care and site closure plan or demonstrate to the Director that no changes to the original post-injection site care and site closure plan are necessary (§146.93(a)(3)). EPA is not requiring formal periodic review and updates to the PISC and site closure plan throughout the injection phase. EPA does not expect that changes to this plan would be implemented until injection operations cease. EPA envisions that owners or operators would take into account similar considerations that guide updates to other project plans, e.g., monitoring and operational data and results of AoR reevaluations. EPA adds that, if any monitoring or other site data indicate a need for amending the post-injection site care plan, the owner or operator is expected to amend the plan accordingly.

EPA adds that, in the final rule, it has revised the text at §146.93(a)(4) as follows: "At any time during the life of the geologic sequestration project, the owner or operator may modify and resubmit the post-injection site care and site closure plan for the Director’s approval within 30 days of such change."

EPA is issuing guidance on development and updating of the GS project plans, including the postinjection site care and site closure plan. The guidance will be available on EPA's web site, at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24256

Comment: Rule Provisions: 146.93 EPA Preamble Question: 39. 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. EPA

Notice 43520.

API Response: See question 38 above regarding post closure time periods.

Response: As described above, EPA acknowledges that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final GS regulation includes a provision that the Director may, at his/her discretion, shorten the post-injection site care timeframe if the owner or operator can demonstrate that the GS project does not pose a risk to USDWs, as specified in §146.93(b)(2). Such a demonstration will be site-specific, and based on pressure monitoring and USDW impacts. Alternatively, the final rule at §146.93(c), also allows the Director to approve an alternative post-injection site care timeframe where an owner or operator can demonstrate during thepermitting process that an alternative post-injection site care timeframe, other than the 50 year default, is appropriate and ensures non-endangerment of USDWs. The demonstration must be based on site-specific information, including the results of site-specific computational modeling; thepredicted timeframe for pressure decline; the predicted rate of carbon dioxide plume migration; sitespecific chemical processes that will result in carbon dioxide trapping; the predicted rate of carbon dioxide trapping; characterization of the confining zone(s); laboratory analyses or studies to verify the information on trapping; the presence of potential conduits for fluid movement and the quality of abandoned well plugs within the AoR; the distance between the injection zone and the USDWs above and/or below the injection zone; and any additional site-specific factors determined by the Director. The demonstration must meet the criteria at §146.93(c)(2) for ensuring the quality and accuracy of the data and models on which the demonstration is based. This demonstration would be submitted as part of the permit application, per §146.82(a)(18), in addition to the PISC and site closure plan required at §146.82(a)(17).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans required under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells, perform post-injection monitoring, demonstrate the appropriateness of an alternative post-injection site care time frame, demonstrate non-endangerment, and perform site closure activities. This guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Frederick R. Eames Letter ID: 0178 Commenter Organization: CCS Alliance Comment ID: 23840 Other EPA Comment Codes and Descriptions: 4710 2.7.1 Proposed submissions required for permit applications (seeking comment)

Comment: B. POST-INJECTION SITE CARE PLAN

The Proposed Rule would require that owners or operators develop a postinjection site care and closure plan, submitted as part of the permit application and approved by the Director. The proposed regulation at 40 C.F.R. $ 146.93 would require the plan to describe: (1) the pressure differential between pre-injection and anticipated post-injection pressures in the injection zone; (2) predicted position of the plume and associated pressure front at the time the site is closed; (3) post-injection monitoring location(s), methods, andproposed frequency of monitoring; and (4) a schedule for submitting postinjection site care and monitoring results to the Director.

These requirements are reasonable given the long-term nature of GS projects. The CCS Alliance also supports the ability to amend the plan should the plan no longer reflect what is likely to occur upon closing the site. Likewise, the CCSAlliance agrees that, upon permanent cessation of injection, the owner or operator should be provided the opportunity to demonstrate that no amendment to the plan is necessary through monitoring and modeling results.

Response: EPA agrees that a post-injection site care monitoring plan is an important tool for GS, and retains this requirement in the final rule, at 146.93(a). Regarding updates to the plan, EPA isrequiring that upon the cessation of injection, the owner or operator submit an amended postinjection site care and site closure plan or demonstrate to the Director that no changes to the original post-injection site care and site closure plan are necessary, as specified in §146.93(a)(3). EPA is not requiring formal periodic review and updates to the PISC and site closure plan throughout the injection phase. EPA does not expect that changes to this plan would be implemented until injection operations cease.

Commenter Name: Robert J. Finley Letter ID: 0180 Commenter Organization: Illinois State Geological Survey Comment ID: 23642

Comment: (b)(3)

What is the definition of a stable plume? Is it related to no detectable change with a given assessment technique; what technique(s) form the standard? If we were able to document that a plume is shrinking, say in a confined geologic structure, due to dissolution into brine and decrease in the supercritical CO2 phase, is that plume unstable?

Response: EPA acknowledges that many site-specific factors will influence the determination of when the CO2 plume and pressure front no longer pose a risk of endangerment to USDWs. It is for this reason that EPA believes that individual UIC Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care is needed. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties.

EPA agrees that a complete cessation of plume movement may not occur at some sites for long time periods due to density differences, natural formation flow gradients and diffusion. EPA clarifies that a complete cessation of plume movement is not required, only a demonstration that the plume and pressure front no longer pose a risk of endangerment to USDWs.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Thomas Curtis Letter ID: 0181 Commenter Organization: American Water Works Association (AWWA) Comment ID: 23700 Other EPA Comment Codes and Descriptions: 4610 2.6.1 Testing and monitoring plan requirement (seeking comment)

Comment: Category: Required Project PlansEPA Request for Comment: EPA seeks comment on the merits of requiring plans for monitoring, AoR, and post-injection site care as part of a permit application.

EPA Notice 43517.

AWWA Response: The requirement for the development of plans for monitoring, AoR, and post-injection site care is necessary and is a very important part of the permit process. The information will provide outside stakeholders with a much better idea of how the project will proceed and can help to assure them that the owner/operator has a clear vision for the life of the project. AWWA recommends that these plans be reviewed at the same time that the area of review is reevaluated. During this review, the plans should be updated based on any operational changes since the last project review period and submitted to the Director for approval. AWWA recommends that a review occur every year for the first ten years of the project, and then should be reviewed every five years until injection ceases.

Response: EPA agrees with the commenter. Owners or operators are required to submit an AoR and corrective action plan, a testing and monitoring plan, and a post-injection site care and site closure plan as part of the permit application, as specified in §146.82(a), to outline how these activities will be performed and how non-endangerment of USDWs will be demonstrated throughout the operational and post-injection site care periods. EPA is developing guidance on how best to develop the various required project plans, including the testing and monitoring plan. The guidance can be found on EPA’s website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

The GS rule also requires owners or operators to review and update the AoR and corrective action plan and the testing and monitoring plan throughout the life of the project, as described at §146.84(c) and §146.90(j). The rule requires at §146.90(j) that the operator revise the testing and monitoring plan to incorporate the results of the most recent AoR reevaluation and recent operational and monitoring data. Owners or operators must review each plan and identify necessary amendments to the plan or demonstrate to the Director that no amendment is needed. These reviews must be performed within one year of an AoR reevaluation, following any significant changes to the facility (e.g., the addition of monitoring or injection wells), or when required by the Director. In no case can reviews occur less often than once every five years. This review frequency is appropriate to ensure that reviews of the plans are conducted on a defined schedule or when there is a change in the AoR or significant change, while adding little burden if an AoR reevaluation confirms that the plans are appropriate as written. See the preamble sections on the plans for additional information.

EPA is not requiring formal periodic review and updates to the PISC and site closure plan throughout the injection phase as with the AoR reevaluation that is required at least every 5 years. EPA does not expect that changes to this plan would be implemented until injection operations cease. EPA is requiring that upon the cessation of injection, the owner or operator submit an amended post-injection site care and site closure plan or demonstrate to the Director that no changes to the original post-injection site care and site closure plan are necessary, as specified in §146.93(a)(3). EPA envisions that owners or operators would take into account similar considerations that guide updates to other project plans, e.g., monitoring and operational data and

results of AoR reevaluations.

EPA has also added a new provision at §144.39(a)(5) identifying the basis for a modification, revocation, or reissuance of a Class VI permit whenever the Director determines that a change in thepermit is necessary based on an amended AoR and corrective action plan, testing and monitoring plan, injection well plugging plan, post-injection site care and site closure plan, or emergency and remedial response plan is necessary.

Commenter Name: Thomas Curtis Letter ID: 0181 Commenter Organization: American Water Works Association (AWWA) Comment ID: 23748 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Part 146.93(a) As previously stated AWWA believes that potential changes in the size of the area of review require that all site plans be reevaluated at the same frequency as the area of review. Therefore, AWWA recommends revising this part to read:

The owner or operator of a Class VI well must prepare, maintain, and comply with a plan for post-injection site care and site closure that meets the requirements of paragraph (a)(2) of this section and is acceptable to the Director. The plan must be reviewed and revised by the owner or operator, and submitted to the Director for approval, at the same frequency and time as the AOR reevaluation.

Response: As described above, the final rule requires review and revision of the post-injection and site care closure plan when injection ceases, as described in §146.93(a)(3). EPA is not requiring formal periodic review and updates to the PISC and site closure plan throughout the injection phase. EPA does not expect that changes to this plan would be implemented until injection operations cease. See the final rule and preamble for further discussion on EPA's final approach.

Commenter Name: Thomas Curtis Letter ID: 0181 Commenter Organization: American Water Works Association (AWWA) Comment ID: 23750 Other EPA Comment Codes and Descriptions: 5300 2.8.3 Site closure activities (40 CFR 146.93)

Comment: Part 146.93(d) There may be cases where the Director would want some of the monitoring wells to remain in service after site closure. While this may not be the case for all projects, for some of the earlier sites, the Director may want to continue minimal monitoring to continue to verify that the plume

characteristics have remained stable.

Response: EPA clarifies that the owner or operator must conduct post-injection site care that is consistent with the approved PISC plan or for the duration of the alternative timeframe approved by the Director pursuant to requirements in §146.93(c), until a demonstration can be made to the satisfaction of the Director that the plume and pressure front no longer pose a risk of endangerment to USDWs. After this determination is made, site closure is approved and the post-injection site care period would end, as specified in §146.93 (b)(1).

If, however, there is reason to believe that additional minimal monitoring is necessary to verify that the plume characteristics have remained stable, this would be considered post-injection site care monitoring. If a reduction in monitoring frequency or methods is appropriate (i.e., an additional year or so of verification of the non-endangerment demonstration), the Director has discretion to authorize an amendment to the post-injection site care and site closure plan. This is consistent with the requirements at §146.93(b)(2).Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24407 Other EPA Comment Codes and Descriptions: 1220 1.1.1.1 Terminology and definitions

Comment: Rule Provision: 146.81(d) [Definition - Post-injection site care]

Proposed CCS Group Recommendations: Post-injection site care means appropriatemonitoring and other actions (including corrective action)

neededfollowing cessation of injection to assure that USDWs are not endangered , AS REQUIRED UNDER §146.93.

Basis for CCS Group Comments: Deleted "appropriate" because the definition of it is not clear. Deleted USDW phrase because it is incorporated in 146 requirements.

Response: Based on its evaluation of all public comments and input on the proposed rule and NODA and Request for Comment, EPA has made many revisions to the GS Rule. See the final rule and preamble for further discussion on EPA's final approach. EPA adds that all post-injection site care must be performed pursuant to the post-injection site care and site closure plan, which must be approved by the Director and demonstrated to include monitoring activities that protect USDWs from endangerment.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24409 Other EPA Comment Codes and Descriptions: 1220 1.1.1.1 Terminology and definitions

Comment: Rule Provision: 146.81(d) [Definition - Site closure]

Proposed CCS Group Recommendations: Site closure MEANS the point/time, as determined by the Director following the requirements under §146.93, at which the owner or operator of a GS site PROJECT is released from post-injection site care responsibilities.

Basis for CCS Group Comments: "GS project" is consistent with other definitions.

Response: Based on its evaluation of all public comments and input on the proposed rule and NODA and Request for Comment, EPA has made many revisions to the GS Rule. See the final rule and preamble for further discussion on EPA's final approach.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24494 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5220 2.8.2.1 Post-injection monitoring activities

Comment: Rule Provision: 146.93(a)(2)

Proposed CCS Group Recommendations: (2) The post-injection site care and site closure plan must include the following information:

(i) The pressure differential between pre-injection and predicted post-injection pressures in the injection zone;(ii) The predicted position of the carbon dioxide plume and associated pressure front at site closure as demonstrated in the area of review evaluation required under § 146.84(b);

(iii) A description of post-injection monitoring location, methods, and proposed frequency; and

(iv) A proposed schedule for submitting post-injection site care monitoring

results to the Director.

Basis for CCS Group Comments: Revisions here reflect changes to §146.93(b)(3)

Response: Based on its evaluation of all public comments and input on the proposed rule and NODA and Request for Comment, EPA has made many revisions to the GS Rule. See the final rule and preamble for further discussion on EPA's final approach.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24495 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.93(a)(3)

Proposed CCS Group Recommendations: Support the proposed language.

Basis for CCS Group Comments: Agree with EPA’s rationale.

Response: EPA agrees that a post-injection site care monitoring plan is an important tool for GS and anticipates that, in some cases, the appropriate post-injection monitoring strategy may end up being different than initially projected and there may be a need to amend the post-injection site care and site closure plan. EPA is requiring that, upon the cessation of injection, the owner or operator submit an amended post-injection site care and site closure plan or demonstrate to the Director that no changes to the original post-injection site care and site closure plan are necessary (146.93(a)(3)). EPA is not requiring formal periodic review and updates to the PISC and site closure plan throughout the injection phase.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24496 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4730 2.7.3 Reporting associated with closure and post-injection site care

Comment: Rule Provision: 146.93(a)(4)

Proposed CCS Group Recommendations: 4) AT ANY TIME DURING THE POST-INJECTIONSITE CARE PHASE, The owner or operator may modify and resubmit the postinjection site care and site closure plan for the Director’s approval within 30 days of such change.

Basis for CCS Group Comments: Technical Clarification.Response: EPA agrees that a post-injection site care monitoring plan is an important tool for GS and anticipates that, in some cases, the appropriate post-injection monitoring strategy may end up being different than initially projected and there may be a need to amend the post-injection site care and site closure plan. EPA is requiring that upon the cessation of injection, the owner or operator submit an amended post-injection site care and site closure plan or demonstrate to the Director that no changes to the original post-injection site care and site closure plan are necessary (146.93(a)(3)). EPA is not requiring formal periodic review and updates to the PISC and site closure plan throughout the injection phase. EPA does not expect that changes to this plan would be implemented until injection operations cease. EPA envisions that owners or operators would take into account similar considerations that guide updates to other project plans, e.g., monitoring and operational data and results of AoR reevaluations. EPA adds that, if any monitoring or other site data indicate a need for amending the post-injection site care plan, the owner or operator is expected to amend the plan accordingly under §146.93(a)(3).

EPA adds that, in the final rule, it has revised the text at §146.93(a)(4) as follows: "At any time during the life of the geologic sequestration project, the owner or operator may modify and resubmit the post-injection site care and site closure plan for the Director’s approval within 30 days of such change."

EPA is issuing guidance on development and updating of the GS project plans, including the postinjection site care and site closure plan. The guidance will be available on EPA's web site at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24502 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.93(d)

Proposed CCS Group Recommendations: Support the proposed language.

Basis for CCS Group Comments: Agree with EPA’s rationale.

Response: EPA acknowledges the commenter’s support; the final rule retains this provision.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24548

Comment: Rule Provisions or Federal Register Cite: 146.93 EPA Preamble Question: 39. 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. EPA

Notice 43520.

CSC Response: See response to Question 38 above regarding post closure time periods.

Response: As described above, EPA acknowledges that there will be circumstances where it can bedemonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final GS regulation includes a provision that the Director may, at his/her discretion, shorten the post-injection site care time frame if the owner or operator can demonstrate that the GS project does not pose a risk to USDWs, as specified in §146.93(b)(2). Alternatively, the final rule at §146.93(c), also allows the Director to approve an alternative post-injection site care timeframe where an owner or operator can demonstrate during the permitting process that an alternative post-injection site care timeframe, other than the 50 year default, is appropriate and ensures non-endangerment of USDWs. The demonstration must be based on site-specific information, including the results of site-specific computational modeling; thepredicted timeframe for pressure decline; the predicted rate of carbon dioxide plume migration; sitespecific chemical processes that will result in carbon dioxide trapping; the predicted rate of carbon dioxide trapping; characterization of the confining zone(s); laboratory analyses or studies to verify the information on trapping; the presence of potential conduits for fluid movement and the quality of abandoned well plugs within the AoR; the distance between the injection zone and the USDWs above and/or below the injection zone; and any additional site-specific factors determined by the Director. The demonstration must meet the criteria at §146.93(c)(2) for ensuring the quality and accuracy of the data and models on which the demonstration is based. This demonstration would be submitted as part of the permit application, per §146.82(a)(18), in addition to the PISC and site closure plan required at §146.82(a)(17).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans required under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells, perform post-injection monitoring, demonstrate the appropriateness of an alternative post-injection site care time frame, demonstrate non-endangerment, and perform site closure activities. This guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Kyle Isakower Letter ID: 0191 Commenter Organization: American Petroleum Institute Comment ID: 23883 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: We recommend the standard in the proposed alternative language for section 146.93(b) below because it sets forth detailed criteria, all of which must be satisfied, to demonstrate that the site does not pose an endangerment to USDWs. The specific criteria listed in our proposal will serve to provide the Director with the requisite information to make the appropriate determination. The advantage of this approach is that it establishes clear criteria that an operator must demonstrate before obtaining site closure based upon particular site characteristics and is, therefore, reasonably applicable to any storage site as opposed to a standard based upon a fixed-duration. Furthermore, it ismore stringent than a purely discretionary approach because it establishes specific criteria that must be shown before site closure may be granted. We believe this language, which is an extension of work done by the World Resources Institute and the Ground Water Protection Council, avoids the noted shortcomings and provides stronger protection for USDWs.

146.93 (b) The owner or operator shall monitor the site following the cessation of injection.

(1) The owner or operator shall continue to conduct monitoring as specified in the Director-approved post-injection site care and site closure plan until closure is authorized pursuant to 146.93(b)(3).

(2) The owner or operator can request and demonstrate to the satisfaction of the Director that the post-injection site care and site closure plan should be revised to reduce the frequency of monitoring.

Response: EPA disagrees with the suggested edits, but believes that the provisions of the final GS rule at §146.93(b) address the commenter’s suggestions. Specifically, the owner or operator must monitor the site until it can be demonstrated that the CO2 plume and pressure front no longer pose a risk of endangerment to USDWs and that monitoring must continue until the owner or operator demonstrates, based on monitoring and other site-specific data, that no additional monitoring is needed to ensure that the GS project does not pose a risk of endangerment to USDWs, as required at §146.93(b)(3). See the final rule and preamble for further discussion on EPA's final approach.

Commenter Name: Jeff W. Sheets Letter ID: 0192 Commenter Organization: ConocoPhillips Comment ID: 23904 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: We recommend the standard in the proposed alternative language for section 146.93(b) below because it sets forth detailed criteria, all of which must be satisfied, to demonstrate that the site does not pose an endangerment to USDWs. The specific criteria listed in our proposal will serve to provide the Director with the requisite information to make the appropriate determination. The advantage of this approach is that it establishes clear criteria that an operator must demonstrate before obtaining site closure based upon particular site characteristics and is, therefore, reasonably applicable to any storage site as opposed to a standard based upon a fixed duration. Furthermore, it is more stringent than a purely discretionary approach because it establishes specific criteria that must be presented before site closure may be granted. We believe this language, which is an extension of work done by the World Resources Institute and the Ground Water Protection Council, avoids the noted shortcomings and provides stronger protection for USDWs.

146.93 (b) The owner or operator shall monitor the site following the cessation of injection.

(1) The owner or operator shall continue to conduct monitoring as specified in the Director-approved post-injection site care and siteclosure plan, until closure is authorized pursuant to 146.93(b)(3).

(2) The owner or operator can request and demonstrate to the satisfaction of the Director that the post-injection site care and site closure plan should be revised to reduce the frequency of monitoring.

Response: EPA disagrees with the suggested edits, but believes that the provisions of the final GS rule at §146.93(b) address the commenter’s suggestions. Specifically, the owner or operator must monitor the site until it can be demonstrated that the CO2 plume and pressure front no longer pose a risk of endangerment to USDWs and that monitoring must continue until the owner or operator demonstrates, based on monitoring and other site-specific data, that no additional monitoring is needed to ensure that the GS project does not pose a risk of endangerment to USDWs, as required at §146.93(b)(3). See the final rule and preamble for further discussion on EPA's final approach.

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24609

Comment: Rule Provisions: 146.93 EPA Rule Issue: 39. EPA is requesting comments on the proposed requirements for well plugging, postinjection site care, and site closure, including the proposed requirements for the post-injection time period. EPA Notice 43520.

Anadarko Petroleum Corporation (APC) Response: It is inappropriate to utilize a fixed period as this does not provide the flexibility to address site-specific issues; instead EPA should adopt a standard that is based on a demonstration of non-endangerment to determine when monitoring is no longer needed. Please see response to EPA 43519.

Response: EPA agrees with commenters that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final GS regulation includes a provision that the Director may, at his or her discretion, shorten the post-injection site care timeframe if the owner or operator can demonstrate that the GS project does not pose an endangerment to USDWs, as specified in §146.93(b)(2). Alternatively, the final rule at §146.93(c), also allows the Director to approve an alternative post-injection site care timeframe where an owner or operator can demonstrate during the permitting process that an alternative post-injection site care timeframe, other than the 50 year default, is appropriate and ensures non-endangerment of USDWs. The demonstration must be based on site-specific information, including the results of site-specific computational modeling; the predicted timeframe for pressure decline; the predicted rate of carbon dioxide plume migration; site-specific chemical processes that will result in carbon dioxide trapping; the predicted rate of carbon dioxide trapping; characterization of the confining zone(s); laboratory analyses or studies to verify the information on trapping; the presence of potential conduits for fluid movement and the quality of abandoned well plugs within the AoR; the distance between theinjection zone and the USDWs above and/or below the injection zone; and any additional sitespecific factors determined by the Director. The demonstration must meet the criteria at §146.93(c)(2) for ensuring the quality and accuracy of the data and models on which the demonstration is based. This demonstration would be submitted as part of the permit application, per §146.82(a)(18), in addition to the PISC and site closure plan required at §146.82(a)(17).

EPA believes that a default post-injection site care timeframe of 50 years, with flexibility to adjustthe 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA believes, however, that to ensure USDW protection from endangerment, a default timeframe for post-injection site care is necessary in most cases. A 50-year post-injection site care timeframe represents a reasonable and protective monitoring period for most GS projects and available data, including data submitted by commenters, do not support a different default timeframe. This determination is based on a review of research studies, industry reports, existing environmental programs, and evaluation of public comments.

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24637 Other EPA Comment Codes and Descriptions: 1220 1.1.1.1 Terminology and definitions

Comment: Rule Provision: 146.81(d) [Definition - Post-injection site care]

Anadarko Petroleum Corporation (APC) Comments: Post-injection site care means appropriatemonitoring and other actions (including corrective action)

neededfollowing cessation of injection to assure that USDWs are not endangered, as required under §146.93.

Rationale: Deleted "appropriate" because the definition of it is not clear. Deleted USDW phrase because it is incorporated in 146 requirements.

Response: Based on its evaluation of all public comments and input on the proposed rule and NODA and Request for Comment, EPA has made many revisions to the GS Rule. See the final rule and preamble for further discussion on EPA's final approach. EPA adds that all post-injection site care must be performed pursuant to the post-injection site care and site closure plan, which must be approved by the Director and demonstrated to include monitoring activities that protect USDWs from endangerment.

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24639 Other EPA Comment Codes and Descriptions: 1220 1.1.1.1 Terminology and definitions

Comment: Rule Provision: 146.81(d) [Definition - Site closure]

Anadarko Petroleum Corporation (APC) Comments: Site closure MEANS the point/time, as determined by the Director following the requirements under §146.93, at which the owner or operator of a GS site PROJECT is released from post-injection site care responsibilities.

Rationale: "GS project" is consistent with other definitions.

Response: Based on its evaluation of all public comments and input on the proposed rule and NODA and Request for Comment, EPA has made many revisions to the GS Rule. See the final rule and preamble for further discussion on EPA's final approach.Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24717 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.93(a)(2)

Anadarko Petroleum Corporation (APC) Comments: (2) The post-injection site care and site closure plan must include the following information:

(i) The pressure differential between preinjection and predicted post-injection pressures in the injection zone;

(ii) The predicted position of the carbon dioxide plume and associated pressure front at site closure as demonstrated in the area of review evaluation required under § 146.84(b);

(iii) A description of post-injection monitoring location, methods, and proposed frequency; and

(iv) A proposed schedule for submitting post-injection site care monitoring

results to the Director.

Rationale: Revisions here reflect changes to §146.93(b)(3)

Response: Based on its evaluation of all public comments and input on the proposed rule and NODA and Request for Comment, EPA has made many revisions to the GS Rule. See the final rule and preamble for further discussion on EPA's final approach.

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24718 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4730 2.7.3 Reporting associated with closure and post-injection site care

Comment: Rule Provision: 146.93(a)(4)

Anadarko Petroleum Corporation (APC) Comments: (4) AT ANY TIME DURING THE POSTINJECTION SITE CARE PHASE, The owner or operator may modify and resubmit the post-injection site care and site closure plan for the Director’s approval within 30 days of such change.

Rationale: Technical Clarification.

Response: EPA agrees that a post-injection site care monitoring plan is an important tool for GS and anticipates that, in some cases, the appropriate post-injection monitoring strategy may end up being different than initially projected and there may be a need to amend the post-injection site care and site closure plan. EPA is requiring that upon the cessation of injection, the owner or operator submit an amended post-injection site care and site closure plan or demonstrate to the Director that nochanges to the original post-injection site care and site closure plan are necessary (146.93(a)(3)). EPA is not requiring formal periodic review and updates to the PISC and site closure plan throughout the injection phase. EPA does not expect that changes to this plan would be implemented until injection operations cease. EPA envisions that owners or operators would take into account similar considerations that guide updates to other project plans, e.g., monitoring and operational data and results of AoR reevaluations. EPA adds that, if any monitoring or other site data indicate a need for amending the post-injection site care plan, the owner or operator is expected to amend the plan accordingly. EPA is issuing guidance with recommended approaches for development and updating of the GS project plans, including the post-injection site care and site closure plan. The guidance will be available on EPA's web site at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

EPA adds that, in the final rule, it has revised the text at §146.93(a)(4) as follows: "At any time during the life of the geologic sequestration project, the owner or operator may modify and resubmit the post-injection site care and site closure plan for the Director’s approval within 30 days of such change."

Commenter Name: John King Letter ID: 0211 Commenter Organization: Shell Exploration and Production Company (SEPCo) Comment ID:

22782 Other EPA Comment Codes and Descriptions: 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: G. Post-Injection Site Care Responsibility

The proposed rule contemplates a long post-operational period of observation and "site care" prior to closure. The requirements contemplated -- including a presumptive 50-year post-injection monitoring period -- are unwarranted and completely unprecedented in the UIC program. Not even hazardous waste injection wells -- which generally operate subject to a demonstration that waste will be contained for at least ten thousand years -- are subject to such burdensome post-injection requirements.

Long term protection of USDWs is ensured up-front, primarily through proper siting as confirmed through the technical evaluation that occurs in the permitting process. Proper well construction, operating, monitoring and testing provide assurance against problems during the operational life of an injection well, but siting doesn’t change, and proper siting must be ensured at the start. Once injection operations cease, there should generally be no need to do more than monitor pressure decay in the injection zone and ensure proper plugging of the injection well. This approach is sufficient for the injection of hazardous waste, and it certainly should be sufficient for the injection of CO2. The premise that careful siting and AOR evaluation are not enough -- that actual monitoring for decades after the cessation of injection is needed -- is foreign to the UIC program and inconsistent with the long and thoroughly-documented success of UIC regulation in the United States.

There is certainly no justification for a presumptive 50-year minimum timeframe for post-injection site care, and such a requirement would likely kill-off commercial investment in geo-sequestration projects. It does not help that the proposed rule provides a mechanism for shortening the presumptive 50-yearrequirement, because the ability to shorten the post-injection site care period would depend on the apparently unlimited discretion of the Director and could not be assessed in any meaningful way before injection operations near completion. Moreover, the possibility of a shorter post-injection site care period is balanced by the possibility that the Director may seek to impose an even longer post-injection site care period. The burdens and regulatory uncertainties of an extended post-injection site care requirement cannot be justified, especially in the context of a regulatory program that requires a "non-endangerment" demonstration before injection can even commence.

Recommendation:

1. EPA should operate from the premise that the UIC program is preventive in

nature.

2. Release from post-injection site care should be determined not by a fixed period of time but rather a performance-based standard that is designed to ensure protection of USDW’s.

Response: EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, a default timeframe for post-injection site care is necessary in most cases. A 50 year post-injection site care timeframe represents a reasonable and protective monitoring period for most GS projects and available data, including data submitted by commenters, do not support a different default timeframe. This determination is based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

EPA agrees that proper site characterization, well construction, and operation are important components of ensuring that USDWs are protected. However, EPA disagrees that this is a substitute for post-injection site care. EPA believes that extensive post-injection monitoring is necessary to protect USDWs from endangerment.

EPA disagrees that the rule affords ¿unlimited discretion¿ to the Director to lengthen the postinjection site care timeframe. Because of the variety of site-specific circumstances at GS sites, EPA believes that Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care monitoring is needed (or whether the timeframe may be shortened), based on the circumstances of a particular project. EPA expects this decision to be made based on relevant site data, including information at §146.93(c)(2), to determine the appropriateness of an alternative post-injection site care time frame if applicable, and in consultation with all potentially impacted parties.

EPA disagrees that a post-injection site care timeframe of 50 years is excessive for most Class VIwells. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titledComputational Modeling of Underground Injection of Carbon Dioxide for Determination of Areaof-Review and Potential Risk to Underground Sources of Drinking Water. EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that alternative timeframes may be appropriate under limited, specific circumstances, which is why EPA is providing the Director discretion to approve an alternative post-injection site care timeframe as long as the owner or operator can meet the requirements provided at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters¿ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; demonstrate the appropriateness of an alternative post-injection site care time frame; perform post-injection monitoring; demonstrate non endangerment; and perform site closure activities. This guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Paul L. Carpinone Letter ID: 0212 Commenter Organization: Tampa Electric Company Comment ID: 22906 Other EPA Comment Codes and Descriptions: 1250 1.1.1.4 Flexibility is needed (performancebased standards); 3500 2.2.3 Area of Review Reevaluation (seeking comment)

Comment: - Because carbon sequestration technology is still developing and the characteristics and limitations of CO2 GS projects will vary greatly from one site to another it is essential to incorporate performance-based standards into the Final Rule, leading to a site-tailored approach to requirements for Area of Review ("AoR") reevaluation and post-injection site care and closure periods.

Response: The PISC requirements in the final GS rule, as specified in §146.93(b), incorporate a combination of a fixed timeframe and a performance standard approach. EPA believes that a default PISC timeframe of 50 years, with Director's discretion to shorten or lengthen this timeframe, combined with a site-specific Director’s discretion to create an alternative PISC time frame, ensures that USDWs are protected. 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 PISCtimeframe during the PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA expects that the Director will consider the types of information the commenter describes in determining whether the plume and pressure front no longer pose a risk of endangerment to USDWs and post-injection site care monitoring may be discontinued. EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA disagrees that the GS regulation should include performance-based standards for AoR calculation. However, EPA believes that consideration of site-specific conditions is appropriate for the AoR calculation and reevaluation process. EPA believes that the flexibility incorporated into the AoR and corrective action plans and the provision for AoR reevaluation as required at §146.84(e) provide for an ongoing review of the site and a dialogue between the Director and the owner or operator to ensure that the most appropriate modeling and corrective action technologies are used to protect USDWs from endangerment. However, EPA believes that setting a minimum reevaluation frequency is appropriate. In the final rule, the Agency changed the minimum frequency for the AoR reevaluation at §146.84(e) from 10 years to at least every 5 years in the final GS rule. EPA believes that this revised frequency addresses 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.

Commenter Name: Paul L. Carpinone Letter ID: 0212 Commenter Organization: Tampa Electric Company Comment ID: 22908 Other EPA Comment Codes and Descriptions: 5432 2.9.1.1 Need to adjust financial responsibility mechanisms (seeking comment)

Comment: - In developing guidance identifying financial responsibility mechanismsavailable for post-injection care, EPA should retain the option of selfinsurance instruments including the corporate financial test. Self-insurance has worked successfully for over two decades under the RCRA program and there is no reason why this option should not also be available for Class VI UIC wells. EPA must also take steps to mitigate the specter of open-ended financial liability for CO2 injection operations after the cessation of the post-injection site care period. Such open-end liability is one of the major impediments to the successful development of a commercial CO2 GS program.

Response: EPA will retain self insurance as an option for financial responsibility for Class VI wells. Owners or operators who choose to self-insure and use the financial test must be able to demonstrate profitability, with a margin sufficient to cover contingencies and unknown obligations, and stability. If the owner or operator meets corporate financial test criteria, this is an indication that the owner or operator can guarantee its ability to satisfy financial obligations based solely on the strength of the company’s financial condition. If an operator or operator is not able to meet the corporate financial test criteria it may arrange a corporate guarantee by demonstrating that its corporate parent meets the financial requirements on its behalf.Under SDWA authority, owners or operators of injection wells must ensure protection of USDWs from endangerment and are subject to liability for enforcement under the Act. The final rule requires that an owner or operator must conduct post-injection site care that is consistent with the approved PISC plan or for the duration of the alternative timeframe approved by the Director pursuant to requirements in §146.93(c), until a demonstration can be made to the satisfaction of the Director that the plume and pressure front no longer pose a risk of endangerment to USDWs. For additional information about the PISC and site closure requirements, see the preamble to the final GS rule.

Once an owner or operator has met all regulatory requirements under Part 146 for Class VI wells and the Director has approved site closure pursuant to requirements at §146.93, the owner or operator will generally no longer be subject to enforcement for regulatory noncompliance. Furthermore, their financial instrument as required under §146.85 will be released if it was not used. However, even if a site closure is approved under §146.93, an owner or operator may be held liable for regulatory noncompliance (including violation of 40 CFR 144.12) in certain circumstances. For example, an owner or operator may be held liable for regulatory noncompliance even after site closure was approved if the Director relied on erroneous information (e.g., erroneous modeling data) provided by the owner or operator when approving site closure.

Additionally, an owner or operator may always be subject to any action the Administrator deems necessary to protect the health of persons under §1431 of the SDWA after site closure if there is unanticipated migration towards or into a USDW that causes or threatens imminent and substantial endangerment to public health. The action may include issuing administrative orders or commencing a civil action for appropriate relief. If the owner or operator fails to comply with the order, they may be subject to a civil penalty for each day in which such violation occurs or failure to comply

continues.

The Agency clarifies that Class VI well permits may be transferred to another owner or operator pursuant to §144.38 whereby generally all other regulatory responsibilities are transferred to that new owner and operator, which includes all potential liabilities associated with meeting the requirements of that permit. Please see further clarification on the issue of long term liability in the preamble of

the final rule.

Furthermore, after site closure an owner or operator may remain liable under tort and other remedies, or under other federal statutes including, but not limited to, Clean Air Act, 42 U.S.C. §§ 7401-7671; CERCLA, 42 U.S.C. § 9601-9675; and RCRA, 42 U.S.C. § 6901-6992. EPA does not have authority to transfer SDWA or other legal liability for Class VI wells to the State or federal government or a third-party fund. See the final rule preamble for further discussion of EPA's final approach.

Commenter Name: Diane VanDe Hei Letter ID: 0213 Commenter Organization: Association of Metropolitan Water Agencies (AMWA) Comment ID:

22952 Other EPA Comment Codes and Descriptions: 1510 1.2.2.3 Need for additional study

Comment: stabilization may continue for several decades." AMWA also recommends that additional research be conducted to better understand the movement of CO2 plumes and that EPA provide guidance to owner/operators about the criteria for monitoring and modeling data that would be necessary to demonstrate that the plume has stabilized and justify site closure.Response: EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate non-endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

EPA agrees that continued research in all GS associated fields will be integral to development of GS technology. EPA plans to, every six years, collect and review project data on early GS projects, including site characterization, operational, monitoring, and modeling data, to determine whether the appropriate amount and types of information and appropriate documentation are being collected, and to determine if modifications to the requirements are appropriate or necessary.

For additional information on these requirements, please also see the discussion of testing and monitoring under EPA’s Final Regulatory Approach in the preamble to the final GS rule.

Commenter Name: Darrick Eugene Letter ID: 0223 Commenter Organization: Texas Carbon Capture and Storage Association Comment ID: 23994 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5300 2.8.3 Site closure activities (40 CFR 146.93)

Comment: Director affirmatively acts to extend the post-injection site care period. These changes are contained in the suggested text below:

§ 146.93 Post-injection site care and site closure. (a) The owner or operator of a Class VI well must prepare, maintain, and comply with a plan for post-injection site care and site closure that meets the requirements of paragraph (a)(2) of this section and is acceptable to the Director. (1) The owner or operator must submit the post-injection site care and site closure plan as a part of the permit application to be approved by the Director. (2) The post-injection site care and site closure plan must include the following information: (i) The pressure differential between pre-injection and predicted post-injection pressures in the injection zone; (ii) The predicted position of the carbon dioxide plume and associated pressure front at site closure as demonstrated in the area of review evaluation required under § 146.84(b); (iii) A description of post-injection monitoring location, methods, and proposed frequency; and (iv) A proposed schedule for submitting post-injection site care monitoring results to the Director. (3) Upon cessation of injection, owners or operators of Class VI wells must either submit an amended post-injection site care and site closure plan or demonstrate to the Director through monitoring data and modeling results that no amendment to the plan is needed.(4) The owner or operator may modify and resubmit the postinjection site care and site closure plan for the Director’s approvalwithin 30 days of such change. (b) The owner or operator shall monitor the site following the cessation of injection to show the position of the carbon dioxide plume and pressure front and demonstrate that USDWs are not being endangered.

*

*

* (3) Prior to authorization forTHE EXPIRATION OF THE PERIOD SPECIFIED IN SUBPART (B)(1), site closure , the owner or operator must submit to the Director a demonstration, based on monitoring and other site specific data, that the carbon dioxide plume and pressure front have stabilized and that no additional monitoring is needed to assure that the geologic sequestration project does not pose an endangerment to USDWs. (4) IF WITHIN 180 DAYS AFTER THE SUBMITTAL OF THE DATA REQUIRED UNDER SUBPARAGRAPH (3), THE DIRECTOR DETERMINES THAT THE GEOLOGICAL SEQUESTRATION PROJECT MAY CONTINUE TO POSE AN ENDANGERMENT TO
USDWS, HE

SHALL SO NOTIFY THE OWNER OR OPERATOR OF HIS DETERMINATION AND THE

BASIS
THEREFORE, AND If such a demonstration cannot be made (i.e., if the carbon dioxide plume and pressure front have not stabilized) after the 50-year period,the owner or operator must submit to the Director a plan to continue post-injection site care. (5) IF WITHIN 180 DAYS AFTER THE SUBMITTAL OF THE DATA REQUIRED UNDER SUBPARAGRAPH (3) ABOVE THE DIRECTOR FAILS TO DETERMINE AND TO NOTIFY THE OWNER OR OPERATOR THAT THE GEOLOGICAL SEQUESTRATION

PROJECT
MAY CONTINUE TO POSE AN ENDANGERMENT TO USDWS, SITE CLOSURE SHALL BE

DEEMED AUTHORIZED BY RULE (c) Notice of intent for site closure. The owner or operator must notify the Director at least 120 days before site closure. At this time, if any changes have been made to the original post- injection site care and site closure plan, the owner or operator must also provide the revised plan. At the discretion of the Director, a shorter notice period may be

allowed. (d) After the Director has authorized site closure OR SITE CLOSURE IS AUTHORIZED BY RULE, the owner or operator must plug all monitoring wells in a manner which will not allow movement of injection or formation fluids that endangers a USDW. (e) Once the Director has authorized site closure, OR SITE CLOSURE IS AUTHORIZED BY RULE, the owner or operator must submit a site closure report within 90 days that must thereafter be retained at a location designated by the Director. The report must include: (1) Documentation of appropriate injection and monitoring well plugging as specified in § 146.92 and paragraph (c) of this section. The owner or operator must provide a copy of a survey plat which has been submitted to the local zoning authority designated by the Director. The plat must indicate the location of the injection well relative to permanently surveyed benchmarks. The owner or operator must also submita copy of the plat to the Regional Administrator of the appropriate EPA Regional Office; (2) Documentation of appropriate notification and information to such State, local and tribal authorities as have authority over drilling activities to enable such State and local authorities to impose appropriate conditions on subsequent drilling activities that may penetrate the injection and confining zone(s); and (3) Records reflecting the nature, composition and volume of the carbon dioxide

stream. (f) Each owner or operator of a Class VI injection well must record a notation on the deed to the facility property or any other document that is normally examined during title search that will in perpetuity provide any potential purchaser of the property the following information: (1) The fact that land has been used to sequester carbon dioxide; (2) The name of the State agency, local authority, and/or tribe with which the survey plat was filed, as well as the address of the Regional Environmental Protection Agency Office to which it was submitted; and (3) The volume of fluid injected, the injection zone or zones into which it was injected, and the period over which injection

occurred. (g) The owner or operator must retain for three years following site closure, records collected during the post-injection site care period. The owner or operator must deliver the records to the Director at the conclusion of the retention period, and the records must thereafter be retained at a location designated by the Director for that purpose.

Response: The PISC requirements in the final GS rule, as specified in §146.93(b), incorporate a combination of a fixed timeframe and a performance standard approach. EPA believes that a default PISC timeframe of 50 years, with Director's discretion to shorten or lengthen this timeframe, combined with a site-specific Director’s discretion to create an alternative PISC time frame, ensures that USDWs are protected. 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA expects that the Director would consider the types of information the commenter describes in determining whether the plume and pressure front no longer pose a risk of endangerment to USDWs and post-injection site care monitoring may be discontinued.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate the appropriateness of an alternative post-injection site care time frame; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Ben Yamagata Letter ID: 0227 Commenter Organization: Coal Utilization Research Council Comment ID: 21784

Comment: -The open-ended requirement for post-injection site care (§146.93(b)).

Response: Please see EPA’s response to the more detailed comment below.

Commenter Name: Neeraj Gupta Letter ID: 0229 Commenter Organization: Battelle Energy Technology (BET) Comment ID: 21865

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

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

Commenter Name: A. James Mayer Letter ID: 0230 Commenter Organization: A. J. Mayer International on behalf of the American Energy Security Initiative Comment ID:

21889 Other EPA Comment Codes and Descriptions: 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: 6. EPA should provide for performance-based requirements for Closure and Post Closure Care. The duration of post-injection site care should be determined by specific conditions and characteristics of the site, and monitoring of the pressure to determine the point at which the injection zone pressure is such that USDWs cannot be impacted.

Response: The PISC requirements in the final GS rule, as specified in §146.93(b), incorporate a combination of a fixed timeframe and a performance standard approach. EPA believes that a default PISC timeframe of 50 years, with Director's discretion to shorten or lengthen this timeframe, combined with a site-specific Director’s discretion to create an alternative PISC time frame, ensures that USDWs are protected. 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 PISC 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 todemonstrate, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.EPA is developing guidance to assist owners or operators in evaluating the well plugging, postinjection site care, and site closure requirements of 146.92 and 146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes how an owner or operator should plug injection and monitoring wells, perform post-injection monitoring, demonstrate the appropriateness of an alternative post-injection site care time frame, demonstrate non-endangerment, and perform site closure activities.

Commenter Name: M. Granger Morgan Letter ID: 0233 Commenter Organization: Carnegie Mellon University on behalf of the CCS Reg Project Comment ID:

21910

Comment: 19. Post-injection site care: We support the site-specific approach to postinjection site care that EPA proposes in section 146.93.

Response: EPA acknowledges the commenter’s support; the final rule retains this provision.

Commenter Name: Kurt Waltzer Letter ID: 0250 Commenter Organization: Clean Air Task Force Comment ID: 22312

Comment: Perhaps inadvertently, the proposed rule does not explicitly require updating of several of the required plans. In most but not all cases, there is a rather ambiguous requirement to "maintain" a given plan. Explicit requirements to make updates as warranted appear to be missing from provisions relating to:

• the post- injection site care and site closure plan required by §146.93 (not only is the word "maintain" used, but the ambiguity inherent in this term is revealed by the instruction in §146.93(a)(3) to consider amendments to this plan "upon cessation of injection" - §146.93 might be read to mean that operators could "maintain" this particular plan simply by considering the need for amendment on one occasion over the life of the facility); and

Response: EPA believes that developing and implementing a post-injection site care and site closure plan is important to ensure protection of USDWs, and agrees that the plan should be revised as needed to account for the most recent information about the site. EPA anticipates that, in some cases, the appropriate post-injection monitoring strategy may end up being different than initially projected and there may be a need to amend the post-injection site care and site closure plan. EPA is requiring that upon the cessation of injection, the owner or operator submit an amended post-injection site care and site closure plan or demonstrate to the Director that no changes to the original post-injection site care and site closure plan are necessary, as specified in §146.93(a)(3). EPA is not requiring formalperiodic review and updates to the PISC and site closure plan throughout the injection phase. EPA does not expect that changes to this plan would be implemented until injection operations cease. EPA envisions that owners or operators would take into account similar considerations that guide updates to other project plans, e.g., monitoring and operational data and results of AoR reevaluations. EPA adds that, if any monitoring or other site data indicate a need for amending the post-injection site care plan, the owner or operator is expected to amend the plan accordingly.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24864 Other EPA Comment Codes and Descriptions: 1220 1.1.1.1 Terminology and definitions

Comment: EPA Proposal: Post-injection site care means appropriate monitoring and other actions (including corrective action) needed following cessation of injection to assure that USDWs are not endangered as required under § 146.93.

GWPC Recommendations: Post-injection site care means monitoring and other actions (including corrective action) following cessation of injection, as required under 146.93.

Rationale: The definition should explain the meaning and not impose substantive requirements. These requirements are already addressed in other sections.

Response: Based on its evaluation of all public comments and input on the proposed rule and NODA and Request for Comment, EPA has made many revisions to the GS Rule. See the final rule and preamble for further discussion on EPA's final approach.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24866 Other EPA Comment Codes and Descriptions: 1220 1.1.1.1 Terminology and definitions

Comment: EPA Proposal: Site closure the point/time, as determined by the Director following the requirements under § 146.93, at which the owner or operator of a GS site is released from post-injection site care responsibilities.

GWPC Recommendations: Site closure means the point/time, as determined by the Director following the requirements under §146.93, at which the owner or operator of a GS project is released from post-injection site care responsibilities.

Rationale: Add "means"

Suggest using "GS project" to be consistent with other definitions

Response: Based on its evaluation of all public comments and input on the proposed rule and NODA and Request for Comment, EPA has made many revisions to the GS Rule. See the final rule and preamble for further discussion on EPA's final approach.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24941 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rulelanguage

Comment: EPA Proposal: (2) The post-injection site care and site closure plan must include the following information:

(i) The pressure differential between pre-injection and predicted post-injection pressures in the injection zone; (ii) The predicted position of the carbon dioxide plume and associated pressure front at site closure as demonstrated in the area of review evaluation required under § 146.84(b);

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

Response: EPA acknowledges the commenter’s support; the final rule retains this provision.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24943 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: EPA Proposal: (3) Upon cessation of injection, owners or operators of Class VI wells must either submit an amended post-injection site care and site closure plan or demonstrate to the Director through monitoring data and modeling results that no amendment to the plan is needed.

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

Response: EPA acknowledges the commenter’s support; the final rule retains this provision.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24944 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: EPA Proposal: (4) The owner or operator may modify and resubmit the postinjection site care and site closure plan for the Director’s approval within 30 days of such change.

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

Response: EPA acknowledges the commenter’s support; the final rule retains this provision.

Comment Code: 5220 2.8.2.1 Post-injection monitoring activities

### Individual Comments

Commenter Name: Michael H. Cochran Letter ID:

0108 Commenter Organization: Bureau of Water, Division of Environment, Kansas Department of Health & Environment (KDHE) Comment

ID: 21986

Comment: more accurate reading. 146.93 (b) (3): Plume stabilization needs to be clarified as to what this means. The plume will never be completely stabile. The CO2 plume will continue to move by a combination of methods including density differences, natural formation flow gradients and diffusion. Recommend dropping the reference to the plume or pressure front having stabilized.

Response: EPA clarifies that in the final rule, §146.93(b)(3) no longer requires the plume and pressure front to have stabilized. EPA acknowledges that many site-specific factors will influence the determination of when the CO2 plume and pressure front no longer pose a risk of endangerment to USDWs. It is for this reason that EPA believes that Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care is needed. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties.

EPA agrees that a complete cessation of plume movement may not occur at some sites for long time periods due to density differences, natural formation flow gradients, and diffusion. EPA clarifies that a complete cessation of plume movement is not required, only a demonstration that the plume and pressure front no longer pose a risk of endangerment to USDWs.

Commenter Name: Leslie Savage Letter ID: 0122 Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24798 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: (1) The owner or operator must submit the post-injection site care and site closure plan as a part of the permit application to be approved by the

Director.

{Redundant - See 146.82(w).}

Response: EPA clarifies that the reference to the post-injection site care and site closure plan, in the final rule at §146.82(a)(17), requires that the plan be included in the attachments to the Class VI permit application. The details of the plan contents are included in §146.93, along with other requirements related to post-injection site care and site closure.

Commenter Name: Leslie Savage Letter ID: 0122 Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24802 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: (b) THE OWNER OR OPERATOR MUST Mustmonitor the site following the

cessation of injection to show the position of the carbon dioxide plume and pressure front and demonstrate that USDWs are not being endangered.(1) THE OWNER OR OPERATOR MUST Mustcontinue to conduct monitoring as specified in the Director-approved post-injection site care and site closure plan for THE PERIOD OF TIME at least 50 yearsfollowing the cessation of injection . At the Director's discretion, the monitoring will continue until THE DIRECTOR DETERMINES THAT the geologic sequestration project no longer poses an endangerment to USDWs.

Response: EPA disagrees with the suggested edits. However, EPA agrees with commenters that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final 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 PISC 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, based on substantial data during thepermitting process, that an alternative PISC timeframe may be appropriate if it ensures nonendangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Leslie Savage Letter ID: 0122 Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24974 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: (2) If the owner or operator can demonstrate to the satisfaction of the Director before 50 years, based on monitoring and other site-specific data, that the GS project no longer poses an endangerment to USDWs, the Director may approve an amendment to the post-injection site care and site closure plan to reduce the frequency of monitoring or may authorize site closure before the end of the 50-year period.

{The period of time an owner or operator is required to conduct post-closure care monitoring should be based on the ability of the pressure to cause endangerment of USDWs. A 50-year post-closure care monitoring period is unprecedented and implies that CO2 presents a greater risk than it does. RRC suggests that EPA strike the phrase "for at least 50 years" and make the time for continued monitoring be based on site specific data. }

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive for most Class VI wells. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that alternative timeframes may be appropriate under limited, specific circumstances, which is why EPA is providing the Director discretion to approve an alternative post-injection site care timeframe as long as the owner or operator can meet the requirements provided at §146.93(c).

EPA acknowledges there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by:(1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the postinjection 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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Christine Reimer Letter ID: 0142 Commenter Organization: National Ground Water Association Comment ID: 22613 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4730 2.7.3 Reporting associated with closure and post-injection site care

Comment: Proposed Rule: 146.93(a)

Proposed revision: (a) The owner or operator of a Class VI well must prepare; maintain; including updating on the same schedule as the update to the Area of Review; and comply with a plan for post-injection site care and site closure that meets the requirements of paragraph (a)(2) of this section and is acceptable to the Director.

Rationale: The Area of Review re-evaluation should trigger a review and updating of the well plugging plan, and the post injection site care and closure plan. NGWA suggests EPA check all timelines and make them compatible.Response: EPA agrees with the commenter that, in some cases, the appropriate post-injection monitoring strategy may end up being different than initially projected at the time of permit application and there may be a need to amend the post-injection site care and site closure plan. EPAis requiring that upon the cessation of injection, the owner or operator submit an amended postinjection site care and site closure plan or demonstrate to the Director that no changes to the original post-injection site care and site closure plan are necessary, as specified in §146.93(a)(3). EPA is not requiring formal periodic review and updates to the PISC and site closure plan throughout the injection phase. EPA does not expect that changes to this plan would be implemented until injection operations cease. EPA envisions that owners or operators will take into account similar considerations that guide updates to other project plans, e.g., monitoring and operational data and

results of AoR reevaluations.

EPA has also added a new provision at §144.39(a)(5) requiring a modification, revocation, or reissuance of a Class VI permit whenever the Director determines that a change in the permit is necessary based on an amended AoR and corrective action plan, testing and monitoring plan, injection well plugging plan, post-injection site care and site closure plan, or emergency and remedial response plan is necessary. This would invoke the public notification procedures of 40 CFR Part 124 and the modification would be incorporated into the permit. EPA adds that, if any monitoring or other site data indicate a need for amending the post-injection site care plan, the owner or operator is expected to amend the plan accordingly.

Commenter Name: Bonnie Lovelace Letter ID: 0152 Commenter Organization: Montana Department of Environmental Quality (MDEQ) Comment ID:

22107 Other EPA Comment Codes and Descriptions: 1620 1.3.2 Induced seismicity

Comment: 7. EPA clearly identifies the risks of seismic effects from geologic sequestration and indicates the need to only select sites that are geologically stable. Each state has a geologic survey which monitors seismic activity. Further, any area can surprise geologists with activity that was unexpected. [An example in Montana would be the usually seismically quiet area near Grass Range that surprisingly had a recent event at over 4 on the Richter scale. In fact, no areas of Montana are seismically at zero on the Richter scale, but may still be appropriate for sequestration.] Each geologic sequestration site should be required to add seismic monitoring that is added to the state's monitoring network. This monitoring should be started as baseline and continued well after closure of injection activities.

Response: EPA acknowledges that induced seismicity is a risk that may be associated with GS but maintains that the risk is low (IPCC, 2005). The GS rule contains several requirements to address seismic risk. First, as part of the site characterization process, owners or operators must submit information about the seismic history of and seismic sources near a proposed GS site, data on known or suspected faults in the AoR, geomechanical information on fractures, stress, ductility, rock strength, and in situ fluid pressures within the confining zone as specified in §146.82(a)(3). This information is evaluated by the Director, who determines the suitability of a potential project site for GS. Any sites with the potential for reopening or reactivation of faults or unacceptable seismic risk that could otherwise interfere with containment will not be permitted as GS sites. During injection, the pressure in the injection zone must not exceed 90 percent of the fracture pressure of the injection zone as specified in §146.88(a); this requirement is intended to prevent the opening of fractures orfaults through over pressurization of the injection zone.

Given the emphasis on site selection to reduce the potential for induced seismicity, EPA disagrees that seismic monitoring is necessary at all GS sites. However, EPA adds that the Director has the authority to require such monitoring under §146.90(i) if he or she believes this to be appropriate based on site-specific information.

EPA does not believe that limiting GS to "stable areas" will provide certainty that seismic events will not occur. The Agency acknowledges that some regions of the country are at risk for infrequent, damage-causing seismic events even if such events have not been recorded in the recent historical record (i.e., in the past several hundred years). For this reason, EPA requires seismic risk to be evaluated on a site-specific basis, through an analysis of seismic history and an evaluation of known or suspected faults in the AoR, geomechanical information on fractures, stress, ductility, rock strength, and in situ fluid pressures within the confining zone as specified in §146.82(a)(3). In addition, if an adverse event, such as a well failure or evidence of fluid movement were to occur, the monitoring requirements at §146.90 and emergency and remedial response requirements as specified in §146.94 provide additional protection.

Commenter Name: James Dooley Letter ID: 0156 Commenter Organization: Joint Global Change Research Institute, Pacific Northwest National Laboratory Comment ID:

22670

Comment: o Page 43540 under "Post-injection site care and site closure." The USEPA should ask for a seismic image or other data that depicts the current extent and placement of the CO2 plume. The current language asks for "the predicted position." If the EPA would like modeling of the predicted position for some purpose that is fine but there is no reason not to ask for data that shows where the plume really is.

Response: EPA clarifies that the purpose of the requirement that the PISC and site closure plan include a prediction of the magnitude of the pressure differential between pre-injection and during post-injection at §146.93(a)(2)(i) is to support planning of the amount of monitoring that is necessary during PISC and planning the length of the PISC timeframe. EPA anticipates that this information will be provided by the computational modeling performed for the AoR delineation.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate non-endangerment; and perform site closure activities. The guidance will be available at http://www.epa.gov/safewater/wells_sequestration.html.

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24203 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.93(a)(1)API Comments: (1) The owner or operator must submit the postinjection site care and site closure plan as a part of the permit application to be approved by

the Director. SHALL CONTINUE TO CONDUCT MONITORING AS SPECIFIED IN THE
DIRECTOR-APPROVED POST-INJECTION SITE CARE AND SITE CLOSURE PLAN,

PURSUANT TO THE PERFORMANCE BASED CRITERIA DESCRIBED IN 146.93(B)(3).

Rationale: Revisions here reflect changes to §146.93(b)(3)

Response: EPA disagrees with the suggested changes, and disagrees that the post-injection monitoring period should be strictly performance-based. The Agency agrees that there will be limited circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs, and has included requirements in the final Class VI rule at §146.93(c) for an owner or operator to substantially demonstrate that an alternative time frame ensures the protection of USDWs. However, EPA anticipates that a default timeframe for post-injection site care will necessary for most GS sites to ensure the protection of USDWs. A 50- year post-injection site care timeframe represents a reasonable and protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments. For this reason, the final GS regulation includes a provision that the Director may, at his or her discretion, shorten the post-injection site care timeframe if the owner or operator can demonstrate that the GS project does not pose an endangerment to USDWs, as specified in §146.93(b)(2). Such a demonstration will be site-specific, and based on pressure monitoring and USDW impacts.

The GS rule requires owners or operators to submit a post-injection site care and site closure plan as part of the permit application, as specified in §146.82(a), in order to outline how these activities willbe performed and how non-endangerment of USDWs will be demonstrated throughout the postinjection site care period.

Commenter Name: Thomas Curtis Letter ID: 0181 Commenter Organization: American Water Works Association (AWWA) Comment ID: 23706 Other EPA Comment Codes and Descriptions: 5280 2.8.2.4 USDW non-endangerment

demonstrations

Comment: AWWA has observed that the proposed regulation is lacking in details on the requirements to demonstrate that the carbon dioxide plume has stabilized. For example, the proposal does not include requirements that the plume pressure must be constant for a certain number of years or that the plume has not migrated for a set period of time. Since AWWA does not claim to be experts on the behavior of carbon dioxide plumes and can not provide recommendations on this topic, AWWA recommends that EPA should engage in research on determining exactly what these criteria should be. For example, when referencing lack of plume movement, what should the trigger time period be (no movement of plume for 10, 15, 20 or more years??). AWWA recommends that EPA clarify what is an acceptable frequency for a lack of change in the plume characteristics and also needs to clarify plume stabilization as this issue could be interpreted differently by different states. Guidance should be prepared by EPA on this topic so that there is consistent application of this requirement across all sequestration projects. A performance based system could also be developed that would require the operator to meet certain criteria to prove that the plume has stabilized. This could beused to justify the closing of the site after the 50-year period of postinjection site care has elapsed. This would allow for a process where long-term monitoring decisions are made in response to the specific characteristics of each project.

AWWA believes that the proposed post-injection site care requirements have been established to prevent endangerment to USDWs. Carbon dioxide can potentially leak from the confining layer into other aquifers that, while not classified as USDWs, may still be considered drinking water sources in some areas of the county. EPA should also consider including requirements in the regulation toaddress the potential for endangerment of these aquifers during the postinjection period. Monitoring requirements should be extended to cover these aquifers, and the post-injection site care plan should include provisions for the protection of aquifers that are not classified as USDWs, but are still considered a future drinking water source.

Response: EPA acknowledges that many site-specific factors will influence the determination of when the CO2 plume and pressure front no longer pose a risk of endangerment to USDWs. It is for this reason that EPA believes that individual UIC Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care is needed. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate the appropriateness of an alternative post-injection site care time frame; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

EPA has conducted research regarding stabilization timeframes. As described in the preamble to the proposed rule, in determining the post-injection site care-timeframe for the proposed regulation, EPA reviewed industry reports, existing environmental programs, and initial GS research studies. EPA provided a synthesis of pertinent results from GS modeling studies in the preamble to the proposed regulation. Further explanation of this analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water." Based on review of these studies, modeling results indicate that the CO2 plume stabilization may occur on the timeframe of 10-100 years after the cessation of injection. EPA believes that a 50-year default post-injection site care timeframe is a reasonable midpoint for most GS projects and available data, including data submitted by commenters, do not support a different default timeframe, and has retained this in the final regulation. EPA will continue research in this area and plans, every six years, to collect and review data on GS projects to determine whether the appropriate amount and types of information and appropriate documentation are being collected, and to determine if modifications to the requirements are appropriate or necessary.Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24493 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.93(a)(1)

Proposed CCS Group Recommendations: (1) The owner or operator must submit the post-injection site care and site closure plan as a part of the permit application to be approved by the Director. SHALL CONTINUE TO CONDUCT

MONITORING AS SPECIFIED IN THE DIRECTOR-APPROVED POST-INJECTION SITE

CARE AND
SITE CLOSURE PLAN, PURSUANT TO THE PERFORMANCE BASED CRITERIA

DESCRIBED IN 146.93(B)(3).

Basis for CCS Group Comments: Revisions here reflect changes to §146.93(b)(3)

Response: EPA disagrees with the suggested changes, and disagrees that the post-injection monitoring period should be strictly performance-based. The Agency agrees that there will be limited circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs, and has included requirements in the final Class VI rule at §146.93(c) for an owner or operator to substantially demonstrate that an alternative time frame ensures the protection of USDWs. However, EPA anticipates that a default timeframe for post-injection site care will necessary for most GS sites to ensure the protection of USDWs. A 50- year post-injection site care timeframe represents a reasonable and protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments. For this reason, the final GS regulation includes a provision that the Director may, at his or her discretion, shorten the post-injection site care timeframe if the owner or operator can demonstrate that the GS project does not pose an endangerment to USDWs, as specified in §146.93(b)(2). Such a demonstration will be site-specific, and based on pressure monitoring and USDW impacts.

The GS rule requires owners or operators to submit a post-injection site care and site closure plan as part of the permit application, as specified in §146.82(a), in order to outline how these activities willbe performed and how non-endangerment of USDWs will be demonstrated throughout the postinjection site care period.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24494 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5200 2.8.2 Post injection site care (seeking comment) (40 CFR 146.93)

Comment: Rule Provision: 146.93(a)(2)

Proposed CCS Group Recommendations: (2) The post-injection site care and site closure plan must include the following information:

(i) The pressure differential between pre-injection and predicted post-injection pressures in the injection zone;(ii) The predicted position of the carbon dioxide plume and associated pressure front at site closure as demonstrated in the area of review evaluation required under § 146.84(b);

(iii) A description of post-injection monitoring location, methods, and proposed frequency; and

(iv) A proposed schedule for submitting post-injection site care monitoring

results to the Director.

Basis for CCS Group Comments: Revisions here reflect changes to §146.93(b)(3)

Response: Based on its evaluation of all public comments and input on the proposed rule and NODA and Request for Comment, EPA has made many revisions to the GS Rule. See the final rule and preamble for further discussion on EPA's final approach.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24497 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: Rule Provision: 146.93(b)

Proposed CCS Group Recommendations: (b) The owner or operator shall monitor the site following the cessation of injection to show the position of the carbon dioxide plume and pressure front and demonstrate that USDWs are not being endangered.

(1) The owner or operator shall continue to conduct monitoring as specified in the Director-approved post-injection site care and site closure plan, UNTIL CLOSURE IS AUTHORIZED PURSUANT TO 146.93(B)(3).

Basis for CCS Group Comments: EPA should also reconsider its proposed 50-year default period for post-injection site care. EPA offers no rationale for this arbitrarily-selected period of 50 years. Establishing a fixed and unusually long time period may create a significant barrier for operators considering entry into CCS operations. Criteria for determining the period for post-injection site care should be performance-based and a function of the site specific characteristics of a project such as project size, geologic factors, and relative risk of the project. Such criteria are provided in our edits to §146.93(b)(3).

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive in most cases or arbitrary. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled"Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Areaof-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe,none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA acknowledges there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments. EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA adds that the purpose of the GS rule is not to incentivize the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24498 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: Rule Provision: 146.93(b)(2)

Proposed CCS Group Recommendations: (2) If the owner or operator can request and

demonstrate to the satisfaction of the Director before 50 years, based on monitoring and other site-specific data, that the geologic sequestration project no longer poses an endangerment to USDWs, the Director may approve an amendment

to THAT the post-injection site care and site closure plan SHOULD BE REVISED to reduce the frequency of monitoring, THE DIRECTOR SHALL APPROVE THE REDUCTION. or may authorize site closure before the end of the 50-year period.

Basis for CCS Group Comments: See rationale stated above for eliminating 50-year period.

Response: As described above, EPA disagrees that a post-injection site care timeframe of 50 years is excessive in most cases or arbitrary, and retains the default 50-year post-injection site caretimeframe in the final rule.

Commenter Name: Kyle Isakower Letter ID: 0191 Commenter Organization: American Petroleum Institute Comment ID: 23881

Comment: performance and as such is more protective of USDWs. Second, the proposal requires a showing that the CO2 plume has "stabilized", which is undefined. Cessation of plume movement is not necessarily essential to show that a project poses no threat of endangerment to USDWs - plumes that are still moving may, nonetheless, remain contained. Instead, it is more protective to show that the plume is not expected to encounter a leakage pathway. Third, the required

Response: EPA agrees that a complete cessation of plume movement may not occur at some sites for long time periods due to density differences, natural formation flow gradients and diffusion. EPA clarifies that under the final rule, a complete cessation of plume movement is not required, only a demonstration that the plume and pressure front no longer pose a risk of endangerment to USDWs.

EPA acknowledges that many site-specific factors will influence the determination of when the CO2 plume and pressure front no longer pose a risk of endangerment to USDWs. It is for this reason that EPA believes that Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care is needed. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties. EPA also recognizes that there may be sites where the 50 year post injection site care timeframe may be either not appropriate or more burdensome than necessary based on site-specific conditions. 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 post-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 processbased on substantial data, that an alternative PISC timeframe may be appropriate if it ensures nonendangerment of USDWs pursuant to requirements at §146.93(c).

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate the appropriateness of an alternative post-injection site care time frame; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Kyle Isakower Letter ID: 0191 Commenter Organization: American Petroleum Institute Comment ID: 23882

Comment: plume is not expected to encounter a leakage pathway. Third, the required showing that "no additional monitoring is needed" does not provide guidance regarding how an operator is to show that no additional monitoring is needed. The proposal below provides specific guidance on what the operator must show.

Response: EPA acknowledges that many site-specific factors will influence the determination of when the CO2 plume and pressure front no longer pose a risk of endangerment to USDWs. It is forthis reason that EPA believes that Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care is needed. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties.

EPA agrees that a complete cessation of plume movement may not occur at some sites for long time periods due to density differences, natural formation flow gradients and diffusion. EPA clarifies that under the final rule, a complete cessation of plume movement is not required, only a demonstration that the plume and pressure front no longer pose a risk of endangerment to USDWs is.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Jeff W. Sheets Letter ID: 0192 Commenter Organization: ConocoPhillips Comment ID: 23902

Comment: USDWs. Second, the proposal requires demonstration that the CO2 plume has "stabilized", which is undefined. Cessation of plume movement is not necessarily essential, and may not be applicable, to show that a project poses no threat of endangerment to USDWs-plumes that are still moving may, nonetheless, be in geological settings which ensure that they remain contained. Instead, it is more protective to show that the plume is not expected to encounter a leakage pathway. Third, the required demonstration that "no additional monitoring is

Response: EPA acknowledges that many site-specific factors will influence the determination of when the CO2 plume and pressure front no longer pose a risk of endangerment to USDWs. It is for this reason that EPA believes that Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care is needed. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties.

EPA agrees that a complete cessation of plume movement may not occur at some sites for long time periods due to density differences, natural formation flow gradients and diffusion. EPA clarifies that under the final rule, a complete cessation of plume movement is not required, only a demonstration that the plume and pressure front no longer pose a risk of endangerment to USDWs is.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://www.epa.gov/safewater/wells_sequestration.html.

Commenter Name: Jeff W. Sheets Letter ID: 0192 Commenter Organization: ConocoPhillips Comment ID: 23903Comment: pathway. Third, the required demonstration that "no additional monitoring is needed" does not provide guidance regarding how an operator is to show that no additional monitoring is needed. The proposal below provides specific guidance on what the operator must show.

Response: As described above, EPA acknowledges that many site-specific factors will influence the determination of when the CO2 plume and pressure front no longer pose a risk of endangerment to USDWs. It is for this reason that EPA believes that Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care is needed. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties.

EPA agrees that a complete cessation of plume movement may not occur at some sites for long time periods due to density differences, natural formation flow gradients and diffusion. EPA clarifies that under the final rule, a complete cessation of plume movement is not required, only a demonstration that the plume and pressure front no longer pose a risk of endangerment to USDWs is.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24716 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.93(a)(1)

Anadarko Petroleum Corporation (APC) Comments: (1) The owner or operator must submit the postinjection site care and site closure plan as a part of the permit application to be approved by the Director. SHALL CONTINUE TO CONDUCT

MONITORING AS SPECIFIED IN THE DIRECTOR-APPROVED POST-INJECTION SITE

CARE AND
SITE CLOSURE PLAN, PURSUANT TO THE PERFORMANCE BASED CRITERIA

DESCRIBED IN 146.93(3).

Rationale: Revisions here reflect changes to §146.93(b)(3)

Response: EPA disagrees with the suggested changes, and disagrees that the post-injection monitoring period should be strictly performance-based. The Agency agrees that there will be limited circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments. EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. The GS rule requires owners or operators to submit a post-injection site care and site closure plan as part of the permit application, as specified in §146.82(a), in order to outline how these activities willbe performed and how non-endangerment of USDWs will be demonstrated throughout the postinjection site care period.

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24719 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: Rule Provision: 146.93(b)(1)

Anadarko Petroleum Corporation (APC) Comments: (1) The owner or operator shallcontinue to conduct monitoring as specified in the Director-approved postinjection site care and site closure plan, for at least 50 years following the cessation of injection. At the Director’s discretion, the monitoring will continue until the geologic sequestration project no longer poses an endangerment to USDWs. PURSUANT TO THE PERFORMANCE BASED CRITERIA

DESCRIBED IN §146.93(B)(3).

Rationale: EPA should also reconsider its proposed 50- year default period for post-injection site care. EPA offers no rationale for this arbitrarily selected period of 50 years. Establishing a fixed and unusually long time period may create a significant barrier for operators considering entry into CCS operations. Criteria for determining the period for postinjection site care should be performance based and a function of the site specific characteristics of a project such as project size, geologic factors, and relative risk of the project. APC offers such criteria in our edits to §146.93(b)(3).

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive in most cases or arbitrary. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that alternative timeframes may be appropriate under limited, specific circumstances.

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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

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

EPA adds that the purpose of the GS rule is not to incentivize the use of GS. Rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24720 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: Rule Provision: 146.93(b)(2)

Anadarko Petroleum Corporation (APC) Comments: (2) If the owner or operator can request and demonstrate to the satisfaction of the Director before 50 years, based on monitoring and other site-specific data, that the geologic sequestration project no longer poses an endangerment to USDWs, the Director may approve an amendment to THAT the post-injection site care and site closure plan SHOULD BE REVISED to reduce the frequency of monitoring. or may authorize site closure before the end of the 50-year period.Rationale: (See above)

Response: As described above, EPA disagrees that a post-injection site care timeframe of 50 years is excessive in most cases or arbitrary, and retains the default 50-year post-injection site care

timeframe in the final rule.

Commenter Name: Kurt Waltzer Letter ID: 0250 Commenter Organization: Clean Air Task Force Comment ID: 22290

Comment: Site closure standards and framework for long-term stewardship

Our Environmental NGO Group did not come to a common set of recommendations on site closure and are either submitting individual comments on this issue or are submitting comments jointly with other groups. We do agree, however, that EPA’s proposed closure standards in §146.93 need revision. In order to assure that site risks have diminished to the point that it is reasonable to discontinue or significantly reduce monitoring, it is essential that the rule require a demonstration of much more than merely ‘plume stabilization’ and that the nature of what must be demonstrated be precisely described. In addition, given the desired permanent nature of CO2 sequestration in the subsurface and the importance to the public of ensuring long-term oversight of project sites, EPA should use its existing regulatory authorities to establish a framework for long-term stewardship and seek whatever additional authorities may be required for this purpose from Congress. This framework should include an entity with responsibility for monitoring and managing sites after closure has been authorized. The proposed rule authorizes operators to stop monitoring, but does not provide for the stewardship of sites following closure.. EPA must rectify this omission. It is important that the post-closure framework include financing provisions that are adequate to ensure proper site stewardship in the long-term.

Response: EPA acknowledges that many site-specific factors will influence the determination of when the CO2 plume and pressure front no longer pose a risk of endangerment to USDWs. It is for this reason that EPA believes that individual UIC Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care is needed. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties.

EPA agrees that a complete cessation of plume movement may not occur at some sites for long time periods due to density differences, natural formation flow gradients and diffusion. EPA clarifies that under the final rule, a complete cessation of plume movement is not required; only a demonstration that the plume and pressure front no longer pose a risk of endangerment to USDWs is required.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate non endangerment; and perform site closure activities.

Regarding establishing a framework for long-term stewardship, EPA clarifies that, once site closureis authorized, the UIC program has no authority over a site. EPA clarifies that long-term liability for GS sites is outside the scope of this rulemaking after a the CO2 plume has been demonstrated to no longer pose an endangerment to USDWs and the site has been properly closed pursuant to §146.93. Once an owner or operator has met all regulatory requirements under Part 146 for Class VI wells and the Director has approved site closure pursuant to requirements at §146.93, the owner or operator will generally no longer be subject to enforcement for regulatory noncompliance.

Separate from EPA’s authority to enforce regulatory compliance, an owner or operator may be subject to a §1431 response order even after proper site closure is approved under §146.93. Under §1431 the Administrator may require an owner or operator to take necessary response measures if he or she receives information that a contaminant is present or is likely to enter a public water system or an USDW, which may present an imminent and substantial endangerment to the health of persons, and the appropriate State and local authorities have not acted to protect the health of such persons. The action may include issuing administrative orders or commencing a civil action for appropriate relief against the owner or operator of a Class VI well. If the owner or operator fails to comply with the order, they may be subject to a civil penalty for each day in which such violation occurs or failure to comply continues.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24940 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.93

EPA Proposal: 13. Post-injection site care and site closure

(a) The owner or operator of a Class VI well must prepare, maintain, and comply with a plan for post-injection site care and site closure that meets the requirements of paragraph (a)(2) of this section and is acceptable to the

Director.

(1) The owner or operator must submit the post-injection site care and site closure plan as a part of the permit application to be approved by the Director.

GWPC Recommendations: Support the proposed EPA language

Rationale: Agree with EPA’s rationale

Response: EPA acknowledges the commenter’s support; the final rule retains this provision.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24942 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.93(a)(2)

(iii) A description of post-injection monitoring location, methods, and proposed frequency; and(iv) A proposed schedule for submitting post-injection site care monitoring

results to the Director.

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

Response: EPA acknowledges the commenter’s support; the final rule retains this provision.

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



### Individual Comments

Commenter Name: Karl R. Moor Letter ID: 0109 Commenter Organization: Southern Company, on behalf of Edison Electric Institute (EEI) Comment ID:

22003 Other EPA Comment Codes and Descriptions: 5260 2.8.2.3 Adjusting the post-injection timeframe (seeking comment)

Comment: EEI urges EPA to defer to site-specific characteristic wherever possible in the regulations.

For example, the proposed regulations contemplate a 50-year post- injection site care period, but the UIC program director can require continued monitoring if he or she deems it necessary to protect underground sources of drinking water. In the notice of proposed rulemaking, EPA states that it is willing to consider other time frames for the post-injection site care period, but instead of a default, the Agency should let the characteristics of each site determine the appropriate length of time for post-injection site care. If the director hasthe discretion to vary the length of the monitoring period based on sitespecific characteristics, establishing a lengthy default period would place an unnecessary burden on those owners and operators who can show that their projects pose no threat to underground sources of drinking water in less than 50 years. In fact, EEI and its members believe that appropriately sited CCS projects will be able to make such a demonstration in substantially less than 50 years, perhaps only 10 years since data suggest that the risk profile of carbon dioxide injection tails off markedly after a decade. Consequently, a lengthy default period would penalize those owners and operators who have taken steps to ensure proper site characterization. Surely, EPA would rather reward - and, therefore, encourage - appropriate siting: Properly managed site characterization and operations are the best way to ensure the highest level of protection for underground sources of drinking water.

Response: EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final 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 PISC period based on site-specific data, pursuant to requirements at §146.93(b); or (2) affordingthe Director discretion to allow a Class VI well owner or operator to demonstrate, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

Because of the variety of site-specific circumstances at GS sites, EPA believes that Directors, inconsultation with operators, will be in the best position to determine whether additional postinjection site care monitoring is needed (or whether the timeframe may be shortened), based on the circumstances of a particular project. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA agrees that proper site characterization is a critical component of ensuring that USDWs are protected. However, EPA disagrees that this is a substitute for post-injection site care. EPA believes that extensive post-injection monitoring is necessary to protect USDWs from endangerment.

EPA adds that the purpose of the GS rule is not to incentivize the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

Commenter Name: George Holliday, PhD, PE, BCEE Letter ID: 0114 Commenter Organization: Holliday Environmental Services, Inc. Comment ID: 22522

Comment: A review of the existing technical literature suggests no author has considered how long sequestration is expected to last. Schlumberger says in their advertising, sequestration is "permanent" separation of CO2 from the near surface waters. Webster Unabridged Dictionary defines "permanent" as meaning unchanging, a very long time, to last indefinitely. Indefinitely is for ever without end. This appears to be an impossible assignment. Governments come and go, people come and to, and most importantly companies (permittees) come and go. The cost of carbon dioxide sequestrations monitoring until the end of time is a monumental expenditure. To circumvent this problem EPA states 50 years should be long enough, even though EPA offers no technical support for this claim. Then EPA says "not to worry," EPA will allow the non-technically trained Regional Director to lengthen or shorten the sequestration reservoir monitoring time based on his vast "inexperience". EPA offers no guidance to assist the untrained, non-engineer Regional Directors in making that determination.

Response: EPA disagrees with this comment. In determining the post-injection site care -timeframe for the proposed regulation, EPA reviewed industry reports, existing environmental programs, and initial GS research studies. EPA provided a synthesis of pertinent results from GS modeling studies in the preamble to the proposed regulation. Further explanation of this analysis was included in an EPA-prepared background document that is available in the federal docket for the GS rule, titled"Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Areaof-Review and Potential Risk to Underground Sources of Drinking Water." Based on review of these studies, modeling results indicate that the CO2 plume stabilization may occur on the timeframe of10-100 years after the cessation of injection. EPA believes that a 50-year default post-injection site care timeframe is a reasonable midpoint for most GS projects and available data, including data submitted by commenters, do not support a different default timeframe, and has retained this in the final regulation. To address concerns that, in some situations, it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs, the final 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA disagrees that the staff making determinations regarding whether to shorten or lengthen the post-injection site care timeframe lack technical training for effective oversight of Class VI wells. Most permitting authority staff have years of experience with the current UIC injection well classes and have relevant specialties in geology, engineering, and related disciplines.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate the appropriateness of an alternative post-injection site care time frame; demonstrate non endangerment; and perform site closure activities. The guidance will be available on EPA's web site, at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: George Holliday, PhD, PE, BCEE Letter ID: 0114 Commenter Organization: Holliday Environmental Services, Inc. Comment ID: 22533

Comment: EPA GUESSES AT THE REQUIRED CLASS VI MONITORING PERIOD

EPA at 73 FR 43518 - 43527 discusses how EPA decided to monitor a sequestration project for 50 years. EPA said 50 years is a long time and if EPA extends the time longer the cost will be too high! EPA provide no rational argument for selecting 50 years: EPA says at 73 FR 43519, "EPA is tentatively proposing a post-injection site care (monitoring) period of 50 years with Director’s discretion to change that period to lengthen or shorten the 50- year period, if appropriate." The best support EPA offers (73 FR 43520) for the 50 year monitoring period is:

"To ensure that the post-injection site care monitoring timeframe is long enough to determine that there is no threat of endangerment to USDWs from injection activities; EPA is proposing a default post-injection site care period of 50years. During this 50-year period, the owner or operator would be required to submit periodic reports providing monitoring results and updated modeling results as appropriate until a demonstration of non-endangerment to USDWs can be

made."

EPA is willing to rely on a technically untrained Regional Administrator counseled by uncertified EPA employees, because EPA does not have technical know-how to determine the appropriate monitoring time period! We question the probability of speculators being in business 50 years after the injectors stop producing income and become a liability. Since EPA is charged only with protecting USDWs and not human life, EPA can, by default, slough the real burden, e.g., protecting human life, onto some other agency. In our opinion this is an Arbitrary and Capricious and a life threatening action on the part of

EPA.

Response: As described above, EPA disagrees with this comment. In determining the post-injection site care-timeframe for the proposed regulation, EPA reviewed industry reports, existing environmental programs, and initial GS research studies. EPA provided a synthesis of pertinent results from GS modeling studies in the preamble to the proposed regulation. Further explanation of this analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water." Based on review of these studies, modeling results indicate that the CO2 plume stabilization may occur on the timeframe of 10-100 years after the cessation of injection. EPA believes that a 50-year default post-injection site care timeframe is a reasonable midpoint for most GS projects and available data, including data submitted by commenters, do not support a different default timeframe, and has retained this in the final regulation.

EPA disagrees that the staff making determinations regarding whether to shorten or lengthen the post-injection site care timeframe lack technical training for effective oversight of Class VI wells. Most permitting authority staff have years of experience with the current UIC injection well classes and have relevant specialties in geology, engineering, and related disciplines.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate the appropriateness of an alternative post-injection site care time frame; demonstrate non endangerment; and perform site closure activities. The guidance will be available on EPA's web site, at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Iain Wright Letter ID: 0118 Commenter Organization: BP Alternative Energy Comment ID: 22068

Comment: My third and final point concerns the appropriate timeframe for site closure. There is no rational basis to mandate a universal, 50-year minimum timeframe for post-injection site care. Such a mandate would kill-off commercial investment in geo-sequestration projects. Worse than that, it would preferentially kill-off the best sites - those with proven seals and the lowest risk of leakage - oiland gas fields.

As the EPA proposal states - the actual time for CO2 plume stabilization will be very "site-specific". A well-selected and managed sequestration site (such as an oil or gas field) that has met its performance objectives (including plume stabilization) will be much more secure and could be closed quickly (say a couple of years). However, (as EPA’s cited examples show), CO2 injected in a poorly-confined deep saline formation could move around for quite a while such that the closure period will have to wait on residual and solubility trapping, and hence, a closure period of several years could be more appropriate. WE

RECOMMEND THAT EPA DOES NOT MANDATE ANY FIXED TIMEFRAME FOR SITE

CLOSURE. BETTER

WOULD BE A SITE-SPECIFIC ASSESSMENT THAT IS RISK AND PERFORMANCE BASED.

Response: EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA adds that the purpose of the GS rule is not to incentivize the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

Commenter Name: Leslie Savage Letter ID: 0122 Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24739

Comment: - The Proposal’s default 50-year post-injection monitoring period, while groundwater monitoring for a Class I hazardous waste injection well is required only until the injection zone pressure is such that USDWs cannot be impacted.

Response: The GS regulations have been tailored to these unique characteristics of GS injection wells. EPA developed the Class VI regulations in recognition that the risks posed by GS to USDWs are fundamentally different than those associated with current injection practices regulated by the UIC program, including Class I hazardous waste injection wells. For example, CO2 is more buoyant, less viscous (i.e., more mobile), and in some cases more corrosive than fluids injected into Class I hazardous waste wells. In addition, the large injection volumes anticipated for GS will likely be much greater than current injection practices. Lastly, CO2 movement in the subsurface is not as well understood as fluids currently injected under the Class I program.In combination, these unique characteristics result in CO2 plumes that may be highly mobile in the subsurface and move vertically upwards. There will also be some unavoidable levels of uncertainty as to the direction and speed of plume movement during and after injection. EPA-funded research by Lawrence Berkeley National Laboratory has shown in preliminary modeling studies of ideal basins for GS that pressure perturbations great enough to force saline fluids into USDWs may cover large areas compared to current injection projects (10s to 100s km2). This research report, entitled "Research Project on CO2 Geological Storage and Groundwater Resources: Large-Scale Hydrological Evaluation and Modeling of the Impact on Groundwater Systems," is available in the rulemaking docket. EPA developed regulations that would appropriately address the larger the area influenced by a GS project, and the resultant, higher likelihood that there may be potential faults, fractures, or abandoned wells that could act as a conduit for USDW contamination. Furthermore, a level of site-characterization typical for Class I hazardous waste injection wells will be extremely

difficult over these vast areas.

Commenter Name: Leslie Savage Letter ID: 0122 Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24754

Comment: 7. EPA should provide for performance-based requirements for Closure and Post Closure Care. For example, the appropriate length of time for post-injection site care should be determined by specific conditions and characteristics of the site, and monitoring of the pressure to determine the point at which the injection zone pressure is such that USDWs cannot be impacted.

Response: EPA agrees with commenters that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Leslie Savage Letter ID: 0122 Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24802 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5220 2.8.2.1 Post-injection monitoring activities

Comment: (b) THE OWNER OR OPERATOR MUST Mustmonitor the site following the

cessation of injection to show the position of the carbon dioxide plume and pressure frontand demonstrate that USDWs are not being endangered.

(1) THE OWNER OR OPERATOR MUST Mustcontinue to conduct monitoring as specified in the Director-approved post-injection site care and site closure plan for THE PERIOD OF TIME at least 50 yearsfollowing the cessation of injection . At the Director's discretion, the monitoring will continue until THE DIRECTOR DETERMINES THAT the geologic sequestration project no longer poses an endangerment to USDWs.

Response: EPA disagrees with the suggested edits. However, EPA agrees with commenters that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final 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 PISC 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, based on substantial data during thepermitting process, that an alternative PISC timeframe may be appropriate if it ensures nonendangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Leslie Savage Letter ID: 0122 Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24804 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5260 2.8.2.3 Adjusting the post-injection timeframe (seeking comment)

Comment: (4) If such a demonstration cannot be made after the 50-year period, must submit to the Director a plan to continue post-injection site care.

{See comment above.}

Response: As described above, the post-injection site care timeframe may be reduced by the Director if the owner or operator can demonstrate that the remaining pressure front and plume no longer pose a risk of endangerment to USDWs. The non-endangerment finding is left to the discretion of the Director, based on site-specific information such as plume movement, pressure decay, and the location of potential leakage pathways. As suggested by the commenter, a complete cessation of plume movement is not required, only a demonstration that the plume and pressure front no longer pose a risk of endangerment to USDWs, as specified in §146.93(b)(2-4). EPA retains this provision in the final GS regulation GS rule also offers owners or operators flexibility regarding the duration of the PISC timeframe by affording the Director discretion to allow a Class VI well owner or operator to demonstrate, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care timeframe of 50 years, with flexibility to adjustthe 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Leslie Savage Letter ID: 0122 Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24974 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5220 2.8.2.1 Post-injection monitoring activities

Comment: (2) If the owner or operator can demonstrate to the satisfaction of the Director before 50 years, based on monitoring and other site-specific data, that the GS project no longer poses an endangerment to USDWs, the Director may approve an amendment to the post-injection site care and site closure plan to reduce the frequency of monitoring or may authorize site closure before the end of the 50-year period.

{The period of time an owner or operator is required to conduct post-closure care monitoring should be based on the ability of the pressure to cause endangerment of USDWs. A 50-year post-closure care monitoring period is unprecedented and implies that CO2 presents a greater risk than it does. RRC suggests that EPA strike the phrase "for at least 50 years" and make the time for continued monitoring be based on site specific data. }

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive for most Class VI wells. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled"Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Areaof-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that alternative timeframes may be appropriate under limited, specific circumstances, which is why EPA is providing the Director discretion to approve an alternative post-injection site care timeframe as long as the owner or operator can meet the requirements provided at §146.93(c).

EPA acknowledges there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by:(1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the postinjection 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 appropriateif it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Jonathan Pershing Letter ID: 0124 Commenter Organization: World Resources Institute (WRI) Comment ID: 23043

Comment: Despite the many consistencies, there are a few important technical differences which are outlined in the GHGT-9 paper. These differences include the definition of faults that pose risk of leakage, injection pressure limits, well construction requirements and capacity estimates, as well as the differences in definition of the post-injection phases of a project. On this last item, EPA proposes a default 50- year monitoring time-frame, while the CCS Guidelines require an operator to demonstrate (via six criteria) that the site no longer poses a danger to human health or the environment, rather than using a default timeframe. This approach was taken because of the expected difference in the time it may take the CO2 plume to stabilize among sites. The CCS Guidelines also mention a more detailed framework for what happens after an operator is no longer responsible for a site. Specifically, the CCS Guidelines encourage stewardship of a site by an entity that would be responsible for any needed monitoring, maintenance of a site, and establishment and operation of a registry

for information about CCS sites.

Response: EPA acknowledges that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA believes however, that to ensure USDW protection from endangerment, a default timeframe forpost-injection site care is necessary. A 50 year post-injection site care timeframe represents a reasonable and protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

Commenter Name: Sam Kitto Letter ID: 0126 Commenter Organization: National Tribal Air Association Comment ID: 23045

Comment: Monitoring

Aside from how the GS rules addresses hazardous substances, the rule includes a default monitoring period of 50-years after closure of an injection well, Unfortunately, the EPA provides no objective, technical rationale as to how it arrived at this monitoring period, such as an engineering analysis, and gets around it by giving discretion to Agency Regional Administrators or jurisdictions with primacy for UIC programs for shortening or lengthening the monitoring period on a case-by-case basis. While the NTAA agrees that there should be such discretion with respect to defining post-closure monitoring periods for injection wells, it should involve substantive input by qualified engineers trained in geologic sequestration. Otherwise, USDWs could end up being adversely impacted as a result of monitoring periods improperly defined by unqualified individuals.

The NTAA therefore recommends that an objective, technical rationale be provided for deciding upon the 50-year monitoring period. In addition, our organization

Response: EPA disagrees with this comment. In determining the post-injection site care-timeframe for the proposed regulation, EPA reviewed industry reports, existing environmental programs, and initial GS research studies. EPA provided a synthesis of pertinent results from GS modeling studies in the preamble to the proposed regulation. Further explanation of this analysis was included in an EPA-prepared background document that is available in the federal docket for the GS rule, titledComputational Modeling of Underground Injection of Carbon Dioxide for Determination of Areaof-Review and Potential Risk to Underground Sources of Drinking Water. Based on review of these studies, modeling results indicate that the CO2 plume stabilization may occur on the timeframe of 10-100 years after the cessation of injection. EPA believes that a 50-year default post-injection site care timeframe is a reasonable midpoint for most GS projects and available data, including data submitted by commenters, do not support a different default timeframe, and has retained this in the final regulation. To address concerns that, in some situations, it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs, the GS regulation includes a provision that the Director may, at his or her discretion shorten or lengthen the post-injection site care timeframe if the owner or operator can demonstrate that the GS project does not pose a risk to USDWs, as specified in §146.93(b)(2).

Alternatively, the final rule at §146.93(c), also allows the Director to approve an alternative postinjection site care timeframe where an owner or operator can demonstrate during the permitting process that an alternative post-injection site care timeframe, other than the 50 year default, isappropriate and ensures non-endangerment of USDWs. The demonstration must be based on sitespecific information, including the results of site-specific computational modeling; the predicted timeframe for pressure decline; the predicted rate of carbon dioxide plume migration; site-specific chemical processes that will result in carbon dioxide trapping; the predicted rate of carbon dioxide trapping; characterization of the confining zone(s); laboratory analyses or studies to verify theinformation on trapping; the presence of potential conduits for fluid movement and the quality of abandoned well plugs within the AoR; the distance between the injection zone and the USDWs above and/or below the injection zone; and any additional site-specific factors determined by the Director. The demonstration must meet the criteria at §146.93(c)(2) for ensuring the quality and accuracy of the data and models on which the demonstration is based. This demonstration would be submitted as part of the permit application, per §146.82(a)(18), in addition to the PISC and site closure plan required at §146.82(a)(17).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters¿ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Because of the variety of site-specific circumstances at GS sites, EPA believes that Directors, inconsultation with operators, will be in the best position to determine whether additional postinjection site care monitoring is needed (or whether the timeframe may be shortened), based on the circumstances of a particular project. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties. EPA agrees that qualified scientists and engineers should be included in any decision to lengthen or shorten the post-injection site care monitoring period, but is not requiring this at §146.93.

Commenter Name: George Holliday, PhD, PE, BCEE Letter ID: 0127 Commenter Organization: Holliday Environmental Services, Inc. Comment ID: 23056 Other EPA Comment Codes and Descriptions: 6210 3.2.1 Comments on the timeframe of the costing analysis (seeking comment)

Comment: C: WITHOUT TECHNICAL SUPPORT, EPA REQUIREs 50 YEARS OF

MONITORING EXECPT BY

SAYING MORE MONITORING IS EXPENSIVE.

1. Sequestration of CO2 is forever, or we don’t need capture the CO2 in the first place. If the CO2 escapes the Earth the World population is doomed, in accordance with the IPPC theory.

2. EPA provides no justification for selecting 50 years, in fact the proposed rule states the economic contractor was told to develop the cost on the basis of 25 years.

3. It is unclear if the cost is based on 25 or 50 years.

Response: EPA disagrees that the monitoring timeframe was selected based on cost. In determining the post-injection site care-timeframe for the proposed regulation, EPA reviewed industry reports, existing environmental programs, and initial GS research studies. EPA provided a synthesis of pertinent results from GS modeling studies in the preamble to the proposed regulation. Further explanation of this analysis was included in an EPA-prepared background document that is available in the federal docket for the GS rule, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources ofDrinking Water." Based on review of these studies, modeling results indicate that the CO2 plume stabilization may occur on the timeframe of 10-100 years after the cessation of injection. EPA believes that a 50-year default post-injection site care timeframe is a reasonable midpoint for most GS projects and available data, including data submitted by commenters, do not support a different default timeframe, and has retained this in the final regulation. However, EPA recognizes that there may be sites where the 50 year post injection site care timeframe may be either not appropriate or more burdensome than necessary based on site-specific conditions. 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Emily Rochon Letter ID: 0129 Commenter Organization: Greenpeace International Comment ID: 23073

Comment: water reservoir and pose the most severe risk to the water supply. Another part of the proposal that we support is the language detailing the procedure for post-closure site care. It is key that after a carbon storage site is closed that it continues to be monitored and we support the 50-year timeframe written in the proposal. Greenpeace however could not be supportive of any length of time shorter than this or any potential allowance for early termination of the

ost-closure site care.

Response: EPA agrees with commenters that a 50 year post-injection site care timeframe represents a reasonable and protective post-injection site monitoring period in most cases and available data, including data submitted by commenters, do not support a different default timeframe. EPA bases this on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments. Furthermore, EPA believes that a 50-year default post-injection site care timeframe is not overly burdensome, does not exaggerate the risks associated with GS, is consistent with other environmental programs, and sufficiently protects USDWs from endangerment. For this reason, the final GS regulation retains the 50 year post-injection site care timeframe, as specified in §146.93(b)(1).

However, EPA disagrees that a 50 year post-injection site care timeframe should be an absolute minimum. Rather, EPA believes, as some commenters suggest, that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-injection period based on site-specific data, pursuant torequirements 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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts as the commenter

suggests.

Commenter Name: Carl Carlsson Letter ID: 0131 Commenter Organization: SUEZ Energy Generation NA, LLC Comment ID: 21537

Comment: Post-injection Site Care SEGNA disagrees with EPA's proposal to lengthen the post-injection site monitoring period to 50 years versus the current 30 year standard. EPA has provided insufficient justification for such an extension, which will add significant costs and adversely impact sequestration projects and their ability to obtain financing. As it currently reads, the proposed rule has provisions for extending

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive for most Class VI wells. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket for the GS rule, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that alternative timeframes may be appropriate under limited, specific circumstances.

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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 isanticipated to occur, to accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA believes however, that to ensure USDW protection from endangerment, a default timeframe for post-injection site care will be necessary in all but a limited number of cases. This default 50 year post-injection site care timeframe represents a reasonable and protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

To the commenters who expressed concern about the cost of post-injection site care, EPA does not agree that post-injection site care timeframes longer than 30 years will be prohibitively expensive. In fact, EPA believes that post-injection site care monitoring will represent a relatively minor component of total project cost, and will provide an essential level of protection from endangerment for USDWs. A discussion of the costs attributed to monitoring technologies (used during injection and the post-injection site care timeframes) is available in the Technology and Cost Document for the GS rule, which is in the federal docket for this rulemaking. EPA believes that it is logical to make use of existing monitoring infrastructure at a GS site in order to ensure USDWs are not endangered.

Commenter Name: Dawn A. Thorne Letter ID:

0134 Commenter Organization: University of Utah Energy and Geoscience Institute on behalf of the Southwest Regional Partnership Comment

ID: 21659 Other EPA Comment Codes and Descriptions: 5260 2.8.2.3 Adjusting the post-injection timeframe (seeking comment)

Comment: - Section 146.93(b)(1) "The owner or operator shall continue to conduct monitoring as specified in the Director-approved post-injection site care and site closure plan for at least 50 years following the cessation of injection. At the Director's discretion, the monitoring will continue until the geologic sequestration project no longer poses an endangerment to USDWs."

Response/Discussion: The SWP recommends adopting a performance-based approach to the site care period so that each site is monitored for as long as necessary, but not longer than necessary in order to avoid an extra cost burden to regulators and owners/operators. The required site-specific "post-injection site care and site closure plan" appears sufficient to convey appropriate monitoring techniques and timescales to the EPA Director.

Response: EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 ondata collected during the PISC period, is appropriate to address the range of sites where GS is anticipated to occur, to accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA acknowledges the commenter’s support of the post-injection site care and site closure plan; the final GS regulation retains this provision.

Commenter Name: Robert Bessette Letter ID: 0139 Commenter Organization: Council of Industrial Boiler Owners (CIBO) Comment ID: 23085 Other EPA Comment Codes and Descriptions: 5400 2.9 Proposed Financial Responsibility and Long-Term Care Requirements

Comment: The 50-year post-closure period for continuing liability, from a practical perspective, is not workable. For example, some CIBO members generate power for a range of applications. It is difficult to imagine a generator taking on liability that would include the construction of a generating plant, the long term operation of that plant, and then the 50-year period after closing the well site. Compounding that difficulty is the possibility that the closure of the well does not coincide with the shut down of the power plant, potentially extending liability to 100 years or beyond, per the discretion of the Director.[FN7 73 Fed. Reg. 43519-20.] This raises the question of why a company would take on a 100-year liability that is essentially out of their control and not really a part of their business. The insurance issue is also a major

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive for most Class VI wells. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled"Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Areaof-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe.

However, EPA recognizes that there may be sites where the 50 year post injection site care timeframe may be either not appropriate or more burdensome than necessary based on site-specific conditions. 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA believes however, that to ensure USDW protection from endangerment, a default timeframe for post-injection site care will be necessary in all but a limited number of cases. This default 50 year post-injection site care timeframe represents a reasonable and protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

EPA also recognizes the concerns associated with ensuring financial responsibility for the long time frames over which post-injection site care will be conducted. EPA is developing guidance on financial responsibility to assist owners or operators in evaluating the requirements of §146.85 and to assist Directors in evaluating financial responsibility demonstrations. The guidance describes the types of financial mechanisms that operators may choose to use when evaluating the financial responsibility requirements for GS wells and it will also include a section on recommended approaches to estimate costs to support accurate financial responsibility demonstrations. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

As described above, the GS regulation applies to the owner or operator of the GS project, not the generator of the CO2.

Commenter Name: Dwight Lockwood, PE, QEP Letter ID: 0141 Commenter Organization: Global Energy, Inc. Comment ID: 23099 Other EPA Comment Codes and Descriptions: 3820 2.3.1 Well construction procedures

Comment: 1.Global strongly believes that excessive rigor in siting and well installation criteria, as well as post closure care and financial assurance for 50-years, would adversely impact acceptance of the program as well as the speed with which large (meaningful) scale carbon management develops.

We appreciate the challenge in balancing security of sequestration. However advocating proven and reliable applications based on use of oil & gas based technology should be adequate to ensure long-term safety and reliability.

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive or that it overstates the risk of GS. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water.

EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data,including data submitted by commenters, do not support a different default timeframe.

However, EPA recognizes that there may be sites where the 50 year post injection site care timeframe may be either not appropriate or more burdensome than necessary based on site-specific conditions. 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters¿ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

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

To the comment about the cost of post-injection site care, EPA does not agree that post-injection sitecare timeframes longer than 30 years will be prohibitively expensive. In fact, EPA believes that postinjection site care monitoring will represent a relatively minor component of total project cost, and will provide an essential level of protection from endangerment for USDWs. A discussion of the costs attributed to monitoring technologies (used during injection and the post-injection site care timeframes) is available in the Technology and Cost Document for the GS rule, which is in the federal docket for this rulemaking. EPA believes that it is logical to make use of existing monitoring infrastructure at a GS site in order to ensure USDWs are not endangered.

EPA also recognizes the concerns associated with ensuring financial responsibility for the long time frames over which post-injection site care will be conducted. EPA is developing guidance on financial responsibility to assist owners or operators in evaluating the requirements of §146.85 and to assist Directors in evaluating financial responsibility demonstrations. The guidance describes the types of financial mechanisms that operators may choose to use when evaluating the financial responsibility requirements for GS wells and it will also include a section on how to estimate costs to support accurate financial responsibility demonstrations. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

EPA recognizes that the oil and gas industry has decades of experience injecting CO2 for the purpose of enhanced recovery and that many of the wells used for ER may be suitable for GS. However, EPA believes that GS is sufficiently different from Class II ER operations to warrant the tailored construction requirements for Class VI wells at §146.86. For example, the volume of CO2 anticipated to be injected in Class VI wells is significantly greater than for Class II wells. Reservoir pressure conditions will be different, with Class VI injection operations involving large volumes ofCO2 and likely having higher pressures within their storage formations than Class II ER projects. Therefore, Class VI GS reservoir pressures will increase more in comparison to Class II ER during the injection phase of the GS project.

Commenter Name: Dwight Lockwood, PE, QEP Letter ID: 0141 Commenter Organization: Global Energy, Inc. Comment ID: 23100

Comment: Our view is that the likelihood of leakage from a GS well is relatively low, making 50-years of post closure monitoring wholly unreasonable.

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive or unreasonable. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled"Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Areaof-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that there may be sites where the 50 year post injection site care timeframe may be either not appropriate or more burdensome than necessary based on site-specific conditions. 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts, as the commenter

suggests.

Commenter Name: Dwight Lockwood, PE, QEP Letter ID: 0141 Commenter Organization: Global Energy, Inc. Comment ID: 23106

Comment: BUT, once that is done, the closure, post-closure and long-term care and monitoring (50-years of financial responsibility) with attendant financial responsibility, needs to be significantly relaxed and made much more reasonable.

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive for most Class VI wells. EPA proposed a default post-injection site care timeframe of 50 years based on areview 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"Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Areaof-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that there may be sites where the 50 year post injection site care timeframe may be either not appropriate or more burdensome than necessary based on site-specific conditions. 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts, as the commenter

suggests.

To the comment expressing concern about financial responsibility, EPA recognizes that there are challenges associated with ensuring funding for activities that will occur far in the future. However, the Agency believes that in order to protect USDWs from endangerment under the SDWA owners or operators must demonstrate under §146.85 that financial resources are available to plug the injection well and provide post-injection site care at the point in time that the first CO2 is injected.

Commenter Name: Christine Reimer Letter ID: 0142 Commenter Organization: National Ground Water Association Comment ID: 22614 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Proposed Rule: 146.93(b)(1)

Proposed revision: (1) The owner or operator shall continue to conduct monitoring as specified in the Director-approved post-injection site care and site closure plan for at least 30 years following the cessation of injection. At the Director's discretion, the monitoring will continue until the geologic sequestration project no longer poses an endangerment to USDWs.

Rationale: NGWA believes some number should be included. 30 years is a number used in other EPA programs. The next question was whether the burden should beplaced on the director to justify the longer number or on the operator to prove the site is stabilizing. It is suggested that the director be allowed to approve both a shorter or longer timeframe. With the next subsection, the burden is placed on the owner or operator to prove a shorter timeframe is acceptable, while allowing in this subsection the director to require monitoring beyond 30 years.

Proposed Rule: 146.93(b)(2)

Proposed revision: (2) If the owner or operator can demonstrate to the satisfaction of the Director that the geologic sequestration project no longer poses an endangerment to USDWs, the Director may approve an amendment to the post-injection site care and site closure plan to reduce the frequency of monitoring or may authorize site closure before the end of the 30-year period.

Rationale: Makes this subsection compatible with 30 year timeframe proposed by NGWA in 146.93(b)(1)

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive for most Class VI wells. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled"Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Areaof-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that there may be sites where the 50 year post injection site care timeframe may be either not appropriate or more burdensome than necessary based on site-specific conditions. 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts, as the commenter

suggests.Commenter Name: Patrick Nugent Letter ID: 0143 Commenter Organization: Texas Pipeline Association (TPA) Comment ID: 23131

Comment: 2. The proposed post-closure care period similarly spans an unrealistic and unnecessarily lengthy period of time. TPA disagrees with the imposition of a default 50-year post-injection site care period. As stated in the preceding

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive for most Class VI wells. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled"Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Areaof-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that there may be sites where the 50 year post injection site care timeframe may be either not appropriate or more burdensome than necessary based on site-specific conditions. 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts, as the commenter

suggests.

Commenter Name: Patrick Nugent Letter ID: 0143 Commenter Organization: Texas Pipeline Association (TPA) Comment ID: 23132

Comment: default 50-year post-injection site care period. As stated in the preceding comment, TPA urges the provision of flexible, site-specific requirements concerning the length of the post-injection site care period that coincide with the timeframe established for financial assurance. A blanket 50-year period

Response: As stated above, EPA disagrees that a post-injection site care timeframe of 50 years is excessive for most Class VI wells. However, EPA recognizes that there may be sites where the 50 year post injection site care timeframe may be either not appropriate or more burdensome than necessary based on site-specific conditions. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion toshorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA clarifies that owners or operators will need to demonstrate and maintain financial responsibility throughout the post-injection site care period, as required at 146.85. EPA recognizes that there are challenges associated with ensuring funding for activities that will occur far in the future. However, the Agency believes that in order to protect USDWs from endangerment under the SDWA operators must demonstrate under §146.85 that financial resources are available to plug the injection well and provide post-injection site care at the point in time that the first CO2 is injected.

Commenter Name: Patrick Nugent Letter ID: 0143 Commenter Organization: Texas Pipeline Association (TPA) Comment ID: 23133

Comment: the timeframe established for financial assurance. A blanket 50-year period would unduly discourage the use of geologic sequestration technology and reduce the number of willing participants in this program. Creation of a default period of 50 years would discourage investment in geologic sequestration technology, and it might also remove the incentive to locate and develop storage sites with the most favorable conditions. While EPA has provided a mechanism to reduce thistime frame on a case-by-case basis, the imposition of a default 50-year postinjection site care period by itself could deter many otherwise-willingparticipants. Accordingly, TPA recommends that EPA provide that the postResponse: EPA recognizes that there are challenges associated with assuring funding for activities that will occur far in the future. However, the Agency believes that operators must demonstrate that financial resources are available to plug the injection well and provide post-injection care at the point in time that the first CO2 is injected. EPA is developing guidance on financial responsibility to assist owners or operators in evaluating the requirements of §146.85 and to assist Directors in evaluating financial responsibility demonstrations. The guidance describes the types of financial mechanisms that operators may choose to use when evaluating the financial responsibility requirements for GS wells and it will also include a section on how to estimate costs to support accurate financial responsibility demonstrations. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

EPA adds that the purpose of the GS rule is not to incentivize the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

Commenter Name: Patrick Nugent Letter ID: 0143 Commenter Organization: Texas Pipeline Association (TPA) Comment ID: 23134

Comment: participants. Accordingly, TPA recommends that EPA provide that the postinjection site care period be established on a case-by-case basis as a part of the permitting process.

Response: EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISCtimeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments. EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; demonstrate the appropriateness of an alternative post-injection site care time frame; perform post-injection monitoring; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://www.epa.gov/safewater/wells_sequestration.html.

Commenter Name: William Kovacs Letter ID: 0148 Commenter Organization: U.S. Chamber of Commerce Comment ID: 21775

Comment: Consider that the proposed regulations contemplate a 50-year post-injection site care period. EPA’s reasoning for proposing this time frame is based on CO2 plume stabilization and protection of USDWs. EPA attempts to ameliorate the harshness of this time frame by stating that the UIC program director can modify it under certain circumstances. A better approach would be to allow the characteristics of each site determine the appropriate length of time for post-injection site care. This would prevent placing an unnecessary burden on those owners and operators who can show that their projects pose no threat to underground sources of drinking water in less than 50 years. In fact, the Chamber believes that appropriately sited CCS projects will need substantially less than 50 years, especially since research suggests that the risk profile of carbon dioxideinjection diminishes dramatically after a decade. Consequently, a lengthy postinjection care period would only serve to penalize those owners and operators who have taken steps to ensure proper site characterization.

As a result, the 50-year timeframe (if retained in the final rule) could have an inhibiting effect on insurers, investors, owners, and operators hoping to participate or invest in CCS activities.

Response: EPA agrees that some owners or operators will be able to demonstrate, in less than 50 years, that the pressure front and plume no longer pose a risk of endangerment to USDWs. However,based on studies, EPA believes that the 50 year default time frame is warranted in most cases based on additional review of research studies and reports and evaluation of public comments.

EPA believes that the best way to address all possibilities, while ensuring USDW protection from endangerment, is to set a 50 year default post-injection site care timeframe, with flexibility to: (1) allow the Director discretion to shorten or lengthen the PISC timeframe during the PISC period based on site-specific data, pursuant to requirements at §146.93(b); or (2) afford the Director discretion to allow a Class VI well owner or operator to demonstrate, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA does not believe that performing the demonstration before 50 years places an additional burden on these owners or operators. EPA clarifies that all operators will need to make this demonstration prior to the Director authorizing site closure; the difference is that some operators will be performing the demonstration earlier than others. As indicated by the commenter, ideally this demonstration will be part of an ongoing communication between the owner or operator and the UIC Director. If an owner or operator believes that an earlier demonstration will be burdensome, nothing in the GS rule requires them to make the demonstration prior to 50 years.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Larry Myer Letter ID:

0149 Commenter Organization: Lawrence Berkeley National Laboratory (Berkeley Lab) U.S. Department of Energy (DOE) Comment ID:

21797

Comment: A 50 year site care period is unnecessary and certainly impractical, and should be removed from the rule. It is unlikely that any owner/operator would, or could, provide assurance of its ability to take responsibility for the fate of the CO2 for 50 years. The risks associated with storage decrease rapidly after injection stops because of stabilization of the plume and dissipation of pressure, so the concept of linking post-injection site care to plume stabilization and pressure decrease is a good one. However, there is not sufficient knowledge at this time to quantify the required time. It is known that the time required for trapping processes, such as residual gas trapping, to immobilize the plume varies, so a single number for the site care period is not appropriate in any event. Given the current state of knowledge the rule should only state that the operator should demonstrate at closure that the plume has sufficiently stabilized and pressure decreased so as to not adversely impact the

USDW.

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive or unnecessary in most cases. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. Thisanalysis was included in an EPA-prepared background document that is available in the federal docket, titled Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water.

EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe.

EPA acknowledges that some studies indicate that trapping may begin in less than 50 years, as the commenter notes; however, this trapping may also take up to hundreds or thousands of years to be complete (IPCC, 2005). If this trapping is not complete, the potential for USDW endangerment still exists as CO2 may persist as a buoyant plume. EPA therefore believes that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

However, 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters¿ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA recognizes that there are challenges associated with assuring funding for activities that will occur far in the future. However, the Agency believes that in order to protect USDWs from endangerment under the SDWA, operators must demonstrate under §146.85 that financial resources are available to plug the injection well and provide post-injection site care at the point in time that the first CO2 is injected.

To the comment about the cost of post-injection site care, EPA does not agree that post-injection sitecare timeframes longer than 30 years will be prohibitively expensive. In fact, EPA believes that postinjection site care monitoring will represent a relatively minor component of total project cost, and will provide an essential level of protection from endangerment for USDWs. A discussion of the costs attributed to monitoring technologies (used during injection and the post-injection site care timeframes) is available in the Technology and Cost Document for the GS rule, which is in the federal docket for this rulemaking. EPA believes that it is logical to make use of existing monitoring infrastructure at a GS site in order to ensure USDWs are not endangered.Commenter Name: Brianne Metzger Letter ID: 0151 Commenter Organization: Spectra Energy Corp Comment ID: 21879

Comment: B. EPA’s Selection Of A 50-Year Post-Injection Site Care Period Is Arbitrary.

Spectra respectfully disagrees with EPA’s selection of a 50-year defaulttimeframe. As an alternative, Spectra recommends that EPA adopt a postinjection site care period of 30 years, similar to that used under RCRA for post-closure care for hazardous waste management units, 40 C.F.R. § 264.117, after which time all responsibility and liability would transfer to the State. The Director should be granted discretion to shorten this timeframe upon a showing that certain performance criteria are met that indicate USDWs are not at any recognizable risk, as discussed more fully above.[15]

A 30-year timeframe with Director discretion to shorten represents a better approach because it provides greater regulatory certainty for owners and operators, financiers, insurers, and other entities involved in CCS projects.[16] By contrast, a 50-year period that could be extended or reduced depending upon periodic assessments of the CO2 plume creates significant uncertainty, subjecting owners and operators to a post-injection site care period that either could end at any time after approximately 10 years or continue indefinitely up to and beyond 100 years. In practice, it is far easier for owners and operators to plan for a 10-year period with the possibility of an extension than a 50-year period that could fluctuate in either direction at the Agency’s discretion, as discussed more fully above.

Furthermore, with respect to USDW endangerment, projects with plumes likely to stabilize within 10 years represent the safest types of projects. A 50-year post-injection site care period would place an undue regulatory and financial burden on these safest of projects. Even with Director discretion to shorten this time period, owners and operators nevertheless would have to plan for a post-injection site care period of at least 50 years, significantly affecting the prospective costs of the project. By comparison, a 30-year timeframe with Director discretion to shorten would seem to favor the development of projects likely to have CO2 plumes that stabilize early and avoid an unnecessarily long post-injection site care period. Similarly, the potential of reduced regulatory and financial burdens that would accompany a 30-year period with Director discretion to shorten creates incentives for project owners and operators to develop and manage projects in a way that maximizes the likelihood of the CO2 plume stabilizing early.

For the foregoing reasons, the EPA’s 50-year post-injection site care period is arbitrary and risks adding to the barriers and obstacles that are currently preventing commercial-scale deployment of CCS. A 30-year period with Director discretion to shorten would provide the same level of protection for USDWs while minimizing regulatory and financial burdens on site owners and operators.

C. After The Post-Injection Site Care Period And Determination That The CO2 Plume Has Stabilized, Owners And Operators Should Be Released From All Site Care Responsibility, Such As Monitoring And Verification Requirements, And Any

Financial Assurance Instruments Should Be Released.The GS Rule provides that owners or operators must demonstrate and maintain financial responsibility for certain corrective actions described in 40 C.F.R. § 146.84 of the Rule. The GS Rule releases owners and operators from financial responsibility requirements at the conclusion of the post-injection site care period once the Director has determined that the injected fluid no longer poses a threat of endangerment to USDWs.

Spectra supports EPA’s approach to releasing owners and operators from anyfurther financial responsibility requirement at the conclusion of the postinjection site care period and upon a determination by the Director that the CO2 plume poses no further risk to USDWs. Establishing firm and discrete limits for post-injection obligations on behalf of owners and operators is essential to the viability of commercial-scale CCS. Open-ended requirements that could continue indefinitely, even after a showing that the CO2 plume has stabilized, would impose an unreasonable burden and likely inhibit project development.

Spectra also proposes that owners and operators be released from any monitoring or verification requirements at the conclusion of the post-injection site-care period and upon a showing that the CO2 plume has stabilized. This approach would have the effect of dovetailing the responsibilities of owners and operators in the post-injection site care period with the transfer of long-term liability to the State. As discussed more fully below, Spectra believes that the eventual transfer of long-term liability to the State should encompass all potential liability - both anticipated site care responsibilities, such as monitoring and verification requirements, as well as any unanticipated migration of the CO2 plume and potential endangerment of USDWs.

15 Modeling results indicate that a CO2 plume will stabilize within 10 to 100 years after the cessation of injection. See Computational Modeling of Underground Injection of Carbon Dioxide for Determine of Are-of-Review and Potential Risk to Underground Sources of Drinking Water, U.S. EPA (2008).

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive in most cases or arbitrary. EPA proposed a default timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA background document available in the federal docket, "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that alternative timeframes may be appropriate under limited, specific circumstances, which is why EPA is providing the Director discretion to approve an alternative post-injection site care timeframe as long as the owner or operator can meet the requirements provided at §146.93(c).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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA agrees that owners or operators should not be subject to additional monitoring or financial responsibility requirements following site closure. The final rule releases owners or operators from these requirements once closure has occurred.

Commenter Name: Jeff Moseley Letter ID: 0155 Commenter Organization: Greater Houston Partnership (GHP) Comment ID: 21260 Other EPA Comment Codes and Descriptions: 5260 2.8.2.3 Adjusting the post-injection timeframe (seeking comment)

Comment: 7. Revise the standard for determining site closure. Criteria should be performance based and a function of site-specific geologic and other risk criteria, rather than being dependent on a 50-year-period or any other fixed period of time; and,

Response: EPA agrees with commenters that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final GS regulation 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA believes however, that to ensure USDW protection from endangerment, a default timeframe for post-injection site care is necessary in most cases. A 50 year post-injection site care timeframe represents a reasonable and protective monitoring period for most GS projects based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public

comments.Commenter Name: James Dooley Letter ID: 0156 Commenter Organization: Joint Global Change Research Institute, Pacific Northwest National Laboratory Comment ID:

22634

Comment: It is Appropriate to Utilize both a Fixed Time Frame and Performance Standard for Establishing the Period of Post Closure Monitoring

Given humanity’s knowledge about GS deployed at the scale of millions of tons per year for decades at a given injection field is quite slim, the USEPA’s proposal of a fixed time frame in conjunction with a performance standard appears to be an appropriate balance between discharging its responsibilities to protect human health and the environment and not placing overly burdensome, unneeded requirements on prospective GS owner / operators (pp 43519-43520). The 50 year time frame will allow owners / operators to budget for post site closure within the bounds of what is currently known. The performance standard is an assurance to the public that a site will not be released until it has reached a certain point of stability. Given where humanity is with GS, the USEPA should be commended for crafting this compromise and should retain this language in subsequent versions of this draft Class VI rule.

Response: EPA acknowledges the commenter’s support and has implemented a combination fixed timeframe and performance standard approach for post-injection site care monitoring for Class VI wells in the final GS rule. The PISC requirements in the final GS rule, as specified in §146.93(b), incorporate a combination of a fixed timeframe and a performance standard approach. EPA believes that a default PISC timeframe of 50 years, with Director's discretion to shorten or lengthen this timeframe, combined with a site-specific Director’s discretion to create an alternative PISC time frame, ensures that USDWs are protected. 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: James Childress Letter ID: 0158 Commenter Organization: Gasification Technologies Council (GTC) Comment ID: 23763

Comment: Concern #8: The owner or operator shall continue to conduct monitoring as specified in the Director- approved post-injection site care and site closure plan for at least 50 years following the cessation of injection. At the Director's discretion, the monitoring will continue until the geologic sequestration project no longer poses an endangerment to USDWs. (Ref: page 43519, Sec. 8. Post-Injection Site Care Timeframe)The time required for post-injection site management should not be arbitrarily set at 50 years. Criteria for defining the time for post-injection management should be performance based and site specific. The choice of 50 years is arbitrary and does not take into account the data and knowledge and modeling verification obtained over a preceding operating and injection period of years and likely decades. The maximum post-injection monitoring period should be defined on reasonable but quantitative, performance-based metrics - for example, that the validated model predicts that 95% of the plume is or will be trapped and that a sensitivity analysis predicts a comfortable margin of safety to minimize approach to any USDWs, thus preventing potential endangerment.

Response: EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final GS regulation 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA believes however, that to ensure USDW protection from endangerment, a default timeframe for post-injection site care is necessary in most cases. A 50 year post-injection site care timeframe represents a reasonable and protective monitoring period for most GS sites based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public

comments.

EPA disagrees that a post-injection site care timeframe of 50 years is excessive in most cases or arbitrary. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled"Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Areaof-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that alternative timeframes may be appropriate under limited, specific circumstances, which is why EPA is providing the Director discretion to approve an alternative post-injection site care timeframe as long as the owner or operator can meet the requirements provided at §146.93(c).Commenter Name: Sandi Tabor Letter ID: 0162 Commenter Organization: Lignite Energy Council (LEC) Comment ID: 21304 Other EPA Comment Codes and Descriptions: 5260 2.8.2.3 Adjusting the post-injection timeframe (seeking comment)

Comment: 5. Combination of Fixed Timeframe and Performance Standard -EPA is seeking comments on the imposition of a 50-year post-injection site care (PISC) standard as a default timeframe with state UIC directors having discretion to adjust the default time period. We urge EPA to remove all reference to default PISC periods and instead require directors to base post-injection site care on site and project specific characteristics. By so doing the goal of supporting the commercialization of CCS technology is better served.

Response: EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final GS regulation 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA believes however, that to ensure USDW protection from endangerment, a default timeframe for post-injection site care is necessary in most cases. A 50 year post-injection site care timeframe represents a reasonable and protective monitoring period for most GS projects based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public

comments.

Commenter Name: Michael Mudd Letter ID: 0167 Commenter Organization: FutureGen Alliance (FGIA) Comment ID: 22463

Comment: Post-Injection Monitoring Period p. 43540-43541

The owner or operator shall continue to conduct monitoring as specified in the Director-approved post-injection site care and site closure plan for at least 50 years following the cessation of injection.If the owner or operator can demonstrate to the satisfaction of the Director before 50 years, based on monitoring and other site-specific data, that the geologic sequestration project no longer poses an endangerment to USDWs.

Comment: The basis for the 50 year minimum period is not clear. The minimum period should be tied to both risk and project specific information. Although there is the possibility that post-injection monitoring period can be reduced given sufficient data, this approach adds significant uncertainty to both the project schedule and cost. It appears unlike that an owner or operator will beable to know with certainty during the planning stage for GS what the postinjection monitoring period will be. The end result is for owners and operators to assume the entire 50 year period, which will have an adverse effect on the cost, schedule and feasibility of the project. A time period of 10 years seems more reasonable, but would need to be confirmed by risk and project specific

information.

Response: EPA clarifies that it proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water."

EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments.

While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that alternative timeframes may be appropriate under limited, specific circumstances, which is why EPA is providing the Director discretion to approve an alternative post-injection site care timeframe as long as the owner or operator can meet the requirements provided at §146.93(c). 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA believes that a 50 year post-injection site care timeframe represents a reasonable and protective monitoring period and available data, including data submitted by commenters, do not support a different default timeframe. Furthermore, EPA believes that a 50-year default post-injection site care timeframe, as required at §146.93(b)(1), is not overly burdensome, does not exaggerate the risks associated with GS, is consistent with other environmental programs, and sufficiently protects USDWs from endangerment.

Commenter Name: Michael J. Miller Letter ID: 0168 Commenter Organization: Electric Power Research Institute (EPRI) Comment ID: 22510

Comment: Preamble, page 43519-43520: "EPA requests comment on the proposed use of a tentative 50-year fixed timeframe that could be modified at the Director’s discretion based on monitoring and modeling data."EPRI COMMENT #17: EPA’s 50-year fixed timeframe described in the preamble appears to be based on professional judgment interpreting a limited number of citations and/or modeling scenarios. We question the need for defining a fixed timeframe of any length because it runs counter to the EPA’s implied intent to close sites based on the owner/operator’s ability to meet specific performance criteria defined in §146.93(b). (See EPRI comment #2, #13, and #18 regarding these criteria (i.e., front tracking and stability)).

Response: EPA disagrees with this comment. In determining the post-injection site care-timeframe for the proposed regulation, EPA reviewed industry reports, existing environmental programs, and initial GS research studies. EPA provided a synthesis of pertinent results from GS modeling studies in the preamble to the proposed regulation. Further explanation of this analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water." Based on review of these studies, modeling results indicate that the CO2 plume stabilization may occur on the timeframe of 10-100 years after the cessation of injection. EPA believes that a 50-year default post-injection site care timeframe is a reasonable midpoint for most GS projects and available data, including data submitted by commenters, do not support a different default timeframe, and has retained this in the final regulation.

EPA agrees that some owners or operators will be able to demonstrate, in less than 50 years, that the pressure front and plume no longer pose a risk of endangerment to USDWs. However, based on studies, EPA believes that the 50 year default time frame is warranted in most cases based on additional review of research studies and reports and evaluation of public comments. EPA believes that the best way to address all possibilities, while ensuring USDW protection from endangerment, is to set a 50 year default post-injection site care timeframe, with flexibility to: (1) allow the Director discretion to shorten or lengthen the PISC timeframe during the PISC period based on site-specific data, pursuant to requirements at §146.93(b); or (2) afford the Director discretion to allow a Class VI well owner or operator to demonstrate, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Theresa Pugh Letter ID: 0169 Commenter Organization: American Public Power Association Comment ID: 23368

Comment: Well Plugging and Post-Injection Site Care -- Pg. 41

APPA believes that the Proposal’s suggested fifty-year default fixed timeframe for the post-injection site care period is arbitrary and will serve to discourage Owners or Operators of CO2 GS sites from seeking to develop innovative ways tosafely close wells in a shorter time period. While there is no single time period that can apply across the board, APPA suggests that 10 years or until the plume

is determined to be stable is sufficient.

Response: EPA disagrees that a post-injection site care timeframe of 50 years is arbitrary. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that alternative timeframes may be appropriate under limited, specific circumstances. For this reason, the Class VI 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a 50 year post-injection site care timeframe represents a reasonable and protective monitoring period and available data, including data submitted by commenters, do not support a different default timeframe. Furthermore, EPA believes that a 50-year default post-injection site care timeframe, as required at §146.93(b)(1), is not overly burdensome, does not exaggerate the risks associated with GS, is consistent with other environmental programs, and sufficiently protects USDWs from endangerment.

EPA adds that the purpose of the GS rule is not to incentivize the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

Commenter Name: Theresa Pugh Letter ID: 0169 Commenter Organization: American Public Power Association Comment ID: 23420

Comment: Well Plugging and Post-Injection Site Care

APPA acknowledges that for some potential power plant owner/operators that the Proposal’s suggested fifty-year default fixed timeframe for the post-injection site care period is arbitrary and will serve to discourage Owners or Operators of CO2 GS sites from seeking to develop innovative ways to safely close wells in a shorter time period. Id. at 43519. EPA acknowledges in the Preamble to the Proposal that it is likely "that the actual time for CO2 plume stabilization...will be very site specific, being influenced by geologic factors such as formation permeability, geochemistry, and the degree of capillary trapping." Id. (emphasis added). EPA then goes on to note that the studies usedfor their preliminary analysis suggest that the length of time required before plume stabilization ranges from ten to one hundred years after cessation of injection - quite a significant range. Id, emphasis added. In the same discussion, EPA reviews a range of suggested time periods, acknowledging that even a ten-year timeframe is suggested by some studies.

APPA understands that a ten-year site closure period may be insufficient in some cases; there is no single time period that would apply to every CO2 GS site across the board. Because of the greatly varied geologic characteristics, APPA believes a post closure period of 10 years or until the plume is determined to be stable. Stability is to be defined by the state Director that he/she does not believe that it can harm USDWs. Given the concerns by the water utilities, APPA defers to AWWA for their expertise in this matter.

Response: As noted above, EPA disagrees that a post-injection site care timeframe of 50 years is arbitrary. In determining the post-injection site care-timeframe for the proposed regulation, EPA reviewed industry reports, existing environmental programs, and initial GS research studies. EPA provided a synthesis of pertinent results from GS modeling studies in the preamble to the proposed regulation. Further explanation of this analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water." Based on review of these studies, modeling results indicate that the CO2 plume stabilization may occur on the timeframe of 10-100 years after the cessation of injection. 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that alternative timeframes may be appropriate under limited, specific circumstances. For this reason, the Class VI 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a 50 year post-injection site care timeframe represents a reasonable and protective monitoring period and available data, including data submitted by commenters, do not support a different default timeframe. Furthermore, EPA believes that a 50-year default post-injection site care timeframe, as required at §146.93(b)(1), is not overly burdensome, does not exaggerate the risks associated with GS, is consistent with other environmental programs, and sufficiently protects USDWs from endangerment.

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24122

Comment: 50-year Default Post-Injection Site Care

EPA should also reconsider its proposed 50-year default period for post-injection site care. EPA offers no rationale for this arbitrarily-selected period of 50 years. Establishing a fixed and unusually long time period, evenwith the Director discretion provided, may create a significant barrier for operators considering entry into CCS operations. Criteria for determining the period for post-injection site care should be performance-based and a function of the site specific characteristics of a project such as project size, geologic factors, and relative risk of the project. Clear guidelines also need to be established regarding when operators have met the performance standards that determine site closure. Specifically, the standard that the project no longer poses an endangerment to USDWs needs to be defined using reasonable risk-based

criteria.

A related concern is that EPA is proposing imposition of financial assurance requirements for activities that may occur more than 50 years in the future, with requirements to be satisfied at the time of permitting. EPA should carefully examine whether at this time, or at the time of permitting, the cost of such activities can be accurately estimated and assumed to be relatively accurate going forward. If not, financial assurance is no better than a guess, and serves only to introduce significant uncertainties into project economics and project finance.

Response: EPA disagrees that a post-injection site care timeframe of 50 years is arbitrary. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that alternative timeframes may be appropriate under limited, specific circumstances. For this reason, the Class VI 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a 50 year post-injection site care timeframe represents a reasonable and protective monitoring period and available data, including data submitted by commenters, do not support a different default timeframe. Furthermore, EPA believes that a 50-year default post-injection site care timeframe, as required at §146.93(b)(1), is not overly burdensome, does not exaggerate the risks associated with GS, is consistent with other environmental programs, and sufficiently protects USDWs from endangerment.

EPA adds that the purpose of the GS rule is not to incentivize the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.EPA recognizes that there are challenges associated with assuring funding for activities that will occur far in the future. However, the Agency believes that in order to protect USDWs from endangerment under the SDWA, operators must demonstrate under §146.85 that financial resources are available to plug the injection well and provide post-injection site care at the point in time that the first CO2 is injected.

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24206 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.93(b)

API Comments: (b) The owner or operator shall monitor the site following the cessation of injection to show the position of the carbon dioxide plume and pressure front and demonstrate that USDWs are not being endangered. (1) The owner or operator shall continue to conduct monitoring as specified in the Director-approved post-injection site care and site closure plan, for at least 50 years following the cessation of injection. At the Director‘s discretion, the monitoring will continue until the geologic sequestration project no longer poses an endangerment to USDWs. UNTIL CLOSURE IS AUTHORIZED PURSUANT TO §146.93(B)(3). (2) If The owner or operator can request and demonstrate to the satisfaction

of the Director before 50 years, based on monitoring and other site-specific data, that the geologic sequestration project no longer poses an endangerment to USDWs, the Director may approve an amendment to THAT the post-injection site care and site closure plan SHOULD BE REVISED to reduce the frequency of monitoring or may authorize site closure before the end of the 50-year period.

Rationale: API, along with the MSDG, believes there are three problems with the closure standard in proposed section 146.93(b). First, the presumption that monitoring should continue for 50 years is unnecessary and counterproductive. A straight performance standard is preferable to this or any other fixed time period because it provides a clearer standard and an incentive to maximize the understanding of site and project performance and as such is more protective of USDWs. Second, the proposal requires a showing that the CO2 plume has "stabilized", which is undefined. Cessation of plume movement is not necessarily essential to show that a project poses no threat of endangerment to USDWs-plumes that are still moving may, nonetheless, remain contained. Instead, it is more protective to show that the plume is not expected to encounter a leakage pathway. Third, the required showing that "no additional monitoring is needed" does not provide guidance regarding how an operator is to show that no additional monitoring is needed. The proposal below provides specific guidance on what the operator must show.

API, in concert with the MSDG, recommends the standard in the proposed alternative language for section 146.93(b) below because it sets forth detailed criteria, all of which must be satisfied, to demonstrate that the site does notpose an endangerment to USDWs. The specific criteria listed in our proposal will serve to provide the Director with the requisite information to make the appropriate determination. The advantage of this approach is that it establishes clear criteria that an operator must demonstrate before obtaining site closure based upon particular site characteristics and is, therefore, reasonably applicable to any storage site as opposed to a standard based upon a fixedduration. Furthermore, it is more stringent than a purely discretionary approach because it establishes specific criteria that must be shown before site closure may be granted. We believe this language, which is an extension of work done by the World Resources Institute and the Ground Water Protection Council, avoids the noted shortcomings and provides stronger protection for USDWs.

Response: EPA disagrees with the suggested changes. As noted above, EPA disagrees that a postinjection site care timeframe of 50 years is excessive for most Class VI wells. EPA believes that a 50-year default post-injection site care timeframe, as required at §146.93(b)(1), is not overly burdensome, does not exaggerate the risks associated with GS, is consistent with other environmental programs, and sufficiently protects USDWs from endangerment.

EPA acknowledges the concerns of some commenters that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the Class VI 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a 50 year post-injection site care timeframe represents a reasonable and protective monitoring period and available data, including data submitted by commenters, do not support a different default timeframe. Furthermore, EPA believes that a 50-year default post-injection site care timeframe, as required at §146.93(b)(1), is not overly burdensome, does not exaggerate the risks associated with GS, is consistent with other environmental programs, and sufficiently protects USDWs from endangerment.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of 146.92 and 146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans required under 146.92 and 146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells, perform post-injection monitoring, demonstrate the appropriateness of an alternative post-injection site care time frame, demonstrate non-endangerment, and perform site closure activities. This guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24209 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5260 2.8.2.3 Adjusting the post-injection timeframe (seeking comment)

Comment: Rule Provision: 146.93(b)(4)API Comments: (4) If such a demonstration cannot be made (i.e., if the carbon dioxide plume and pressure front have not stabilized) after the 50-year period,the owner or operator must submit to the Director a plan to continue postinjection site care.

Rationale: No longer necessary given changes above.

Response: As described above, EPA believes that to ensure USDW protection from endangerment, a default timeframe for post-injection site care is necessary in most cases. A 50-year post-injection site care timeframe represents a reasonable and protective monitoring period for most GS projects based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments. However, EPA recognizes that alternative timeframes may be appropriate under limited, specific circumstances. For this reason, the Class VI 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24255

Comment: Rule Provisions: 73 FR 43519-20, 146.93(b) EPA Preamble Question: 38. EPA is proposing using a combination of fixed timeframe and a performance standard as described above. EPA is tentatively proposing a post-injection site care (monitoring) period of 50 years with Director’s discretion to change that period to lengthen or shorten the 50 year period if appropriate. EPA requests comment on the proposed use of a tentative 50 year fixed timeframe that could be modified at the Director’s discretion based on monitoring and modeling data. EPA Notice 43519.

API Response: API strongly objects to the use of a 50-year default monitoring period. EPA offers no rationale for this arbitrarily-selected period of 50 years. Establishing a fixed and unusually long time period may create a significant barrier for operators considering entry into CCS operations. Criteria for determining the period for post-injection site care should be Performance-based and a function of the site specific characteristics of a project such as project size, geologic factors, and relative risk of the project. (API offers such criteria in our edits to §146.93(b)(3).)

Clear guidelines also need to be established regarding when operators have met the performance standards that determine site closure. Specifically, the standard that the project no longer poses an endangerment to USDWs needs to be defined using reasonable risk-based criteria.

Response: EPA disagrees that the post-injection monitoring period is arbitrary. In determining the post-injection site care-timeframe for the proposed regulation, EPA reviewed industry reports, existing environmental programs, and initial GS research studies. EPA provided a synthesis of pertinent results from GS modeling studies in the preamble to the proposed regulation. Furtherexplanation of this analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water." Based on review of these studies, modeling results indicate that the CO2 plume stabilization may occur on the timeframe of 10-100 years after the cessation of injection. EPA believes that a 50- year default post-injection site care timeframe is a reasonable midpoint for most GS projects and available data, including data submitted by commenters, do not support a different default timeframe, and has retained this in the final regulation. However, EPA recognizes that there may be sites where the 50 year post injection site care timeframe may be either not appropriate or more burdensome than necessary based on site-specific conditions. 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of 146.92 and 146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans required under 146.92 and 146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells, perform post-injection monitoring, demonstrate the appropriateness of an alternative post-injection site care time frame, demonstrate non-endangerment, and perform site closure activities. This guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: James Rower Letter ID: 0173 Commenter Organization: Utility Solid Waste Activities Group (USWAG) Comment ID: 23504

Comment: 12. Well Plugging and Post-Injection Site Care

USWAG believes that the Proposal's suggested fifty-year default fixed timeframe for the post-injection site care period is arbitrary and will serve to discourage Owners or Operators of CO2 GS sites from seeking to develop innovative ways to safely close wells in a shorter time period. Id. at 43519. EPA acknowledges that it is likely "that the actual time for CO2 plume stabilization ... will be very site specific, being influenced by geologic factors such as formation permeability, geochemistry, and the degree of capillary trapping." Id. (emphasis added). In fact, EPA observes that the studies used for their preliminary analysis suggest that the length of time required before plume stabilization ranges from ten to one hundred years aftercessation of injection - quite a significant range. Id.

While a ten-year site closure period may be insufficient in some cases, it is clear that there is no single time period that would apply to every CO2 GS site across the board. Because of the greatly varied characteristics and needs of different CO2 GS projects, application of a performance-based standard which is highly site-specific, rather than any default time period, is the most appropriate approach to the postinjection site care requirements. While theProposal would give the Director discretion to decrease or increase the postinjection site care and closure period, the inclusion of a fifty-year default timeframe is likely to discourage Owners or Operators from working to develop technology that would facilitate safe and quick site closure; the fifty-year default may even have a chilling effect on the Program as a whole, discouraging would-be Owners or Operators from undertaking a CO2 GS project that could impose requirements decades into the future even when unnecessary. In contrast, by tailoring requirements to a given site, a performance-based standard would encourage the development of methods and technology that would achieve long-term protection of USDWs with well closure after a shorter period of time.

Response: EPA agrees with commenters that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final GS regulation 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments. EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA adds that the purpose of the GS rule is not to incentivize the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

Commenter Name: Pamela Faggert Letter ID: 0175 Commenter Organization: Dominion Comment ID: 23525

Comment: 4. Post-injection Site Care

The proposed rule's post injection site care (PISC) period of 50 years, subjectto Director discretion, is arbitrary and unnecessary. The PISC should be set based on a site-specific performance-based approach.

The PISC period should be based not on an arbitrary default but on a site specific performance-based approach.

Response: EPA disagrees that a post-injection site care timeframe of 50 years is arbitrary. In determining the post-injection site care-timeframe for the proposed regulation, EPA reviewed industry reports, existing environmental programs, and initial GS research studies. EPA provided a synthesis of pertinent results from GS modeling studies in the preamble to the proposed regulation. Further explanation of this analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water." Based on review of these studies, modeling results indicate that the CO2 plume stabilization may occur on the timeframe of 10-100 years after the cessation of injection. EPA believes that a 50-year default post-injection site care timeframe is a reasonable midpoint for most GS projects and available data, including data submitted by commenters, do not support a different default timeframe, and has retained this in the final regulation. To address concerns that, in some situations, it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs, the GS regulation 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 post-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 onsubstantial data, that an alternative PISC timeframe may be appropriate if it ensures nonendangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments. EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Kenneth Nemeth Letter ID: 0176 Commenter Organization: Southern States Energy Board Comment ID: 23545

Comment: casing should not be required. No specific timeframe for post closure care should be specified, and it should be based on performance standards demonstrated by the owner/operator. Corrosion monitoring is unnecessary, as it

Response: EPA agrees with commenters that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final GS regulation offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion toshorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments. EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Quinlan J. Shea Letter ID: 0177 Commenter Organization: Edison Electric Institute Comment ID: 23554

Comment: Another general area of concern discussed in our comments involves the proposed rule‘s provisions for closure and post-injection site care (PISC). In particular, EEI is concerned with the proposed imposition of a PISC period spanning, as a matter of default, 50 years after cessation of injection. Establishing a default time period for PISC, in particular one as lengthy as 50 years, is unnecessary and undesirable. The dual goals of protecting USDW and supporting the commercialization of CCS technology are far better served through a site-specific, performance-based approach.

Response: EPA agrees with commenters that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final GS regulation 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments. EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilizesite-specific data, and be based on pressure monitoring and USDW impacts. EPA adds that the purpose of the GS rule is not to incentivize the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

Commenter Name: Quinlan J. Shea Letter ID: 0177 Commenter Organization: Edison Electric Institute Comment ID: 23566 Other EPA Comment Codes and Descriptions: 5430 2.9.1 Comments on proposed financial responsibility requirements (40 CFR 146.85)

Comment: iii. Appropriate risk management approaches. The Agency should avoid development of risk management approaches that discourage CCS deployment or create additional uncertainty, and should seek where possible to bring greater certainty to the long-term obligations and risks associated with a GS project. For example, requiring financial assurance for potential liabilities more than 50 years in the future may deter and even prevent investment in CCS projects. Post-injection monitoring and financial assurance requirements are both important, but should not undermine the goals of the regulations, particularly when potential risks decrease substantially after injection is complete.

Response: EPA adds that the purpose of the GS rule is not to incentivize the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

EPA disagrees that the requirements for financial responsibility are overly stringent. The goal of financial responsibility is to ensure that financial resources are available to prevent the endangerment of USDWs from improper plugging, remediation, and management of wells in the event that the owner or operator experiences financial difficulties throughout the life of the project.

EPA believes that minimum financial responsibility requirements are necessary to hold well owners or operators accountable for the safe operation and closure of the well to avoid endangerment of USDWs while avoiding expense and risk to the public.

Regarding the need for financial assurance for a 50-year post-injection period, EPA believes that to ensure USDW protection from endangerment, a default timeframe for post-injection site care is necessary. A 50 year post-injection site care timeframe represents a reasonable and protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

EPA agrees with commenters that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final GS regulation 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care timeframe of 50 years, with flexibility to adjustthe 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Quinlan J. Shea Letter ID: 0177 Commenter Organization: Edison Electric Institute Comment ID: 23592

Comment: E. Closure and Post-Injection Site Care

The fourth general area of concern discussed in these comments involves the proposed rules‘ provisions for closure and post-injection site care (PISC). In particular, EEI is concerned with the proposed imposition of a PISC period spanning, as a matter of default, 50 years after cessation of injection. The proposed rules would vest discretion in the UIC program director to adjust the 50-year default time period upward or downward, with monitoring to continue "until the geologic sequestration project no longer poses an endangerment to

USDWs."

Establishing a default time period for PISC, in particular a default time period as lengthy as 50 years, is unnecessary and undesirable, and the dual goals of protecting USDW and supporting the commercialization of CCS technology are far better served through a site-specific, performance-based approach. To EEI offers the following supporting points:

- A default time period is unnecessary: As noted above, the proposed ruleswould, in conjunction with establishing the 50-year default period for postinjection activities, vest discretion in the UIC program director to shorten or lengthen the PISC period based on the characteristics of a particular project. As discussed further below, a PISC period based on site- and project-specific characteristics ably serves to meet the dual goals of EPA‘s rulemaking effort; given the proposed performance-based, discretionary aspect of the PISC-period determination, a default overlay period is unnecessary. Further, from the perspective of offering protection to USDW, such a default period offers no additional protection above and beyond what a performance-based standard will

offer.

- A default time period is unduly burdensome for operators: Establishing a default time period also risks placing unnecessary regulatory burdens on owners and operators who can clearly establish from the outset that no threat to USDW will be posed within a shorter time frame than whatever default may be

established.

- A 50-year default time period is unprecedented under the UIC program and unwarranted for CO2: Even assuming that imposition of a default period were appropriate, the unique characteristics of CO2 do not justify imposition of such a lengthy default PISC period for GS projects. EEI and its members believe that appropriately sited projects could demonstrate the absence of endangerment toUSDW in substantially less than 50 years; indeed, data suggest the risk profile of injected CO2 drops rapidly just 10 years after cessation.[FN7] Further, imposing requirements on CO2 storage projects that are far beyond those currently in place even for injection of hazardous wastes is unnecessary and will only engender public misperceptions regarding the safety of such projects.

- A default time period may not appropriately incentivize proper site characterization: Proper siting is the key to ensuring safety and effectiveness of storage projects, and the rules should work to incentivize, rather than discourage, the utmost due diligence in the siting process. While EPA‘s proposal would provide for the exercise of discretion to lengthen or shorten the PISC period, placing the burden of proof on permittees that a departure from the default is justified fails to recognize the enormous efforts associated with proper site characterization.

- A 50-year default period may introduce unnecessary financial uncertainty: As currently proposed, the rules would require operators to obtain, as a baseline and at the time of permitting, financial assurance running through the default 50-year PISC period. Thus, operators would be likely required to assure activities that would not occur for more than 50 years, with discretion vested n the UIC program director to extend that time period--and thus the required period for demonstrating financial assurance. The end result could be an obligation to provide financial assurance for activities running through at least 70 years in the future (according to EPA‘s assumption of a 20-year injection period), or more. Further, in actuality, the PISC period could prove to be considerably shorter, rendering the initial burden placed upon the operator unnecessary. EEI urges the Agency to consider carefully, in connection with each proposed requirement that is tied to a financial assurance requirement, the ability for operators to quantify the activities being assured at the time of permitting--the basis of any financial assurance mechanism--as well as the potential burden and expense associated with the proposal. Given the ongoing credit crisis, an unjustifiably lengthy PISC period may make obtaining the necessary financial assurance impossible, stunting or stopping commercial development of CCS.

Instead of a default time period--particularly one as lengthy as 50 years--EEI urges EPA to implement a performance-based approach that considers the circumstances of a particular project, bounded by appropriate parameters for its application. As discussed throughout these comments, EEI also encourages the Agency to establish clear parameters for such a performance-based approach--and in particular a clear set of guidelines for demonstrating that the injectate has "stabilized" and for meeting the non-endangerment standard.

[FN7] S. Benson, Carbon Dioxide Capture and Storage: Research Pathways, Progress and Potential, GCEP Annual Symposium, October 2007: http://pangea.stanford.edu/research/bensonlab/presentations/index.html.

Response: EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final GS regulation offers owners or operators flexibility regarding the duration of thePISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments. EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA adds that the purpose of the GS rule is not to incentivize the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

EPA does not believe that performing the demonstration before 50 years places an additional burden on these owners or operators. EPA clarifies that all operators will need to make this demonstration prior to the Director authorizing site closure; the difference is that some operators will be performing the demonstration earlier than others. As indicated by the commenters, ideally this demonstration will be part of an ongoing communication between the owner or operator and the UIC Director. If an owner or operator believes that an earlier demonstration will be burdensome, they are not required to

make the demonstration.

EPA recognizes that there are challenges associated with assuring funding for activities that will occur far in the future. However, the Agency believes that in order to protect USDWs from endangerment under the SDWA operators must demonstrate under §146.85 that financial resources are available to plug the injection well and provide post-injection site care at the point in time that the first CO2 is injected.

EPA also recognizes the concerns associated with assuring financial responsibility for the long time frames over which post-injection site care will be conducted. EPA is developing guidance on financial responsibility to assist owners or operators in evaluating the requirements of §146.85 and to assist Directors in evaluating financial responsibility demonstrations. The guidance describes the types of financial mechanisms that operators may choose to use when evaluating the financial responsibility requirements for GS wells and it will also include a section on how to estimate costs to support accurate financial responsibility demonstrations. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Frederick R. Eames Letter ID: 0178 Commenter Organization: CCS Alliance Comment ID: 23814 Other EPA Comment Codes and Descriptions: 5400 2.9 Proposed Financial Responsibility and Long-Term Care Requirements

Comment: A. FIFTY YEAR TIME FRAME FOR POST-CLOSURE SITE CARERESPONSIBILITY

The Proposed Rule states that the timeframe over which CO2 will be trapped depends on the properties of the receiving formation and the injected CO2 stream. Currently available information does not provide a complete understanding of the time required to stabilize geologically sequestered CO2 under various conditions: however, some experience does exist and has led some to develop extrapolative estimates for related geologies. Some believe that in a significant number of cases, a 10 to 30 year timeframe will be sufficient to determine that the remaining pressure in plugged wells will not lift fluid to overlying strata. Any uncertainty in characterizing post-injection site care timeframes for GS, while challenging, could be dealt with through a maximum time period, performance standards, and Director discretion.

The CCS Alliance recommends establishing a maximum 30-year post-operation site care and financial responsibility period. The Director would have discretion to shorten -- but not to lengthen -- this period if the owner or operator meets certain enumerated performance standards based on available data on pressure. fluid movement, mineralization and/or dissolution reactions to show whether movement of the plume and pressure front have ceased. Once the thirty-year period is reached -- or shorter if the performance standards are met -- a government backstop would be triggered, thereby ensuring that a risk management mechanism is in place beyond the responsibility of the owner or operator. Investment requires assumptions about the amount of capital required and for how long it is required. If either the maximum amount of capital or the term cannot be established, investment is deterred. Further, because most capital available will not commit for terms longer than thirty years, and the duration for which it is available is generally inversely proportional to risk. Thus, long term capital for even low frequency but high severity risks is difficult to obtain. To assure public funds can be leveraged with private investment to assure widespread deployment of this climate risk mitigating technology, a balance of risk and reward is required in the policy development that underpins this UIC regulation.

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive for most Class VI wells. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled"Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Areaof-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that alternative timeframes may be appropriate under limited, specific circumstances. For this reason, the Class VI 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 timeframeduring the PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a 50 year post-injection site care timeframe represents a reasonable and protective monitoring period and available data, including data submitted by commenters, do not support a different default timeframe. Furthermore, EPA believes that a 50-year default post-injection site care timeframe, as required at §146.93(b)(1), is not overly burdensome, does not exaggerate the risks associated with GS, is consistent with other environmental programs, and sufficiently protects USDWs from endangerment.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA disagrees that the requirements on financial responsibility are overly stringent. The goal of financial responsibility is to ensure that financial resources are available to prevent the endangerment of USDWs from improper plugging, remediation, and management of wells in the event that the owner or operator experiences financial difficulties. EPA adds that the purpose of the GS rule is not to encourage the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

Commenter Name: Frederick R. Eames Letter ID: 0178 Commenter Organization: CCS Alliance Comment ID: 23822

Comment: VI. SPECIAL FOCUS: FINANCIAL ASSURANCE AND LONG TERM SITE

RESPONSIBILITY

Financial assurance and long-term site responsibility are an area of special focus for the CCS Alliance. As noted above. we believe the proposed 50-year time frame for site care responsibility after a GS facility has ceased operation is too long, and there should be a known end point fur site care responsibility up front. In addition to these concerns, we offer the following comments on

financial assurance.

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive for most Class VI wells. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled""Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Areaof-Review and Potential Risk to Underground Sources of Drinking Water."" EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, includingdata submitted by commenters, do not support a different default timeframe.

However, EPA recognizes that alternative timeframes may be appropriate under limited, specific circumstances. For this reason, the Class VI 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a 50 year post-injection site care timeframe represents a reasonable and protective monitoring period and available data, including data submitted by commenters, do not support a different default timeframe. Furthermore, EPA believes that a 50-year default post-injection site care timeframe, as required at §146.93(b)(1), is not overly burdensome, does not exaggerate the risks associated with GS, is consistent with other environmental programs, and sufficiently protects USDWs from endangerment.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters¿ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA recognizes that there are challenges associated with assuring funding for activities that will occur far in the future. However, the Agency believes that in order to protect USDWs from endangerment under the SDWA operators must demonstrate under §146.85 that financial resources are available to plug the injection well and provide post-injection site care at the point in time that the first CO2 is injected.

EPA also recognizes the concerns associated with assuring financial responsibility for the long time frames over which post-injection site care will be conducted. EPA is developing guidance on financial responsibility to assist owners or operators in evaluating the requirements of §146.85 and to assist Directors in evaluating financial responsibility demonstrations. The guidance describes the types of financial mechanisms that operators may choose to use when evaluating the financial responsibility requirements for GS wells and it will also include a section on how to estimate costs to support accurate financial responsibility demonstrations. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Frederick R. Eames Letter ID: 0178 Commenter Organization: CCS Alliance Comment ID: 23841

Comment: C. POST-INJECTION SITE CARE PERIOD AND FINANCIAL RESPONSIBILITY

The Agency has proposed a post-injection site care and financial responsibility period of 50 years, which can be shortened or lengthened based on the discretion of the Director. The CCS Alliance agrees, in part, with this suggested use of a combination of a fixed timeframe and performance standard. However, aspreviously explained, the CCS Alliance recommends establishing a maximum 30-year post-closure period and providing the Director with discretion to shorten -- but not lengthen -- this period if the owner or operator meets certain enumerated performance standards based on available data on pressure, fluid movement. mineralization and/or dissolution reactions to show whether the plume and pressure front have stabilized.

CCS is an activity the Agency hopes to encourage. A 50-year post-injection site care default is longer than any period of post-operation site care of which the Alliance is aware. The potential for threats to USDWs will have been considered prior to site operation. and will have been reconsidered throughout the life of the project, not only by the regulator, but by the owner or operator, entities providing financial support, and providers of risk management products and services. Continuance of injection will have depended upon an assessment of the potential for threats to USDWs at numerous points during the site's operation.

EPA suggests that when owners or operators show that "models predicting CO2 movement are consistent with monitoring results and that there are no longer risks of endangerment to USDWs. they could request that the Director authorize site closure."[FN43] The CCS Alliance suggests that if EPA considers the relationship between modeling results and actual plume movement in determining the continuation of post- injection site responsibility, the standard need not be "consistency." Models may predict a range of outcomes. Notwithstanding falling outside the modeled range, actual plume movement may be safe. including

when there are no USDWs in the area. The Alliance recommends that the rule authorize Directors to end the post-injection site responsibility period prior to the 30-year period, taking into account their ability reasonably to predict

the likelihood of minimal or no risk to USDWs.

[FN43] Proposed Rule. 73 Fed. Reg. at p. 43491 (emphasis added).

Response: EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the Class VI 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA agrees that proper site characterization is a critical component of ensuring that USDWs are protected. However, EPA disagrees that this is a substitute for post-injection site care. EPA believes that extensive post-injection monitoring is necessary to protect USDWs from endangerment.Commenter Name: Robert J. Finley Letter ID: 0180 Commenter Organization: Illinois State Geological Survey Comment ID: 23641 Other EPA Comment Codes and Descriptions: 5260 2.8.2.3 Adjusting the post-injection timeframe (seeking comment)

Comment: 146.93

(b)(1)

Monitoring for 50 years following cessation of injection has no particular basis in research and should not be the rule against which an operator should be required to seek an exception as provided for in (b)(2). Rather, the regulations should require a maximum post-injection site monitoring plan for, for example, 15 years to include comprehensive reservoir assessment, modeling, and simulation based on data collection during injection and then specifically at closure, followed by five years after closure, 10 years after closure, and 15 years after closure. These suggested intervals have a basis in the changes seen in the 4D seismic as Sleipner that show demonstrable geophysical responses based on injection and plume development over about a 10 year period. Other groups have suggested 10 years of total post-closure monitoring, thus other repeat periods for site surveys may be suggested and should be considered. For the example suggested here, the data taken at closure forms a baseline, such as plume extent based on a 3D seismic survey or other geophysical techniques, and three subsequent surveys at five-year intervals could document plume migration and would serve to validate reservoir simulation. If the total of four such example surveys (closure, +5, +10, and +15) and/or other appropriate monitoring techniques, and the reservoir modeling and simulation, demonstrate a consistent and predictable understanding of subsurface behavior that does not endanger USDWs going forward, then the operator should be deemed to have fulfilled site closure responsibilities. To repeat, there is no basis for the suggested 50 years of monitoring.

Response: EPA disagrees that there is no basis for the 50 year timeframe. In determining the postinjection site care-timeframe for the proposed regulation, EPA reviewed industry reports, existing environmental programs, and initial GS research studies. EPA provided a synthesis of pertinent results from GS modeling studies in the preamble to the proposed regulation. Further explanation of this analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water." Based on review of these studies, modeling results indicate that the CO2 plume stabilization may occur on the timeframe of 10-100 years after the cessation of injection. EPA believes that a 50-year default post-injection site care timeframe is a reasonable midpoint for most GS projects and available data, including data submitted by commenters, do not support a different default timeframe, and has retained this in the final regulation.

However, EPA recognizes that there may be sites where the 50 year post injection site care timeframe may be either not appropriate or more burdensome than necessary based on site-specific conditions. For this reason, the Class VI 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 PISC 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 todemonstrate, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA clarifies that, throughout the post-injection site care timeframe, owners and operators must submit monitoring data results to the Director. At these times (or at 5 year intervals), the owner or operator may wish to discuss whether performing a non-endangerment demonstration may be appropriate. This scenario affords many of the suggestions the commenter offers.

Commenter Name: Thomas Curtis Letter ID: 0181 Commenter Organization: American Water Works Association (AWWA) Comment ID: 23705

Comment: Category: Post-Injection

EPA Request for Comment: EPA requests comment on the proposed use of a tentative 50-year fixed timeframe that could be modified at the Director’s discretion based on monitoring and modeling data. EPA Notice 43519.

EPA is requesting comments on the proposed requirements for well plugging, postinjection site care, and site closure, including the proposed requirements for the post-injection time period. EPA Notice 43520.

AWWA Response: AWWA recommends that the time period for post-injection site care be set at a minimum of 50-years and that the Director not be given any discretion to shorten this time period. After this 50-year period, the operator must continue to monitor until such time as they can demonstrate that the plume has stabilized and that it does not present any potential danger to USDWs or other potential sources of drinking water. This requirement is not overly prescriptive or burdensome given the information available on the long-term behavior of carbon dioxide plumes. This time period is necessary to monitor the site for changes that may occur over a longer amount of time, such as gradual leakages, fault movement, or sudden seismic shifts. After this time period, the owner/operator may apply to the Director for a modification or termination of the monitoring requirements.

Response: EPA agrees that a 50 year post-injection site care timeframe represents a reasonable and protective post-injection site monitoring period for most GS projects and available data, including data submitted by commenters, do not support a different default timeframe. EPA bases this on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments. Furthermore, EPA believes that a 50-year default post-injection site care timeframe is not overly burdensome, does not exaggerate the risks associated with GS, is consistent with other environmental programs, and sufficiently protects USDWs from endangerment. For this reason, the final GS regulation retains the 50 year post-injection site care timeframe, as specified in §146.93(b)(1).However, EPA disagrees that a 50 year post-injection site care timeframe should be an absolute minimum. Rather, EPA believes, as some commenters suggest, that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Thomas Curtis Letter ID: 0181 Commenter Organization: American Water Works Association (AWWA) Comment ID: 24372 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Part 146.93(b)(2) AWWA recommends that there should be a minimum 50 year postinjection monitoring period for all carbon sequestration projects. This time period is necessary to monitor the site for changes that may occur over a longer amount of time, such as gradual leakages, or sudden seismic shifts. After this time period, the owner/operator may apply to the Director for a modification or termination of the monitoring requirements. AWWA recommends revising this part

to read:

If, after the 50-year post-injection monitoring period, the owner or operator can demonstrate to the satisfaction of the Director, based on monitoring and other site-specific data, that the geologic sequestration project no longer poses an endangerment to USDWs, the Director may approve an amendment to the post-injection site care and site closure plan to reduce the frequency of monitoring or may authorize site closure before the end of the 50-year period.

Response: As described above, EPA agrees with commenters that a 50 year post-injection site care timeframe represents a reasonable and protective post-injection site monitoring period in most cases and available data, including data submitted by commenters, do not support a different default timeframe. EPA bases this on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments. Furthermore, EPA believes that a 50- year default post-injection site care timeframe is not overly burdensome, does not exaggerate the risks associated with GS, is consistent with other environmental programs, and sufficiently protectsUSDWs from endangerment. For this reason, the final GS regulation retains the 50 year postinjection site care timeframe, as specified in §146.93(b)(1).However, EPA disagrees that a 50 year post-injection site care timeframe should be an absolute minimum. Rather, EPA believes, as some commenters suggest, that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Wendy Jacobs Letter ID: 0183 Commenter Organization: Harvard Law School Environmental Law and Policy

Center Comment ID:

25144 Other EPA Comment Codes and Descriptions: 5260 2.8.2.3 Adjusting the post-injection timeframe (seeking comment)

Comment: C. EPA Should Clarify the Site Closure Standard

EPA is proposing a "combination of fixed timeframe and performance standard" approach to site closure. 73 Fed. Reg. at 43,519. Under the proposal, the owner or operator would be required to undertake "post-injection site care" following the permanent cessation of injection activities at the site, which would include "submit[ting] periodic reports providing monitoring results and updated modeling results as appropriate until a demonstration of nonendangerment to USDWs can be made." Id. at 43,520. Specifically, the owner or operator would need to demonstrate "that the carbon dioxide plume and pressure front have stabilized and that no additional monitoring is needed to assure that the geologic sequestration project does not pose an endangerment to USDWs." Id. at 43,541 (proposed 40 C.F.R. § 146.93(b)(3)). Once the owners or operators provide documentation to show that this standard has been met, they can request that the Director authorize site closure. Id. at 43,520. By default, the "post-injection site care" period would last for 50 years following cessation of injection activities; however, the Director would have discretion to shorten the 50-year timeframe if the owner or operator could demonstrate "stabilization/no endangerment" in less than 50 years, or conversely, to lengthen the timeframe if the owner or operator failed to make a demonstration within 50 years. Id.As a general matter, ELPC and ETIP agree that a combination of a fixed timeframe and a performance standard strikes a good balance and is preferable to relying upon only one of those elements. Adherence to an exacting performance standard alone, defined before commercial deployment of CCS technologies, could preclude owner or operators from taking advantage of best practices as they are developed. Adherence to a single fixed timeframe could allow owner or operators to abandon well sites even as monitoring data indicates a threat to a USDW. Requiring the owner or operator to meet a flexible performance standard throughout a baseline period of 50 years would ensure that post-injection site care, including monitoring and verification, would continue as long as necessary to prevent endangerment of USDWs and require post-injection monitoring and modeling even if the data appear to show "stabilization" within a short timeframe. This would be especially prudent in the short term, given lack of data and experience with large-scale, long-term GS projects.

Response: EPA agrees and has implemented a combination fixed timeframe and performance standard approach for post-injection site care monitoring for Class VI wells. EPA believes that a default PISC timeframe of 50 years, with Director's discretion to shorten or lengthen this timeframe, combined with a site-specific Director’s discretion to create an alternative PISC time frame, ensures that USDWs are protected. 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Bradley J. Field Letter ID: 0186 Commenter Organization: New York State Dept. of Environmental Conservation

Div. of Mineral Resources Comment ID:

25211

Comment: 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 modified at the Director’s discretion based on monitoring and modeling data.

NYSDEC-DMN Response: Given that current injection and reservoir 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 may be more appropriate to allow GSprojects to move forward. It would be better to prescribe a shorter period with discretion to go longer, rather than vice versa, as such would better facilitate project planning. Regardless, it is critical that the Director have the discretion to increase or decrease the period based on the specifics of a particular project.

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive for most Class VI wells. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled"Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Areaof-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that alternative timeframes may be appropriate under limited, specific circumstances.

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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

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

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Bradley J. Field Letter ID: 0186 Commenter Organization: New York State Dept. of Environmental Conservation

Div. of Mineral Resources Comment ID:

25212

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 that current injection and reservoir 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 may be more appropriate to allow GS projects to move forward. It would be better to prescribe a shorter period with discretion to go longer, rather than vice versa, as such would better facilitate project planning. Regardless, it is critical that the Director have the discretion to increase or decrease the period based on the specifics of a particular project.

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive for most Class VI wells. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled"Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Areaof-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that alternative timeframes may be appropriate under limited, specific circumstances.

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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

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

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Daniel Plath Letter ID: 0188 Commenter Organization: NiSource, Inc. Comment ID: 25240

Comment: 7. Post Site Care and Site Closure (146.93)A fixed time period of 50 years of post injection site monitoring before site closure can occur is highly speculative as noted by EPA in the Preamble. NiSource believes that the appropriate method is a performance-based standard which is site specific. While we recognize the potential flexibility granted in 146.92(b)(2) for the Director to permit a shorter time period if supported by the data, the reality is that when a potential operator is evaluating development of a site, the 50 year monitoring period will be used. This may have the chilling effect of discouraging would-be developers from undertaking a GS project in the first place. On the other hand, if while collecting site evaluation data a potential operator has the ability to model the potential closure period based on the expected performance of the reservoir, then they are likely to be more willing to undertake the project if the initial data indicates a more reasonable site closure time frame. This would also encourage the development of new technologies to more efficiently manage the closure period.

Based on many of the other discussions taking place on the GS topic, such as the Interstate Oil and Gas Compact Commission's recommendations, this is a topic that may likely have a legislative solution as opposed to a regulatory solution. The primary outcome of EPA's inclusion of this feature in the Final Rule has the potential of encumbering efforts to develop GS as a viable means of long-term storage of CO2.

Response: EPA agrees with commenters that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

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

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA adds that the purpose of the GS rule is not to incentivize the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24497 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5220 2.8.2.1 Post-injection monitoring activities

Comment: Rule Provision: 146.93(b)

Proposed CCS Group Recommendations: (b) The owner or operator shall monitor the site following the cessation of injection to show the position of the carbon dioxide plume and pressure front and demonstrate that USDWs are not being endangered.

(1) The owner or operator shall continue to conduct monitoring as specified in the Director-approved post-injection site care and site closure plan, UNTIL CLOSURE IS AUTHORIZED PURSUANT TO 146.93(B)(3).

Basis for CCS Group Comments: EPA should also reconsider its proposed 50-year default period for post-injection site care. EPA offers no rationale for this arbitrarily-selected period of 50 years. Establishing a fixed and unusually long time period may create a significant barrier for operators considering entry into CCS operations. Criteria for determining the period for post-injection site care should be performance-based and a function of the site specific characteristics of a project such as project size, geologic factors, and relative risk of the project. Such criteria are provided in our edits to §146.93(b)(3).

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive in most cases or arbitrary. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled"Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Areaof-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA acknowledges there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of researchstudies, industry reports, and existing environmental programs, and evaluation of public comments. EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA adds that the purpose of the GS rule is not to incentivize the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24498 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5220 2.8.2.1 Post-injection monitoring activities

Comment: Rule Provision: 146.93(b)(2)

Proposed CCS Group Recommendations: (2) If the owner or operator can request and

demonstrate to the satisfaction of the Director before 50 years, based on monitoring and other site-specific data, that the geologic sequestration project no longer poses an endangerment to USDWs, the Director may approve an amendment

to THAT the post-injection site care and site closure plan SHOULD BE REVISED to reduce the frequency of monitoring, THE DIRECTOR SHALL APPROVE THE REDUCTION. or may authorize site closure before the end of the 50-year period.

Basis for CCS Group Comments: See rationale stated above for eliminating 50-year period.

Response: As described above, EPA disagrees that a post-injection site care timeframe of 50 years is excessive in most cases or arbitrary, and retains the default 50-year post-injection site care

timeframe in the final rule.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24500 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5260 2.8.2.3 Adjusting the post-injection timeframe (seeking comment)

Comment: Rule Provision: 146.93(b)(4)

Proposed CCS Group Recommendations: (4) If such a demonstration cannot be made (i.e., if the carbon dioxide plume and pressure front have not stabilized) after the 50-year period, the owner or operator must submit to the Director a plan to continue post-injection site care.

Basis for CCS Group Comments: No longer necessary with 50-year period deletion.

Response: As described above, EPA believes that to ensure USDW protection from endangerment, adefault timeframe for post-injection site care is necessary in most cases. A 50-year post-injection site care timeframe represents a reasonable and protective monitoring period for most GS sites based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24547

Comment: Rule Provisions or Federal Register Cite: 73 FR 43519-20, 146.93(b) EPA Preamble Question: 38. EPA is proposing using a combination of fixed timeframe and a performance standard as described above. EPA is tentatively proposing a post-injection site care (monitoring) period of 50 years with Director’s discretion to change that period to lengthen or shorten the 50 year period if appropriate. EPA requests comment on the proposed use of a tentative 50 year fixed timeframe that could be modified at the Director’s discretion based on monitoring and modeling data. EPA Notice 43519.

CSC Response: We believe there are three problems with the closure standard in proposed section 146.93(b). First, the presumption that monitoring should continue for 50 years is unnecessary and counterproductive. A straight performance standard is preferable to this or any other fixed time period because it provides a clearer standard and an incentive to maximize the understanding of site and project performance and as such is more protective of USDWs. Second, the proposal requires a showing that the CO2 plume has "stabilized", which is undefined. Cessation of plume movement is not necessarily essential to show that a project poses no threat of endangerment to USDWs-plumes that are still moving may, nonetheless, remain contained. Instead, it is more protective to show that the plume is not expected to encounter a leakage pathway. Third, the required showing that "no additional monitoring is needed" does not provide guidance regarding how an operator is to show that no additional monitoring is needed. The proposal below provides specific guidance on what the operator must show.

We recommend the standard in the proposed alternative language for section 146.93(b) because it sets forth detailed criteria, all of which must be satisfied, to demonstrate that the site does not pose an endangerment to USDWs. The specific criteria listed in our proposal will serve to provide the Director with the requisite information to make the appropriate determination. The advantage of this approach is that it establishes clear criteria that an operator must demonstrate before obtaining site closure based upon particular site characteristics and is, therefore, reasonably applicable to any storage site as opposed to a standard based upon a fixed-duration. Furthermore, it is more stringent than a purely discretionary approach because it establishes specific criteria that must be shown before site closure may be granted. We believe this language, which is an extension of work done by the World Resources Institute and the Ground Water Protection Council, avoids the noted shortcomings and provides stronger protection for USDWs.

This is the same recommendation as presented by the multi-stakeholder group, in which the Carbon Sequestration Council participatedResponse: EPA disagrees with the suggested changes. As noted above, EPA disagrees that a postinjection site care timeframe of 50 years is excessive for most Class VI wells. EPA acknowledges the concerns of some commenters that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

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

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of 146.92 and 146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans required under 146.92 and 146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells, perform post-injection monitoring, demonstrate the appropriateness of an alternative post-injection site care time frame, demonstrate non-endangerment, and perform site closure activities. This guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Kyle Isakower Letter ID: 0191 Commenter Organization: American Petroleum Institute Comment ID: 23880

Comment: Closure Standard

We believe there are three problems with the closure standard in proposed section 146.93(b). First, the presumption that monitoring should continue for 50 years is unnecessary and counterproductive. A straight performance standard is preferable to this or any other fixed time period because it provides a clearer standard and an incentive to maximize the understanding of site and project performance and as such is more protective of USDWs. Second, the proposal

Response: The post-injection site care requirements in the final GS rule, §146.93(b), incorporate a combination of a 50-year default post-injection site care timeframe, in conjunction with a performance standard, for Class VI wells. The GS rule offers owners or operators flexibilityregarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

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

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA expects that the Director will consider the types of information the commenter describes in determining whether the plume and pressure front no longer pose a risk of endangerment to USDWs and post-injection site care monitoring may be discontinued.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate the appropriateness of an alternative post-injection site care time frame; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

EPA adds that the purpose of the GS rule is not to incentivize the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

Commenter Name: Jeff W. Sheets Letter ID: 0192 Commenter Organization: ConocoPhillips Comment ID: 23901

Comment: Closure Standard

ConocoPhillips believes there are three problems with the closure standard in proposed section 146.93(b). First, the presumption that monitoring should continue for 50 years is unnecessary and potentially counterproductive. A straight performance standard is preferable to this or any other fixed time period because it provides a clearer standard and an incentive to maximize the understanding of site and project performance and as such is more protective of USDWs. Second, the proposal requires demonstration that the CO2 plume hasResponse: The post-injection site care requirements in the final GS rule, §146.93(b), incorporate a combination of a 50-year default post-injection site care timeframe, in conjunction with a performance standard, for Class VI wells. 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

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

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA expects that the Director will consider the types of information the commenter describes in determining whether the plume and pressure front no longer pose a risk of endangerment to USDWs and post-injection site care monitoring may be discontinued.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate the appropriateness of an alternative post-injection site care time frame; demonstrate non endangerment; and perform site closure activities. This guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

EPA adds that the purpose of the GS rule is not to incentivize the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

Commenter Name: John R. Baza Letter ID: 0193 Commenter Organization: Utah Division of Oil, Gas, and Mining Comment ID: 23917 Other EPA Comment Codes and Descriptions: 5260 2.8.2.3 Adjusting the post-injection timeframe (seeking comment)

Comment: Post Site Care Responsibility

EPAs proposed rule sets the post-injection care period at 50 years. This may be modified if it can be demonstrated that the plume has stabilized and the pressure has dissipated. Setting a 50-year period may be unnecessarily long. TheDivision’s recommendation is that a shorter period be prescribed and then the regulating agency may have the discretion to set a longer post-injection care period if the specifics of a project indicate such a need.

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive for most Class VI wells. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled"Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Areaof-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA acknowledges there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, a default timeframe for post-injection site care will be necessary in all but a limited number of cases. This default 50 year post-injection site care timeframe represents a reasonable and protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments. EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Andy Horn Letter ID: 0196 Commenter Organization: Colorado Ground Water Association (CGWA) Comment ID: 23933 Other EPA Comment Codes and Descriptions: 5260 2.8.2.3 Adjusting the post-injection timeframe (seeking comment)

Comment: Issue 11. The post-closure operator liability timeframe of 50 years should be considered a minimum and should be extended in the event monitoring and modeling data indicate potential failure may require mitigation.

Response: EPA agrees with commenters that a 50 year post-injection site care timeframe represents a reasonable and protective monitoring period for most cases. EPA bases this on a review ofresearch studies, industry reports, existing environmental programs, and evaluation of public comments. Furthermore, EPA believes that a 50-year default post-injection site care timeframe is not overly burdensome, does not exaggerate the risks associated with GS, is consistent with other environmental programs, and sufficiently protects USDWs from endangerment. For this reason, the final GS regulation retains the 50 year post-injection site care timeframe, as specified in §146.93(b)(1).

However, EPA disagrees that a 50-year post-injection site care timeframe should be an absolute minimum. Rather, EPA recognizes that there may be sites where the 50 year post injection site care timeframe may be either not appropriate or more burdensome than necessary based on site-specific conditions. 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). Such a demonstration will be site-specific, and based on pressure monitoring and USDW impacts. EPA clarifies that in no cases will site closure be authorized until the owner or operator demonstrates to the satisfaction of the Director that the site no longer poses a risk of endangerment to USDWs.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Paul Pike Letter ID: 0198 Commenter Organization: Ameren Corporation Comment ID: 23953

Comment: POST-INJECTION SITE CARE

The imposition of a fifty-year default fixed timeframe for the post-injection site care period will discourage Ameren from seeking to develop CO2 GS wells. We agree with EPA that it is likely "that the actual time for CO2 plume stabilization ... will be very site specific, being influenced by geologic factors such as formation permeability, geochemistry, and the degree of capillary trapping." 73 Fed. Reg. at 43519. (emphasis added). We believe that there is no single time period that would apply to every CO2 GS site across the board, due to the greatly varied characteristics and needs of different CO2 GSprojects, application of a performance-based standard which is highly sitespecific, rather than a default time period, is an appropriate approach to the post-injection site care requirements. Tailoring requirements to a given site, a performance-based standard could also encourage the development of methods and technology that would achieve long-term protection of USDWs.

Response: EPA agrees with commenters that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk ofendangerment 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

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

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA adds that the purpose of the GS rule is not to incentivize the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24608

Comment: Rule Provisions: 73 FR 43519-20, 146.93(b) EPA Rule Issue: 38. EPA is proposing using a combination of fixed timeframe anda performance standard as described above. EPA is tentatively proposing a postinjection site care (monitoring) period of 50 years with Director’s discretion to change that period to lengthen or shorten the 50 year period if appropriate. EPA requests comment on the proposed use of a tentative 50 year fixed timeframe that could be modified at the Director’s discretion based on monitoring and modeling data. EPA Notice 43519.

Anadarko Petroleum Corporation (APC) Response: APC strongly objects to the use of a 50-year default monitoring period. EPA offers no rationale for this arbitrarily-selected period of 50 years. Establishing a fixed and unusually long time period may create a significant barrier for operators considering entry into CCS operations. Criteria for determining the period for post-injection site care should be performancebased and a function of the site specific characteristics of a project such as project size, geologic factors, and relative risk of the project. (APC offers such criteria in the edits to §146.93(b)(3).)

Clear guidelines also need to be established regarding when operators have met the performance standards that determine site closure. Specifically, the standard that the project no longer poses an endangerment to USDWs needs to bedefined using reasonable risk-based criteria.

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive in most cases or arbitrary. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled"Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Areaof-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that alternative timeframes may be appropriate under limited, specific circumstances.

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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

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

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells, perform post-injection monitoring, demonstrate the appropriateness of an alternative post-injection site care time frame, demonstrate non-endangerment, and perform site closure activities.Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and postinjection site care and site closure plans under §146.92 and §146.93. This guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24719Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5220 2.8.2.1 Post-injection monitoring activities

Comment: Rule Provision: 146.93(b)(1)

Anadarko Petroleum Corporation (APC) Comments: (1) The owner or operator shallcontinue to conduct monitoring as specified in the Director-approved postinjection site care and site closure plan, for at least 50 years following the cessation of injection. At the Director’s discretion, the monitoring will continue until the geologic sequestration project no longer poses an endangerment to USDWs. PURSUANT TO THE PERFORMANCE BASED CRITERIA

DESCRIBED IN §146.93(B)(3).

Rationale: EPA should also reconsider its proposed 50- year default period for post-injection site care. EPA offers no rationale for this arbitrarily selected period of 50 years. Establishing a fixed and unusually long time period may create a significant barrier for operators considering entry into CCS operations. Criteria for determining the period for postinjection site care should be performance based and a function of the site specific characteristics of a project such as project size, geologic factors, and relative risk of the project. APC offers such criteria in our edits to §146.93(b)(3).

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive in most cases or arbitrary. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled"Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Areaof-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that alternative timeframes may be appropriate under limited, specific circumstances.

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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilizesite-specific data, and be based on pressure monitoring and USDW impacts.

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

EPA adds that the purpose of the GS rule is not to incentivize the use of GS. Rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24720 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5220 2.8.2.1 Post-injection monitoring activities

Comment: Rule Provision: 146.93(b)(2)

Anadarko Petroleum Corporation (APC) Comments: (2) If the owner or operator can request and demonstrate to the satisfaction of the Director before 50 years, based on monitoring and other site-specific data, that the geologic sequestration project no longer poses an endangerment to USDWs, the Director may approve an amendment to THAT the post-injection site care and site closure plan SHOULD BE REVISED to reduce the frequency of monitoring. or may authorize site closure before the end of the 50-year period.

Rationale: (See above)

Response: As described above, EPA disagrees that a post-injection site care timeframe of 50 years is excessive in most cases or arbitrary, and retains the default 50-year post-injection site care

timeframe in the final rule.

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24722 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5260 2.8.2.3 Adjusting the post-injection timeframe (seeking comment)

Comment: Rule Provision: 146.93(b)(4)

Anadarko Petroleum Corporation (APC) Comments: (4) If such a demonstration cannot be made (i.e., if the carbon dioxide plume and pressure front have not stabilized) after the 50-year period, the owner or operator must submit to the Director a plan to continue post-injection site care.

Rationale: No longer necessary given changes above.

Response: As described above, EPA disagrees that a post-injection site care timeframe of 50 years is excessive in most cases or arbitrary, and retains the default 50-year post-injection site care

timeframe in the final rule. .Commenter Name: Chris M. Hobson Letter ID: 0201 Commenter Organization: Southern Company Comment ID: 22175 Other EPA Comment Codes and Descriptions: 5300 2.8.3 Site closure activities (40 CFR 146.93)

Comment: Post-Injection Site Care and Closure

Southern Company opposes a default fifty-year timeframe - or any fixed default length of time - for the post-injection site care period. ¡d. at 43519. A default post-injection site care period is of little value given the widely varied characteristics of future CO2 GS sites, and the significant discrepancy between the appropriate post-injection site care period for various Class VI wells. As EPA itself recognizes, the actual time required for plume stabilization following cessation of injection will be "very site specific." ¡d. A site-specific determination, based on conditions at a particular Class VI well, will be necessary in the case of every CO2 GS project under the UIC Program. The Final Rule should define a performance-based standard for site closure and leave the site-specific analysis and determination of appropriate post-injection site care period to the Director. Potential Owners or Operators are likely to shy away from undertaking a CO2 GS project if the Program's requirements may extend decades into the future even when those requirements are no longer necessary. A performance-based standard allowing for site-specific closure period determinations will avoid the chilling effect that any default fixed timeframe for post-injection site care and closure will have on participation and investment in C02 GS projects. Moreover, the site-specific approach will ensure that an appropriate post-injection site care period is identified to meet the needs of each individual Class VI operation.

Response: EPA agrees with commenters that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

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

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.Commenter Name: John Corra Letter ID: 0205 Commenter Organization: Wyoming Department of Environmental Quality (DEQ) Comment ID:

22198 Other EPA Comment Codes and Descriptions: 5260 2.8.2.3 Adjusting the post-injection timeframe (seeking comment)

Comment: 4.Requiring a fixed timeframe post-injection site care (monitoring) period of 50

years:

a.We recommend that a performance standard be applied to determine the period of post-injection site care -that post-injection site care continues until the plume is stabilized and will not endanger USDWs.

b. We recommend that the Director should be provided discretion to shorten or lengthen the proposed post-injection site care period of 50 years accordingly.

Response: EPA agrees with commenters that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

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

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Michael Stroben Letter ID: 0209 Commenter Organization: Duke Energy Comment ID: 22687

Comment: FINANCIAL RESPONSIBIILITY AND RISK MANAGEMENT APPROACH

EPA is proposing a default time period of fifty years for post-injection activities. Although the proposed rules would gives the Director the discretion to adjust the default time period, such a provision will create tremendous uncertainty and impose unnecessary regulatory burden and cost on regulators. Protecting USDW and commercializing GS technology for CO2 would be better servedby focusing on site characterization and a site-specific performance based approach to well closure that takes into consideration the particular needs of each CO2 sequestration site. In addition, a fifty-year default period could actually discourage owners or operators from undertaking proper site characterization and working to develop innovative ways to safety close wells in a shorter time period. It would also introduce significant financial uncertainty that could make actually obtaining necessary financial assurances Difficult if not impossible.

Response: EPA agrees with commenters that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

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

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. To the comment expressing concern about financial responsibility, EPA recognizes that there are challenges associated with assuring funding for activities that will occur far in the future. However, the Agency believes that in order to protect USDWs from endangerment under the SDWA operators must demonstrate under §146.85 that financial resources are available to plug the injection well and provide post-injection site care at the point in time that the first CO2 is injected.

EPA adds that the purpose of the GS rule is not to incentivize the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

EPA agrees that proper site characterization is a critical component of ensuring that USDWs are protected. However, EPA disagrees that this is a substitute for post-injection site care. EPA believes that extensive post-injection monitoring is necessary to protect USDWs from endangerment.

Commenter Name: Richard Guinn Letter ID: 0210 Commenter Organization: Eastman Chemical Company Comment ID: 22699

Comment: 8. The period of post-injection site management should be performance-based andnot be arbitrarily set at 50 years.

Response: EPA agrees with commenters that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

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

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA disagrees that the post-injection site care timeframe of 50 years in the final rule is excessive in most cases or arbitrary. In determining the post-injection site care-timeframe for the proposed regulation, EPA reviewed industry reports, existing environmental programs, and initial GS research studies. EPA provided a synthesis of pertinent results from GS modeling studies in the preamble to the proposed regulation. Further explanation of this analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water." Based on review of these studies, modeling results indicate that the CO2 plume stabilization may occur on the timeframe of 10-100 years after the cessation of injection. EPA believes that a 50-year default post-injection site care timeframe is a reasonable midpoint for most GS projects and available data, including data submitted by commenters, do not support a different default timeframe, and has retained this in the final regulation.

Commenter Name: Richard Guinn Letter ID: 0210 Commenter Organization: Eastman Chemical Company Comment ID: 22740 Other EPA Comment Codes and Descriptions: 5260 2.8.2.3 Adjusting the post-injection timeframe (seeking comment)

Comment: In addition, EPA seeks comment on whether the Director should be allowed to shorten the timeframe based on performance information, and whether EPA should require a shorter or longer post injection period if data suggests the time frame should be adjusted. EPA Notice 125-26.

EPA should allow the Director to shorten the timeframe based on performanceinformation. However, an open-ended time period results in a high degree of uncertainty regarding cost exposure to a project developer. It also leaves a site open to future liability from "reopeners" by the regulatory community. To avoid this latter scenario, a maximum monitoring period should be defined in terms of clear, performance-based risk metrics - for example, that the validated model predicts that 95% of the plume is or will be trapped and that a sensitivity analysis predicts a comfortable margin of safety and diminimus risk of endangerment to any USDWs.

Response: EPA disagrees that the Director should not have discretion to shorten or lengthen the post-injection site care monitoring period. Because of the variety of site-specific circumstances at GS sites, EPA believes that Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care monitoring is needed (or whether the timeframe may be shortened), based on the circumstances of a particular project. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties to ensure USDW protection. The final GS regulation retains the provision that the Director may, at his or her discretion, shorten the post-injection site care timeframe if the owner or operator can demonstrate that the GS project does not pose an endangerment to USDWs, as specified in §146.93(b)(2).Alternatively, the final rule at §146.93(c), also allows the Director to approve an alternative postinjection site care timeframe where an owner or operator can demonstrate during the permitting process that an alternative post-injection site care timeframe, other than the 50 year default, isappropriate and ensures non-endangerment of USDWs. The demonstration must be based on sitespecific information, including the results of site-specific computational modeling; the predicted timeframe for pressure decline; the predicted rate of carbon dioxide plume migration; site-specific chemical processes that will result in carbon dioxide trapping; the predicted rate of carbon dioxide trapping; characterization of the confining zone(s); laboratory analyses or studies to verify the information on trapping; the presence of potential conduits for fluid movement and the quality of abandoned well plugs within the AoR; the distance between the injection zone and the USDWs above and/or below the injection zone; and any additional site-specific factors determined by the Director. The demonstration must meet the criteria at §146.93(c)(2) for ensuring the quality and accuracy of the data and models on which the demonstration is based. This demonstration would be submitted as part of the permit application, per §146.82(a)(18), in addition to the PISC and site closure plan required at §146.82(a)(17).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: John King Letter ID: 0211 Commenter Organization: Shell Exploration and Production Company (SEPCo) Comment ID:

22762

Comment: F. 50-year Default Post-Injection Site Care

SEPCO objects to the use of a 50-year default monitoring period. EPA offers norationale for this arbitrarily selected period of 50 years and establishing a fixed and unusually long time period may create a significant barrier for operators considering entry into CCS operations.

Response: EPA disagrees with this comment. In determining the post-injection site care-timeframe for the proposed regulation, EPA reviewed industry reports, existing environmental programs, and initial GS research studies. EPA provided a synthesis of pertinent results from GS modeling studies in the preamble to the proposed regulation. Further explanation of this analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water." Based on review of these studies, modeling results indicate that the CO2 plume stabilization may occur on the timeframe of 10-100 years after the cessation of injection. EPA believes that a 50-year default post-injection site care timeframe is a reasonable midpoint for most GS projects and available data, including data submitted by commenters, do not support a different default timeframe, and has retained this in the final regulation. However, EPA recognizes that there may be sites where the 50 year post injection site care timeframe may be either not appropriate or more burdensome than necessary based on site-specific conditions. 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: John King Letter ID: 0211 Commenter Organization: Shell Exploration and Production Company (SEPCo) Comment ID:

22782 Other EPA Comment Codes and Descriptions: 5200 2.8.2 Post injection site care (seeking comment) (40 CFR 146.93)

Comment: G. Post-Injection Site Care Responsibility

The proposed rule contemplates a long post-operational period of observation and "site care" prior to closure. The requirements contemplated -- including a presumptive 50-year post-injection monitoring period -- are unwarranted and completely unprecedented in the UIC program. Not even hazardous waste injection wells -- which generally operate subject to a demonstration that waste will be contained for at least ten thousand years -- are subject to such burdensome post-injection requirements.Long term protection of USDWs is ensured up-front, primarily through proper siting as confirmed through the technical evaluation that occurs in the permitting process. Proper well construction, operating, monitoring and testing provide assurance against problems during the operational life of an injection well, but siting doesn’t change, and proper siting must be ensured at the start. Once injection operations cease, there should generally be no need to do more than monitor pressure decay in the injection zone and ensure proper plugging of the injection well. This approach is sufficient for the injection of hazardous waste, and it certainly should be sufficient for the injection of CO2. The premise that careful siting and AOR evaluation are not enough -- that actual monitoring for decades after the cessation of injection is needed -- is foreign to the UIC program and inconsistent with the long and thoroughly-documented success of UIC regulation in the United States.

There is certainly no justification for a presumptive 50-year minimum timeframe for post-injection site care, and such a requirement would likely kill-off commercial investment in geo-sequestration projects. It does not help that the proposed rule provides a mechanism for shortening the presumptive 50-year requirement, because the ability to shorten the post-injection site care period would depend on the apparently unlimited discretion of the Director and could not be assessed in any meaningful way before injection operations near completion. Moreover, the possibility of a shorter post-injection site care period is balanced by the possibility that the Director may seek to impose an even longer post-injection site care period. The burdens and regulatory uncertainties of an extended post-injection site care requirement cannot be justified, especially in the context of a regulatory program that requires a "non-endangerment" demonstration before injection can even commence.

Recommendation:

1. EPA should operate from the premise that the UIC program is preventive in

nature.

2. Release from post-injection site care should be determined not by a fixed period of time but rather a performance-based standard that is designed to ensure protection of USDW’s.

Response: EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, a default timeframe for post-injection site care is necessary in most cases. A 50 year post-injection site care timeframe represents a reasonable and protective monitoring period for most GS projects and available data, including data submitted by commenters, do not support a different default timeframe. Thisdetermination is based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

EPA agrees that proper site characterization, well construction, and operation are important components of ensuring that USDWs are protected. However, EPA disagrees that this is a substitute for post-injection site care. EPA believes that extensive post-injection monitoring is necessary to protect USDWs from endangerment.

EPA disagrees that the rule affords ¿unlimited discretion¿ to the Director to lengthen the postinjection site care timeframe. Because of the variety of site-specific circumstances at GS sites, EPA believes that Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care monitoring is needed (or whether the timeframe may be shortened), based on the circumstances of a particular project. EPA expects this decision to be made based on relevant site data, including information at §146.93(c)(2), to determine the appropriateness of an alternative post-injection site care time frame if applicable, and in consultation with all potentially impacted parties.

EPA disagrees that a post-injection site care timeframe of 50 years is excessive for most Class VI wells. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titledComputational Modeling of Underground Injection of Carbon Dioxide for Determination of Areaof-Review and Potential Risk to Underground Sources of Drinking Water. EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that alternative timeframes may be appropriate under limited, specific circumstances, which is why EPA is providing the Director discretion to approve an alternative post-injection site care timeframe as long as the owner or operator can meet the requirements provided at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters¿ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; demonstrate the appropriateness of an alternative post-injection site care time frame; perform post-injection monitoring; demonstrate non endangerment; and perform site closure activities. This guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.Commenter Name: Diane VanDe Hei Letter ID: 0213 Commenter Organization: Association of Metropolitan Water Agencies (AMWA) Comment ID:

22951 Other EPA Comment Codes and Descriptions: 5260 2.8.2.3 Adjusting the post-injection timeframe (seeking comment)

Comment: - 73 FR 43519 -EPA requests comment on the proposed use of a tentative 50-year fixed [post injection site care] timeframe that could be modified at the Director’s discretion based on monitoring and modeling data.

Response: AMWA supports a minimum 50-year time frame for post-injection site care and recommends that the Director not be given any discretion to shorten this time period. EPA notes in the proposal that "the potential risks of endangering USDWs will not decline within that timeframe given that stabilization may continue for several decades." AMWA also recommends that

Response: EPA disagrees that the Director should not have discretion to shorten or lengthen thepost-injection site care monitoring period. EPA believes that 50 years is an appropriate default postinjection site care timeframe. However, EPA recognizes that there may be sites where the 50 year post injection site care timeframe may be either not appropriate or more burdensome than necessary based on site-specific conditions. 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Ronald Evans Letter ID: 0215 Commenter Organization: Denbury Resources, Inc. (DRI) Comment ID: 24282 Other EPA Comment Codes and Descriptions: 1360 1.1.3.4 Effectiveness of trapping mechanisms

Comment: B. The Proposed 50-year Term for Post-Injection Site Care Is Unreasonably Long

Denbury strongly objects to the use of a 50-year timeframe for continuous monitoring during post-injection site care. Our objection stems from therelative risks associated with the various phases of geologic storage operations, the recognized progression of various geologic trapping mechanisms (which means that risks of unexpected migration diminish over time), the creation of artificial impediments to financial assurance and the sagacity of other regulatory proposals.

First, we believe that published and reputable literature suggests that a 50- year timeframe for post-injection site care is too long and wholly unrelated to the risks associated with geologic storage. For well-sited, characterized, operated and managed sites, the risks accumulate during the operational phase, but decline as sites move from post-injection site care to closure to eventual long-term care. Prevailing scientific opinion expects the risk profile to diminish with time.[FN35] As Lindene and Trabucchi suggest, "the risk of some events occurring that result in an unexpected release of carbon dioxide more than 10 years after termination of injection will become increasingly remote due to geochemistry conditions."[FN36] The geochemistry conditions they reference include the four main mechanisms which trap CO2 in well-chosen geological formations - 1) structural trapping -- which is addressed in the proposed rule and is not necessary to discuss further here; 2) residual CO2 trapping -- where CO2 is trapped by capillary forces in the interstices of the rock formation, a process which develops about 10 years after injection; 3) dissolution or solubility trapping -- where the CO2 dissolves into the brine found in the geological formation and sinks because the CO2 saturated brine is more dense than non-CO2 saturated brine, a process taking place between 10 and 100 years after injection; and finally, 4) mineralization or mineral trapping -- which occurs when dissolved CO2 chemically reacts with the formation rock to produce minerals, a process requiring hundreds of years.[FN37]

Given that the greatest risk of a release occurs during the operational stage of a storage project, and that residual and dissolution trapping start well in advance of 50 years, it is difficult to understand why a 50-year timeframe for post-injection site care was chosen. A 50-year post-injection site care timeframe simply does not correlate to the relative risks associated with geological storage and the function of geologic trapping mechanisms that limit the risk of unexpected releases of CO2 after the termination of injection activity.

Furthermore, other respected models use a much shorter period. For instance, the IOGCC Model Rules and Legislation stipulate a 10 year post-injection site care period.[FN38] Under the IOGCC Model, the operator of the storage site is the responsible party and is required to maintain an operational bond for the equivalent of a post-injection site care period and until closure. This 10 year post-injection site care period is more plainly related to the relative risks of geologic storage and the geochemical reactions discussed above. Also, in the preamble, EPA acknowledges that a 30-year post-closure care period is recognized as the industry standard for the injection of hazardous waste.[FN39]

[35] See Intergovernmental Panel on Climate Change, Special Report on Carbon Dioxide Capture and Storage, 208 (Bert, Metz, et al. eds., 2005); see also Sally Benson, "Carbon Dioxide Capture and Storage: Research Pathways, Progress andPotential," Global Climate & Energy Project Annual Symposium, October 2007,

available at http://pangea.stanford.edu/research/bensonlab/presentations/Carbon%20Dioxide%20C apture%20and%20St orage%20-%20Research%20Pathways%20Progress%20and%20Potential.pdf (hereafter "Benson 2007").

[36] Chiara Trabucchi and Lindene Patton, "Storing Carbon: Options for Liability Risk Management, Financial Responsibility," Daily Environment Report, Bureau of National Affairs, pg. 8 (Sept. 3, 2008).

[37] See IPCC Special Report on CCS, supra n.2, at 208; see also Benson 2007, supra n.35.

[38] See generally IOGCC, "Storage of Carbon Dioxide in Geologic Structures: A Legal and Regulatory Guide for States and Provinces" (September 2007) (publishing Model Statute and Rules for CO2 storage). The proposed 10 year default period for maintaining operator responsibility is at Model General Rules and Regulations, Section 2.0 (f) (defining "CSP Closure Period" as 10 years unless otherwise designated by the State Regulatory Agency). See also at Section 4.0 (b) (10) (requiring performance bond to be maintained for 10 years after closure of the facility in accordance with Section 9.0). The discussion of the Model Statute and Regulation also mentions other potential periods of "10 or 29 years, etc." IOGCC, supra, at 30.

[39] See 73 Fed. Reg. at 43,510.

Response: EPA agrees that some owners or operators will be able to demonstrate, in less than 50 years, that the pressure front and plume no longer pose a risk of endangerment to USDWs. However, based on studies, EPA believes that the 50-year default time frame is warranted in most cases based on additional review of research studies and reports and evaluation of public comments.

EPA believes that the best way to address all possibilities, while ensuring USDW protection from endangerment, is to set a 50 year default post-injection site care timeframe, with flexibility to: (1) allow the Director discretion to shorten or lengthen the PISC timeframe during the PISC period based on site-specific data, pursuant to requirements at §146.93(b); or (2) afford the Director discretion to allow a Class VI well owner or operator to demonstrate, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters¿ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA clarifies that, in determining the post-injection site care-timeframe for the proposed regulation, EPA reviewed industry reports, existing environmental programs, and initial GS research studies.EPA provided a synthesis of pertinent results from GS modeling studies in the preamble to the proposed regulation. Further explanation of this analysis was included in an EPA-prepared background document that is available in the federal docket, titled ""Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water."" Based on review of these studies, modeling results indicate that the CO2 plume stabilization may occur on the timeframe of 10-100 years after the cessation of injection. EPA believes that a 50-year default post-injection site care timeframe is a reasonable midpoint for most GS projects and available data, including data submitted by commenters, do not support a different default timeframe, and has retained this in the final regulation.

To the comment about the cost of post-injection site care, EPA does not agree that post-injection sitecare timeframes longer than 30 years will be prohibitively expensive. In fact, EPA believes that postinjection site care monitoring will represent a relatively minor component of total project cost, and will provide an essential level of protection from endangerment for USDWs. A discussion of the costs attributed to monitoring technologies (used during injection and the post-injection site care timeframes) is available in the Technology and Cost Document for the GS rule, which is in the federal docket for this rulemaking. EPA believes that it is logical to make use of existing monitoring infrastructure at a GS site in order to ensure USDWs are not endangered.

EPA also recognizes the concerns associated with assuring financial responsibility for the long timeframes over which post-injection site care will be conducted. However, the Agency believes that, in order to protect USDWs from endangerment under the SDWA, operators must demonstrate under §146.85 that financial resources are available to plug the injection well and provide post-injection site care at the point in time that the first CO2 is injected. EPA is developing guidance on financial responsibility to assist owners or operators in evaluating the requirements of §146.85 and to assist Directors in evaluating financial responsibility demonstrations. The guidance describes the types of financial mechanisms that operators may choose to use when evaluating the financial responsibility requirements for GS wells and it will also include a section on how to estimate costs to support accurate financial responsibility demonstrations. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Ronald Evans Letter ID: 0215 Commenter Organization: Denbury Resources, Inc. (DRI) Comment ID: 24283 Other EPA Comment Codes and Descriptions: 5400 2.9 Proposed Financial Responsibility and Long-Term Care Requirements

Comment: Finally, this 50-year timeframe raises barriers to obtaining financial assurance for prospective projects. Section 146.85 of the Proposed Rule requires the owner or operator to maintain financial responsibility for corrective action, injection well plugging, post-injection site care and site closure. Undoubtedly owners/operators will enter the private sector financial assurance market forsome period in order to meet this requirement. An uncertain or a 50-year postinjection site care timeframe creates impediments to managing this financial responsibility. We believe that both an indeterminate or an exceedingly long post-injection site-care period will discourage the development of private sector products to address financial responsibility and discourage sequestration in general.

Response: EPA disagrees that the requirements for financial responsibility are overly stringent orunreasonable. The goal of financial responsibility is to ensure that financial resources are available to prevent the endangerment of USDWs from improper plugging, remediation, and management of wells in the event that the owner or operator experiences financial difficulties throughout the life of the project. See the final rule and preamble for further discussion of EPA's final approach to financial responsibility.

EPA believes that minimum financial responsibility requirements are necessary to hold well owners or operators accountable for the safe operation and proper site closure of the well in order to protect USDWs while also avoiding expense and risk to the public. EPA adds that the purpose of the GS rule is not to encourage the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

Commenter Name: Ronald Evans Letter ID: 0215 Commenter Organization: Denbury Resources, Inc. (DRI) Comment ID: 24284

Comment: Given the limited risk profile of the post-operational phase of geologic storage, the precedent set by other proposals, and the likely impediments to financial responsibility and insurance caused by an uncertain or exceedingly lengthy post-injection site care period, we think that a 50-year post-injection site care period is unsupported by the science, unnecessary to protect USDWs and unwarranted by current EOR experience. While we agree that in most instances site-specific performance standards are most appropriate, we believe that in

this instance a definite and reasonable timeframe should be established that is supported by the relative risks involved and that facilitates the development of financial assurance products. We believe a 10 year post-injection site care period protects USDWs, facilitates post-injection financial assurance and is consistent with our understanding of how geologic trapping of CO2 occurs.

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive in most cases or arbitrary. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled"Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Areaof-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that alternative timeframes may be appropriate under limited, specific circumstances.

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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA believes however, that to ensure USDW protection from endangerment, a default timeframe for post-injection site care will be necessary in all but a limited number of cases. This default 50 year post-injection site care timeframe represents a reasonable and protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

EPA adds that the purpose of the GS rule is not to incentivize the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

To the comment about the cost of post-injection site care, EPA does not agree that post-injection sitecare timeframes longer than 30 years will be prohibitively expensive. In fact, EPA believes that postinjection site care monitoring will represent a relatively minor component of total project cost, and will provide an essential level of protection from endangerment for USDWs. A discussion of the costs attributed to monitoring technologies (used during injection and the post-injection site care timeframes) is available in the Technology and Cost Document for the GS rule, which is in the federal docket for this rulemaking. EPA believes that it is logical to make use of existing monitoring infrastructure at a GS site in order to ensure USDWs are not endangered.

Commenter Name: Ronald Evans Letter ID: 0215 Commenter Organization: Denbury Resources, Inc. (DRI) Comment ID: 24313 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5300 2.8.3 Site closure activities (40 CFR 146.93)

Comment: I. § 146.93 Post-injection site care and site closure.

The proposed rule establishes a 50 year default period for post-injection site care. There is, however, no factual or scientific basis for such an extensive period. Under EPA’s Resource Conservation and Recovery Act rules, which regulate the disposal of hazardous wastes, post closure care is limited to 30 years.[FN45] Defaulting to an excessively long period will increase costs and introduce greater regulatory uncertainty, which will discourage capital formation around CO2 sequestration. A more prudent regulatory approach is to set a minimum period for site care, ten years, with allowance for the Director to extend the period if facts and circumstances warrant a longer post-injection site care period.

Additionally, the proposed rule’s 50 year default post injection site care period, is an illusory deadline, as it is not self-executing. Under the rules, post injection site care must continue indefinitely until the Director authorizes closure. The closure approval process could take years, even decades, as the Director has no regulatory incentive to act on any post injection site care report. Meanwhile, a permittee may be required to continue unnecessary andexpensive monitoring and reporting indefinitely.

Denbury suggests that the post-injection site care rules be reconfigured to require a more limited mandatory post-injection site care timeframe, and to allow for closure at the end of that period unless the Director affirmatively acts to extend the post-injection site care period. These changes are contained in the suggested text below:

§ 146.93 Post-injection site care and site closure. (a) The owner or operator of a Class VI well must prepare, maintain, and comply with a plan for post-injection site care and site closure that meets the requirements of paragraph (a)(2) of this section and is acceptable to the Director. (1) The owner or operator must submit the post-injection site care and site closure plan as a part of the permit application to be approved by the Director. (2) The post-injection site care and site closure plan must include the following information: (i) The pressure differential between pre-injection and predicted post-injection pressures in the injection zone; (ii) The predicted position of the carbon dioxide plume and associated pressure front at site closure as demonstrated in the area of review evaluation required under § 146.84(b); (iii) A description of post-injection monitoring location, methods, and proposed frequency; and (iv) A proposed schedule for submitting post-injection site care monitoring results to the Director. (3) Upon cessation of injection, owners or operators of Class VI wells must either submit an amended post-injection site care and site closure plan or demonstrate to the Director through monitoring data and modeling results that no amendment to the plan is needed.(4) The owner or operator may modify and resubmit the postinjection site care and site closure plan for the Director’s approval within 30 days of such change. (b) The owner or operator shall monitor the site following the cessation of injection to show the position of the carbon dioxide plume and pressure front and demonstrate that USDWs are not being endangered. (1) The owner or operator shall continue to conduct monitoring as specified in the Director-approved post-injection site care and site closure plan for at least 5010 years following the cessation of injection. At theUPON A DETERMINATION BY THE Director ’s THAT THE GEOLOGIC SEQUESTRATION PROJECT MAY POSE AN ENDANGERMENT TO

USDWS discretion , THE DIRECTOR, AT HIS DISCRETION, MAY REQUIRE the monitoring willTO continue FOR A TIME PERIOD SPECIFIED BY

THE DIRECTOR until the geologic sequestration project no longer poses an endangerment to USDWs. (2) If the owner or operator can demonstrate to the satisfaction

of the Director before 5010 years, based on monitoring and other site-specific data, that the geologic sequestration project no longer poses an endangerment to USDWs, the Director may approve an amendment tothe post injection site care and site closure plan to reduce the frequency of monitoring or may authorize site closure before the end of

the 5010 year period. (3) Prior to authorization forTHE EXPIRATION OF THE 10
YEAR POST-INJECTION SITE CARE PERIOD, site closure , the owner or operator must submit to the Director a demonstration, based on monitoring and other site specific data, that the carbon dioxide plume and pressure front have stabilized and that no additional monitoring is needed to assure that the geologic sequestration project does not pose an endangerment to USDWs. (4) IF WITHIN 180 DAYS AFTER THE SUBMITTAL OF THE DATA REQUIRED UNDER SUBPARAGRAPH (3) ABOVE THE DIRECTOR DETERMINES THAT THE

GEOLOGICAL SEQUESTRATION PROJECT MAY CONTINUE TO POSE AN ENDANGERMENT TO
USDWS, HE

SHALL SO NOTIFY THE OWNER OR OPERATOR OF HIS DETERMINATION AND THE

BASIS
THEREFORE, AND If such a demonstration cannot be made (i.e., if the carbon dioxide plume and pressure front have not stabilized) after the 50-year period,the owner or operator must submit to the Director a plan to continue post-injection site care. (5) IF WITHIN 180 DAYS AFTER THE SUBMITTAL OF THE DATA REQUIRED UNDER SUBPARAGRAPH (3) ABOVE THE DIRECTOR FAILS TO DETERMINE AND TO NOTIFY THE OWNER OR OPERATOR THAT THE GEOLOGICAL SEQUESTRATION

PROJECT
MAY CONTINUE TO POSE AN ENDANGERMENT TO USDWS, SITE CLOSURE SHALL BE

DEEMED AUTHORIZED BY RULE (c) Notice of intent for site closure. The owner or operator must notify the Director at least 120 days before site closure. At this time, if any changes have been made to the original post-injection site care and site closure plan, the owner or operator must also provide the revised plan. At the discretion of the Director, a shorter notice period may be allowed. (d) After the Director has authorized site closure OR SITE CLOSURE IS AUTHORIZED BY RULE, the owner or operator must plug all monitoring wells in a manner which will not allow movement of injection or formation fluids that endangers a USDW. (e) Once the Director has authorized site closure, OR SITE CLOSURE IS AUTHORIZED BY RULE, the owner or operator must submit a site closure report within 90 days that must thereafter be retained at a location designated by the Director. The report must include: (1) Documentation of appropriate injection and monitoring well plugging as specified in § 146.92 and paragraph (c) of this section. The owner or operator must provide a copy of a survey plat which has been submitted to the local zoning authority designated by the Director. The plat must indicate the location of the injection well relative to permanently surveyed benchmarks. The owner or operator must also submit a copy of the plat to the Regional Administrator of the appropriate EPA Regional Office; (2) Documentation of appropriate notification and information tosuch State, local and tribal authorities as have authority over drilling activities to enable such State and local authorities to impose appropriate conditions on subsequent drilling activities that may penetrate the injection and confining zone(s); and (3) Records reflecting the nature, composition and volume of the

carbon dioxide stream. (f) Each owner or operator of a Class VI injection well must record a notation on the deed to the facility property or any other document that is normally examined during title search that will in perpetuity provide any potential purchaser of the property the following information: (1) The fact that land has been used to sequester carbon dioxide; (2) The name of the State agency, local authority, and/or tribe with which the survey plat was filed, as well as the address of the Regional Environmental Protection Agency Office to which it was submitted; and (3) The volume of fluid injected, the injection zone or zones into which it was injected, and the period over which injection

occurred. (g) The owner or operator must retain for three years following site closure, records collected during the post-injection site care period. The owner or operator must deliver the records to the Director at the conclusion of the retention period, and the records must thereafter be retained at a location designated by the Director for that purpose.

[45] 40 C.F.R. § 264.117(a)(1)

Response: The post-injection site care requirements in the final GS rule, §146.93(b), incorporate a combination of a 50-year default post-injection site care timeframe, in conjunction with a performance standard, for Class VI wells. 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

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

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA expects that the Director will consider the types of information the commenter describes in determining whether theplume and pressure front no longer pose a risk of endangerment to USDWs and post-injection site care monitoring may be discontinued.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells, perform post-injection monitoring, demonstrate the appropriateness of an alternative post-injection site care time frame, demonstrate non-endangerment, and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Edward Steadman Letter ID: 0220 Commenter Organization: The Energy and Environmental Research Center at the University of North Dakota Comment ID:

21627

Comment: Page 43519. Combination of Fixed Time Frame and Performance Standard (monitoring). The EPA is proposing a postinjection monitoring period of 50 years, with the director having some discretion to either shorten or lengthen that time period. Based on the proposed text, 50 years is the default time period for postinjection monitoring until data on pressure, fluid movement, mineralization, and/or dissolution reactions support a determination that the plume has stabilized and does not pose a risk to USDWs. Referring to this as the "default" time period and requiring the acquisition of described data sets to modify the time period for monitoring indicate that a significant amount of characterization effort would have to be conducted during the postinjection period, perhaps over several years, to get such a change. The EPA acknowledges that modeling results indicate that CO2 plume stabilization likely occurs on the time frame of 10 to 100 years after injection stops. One example of a GS site where plume stabilization could very well take 50 years or more is a site where there is no significant structural trapping element to the reservoir. A plume at such a location may behave in a less predictable manner and expand or migrate a significant distance before it stabilizes. However, CO2 injected into a thoroughly confined high-relief structure (e.g., pinnacle reef, carbonate mound, anticline, etc.) would likely stabilize relatively quickly. Barring a seismic event that breaches the seal, the movement of such a plume would be nil because it would literally have nowhere to go. In those cases, requiring the continued collection of several types of data for several years in order to prove what was probably obvious years before injection ceased would serve no real purpose other than to satisfy an arbitrary regulation. The nature of structural

characteristics at each site under consideration for GS will be identified almost immediately, defined in detail during the earliest stages of site evaluation, and the understanding of their geometry will likely be further refined over the course of monitoring during the injection phase of the project. It is also important to keep in mind that the injection phase of GS projects, and the monitoring that goes with them, will, in most cases, be conducted for decades. Over those years, knowledge of the reservoir system will increase, and by the time the injection phase comes to an end, there will be ample data to make informed decisions regarding an appropriate postinjection monitoring period. All of this leads to a logical conclusion that the establishment ofpostinjection monitoring periods should be site-specific and flexible. The 50- year site monitoring statement appears to have no rational basis and might effectively eliminate commercial activity.

In summary, the proposed default monitoring time frame should be eliminated and replaced with a solely performance-based standard that reflects the specifics of a project and the knowledge of that project gained through the procedures and processes that are already required. The proposed rule gives the program director discretion to extend or shorten the postinjection site care period based on project-specific considerations; therefore, it seems unnecessary to, by rule, establish a lengthy default period.

Response: EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

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

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Darrick Eugene Letter ID: 0223 Commenter Organization: Texas Carbon Capture and Storage Association Comment ID: 23963

Comment: Point #6: The proposed Post-injection Site Care period is too long based on prevailing science and risk profiles. The proposed rule establishes a default 50-year timeframe for the length of the post-injection site care period. TxCCSA strongly objects to the use of a 50-year timeframe for post-injection site care. Our objection stems from the relative risks associated with the various phases of geologic storage operations, the function of various geologic trapping mechanisms, the creation of artificial impediments to financial assurance and the sagacity of other regulatory proposals.

First, we believe as the literature suggests that a 50-year timeframe for postinjection site care is too long and wholly unrelated to the risks associated with geologic storage. For well-sited, characterized, operated and managedsites, the risks accumulate during the operational phase, and decline as sites move from post-injection site care to closure to eventual long-term care. Therefore, prevailing scientific opinion expects the risk profile to diminish with time.[FN6] As Patton and Trabucchi suggest "the likelihood that the risk of some events occurring that result in an unexpected release of carbon djoxide more than 10 years after termination of injection will become increasingly remote due to geochemistry conditions." [FN7] The geochemistry conditions they reference include the four main mechanisms which trap CO2 in well-chosen geological formations -- 1) structural trapping - which is addressed in the proposed rule and is not necessary to discuss further here; 2) residual trapping -where CO2 is trapped by capillary forces in the interstices of the rock formation which develops about 10 years after injection; 3) dissolution or solubility trapping -where the CO2 dissolves into the brine found in the geological formation and sinks because the CO2 saturated brine is heavier than non-CO2 saturated brine, taking place between 10 and 100 years after injection; and 4) finally mineralization or mineral trapping - which happens when dissolved CO2 chemically reacts with the formation rock to produce minerals, a process requiring hundreds of years.[FN8]

Given that the greatest risk occurs during the operational stage of a geologic storage project and that residual and dissolution trapping start well in advance of 50 years, it is difficult to understand why a 50year timeframe for postinjection site care was chosen. A 50-year post-injection site care timeframe is simply unrelated to the relative risks associated with geological storage and the function of geologic trapping mechanisms that limit the risk of unexpected release of CO2 after the termination of injection activity.

Furthermore, other respected models suggest a much shorter period. For instance. the IOGCC Model Rules and Legislation stipulate a 10-29 year post-injection site care period.[FN9] Under the IOGCC Model, the operator of the storage site is the responsible party and is required to maintain an operational bond during the equivalent of a post-injection site care period and until closure. This 10-29 year post-injection site care period more easily relates to the relative risks of geologic storage and the geochemical reactions discussed above. Also, in the Preamble, EPA acknowledges that a 30-year post-closure care period is recognized as the industry standard for the injection of hazardous waste.[FN10]

6 See Intergovernmental Panel on Climate Change, Special Report on Carbon Dioxide Capture und Storage, 208 (Bert, Metz, et al. eds., 2005); see also Sally M. Benson, Carbon Dioxide Capture and Storage: Research Pathways, Progress and Potential, Global Climate & Energy Project Annual Symposium, October 2007,

available at http://pangea.stanford.edulresearctv'bensonlab/presentations/Carbon%20Dioxide%20CaptureYa20and%20Storage%2OY020ResearchO/020Palhways%20Progress'Y020and%20Potential.pdf. 7 Chiara Trabucchi and Lindene Patton, Storing Carbon: Optionsfor Liability Risk. Management, Financial Responsibility, Daily Environment Report, Bureau of National Affairs, pg. 8 (Sept. 3, 2008). 8 See IPCC 2005 Repon, supra, at 208; see also Benson 9 See Task Force on Carbon Capture and Geologic Storage, The Interstate Oil andGas Compact Commission, Storage of Carbon Dioxide in Geologic Structures: A Legal and Regulatory Guide for States and Provinces (Sept. 25,2007) available at http://iogcc.mysbopify.comlcollectionslfrontpagelproductslco2-storage-a ·Legal·and regulatory-guide-for-states-2008. 10 See 73 Fed. Reg. at 43510.

Response: EPA agrees that some owners or operators will be able to demonstrate, in less than 50 years, that the pressure front and plume no longer pose a risk of endangerment to USDWs. However, based on studies, EPA believes that the 50 year default time frame is warranted based on additional review of research studies and reports and evaluation of public comments.

EPA believes that the best way to address all possibilities, while ensuring USDW protection from endangerment, is to set a 50 year default post-injection site care timeframe, with flexibility to: (1) allow the Director discretion to shorten or lengthen the PISC timeframe during the PISC period based on site-specific data, pursuant to requirements at §146.93(b); or (2) afford the Director discretion to allow a Class VI well owner or operator to demonstrate, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters¿ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA clarifies that, in determining the post-injection site care-timeframe for the proposed regulation, EPA reviewed industry reports, existing environmental programs, and initial GS research studies. EPA provided a synthesis of pertinent results from GS modeling studies in the preamble to the proposed regulation. Further explanation of this analysis was included in an EPA-prepared background document that is available in the federal docket, titled ""Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water."" Based on review of these studies, modeling results indicate that the CO2 plume stabilization may occur on the timeframe of 10-100 years after the cessation of injection. EPA believes that a 50-year default post-injection site care timeframe is a reasonable midpoint for most GS projects and available data, including data submitted by commenters, do not support a different default timeframe, and has retained this in the final regulation.

To the comment about the cost of post-injection site care, EPA does not agree that post-injection sitecare timeframes longer than 30 years will be prohibitively expensive. In fact, EPA believes that postinjection site care monitoring will represent a relatively minor component of total project cost, and will provide an essential level of protection from endangerment for USDWs. A discussion of the costs attributed to monitoring technologies (used during injection and the post-injection site care timeframes) is available in the Technology and Cost Document for the GS rule, which is in the federal docket for this rulemaking. EPA believes that it is logical to make use of existing monitoring infrastructure at a GS site in order to ensure USDWs are not endangered.

EPA also recognizes the concerns associated with assuring financial responsibility for the long timeframes over which post-injection site care will be conducted. However, the Agency believes that in order to protect USDWs from endangerment under the SDWA operators must demonstrate under §146.85 that financial resources are available to plug the injection well and provide post-injection site care at the point in time that the first CO2 is injected. EPA is developing guidance on financial responsibility to assist owners or operators in evaluating the requirements of §146.85 and to assist Directors in evaluating financial responsibility demonstrations. The guidance describes the types of financial mechanisms that operators may choose to use when evaluating the financial responsibility requirements for GS wells and it will also include a section on how to estimate costs to support accurate financial responsibility demonstrations. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Darrick Eugene Letter ID: 0223 Commenter Organization: Texas Carbon Capture and Storage Association Comment ID: 23964 Other EPA Comment Codes and Descriptions: 5430 2.9.1 Comments on proposed financial responsibility requirements (40 CFR 146.85)

Comment: Finally, when mapped to the requirement for financial assurance, this 50-year timeframe requirement raises barriers to obtaining financial assurance for prospective projects. Section 146.85 of the Proposed Rule requires the owner or operator to maintain financial responsibility for corrective action, injection well plugging, post-injection site care and site closure. Undoubtedly owners/operators will enter the private sector financial assurance market for some period in order to meet this requirement. Both an uncertain or 50-year post-injection site care timeframe create impediments to financial responsibility. We believe that an uncertain or exceedingly long post-injection site-care period will discourage the development of private sector products to address financial responsibility and discourage geologic storage in general.

Given the limited risk profile of the post-operational phase of geologic storage, the impediments to financial responsibility and insurance caused by an uncertain or exceedingly lengthy post-injection site care period and the precedent set by other proposals, we think that a 50-year post-injection site care period is unsupported by the science, unnecessary to protect USDWs and unwarranted by current EOR experience.

Response: As described above, EPA disagrees that a post-injection site care timeframe of 50 years is excessive. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled"Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Areaof-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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, there are circumstances (e.g., little development of mineral trapping of CO2) under which the potential risks of endangering USDWs will likely not decline within these timeframes. EPA believes that a 50 year post-injection site care timeframe represents a reasonable and protective monitoring period and available data do not support a different timeframe. Furthermore, EPA believes that a 50-year default post-injection site caretimeframe, as required at §146.93(b)(1), is not overly burdensome, does not exaggerate the risks associated with GS, is consistent with other environmental programs, and sufficiently protects USDWs from endangerment.

To the comment expressing concern about financial responsibility, EPA recognizes that there are challenges associated with assuring funding for activities that will occur far in the future. However, the Agency believes that in order to protect USDWs from endangerment under the SDWA operators must demonstrate under §146.85 that financial resources are available to plug the injection well and provide post-injection site care at the point in time that the first CO2 is injected. EPA is developing guidance on financial responsibility to assist owners or operators in evaluating the requirements of §146.85 and to assist Directors in evaluating financial responsibility demonstrations. The guidance describes the types of financial mechanisms that operators may choose to use when evaluating the financial responsibility requirements for GS wells and it will also include a section on how to estimate costs to support accurate financial responsibility demonstrations. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

EPA adds that the purpose of the GS rule is not to incentivize the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

EPA acknowledges the concerns of some commenters that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final GS regulation includes a provision that the Director may, at his/her discretion, shorten the post-injection site care timeframe if the owner or operator can demonstrate that the GS project does not pose a risk to USDWs, as specified in §146.93(b)(2). Such a demonstration will be site-specific, and based on pressure monitoring and USDW impacts.

EPA disagrees that the requirements for financial responsibility are overly stringent. The goal of financial responsibility is to ensure that resources are available to prevent the endangerment of USDWs from improper plugging, remediation, and management of wells in the event that the owner or operator experiences financial difficulties throughout the life of the project.

Commenter Name: Darrick Eugene Letter ID: 0223 Commenter Organization: Texas Carbon Capture and Storage Association Comment ID: 23993 Other EPA Comment Codes and Descriptions: 5260 2.8.2.3 Adjusting the post-injection timeframe (seeking comment)

Comment: 10. § 146.93 Post-injection site care and site closure.

The proposed rule establishes a 50 year default period for post-injection site care. There is, however, no factual or scientific basis for such an extensive period. Under EPA’s Resource Conservation and Recovery Act rules, which regulate the disposal of hazardous wastes, post closure care is limited to 30 years. Defaulting to an excessively long period will increase costs and introduce greater regulatory uncertainty, which will discourage capital formation around CO2 sequestration.

Additionally, even though the proposed rule appears to include a 50 year default post injection site care period, in reality, that deadline is illusory as it isnot self executing. Under the rules, post injection site care must continue indefinitely until the Director authorizes closure. The closure approval process could take years, even decades, as the Director has no regulatory incentive to act on any post injection site care report. Meanwhile, a permittee may be required to continue unnecessary and expensive monitoring and reporting indefinitely.

Whether the post-injection site care period is site-specific, or 10 to 50 years, TxCCSA suggests that the post-injection site care provision be reconfigured to be self-executing and allow for closure at the end of that period unless the Director affirmatively acts to extend the post-injection site care period. These

Response: Because of the variety of site-specific circumstances at GS sites, EPA believes that individual UIC Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care monitoring is needed (or whether the timeframe may be shortened), based on the circumstances of a particular project. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties, and will not be made arbitrarily.

EPA believes that 50 years is an appropriate default post-injection site care timeframe. However, EPA recognizes that, in some cases, the post-injection site care timeframe may need to be lengthened or shortened based on site-specific circumstances. For instance, if after 50 years, monitoring data indicates that the CO2 plume is still moving and may endanger a USDW, monitoring should continue on a regular basis. Conversely, if it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs, continuing post-injection site care would be unnecessary (see 146.93(b)(2)).

EPA disagrees that the 50 year timeframe is unsupported. In determining the post-injection site caretimeframe for the proposed regulation, EPA reviewed industry reports, existing environmental programs, and initial GS research studies. EPA provided a synthesis of pertinent results from GS modeling studies in the preamble to the proposed regulation. Further explanation of this analysis was included in an EPA-prepared background document that is available in the federal docket, titled"Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Areaof-Review and Potential Risk to Underground Sources of Drinking Water." Based on review of these studies, modeling results indicate that the CO2 plume stabilization may occur on the timeframe of 10-100 years after the cessation of injection. EPA believes that a 50-year default post-injection site care timeframe is a reasonable midpoint, and has retained this in the final regulation.

EPA believes that, given the unique challenges associated with GS of large volumes of injected CO2, post-injection site care should continue until it can be demonstrated that the CO2 plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final regulation retains the requirement at §146.93(b)(3) that the owner or operator must submit to the Director a demonstration, based on monitoring and other site-specific data, that no additional monitoring is needed to ensure that the GS project does not pose a risk of endangerment to USDWs. Additionally, the permitting authorities responsible for Class VI wells will maintain an active role with the owner or operator in order to ensure protection of USDWs from endangerment.

EPA disagrees with the commenter's suggestion regarding self-execution. EPA believes that, given the unique challenges associated with GS of large volumes of injected CO2, post-injection site care should continue until it can be demonstrated that the CO2 plume and pressure front no longer pose arisk of endangerment to USDWs. For this reason, the final regulation retains the requirement at 146.93(b)(3) that the owner or operator must submit to the Director a demonstration, based on monitoring and other site-specific data, that no additional monitoring is needed to ensure that the GS project does not pose a risk of endangerment to USDWs. Additionally, the permitting authorities responsible for Class VI wells will maintain an active role with the owner or operator in order to ensure protection of USDWs from endangerment.

Commenter Name: Tiffany Rau Letter ID: 0224 Commenter Organization: Hydrogen Energy International Comment ID: 21695

Comment: (C) SITE CLOSURE PERIOD

EPA correctly states in its Preamble that defining the post-injection site care period is "difficult to define because it is based on site-specific considerations." (73 Fed. Reg. at 43519.) The three studies cited by EPA also concluded that "the actual time for CO2 plume stabiliziation . . . will be very site-specific, being influenced by geologic factors such as formation permeability, geochemistry, and the degree of capillary trapping." (Id.) However, the Proposed Rule establishes a default 50-year period (following the cessation of injection) during which the operator must conduct monitoring to demonstrate that "the carbon dioxide plume and pressure front have stabilized and the geologic sequestration project does not pose an endangerment to USDWs." (See § 146.93(b).) The designation of a 50year time-period without regard to particular site characteristics is arbitrary and not supported by existing scientific studies or industry experience. Moreover, the 50-year timeframe does not provide any incremental benefit as compared with a performance standard to protecting USDWs; rather, it will be a significant deterrent to commercial investment in geologic sequestration projects.

Response: EPA disagrees that the 50 year time frame is unsupported. In determining the postinjection site care-timeframe for the proposed regulation, EPA reviewed industry reports, existing environmental programs, and initial GS research studies. EPA provided a synthesis of pertinent results from GS modeling studies in the preamble to the proposed regulation. Further explanation of this analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water." Based on review of these studies, modeling results indicate that the CO2 plume stabilization may occur on the timeframe of 10-100 years after the cessation of injection. EPA believes that a 50-year default post-injection site care timeframe is a reasonable midpoint for most GS projects and available data, including data submitted by commenters, do not support a different default timeframe, and has retained this in the final regulation.

However, EPA recognizes that there may be sites where the 50 year post injection site care timeframe may be either not appropriate or more burdensome than necessary based on site-specific conditions. 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at§146.93(c).

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

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Tiffany Rau Letter ID: 0224 Commenter Organization: Hydrogen Energy International Comment ID: 21696 Other EPA Comment Codes and Descriptions: 5260 2.8.2.3 Adjusting the post-injection timeframe (seeking comment)

Comment: HEI urges EPA to adopt the performance standard that EPA considered in its review. EPA considered three options: (1) fixed period; (2) performance standard; and (3) combination of fixed period and performance standard; EPA states it adopted the latter approach. (73 Fed. Reg. at 43519.) While the Proposed Rule allows a Director to reduce the 50-year minimum (§146.93(b)(2)), the practical effect will be the 50-year timeframe applies unless an operator is able to overcome the presumption built into the Proposed Rule that 50 years is adequate. Indeed, this is more prescriptive than the requirement for Class I hazardous wells, which provides that the timeframe for post-injection site care ends when the plume has stabilized and cannot endanger USDWs. (Id.; 40 CFR §146.71.)

Response: EPA agrees that some owners or operators will be able to demonstrate, in less than 50 years, that the pressure front and plume no longer pose a risk of endangerment to USDWs. However, based on studies, EPA believes that the 50 year default time frame is warranted based on additional review of research studies and reports and evaluation of public comments.

However, EPA recognizes that there may be sites where the 50 year post injection site care timeframe may be either not appropriate or more burdensome than necessary based on site-specific conditions. EPA believes that the best way to address all possibilities, while ensuring USDW protection from endangerment, is to set a 50 year default post-injection site care timeframe, with flexibility to: (1) allow the Director discretion to shorten or lengthen the PISC timeframe during the PISC period based on site-specific data, pursuant to requirements at §146.93(b); or (2) afford the Director discretion to allow a Class VI well owner or operator to demonstrate, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care timeframe of 50 years, with flexibility to adjust the timeframe for a limited number of GS projects during the permitting process where substantialdata 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Brian Williams Letter ID: 0225 Commenter Organization: BP Alternative Energy North America, Inc. (BP) Comment ID: 21746

Comment: (C) SITE CLOSURE PERIOD

EPA correctly states in its Preamble that defining the post-injection site care period is "difficult to define because it is based on site-specific considerations." (73 Fed. Reg. at 43519.) The three studies cited by EPA also concluded that "the actual time for CO2 plume stabiliziation . . . will be very site-specific, being influenced by geologic factors such as formation permeability, geochemistry, and the degree of capillary trapping." (Id.) However, the Proposed Rule establishes a default 50-year period (following the cessation of injection) during which the operator must conduct monitoring to demonstrate that "the carbon dioxide plume and pressure front have stabilized and the geologic sequestration project does not pose an endangerment to USDWs." (See § 146.93(b).) The designation of a 50-year time-period without regard to particular site characteristics is arbitrary and not supported by existing scientific studies or industry experience. Moreover, the 50-year timeframe does not provide any incremental benefit as compared with a performance standard to protecting USDWs; rather, it will be a significant deterrent to commercial investment in geologic sequestration projects.

Response: EPA disagrees that the 50 year time frame is unsupported. In determining the postinjection site care-timeframe for the proposed regulation, EPA reviewed industry reports, existing environmental programs, and initial GS research studies. EPA provided a synthesis of pertinent results from GS modeling studies in the preamble to the proposed regulation. Further explanation of this analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water." Based on review of these studies, modeling results indicate that the CO2 plume stabilization may occur on the timeframe of 10-100 years after the cessation of injection. EPA believes that a 50-year default post-injection site care timeframe is a reasonable midpoint for most GS projects and available data, including data submitted by commenters, do not support a different default timeframe, and has retained this in the final regulation.

However, EPA recognizes that there may be sites where the 50 year post injection site care timeframe may be either not appropriate or more burdensome than necessary based on site-specific conditions. 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Brian Williams Letter ID: 0225 Commenter Organization: BP Alternative Energy North America, Inc. (BP) Comment ID: 21753 Other EPA Comment Codes and Descriptions: 5260 2.8.2.3 Adjusting the post-injection timeframe (seeking comment)

Comment: BP urges EPA to adopt the performance standard that EPA considered in its review. EPA considered three options: (1) fixed period; (2) performance standard; and (3) combination of fixed period and performance standard; EPA states it adopted the latter approach. (73 Fed. Reg. at 43519.) While the Proposed Rule allows a Director to reduce the 50-year minimum (§146.93(b)(2)), the practical effect will be the 50-year timeframe applies unless an operator is able to overcome the presumption built into the Proposed Rule that 50 years is adequate. Indeed, this is more prescriptive than the requirement for Class I hazardous wells, which provides that the timeframe for post-injection site care ends when the plume has stabilized and cannot endanger USDWs. (Id.; 40 CFR §146.71.)

Response: EPA agrees that some owners or operators will be able to demonstrate, in less than 50 years, that the pressure front and plume no longer pose a risk of endangerment to USDWs. However, based on studies, EPA believes that the 50 year default time frame is warranted based on additional review of research studies and reports and evaluation of public comments.

EPA believes that the best way to address all possibilities, while ensuring USDW protection from endangerment, is to set a 50 year default post-injection site care timeframe, with flexibility to: (1) allow the Director discretion to shorten or lengthen the PISC timeframe during the PISC period based on site-specific data, pursuant to requirements at §146.93(b); or (2) afford the Director discretion to allow a Class VI well owner or operator to demonstrate, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions,and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Andrew Duguid Letter ID: 0226 Commenter Organization: Schlumberger Carbon Services Comment ID: 24071 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5260 2.8.2.3 Adjusting the post-injection timeframe (seeking comment)

Comment: §146.93 Post-injection site care and site closure.

Proposed Rule: (1) The owner or operator shall continue to conduct monitoring as specified in the Director-approved post-injection site care and site closure plan for at least 50 years following the cessation of injection. At the Director’s discretion, the monitoring will continue until the geologic sequestration project no longer poses an endangerment to USDWs.

Schlumberger Suggested Revision: (1) The owner or operator shall continue to conduct monitoring as specified in the Director-approved post-injection site care and site closure plan, pursuant to the performance based criteria described in 146.93(3).

Schlumberger Rationale: The 50 year default period is not based on any scientific or technical information and could be considered arbitrary and capricious.

Proposed Rule: (2) If the owner or operator can demonstrate to the satisfaction of the Director before 50 years, based on monitoring and other site-specific data, that the geologic sequestration project no longer poses an endangerment to USDWs, the Director may approve an amendment to the post-injection site care and site closure plan to reduce the frequency of monitoring or may authorize site closure before the end of the 50-year period.

Schlumberger Suggested Revision: (2) If the owner or operator can demonstrate to the satisfaction of the Director that the geologic sequestration project no longer poses an endangerment to USDWs, the Director may approve an amendment to the post- injection site care and site closure plan to reduce the frequency of monitoring or may authorize site closure.

Schlumberger Rationale: -

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive in most cases or is arbitrary and capricious. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water."

EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a change in the proposed timeframe. While the 10- or 30-year timeframe suggested by some of thesecommenters may be within the timeframe suggested in some studies, EPA believes that the potential risks of endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that alternative timeframes may be appropriate under limited, specific

circumstances.

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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

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

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate the appropriateness of an alternative post-injection site care time frame; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Ben Yamagata Letter ID: 0227 Commenter Organization: Coal Utilization Research Council Comment ID: 21790

Comment: Post-Injection Site Care

EPA’s proposed 50-years default timeframe for Class VI wells post-injection site care (PISC) is not justifiable, and likely will raise long-term uncertainty about liability associated with a CO2 injection project. Furthermore, the hybrid default/performancebased standard permits the agency to lengthen this period, making it impossible for a CCS project developer to understand the timeframe of its regulatory obligation at project inception. This long-term regulatory uncertainty presents an insurmountable risk. There is documented data that the risk drops off considerably after ten years. [FN3] CURC endorses the Interstate Oil and Gas Compact Commission (IOGCC)’s recommendation for a 10year postclosure site care period. [FN4] The IOGCC proposed rules draw from two decades of state regulatory and industry experience with compression transport, and injection of CO2 from enhanced oil recovery.

[FN3: Sally M. Benson, "Monitoring Carbon Dioxide Sequestration in Deep Geological Formations for Inventory Verification and Carbon Credits" (2006). [FN4: The Interstate Oil and Gas Compact Commission Task Force on Carbon Capture and Geologic Storage, "Storage of Carbon Dioxide in Geologic Structures: A Legal and Regulatory Guide for States and Provinces" (2007) [hereinafter IOGCC Model Rules].]

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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, there are circumstances (e.g., little development of mineral trapping of CO2) under which the potential risks of endangering USDWs will likely not decline within these timeframes. EPA believes that a 50 year post-injection site care timeframe represents a reasonable and protective monitoring period and available data do not support a different timeframe. Furthermore, EPA believes that a 50-year default post-injection site care timeframe, as required at §146.93(b)(1), is not overly burdensome, does not exaggerate the risks associated with GS, is consistent with other environmental programs, and sufficiently protects USDWs from endangerment.

To the comment expressing concern about financial responsibility, EPA recognizes that there are challenges associated with assuring funding for activities that will occur far in the future. However, the Agency believes that in order to protect USDWs from endangerment under the SDWA operators must demonstrate under §146.85 that financial resources are available to plug the injection well and provide post-injection site care at the point in time that the first CO2 is injected. EPA is developing guidance on financial responsibility to assist owners or operators in evaluating the requirements of §146.85 and to assist Directors in evaluating financial responsibility demonstrations. The guidance describes the types of financial mechanisms that operators can use to meet the financial responsibility requirements for GS wells and it will also include a section on how to estimate costs to support accurate financial responsibility demonstrations. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

EPA adds that the purpose of the GS rule is not to incentivize the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

EPA acknowledges the concerns of some commenters that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final GS regulation includes a provision that the Director may, at his/her discretion, shorten the post-injection site care timeframe if the owner oroperator can demonstrate that the GS project does not pose a risk to USDWs, as specified in §146.93(b)(2). Such a demonstration will be site-specific, and based on pressure monitoring and USDW impacts.

Commenter Name: Neeraj Gupta Letter ID: 0229 Commenter Organization: Battelle Energy Technology (BET) Comment ID: 21866

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

Response: EPA agrees with commenters that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

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

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate the appropriateness of an alternative post-injection site care time frame; demonstrate non endangerment; and perform site closure activities.Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and postinjection site care and site closure plans under §146.92 and §146.93. This guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.Commenter Name: A. James Mayer Letter ID: 0230 Commenter Organization: A. J. Mayer International on behalf of the American Energy Security Initiative Comment ID:

21874

Comment: 3. The proposed 50-year post-injection site care timeframe discriminates against smaller operators. The extraordinarily long-term obligation this provision creates will almost certainly prevent some small and middle-size companies from undertaking otherwise successful and beneficial CO2 injection projects because of the significant financial burden imposed.

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive for most Class VI wells. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled"Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Areaof-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that alternative timeframes may be appropriate under limited, specific circumstances.

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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

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

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA adds that the purpose of the GS rule is not to incentivize the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment, regardless of the size of the project. EPA adds that as part of the rulemaking process, the Agency has evaluated the impacts of the GS rule on small entities and determined that it will not have a significant economic impact on a substantial number of small entities. See thediscussion of the Regulatory Flexibility Act in the preamble to the final GS rule.

Commenter Name: A. James Mayer Letter ID: 0230 Commenter Organization: A. J. Mayer International on behalf of the American Energy Security Initiative Comment ID:

21889 Other EPA Comment Codes and Descriptions: 5200 2.8.2 Post injection site care (seeking comment) (40 CFR 146.93)

Comment: 6. EPA should provide for performance-based requirements for Closure and Post Closure Care. The duration of post-injection site care should be determined by specific conditions and characteristics of the site, and monitoring of the pressure to determine the point at which the injection zone pressure is such that USDWs cannot be impacted.

Response: The PISC requirements in the final GS rule, as specified in §146.93(b), incorporate a combination of a fixed timeframe and a performance standard approach. EPA believes that a default PISC timeframe of 50 years, with Director's discretion to shorten or lengthen this timeframe, combined with a site-specific Director’s discretion to create an alternative PISC time frame, ensures that USDWs are protected. 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.EPA is developing guidance to assist owners or operators in evaluating the well plugging, postinjection site care, and site closure requirements of 146.92 and 146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes how an owner or operator should plug injection and monitoring wells, perform post-injection monitoring, demonstrate the appropriateness of an alternative post-injection site care time frame, demonstrate non-endangerment, and perform site closure activities.

Commenter Name: M. Granger Morgan Letter ID: 0233 Commenter Organization: Carnegie Mellon University on behalf of the CCS Reg Project Comment ID:

21911 Other EPA Comment Codes and Descriptions: 5280 2.8.2.4 USDW non-endangerment

demonstrations

Comment: 20. Site closure: We support the general approach that EPA proposes to determine the length of the post-injection site care period (a performance standard, anchored by a suggested duration of several decades). However, we suggest three modifications: 1) The rule should require that the post-injection site care andsite-closure plan specify thresholds for demonstrating that the GS project no longer poses an endangerment to USDWs; 2) The rule should provide mechanisms to coordinate information and allocate responsibility if site conditions during the post-injection site care period are altered by operations of another GS project in the basin; and, 3) The 50-year time period should not become a prescriptive default. There is not yet enough experience to set this as the suggested duration of the post-injection site care period. For now, a performance standard alone is preferable and creates the right incentives to protect USDWs. After experience has been gained from early projects, the rule could be amended to include a suggested duration.

Response: EPA agrees that the rule should not specify the criteria for setting the monitoring timeframe. Instead, EPA believes that such determinations are site-specific and should be described in a project-specific post-injection site care and site closure plan. However, EPA disagrees that the plan should specify thresholds for demonstrating that the GS project no longer poses a risk of endangerment to USDWs, but agrees that this demonstration should be an important consideration.EPA is developing guidances with recommended approaches for developing and implementing postinjection site care and site closure plans and guidance that describes recommended approaches for how an owner or operator could plug injection and monitoring wells, perform post-injection monitoring, demonstrate non endangerment, and perform site closure activities. The guidances will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

EPA agrees with commenters that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final GS regulation includes a provision that the Director may, at his or her discretion, shorten the post-injection site care timeframe if the owner or operator can demonstrate that the GS project does not pose an endangerment to USDWs, as specified in §146.93(b)(2). Such a demonstration will be site-specific, and based on pressure monitoring and USDW impacts. EPAbelieves however, that to ensure USDW protection from endangerment, a default timeframe for postinjection site care is necessary. A 50-year post-injection site care timeframe represents a reasonable and protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

Commenter Name: Abbie Krebsbach Letter ID: 0235 Commenter Organization: Montana-Dakota Utilities Co. Comment ID: 23186 Other EPA Comment Codes and Descriptions: 5430 2.9.1 Comments on proposed financial responsibility requirements (40 CFR 146.85)

Comment: Closure and Post Injection Site Care (PISC)

Establishing a default time period for PISC, in particular a default time period as lengthy as 50 years as proposed in the rule, is unnecessary and undesirable, and the dual goals of protecting USDW and supporting the commercialization of CCS technology are far better served through a site-specific, performance-based approach. Montana-Dakota believes that the unique characteristics of CO2 do not justify imposition of such a lengthy default PISC period for GS projects. Appropriately sited projects should demonstrate the absence of endangerment to USDW in substantially less than 50 years.Further, imposing requirements on CO2 storage projects that are far beyond those currently in place even for injection of hazardous wastes is unnecessary and will only engender public misperceptions regarding the safety of such projects. There is potential for an obligation to provide financial assurance for activities running through 70 years into the future (according to EPA's assumption of a 20-year injection period), or more. Especially, given the ongoing credit crisis, an unjustifiably lengthy PISC period may make obtaining the necessary financial assurance impossible, stunting or stopping commercial development of CCS.

Montana-Dakota urges EPA to implement a performance-based approach that considers the circumstances of a particular project, bounded by appropriate parameters for its application, and also encourages the EPA to establish clear parameters for such a performance-based approach, and in particular, a clear set of guidelines for demonstrating that the injectate has "stabilized", and for meeting the non-endangerment standard.

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA background document in the federal docket, "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water." While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data 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, there are circumstances (e.g., little development of mineral trapping of CO2) under which the potential risks of endangeringUSDWs will likely not decline within these timeframes. EPA believes that a 50-year default postinjection site care timeframe, as required at §146.93(b)(1), is not overly burdensome, does not exaggerate the risks associated with GS, is consistent with other environmental programs, and sufficiently protects USDWs from endangerment.

EPA acknowledges that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final GS regulation allows the Director to shorten the post-injection site care timeframe if the owner or operator can demonstrate that the GS project does not pose a risk to USDWs, as specified in §146.93(b)(2). Such a demonstration will be site-specific, and based on pressure monitoring and USDW impacts. EPA believes however, that to ensure USDW protection from endangerment, a default timeframe for post-injection site care is necessary.

EPA adds that the purpose of the GS rule is not to incentivize the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

EPA also recognizes the concerns associated with assuring financial responsibility for the long timeframes over which post-injection site care will be conducted. EPA is developing guidance on financial responsibility to assist owners or operators in evaluating the requirements of §146.85 and to assist Directors in evaluating financial responsibility demonstrations. The guidance describes the types of financial mechanisms that operators may choose to use when evaluating the financial responsibility requirements for GS wells and it will also include a section on how to estimate costs tosupport accurate financial responsibility demonstrations. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

EPA disagrees that the requirements for financial responsibility are overly stringent. The goal of financial responsibility is to ensure that financial resources are available to prevent the endangerment of USDWs from improper plugging, remediation, and management of wells in the event that the owner or operator experiences financial difficulties throughout the life of the project.

EPA believes that minimum financial responsibility requirements are necessary to prevent endangerment of USDWs by holding well owners or operators accountable for the safe operation and closure of the well and to avoid expense and risk to the public. See the final rule and preamble for further discussion of EPA's final approach to financial responsibility. EPA adds that the purpose of the GS rule is not to encourage the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

Commenter Name: Robert E. Carter Jr. Letter ID: 0236 Commenter Organization: Indiana Department of Natural Resources (IDNR) Comment ID: 29222

Comment: States like Indiana with a proven track record of effectively managing similar programs have indeed demonstrated an ability to adapt to evolving technologies and we believe do possess the capability to effectively address long-termstorage issues. In fact, as indicated earlier in our comments, many of the longterm issues associated with CCGS operations will be outside the purview of the UIC Program and will need to be addressed by states as they enact appropriate CCGS legislation. EPA should consider implementing rules which afford states with the greatest flexibility to select regulatory options that are best suited to their specific needs and conditions. Specific examples of requirements that may be too prescriptive include:

7. Fixed 50-year post-injection time period.

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive and clarifies that the 50 year period is not fixed. For example, EPA acknowledges that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final GS regulation includes a provision that the Director may, at his/her discretion, shorten the post-injection site care timeframe if the owner or operator can demonstrate that the GS project does not pose a risk to USDWs, as specified in §146.93(b)(2). Such a demonstration will be site-specific, and based on pressure monitoring and USDW impacts. EPA believes however, that to ensure USDW protection from endangerment, a default timeframe for post-injection site care is necessary. A 50 year post-injection site care timeframe represents a reasonable and protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public

comments.

Commenter Name: Philip Papadeas Letter ID: 0238 Commenter Organization: Sandia Technologies, LLC Comment ID: 23358

Comment: §146.93 (a)(4)(b)(1) Re:Monitoring for 50 years How is the operator going to monitor for 50 years, when their facility isclosed, bankrupt, or remains insolvent, while other sites adjacent and in direct influence may remain active and operational? This time is not work-able, and should be consistent with EPA’s best analog, the 30-year post-closure rule from UIC Class I wells. Monitoring should continue only to the point when pressure

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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, there are circumstances (e.g., little development of mineral trapping of CO2) under which the potential risks of endangering USDWs will likely not decline within these timeframes. EPA believes that a 50 year post-injection site care timeframe represents a reasonable and protective monitoring period and available data do not support a different timeframe. Furthermore, EPA believes that a 50-year default post-injection site care timeframe, as required at §146.93(b)(1), is not overly burdensome, does not exaggerate the risks associated with GS, is consistent with other environmental programs, and sufficiently protects USDWs from endangerment.

EPA acknowledges the concerns of some commenters that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final GS regulation includes a provision that the Director may, at his/her discretion, shorten the post-injection site care timeframe if the owner or operator can demonstrate that the GS project does not pose a risk to USDWs, as specified in §146.93(b)(2). Such a demonstration will be site-specific, and based on pressure monitoring and USDW impacts.

To the comment expressing concern about financial responsibility, EPA recognizes that there are challenges associated with assuring funding for activities that will occur far in the future. However, the Agency believes that in order to protect USDWs from endangerment under the SDWA operators must demonstrate under §146.85 that financial resources are available to plug the injection well and provide post-injection site care at the point in time that the first CO2 is injected.. EPA is developing guidance on financial responsibility to assist owners or operators in evaluating the requirements of §146.85 and to assist Directors in evaluating financial responsibility demonstrations. The guidance describes the types of financial mechanisms that operators may choose to use when evaluating the financial responsibility requirements for GS wells and it will also include a section on how to estimate costs to support accurate financial responsibility demonstrations. http://www.epa.gov/safewater/uic/wells_sequestration.htm.

EPA adds that the purpose of the GS rule is not to incentivize the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

Commenter Name: Philip Papadeas Letter ID: 0238Commenter Organization: Sandia Technologies, LLC Comment ID: 23360

Comment: 50-year monitoring is severe, and has no basis in other EPA operational considerations. No site continuity would be present, well operational records lost, and personnel retired with expertise dissipated.

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive and clarifies that the record supports EPA’s final approach. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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, there are circumstances (e.g., little development of mineral trapping of CO2) under which the potential risks of endangering USDWs will likely not decline within these timeframes. EPA believes that a 50 year post-injection site care timeframe represents a reasonable and protective monitoring period and available data do not support a different timeframe. Furthermore, EPA believes that a 50-year default post-injection site care timeframe, as required at §146.93(b)(1), is not overly burdensome, does not exaggerate the risks associated with GS, is consistent with other environmental programs, and sufficiently protects USDWs from endangerment.

EPA acknowledges that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final GS regulation includes a provision that the Director may, at his/her discretion, shorten the post-injection site care timeframe if the owner or operator can demonstrate that the GS project does not pose a risk to USDWs, as specified in §146.93(b)(2). Such a demonstration will be site-specific, and based on pressure monitoring and USDW impacts.

EPA disagrees that a 50 year post-injection site care period would contribute to lack of site continuity or loss of operational records or staff expertise. EPA understands that changes in staff or ownership occur associated with all injection operations that operate over timeframes of several years or decades, and believes that owners and operators granted UIC permits have a responsibility to maintain continuity in expertise and data associated with the project.

Commenter Name: Mark Bohrer Letter ID: 0241 Commenter Organization: North Dakota Industrial Commission Comment ID: 23261 Other EPA Comment Codes and Descriptions: 5260 2.8.2.3 Adjusting the post-injection timeframe (seeking comment)

Comment: 38. EPA is proposing using a combination of fixed timeframe and a performance standard as described above. EPA is tentatively proposing a post-injection site care (monitoring) period of 50 years with Director’s discretion to change that period to lengthen or shorten the 50-year period if appropriate. EPA requests comment on the proposed use of a tentative 50-year fixed timeframe that could be modified at the Director’s discretion based on monitoring and modeling data. EPA

Notice 43519.A performance-based time period is appropriate rather than a fixed timeframe.

Response: EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

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

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Mark Bohrer Letter ID: 0241 Commenter Organization: North Dakota Industrial Commission Comment ID: 23262 Other EPA Comment Codes and Descriptions: 5260 2.8.2.3 Adjusting the post-injection timeframe (seeking comment)

Comment: 39. 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. EPA Notice 43520.

A performance-based time period is appropriate rather than a fixed timeframe.

Response: EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, a default timeframe for post-injection site care will be necessary in all but a limited number of cases. This default 50 year post-injection site care timeframe represents a reasonable and protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Mark Bohrer Letter ID: 0241 Commenter Organization: North Dakota Industrial Commission Comment ID: 23306

Comment: 146.93(b) A performance-based time period is appropriate rather than a fixed timeframe. Establishing an arbitrary and long time frame will inhibit operators from entering into this activity.

Response: EPA acknowledges that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

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

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Kevin Wanttaja Letter ID: 0248 Commenter Organization: Western Energy Supply and Transmission

Associates Comment ID:

22243 Other EPA Comment Codes and Descriptions: 5430 2.9.1 Comments on proposed financial responsibility requirements (40 CFR 146.85)

Comment: – WEST urges EPA to avoid utilizing risk management approaches that discourage CCS development. WEST strongly believes that regulatory certainty is crucial, if meaningful investment is going to flow to CCS technologies and deployment. Certainty needs to be brought to long-term obligations, liabilities and risks associated with GS projects. To assist in this regard, EPA should set a limitof 50 years in the future for liabilities to GS project owners and operators. Extending this limit beyond 50 years may severely limit financial investments in CCS projects. Post injection monitoring and financial assurance requirements are important, but need to be tailored to comport with the potential risks, which decrease significantly after injection is complete.

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive for most Class VI wells. However, EPA acknowledges that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA recognizes that there are challenges associated with ensuring funding for activities that will occur far in the future. However, the Agency believes that operators must demonstrate that financial resources are available to plug the injection well and provide post-injection care at the point in time that the first CO2 is injected. EPA also recognizes the concerns associated with ensuring financial responsibility for the long time frames over which post-injection site care will be conducted. EPA is developing guidance on financial responsibility to assist owners or operators in evaluating the requirements of §146.85 and to assist Directors in evaluating financial responsibility demonstrations. The guidance describes the types of financial mechanisms that operators may choose to use when evaluating the financial responsibility requirements for GS wells and it will also include a section on how to estimate costs to support accurate financial responsibility demonstrations. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

EPA adds that the purpose of the GS rule is not to incentivize the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

EPA disagrees that the requirements for financial responsibility are overly stringent. The goal of financial responsibility for purposes of this rule is to ensure that financial resources are available to prevent the endangerment of USDWs from improper plugging, remediation, and management of wells in the event that the owner or operator experiences financial difficulties throughout the life of the project.

EPA expects the cost of meeting the financial responsibility requirements to be proportionate to the expected costs of each GS activity. The minimum financial responsibility requirements provided are necessary to prevent endangerment of USDWs by holding well owners or operators accountable for the safe operation and closure of the well while avoiding expense and risk to the public. See the finalrule and preamble for further discussion of EPA's final approach to financial responsibility. EPA adds that the purpose of the GS rule is not to encourage the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

Commenter Name: James T. Sims Letter ID: 0249 Commenter Organization: Western Business Roundtable Comment ID: 22264 Other EPA Comment Codes and Descriptions: 5400 2.9 Proposed Financial Responsibility and Long-Term Care Requirements

Comment: 5. Make Risk Management Approaches Reasonable - We strongly urge EPA to avoid utilizing risk management approaches that discourage CCS deployment. Regulatory certainty is absolutely crucial, if meaningful investment is going to flow to CCS technologies and implementation.

EPA can be helpful in that regard by bringing certainty to the long-term obligations and risks associated with geologic sequestration projects. For example, EPA should refrain from requiring financial assurance for potential liabilities more than 50 years in the future. Extending those requirements anyfurther may deter and even prevent investment in CCS projects. Likewise, postinjection monitoring and financial assurance requirements are important, but need to be tailored to comport with the potential risks, which decrease substantially after injection is complete.

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive for most Class VI wells. EPA recognizes that there are challenges associated with assuring funding for activities that will occur far in the future. However, the Agency believes that operators mustdemonstrate that financial resources are available to plug the injection well and provide postinjection care at the point in time that the first CO2 is injected.

EPA disagrees that the requirements for financial responsibility are overly stringent. The goal of financial responsibility is to ensure that financial resources are available to prevent the endangerment of USDWs from improper plugging, remediation, and management of wells in the event that the owner or operator experiences financial difficulties throughout the life of the project.

EPA believes that minimum financial responsibility requirements are necessary to hold well owners or operators accountable for the safe operation and through closure of the well and avoid expense and risk to the public. EPA adds that the purpose of the GS rule is not to encourage the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment. See the final rule and preamble for further discussion of EPA's final approach to financial responsibility.

Under SDWA authority, owners or operators of injection wells must ensure protection of USDWs from endangerment and are subject to liability for enforcement under the Act. The final rule requires that an owner or operator must conduct post-injection site care that is consistent with the approved PISC plan or for the duration of the alternative timeframe approved by the Director pursuant to requirements in §146.93(c), until a demonstration can be made to the satisfaction of the Director that the plume and pressure front no longer pose a risk of endangerment to USDWs. For additional information about the PISC and site closure requirements, see the preamble to the final GS rule.EPA also recognizes the concerns associated with assuring financial responsibility for the long timeframes over which post-injection site care will be conducted. EPA is developing guidance on financial responsibility to assist owners or operators in evaluating the requirements of §146.85 and to assist Directors in evaluating financial responsibility demonstrations. The guidance describes the types of financial mechanisms that operators may choose to use when evaluating the financial responsibility requirements for GS wells, and it will also include a section on how to estimate costs to support accurate financial responsibility demonstrations. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

EPA adds that the purpose of the GS rule is not to incentivize the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment. See the final rule and preamble for further discussion of EPA's final approach to financial responsibility.

EPA acknowledges that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters¿ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Mike Nasi Letter ID: 0254 Commenter Organization: Clean Coal Technology Foundation of Texas Comment ID: 22366 Other EPA Comment Codes and Descriptions: 1250 1.1.1.4 Flexibility is needed (performancebased standards)

Comment: 3. Post-Closure Care

The proposal includes a default monitoring period of 50 years after closure of an injection well, but fails to provide the necessary justification for setting the default monitoring period for this time period. CCTF does not believe that there is a sufficient connection between this time period and the relative risks associated with geologic sequestration of CO2. Consistent with our previous comments, we urge EPA to incorporate performance-based standards, so as to lead to site specific approaches. In this context, we believe that post-injection site care should be based on site and project specific characteristics rather than a prescribed and lengthy time period, especially a default time period that does not seem to be supported by relevant literature.

Although provision is made in the proposed rule for a potential shortening ofthe post-closure monitoring period, the reality under the existing program is that permitting authorities almost without exception default to the maximum statutory monitoring period. Because there is no reason to believe that permitting authorities will take a different approach here, the practical impact of including the 50 year period in the rule will be that operators will be required to monitor for that time period with only rare exceptions. There is simply no technical justification for such an extended monitoring period, especially given the decades of experience showing the 30 year monitoring period to be fully protective of human health and the environment.

Response: EPA disagrees with this comment. In determining the post-injection site care timeframe for the proposed regulation, EPA reviewed industry reports, existing environmental programs, and initial GS research studies. EPA provided a synthesis of pertinent results from GS modeling studies in the preamble to the proposed regulation. Further explanation of this analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water." Based on review of these studies, modeling results indicate that the CO2 plume stabilization may occur on the timeframe of 10-100 years after the cessation of injection. EPA believes that a 50-year default post-injection site care timeframe is a reasonable midpoint, and has retained this in the final regulation.

EPA disagrees that a post-injection site care timeframe of 50 years is excessive for most Class VI wells. 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that alternative timeframes may be appropriate under limited, specific circumstances.

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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA believes however, that to ensure USDW protection from endangerment, a default timeframe for post-injection site care will be necessary in all but a limited number of cases. This default 50 year post-injection site care timeframe represents a reasonable and protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24821

Comment: EPA Rule Issue: 38. EPA is proposing using a combination of fixed timeframe anda performance standard as described above. EPA is tentatively proposing a postinjection site care (monitoring) period of 50 years with Director’s discretion to change that period to lengthen or shorten the 50 year period if appropriate. EPA requests comment on the proposed use of a tentative 50 year fixed timeframe that could be modified at the Director’s discretion based on monitoring and modeling data. EPA Notice 43519.

GWPC CO2 Committee Response: It is inappropriate to utilize a fixed period. A demonstration of non endangerment is an appropriate means of deciding when monitoring is no longer needed. The Committee recommends using a combination of the non-endangerment standard with specific performance standards as follows:

Prior to authorization for site closure, the owner or operator must demonstrate to the Director, based on monitoring, other site-specific data, and modeling that is reasonably consistent with site performance, that no additional monitoring is needed to assure that the geologic sequestration project does not and is not expected to pose an endangerment to USDWs. The Director shall approve closure if the owner or operator demonstrates, based on the current understanding of the site, including monitoring data and/or modeling, all of the following: (i) the estimated magnitude and extent of the project footprint (CO2 plume and the area of elevated pressure) ; (ii) the estimated location of the detectable CO2 plume; (iii) that there is no significant leakage of either CO2 or displaced formation fluids that is endangering USDWs; (iv) that the injected or displaced fluids are not expected to migrate in the future in a manner that encounters a potential leakage pathway into a USDW; (v) that the injection wells at the site completed into or through the injection zone or confining zone are plugged and abandoned in accordance with these requirements; and (vi) any remaining project monitoring wells at the site are being managed by a person and in a manner acceptable to the Director.

Rationale: The fixed timeframe is not adequately supported by scientific and technical evidence and represents an unnecessary departure from the use of performance standards, which EPA has recognized as the preferred approach in most other situations. The use of "stabilization" as a performance standard is not advised because of the difficulties of dealing with background movement within the injection zone. The most important demonstration is containment, not just movement.

Response: EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24945 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5280 2.8.2.4 USDW non-endangerment demonstrations

Comment: Rule Provision: 146.93(b)

EPA Proposal: (b) The owner or operator shall monitor the site following the cessation of injection to show the position of the carbon dioxide plume and pressure front and demonstrate that USDWs are not being endangered.

(1) The owner or operator shall continue to conduct monitoring as specified in the Director-approved post-injection site care and site closure plan for at least 50 years following the cessation of injection. At the Director’s discretion, the monitoring will continue until the geologic sequestration project no longer poses an endangerment to USDWs.

GWPC Recommendations: (b) The owner or operator shall monitor the site following the cessation of injection.

(1) The owner or operator shall continue to conduct monitoring as specified in the Director-approved post-injection site care and site closure plan until closure is authorized pursuant to 146.93(b)(3).

Rationale: Eliminate the 50 year requirement.

There is no justification for extending completed projects for the presumptive 50 years, and it will be difficult to accept much shorter demonstration periods with the 50 year presumption in the regulations. Default 50-year period defeats

incentives for best site identification and best MMV

Need for site-specific considerations and use of data

Need achievable and definable standard

Response: EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For thisreason, the final GS regulation includes a provision that the Director may, at his or her discretion, shorten the post-injection site care timeframe if the owner or operator can demonstrate that the GS project does not pose an endangerment to USDWs, as specified in §146.93(b)(2). Such a demonstration will be site-specific, and based on pressure monitoring and USDW impacts.Alternatively, the final rule at §146.93(c), also allows the Director to approve an alternative postinjection site care timeframe where an owner or operator can demonstrate during the permitting process that an alternative post-injection site care timeframe, other than the 50 year default, isappropriate and ensures non-endangerment of USDWs. The demonstration must be based on sitespecific information, including the results of site-specific computational modeling; the predicted timeframe for pressure decline; the predicted rate of carbon dioxide plume migration; site-specific chemical processes that will result in carbon dioxide trapping; the predicted rate of carbon dioxide trapping; characterization of the confining zone(s); laboratory analyses or studies to verify the information on trapping; the presence of potential conduits for fluid movement and the quality of abandoned well plugs within the AoR; the distance between the injection zone and the USDWs above and/or below the injection zone; and any additional site-specific factors determined by the Director. The demonstration must meet the criteria at §146.93(c)(2) for ensuring the quality and accuracy of the data and models on which the demonstration is based. This demonstration would be submitted as part of the permit application, per §146.82(a)(18), in addition to the PISC and site closure plan required at §146.82(a)(17).

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

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24946 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5260 2.8.2.3 Adjusting the post-injection timeframe (seeking comment)

Comment: Rule Provision: 146.93(b)

EPA Proposal: (2) If the owner or operator can demonstrate to the satisfaction of the Director before 50 years, based on monitoring and other site-specific data, that the geologic sequestration project no longer poses an endangerment to USDWs, the Director may approve an amendment to the post-injection site care and site closure plan to reduce the frequency of monitoring or may authorize site closure before the end of the 50-year period.

GWPC Recommendations: (2) The owner or operator can request and demonstrate to the satisfaction of the Director that the post-injection site care and siteclosure plan should be revised to reduce the frequency of monitoring.

Rationale: See above regarding elimination of 50-year presumptive time period.

Response: As described above, EPA disagrees that a post-injection site care timeframe of 50 years is excessive for most Class VI wells. However, EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24948 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5260 2.8.2.3 Adjusting the post-injection timeframe (seeking comment)

Comment: EPA Proposal: (4) If such a demonstration cannot be made (i.e., if the carbon dioxide plume and pressure front have not stabilized) after the 50-year period,the owner or operator must submit to the Director a plan to continue postinjection site care.

GWPC Recommendations: Delete

Rationale: No longer necessary if 50 year time period is removed.

Response: As described above, EPA believes that, to ensure USDW protection from endangerment, a default timeframe for post-injection site care is necessary in most cases. A 50 year post-injection site care timeframe represents a reasonable and protective monitoring period for most GS sites based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

EPA believes that a 50-year default post-injection site care timeframe, as required at §146.93(b)(1), is not overly burdensome, does not exaggerate the risks associated with GS, is consistent with other environmental programs, and sufficiently protects USDWs from endangerment.

Commenter Name: Claire Olson Letter ID: 0260 Commenter Organization: Basin Electric Power Cooperative Comment ID: 22400Comment: "8. Proposed Well Plugging, Post-Injection Site Care, and Site Closure Requirements"

EPA is proposing to impose a 50-year post-injection site care (PISC) standard as the default timeframe with the UIC State Director having the discretion to adjust this time period. Setting the tentative 50-year fixed timeframe that could be modified at the State Director's discretion based on monitoring and modeling data does provide some flexibility. However, Basin Electric urges the EPA to set the timeframe rules in an order that minimizes early risk projects and rewards early movers. The recently passed Emergency Economic Stabilization bill that has become law (HR. 1428) provides in Division B sec. 115 tax incentives for carbon dioxide sequestration either in secure geological storage or used as a tertiary injectant in a qualified enhanced oil or natural gas recovery project. It is imperative that the monitoring rules do not inhibit the ability of the Secretary of Treasury to give the credit to the appropriate taxpayer who has captured the carbon dioxide. Requiring 50 years of monitoring could preclude early commercial activity. The operator should be responsible for the fixed timeframe of 10 years; however, provisions must be enacted for an eventual transfer of liability and long-term monitoring to the government, most likely the state. The Interstate Oil and Gas Commission 10-year recommendation was reviewed and rejected. However, since the State Director could modify the timeframe by extending the monitoring time based on monitoring and modeling data, Basin Electric suggests lowering the fixed timeframe to 10 years.

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive for most Class VI wells. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled"Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Areaof-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that alternative timeframes may be appropriate under limited, specific circumstances.

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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions,and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

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

EPA adds that the comment related to the Emergency Economic Stabilization bill is outside the scope of this rulemaking. EPA adds that the purpose of the GS rule is not to incentivize the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

Letter ID: 0263 Commenter Organization: Interstate Oil & Gas Compact Commission Comment ID: 22825 Other EPA Comment Codes and Descriptions: 5260 2.8.2.3 Adjusting the post-injection timeframe (seeking comment)

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

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

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

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

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

IOGCC Response: Given documented evidence to date that there is a decreasing risk of leakage after injection ceases, The IOGCC has concluded that a 50 year fixed timeframe is both unnecessary and too long. What is absolutely critical here is that there be Director discretion to increase or decrease the period based on the specifics of a particular project. In the view of the IOGCC, it would be better to prescribe a shorter period with discretion to go longer, rather than vice versa, as such would better facilitate project planning.III A. 8 Proposed Well Plugging, Post-Injection site Care, and Site Closure Requirements

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

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

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive or unnecessary for most GS sites. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water."

EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that alternative timeframes may be appropriate under limited, specific

circumstances.

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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA believes however, that to ensure USDW protection from endangerment, a default timeframe for post-injection site care will be necessary in all but a limited number of cases. This default 50 year post-injection site care timeframe represents a reasonable and protective monitoring period based ona review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

Commenter Name: Steven Chester Letter ID: 0264 Commenter Organization: Michigan Department of Environmental Quality (MDEQ) Comment ID:

22845

Comment: EPA (III . A. 8.) proposes a 50-year post-closure monitoring period .

- Staff believes that the 50-year time period is probably too long as there is no certainty that the entity that originated the sequestration project will be in existence for such a long period.

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive for most GS sites. However, EPA recognizes that there may be sites where the 50 year post injection site care timeframe may be either not appropriate or more burdensome than necessary based on site-specific conditions. 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

To the comment that the entity that originated the project may not be in existence for such a long period, the Agency believes that in order to protect USDWs from endangerment under the SDWA, operators must demonstrate under §146.85 that financial resources are available to plug the injection well and provide post-injection site care at the point in time that the first CO2 is injected. EPA understands that changes in staff or ownership occur associated with all injection operations that operate over timeframes of several years or decades, and believes that owners and operators granted UIC permits have a responsibility to maintain continuity in expertise and data associated with the project.

Commenter Name: Michael Moore Letter ID: 0265 Commenter Organization: North American Carbon Capture & Storage Association (NACCSA) Comment ID:

22867Comment: 5. Closure and Post-Injection Site Care

An additional key area of concern for NACCSA is the proposed rule's provision imposing a 50 year default time period following cessation of injection activities to serve as the closure and post-injection site care ("PISC") period, throughout which monitoring activities and corresponding financial assurance requirements would continue. Under the proposal, the program director would have discretion to adjust the time period upward or downward, with the effect that the PISC period would continue "until the geologic sequestration project no longer poses an endangerment to USDWs."

NACCSA understands that a fair amount of certainty may be achieved through setting some default period of time for the PISC. Establishing such a lengthy default time period also places unnecessary burdens on owners and operators who can clearly establish that no threat to USDWs will be posed within a shorter time frame than whatever default may be established.

Response: EPA agrees that some owners or operators will be able to demonstrate, in less than 50 years, that the pressure front and plume no longer pose a risk of endangerment to USDWs. However, based on studies, EPA believes that the 50 year default time frame is warranted in most cases based on additional review of research studies and reports and evaluation of public comments.

EPA believes that the best way to address all possibilities, while ensuring USDW protection from endangerment, is to set a 50 year default post-injection site care timeframe, with flexibility to: (1) allow the Director discretion to shorten or lengthen the PISC timeframe during the PISC period based on site-specific data, pursuant to requirements at §146.93(b); or (2) afford the Director discretion to allow a Class VI well owner or operator to demonstrate, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Michael Moore Letter ID: 0265 Commenter Organization: North American Carbon Capture & Storage Association (NACCSA) Comment ID:

22868 Other EPA Comment Codes and Descriptions: 1250 1.1.1.4 Flexibility is needed (performancebased standards); 5260 2.8.2.3 Adjusting the post-injection timeframe (seeking comment)

Comment: NACCSA urges the Agency to adopt a performance-based approach more in keeping with the actual risks posed by CCS projects. NACCSA believes that the site specific nature of CO2 storage projects will require each project to be judged on its own merit. If a project can show, at any time after the cessation of injection, that there is sufficiently small risk of endangerment to USDWs, monitoring should no longer be required. Given that under the proposed rule, the program director wouldretain discretion to lengthen or shorten the PISC period as necessary to protect USDWs, a performance based approach is in keeping with the spirit of the draft rule. Furthermore, performance based approach is more in keeping with the realty of potential risks associated with CO2 storage would minimize disincentivization of CCS projects while providing an equivalent degree of protection for USDWs. NACCSA believes that the performance-based approach, currently proposed by EPA as an element of the rule, would be beneficial to project operators and investors and for the protection of USDWs. The final rule should include specific and appropriate circumstances that the program director will consider in exercising discretion in this regard, so that project operators and investors have a clear idea of the bar they will be required to meet in order to close out the PISC period.

Response: As described above, EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: David Hawkins Letter ID: 0272 Commenter Organization: Natural Resources Defense Council Comment ID: 24079 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: D. Closure

[FR p. 43540, §146.93(b)] EPA has proposed an arrangement whereby the operator continues to monitor the site for a minimum of 50 years after the cessation of injection, unless the operator can demonstrate to the satisfaction of the Director that the project no longer poses an endangerment to USDWs and that the CO2 plume and pressure front have stabilized.

While 50 years is not a number that will apply in all cases and projects, we do believe that it is appropriate as a default at today’s level of our understanding and operational experience with GS. The option that operators have under the current proposal to obtain approval for a lower number, based on actual project performance, should be sufficient to deal with situations where 50 years can be demonstrated to be unnecessarily long. Along the same lines,there might be situations where 50 years would not suffice, and where the Director should require a longer period, as per the current proposal. In assessing non-endangerment to USDWs and plume/pressure front stabilization, we believe that the EPA should be far more specific in its requirements. We offer the following language as a suggested revision to §146.93(b):

"(b) The owner or operator shall monitor the site following the cessation of injection.

(1) The owner or operator shall continue to conduct monitoring as specified in the Director-approved post-injection site care and site closure plan for at least 50 years following the cessation of injection or until closure is

authorized.

(2)If the owner or operator can demonstrate to the satisfaction of the Director before 50 years, based on/pursuant to the criteria in (b), that the geologic sequestration project does not and is not expected to pose an endangerment to USDWs or result in releases to the atmosphere, the Director may approve an amendment to the post-injection site care and site closure plan to reduce the frequency of monitoring or may authorize site closure before the end of the 50- year period.

(3) Prior to authorization for site closure, the owner or operator must demonstrate to the Director, based on monitoring, other site-specific data, and modeling that is consistent with site performance, that no additional monitoring is needed to assure that the geologic sequestration project does not and is not expected to pose an endangerment to USDWs or any release to the atmosphere. The owner or operator must demonstrate, based on the current understanding of the site, including monitoring data and modeling, all of the following: (i) the magnitude and extent of the project footprint (CO2 plume and the area of elevated pressure); (ii) the location of the detectable CO2 plume; (iii) that there is no significant leakage of either CO2 or displaced formation fluids that is endangering USDWs or creating a potential release to the atmosphere; (iv) that the injected or displaced fluids are not expected to migrate in the future in a manner that encounters a potential leakage pathway into a USDW or to the atmosphere; (v) that the injection wells at the site completed into or through the injection zone or confining zone are plugged and abandoned in accordance with these requirements; and (vi) any remaining project monitoring wells at the site are being managed by a person and in a manner acceptable to the Director.

(4) If such a demonstration cannot be made after the 50-year period, the owner or operator must submit to the Director a plan to continue post-injection site

care."

Response: EPA agrees that a 50 year post-injection site care timeframe represents a reasonable and protective post-injection site monitoring period for most projects and available data, including data submitted by commenters, do not support a different default timeframe. EPA bases this on a review of research studies, industry reports, and existing environmental programs, and evaluation of public

comments.However, EPA recognizes that there may be sites where the 50 year post injection site care timeframe may be either not appropriate or more burdensome than necessary based on site-specific conditions. 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

In response to comments to be more specific, EPA believes §146.93 is sufficiently specific for the purposes of protecting USDWs. Furthermore, the commenter’s proposed language regarding released CO2 emissions into the air are outside the scope of this rulemaking and EPA’s authority under the

SDWA.

Commenter Name: Mark Vickery Letter ID: 0280 Commenter Organization: Texas Commission on Environmental Quality Comment ID: 24104 Other EPA Comment Codes and Descriptions: 1220 1.1.1.1 Terminology and definitions; 5280 2.8.2.4 USDW non-endangerment demonstrations

Comment: (e) Concern exists regarding the need for (i) a standard (in concentration or saturation) for defining the edge of a CO2 plume, (ii) clear definition of the term "stabilization" as applied to fate and transport of an injected CO2 plume and pressure front, and (iii) a clarified specification of the performance standard for the necessary demonstration to enable termination of the iterative process of monitoring/modeling and related corrective action. If "stabilization" means absence of plume movement or pressure change, it is our understanding from CO2-GS research efforts that indefinitely long periods of monitoring, modeling, and corrective action may be required in contrast to the default period of fifty years cited in the proposed rules and preamble. A more appropriate basis for demonstrations of protection of underground sources of drinking water (USDW) would be keyed to the presence of induced pressure conditions in the injection zone, spatially and temporally. When and where such pressure conditions are insufficient to cause endangerment of a USDW through leakage pathways such as improperly constructed or plugged wells or transmissible faults, the required USDW protection should be considered to be present. Accordingly, if the termination of monitoring, modeling, and corrective action is ultimatelydependent on making the subject demonstration, it is recommended that the "fifty year" specification be deleted from the rule. This would conform the requirements for post-injection site care for Class VI wells more closely to the post-closure care specifications and concepts existing for Class I wells.

Response: EPA disagrees that the rule should specify the criteria for setting the monitoring timeframe. Instead, EPA believes that such determinations are site-specific and should be described in a project specific post-injection site care and site closure plan. EPA also believes that periodic reviews and updates, where necessary, to the plan are important to ensuring that the site continues to be managed effectively and to determine whether shortening the monitoring timeframe is appropriate.

EPA acknowledges that many site-specific factors will influence the determination of when the CO2 plume and pressure front no longer pose a risk of endangerment to USDWs. It is for this reason that EPA believes that individual UIC Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care is needed. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties.

EPA agrees that a complete cessation of plume movement may not occur at some sites for long time periods due to density differences, natural formation flow gradients and diffusion. EPA clarifies that a complete cessation of plume movement is not required, only a demonstration that the plume and pressure front no longer pose a risk of endangerment to USDWs.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of 146.92 and 146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under 146.92 and 146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Mark Vickery Letter ID: 0280 Commenter Organization: Texas Commission on Environmental Quality Comment ID: 24110 Other EPA Comment Codes and Descriptions: 5280 2.8.2.4 USDW non-endangerment

demonstrations

Comment: (f) TCEQ agrees with EPA's approach that financial assurance for post-injection site care may be required for a period less than or greater than fifty years as proposed in 146.93, depending on a site specific demonstration to the Director. However, consistent with TCEQ's comments under Principal Concern 1, TCEQ also encourages EPA to delete the fifty-year threshold requirement in consideration of EPA's indication that the duration of financial assurance should ultimately be keyed to whatever site-specific time is necessary to meet the post-injection site care performance standard of demonstration of non-endangerment ofUSDWs.

Response: EPA agrees that financial responsibility must be maintained throughout the post-injection site care timeframe, regardless of its ultimate length. The GS rule requires this, at 146.85.

EPA also agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason,the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by:(1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the postinjection 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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Greg Shubel Letter ID: 0284 Commenter Organization: Inter-Tribal Council of Michigan, Inc Comment ID: 25303

Comment: "Based on a review of the three studies used for this preliminary analysis, modeling results indicate that the CO2 plume stabilized on the time frame of 10-100 years after the cessation of injection (USEPA, 2008d). EPA requests comment on the proposed use of a tentative 50-year fixed timeframe that could be modified at the Director's discretion based on monitoring and modeling data." (Page 29 of 51)

ITCMI ESD would like to see monitoring and modeling data at a minimum 100 years, this will ensure the owner/operator be responsible for remediation efforts for a longer period. ..

Response: EPA acknowledges that monitoring for a significant period of time may be necessary in most cases; however, the Agency believes that setting a fixed monitoring timeframe of 100 years, as the commenter suggests, is overly burdensome and is not necessary at most GS sites to ensure protection of USDWs from endangerment. EPA bases this on a review of research studies, industry reports, existing environmental programs, and evaluation of public comments.

Instead, the final GS rule retains the 50-year default post-injection site care timeframe, in conjunction with a performance standard, for Class VI wells. The GS rule provides the Director with discretion to extend the timeframe (e.g., if, after 50 years, monitoring data indicates that the CO2 plume may endanger a USDW), or shorten the timeframe (if the owner or operator can demonstrate that the GS project does not pose an endangerment to USDWs), under §146.93(b)(2). Such a demonstration will be site-specific, and based on pressure monitoring and USDW impacts. Thus, 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 post-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 permittingprocess based on substantial data, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Michele Schoepper Letter ID: 0503 Commenter Organization: American Petroleum Institute Comment ID: 21174

Comment: EPA should also reconsider its proposed 50-year default period post injection site care. EPA offers no rationale for this arbitrarily selected period of 50 years. Establishing a fixed and unusually long time period may create a significant barrier for operators considering entry into CCS operations.

Criteria for determining the period for proposed injection site care should be performance based and a function of the site-specific characteristics of a project, such as the project's size, the geologic factors, and the relative risks of the project.

Response: EPA disagrees with this comment. In determining the post-injection site care-timeframe for the proposed regulation, EPA reviewed industry reports, existing environmental programs, and initial GS research studies. EPA provided a synthesis of pertinent results from GS modeling studies in the preamble to the proposed regulation. Further explanation of this analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water." Based on review of these studies, modeling results indicate that the CO2 plume stabilization may occur on the timeframe of 10-100 years after the cessation of injection. EPA believes that a 50-year default post-injection site care timeframe is a reasonable midpoint for most GS projects and available data, including data submitted by commenters, do not support a different default timeframe, and has retained this in the final regulation.

To address concerns that, in some situations, it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs, 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 post-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 onsubstantial data, that an alternative PISC timeframe may be appropriate if it ensures nonendangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Iain Wright Letter ID: 0508 Commenter Organization: BP Alternative Energy Comment ID: 21184

Comment: So moving to my third and final point concerns the appropriate time frame for site closure. There is no rational basis to mandate the universal 50-year minimum time frame for post-injection site care. Such a mandate would kill off commercial investment in geo-sequestration projects. Worse than that, it would preferentially kill off all the best sites. It is with proven seals and the lowest risk of leakage - oil and gas fields.

As the EPA proposal states the actual time for CO2 -plume stabilization will be very site-specific. Well selected and managed sequestration sites, such as an oil or gas field that has met its performance objectives, including plume stabilization, would be much more secure and could be closed relatively quickly, say a couple of years.

However, as the EPA's cited examples show, CO2 injection in a poorly confined saline formation could be run for a while, such that the closure period and have to wait on residual and solubility trapping. Hence, a closure period of several years would be more appropriate.

We recommend that EPA does not mandate any fixed time frame for site closure. Much better would be a site-specific assessment that is risk and performance based. Thank you.

Response: EPA disagrees with this comment. In determining the post-injection site care-timeframe for the proposed regulation, EPA reviewed industry reports, existing environmental programs, and initial GS research studies. EPA provided a synthesis of pertinent results from GS modeling studies in the preamble to the proposed regulation. Further explanation of this analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water." Based on review of these studies, modeling results indicate that the CO2 plume stabilization may occur on the timeframe of 10-100 years after the cessation of injection. EPA believes that a 50-year default post-injection site care timeframe is a reasonable midpoint for most GS projects and available data, including data submitted by commenters, do not support a different default timeframe, and has retained this in the final regulation.

However, EPA recognizes that there may be sites where the 50 year post injection site care timeframe may be either not appropriate or more burdensome than necessary based on site-specific conditions. For this reason, the GS rule offers owners or operators flexibility regarding the durationof the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Scott Anderson Letter ID: 0510 Commenter Organization: Environmental Defense Fund Comment ID: 21217

Comment: We disagree, however, with API and differ with BP that, that the 50-year default period is being used in an arbitrary way. It's only being used as a default, one that can be shortened or lengthened depending on the circumstances of the particular case.

The problem that we see with the proposed closure standard, and the reason that we agree that it needs to be improved, is really two-fold, which is about, frankly, as many folds as we'd like to come up with since it's a two-fold

standard.

The proposal, the bottom line says that you can either extend the 50-year period or decrease it upon a demonstration based on monitoring and other site-specific data, that the carbon dioxide plume and pressure front have stabilized. And, the second con, and that no additional monitoring is needed to assure that the geologic sequestration project does not pose an endangerment to USDWs.

But the problem with the first part is that performance standard is that, as studies included in this docket, support documents that show there are circumstances where it could take centuries, or even in excess of a thousand years for the CO2 plume to completely stabilize. That part of the standard is not very realistic.

The second part of the standard, showing that, that no additional monitoring needed, is needed is really just a restatement of the question. The question that we all need answered, regulators, the public, industry, is what does it take in order to decide whether additional monitoring is necessary.So that's why we agree with API and BP that this standard does need to work, and that what we need is a performance standard that really tells us when we can be sure that no additional monitoring is needed and it's time to -- that performance standards should be site-specific, which is really to say that it should depend on the circumstances and not the, something that's triggered by the simple passage time whether it's 50 years, or 150 years, or five years.

Response: EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA agrees that a determination of when the post-injection site care timeframe ends will be sitespecific. EPA is developing guidance to assist owners or operators in evaluating well plugging, postinjection site care, and site closure requirements of 146.92 and 146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under 146.92 and 146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate the appropriateness of an alternative post-injection site care time frame; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Scott Anderson Letter ID: 0520 Commenter Organization: Environmental Defense Fund Comment ID: 21426

Comment: I would also like to agree in part and strongly disagree in part with my good friends from API and the National Association of Carbon Capture and Storage folks on this closure standard. The disagreement is this; we think that to call the fifty year default period arbitrary is just not accurate. If it said fifty years period without any ability to flex either direction, perhaps that would be arbitrary. Now that said, that does not mean that we support the proposed rule standard for approving site closure. In fact, the opposite. We think it needs to be substantially reworked and we do not even think you necessarily need adefault period in order to have a solid performance standard for this. I am not going to go into exactly what we would substitute instead, but I can say that it will be generally consistent and perhaps precisely the same as comments that are being developed by the Ground Water Protection Council.

Response: EPA based the GS post-injection site care and site closure requirements at §146.93 on existing experience with injection activities, available data from GS pilot projects, and research studies. EPA believes that all available data indicates that the injection well plugging and site closure provisions provide appropriate safeguards for protection of USDWs from endangerment.

EPA acknowledges that there are unknowns associated with early GS project deployment and the long term storage of CO2 for GS. For these reasons, the Agency is using an adaptive approach to regulating GS injection. The Agency plans, every six years, to collect and review data on GS projects to determine whether the appropriate amount and types of information and appropriate documentation are being collected, and to determine if modifications to the requirements are appropriate or necessary.

Commenter Name: Steve Crookshank Letter ID: 0523 Commenter Organization: American Petroleum Institute (API) Comment ID: 21357

Comment: EPA should also reconsider a proposed fifty year default period proposed injection site care. EPA offers no rationale for this arbitrarily selected period of fifty years. Establishing a fixed and unusually long time period may create a significant barrier for operators considering entry into CCS operations. Criteria for determining the period post injection site care should be performance based and a function of the site specific characteristics of the project such as project size, geologic factors and the relative risks of the project.

Response: EPA disagrees that the decision to use a default 50 year period for PISC was arbitrarily made. In determining the post-injection site care-timeframe for the proposed regulation, EPA reviewed industry reports, existing environmental programs, and initial GS research studies. EPA provided a synthesis of pertinent results from GS modeling studies in the preamble to the proposed regulation. Further explanation of this analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water." Based on review of these studies, modeling results indicate that the CO2 plume stabilization may occur on the timeframe of 10-100 years after the cessation of injection. EPA believes that a 50 year post-injection site care timeframe represents a reasonable and protective monitoring period and available data, including data submitted by commenters, do not support a different default timeframe. Furthermore, EPA believes that a 50-year default post-injection site care timeframe, as required at §146.93(b)(1), is not overly burdensome, does not exaggerate the risks associated with GS, is consistent with other environmental programs, and sufficiently protects USDWs from endangerment.

However, EPA recognizes that there may be sites where the 50 year post injection site care timeframe may be either not appropriate or more burdensome than necessary based on site-specific conditions. 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Kevin Frederick Letter ID: 0525 Commenter Organization: Wyoming Department of Environmental Quality Comment ID: 21405

Comment: We do not support requiring a fixed time frame for post injection site care of fifty years. We recommend that a performance standard be applied to determine a period of post injection site care. That post injection site care continues until the plume is stabilized and cannot endanger USDW's.

Response: EPA agrees with commenters that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.Commenter Name: Cynthia Lane Letter ID: 0528 Commenter Organization: American Water Works Association (AWWA) Comment ID: 21390 Other EPA Comment Codes and Descriptions: 5260 2.8.2.3 Adjusting the post-injection timeframe (seeking comment)

Comment: Finally, AWWA supports the rule requirement for the fifty year period for post injection site care. However, we suggest that it be set at a fifty year minimum with no discretion to shorten. Given the potential scope of carbon sequestration, this will provide for consistent approach across the U.S., provide strong long term protective measures of USDW's.

In conclusion, AWWA is concerned that the proposed large scale sequestration of carbon dioxide in underground aquifers may have a significant impact on the public, the environment and drinking water utilities. We are also concerned that

Response: EPA agrees that a 50 year post-injection site care timeframe represents a reasonable and protective post-injection site monitoring period for most projects and available data, including data submitted by commenters, do not support a different default timeframe. EPA bases this on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments. Furthermore, EPA believes that a 50-year default post-injection site care timeframe is not overly burdensome, does not exaggerate the risks associated with GS, is consistent with other environmental programs, and sufficiently protects USDWs from endangerment. For this reason, the final GS regulation retains the 50 year post-injection site care timeframe, as specified in §146.93(b)(1).

However, EPA disagrees that a 50 year post-injection site care timeframe should be an absolute minimum. Rather, EPA believes, as some commenters suggest, that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Mike Moore Letter ID: 0532Commenter Organization: North American Carbon Capture and Storage Association (NACCSA) Comment ID:

21369

Comment: The third area of concern is the proposed fifty year default post injection site care period. While some minimum period may be appropriate, a fifty year period is arbitrary and unwarranted by the specific characteristics of carbon dioxide. We note that the program director has discretion to extend or shorten the period without guidance. NACSA proposes that the rule adopt a period of performance based standard based on project specific information gained through the site characterization and monitoring phase. Alternatively the Agency should shorten the default period significantly to reflect the time required to assess CCS project work.

Response: EPA disagrees that the decision to use a default 50 year time period for PISC was arbitrarily made. In determining the post-injection site care-timeframe for the proposed regulation, EPA reviewed industry reports, existing environmental programs, and initial GS research studies. EPA provided a synthesis of pertinent results from GS modeling studies in the preamble to the proposed regulation. Further explanation of this analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water." Based on review of these studies, modeling results indicate that the CO2 plume stabilization may occur on the timeframe of 10-100 years after the cessation of injection. EPA believes that a 50 year post-injection site care timeframe represents a reasonable and protective monitoring period and available data, including data submitted by commenters, do not support a different default timeframe. Furthermore, EPA believes that a 50-year default post-injection site care timeframe, as required at §146.93(b)(1), is not overly burdensome, does not exaggerate the risks associated with GS, is consistent with other environmental programs, and sufficiently protects USDWs from endangerment.

To address concerns that, in some situations, it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs, 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 post-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 onsubstantial data, that an alternative PISC timeframe may be appropriate if it ensures nonendangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: George Peridas Letter ID: 0534 Commenter Organization: Natural Resources Defense Council (NRDC) Comment ID: 21458 Other EPA Comment Codes and Descriptions: 5260 2.8.2.3 Adjusting the post-injection timeframe (seeking comment)Comment: The closure standards I agree with Scott, I do not think that fifty years is arbitrary. I do not think that it is the magic number or that it will be appropriate for every single site. Nonetheless, I think it is a good benchmark, but we do need to have other flexibility to revise this upwards or downwards as project data comes in.

I think what needs a little bit of refinement is the phrase at the discretion of

the administrator. I think that should be some more concrete criteria as to when the administrator should reserve the rights to require certain techniques to be used on other requirements in the rule.

Response: EPA agrees that the Director should have discretion to shorten or lengthen the postinjection site care monitoring period, and has retained this provision in the final GS rule at 146.93(b)(2). 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

Because of the variety of site-specific circumstances at GS sites, EPA believes that individual UIC Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care monitoring is needed (or whether the timeframe may be shortened), based on the circumstances of a particular project. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate the appropriateness of an alternative post-injection site care time frame; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

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

Commenter Name: George Peridas Letter ID: 0534Commenter Organization: Natural Resources Defense Council (NRDC) Comment ID: 21463

Comment: and I do also agree with the performance based closure standard rather than the mere passage of a number of years which could be ten, it could be fifty. I really do think that we need to look at what happens in each project rather than saying if you have been through a number of years, then it is fine.

Response: EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

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



### Individual Comments

Commenter Name: Karl R. Moor Letter ID: 0109 Commenter Organization: Southern Company, on behalf of Edison Electric Institute (EEI) Comment ID:

22003 Other EPA Comment Codes and Descriptions: 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: EEI urges EPA to defer to site-specific characteristic wherever possible in the regulations.

For example, the proposed regulations contemplate a 50-year post- injection site care period, but the UIC program director can require continued monitoring if he or she deems it necessary to protect underground sources of drinking water. In the notice of proposed rulemaking, EPA states that it is willing to consider other time frames for the post-injection site care period, but instead of a default, the Agency should let the characteristics of each site determine the appropriate length of time for post-injection site care. If the director hasthe discretion to vary the length of the monitoring period based on sitespecific characteristics, establishing a lengthy default period would place an unnecessary burden on those owners and operators who can show that their projects pose no threat to underground sources of drinking water in less than 50 years. In fact, EEI and its members believe that appropriately sited CCS projects will be able to make such a demonstration in substantially less than 50 years, perhaps only 10 years since data suggest that the risk profile of carbon dioxide injection tails off markedly after a decade. Consequently, a lengthy default period would penalize those owners and operators who have taken steps to ensure proper site characterization. Surely, EPA would rather reward - and, therefore, encourage - appropriate siting: Properly managed site characterization and operations are the best way to ensure the highest level of protection for underground sources of drinking water.

Response: EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

Because of the variety of site-specific circumstances at GS sites, EPA believes that Directors, inconsultation with operators, will be in the best position to determine whether additional postinjection site care monitoring is needed (or whether the timeframe may be shortened), based on the circumstances of a particular project. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA agrees that proper site characterization is a critical component of ensuring that USDWs are protected. However, EPA disagrees that this is a substitute for post-injection site care. EPA believes that extensive post-injection monitoring is necessary to protect USDWs from endangerment.

EPA adds that the purpose of the GS rule is not to incentivize the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

Commenter Name: Doug Louis Letter ID: 0121 Commenter Organization: Kansas Corporation Commission Comment ID: 22084

Comment: The proposed rule sets the post-injection site care period at a default period of 50 years.

KCC staff agrees the UIC program Director should have the authority to shortenor lengthen the post-injection site care period if the owner/operator demonstrates a different time period is appropriate.

Response: EPA acknowledges the commenter’s support; the final GS regulation retains this provision at §146.93(b)(2). Such a demonstration will be site-specific, and based on pressure monitoring and USDW impacts.

Commenter Name: Leslie Savage Letter ID: 0122 Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24804 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: (4) If such a demonstration cannot be made after the 50-year period, must submit to the Director a plan to continue post-injection site care.

{See comment above.}

Response: As described above, the post-injection site care timeframe may be reduced by the Director if the owner or operator can demonstrate that the remaining pressure front and plume no longer pose a risk of endangerment to USDWs. The non-endangerment finding is left to the discretion of the Director, based on site-specific information such as plume movement, pressure decay, and the location of potential leakage pathways. As suggested by the commenter, a complete cessation of plume movement is not required, only a demonstration that the plume and pressure front no longer pose a risk of endangerment to USDWs, as specified in §146.93(b)(2-4). EPA retains this provision in the final GS regulation GS rule also offers owners or operators flexibility regarding the duration of the PISC timeframe by affording the Director discretion to allow a Class VI well owner or operator to demonstrate, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Sam Kitto Letter ID: 0126 Commenter Organization: National Tribal Air Association Comment ID: 23046

Comment: for deciding upon the 50-year monitoring period. In addition, our organization recommends that the GS rule specifically require that qualified engineers trained in geologic sequestration be substantively involved in any decision regarding the shortening or lengthening of the post-closure monitoring period of an injection well.

Response: EPA agrees and expects that qualified scientists and engineers will be involved in any decision by the Director to lengthen or shorten the post-injection site care monitoring period, but is not requiring this at §146.93.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 postinjection 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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

Because of the variety of site-specific circumstances at GS sites, EPA believes that individual UIC Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care monitoring is needed (or whether the timeframe may be shortened) or if an alternative PISC timeframe is appropriate, based on the circumstances of a particular project. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties.

Commenter Name: Carl Carlsson Letter ID: 0131 Commenter Organization: SUEZ Energy Generation NA, LLC Comment ID: 21538

Comment: financing. As it currently reads, the proposed rule has provisions for extending this period in the event that performance standards are not met, so the standard would be adequately protective with a 30-year requirement.

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive for most Class VI wells. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient 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, there are circumstances (e.g., little development of mineral trapping of CO2) under which the potential risks of endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe.

EPA acknowledges there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by:(1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the postinjection 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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Dawn A. Thorne Letter ID:

0134Commenter Organization: University of Utah Energy and Geoscience Institute on behalf of the Southwest Regional Partnership Comment

ID: 21659 Other EPA Comment Codes and Descriptions: 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: - Section 146.93(b)(1) "The owner or operator shall continue to conduct monitoring as specified in the Director-approved post-injection site care and site closure plan for at least 50 years following the cessation of injection. At the Director's discretion, the monitoring will continue until the geologic sequestration project no longer poses an endangerment to USDWs."

Response/Discussion: The SWP recommends adopting a performance-based approach to the site care period so that each site is monitored for as long as necessary, but not longer than necessary in order to avoid an extra cost burden to regulators and owners/operators. The required site-specific "post-injection site care and site closure plan" appears sufficient to convey appropriate monitoring techniques and timescales to the EPA Director.

Response: EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA acknowledges the commenter’s support of the post-injection site care and site closure plan; the final GS regulation retains this provision.

Commenter Name: Brianne Metzger Letter ID: 0151 Commenter Organization: Spectra Energy Corp Comment ID: 21878

Comment: A. The Director Should Have the Discretion To Shorten The Post-Injection Site Care Period, But Not Extend It.

EPA is proposing a post-injection site care period of 50 years. The Director would have discretion to extend this period if after 50 years USDWs still face potential endangerment or modeling and monitoring results demonstrate that the CO2 plume and pressure front have not yet stabilized. The Director also could reduce this period if data on pressure, fluid movement, mineralization, and/or dissolution reactions indicate that the plume and pressure front have ceased and the injectate does not pose a risk to USDWs. EPA requested comment on the proposed use of a tentative 50-year fixed timeframe that could be modified atthe Director’s discretion based on monitoring and modeling data.

Spectra supports EPA’s approach granting the Director discretion to adjust the timeframe based on the risk posed to USDWs. This approach takes into account the site-specific nature of CCS projects and recognizes the importance of creating a rule that does not place unnecessary regulatory, financial, or technical burdens on site owners and operators. However, Spectra proposes limiting Director discretion to the ability to shorten the post-injection site care period, upon meeting certain performance-based criteria that indicate the CO2 plume has stabilized and poses no recognizable risk to USDWs. This creates an incentive for project operators to adhere to best practices and could potentially encourage CCS project development.

Spectra respectfully disagrees with granting the Director the discretion to extend the post-injection site care period beyond the fixed, pre-determined time period, on grounds that this places an unreasonable and potentially prohibitive financial risk on site operators. Specifically, owners or operators whose post-injection site care period is extended may be unable to secure additional financial assurance to cover the additional period of time. EPA cannot assume that owners or operators would be able to renew or extend the risk management instrument it procured prior to commencing injection and storage operations, nor can it assume that an owner or operator would be able to secure a new risk management instrument in the market. The possibility of an extension creates a risk for owners or operators that they may have to finance post-injection site care well beyond the default period, which would increase project costs and potentially inhibit CCS project development altogether. Furthermore, the extension of a post-injection site care period for an owner or operator that is no longer solvent exposes the public to unnecessary risk and would require governmental intervention. Rather than the possibility of an extension at the Director’s discretion, Spectra believes that a fixed post-injection site care period with the possibility of it being shortened upon meeting certain performance criteria that are evaluated on a site-by-site basis creates an incentive for operators to adhere to best practices and removes what would be a major deterrent from CCS project development. Spectra further believes that EPA should develop such performance criteria as soon as possible and in a manner that provides a realistic possibility that sites with stabilized CO2 plumes would qualify for a shorter post-injection site care period.

Response: EPA disagrees that the Director should not have discretion to lengthen the post-injection site care monitoring period. EPA believes that 50 years is an appropriate default post-injection site care timeframe in most cases. However, EPA recognizes that, in some cases, the post-injection site care timeframe may need to be lengthened based on site-specific circumstances. For instance, if after 50 years, monitoring data indicates that the CO2 plume is still moving and may endanger a USDW, monitoring should continue on a regular basis, as specified in §146.93(b)(2).

Because of the variety of site-specific circumstances at GS sites, EPA believes that Directors, inconsultation with operators, will be in the best position to determine whether additional postinjection site care monitoring is needed (or whether the timeframe may be shortened), based on the circumstances of a particular project. EPA expects this decision to be made based on relevant sitedata and in consultation with all potentially impacted parties.

Commenter Name: Jeff Moseley Letter ID: 0155 Commenter Organization: Greater Houston Partnership (GHP) Comment ID: 21260 Other EPA Comment Codes and Descriptions: 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: 7. Revise the standard for determining site closure. Criteria should be performance based and a function of site-specific geologic and other risk criteria, rather than being dependent on a 50-year-period or any other fixed period of time; and,

Response: EPA agrees with commenters that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final GS regulation 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA believes however, that to ensure USDW protection from endangerment, a default timeframe for post-injection site care is necessary in most cases. A 50 year post-injection site care timeframe represents a reasonable and protective monitoring period for most GS projects based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public

comments.

Commenter Name: James Childress Letter ID: 0158 Commenter Organization: Gasification Technologies Council (GTC) Comment ID: 23790

Comment: In addition, EPA seeks comment on whether the Director should be allowed to shorten the timeframe based on performance information, and whether EPA should require a shorter or longer post injection period if data suggests the time frame should be adjusted. EPA Notice 125-26.

EPA should allow the Director to shorten the timeframe based on performance information. However, an open-ended time period results in a high degree of uncertainty regarding cost exposure to a project developer. It also leaves a site open to future liability from "reopeners" by the regulatory community. To avoid this latter scenario, a maximum monitoring period should be defined in terms of clear, performance-based risk metrics - for example, that the validated model predicts that 95% of the plume is or will be trapped and that a sensitivity analysis predicts a comfortable margin of safety and diminimus riskof endangerment to any USDWs.

Response: EPA disagrees that the Director should not have discretion to shorten or lengthen the post-injection site care monitoring period or that it creates a “high degree of uncertainty regarding cost exposure.” Because of the variety of site-specific circumstances at GS sites, EPA believes that individual UIC Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care monitoring is needed (or whether the timeframe may be shortened), based on the circumstances of a particular project. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties to ensure USDW protection.

EPA recognizes that there are challenges associated with assuring funding for activities that will occur far in the future. However, the Agency believes that operators must demonstrate that financial resources are available to plug the injection well and provide post-injection care at the point in time that the first CO2 is injected. EPA also recognizes the concerns associated with assuring financial responsibility for the long time frames over which post-injection site care will be conducted. EPA is developing guidance on financial responsibility to assist owners or operators in evaluating the requirements of §146.85 and to assist Directors in evaluating financial responsibility demonstrations. The guidance describes the types of financial mechanisms that operators may choose to use when evaluating the financial responsibility requirements for GS wells and it will also include a section on how to estimate costs to support accurate financial responsibility demonstrations. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Sandi Tabor Letter ID: 0162 Commenter Organization: Lignite Energy Council (LEC) Comment ID: 21304 Other EPA Comment Codes and Descriptions: 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: 5. Combination of Fixed Timeframe and Performance Standard -EPA is seeking comments on the imposition of a 50-year post-injection site care (PISC) standard as a default timeframe with state UIC directors having discretion to adjust the default time period. We urge EPA to remove all reference to default PISC periods and instead require directors to base post-injection site care on site and project specific characteristics. By so doing the goal of supporting the commercialization of CCS technology is better served.

Response: EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final GS regulation 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilizesite-specific data, and be based on pressure monitoring and USDW impacts. EPA believes however, that to ensure USDW protection from endangerment, a default timeframe for post-injection site care is necessary in most cases. A 50 year post-injection site care timeframe represents a reasonable and protective monitoring period for most GS projects based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public

comments.

Commenter Name: Michael J. Miller Letter ID: 0168 Commenter Organization: Electric Power Research Institute (EPRI) Comment ID: 22511 Other EPA Comment Codes and Descriptions: 5280 2.8.2.4 USDW non-endangerment

demonstrations

Comment: Preamble, page 43520: "Once the owners or operators provide documentation that demonstrates that the models predicting CO2 movement are consistent with monitoring results and that there are no longer risks of endangerment to USDWs, they could request that the Director authorize site closure. EPA is also proposing to allow the Director to shorten or lengthen the 50-year time frame based on performance of the site... EPA wishes to emphasize that site closure cannot occur until monitoring and modeling data establish to the Director’s satisfaction that potential risks of endangerment to USDWs have ceased."

EPRI COMMENT #18: EPA’s requirement for demonstrating plume stability for site closure is based on the ability to both observe and successfully model the speed and stability of the advancing CO2 front, a very discrete boundary that is difficult to define, model accurately when complex reservoir heterogeneity and fast flow pathways are present, and measure in the field on a large scale. (See also EPRI’s comment #2 on defining the front). If remote methods like surface seismic, cross-well seismic or gravity are not successful in tracking front position, and CO2 is never directly detected in sentinel observations wells, then model validation based on CO2 front position may be questioned. In such a case, if the model predicts the continued advance of the CO2 front while the observed data do not, the EPA Director may not be satisfied with the absence of a potential risk of endangerment to USDWs and may unnecessarily delay site

closure for decades. EPRI recommends that the final rule contain alternative provisions for site closure if model validation is unsuccessful.

Response: EPA acknowledges that many site-specific factors will influence the determination of when the CO2 plume and pressure front no longer pose a risk of endangerment to USDWs. It is for this reason that EPA believes that individual UIC Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care is needed. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties.

EPA also agrees that a complete cessation of plume movement may not occur at some sites for long time periods due to density differences, natural formation flow gradients and diffusion. EPA clarifies that a complete cessation of plume movement is not required, only a demonstration that the plume and pressure front no longer pose a risk of endangerment to USDWs.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance willassist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24209 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: Rule Provision: 146.93(b)(4)

API Comments: (4) If such a demonstration cannot be made (i.e., if the carbon dioxide plume and pressure front have not stabilized) after the 50-year period,the owner or operator must submit to the Director a plan to continue postinjection site care.

Rationale: No longer necessary given changes above.

Response: As described above, EPA believes that to ensure USDW protection from endangerment, a default timeframe for post-injection site care is necessary in most cases. A 50-year post-injection site care timeframe represents a reasonable and protective monitoring period for most GS projects based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments. However, EPA recognizes that alternative timeframes may be appropriate under limited, specific circumstances. For this reason, the Class VI 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24257

Comment: Rule Provisions: 146.93(b)(2) EPA Preamble Question: 40. In addition, EPA seeks comment on whether the Director should be allowed to shorten the timeframe based on performance information, and whether EPA should require a shorter or longer post injection period if data suggests the time frame should be adjusted. EPA Notice 43520.

API Response: See question 38 above regarding post closure time periods.

Response: As described above, EPA recognizes that there may be sites where the 50 year post injection site care timeframe may be either not appropriate or more burdensome than necessary based on site-specific conditions. 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 post-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 owneror operator to demonstrate, during the permitting process based on substantial data, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of 146.92 and 146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans required under 146.92 and 146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells, perform post-injection monitoring, demonstrate the appropriateness of an alternative post-injection site care time frame, demonstrate non-endangerment, and perform site closure activities. This guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Robert J. Finley Letter ID: 0180 Commenter Organization: Illinois State Geological Survey Comment ID: 23641 Other EPA Comment Codes and Descriptions: 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: 146.93

(b)(1)

Monitoring for 50 years following cessation of injection has no particular basis in research and should not be the rule against which an operator should be required to seek an exception as provided for in (b)(2). Rather, the regulations should require a maximum post-injection site monitoring plan for, for example, 15 years to include comprehensive reservoir assessment, modeling, and simulation based on data collection during injection and then specifically at closure, followed by five years after closure, 10 years after closure, and 15 years after closure. These suggested intervals have a basis in the changes seen in the 4D seismic as Sleipner that show demonstrable geophysical responses based on injection and plume development over about a 10 year period. Other groups have suggested 10 years of total post-closure monitoring, thus other repeat periods for site surveys may be suggested and should be considered. For the example suggested here, the data taken at closure forms a baseline, such as plume extent based on a 3D seismic survey or other geophysical techniques, and three subsequent surveys at five-year intervals could document plume migration and would serve to validate reservoir simulation. If the total of four such example surveys (closure, +5, +10, and +15) and/or other appropriate monitoring techniques, and the reservoir modeling and simulation, demonstrate a consistent and predictable understanding of subsurface behavior that does not endanger USDWs going forward, then the operator should be deemed to have fulfilled siteclosure responsibilities. To repeat, there is no basis for the suggested 50 years of monitoring.

Response: EPA disagrees that there is no basis for the 50 year timeframe. In determining the postinjection site care-timeframe for the proposed regulation, EPA reviewed industry reports, existing environmental programs, and initial GS research studies. EPA provided a synthesis of pertinent results from GS modeling studies in the preamble to the proposed regulation. Further explanation of this analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water." Based on review of these studies, modeling results indicate that the CO2 plume stabilization may occur on the timeframe of 10-100 years after the cessation of injection. EPA believes that a 50-year default post-injection site care timeframe is a reasonable midpoint for most GS projects and available data, including data submitted by commenters, do not support a different default timeframe, and has retained this in the final regulation.

However, EPA recognizes that there may be sites where the 50 year post injection site care timeframe may be either not appropriate or more burdensome than necessary based on site-specific conditions. For this reason, the Class VI 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA clarifies that, throughout the post-injection site care timeframe, owners and operators must submit monitoring data results to the Director. At these times (or at 5 year intervals), the owner or operator may wish to discuss whether performing a non-endangerment demonstration may be appropriate. This scenario affords many of the suggestions the commenter offers.

Commenter Name: Wendy Jacobs Letter ID: 0183 Commenter Organization: Harvard Law School Environmental Law and Policy

Center Comment ID:

25144 Other EPA Comment Codes and Descriptions: 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: C. EPA Should Clarify the Site Closure Standard

EPA is proposing a "combination of fixed timeframe and performance standard" approach to site closure. 73 Fed. Reg. at 43,519. Under the proposal, the owner or operator would be required to undertake "post-injection site care" following the permanent cessation of injection activities at the site, which would include "submit[ting] periodic reports providing monitoring results and updated modelingresults as appropriate until a demonstration of nonendangerment to USDWs can be made." Id. at 43,520. Specifically, the owner or operator would need to demonstrate "that the carbon dioxide plume and pressure front have stabilized and that no additional monitoring is needed to assure that the geologic sequestration project does not pose an endangerment to USDWs." Id. at 43,541 (proposed 40 C.F.R. § 146.93(b)(3)). Once the owners or operators provide documentation to show that this standard has been met, they can request that the Director authorize site closure. Id. at 43,520. By default, the "post-injection site care" period would last for 50 years following cessation of injection activities; however, the Director would have discretion to shorten the 50-year timeframe if the owner or operator could demonstrate "stabilization/no endangerment" in less than 50 years, or conversely, to lengthen the timeframe if the owner or operator failed to make a demonstration within 50 years. Id.

As a general matter, ELPC and ETIP agree that a combination of a fixed timeframe and a performance standard strikes a good balance and is preferable to relying upon only one of those elements. Adherence to an exacting performance standard alone, defined before commercial deployment of CCS technologies, could preclude owner or operators from taking advantage of best practices as they are developed. Adherence to a single fixed timeframe could allow owner or operators to abandon well sites even as monitoring data indicates a threat to a USDW. Requiring the owner or operator to meet a flexible performance standard throughout a baseline period of 50 years would ensure that post-injection site care, including monitoring and verification, would continue as long as necessary to prevent endangerment of USDWs and require post-injection monitoring and modeling even if the data appear to show "stabilization" within a short timeframe. This would be especially prudent in the short term, given lack of data and experience with large-scale, long-term GS projects.

Response: EPA agrees and has implemented a combination fixed timeframe and performance standard approach for post-injection site care monitoring for Class VI wells. EPA believes that a default PISC timeframe of 50 years, with Director's discretion to shorten or lengthen this timeframe, combined with a site-specific Director’s discretion to create an alternative PISC time frame, ensures that USDWs are protected. 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Bradley J. Field Letter ID: 0186Commenter Organization: New York State Dept. of Environmental Conservation

Div. of Mineral Resources Comment ID:

25213

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

NYSDEC-DMN Response: Given that current injection and reservoir 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 may be more appropriate to allow GS projects to move forward. It would be better to prescribe a shorter period with discretion to go longer, rather than vice versa, as such would better facilitate project planning. Regardless, it is critical that the Director have the discretion to increase or decrease the period based on the specifics of a particular project.

Response: EPA acknowledges that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective 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 timeframe of 50 years is excessive for most Class VI wells. EPA proposed a default post-injection site 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 potential risks of endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different

default timeframe.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190Commenter Organization: Carbon Sequestration Council Comment ID: 24500 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: Rule Provision: 146.93(b)(4)

Proposed CCS Group Recommendations: (4) If such a demonstration cannot be made (i.e., if the carbon dioxide plume and pressure front have not stabilized) after the 50-year period, the owner or operator must submit to the Director a plan to continue post-injection site care.

Basis for CCS Group Comments: No longer necessary with 50-year period deletion.

Response: As described above, EPA believes that to ensure USDW protection from endangerment, a default timeframe for post-injection site care is necessary in most cases. A 50-year post-injection site care timeframe represents a reasonable and protective monitoring period for most GS sites based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24549

Comment: Rule Provisions or Federal Register Cite: 146.93(b)(2) EPA Preamble Question: 40. In addition, EPA seeks comment on whether the Director should be allowed to shorten the timeframe based on performance information, and whether EPA should require a shorter or longer post injection period if data suggests the time frame should be adjusted. EPA Notice 43520.

CSC Response: See response to Question 38 above regarding post closure time periods.

Response: As described above, EPA acknowledges that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of 146.92 and 146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans required under 146.92 and 146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells, perform post-injection monitoring, demonstrate the appropriateness of an alternative post-injection site care time frame, demonstrate non-endangerment, and perform site closure activities. This guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.Commenter Name: John R. Baza Letter ID: 0193 Commenter Organization: Utah Division of Oil, Gas, and Mining Comment ID: 23917 Other EPA Comment Codes and Descriptions: 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: Post Site Care Responsibility

EPAs proposed rule sets the post-injection care period at 50 years. This may be modified if it can be demonstrated that the plume has stabilized and the pressure has dissipated. Setting a 50-year period may be unnecessarily long. The Division’s recommendation is that a shorter period be prescribed and then the regulating agency may have the discretion to set a longer post-injection care period if the specifics of a project indicate such a need.

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive for most Class VI wells. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled"Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Areaof-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA acknowledges there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, a default timeframe for post-injection site care will be necessary in all but a limited number of cases. This default 50 year post-injection site care timeframe represents a reasonable and protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments. EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Andy Horn Letter ID: 0196Commenter Organization: Colorado Ground Water Association (CGWA) Comment ID: 23933 Other EPA Comment Codes and Descriptions: 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: Issue 11. The post-closure operator liability timeframe of 50 years should be considered a minimum and should be extended in the event monitoring and modeling data indicate potential failure may require mitigation.

Response: EPA agrees with commenters that a 50 year post-injection site care timeframe represents a reasonable and protective monitoring period for most cases. EPA bases this on a review of research studies, industry reports, existing environmental programs, and evaluation of public comments. Furthermore, EPA believes that a 50-year default post-injection site care timeframe is not overly burdensome, does not exaggerate the risks associated with GS, is consistent with other environmental programs, and sufficiently protects USDWs from endangerment. For this reason, the final GS regulation retains the 50 year post-injection site care timeframe, as specified in §146.93(b)(1).

However, EPA disagrees that a 50-year post-injection site care timeframe should be an absolute minimum. Rather, EPA recognizes that there may be sites where the 50 year post injection site care timeframe may be either not appropriate or more burdensome than necessary based on site-specific conditions. 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). Such a demonstration will be site-specific, and based on pressure monitoring and USDW impacts. EPA clarifies that in no cases will site closure be authorized until the owner or operator demonstrates to the satisfaction of the Director that the site no longer poses a risk of endangerment to USDWs.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24610

Comment: Rule Provisions: 146.93(b)(2) EPA Rule Issue: 40. In addition, EPA seeks comment on whether the Director should be allowed to shorten the timeframe based on performance information, and whether EPA should require a shorter or longer post injection period if data suggests the time frame should be adjusted. EPA Notice 43520.

Anadarko Petroleum Corporation (APC) Response: It is inappropriate to utilize a fixed period; instead a demonstration of non endangerment is an appropriate means of deciding when monitoring is no longer needed. Please see response toEPA 43519.

Response: EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24722 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: Rule Provision: 146.93(b)(4)

Anadarko Petroleum Corporation (APC) Comments: (4) If such a demonstration cannot be made (i.e., if the carbon dioxide plume and pressure front have not stabilized) after the 50-year period, the owner or operator must submit to the Director a plan to continue post-injection site care.

Rationale: No longer necessary given changes above.

Response: As described above, EPA disagrees that a post-injection site care timeframe of 50 years is excessive in most cases or arbitrary, and retains the default 50-year post-injection site care

timeframe in the final rule. .

Commenter Name: John Corra Letter ID: 0205 Commenter Organization: Wyoming Department of Environmental Quality (DEQ) Comment ID:

22198 Other EPA Comment Codes and Descriptions: 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: 4.Requiring a fixed timeframe post-injection site care (monitoring) period of 50

years:a.We recommend that a performance standard be applied to determine the period of post-injection site care -that post-injection site care continues until the plume is stabilized and will not endanger USDWs.

b. We recommend that the Director should be provided discretion to shorten or lengthen the proposed post-injection site care period of 50 years accordingly.

Response: EPA agrees with commenters that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

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

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Richard Guinn Letter ID: 0210 Commenter Organization: Eastman Chemical Company Comment ID: 22714

Comment: Concern #8: The owner or operator shall continue to conduct monitoring as specified in the Director-approved post-injection site care and site closure plan for at least 50 years following the cessation of injection. At the Director’s discretion, the monitoring will continue until the geologic sequestration project no longer poses an endangerment to USDWs. (Ref: page 43519, Sec. 8. Post-Injection Site Care Timeframe)

The time required for post-injection site management should not be arbitrarily set at 50 years. Criteria for defining the time for post-injection management should be performance based and site specific. The choice of 50 years is arbitrary and does not take into account the data and knowledge and modeling verification obtained over a preceding operating and injection period of years and likely decades. The maximum post-injection monitoring period should be defined on reasonable but quantitative, performance-based metrics - for example, that the validated model predicts that 95% of the plume is or will be trappedand that a sensitivity analysis predicts a comfortable margin of safety to minimize approach to any USDWs, thus preventing potential endangerment. Concern

Response: EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

EPA disagrees that a post-injection site care timeframe of 50 years is excessive in most cases or arbitrary. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titledComputational Modeling of Underground Injection of Carbon Dioxide for Determination of Areaof-Review and Potential Risk to Underground Sources of Drinking Water. EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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, there are circumstances (e.g., little development of mineral trapping of CO2) under which the potential risks of endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters¿ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA recognizes that there are challenges associated with assuring funding for activities that will occur far in the future. However, the Agency believes that operators must demonstrate that financial resources are available to plug the injection well and provide post-injection care at the point in time that the first CO2 is injected. EPA also recognizes the concerns associated with assuring financial responsibility for the long time frames over which post-injection site care will be conducted. EPA is developing guidance on financial responsibility to assist owners or operators in evaluating the requirements of §146.85 and to assist Directors in evaluating financial responsibility demonstrations. The guidance describes the types of financial mechanisms that operators may choose to use when evaluating the financial responsibility requirements for GS wells and it will also include a section on how to estimate costs to support accurate financial responsibility demonstrations. The guidance willbe available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Richard Guinn Letter ID: 0210 Commenter Organization: Eastman Chemical Company Comment ID: 22740 Other EPA Comment Codes and Descriptions: 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: In addition, EPA seeks comment on whether the Director should be allowed to shorten the timeframe based on performance information, and whether EPA should require a shorter or longer post injection period if data suggests the time frame should be adjusted. EPA Notice 125-26.

EPA should allow the Director to shorten the timeframe based on performance information. However, an open-ended time period results in a high degree of uncertainty regarding cost exposure to a project developer. It also leaves a site open to future liability from "reopeners" by the regulatory community. To avoid this latter scenario, a maximum monitoring period should be defined in terms of clear, performance-based risk metrics - for example, that the validated model predicts that 95% of the plume is or will be trapped and that a sensitivity analysis predicts a comfortable margin of safety and diminimus risk of endangerment to any USDWs.

Response: EPA disagrees that the Director should not have discretion to shorten or lengthen the post-injection site care monitoring period. Because of the variety of site-specific circumstances at GS sites, EPA believes that Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care monitoring is needed (or whether the timeframe may be shortened), based on the circumstances of a particular project. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties to ensure USDW protection. The final GS regulation retains the provision that the Director may, at his or her discretion, shorten the post-injection site care timeframe if the owner or operator can demonstrate that the GS project does not pose an endangerment to USDWs, as specified in §146.93(b)(2).Alternatively, the final rule at §146.93(c), also allows the Director to approve an alternative postinjection site care timeframe where an owner or operator can demonstrate during the permitting process that an alternative post-injection site care timeframe, other than the 50 year default, isappropriate and ensures non-endangerment of USDWs. The demonstration must be based on sitespecific information, including the results of site-specific computational modeling; the predicted timeframe for pressure decline; the predicted rate of carbon dioxide plume migration; site-specific chemical processes that will result in carbon dioxide trapping; the predicted rate of carbon dioxide trapping; characterization of the confining zone(s); laboratory analyses or studies to verify the information on trapping; the presence of potential conduits for fluid movement and the quality of abandoned well plugs within the AoR; the distance between the injection zone and the USDWs above and/or below the injection zone; and any additional site-specific factors determined by the Director. The demonstration must meet the criteria at §146.93(c)(2) for ensuring the quality and accuracy of the data and models on which the demonstration is based. This demonstration would be submitted as part of the permit application, per §146.82(a)(18), in addition to the PISC and site closure plan required at §146.82(a)(17).

EPA believes that a default post-injection site care timeframe of 50 years, with flexibility to adjust the timeframe for a limited number of GS projects during the permitting process where substantialdata 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Diane VanDe Hei Letter ID: 0213 Commenter Organization: Association of Metropolitan Water Agencies (AMWA) Comment ID:

22951 Other EPA Comment Codes and Descriptions: 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: - 73 FR 43519 -EPA requests comment on the proposed use of a tentative 50-year fixed [post injection site care] timeframe that could be modified at the Director’s discretion based on monitoring and modeling data.

Response: AMWA supports a minimum 50-year time frame for post-injection site care and recommends that the Director not be given any discretion to shorten this time period. EPA notes in the proposal that "the potential risks of endangering USDWs will not decline within that timeframe given that stabilization may continue for several decades." AMWA also recommends that

Response: EPA disagrees that the Director should not have discretion to shorten or lengthen thepost-injection site care monitoring period. EPA believes that 50 years is an appropriate default postinjection site care timeframe. However, EPA recognizes that there may be sites where the 50 year post injection site care timeframe may be either not appropriate or more burdensome than necessary based on site-specific conditions. 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Darrick Eugene Letter ID: 0223 Commenter Organization: Texas Carbon Capture and Storage Association Comment ID: 23993Other EPA Comment Codes and Descriptions: 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: 10. § 146.93 Post-injection site care and site closure.

The proposed rule establishes a 50 year default period for post-injection site care. There is, however, no factual or scientific basis for such an extensive period. Under EPA’s Resource Conservation and Recovery Act rules, which regulate the disposal of hazardous wastes, post closure care is limited to 30 years. Defaulting to an excessively long period will increase costs and introduce greater regulatory uncertainty, which will discourage capital formation around CO2 sequestration.

Additionally, even though the proposed rule appears to include a 50 year default post injection site care period, in reality, that deadline is illusory as it is not self executing. Under the rules, post injection site care must continue indefinitely until the Director authorizes closure. The closure approval process could take years, even decades, as the Director has no regulatory incentive to act on any post injection site care report. Meanwhile, a permittee may be required to continue unnecessary and expensive monitoring and reporting indefinitely.

Whether the post-injection site care period is site-specific, or 10 to 50 years, TxCCSA suggests that the post-injection site care provision be reconfigured to be self-executing and allow for closure at the end of that period unless the Director affirmatively acts to extend the post-injection site care period. These

Response: Because of the variety of site-specific circumstances at GS sites, EPA believes that individual UIC Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care monitoring is needed (or whether the timeframe may be shortened), based on the circumstances of a particular project. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties, and will not be made arbitrarily.

EPA believes that 50 years is an appropriate default post-injection site care timeframe. However, EPA recognizes that, in some cases, the post-injection site care timeframe may need to be lengthened or shortened based on site-specific circumstances. For instance, if after 50 years, monitoring data indicates that the CO2 plume is still moving and may endanger a USDW, monitoring should continue on a regular basis. Conversely, if it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs, continuing post-injection site care would be unnecessary (see 146.93(b)(2)).

EPA disagrees that the 50 year timeframe is unsupported. In determining the post-injection site caretimeframe for the proposed regulation, EPA reviewed industry reports, existing environmental programs, and initial GS research studies. EPA provided a synthesis of pertinent results from GS modeling studies in the preamble to the proposed regulation. Further explanation of this analysis was included in an EPA-prepared background document that is available in the federal docket, titled"Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Areaof-Review and Potential Risk to Underground Sources of Drinking Water." Based on review of these studies, modeling results indicate that the CO2 plume stabilization may occur on the timeframe of 10-100 years after the cessation of injection. EPA believes that a 50-year default post-injection sitecare timeframe is a reasonable midpoint, and has retained this in the final regulation.

EPA believes that, given the unique challenges associated with GS of large volumes of injected CO2, post-injection site care should continue until it can be demonstrated that the CO2 plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final regulation retains the requirement at §146.93(b)(3) that the owner or operator must submit to the Director a demonstration, based on monitoring and other site-specific data, that no additional monitoring is needed to ensure that the GS project does not pose a risk of endangerment to USDWs. Additionally, the permitting authorities responsible for Class VI wells will maintain an active role with the owner or operator in order to ensure protection of USDWs from endangerment.

EPA disagrees with the commenter's suggestion regarding self-execution. EPA believes that, given the unique challenges associated with GS of large volumes of injected CO2, post-injection site care should continue until it can be demonstrated that the CO2 plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final regulation retains the requirement at 146.93(b)(3) that the owner or operator must submit to the Director a demonstration, based on monitoring and other site-specific data, that no additional monitoring is needed to ensure that the GS project does not pose a risk of endangerment to USDWs. Additionally, the permitting authorities responsible for Class VI wells will maintain an active role with the owner or operator in order to ensure protection of USDWs from endangerment.

Commenter Name: Tiffany Rau Letter ID: 0224 Commenter Organization: Hydrogen Energy International Comment ID: 21696 Other EPA Comment Codes and Descriptions: 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: HEI urges EPA to adopt the performance standard that EPA considered in its review. EPA considered three options: (1) fixed period; (2) performance standard; and (3) combination of fixed period and performance standard; EPA states it adopted the latter approach. (73 Fed. Reg. at 43519.) While the Proposed Rule allows a Director to reduce the 50-year minimum (§146.93(b)(2)), the practical effect will be the 50-year timeframe applies unless an operator is able to overcome the presumption built into the Proposed Rule that 50 years is adequate. Indeed, this is more prescriptive than the requirement for Class I hazardous wells, which provides that the timeframe for post-injection site care ends when the plume has stabilized and cannot endanger USDWs. (Id.; 40 CFR §146.71.)

Response: EPA agrees that some owners or operators will be able to demonstrate, in less than 50 years, that the pressure front and plume no longer pose a risk of endangerment to USDWs. However, based on studies, EPA believes that the 50 year default time frame is warranted based on additional review of research studies and reports and evaluation of public comments.

However, EPA recognizes that there may be sites where the 50 year post injection site care timeframe may be either not appropriate or more burdensome than necessary based on site-specific conditions. EPA believes that the best way to address all possibilities, while ensuring USDW protection from endangerment, is to set a 50 year default post-injection site care timeframe, with flexibility to: (1) allow the Director discretion to shorten or lengthen the PISC timeframe during the PISC period based on site-specific data, pursuant to requirements at §146.93(b); or (2) afford the Director discretion to allow a Class VI well owner or operator to demonstrate, based on substantialdata during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Tiffany Rau Letter ID: 0224 Commenter Organization: Hydrogen Energy International Comment ID: 21697

Comment: EPA should adopt the performance-based standard that it considered previously. Accordingly, the post-injection site care period ends when monitoring and other site-specific data demonstrate that the geologic sequestration project does notpose an endangerment to USDWs. (See e.g., 73 Fed. Reg. 43520.) A performancebased approach is consistent with technical knowledge and historic industry experience. The site closure period would be appropriately based on particularsite characteristics and historic site performance. For example, a wellselected and -managed sequestration site (such as an existing oil or gas field) that has met its performance objectives (including plume stabilization) will be much more secure and could be closed reasonably quickly (potentially, in as few as 2-3 years). At other sites that are less well confined (e.g., deep saline formation without a conventional 4-way closure), the CO2 could move around for some time even after injection ceases before stabilizing, and might therefore require a longer period to allow for additional residual and solubility trapping.

In summary, HEI recommends that EPA adopt a performance-based approach to determine the timeframe for site closure. We also support the site closure standard offered in the MSDG Proposal for section 146.93(b), which sets forth

detailed criteria that must be satisfied to demonstrate that the site does not pose an endangerment to USDWs. The advantage of the MSDG Proposal as opposed to a fixed period is it establishes clear criteria that an operator must demonstrate before obtaining site closure based upon particular site characteristics and is, therefore, reasonable applicable to any storage site as opposed to a standard based upon a fixed-duration. The current proposal of 50- years minimum, even subject to potential reduction, would result in significantly discouraging the deployment of this technology at commercial scale without providing measurable additional protection of USDWs.

Response: EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 beappropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA adds that the purpose of the GS rule is not to incentivize the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

Commenter Name: Brian Williams Letter ID: 0225 Commenter Organization: BP Alternative Energy North America, Inc. (BP) Comment ID: 21753 Other EPA Comment Codes and Descriptions: 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: BP urges EPA to adopt the performance standard that EPA considered in its review. EPA considered three options: (1) fixed period; (2) performance standard; and (3) combination of fixed period and performance standard; EPA states it adopted the latter approach. (73 Fed. Reg. at 43519.) While the Proposed Rule allows a Director to reduce the 50-year minimum (§146.93(b)(2)), the practical effect will be the 50-year timeframe applies unless an operator is able to overcome the presumption built into the Proposed Rule that 50 years is adequate. Indeed, this is more prescriptive than the requirement for Class I hazardous wells, which provides that the timeframe for post-injection site care ends when the plume has stabilized and cannot endanger USDWs. (Id.; 40 CFR §146.71.)

Response: EPA agrees that some owners or operators will be able to demonstrate, in less than 50 years, that the pressure front and plume no longer pose a risk of endangerment to USDWs. However, based on studies, EPA believes that the 50 year default time frame is warranted based on additional review of research studies and reports and evaluation of public comments.

EPA believes that the best way to address all possibilities, while ensuring USDW protection from endangerment, is to set a 50 year default post-injection site care timeframe, with flexibility to: (1) allow the Director discretion to shorten or lengthen the PISC timeframe during the PISC period based on site-specific data, pursuant to requirements at §146.93(b); or (2) afford the Director discretion to allow a Class VI well owner or operator to demonstrate, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care timeframe of 50 years, with flexibility to adjustthe 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Brian Williams Letter ID: 0225 Commenter Organization: BP Alternative Energy North America, Inc. (BP) Comment ID: 21754

Comment: EPA should adopt the performance-based standard that it considered previously. Accordingly, the post-injection site care period ends when monitoring and other site-specific data demonstrate that the geologic sequestration project does not pose an endangerment to USDWs. (See e.g., 73 Fed. Reg. 43520.) A performancebased approach is consistent with technical knowledge and historic industry experience. The site closure period would be appropriately based on particular site characteristics and historic site performance. For example, a

well-selected and managed sequestration site (such as an existing oil or gas field) that has met its performance objectives (including plume stabilization) will be much more secure and could be closed reasonably quickly (potentially, in as few as 2-3 years). At other sites that are less well confined (e.g., deep saline formation without a conventional 4-way closure), the CO2 could move around for some time even after injection ceases before stabilizing, and might therefore require a longer period to allow for additional residual and solubility trapping.

In summary, BP recommends that EPA adopt a performance-based approach to determine the timeframe for site closure. We also support the site closure standard offered in the MSDG Proposal for section 146.93(b), which sets forth

detailed criteria that must be satisfied to demonstrate that the site does not pose an endangerment to USDWs. The advantage of the MSDG Proposal as opposed to a fixed period is it establishes clear criteria that an operator must demonstrate before obtaining site closure based upon particular site characteristics and is, therefore, reasonable applicable to any storage site as opposed to a standard based upon a fixed-duration. The current proposal of 50- years minimum, even subject to potential reduction, would result in significantly discouraging the deployment of this technology at commercial scale without providing measurable additional protection of USDWs.

Response: EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

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

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA adds that the purpose of the GS rule is not to incentivize the use of GS; rather, the purpose of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs from endangerment.

Commenter Name: Andrew Duguid Letter ID: 0226 Commenter Organization: Schlumberger Carbon Services Comment ID: 23998 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5300 2.8.3 Site closure activities (40 CFR 146.93)

Comment: 3. Schlumberger does not support the default post injection site care period of 50 years. We feel that because the characterization and operation of the site will be based on the specific attributes of the site that the length of post injection site care should also be site specific information. In particular the criteria for ending the PISC period should be based on site performance and risk. We support the idea that the director approves final site closure. We suggest the following language for Section 146.93(b)(1):

(1) The owner or operator shall continue to conduct monitoring as specified in the Director-approved post-injection site care and site closure plan, pursuant to the performance based criteria described in 146.93(b)(3).

We suggest the following language for section 146.93(b)(2)

(2) If the owner or operator can demonstrate to the satisfaction of the Director that the geologic sequestration project no longer poses an endangerment to USDWs, the Director may approve an amendment to the post- injection site care and site closure plan to reduce the frequency of monitoring or may authorize site closure.

And we suggest the following language for section 146.93(b)(3)

(3) Prior to authorization for site closure, the owner or operator mustdemonstrate to the Director, based on monitoring and other sitespecific data that no additional monitoring is needed to assure that the geologic sequestration project does not pose an endangerment to USDWs, considering the following:.

(i) the estimated magnitude and extent of the AOR based on measurementsand modeling; (ii) that CO2 movement and pressure changes match model predictions, (iii) the estimated location of the detectable CO2 plume based on measurement and modeling (measuring magnitude of saturation within the plume or mapping the edge of it); (iv) that there is no evidence of significant leakage of either CO2 or formation fluids that endanger USDWs; (v) that the CO2 plume and displaced formation fluid are not expected to migrate in the future in a manner that encounters a potential leakage pathway; and, (vi) that wells at the site are not leaking and have maintained integrity.

Response: The PISC requirements in the final GS rule, as specified in §146.93(b), incorporate a combination of a fixed timeframe and a performance standard approach. EPA believes that a default PISC timeframe of 50 years, with Director's discretion to shorten or lengthen this timeframe, combined with a site-specific Director’s discretion to create an alternative PISC time frame, ensures that USDWs are protected. 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA expects that the Director would consider the types of information the commenter describes in determining whether the plume and pressure front no longer pose a risk of endangerment to USDWs and post-injection site care monitoring may be discontinued.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate the appropriateness of an alternative post-injection site care time frame; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Andrew Duguid Letter ID: 0226 Commenter Organization: Schlumberger Carbon Services Comment ID: 24071 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: §146.93 Post-injection site care and site closure.Proposed Rule: (1) The owner or operator shall continue to conduct monitoring as specified in the Director-approved post-injection site care and site closure plan for at least 50 years following the cessation of injection. At the Director’s discretion, the monitoring will continue until the geologic sequestration project no longer poses an endangerment to USDWs.

Schlumberger Suggested Revision: (1) The owner or operator shall continue to conduct monitoring as specified in the Director-approved post-injection site care and site closure plan, pursuant to the performance based criteria described in 146.93(3).

Schlumberger Rationale: The 50 year default period is not based on any scientific or technical information and could be considered arbitrary and capricious.

Proposed Rule: (2) If the owner or operator can demonstrate to the satisfaction of the Director before 50 years, based on monitoring and other site-specific data, that the geologic sequestration project no longer poses an endangerment to USDWs, the Director may approve an amendment to the post-injection site care and site closure plan to reduce the frequency of monitoring or may authorize site closure before the end of the 50-year period.

Schlumberger Suggested Revision: (2) If the owner or operator can demonstrate to the satisfaction of the Director that the geologic sequestration project no longer poses an endangerment to USDWs, the Director may approve an amendment to the post- injection site care and site closure plan to reduce the frequency of monitoring or may authorize site closure.

Schlumberger Rationale: -

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive in most cases or is arbitrary and capricious. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water."

EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that alternative timeframes may be appropriate under limited, specific

circumstances.

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 post-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, duringthe permitting process based on substantial data, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

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

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate the appropriateness of an alternative post-injection site care time frame; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Andrew Duguid Letter ID: 0226 Commenter Organization: Schlumberger Carbon Services Comment ID: 24970 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Proposed Rule: (4) If such a demonstration cannot be made (i.e., if the carbon dioxide plume and pressure front have not stabilized) after the 50 year period,the owner or operator must submit to the Director a plan to continue postinjection site care.

Schlumberger Suggested Revision: Delete

Schlumberger Rationale: No longer necessary

Response: As described above, EPA believes that a default post-injection site care timeframe of 50 years, with allowance of Director's discretion to shorten or lengthen this timeframe or approve an alternative PISC timeframe, is appropriate to ensure that USDWs are protected, while accounting for the variety of site-specific circumstances that may come in to play at GS sites. EPA expects that the Director would consider the types of information the commenter describes in determining whether the plume and pressure front no longer pose a risk of endangerment to USDWs and post-injection site care monitoring may be discontinued.

Commenter Name: Philip Papadeas Letter ID: 0238Commenter Organization: Sandia Technologies, LLC Comment ID: 23359

Comment: UIC Class I wells. Monitoring should continue only to the point when pressure dissipates to below minimum driving force pressures required to move fluid to a

USDW.

Response: EPA agrees that determinations about when post-injection site monitoring may bediscontinued will be based on pressure observations. However, EPA clarifies that the nonendangerment demonstration should address more than changes in pressure; for example, fluid movement within the subsurface must also be considered. EPA expects that the Director would consider the types of information the commenter describes in determining whether the plume and pressure front no longer pose a risk of endangerment to USDWs and post-injection site care monitoring may be discontinued.

Under the combined fixed timeframe and performance standard approach for Class VI wells, the post-injection site care timeframe may be reduced by the Director if the owner or operator can demonstrate that the remaining pressure front and plume no longer pose a risk of endangerment toUSDWs. The non-endangerment finding is left to the discretion of the Director, based on sitespecific information such as plume movement, pressure decay, and the location of potential leakage pathways.

EPA adds that the final GS rule at §146.93(c), also allows the Director to approve an alternative post-injection site care timeframe where an owner or operator can demonstrate during the permitting process that an alternative post-injection site care timeframe, other than the 50 year default, is appropriate and ensures non-endangerment of USDWs.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate the appropriateness of an alternative post-injection site care time frame; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Mark Bohrer Letter ID: 0241 Commenter Organization: North Dakota Industrial Commission Comment ID: 23261 Other EPA Comment Codes and Descriptions: 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: 38. EPA is proposing using a combination of fixed timeframe and a performance standard as described above. EPA is tentatively proposing a post-injection site care (monitoring) period of 50 years with Director’s discretion to change that period to lengthen or shorten the 50-year period if appropriate. EPA requests comment on the proposed use of a tentative 50-year fixed timeframe that could be modified at the Director’s discretion based on monitoring and modeling data. EPA

Notice 43519.

A performance-based time period is appropriate rather than a fixed timeframe.

Response: EPA agrees that there will be circumstances where it can be demonstrated in less than 50years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

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

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Mark Bohrer Letter ID: 0241 Commenter Organization: North Dakota Industrial Commission Comment ID: 23262 Other EPA Comment Codes and Descriptions: 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: 39. 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. EPA Notice 43520.

A performance-based time period is appropriate rather than a fixed timeframe.

Response: EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

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

EPA believes that a default post-injection site care timeframe of 50 years, with flexibility to adjust the timeframe for a limited number of GS projects during the permitting process where substantialdata 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Mark Bohrer Letter ID: 0241 Commenter Organization: North Dakota Industrial Commission Comment ID: 23263

Comment: 40. In addition, EPA seeks comment on whether the Director should be allowed to shorten the timeframe based on performance information, and whether EPA should require a shorter or longer post injection period if data suggests the time frame should be adjusted. EPA Notice 43520.

A performance-based time period is appropriate rather than a fixed timeframe.

Response: The PISC requirements in the final GS rule, as specified in §146.93(b), incorporate a combination of a fixed timeframe and a performance standard approach. EPA believes that a default PISC timeframe of 50 years, with Director's discretion to shorten or lengthen this timeframe, combined with a site-specific Director’s discretion to create an alternative PISC time frame, ensures that USDWs are protected. 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24946 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: Rule Provision: 146.93(b)

EPA Proposal: (2) If the owner or operator can demonstrate to the satisfaction of the Director before 50 years, based on monitoring and other site-specificdata, that the geologic sequestration project no longer poses an endangerment to USDWs, the Director may approve an amendment to the post-injection site care and site closure plan to reduce the frequency of monitoring or may authorize site closure before the end of the 50-year period.

GWPC Recommendations: (2) The owner or operator can request and demonstrate to the satisfaction of the Director that the post-injection site care and site closure plan should be revised to reduce the frequency of monitoring.

Rationale: See above regarding elimination of 50-year presumptive time period.

Response: As described above, EPA disagrees that a post-injection site care timeframe of 50 years is excessive for most Class VI wells. However, EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24948 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: EPA Proposal: (4) If such a demonstration cannot be made (i.e., if the carbon dioxide plume and pressure front have not stabilized) after the 50-year period,the owner or operator must submit to the Director a plan to continue postinjection site care.

GWPC Recommendations: Delete

Rationale: No longer necessary if 50 year time period is removed.

Response: As described above, EPA believes that, to ensure USDW protection from endangerment, a default timeframe for post-injection site care is necessary in most cases. A 50 year post-injection site care timeframe represents a reasonable and protective monitoring period for most GS sites based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.EPA believes that a 50-year default post-injection site care timeframe, as required at §146.93(b)(1), is not overly burdensome, does not exaggerate the risks associated with GS, is consistent with other environmental programs, and sufficiently protects USDWs from endangerment.

Letter ID: 0263 Commenter Organization: Interstate Oil & Gas Compact Commission Comment ID: 22825 Other EPA Comment Codes and Descriptions: 5240 2.8.2.2 Post injection timeframe (seeking comment)

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

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

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

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

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

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

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

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

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

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive or unnecessary for most GS sites. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water."

EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that alternative timeframes may be appropriate under limited, specific

circumstances.

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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

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

Commenter Name: Michael Moore Letter ID: 0265 Commenter Organization: North American Carbon Capture & Storage Association (NACCSA) Comment ID:

22854

Comment: - Closure and Post-Injection Site Care: NACCSA urges the Agency to adopt a shorter default time period than the 50 year period currently proposed. Although a fair amount of certainty may be achieved through setting some defaultperiod of time for the post-injection site care period, the proposed 50 year default is both arbitrary and unjustifiably long. Further, while NACCSA supports the concept of a performance-based component, the rules should include specific and appropriate circumstances that the program director will consider in exercising any discretion in this regard.

Response: EPA disagrees that a post-injection site care timeframe of 50 years is excessive for most Class VI wells. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, industry reports, and existing environmental programs. This analysis was included in an EPA-prepared background document that is available in the federal docket, titledComputational Modeling of Underground Injection of Carbon Dioxide for Determination of Areaof-Review and Potential Risk to Underground Sources of Drinking Water. EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or other evidence to warrant a 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 endangering USDWs will likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that alternative timeframes may be appropriate under limited, specific circumstances, which is why EPA is providing the Director discretion to approve an alternative post-injection site care timeframe as long as the owner or operator can meet the requirements provided at §146.93(c).

EPA acknowledges there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by:(1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the postinjection 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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters¿ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

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

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of 146.92 and 146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under 146.92 and 146.93. The guidance describes recommended approaches for how an owneror operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate the appropriateness of an alternative post-injection site care time frame; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Michael Moore Letter ID: 0265 Commenter Organization: North American Carbon Capture & Storage Association (NACCSA) Comment ID:

22868 Other EPA Comment Codes and Descriptions: 1250 1.1.1.4 Flexibility is needed (performancebased standards); 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: NACCSA urges the Agency to adopt a performance-based approach more in keeping with the actual risks posed by CCS projects. NACCSA believes that the site specific nature of CO2 storage projects will require each project to be judged on its own merit. If a project can show, at any time after the cessation of injection, that there is sufficiently small risk of endangerment to USDWs, monitoring should no longer be required. Given that under the proposed rule, the program director would retain discretion to lengthen or shorten the PISC period as necessary to protect USDWs, a performance based approach is in keeping with the spirit of the draft rule. Furthermore, performance based approach is more in keeping with the realty of potential risks associated with CO2 storage would minimize disincentivization of CCS projects while providing an equivalent degree of protection for USDWs. NACCSA believes that the performance-based approach, currently proposed by EPA as an element of the rule, would be beneficial to project operators and investors and for the protection of USDWs. The final rule should include specific and appropriate circumstances that the program director will consider in exercising discretion in this regard, so that project operators and investors have a clear idea of the bar they will be required to meet in order to close out the PISC period.

Response: As described above, EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Kevin Frederick Letter ID: 0525Commenter Organization: Wyoming Department of Environmental Quality Comment ID: 21397

Comment: We agree that the directors should be provided discretion to shorten or lengthen the proposed post injection site care monitoring period based on performance

information.

Response: EPA agrees that the Director should have discretion to shorten or lengthen the postinjection site care monitoring period, and has retained this provision in the final GS rule at 146.93(b)(2). EPA adds that the final rule at §146.93(c), also allows the Director to approve an alternative post-injection site care timeframe where an owner or operator can demonstrate during the permitting process that an alternative post-injection site care timeframe, other than the 50 year default, is appropriate and ensures non-endangerment of USDWs.

Because of the variety of site-specific circumstances at GS sites, EPA believes that individual UIC Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care monitoring is needed (or whether the timeframe may be shortened) or whether an alternative PISC timeframe is appropriate, based on the circumstances of a particular project. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties.

Commenter Name: Cynthia Lane Letter ID: 0528 Commenter Organization: American Water Works Association (AWWA) Comment ID: 21390 Other EPA Comment Codes and Descriptions: 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: Finally, AWWA supports the rule requirement for the fifty year period for post injection site care. However, we suggest that it be set at a fifty year minimum with no discretion to shorten. Given the potential scope of carbon sequestration, this will provide for consistent approach across the U.S., provide strong long term protective measures of USDW's.

In conclusion, AWWA is concerned that the proposed large scale sequestration of carbon dioxide in underground aquifers may have a significant impact on the public, the environment and drinking water utilities. We are also concerned that

Response: EPA agrees that a 50 year post-injection site care timeframe represents a reasonable and protective post-injection site monitoring period for most projects and available data, including data submitted by commenters, do not support a different default timeframe. EPA bases this on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments. Furthermore, EPA believes that a 50-year default post-injection site care timeframe is not overly burdensome, does not exaggerate the risks associated with GS, is consistent with other environmental programs, and sufficiently protects USDWs from endangerment. For this reason, the final GS regulation retains the 50 year post-injection site care timeframe, as specified in §146.93(b)(1).

However, EPA disagrees that a 50 year post-injection site care timeframe should be an absolute minimum. Rather, EPA believes, as some commenters suggest, that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-injection period based on site-specific data, pursuant torequirements 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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Doug Louis Letter ID: 0530 Commenter Organization: Kansas Corporation Commission Comment ID: 21347

Comment: Proposed well plugging post injection site care and site closure requirements. The proposed rule sets the post injection site care period at a default period of fifty years. KCC agrees that the UIC program director should have the authority to shorten or lengthen the post injection site care period if the owner/operator demonstrates a different time period is appropriate.

Response: EPA agrees that the Director should have discretion to shorten or lengthen the postinjection site care monitoring period, and has retained this provision in the final GS rule at 146.93(b)(2). EPA adds that the final rule at §146.93(c), also allows the Director to approve an alternative post-injection site care timeframe where an owner or operator can demonstrate during the permitting process that an alternative post-injection site care timeframe, other than the 50 year default, is appropriate and ensures non-endangerment of USDWs.

Because of the variety of site-specific circumstances at GS sites, EPA believes that individual UIC Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care monitoring is needed (or whether the timeframe may be shortened) or whether an alternative PISC timeframe is appropriate, based on the circumstances of a particular project. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties.

Commenter Name: George Peridas Letter ID: 0534 Commenter Organization: Natural Resources Defense Council (NRDC) Comment ID: 21458 Other EPA Comment Codes and Descriptions: 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: The closure standards I agree with Scott, I do not think that fifty years is arbitrary. I do not think that it is the magic number or that it will be appropriate for every single site. Nonetheless, I think it is a good benchmark, but we do need to have other flexibility to revise this upwards or downwards asproject data comes in.

I think what needs a little bit of refinement is the phrase at the discretion of

the administrator. I think that should be some more concrete criteria as to when the administrator should reserve the rights to require certain techniques to be used on other requirements in the rule.

Response: EPA agrees that the Director should have discretion to shorten or lengthen the postinjection site care monitoring period, and has retained this provision in the final GS rule at 146.93(b)(2). 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

Because of the variety of site-specific circumstances at GS sites, EPA believes that individual UIC Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care monitoring is needed (or whether the timeframe may be shortened), based on the circumstances of a particular project. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate the appropriateness of an alternative post-injection site care time frame; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

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

Comment Code: 5280 2.8.2.4 USDW non-endangerment demonstrations



### Individual CommentsCommenter Name: Leslie Savage Letter ID: 0122 Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24803 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: (3) Prior to authorization for site closure, must submit to the Director a demonstration, based on monitoring and other site-specific data, that the carbon dioxide plume and pressure front have stabilized and that no additional monitoring is needed to assure that the GS project does not pose an endangerment to USDWs.

{The carbon dioxide plume will continue to move with other formation fluids - they are never static. The real test should be whether or not the pressure has dissipated and the pressure front stabilized to the point that there is no threat of endangering USDWs.}

Response: EPA did not make the suggested change. EPA agrees that a complete cessation of plume movement may not occur at some sites for long time periods due to density differences, natural formation flow gradients and diffusion. EPA clarifies that a complete cessation of plume movement is not required, only a demonstration that the plume and pressure front no longer pose a risk of endangerment to USDWs.

EPA acknowledges that many site-specific factors will influence the determination of when the CO2 plume and pressure front no longer pose a risk of endangerment to USDWs. It is for this reason that EPA believes that individual UIC Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care is needed. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: James Dooley Letter ID: 0156 Commenter Organization: Joint Global Change Research Institute, Pacific Northwest National Laboratory Comment ID:

22650 Other EPA Comment Codes and Descriptions: 4730 2.7.3 Reporting associated with closure and post-injection site care

Comment: o Page 43517. Records retention of only 3 years after site closure. That seems incredibly short. Also it is not clear how this requirement to hold on to these data for three years after site closure is consistent with the owner operators requirement to discharge its responsibilities under the post closure period including establishing that non-endangerment continues to be the case. Wouldn’t access to baseline and data collected during the period of principal operations be needed to report out these findings during the period of post closure. This short record retention period also seems to undercut assertion of a open continuous dialogue being a center piece of how USEPA and any states that haveClass VI primacy will ensure public safety.

Response: EPA has changed the recordkeeping requirement in the final rule to require that owners or operators retain records collected during the post-injection site care period for at least 10 years following site closure. EPA believes that the requirements that the owner or operator retain for ten years following site closure, records collected during the post-injection site care period at §146.93(f) and §146.93(h) are appropriate to ensure that data are available to support non-endangerment demonstrations and to address any concerns that may arise following site closure. This data will also support EPA's review of project data as part of the adaptive rulemaking approach.

Commenter Name: James Dooley Letter ID: 0156 Commenter Organization: Joint Global Change Research Institute, Pacific Northwest National Laboratory Comment ID:

22665 Other EPA Comment Codes and Descriptions: 1360 1.1.3.4 Effectiveness of trapping mechanisms

Comment: - Page 43519. Consider explicitly referencing the work laid out by Benson to support the statement that physical and geochemical trapping mechanisms will help to improve the integrity of storage as time moves forward. This is a critically important "but widely misunderstood" point about how GS will work in practice. It would be good to include at least one citation to technical work to back up this point.

o OTC 19244. Multi-Phase Flow and Trapping of CO2 in Saline Aquifers. Sally M. Benson, SPE, Stanford University. Copyright 2008, Offshore Technology Conference This paper was prepared for presentation at the 2008 Offshore Technology Conference held in Houston, Texas, U.S.A., 5-8 May 2008.

Response: EPA added the Benson study to the final rule preamble (and has made it available in the rulemaking docket).

Commenter Name: Michael J. Miller Letter ID: 0168 Commenter Organization: Electric Power Research Institute (EPRI) Comment ID: 22511 Other EPA Comment Codes and Descriptions: 5260 2.8.2.3 Adjusting the post-injection timeframe (seeking comment)

Comment: Preamble, page 43520: "Once the owners or operators provide documentation that demonstrates that the models predicting CO2 movement are consistent with monitoring results and that there are no longer risks of endangerment to USDWs, they could request that the Director authorize site closure. EPA is also proposing to allow the Director to shorten or lengthen the 50-year time frame based on performance of the site... EPA wishes to emphasize that site closure cannot occur until monitoring and modeling data establish to the Director’s satisfaction that potential risks of endangerment to USDWs have ceased."

EPRI COMMENT #18: EPA’s requirement for demonstrating plume stability for site closure is based on the ability to both observe and successfully model the speed and stability of the advancing CO2 front, a very discrete boundary that is difficult to define, model accurately when complex reservoir heterogeneity and fast flow pathways are present, and measure in the field on a large scale. (Seealso EPRI’s comment #2 on defining the front). If remote methods like surface seismic, cross-well seismic or gravity are not successful in tracking front position, and CO2 is never directly detected in sentinel observations wells, then model validation based on CO2 front position may be questioned. In such a case, if the model predicts the continued advance of the CO2 front while the observed data do not, the EPA Director may not be satisfied with the absence of a potential risk of endangerment to USDWs and may unnecessarily delay site

closure for decades. EPRI recommends that the final rule contain alternative provisions for site closure if model validation is unsuccessful.

Response: EPA acknowledges that many site-specific factors will influence the determination of when the CO2 plume and pressure front no longer pose a risk of endangerment to USDWs. It is for this reason that EPA believes that individual UIC Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care is needed. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties.

EPA also agrees that a complete cessation of plume movement may not occur at some sites for long time periods due to density differences, natural formation flow gradients and diffusion. EPA clarifies that a complete cessation of plume movement is not required, only a demonstration that the plume and pressure front no longer pose a risk of endangerment to USDWs.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24123

Comment: factors, and relative risk of the project. Clear guidelines also need to be established regarding when operators have met the performance standards that determine site closure. Specifically, the standard that the project no longer poses an endangerment to USDWs needs to be defined using reasonable risk-based

criteria.

Response: EPA believes that many site-specific factors will influence the determination of when the CO2 plume and pressure front no longer pose a risk of endangerment to USDWs, and therefore is not defining the criteria in the final rule. It is for this reason that EPA believes that individual UIC Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care is needed. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties.

The post-injection site care requirements in the final GS rule incorporate a combination of a fixed timeframe and a performance standard approach. The final GS rule offer 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of 146.92 and 146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under 146.92 and 146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; demonstrate the appropriateness of an alternative post-injection site care time frame; perform post-injection monitoring; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24207

Comment: API, in concert with the MSDG, recommends the standard in the proposed alternative language for section 146.93(b) below because it sets forth detailed criteria, all of which must be satisfied, to demonstrate that the site does not pose an endangerment to USDWs. The specific criteria listed in our proposal will serve to provide the Director with the requisite information to make the appropriate determination. The advantage of this approach is that it establishes clear criteria that an operator must demonstrate before obtaining site closure based upon particular site characteristics and is, therefore, reasonably applicable to any storage site as opposed to a standard based upon a fixedduration. Furthermore, it is more stringent than a purely discretionary approach because it establishes specific criteria that must be shown before site closure may be granted. We believe this language, which is an extension of work done by the World Resources Institute and the Ground Water Protection Council, avoids the noted shortcomings and provides stronger protection for USDWs.

Response: EPA believes that many site-specific factors will influence the determination of when the CO2 plume and pressure front no longer pose a risk of endangerment to USDWs, and therefore is not defining the criteria in the final rule. It is for this reason that EPA believes that individual UIC Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care is needed. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells, perform post-injection monitoring, demonstrate non-endangerment, and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24208 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rulelanguage

Comment: Rule Provision: 146.93(b)(3)

API Comments: (3) Prior to authorization for site closure, the owner or operator

MUST submit to the Director a demonstration , DEMONSTRATE TO THE DIRECTOR, based on monitoring, and other site-specific data, AND MODELING THAT IS

REASONABLY CONSISTENT WITH SITE PERFORMANCE that the carbon dioxide plume and pressure front have stabilized and that no additional monitoring is needed to assure that the geologic sequestration project does not AND IS NOT EXPECTED TO pose an endangerment to USDWs. THE DIRECTOR SHALL APPROVE CLOSURE IF THE

OWNER
OR OPERATOR DEMONSTRATES, BASED ON THE CURRENT UNDERSTANDING OF THE
SITE, INCLUDING MONITORING DATA AND/OR MODELING, ALL OF THE FOLLOWING: (I)

THE ESTIMATED MAGNITUDE AND EXTENT OF THE PROJECT FOOTPRINT (CO2 PLUME

AND THE AREA OF ELEVATED PRESSURE), (II) THE ESTIMATED LOCATION OF THE DETECTABLE CO2
PLUME; (III) THAT THERE IS NO SIGNIFICANT LEAKAGE OF EITHER CO2 OR DISPLACED

FORMATION FLUIDS THAT IS ENDANGERING USDWS; (IV) THAT THE INJECTED OR DISPLACED

FLUIDS ARE

NOT EXPECTED TO MIGRATE IN THE FUTURE IN A MANNER THAT ENCOUNTERS A

POTENTIAL LEAKAGE PATHWAY INTO A USDW; (V) THAT THE INJECTION WELLS AT THE SITE

COMPLETED

INTO OR THROUGH THE INJECTION ZONE OR CONFINING ZONE ARE PLUGGED AND

ABANDONED IN ACCORDANCE WITH THESE REQUIREMENTS; AND (VI) ANY REMAINING PROJECT

MONITORING

WELLS AT THE SITE ARE BEING MANAGED BY A PERSON AND IN A MANNER

ACCEPTABLE TO

THE DIRECTOR.

Rationale: API edits establish the performance based criteria for selecting the monitoring period. EPA should recognize that under any given set of site specific conditions some of these criteria may not be fully satisfied. EPA should retain the ability to waive individual monitoring criteria described here

to reflect that situation.

Rule Provision: 146.93(b)(4)

API Comments: (4) If such a demonstration cannot be made (i.e., if the carbon dioxide plume and pressure front have not stabilized) after the 50-year period,the owner or operator must submit to the Director a plan to continue postinjection site care.

Rationale: No longer necessary given changes above.Response: EPA disagrees that the rule should specify the criteria for setting the monitoring timeframe. Instead, EPA believes that such determinations are site-specific and should be described in a project specific post-injection site care and site closure plan. EPA also believes that periodic reviews and updates, where necessary, to the plan are important to ensuring that the site continues to be managed effectively and to determine whether shortening the monitoring timeframe is appropriate. The post-injection site care requirements in the final GS rule incorporate a combination of a fixed timeframe and a performance standard approach. The final GS rule offer owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Directordiscretion to shorten or lengthen the PISC timeframe during the post-injection period based on sitespecific 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 onsubstantial data, that an alternative PISC timeframe may be appropriate if it ensures nonendangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells, perform post-injection monitoring, demonstrate the appropriateness of an alternative post-injection site care time frame, demonstrate non-endangerment, and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Thomas Curtis Letter ID: 0181 Commenter Organization: American Water Works Association (AWWA) Comment ID: 23706 Other EPA Comment Codes and Descriptions: 5220 2.8.2.1 Post-injection monitoring activities

Comment: AWWA has observed that the proposed regulation is lacking in details on the requirements to demonstrate that the carbon dioxide plume has stabilized. For example, the proposal does not include requirements that the plume pressure must be constant for a certain number of years or that the plume has not migrated for a set period of time. Since AWWA does not claim to be experts on the behavior of carbon dioxide plumes and can not provide recommendations on this topic, AWWA recommends that EPA should engage in research on determining exactly what these criteria should be. For example, when referencing lack of plume movement, what should the trigger time period be (no movement of plume for 10, 15, 20 or more years??). AWWA recommends that EPA clarify what is an acceptable frequency for a lack of change in the plume characteristics and also needs to clarify plume stabilization as this issue could be interpreted differently by different states. Guidance should be prepared by EPA on this topic so that there is consistent application of this requirement across all sequestration projects. A performance based system could also be developed that would require the operator to meet certain criteria to prove that the plume has stabilized. This could be used to justify the closing of the site after the 50-year period of post-injection site care has elapsed. This would allow for a process where long-term monitoring decisions are made in response to the specific characteristics of each project.

AWWA believes that the proposed post-injection site care requirements have been established to prevent endangerment to USDWs. Carbon dioxide can potentially leak from the confining layer into other aquifers that, while not classified as USDWs, may still be considered drinking water sources in some areas of the county. EPA should also consider including requirements in the regulation toaddress the potential for endangerment of these aquifers during the postinjection period. Monitoring requirements should be extended to cover these aquifers, and the post-injection site care plan should include provisions for the protection of aquifers that are not classified as USDWs, but are still considered a future drinking water source.

Response: EPA acknowledges that many site-specific factors will influence the determination of when the CO2 plume and pressure front no longer pose a risk of endangerment to USDWs. It is for this reason that EPA believes that individual UIC Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care is needed. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate the appropriateness of an alternative post-injection site care time frame; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

EPA has conducted research regarding stabilization timeframes. As described in the preamble to the proposed rule, in determining the post-injection site care-timeframe for the proposed regulation, EPA reviewed industry reports, existing environmental programs, and initial GS research studies. EPA provided a synthesis of pertinent results from GS modeling studies in the preamble to the proposed regulation. Further explanation of this analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water." Based on review of these studies, modeling results indicate that the CO2 plume stabilization may occur on the timeframe of 10-100 years after the cessation of injection. EPA believes that a 50-year default post-injection site care timeframe is a reasonable midpoint for most GS projects and available data, including data submitted by commenters, do not support a different default timeframe, and has retained this in the final regulation. EPA will continue research in this area and plans, every six years, to collect and review data on GS projects to determine whether the appropriate amount and types of information and appropriate documentation are being collected, and to determine if modifications to the requirements are appropriate or necessary.

Commenter Name: Wendy Jacobs Letter ID: 0183Commenter Organization: Harvard Law School Environmental Law and Policy

Center Comment ID:

25145

Comment: EPA should, however, clarify the performance standard element by defining the key term "stabilized" in the context of GS.[FN6] See 73 Fed. Reg. at 43,540-41 (proposed 40 C.F.R. § 146.93(b)(2)). It is unclear whether "stabilized" refers to certain measurable physical properties of the "carbon dioxide plume and pressure front" (such as pressure), or broadly describes some macro-state (for example, no movement of the CO2 over a specified period of time) that EPA is using as a proxy for USDW safety, or something else. EPA has promulgated more specific closure and post-closure standards for Class I wells and should follow suit here to avoid confusion, uncertainty, and potential threats to drinking water supplies.

[FN6] The term "stabilize" is also used in existing regulations governing surface impoundments under RCRA. See 40 C.F.R. § 264.228(a)(2)(ii) ("At closure, the owner or operator must . . . stabilize remaining wastes to a bearing capacity sufficient to support final cover . . . ."). Although the term is not defined in those regulations either, those regulations do impose other specific requirements on the owner or operator (e.g., cover the surface impoundment with a final cover) that are measured in terms of specific factors like migration, erosion, maintenance, and permeability. See 40 C.F.R. § 264.228(a)(2)(iii) (A)-(E).

The owner or operator of a Class I hazardous waste injection well must observe and record "pressure decay" observations and show conformance to predicted values before site closure will be authorized. 40 C.F.R. § 146.71(d). During post-closure care, the owner or operator of a Class I well is required to continue monitoring "until pressure in the injection zone decays to the point that the well’s cone of influence no longer intersects the base of the lowermost USDW." 40 C.F.R. § 146.72(b)(2). These standards provide more guidance than does the proposed regulation.

ELPC and ETIP are sensitive to the numerous outstanding technical issues surrounding wide-scale use of CCS technologies and the importance of demonstration projects to solve many of those questions. Accordingly, while we view the EPA’s undefined use of the term "stabilization" as problematic for a closure standard, we are not prepared to recommend numerical monitoring targets or reach the specificity of the Class I well regulations. Even so, there is ample room for the EPA to adopt a stronger and better-defined post-injection site care standard that gives greater assurances that USDWs will not be threatened while still allowing flexibility for innovation.

The World Resources Institute (WRI) recommendations avoid explicit use of the term "stabilization" and instead focus on the endangerment issue. Completion of the WRI post-injection monitoring requirements occurs when the owner or operator demonstrates "with a high degree of confidence that the storage project does not endanger human health or the environment." SARAH M. FORBES ET AL., WORLD
RESOURCES INSTITUTE, CCS GUIDELINES: GUIDELINES FOR CARBON DIOXIDE
CAPTURE,TRANSPORT, AND STORAGE 103 (2008) [hereinafter WRI GUIDELINES]. WRI suggests that an owner or operator can make this demonstration by showing:

1.the estimated magnitude and extent of the project footprint (CO2 plume and the area of elevated pressure), based on measurements and modeling;

2.that CO2 movement and pressure changes match model predictions;

3.the estimated location of the detectable CO2 plume based on measurement and modeling (measuring magnitude of saturation within the plume or mapping the edge of it);

4.either (a) no evidence of significant leakage of injected or displaced fluids into formations outside the confining zone, or (b) the integrity of the confining zone;

5.that, based on the most recent geologic understanding of the site, including monitoring data and modeling, the [CO2 plume and formation water] are not expected to migrate in the future in a manner that encounters a potential leakage pathway; and

6.that wells at the site are not leaking and have maintained integrity.

Id. Requirements four, five, and six all address stabilization, but in language more precise than the approach offered by EPA. Where EPA leaves open the definition of "stabilize," WRI offers a more exacting standard built from terms like "leakage," "integrity," and "migrate." The WRI approach provides a standard more certain to ensure that non-endangerment is achieved while preserving flexibility for owner or operators to develop best practices as CCS continues to develop. In addition, WRI’s more specific closure standard is more consistent with the models employed in existing EPA regulations for Class I wells. See supra pp. 9-10.

Response: EPA acknowledges that many site-specific factors will influence the determination of when the CO2 plume and pressure front no longer pose a risk of endangerment to USDWs. It is for this reason that EPA believes that individual UIC Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care is needed. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties.

EPA disagrees that the rule should specify the criteria for setting the monitoring timeframe. Instead, EPA believes that such determinations are site-specific and should be described in a project specific post-injection site care and site closure plan. EPA also believes that periodic reviews and updates, where necessary, to the plan are important to ensuring that the site continues to be managed effectively and to determine whether shortening the monitoring timeframe is appropriate.

EPA agrees that a complete cessation of plume movement may not occur at some sites for long time periods due to density differences, natural formation flow gradients and diffusion. EPA clarifies that a complete cessation of plume movement is not required, only a demonstration that the plume and pressure front no longer pose a risk of endangerment to USDWs.EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24499 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.93(b)(3)

Proposed CCS Group Recommendations: (3) Prior to authorization for site closure, the owner or operator must DEMONSTRATE TO THE DIRECTOR, BASED ON MONITORING,
OTHER SITE-SPECIFIC DATA, AND MODELING THAT IS REASONABLY CONSISTENT

WITH SITE
PERFORMANCE, THAT NO ADDITIONAL MONITORING IS NEEDED TO ASSURE THAT

THE GEOLOGIC SEQUESTRATION PROJECT DOES NOT AND IS NOT EXPECTED TO POSE AN

ENDANGERMENT TO

USDWS. THE DIRECTOR SHALL APPROVE CLOSURE IF THE OWNER OR OPERATOR
DEMONSTRATES,
BASED ON THE CURRENT UNDERSTANDING OF THE SITE, INCLUDING MONITORING

DATA AND/OR MODELING, ALL OF THE FOLLOWING: (I) THE ESTIMATED MAGNITUDE AND EXTENT

OF THE PROJECT FOOTPRINT (CO2 PLUME AND THE AREA OF ELEVATED PRESSURE) ; (II) THE

ESTIMATED LOCATION OF THE DETECTABLE CO2 PLUME; (III) THAT THERE IS NO

SIGNIFICANT LEAKAGE OF EITHER CO2 OR DISPLACED FORMATION FLUIDS THAT IS ENDANGERING USDWS; (IV) THAT THE INJECTED OR DISPLACED FLUIDS ARE NOT

EXPECTED

TO MIGRATE IN THE FUTURE IN A MANNER THAT ENCOUNTERS A POTENTIAL

LEAKAGE PATHWAY INTO A USDW; (V) THAT THE INJECTION WELLS AT THE SITE COMPLETED INTO OR

THROUGH

THE INJECTION ZONE OR CONFINING ZONE ARE PLUGGED AND ABANDONED IN

ACCORDANCE WITH THESE REQUIREMENTS; AND (VI) ANY REMAINING PROJECT MONITORING

WELLS AT THE

SITE ARE BEING MANAGED BY A PERSON AND IN A MANNER ACCEPTABLE TO THE

DIRECTOR.

Basis for CCS Group Comments: We believe there are three problems with the closure standard in proposed section 146.93(b). First, the presumption that monitoring should continue for 50 years is unnecessary and counterproductive. Astraight performance standard is preferable to this or any other fixed time period because it provides a clearer standard and an incentive to maximize the understanding of site and project performance and as such is more protective of USDWs. Second, the proposal requires a showing that the CO2 plume has "stabilized", which is undefined. Cessation of plume movement is not necessarily essential to show that a project poses no threat of endangerment to USDWs-plumes that are still moving may, nonetheless, remain contained. Instead, it is more protective to show that the plume is not expected to encounter a leakage pathway. Third, the required showing that "no additional monitoring is needed" does not provide guidance regarding how an operator is to show that no additional monitoring is needed. The proposal below provides specific guidance on what the operator must show.

We recommend the standard in the proposed alternative language for section 146.93(b) below because it sets forth detailed criteria, all of which must be satisfied, to demonstrate that the site does not pose an endangerment to USDWs. The specific criteria listed in our proposal will serve to provide the Director with the requisite information to make the appropriate determination. The advantage of this approach is that it establishes clear criteria that an operator must demonstrate before obtaining site closure based upon particular site characteristics and is, therefore, reasonably applicable to any storage site as opposed to a standard based upon a fixed-duration. Furthermore, it is more stringent than a purely discretionary approach because it establishes specific criteria that must be shown before site closure may be granted. We believe this language, which is an extension of work done by the World Resources Institute and the Ground Water Protection Council, avoids the noted shortcomings and provides stronger protection for USDWs.

This is the same recommendation as presented by the multi-stakeholder group, in which the Carbon Sequestration Council participated.

Response: EPA disagrees that the rule should specify the criteria for setting the monitoring timeframe. Instead, EPA believes that such determinations are site-specific and should be described in a project specific post-injection site care and site closure plan. EPA also believes that periodic reviews and updates, where necessary, to the plan are important to ensuring that the site continues to be managed effectively and to determine whether shortening the monitoring timeframe is appropriate. The post-injection site care requirements in the final GS rule incorporate a combination of a fixed timeframe and a performance standard approach. The final GS rule offer 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 isanticipated to occur, to accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells, perform post-injection monitoring, demonstrate the appropriateness of an alternative post-injection site care time frame, demonstrate non-endangerment, and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Kyle Isakower Letter ID: 0191 Commenter Organization: American Petroleum Institute Comment ID: 23884 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: (3) Prior to authorization for site closure, the owner or operator must demonstrate to the Director, based on monitoring, other site-specific data, and modeling that is reasonably consistent with site performance, that no additional monitoring is needed to assure that the geologic sequestration project does not and is not expected to pose an endangerment to USDWs. The Director shall approve closure if the owner or operator demonstrates, based on the current understanding of the site, including monitoring data and/or modeling, all of the following: (i) the estimated magnitude and extent of the project footprint (CO2 plume and the area of elevated pressure) ; (ii) the estimated location of the detectable CO2 plume; (iii) that there is no significant leakage of either CO2 or displaced formation fluids that is endangering USDWs; (iv) that the injected or displaced fluids are not expected to migrate in the future in a manner that encounters a potential leakage pathway into a USDW; (v) that the injection wells at the site completed into or through the injection zone or confining zone are plugged and abandoned in accordance with these requirements; and (vi) any remaining project monitoring wells at the site are being managed by a person and in a manner acceptable to the Director.

Response: EPA disagrees that the rule should specify the criteria for setting the monitoring timeframe. Instead, EPA believes that such determinations are site-specific and should be described in a project specific post-injection site care and site closure plan. EPA also believes that periodic reviews and updates, where necessary, to the plan are important to ensuring that the site continues to be managed effectively and to determine whether shortening the monitoring timeframe is appropriate. The post-injection site care requirements in the final GS rule offer 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate the appropriateness of an alternative post-injection site care time frame; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Jeff W. Sheets Letter ID: 0192 Commenter Organization: ConocoPhillips Comment ID: 23905 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: (3) Prior to authorization for site closure, the owner or operator must demonstrate to the Director, based on monitoring, other site-specific data, and modeling that is reasonably consistent with site performance, that no additional monitoring is needed to assure that the geologic sequestration project does not and is not expected to pose an endangerment to USDWs. The Director shall approve closure if the owner or operator demonstrates, based on the current understanding of the site, including monitoring data and/or modeling, all of the following: (i) the estimated magnitude and extent of the project footprint (CO2 plume and the area of elevated pressure) ; (ii) the estimated location of the detectable CO2 plume; (iii) that there is no significant leakage of either CO2 or displaced formation fluids that is endangering USDWs; (iv) that the injected or displaced fluids are not expected to migrate in the future in a manner that encounters a potential leakage pathway into a USDW; (v) that the injection wells at the site completed into or through the injection zone or confining zone are plugged and abandoned in accordance with these requirements; and (vi) any remaining project monitoring wells at the site are being managed by a person and in a manner acceptable to the Director.

Response: EPA disagrees that the rule should specify the criteria for setting the monitoring timeframe. Instead, EPA believes that such determinations are site-specific and should be described in a project specific post-injection site care and site closure plan. EPA also believes that periodic reviews and updates, where necessary, to the plan are important to ensuring that the site continues to be managed effectively and to determine whether shortening the monitoring timeframe is appropriate. The post-injection site care requirements in the final GS rule offer 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 post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate the appropriateness of an alternative post-injection site care time frame; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24721 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.93(b)(3)

Anadarko Petroleum Corporation (APC) Comments: (3) Prior to authorization for site closure, the owner or operator must submit to the Director a

demonstration , DEMONSTRATE TO THE DIRECTOR, based on monitoring, and other site-specific data, AND MODELING THAT IS REASONABLY CONSISTENT WITH SITE

PERFORMANCE that the carbon dioxide plume and pressure front have stabilized

and that no additional monitoring is needed to assure that the geologic sequestration project does not pose an endangerment to USDWs.

THE OWNER OR OPERATOR MUST DEMONSTRATE, BASED ON THE CURRENT

UNDERSTANDING OF
THE SITE, INCLUDING MONITORING DATA AND/OR MODELING, ALL OF THE FOLLOWING: (I) THE ESTIMATED MAGNITUDE AND EXTENT OF THE PROJECT FOOTPRINT (CO2

PLUME AND THE AREA OF ELEVATED PRESSURE); (II) THE ESTIMATED LOCATION OF THE

DETECTABLE CO2 PLUME ; (III) THAT THERE IS NO SIGNIFICANT LEAKAGE OF EITHER CO2 OR

DISPLACED FORMATION FLUIDS THAT IS ENDANGERING USDWS; (IV) THAT THE INJECTED OR

DISPLACED

FLUIDS ARE NOT EXPECTED TO MIGRATE IN THE FUTURE IN A MANNER THAT

ENCOUNTERS A POTENTIAL LEAKAGE PATHWAY INTO A USDW; (V) THAT THE INJECTION WELLS ATTHE SITE

COMPLETED INTO OR THROUGH THE INJECTION ZONE OR CONFINING ZONE ARE

PLUGGED AND ABANDONED IN ACCORDANCE WITH THESE REQUIREMENTS; AND (VI) ANY

REMAINING PROJECT

MONITORING WELLS AT THE SITE ARE BEING MANAGED BY A PERSON AND IN A

MANNER

ACCEPTABLE TO THE DIRECTOR.

Rationale: APC edits establish the performance based criteria for selecting the monitoring period.

EPA should recognize that under any given set of site specific conditions some of these criteria may not be fully satisfied. EPA should retain the ability to waive individual monitoring criteria described here to reflect that situation.

Response: EPA disagrees that the rule should specify the criteria for setting the monitoring timeframe. Instead, EPA believes that such determinations are site-specific and should be described in a project-specific post-injection site care and site closure plan. EPA also believes that periodic reviews and updates, where necessary, to the plan are important to ensuring that the site continues to be managed effectively and to determine whether shortening the monitoring timeframe is appropriate. The post-injection site care requirements in the final GS rule incorporate a combination of a fixed timeframe and a performance standard approach. The final GS rule offer owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Directordiscretion to shorten or lengthen the PISC timeframe during the post-injection period based on sitespecific 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 onsubstantial data, that an alternative PISC timeframe may be appropriate if it ensures nonendangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells, perform post-injection monitoring, demonstrate the appropriateness of an alternative post-injection site care time frame, demonstrate non-endangerment, and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: John King Letter ID: 0211 Commenter Organization: Shell Exploration and Production Company (SEPCo) Comment ID:

22752

Comment: - Closure and Post-Injection Site Care: Criteria for determining the period forpost-injection site care should be performance-based and a function of the sitespecific characteristics of a project such as project size, geologic factors, and relative risk of the project. (API offers such criteria in their edits to §146.93(b)(3).) Clear guidelines also need to be established regarding when operators have met the performance standards that determine site closure. Specifically, the standard that the project no longer poses an endangerment to USDWs needs to be defined using reasonable risk-based criteria.

Response: The post-injection site care requirements in the final GS rule incorporate a combination of a fixed timeframe and a performance standard approach. The final GS rule offer owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Directordiscretion to shorten or lengthen the PISC timeframe during the post-injection period based on sitespecific 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 onsubstantial data, that an alternative PISC timeframe may be appropriate if it ensures nonendangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate the appropriateness of an alternative post-injection site care time frame; demonstrate non-endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Edward Steadman Letter ID: 0220 Commenter Organization: The Energy and Environmental Research Center at the University of North Dakota Comment ID:

21589 Other EPA Comment Codes and Descriptions: 1670 1.3.7 Other/miscellaneous risks

Comment: Page 43498. Regarding the statement, "the measures outlined in today’s proposed rulemaking to prevent endangerment of USDWs may also prevent migration of CO2 to

the subsurface."

This statement is fine, as long as protecting leakage to the atmosphere does not lead to stricter measures than would be required to protect USDWs. For example, regulations should be driven by a desire to maintain a leakage rate below a certain percentage of the injected volume, unless that percentage can be demonstrated to adversely affect USDWs. Another way to state it is this: a 1% leakage rate may or may not adversely affect USDWs; therefore, a 1% rate should not necessarily be unacceptable.

Response: EPA clarifies that all requirements in the GS rule are for the purpose of preventingendangerment to USDWs, and that the tailored permitting, siting, construction, operation, monitoring, and post-injection site care requirements in the GS rule are intended to prevent leakage from injection formations and protect USDWs.

EPA acknowledges that there are potential risks associated with GS. The purpose of the Class VI requirements is to minimize and mitigate potential/identified risks through proper site characterization, well construction, operation, monitoring, post-injection site care, and site closure and to ensure protection of USDWs. The Agency clarifies that, under SDWA, EPA does not have the authority to directly regulate air emissions via CO2 leakage to the surface. However, the GS rule requires that CO2 injected for GS remain confined in the injection zone. Leakage outside of the injection zone as defined in a Class VI permit, which may be evidenced by leakage to the surface, would be a permit violation if a USDW is endangered.

Commenter Name: M. Granger Morgan Letter ID: 0233 Commenter Organization: Carnegie Mellon University on behalf of the CCS Reg Project Comment ID:

21911 Other EPA Comment Codes and Descriptions: 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: 20. Site closure: We support the general approach that EPA proposes to determine the length of the post-injection site care period (a performance standard, anchored by a suggested duration of several decades). However, we suggest three modifications: 1) The rule should require that the post-injection site care and site-closure plan specify thresholds for demonstrating that the GS project no longer poses an endangerment to USDWs; 2) The rule should provide mechanisms to coordinate information and allocate responsibility if site conditions during the post-injection site care period are altered by operations of another GS project in the basin; and, 3) The 50-year time period should not become a prescriptive default. There is not yet enough experience to set this as the suggested duration of the post-injection site care period. For now, a performance standard alone is preferable and creates the right incentives to protect USDWs. After experience has been gained from early projects, the rule could be amended to include a suggested duration.

Response: EPA agrees that the rule should not specify the criteria for setting the monitoring timeframe. Instead, EPA believes that such determinations are site-specific and should be described in a project-specific post-injection site care and site closure plan. However, EPA disagrees that the plan should specify thresholds for demonstrating that the GS project no longer poses a risk of endangerment to USDWs, but agrees that this demonstration should be an important consideration.EPA is developing guidances with recommended approaches for developing and implementing postinjection site care and site closure plans and guidance that describes recommended approaches for how an owner or operator could plug injection and monitoring wells, perform post-injection monitoring, demonstrate non endangerment, and perform site closure activities. The guidances will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

EPA agrees with commenters that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final GS regulation includes a provision that the Director may, at his or her discretion, shorten the post-injection site care timeframe if the owner or operator can demonstrate that the GS project does not pose an endangerment to USDWs, as specified in §146.93(b)(2). Such ademonstration will be site-specific, and based on pressure monitoring and USDW impacts. EPAbelieves however, that to ensure USDW protection from endangerment, a default timeframe for postinjection site care is necessary. A 50-year post-injection site care timeframe represents a reasonable and protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24945 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: Rule Provision: 146.93(b)

EPA Proposal: (b) The owner or operator shall monitor the site following the cessation of injection to show the position of the carbon dioxide plume and pressure front and demonstrate that USDWs are not being endangered.

(1) The owner or operator shall continue to conduct monitoring as specified in the Director-approved post-injection site care and site closure plan for at least 50 years following the cessation of injection. At the Director’s discretion, the monitoring will continue until the geologic sequestration project no longer poses an endangerment to USDWs.

GWPC Recommendations: (b) The owner or operator shall monitor the site following the cessation of injection.

(1) The owner or operator shall continue to conduct monitoring as specified in the Director-approved post-injection site care and site closure plan until closure is authorized pursuant to 146.93(b)(3).

Rationale: Eliminate the 50 year requirement.

There is no justification for extending completed projects for the presumptive 50 years, and it will be difficult to accept much shorter demonstration periods with the 50 year presumption in the regulations. Default 50-year period defeats

incentives for best site identification and best MMV

Need for site-specific considerations and use of data

Need achievable and definable standard

Response: EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final GS regulation includes a provision that the Director may, at his or her discretion, shorten the post-injection site care timeframe if the owner or operator can demonstrate that the GS project does not pose an endangerment to USDWs, as specified in §146.93(b)(2). Such a demonstration will be site-specific, and based on pressure monitoring and USDW impacts.Alternatively, the final rule at §146.93(c), also allows the Director to approve an alternative postinjection site care timeframe where an owner or operator can demonstrate during the permittingprocess that an alternative post-injection site care timeframe, other than the 50 year default, isappropriate and ensures non-endangerment of USDWs. The demonstration must be based on sitespecific information, including the results of site-specific computational modeling; the predicted timeframe for pressure decline; the predicted rate of carbon dioxide plume migration; site-specific chemical processes that will result in carbon dioxide trapping; the predicted rate of carbon dioxide trapping; characterization of the confining zone(s); laboratory analyses or studies to verify the information on trapping; the presence of potential conduits for fluid movement and the quality of abandoned well plugs within the AoR; the distance between the injection zone and the USDWs above and/or below the injection zone; and any additional site-specific factors determined by the Director. The demonstration must meet the criteria at §146.93(c)(2) for ensuring the quality and accuracy of the data and models on which the demonstration is based. This demonstration would be submitted as part of the permit application, per §146.82(a)(18), in addition to the PISC and site closure plan required at §146.82(a)(17).

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

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24947 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: EPA Proposal: (3) Prior to authorization for site closure, the owner or operatormust submit to the Director a demonstration, based on monitoring and other sitespecific data, that the carbon dioxide plume and pressure front have stabilized and that no additional monitoring is needed to assure that the geologic sequestration project does not pose an endangerment to USDWs.

GWPC Recommendations: (3) Prior to authorization for site closure, the owner oroperator must demonstrate to the Director, based on monitoring, other sitespecific data, and modeling that is reasonably consistent with site performance, that no additional monitoring is needed to assure that the geologic sequestration project does not and is not expected to pose an endangerment to USDWs. The Director shall approve closure if the owner or operator demonstrates, based on the current understanding of the site, including monitoring data and/or modeling, all of the following: (i) the estimated magnitude and extent of the project footprint (CO2 plume and the area of elevated pressure) ; (ii) the estimated location of the detectable CO2 plume; (iii) that there is no significant leakage of either CO2 or displaced formation fluids that isendangering USDWs; (iv) that the injected or displaced fluids are not expected to migrate in the future in a manner that encounters a potential leakage pathway into a USDW; (v) that the injection wells at the site completed into or through the injection zone or confining zone are plugged and abandoned in accordance with these requirements; and (vi) any remaining project monitoring wells at the site are being managed by a person and in a manner acceptable to the Director.

Rationale: The GWPC revised this section to establish the performance based criteria for selecting the monitoring period.

Response: EPA disagrees that the rule should specify the criteria for setting the monitoring timeframe. Instead, EPA believes that such determinations are site-specific and should be described in a project specific post-injection site care and site closure plan. EPA also believes that periodic reviews and updates, where necessary, to the plan are important to ensuring that the site continues to be managed effectively and to determine whether shortening the monitoring timeframe is appropriate.

As described above, EPA agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Mark Vickery Letter ID: 0280 Commenter Organization: Texas Commission on Environmental Quality Comment ID: 24104 Other EPA Comment Codes and Descriptions: 1220 1.1.1.1 Terminology and definitions; 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: (e) Concern exists regarding the need for (i) a standard (in concentration or saturation) for defining the edge of a CO2 plume, (ii) clear definition of the term "stabilization" as applied to fate and transport of an injected CO2 plume and pressure front, and (iii) a clarified specification of the performance standard for the necessary demonstration to enable termination of the iterative process of monitoring/modeling and related corrective action. If "stabilization" means absence of plume movement or pressure change, it is our understanding from CO2-GS research efforts that indefinitely long periods of monitoring, modeling, and corrective action may be required in contrast to the default period of fifty years cited in the proposed rules and preamble. A more appropriate basis fordemonstrations of protection of underground sources of drinking water (USDW) would be keyed to the presence of induced pressure conditions in the injection zone, spatially and temporally. When and where such pressure conditions are insufficient to cause endangerment of a USDW through leakage pathways such as improperly constructed or plugged wells or transmissible faults, the required USDW protection should be considered to be present. Accordingly, if the termination of monitoring, modeling, and corrective action is ultimately dependent on making the subject demonstration, it is recommended that the "fifty year" specification be deleted from the rule. This would conform the requirements for post-injection site care for Class VI wells more closely to the post-closure care specifications and concepts existing for Class I wells.

Response: EPA disagrees that the rule should specify the criteria for setting the monitoring timeframe. Instead, EPA believes that such determinations are site-specific and should be described in a project specific post-injection site care and site closure plan. EPA also believes that periodic reviews and updates, where necessary, to the plan are important to ensuring that the site continues to be managed effectively and to determine whether shortening the monitoring timeframe is appropriate.

EPA acknowledges that many site-specific factors will influence the determination of when the CO2 plume and pressure front no longer pose a risk of endangerment to USDWs. It is for this reason that EPA believes that individual UIC Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care is needed. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties.

EPA agrees that a complete cessation of plume movement may not occur at some sites for long time periods due to density differences, natural formation flow gradients and diffusion. EPA clarifies that a complete cessation of plume movement is not required, only a demonstration that the plume and pressure front no longer pose a risk of endangerment to USDWs.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of 146.92 and 146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under 146.92 and 146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Mark Vickery Letter ID: 0280 Commenter Organization: Texas Commission on Environmental Quality Comment ID: 24110 Other EPA Comment Codes and Descriptions: 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: (f) TCEQ agrees with EPA's approach that financial assurance for post-injection site care may be required for a period less than or greater than fifty years as proposed in 146.93, depending on a site specific demonstration to the Director. However, consistent with TCEQ's comments under Principal Concern 1, TCEQ also encourages EPA to delete the fifty-year threshold requirement in consideration of EPA's indication that the duration of financial assurance should ultimately be keyed to whatever site-specific time is necessary to meet the post-injectionsite care performance standard of demonstration of non-endangerment ofUSDWs.

Response: EPA agrees that financial responsibility must be maintained throughout the post-injection site care timeframe, regardless of its ultimate length. The GS rule requires this, at 146.85.

EPA also agrees that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by:(1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the postinjection 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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: A. Scott Anderson Letter ID: 0293 Commenter Organization: Environmental Defense Fund Comment ID: 25278

Comment: (1). It is critical that the rule contain a "closure standard" for GS projects that is feasible, scientifically rigorous, and adequate for purposed of fostering public confidence in GS technology. Unless EPA develops an adequate closure standard, there is no reason to expect the public to have confidence in this technology. We believe that the standard ought to be based on the suggestions made in the December 23 letter;

Response: EPA agrees that authorization of site closure must be feasible, scientifically rigorous, and foster public confidence in GS technology, but disagrees that the rule should set specific criteria. EPA believes that many site-specific factors will influence the determination of when the CO2 plume and pressure front no longer pose a risk of endangerment to USDWs. It is for this reason that EPA believes that individual UIC Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care is needed. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of 146.92 and 146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under 146.92 and 146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring;demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Comment Code: 5300 2.8.3 Site closure activities (40 CFR 146.93)



### Individual Comments

Commenter Name: Michael H. Cochran Letter ID:

0108 Commenter Organization: Bureau of Water, Division of Environment, Kansas Department of Health & Environment (KDHE) Comment

ID: 21988 Other EPA Comment Codes and Descriptions: 4730 2.7.3 Reporting associated with closure and post-injection site care

Comment: 146.93 (f): This will be impractical for large sequestration projects due to the paperwork and legal work to deal with a significant number of parties.

Response: EPA disagrees that the owner or operator should not be responsible for record retention such as site closure reports. EPA believes that the requirements that the owner or operator retain for ten years following site closure, records collected during the post-injection site care period at §146.93(f) and §146.93(h) are appropriate for the post-injection and site closure period to ensure that data are available to support non-endangerment demonstrations and to address any concerns that may arise following site closure. This data will also support EPA's review of project data as part of the adaptive rulemaking approach.

Commenter Name: Leslie Savage Letter ID: 0122 Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24807 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4730 2.7.3 Reporting associated with closure and post-injection site care

Comment: (e) Once the Director has authorized site closure, THE OWNER OR OPERATOR must submit a site closure report within 90 days that must thereafter be retained at a location designated by the Director. The report must include:

(1) Documentation of appropriate injection and monitoring well plugging as specified in §146.92 and paragraph (c) of this section. Must provide a copy of a survey plat which has been submitted to the local zoning authority designated by the Director, which indicates the location of the injection well relative to permanently surveyed benchmarks. Must also submit a copy of the plat to the regional administrator of the appropriate EPA Regional Office ;

{Why is this necessary? The EPA regional office will have access to all records at the State. }

Response: The GS regulation at §146.93(g) requires the owner or operator to record a notation on the deed to the facility property or other similar document examined during a title search that the land has been used to sequester CO2 at the time of site closure.Commenter Name: Leslie Savage Letter ID: 0122 Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24808 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4730 2.7.3 Reporting associated with closure and post-injection site care

Comment: (f) THE OWNER OR OPERATOR MUST Mustrecord a notation on the deed to the facility property or any other document that is normally examined during title search that will in perpetuity provide any potential purchaser of the property the following information:

(1) The fact that land has been used to sequester carbon dioxide; (2) The name of the State agency, local authority, and/or tribe with which the survey plat was filed , as well as the address of the Regional EPA Office to

which it was submitted ; and (3) The volume of fluid injected, the injection

zone or zones into which it was injected, and the period over which injection occurred.

Response: The GS regulation at §146.93(g) requires the owner or operator to record a notation that the land has been used to sequester CO2 on the deed to the facility property at the time of site

closure.

Commenter Name: Leslie Savage Letter ID: 0122 Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24809 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4730 2.7.3 Reporting associated with closure and post-injection site care

Comment: (g) Must retain for three years following site closure, records collected during the post-injection site care period. THE OWNER OR OPERATOR MUST Must deliver the records to the Director at the conclusion of the retention period, and the records must thereafter be retained at a location designated by the Director for that purpose.

Response: EPA disagrees that the owner or operator should not be responsible for record retention such as site closure reports. EPA believes that the requirements that the owner or operator retain for ten years following site closure, records collected during the post-injection site care period at §146.93(f) and §146.93(h) are appropriate for the post-injection and site closure period to ensure that data are available to support non-endangerment demonstrations and to address any concerns that may arise following site closure. This data will also support EPA's review of project data as part of the adaptive rulemaking approach.

Commenter Name: Bonnie Lovelace Letter ID: 0152 Commenter Organization: Montana Department of Environmental Quality (MDEQ) Comment ID:

22132

Comment: 146.93(f): MDEQ supports the requirement to make known to any land owners or future purchasers the existence of the plume below their land.

Response: The GS regulation at §146.93(g) requires the owner or operator to record a notation that the land has been used to sequester CO2 on the deed to the facility property at the time of site

closure.Commenter Name: James Dooley Letter ID: 0156 Commenter Organization: Joint Global Change Research Institute, Pacific Northwest National Laboratory Comment ID:

22635

Comment: Requirement to Document GS Sites and Pass that Information on to Future Potential Users of the Land Above as well as any Subsurface Zones Is Appropriate Page 43541. It is appropriate for the USEPA to require that steps be taken to document the CO2 injection formation and to ensure that information is passed on into the future. The steps spelled out here are reasonable and not overly burdensome (e.g., survey plat and deed for land must include a notation that the deep subsurface was used for CO2 storage). This language should be retained in subsequent versions of the Class VI rule.

Response: The GS regulation at §146.93(g) requires the owner or operator to record a notation that the land has been used to sequester CO2 on the deed to the facility property at the time of site

closure.

Commenter Name: James Childress Letter ID: 0158 Commenter Organization: Gasification Technologies Council (GTC) Comment ID: 23777 Other EPA Comment Codes and Descriptions: 1220 1.1.1.1 Terminology and definitions

Comment: §146.93 Post-injection site care and site closure (b)(3) "Prior to authorization for site closure, the owner or operator must submit to the Director a demonstration, based on monitoring and other site-specific data, that the carbon dioxide plume and pressure front have stabilized and that no additional monitoring is needed to assure that the geologic sequestration project does not pose an endangerment to USDWs."

Clarification of the term "stabilized" is needed. We recommend that the term "stabilized" does not necessarily mean the plume and pressure front are no longer moving, but that the rate and direction as defined by confinement zones no longer place an USDW at risk. Long-term monitoring should have an "end point" defined. Often termed an "exit strategy", this is a key point that is agreed upon by all parties about what is a "stable condition". Monitoring data includes a prescribed amount of error, thus statistics or other analyses may be required

to define a "stable condition".

Response: EPA acknowledges that many site-specific factors will influence the determination of when the CO2 plume and pressure front no longer pose a risk of endangerment to USDWs. It is for this reason that EPA believes that individual UIC Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care is needed. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties.

EPA agrees that a complete cessation of plume movement may not occur at some sites for long time periods due to density differences, natural formation flow gradients and diffusion. EPA clarifies that a complete cessation of plume movement is not required, only a demonstration that the plume and pressure front no longer pose a risk of endangerment to USDWs.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance willassist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Kyle Isakower Letter ID: 0170 Commenter Organization: American Petroleum Institute Comment ID: 24210 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4730 2.7.3 Reporting associated with closure and post-injection site care

Comment: Rule Provision: 146.93(e)

API Comments: (e) Once the Director has authorizeS dsite closure, the owner or operator must submit a site closure report within 90 days that must thereafter be retained at a location designated by the Director. AFTER COMPLETION OF ALL CLOSURE OPERATIONS. The report must include:

(1) Documentation of appropriate injection and monitoring well plugging as specified in §146.92 and paragraph (c) of this section. The owner or operator must provide a copy of a survey plat which has been submitted to the local zoning authority designated by the Director. The plat must indicate the location of the injection well(S) relative to permanently surveyed benchmarks. The owner or operator must also submit a copy of the plat to the Regional Administrator of the appropriate EPA Regional Office;

Rationale: Once the site closure report is submitted to the Director, the operator cease to bear responsibility for any further record retention. At this point, EPA becomes the steward of information for the project.

Response: EPA disagrees that the owner or operator should not be responsible for record retention such as site closure reports. EPA believes that the requirements that the owner or operator retain, for ten years following site closure, records collected during the post-injection site care period at §146.93(f) and §146.93(h) are appropriate for the post-injection and site closure period to ensure that data are available to support non-endangerment demonstrations and to address any concerns that may arise following site closure. This data will also support EPA's review of project data as part of the adaptive rulemaking approach.

Commenter Name: Frederick R. Eames Letter ID: 0178 Commenter Organization: CCS Alliance Comment ID: 23843

Comment: D. SITE CLOSURE

The CCS Alliance recommends including a provision releasing sites certified as closed from further monitoring and verification requirements, as well as releasing any outstanding financial assurance instruments.

Response: EPA disagrees that the owner or operator should not be responsible for record retention such as site closure reports. EPA believes that the requirements that the owner or operator retain for ten years following site closure, records collected during the post-injection site care period at§146.93(f) and §146.93(h) are appropriate for the post-injection and site closure period to ensure that data are available to support non-endangerment demonstrations and to address any concerns that may arise following site closure. This data will also support EPA's review of project data as part of the adaptive rulemaking approach.

Commenter Name: Thomas Curtis Letter ID: 0181 Commenter Organization: American Water Works Association (AWWA) Comment ID: 23749 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Part 146.93(b)(3) When addressing plume stabilization in association with site closure, it is important to realize that the carbon dioxide plume will never be completely stable. The carbon dioxide plume will continue to move by a combination of methods including density differences, natural formation flow gradients and diffusion. AWWA recommends that EPA engage in research to provide specific criteria on what exactly it would mean for the plume to have stabilized. If left up to the discretion of the various Directors, stabilization could be defined in many different ways. In order to have a consistent application of this part of the regulation, EPA should define the specific situations in which the plume could be considered "stable." AWWA recommends revising this part to read:

Prior to authorization for site closure, the owner or operator must demonstrate to the Director, based on monitoring and other site-specific data that no additional monitoring is needed to assure that the geologic sequestration project does not pose an endangerment to USDWs. The demonstration must demonstrate all of the following:

(i) the estimated magnitude and extent of the project footprint (CO2 plume and the area of elevated pressure) based on measurements and modeling; (ii) that CO2 movement and pressure changes match model predictions, (iii) the estimated location of the detectable CO2 plume based on measurement and modeling (measuring magnitude of saturation within the plume or mapping the edge of it); (iv) that there is no evidence of significant leakage of either CO2 or displaced formation fluids that endanger USDWs; (v) that the CO2 plume and displaced formation fluid are not expected to migrate in the future in a manner that encounters a potential leakage pathway; (vi) that the injection wells at the site completed into or through the injection zone or confining zone are properly plugged and abandoned; and, (vii) any remaining project monitoring wells at the site are being managed by a person and in a manner acceptable to the Director.

Response: EPA acknowledges that many site-specific factors will influence the determination of when the CO2 plume and pressure front no longer pose a risk of endangerment to USDWs. It is for this reason that EPA believes that individual UIC Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care is needed. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties.EPA agrees that a complete cessation of plume movement may not occur at some sites for long time periods due to density differences, natural formation flow gradients and diffusion. EPA clarifies that a complete cessation of plume movement is not required, only a demonstration that the plume and pressure front no longer pose a risk of endangerment to USDWs.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Thomas Curtis Letter ID: 0181 Commenter Organization: American Water Works Association (AWWA) Comment ID: 23750 Other EPA Comment Codes and Descriptions: 5200 2.8.2 Post injection site care (seeking comment) (40 CFR 146.93)

Comment: Part 146.93(d) There may be cases where the Director would want some of the monitoring wells to remain in service after site closure. While this may not be the case for all projects, for some of the earlier sites, the Director may want to continue minimal monitoring to continue to verify that the plume

characteristics have remained stable.

Response: EPA clarifies that the owner or operator must conduct post-injection site care that is consistent with the approved PISC plan or for the duration of the alternative timeframe approved by the Director pursuant to requirements in §146.93(c), until a demonstration can be made to the satisfaction of the Director that the plume and pressure front no longer pose a risk of endangerment to USDWs. After this determination is made, site closure is approved and the post-injection site care period would end, as specified in §146.93 (b)(1).

If, however, there is reason to believe that additional minimal monitoring is necessary to verify that the plume characteristics have remained stable, this would be considered post-injection site care monitoring. If a reduction in monitoring frequency or methods is appropriate (i.e., an additional year or so of verification of the non-endangerment demonstration), the Director has discretion to authorize an amendment to the post-injection site care and site closure plan. This is consistent with the requirements at §146.93(b)(2).

Commenter Name: Thomas Curtis Letter ID: 0181 Commenter Organization: American Water Works Association (AWWA) Comment ID: 24373 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Part 146.93(c) AWWA recommends that this part of the rule needs to include a directive that the Director needs to provide approval for site closure prior to implementation of the site-closure plan. AWWA recommends revising this part to

read:

Notice of intent for site closure. The owner or operator must notify the Director at least 120 days before site closure. At this time, if any changeshave been made to the original post-injection site care and site closure plan, the owner or operator must also provide the revised plan. The Director must provide approval for site closure prior to the implementation of the site closure plan. At the discretion of the Director, a shorter notice period may be

allowed.

Response: EPA considers the combination of the Director's evaluation of the data submitted to support a demonstration of non-endangerment of USDWs, as specified in §146.93(b)(3), and the Director's receipt of and agreement with the notification of intent for site closure as confirmation that GS site closure can proceed.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190 Commenter Organization: Carbon Sequestration Council Comment ID: 24503 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4730 2.7.3 Reporting associated with closure and post-injection site care

Comment: Rule Provision: 146.93(e)

Proposed CCS Group Recommendations: (e) Once the Director has

authorizeS dsite closure, the owner or operator must submit a site closure report within 90 days that must thereafter be retained at a location designated by the Director. AFTER COMPLETION OF ALL CLOSURE OPERATIONS. The report must include:

(1) Documentation of appropriate injection and monitoring well plugging as specified in §146.92 and paragraph (c) of this section. The owner or operator must provide a copy of a survey plat which has been submitted to the local zoning authority designated by the Director. The plat must indicate the location of the injection well(S) relative to permanently surveyed benchmarks. The owner or operator must also submit a copy of the plat to the Regional Administrator of the appropriate EPA Regional Office;

Basis for CCS Group Comments: Once the site closure report is submitted to the Director, the operator cease to bear responsibility for any further record retention. At this point, EPA becomes the steward of information for the project.

Rule Provision: 146.93(e)(2)

Proposed CCS Group Recommendations: Support the proposed language.

Basis for CCS Group Comments: Agree with EPA’s rationale.

Rule Provision: 146.93(f)

Proposed CCS Group Recommendations: Support the proposed language.

Basis for CCS Group Comments: Agree with EPA’s rationale.

Rule Provision: 146.93(g)Proposed CCS Group Recommendations: Support the proposed language.

Basis for CCS Group Comments: Agree with EPA’s rationale.

Response: EPA disagrees that the owner or operator should not be responsible for record retention such as site closure reports. EPA believes that the requirements that the owner or operator retain for ten years following site closure, records collected during the post-injection site care period at §146.93(f) and §146.93(h) are appropriate for the post-injection and site closure period to ensure that data are available to support non-endangerment demonstrations and to address any concerns that may arise following site closure. This data will also support EPA's review of project data as part of the adaptive rulemaking approach.

The GS regulation at §146.93(g) requires the owner or operator to record a notation on the deed to the facility property or other similar document examined during a title search that the land has been used to sequester CO2 at the time of site closure.

EPA acknowledges the commenter’s support of the other parts; the final rule retains these provisions.

Commenter Name: Craig R. Walters Letter ID: 0200 Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24723 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4730 2.7.3 Reporting associated with closure and post-injection site care

Comment: Rule Provision: 146.93(e)

Anadarko Petroleum Corporation (APC) Comments: (e) Once the Director has authorized site closure, the owner or operator must submit a site closure report within 90 days that must thereafter be retained at a location designated by

the Director. AFTER COMPLETION OF ALL CLOSURE OPERATIONS. The report must

include:

(1) Documentation of appropriate injection and monitoring well plugging as specified in §146.92 and paragraph (c) of this section. The owner or operator must provide a copy of a survey plat which has been submitted to the local zoning authority designated by the Director. The plat must indicate the location of the injection well(S) relative to permanently surveyed benchmarks. The owner or operator must also submit a copy of the plat to the Regional Administrator of the appropriate EPA Regional Office;

Rationale: Once the site closure report is submitted to the Director, the operator cease to bear responsibility for any further record retention. At this point, EPA becomes the steward of information for the project.

Response: EPA disagrees that the owner or operator should not be responsible for record retention such as site closure reports. EPA believes that the requirements that the owner or operator retain for ten years following site closure, records collected during the post-injection site care period at §146.93(f) and §146.93(h) are appropriate for the post-injection and site closure period to ensure that data are available to support non-endangerment demonstrations and to address any concerns that may arise following site closure. This data will also support EPA's review of project data as part of theadaptive rulemaking approach.

Commenter Name: Chris M. Hobson Letter ID: 0201 Commenter Organization: Southern Company Comment ID: 22175 Other EPA Comment Codes and Descriptions: 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: Post-Injection Site Care and Closure

Southern Company opposes a default fifty-year timeframe - or any fixed default length of time - for the post-injection site care period. ¡d. at 43519. A default post-injection site care period is of little value given the widely varied characteristics of future CO2 GS sites, and the significant discrepancy between the appropriate post-injection site care period for various Class VI wells. As EPA itself recognizes, the actual time required for plume stabilization following cessation of injection will be "very site specific." ¡d. A site-specific determination, based on conditions at a particular Class VI well, will be necessary in the case of every CO2 GS project under the UIC Program. The Final Rule should define a performance-based standard for site closure and leave the site-specific analysis and determination of appropriate post-injection site care period to the Director. Potential Owners or Operators are likely to shy away from undertaking a CO2 GS project if the Program's requirements may extend decades into the future even when those requirements are no longer necessary. A performance-based standard allowing for site-specific closure period determinations will avoid the chilling effect that any default fixed timeframe for post-injection site care and closure will have on participation and investment in C02 GS projects. Moreover, the site-specific approach will ensure that an appropriate post-injection site care period is identified to meet the needs of each individual Class VI operation.

Response: EPA agrees with commenters that there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-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 ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

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

EPA believes that a default post-injection site care 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 isanticipated to occur, to accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

Commenter Name: Richard Guinn Letter ID: 0210 Commenter Organization: Eastman Chemical Company Comment ID: 22727

Comment: §146.93 Post-injection site care and site closure (b)(3) "Prior to authorization for site closure, the owner or operator must submit to the Director a demonstration, based on monitoring and other site-specific data, that the carbon dioxide plume and pressure front have stabilized and that no additional monitoring is needed to assure that the geologic sequestration project does not pose an endangerment to USDWs."

Clarification of the term "stabilized" is needed. We recommend that the term "stabilized" does not necessarily mean the plume and pressure front are no longer moving, but that the rate and direction as defined by confinement zones no longer place an USDW at risk. Long-term monitoring should have an "end point" defined. Often termed an "exit strategy", this is a key point that is agreed upon by all parties about what is a "stable condition". Monitoring data includes a prescribed amount of error , thus statistics or other analyses may be required

to define a "stable condition".

Response: EPA acknowledges that many site-specific factors will influence the determination of when the CO2 plume and pressure front no longer pose a risk of endangerment to USDWs. It is for this reason that EPA believes that individual UIC Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care is needed. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties.

EPA agrees that a complete cessation of plume movement may not occur at some sites for long time periods due to density differences, natural formation flow gradients and diffusion. EPA clarifies that a complete cessation of plume movement is not required, only a demonstration that the plume and pressure front no longer pose a risk of endangerment to USDWs.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Ronald Evans Letter ID: 0215 Commenter Organization: Denbury Resources, Inc. (DRI) Comment ID: 24313 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5240 2.8.2.2 Post injection timeframe (seeking comment)

Comment: I. § 146.93 Post-injection site care and site closure.The proposed rule establishes a 50 year default period for post-injection site care. There is, however, no factual or scientific basis for such an extensive period. Under EPA’s Resource Conservation and Recovery Act rules, which regulate the disposal of hazardous wastes, post closure care is limited to 30 years.[FN45] Defaulting to an excessively long period will increase costs and introduce greater regulatory uncertainty, which will discourage capital formation around CO2 sequestration. A more prudent regulatory approach is to set a minimum period for site care, ten years, with allowance for the Director to extend the period if facts and circumstances warrant a longer post-injection site care period.

Additionally, the proposed rule’s 50 year default post injection site care period, is an illusory deadline, as it is not self-executing. Under the rules, post injection site care must continue indefinitely until the Director authorizes closure. The closure approval process could take years, even decades, as the Director has no regulatory incentive to act on any post injection site care report. Meanwhile, a permittee may be required to continue unnecessary and expensive monitoring and reporting indefinitely.

Denbury suggests that the post-injection site care rules be reconfigured to require a more limited mandatory post-injection site care timeframe, and to allow for closure at the end of that period unless the Director affirmatively acts to extend the post-injection site care period. These changes are contained in the suggested text below:

§ 146.93 Post-injection site care and site closure. (a) The owner or operator of a Class VI well must prepare, maintain, and comply with a plan for post-injection site care and site closure that meets the requirements of paragraph (a)(2) of this section and is acceptable to the Director. (1) The owner or operator must submit the post-injection site care and site closure plan as a part of the permit application to be approved by the Director. (2) The post-injection site care and site closure plan must include the following information: (i) The pressure differential between pre-injection and predicted post-injection pressures in the injection zone; (ii) The predicted position of the carbon dioxide plume and associated pressure front at site closure as demonstrated in the area of review evaluation required under § 146.84(b); (iii) A description of post-injection monitoring location, methods, and proposed frequency; and (iv) A proposed schedule for submitting post-injection site care monitoring results to the Director. (3) Upon cessation of injection, owners or operators of Class VI wells must either submit an amended post-injection site care and site closure plan or demonstrate to the Director through monitoring data and modeling results that no amendment to the plan is needed.(4) The owner or operator may modify and resubmit the postinjection site care and site closure plan for the Director’s approvalwithin 30 days of such change. (b) The owner or operator shall monitor the site following the cessation of injection to show the position of the carbon dioxide plume and pressure front and demonstrate that USDWs are not being endangered. (1) The owner or operator shall continue to conduct monitoring as specified in the Director-approved post-injection site care and site closure plan for at least 5010 years following the cessation of injection. At theUPON A DETERMINATION BY THE Director ’s THAT THE GEOLOGIC SEQUESTRATION PROJECT MAY POSE AN ENDANGERMENT TO

USDWS discretion , THE DIRECTOR, AT HIS DISCRETION, MAY REQUIRE the monitoring willTO continue FOR A TIME PERIOD SPECIFIED BY

THE DIRECTOR until the geologic sequestration project no longer poses an endangerment to USDWs. (2) If the owner or operator can demonstrate to the satisfaction

of the Director before 5010 years, based on monitoring and other site-specific data, that the geologic sequestration project no longer poses an endangerment to USDWs, the Director may approve an amendment to the post injection site care and site closure plan to reduce the frequency of monitoring or may authorize site closure before the end of

the 5010 year period. (3) Prior to authorization forTHE EXPIRATION OF THE 10
YEAR POST-INJECTION SITE CARE PERIOD, site closure , the owner or operator must submit to the Director a demonstration, based on monitoring and other site specific data, that the carbon dioxide plume and pressure front have stabilized and that no additional monitoring is needed to assure that the geologic sequestration project does not pose an endangerment to USDWs. (4) IF WITHIN 180 DAYS AFTER THE SUBMITTAL OF THE DATA REQUIRED UNDER SUBPARAGRAPH (3) ABOVE THE DIRECTOR DETERMINES THAT THE

GEOLOGICAL SEQUESTRATION PROJECT MAY CONTINUE TO POSE AN ENDANGERMENT TO
USDWS, HE

SHALL SO NOTIFY THE OWNER OR OPERATOR OF HIS DETERMINATION AND THE

BASIS
THEREFORE, AND If such a demonstration cannot be made (i.e., if the carbon dioxide plume and pressure front have not stabilized) after the 50-year period,the owner or operator must submit to the Director a plan to continue post-injection site care. (5) IF WITHIN 180 DAYS AFTER THE SUBMITTAL OF THE DATA REQUIRED UNDER SUBPARAGRAPH (3) ABOVE THE DIRECTOR FAILS TO DETERMINE AND TO NOTIFY THE OWNER OR OPERATOR THAT THE GEOLOGICAL SEQUESTRATION

PROJECT
MAY CONTINUE TO POSE AN ENDANGERMENT TO USDWS, SITE CLOSURE SHALL BE

DEEMED AUTHORIZED BY RULE (c) Notice of intent for site closure. The owner or operator must notify the Director at least 120 days before site closure. At this time, if any changes have been made to the original post-injection site care and site closure plan, the owner or operator must also provide the revised plan. At the discretion of the Director, a shorter notice period may be allowed.(d) After the Director has authorized site closure OR SITE CLOSURE IS AUTHORIZED BY RULE, the owner or operator must plug all monitoring wells in a manner which will not allow movement of injection or formation fluids that endangers a USDW. (e) Once the Director has authorized site closure, OR SITE CLOSURE IS AUTHORIZED BY RULE, the owner or operator must submit a site closure report within 90 days that must thereafter be retained at a location designated by the Director. The report must include: (1) Documentation of appropriate injection and monitoring well plugging as specified in § 146.92 and paragraph (c) of this section. The owner or operator must provide a copy of a survey plat which has been submitted to the local zoning authority designated by the Director. The plat must indicate the location of the injection well relative to permanently surveyed benchmarks. The owner or operator must also submit a copy of the plat to the Regional Administrator of the appropriate EPA Regional Office; (2) Documentation of appropriate notification and information to such State, local and tribal authorities as have authority over drilling activities to enable such State and local authorities to impose appropriate conditions on subsequent drilling activities that may penetrate the injection and confining zone(s); and (3) Records reflecting the nature, composition and volume of the

carbon dioxide stream. (f) Each owner or operator of a Class VI injection well must record a notation on the deed to the facility property or any other document that is normally examined during title search that will in perpetuity provide any potential purchaser of the property the following information: (1) The fact that land has been used to sequester carbon dioxide; (2) The name of the State agency, local authority, and/or tribe with which the survey plat was filed, as well as the address of the Regional Environmental Protection Agency Office to which it was submitted; and (3) The volume of fluid injected, the injection zone or zones into which it was injected, and the period over which injection

occurred. (g) The owner or operator must retain for three years following site closure, records collected during the post-injection site care period. The owner or operator must deliver the records to the Director at the conclusion of the retention period, and the records must thereafter be retained at a location designated by the Director for that purpose.

[45] 40 C.F.R. § 264.117(a)(1)

Response: The post-injection site care requirements in the final GS rule, §146.93(b), incorporate a combination of a 50-year default post-injection site care timeframe, in conjunction with a performance standard, for Class VI wells. 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 post-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 analternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

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

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA expects that the Director will consider the types of information the commenter describes in determining whether the plume and pressure front no longer pose a risk of endangerment to USDWs and post-injection site care monitoring may be discontinued.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells, perform post-injection monitoring, demonstrate the appropriateness of an alternative post-injection site care time frame, demonstrate non-endangerment, and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Darrick Eugene Letter ID: 0223 Commenter Organization: Texas Carbon Capture and Storage Association Comment ID: 23994 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5200 2.8.2 Post injection site care (seeking comment) (40 CFR 146.93)

Comment: Director affirmatively acts to extend the post-injection site care period. These changes are contained in the suggested text below:

§ 146.93 Post-injection site care and site closure. (a) The owner or operator of a Class VI well must prepare, maintain, and comply with a plan for post-injection site care and site closure that meets the requirements of paragraph (a)(2) of this section and is acceptable to the Director. (1) The owner or operator must submit the post-injection site care and site closure plan as a part of the permit application to be approved by the Director. (2) The post-injection site care and site closure plan must include the following information: (i) The pressure differential between pre-injection and predicted post-injection pressures in the injection zone; (ii) The predicted position of the carbon dioxide plumeand associated pressure front at site closure as demonstrated in the area of review evaluation required under § 146.84(b); (iii) A description of post-injection monitoring location, methods, and proposed frequency; and (iv) A proposed schedule for submitting post-injection site care monitoring results to the Director. (3) Upon cessation of injection, owners or operators of Class VI wells must either submit an amended post-injection site care and site closure plan or demonstrate to the Director through monitoring data and modeling results that no amendment to the plan is needed.(4) The owner or operator may modify and resubmit the postinjection site care and site closure plan for the Director’s approval within 30 days of such change. (b) The owner or operator shall monitor the site following the cessation of injection to show the position of the carbon dioxide plume and pressure front and demonstrate that USDWs are not being endangered.

*

*

* (3) Prior to authorization forTHE EXPIRATION OF THE PERIOD SPECIFIED IN SUBPART (B)(1), site closure , the owner or operator must submit to the Director a demonstration, based on monitoring and other site specific data, that the carbon dioxide plume and pressure front have stabilized and that no additional monitoring is needed to assure that the geologic sequestration project does not pose an endangerment to USDWs. (4) IF WITHIN 180 DAYS AFTER THE SUBMITTAL OF THE DATA REQUIRED UNDER SUBPARAGRAPH (3), THE DIRECTOR DETERMINES THAT THE GEOLOGICAL SEQUESTRATION PROJECT MAY CONTINUE TO POSE AN ENDANGERMENT TO
USDWS, HE

SHALL SO NOTIFY THE OWNER OR OPERATOR OF HIS DETERMINATION AND THE

BASIS
THEREFORE, AND If such a demonstration cannot be made (i.e., if the carbon dioxide plume and pressure front have not stabilized) after the 50-year period,the owner or operator must submit to the Director a plan to continue post-injection site care. (5) IF WITHIN 180 DAYS AFTER THE SUBMITTAL OF THE DATA REQUIRED UNDER SUBPARAGRAPH (3) ABOVE THE DIRECTOR FAILS TO DETERMINE AND TO NOTIFY THE OWNER OR OPERATOR THAT THE GEOLOGICAL SEQUESTRATION

PROJECT
MAY CONTINUE TO POSE AN ENDANGERMENT TO USDWS, SITE CLOSURE SHALL BE

DEEMED AUTHORIZED BY RULE (c) Notice of intent for site closure. The owner or operator must notify the Director at least 120 days before site closure. At this time, if any changes have been made to the original post- injection site care and site closure plan, the owner or operator must also provide the revised plan. At the discretion of the Director, a shorter notice period may be

allowed. (d) After the Director has authorized site closure OR SITE CLOSURE IS AUTHORIZED BY RULE, the owner or operator must plug all monitoring wellsin a manner which will not allow movement of injection or formation fluids that endangers a USDW. (e) Once the Director has authorized site closure, OR SITE CLOSURE IS AUTHORIZED BY RULE, the owner or operator must submit a site closure report within 90 days that must thereafter be retained at a location designated by the Director. The report must include: (1) Documentation of appropriate injection and monitoring well plugging as specified in § 146.92 and paragraph (c) of this section. The owner or operator must provide a copy of a survey plat which has been submitted to the local zoning authority designated by the Director. The plat must indicate the location of the injection well relative to permanently surveyed benchmarks. The owner or operator must also submit a copy of the plat to the Regional Administrator of the appropriate EPA Regional Office; (2) Documentation of appropriate notification and information to such State, local and tribal authorities as have authority over drilling activities to enable such State and local authorities to impose appropriate conditions on subsequent drilling activities that may penetrate the injection and confining zone(s); and (3) Records reflecting the nature, composition and volume of the carbon dioxide

stream. (f) Each owner or operator of a Class VI injection well must record a notation on the deed to the facility property or any other document that is normally examined during title search that will in perpetuity provide any potential purchaser of the property the following information: (1) The fact that land has been used to sequester carbon dioxide; (2) The name of the State agency, local authority, and/or tribe with which the survey plat was filed, as well as the address of the Regional Environmental Protection Agency Office to which it was submitted; and (3) The volume of fluid injected, the injection zone or zones into which it was injected, and the period over which injection

occurred. (g) The owner or operator must retain for three years following site closure, records collected during the post-injection site care period. The owner or operator must deliver the records to the Director at the conclusion of the retention period, and the records must thereafter be retained at a location designated by the Director for that purpose.

Response: The PISC requirements in the final GS rule, as specified in §146.93(b), incorporate a combination of a fixed timeframe and a performance standard approach. EPA believes that a default PISC timeframe of 50 years, with Director's discretion to shorten or lengthen this timeframe, combined with a site-specific Director’s discretion to create an alternative PISC time frame, ensures that USDWs are protected. 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at§146.93(c). EPA expects that the Director would consider the types of information the commenter describes in determining whether the plume and pressure front no longer pose a risk of endangerment to USDWs and post-injection site care monitoring may be discontinued.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate the appropriateness of an alternative post-injection site care time frame; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Andrew Duguid Letter ID: 0226 Commenter Organization: Schlumberger Carbon Services Comment ID: 23998 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 5260 2.8.2.3 Adjusting the post-injection timeframe (seeking comment)

Comment: 3. Schlumberger does not support the default post injection site care period of 50 years. We feel that because the characterization and operation of the site will be based on the specific attributes of the site that the length of post injection site care should also be site specific information. In particular the criteria for ending the PISC period should be based on site performance and risk. We support the idea that the director approves final site closure. We suggest the following language for Section 146.93(b)(1):

(1) The owner or operator shall continue to conduct monitoring as specified in the Director-approved post-injection site care and site closure plan, pursuant to the performance based criteria described in 146.93(b)(3).

We suggest the following language for section 146.93(b)(2)

(2) If the owner or operator can demonstrate to the satisfaction of the Director that the geologic sequestration project no longer poses an endangerment to USDWs, the Director may approve an amendment to the post- injection site care and site closure plan to reduce the frequency of monitoring or may authorize site closure.

And we suggest the following language for section 146.93(b)(3)

(3) Prior to authorization for site closure, the owner or operator mustdemonstrate to the Director, based on monitoring and other sitespecific data that no additional monitoring is needed to assure that the geologic sequestration project does not pose an endangerment to USDWs, considering the following:.

(i) the estimated magnitude and extent of the AOR based on measurements and modeling; (ii) that CO2 movement and pressure changes match model predictions, (iii) the estimated location of the detectable CO2 plume based on measurement and modeling (measuring magnitude of saturation within the plume or mapping the edge of it); (iv) that there is no evidence of significant leakage of either CO2 or formation fluids that endanger USDWs; (v) that the CO2 plume and displaced formation fluid are not expected to migrate in the future in a manner that encounters a potential leakage pathway; and, (vi) that wells at the site are not leaking and have maintained integrity.

Response: The PISC requirements in the final GS rule, as specified in §146.93(b), incorporate a combination of a fixed timeframe and a performance standard approach. EPA believes that a default PISC timeframe of 50 years, with Director's discretion to shorten or lengthen this timeframe, combined with a site-specific Director’s discretion to create an alternative PISC time frame, ensures that USDWs are protected. 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 PISC 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, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropriate if it ensures non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA expects that the Director would consider the types of information the commenter describes in determining whether the plume and pressure front no longer pose a risk of endangerment to USDWs and post-injection site care monitoring may be discontinued.

EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts.

EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; perform post-injection monitoring; demonstrate the appropriateness of an alternative post-injection site care time frame; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.Commenter Name: Andrew Duguid Letter ID: 0226 Commenter Organization: Schlumberger Carbon Services Comment ID: 24072 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Proposed Rule: (3) Prior to authorization for site closure, the owner or operator must submit to the Director a demonstration, based on monitoring and other site-specific data, that the carbon dioxide plume and pressure front have stabilized and that no additional monitoring is needed to assure that the geologic sequestration project does not pose an endangerment to USDWs.

Schlumberger Suggested Revision: (3) Prior to authorization for site closure, the owner or operator must demonstrate to the Director, based on monitoring and other site-specific data that no additional monitoring is needed to assure that the geologic sequestration project does not pose an endangerment to USDWs, considering the following:. (i) the estimated magnitude and extent of the AOR based on measurements and modeling; (ii) that CO2 movement and pressure changes match model predictions, (iii) the estimated location of the detectable CO2 plume based on measurement and modeling (measuring magnitude of saturation within (iv) that there is no evidence of significant leakage of either CO2 or formation fluids that endanger USDWs; (v) that the CO2 plume and displaced formation fluid are not expected to migrate in the future in a manner that encounters a potential leakage pathway; and, (vi) that wells at the site are not leaking and have maintained integrity.

Schlumberger Rationale: Establishes the performance based criteria for selecting the monitoring period. the plume or mapping the edge of it);

Response: The post-injection site care requirements in the final GS rule, §146.93(b), incorporate a combination of a fixed timeframe and a performance standard approach. Specifically , 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 post-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 processbased on substantial data, that an alternative PISC timeframe may be appropriate if it ensures nonendangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from endangerment, 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 protective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments. EPA believes that a default post-injection site care 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 accommodate site-specific circumstances and various geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW impacts. EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of 146.92 and 146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closureplans under 146.92 and 146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; demonstrate the appropriateness of an alternative post-injection site care time frame; perform post-injection monitoring; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Andrew Duguid Letter ID: 0226 Commenter Organization: Schlumberger Carbon Services Comment ID: 24073 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Proposed Rule: (e) Once the Director has authorized site closure, the owner or operator must submit a site closure report within 90 days that must thereafter be retained at a location designated by the Director. The report must include:

Schlumberger Suggested Revision: (e) Once the Director has authorized site closure, the owner or operator must submit a site closure report within 90 days after completion of all closure operations. The report must include:

Schlumberger Rationale: What is the retention period? Many other programs have a three year limit for retention of records. EPA is the steward of information at this point of the project, not the owner or operator.

Response: EPA disagrees that the owner or operator should not be responsible for record retention such as site closure reports. EPA believes that the requirements that the owner or operator retain for ten years following site closure, records collected during the post-injection site care period at §146.93(f) and §146.93(h) are appropriate for the post-injection and site closure period to ensure that data are available to support non-endangerment demonstrations and to address any concerns that may arise following site closure. This data will also support EPA's review of project data as part of the adaptive rulemaking approach.

Commenter Name: Andrew Duguid Letter ID: 0226 Commenter Organization: Schlumberger Carbon Services Comment ID: 24074 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Proposed Rule: (1) Documentation of appropriate injection and monitoring well plugging as specified in §146.92 and paragraph (c) of this section. The owner or operator must provide a copy of a survey plat which has been submitted to the local zoning authority designated by the Director. The plat must indicate the location of the injection well relative to permanently surveyed benchmarks. The owner or operator must also submit a copy of the plat to the Regional Administrator of the appropriate EPA Regional Office;

Schlumberger Suggested Revision: (1) Documentation of appropriate injection and monitoring well plugging as specified in §146.92 and paragraph (c) of this section. The owner or operator must provide a copy of a survey plat which has been submitted to the local zoning authority designated by the Director. The plat must indicate the location of the injection well(s) relative to permanently surveyed benchmarks. The owner or operator must also submit a copy of the platto the Regional Administrator of the appropriate EPA Regional Office;

Schlumberger Rationale: -

Response: The GS regulation at §146.93(g) requires the owner or operator to record a notation on the deed to the facility property or other similar document examined during a title search that the land has been used to sequester CO2 on the deed to the facility property at the time of site closure.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24949 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.93(c)

EPA Proposal: (c) Notice of intent for site closure. The owner or operator must notify the Director at least 120 days before site closure. At this time, if any changes have been made to the original post-injection site care and site closure plan, the owner or operator must also provide the revised plan. At the discretion of the Director, a shorter notice period may be allowed.

GWPC Recommendations: No recommendation

Rationale: Need for site-specific considerations and use of data

Response: EPA acknowledges the comment. For additional information on EPA's final regulatory approach, please see the final rule and preamble as well as the rulemaking docket.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24950 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language

Comment: Rule Provision: 146.93(d)

EPA Proposal: (d) After the Director has authorized site closure, the owner or operator must plug all monitoring wells in a manner which will not allow movement of injection or formation fluids that endangers a USDW.

GWPC Recommendations: No recommendation

Rationale: Need for site-specific considerations and use of data

Response: EPA acknowledges the comment. For additional information on EPA's final regulatory approach, please see the final rule and preamble as well as the rulemaking docket.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24951 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4730 2.7.3 Reporting associated with closure and post-injection site careComment: EPA Proposal: (e) Once the Director has authorized site closure, the owner or operator must submit a site closure report within 90 days that must thereafter be retained at a location designated by the Director. The report must include:

(1) Documentation of appropriate injection and monitoring well plugging as specified in § 146.92 and paragraph (c) of this section. The owner or operator must provide a copy of a survey plat which has been submitted to the local zoning authority designated by the Director. The plat must indicate the location of the injection well relative to permanently surveyed benchmarks. The owner or operator must also submit a copy of the plat to the Regional Administrator of the appropriate EPA Regional Office;

GWPC Recommendations: (e) Once the Director has authorized site closure, the owner or operator must submit a site closure report within 90 days after completion of all closure operations. The report must include:

(1) Documentation of appropriate injection and monitoring well plugging as specified in §146.92 and paragraph (c) of this section. The owner or operator must provide a copy of a survey plat which has been submitted to the local zoning authority designated by the Director. The plat must indicate the location of the injection well(s) relative to permanently surveyed benchmarks. The owner or operator must also submit a copy of the plat to the Regional Administrator of the appropriate EPA Regional Office;

Rationale: What is the retention period? Many other programs have a three year limit for retention of records. EPA is the steward of information at this point of the project, not the owner or operator.

Response: The GS regulation at §146.93(g) requires the owner or operator to record a notation on the deed to the facility property or other similar document examined during a title search that the land has been used to sequester CO2 on the deed to the facility property at the time of site closure.

Regarding record retention, EPA has clarified the recordkeeping requirements in the final GS rule, which includes requirements that well plugging reports, as required at §146.92(d), post-injection site care data, as required at §146.93(f), and site closure reports, as required at §146.93(h), must be kept by the owner or operator for ten years after site closure. EPA believes that longer record retention times for GS wells are appropriate and necessary for the post-injection and site closure period to ensure that data are available to support non-endangerment demonstrations and to address any concerns that may arise following site closure. This data will also support EPA's review of project data as part of the adaptive rulemaking approach.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24952 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4730 2.7.3 Reporting associated with closure and post-injection site care

Comment: EPA Proposal: (2) Documentation of appropriate notification and information to such State, local and tribal authorities as have authority over drilling activities to enable such State and local authorities to impose appropriate conditions on subsequent drilling activities that may penetrate the injectionand confining zone(s); and

(3) Records reflecting the nature, composition and volume of the carbon dioxide

stream.

GWPC Recommendations: No recommendation

Rationale: Need for site-specific considerations and use of data

Response: The GS regulation at §146.93(g) requires the owner or operator to record a notation on the deed to the facility property or other similar document examined during a title search that the land has been used to sequester CO2 on the deed to the facility property at the time of site closure.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24953 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4730 2.7.3 Reporting associated with closure and post-injection site care

Comment: Rule Provision: 146.93

EPA Proposal: (f) Each owner or operator of a Class VI injection well must record a notation on the deed to the facility property or any other document that is normally examined during title search that will in perpetuity provide any potential purchaser of the property the following information:

(1) The fact that land has been used to sequester carbon dioxide; (2) The name of the State agency, local authority, and/or tribe with which the survey plat was filed, as well as the address of the Regional Environmental Protection Agency Office to which it was submitted; and

GWPC Recommendations: No recommendation

Rationale: Need for site-specific considerations and use of data

Response: The GS regulation at §146.93(g) requires the owner or operator to record a notation on the deed to the facility property or other similar document examined during a title search that the land has been used to sequester CO2 on the deed to the facility property at the time of site closure.

Commenter Name: Michel Paque Letter ID: 0259 Commenter Organization: Ground Water Protection Council Comment ID: 24954 Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule language; 4730 2.7.3 Reporting associated with closure and post-injection site care

Comment: EPA Proposal: (3) The volume of fluid injected, the injection zone or zones into which it was injected, and the period over which injection occurred.

(g) The owner or operator must retain for three years following site closure, records collected during the post-injection site care period. The owner or operator must deliver the records to the Director at the conclusion of the retention period, and the records must thereafter be retained at a locationdesignated by the Director for that purpose.

GWPC Recommendations: No recommendation

Rationale: Need for site-specific considerations and use of data

Response: The GS regulation at §146.93(g) requires the owner or operator to record a notation on the deed to the facility property or other similar document examined during a title search that the land has been used to sequester CO2 on the deed to the facility property at the time of site closure.

Commenter Name: Donn Miller Letter ID: 0270 Commenter Organization: State of Oregon, Water Resources Department Comment ID: 22891

Comment: 146.93 Post-Injection Site Care and Site Closure. (e) We ask that the site closure reports be posted on-line.

Response: EPA disagrees that the owner or operator should not be responsible for record retention such as site closure reports. EPA believes that the requirements that the owner or operator retain for ten years following site closure, records collected during the post-injection site care period at §146.93(f) and §146.93(h) are appropriate for the post-injection and site closure period to ensure that data are available to support non-endangerment demonstrations and to address any concerns that may arise following site closure. This data will also support EPA's review of project data as part of the adaptive rulemaking approach.

In response to the suggestion that the site closure reports be posted on-line, this information would be part of the administrative record on the site, and specific options for access to those records would be the decision of the permitting authority.

Commenter Name: Michele Schoepper Letter ID: 0503 Commenter Organization: American Petroleum Institute Comment ID: 21175

Comment: Clear guidelines also need to be established regarding when operators have met the performance standards that determine site closure. Specifically, the standard that the project no longer poses an endangerment to USDWs needs to be defined using reasonable site- specific criteria.

Response: EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of 146.92 and 146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under 146.92 and 146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; demonstrate the appropriateness of an alternative post-injection site care time frame; perform post-injection monitoring; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Scott Anderson Letter ID: 0510 Commenter Organization: Environmental Defense Fund Comment ID: 21230

Comment: And my final point I've actually already made, which is that we suggest that you need to improve the standards for authorizing and site closure.Thank you.

Response: As described above, EPA disagrees that the rule should set specific criteria. EPA believes that many site-specific factors will influence the determination of when the CO2 plume and pressure front no longer pose a risk of endangerment to USDWs. It is for this reason that EPA believes that individual UIC Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care is needed. EPA expects this decision to be made based on relevant site data and in consultation with all potentially impacted parties. EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of 146.92 and 146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under 146.92 and 146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; demonstrate the appropriateness of an alternative post-injection site care time frame; perform post-injection monitoring; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Steve Crookshank Letter ID: 0523 Commenter Organization: American Petroleum Institute (API) Comment ID: 21358

Comment: Clear guidelines also need to be established regarding when operators have met the performance standards that determine site closure. Specifically, the standard that the project no longer poses an endangerment to USDW's needs to be defined using reasonable risk based criteria. EPA should also reconsider its

Response: EPA is developing guidance to assist owners or operators in evaluating well plugging, post-injection site care, and site closure requirements of 146.92 and 146.93. Additionally, the guidance will assist Directors in evaluating proposed well plugging plans and post-injection site care and site closure plans under 146.92 and 146.93. The guidance describes recommended approaches for how an owner or operator could plug injection and monitoring wells; demonstrate the appropriateness of an alternative post-injection site care time frame; perform post-injection monitoring; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.