This comment letter response contains two parts:

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

Notes about the response letters:

• The response letters were generated by a data base used to track the content of all public

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

was assigned a Letter ID that corresponds to the last four digits of the docket number of the

original comment (as posted on www.regulations.gov).

• Each response letter includes: comment text; an EPA

‐ assigned comment code; and an

individual response. These are described and explained below.

• The data base contains Comment text from the letters submitted by commenters.

Many hard copy letters were scanned into electronic format for inclusion in the data

base. As a result, there may be some typographical errors attributable to optical

character recognition issues. However, all original submittals were reviewed in the

process of drafting responses to ensure that the comment content was understood and

appropriately addressed.

• The content of each comment letter was divided into topic areas and assigned a unique

Comment ID. Additionally, one or more Comment Codes (i.e., unique topic area ID) was assigned to each discrete point raised by a commenter. This information was added to

the data base. To inform final rulemaking decisions, all comments and information

received on a given topic were reviewed by technical experts in each rule area (e.g., on

construction requirements).

• Following decisions on the final rule requirements, Individual responses were drafted

by topic area to ensure completeness and consistency of the responses with the final

rule and other responses to similar comments. Each discrete point made by a

commenter was given a unique response.

• Upon completion of comment responses, all information was entered into the data base.

Each letter response is a compilation of each comment and its individual response, compiled in the order of the original comment letter. As a result of this process, there is

repetition in the response text. The Agency believes this approach ensures completeness

and attention to each comment letter that was submitted.

• All comments in a topic area were reviewed, evaluated, and responded to concurrently.

Responses on each topic area are compiled and are also available in the rulemaking docket.December 8, 2008

Water Docket Environmental Protection Agency

Mailcode: 2822T 1300 Pennsylvania Avenue NW Washington, DC 20460

Re: Docket ID No. EPA-HQ-OW-2008-0390

Electronically Delivered: Via: www.regulations.gov

To Whom It May Concern:

Company Introduction and Frame of Reference for Comments

Global Energy, Inc. (Global) appreciates the opportunity to comment on the Proposed

Rule: 40 CFR Parts 144 and 146 Federal Requirements Under the Underground Injection Control (UIC) Progr am For Carbon Dioxide (CO 2 ) Geologic Sequestration (GS)

Wells.

Global is actively developing gasificat ion based energy production projects, with particular focus on the production of Synthet ic Natural Gas (SNG), Fischer-Tropsch (F-T) liquids, Hydrogen, as well as electric power generation via Integrated Gasification Combined Cycle (IGCC) technology. Oxygen blown, slagging gasification is the only version of gasification we co nsider to be true gasification. These are closed systems without primary stack or vent . Carbonaceous feedstock such as Petroleum Coke (petcoke), coal, as well as renewable and biomass material s can all readily be converted into synthetic gas and by further processing into these other products. We have a project partially under construction in Li ma, Ohio that may well be the first of the next generation gasification facili ties in this country. T he above mentioned products all include carbon capture as inherent process st eps for meeting product specification. In IGCC power generation, carbon capture may be “post-combustion”, but the superior path would be “pre-combustion”, which result s in a hydrogen rich fuel and carbon capture, resulting in CO 2 emission performance comparabl e or superior to that of natural gas. The critical consideration with thes e processes is management of the captured CO 2 !

Importantly, and most relevant to this propos ed rule, our corporate vision and intention is to implement GS and Enhanced Oil Recovery (EOR) on all our projects. To this end we have identified both EOR and GS oppor tunities and geologic horizons within reasonable proximity to our Lima Energy IGCC Facility. While these will both require dedicated effort to implement, we are excited about the pros pect. More specifically, with respect to this rule, the known geo logic horizon immedi ately beneath the Lima facility, with extensive aerial extent, depth and thickness, has already been

demonstrated to be well suited to GS. Moreov er, the horizon has already been used for UIC purposes, with both geologic and seismic evaluation.

Global Energy Inc, Suite 2300, 312 Wal nut Street, Cincinnati, OH 45202, USA

Tel: 513-621-0077 • Fax: 513-621-59472

Global Energy Inc, Suite 2300, 312 Wal nut Street, Cincinnati, OH 45202, USA

Tel: 513-621-0077 • Fax: 513-621-5947 Introduction

Global appreciates the opport unity to comment on this proposed rule, for the protection of USDW by appropriate siting and installation of Class VI Wells for the Injection and

GS of CO 2 . We strongly support the broad intent of the rule and believe it will ultimately foster accelerated implementation of carbon management programs. The US Department of Energy has id entified numerous feasible lo cations across the country, some of which are very large and extensive, for geologic sequestrati on. Some of these are today being used with DOE’s Regional Testing Programs.

1. The siting criteria, includi ng defining of the appropriate “Area of Review”, seismic

evaluation, extensive modeling and characterization are su fficiently rigorous that it is reasonable to anticipate minimal risks of leak age will exist long term. This minimal risk therefore argues in favor of a simple and pr agmatic program.

2. Well installation, operation, monitoring, record keepin g, and corrective action are similarly rigorous and reas onably pragmatic; and they materially minimize the potential for inappropriate actions.

Specific Comments

Delegation of Authority

1. Global supports EPA’s in tent to delegate implement ation of the program to authorized state agencies, and recommends ensuring that the state has ultimate decision authority over lower government ent ities such as counties and cities. The authority should also prescri be appropriate public involvement in siting decisions, and a process for review. They should how ever not allow extensive obstruction of technically decided decisions, or the pr ogram will have limited adoption and support.

2. EPA should set standards and criteria that will result in “reasonably consistent” implementation and results regar dless of geographic location.

3. EPA should establish a hierarchy of aut hority for decision making and oversight, to ensure interstate and inter-jurisdictional conflicts are avoided. In this, Global appreciates that some states have moved ahead to implem ent carbon management programs. However, it is our view that effective an d early implementation will be best served by consistency across the board. We theref ore encourage EPA to review the programs of all states and se lect the common threads that are most suitable to early and effe ctive implementation.3

Global Energy Inc, Suite 2300, 312 Wal nut Street, Cincinnati, OH 45202, USA

Tel: 513-621-0077 • Fax: 513-621-5947 Risk Management

1. Global concurs with the EPA view that t he risk of asphyxiation and acute or chronic

health effects is minimal. Pipeline leaks are rare and readily managed by existing authorities. Similarly we llhead and well leaks are uncommon and are readily managed with current technologies. EPA proposals for surface and down-hole shutoffs are reasonable additions to mechanical designs.

2. Global also agrees that, adverse impacts to ecosystems from CO 2 injection activities, is similarly minimal. Lea ks will be small and flor a do benefit from CO 2 for growth.

3. Global supports EPA’s view that the oil and gas industries have experience that can inform and facilitate pragmatic implementation of this rule. Activities to support siting, and well installation, are read ily accomplished and are common to those

industries.

Implementation

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 applicatio ns based on use of oil & gas based technology should be adequate to ensure long-term safety and reliability.

Our view is that the likelihood of leakage from a GS well is relatively low, making 50-years of post closure moni toring wholly unreasonable.

2. Your note about the Wey burn EOR project in Saskatchewan Province, Canada is valid and highly relevant. Not only has the project demonstrated the commercial viability of EOR, but it has also rigorously demonstrated measurable, quantified and verified carbon storage. That is, the CO 2 is remaining in horizon and is conforming to and validating model predictions.

3. We highly recommend that EPA think in terms of the “80-20 rule” of pragmatism when determining how to implement the conversion of an EOR well to a sequestration well. It is arguable that an EOR well is sufficiently relevant to a

Class-6 well and has sufficient integrity to give it credit (a t least partial credit) in the carbon injection and storage calculus. Reasonable mechanical retrofits may be appropriate, without having to r eplace casing, for example.

In this we strongly support the EPA s uggestion that EOR wells might be “grandfathered” when consi dering conversion to a GS well. Reasonable rework, though not reinstallation (or re-cementing, for example) might be decided on a case-by-case basis. That is, a single well, or a few wells, are not likely to materially

affect USDW.4

Global Energy Inc, Suite 2300, 312 Wal nut Street, Cincinnati, OH 45202, USA

Tel: 513-621-0077 • Fax: 513-621-5947 4. We strongly support that EPA should esta blish national standard and guidelines, and delegate implementation to states . Site selection and well installation criteria should be clear but flexible, affording states di scretion and judgment wit h respect to risk

management.

CO 2 as Hazardous Waste (RCRA or CERCLA)

1. We support the EPA view that injectate should be characterized relative to 40 CFR

Part 261. We further belie ve that the stream can be treated to remove undesired contaminants – to the levels that thresholds are not triggered.

2. Characterization and certification in t he permit application should be a sufficient basis for assurance here. Periodic sampling and analysis on some reasonable frequency during injection is acceptable. On the other hand, we do not believe that this measurement and reporting needs to be more than perhaps quarterly, as the adverse impact of exceedances for relative ly short periods is not likely to be geologically significant very fast. Correct ive action to mitigate the effects of an incorrect injection fluid (but not to rem edy an injection alr eady accomplished) needs to be pragmatic and not onerous.

3. As with Class I well liability exempti ons, Class VI wells, once their injectate is characterized and approved (as not tri ggering CERCLA or RCRA), and regular sampling of the stream for qua lity control is implemented Æ then a similar exemption

is warranted.

Alternative Selection

1. EPA proposes four alternatives for GS regulations and asks for comments on them. Our fundamental belief is that the program should be as simple and pragmatic as possible, and in recognition of the initial rigor involved, once the well is sited, and installed, the risk of a leak is extremely minimal.

2. As such, we support EPA’s selection of Al ternative 2, as a balance between the rigor and the security, delegating much of implementation to the states, who have local knowledge.

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.

Modeling

1. We support computational fluid flow modeli ng during injection well site selection, as well as conformational modeling to confirm performance from time to time. This is related to the periodic re-e valuation of the Area of Re view. It seems that the geology and capacity of the horizon can di ctate the frequency – but perhaps five years will prove reasonable in many cases.5

Global Energy Inc, Suite 2300, 312 Wal nut Street, Cincinnati, OH 45202, USA

Tel: 513-621-0077 • Fax: 513-621-5947 2. There is an increasing body of knowledge that computat ional fluid flow modeling is

feasible and can inform an in jection operation about perf ormance, and point toward changes that may be appropriate. We ar e familiar with those involved with the Weyburn Field in Cana da, mentioned by EPA.

Well Installation

1. We support the basic and conservative in stallation criteria pr oposed. We question whether casing to the injection horizon, cem enting the full length is really necessary. It seems certain that experts in geology and well installati on should have the latitude to determine the appropriate installation method. Appr opriate instrumentation and

shut-offs are reasonable.

2. Horizontal well technology is well known and within the ex pertise of drilling companies today. We strongly support the use of horizontal wells for this application. As noted in the discussion, EPA acknowledges that horizontal wells will provide excellent benef its, particularly with respect to injection volume and capacity of the geology to handle the rate of injecti on; as well as minimi zing the number of surface sites to achieve the desired injection volume and rate.

3. We recommend that specifics of the site, as well as fluid and geologic

characteristics, dictate the materials used in well construction, particularly whether stainless steel is really appropriate. We suspect Grade 316 stainless may not always be appropriate or necessary especia lly when considering conversion of EOR wells to GS duty.

4. Certainly acid resistant cement represents a modest cost for the benefit of long term well integrity.

Well Operation

1. We do not believe that hydraulic fracturi ng should be restricted or prohibited where it can be demonstrated that existing faults are sufficiently remote from the injection site or the geology is otherwise appropriate for it.

2. Similarly, we also believe that the geology itself can inform the siting process and application as to whether frac turing will be appropriate, even without existing faults in proximity to the well location.

3. Injection pressure limitations, contro lled by instrumentati on, and monitored and recorded, are appropriate. We support t he reasonableness of the suggested 90 percent criteria as a pre ssure limitation. We also counsel reasonableness with respect to selecting what that pressure is.

4. We believe discretion afforded the states for implementation of this program is

warranted.6

Global Energy Inc, Suite 2300, 312 Wal nut Street, Cincinnati, OH 45202, USA

Tel: 513-621-0077 • Fax: 513-621-5947 5. Automatic shutoff down hole, in addition to surface shut off, is appropriate.

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 requi rements, is also quite reasonable.

Proximity to USDW

1. State discretion to deci de whether injecti on below the lower most USDW is necessary. It is reasonable that certain comb inations of geologic strata can readily protect a USDW from above not just from below.

Again, we appreciate the oppor tunity to provide these comments and look forward to well-founded regulations that provide a pragmatic, cost effective and expeditious path forward in the management of carbon dioxid e via the utilization of Class VI wells.

Respectfully Submitted,

__________________ _________ Dwight N. Lockw ood, PE, QEP Group Vice President

P: 513.621.0077

Email: dnlockwood@ globalenergyinc.comLetter ID: 0141 Commenter: Dwight Lockwood, PE, QEP Organization: Global Energy, Inc.

Letter ID: 0141 Comment ID: 23089 Letter Lines: 69 to 74

Comment Code: 1420 1.2.1.1 Support the GS rulemaking

Comment: the Injection and GS of CO2. We strongly support the broad intent of the rule and believe it will ultimately foster accelerated implementation of carbon management programs. The US Department of Energy has identified numerous feasible locations across the country, some of which are very large and extensive, for geologic se questration. Some of these ar e today being used with DOE’s Regional Testing Programs.

Individual Response: EPA believes that the creation of a new injection well class (VI) under the existing UIC Program is necessary to enable the use of GS as a climate change mitigation technology in a manner that protects USDWs from endangerment. EPA agrees that the UIC Program, under the authority of the SDWA, provides a strong fram ework for regulating injection of CO2 for GS and adds that the GS regulati on tailors the UIC requirements to address the unique issues associated with large-scale GS including large injection volumes, the relative buoyancy of CO2, its corrosivity in the presence of water, the potenti al presence of impurities in captured CO2, and its mobility within subs urface geologic formations. For additional information on site characterization, please also see the discussion of EPA’s Final Regulatory Approach in the preamble to the final GS rule.

Letter ID: 0141 Comment ID: 23090 Letter Lines: 76 to 80

Comment Code: 3100 2.1 Proposed Geologic Siting Requirements (40 CFR 146.83)

Comment: 1. The siting criteria, including defining of the appropriate Area of Review, seismic evaluation, extensive modeling a nd characterization are sufficiently rigorous that it is reasonable to anticipat e minimal risks of leakage will exist long term. This minimal risk therefor e argues in favor of a simple and pragmatic program.

Individual Response: EPA acknowledges the comment and belie ves that a detailed geological site characterization (required under §146.82) is essential to evalua ting the presence and adequacy of the various geologic features necessary to receive a nd confine injected CO2 for GS. The requirements for geologic site characteriza tion 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 appr opriate for the unique natu re of injecting large volumes of CO2 into a variety of geologi cal formations for long-term storage.

1Letter ID: 0141 Comment ID: 23091 Letter Lines: 82 to 84

Comment Code: 1420 1.2.1.1 Support the GS rulemaking

Comment Code: 3820 2.3.1 Well construction procedures

Comment: 2.Well installation, operation, monitori ng, record keeping, and corrective action are similarly rigor ous and reasonably pragmatic; and they materially minimize the potential for inappropriate actions.

Individual Response: EPA acknowledges the comment and ag rees that protection of USDWs from endangerment and prevention of fluid m ovement between formations is paramount. Appropriately designed and constructed wells ar e 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-op erational testing of Class VI wells at §§146.86

and 146.87.

EPA believes that the creation of a new inject ion well class (VI) under th e existing UIC Program is necessary to enable the use of GS as a clim ate change mitigation technology in a manner that protects USDWs from endangerment. EPA agrees that the UIC Program, under the authority of the SDWA, provides a strong framework for regulat ing injection of CO2 for GS and adds that the GS regulation tailors the UIC requirements to address the unique i ssues associated with large-scale GS including large injection volumes, the relative buoya ncy of CO2, its corrosivity in the presence of water, the potential presence of impurities in captured CO2, and its mobility within subsurface geologic formations.

Letter ID: 0141 Comment ID: 23092 Letter Lines: 90 to 92

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

Comment: 1.Global supports EPA’s intent to delega te implementation of the program to authorized state agencies, and recommends ensuring that the state has ultimate decision authority over lower government entities such as counties and cities.

Individual Response: EPA agrees with commenters on the importance of states having primacy for GS wells given the variety of geologic settin gs in which GS will be applied. EPA recognizes

that State, Tribal, Territorial, a nd DI UIC Program Direct ors are in the best position to evaluate the unique issues related to well depth, geol ogy, and hydrogeology that are posed by a Class VI well. Some degree of flexibility is needed for Cl ass VI wells because each decision made will be site-specific and conditions will di ffer from state to state. The GS rule balances the need for these site-specific decisions with the need for mi nimum standards to ensure national consistency.

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

2primacy for Class VI only.

However, given the potential for CCS (encom passing capture, transportation, and geologic sequestration) to be an important part of a na tional priority to address climate change, EPA believes that providing states the flexibility to obtain primacy for Class VI wells independently of other well classes can help foster effective management of CCS. EPA believes that allowing independent Class VI primacy may encourage states to take res ponsibility for implementation of Class VI regulations and provide for a more co mprehensive approach to managing CCS projects by promoting the integration of GS activities under SDWA in to a broader framework for managing CCS. Furthermore, GS operations involve ancillary activities (e.g., pipeline operations, pore space ownership, land use rights, and surface access) for which states can call upon other authorities that exist at the state leve l (but outside UIC author ity) to provide a more comprehensive CCS management approach.

Regarding authority provided to local governments, EPA clarifies that its authority to delegate primary enforcement responsibility extends only to states (includi ng tribes and territories), not local governments. EPA notes th at local governments have the right to provide input on a proposed Class VI permit during the public notic e and comment period (consistent with Part 124) required to be included in every State approved program under §145.11. Additionally, the state is required to have a program which ensure s consideration of all comments before a final permit decision is made.

Letter ID: 0141 Comment ID: 23093 Letter Lines: 93 to 96

Comment Code: 5500 2.1 Comments on Involving the Public in Permitting Decisions

Comment: The authority should also prescribe appr opriate public involvement in siting decisions, and a process for review. They should however not allow extensive obstruction of technically decided decisi ons, or the program will have limited adoption and support.

Individual Response: The Agency believes that public particip ation is an important part of the UIC permitting process and wants to ensure wi de access to decision-making processes and information on projects that may affect the pub lic. GS permitting authorities must follow the existing public participat ion requirements for UIC permits as specified in 40 CFR Part 124. These regulations lay out the pr ocedures for decision making and include requirements such as requiring the Director to notify th e public regarding the availabili ty of the draft permit and allow him or her to request a public hearing on the draft permit. EPA encourages operators and permitting agencies to begin communicating with the public by providing information as early in the process as possible. Encouraging public par ticipation allows the permitting authority to understand public viewpoints, preferences, and con cerns about the project, which might help avoid public misperceptions about th e nature and safety of GS projects and forestall resistance later in the permitting effort.

3Letter ID: 0141 Comment ID: 23094 Letter Lines: 98 to 107

Comment Code: 1260 1.1.1.5 More certainty/stringency is needed

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

Comment: 2.EPA should set standards and criteria that will result in reasonably consistent implementation and results regardless of geographic location.

3.EPA should establish a hierarchy of authority for decision making and oversight, to ensure interstate and inte r- jurisdictional conf licts are avoided. In this, Global appreciates that some states have moved ahead to implement carbon management programs. However, it is our view that e ffective and early implementation will be best served by consistency across the board. We therefore encourage EPA to review the pr ograms of all states and select the

common threads that are most suitable to early and effective implementation.

Individual Response: EPA agrees that it is important to balance flexibility and national consistency. The GS rule sets forth minimum Fede ral requirements, tailored to the unique nature

of CO2 GS, which must be met in order to en sure USDW protection fr om endangerment. EPA acknowledges the importance of fl exibility for certain Class VI well requirements given the variety of geologic settings in which GS will be applied and therefore affords the Director discretion when making permitting decisions. Su ch requirements where the Director has discretion include whether to requi re owners or operators to id entify and characterize additional confining zones, as specified in §146.83, whether to require surface air monitoring and/or soil gas monitoring, as specified in §146.90, and whether to extend or shorten the post-injection site care period or approve an alternative post-injecti on site care timeframe as part of the permitting process, as specified in §146.93. The GS rule balances the need for site-specific decisions with

the need for minimum standards to ensure na tional consistency and USDW protection from endangerment while also ensuring that states have the data they need to make permitting decisions. EPA Headquarters also plans to review initial permits to ensure that the final rule, including all permitting decisions, are implemented consistently, and to ensure that USDW protection goals are consistently me t across differing geologic situations.

EPA understands that the CO2 plumes for large GS projects may cross State, Tribal, Territorial, or EPA Regional boundaries. The final GS rule, at §146.82(a)(2), requires the owner or operator to identify all State, Tribal, and Territorial boundaries within the AoR. Based on this information, the Director must provide written notif ication to all States, Tribes, and Territories to inform them of the permit app lication, as specified in §146.82(b) , and ensure that they are involved in any necessary processes (e.g., develo pment of the emergency and remedial response plan, as specified in §146.94). The Agency enc ourages transparency in the permitting process and anticipates that State-State/State-Tribal communication on GS permitting will facilitate information sharing and encourag e safe, protective projects.

Because some GS projects will require coordi nation across State, Tribal, and Territorial jurisdictions, the Agency will work with the appropriate entities to facilitate communication among States, Tribes, and Territories during th e implementation phase of the GS regulation.

4Such communication may involve other organi zations such as the Sierra Club, NDWAC, associations, and other experts. However, the responsibility for addressing such subjects ultimately rests with the States, Tribes, and Terr itories with primacy. EPA is developing primacy implementation materials for states that descri be recommended approaches to addressing transboundary issues during the permitting of Class VI wells under the GS regulation. The materials will be available at http://water.epa.gov/t ype/groundwater/uic/wells_sequestration.cfm.

In response to questions about which state or region would oversee the permit for projects where the AoR spans State, Tribal, or Territorial bounda ries, EPA clarifies that issuance and oversight of a GS permit, including any associated AoR boundary-related coordination, is the responsibility of the primacy (State, Tribe, or Territory) or regional DI program in the state where the injection well is located.

Letter ID: 0141 Comment ID: 23095 Letter Lines: 111 to 114

Comment Code: 1650 1.3.5 Human health impacts

Comment: 1.Global concurs with the EPA view that the risk of asphyxiat ion and acute or chronic health effects is minimal. Pipe line leaks are rare and readily managed by existing authorities. Similarly wellh ead and well leaks are uncommon and are readily managed with current technologi es. EPA proposals for surface and downIndividual Response: EPA recognizes that injecting large volumes of CO2 for GS poses unique challenges that, if not properly managed, could endanger drinking water s ources and have other adverse impacts. However, with proper site sele ction, the final, tailored, Class VI requirements address the large volumes of CO2 injected, its bu oyancy, potential corrosivity in the presence of water, and potential impurities in the CO2 stream. In addition, EP A expects the tailored permitting, siting, construction, operation, monitoring, and post-injection site care requirements in the GS rule to prevent leakage from injection formations and protect USDWs. EPA adds that pipeline leaks and risk of asphyxiation are outside the scope of the GS rulemaking.

Letter ID: 0141 Comment ID: 23096 Letter Lines: 114 to 115

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

Comment: readily managed with current technologi es. EPA proposals for surface and downhole shutoffs are reasonable additions to mechanical designs.

Individual Response: After evaluating the risks and benefi ts of down-hole shut-off systems and considering additional research, EPA will not re quire automatic down-hole shut-off devices for onshore Class VI wells since it is not necessary in all cases to ensure protection of USDWs from endangerment. Instead, the final rule, at §146.88(e)(2 ), requires that owne rs or operators of

onshore Class VI wells install automatic surface shut-off devices. The rule affords Director's

discretion to mandate automatic down-hole shut -off devices in onshore situations that may warrant their use. However, the Agency believ es that offshore Class VI wells present unique

5construction and operational conditi ons, including isolation from shorelines and the need to construct wells through the water column and the subsurface, which may delay response time in

the event of well difficulties. Th e rule requires, at §146.88(e)(3), that owners or operators of

offshore wells within State territorial waters install automatic down-hole shut-off systems. EPA believes that these requirements at §146.88(e) ensure that proper precautions are taken to prevent subsurface fluid movement and ensure protection of USDWs.

Letter ID: 0141 Comment ID: 23097 Letter Lines: 117 to 119

Comment Code: 1660 1.3.6 Ecosystem impacts (soil, air, surface water)

Comment: 2.Global also agrees that, adverse imp acts to ecosystems from CO2 injection activities, is similarly minimal. Leaks will be small and flora do benefit from CO2 for growth.

Individual Response: EPA acknowledges that there are potent ial risks associated with GS. The purpose of the Class VI requirements is to minimize and mitigate potential/identified risks through proper site characterization, well cons truction, operation, monitoring, post-injection site

care, and site closure and to en sure protection of USDWs. EPA be lieves that the measures in the GS rule that directly mitigate the possibility of CO2 leakage out of the injection zone will also indirectly mitigate the risks to receptors mentioned by the commenters, including fresh water, wildlife, ecosystems, and agriculture.

Letter ID: 0141 Comment ID: 23098 Letter Lines: 121 to 124

Comment Code: 1940 1.4.4.3 Consultations with Industry; experience with other wells

Comment: 3.Global supports EPA’s view that the oil and gas industries have experience that can inform and facilitate pragmatic implementation of this rule. Activities to support siting, and well in stallation, are readily accomplished

and are common to those industries.

Individual Response: EPA recognizes that the oil and gas industry has decades of experience injecting CO2 for the purpose of ER, and that site s used for ER may be suitable for GS and may be among the first GS sites. EPA also recognizes that a by-product of ER activities is that a certain percentage of the CO2 is trapped in the receiving formation.

Also, since field experience and well constr uction, injection, and m onitoring information relevant to GS comes from operations that inject acid gas or inject CO2 for ER, the Agency has conducted evaluations regarding these commercial field operations and c ontinues to track GSrelevant developments in these commercial operations. Some of the research that informs the

final GS rule was conducted at ER sites.

6Letter ID: 0141 Comment ID: 23099 Letter Lines: 128 to 135

Comment Code: 3820 2.3.1 Well construction procedures

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

Comment: 1.Global strongly believes that excessive rigor in siting a nd well installation criteria, as well as post closure care a nd financial assurance for 50-years, would adversely impact acceptance of the pr ogram as well as the speed with which large (meaningful) scale carbon management develops.

We appreciate the challenge in balanci ng security of sequestration. However advocating proven and reliable applicatio ns based on use of oil & gas based technology should be adequate to ensure long-term safety and reliability.

Individual Response: EPA disagrees that a post-injection si te 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 in cluded 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 variou s default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested that EPA shorten the monitoring timeframe, none of the commenters provided sufficient data or

other evidence to warrant a ch ange in the proposed timeframe. While the 10- or 30-year timeframe suggested by some of 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 site s where the 50 year post injection site care timeframe may be either not appropriate or more burdensome than necessary based on sitespecific conditions. For this reason, the GS rule o ffers owners or operators flexibility regarding

the duration of the PISC timefra me by: (1) allowing the Direct or discretion to shorten or lengthen the PISC timeframe during the post-in jection period based on site-specific data, pursuant to requirements at §146.93(b) ; or (2) affording the Director discretion to allow a Class VI well owner or operator to demonstrate, during the permitting process based on substantial data, that an alternative PISC timeframe may be appropriate if it ensu res non-endangerment of USDWs pursuant to requirements at §146.93(c).

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

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

7impacts.

EPA believes however, that to ensure USDW protection from enda ngerment, a default timeframe for post-injection site care will be necessary in al l but a limited number of cases. This default 50 year post-injection site care ti meframe represents a reasonable and protective monitoring period

based on a review of research studies, industr y reports, and existing environmental programs, and evaluation of public comments.

To the comment about the cost of post-injection site care, EPA does not ag ree 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 re present 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 monitori ng technologies (used durin g injection and the postinjection site care timeframes) is available in the Technology and Cost Document for the GS

rule, which is in the federal docket for this rule making. 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 fina ncial responsibil ity for the long time frames over which post-injection site care will be conducted. EPA is developing guidance on financial responsibility to a ssist owners or operators in evaluating the requirements of §146.85 and to assist Directors in evaluating fi nancial 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 s upport accurate financial respon sibility demonstrations. The guidance will be available at h ttp://water.epa.gov/type /groundwater/uic/wells_sequestration.cfm.

EPA recognizes that the oil and gas industry has decades of e xperience injecting CO2 for the purpose of enhanced recovery and that many of th e wells used for ER may be suitable for GS. However, EPA believes that GS is sufficiently di fferent 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 wi ll be different, with Class VI injection operations involving large volumes of CO2 and likely having higher pressures within th eir 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 th e GS project.

Letter ID: 0141 Comment ID: 23100 Letter Lines: 137 to 138

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

Comment: Our view is that the likelihood of leakag e from a GS well is relatively low, making 50-years of post closure m onitoring wholly unreasonable.

Individual Response: EPA disagrees that a post-injection si te care timeframe of 50 years is excessive or unreasonable. EPA proposed a default post-injection site care timeframe of 50 years

8based on a review of research studies, industr y reports, and existing environmental programs. This analysis was included in an EPA-prepar ed background document that is available in the federal docket, titled "Computa tional Modeling of Underground In jection of Carbon Dioxide for

Determination of Area-of-Review and Potentia l 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 numer ous 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. Wh ile the 10- or 30-year timeframe suggested by some of these commenters may be within the ti meframe suggested in some studies, EPA believes that the potential risks of endangering USDWs w ill 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 site s where the 50 year post injection site care timeframe may be either not appropriate or more burdensome than necessary based on sitespecific conditions. For this reason, the GS rule o ffers owners or operators flexibility regarding

the duration of the PISC timefra me by: (1) allowing the Direct or discretion to shorten or lengthen the PISC timeframe during the post-in jection period based on site-specific data, pursuant to requirements at §146.93(b) ; or (2) affording the Director discretion to allow a Class VI well owner or operator to demonstrate, during the permitting process based on substantial data, that an alternative PISC timeframe may be appropriate if it ensu res non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site car e timeframe of 50 years, with flexibility to adjust the timeframe for a limited number of GS projects during the permitting process where

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

Letter ID: 0141 Comment ID: 23101 Letter Lines: 140 to 144

Comment Code: 1858 1.4.2.4 International GS efforts

Comment: 2.Your note about the Weyburn EOR project in Saskatchewan Province, Canada is valid and highly relevant. Not only has the project demonstrated the commercial viability of EOR, but it has also rigorous ly demonstrated measurable, quantified and verified carbon storage. That is, the CO2 is remaining in horizon and is conforming to and validating model predictions.

Individual Response: EPA acknowledges the comment about Weyburn, and agrees that

activities there have relevance for the rule. EPA ha s monitored progress at th e site to gain input and information regarding GS, and will continue to do so.

EPA is using an adaptive approach to regulati ng GS. EPA plans to collect and review project

9data every six years on early GS projects to dete rmine whether the appropriate amount and types of information and appropriate documentation are required and being collected. The Agency will

evaluate the information and determine if m odifications to the requirements are necessary.

Letter ID: 0141 Comment ID: 23102 Letter Lines: 146 to 158

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

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

Comment: 3.We highly recommend that EPA think in terms of the 80-20 rule of pragmatism when determining how to implement the conversion of an EOR well to a sequestration well. It is arguable that an EOR well is sufficiently relevant to a Class-6 well and has sufficient integrity to give it credit (at least partial credit) in the carbon injecti on and storage calcu lus. Reasonable mechanical retrofits may be appropriate , without having to replace casing, for example.

In this we strongly support the EPA suggestion that EOR wells might be grandfathered when considering conversi on to a GS well. Reasonable rework, though not reinstallation (or re- cementing, for example) might be decided on a case-by-case basis. That is, a single well, or a few wells, are not likely to materially affect USDW.

Individual Response: EPA agrees that many Class II well s are designed and constructed to withstand exposure to CO2. The final GS rule provi des for the construction of these wells to be grandfathered per §146.81(c), provid ed the owner or operator can demonstrate to the Director that the wells were engineered and constructed to meet th e requirements at §146.86(a) and ensure protection of USDWs, in lieu of requirements at §146.86(b) and §146.87(a).

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

USDWs when there is an increased risk to USDWs as compared to traditi onal Class II operations while allowing for site-specific flexibility. EPA adds that, following re-permitting as Class VI wells, these projects must be subject to th e operational, MIT, monitoring, reporting, plugging, and post-injection site care and site clos ure requirements in the final GS rule.

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

10long-term storage of large volumes of CO2. The guidance describes recommended methods the Director may use when determining changes in risk to USDWs from projects, and how the Director may determine whether a project should be regulated within th e Class II or Class VI UIC program. This guidance will be available on EPA’s website at http://water.epa.gov/type/groundwater /uic/wells_sequestration.cfm.

Letter ID: 0141 Comment ID: 23103 Letter Lines: 160 to 163

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

Comment: 4.We strongly support that EPA should establish national standard and guidelines, and delegate implementation to states. Site selection and well

installation criteria should be clear but flexible, affording states discretion and judgment with respect to risk management.

Individual Response: As described above, EPA will allow states to apply for primacy for Class VI wells independently of primacy for other we ll classes. The Agency will allow independent primacy for Class VI wells under §145.1(i) of the final GS rule.

EPA is developing guidance materials and plans to conduct on-line and in-person training for

States, Tribes, and Territories that describe th e technical and administra tive issues on developing and implementing GS regulations that are the equivalent of minimu m Federal criteria and requirements. EPA is also devel oping materials for owners or ope rators on site characterization and well construction. The guidances will be available at http://water.epa.gov/type/groundwat er/uic/wells_se questration.cfm.

EPA expects that both Headquarters and the Regions will work closely with the states during the early permitting process to ensure that flexibility is applied in a manner that ensures a consistent level of USDW protection from endangerment. EP A designed flexibility into the regulations to ensure that site-specific factors can be account ed for and expects that permit writers will use discretion where site-specific fact ors are important. As part of its adaptive approach, EPA also plans to review initial permits (after they are granted) to ensure that USDW protection goals have been consistently met across differing geologi c situations. If necessary, EPA will reevaluate the flexibility granted to states in the rule.

Letter ID: 0141 Comment ID: 23104 Letter Lines: 165 to 183

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

Comment Code: 1640 1.3.4 CERCLA issues (seeking comment)

Comment Code: 4620 2.6.2 Injectate monitoring

Comment: CO2 as Hazardous Waste (RCRA or CERCLA)

1.We support the EPA view that injectate should be characterized relative to 40

11CFR Part 261. We further believe that th e stream can be treated to remove

undesired contaminants to the levels that thresholds ar e not triggered.

2.Characterization and certification in the permit application should be a

sufficient basis for assurance here. Peri odic sampling and an alysis on some reasonable frequency during injection is acceptable. On the other hand, we do

not believe that this measurement and re porting needs to be more than perhaps quarterly, as the adverse impact of exceed ances for relatively short periods is not likely to be geologica lly significant very fast. Corrective action to mitigate the effects of an incorrect in jection fluid (but not to remedy an injection already accomplished) needs to be pragmatic and not onerous.

3.As with Class I well liability exem ptions, Class VI wells, once their injectate is characterized and approved (as not triggering CERCLA or RCRA), and regular sampling of the stream for quali ty control is implemented then a similar exemption is warranted.

Individual Response: EPA agrees that monitoring of the injectate prior to and during injection is important to allow for comparison of baseline data and operational-phase monitoring results to provide warning of potential USDW endangerment. For this reason owners or operators must perform an analysis of the chemical and physical characteristics of the CO2 stream, as required at §146.82 (a)(7)(iv). In addition, Section §146.90(a) requires owners or operators to perform analysis of the CO2 stream during injection operations with sufficient frequency to yield data representative of its chemical and physical characteristics.

The necessary frequency of injectate analysis will be project-specifi c and will depend upon the CO2 source and the likelihood of variability in injectate composition. For example, a CO2- capture process from a coal-fired power plant with a consistent coal source and operating parameters is likely to produce a CO2 stream w ith a fairly consistent composition. A process with a changing composition of coal may have more variability in the purity of the CO2 that is captured. In such a setting, more frequent sa mpling may be appropriate. The details of the sampling should be described in the testing and monitoring plan, which will be approved by the Director based on a review of site-specific in formation, including information on the source and characteristics of the injectate.

EPA clarifies that, following an initial characterization of the injectate, EPA expects that the permit would stipulate the acceptable compositi on of the injectate (e.g., as CO2 plus an acceptable range of expected impurities). Any dive rgence from this would be a permit violation.

EPA notes however, that the final GS rule, which adds new regulations for Class VI wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA regulations. Accordingly, the CO2 stream characterizati on requirements under the GS rule would not substitute for the obligation of a generator of RCRA solid waste to characterize its waste in accordance with EPA’s RCRA regulations. Inj ection of a RCRA hazardous waste may only occur in a Class I hazardous waste injection well.

12EPA notes that CO2 itself is not listed as a hazardous substance under CERCLA, although the CO2 stream may contain a listed hazardous s ubstance (such as mercury) or may mobilize substances in the subsurface that could react with ground water to produce listed hazardous substances (such as sulfuric acid). Whether su ch substances may result in CERCLA liability from a sequestration facility depe nds entirely on the composition of the specific CO2 stream and

the environmental media in which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42 U. S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S. C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential releases from the well which are outside the scope of the Class VI permit.

The commenter’s reference to a Class I liabilit y exemption is unclear and not legally correct. Furthermore, after site closure an owner or ope rator may remain liable under tort and other

remedies, or under other federal statutes includi ng, 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 SD WA 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.

Letter ID: 0141 Comment ID: 23105 Letter Lines: 185 to 194

Comment Code: 2330 1.7.3 Comments on Alternative 2

Comment: Alternative Selection

1.EPA proposes four alternatives for GS regulations and asks for comments on

them. Our fundamental belief is that th e program should be as simple and pragmatic as possible, and in recognition of the in itial rigor involved, once the well is sited, and installed, the risk of a leak is extremely minimal.

2.As such, we support EPA’s selection of A lternative 2, as a ba lance between the rigor and the security, delegating much of implementation to the states, who have local knowledge.

Individual Response: EPA clarifies that it proposed Altern ative 3 and subsequently has chosen

Alternative 3 in the final rule. The technical re quirements in Alterna tive 3 provide a balance between rigor and security a nd build upon the long-standing UIC regulatory framework for deep wells and are appropriately tailored to address the unique nature of fu ll-scale CO2 GS, including the volumes of CO2 to be injected, the buoyant and mobile nature of the injectate, and its corrosivity in the presence of water to ensure the protection of USDW s. Although Alternative 2 (General Requirements Approach) provides st andards for siting, construction, operation, and monitoring associated with basic deep well desi gn and operation, EPA does not believe that this alternative is appropriate for GS because it doe s not contain requirements tailored to meet the unique challenges of long-term CO2 GS, including the potentia lly large injection volumes, buoyancy, corrosivity in the presen ce of water, and low viscosity and therefore cannot ensure protection of USDWs.

13EPA believes that the GS rule (Alternative 3) offers the flexibility and discretion desired by commenters preferring Alternativ e 2 while protecting USDWs from endangerment. The final GS regulation gives the Director disc retion to set permit criteria that are appropriate to site-specific conditions. The regulation pr ovides flexibility to select approp riate sites and target formations (under §146.82), well construction specifics (under §146.86), and te sting and monitoring regimes (under §146.90), provided the owner or operator can demonstrate that the injection and storage will not endanger USDWs and that minimum requi rements for the site are met. Commenters representing electric utilities, water associations, and states supported Alternative 3 and the flexibility it provides to permitting authorities to make case-by-case permitting decisions while ensuring the protection of USDWs.

Letter ID: 0141 Comment ID: 23106 Letter Lines: 196 to 198

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

Comment: BUT, once that is done, the closure, post-closure and long-term care and monitoring (50-years of financial resp onsibility) with attendant financial responsibility, needs to be significantly re laxed and made much more reasonable.

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

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

different default timeframe. However, EPA recognizes that there may be site s where the 50 year post injection site care timeframe may be either not appropriate or more burdensome than necessary based on sitespecific conditions. For this reason, the GS rule o ffers owners or operators flexibility regarding

the duration of the PISC timefra me by: (1) allowing the Direct or discretion to shorten or lengthen the PISC timeframe during the post-in jection period based on site-specific data, pursuant to requirements at §146.93(b) ; or (2) affording the Director discretion to allow a Class VI well owner or operator to demonstrate, during the permitting process based on substantial data, that an alternative PISC timeframe may be appropriate if it ensu res non-endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site car e timeframe of 50 years, with flexibility to adjust the timeframe for a limited number of GS projects during the permitting process where

substantial data exists to demonstrate that an alternative timeframe would be protective of

14USDWs, or based on data collected during the PISC period, is appropriate to address the range of sites where GS is anticipated to occur, to ac commodate site-specific circumstances and various geologic conditions, and addre sses commenters’ concerns, wh ile ensuring USDW protection. Both approaches will utilize si te-specific data, and be based on pressure monitoring and USDW impacts, as the commenter suggests.

To the comment expressing concern about financia l responsibility, EPA rec ognizes 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 demonstrat e under §146.85 that fina ncial 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.

Letter ID: 0141 Comment ID: 23107 Letter Lines: 200 to 204

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

Comment: Modeling

1.We support computational fluid flow modeling during injection well site

selection, as well as conformational mode ling to confirm performance from time to time. This is related to the periodi c re-evaluation of the Area of Review.

Individual Response: EPA acknowledges the commenter’s s upport of the modeling approach, and agrees that reevaluation of the AoR as required at 146.84(e) must incorporate monitoring and operational data gathered sin ce the last model run. This will serve to verify that the CO2 plume and pressure front are moving through the subsurface as predicted, that the delineation model is accurate (or identify need ed changes), and refi ne testing and monitoring activities to ensure that USDWs are protecte d from endangerment and that there would be adequate warning of potential problems at the site befo re any endangerment could occur.

Letter ID: 0141 Comment ID: 23108 Letter Lines: 205 to 206

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

Comment: It seems that the geology and capacity of the horizon can dictate the frequency but perhaps five years will prove reasonable in many cases.

Individual Response: EPA agrees that site-specific fact ors should be considered in the

reevaluation schedule, and notes that the AoR and corrective acti on plan must specify the sitespecific monitoring and operationa l conditions that warrant r eevaluation, as specified in §146.84(b)(2)(ii). In addition, the Director has discretion to require more frequent AoR

reevaluation if he or she has r eason to believe, based on site-speci fic information, that a five-year

15reevaluation schedule is not su fficiently protective of USDWs. However, EPA believes that setting a minimum reevaluation frequency is appr opriate. In the final rule, the Agency changed the minimum frequency for the AoR reevaluation at §146.84(e) from 10 years to 5 years in the

final GS rule. EPA believes that this revised frequency addresses commenters' concerns about the inherent uncertainties in modeling CO2 m ovement, the emerging nature of GS technology, risk-based targeting of monitoring activities, and the unique nature of CO2 GS. In addition, the

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

Letter ID: 0141 Comment ID: 23109 Letter Lines: 208 to 211

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

Comment: 2.There is an increasing body of knowledge that com putational fluid flow modeling is feasible and can inform an injection operation about performance, and point toward changes that may be appropriate. We are familiar with those involved with the Weyburn Field in Canada, mentioned by EPA.

Individual Response: EPA also agrees that numerical com putation, as required at 146.84(c)(1), may be necessary to calculate the complex AoR for a GS project. EPA believes that predicting the complex multiphase buoyant flow of the CO 2, co-injectates, and compounds that may be mobilized due to injection requires the sophistica tion of computational models and in some cases may specifically require certain num erical models. EPA also agrees that physical measurement, (i.e. monitoring) is an important component to protecting USDWs from endangerment and will serve to calibrate computational model predicti ons during the AoR reeval uation to ensure that the AoR adequately represents the extent of the CO2 plume and pressure front.

Letter ID: 0141 Comment ID: 23110 Letter Lines: 213 to 215

Comment Code: 3820 2.3.1 Well construction procedures

Comment: Well Installation

1.We support the basic and conservative installation criteria proposed. We

Individual Response: EPA acknowledges the comment and belie ves that 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 testi ng of Class VI wells at §§146.86 and 146.87.

Letter ID: 0141 Comment ID: 23111 Letter Lines: 215 to 219

16Comment Code: 3822 2.3.1.1 Depth of surface casing (seeking comment)

Comment Code: 3824 2.3.1.2 Cementing of long-string casing (seeking comment)

Comment: 1.We support the basic and conservative installation criteria proposed. We question whether casing to the injecti on horizon, cementing the full length is really necessary. It seems certain that experts in geology and well

installation should have the latitude to determine the approp riate installation method. Appropriate instrumentation and shut-offs are reasonable.

Individual Response: EPA believes that the requirements for surface and long-string casing are necessary and also that they offer appropriate flexibility. The final GS rule requires, at §146.86(b)(2), that the surface casing must extend through the base of the lowermost USDW and

be cemented to the surface, and that at least one long string casing must be cemented to the surface in one or more stages at §146.86(b)(3). It does not, however, specify how cementing would be accomplished, and gives flexibility to the owner or operator to propose alternate methods to provide a sufficient amount of cement to meet the standard that USDWs are protected from endangerment, subject to the approval of the Director.

EPA notes that there are many potential ways to meet the requirement, such as the use of staged cementing. See the discussion of Class VI well cons truction requirements in the preamble to the

final GS rule for additional information. A dditionally, EPA is developing guidance on the construction of Class VI wells. This guida nce will be available on EPA’s website at http://water.epa.gov/type/groundwat er/uic/wells_se questration.cfm.

EPA adds that other aspects of the rule allow flexibility based on site-s pecific considerations: with their permit applications, owners or operators must submit proposed well construction procedures, as specified at §146.82(a)(12), that address the specific drilling and injection environment and the chemical and physical nature of the CO2 injected stream. The Director must evaluate the appropriateness of the proposed c onstruction based on site-specific information about the injection project, including injection pressures, injection a nd confining zone lithology,

and information about the carbon dioxide stream , as provided in the final GS rule at §146.86(b)(1).

Letter ID: 0141 Comment ID: 23112 Letter Lines: 219 to 219

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

Comment: method. Appropriate instrumentation and shut-offs are reasonable.

Individual Response: As described above, 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 auto matic surface shut-off devices. The rule affords

Director's discretion to mandate automatic down-hole shut-off devi ces in onshore situations that may warrant their use. However, the Agency beli eves that offshore Class VI wells present unique construction and operational conditi ons, including isolation from shorelines and the need to

17construct wells through the water column and the subsurface, which may delay response time in

the event of well difficulties. Th e rule requires, at §146.88(e)(3), that owners or operators of

offshore wells within State territorial waters install automatic down-hole shut-off systems.

EPA believes that requiring the in stallation of automatic surfa ce shut-off devices for onshore wells (and affording Director's discretion to require down-hole devices wher e necessary) ensures that proper precautions are taken to prevent subs urface fluid movement a nd ensure protection of

USDWs, human health, and the environment.

Letter ID: 0141 Comment ID: 23113 Letter Lines: 221 to 227

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

Comment: 2.Horizontal well technology is well known and within the expe rtise of drilling companies today. We strongly support th e use of horizontal wells for this application. As noted in the discussion, EPA acknowledges that horizontal wells will provide excellent benefits, particular ly with respect to injection volume and capacity of the geology to handle th e rate of injection; as well as minimizing the number of surface sites to achieve the desired injection volume

and rate.

Individual Response: In the final rule, EPA allows the use of horizontal wells at GS projects. In the proposed rule, EPA sought comment on the appr opriateness of horizontal drilling techniques

for Class VI wells, and commenters representing energy companies, el ectric utilities, the oil and gas industry, CCS associations, states, and the public, unanimously suppo rted the concept and provided many reasons why horizonta l wells could be beneficial at GS sites. Based on an evaluation of these comments and additional research by EPA, the Agency has concluded that horizontal wells that are properly constructed, logged, and tested for mechanical integrity (i.e., to meet the requirements of the GS rule) can ensu re the protection of USDW s from endangerment.

Letter ID: 0141 Comment ID: 23114 Letter Lines: 229 to 233

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

Comment: 3.We recommend that specifics of the site, as well as fluid and geologic

characteristics, dictate the materials us ed in well construc tion, particularly whether stainless steel is really approp riate. We suspect Grade 316 stainless may not always be appropriate or nece ssary especially when considering conversion of EOR wells to GS duty.

Individual Response: EPA clarifies that Grade 316 stainless steel is not a specified material. It is discussed in the preamble to th e proposed rule as an example of materials that have been used successfully in similar situations. The determination of the best material to use is left for the Director to approve based upon case-specific information as provided under §146.86(b)(1).

18See the discussion of Class VI well construction requirements in the preamble to the final GS rule for additional information. Additionally, EP A is developing guidance on the construction of Class VI wells. This guidance will be available on EPA’s website at http://water.epa.gov/type/groundwater /uic/wells_sequestration.cfm.

Letter ID: 0141 Comment ID: 23115 Letter Lines: 235 to 236

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

Comment: 4.Certainly acid resistant cement represents a modest cost for the benefit of long term well integrity.

Individual Response: EPA acknowledges the comment and agrees that cement that is compatible with the CO2 and formation fluids will enhance Class VI well integrity. EPA also agrees that developing technology in the field of acid-resistant cement will provide the industry

with future benefits. In the interest of USDW protection, the Agency requ ires that the materials used in Class VI wells be compatible with fl uids with which they may come in contact, as specified in §146.86(b)(1).

EPA adds that the requirements at §146.86(b)(1) st ate that materials must meet or exceed standards developed for such materials by the American Petroleum Institute, ASTM International, or comparable standards acceptable to the Director. This requirement invokes the expertise of these bodies and allows the use of technologies that are yet to be developed.

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

Letter ID: 0141 Comment ID: 23116 Letter Lines: 238 to 246

Comment Code: 4120 2.4.1.2 Allowing hydraulic fracturing during GS (seeking comment)

Comment: Well Operation

1.We do not believe that hydraulic fracturi ng should be restricted or prohibited

where it can be demonstrated that existi ng faults are sufficiently remote from the injection site or the geology is otherwise appropriate for it.

2.Similarly, we also believe that the geology itself can inform the siting process and application as to whether fracturing will be appropriate, even without existing faults in pr oximity to the well location.

Individual Response: The final rule allows the use of hydr aulic fracturing for purposes of Class

19VI injection, where approved by the Director. Hydraulic fracturi ng is one of several stimulation technologies available to improve we llbore and formation injectivity.

EPA agrees that site-specific information will inform the siti ng process and decisions about whether fracturing is appropriate. Owners or ope rators must submit a proposed stimulation program as part of the permit application unde r §146.82(a)(9); the plan mu st demonstrate that any stimulation activities will not compromise the integrity of the confining zone. The Director will evaluate the owner or operator's proposed stimu lation plan in the context of all information about the site, and the owner or operator mu st perform stimulation only as approved.

EPA clarifies that all stimula tion, including hydraulic fracturing, must be approved by the Director and that §146.88(a) permits injection pr essure to exceed 90 percent of the fracture pressure only during well stimulation. The final rule at §146.91(d)(2) also requires that the owner or operator notify the Director 30 days before performing stimulati on during the operational phase of a GS project; this will provide an addi tional opportunity for the Di rector to review the owner or operator's plans for stimulation and add other requirements as needed. EPA clarifies that UIC regulations prohibit fracturing of the c onfining zone at any ti me during injection or stimulation in order to protect USDWs from endangerment.

Letter ID: 0141 Comment ID: 23117 Letter Lines: 248 to 251

Comment Code: 4110 2.4.1.1 Injection pressure limitations

Comment: 3.Injection pressure limitations, controlle d by instrumentation, and monitored and recorded, are appropriate. We support the reasonableness of the suggested 90 percent criteria as a pressure limitation. We also counsel reasonableness with respect to selecting what that pressure is.

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

Letter ID: 0141 Comment ID: 23118 Letter Lines: 253 to 254

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

Comment: 4.We believe discretion afforded the stat es for implementation of this program

is warranted.

Individual Response: EPA agrees with commenters on th e importance of allowing Directors discretion given the variety of geologic settings in which GS will be applied. EPA recognizes

that State, Tribal, Territorial, a nd DI UIC Program Direct ors are in the best position to evaluate the unique issues related to well depth, geol ogy, and hydrogeology that are posed by a Class VI

20well. Some degree of flexibility is needed for Cl ass VI wells because each decision made will be site-specific and conditions will di ffer from state to state. The GS rule balances the need for these site-specific decisions with the need for mi nimum standards to ensure national consistency. To ensure the final rule is applied consisten tly, EPA is developing guidance materials and plans to conduct on-line and in-person training for Stat es, Tribes, and Territories that describe the process of applying for and rece iving primary enforcement responsibility (primacy) for GS Class

VI wells under Section 1422 of SDWA, as well as the technical and admini strative issues related to developing GS regulations that are the equivalent of minimum Federal criteria and requirements. The guidance will be available at http://water.epa.gov/type/groundwat er/uic/wells_se questration.cfm.

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

As part of its adaptive approach, if EPA finds that there is not sufficient consistency in the permits and that USDWs are not being sufficiently protected from endangerment, it will consider changes to the permit requirements in the future.

Letter ID: 0141 Comment ID: 23119 Letter Lines: 256 to 256

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

Comment: 5.Automatic shutoff down hole, in addition to surface shut off, is appropriate.

Individual Response: As described above, 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 auto matic surface shut-off devices. The rule affords

Director's discretion to mandate automatic down-hole shut-off devi ces in onshore situations that may warrant their use. However, the Agency beli eves that offshore Class VI wells present unique construction and operational conditi ons, including isolation from shorelines and the need to construct wells through the water column and the subsurface, which may delay response time in

the event of well difficulties. Th e rule requires, at §146.88(e)(3), that owners or operators of

offshore wells within State territorial waters install automatic down-hole shut-off systems.

Letter ID: 0141 Comment ID: 23120

Comment: Individual Response:

21Letter ID: 0141 Comment ID: 23121 Letter Lines: 258 to 260

Comment Code: 4546 2.5.2.2 MIT frequency (seeking comment)

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

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 require ments, is also quite reasonable.

Individual 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, inst ead of periodic testing, which is required for most other types of deep injecti on wells is appropriate because the potentially corrosive nature of CO2 injectate streams in the presence of water enables the immediate identification of corrosionrelated internal mechanical integrity problems th at could lead to signi ficant well problems and

failure.

Continuous monitoring was found to be very importa nt in an EPA study of UIC Class I internal MIT failure rates and causes (USEPA 1993). Th e 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 annul us monitoring be reporte d on a semiannual basis.

EPA is retaining the semi-annual reporting requireme nt in the final rule at §146.91(a) in order to ensure that permitting authorities can maintain 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.

Letter ID: 0141 Comment ID: 23122 Letter Lines: 262 to 266

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

USDW

Comment: Proximity to USDW

1.State discretion to decide whether inj ection below the lower most USDW is necessary. It is reasonable that certain combinations of geologic strata can readily protect a USDW from a bove not just from below.

Individual Response: EPA acknowledges that there are lim ited circumstances where injection

2223 above the lowermost USDW can be performe d in a manner that protects USDWs from endangerment, as long as appropriate protections are in place. The final GS rule at §146.95 establishes a process by which owne rs or operators can seek a waiv er of the Class VI injection depth requirements for inject ion into non-USDW formations above and/or between USDWs. Determinations regarding the appr opriateness of an injection dept h waiver would be made by the Director, based on site-specific information.

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