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.Letter ID: 0123

Commenter: John Stormon Organization: Washington State Dept. of Ecology

Letter ID: 0123 Comment ID: 22996 Letter Lines: 39 to 53

Comment Code: 1350 1.1.3.3 Comments on the need for GS technology

Comment Code: 1420 1.2.1.1 Support the GS rulemaking

Comment: federal UIC regulations for the Geologic Sequestration of Car bon Dioxide. It is good to see that EPA has proposed a well defined, environmentally protective program through these rules for the geol ogic sequestration of carbon dioxide. I'm sure that EPA will receive many comment s targeted at weakening or removing key parts of the proposed re gulatory program; contrary to the arguments of some industry voices, geologic sequestration of carbon dioxi de is new, untested technology that, if poorly implemented, could have large and long lasting environmental impacts including potentia lly degrading the quality of our ground water resources (USDW). Please help to encourage the use of this important technology by keeping a strong, environmenta lly protective regulatory program. One early disaster could destroy geologic sequestrati on of carbon dioxide as a

strategy we can use to re spond to rising atmospheric CO2 levels. Caution is

warranted in the first se t of regulations. Once e xperience with geologic sequestration has been gained, the re gulations may be streamlined where appropriate.

Individual Response: EPA agrees that the implementation of the GS rule in a manner that ensures protection of USDWs from endangerment is important to establishing a foundation for

further advances in the field of CO2 GS. EPA acknowledges the need for regulatory certainty: the final GS requirements provide a level of cer tainty by setting forth unique requirements for GS. These requirements include: the tailored AoR delineation process at §146.84, the types of monitoring appropriate to GS projects at §146.90 and the post-inj ection site care process at §146.93. For additional information on these requir ements, please also see the discussion of EPA’s Final Regulatory Approach in th e preamble to the final GS rule.

To protect USDWs from endangerment and meet the potentially fast pace of GS deployment, EPA is using an adaptive approach to regula ting CO2 injection for GS. The Agency plans to collect and review data every six years on GS projects to dete rmine whether the appropriate amount and types of information and appropria te documentation are being collected, and to determine if modifications to the requiremen ts are appropriate or necessary. An adaptive approach will allow regulatory development to pr oceed in time to meet the current and future demands for Class VI permits, while EPA continues to gather data from pilot projects and other

research as it becomes available.

While EPA agrees with commenters that a stab le, predictable, nati onally consistent, and workable regulatory framework is important, EPA st resses that the focus of the GS rule is to

1ensure that, where GS is deployed, it is conduc ted in a manner that protects USDWs from endangerment.

Letter ID: 0123 Comment ID: 22997 Letter Lines: 57 to 68

Comment Code: 1510 1.2.2.3 Need for additional study

Comment: Pilot Studies: Consider specifically including a streamlined process to encourage Pilot Studies at potential ge ologic sequestration projects. Thorough site characterization is the most impo rtant requirement fo r most geologic sequestration projects. Site characterization will be extremely expensive. EPA should consider some method to encourage pot ential projects to start with pilot studies, designed to collect detailed site characterization information and test analytical models prior to full scale project construction. In Washington we have included a special consideration for pilot studies in our geologic sequestration rule [WAC 173-218-115(4)(b)]. Of course this is also a potential loop-hole, so it is also im portant that pilot study perm its have limits intended to prevent them from being used as a by-pass of the permitting process for full scale sequestration projects.

Individual Response: EPA clarifies that, with the promul gation of the GS rule, it no longer considers it appropriate to permit CO2 injecti on wells that are testing the injectivity or appropriateness of an individual fo rmation (e.g., as a prelude to a co mmercial-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 th e Class V experimental technology well classification to clarify perm itting for Class V wells. This addendum will address shifting of Class V experi mental projects to full-scale GS projects and the future use of the Class V experimental technology well s ubclass for research a nd testing of new GS technologies. For additional information, please see the section entitled, “How Does This Rule Affect Existing Injection Wells Under the UIC Progr am?” in the preamble to the final GS rule.

Letter ID: 0123 Comment ID: 22998 Letter Lines: 70 to 84

Comment Code: 1600 1.3 Risk Associated with CO2 GS

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: Risk: Geologic Sequestration is not the same as Enhanced Oil Recovery (EOR) and needs to have much high standards th an EOR activities have had to date. Protecting USDW is the most important aspe ct of the UIC program for the geologic sequestration of carbon dioxide. Although lim ited experience has been gained by the oil and gas industry injecting CO2 into proven structural traps for EOR,

2this experience has limited carry over to broader strategies for geologic sequestration. Geologic sequest ration, unlike EOR, is bei ng considered in basins without proven oil and gas capture and hol ding reservoirs. Even where exhausted oil and gas reservoirs are being cons idered for geologic sequestration, the amount of carbon dioxide to be injected is far greater than used for EOR and the goals of the injection are different. Th ere is an unknown, lik ely large, level of risk associated with large geologic sequestration projects. The regulatory

standards for site selection, site ch aracterization and ongoing monitoring should be kept high to help ensure that the worst case scenarios are never

realized.

Individual Response: EPA agrees that the nature and ri sks of CO2 injection for long-term storage are different from Class II CO2 injection for ER, and that tailored requirements for GS wells are necessary to protect USDWs from endangerment. For this reason, the Agency tailored UIC requirements for Class VI wells that addres s the general risks deep injection may pose to USDWs and specifically address th e unique nature of CO2 GS (i.e ., very large volumes, very long time-periods, and reservoi r pressure conditions).

EPA recognizes that injecting large volumes of CO2 for GS poses unique challenges that, if not properly managed, could endanger drinking water sources or have other adverse impacts. Although EPA believes that a lot can be learned from the EOR experience, EPA agrees that

caution is warranted and has, as a result, develo ped a new well class with requirements tailored to address the unique challenges posed by GS a nd potential risks associated with long-term injection of CO2. For example, these requirement s include the tailored AoR delineation process per §146.84, monitoring that is appropriate to GS projects per §146.90, and extended postinjection site care per §146.93.

As part of its adaptive rulemaking approach, the Agency 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.

Letter ID: 0123 Comment ID: 22999 Letter Lines: 86 to 93

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: EOR: Keep a strong separation between the programs for EOR and geologic sequestration. EOR occurs in areas with oil reservoirs, with little contemplation to the site's long term storage and CO2 containment characteristics. Although some oil and gas reservoirs are likely to have very good potential as geologic sequestration s ites, the determination of which reservoirs should be based upon excellent site characterization work that verifies that they will provide good lo ng term geologic sequestration with few

environmental risks.

3Individual Response: As described above, EPA agrees th at the nature and risks of CO2 injection for long-term storage is different from Class II CO2 injection for ER, and that tailored requirements for GS wells are a ppropriate and necessary to prot ect USDWs from endangerment. For this reason, the Agency tailored UIC requireme nts for Class VI wells that address the general risks deep injection may pose to USDWs and specifically address the unique nature of CO2 GS (i.e., very large volumes, very long time-periods , and reservoir pressure conditions). EPA adds that the decision to permit GS at a given site will be based on th e suitability of that particular site, not on the type of geologic formation. Furt hermore, EPA clarifies that injection of carbon dioxide for the purpose of enhanced recovery is regulated under Class II. Owners or operators may use depleted oil and gas reservoirs for GS provided the injection is intended for long-term storage and the well meets the standards in §146.86( a). EPA is allowing the construction of Class II EOR wells to be grandfathered per §146.81( c), provided the owner or operator can

demonstrate to the Director that the wells we re engineered and constructed to meet the requirements at §146.86(a) and ensure prot ection of USDWs from endangerment.

Letter ID: 0123 Comment ID: 23000 Letter Lines: 95 to 100

Comment Code: 4322 2.4.4.1.1 Comments in favor of requiri ng injection below the lowermost

USDW

Comment: Injection Zones: Geologic sequestration should only be allowed beneath the lowest USDW. Protecting USDW is the most important aspect of the UIC program for the geologic sequestration of carbon dioxi de. As proposed in the federal rules for geologic sequestration these sites s hould all be kept beneath the lowest USDW, to prevent the degradation of futu re ground water resources that we are likely to need in the coming centuries.

Individual Response: EPA agrees that protecting USDWs from endangerment must be a top priority. The Agency believes that there are limited circumstances where injection above the lowermost USDW can be performed in a manner that protects USDWs, as long as appropriate protections are in place. The final GS rule at §146.95 establishes a process by which owners or operators can seek a waiver of the Class VI in jection depth requirement s for injection into nonUSDW formations above and/or between USDWs. The waiver approach requires the submission of extensive, site-specific information (in conj unction with the permit appl ication submission) to demonstrate that injection of CO2 into a non-US DW that is above or between USDWs can be done in a manner that is protective of USDWs. It establishes: 1) requirements specifying information that owners or operators must subm it, and Directors must consider, in consultation with PWSS Directors; 2) procedur es for public notice of a waiver application a nd for DirectorRegional Administrator communicat ion; 3) the waiver issuance process; and, 4) additional requirements that apply to owners or operators of Class VI wells granted a waiver of the injection depth requirements to ensure USDW protection above and below the injection zone.

The final rule also establishes limited circumst ances under which expansions of the areal extent of aquifer exemptions may be granted for ow ners or operators of Class II EOR/EGR wells transitioning to Class VI injec tion for GS. Additionally, the rule does not categorically preclude or prohibit inject ion into any type of formation.

4EPA believes that the requirements at §146.95 w ill ensure USDW protection while providing flexibility to UIC Program Dir ectors and owners or operators who undertake CO2 injection for GS. The Agency believes this approach: 1) responds to concerns a bout local and regional geologic storage capacity limitations imposed by the proposed injection depth requirements; 2) allows for a more site-specific assessment of injection depth for GS projects; 3) accommodates injection into different formation types; 4) allo ws 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 aquifer exemptions for GS. Finally, EPA’s approach to addressing injecti on depth variability thr ough a waiver process responds to concerns about future drinking water resource availability and the need to ensure that high quality water remains available in sufficien t quantities to supply dr inking water needs. For additional information on the waiver approach, pleas e see the final rule and preamble, as well as EPA's responses to comments on the Notice of Data Availability and Request for Comment.

Letter ID: 0123 Comment ID: 23001 Letter Lines: 102 to 106

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

Comment: Containment or a caprock are critical to prevent the migration of CO2 upward into shallower USDWs. Allowing the dire ctor to require a dditional confining zones will allow regulators to include additional protective standards where

needed and could allow use of an othe rwise marginal formation for geologic sequestration.

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

characterize additional zones.

Letter ID: 0123 Comment ID: 23002 Letter Lines: 108 to 114

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

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

Comment: Area of Review: The proposed standards co rrectly require not just modeling, but tracking of the actual CO2 plume and pressu re front, with peri odic reevaluation

of the modeled behavior as additional e xperience is gained at a sequestration project. Modeling is a good method of predicting the be havior of injected CO2 but should not be relied upon without monitori ng to verify the accuracy of the modeled predictions. The model will be continually refined throughout the life a sequestration project.

5Individual 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 since the last model run.

EPA agrees with commenters on the importance of monitoring at GS sites and emphasizes that monitoring of injection activit ies will be an important comp onent of every GS project. Monitoring associated with injection wells and th e movement of the CO2 plume is necessary to verify that the injectate is confined in the target formations and does not endanger USDWs.

EPA agrees that monitoring data should be used to review model assumptions, verify computational model projections, and, when nece ssary, provide input for model refinements. As data are collected at an injection site, model pa rameters can be adjusted to match observations (i.e., for model calibration), which in turn improve s the predictive capability of the model. As a GS project proceeds, both monitoring and modeling will evolve, with monitoring results supporting effective AoR reevaluations and leading to improved model predictions.

Letter ID: 0123 Comment ID: 23003 Letter Lines: 116 to 127

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

Comment: Well Standards: The well construction st andards may be difficult or impossible to meet in some geologic settings. The standards require a surface casing

installed to the lowermost USDW and cem ented to the surface. In geologic settings with bedrock and deep drinki ng water quality aquifers, it may be impossible to set the surface casings this deep. Washington's Columbia River basalts may be as deep as 10,000 ft, much of that depth with drinking water quality ground water. The multiple flows and fractures in these beds make for difficult drilling and frequently require setting intermediate casings. The standards should allow a pr otective casing program th at can be reliably installed in all geologic settings. De ep aquifers may provide the most protective geologic settings for CO2 in jection; the sta ndards should not discourage their use.

Individual Response: EPA disagrees that the surface casing requirements in the GS rule preclude injection below deep USDWs. The fina l GS rule at §146.86(b)(2) requires that surface casing extend through the base of the lowermos t USDW and be cemented to the surface through the use of single or multiple strings of casing and cement. It does not, however, specify how cementing must be accomplished, and gives flexib ility 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. EPA notes that th ere are many potential ways to meet the requirement, such as the use of staged cementing.

EPA recognizes concerns regardi ng construction of Class VI wells where the lowermost USDW is very deep. To further address comments on d eep injection wells, the final GS rule at §146.95 includes requirements for owners or operators that seek a waiver of the injection depth

6requirements. Owners or operators of Class VI wells operating under in jection depth waivers must comply with additional cons truction requirements to ensure th at wells used to inject above or between USDWs are protective. See the discussion of the waiver approach in the preamble to

the final GS rule for additional information.

Letter ID: 0123 Comment ID: 23004 Letter Lines: 129 to 132

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

Comment: Downhole valves and other required downhol e equipment may impact or prevent certain monitoring techniques. It is important to require appropriate safeguards but establishing prescriptive safeguards may be counter productive and are likely to prevent the use of cutting edge tec hnologies as new methods are developed.

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

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

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

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

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

Letter ID: 0123 Comment ID: 23005 Letter Lines: 134 to 140

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

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

Comment: Monitoring: Direct monitoring of the form ations immediately above the confining layer for a geologic sequestr ation injection zone is an important requirement for the early detection of unacceptable leak age. Monitoring wells installed into this monitoring zone will be quite ex pensive but should be required for all projects. Geophysical methods and other indirect monitoring, while useful,

should not be allowed to substitute for all direct monitoring above the confining layer.

Individual Response: EPA disagrees that pressure monitoring above the confining zone is appropriate. Instead, EPA believes th at pressure monitoring in the in jection zone is necessary to track the development and movement of the pre ssure front and CO2 plume. The final rule (at

7§146.90(g)) requires owners or operators to perfor m monitoring to track the extent of the CO2 plume and pressure front. The owner or operator mu st use direct methods to monitor for pressure changes in the injection zone. Indirect me thods (e.g., seismic, electrical, gravity, or electromagnetic surveys and/or down-hole CO2 detection tools) are also required unless the Director determines, based on site-specific ge ology, that such methods are not appropriate.

EPA believes that pressure monitoring within th e injection zone is necessary because any such monitoring above the confining z one would not detect movement of the pressure front unless a breach of the confining zone occurs. EPA believe s that monitoring using wells in the injection zone (i.e., that penetrate the conf ining zone) can be safely perform ed if the wells are constructed to prevent flow between the injection zone and USDWs or other layers above the confining zone. Such construction technologies ex ist 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 adds that owners or operators may consider performi ng additional pressure monitoring in wells that are above the confining zone (e.g., in the same wells used to perform ground water quality monitoring required at §146.90(d)) to provide additional verification that no pressure ch anges are occurr ing above the confining zone due to CO2 leakage and that th e Director has the authority to require such monitoring under §146.90(i). Monitoring also identifies needed remedi al actions, provides inputs for AoR reevaluation modeling, and targets ad ditional geochemical and surface monitoring needs. Knowledge of the location of the CO2 plume and the associated pressure front will assure the public that GS projects are proceeding accord ing to plan, provide sufficient information to the owner or operator and Director, or allow for a ppropriate actions to addr ess any indication that USDWs may be endangered.

EPA also agrees that direct monitoring for gr ound water quality above th e confining zone is important, and the GS rule requires this at §146.90(d). Monitoring in additional formations, e.g., the injection zone, may also be necessary, and if the Director believes such monitoring is warranted he/she has the authority to require th at it be included in the testing and monitoring plan.

Letter ID: 0123 Comment ID: 23006 Letter Lines: 142 to 151

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

Comment: The number of wells drilled through the conf ining layer into th e injection zone should be minimized. Each well represents a risk of establishing a pathway for the migration of CO2 or in-s itu fluids into shallower a quifers. Projects may be able to get sufficient monitoring data from injection wells to minimize the need for stand-alone injection zone monitoring wells.

Decisions on the level of direct and indi rect monitoring should be made on a site by site basis, based upon the geol ogic characteristics, but some direct monitoring must be required above the conf ining layer to confirm that indirect monitoring is accurate.

8Individual Response: As described above, EPA believes that direct pressure monitoring in the injection zone is necessary to track the development and moveme nt of the pressure front and CO2 plume.

EPA believes that monitoring using wells in the in jection zone (i.e., that penetrate the confining zone) can be safely performed if the wells are co nstructed to prevent flow between the injection zone and USDWs or other layers above the conf ining 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 th e manageable risk of those monitoring wells serving as conduits for fluid movement. EPA a dds that owners or operators may consider performing additional pressure monitoring in wells that are above the confining zone (e.g., in the same wells used to perform ground water qualit y monitoring required at §146.90(d)) to provide additional verification that no pr essure changes are occurring above the conf ining zone due to CO2 leakage and that the Director has the aut hority to require such monitoring at §146.90(i). EPA adds that the final rule also requires ge ochemical monitoring above the confining zone, at §146.90(d).

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

In addition, in January 2009, DOE published a best practices manua l entitled "Monitoring, Verification, and Accounting of CO2 Storedin Deep Geologic Formations" (DOE/NETL311/081508); this manual is included in the docket for the final GS rule.

Letter ID: 0123 Comment ID: 23007 Letter Lines: 153 to 157

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

Comment Code: 4630 2.6.3 Corrosion monitoring

Comment: Periodic corrosion and well integrity test ing is important for all pollution prevention programs. This well testing will help operators to focus maintenance and repair activities on the wells that are degrading. It is far better to prevent leakage from a well breach than to fix the well after discovering that

it has leaked.

Individual Response: EPA agrees with the commenter; the final rule requires both internal and external mechanical integrity testing. Mechanical integrity testing is one of the cornerstones of

9the existing EPA UIC program. The MIT requi rements at §146.89, along with the corrosion monitoring required at §146.90(c), ensure protection of USDWs from endangerment and provide an important early warning of potential problems in the inje ction well. Routine mechanical integrity testing of injection wells provides data that enables the identifi cation and remediation of well integrity problems before they lead to leakage and/or endangerment of USDWs. For additional information, please s ee the discussion of MITs in the final rule preamble.

EPA also agrees that corrosion monitoring is a ppropriate given the potenti ally corrosive nature of the CO2 stream. CO2 in the presence of water becomes acidic, potentially accelerating

corrosion of well materials. The CO2 stream for a GS project may also c ontain small volumes of impurities that could contribute to corrosion. For th ese reasons, the final rule requires quarterly corrosion monitoring (at §146.90(c)).

Letter ID: 0123 Comment ID: 23008 Letter Lines: 159 to 167

Comment Code: 5800 2.13 Comments on emergency and re medial response (40 CFR 146.94)

Comment: Remedial Action: Establish triggers fo r entering remedial action during the negotiation of the geologic sequest ration permit. Identification of environmental impacts from monitoring at a permitted facility is frequently followed by a prolonged legal discussion of when these impacts become large enough to trigger remedial actions. EPA s hould consider moving this discussion to the initial permitting process so that the operator and regulatory agency agree before impacts are observed. This will help all to understand where the threshold is and will help to prevent le gal efforts intended to delay beginning

remedial actions when environmen tal impacts have been observed.

Individual Response: EPA believes that the final rule takes a proactive approach to remedial actions by requiring, under §146.94, each permit app lication to include an emergency and remedial response plan so that both the owne r or operator and the Di rector may immediately respond to any fluid movement that may endang er a USDW at GS sites. Furthermore, EPA believes that each response action will be site- and event- specific, and that setting specific environmental impact triggers outside of a s howing of USDW endangerment in advance would not be practical or account for every potential scenario. For this reason, the emergency and remedial response requirements at §146.94 are designe d to ensure that, in the unlikely event of endangerment, the owner or operator will immedi ately cease injection (i.e., take immediate action to avoid any further endangerment) and in itiate a dialogue with the Director as soon as possible to identify appropriate next steps based on the circumstances.

EPA clarifies that, if the owner or operator obtains evidence th at USDWs may be endangered or that leakage is occurring, he or she must cease injection, take all steps reasonably necessary to identify and characterize any release, notif y the Director, and implement the approved emergency and remedial response plan (§146.94(b)).

10Letter ID: 0123 Comment ID: 23009 Letter Lines: 169 to 174

Comment Code: 5400 2.9 Proposed Financial Respons ibility and Long-Term Care Requirements

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

Comment: Financial Assurance: Financial assurance accounts, funded with real assets must be required. Financial tests and self insurance are of no value if a company becomes financially insolvent. As we have recently seen in the financial world, the collapse of a company can occur quite rapidly. Financial assurance is only

of value if the assets remain in th e account after the company's financial

demise.

Individual Response: EPA agrees that assuring financial responsibility for corrective action on wells in the AoR, injection well plugging, PISC and site closure, and emergency and remedial response at Class VI sites is an important comp onent of ensuring that USDWs are protected. The goal of financial responsibility is to ensure that financial reso urces are available to prevent endangerment of USDWs from improper plugging, remediation, and management of wells in the event that the owner or operator experiences financial difficulties.

EPA will retain self-insurance as an option to de monstrate financial responsibility for Class VI wells. EPA believes, based on input by commenters, that self-insur ance, if properly used, can be an appropriate option for certain owners or operato rs. Self-insurance has b een used successfully in the past (e.g., under the Class I and RCRA pr ograms). EPA recognizes that there are some

concerns about the use of self insurance, including those mentioned by the commenters, and is developing guidance (availa ble on EPA’s website at http://water.epa.gov/type/groundwat er/uic/wells_sequest ration.cfm) to assist Directors in evaluating the appropriateness of self-insurance in specific circumstances, such as how to evaluate owners or operators' demonstrations of financial worthiness or whether certain owners or operators pose too great a fina ncial risk to use self-insuran ce as a financial responsibility instrument. EPA acknowledges that states may not be authorized under state law to allow for self

insurance or other financial inst ruments. Therefore, states may prohibit the use of any financial

instruments included in the rule, including self insurance, for Cla ss VI wells. See the final rule and preamble for further discussion of EPA's fi nal approach to financial responsibility.

Letter ID: 0123 Comment ID: 23010 Letter Lines: 176 to 188

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

Comment: Non-CO2 Contaminants: The proposed standa rd will allow co-disposal of imported

non-CO2 waste streams. One of the most disturbing aspects of the proposed

standards would allow non-CO2 contaminants to be injected w ith the CO2 unless

the contaminants would make the CO2 a h azardous waste. Injected gases may not qualify as a hazardous waste under current standards. It appears that the proposed rules would allow a facility to import waste materials to add to the

1112 CO2 and be injected as a cheap disposal option; this should be prevented. Washington State prohibits th e injection non-CO2 contamin ants if technology is available for their removal; Washington also prohibits the use of underground injection for most waste disposal. An a lternative option would be to allow nonCO2 contaminants only as specifically a ddressed in a facility's permit and a

statement that the non-CO2 contaminants must be by-products of the CO2 stream and may not be imported for disposal by injection with the CO2.

Individual Response: The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a percent CO2). Instead, the GS rule addresse s the quality and quantity of impurities by requiring owners or operators to submit information on the source of the CO2 and its physical and chemical propertie s. Specifically, the GS rule requi res the owner or operator to submit data about the site, including an analysis of the chemical and physi cal characteristics of the CO2 stream, as required at §146.82(a)(7)(iv), and informati on on the compatibility of the CO2 stream with fluids in the injection zone a nd minerals in both the in jection and the confining

zones and the materials used to construct the well, per §146.82(c)(3). This information can help the Director determine the potential for geoche mical reactions between the injectate (CO2) and the host geologic formations, which could result in the plugging of pore spaces or the dissolution

of formation minerals.