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 23, 2008

Ms Cynthia Dougherty

Director, Office of Ground Water and Drinking Water US Environmental Protection Agency 1400 Pennsylvania Ave Washington D.C. 20002

Dear Ms Dougherty,

The following is submitted in response to: Federal Requirements Under the Underground Injection Control (UIC ) Program for Carbon Dioxide (CO 2 ) Geologic Sequestration (GS) Wells; Proposed Rule (Docket ID No. EPA-HQ-OW-2008-0390)

On behalf of the Board of Directors a nd member states of the Ground Water Protection Council, (GWPC), I am pleased to transmit th e attached documents in response to the United States Environmental Protection Agen cy’s request for comments on its Proposed Rule for carbon capture and storage (CCS). Our submittal contains three parts:

1) Official comments reviewed and adopted by the GWPC Board of Directors: GWPC Recommendations to USEPA on Proposed CO2 UIC Rule Final 12-23-08

2) Technical comments, prepared by the GW PC CO2 Committee of 12 experts with

substantial educational a nd technical experience repr esenting a diverse group of interests and backgrounds: CO2 Committee Response to USEPA on Notice Questions Final 12-23-08

3) A Resolution Regarding Delegation of Prim ary Enforcement Authority to States For The Geo-sequestration of Carbon Dioxide , adopted by the GWPC Board of Directors that strongly suppor ts full program delegation of Class VI wells and the option for partial primacy as well.The GWPC committed hundreds of hours of technical discussions, both at scheduled meetings and also within its CO2 Committ ee meetings. The technical comments provided as a result, represent a signifi cant cross cut of state oil and gas, and public water supply agencies, environmental associations, nationa l labs, universities, producing and service companies. At GWPC meetings there were multiple presentations made on the issues and a broad opportunity for public comment a nd participation was made available.

GWPC member states and indi vidual participants made numerous comments throughout this Rule development process commendi ng the USEPA Office of Ground Water and Drinking Water on providing opportunity for comment and the extent to which the

OGWDW went to insure that a wide variety of experts and views were involved in the process. We wish to thank th em for these exceptional efforts.

The GWPC is the only nationa l association wherein a body of expertise on the technical and regulatory aspect of all types of underg round injection control wells exists. We believe that our mission to protect and cons erve ground water for all beneficial uses coupled with our commitment to applying sound science in efforts such as this, creates a strong basis for these comments and future Ru le development. If you should desire any additional information on any of the subm itted documents, please don’t hesitate to

contact us.

Respectfully Submitted

Michel J Paque Secretary and Executive DirectorRESOLUTION 08-1

REGARDING DELEGATION OF PR IMARY ENFORCEMENT AUTHORITY TO STATES FOR THE

GEOSEQUESTRATION OF CARBON DIOXIDE

WHEREAS, the United States Environmen tal Protection Agency (USEPA) has de termined the geologic sequestration of carbon dioxide is a process that falls within the jurisdiction of the Safe Drinking Water Act (SDWA), Underground Injection Control (UIC) program; and

WHEREAS, the USEPA has developed a proposed federal ru le under the UIC program to regulate the practice of geologic sequestration of carbon dioxide; and

WHEREAS, the USEPA has proposed the creation of a new injection well class for carbon dioxide geologic sequestration injection wells with the designation of Class VI; and

WHEREAS, upon adoption of a federal rule states will lack primacy enforcemen t authority (Primacy) for Class VI wells until such authority is delegated to the states by USEPA; and

WHEREAS, the USEPA has indicated the delegation of prim acy for Class VI wells will fall under the authority of

Section 1422 of the SDWA; and

WHEREAS, it is the current practice of USEPA to only delegate primacy under Section 1422 of th e SDWA if a state accepts primacy for all well classes other than Class II wells; and

WHEREAS, it is in the best interest of protecting ground water resources fo r the geologic sequestration of carbon dioxide to be regulated at the state level; and

WHEREAS, the GWPC is an association of state admini strators of underground injec tion control and ground water protection programs that will be responsible for admini stering programs for the geologic sequestration of carbon

dioxide; and

WHEREAS, any requirement by USEPA that states accept primacy for Class I, I II, IV and V wells, as a condition for obtaining primacy for Class VI wells will cr eate an unreasonable burden upon states; and

WHEREAS, any requirement by USEPA that states with primacy for Class I, III, IV and V wells also accept primacy for Class VI wells will compromise the states ability to de cide how best to administer the states UIC program and may unnecessarily disrupt th e states’ UIC program;

NOW THEREFORE BE IT RESOLVED THAT, the GWPC recommends USEPA provide for the voluntary and separate delegation of primacy to the states for Class VI wells under the UI C program unless the state requests the delegation be made a part of a state UIC primacy program.

Passed by the Board

Attest Michel J. Paque, SecretaryNovember 6, 20081335843.5GWPC CO2 Committee Responses to EPA Notice QuestionsEPA NoticeQuestionsEPA Rule IssueGWPC CO2 Committee ResponseRationale73 FR 435048. Class VI requirements and permitswill need to be carefully structured toensure that they do not “authorize”inappropriate hazardous releases. Thiswould include clarifying if there are potentialreleases from the well which are outside thescope of the Class VI permit. EPA requestscomment on particular situations where thismight occur. EPA notice 43504.CERCLA application should be avoided or sortedout and affirmed by Congress to indicate that itwould not apply; municipal operators have majorconcern over this potential because cities will bearound long-term and look like deep pocketsAs EPA has noted, CERCLA liability does not applyto federally permitted releases (FPRs), includingreleases covered by a UIC permit, even if GS wouldlead to a hazardous substance release. Nor shouldCERCLA liability apply to any downstream reactionsor transformations resulting from FPRs.Accordingly, there appears to be little real potentialfor CERCLA liability resulting from GS. Yet EPAneeds to clarify that CERCLA liability is extremelyunlikely to result from any GS operation that has notinjected streams that are not covered by its UICpermit.Even the potential for CERCLA liability is viewedwith such apprehension because of theoverwhelmingly negative effects that such liabilityhas had on the investing community, however,that EPA’s discussion ofthat possibility withoutsubstantial clarification is very likely to have achilling effect on the support for development anddeployment of CCS technologies.73 FR 435049. EPA alsorequests comment onother considerations associated with thepresence of impurities in the CO2 streamrelated to CERCLA. EPA Notice 43504.The only need is to address constituents in a CO2stream that would defeat capture, compression,transport or GS, and these can be addressedthrough the use of special materials in many cases.The focus should be on compatibility rather than onany need for purification.73 FR 4350610. EPA’s proposal would provide theDirector the discretion to require the owneror operator to identify and characterizeAny showing of secondary containment isunnecessary once the requirement for containmenthas been satisfied by providing for an adequateAny emphasis on the availability of additionalconfining zones is likely to cause confusion overthe adequacy of projects that satisfy the actualNovember 7, 2008GWPC CO2 Committee Response2EPA NoticeQuestionsEPA Rule IssueGWPC CO2 Committee ResponseRationaleadditional confining and containment zonesabove the primary (i.e., lowermost)confining zone that could further impedevertical fluid movement and allow forpressure dissipation. EPA says that theselayers could provide additional sites formonitoring, mitigation, and remediation.EPA’s proposal would notrequire that theseadditional zones be identified for all GSsites because their absence does notnecessarily indicate inappropriateness of aGS site. However, if such zones arepresent, information about theircharacteristics can provide inputs forpredictive models, identify appropriatemonitoring locations, and improve publicconfidence in and acceptance of aproposed GS site. EPA specifically seekscomment on the merits of requiring theidentification of these additional zones.EPA Notice 43506.confining zone. References to additional confiningand containment zones is more likely to lead toconfusion than support.requirements but do not also provide what is bydefinition redundant and unnecessary layers ofprotection. Moreover, discussions of additionalconfining zones could undercut the ability to usebeneficially any additional formations in the areaof interest covered by a proposed project.73 FR 4351225. EPA is also requesting commentson whether aquifer exemptions should beallowed for the purpose of Class VIinjection, and under what conditions shouldsuch aquifer exemptions be approved. EPANotice 43512.The committee recommends that aquifeexemptions be allowed.rAt this time, the Committeeis not recommending any specific need for newaquifer exemption criteria created because theexisting criteria are perceived to be sufficient toallow aquifer exemptions as needed for GS. Evenwithout changes, the aquifer exemptionrequirements in the UIC program would allowoperators to obtain appropriate exemptions for GSoperations.73 FR 4351226. EPA seeks comment on whetherthe Agency should set a minimum injectiondepth requirement for CO2 GS, rather thanrequire that such injection take place belowthe lowermost USDW. EPA Notice 43512.There should not be a minimum depth establishedAND there should be no blanket restrictionconcerning proximity to USDWs but should insteadbe based on ability to protect USDWs.The presence of numerous oil and gas reservoirsabove demonstrates the ability of geologicformations at those depths to trap and containfluids comparable to CO2 streams.November 7, 2008GWPC CO2 Committee Response3EPA NoticeQuestionsEPA Rule IssueGWPC CO2 Committee ResponseRationale73 FR 43513-1527. EPA’s proposal allows Directors’discretion on whether to require the use oftracers, and if so, what types of tracers.EPA seeks comment on the use of tracersin CO2 GS operations, and any potentialimpact of tracers on human health orecosystems as they relate to USDWs. EPANotice 43513.Due to the knowledge gaps in the use of tracers inthis type of environment language regardingDirectors discretion is OK. However, furtherresearch needs to be conducted before any finallanguage to allow the use of tracers is approved.73 FR 4351733. EPA seeks comment on theappropriate amount and types of monitoringthat should be conducted at a GS site.Specifically, EPA seeks comment regardingthe usefulness of indirect geophysicalmonitoring and surface air and soil gasmonitoring. In addition, EPA seekscomment regarding the use of a Directorapproved monitoring plan for GS sites.EPA Notice 43517.Although actual monitoring of injection formationmight be considered mosteffective you still havethe potential problem of putting holes in theconfining formation. Perhaps the use of seismic toplace monitoring wells into the injection zone wouldbe an appropriate approach. The number ofmonitoring wells should not be established inadvance. Obviously the UIC program does nothave complete control over monitoring wellconstruction or operation or closure. With respectto soil and air monitoring there is a question as tothe efficacy of these as a means of protectingUSDWs.73 FR 4351837. In addition to the aboverecordkeeping and reporting requirements,EPA considered a requirement for ownersor operators of GS sites to provide anannual report during the lifetime of theproject, including the post-injection period,regarding the GS operation. Although EPAhas not included a requirement for thisreport in its proposal, EPA seeks commentregarding the necessity for such an annualreport. EPA Notice 43518.See Workgroup recommendation 7.6 for furtherdetails.Report annually, or at a frequency acceptable to theDirector, the characteristics and cumulativevolumes (annual and total) of injected fluids,injection pressures, injection rates, annularpressures for each injection well, the results of anymechanical integrity tests conducted during thistime period, available site integrity monitoringresults, the extent of the injected CO2 and thepressure front based on current data.Update site operations as appropriate and sitemodeling results annually, or at a frequencyacceptable to the Director, to reflect current data.Compare the updated results to the previousNovember 7, 2008GWPC CO2 Committee Response4EPA NoticeQuestionsEPA Rule IssueGWPC CO2 Committee ResponseRationaleresults. Identify and explain to the Director anydiscrepancies between the updated results and theprevious results.Note: Technology transfer is a better forum fordriving regulatory changes. Do not support annualreporting as outlined in the preamble.November 7, 2008GWPC CO2 Committee Response5EPA NoticeQuestionsEPA Rule IssueGWPC CO2 Committee ResponseRationale73 FR 43519-20146.93(b)38. EPA is proposing using acombination of fixed timeframe and aperformance standard as described above.EPA is tentatively proposing a post-injectionsite care (monitoring) period of 50 yearswith Director’s discretion to change thatperiod to lengthen or shorten the 50 yearperiod if appropriate. EPA requestscomment on the proposed use of atentative 50 year fixed timeframe that couldbe modified at the Director’s discretionbased on monitoring and modeling data.EPA Notice 43519.It is inappropriate to utilize a fixed period. Ademonstration of non endangerment is anappropriate means of deciding when monitoring isno longer needed. The Committee recommendsusing a combination of the non-endangermentstandard with specific performance standards asfollows:Prior to authorization for site closure, the owner oroperator must demonstrate to the Director, basedon monitoring, other site-specific data, andmodeling that is reasonably consistent with siteperformance, that no additional monitoring isneeded to assure that the geologic sequestrationproject does not and is not expected to pose anendangerment to USDWs. The Director shallapprove closure if the owner or operatordemonstrates, based onthe current understandingof the site, including monitoring data and/ormodeling, all of the following: (i) the estimatedmagnitude and extent of the project footprint (CO2plume and the area of elevated pressure) ; (ii) theestimated location of the detectable CO2 plume; (iii)that there is no significant leakage of either CO2 ordisplaced formation fluids that is endangeringUSDWs; (iv) that the injected or displaced fluids arenot expected to migrate in the future in a mannerthat encounters a potential leakage pathway into aUSDW; (v) that the injection wells at the sitecompleted into or through the injection zone orconfining zone are plugged and abandoned inaccordance with these requirements; and (vi) anyremaining project monitoring wells at the site arebeing managed by a person and in a manneracceptable to the Director.The fixed timeframe is not adequately supportedby scientific and technical evidence andrepresents an unnecessary departure from theuse of performance standards, which EPA hasrecognized as the preferred approach in mostother situations. The use of “stabilization” as aperformance standard is not advised because ofthe difficulties of dealing with backgroundmovement within the injection zone. The mostimportant demonstration is containment, not justmovement.November 7, 2008GWPC CO2 Committee Response6EPA NoticeQuestionsEPA Rule IssueGWPC CO2 Committee ResponseRationale144.3641. Current UIC guidance describestrust funds as a form of financial assurance.The owner or operator may deposit fundsinto the trust fund in phases; that is, eitherover the term of the initial permit or over theremaining operating life of the injection well,as estimated in the well plugging plan,whichever period is shorter. Because of thepossibility that the owner or operator mayface financial distress prior to the trustbeing fully funded, EPA is considering aguidance approach that would recommendadopting a pay in period of three years forGS projects, consistent with other similarprograms in the Agency. EPA Notice43521.The Committee recommends that financialassurance requirements be based on costing ofplans, with updating as appropriate to account forchanged conditions and modified plans. Themethods of providing FA should remain flexible, asEPA has proposed, to allow markets to adapt to therequirements and to identify methods for providingFA. Under any circumstances, EPA shouldcontinue to use self-insurance mechanisms througha financial test. Any development of guidance forspecific FA instrumentsshould await the initialexperience with those instruments, but wouldprobably be addressed better through guidancethan regulations to maintain a greater amount offlexibility to adapt to changes in the market that arelikely to follow increased understanding of thetechnologies involved and operating experiencewith those technologies. All FA requirementsshould be released at closure.For any particular instrument, the pay-in periodshould be commensurate with the risk profile.i.e. greater risk = faster pay-in.The plans should be updated as appropriate inconjunction with the iterative process of AoRreevaluations using data from monitoring andoperational experience to reevaluate themodeling.73 FR 4352142. Current UIC regulations for Class Ihazardous waste injection allow for the useof insurance for purposes of demonstratingfinancial responsibility. However, insurancewas not included as part of the guidanceprovided for Class II injection because thisinsurance mechanism was and still is,rarely used for the purpose ofdemonstrating financial assurance forinjection wells. EPA is assessing whether toprovide guidance on the use of insuranceproviders and, if so, whether to updateeligibility requirementsfor insurers for GSwells consistent with other current Federalagency practices. EPA Notice 43521.Leave the door open for establishing financialsmechanisms on a project by project basis. Therulemaking should not prescribe or precludeparticular financial instruments. The issue offinancial assurance is complex and must beconsidered in significant detail and should be basedon the initial experience gained from the use of FAmechanisms before any guidance or regulation isissued.November 7, 2008GWPC CO2 Committee Response7EPA NoticeQuestionsEPA Rule IssueGWPC CO2 Committee ResponseRationale73 FR 4352243. EPA is assessing whether afinancial ratings threshold for all companiesusing a self-guarantee, similar to thoseused by other Federal agencies, isappropriate. The Agency also is consideringwhat constitutes an appropriate financialrating threshold, and whether a financialrating greater than BBB or Baa (i.e., thecurrent rating threshold established underthe UIC regulations) is appropriate for GSwells. EPA Notice 43522.See response to #41.146.8544. EPA is requesting comments onwhether financial responsibility mechanismsto be recommended in EPA guidanceshould be adjusted in the mannerdescribed, whether additional instrumentsshould be included, and whether otheradjustments to the financial responsibilitymechanisms should be considered, allsubject to EPA’s authority under the SDWA.EPA Notice 43522.See response to #4173 FR 4352245. The Agency is also requestingcomment on allowing separate financialdemonstrations to be submitted for theplugging of the injection well and for thepost-injection site care requirements. EPANotice 43522.The Committee supports the use of separatefinancial demonstrations for the plugging of theinjection well and for the post-injection site carerequirements based on the greater experience withwell plugging requirements and methods. It will beeasier to retain certainty for these actions and touse established FA methods.EPA should look into the options available forsingle bonding with phased release and multiplebonding, as is done under SMCRA.November 7, 2008GWPC CO2 Committee Response8EPA NoticeQuestionsEPA Rule IssueGWPC CO2 Committee ResponseRationale73 FR 4352346. EPA requests comment onadopting the existing requirements forpublic participation at 40 CFR Part 25 and40 CFR Part 124 and whether additionalrequirements should be included to reflectthe availability of new tools fordisseminating and gathering information.Such tools include cable networks, theInternet, and other new technology. EPANotice 43523.Public participation requirements for Class VI wellpermitting should follow established requirementsfor UIC program permitting, which have provensuccessful. Any modifications to account fortechnological advances should be considered on aprogram-wide basis; there is nothing unique aboutGS in this respect.73 FR 43522-2347. EPA alsorequests comment onways to enhance the public participationprocess, including engaging communities inthe site characterization process as soon ascandidate locationsare identified. EPANotice 43523.This is best left up to the discretion of the regulator.Establishing a process may provide a standard thatcan be followed by developers. There was concernabout the term “as soon as”. If included, this termshould be changed to a more reasonable periodfollowing applicant evaluation of a site. Publicparticipation requirements should be similar to otherportions of the UIC program (e.g. Class I). Theprogram should assure a public hearings processwhen warranted by substantive issues and affectedstakeholders but the timing and particulars of theprocess should not be prescribed in the rule.73 FR 4352348. To gain authority for Class VI wells,States, Territories, and Tribes will berequired to show that their regulations areat least as stringent as, and may be morestringent than, the proposed minimumFederal requirements (e.g., inspection,operation, monitoring, and recordkeepingrequirements that well owners or operatorsmust meet). Such Primacy States,Territories, and Tribes are authorized underSection 1422 of the SDWA. EPA Notice43523.Retain current requirement, but recognize thatgeology varies from state to state and somemodifications may be appropriate that will result invariations that are not less stringent, but simplyadapted to different circumstances. There shouldalso be some recognition that the beneficial effectsof GS may be enhanced by allowing flexibility foradaptation of state requirements.November 7, 2008GWPC CO2 Committee Response9EPA NoticeQuestionsEPA Rule IssueGWPC CO2 Committee ResponseRationale73 FR 4352349. There may be benefits to parsingout primacy for Class VI wells, howeverEPA has not made a decision on this.Allowing States, Territories, and Tribes toacquire primacy for only Class VI wells mayencourage them to assume theresponsibility of implementation and providefor a more comprehensive approach tomanaging CCS projects (e.g., capture,transportation, and geologic sequestration).EPA is seeking comment on the merits andpossible disadvantages of allowing primacyapproval for Class VI wells independent ofother well classes. EPA Notice 43523.Resolution 08-1 of the GWPC strongly urgesUSEPA to allow for the granting of individualprimacy to states for the Class VI program. Wefurther support the preservation of state authority todetermine what agencieswill exercise primacy,strongly urge USEPA toprovide adequate funding,which will require a substantial increase abovecurrent funding levels both to meet both existingUIC program needs and the additional resourcesanticipated to be necessary for the Class VIprogram. Ramp up of resources, personnel, andtraining should precede anticipated heavy demand.Submit GWPC resolution 08-173 FR 4352751. The Agency assumes threemonitoring wells per injection well for thepurpose of estimating national costs;however, the Agency recognizes thatoperators and primacy agency Directorsmay choose more or fewer monitoring wellsdepending on project site characteristics.Because the monitoring wells andassociated costs represent a significantcomponent of the Cost Analysis, theAgency acknowledges that this factor maybe significant in the overall uncertainty ofthe Cost Analysis. EPA requests commenton whether three monitoring wells perinjection well is an appropriate costingassumption. EPA Notice 43527.The group is unsure asto EPA’s methodology fordeciding on the number of monitoring wells sinceeach project could be vastly different requiring awide variety in numbers and types of any necessarymonitoring wells. Also, it was felt that the statementregarding the fact that monitoring wells are asignificant portion ofthe costs has not beensupported by independent analysis as yet.Therefore, the issue of numbers of monitoring wellsis not yet ripe for a decision.There should not be a requirement for monitor wellsinto the injection zone, and monitor wells should notbe required for the purpose of tracking the plume orpressure front.73 FR 4353152. The public is invited to submitcomments or identify peer-reviewed studiesand data that assess the effects of early lifeexposure to changes in drinking waterquality that may be caused by geologicsequestration of carbon dioxide. EPANotice 43531.Studies already exist that address potentialexposure issues, but there should be a recognitionof the very low potential for exposure that exists forGS projects.November 7, 2008GWPC CO2 Committee Response10December 19, 2008GWPC RecommendationsPage 1 of 401Recommendations of the Ground Water Protection Council (GWPC)Rule ProvisionEPA ProposalGWPC RecommendationsRationalePart 1441. The authority citation for part 144continues to read as follows:Authority: 42 U.S.C. 300f et seq.; ResourceConservation and Recovery Act, 42 U.S.C.6901 et seq.No comment necessary144.12. Section 144.1 is amended as follows:Adding new paragraph (f)(1)(viii); andb. Revising the first two sentences inparagraph (g) introductory text.* * * * *(f) * * *(1) * * *(viii) Subpart H of this part sets forthrequirements for owners or operators ofClass VI injection wells.* * * * *(g)Scope of the permit or rule requirement.The UIC Permit Program regulatesunderground injections by six classes ofwells (see definition of ‘‘well injection,’’ §144.3). The six classes of wells are set forthin § 144.6. All owners or operators of theseinjection wells must be authorized either bypermit or rule by the Director. * * *Support revision to include a sixth class of wells.December 19, 2008GWPC RecommendationsPage 2 of 402Rule ProvisionEPA ProposalGWPC RecommendationsRationale144.63. Section 144.6 is amended as follows:Revising paragraph (e); andb. Adding new paragraph (f).* * * * *(e)Class V.Injection wells not included inClass I, II, III, IV, or VI. Specific types ofClass V injection wells are described in §144.81.(f)Class VI.Wells used for geologicsequestration of carbon dioxide beneath thelowermost formation containing a USDW.(4) For enhanced recovery of oil or natural gaswhere geologic sequestration is occurringduring or in connection with enhancedrecovery of oil or natural gasprovided(i) thereis reasonable expectation of more thaninsignificant future production volumes or ratesas a result of carbon dioxide injection and (ii)operating pressures are no higher thanreasonably necessary to produce suchvolumes or rates;(f) Class VI. Wells injecting a carbon dioxidestream for geologic sequestration exceptthose wells described in subsection (b)(4) ofthis section or otherwise excluded from thisClass.There should not be a blanket prohibitionconcerning injection above USDW’s or at specificlevels. The determination of injection zones shouldbe based upon appropriate containment. This isespecially true in light of recent calls for changes inthe definition of a USDW to include formationsgreater than 10K PPM TDS and the fact thatseveral states including Wyoming and Californiamight be prevented from instituting geologicsequestration as a practical matter if injection werelimited to above USDW’s due to the great depth ofsome USDW’s. This would create a situation whereotherwise good injection zones are artificiallyexcluded, thus decreasing the overall availability ofgeologic sequestration in the U.S.The GWPC also recommends EPA considerretaining all geologic sequestration in oil and gasreservoirs under the jurisdiction of Class II UICprograms and create a subclass within this programfor geologic storage of carbon dioxide. Thissubclass (Class II GS) would be used for thosewells that depart from the traditional uses of Class IIwells for enhanced recovery, and result in theapplication of Class VI standards. This changewould eliminate any confusion over whether a ClassII CO2 injection well used for enhanced recoverymight also need a Class VI permit and would avoidthe need to change jurisdiction for a well from onestate agency to another over time.144.154. Adding § 144.15 to read as follows.§ 144.15 Prohibition of non-experimentalClass V wells for geologic sequestration.The construction, operation ormaintenance of any non-experimental ClassV geologic sequestration well is prohibited.This provision should be deleted if EPA doeslimit Class VI wells to injection below thelowermost USDW in the final rule to allowDirectors to selectively authorize GS in areaswith USDWs below the injection zone.In addition, it is recommended that all GS intobasalts, coal seams, salt domes, and shales beconducted under Class V as experimental wellsinitially and then as commercial scale Class Vwells/projects if the experimental projectsdemonstrate that these sites can be suitable forgeological sequestration while preventingendangerment of USDWs.Keeping these wells under Class V would allowEPA and the states to gainenough experience todevelop suitable permitting requirements for suchwells and to tailor those requirements until theagencies are ready to adapt the Class VIregulations.December 19, 2008GWPC RecommendationsPage 3 of 403Rule ProvisionEPA ProposalGWPC RecommendationsRationale144.185. Adding § 144.18 to read as follows.§ 144.18 Requirements for class VIwells.Owners or operators of Class VIwells must obtain a permit. Class VI wellsare not authorized by rule to inject.Support the proposed language.Agree with EPA’s rationale.144.366. Section 144.36 is amended by revisingthe first two sentences in paragraph (a) toread as follows:§ 144.36 Duration of permits.(a) Permits for Class I and V wellsshall be effective for a fixed term not toexceed 10 years. UICPermits for Class II,III and VI wells shall be issued for a periodup to the operating life of the facility. * * ** * * * *Support the proposed language.The proposed provision is considered acceptable aslong as the iterative reevaluation processestablished for AoRs also applies to other aspectsof the project including modeling, characterization,operational decisions, monitoring, financialassurance, etc. It is recognized that Directors mayalso depend on 144.39 regarding modification andrevocation of Class VI permits.7. Section 144.39 is amended byrevising the second sentence in paragraph(a) introductory text and by revising thesecond sentence in paragraph (a)(3)introductory text to read as follows:§ 144.39 Modification or revocation andreissuance of permits.* * * * *Support the proposed language.Agree with EPA’s rationale.144.39(a) * * * For Class I hazardouswaste injection wells,Class II, Class III orClass VI wells the following may be causesfor revocation and reissuance as well asmodification; and for all other wells thefollowing may be cause for revocation orreissuance as well as modification when thepermittee requests or agrees. * * ** * * * *(3) * * * Permits other than forClass I hazardous waste injection wells,Class II, Class III or Class VI wells may bemodified during their terms for this causeonly as follows: * * *Support the proposed language.Agree with EPA’s rationale.December 19, 2008GWPC RecommendationsPage 4 of 404Rule ProvisionEPA ProposalGWPC RecommendationsRationale* * * * *144.518. Section 144.51 is amended byrevising the first sentence in paragraph(q)(1) and the first sentence in paragraph(q)(2) to read as follows:§ 144.51 Conditions applicable to allpermits.* * * * *(q) * * *(1) The owner or operator of a ClassI, II, III or VI well permitted under this partshall establish mechanical integrity prior tocommencing injection or on a scheduledetermined by the Director. Thereafter theowner or operator of Class I, II, and III wellsmust maintain mechanical integrity asdefined in § 146.8 and the owner or operatorof Class VI wells must maintain mechanicalintegrity as defined in § 146.89 of thischapter. * * *(q) * * *(1) The owner or operator of a Class I, II,III or VI well permitted under this part shallestablish mechanical integrity prior tocommencing injection or on a scheduledetermined by the Director. Thereafter the owneror operator of Class I, II, and III wells mustmaintain mechanical integrity as defined in§146.8 and the owner or operator of Class VIwells must maintain mechanical integrity asdefined in §146.89 of this chapter.EPA may want to reconsiderthe use of the term “or”as this implies that an initial MIT can be optionalbased on Directors discretion which contradicts146.89 with respect to Class VI wells. Alternatively,the two provisions can be read together to requirean initial MIT and to give the Director limiteddiscretion to allow the scheduling of the initial MITafter some injection has occurred, such as may berequired during initial testing of the well andinjection zone.(2) When the Director determinesthat a Class I, II, III or VI well lacksmechanical integrity pursuant to § 146.8 or §146.89 for Class VI of this chapter, he/sheshall give written notice of his/ herdetermination to the owner or operator. * *** * * * *Support the proposed language.Agree with EPA’s rationale.144.529. Section 144.52 is amended byrevising paragraph (a)(8) to read as follows:§ 144.52 Establishing permit conditions.(a) * * *(8)Mechanical integrity. A permitfor any Class I, II, III or VI well or injectionproject which lacks mechanical integrityshall include, and for any Class V well mayinclude, a condition prohibiting injectionoperations until the permittee shows to thesatisfaction of the Director under § 146.08 orSupport the proposed language.Agree with EPA’s rationale.December 19, 2008GWPC RecommendationsPage 5 of 405Rule ProvisionEPA ProposalGWPC RecommendationsRationale§ 146.89 for Class VI that the well hasmechanical integrity.* * * * *144.55§ 144.55 Corrective action.(a)Coverage.Applicants for ClassI, II, (other than existing), III or VI injectionwell permits shall identify the location of allknown wells within the injection well’s areaof review which penetrate the injection zone,or in the case of Class II wells operatingover the fracture pressure of the injectionformation, all known wells within the area ofreview penetrating formations affected bythe increase in pressure. Applicants forClass VI shall perform corrective action asspecified in § 146.84.* * ** * * * *Support the proposed language.Agree with EPA’s rationale.144.8011. Section 144.80 is amended byrevising the first sentence in paragraph (e)and by adding paragraph (f) to read asfollows:§ 144.80 What is a Class V injection well?* * * * *(e)Class V. Injection wells notincluded in Class I, II, III, IV or VI. * * *(f)Class VI. Wells used for geologicsequestration of carbon dioxide.(4) For enhanced recovery of oil ornatural gas where geologic sequestration isoccurring during or in connection withenhanced recovery of oil or natural gasprovided(i) there is reasonable expectation ofmore than insignificant future productionvolumes or rates as a result of carbon dioxideinjection and (ii) operating pressures are nohigher than reasonably necessary to producesuch volumes or rates;(f) Class VI. Wells injecting a carbon dioxidestream for geologic sequestration exceptthose wells described in subsection (b)(4) ofthis section or otherwise excluded from thisClass.There should not be a blanket prohibitionconcerning injection above USDW’s or at specificlevels. The determination of injection zones shouldbe based upon appropriate containment. This isespecially true in light of recent calls for changes inthe definition of a USDW to include formationsgreater than 10K PPM TDS and the fact thatseveral states including Wyoming and Californiamight be prevented from instituting geologicsequestration as a practical matter if injection werelimited to above USDW’s due to the great depth ofsome USDW’s. This would create a situation whereotherwise good injection zones are artificiallyexcluded, thus decreasing the overall availability ofgeologic sequestration in the U.S.The GWPC also recommends EPA considerretaining all geologic sequestration in oil and gasreservoirs under the jurisdiction of Class II UICprograms and create a subclass within this programfor geologic storage of carbon dioxide. Thissubclass (Class II GS) would be used for thosewells that depart from the traditional uses of Class IIwells for enhanced recovery, and result in theapplication of Class VI standards. This changeDecember 19, 2008GWPC RecommendationsPage 6 of 406Rule ProvisionEPA ProposalGWPC RecommendationsRationalewould eliminate any confusion over whether a ClassII CO2 injection well used for enhanced recoverymight also need a Class VI permit and would avoidthe need to change jurisdiction for a well from onestate agency to another over time.Part 14612. The authority citation for part146 continues to read as follows:Authority: Safe Drinking Water Act42, U.S.C. 300f et seq.; ResourceConservation and Recovery Act, 42 U.S.C.6901et seq.Support the proposed language.Agree with EPA’s rationale.146.513. Section 146.5 is amended asfollows:a. Revising the first sentence inparagraph (e) introductory text; andb. Adding paragraph (f).(f) Class VI. Wells used for geologicsequestration of carbon dioxide beneath thelowermost formation containing anunderground source of drinking water(USDW).(4) For enhanced recovery of oil or natural gaswhere geologic sequestration is occurringduring or in connection with enhancedrecovery of oil or natural gasprovided(i) thereis reasonable expectation of more thaninsignificant future production volumes or ratesas a result of carbon dioxide injection and (ii)operating pressures are no higher thanreasonably necessary to produce suchvolumes or rates;(f) Class VI. Wells injecting a carbon dioxidestream for geologic sequestration exceptthose wells described in subsection (b)(4) ofthis section or otherwise excluded from thisClass.There should not be a blanket prohibitionconcerning injection above USDW’s or at specificlevels. The determination of injection zones shouldbe based upon appropriate containment. This isespecially true in light of recent calls for changes inthe definition of a USDW to include formationsgreater than 10K PPM TDS and the fact thatseveral states including Wyoming and Californiamight be prevented from instituting geologicsequestration as a practical matter if injection werelimited to above USDW’s due to the great depth ofsome USDW’s. This would create a situation whereotherwise good injection zones are artificiallyexcluded, thus decreasing the overall availability ofgeologic sequestration in the U.S.The GWPC also recommends EPA considerretaining all geologic sequestration in oil and gasreservoirs under the jurisdiction of Class II UICprograms and create a subclass within this programfor geologic storage of carbon dioxide. Thissubclass (Class II GS) would be used for thosewells that depart from the traditional uses of Class IIwells for enhanced recovery, and result in theapplication of Class VI standards. This changewould eliminate any confusion over whether a ClassII CO2 injection well used for enhanced recoverymight also need a Class VI permit and would avoidthe need to change jurisdiction for a well from onestate agency to another over time.December 19, 2008GWPC RecommendationsPage 7 of 407Rule ProvisionEPA ProposalGWPC RecommendationsRationalePart 146Subpart H14. Subpart H is added to read asfollows:Subpart H—Criteria and StandardsApplicable to Class VI WellsSec.146.82 Required Class VI permitinformation.146.83 Minimum criteria for siting.146.84 Area of review and correctiveaction.146.85 Financial responsibility.146.86 Injection well constructionrequirements.146.87 Logging, sampling, and testingprior to injection well operation.Support the proposed language.Agree with EPA’s rationale.146.81Applicability.(a) This subpart establishes criteriaand standards for underground injectioncontrol programs to regulate Class VIcarbon dioxide geologic sequestrationinjection wells.Support the proposedEPA language.Agree with EPA’s rationale.(b) This subpart applies to wellsused to inject carbon dioxide specifically forthe purpose of geologicsequestration, i.e.,the long-term containment of a gaseous,liquid or supercritical carbon dioxide streamin subsurface geologic formations.(b) This subpart applies to wells used toinject carbon dioxide streams into salineformations for the purpose of geologicsequestration, i.e., the long-term containment ofa carbon dioxide stream in subsurface geologicformations.Use of the term “specifically” was removed as itimplied Class VI wells could not be used for multiplepurposes and still be Class VIRemove “gaseous, liquid or supercritical” as theseterms are implied by the use of the term carbondioxide.See the rationale discussion under 146.85regarding inclusion or exclusion of the term “saline”(c) This subpart applies to ownersand operators of permitor rule-authorizedClass I industrial, Class II, or Class Vexperimental carbon dioxide injectionprojects who seek to apply for a Class VIgeologic sequestration permit for their wellor wells. If the Director determines thatUSDWs will not be endangered, such wellsare exempt, at the Director’s discretion, fromthe casing and cementing requirements at(c) This subpart applies to owners andoperators of permit or rule-authorized Class Iindustrial, Class II, or Class V experimentalcarbon dioxide injection projects who seek toapply for a Class VI geologic sequestrationpermit for their well or wells or to convert to ClassII GS operation. If the Director determines thatUSDWs will not be endangered, such wells areexempt, at the Director’s discretion, from suchClass VI requirements contained in this subpartThe proposed EPA waiverapplies only to thecasing and cementing requirements. Directorsshould have the flexibility to waive otherrequirements as appropriate for conversions toClass VI.December 19, 2008GWPC RecommendationsPage 8 of 408Rule ProvisionEPA ProposalGWPC RecommendationsRationale§§ 146.86(b) and 146.87(a)(1) through (3).as the Director specifies.146.81(d)Definitions(d)Definitions.The followingdefinitions apply to this subpart. To theextent that these definitions conflict withthose in § 146.3 these definitions govern:Area of reviewmeans the regionsurrounding the geologic sequestrationproject that may be impacted by the injectionactivity. The area of review is based oncomputational modeling that accounts forthe physical and chemical properties of allphases of the injected carbon dioxidestream.Area of reviewmeans the subsurface threedimensional extent of the carbon dioxide streamplume associated pressure front, and displacedbrine, as well as the overlying formations andsurface area above that delineated region.Suggest removal of the second sentence andreplacement with : “It includes the subsurface threedimensional extent of the carbon dioxide plume,associated pressure front, and displaced brine, aswell as the surface area above that delineatedregion.”Comment on the inclusion of the word “surrounding”because the AoR should be co-extensive with thearea defined by the Carbon Sequestration Project.Inclusion of “surrounding” makes this definitionopen-ended and ambiguous.Carbon dioxide plumemeans theunderground extent, in three dimensions, ofan injected carbon dioxide stream.Carbon dioxide streammeans carbondioxide that has been captured from anemission source (e.g., a power plant), plusincidental associated substances derivedfrom the source materials and the captureprocess, and any substances added to thestream to enable or improve the injectionprocess. This subpart does not apply to anycarbon dioxide stream that meets thedefinition of a hazardous waste under 40CFR part 261.Carbon dioxide streammeans carbon dioxide,plus associated substances derived from thesource materials and any processing, and anysubstances added to the stream to enable orimprove the injection process. This subpart doesnot apply to any carbondioxide stream thatmeets the definition of a hazardous waste under40 CFR part 261.Insert the definition “Computational modelingmeans a mathematical model that is appropriate tothe site geometry and takes into account thedifferences between the formation and injectionfluids.”Source of CO2 should not be an issue in thecontext of defining the CO2 stream.Confining zonemeans a geologic formation,group of formations, or part of a formationstratigraphically overlying the injection zonethat acts as a barrier to fluid movement.Confining zonemeans a geological formation,group of formations, or part of a formation that iscapable of limiting fluid movement from aninjection zone.The current UIC program definition of confiningzone is preferable to theproposed definition. Thereare no special circumstances for CO2 streams thatwarrant a changeCorrective actionmeans the use of Directorapproved methods to assure that wellswithin the area of review do not serve asconduits for the movement of fluids intounderground sources of drinking waterSupport the proposedEPA language.Agree with EPA’s rationale.December 19, 2008GWPC RecommendationsPage 9 of 409Rule ProvisionEPA ProposalGWPC RecommendationsRationale(USDW).“Faultmeans a surface or zone of rock fracturealong which there has [or has not] beendisplacement.”Add definition of fault to clarify use in otherprovisions. This is the current definition with theinsertion of the words “or has not” beforedisplacement to recognize that faults can existwhere there has been no displacement.Geologic sequestrationmeans the long-termcontainment of a gaseous, liquid orsupercritical carbon dioxide stream insubsurface geologic formations. This termdoes not apply to its capture or transport.Geologic sequestrationmeans the long-termcontainment of a carbon dioxide stream insubsurface geologic formations. This term doesnot apply to its capture or transport.Suggest removing “gaseous, liquid or supercritical”as these terms are implied by the use of the termcarbon dioxide.Geologic sequestration projectmeans aninjection well or wells used to emplace acarbon dioxide stream beneath thelowermost formation containing a USDW. Itincludes the subsurface three-dimensionalextent of the carbon dioxide plume,associated pressure front, and displacedbrine, as well as the surface area above thatdelineated region.Geologic sequestration projectmeans aninjection well or wellsused to emplace a carbondioxide stream into an injection zone for geologicsequestration.Replace “beneath the lowermost formationcontaining a USDW “with “into an injection zone”Suggest moving the second sentence to thedefinition of AOR.No EPA definitionGeologic sequestration sitemeansThe GWPC believes a definition for this term isneeded as the term is referenced in later sections ofthe rule.Injection zonemeans a geologic formation,group of formations, or part of a formationthat is of sufficient areal extent, thickness,porosity, and permeability to receive carbondioxide through a well or wells associatedwith a geologic sequestration project.Injection zonemeans a geological ‘‘formation’’,group of formations, or part of a formationreceiving fluids through a well.Existing definition in the CFR is sufficient and doesnot need to be changed. Furthermore, addingsufficiency is not a definitional issue and should bedealt with elsewhere.Post-injection site caremeans appropriatemonitoring and other actions (includingcorrective action) needed followingcessation of injection to assure that USDWsare not endangered as required under §146.93.Post-injection site caremeans monitoring andother actions (including corrective action)following cessation of injection, as required under146.93.The definition should explain the meaning and notimpose substantive requirements. Theserequirements are already addressed in othersections.December 19, 2008GWPC RecommendationsPage 10 of 4010Rule ProvisionEPA ProposalGWPC RecommendationsRationalePressure frontmeans the zone of elevatedpressure that is created by the injection ofcarbon dioxide into the subsurface. For thepurposes of this subpart, the pressure frontof a carbon dioxide plume refers to a zonewhere there is a pressure differentialsufficient to cause the movement of injectedfluids or formation fluids into a USDW.Pressure frontmeans the zone of elevatedpressure that is created by the injection of thecarbon dioxide stream into the subsurface, wherethere is a pressure differential sufficient to causemovement of the carbon dioxide stream orformation fluids from the injection zone into aUSDW.Proposal removes words that are unnecessary toprovide clarity and would only serve to confuse.Insert “from the injectionzone” for clarification.Site closurethe point/time, as determined bythe Director following the requirementsunder § 146.93, at which the owner oroperator of a GS site is released from postinjection site careresponsibilities.Site closuremeans the point/time, as determinedby the Director following the requirements under§146.93, at which the owner or operator of a GSproject is released from post-injection site careresponsibilities.Add “means”Suggest using “GS project” to be consistent withother definitionsTransmissive fault or fracturemeans a faultor fracture that has sufficient permeabilityand vertical extent to allow fluids to movebetween formations.Transmissive fault or fracturemeans a fault orfracture that has sufficient permeability andvertical extent to allow fluids to move beyond theconfining zone.Recommends changing “between formations “ to“beyond the confining zone.” The term betweenformations is insufficient as it could also includemultiple zones within a injection zone.146.82Required Class VI permit informationThis section sets forth the information whichthe owner or operatormust submit to theDirector in order to be permitted as a ClassVI well. The application for a permit forconstruction and operation of a Class VI wellmust include the following:Support the proposedEPA language.Agree with EPA’s rationale.146.82(a)(a) Information required in 40 CFR144.31(e)(1) through (6);Support the proposedEPA language.Agree with EPA’s rationale.(b) A map showing the injection well(s) forwhich a permit is sought and the applicablearea of review. Within the area of review,the map must show the number, or nameand location of all injection wells, producingwells, abandoned wells, plugged wells or dryholes, deep stratigraphic boreholes, State orEPA approved subsurface cleanup sites,surface bodies of water, springs, mines(surface and subsurface), quarries, waterwells and other pertinent surface featuresincluding structures intended for humanoccupancy and roads. The map should alsoshow faults, if known or suspected. Onlyinformation of public record is required to be(b) A surface map showing the proposedlocations for the injection well(s) for which apermit is sought and the applicable area ofreview. Within the area of review, the map mustshow the number, or name and location of allknown injection wells, producing wells,abandoned wells, plugged wells or dry holes,deep stratigraphic boreholes, State or EPAapproved subsurface cleanup sites, surfacebodies of water, springs, mines (surface andsubsurface), quarries, water wells and otherpertinent surface features including structuresintended for human occupancy and roads. Onlyinformation of public record is required to beInsert “known” before “injection”Suggests removing highlighted text as faults are notshown on maps unless there is a surfaceexpression of the fault. Also, faults are detailed in(d) below and this language appears redundant.December 19, 2008GWPC RecommendationsPage 11 of 4011Rule ProvisionEPA ProposalGWPC RecommendationsRationaleincluded on this map;included on this map;(c) The area of review based onmodeling, using data obtained duringlogging and testing of the well and theformation as required by paragraphs (l), (r),and (s) of this section;(c) A map delineating the area of reviewbased upon modeling, using all available dataincluding data available from any logging andtesting of wells within the area of review.Is this supposed to be a map, a tabular display, across section or series of cross sections etc... Thisappears to be related to a condition where a well isalready drilled. This doesnot align with requestinginformation to receive a permit.(d) Information on the geologic structure andhydrogeologic properties of the proposedstorage site and overlying formations,including:(1) Maps and cross sections of the area ofreview;(2) Location, orientation, and properties ofknown or suspected faults and fractures thatmay transect the confining zone(s) in thearea of review and a determination that theywould not interfere with containment;(d) Sufficient information on the geologicstructure and reservoir properties of theproposed storage site and overlying formations,including:(1) Isopach maps of the proposed injection andconfining zone(s), a structural contour mapaligned with the top of the proposed injectionzone, and at least two geologic cross sections ofthe area of review reasonably perpendicular toeach other showing the geologic formations fromthe surface to total depth.(2) Location, orientation,and properties of knownor suspected subsurface faults that may transectthe confining zone(s) in the area of review and adetermination that they would not interfere withcontainment;Fractures can be incredibly small and it is virtuallyimpossible to find all subsurface fractures. TheGWPC also recommends addition of the term“Sufficient” before the information sought in (d) asthis is more precise.(3) Information on seismic historyincluding the presence and depth of seismicsources and a determination that theseismicity would not interfere withcontainment;(4) Data on the depth, areal extent,thickness, mineralogy, porosity, permeabilityand capillary pressure of the injection andconfining zone(s); including geology/facieschanges based on field data which mayinclude geologic cores, outcrop data,seismic surveys, well logs, and names andlithologic descriptions;(5) Geomechanical information onfractures, stress, ductility, rock strength, andin situ fluid pressures within the confiningzone; and(3) Information on seismic history thathave affected the proposed area of reviewincluding knowledge of previous seismic eventsand history of these events, including thepresence and depth of seismic sources and adetermination that the seismicity would notcompromise containment;(4) Data sufficient to demonstrate theeffectiveness of the injection and confiningzone(s), including data on the depth, arealextent, thickness, mineralogy, porosity, verticalpermeability reservoir pressure and of theinjection and confining zone(s) within the area ofreview; including geologic changes based onfield data which may include geologic cores,outcrop data, seismic surveys, well logs, capillarypressure tests and names and lithologicdescriptions;(5) Geomechanical information on theCapillary pressure is too hard to measure outsidethe lab; how comparable are lab results to whatgoes into the ground. Sidewall core may not besufficient to do this, and it is difficult to core thewhole of the confining and injection zones.Rewording keeps the usefulness of capillarypressure in the provision without making it amandatory use.December 19, 2008GWPC RecommendationsPage 12 of 4012Rule ProvisionEPA ProposalGWPC RecommendationsRationaleconfining zone(s) within the area of review; and(6) Geologic and topographic mapsand cross sections illustrating regionalgeology, hydrogeology, and the geologicstructure of the local area.Support the EPA language.146.82(e)(e) A tabulation of all wells within thearea of review which penetrate the injectionor confining zone(s). Such data mustinclude a descriptionof each well’s type,construction, date drilled, location, depth,record of plugging and/ or completion, andany additional information the Director mayrequire;(e) A compilation of all artificialpenetrations within the area of review whichpenetrate the injection or confining zone(s).Such data must include a description of eachwell’s type, construction, date drilled, location,depth, record of plugging and/ or completion, andany additional information the Director mayrequire;The GWPC felt that the term compilation was moreappropriate than tabulationbecause tabulation astabulation implies a spreadsheet while compilationcan take numerous forms.(f) Maps and stratigraphic crosssections indicating the general vertical andlateral limits of all USDWs, water wells andsprings within the area of review, theirpositions relative to the injection zone(s) andthe direction of water movement, whereknown;(f) Maps and stratigraphic cross sectionsindicating the general vertical and lateral limits ofall USDWs, the location of water wells andperennial springs within the area of review, theirpositions relative to the injection zone(s) and thedirection of water movement, where known;Clarification: Use of the term perennial beforesprings will prevent a requirement to list very minor,intermittent springs which are not hydrologicallysignificant.(g) Baseline geochemical data onsubsurface formations, including all USDWsin the area of review;(g) Compilation of available baselinegeochemical data on the proposed injection zoneand nearest adjacent porous and permeableformation to the confining zone, existing utilizedwater supply aquifers and any other USDWsdesignated by the Director.It will be unduly burdensome to address “allUSDWs” in some contexts.This revision allows formore appropriate focusing on those USDWsdesignated by the Director.(h) Proposed operating data:(1) Average and maximum daily rateand volume of the carbon dioxide stream;(2) Average and maximum injectionpressure;(3) The source of the carbon dioxidestream; and(4) An analysis of the chemical andphysical characteristics of the carbondioxide stream;(h) Proposed operating data:(1) Average and maximum daily injectionrate and volume of the carbon dioxide stream;(2) Average and maximum surfaceinjection pressure;(3) The source of the carbon dioxidestream; and(4) An analysis of the chemical andphysical characteristics of the carbon dioxidestream;Clarification: Addition of the term surface in (h)(d)will make it clear as to where the injection pressureis to measured.December 19, 2008GWPC RecommendationsPage 13 of 4013Rule ProvisionEPA ProposalGWPC RecommendationsRationale146.82(i)(i) The compatibility of the carbondioxide stream with fluids in the injectionzone and minerals in both the injection andthe confining zone(s), based on the resultsof the formation testing program, and withthe materials used to construct the well;(j) Proposed formation testingprogram to obtain an analysis of thechemical and physical characteristics of theinjection zone and confining zone;Support the proposedEPA language.Agree with EPA’s rationale.(k) Proposed stimulation programand a determination that stimulation will notinterfere with containment;(l) The results of the formationtesting program as required in paragraph (j)of this section;(m) Proposed procedure to outlinesteps necessary to conduct injectionoperation;(n) Schematic or other appropriatedrawings of the surface and subsurfaceconstruction details of the well;(o) Injection well constructionprocedures that meet the requirements of §146.86;(k) Proposed stimulation program and adetermination that stimulation will notcompromise containment;(l) The results of the formation testingprogram as required in paragraph (j) of thissection;(m) Proposed procedure to outline stepsnecessary to conduct injection operation;(n) A wellbore schematic of thesubsurface construction details and surfacewellhead construction.(o) Injection well construction proceduresthat meet the requirements of § 146.86;“Interfere” is too ambiguous and should be replacedby “compromise” which limits concerns to situationswhere containment may be lost.(p) Proposed area of review andcorrective action plan that meets therequirements under § 146.84;(q) The status of corrective actionon wells in the area of review;(r) All available logging and testingprogram data on the well required by §146.87;(s) A demonstration of mechanicalintegrity pursuant to§ 146.89;(t) A demonstration, satisfactory tothe Director, that the applicant has met thefinancial responsibility requirements under §(p) Proposed corrective action plan forartificial penetrations within the area of review, ifnecessary(q) All available logging and testingprogram data on the well required by § 146.87;(r) The proposed demonstration methodfor mechanical integrity pursuant to(s) A demonstration, satisfactory to theDirector, that the applicant has met the financialresponsibility requirements under § 146.85;(q) Should be deleted because it is not part of anapplication process but, rather a post permittingactivity. This would result in a re-numbering of thesubsections after the new (q).December 19, 2008GWPC RecommendationsPage 14 of 4014Rule ProvisionEPA ProposalGWPC RecommendationsRationale146.85;146.82(u)(u) Proposed testing and monitoringplan required by§ 146.90;(v) Proposed injection well pluggingplan required by§ 146.92(b);(w) Proposed post-injection site careand site closure plan required by §146.93(a);(x) Proposed emergency andremedial response plan required by §146.94; and(y) Any other information requestedby the Director.(t) Proposed testing and monitoring planrequired by§ 146.90;(u) Proposed injection and monitoringwell(s) plugging plan required by§ 146.92(b);(v) Proposed post-injection site care andsite closure plan required by § 146.93(a);(w) Proposed emergency and remedialresponse plan required by § 146.94; and(x) Any other information requested bythe Director.Need to address the plugging of monitoring well(s),if any, included in the project.146.83Minimum criteria for siting(a) Owners or operators of Class VIwells must demonstrate to the satisfaction ofthe Director that thewells will be sited inareas with a suitable geologic system. Thegeologic system must be comprised of:(1) An injection zone of sufficientareal extent, thickness, porosity, andpermeability to receive the total anticipatedvolume of the carbon dioxide stream;Support the proposedEPA language.Agree with EPA’s rationale.(2) A confining zone(s) that is free oftransmissive faults or fractures and ofsufficient areal extent and integrity to containthe injected carbon dioxide stream anddisplaced formation fluids and allow injectionat proposed maximum pressures andvolumes without initiating or propagatingfractures in the confining zone(s); and(2) A confining zone(s) that is laterallycontinuous and free of known transecting,transmissive faults or fractures over an areasufficient to prevent the movement of fluids into aUSDW;Suggest using the Class I regulation for thisparagraph (2) in 146.62(c) with the addition ofreactivation of existing faults or fractures and beforethe terms faults or fractures the word known shouldbe added.(b) At the Director’s discretion,owners or operators of Class VI wells mustDelete paragraphThis paragraph creates a presumption thatadditional zones WILL be required. It is alsoDecember 19, 2008GWPC RecommendationsPage 15 of 4015Rule ProvisionEPA ProposalGWPC RecommendationsRationaleidentify and characterize additional zonesthat will impede vertical fluid movement, arefree of faults and fractures that may interferewith containment, allow for pressuredissipation, and provide additionalopportunities for monitoring, mitigation andremediation.redundant from previous sections.146.84146.84. Area of review and corrective action(a) The area of review is the regionsurrounding the geologic sequestrationproject that may be impacted by the injectionactivity. The area of review is based oncomputational modeling that accounts forthe physical and chemical properties of allphases of the injected carbon dioxidestream.(a) The area of review is based oncomputational modeling that accounts for thephysical and chemical properties of all phases ofthe injected carbon dioxide stream.This is the same as the definition of “Area of review”that was revised by the GWPC .to delete the firstsentence.Comments on many provisions are predicated onproposed changes in definitions(b) The owner or operator of a ClassVI well must prepare, maintain, and complywith a plan to delineate the area of reviewfor a proposed geologic sequestrationproject, periodically reevaluate thedelineation, and perform corrective actionthat meets the requirements of this sectionand is acceptable to the Director. As a partof the permit application for approval by theDirector, the owner oroperator must submitan area of review and corrective action planthat includes the following information:(1) The method for delineating thearea of review that meets the requirementsof paragraph (c) of this section, including themodel to be used, assumptions that will bemade, and the site characterization data onwhich the model will be based;(b) The owner or operator of a Class VIwell must prepare, maintain, and comply with aplan to delineate the area of review for aproposed geologic sequestration project,reevaluate the delineation, and performcorrective action that meets the requirements ofthis section in a manner and at a frequencyacceptable to the Director. As a part of the permitapplication, the owner or operator must submitan area of review and corrective action plan thatincludes the following information:Suggest deletion of “periodically.” See Workgrouprecommendation 7.6 fromRecommendations for the RegulatoryManagement of Geologic Sequestration of CO2Under the UIC ProgramReplace with “in a manner and at a frequency”Delete “for approval by the Director,”. Director’sapproval is implicit in a permit application.146.84(b)(2)(2) A description of:(i) The minimum fixed frequency,not to exceed 10 years, the owner oroperator proposes to reevaluate the area ofreview;(ii) The monitoring and operationalconditions that would warrant a reevaluationDelete (i) and (ii)Suggest deletion of(i) as this is handled by “mannerand at a frequency acceptable to the Director in (b)Suggest deletion of (ii) for same reason ascomment on (i)December 19, 2008GWPC RecommendationsPage 16 of 4016Rule ProvisionEPA ProposalGWPC RecommendationsRationaleof the area of review prior to the nextscheduled reevaluation as determined bythe minimum fixed frequency established inparagraph (b)(2)(i) of this section.(iii) How monitoring and operationaldata (e.g., injection rateand pressure) willbe used to inform an area of reviewreevaluation; and(iv) How corrective action will beconducted to meet the requirements ofparagraph (d) of this section, including whatcorrective action will be performed prior toinjection and what, if any, portions of thearea of review will have corrective actionaddressed on a phased basis and how thephasing will be determined; how correctiveaction will be adjustedif there are changesin the area of review; and how site accesswill be guaranteed for future correctiveaction.(iv) How corrective action will beconducted to meet the requirements ofparagraph (d) of this section, including whatcorrective action willbe performed prior toinjection and what, if any, portions of the area ofreview will have corrective action addressed on aphased basis and how the phasing will bedetermined; how corrective action will beadjusted if there are changes in the area ofreview; and how site access will be assured forfuture corrective action.Replace “guaranteed” with ”assured” Future accesscannot be absolutely guaranteed for an area inadvance that may not even be within theboundaries of the AOR/ project. However,assurance of access is a standard that is lessonerous than guaranteed, it is firmer than anotherstandard such as “arranged”146.84(c)(c) Owners or operators of Class VIwells must perform the following actions todelineate the area of review, identify all wellsthat require corrective action, and performcorrective action on those wells:(1) Predict, using computationalmodeling, the projected lateral and verticalmigration of the carbon dioxide plume andformation fluids in the subsurface from thecommencement of injection activities untilthe plume movement ceases, pressuredifferentials sufficient to cause themovement of injected fluids or formationfluids into a USDW are no longer present, orafter a fixed time period as determined bythe Director. The model must:(c) Owners or operators of Class VI wellsmust perform the following actions to delineatethe area of review, identify all wells that requirecorrective action, and perform corrective actionon those wells:(1) Predict, using computationalmodeling, the projected lateral and verticalmigration of the carbon dioxide plume andformation fluids in the subsurface from thecommencement of injection activities until theplume movement ceases, pressure differentialssufficient to cause the movement of injectedfluids or formation fluids into a USDW are nolonger present, or for a fixed time period asdetermined by the Director. The model must:Should say “for” not “after.”146.84(c)(i)(i) Be based on detailed geologicdata collected to characterize the injectionzone, confining zone and any additionalzones; and anticipated operating data,including injection pressures, rates and totalvolumes over the proposed life of the(i) Be based on detailed geologic datacollected to characterize the injection zone,confining zone; and anticipated operating data,including injection pressures, rates and totalvolumes over the duration of injection;(ii) Take into account relevant geologicSuggest deletion of “any additional zones”. You donot need to include any additional zones if you usethe current CFR definition ofconfining zone since itincludes multiple zones.Should be geologic not geological for consistencywith other provisions because geologicDecember 19, 2008GWPC RecommendationsPage 17 of 4017Rule ProvisionEPA ProposalGWPC RecommendationsRationalegeological sequestration project;(ii) Take into account any geologicheterogeneities, data quality, and theirpossible impact on model predictions; and(iii) Considerpotential migrationthrough faults, fractures, and artificialpenetrations.heterogeneities, and data quality, and theirpossible impact on model predictions; and(iii) Consider potential migration throughfaults, fractures, and artificial penetrations.sequestration project is defined.Suggest “duration of injection” instead of “life of thegeological sequestration project”Suggest “relevant” instead of any in (ii)Insert “and” between “heterogeneities” and “data”(2) Using methods approved by theDirector, identify all penetrations, includingactive and abandoned wells andunderground mines, in the area of reviewthat may penetrate the confining zone.Provide a description of each well’s type,construction, date drilled, location, depth,record of plugging and/or completion, andany additional information the Director mayrequire; and(2) Using methods approved by theDirector, identify all known artificial penetrationsinto the confining zone, including active andabandoned wells and underground mines, in thearea of review that may penetrate the confiningzone. Provide a description of each well’s type,construction, date drilled, location, depth, recordof plugging and/or completion, and any additionalinformation the Director may require; andInsert “known artificial penetrations into theconfining zone”(3) Determine which abandonedwells in the area of review have beenplugged (as required by § 146.92) in amanner that prevents the movement ofcarbon dioxide or associated fluids that mayendanger USDWs(3) Determine which abandoned wellsidentified in 146.84 (c) (2) have been plugged (asrequired by §146.92) in a manner that preventsthe movement of carbon dioxide or displacedformation fluids that may endanger USDWs.Add identified in 146.84 (c) (2)Remove “area of review” as redundant.Suggest change “associated fluids” to “displacedformation fluids.” Associated fluids is not defined soif EPA means displaced formation fluids theregulation should just use this term. Otherwise, youneed to define associated fluids.146.84(d)(d) Owners or operators of Class VIwells must perform corrective action on allwells in the area of review that aredetermined to need corrective action usingmethods necessary to prevent themovement of fluid into or between USDWsincluding use of corrosion resistantmaterials, where appropriate.(d) Owners or operators of Class VI wellsmust perform corrective action using materialssuitable for use with carbon dioxide streams, onall wells identified in146.84(c)(2) that aredetermined to need corrective action”.Re-write as follows” Owners or operators of ClassVI wells must performcorrective action usingcorrosion resistant materials, when appropriate, onall wells identified in 146.84(c)(2) that aredetermined to need corrective action”.(e) If monitoring data indicate anendangerment to USDWs, the owner oroperator must notify the Director and ceaseoperations as required by § 146.94.DeleteWhy is this needed if 146.94 already specifies thenotification and cessation of injection?December 19, 2008GWPC RecommendationsPage 18 of 4018Rule ProvisionEPA ProposalGWPC RecommendationsRationale(f) At the minimum fixed frequency,not to exceed 10 years, as specified in thearea of review and corrective action plan, orwhen monitoring and operational conditionswarrant, owners or operators must:(1) Reevaluate the area of review inthe same manner specified in paragraph(c)(1) of this section;(2) Identify all wells in thereevaluated area of review that requirecorrective action in the same mannerspecified in paragraph (c)(2) of this section;(f) As specified in the approved area ofreview and corrective action plan, or whenmonitoring and operational conditions warrant,owners or operators must(1) Reevaluate the area of review in thesame manner specified in paragraph (c)(1) of thissection;(2) Identify all wells in the reevaluatedarea of review that require corrective action in thesame manner specified in paragraph (c)(2) of thissection;Delete “At the minimum fixed frequency, not toexceed 10 years”.Insert “approved” before “area of review” in (f).(3) Perform corrective action onwells requiring corrective action in thereevaluated area of review in the samemanner specified in paragraph (c)(3) of thissection; and(4) Submit an amended area ofreview and corrective action plan ordemonstrate to the Director throughmonitoring data and modeling results that noamendment to the area of review andcorrective action plan is needed.(3) Perform corrective action on wellsrequiring corrective action in the reevaluatedarea of review in the same manner specified inparagraph (c)(3) of this section; and(4) Submit an amended area of reviewand corrective action plan or demonstrate to theDirector through monitoring data and modelingresults that no change to the area of review andcorrective action plan is needed.Suggest “change” instead of “amendment” in (4)because the term amendment is typically construedto mean an official permit modification process.146.84(g)(g) The emergency and remedialresponse plan (as required by § 146.94) anda demonstration of financial responsibility(as described by § 146.85) must account forthe entire area of review, regardless ofwhether or not corrective action in the areaof review is phased.(g) The emergency and remedialresponse plan (as required by § 146.94) and ademonstration of financial responsibility (asdescribed by § 146.85) must account for theentire area of review [as modified], regardless ofwhether or not corrective action in the area ofreview is phased.Need to add phrase to account for the periodicreevaluations and possible revisions that will beoccurring. Addition of the term [as modified]addresses this concern.146.85146.85 Financial responsibility(a) The owner or operator mustdemonstrate and maintain financialresponsibility and resources for correctiveaction (that meets the requirements of §146.84), injection well plugging (that meetsthe requirements of § 146.92), post-injectionsite care and site closure (that meets therequirements of § 146.93), and emergencyand remedial response (that meets therequirements ofNo specific language recommended. SeerationaleMaintenance of plugging liability until site closurerelease by the Director is probably not needed oncethe well has been plugged. Should the owner/operator be allowed to make a demonstration to theDirector for the partial release of other financialresponsibility elements?December 19, 2008GWPC RecommendationsPage 19 of 4019Rule ProvisionEPA ProposalGWPC RecommendationsRationale§ 146.94) in a manner prescribed by theDirector until:(1) The Director receives andapproves the completed post-injection sitecare and site closure plan; and(2) The Director determines that thesite has reached the end of the postinjection site care period.(b) The owner or operator mustprovide to the Director, at a frequencydetermined by the Director, written updatesof adjustments to the cost estimate toaccount for any amendments to the area ofreview and corrective action plan (§ 146.84),the injection well plugging plan (§ 146.92),and the post-injection site care and siteclosure plan (§ 146.93).(b) The owner or operator must provideto the Director, at a frequency determined by theDirector, but no more frequently than annually,written updates or adjustments to the costestimate to account for any changes to: the areaof review and corrective action plan (§146.84),the injection well plugging plan (§146.92), andthe post-injection site care and site closure plan(§146.93).Does this contemplate both upward and downwardadjustments?Suggest “change” instead of amendments.Clarification on what is meant by “updates oradjustments” would be beneficial e.g. what isincluded, at what frequency etc...146.85(c)(c) The owner or operator mustnotify the Director of adverse financialconditions such as bankruptcy that mayaffect the ability to carry out injection wellplugging and post-injection site care and siteclosure.(c) The owner or operator must notify theDirector of adverse financial conditions that mayaffect the ability to carry out injection wellplugging and post-injection site care and siteclosure.Delete “such as bankruptcy” from (c). Suchexamples of potential circumstances areunnecessary.(d) The operator must provide anadjustment of the cost estimate to theDirector if the Director has reason to believethat the original demonstration is no longeradequate to cover the cost of injection wellplugging (as required by § 146.92) and postinjection site care and site closure (asrequired by § 146.93).(d) The operator must provide anadjustment of the cost estimate to the Director ifthe Director has reason to believe that the mostrecent demonstration is no longer adequate tocover the cost of injection well plugging (asrequired by § 146.92) and post-injection site careand site closure (as required by § 146.93).The reference should be to the last demonstrationnot the original demonstrationThis is a one time extraordinary event. Regularupdates are covered by 146.85(b).Recognize that these will be updated periodically.146.866. Injection well construction requirements(a) General. The owner or operatormust ensure that all Class VI wells areconstructed and completed to:(1) Prevent the movement of fluidsinto or between USDWs or into anyunauthorized zones;(2) Permit the use of appropriate(a) General. The owner or operator mustensure that all Class VIwells are constructed andcompleted to:(1) Prevent the movement of fluidcontaining any contaminant into USDWs per 40CFR Part 144.12(a).(2) Permit the use of appropriate testingdevices and workover tools; and(3) Permit continuous monitoring of theMirror language concerning endangerment standardin (1).The GWPC suggests re-wording (a)(1) to simplifyand make it consistent with the CFR definitions offluid movement.December 19, 2008GWPC RecommendationsPage 20 of 4020Rule ProvisionEPA ProposalGWPC RecommendationsRationaletesting devices and workover tools; and(3) Permit continuous monitoring ofthe annulus space between the injectiontubing and long string casing.annulus space between the injection tubing andlong string casing.(b) Casing and Cementing of ClassVI Wells.(1) Casing and cement or othermaterials used in the construction of eachClass VI well must have sufficient structuralstrength and be designed for the life of thegeologic sequestration project. All wellmaterials must be compatible with fluids withwhich the materials may be expected tocome into contact and meet or exceedstandards developed for such materials bythe American Petroleum Institute, ASTMInternational, or comparable standardsacceptable to the Director. The casing andcementing program must be designed toprevent the movement of fluids into orbetween USDWs. In order to allow theDirector to determine and specify casing andcementing requirements, the owner oroperator must provide the followinginformation:(1) Casing and cement or other materialsused in the construction of each Class VI wellmust have sufficient structural strength and bedesigned for the life of the operating life of thewell. All well materialsmust be compatible withfluids with which the materials may be expectedto come into contact and meet or exceed teststandards or practices developed for suchmaterials by the American Petroleum Institute,ASTM International, or comparable standardsacceptable to the Director. The casing andcementing program must be designed to preventthe movement of fluids into or between USDWs.In order to allow the Director to determine andspecify casing and cementing requirements, theowner or operator must provide the followinginformation:Suggest substituting “operating life of the well” for“the life of the geologic sequestration project” in (1)The GWPC determined that geologic sequestrationproject was a nebulous term that could not becalculated and thus would have no meaning indesigning a casing or cementing program.IMirror the non endangerment standard.146.86(b)(1)(i) Depth to the injection zone;(ii) Injection pressure, externalpressure, internal pressure and axialloading;(iii) Hole size;(iv) Size and grade of all casingstrings (wall thickness,external diameter,nominal weight, length, joint specificationand construction material);(v) Corrosiveness of the carbondioxide stream, and formation fluids;(vi) Down-hole temperatures;(vii) Lithology of injection and(i) Depth to the injection zone;(iii) Hole size;(iv) Size and grade of all casing strings(wall thickness, external diameter, nominalweight, length, joint specification andconstruction material);(v) Predicted corrosiveness of thcombined carbon dioxide stream and formationfluids;e(vi) Down-hole temperatures andpressures;(vii) Lithology of injection and confiningzones;What is meant by external and internal pressure?Recommend deleting (ii).Insert “and pressures” in (vi)Cannot measure the corrosiveness of the CO2stream because it is not corrosive. Only liquids willyield pH measurements.December 19, 2008GWPC RecommendationsPage 21 of 4021Rule ProvisionEPA ProposalGWPC RecommendationsRationaleconfining zones;(viii) Type or grade of cement; and(ix) Quantity, chemical composition,and temperature of the carbon dioxidestream.(viii) Type or grade of cement andadditives; and(ix) Quantity, chemical composition, andtemperature of the carbon dioxide stream.Insert “and additives” in (viii)(2) Surface casing must extendthrough the base of the lowermost USDWand be cemented to the surface.(2) Surface casing must extend throughthe base of the lowermost USDW above theinjection zone and be cemented to the surface.Insert “above the injection zone” in (2) after“USDW.” In some parts of the US the USDW is verydeep and this standard may preclude geologicsequestration in these areas. EPA should considerallowing the Director toexercise discretion toapprove alternative meansof achieving continuouscement around the well in such areas.(3) At least one long string casing,using a sufficient number of centralizers,must extend to the injection zone and mustbe cemented by circulating cement to thesurface in one or more stages.(3) At least one long string casing, usinga sufficient number of centralizers, which at aminimum, would create a cement bond throughthe confining zone, and which must extend to theinjection zone and must be isolated by placingcement and/or other isolation technologies asnecessary to provide adequate isolation of theinjection zone and provide for protection ofUSDWs.Cementing to surface is not necessary to protectUSDWS, and may have negative consequences, asfollows. Cement to surface would eliminate theability to monitor pressures in this annulus andwould limit flexibility of remedial options. As revised,the proposal would allow for application anddevelopment of alternative technologies. See APIRP90 for description of risk-based approach formanaging situations involving annular casingpressure. Industry experience with CO2 EORunder the class II program demonstrates theeffectiveness of existing cementing procedures.146.86(b)(4) Circulation of cement may beaccomplished by staging. The Director mayapprove an alternative method of cementingin cases where the cement cannot berecirculated to the surface, provided theowner or operator can demonstrate by usinglogs that the cement does not allow fluidmovement behind the well bore.DeleteSame as above(5) Cement and cement additivesmust be compatible with the carbon dioxidestream and formation fluids and of sufficientquality and quantity to maintain integrity overthe design life of the geologic sequestrationproject. The integrity and location of thecement shall be verified using technologycapable of evaluating cement quality radiallyand identifying the location of channels to(5) Cement and cement additives mustbe suitable for use with the carbon dioxidestream and formation fluids and of sufficientquality and quantity to maintain integrity over theoperating life the well. The integrity and locationof the cement shall be verified using technologycapable of evaluating cement quality radially andidentifying the location of channels to ensure thatUSDWs are not endangered.Experience with CO2 EOR under the class IIprogram demonstrates the effectiveness of existingcementing materials and procedures. Standard APIcements have been used in numerous CO2 EORoperations without adverse consequences.Reference API CO2 EOR report and Carey et al.Bill Carey (SACROC) and Walter Crow (CCP2 -placement and annular gap more important thantype).December 19, 2008GWPC RecommendationsPage 22 of 4022Rule ProvisionEPA ProposalGWPC RecommendationsRationaleensure that USDWs are not endangered.Once thewell is plugged, the plug will isolate theother portions of the well from the injected fluids.146.86(c)(c) Tubing and packer.(1) All owner and operators of ClassVI wells must inject fluids through tubingwith a packer set at a depth opposite acemented interval at the location approvedby the Director.(2) In order for the Director todetermine and specify requirements fortubing and packer, the owner or operatormust submit the following information:(i) Depth of setting;(ii) Characteristics of the carbondioxide stream (chemical content,corrosiveness, temperature, and density);(c) Tubing and packer.(1) All owner and operators of Class VIwells must inject fluids through tubing with apacker set at a depth opposite a cementedinterval at the location approved by the Director.(2) In order for the Director to determineand specify requirements for tubing and packer,the owner or operator must submit the followinginformation:(i) Depth of setting;(ii) Composition of the carbon dioxidestream;What does corrosiveness mean? How is itmeasured?Cannot measure the corrosiveness of a carbondioxide stream.Composition of the cO2 stream is needed to designa tubing and packer system. The other listedcharacteristics are not needed.146.86(c)(2)(iii) Injection pressure;(iv) Annular pressure;(v) Injection rate (intermittent orcontinuous) and volume of the carbondioxide stream;(vi) Size of casing; and(vii) Tubing tensile, burst, andcollapse strengths.(iii) Maximumproposed Injectiontemperature and pressure;(iv) Maximum proposed Annularpressure;(v) Maximum proposed Injection rate(intermittent or continuous) and volume of thecarbon dioxide stream;It is more helpful to know the recommendedinformation.The GWPC also recommends addition of the term“proposed in (iii), (iv) and(v) as this section relatesto an application and not to actual establishedpermit conditions146.877. Logging, sampling, and testing prior toinjection well operation(a) During the drilling andconstruction of a Class VI injection well, theowner or operator must run appropriate logs,surveys and tests to determine or verify thedepth, thickness, porosity, permeability, andlithology of, and the salinity of any formationfluids in, all relevant geologic formations toassure conformance with the injection wellconstruction requirements under § 146.86,(a) During the drilling and construction ofa Class VI injection well, the owner or operatormust run appropriate logs, surveys and tests todetermine or verify the depth, thickness, porosity,permeability, and lithology of, and the salinity ofany formation fluids in, all relevant geologicformations to assure conformance with theinjection well construction requirements under§146.86, and to establish accurate baseline dataagainst which future measurements may becompared. The owner or operator must submit tothe Director a descriptive report prepared by aIn well defined areas, these evaluations arefrequently unnecessary. The director should havediscretion to select the appropriate requirementsnecessary to ensure sufficient baseline data andinformation are available. For example, in an areawhere a number of wells are being drilled, thelogging of surface hole yields little useful additionalinformation.In particular, this change would allow the Director toreduce the requirements when multiple wells areinstalled for a project.December 19, 2008GWPC RecommendationsPage 23 of 4023Rule ProvisionEPA ProposalGWPC RecommendationsRationaleand to establish accurate baseline dataagainst which future measurements may becompared. The owner or operator mustsubmit to the Director a descriptive reportprepared by a knowledgeable log analystthat includes an interpretation of the resultsof such logs and tests. At a minimum, suchlogs and tests must include:knowledgeable log analyst that includes aninterpretation of the results of such logs andtests. The Director may require such logs andtests as may be needed after taking into accountthe availability of similar data in the area of thedrilling site, the construction plan, and the needfor additional information that may arise fromtime to time as the construction of the wellprogresses and these may include the following:(1) Deviation checks during drillingon all holes constructed by drilling a pilothole which are enlarged by reaming oranother method. Such checks must be atsufficiently frequent intervals to determinethe location of the borehole and to assurethat vertical avenues for fluid movement inthe form of diverging holes are not createdduring drilling; andSupport the proposedEPA language.Agree with EPA’s rationale.146.87(a)(2) Before and upon installation ofthe surface casing:Support the proposedEPA language.Agree with EPA’s rationale.(i)Resistivity,spontaneouspotential, and caliper logs before the casingis installed; and(i) Resistivity, spontaneous potential, and caliperlogs before the casing is installed; andAfter a few wells are drilled in an area, theseevaluations are frequently unnecessary and yieldlittle new information. This is an example of why it isappropriate to make this a discretionary rather thanmandatory requirement. The proposed revision to146.87(a) would give the Director the necessarydiscretion.(ii) A cement bond and variabledensity log, and a temperature log after thecasing is set and cemented.(ii) A cement bond and variable density log, anda temperature log after the casing is set andcemented.Unusual to run these logs in a surface hole due touniformity of shallow geology. This is an example ofwhy it is appropriate to make this a discretionaryrather than mandatory requirement. The proposedrevision to 146.87(a) would give the Director thenecessary discretion.(3) Before and upon installation ofthe long string casing:Support the proposed EPA language.Agree with EPA’s rationale.(i)Resistivity,spontaneouspotential, porosity, caliper, gamma ray,fracture finder logs, and any other logs theDirector requires for the given geologybefore the casing is installed; andSupport the proposed EPA language.December 19, 2008GWPC RecommendationsPage 24 of 4024Rule ProvisionEPA ProposalGWPC RecommendationsRationale(ii) A cement bond and variabledensity log, and a temperature log after thecasing is set and cemented.(ii) Cement evaluation logs after thecasing is set and cemented to evaluate cementquality with sufficient radialresolution to identifychannels or missing cement.Acceptable to specify basic logging requirements,however, special logs should not be specified. Anyother information from the area should be drawn on.Provides more flexibility to select the appropriatelog to demonstrate adequate cement bond.146.87(a)(4)(4) A series of tests designed todemonstrate the internal and externalmechanical integrity of injection wells, whichmay include:(i) A pressure test with liquid or gas;(ii) A tracer survey such as oxygenactivation logging;(iii) A temperature or noise log;(iv) A casing inspection log, ifrequired by the Director; and(5) Any alternative methods thatprovide equivalent or better information andthat are required of and/or approved of bythe Director.(4) Test(s) designed to demonstrate theinternal and external mechanical integrity ofinjection wells, which may include:(i) A pressure test with liquid or gas;(ii) Diagnostic tools such as oxygenactivation logging;(iii) A temperature or noise log; and(iv) A casing inspection log.(5)Accept the EPA language andnumbering.Technical and grammatical correctionsIn (iv), “if required by the Director” is unnecessary.We interpret that (5) applies to 146.87(a)146.87(b)(b) The owner or operator must takeand submit to the Director whole cores orsidewall cores of the injection zone andconfining system and formation fluidsamples from the injection zone(s). TheDirector may accept cores from nearby wellsif the owner or operator can demonstratethat core retrieval is not possible and thatsuch cores are representative of conditionsat the well. The Director may require theowner or operator to core other formations inthe borehole.(b) The owner or operator must submit tothe Director a report describing whole cores orsidewall cores representative of the injectionzone and confining system and formation fluidsamples from the injection zone(s). The Directormay accept data from cores and fluid samplesfrom nearby wells if the owner or operator candemonstrate that such data are representative ofconditions in the wellbore.The information required should be sufficient toproperly describe the injection and confining zones.(c) The owner or operator mustrecord the fluid temperature, pH,conductivity, reservoir pressure and thestatic fluid level of the injection zone(s).(c) Prior to injection well operation, theowner or operator must record the formationtemperature, formation fluid pH and conductivity,and reservoir pressure of the injection zone(s).Technical corrections. Reservoir pressure andstatic fluid level are redundant parameters.December 19, 2008GWPC RecommendationsPage 25 of 4025Rule ProvisionEPA ProposalGWPC RecommendationsRationale(d) At a minimum, the owner oroperator must determine or calculate thefollowing information concerning theinjection and confining zone(s):(1) Fracture pressure;(2) Other physical and chemicalcharacteristics of the injection and confiningzones; and(3) Physical and chemicalcharacteristics of the formation fluids in theinjection zone.Delete allWith the exception of calculating fracture pressure,the requirements of this section appear redundantto other requirements of prior sections.Recommend moving injection pressure to old (e),now renumbered as (d).(2) and (3) are also too vague.(e) Upon completion, but prior tooperation, the owner or operator mustconduct the following tests to verifyhydrogeologic characteristics of the injectionzone:(1) A pump test; or(2) Injectivity tests.(d) At any time prior to injection welloperation, the owner or operator must determinefracture pressures of the injection and confiningzones and conduct tests to verify hydrogeologicand geomechanical characteristics of theinjection zone, e.g.,injectivity tests.Allows the use of information such as leak off testsconducted during the drilling operation.Delete (1)It was felt that Geomechanical properties were atleast as important as hydrogeologic characteristics.The results of a pump test (pumping fluid from thewell) has no relevance for an injection well.If current (d) is deleted as recommended, this wouldbecome (d)146.87(f)(f) The owner or operator mustprovide the Director with the opportunity towitness all logging and testing by thissubpart. The owner or operator must submita schedule of such activities to the Director30 days prior to conducting the first test andsubmit any changes to the schedule 30 daysprior to the next scheduled test.(e) The owner or operator must providethe Director with the opportunity to witness alllogging and testing by this subpart. The owner oroperator must submit a schedule of suchactivities to the Director upon spudding the welland submit any changes to the schedule 48hours prior to the scheduled test.The changes reflect the realities of flexible rigschedules and are fully consistent with currentClass II requirements and practices.If current (d) is deleted as recommended, this wouldbecome (e)146.888. Injection well operating requirements(a) Except during stimulation, theowner or operator must ensure that injectionpressure does not exceed 90 percent of thefracture pressure of the injection zone so asto assure that the injection does not initiatenew fractures or propagate existing fracturesin the injection zone. In no case mayinjection pressure initiate fractures in theconfining zone(s) or cause the movement ofinjection or formation fluids that endangers a(a) The owner or operator must comply with amaximum injection pressure limit approved bythe Director and specified in the permit. Inapproving a maximum injection pressure limit,the Director shall consider the results of welltests and, where appropriate, geomechanicalor other studies that assess the risks of tensilefailure and shear failure. The Director shallapprove limits that, with a reasonable degreeof certainty, will avoid initiation or propagationof fractures in the confining zone or causeotherwise non-transmissive faults transectingMaintaining the integrity ofthe confining zone is thecritical parameter. We believe establishing amaximum pressure based on an arbitrarypercentage of injection zone fracture pressure doesnot address the issue of confining zone integrity inan appropriate way.December 19, 2008GWPC RecommendationsPage 26 of 4026Rule ProvisionEPA ProposalGWPC RecommendationsRationaleUSDW.the confining zone to become transmissive. Inno case may injection pressure causemovement of injection or formation fluids in amanner prohibited by 40 CFR Part 144.12(a).(b) Injection between the outer-mostcasing protecting USDWs and the well boreis prohibited.(b) Injection of the CO2 stream betweenthe outermost casingprotecting USDWs and thewell bore is prohibited.Routine injection into zones other than the targetinterval(s) should be prohibited, however, wordingof this requirement is not clear as to which intervalis being addressed. An absolute prohibition oninjection may also limit diagnostic options that couldbe useful.Sometimes inject other things to remediate well.(c) The owner oroperator must fillthe annulus between the tubing and the longstring casing with a non-corrosive fluidapproved by the Director. The owner oroperator must maintain on the annulus apressure that exceeds the operatinginjection pressure, unless the Directordetermines that such requirement mightharm the integrity of the well.(c) The owner or operator must fill theannulus between the tubing and the long stringcasing with a corrosion inhibiting fluid approvedby the Director. The owner or operator mustmaintain a positive pressure on the annulus.Agency and Industry experience with the Class IIUIC program does not support this requirement.The standard proposed by EPA is consistent withneither the risk level related to CO2 nor thespecifications needed to monitor the annular spacefor leakage.146.88(d)(d) Other than during periods of wellworkover (maintenance) approved by theDirector in which the sealed tubing-casingannulus is of necessity disassembled formaintenance or corrective procedures, theowner or operator must maintain mechanicalintegrity of the injection well at all times.Support the proposedEPA language.Agree with EPA’s rationale.December 19, 2008GWPC RecommendationsPage 27 of 4027Rule ProvisionEPA ProposalGWPC RecommendationsRationale146.88(e) The owner or operator mustinstall and use continuous recording devicesto monitor: The injection pressure; the rate,volume, and temperature of the carbondioxide stream; and the pressure on theannulus between the tubing and the longstring casing and annulus fluid volume; andmust install and use alarms and automaticdown-hole shut-off systems, designed toalert the operator and shut-in the well whenoperating parameters such as annuluspressure, injection rate or other parametersapproved by the Director diverge beyondpermitted ranges and/or gradients specifiedin the permit;(e) The owner or operator must installand use continuous recording devices to monitor:the injection pressure; the rate, volume, andtemperature of the carbondioxide stream. Theowner or operator must regularly monitor thepressure on the annulus between the tubing andthe long string casing. The owner or operatormust install, test and use alarms and automaticshut-off systems, designedto alert the operatorand shut-in the well when operating parameterssuch as injection rate, injection pressure, or otherparameters approved by the Director divergebeyond ranges and/or gradients specified in thepermit;Over-pressure protection is best achieved byensuring compatibility of the casing/tubing materialdesign strength with the surface injection(compression) system. Down-hole shut-in devicesmay be appropriate, however, for site-specificsituations of unique potential impact (such asoffshore or near airports),but they should not bemandated for all injection sites.146.88(f) If a down-hole automaticshutdown is triggered or a loss ofmechanical integrity is discovered, theowner or operatormust immediatelyinvestigate and identify as expeditiously aspossible the cause of the shutoff. If, uponsuch investigation, the well appears to belacking mechanical integrity, or if monitoringrequired under paragraph (e) of this sectionotherwise indicates that the well may belacking mechanical integrity, the owner oroperator must:(f) If an automatic shutdown is triggeredor a loss of mechanical integrity is discovered,the owner or operator must immediatelyinvestigate and identify as expeditiously aspossible the cause. If, upon such investigation,the well appears to be lacking mechanicalintegrity, or if monitoring required underparagraph (e) of this section otherwise indicatesthat the well may be lacking mechanical integrity,the owner or operator must:Eliminates requirement for down-hole shutoffdevice. Although the use of downhole shutoffvalves may be needed in some applications, theirrequired use would be less than ideal for manyreasons such as the fact that since they are adownhole installation, integrity and maintenance ofthe valves is difficult. Further the installation ofsurface valves would allow for more control andprovide for visual inspection. Since the key is toshut down the injection flow if a parameter isexceeded, the use of surface valves would be justas effective as downhole valves.146.88(f)(1) Immediately cease injection;(2) Take all steps reasonablynecessary to determinewhether there mayhave been a release of the injected carbondioxide stream into any unauthorized zone;(3) Notify the Director within 24hours;(4) Restore and demonstratemechanical integrity to the satisfaction of theDirector prior to resuming injection; and(5) Notify the Director when injectioncan be expected to resume.Support the proposed EPA language for (1), (2),and(5)(3) Notify the Directorwithin 24 hours ofdiscovery;(4) Restore and demonstrate mechanicalintegrity to the satisfaction of the director as soonas practicable and prior to resuming injection.Needs to be reasonable and allow for time followingdiscovery.It was felt that some timeframe for restoration ofmechanical integrity should be added to (4)146.899. Mechanical integrity(a) A Class VI well has mechanicalSupport the proposedEPA language.Agree with EPA’s rationale.December 19, 2008GWPC RecommendationsPage 28 of 4028Rule ProvisionEPA ProposalGWPC RecommendationsRationaleintegrity if:(1) There is no significant leak in thecasing, tubing or packer; and(2) There is no significant fluidmovement into a USDW through channelsadjacent to the injection well bore.(b) To evaluate the absence ofsignificant leaks under paragraph (a)(1) ofthis section, owners or operators must,following an initial annulus pressure test,continuously monitor injection pressure,rate, injected volumes, and pressure on theannulus between tubing and long stemcasing and annulus fluid volume as specifiedin § 146.88(e);(b) To evaluate the absence of significantleaks under paragraph (a)(1) of this section,owners or operators must, following an initialannulus pressure test, continuously monitor andrecord at least daily injection pressure, rate,injected volumes, and pressure on the annulusbetween tubing and long stem casing andannulus fluid volume as specified in §146.88 (e);We believe that injection parameters must not onlybe monitored but should be recorded at least daily.We further believe the use of monitoring with digitalequipment which records readings on anappropriate frequency should be consideredcontinuous for purposes of this section.146.89(c)(c) At least once per year, the owneror operator must use one of the followingmethods to determine the absence ofsignificant fluid movement under paragraph(a)(2) of this section:(1) A tracer survey such as oxygenactivation logging;(2) A temperature or noise log; or(3) A casing inspection log, ifrequired by the Director.(c) At least once per year, the owner oroperator must confirm theabsence of significantfluid movement under paragraph (a)(2) of thissection using a method acceptable to theDirector (e.g. including diagnostic surveys suchas oxygen-activation logging or temperature ornoise logs).Delete (1)Delete (2)Delete (3)Revised text supports a performance-basedapproach and allows the development and use ofnew technologies as they become available.December 19, 2008GWPC RecommendationsPage 29 of 4029Rule ProvisionEPA ProposalGWPC RecommendationsRationale(d) The Director may require anyother test to evaluate mechanical integrityunder paragraph (a)(1) or (a)(2) of thissection. Also, the Director may allow theuse of a test to demonstrate mechanicalintegrity other than those listed above withthe written approval of the Administrator. Toobtain approval, the Director must submit awritten request to the Administrator, whichmust set forth the proposed test and alltechnical data supporting its use. TheAdministrator must approve the request if itwill reliably demonstrate the mechanicalintegrity of wells for which its use isproposed. Any alternate method approvedby the Administrator will be published in theFederal Register and may be used in allStates in accordance with applicable Statelaw unless its use is restricted at the time ofapproval by the Administrator.Support the proposedEPA language.Agree with EPA’s rationale.146.89(e)(e) In conducting and evaluating thetests enumerated in this section or others tobe allowed by the Director, the owner oroperator and the Director must applymethods and standards generally acceptedin the industry. When the owner or operatorreports the results of mechanical integritytests to the Director, he/she shall include adescription of the test(s) and the method(s)used. In making his/her evaluation, theDirector must review monitoring and othertest data submitted since the previousevaluation.Support the proposedEPA language.Agree with EPA’s rationale.(f) The Director may requireadditional or alternative tests if the resultspresented by the owner or operator underparagraph (d) of this section are notsatisfactory to the Director to demonstratethat there is no significant leak in the casing,tubing or packer or significant movement offluid into or between USDWs resulting fromthe injection activity as stated in paragraphs(a)(1) and (2) of this section.Support the proposedEPA language.Agree with EPA’s rationale.December 19, 2008GWPC RecommendationsPage 30 of 4030Rule ProvisionEPA ProposalGWPC RecommendationsRationale146.9010. Testing and monitoring requirementsThe owner or operator of a Class VI wellmust prepare, maintain, and comply with atesting and monitoring plan to verify that thegeologic sequestration project is operatingas permitted and is not endangeringUSDWs. The testing and monitoring planmust be submitted with the permitapplication, for Director approval, and mustinclude a descriptionof how the owner oroperator will meet the requirements of thissection. Testing and monitoring associatedwith geologic sequestration projects must, ata minimum, include:Support the proposedEPA language.Agree with EPA’s rationale.146.90(a) Analysis of the carbon dioxidestream with sufficient frequency to yield datarepresentative of its chemical and physicalcharacteristics;(b) Installation and use, exceptduring well workovers as defined in §146.86(d), of continuous recording devicesto monitor injection pressure, rate andvolume; the pressure on the annulusbetween the tubing and the long stringcasing; and the annulus fluid volume;Support the proposed EPA language in (a)(b) Installation and use, except duringwell workovers as defined in §146.88(d), ofcontinuous monitoring devices (including digitaldevices capturing periodic data) to monitorinjection pressure, rate and volume; and recordat least daily the pressure on the annulusbetween the tubing and the long string casing;146.86(d) does not exist; perhaps 146.88(d) is whatwas apparently intended.146.90(c) Corrosion monitoring of the wellmaterials for loss of mass, thickness,cracking, pitting and other signs of corrosionmust be performed on a quarterly basis toensure that the well components meet theminimum standards for material strengthand performance set forth in § 146.86(b) by:(c) Corrosion monitoring of the wellmaterials for loss of mass, thickness, cracking,pitting and other signs of corrosion must beperformed and recorded at least quarterly andmay be modified to be less frequent as approvedby the Director based on construction materials,operating conditions, and monitoring history toensure that the well components meet theminimum standards for material strength andperformance set forth in §146.86(b) by:Allows application of performance based approach.Allows less frequent monitoring, for example, wherecorrosion resistant materials are used.146.90(c)(1) Placing coupons of the wellconstruction materials in contact with thecarbon dioxide stream; or(2) Routing the carbon dioxidestream through a loop constructed with thematerial used in the well; or(1) Analyzing coupons of the wellconstruction materials placed in contact with thecarbon dioxide stream; or(2) Routing the carbon dioxide streamthrough a loop constructed with the material usedin the well and inspecting the materials in theClarification editsDecember 19, 2008GWPC RecommendationsPage 31 of 4031Rule ProvisionEPA ProposalGWPC RecommendationsRationale(3) Using an alternative methodapproved by the Director;loop; or(3) Using an alternative method,materials, or time period approved by theDirector;146.90(d)(d) Periodic monitoring of theground water quality and geochemicalchanges above the confining zone(s) thatmay be a result of carbon dioxide movementthrough the confining zone or additionalidentified zones:(1) The location and number ofmonitoring wells must be based on specificinformation about the geologic sequestrationproject, including injection rate and volume,geology, the presence of artificialpenetrations and other factors;(2) The monitoring frequency andspatial distribution of monitoring wells mustbe based on baseline geochemical data thathas been collected under § 146.82(a)(6) andany modeling results in the area of reviewevaluation required by § 146.84(b);(d) Periodic monitoring of reservoirformation fluid quality in a permeable andporous formation as near as practicable to theconfining zone(s) for geochemical changes thatmay be a result of carbon dioxide or displacedformation fluid movement:(1) The location and number ofmonitoring wells must be based on specificinformation about the geologic sequestrationproject, including injection rate and volume,geology, the presence of artificial penetrationsand other relevant factors as warranted by a riskassessment;(2) The monitoring frequency and spatialdistribution of monitoring wells must be based ongeological, geochemical and geophysical datathat has been collected under §146.82(d) andany modeling results in the area of reviewevaluation required by §146.84(b);Drilling monitoring wells should be carefullyconsidered since each well introduces a potentialpathway for movement.[Geochemical data do not have a high degree ofrelevance in selecting monitoring well sites.]146.90(e) A demonstration of externalmechanical integrity pursuant to § 146.89(c)at least once per year throughout theduration of the geologic sequestrationproject;(f) A pressure fall-off test at leastonce every five years unless more frequenttesting is required by the Director based onsite specific information;(e) A demonstration of externalmechanical integrity pursuant to §146.89(c) atleast once per year until the well is plugged;(f) A pressure fall-off test or otherequivalent test that identifies reservoir conditionswith respect to flow dynamics at least once everyfive years unless more frequent testing isrequired by the Director based on site specificinformation;Redundant to section 146.89(g) Testing and monitoring to trackthe extent of the carbon dioxide plume andthe position of the pressure front by eithermonitoring for pressure changes in the firstformation overlying the confining zone orusing indirect, geophysical techniques (e.g.,seismic, electrical, gravity, orelectromagnetic surveys and/or down-hole(g) Testing and monitoring to track theextent of the carbon dioxide plume and theposition of the pressure front.Monitoring outside of the injection zone provideslittle information of value for tracking and monitoringthe injected plume. Examples of how to test andmonitor could be included in the Preamble but neednot be included in the rule itself.December 19, 2008GWPC RecommendationsPage 32 of 4032Rule ProvisionEPA ProposalGWPC RecommendationsRationalecarbon dioxide detection tools);146.90(h) At the Director’s discretion,surface air monitoring and/or soil gasmonitoring to detect movement of carbondioxide that could endanger a USDW.(h) At the Director’s discretion based onsite-specific conditions and risk-based factors,surface air monitoring and/or soil gas monitoringto detect movement of carbon dioxide that couldendanger a USDW.In most situations soil and air monitoring does notprovide an effective method of protecting USDWs.146.90(h)(1) The testing and monitoring planmust be based on potential vulnerabilitieswithin the area of review;(2) The monitoring frequency andspatial distribution of surface air monitoringand/or soil gas monitoring must reflectbaseline data and the monitoring plan mustinclude how the proposed monitoring willyield useful information on the area ofreview delineation and/or compliance withstandards under 40 CFR 144.12;(1) The testing and monitoring plan mustbe based on site-specific geologicfactors, modeling, and riskassessment within the area ofreview;(2) Agree with EPA languageThe GWPC feels that the term “potentialvulnerabilities” is too nebulous. We suggestreplacing this term with the term “site-specificgeologic factors, modeling, and risk-assessment.”146.90(i)(i) Any additional monitoring, asrequired by the Director, necessary tosupport, upgrade, and improvecomputational modeling of the area ofreview evaluation required under §146.84(b) and to determine compliance withstandards under 40 CFR 144.12; and(j) A quality assurance andsurveillance plan for all testing andmonitoring requirements.Support the proposedEPA language.Agree with EPA’s rationale.146.9111. Reporting requirements.The owner or operator must, at a minimum,provide the following reports to the Director,for each permitted Class VI well:(a) Semi-annual reports containing:(1) Any changes to the physical,chemical and other relevant characteristicsof the carbon dioxide stream from the(a) Semi-annual or at a frequencydetermined by the Directorreports containing:(1) Any significant changes to thephysical, chemical and other relevantcharacteristics of the carbon dioxide stream fromthe proposed operating data;Should be semi-annual unless otherwisedeterminedDecember 19, 2008GWPC RecommendationsPage 33 of 4033Rule ProvisionEPA ProposalGWPC RecommendationsRationaleproposed operating data;(2) Monthly average, maximum andminimum values for injection pressure, flowrate and volume, and annular pressure;146.91(a)(3) A description of any event thatexceeds operating parameters for annuluspressure or injection pressure as specified inthe permit;(4) A description of any event whichtriggers a shutdown device requiredpursuant to § 146.88(e) and the responsetaken;(5) The monthly volume of thecarbon dioxide streaminjected over thereporting period and project cumulatively;(6) Monthly annulus fluid volumeadded; and(7) The results of monitoringprescribed under § 146.90.(3) A description of any event thatsignificantly exceeds operating parameters forannulus pressure or injection pressure asspecified in the permit;(4) A description of any event whichtriggers a shutdown device required pursuant to§146.88(e) and the response taken;EPA should consider somesignificance thresholdon reporting these events, toavoid reporting eventswould be of limited interest or consequence.(b) Report, within 30 days theresults of:(1) Periodic tests of mechanicalintegrity;(2) Any other test of the injectionwell conducted by the permittee if requiredby the Director; and(3) Any well workover.(c) Owners or operators mustsubmit reports in an electronic formatacceptable to the Director. At the discretionof the Director, other formats may beaccepted.Support the proposed EPA language.Agree with EPA’s rationale.146.9212. Injection well plugging.(a) Prior to the well plugging, theowner or operator must flush each Class VIinjection well with a buffer fluid, determinebottomhole reservoir pressure, and performa final mechanical integrity test.(a) Prior to the well plugging, the owneror operator must flush each Class VI injectionwell with a buffer fluid, determine bottomholereservoir pressure, and perform a final externalmechanical integrity test.Many of the components that would be tested by aninternal MIT are removed or tested during theplugging process. Consequently, the GWPCsuggests including the term internal to the languagefor clarification.December 19, 2008GWPC RecommendationsPage 34 of 4034Rule ProvisionEPA ProposalGWPC RecommendationsRationale146.92(b)(b) Well Plugging Plan. The owneror operator of a Class VI well must prepare,maintain, and comply with a plan that isacceptable to the Director. The requirementto maintain and implement an approved planis directly enforceable regardless of whetherthe requirement is a condition of the permit.The well plugging plan must be submitted aspart of the permit application and mustinclude the following information:Support the proposedEPA language.Agree with EPA’s rationale.(1) Appropriate test or measure todetermine bottomhole reservoir pressure;(2) Appropriate testing methods toensure mechanical integrity as specified in §146.89;(3) The type and number of plugs tobe used;(4) The placement of each plugincluding the elevation of the top and bottomof each plug;(5) The type and grade and quantityof material to be used in plugging. Thematerial must be compatible with the carbondioxide stream; and(6) The method of placement of theplugs.Support the proposed EPA language for (1), (3),(4) and (6)(2) Appropriate testing methods toensure final external mechanical integrity asspecified in §146.89(c);(5) The type and grade and quantity ofmaterial to be used in plugging. The materialmust be suitable for use with the carbon dioxidestream; andMany of the components that would be tested by aninternal MIT are removed or tested during theplugging process. Consequently, the GWPCsuggests adding the term external to the languagefor clarification.(c) Notice of intent to plug. Theowner or operator must notify the Director atleast 60 days before plugging of a well. Atthis time, if any changes have been made tothe original well plugging plan, the owner oroperator must also provide the revised wellplugging plan. At the discretion of theDirector, a shorter notice period may beallowed.Support the proposedEPA language.Agree with EPA’s rationale.146.92(d)(d) Plugging report. Within 60 daysafter plugging or at the time of the nextsemi-annual report (whichever occursearlier) the owner or operator must submit aplugging report to the Director. If the semiannual report is due less than 15 days after(d) Plugging report. Within 60 days afterplugging the owner or operator must submit aplugging report to the Director. The report mustbe certified as accurate by the owner or operatorand by the person who performed the pluggingSimplificationDecember 19, 2008GWPC RecommendationsPage 35 of 4035Rule ProvisionEPA ProposalGWPC RecommendationsRationalecompletion of plugging, then the report mustbe submitted within 60 days after plugging.The report must be certified as accurate bythe owner or operator and by the personwho performed the plugging operation (ifother than the owner or operator.)operation (if other than the owner or operator.)146.9313. Post-injection site care and site closure(a) The owner or operator of a ClassVI well must prepare, maintain, and complywith a plan for post-injection site care andsite closure that meets the requirements ofparagraph (a)(2) of this section and isacceptable to the Director.(1) The owner or operator mustsubmit the post-injection site care and siteclosure plan as a part of the permitapplication to be approved by the Director.Support the proposed EPA languageAgree with EPA’s rationale(2) The post-injection site care andsite closure plan must include the followinginformation:(i) The pressure differential betweenpre-injection and predicted post-injectionpressures in the injection zone;(ii) The predicted position of thecarbon dioxide plume and associatedpressure front at site closure asdemonstrated in the area of reviewevaluation required under § 146.84(b);Support the proposedEPA language.Agree with EPA’s rationale.146.93(a)(2)(iii) A description of post-injectionmonitoring location, methods, and proposedfrequency; and(iv) A proposed schedule forsubmitting post-injection site care monitoringresults to the Director.Support the proposedEPA language.Agree with EPA’s rationale.(3) Upon cessation of injection,owners or operators of Class VI wells musteither submit an amended post-injection sitecare and site closure plan or demonstrate tothe Director through monitoring data andmodeling results that no amendment to theSupport the proposedEPA language.Agree with EPA’s rationale.December 19, 2008GWPC RecommendationsPage 36 of 4036Rule ProvisionEPA ProposalGWPC RecommendationsRationaleplan is needed.(4) The owner or operator maymodify and resubmit the post-injection sitecare and site closure plan for the Director’sapproval within 30 days of such change.Support the proposedEPA language.Agree with EPA’s rationale.146.93(b)(b) The owner or operator shallmonitor the site following the cessation ofinjection to show the position of the carbondioxide plume and pressure front anddemonstrate that USDWs are not beingendangered.(1) The owner or operator shallcontinue to conduct monitoring as specifiedin the Director-approved post-injection sitecare and site closure plan for at least 50years following the cessation of injection. Atthe Director’s discretion, the monitoring willcontinue until the geologic sequestrationproject no longer poses an endangerment toUSDWs.(b) The owner or operator shall monitorthe site following the cessation of injection.(1) The owner or operator shall continueto conduct monitoring as specified in theDirector-approved post-injection site care andsite closure plan until closure is authorizedpursuant to 146.93(b)(3).Eliminate the 50 year requirement.There is no justification for extending completedprojects for the presumptive 50 years, and it will bedifficult to accept much shorter demonstrationperiods with the 50 year presumption in theregulations. Default 50-year period defeatsincentives for best site identification and best MMVNeed for site-specific considerations and use ofdataNeed achievable and definable standard146.93(b)(2) If the owner or operator candemonstrate to the satisfaction of theDirector before 50 years, based onmonitoring and other site-specific data, thatthe geologic sequestration project no longerposes an endangerment to USDWs, theDirector may approve an amendment to thepost-injection site care and site closure planto reduce the frequency of monitoring ormay authorize site closure before the end ofthe 50-year period.(2) The owner or operator can requestand demonstrate to the satisfaction of theDirector that the post-injection site care and siteclosure plan should be revised to reduce thefrequency of monitoring.See above regarding elimination of 50-yearpresumptive time period.(3) Prior to authorization for siteclosure, the owner or operator must submitto the Director a demonstration, based onmonitoring and other site-specific data, thatthe carbon dioxide plume and pressure fronthave stabilized and that no additional(3) Prior to authorization for site closure,the owner or operator must demonstrate to theDirector, based on monitoring, other site-specificdata, and modeling that is reasonably consistentwith site performance, that no additionalmonitoring is needed to assure that the geologicThe GWPC revised this section to establish theperformance based criteria for selecting themonitoring period.December 19, 2008GWPC RecommendationsPage 37 of 4037Rule ProvisionEPA ProposalGWPC RecommendationsRationalemonitoring is needed to assure that thegeologic sequestration project does notpose an endangerment to USDWs.sequestration project does not and is notexpected to pose an endangerment to USDWs.The Director shall approve closure if the owner oroperator demonstrates, based on the currentunderstanding of the site, including monitoringdata and/or modeling, all of the following: (i) theestimated magnitude and extent of the projectfootprint (CO2 plume and the area of elevatedpressure) ; (ii) the estimated location of thedetectable CO2 plume; (iii) that there is nosignificant leakage of either CO2 or displacedformation fluids that is endangering USDWs; (iv)that the injected or displaced fluids are notexpected to migrate in the future in a manner thatencounters a potential leakage pathway into aUSDW; (v) that the injection wells at the sitecompleted into or through the injection zone orconfining zone are plugged and abandoned inaccordance with these requirements; and (vi) anyremaining project monitoring wells at the site arebeing managed by a person and in a manneracceptable to the Director.(4) If such a demonstration cannotbe made (i.e., if the carbon dioxide plumeand pressure front have not stabilized) afterthe 50-year period, the owner or operatormust submit to the Director a plan tocontinue post-injection site care.DeleteNo longer necessary if 50 year time period isremoved.146.93(c)(c) Notice of intent for site closure.The owner or operator must notify theDirector at least 120 days before siteclosure. At this time, if any changes havebeen made to the original post-injection sitecare and site closure plan, the owner oroperator must also provide the revised plan.At the discretion of the Director, a shorternotice period may be allowed.No recommendationNeed for site-specific considerations and use ofdata146.93(d)(d) After the Director has authorizedsite closure, the owner or operator must plugall monitoring wells in a manner which willnot allow movement of injection or formationfluids that endangers a USDW.No recommendationNeed for site-specific considerations and use ofdataDecember 19, 2008GWPC RecommendationsPage 38 of 4038Rule ProvisionEPA ProposalGWPC RecommendationsRationale(e) Once the Director has authorizedsite closure, the owner or operator mustsubmit a site closure report within 90 daysthat must thereafter be retained at a locationdesignated by the Director. The report mustinclude:(1) Documentation of appropriateinjection and monitoring well plugging asspecified in § 146.92 and paragraph (c) ofthis section. The owner or operator mustprovide a copy of a survey plat which hasbeen submitted to the local zoning authoritydesignated by the Director. The plat mustindicate the location of the injection wellrelative to permanently surveyedbenchmarks. The owner or operator mustalso submit a copy of the plat to theRegional Administrator of the appropriateEPA Regional Office;(e) Once the Director has authorized siteclosure, the owner or operator must submit a siteclosure report within 90 days after completion ofall closure operations. The report must include:(1) Documentation of appropriateinjection and monitoring well plugging asspecified in §146.92 and paragraph (c) of thissection. The owner or operator must provide acopy of a survey plat which has been submittedto the local zoning authority designated by theDirector. The plat must indicate the location ofthe injection well(s) relative to permanentlysurveyed benchmarks. The owner or operatormust also submit a copy of the plat to theRegional Administrator of the appropriate EPARegional Office;What is the retention period? Many other programshave a three year limit forretention of records. EPAis the steward of information at this point of theproject, not the owner or operator.(2) Documentation of appropriatenotification and information to such State,local and tribal authorities as have authorityover drilling activities to enable such Stateand local authorities to impose appropriateconditions on subsequent drilling activitiesthat may penetrate the injection andconfining zone(s); and(3) Records reflecting the nature,composition and volume of the carbondioxide stream.No recommendationNeed for site-specific considerations and use ofdata146.93(f) Each owner or operator of aClass VI injection well must record anotation on the deed to the facility propertyor any other document that is normallyexamined during title search that will inperpetuity provide any potential purchaser ofthe property the following information:(1) The fact that land has been usedto sequester carbon dioxide;(2) The name of the State agency,local authority, and/or tribe with which thesurvey plat was filed, as well as the addressNo recommendationNeed for site-specific considerations and use ofdataDecember 19, 2008GWPC RecommendationsPage 39 of 4039Rule ProvisionEPA ProposalGWPC RecommendationsRationaleof the Regional Environmental ProtectionAgency Office to which it was submitted;and(3) The volume of fluid injected, theinjection zone or zones into which it wasinjected, and the period over which injectionoccurred.(g) The owner or operator mustretain for three years following site closure,records collected during the post-injectionsite care period. The owner or operatormust deliver the records to the Director atthe conclusion of the retention period, andthe records must thereafter be retained at alocation designated by the Director for thatpurpose.No recommendationNeed for site-specific considerations and use ofdata146.9414. Emergency and remedial response.(a) As part of the permit application,the owner or operator must provide theDirector with an emergency and remedialresponse plan that describes actions to betaken to address movement of the injectionor formation fluids that may cause anendangerment to a USDW duringconstruction, operation, closure and postclosure periods.146.94(b)(b) If the owner or operator obtainsevidence that the injected carbon dioxidestream and associated pressure front maycause an endangerment to a USDW, theowner or operator must:(1) Immediately cease injection;(2) Take all steps reasonablynecessary to identify and characterize anyrelease;(3) Notify the Director within 24hours; and(4) Implement the emergency and(b) If the owner or operator obtainsevidence that the injected carbon dioxide stream,displaced formation fluids or associated pressurefront endangers a USDW, the owner or operatormust:(1) Immediately cease injection;(2) Take all steps reasonably necessaryto identify and characterize the endangermentposed;(3) Notify the Director or the designatedrepresentative within 24 hours of becomingaware of the endangerment; andThe GWPC felt the notification period neededclarification since it did not specify when the clockbegan to run for the 24 hour notice period. Further,it was felt that notification of someone representingthe Director would also constitute appropriatenotice.December 19, 2008GWPC RecommendationsPage 40 of 4040Rule ProvisionEPA ProposalGWPC RecommendationsRationaleremedial response plan approved by theDirector.(4) Implement the emergency andremedial response plan approved by theDirector.(c) The Director may allow theoperator to resume injection prior toremediation if the owner or operatordemonstrates that the injection operation willnot endanger USDWs.(d) The owner or operator mustnotify the Director and obtain his approvalprior to conducting any well workover.Support the proposed EPA language for (c)(d) The owner or operator must notify theDirector prior to conducting any well workover inresponse to any case of endangerment.In critical situations, time spent obtaining approvalcould adversely affect the ability to conductoperations or increase the level of endangerment.Letter ID: 0259 Commenter: Michel Paque Organization: Ground Wate r Protection Council

Letter ID: 0259 Comment ID: 24811 Letter Lines: 81 to 127

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

Comment: RESOLUTION 08-1

REGARDING DELEGATION OF PRIMARY EN FORCEMENT AUTHORITY TO STATES

FOR THE GEOSEQUESTRATION OF CARBON DIOXIDE

WHEREAS, the United States Environmen tal Protection Agency (USEPA) has determined the geologic sequestration of carbon dioxide is a process that falls within the jurisdiction of the Safe Drinking Water Act (SDWA), Underground Injection Control (U IC) program; and

WHEREAS, the USEPA has developed a propos ed federal rule under the UIC program to regulate the practice of geologi c sequestration of carbon dioxide; and

WHEREAS, the USEPA has proposed the creatio n of a new injection well class for carbon dioxide geologic sequestration inje ction wells with th e designation of

Class VI; and

WHEREAS, upon adoption of a federal rule states will lack primacy enforcement authority (Primacy) for Class VI wells un til such authority is delegated to the states by USEPA; and

WHEREAS, the USEPA has indicated the dele gation of primacy for Class VI wells will fall under the authority of Section 1422 of the SDWA; and

WHEREAS, it is the curren t practice of USEPA to onl y delegate primacy under Section 1422 of the SDWA if a state accep ts primacy for all well classes other

than Class II wells; and

WHEREAS, it is in the best interest of protecting gr ound water resources for the geologic sequestration of carbon dioxide to be regulated at th e state level; and

WHEREAS, the GWPC is an association of state admi nistrators of underground injection control and ground water protecti on programs that will be responsible for administering programs for the geologi c sequestration of carbon dioxide; and

WHEREAS, any requirement by USEPA that st ates accept primacy for Class I, III, IV and V wells, as a condition for obtaining primacy for Class VI wells will

1create an unreasonable burden upon states; and

WHEREAS, any requirement by USEPA that stat es with primacy for Class I, III, IV and V wells also accept primacy for Class VI wells will compromise the states ability to decide how best to admini ster the states UI C program and may unnecessarily disrupt the states’ UIC program;

NOW THEREFORE BE IT RESOLVED THAT, th e GWPC recommends USEPA provide for

the voluntary and separate delegation of primacy to the states for Class VI wells under the UIC program unless the state request s the delegation be made a part of a state UIC primacy program.

Individual Response: EPA agrees that states should be al lowed to obtain primacy for Class VI wells independently of other well classes, and wi ll allow independent primacy for Class VI wells under §145.1(i) of the final GS rule. In the past , EPA has not accepted UIC primacy applications

for individual well classes unde r Section 1422 of SDWA. In other words, if a State wanted primacy for Class I wells, the State would also ne ed to accept responsibilit y for Class III, IV, and V wells. This policy has been in place since the initiation of the UIC Program in the early 1980s and was intended to encourage states to take full responsibility fo r UIC programs, avoid duplication of efforts, and provide for administrative efficiencies.

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.

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

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

2EPA clarifies that states should be able to obtain primacy for Cla ss VI wells independent of other well classes provided they devel op regulations that are at leas t as stringent as the minimum Federal requirements (e.g., permitting, inspec tion, operation, monitoring, and recordkeeping requirements) provided in the final GS rule. EPA believes that existing programs can adapt their expertise to the new requirements for Class VI wells and will be able to develop a primacy application for Class VI wells under section 1422 of SDWA and en sure that their GS programs integrate into national climate change priori ties and protect USDWs from endangerment.

EPA recognizes that some states have already begun legislative e fforts that are wider in scope

than the Federal GS rule and believes that allo wing Class VI primacy (i ndependent of other well classes) may encourage states to take responsibility for implemen tation of a more comprehensive approach to managing CCS proj ects (e.g., capture, transportati on, and geologic sequestration).

Letter ID: 0259 Comment ID: 24812 Letter Lines: 147 to 171

Comment Code: 1640 1.3.4 CERCLA issues (seeking comment)

Comment: EPA Rule Issue: 8. Class VI requirements and permits will need to be carefully structured to ensure that they do not "authorize" inappr opriate hazardous releases. This would include clarifying if there are potential releases from the well which are outside the scope of the Cl ass VI permit. EPA requests comment on particular situations where this might occur. EPA notice 43504.

GWPC CO2 Committee Response: CERCLA applica tion should be avoided or sorted out and affirmed by Congress to indicate that it would not apply; municipal operators have major concern over this potential because cities will be around long-term and look like deep pockets

As EPA has noted, CERCLA liability does not apply to federally permitted releases (FPRs), including releases covered by a UIC pe rmit, even if GS would

lead to a hazardous substance release. Nor should CERCLA liability apply to any

downstream reactions or transformations re sulting from FPRs. Accordingly, there appears to be little real potential for CERCLA liability resulting from GS. Yet EPA needs to clarify that CERCLA liability is extremely unlikely to result from any GS operation that has not injected st reams that are not covered by its UIC permit.

Rationale: Even the potential for CERCLA liability is viewed with such apprehension because of the overwhelmingl y negative effects that such liability has had on the investing community, howev er, that EPA’s discussion of that possibility without substant ial clarification is very likely to have a chilling effect on the support for development a nd deployment of CCS technologies.

Individual Response: CERCLA exempts from liability, un der CERCLA section 107, 42 U.S.C.

39607, certain “federally permitted releases” (FPR ) as defined in CERCLA, 42 U.S.C. 9601(10). Therefore, Class VI requirements and permits will n eed to be carefully structured to ensure that they do not “authorize” inappropriate releases, and would need to prevent potential releases from the well which are outside the scope of the Class VI permit.

Furthermore, EPA is promulgating the GS rule un der the authority of th e SDWA. To the extent the commenter is seeking interpretations of CE RCLA and its related pr ovisions, such as the definition of a federally permitted release, such interpretations are beyond the scope of this rulemaking.

The UIC program Director has authority under SDWA §1423 to address potential compliance issues (e.g., potential releases that may endanger USDWs) resulting from injection violations in the unlikely event that a remedi al response is necessary. Although EPA anticipates that the need for emergency or remedial actions at GS sites wi ll be rare, the GS rule requires, at §146.94, that emergency and remedial response plans be deve loped and updated to address such events and that owners or operators demonstr ate that financial resources are set aside to implement the plans if necessary, per §146.85.

Regarding long term liability, once an owner or operator has met all regu latory requirements

under Part 146 for Class VI wells and the Dire ctor has approved site closure pursuant to requirements at §146.93, the owner or operato r will generally no longer be subject to enforcement for regulatory noncompliance. Furtherm ore, their financial instrument as required under §146.85 will be released if it was not used. However, even if a site closure is approved under §146.93, an owner or operator may be held liable for regulatory noncompliance (including violation of 40 CFR 144.12) in ce rtain circumstances. For example, an owner or operator may be held liable for regulatory noncompliance even afte r site closure was approved if the Director relied on erroneous information (e.g., erroneous modeling data) provid ed by the owner or operator when approving site closure.

Separate from EPA’s authority to enforce regul atory compliance, an owner or operator may be subject to a §1431 response orde r even after proper site cl osure is approved under §146.93. Under §1431 the Administrator may require an ow ner or operator to take necessary response

measures if he or she receives information that a contaminant is present or is likely to enter a public water system or an USDW, which may pres ent an imminent and s ubstantial endangerment to the health of persons, and the appropriate Stat e and local authorities ha ve not acted to protect the health of such persons. Th e action may include issuing admi nistrative orders or commencing a civil action for appropriate relief against the ow ner or operator of a Class VI well. If the owner or operator fails to comply with the order, they may be subject to a civil penalty for each day in

which such violation occurs or failure to comply continues.

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.

4EPA adds that promoting the use of GS is outsi de the scope of the GS rule. Rather, the purpose of the GS regulation is to ensu re that, where deployed, GS is c onducted in a manner that protects USDWs from endangerment.

Letter ID: 0259 Comment ID: 24813 Letter Lines: 173 to 182

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

Comment Code: 1640 1.3.4 CERCLA issues (seeking comment)

Comment: EPA Notice Questions: 73 FR 43504

EPA Rule Issue: 9. EPA also requests comm ent on other consider ations associated with the presence of impurities in the CO 2 stream related to CERCLA. EPA Notice

43504.

GWPC CO2 Committee Response: The only need is to address constituents in a CO2

stream that would defeat capture, compression, transport or GS, and these can be addressed through the use of special materials in many cases. The focus should be on compatibility rather than on any need for purification.

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.

Letter ID: 0259 Comment ID: 24814 Letter Lines: 186 to 210

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

Comment: EPA Rule Issue: 10. EPA’s proposal would pr ovide the Director the discretion to require the owner or operator to identify and characterize additional confining and containment zones above the primary (i .e., lowermost) confining zone that could further impede vertical fluid moveme nt and allow for pressure dissipation. EPA says that these layers could pr ovide additional site s for monitoring, mitigation, and remediation. EPA’s propos al would not require that these

additional zones be identifie d for all GS sites because their absence does not

5necessarily indicate inappropria teness of a GS site. Howe ver, if such zones are present, information about their ch aracteristics can pr ovide inputs for predictive models, identify appropriate m onitoring locations, and improve public confidence in and acceptance of a proposed GS site. EPA specifically seeks comment on the merits of requiring the iden tification of these additional zones.

EPA Notice 43506.

GWPC CO2 Committee Response: Any showing of secondary containment is unnecessary once the requirement for containment ha s been satisfied by providing for an adequate confining zone. References to additional confining and containment zones is more likely to lead to confusion than support.

Rationale: Any emphasis on the availability of additional confining zones is likely to cause confusion over the adequacy of projects that satisfy the actual requirements but do not also provide wh at is by definition redundant and unnecessary layers of protection. Moreover, discussions of additional confining zones could undercut the ability to use be neficially any additional formations in the area of interest covered by a proposed project.

Individual Response: EPA retains the requirement to iden tify additional containment/confining zones, if required by the Di rector, as proposed (§146.83(b)). EPA acknowledges that such additional zones may not be needed in all circumst ances, and clarifies that this requirement is at

the Director's discretion, based on his or her understanding of a part icular site. EPA believes that, in some situations, the presence of additional confining and containment zones above the primary (i.e., lowermost) confining zone can improve USDW protecti on. These layers could further impede vertical fluid movement and al low for pressure dissipation, and also provide additional sites for monitoring, mitigation, and re mediation. The Agency's decision is supported by commenters representing states, water associati ons, and an electric utility who assert that these requirements promote a flexible, risk-base d, site-specific approach to characterizing and permitting a site for GS projects, and are intende d to improve understanding of the project as a whole and promote better modeling of the site.

Letter ID: 0259 Comment ID: 24815 Letter Lines: 212 to 223

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

circumstances

Comment: EPA Notice Questions: 73 FR 43512

EPA Rule Issue: 25. EPA is also requ esting comments on whether aquifer exemptions should be allowed for the pur pose of Class VI injection, and under what conditions should such aquifer ex emptions be approved. EPA Notice 43512.

GWPC CO2 Committee Response: The committee r ecommends that aquifer exemptions be

allowed. At this time, the Committee is not recommending any specific need for new aquifer exemption criteria create d because the existing criteria are

6perceived to be sufficient to allow aquife r exemptions as needed for GS. Even without changes, the aquifer exemption re quirements in the UIC program would allow operators to obtain appropriate exemptions for GS operations.

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

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

EOR/EGR wells to Class VI.

EPA clarifies that all decisions regarding whethe r expansion of existing aquifer exemptions will

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

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

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

Letter ID: 0259 Comment ID: 24816 Letter Lines: 225 to 237

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

Comment: EPA Notice Questions: 73 FR 43512

EPA Rule Issue: 26. EPA seeks comment on wh ether the Agency should set a minimum injection depth requirement for CO2 GS, rath er than require that such injection take place below the lowermost USDW. EPA Notice 43512.

GWPC CO2 Committee Response: There should not be a minimum depth established AND

7there should be no blanket restriction c oncerning proximity to USDWs but should instead be based on ability to protect USDWs.

Rationale: The presence of numerous oil a nd gas reservoirs above demonstrates the ability of geologic formations at thos e depths to trap and contain fluids comparable to CO2 streams.

Individual Response: EPA agrees that it is not appropriate to set a mi nimum injection depth for GS projects and the Agency believes that a determ ination of site-suitabili ty for GS (i.e., that

subsurface formations will receiv e and confine injected CO2) s hould be made on a site-specific basis. The GS rule, at §146.82, requires the owne r or operator to provide extensive site- and project-specific information to the Director to demonstrate that the site meets the minimum site criteria at §146.83, that the CO2 will be contai ned within the injection formation, and that USDWs will be protected from endangerment.

EPA acknowledges that there are limited circum stances where injectio n above the lowermost USDW can be performed in a manner that protec ts USDWs, as long as appropriate protections are in place. The final GS rule at §146.95 establis hes a process by which owners or operators can seek a waiver of the Class VI injection de pth requirements for in jection into non-USDW

formations above and/or between USDWs. The waiver approach requires the submission of extensive, site-specific information (in conjunc tion with the permit appl ication submission) to demonstrate that injection of CO2 into a non-US DW that is above or between USDWs can be done in a manner that is protective of USDWs. Th e requirements are designed to ensure that the owner or operator, the Director, and the Regional Administrator cons ider, on a site specific basis, the implications, benefits, and challenges associat ed with GS and ensuring water availability and USDW protection. For additional information on the waiver approach, please see the final rule and preamble, as well as EPA's responses to comments on the Notice of Data Availability and Request for Comment.

Letter ID: 0259 Comment ID: 24817 Letter Lines: 239 to 249

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

Comment: EPA Notice Questions: 73 FR 43513-15

EPA Rule Issue: 27. EPA’s proposal allows Directors’ discre tion on whether to require the use of tracers, and if so, what types of tracers. EPA seeks comment on the use of tracers in CO2 GS operations, and any potential impact of tracers on human health or ecosystems as they relate to USDWs. EPA Notice 43513.

GWPC CO2 Committee Response: Due to the know ledge gaps in the use of tracers in this type of environment language regardi ng Directors discretion is OK. However,

further research needs to be conducted be fore any final language to allow the use of tracers is approved.

8Individual Response: EPA agrees that the use of tracers shoul d not be required at all GS sites, but should be available as an option. For this reason, EPA does not require the use of tracers at

all GS sites; however, the Director has discretion to require their us e if he/she determines that the use of tracers could improve monitoring of the site and enhance USDW protection from endangerment. The rule will also allow their use if proposed by the owner or operator and approved by the Director.

EPA continues to follow new and ongoing research on the safety and efficacy of tracers. For example, studies at the Frio Brine Pilot Experi ment site (Dayton, TX) used various types of tracers, including perfluorocar bon tracers (PFTs), sulfur hexa fluoride, and the noble gases krypton, neon, and xenon. These studies (e.g., Phel ps and Cole, 2008; Hovorka et al., 2004; McCallum et al., 2005) found that tracers can pr ovide useful CO2 monitoring information at injection wells at depth and at near-surface locations. At Frio, tr acers enabled quantification of CO2 plume behavior and provide d a technique for model validity testing (McCallum et al., 2005). EPA will continue to track re search related to tracer use.

EPA has been following new and ongoing research on the safety and efficacy of tracers, including their efficiency and cost-effectiveness. The Agency plans to, every six years, collect and review data on GS projects to determin e whether the appropriate amount and types of information and appropriate documentation are being collected, and to determine if modifications to the requirements are appropriate or necessary.

Letter ID: 0259 Comment ID: 24818 Letter Lines: 251 to 265

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

Comment: EPA Notice Questions: 73 FR 43517

EPA Rule Issue: 33. EPA seeks comment on the appropriate amount and types of monitoring that should be conducted at a GS site. Specifically, EPA seeks comment regarding the usefulness of indi rect geophysical monitoring and surface air and soil gas monitoring. In addition, EPA seeks commen t regarding the use of a Director-approved monitoring plan for GS sites. EPA Notice 43517.

GWPC CO2 Committee Response: Although actual monitoring of injection formation might be considered most effective you still have the poten tial problem of putting holes in the confining formation. Perhaps the use of seismic to place monitoring wells into the injection zone would be an appropriate approach. The number of monitoring wells should not be established in advance. Obviously the UIC program does not have complete contro l over monitoring well construction or operation or closure. With respect to soil and air monitoring there is a

Individual Response: The final rule (at §146.90(g)) requires owners or operators to perform monitoring to track the extent of the CO2 plume and pressure fr ont. The owner or operator must use direct methods to monitor for pressure chan ges in the injection zone. Indirect methods (e.g.,

9seismic, electrical, gravity, or electromagnetic surveys and/or down-hol e CO2 detection tools) are also required unless the Di rector determines, based on s ite-specific geology, that such methods are not appropriate.

Pressure monitoring within the injection zone is necessary because any such monitoring above the confining zone would not de tect movement of the pressure front unless a breach of the confining zone occurs. EPA believes that monitori ng using wells in the inje ction zone (i.e., that penetrate the confining zone) can be safely performed if the wells are constructed to prevent flow between the injection zone a nd USDWs or other layers above the confining zone. Such construction technologies exist and have been us ed 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. Monitoring al so identifies needed re medial actions, provides inputs for AoR reevaluation modeling, and ta rgets additional geochemical and surface monitoring needs. Knowledge of th e location of the CO2 plume and the associated pressure front will assure the public that GS projects are proceeding according to plan, provide sufficient information to the owner or operator and Director, or allow for appropriate actions to address any

indication that USDWs may be endangered.

EPA notes that plugging of monitoring wells must be addressed as part of the post-injection site care and site closure plan required under §146.93. EPA is developing guidance on well

construction that will include recommendations for monitoring well c onstruction. The guidance

will be available on EPA’s website at http://water.epa.gov/type/groundwat er/uic/wells_se questration.cfm.

EPA acknowledges that, at certain sites, there ma y be a need for more or different monitoring schemes (which may include monitoring in the conf ining zone), and adds that it is important to balance the need for adequate monitoring that ensures USDW protection from endangermentagainst too many artificial penetrations which could serve as conduits for fluid migration. Sitespecific testing and monitoring plans should describe the proposed monitoring regime, including the number and location of monitoring wells, wh ich must be approved by the Director.

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 pre ssure front, and soil gas and su rface 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/u ic/wells_sequestration.cfm. In addition, in January 2009, DOE published a best practices ma nual entitled "Monitoring, Verification, and Accounting of CO2 Stored in Deep Geol ogic Formations" (DOE /NETL-311/081508); this

manual is included in the docke t for the final GS rule.

10Letter ID: 0259 Comment ID: 24819 Letter Lines: 265 to 266

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

Comment: operation or closure. With respect to soil and air monitoring there is a question as to the efficacy of these as a means of pr otecting USDWs.

Individual Response: EPA acknowledges that air and soil ga s monitoring are subject to sitespecific limitations and may not be suitable in all settings as a me thod to ensure USDW protection. However, EPA does not believe that this should entirely preclude their use. If surface monitoring were the only monitoring method employed to ensu re USDW protection, direct

correlation of CO2 at the surface with CO2 in th e subsurface might be difficult; however, when combined with information gathered through othe r monitoring techniques required of GS well owners and operators (e.g., monitoring wells, geophysical te chniques), air and soil gas monitoring may provide valuable data on the magnitude and location of a leak.

Used in conjunction with deep subsurface monitoring, as required at §146.90, and as part of a multi-barrier approach to protecting USDWs fr om endangerment, surface air and soil gas monitoring will increase USDW protection, enable immediate no tification of the UIC Director in the case of potential USDW endangerme nt, and facilitate remedial action.

The decision to use surface monitoring and the selection of monitoring methods will be sitespecific (e.g., may be influenced by geology, in jection depth, and opera tional conditions) and must be based on potential risks to USDWs within the AoR. The final rule at §146.90(h) retains

the allowance for surface air and soil gas monitoring at the discreti on of the Director as a means of identifying leaks that may pose a risk to USDWs and informing emergency notification of a Class VI owner or operator and UI C Director in the event of a USDW endangerment, pursuant to requirements at §146.91(c).

Letter ID: 0259 Comment ID: 24820 Letter Lines: 268 to 295

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

Comment: EPA Notice Questions: 73 FR 43518

EPA Rule Issue: 37. In addition to th e above recordkeeping and reporting requirements, EPA considered a requirement for owners or operators of GS sites to provide an annual report during the lifetime of the proj ect, including the post-injection period, regarding the GS operation. Although EPA has not included a requirement for this report in its pr oposal, EPA seeks comment regarding the necessity for such an annual report. EPA Notice 43518.

GWPC CO2 Committee Response: See Workgroup recommendation 7.6 for further

details.

11Report annually, or at a frequency acceptable to the Director, the characteristics and cumulative volumes (a nnual and total) of injected fluids, injection pressures, injection rates, a nnular pressures for each injection well, the results of any mechanical integrity tests conducted during this time period, available site integrity monitoring results , the extent of the injected CO2 and the pressure front ba sed on current data.

Update site operations as appropriate and site modeling results annually, or at a frequency acceptable to the Direct or, to reflect current data.

Compare the updated results to the previ ous results. Identify and explain to the Director any discrepancies between the updated results and the previous

results.

Note: Technology transfer is a better fo rum for driving regulatory changes. Do not support annual reporting as outlined in the preamble.

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

The final GS regulation does not include a re quirement for an annual report. Instead, EPA believes that periodic reevaluation of the AoR, as required at §146.84(e), along with any revisions to the required plans that may be necessary based on the AoR reevaluation, will promote an ongoing relationship between the permitti ng authority and the owner or operator. The final GS rule, at §§146.84(c), 146.90(j), and 146.94(d) , requires owners or operators to review and update the AoR and corrective action plan, the testing and monitoring plan, and the emergency and remedial response plan throughout the life of the project. Owners or operators must review each plan and identify necessary am endments to the plan or demonstrate to the

Director that no amendment is needed. These revi ews must be performed w ithin one year of an AoR reevaluation, following any significant chan ges to the facility (e.g., the addition of monitoring or injection wells), or when required by the Director . In no case can reviews occur

less often than once every five years.

For additional information, please see the final ru le and the preamble for a discussion of EPA's final approach to reco rdkeeping and reporting.

Letter ID: 0259 Comment ID: 24821 Letter Lines: 299 to 336

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

Comment: EPA Rule Issue: 38. EPA is proposing using a combination of fixed timeframe and a performance standard as described above. EPA is tent atively proposing a postinjection site care (monitoring) period of 50 years with Director’s discretion to change that period to le ngthen or shorten the 50 year period if appropriate.

12EPA requests comment on the proposed use of a tentative 50 year fixed timeframe

that could be modified at the Direct or’s discretion base d on monitoring and modeling data. EPA Notice 43519.

GWPC CO2 Committee Response: It is inap propriate to utilize a fixed period. A demonstration of non endangerment is an appropriate means of deciding when monitoring is no longer needed. The Committ ee recommends using a combination of the non-endangerment standard with speci fic performance standards as follows:

Prior to authorization for site closure, the owner or operator must demonstrate to the Director, based on monitoring, ot her site-specific da ta, and modeling that is reasonably consistent with site performance, that no additional monitoring is needed to assure that the geologic sequestration project does not and is not expected to pose an endangerme nt to USDWs. The Director shall approve closure if the owner or operator demonstrates, based on the current understanding of the site, in cluding monitoring data and/ or modeling, all of the following: (i) the estimated magnitude and extent of the projec t footprint (CO2 plume and the area of elevated pressure) ; (ii) the estimated location of the detectable CO2 plume; (iii) that there is no significant leakage of either CO2 or displaced formation fluids that is e ndangering USDWs; (iv) that the injected or displaced fluids are not expected to migrate in the future in a manner that encounters a potential leakage pathway into a USDW; (v) that th e injection wells at the site completed into or through the injection zone or confining zone are plugged and abandoned in accordance with these requirements; and (vi) any remaining project monitoring wells at the site are being managed by a person and in a manner acceptable to the Director.

Rationale: The fixed timeframe is not ad equately supported by scientific and technical evidence and represents an unnecessary departure from the use of performance standards, which EPA has rec ognized as the prefe rred approach in

most other situations. The use of "stabilization" as a performance standard is

not advised because of the difficu lties of dealing with background movement within the injection zone. Th e most important demonstration is containment, not just movement.

Individual Response: EPA agrees that there will be circumst ances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to

USDWs. For this reason, the GS ru le offers owners or operators flexibility regard ing the duration of the PISC timeframe by: (1) allowing the Direct or discretion to shorten or lengthen the PISC timeframe during the post-injecti on period based on site-specific da ta, pursuant to requirements at §146.93(b); or (2) affording the Director discretion to allow a Class VI well owner or operator to demonstrate, during the permitting process based on substantial data, that an alternative PISC timeframe may be appropriate if it ensu res non-endangerment of USDWs pursuant to requirements at §146.93(c).

EPA believes however, that to ensure USDW protection from enda ngerment, a default timeframe

13for post-injection site care will be necessary in most cases. The default 50 year post-injection site care timeframe represents a reasonable and prot ective monitoring period based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public

comments.

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

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

Letter ID: 0259 Comment ID: 24822 Letter Lines: 338 to 368

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

Comment: EPA Notice Questions: 144.36

EPA Rule Issue: 41. Current UIC guidance describes trust funds as a form of financial assurance. The owner or operat or may deposit funds into the trust fund in phases; that is, either over the te rm of the initial permit or over the remaining operating life of the injection well, as estimated in the well plugging plan, whichever period is shorter. Because of th e possibility that the owner or operator may face financial di stress prior to the trust being fully funded, EPA is considering a guidance appr oach that would recommend adopting a pay in period of three years for GS pr ojects, consistent with other similar programs in the Agency. EPA Notice 43521.

GWPC CO2 Committee Response: The Committee recommends that financial assurance requirements be based on costing of pl ans, with updating as appropriate to account for changed conditions and modified plans. The methods of providing FA should remain flexible, as EPA has propose d, to allow markets to adapt to the requirements and to identify methods for providing FA. Under any circumstances,

EPA should continue to use self-insurance mechanisms through a financial test. Any development of guidance for specific FA instruments should await the initial experience with those instruments, but would probably be ad dressed better through guidance than regulations to mainta in a greater amount of flexibility to adapt to changes in the ma rket that are likely to follow increased understanding of the technologies involved and operati ng experience with th ose technologies. All FA requirements should be released at closure.

Rationale: For any particular instru ment, the pay-in period should be commensurate with the risk profile. i. e. greater risk = faster pay-in.

14The plans should be updated as appropriate in conjunction with the iterative process of AoR reevaluations using da ta from monitoring and operational experience to reevaluate the modeling.

Individual Response: Owners or operators may choose from a variety of financial instruments to meet their financial responsibility obligations under the rule, provided th e Director determines that the operator's proposed financ ial responsibility demonstration is adequate to protect USDWs from endangerment, which means the ability of th e owner or operator to pay for each activity for which financial responsibility must be demonstr ated, including correctiv e action on wells in the AoR, injection well plugging, PISC and site cl osure, and emergency and remedial response throughout the life of the project. The final GS rule specifies at §146.85(a)(1) the permitted types of financial responsibility instru ments. See the final rule and pr eamble for further discussion of EPA's final approach to financial responsibility.

EPA will retain self insurance as an option for financial responsibility for Class VI wells. EPA believes that if properly used, the financial test can be an appropriate option for some owners or operators. EPA recognizes that it is important fo r self-insurers to be credit-worthy, otherwise USDWs may not be adequately protected. Owner or operators who choose to self-insure and use

the financial test must be able to demonstrate profitability, with a margin sufficient to cover contingencies and unknown obligations, and stabilit y. If the owner or operator meets corporate

financial test criteria, this is an indication that the owner or operator can guarantee its ability to satisfy financial obligations based solely on the strength of the company’ s financial condition. If an operator or operator is not ab le to meet the corporate financ ial test criteria may arrange a corporate guarantee by demonstrating that its cor porate parent meets the financial requirements

on its behalf.

EPA acknowledges that there may be several possi ble approaches to setting pay-in periods for trust funds. The final rule require s that the Director approve the use and length of pay-in periods. EPA is developing guidance (a vailable on EPA's website at http://water.epa.gov/type/groundwat er/uic/wells_sequest ration.cfm) that describes the types of financial instruments that owners or operato rs can use to meet financial responsibility requirements for GS wells. Specifically, the guida nce will discuss pay-in periods and provide guidance for Directors to use in determining an appropriate pay-in period. EPA adds that owners or operators may choose from a variety of fi nancial instruments to meet their financial responsibility needs.

EPA also agrees that it is impor tant to periodically update cost estimates that support financial responsibility determinations. EP A clarifies that the GS rule, at §146.85(c), requires the owner or operator to provide annual updates to the cost estimate to account for any amendments to the AoR and corrective action plan, the injection well plugging plan, the PISC and site closure plan, and the emergency and remedial response plan. The owner or operator must also adjust the cost estimate annually for inflation. EPA adds that the Director can also require the owner or operator to provide an adjustment of the cost estimate if the Director determines that the original demonstration is no longer adequa te, as specified at §146.85(e).

15Letter ID: 0259 Comment ID: 24823 Letter Lines: 370 to 408

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

Comment: EPA Notice Questions: 73 FR 43521

EPA Rule Issue: 42. Current UIC regu lations for Class I hazardous waste injection allow for the use of insurance for purposes of demons trating financial responsibility. However, insurance was not included as part of the guidance provided for Class II injection because th is insurance mechanism was and still is, rarely used for the purpose of de monstrating financia l assurance for injection wells. EPA is assessing whethe r to provide guidance on the use of insurance providers and, if so, whether to update eligibility requirements for

insurers for GS wells consistent with other current Federal agency practices.

EPA Notice 43521.

GWPC CO2 Committee Response: Leave the door open for establis hing financials mechanisms on a project by project basis. The rulemaking should not prescribe or preclude particular fina ncial instruments. The issu e of financial assurance is complex and must be considered in significant detail and should be based on the initial experience gained from the use of FA mechanisms before any guidance or regulation is issued.

EPA Notice Questions: 73 FR 43522

EPA Rule Issue: 43. EPA is assessing whet her a financial ratings threshold for all companies using a self-guarantee, si milar to those used by other Federal agencies, is appropriate. The Agency also is considering what constitutes an appropriate financial rating threshold, and whether a financial rating greater than BBB or Baa (i.e., the current rati ng threshold established under the UIC regulations) is appropriate for GS wells. EPA Notice 43522.

GWPC CO2 Committee Response: See response to #41.

EPA Notice Questions: 146.85

EPA Rule Issue: 44. EPA is request ing comments on whether financial responsibility mechanisms to be recommended in EPA gui dance should be adjusted

in the manner described, whether additional instruments should be included, and whether other adjustments to the financia l responsibility mechanisms should be considered, all subject to EPA’s aut hority under the SDWA. EPA Notice 43522.

GWPC CO2 Committee Response: See response to #41

Individual Response: As described above, owners or opera tors may choose from a variety of

16financial instruments listed in §146.85(a) to m eet their financial responsibility obligations, provided the Director determines that the operator's proposed financial responsibility demonstration is adequate to prevent endangerm ent of USDWs by demonstrating the ability to pay for each activity for which financial res ponsibility must be demonstrated, including corrective action on wells in the AoR, injecti on well plugging, PISC a nd site closure, and emergency and remedial response.

Letter ID: 0259 Comment ID: 24824 Letter Lines: 410 to 423

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

Comment: EPA Notice Questions: 73 FR 43522

EPA Rule Issue: 45. The Agency is also requesting comment on allowing separate

financial demonstrations to be submitted for the plugging of the injection well and for the post-injection site care requirements. EPA Notice 43522.

GWPC CO2 Committee Response: The Comm ittee supports the use of separate financial demonstrations for the pluggi ng of the injection well and for the post-injection site care requirements base d on the greater experience with well plugging requirements and methods. It will be easier to reta in certainty for

these actions and to use established FA methods.

Rationale: EPA should look into the opti ons available for single bonding with phased release and multiple bonding, as is done under SMCRA.

Individual Response: EPA will allow owners or operators to use separate or multiple financial responsibility instruments for different GS activ ities. However, owners or operators must demonstrate adequate financial responsibility for all required activities with their permit applications per §146.82(a)(14). In addition, on an annual basis, the owner or operator must adjust the cost estimate for inflat ion, increase or decrease the valu e of the financial instrument to match the cost estimate, and provide any upda ted information relate d to their financial responsibility instrument(s), or at any other time deemed appropriate by the Director. These annual reviews provide a mechanism for revisi ng cost estimates up or down to account for changes in the project, includi ng the execution of environmental obligations as phases of a GS project are completed.

EPA is developing guidance on financial responsibility for Class VI wells. The guidance will

include a discussion on how best to estimate costs to assist Class VI well owners or operators, third party insurers or providers of financial instruments, and permitting authorities in developing estimates of the costs associated with various GS activities. EPA will also discuss approaches to evaluate the appropriateness of single and multiple bonding and phased release of bonds in the guidance. EPA will review the requirements under SMCRA as it develops the guidance and incorporate any rele vant information. This guidance will be available on EPA's website at http://water.epa.gov/type/gr oundwater/uic/wells_se questration.cfm.

17Letter ID: 0259 Comment ID: 24825 Letter Lines: 425 to 437

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

Comment: EPA Notice Questions: 73 FR 43523

EPA Rule Issue: 46. EPA requests comment on adopting the existing requirements for public participation at 40 CFR Part 25 and 40 CFR Part 124 and whether additional requirements should be included to reflect the ava ilability of new tools for disseminating and gathering in formation. Such tools include cable

networks, the Internet, and othe r new technology. EPA Notice 43523.

GWPC CO2 Committee Response: Public partic ipation requirements for Class VI well permitting should follow established requirements for UIC program permitting, which have proven successful. Any modifi cations to account for technological advances should be considered on a program -wide basis; there is nothing unique about GS in this respect.

Individual Response: EPA agrees that the existing UIC pub lic participation requirements as specified in 40 CFR 25 and 40 CFR 124 are appropria te for GS projects. In addition, because of the unique nature of GS projects, and the anticipa ted level of public intere st in GS projects, EPA is not requiring the use of new information technol ogies, but encourages GS operators to use new information technologies whenever possible to ke ep the public informed of GS projects. EPA encourages early public involvement in GS projects. Providing th e public with accurate, project specific information in the early stages of each GS project can help clar ify project details and avoid public misperceptions about the nature and sa fety of GS projects, a nd will allow a potential GS owner or operator and the permitting agency to address the public's concerns before the permitting process is complete.

In response to the suggestion to apply additional public participa tion requirements to all injection

well classes, EPA notes that this is beyond the scope of the GS rulemaking.

Letter ID: 0259 Comment ID: 24826 Letter Lines: 439 to 454

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

Comment: EPA Notice Questions: 73 FR 43522-23

EPA Rule Issue: 47. EPA also requests co mment on ways to enhance the public participation process, including e ngaging communities in the site characterization process as soon as ca ndidate locations are identified. EPA

Notice 43523.

18GWPC CO2 Committee Response: This is be st left up to the discretion of the regulator. Establishing a process may provide a standard that can be followed by developers. There was concern about the term "as soon as". If included, this term should be changed to a more reasonable period following applicant evaluation of a site. Public participat ion requirements should be similar to other portions of the UIC program (e.g. Cl ass I). The program should assure a public hearings process when warranted by substantive issues and affected stakeholders but the timing and particul ars of the process should not be prescribed in the rule.

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. Generally, these regulations require the Director to notify the public regarding the availability of the draft permit and allow him or her to re quest a public hearing on the draft permit. Furthermore, §124.12(a) requires the Director to hold a public hear ing whenever he or she finds based on received comments articulating a significant degree of public interest in a draft permit.

EPA encourages operators and permitting agenci es to begin involving the public by providing information as early in the process as possible. Such information exchange can affect how the local community and surrounding communities percei ve potential environmental, economic, or

health effects.

Letter ID: 0259 Comment ID: 24827 Letter Lines: 473 to 493

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

Comment: EPA Notice Questions: 73 FR 43523

EPA Rule Issue: 49. There may be benefits to parsing out primacy for Class VI

wells, however EPA has not made a d ecision on this. Allowing States, Territories, and Tribes to acquire primacy for only Class VI wells may encourage them to assume the responsibility of implementation and provide for a more comprehensive approach to managing CCS projects (e.g., capture, transportation, and geologic sequestration). EPA is seeki ng comment on the merits and possible disadvantages of allowing primacy approva l for Class VI wells independent of

other well classes. EPA Notice 43523.

GWPC CO2 Committee Response: Resolution 08-1 of the GWPC strongly urges USEPA to allow for the granting of individual primacy to states for the Class VI program. We further support the preservation of state authority to determine what agencies will exercise primacy, strongly urge USEPA to provide adequate funding, which will require a substantial increase above current funding levels both to meet both existing UIC program needs and the additional resources anticipated to

19be necessary for the Class VI program. Ramp up of resources, personnel, and training should precede anticipated heavy demand.

Rationale: Submit GWPC resolution 08-1

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

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

EPA will also incorporate Class VI wells into the UIC Program's grant allocation process. The

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

Letter ID: 0259 Comment ID: 24828 Letter Lines: 495 to 514

Comment Code: 6220 3.2.2 Assumptions about the number of monitoring wells (seeking comment)

Comment: EPA Notice Questions: 73 FR 43527

EPA Rule Issue: 51. The Agency assumes th ree monitoring wells per injection well for the purpose of estimating national co sts; however, the Agency recognizes that operators and primacy agency Direct ors may choose more or fewer monitoring wells depending on project site character istics. Because the monitoring wells and associated costs represent a significan t component of the Cost Analysis, the Agency acknowledges that this factor may be significant in the overall uncertainty of the Cost Analysis. EP A requests comment on whether three monitoring wells per injection well is an appropriate costing assumption. EPA

Notice 43527.

GWPC CO2 Committee Response: The group is unsure as to EPA’s methodology for deciding on the number of monitoring wells since each project could be vastly different requiring a wide variety in numbers and types of any necessary monitoring wells. Also, it was felt that th e statement regarding the fact that monitoring wells are a significant portion of the cost s has not been supported by independent analysis as yet. Therefor e, the issue of numbers of monitoring wells is not yet ripe for a decision.

20Individual Response: EPA recognizes that the number of m onitoring wells associated with GS projects will be site-specific and vary based on many factors, including the local geologic characteristics, the presence of other injection wells, the size of the AoR, and volumes of CO2 injected. The proposed rule Cost Analysis descri bed the number of monitori ng wells as a ratio to the number of injection wells; EPA clarifies that the number of injection wells was based on the size of the AoR and the type of project. Therefor e, the number of monitori ng wells was indirectly based on the size of the AoR. Because ER projec t sites have injection wells that are more

clustered than those in saline formations, the AoR and the number of monitoring wells were anticipated to be smaller at an ER project si te compared to a saline formation project. EPA retained this assumption regarding the density of injection wells fo r the final rule analysis, but it changed its assumption on the number of monitori ng wells at each site. For the final rule, the Agency assumes one monitoring well above the inj ection zone per two square miles of AoR; for monitoring wells into the injection zone, the Agency assumes one monitoring well per four square miles. EPA assumes monitoring wells into th e injection zone will also be used to sample above the injection zone. The number of monitoring wells assumed for each project type is presented in Exhibit 5.2 of the Cost Analysis.

Because the actual number of monitoring wells that will be necessary for a given project site is

uncertain, EPA tested the sensitiv ity of overall cost estimates to the number of monitoring wells by applying a 25 percent decrease and increase in monitoring wells per project type to the original assumptions. This change results in a nnualized incremental rule costs approximately 16 percent less and 16 percent greate r than costs estimated for the primary analysis (as shown in Exhibit 5.26 of the Cost Analysis). For addi tional information on EPA's final regulatory approach, including testing and monitoring requireme nts, please see the final rule and preamble.

EPA is developing guidance on monitoring and testi ng to assist owners/ope rators and Directors in evaluating requirements under §146.90, including developing determining the appropriate number of monitoring wells for a GS site. This guidance will be available on EPA’s website at http://water.epa.gov/type/groundwater /uic/wells_sequestration.cfm.

Letter ID: 0259 Comment ID: 24829 Letter Lines: 515 to 517

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

Comment: There should not be a requirement for mon itor wells into the in jection zone, and monitor wells should not be required for the purpose of tracking the plume or pressure front.

Individual Response: EPA maintains that plume tracking and pressure monitoring are key components of monitoring at GS sites. A ri gorous plume tracking and pressure monitoring scheme, such as one that meets the requireme nts at §146.90(g), is imperative for ensuring that the CO2 plume is contained within the injec tion zone. The final GS rule, at §146.90(g)(1), requires GS well owners or operators to use dire ct methods to monitor fo r pressure changes in the injection zone. The purpose of monitoring in the injection zone is to track the development

21and movement of the pressure front and CO2 pl ume. This will support an understanding of site performance and verify predictive modeling. Pressu re monitoring within th e injection zone is necessary because any such monitoring above the confining zone would not detect movement of the pressure front unless a breach of the confining zone occurs.

Letter ID: 0259 Comment ID: 24830 Letter Lines: 519 to 528

Comment Code: 7700 4.7 Executive Order 13045: Child ren's Health Protection

Comment: EPA Notice Questions: 73 FR 43531

EPA Rule Issue: 52. The public is invited to submit comments or identify peerreviewed studies and data that assess the effects of early life exposure to changes in drinking water quality that may be caused by geologic sequestration

of carbon dioxide. EPA Notice 43531.

GWPC CO2 Committee Response: Studies al ready exist that address potential exposure issues, but there should be a recognition of the very low potential for exposure that exists for GS projects.

Individual Response: EPA is funding research related to the potential for USDW contamination associated with GS projects. In addition, the Agen cy is tracking external research that focuses on potential exceedances of drinking water standards, which were developed by EPA and take into account impacts on children's health.

In the August 31, 2009, Notice of Data Availabi lity (NODA) and Request for Comment (74 FR 44802), EPA published the results of a study in which Lawrence Berkeley National Laboratory (LBNL) evaluated the potential for GS to cause changes in ground water quality as a result of CO2 leakage and subsequent mobilization of trace elements such as arsenic, barium, cadmium, mercury, lead, antimony, selenium, zinc, and uranium (Birkholzer et al., 2008a). LBNL

estimated the amount of trace elements from na tive mineral species that could potentially be mobilized by the intrusion of CO 2 and the potential ground water con centrations that could result to determine the potential for drinking water standards to be exceeded. EPA has also examined potential methods for conducting treatment of wa ter affected by a CO2 leak; this study is presented in the final rulemaking docket.

EPA continues to fund research in this area. In December 2009, EPA's Office of Research and Development (ORD) awarded a Science to Achieve Results (STAR) grant to Clemson University to investigate the potential for GS to affect USDWs. This research will involve laboratory experiments and modeling simulations to invest igate the fate of dissolved CO2 in underground geologic formations and to determine possible ri sks associated with the dissolution of CO2 in underground aquifers. This STAR Grant is among six such grants awarded to major universities and institutions focusing on: "Integrated De sign, Modeling and Monitoring of Geologic Sequestration of Anthropogenic Carbon Dioxide to Safeguard Sources of Drinking Water."

EPA clarifies that the purpose of the GS rule is to protec t USDWs from endangerment through

22permitting, siting, construction, operation, injection, a nd post-injection site care and site closure requirements that are tailored to address the unique nature of GS. The Class VI requirements,

therefore, minimize health risk s to all populations, including ch ildren. The "Risk and Occurrence Document for the Geologic Sequestration Rule making," available in the rulemaking docket, presents a broad discussion of risks to human h ealth and the environment associated with GS, including those addressed under SDWA authority and those environmental and human health impacts that are beyond the scope of the SDWA.

As part of its adaptive rulemaking approac h, EPA plans to collect and review available

information such as the research described abov e and data every six year s on early GS projects, including impacts to USDWs and dr inking water quality that may aff ect the health of children, to determine whether the appropriate amount and t ypes of information and documentation are being

collected, and to determine if modifications to the requirements are a ppropriate or necessary.

Letter ID: 0259 Comment ID: 24831 Letter Lines: 539 to 547

Comment Code: 1000 1. General and Administrative Comments

Comment: Rule Provision: Part 144

EPA Proposal:1. The authority citation fo r part 144 continues to read as

follows:

Authority: 42 U.S.C. 300f et seq.; Res ource Conservation and Recovery Act, 42 U.S.C. 6901 et seq.

GWPC Recommendations: No comment necessary

Individual Response: EPA acknowledges the comment. The fi nal rule retain s this text.

Letter ID: 0259 Comment ID: 24832 Letter Lines: 549 to 573

Comment Code: 2020 1.5.1 Support Class VI designation

Comment: Rule Provision: 144.1

EPA Proposal:2. Section 144.1 is amended as follows:

Adding new paragraph (f)(1) (viii); and b. Revising the first two sentences in paragraph (g) introductory text.

* * * * *

(f) * * *

23(1) * * *

(viii) Subpart H of this part sets forth requirements for owners or operators of Class VI injection wells.

* * * * *

(g) Scope of the permit or rule requirem ent. The UIC Permit Program regulates underground injections by six classes of wells (see definition of "well injection," § 144.3). The six classes of wells are set forth in § 144.6. All owners or operators of these injection we lls must be authorized either by permit or rule by the Director. * * *

GWPC Recommendations: Support revision to include a sixth class of wells.

Individual Response: EPA agrees that tailored requirements for Class VI wells are necessary to address the unique nature of in jecting large volumes of CO2 a nd to ensure that USDWs are protected from endangerment. The GS rule c ontains tailored requirements for the permitting, geologic site characterization, AoR and corre ctive action, well construction, operation, mechanical integrity testing, monitoring, well plu gging, post-injection site care, and site closure of GS wells that directly addre ss issues unique to the nature of large-scale CO2 injection for GS.

Letter ID: 0259 Comment ID: 24833 Letter Lines: 575 to 611

Comment Code: 2000 1.5 Need for a New Class of Injection Well

Comment: Rule Provision: 144.6

EPA Proposal: 3. Section 144.6 is amended as follows:

Revising paragraph (e); and

b. Adding new paragraph (f).

* * * * *

(e) Class V. Injection wells not includ ed in Class I, II, III, IV, or VI. Specific types of Class V injecti on wells are described in § 144.81.

(f) Class VI. Wells used for geologic se questration of carbon dioxide beneath the lowermost formation containing a USDW.

GWPC Recommendations: (4) For enhanced r ecovery of oil or natural gas where geologic sequestration is occurring duri ng or in connection with enhanced recovery of oil or natural gas provided (i) there is reasonable expectation of

24more than insignificant future production volumes or rate s as a result of carbon dioxide injection and (ii) operating pressures are no higher than reasonably necessary to produce such volumes or rates;

(f) Class VI. Wells injecting a car bon dioxide stream for geologic sequestration except those wells described in subsection (b)(4) of this section

or otherwise excluded from this Class.

Rationale: There should not be a blanket prohibition concerning injection above USDW’s or at specific le vels. The determination of injection zones should be based upon appropriate containment. This is especially true in light of recent calls for changes in the definition of a US DW to include formations greater than

10K PPM TDS and the fact that several states including Wyoming and California might be prevented from instituting geol ogic sequestration as a practical matter if injection were limited to above USDW’s due to the great depth of some USDW’s.

This would create a situation where otherwise good inje ction zones are artificially excluded, thus decreasing the overall availability of geologic sequestration in the U.S.

Individual Response: EPA acknowledges that there are lim ited circumstances where injection above the lowermost USDW can be performed in a manner that protects USDWs. The final GS rule at §146.95 establishes a proce ss by which owners or operators can seek a waiver of the Class VI injection depth requirements. The waiver approach requires th e submission of extensive, sitespecific information (in conjunction with the perm it application submittal) to demonstrate that injection of CO2 into a formation that is abov e or between USDWs can be done in a manner that is protective of USDWs. The requirements are de signed to ensure the ow ner or operator, the Director, and the Regional Administrator consider, on a site specific basis, the implications, benefits, and challenges associated with GS and ensuring water availability and USDW protection.

Letter ID: 0259 Comment ID: 24835 Letter Lines: 613 to 621

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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: The GWPC also recommends EPA consider retaining all geologi c sequestration in oil and gas reservoirs under the juri sdiction of Class II UIC programs and create a subclass within this program fo r geologic storage of carbon dioxide. This subclass (Class II GS) would be used for those wells that depart from the

traditional uses of Class II wells for e nhanced recovery, and result in the application of Class VI standards. This change would eliminate any confusion over whether a Class II CO2 injection well us ed for enhanced recovery might also need a Class VI permit and would avoid th e need to change jurisdiction for a well from one state agency to another over time.

25Individual Response: EPA disagrees that the risks posed by long term storage of CO2 for GS can be addressed under existing UIC requirements, such as those for Class II wells. EPA believes

and the administrative record s upports that there are significan t differences between how EOR and GS projects are operated, as well as the di fferent risks posed by these different injection activities. The new tailored approach of the GS rule was designed to address the general risks deep injection may pose to USDWs and was tailore d specifically to addr ess the risks posed by long term storage of CO2 (i.e., very large volumes, very long time-periods, and reservoir pressure conditions).

In response to the comment on the burden of cha nging regulatory agencies in the middle of an operation, EPA clarifies that primacy is granted to a state, not to a specif ic agency within that state, and states may choose which agency impl ements the Class VI program. States may, for example, choose an environmental quality prot ection agency (non-Cla ss II) or the state's traditional oil and gas regulatory agency to implement the Class VI program as long as the program meets the minimum federa l requirements for Class VI we lls as required under section 1422 of SDWA. Some states manage all inject ion well classes under Section 1422 and through a single agency, while in other states, Class II programs are run by oil and gas agencies.

Regardless of the specific Agency the state select s to assume regulatory authority for Class VI operations, the state must obtain primacy for th e 1422 Class VI program. Furthermore, the state may determine that a memorandum of understand ing (MOU) between several state agencies regarding specific projects can f acilitate this process without needing to change regulatory agencies after Class II projects have transitioned to a Class VI permit.

Letter ID: 0259 Comment ID: 24836 Letter Lines: 625 to 647

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 2048 1.5.2.4 Oppose Class VI/ Support Class V experimental technology well

Comment: EPA Proposal: 4. Adding § 144.15 to read as follows.

§ 144.15 Prohibition of non-experimental Class V wells for geologic sequestration.

The construction, operation or maintenan ce of any non-experimental Class V geologic sequestration well is prohibited.

GWPC Recommendations: This provision shou ld be deleted if EPA does limit Class VI wells to injection below the lowermost USDW in the final rule to allow Directors to selectively authorize GS in areas with USDWs below the injection

zone.

In addition, it is recommended that all GS into basalts, coal seams, salt domes,

and shales be conducted under Class V as e xperimental wells initially and then as commercial scale Class V wells/pro jects if the experimental projects

26demonstrate that these sites can be suitable for geological sequestration while preventing endangerment of USDWs.

Rationale: Keeping these wells under Class V would allow EPA and the states to gain enough experience to develop suitable permitting requirements for such wells and to tailor those requirements un til the agencies are ready to adapt the Class VI regulations.

Individual Response: The text at 144.15 is retained in th e final regulation; the construction, operation or maintenance of any non-experimental Class V GS well is prohibited under the final rule. The final rule contains tailored requirements for Class VI wells to ensure that GS projects are permitted sited, constructed, operated, and closed in a manner that does not endanger

USDWs.

EPA also clarifies that the final GS rule does no t categorically preclude injection of CO2 into any formation types. Existing experimental GS projects may be permitted as described in UIC Program Guidance #83: Using the Class V Expe rimental Technology Well Classification for Pilot Carbon Geologic Sequestration Projects, which provided information for permitting authorities to consider when permitting experiment al GS projects (i.e., those projects that are designed to test new, unproven technologies, per the definition of a Class V experimental technology well). EPA adds that, fo llowing finalization of the GS ru le, all GS projects that are not for experimental purposes must be re-permitted as Class VI wells and be subject to the final GS requirements. EPA expects th at, after promulgation of the fi nal rule, a limited number of experimental injection projects to test GS technology will continue, e.g., to inform the technology associated with GS into ba salts, coal seams, and salt domes.

The Agency also clarifies that it does not consider it appropriate to permit CO2 injection wells that are testing the injectivity or appropriateness of an individual forma tion (e.g., as a prelude to a commercial-scale operation) as Class V expe rimental technology wells. Such wells must be permitted as Class VI wells.

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

Letter ID: 0259 Comment ID: 24837 Letter Lines: 649 to 660

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment: Rule Provision: 144.18

EPA Proposal: 5. Adding § 144.18 to read as follows.

27§ 144.18 Requirements for class VI wells.

Owners or operators of Class VI wells mu st obtain a permit. Class VI wells are not authorized by rule to inject.

GWPC Recommendations: Support the proposed language.

Rationale: Agree with EPA’s rationale.

Individual Response: EPA acknowledges the comment. For additional information on EPA's final regulatory approach, please see the final rule and preamble as well as the rulemaking

docket.

Letter ID: 0259 Comment ID: 24838 Letter Lines: 662 to 681

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3500 2.2.3 Area of Review Reevaluation (seeking comment)

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

Comment: Rule Provision: 144.36

EPA Proposal: 6. Section 144.36 is amended by revising the first two sentences in paragraph (a) to read as follows:

§ 144.36 Duration of permits.

(a) Permits for Class I and V wells shall be effective for a fixed term not to exceed 10 years. UIC Permits for Class II, III and VI wells shall be issued for a period up to the operating lif e of the facility. * * *

* * * * *

GWPC Recommendations: Support the proposed language.

Rationale: The proposed provision is cons idered acceptable as long as the iterative reevaluation process establishe d for AoRs also applies to other aspects of the project including mode ling, characterization, operational decisions, monitoring, financial assuran ce, etc. It is recognized that Directors may also depend on 144.39 regard ing modification and revocation of Class VI permits.

Individual Response: EPA acknowledges the commenter’s suppor t and notes that the final rule retains this requirement. The final rule maintains the lifetime permit provision and clarifies that the permit extends through the post-injection site care period (144.36(a )). It also adds a requirement that the Director review each Class VI permit at least once every 5 years to

determine whether it should be modified, re voked and reissued, terminated or a minor

28modification made as provided in §§144.39, 144.40, or 144.41. The Director’s review will be informed by the owners’ or operato rs’ iterative reev aluation of the project. Specifically, the final rule includes a requirement that the AoR be reev aluated at least every five years, and also requires owners or operators to review and update the AoR and corrective action plan, the testing and monitoring plan, and the emergency and reme dial response plan th roughout the life of the project (146.84(e), 146.90(j), and 146.94(d)). Owners or operators must review each plan and identify necessary amendments or demonstrate to the Director that no amendment is needed. In

no case can reviews occur less often than once ev ery five years. The iterative process and subsequent plan reevaluations ensure that time and resources are committed to the most critical aspects of the permit in preventing endangermen t to USDWs. EPA believes that the iterative process of developing and executing the various pl ans required of GS well operators in the final rule (e.g., for AoR and corrective action, testi ng and monitoring, inject ion well plugging, postinjection site care, and emergenc y and remedial response) is tail ored to the unique aspects of— and is more appropriate for–GS than es tablishing a finite permit duration.

EPA emphasizes that the final rule requires owners or operators to revise their cost estimates for financial assurance within 60 days of amendmen ts to the AoR and corrective action plan, the injection well plugging plan, the po st-injection site care and site closure plan, or the emergency and remedial response plan (40 CFR 146.85(c)(2).

EPA emphasizes that, the Director has the author ity to revise the permit if project operations change or if the Director belie ves based on monitoring or operati onal data that the project may endanger USDWs. EPA has also added text to 144.39(a)(5) that permit m odifications would be required if the Director determines that a modification is necessary based on an AoR reevaluation, amendments to any of the project pl ans, or a review of the testing and monitoring results. The Director may also choose to re quire minor permit modifications under 40 CFR 144.41, depending on the extent of the plan amendm ent. All permit modifications, except minor modifications under 40 CFR 144.41, require an oppor tunity for public comment on the portion of the permit that is being reopened pursuant to requirements under 40 CFR Part 124.

Letter ID: 0259 Comment ID: 24839 Letter Lines: 683 to 693

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 5900 2.14 Other administrative re quirements under 40 CFR 144

Comment: EPA Proposal: 7. Section 144.39 is amended by revising the second sentence in paragraph (a) introductory text and by re vising the second sentence in paragraph (a)(3) introductory text to read as follows:

§ 144.39 Modification or revocation and reissuance of permits.

* * * * *

GWPC Recommendations: Support the proposed language.

Rationale: Agree with EPA’s rationale.

29Individual Response: EPA acknowledges the comment. Pleas e see the remainder of EPA's responses to this comment letter for further de tails. For additional information on EPA's final regulatory approach, please see the final rule and preamble as well as the rulemaking docket.

Letter ID: 0259 Comment ID: 24840 Letter Lines: 695 to 711

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 5900 2.14 Other administrative re quirements under 40 CFR 144

Comment: Rule Provision: 144.39

EPA Proposal: (a) * * * For Class I h azardous waste injection wells, Class

II, Class III or Class VI wells the fo llowing may be causes for revocation and

reissuance as well as modification; and fo r all other wells the following may be

cause for revocation or reissuance as we ll as modification when the permittee requests or agrees. * * *

* * * * *

(3) * * * Permits other than for Cla ss I hazardous waste injection wells,

Class II, Class III or Class VI wells ma y be modified during their terms for this cause only as follows: * * * * * * * *

GWPC Recommendations: Support the proposed language.

Rationale: Agree with EPA’s rationale.

Individual Response: EPA acknowledges the comment. Pleas e see the remainder of EPA's responses to this comment letter for further de tails. For additional information on EPA's final regulatory approach, please see the final rule and preamble as well as the rulemaking docket.

Letter ID: 0259 Comment ID: 24842 Letter Lines: 748 to 757

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 5900 2.14 Other administrative re quirements under 40 CFR 144

Comment: EPA Proposal: (2) When the Director determ ines that a Class I, II, III or VI

well lacks mechanical inte grity pursuant to § 146.8 or § 146.89 for Class VI of this chapter, he/she shall give written notice of his/ her determination to the owner or operator. * * *

* * * * *

30GWPC Recommendations: Support the proposed language.

Rationale: Agree with EPA’s rationale.

Individual Response: EPA acknowledges the comment. Pleas e see the remainder of EPA's responses to this comment letter for further de tails. For additional information on EPA's final regulatory approach, please see the final rule and preamble as well as the rulemaking docket.

Letter ID: 0259 Comment ID: 24843 Letter Lines: 759 to 778

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 5900 2.14 Other administrative re quirements under 40 CFR 144

Comment: Rule Provision: 144.52

EPA Proposal: 9. Section 144.52 is amende d by revising paragraph (a)(8) to

read as follows:

§ 144.52 Establishing permit conditions.

(a) * * *

(8) Mechanical integrity. A permit for a ny Class I, II, III or VI well or injection project which lacks mechanical integrity shall include, and for any Class V well may include, a condition pr ohibiting injection operations until the permittee shows to the satisfaction of the Director under § 146.08 or § 146.89 for Class VI that the well has mechanical integrity.

* * * * *

GWPC Recommendations: Support the proposed language.

Rationale: Agree with EPA’s rationale.

Individual Response: EPA acknowledges the comment. Pleas e see the remainder of EPA's responses to this comment letter for further de tails. For additional information on EPA's final regulatory approach, please see the final rule and preamble as well as the rulemaking docket.

Letter ID: 0259 Comment ID: 24844 Letter Lines: 780 to 796

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 5900 2.14 Other administrative re quirements under 40 CFR 144

31Comment: Rule Provision: 144.55

EPA Proposal: § 144.55 Corrective action.

(a) Coverage. Applicants for Class I, II, (other than existing), III or VI injection well permits shall identify the location of a ll known wells within the injection well’s area of review which pe netrate the injection zone, or in the case of Class II wells operating over the fracture pressure of the injection

formation, all known wells within the area of review penetrating formations affected by the increase in pressure. A pplicants for Class VI shall perform corrective action as spec ified in § 146.84.* * *

* * * * *

GWPC Recommendations: Support the proposed language.

Rationale: Agree with EPA’s rationale.

Individual Response: EPA acknowledges the comment. Pleas e see the remainder of EPA's responses to this comment letter for further de tails. For additional information on EPA's final regulatory approach, please see the final rule and preamble as well as the rulemaking docket.

Letter ID: 0259 Comment ID: 24845 Letter Lines: 798 to 840

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

USDW

Comment: Rule Provision: 144.80

EPA Proposal: 11. Section 144.80 is amended by revising the first sentence in paragraph (e) and by adding paragr aph (f)to read as follows:

§ 144.80 What is a Class V injection well? * * * * *

(e) Class V. Injection wells not included in Class I, II, III, IV or VI. * *

*

(f) Class VI. Wells used for geologi c sequestration of carbon dioxide.

GWPC Recommendations: (4) For enhanced r ecovery of oil or natural gas where geologic sequestration is occurring duri ng or in connection with enhanced recovery of oil or natural gas provided (i) there is reasonable expectation of more than insignificant future production volumes or rate s as a result of carbon

32dioxide injection and (ii) operating pressures are no higher than reasonably necessary to produce such volumes or rates;

(f) Class VI. Wells injecting a car bon dioxide stream for geologic sequestration except those wells described in subsection (b)(4) of this section

or otherwise excluded from this Class.

Rationale: There should not be a blanket prohibition concerning injection above USDW’s or at specific le vels. The determination of injection zones should be based upon appropriate containment. This is especially true in light of recent calls for changes in the definition of a US DW to include formations greater than

10K PPM TDS and the fact that several states including Wyoming and California might be prevented from instituting geol ogic sequestration as a practical matter if injection were limited to above USDW’s due to the great depth of some USDW’s.

This would create a situation where otherwise good inje ction zones are artificially excluded, thus decreasing the overall availability of geologic sequestration in the U.S.

The GWPC also recommends EPA consider retaining all geologi c sequestration in oil and gas reservoirs under the juri sdiction of Class II UIC programs and create a subclass within this program fo r geologic storage of carbon dioxide. This subclass (Class II GS) would be used for those wells that depart from the

traditional uses of Class II wells for e nhanced recovery, and result in the application of Class VI standards. This change would eliminate any confusion over whether a Class II CO2 injection well us ed for enhanced recovery might also need a Class VI permit and would avoid th e need to change jurisdiction for a well from one state agency to another over time.

Individual Response: EPA acknowledges that there are lim ited circumstances where injection above the lowermost USDW can be performe d in a manner that protects USDWs from endangerment, as long as appropriate protections are in place. The final GS rule at §146.95 establishes a process by which owne rs or operators can seek a waiv er of the Class VI injection depth requirements for injecti on into non-USDW formations above and/or between USDWs. It establishes: 1) requirements spec ifying information that owners or operators must submit, and

Directors must consider, in consultation with PW SS Directors; 2) procedures for public notice of a waiver application and for Director-Regiona l Administrator communicat ion; 3) the waiver issuance process; and, 4) additiona l requirements that apply to owne rs or operators of Class VI wells granted a waiver of the in jection depth requirements to en sure USDW protection above and below the injection zone.

EPA adds that it has revised the definition of a Cl ass VI well to read as follows: “Wells that are not experimental in nature that are used for geologic sequestra tion of carbon dioxide beneath the lowermost formation containing a USDW; or, we lls used for geologic sequestration of carbon dioxide that have been granted a waiver of the injection depth requirements pursuant to requirements at §146.95 of this chapter; or, we lls used for geologic sequestration of carbon

dioxide that have received an e xpansion to the areal extent of an existing Class II enhanced oil

33recovery or enhanced gas rec overy aquifer exemption pursuant to §§146.4 of this chapter and 144.7(d).”

For additional information on the waiver approa ch, please see the final rule and preamble, as well as EPA's responses to comments on the No tice of Data Availability and Request for

Comment.

In response to the comment that GS wells shoul d be regulated as Class II wells, EPA believes that injection for the primary purpose of long term storage is sufficiently different from Class II ER operations and warrant s tailored requirements. For exampl e, the volume of CO2 anticipated to be injected in Class VI wells is significantly greater than for Class II wells. Reservoir pressure

conditions will also be different, with Class VI injection operations involving large volumes of CO2 and likely having higher pressure s within their storage formations than Class II ER projects. The Director has the authority to determine at wh at point a Class VI permit is required for those projects that are transitioning from the primar y purpose of EOR to long term storage of CO2. The final regulation provides a set of technical factors for the Direct or to evaluate in making this determination, at §144.19. EPA believes that this approach provides su fficient protection of

USDWs when there is an increased risk to USDWs as compared to traditi onal Class II operations while allowing for site-specific flexibility. EPA is developing guidance on transitioning permits from Class II to Class VI. The guidance will assist Directors in determining whether an injection project should be transitioned from Class II where the primary purpose is oil and gas production to Class VI where the primary purpose is long-t erm storage of large volumes of CO2. This guidance will be available on EPA’s website at http://water.epa.gov/type/groundwater /uic/wells_sequestration.cfm.

EPA also recognizes that ther e is increasing demand for wate r resources and that technology improvements may make high TDS aquifers viable drinking water sources. However, EPA is not changing the USDW definition; changing the definition of a USDW is outside the scope of the GS rulemaking. The GS rule focuses on ensuring protection of USDWs, as required under the SDWA, by establishing regulations to ensure the safe injection of CO2 for long-term storage.

Letter ID: 0259 Comment ID: 24846 Letter Lines: 832 to 840

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: The GWPC also recommends EPA consider retaining all geologi c sequestration in oil and gas reservoirs under the juri sdiction of Class II UIC programs and create a subclass within this program fo r geologic storage of carbon dioxide. This subclass (Class II GS) would be used for those wells that depart from the

traditional uses of Class II wells for e nhanced recovery, and result in the application of Class VI standards. This change would eliminate any confusion over whether a Class II CO2 injection well us ed for enhanced recovery might also need a Class VI permit and would avoid th e need to change jurisdiction for a well from one state agency to another over time.

34Individual Response: EPA disagrees that the risks posed by long term storage of CO2 for GS can be addressed under existing UIC requirements, such as those for Class II wells. EPA believes

and the administrative record s upports that there are significan t differences between how EOR and GS projects are operated, as well as the di fferent risks posed by these different injection activities. The new tailored approach of the GS rule was designed to address the general risks deep injection may pose to USDWs and was tailore d specifically to addr ess the risks posed by long term storage of CO2 (i.e., very large volumes, very long time-periods, and reservoir pressure conditions).

In response to the comment on the burden of cha nging regulatory agencies in the middle of an operation, EPA clarifies that primacy is granted to a state, not to a specif ic agency within that state, and states may choose which agency impl ements the Class VI program. States may, for example, choose an environmental quality prot ection agency (non-Cla ss II) or the state's traditional oil and gas regulatory agency to implement the Class VI program as long as the program meets the minimum federa l requirements for Class VI we lls as required under section 1422 of SDWA. Some states manage all inject ion well classes under Section 1422 and through a single agency, while in other states, Class II programs are run by oil and gas agencies.

Regardless of the specific Agency the state select s to assume regulatory authority for Class VI operations, the state must obtain primacy for th e 1422 Class VI program. Furthermore, the state may determine that a memorandum of understand ing (MOU) between several state agencies regarding specific projects can f acilitate this process without needing to change regulatory agencies after Class II projects have transitioned to a Class VI permit.

Letter ID: 0259 Comment ID: 24847 Letter Lines: 713 to 746

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3866 2.3.3.3 Logging and testing requirements (40 CFR 146.87)

Comment: Rule Provision: 144.51

EPA Proposal: 8. Section 144.51 is amended by revising the first sentence in paragraph (q)(1) and the first sentence in paragraph (q)(2) to read as follows:

§ 144.51 Conditions applicable to all permits.

* * * * *

(q) * * *

(1) The owner or operator of a Class I, II, III or VI well permitted under this part shall establish mechanical integrity prior to commencing injection or on a schedule determined by the Director. Ther eafter the owner or operator of Class

I, II, and III wells must maintain mech anical integrity as defined in § 146.8 and the owner or operator of Class VI wells must maintain mechanical integrity

35as defined in § 146.89 of this chapter. * * *

GWPC Recommendations: (q) * * *

(1) The owner or operator of a Class I, II, III or VI well permitted under this part shall establish mechanical integrity prior to commencing injection or on a schedule determined by the Director. Ther eafter the owner or operator of Class

I, II, and III wells must maintain mechan ical integrity as de fined in §146.8 and the owner or operator of Class VI wells mu st maintain mechanical integrity as defined in §146.89 of this chapter.

Rationale: EPA may want to reconsider the use of the term "or" as this implies that an initial MIT can be optional based on Directors discretion which contradicts 146.89 with respect to Cla ss VI wells. Alternatively, the two provisions can be read toge ther to require an initia l MIT and to give the Director limited discretion to allow the scheduling of the initial MIT after some injection has occurred, such as ma y be required during initial testing of the well and injection zone.

Individual Response: EPA disagrees that the suggested edit is needed, and clarifies that all owners or operators must demonstrate internal and external mechani cal integrity prior to commencing injection as required at §146.87(a)(4).

Letter ID: 0259 Comment ID: 24848 Letter Lines: 842 to 851

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 5900 2.14 Other administrative re quirements under 40 CFR 144

Comment: Rule Provision: Part 146

EPA Proposal: 12. The authority citation fo r part 146 continues to read as

follows:

Authority: Safe Drinking Water Act 42, U.S.C. 300f et seq.; Resource Conservation and Recovery Ac t, 42 U.S.C. 6901 et seq.

GWPC Recommendations: Support the proposed language.

Individual Response: EPA acknowledges the comment. Pleas e see the remainder of EPA's responses to this comment letter for further de tails. For additional information on EPA's final regulatory approach, please see the final rule and preamble as well as the rulemaking docket.

36Letter ID: 0259 Comment ID: 24849 Letter Lines: 854 to 896

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

USDW

Comment: Rule Provision: 146.5

EPA Proposal: 13. Section 146.5 is amended as follows:

a. Revising the first sentence in pa ragraph (e) introduc tory text; and

b. Adding paragraph (f).

(f) Class VI. Wells used for geologic se questration of carbon dioxide beneath the lowermost formation containing an underground source of drinking water (USDW).

GWPC Recommendations: (4) For enhanced r ecovery of oil or natural gas where geologic sequestration is occurring duri ng or in connection with enhanced recovery of oil or natural gas provided (i) there is reasonable expectation of more than insignificant future production volumes or rate s as a result of carbon dioxide injection and (ii) operating pressures are no higher than reasonably necessary to produce such volumes or rates;

(f) Class VI. Wells injecting a car bon dioxide stream for geologic sequestration except those wells described in subsection (b)(4) of this section

or otherwise excluded from this Class.

Rationale: There should not be a blanket prohibition concerning injection above USDW’s or at specific le vels. The determination of injection zones should be based upon appropriate containment. This is especially true in light of recent calls for changes in the definition of a US DW to include formations greater than

10K PPM TDS and the fact that several states including Wyoming and California might be prevented from instituting geol ogic sequestration as a practical matter if injection were limited to above USDW’s due to the great depth of some USDW’s.

This would create a situation where otherwise good inje ction zones are artificially excluded, thus decreasing the overall availability of geologic sequestration in the U.S.

The GWPC also recommends EPA consider retaining all geologi c sequestration in oil and gas reservoirs under the juri sdiction of Class II UIC programs and create a subclass within this program fo r geologic storage of carbon dioxide. This subclass (Class II GS) would be used for those wells that depart from the

traditional uses of Class II wells for e nhanced recovery, and result in the application of Class VI standards. This change would eliminate any confusion

37over whether a Class II CO2 injection well us ed for enhanced recovery might also need a Class VI permit and would avoid th e need to change jurisdiction for a well from one state agency to another over time.

Individual Response: Please see the response to the comment er’s suggested revision to §144.80.

Letter ID: 0259 Comment ID: 24850 Letter Lines: 888 to 896

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: The GWPC also recommends EPA consider retaining all geologi c sequestration in oil and gas reservoirs under the juri sdiction of Class II UIC programs and create a subclass within this program fo r geologic storage of carbon dioxide. This subclass (Class II GS) would be used for those wells that depart from the

traditional uses of Class II wells for e nhanced recovery, and result in the application of Class VI standards. This change would eliminate any confusion over whether a Class II CO2 injection well us ed for enhanced recovery might also need a Class VI permit and would avoid th e need to change jurisdiction for a well from one state agency to another over time.

Individual Response: EPA disagrees that the risks posed by long term storage of CO2 for GS can be addressed under existing UIC requirements, such as those for Class II wells. EPA believes

and the administrative record s upports that there are significan t differences between how EOR and GS projects are operated, as well as the di fferent risks posed by these different injection activities. The new tailored approach of the GS rule was designed to address the general risks deep injection may pose to USDWs and was tailore d specifically to addr ess the risks posed by long term storage of CO2 (i.e., very large volumes, very long time-periods, and reservoir pressure conditions).

In response to the comment on the burden of cha nging regulatory agencies in the middle of an operation, EPA clarifies that primacy is granted to a state, not to a specif ic agency within that state, and states may choose which agency impl ements the Class VI program. States may, for example, choose an environmental quality prot ection agency (non-Cla ss II) or the state's traditional oil and gas regulatory agency to implement the Class VI program as long as the program meets the minimum federa l requirements for Class VI we lls as required under section 1422 of SDWA. Some states manage all inject ion well classes under Section 1422 and through a single agency, while in other states, Class II programs are run by oil and gas agencies.

Regardless of the specific Agency the state select s to assume regulatory authority for Class VI operations, the state must obtain primacy for th e 1422 Class VI program. Furthermore, the state may determine that a memorandum of understand ing (MOU) between several state agencies regarding specific projects can f acilitate this process without needing to change regulatory agencies after Class II projects have transitioned to a Class VI permit.

38Letter ID: 0259 Comment ID: 24851 Letter Lines: 898 to 915

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment: Rule Provision: Part 146 Subpart H

EPA Proposal: 14. Subpart H is added to read as follows:

Subpart H - Criteria and Standards Applicable to Class VI Wells

Sec.

146.82 Required Class VI permit information. 146.83 Minimum criteria for siting.

146.84 Area of review a nd corrective action. 146.85 Financial responsibility. 146.86 Injection well constr uction requirements. 146.87 Logging, sampling, and testing prio r to injection well operation.

GWPC Recommendations: Support the proposed language.

Rationale: Agree with EPA’s rationale.

Individual Response: EPA acknowledges the comment. For additional information on EPA's final regulatory approach, please see the final rule and preamble as well as the rulemaking

docket.

Letter ID: 0259 Comment ID: 24852 Letter Lines: 927 to 944

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment: EPA Proposal: (b) This subpart applies to wells used to inject carbon dioxide specifically for the purpose of geologi c sequestration, i.e., the long-term containment of a gaseous, liquid or s upercritical carbon dioxide stream in subsurface geologic formations.

GWPC Recommendations: (b) This subpart ap plies to wells used to inject carbon

dioxide streams into saline forma tions for the purpose of geologic sequestration, i.e., the long-term contai nment of a carbon dioxide stream in subsurface geologic formations.

Rationale: Use of the term "specifically " was removed as it implied Class VI wells could not be used for multiple purposes and still be Class VI

Remove "gaseous, liquid or supercritical " as these terms are implied by the use

39of the term carbon dioxide.

See the rationale discussion under 146.85 re garding inclusion or exclusion of

the term "saline"

Individual Response: EPA disagrees with the suggested change. EPA believes that this paragraph, along with the definition of a CO2 stream at §146.81(d), appropriately convey the allowable injection activities that may be perm itted as Class VI. For additional information on EPA's final regulatory approach, please see the fi nal rule and preamble as well as the rulemaking

docket.

Letter ID: 0259 Comment ID: 24853 Letter Lines: 946 to 964

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment: EPA Proposal: (c) This subpart applies to owners and operators of permit or

rule-authorized Class I industrial, Cla ss II, or Class V experimental carbon dioxide injection projects who seek to apply for a Class VI geologic sequestration permit for their well or wells. If the Director determines that USDWs will not be endangered, such wells are exempt, at the Director’s discretion, from the casing and cementi ng requirements at §§ 146.86(b) and 146.87(a)(1) through (3).

GWPC Recommendations: (c) This subpart appl ies to owners and operators of permit

or rule-authorized Class I industrial, Class II, or Cl ass V experimental carbon dioxide injection projects who seek to apply for a Class VI geologic sequestration permit for their well or we lls or to convert to Class II GS operation. If the Director determines th at USDWs will not be endangered, such wells are exempt, at the Director’s disc retion, from such Class VI requirements contained in this subpart as the Director specifies.

Rationale: The proposed EPA waiver app lies only to the casing and cementing requirements. Directors shoul d have the flexibility to waive other requirements as appropriate for conversions to Class VI.

Individual Response: EPA disagrees with commenters who suggest that other requirements (outside of well construction) should also be grandfathered. Following re-permitting of the project as GS, many of the unique factors of GS sites (e.g., increased reservoir pressures associated with large volumes of stored CO2 a nd the corrosivity of CO2 in the presence of water) will result in an increased risk profile, warra nting the specific requirements in the final GS rule. Therefore, following re-permitting as Class VI wells, these projects must be subject to the operational, MIT, monitoring, reporting, plugging, a nd post-injection site ca re and site closure requirements in the final GS rule. See the discus sion of EPA's final regulatory approach in the preamble to the GS rule for additional detail on these requirements.

40Letter ID: 0259 Comment ID: 24854 Letter Lines: 966 to 989

Comment Code: 1220 1.1.1.1 Terminology and definitions

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

Comment: Rule Provision: 146.81(d) Definitions

EPA Proposal: (d) Definitions. The following definitions apply to this subpart. To the extent that these defi nitions conflict with those in § 146.3 these definitions govern:

Area of review means the region surrounding the geologic sequestration project that may be impacted by the injection ac tivity. The area of review is based on computational modeling that accounts for th e physical and chemi cal properties of all phases of the injected carbon dioxide stream.

GWPC Recommendations: Area of review means the subsurface three-dimensional extent of the carbon dioxide stream pl ume associated pressure front, and displaced brine, as well as the overlying formations and surface area above that delineated region.

Rationale: Suggest removal of the second sentence and replacem ent with : "It

includes the subsurface three-dimensional extent of the carbon dioxide plume, associated pressure front, and displaced brine, as well as the surface area above that delineated region."

Comment on the inclusion of the word "surrounding" because the AoR should be coextensive with the area defined by the Ca rbon Sequestration Project. Inclusion of "surrounding" makes this defi nition open-ended and ambiguous.

Individual Response: Based on review of all public comments on the AoR definition at 146.84(a), the Agency has modified it to read as follows: The region surrounding the geologic sequestration project where USDWs may be e ndangered by the injecti on activity. The area of review is delineated using computational mode ling that accounts for the physical and chemical properties of all phases of the injected CO 2 stream and is based on available site characterization, monitoring, and operational data. The definition in the proposed rule accounted for the varying physical and chemical propertie s of the CO2 including free-phase and waterdissolved CO2, as the commenter suggests. The defin ition in the final rule wi ll continue to do so. EPA is developing guidance on AoR and corrective act ion at GS Class VI s ites to assist owners or operators and Directors in evaluating requi rements and proposed AoR and corrective action plans under 146.84. The guidance describes EPA's reco mmended approaches for the data to be

considered in an initial AoR delineation, how to apply computat ional modeling to delineate the AoR, performing corrective action at GS sites, and, when appropriate, completing AoR reevaluations. The guidance will be available on EPA's web site, at

41http://water.epa.gov/type/groundwat er/uic/wells_se questration.cfm.

Letter ID: 0259 Comment ID: 24855 Letter Lines: 991 to 1005 ; 1011 to 1011

Comment Code: 1220 1.1.1.1 Terminology and definitions

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

Comment: EPA Proposal: Carbon dioxide plume mean s the underground extent, in three dimensions, of an injected carbon dioxide stream.

Carbon dioxide stream means carbon dioxide that has been captured from an emission source (e.g., a power plant), plus incidental associated substances

derived from the source materials and th e capture process, and any substances added to the stream to enable or improve the injection process. This subpart does not apply to any carbon dioxide str eam that meets the definition of a hazardous waste under 40 CFR part 261.

GWPC Recommendations: Carbon dioxide stream means carbon dioxide, plus

associated substances derived from the source materials and any processing, and any substances added to the stream to en able or improve the injection process. This subpart does not apply to any ca rbon dioxide stream that meets the definition of a hazardous waste under 40 CFR part 261.

Source of CO2 should not be an issue in the context of defining the CO2 stream.

Individual Response: The final GS rule retains the defini tion of a CO2 stream as proposed. The GS regulation applies to injecti on of CO2 for the purpose of GS, regardless of the source of the CO2. It is beyond the scope of the GS rule and the UIC Program’s authority to require or set standards for upstream generators of CO2 or purification facilities . For purposes of GS, the UIC program’s authority under the SDWA is limited to ensuring that GS projects are sited, constructed, operated, and closed in a manner that protects USDWs. The GS rule does not apply to generators of CO2. Additionally, EPA ha s received numerous comments regarding the applicability of the RCRA regulations and st atute to CO2 streams that are geologically sequestered under the final Class VI UIC well requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specificall y to examine the issue of RCRA applicability to CO2 streams being geologically sequestere d, including the possible option of a conditional exemption from the RCRA requirements for CO2 GS in Class VI wells. EPA will consider these comments as part of its development of that propos al. The Agency will consider issues particular to RCRA in the context of that separate rulemaking, and recommends that the commenter read that proposed rule when it is published. The Ag ency notes that commenters who wish to submit comments on the RCRA proposal will need to do so during the comment period for that rule. Finally, EPA also notes 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.

42Letter ID: 0259 Comment ID: 24856 Letter Lines: 1007 to 1009

Comment Code: 1220 1.1.1.1 Terminology and definitions

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

Comment: Rationale: Insert the definition "Computa tional modeling means a mathematical model that is appropriate to the site geometry and takes into account the

differences between the forma tion and injection fluids."

Individual Response: The final rule does not define computational modeling. The preamble to the proposed GS regulation and the modeling background document "C omputational Modeling of Underground Injection of Carbon Dioxide for De termination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water" (cited in the proposed rule preamble as

USEPA, 2008d include FR citati on) discuss, in detail, what EPA believes constitutes a computational model. Appropriate models may incorporate numerical, analytical, or semianalytical approaches. These models solve a series of governing equa tions to predict the composition and volumetric fraction of each phase state, as well as fluid pressures, as a function of location and time for a partic ular set of conditions. EPA is developing guidance on AoR and

corrective action at GS Class VI sites to assist owners or operators and Directors in evaluating requirements and proposed AoR and correc tive action plans under 146.84. The guidance

describes the data that EPA recommends to be considered in an initia l AoR delineation, how to apply computational modeling to delineate the Ao R, performing corrective action at GS sites, and, when appropriate, completing AoR reevalua tions. The guidance will be available on EPA's web site, at http://water.epa.gov/type/g roundwater/uic/wells_s equestration.cfm.

Letter ID: 0259 Comment ID: 24857 Letter Lines: 1013 to 1023

Comment Code: 1220 1.1.1.1 Terminology and definitions

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

Comment: EPA Proposal: Confining zone means a geolog ic formation, group of formations, or part of a formation stratigraphically overl ying the injection zone that acts as

a barrier to fluid movement.

GWPC Recommendations: Confining zone m eans a geological formation, group of formations, or part of a formation that is capable of limiting fluid movement from an injection zone.

Rationale: The current UIC program definition of confining zone is preferable to the proposed definition. There are no sp ecial circumstances for CO2 streams that warrant a change

Individual Response: EPA acknowledges the comment and the fi nal rule retains this text as proposed. EPA believes that the definitions used fo r injection zone and confining zone for Class

43VI GS are appropriately tailored to address the unique risks a nd challenges posed by GS of CO2

streams.

Letter ID: 0259 Comment ID: 24858 Letter Lines: 1025 to 1031

Comment Code: 1220 1.1.1.1 Terminology and definitions

Comment Code: 3400 2.2.2 Corrective Action

Comment: EPA Proposal: Corrective action means the us e of Director approved methods to

assure that wells within the area of re view do not serve as conduits for the movement of fluids into underground sources of drinking water (USDW).

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

Individual Response: EPA acknowledges the commenter’s support; the final GS rule retains the

definition.

Letter ID: 0259 Comment ID: 24859 Letter Lines: 1033 to 1039

Comment Code: 1220 1.1.1.1 Terminology and definitions

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

Comment: GWPC Recommendations: "Fault means a su rface or zone of rock fracture along

which there has [or has not] been displacement."

Rationale: Add definition of fault to clarify use in other provisions. This is

the current definition with the insertion of the words "or has not" before displacement to recognize that faults can exist where there has been no displacement.

Individual Response: Based on its evaluation of all public comments and input on the proposed rule and NODA and Response to Comments EPA has made many revisions to the GS Rule. See

the final rule and the discussion of site charac terization in the preamble for further discussion on EPA's final approach. EPA does not define "fault" but defines "transmissive fault or fracture." EPA has retained the proposed definition, which is the same as the existing definition at §148.2,

to address transmissive faults and fractu res that extend beyond the confining zone.

Letter ID: 0259 Comment ID: 24860 Letter Lines: 1041 to 1050

Comment Code: 1220 1.1.1.1 Terminology and definitions

44Comment: EPA Proposal: Geologic sequestration me ans the long-term containment of a gaseous, liquid or supercritical carbon dioxide stream in subsurface geologic formations. This term does not appl y to its capture or transport.

GWPC Recommendations: Geologic sequestration means the long-term containment of a carbon dioxide stream in subsurface ge ologic formations. This term does not apply to its capture or transport.

Rationale: Suggest removing "gaseous, liqui d or supercritical" as these terms are implied by the use of the term carbon dioxide.

Individual Response: EPA disagrees with the suggested edit. However, the Agency has modified the definition of geologic sequestrati on at §146.81(d) to read as follows: “[T]he longterm containment of a gaseous, liquid, or s upercritical carbon dioxide stream in subsurface geologic formations. This term does not appl y to carbon dioxide captu re or transport.”

Based on its evaluation of all public comments and input on the proposed rule and the NODA and Request for Comment, EPA has made many revisions to the Cla ss VI GS rule. Please see the final rule and preamble for additional information.

Letter ID: 0259 Comment ID: 24861 Letter Lines: 1052 to 1065

Comment Code: 1220 1.1.1.1 Terminology and definitions

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

USDW

Comment: EPA Proposal: Geologic sequestration proj ect means an injection well or wells used to emplace a carbon dioxide stream beneath the lowermost formation containing a USDW. It includes the subsur face three-dimensional extent of the carbon dioxide plume, associated pressure front, and displaced brine, as well as the surface area above that delineated region.

GWPC Recommendations: Geologic sequestration project means an injection well or wells used to emplace a carbon dioxide stream into an injection zone for geologic sequestration.

Rationale: Replace "beneath the lowermos t formation containing a USDW "with "into an injection zone"

Suggest moving the second sentence to the definition of AOR.

Individual Response: In the final rule, EPA revised the de finition of a geologic sequestration project to account for the new requirements to in clude “wells used for geologic sequestration of carbon dioxide that have been granted a waiver of the injection depth re quirements pursuant to requirements at §146.95.”

45Letter ID: 0259 Comment ID: 24862 Letter Lines: 1069 to 1072

Comment Code: 1220 1.1.1.1 Terminology and definitions

Comment: GWPC Recommendation: Geologic sequestration site means

Rationale: The GWPC believes a definition for this term is needed as the term is

referenced in later se ctions of the rule.

Individual Response: EPA disagrees that a definition of ge ologic sequestration site is needed. EPA notes that a geologic sequestration site, und er §146.83(a), comprises: “( 1) An injection zone of sufficient areal extent, thickness, porosity, and permeability to receive the total anticipated volume of the carbon dioxide stream; [and] (2) Conf ining zones free of transmissive faults or

fractures and of sufficient areal extent and integrity to contain the injected carbon dioxide stream and displaced formation fluids and allow injec tion at proposed maximum pressures and volumes without initiating or prop agating fractures in th e confining zone(s).”

Based on its evaluation of all public comments and input on the proposed rule and the NODA and Request for Comment, EPA has made many revisions to the Cla ss VI GS rule. Please see the final rule and preamble for additional information.

Letter ID: 0259 Comment ID: 24863 Letter Lines: 1074 to 1084

Comment Code: 1220 1.1.1.1 Terminology and definitions

Comment: EPA Proposal: Injection zone means a geol ogic formation, group of formations, or part of a formation that is of suffici ent a real extent, thickness, porosity, and permeability to receive carbon dioxide through a well or wells associated with a geologic sequestration project.

GWPC Recommendations: Injection zone m eans a geological "formation", group of formations, or part of a formati on receiving fluids through a well.

Rationale: Existing definition in the CFR is sufficient and does not need to be changed. Furthermore, adding sufficiency is not a definitional issue and should

be dealt with elsewhere.

Individual Response: EPA disagrees with the suggested edit . The final definition of injection zone at §146.81(d) remains unchanged and reads as follows: “[A] geologic formation, group of formations, or part of a formation that is of sufficient areal extent, thickness, porosity, and permeability to receive carbon dioxide through a well or wells associated with a geologic sequestration project.”

Based on its evaluation of all public comments and input on the proposed rule and the NODA,

46and Request for Comment EPA has made many revisions to the GS rule. Please see the final rule and preamble for additional information.

Letter ID: 0259 Comment ID: 24864 Letter Lines: 1086 to 1095

Comment Code: 1220 1.1.1.1 Terminology and definitions

Comment Code: 5200 2.8.2 Post injection site care (seeking comment) (40 CFR 146.93)

Comment: EPA Proposal: Post-injection site care m eans appropriate monitoring and other actions (including corrective action) need ed following cessation of injection to

assure that USDWs are not enda ngered as required under § 146.93.

GWPC Recommendations: Post-injection s ite care means monitoring and other actions (including corrective action) fo llowing cessation of injection, as required under 146.93.

Rationale: The definition should explain the meaning and not impose substantive requirements. These requirements are al ready addressed in other sections.

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

Letter ID: 0259 Comment ID: 24865 Letter Lines: 1097 to 1111

Comment Code: 1220 1.1.1.1 Terminology and definitions

Comment: EPA Proposal: Pressure front means the zone of elevated pressure that is created by the injection of carbon dioxide into the subsurface. For the purposes of this subpart, the pressure front of a carbon dioxide plume refers to a zone where there is a pressure differential sufficient to cause the movement of injected fluids or formation fluids into a USDW.

GWPC Recommendations: Pressure front means th e zone of elevated pressure that is created by the injection of the carbon dioxi de stream into the subsurface, where there is a pressure differential suffici ent to cause movement of the carbon

dioxide stream or forma tion fluids from the injec tion zone into a USDW.

Rationale: Proposal removes words that ar e unnecessary to provide clarity and would only serve to confuse.

Insert "from the injection zone" for clarification.

Individual Response: EPA disagrees with the suggested edit . The final definition of pressure front at §146.81(d) is unchanged and reads as follows : “[T]he zone of elevat ed pressure that is

47created by the injection of carbon dioxide into the subsurface. Fo r the purposes of this subpart, the pressure front of a carbon dioxide plume refers to a zone where there is a pressure differential sufficient to cause the movement of injected fluids or formation fluids into a USDW.”

Based on its evaluation of all public comments and input on the proposed rule and the NODA and Request for Comment, EPA has made many revisions to the Cla ss VI GS rule. Please see the final rule and preamble for additional information.

Letter ID: 0259 Comment ID: 24866 Letter Lines: 1113 to 1124

Comment Code: 1220 1.1.1.1 Terminology and definitions

Comment Code: 5200 2.8.2 Post injection site care (seeking comment) (40 CFR 146.93)

Comment: EPA Proposal: Site closure the point/time, as determined by the Director following the requirements under § 146.93, at which the owner or operator of a GS site is released from post-inje ction site care re sponsibilities.

GWPC Recommendations: Site closure mean s the point/time, as determined by the Director following the requirements under §146.93, at which the owner or operator of a GS project is releas ed from post-injection site care responsibilities.

Rationale: Add "means"

Suggest using "GS project" to be co nsistent with ot her definitions

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

Letter ID: 0259 Comment ID: 24867 Letter Lines: 1126 to 1136

Comment Code: 1220 1.1.1.1 Terminology and definitions

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

Comment: EPA Proposal: Transmissive fault or fractur e means a fault or fracture that has sufficient permeability and vertical extent to allow fluids to move between

formations.

GWPC Recommendations: Transmissive fault or fracture means a fault or fracture that has sufficient permeability and verti cal extent to allow fluids to move beyond the confining zone.

Rationale: Recommends changing "between formations" to "beyond the confining

zone." The term between formations is insufficient as it could also include

48multiple zones within a injection zone.

Individual Response: EPA has retained the proposed definition, which is the same as the existing definition at §148.2, to a ddress transmissive faults and fractures that extend beyond the confining zone.

Letter ID: 0259 Comment ID: 24868 Letter Lines: 1138 to 1157

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment: Rule Provision: 146.82

EPA Proposal: Required Class VI permit information

This section sets forth the information wh ich the owner or operator must submit to the Director in order to be permitted as a Class VI well. The application for a permit for construction and operation of a Class VI well must include the following:

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

Rule Provision: 146.82(a)

EPA Proposal: (a) Information require d in 40 CFR 144.31(e)(1) through (6);

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

Individual Response: EPA acknowledges the comment. For additional information on EPA's final regulatory approach, please see the final rule and preamble as well as the rulemaking

docket.

Letter ID: 0259 Comment ID: 24869 Letter Lines: 1159 to 1184

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3130 2.1.3 Comments that operators s hould submit more (or different) geologic data than proposed

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

Comment: EPA Proposal: (b) A map showing the inje ction well(s) for which a permit is sought and the applicable area of review. Within the area of review, the map

49must show the number, or name and lo cation of all injec tion wells, producing wells, abandoned wells, plugged wells or dry holes, deep stratigraphic boreholes, State or EPA approved subsur face cleanup sites, surface bodies of water, springs, mines (surface and subs urface), quarries, water wells and other pertinent surface features including struct ures intended for human occupancy and roads. [Highlighted text: The map sh ould also show faults, if known or suspected.] Only information of public record is required to be included on this

map;

GWPC Recommendations: (b) A surface map sh owing the proposed locations for the injection well(s) for which a permit is sought and the applicable area of

review. Within the area of review, the map must show the number, or name and location of all known injection wells, pr oducing wells, abandoned wells, plugged wells or dry holes, deep stratigraphi c boreholes, State or EPA approved subsurface cleanup sites, surface bodies of water, springs, mines (surface and subsurface), quarries, water wells and other pertinent su rface features including structures intended for human occ upancy and roads. Only information of public record is required to be included on this map;

Rationale: Insert "known" before "injection"

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

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

information.

EPA acknowledges but did not make the suggested edits. EPA believes that all of the site characterization requirements at §146.82, includi ng geomechanical inform ation and geologic and topographic maps and cross sections, are essentia l to proper siting of a GS well and are the

foundation for a detailed understand ing of the local and regional geology, and that the owner or operator should collect this information, regard less of whether it is know n in advance of the siting process. Collecting and evaluating this da ta supports important ev aluations regarding the suitability of the site to recei ve and contain injected CO2.

EPA acknowledges that some smaller fractures may not be detectable during the site

50characterization process, and cl arifies that §146.82(a)(3 )(ii) requires the ow ner or operator to submit data on known or suspected faults and fractures (i.e., not al l fractures). Other requirements for GS injection wells and sites can mitigate the potential impacts of unidentified fractures. These include limitations on injec tion pressures to avoid propagation of existing fractures in the confining zone (§146.88(a)), co llection and assessments of CO2 monitoring data at the site, and AoR reevaluations (§146.84(e)) to assess possible CO2 movement through highpermeability regions (i.e., faults and/or fractures) not detected in the initial site characterization.

Letter ID: 0259 Comment ID: 24870 Letter Lines: 1186 to 1197

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

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

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

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

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

Individual Response: EPA recognizes that information necessa ry for an area of review may not

be available until after a well has been drilled and formation testing can occur. EPA revised §146.82 so that the final regulati on specifies separate requirements for information to be submitted with the permit application and befo re well construction is approved (at §146.82(a)) and information to be submitted before opera tion of the well is authorized (at §146.82(c)) including The final area of review based on modeling, using data obtained during logging and testing of the well and th e formation §146.82(c)(1).

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

Letter ID: 0259 Comment ID: 24871 Letter Lines: 1199 to 1223

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

51Comment Code: 3130 2.1.3 Comments that operators s hould submit more (or different) geologic data than proposed

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

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

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

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

GWPC Recommendations: (d) Sufficient info rmation on the geologic structure and reservoir properties of the proposed stor age site and overlying formations, including:

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

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

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

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

Individual Response: EPA acknowledges that some smaller fractures may not be detectable during the site characterization pr ocess, and clarifies that §146.82( a)(3)(ii) require s the owner or operator to submit data on known or suspected fau lts and fractures (i.e., no t all fractures). Other requirements for GS injection wells and sites can mitigate the potential impacts of unidentified fractures. These include limitations on injec tion pressures to avoid propagation of existing fractures in the confining zone (§146.88(a)), co llection and assessments of CO2 monitoring data at the site, and AoR reevaluations (§146.84(e)) to assess possible CO2 movement through highpermeability regions (i.e., faults and/or fractures) not detected in the initial site characterization.

EPA disagrees with the other suggested edits beca use the GS rule, as written, affords flexibility to owners or operators and Directors to tailor the site characterization process to the unique

features of the site. Please see the final rule a nd the discussion of geologic site characterization in the preamble for additional information.

52Letter ID: 0259 Comment ID: 24872 Letter Lines: 1225 to 1258

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3130 2.1.3 Comments that operators s hould submit more (or different) geologic data than proposed

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

Comment: EPA Proposal: (3) Information on seismic history including the presence and depth of seismic sources and a determin ation that the seismicity would not

interfere with containment;

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

(5) Geomechanical information on fractur es, stress, ductilit y, rock strength, and in situ fluid pressures w ithin the confining zone; and

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

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

(5) Geomechanical information on the c onfining zone(s) with in the area of

review; and

Rationale: Capillary pressure is too hard to measur e outside the lab; how comparable are lab results to what goes into the ground. Sidewall core may not

be sufficient to do this, and it is difficu lt to core the whole of the confining and injection zones. Rewording keeps the us efulness of capillary pressure in the provision without making it a mandatory use.

Individual Response: EPA acknowledges that laboratory met hods are standard for determining capillary pressures regardless of formation perm eability and that in si tu measurements would require drilling of a well. However, EPA also antici pates that test wells will be drilled to support

53geologic site characterization of the proposed GS sites and can be used to collect subsurface samples (for laboratory determination of cap illary pressure) and take other necessary

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

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

Letter ID: 0259 Comment ID: 24873 Letter Lines: 1260 to 1263

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

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

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

GWPC Recommendations: Support the EPA language.

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

Letter ID: 0259 Comment ID: 24874 Letter Lines: 1265 to 1281

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

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

Comment: Rule Provision: 146.82(e)

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

GWPC Recommendations: (e) A compilation of all artificial penetrations within

54the area of review which penetrate the inje ction or confining zone(s). Such data must include a description of each well’ s type, construction, date drilled, location, depth, record of plugging and/ or completion, and any additional information the Director may require;

Rationale: The GWPC felt that the term compilation was more appropriate than

tabulation because tabulation as tabu lation implies a spreadsheet while compilation can take numerous forms.

Individual Response: EPA used the term tabulation in the fina l rule because it is the same term used in the same requirement for other we ll classes; and, the regulated community and permitting officials are familia r with existing terminology.

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

Letter ID: 0259 Comment ID: 24875 Letter Lines: 1283 to 1295

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

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

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

direction of water movement, where known;

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

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

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

55Based on its evaluation of all public comment s and input on the proposed rule and NODA and Response to Comments EPA has ma de many revisions to the GS Rule. See the final rule and preamble for further discussion on EPA's final approach.

Letter ID: 0259 Comment ID: 24876 Letter Lines: 1297 to 1307

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

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

Comment: EPA Proposal: (g) Baseline geochemical da ta on subsurface formations, including

all USDWs in the area of review;

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

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

the Director.

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

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

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

Letter ID: 0259 Comment ID: 24877 Letter Lines: 1309 to 1430

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3150 2.1.5 Comments on required permit information (40 CFR 146.82)

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

56comment)

Comment: EPA Proposal: (h) Propo sed operating data:

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

dioxide stream;

GWPC Recommendations: (h) Proposed operating data:

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

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

dioxide stream;

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

Rule Provision: 146.82(i)

EPA Proposal: (i) The compatib ility of the carbon dioxide stream with fluids in the injection zone and minerals in both the injection and the confining zone(s),

based on the results of the formation test ing program, and with the materials

used to construct the well;

(j) Proposed formation testing program to obt ain an analysis of the chemical and physical characteristics of the inje ction zone and confining zone;

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

EPA Proposal: (k) Proposed stimulation program and a determination that

stimulation will not interfere with containment;

(l) The results of the formation testing pr ogram as required in paragraph (j) of

this section;

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

(n) Schematic or other appropriate draw ings of the surface and subsurface

construction details of the well;

57(o) Injection well constructi on procedures that meet the requirements of §

146.86;

GWPC Recommendations: (k) Proposed stimul ation program and a de termination that stimulation will not compromise containment;

(l) The results of the formation testing pr ogram as required in paragraph (j) of

this section;

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

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

wellhead construction.

(o) Injection well constructi on procedures that meet the requirements of §

146.86;

Rationale: "Interfere" is t oo ambiguous and should be replaced by "compromise"

which limits concerns to situations where containment may be lost.

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

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

(r) All available logging and testing program data on the well required by §

146.87;

(s) A demonstration of mechanical integrity pursuant to § 146.89;

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

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

(q) All available logging a nd testing program data on th e well required by §

146.87;

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

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

58Rationale: (q) Should be deleted because it is not part of an applicationprocess but, rather a post permitting activity. This would result in a renumbering of the subsecti ons after the new (q).

Rule Provision: 146.82(u)

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

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

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

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

(y) Any other information re quested by the Director.

GWPC Recommendations: (t) Proposed testi ng and monitoring plan required by §

146.90;

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

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

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

(x) Any other information re quested by the Director.

Rationale: Need to address the plugging of monitoring well(s), if any, included in the project.

Individual Response: EPA acknowledges the commenter’s s upport for portions of the subject requirements. EPA disagrees that the technical cl arifications suggested are necessary. EPA adds that it is developing guidance for owners or ope rators on the geologic si te characterization and AoR and corrective action processe s. These guidances will provide recommendations and clarify the intent of all required elem ents of a permit application. The guidances can be found on EPA’s website at http://water.epa.gov/type/gr oundwater/uic/wells_se questration.cfm.

Letter ID: 0259 Comment ID: 24878 Letter Lines: 1432 to 1446

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment: Rule Provision: 146.83

59EPA Proposal: Minimum criteria for siting

(a) Owners or operators of Class VI wells must demonstrate to the satisfaction

of the Director that the wells will be s ited in areas with a suitable geologic system. The geologic system must be comprised of:

(1) An injection zone of sufficient ar eal extent, thickness, porosity, and permeability to receive the total antic ipated volume of the carbon dioxide

stream;

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

Individual Response: EPA acknowledges the comment and the final rule retains the text at §146.83(a) as proposed.

Letter ID: 0259 Comment ID: 24879 Letter Lines: 1448 to 1460

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3110 2.1.1 Proposed siting requirements (i.e., injection/confining zones, trapping mechanism)

Comment: EPA Proposal: (2) A confining zone(s) that is free of transmissive faults or

fractures and of sufficient areal extent and integrity to contain the injected carbon dioxide stream and displaced forma tion fluids and allo w injection at proposed maximum pressures and volume s without initiatin g or propagating fractures in the confining zone(s); and

GWPC Recommendations: (2) A confining zone (s) that is latera lly continuous and free of known transecting, transmissive faults or fractures over an area sufficient to prevent the moveme nt of fluids into a USDW;

Rationale: Suggest using the Class I re gulation for this paragraph (2) in 146.62(c) with the addition of reactivation of existing faults or fractures and

before the terms faults or fractur es the word known should be added.

Individual Response: The Agency believes that the re quirement at §146.83(a)(2) that the confining zone to be free of transmissive faults or fractures is appropriate for Class VI wells and is necessary to ensure containment of the inject ate and that requiring the confining zone to be free of transmissive faults maximizes protec tion of USDWs from enda ngerment. EPA believes that the text regarding propagation of faults and fractures is impor tant to avoid the potential for fluid movement and to ensure that injection is at appropriate pressures. Class I hazardous waste injection well operators must also meet a similar re quirement that the site is free of transmissive faults or fractures; they have successfully made such demonstrations in the past. While core

60samples obtained through drilling and hydraulic testing are direct methods to obtain such information, geophysical techniques such as seismic or electromagnetic surveys can also be used in many geologic settings to demonstrate the absen ce of or identify and characterize the presence

of faults or fractures. EPA adds that the Direct or will evaluate all geologic data on the site to ensure protection of USDWs from endangerment before approving a site for a GS project.

Letter ID: 0259 Comment ID: 24880 Letter Lines: 1462 to 1471

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment: EPA Proposal: (b) At the Dire ctor’s discretion, owners or operators of Class VI wells must identify and characterize additi onal zones that will impede vertical

fluid movement, are free of faults and fractures that may interfere with containment, allow for pressure di ssipation, and provide additional opportunities for monitoring, m itigation and remediation.

GWPC Recommendations: Delete paragraph

Rationale: This paragraph creates a presumption that additional zones WILL be required. It is also redundant from previous sections.

Individual Response: EPA clarifies that secondary confini ng zones are not required for all GS sites. Rather, secondary confini ng zones are required when the Di rector determines that these zones are needed to maximize the protection of USDWs from endangerment. EPA retains the requirement to identify additional containment/confining zones, if required by the Director, as proposed (e.g., §146.83(b)). EPA believes that, in some situations, the presence of additional confining and containment zones above the pr imary (i.e., lowermost) confining zone can improve USDW protection. These layers could fu rther impede vertical fluid movement and allow for pressure dissipation, and also provide additional sites for monitoring, mitigation, and

remediation.

Letter ID: 0259 Comment ID: 24881 Letter Lines: 1473 to 1489

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment: Rule Provision: 146.84

EPA Proposal: 146.84. Area of revi ew and corrective action

(a) The area of review is the region surrounding the geologic sequestration project that may be impacted by the inje ction activity. The area of review is based on computational mode ling that accounts for the physical and chemical

61properties of all phases of the injected carbon dioxide stream.

GWPC Recommendations: (a) The area of review is based on computational modeling that accounts for the physi cal and chemical propertie s of all phases of the injected carbon dioxide stream.

Rationale: This is the same as the defi nition of "Area of review" that was revised by the GWPC .to delete the first sentence.

Comments on many provisions are predicat ed on proposed changes in definitions

Individual Response: The Agency has carefully considered all comments on the AoR definition at 146.84(a) and modified it to read as follows: The region surrounding the geologic sequestration project where USDWs may be e ndangered by the injecti on activity. The area of review is delineated using computational mode ling that accounts for the physical and chemical properties of all phases of the injected CO 2 stream and is based on available site

characterization, monitori ng, and operational data.

Letter ID: 0259 Comment ID: 24882 Letter Lines: 1491 to 1521

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3700 2.2.5 Comments on the requirement for an AoR and corrective action plan

Comment: EPA Proposal: (b) The owner or operator of a Class VI well must prepare, maintain, and comply with a plan to delin eate the area of review for a proposed geologic sequestration proj ect, periodically reevalua te the delineation, and perform corrective action that meets the requirements of this section and is acceptable to the Director. As a part of the permit application for approval by the Director, the owner or operator must submit an area of review and corrective action plan that includes the following information:

(1) The method for delineating the area of re view that meets the requirements of paragraph (c) of this section, including th e model to be used, assumptions that

will be made, and the site characterization data on which the model will be

based;

GWPC Recommendations: (b) The owner or operat or of a Class VI we ll must prepare, maintain, and comply with a plan to delin eate the area of review for a proposed geologic sequestration project, reeval uate the delineation, and perform corrective action that meets the requirements of this section in a manner and at a frequency acceptable to the Director. As a part of the perm it application, the owner or operator must submit an area of review and corrective action plan that includes the following information:

Rationale: Suggest deletion of "periodi cally." See Workgroup recommendation 7.6

62from

Recommendations for the Regulatory Manage ment of Geologic Sequestration of CO2 Under the UIC Program

Replace with "in a manner and at a frequency"

Delete "for approval by the Director,". Director’s approval is implicit in a permit application.

Individual Response: EPA disagrees with the suggested cha nge, and is retaining the approach of setting a minimum fixed frequency for reeval uating the AoR but has, based on commenters' input, changed the frequency from 10 years to at least every 5 years, as specified in §146.84(e). EPA agrees with commenters that site-specific in formation is an important factor in determining an appropriate AoR reevaluation frequency, and adds that the owner or operator's AoR and corrective action plan must describe the minimu m fixed frequency for reevaluating the AoR and the site-specific conditions on which this freque ncy is based. EPA adds that the Director will evaluate the proposed plan in connection with a review of a vast amount of geologic and proposed operating data in determining whether to approve the plan. EPA is developing guidance describing approaches to prepari ng all of the required GS project plans, which will address considerations for determining an appropriate AoR reevaluation schedule. The guidance will be

available on EPA's web site, at http://water.epa.gov/type/groundwater /uic/wells_sequestration.cfm.

Letter ID: 0259 Comment ID: 24883 Letter Lines: 1523 to 1542

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3500 2.2.3 Area of Review Reevaluation (seeking comment)

Comment Code: 3700 2.2.5 Comments on the requirement for an AoR and corrective action plan

Comment: Rule Provision: 146.84(b)(2)

EPA Proposal: (2) A description of:

(i) The minimum fixed frequency, not to exc eed 10 years, the ow ner or operator proposes to reevaluate the area of review;

(ii) The monitoring and operational conditi ons that would warra nt a reevaluation of the area of review prior to the next scheduled reevaluation as determined by the minimum fixed frequency established in paragraph (b)(2)(i) of this section.

(iii) How monitoring and operational data (e.g., injection rate and pressure)

will be used to inform an area of review reevaluation; and

GWPC Recommendations: Delete (i) and (ii)

63Rationale: Suggest deletion of (i) as th is is handled by "manner and at a frequency acceptable to the Director in (b)

Suggest deletion of (ii) for sa me reason as comment on (i)

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

establish conditions for corrective action, and ensure protec tion of USDWs from endangerment.

EPA clarifies that if site m onitoring data agrees with the existing AoR delin eation, a model recalibration may not be necessary, and the AoR reevaluation may consist of a demonstration

that the current AoR delineation is ad equate based on site monitoring data.

Letter ID: 0259 Comment ID: 24884 Letter Lines: 1544 to 1564

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3400 2.2.2 Corrective Action

Comment: EPA Proposal: (iv) How corrective acti on will be conducted to meet the requirements of paragraph (d) of this section, including what corrective action will be performed prior to injection and what, if any, portions of the area of

review will have corrective action ad dressed on a phased basis and how the phasing will be determined; how corrective action will be adjusted if there are changes in the area of review; and how site access will be guaranteed for future

corrective action.

GWPC Recommendations: (iv) How correctiv e action will be conducted to meet the requirements of paragraph (d) of this section, including what corrective action will be performed prior to injection and what, if any, portions of the area of

review will have corrective action ad dressed on a phased basis and how the phasing will be determined; how corrective action will be adjusted if there are changes in the area of review; and how s ite access will be assured for future

corrective action.

Rationale: Replace "guaranteed" with "a ssured" Future access cannot be absolutely guaranteed for an area in adva nce that may not even be within the boundaries of the AOR/ project. However, a ssurance of access is a standard that is less onerous than guaranteed, it is fi rmer than another standard such as "arranged"

64Individual Response: EPA is retaining this requiremen t as proposed. The purpose of the corrective action requirement at §146.84(d) is to ensure that a ll wells in the AoR that have the potential to cause the movement of CO2 or other fluids in to or between USDWs receive appropriate corrective action. In general, to meet this requirement, the owner or operator will most likely need to obtain the right of access to wells that may require corrective action, and demonstrate they have done this in their pr oposed AoR and corrective action plan. In the AoR and corrective action plan, the owner or operato r must describe how site access will be guaranteed for future corrective actio n, as specified in §146.84(b)(2)(iv).

Letter ID: 0259 Comment ID: 24885 Letter Lines: 1566 to 1590

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment: Rule Provision: 146.84(c)

(c) Owners or operators of Class VI wells must perform the following actions to delineate the area of review, identify all wells that require corrective action, and perform corrective action on those wells:

(1) Predict, using computational modeli ng, the projected lateral and vertical migration of the carbon dioxide plume and formation fluids in the subsurface from the commencement of injection activ ities until the plume movement ceases, pressure differentials sufficient to cause the movement of injected fluids or formation fluids into a USDW are no longe r present, or after a fixed time period as determined by the Director. The model must:

GWPC Recommendations: (c) Owners or operators of Class VI wells must perform the following actions to delineate the area of review, identify all wells that require corrective action, and perfor m corrective action on those wells:

(1) Predict, using computational modeli ng, the projected lateral and vertical migration of the carbon dioxide plume a nd formation fluids in the subsurface from the commencement of injection activ ities until the plume movement ceases, pressure differentials sufficient to cause the movement of injected fluids or formation fluids into a USDW are no longe r present, or for a fixed time period as determined by the Director. The model must:

Rationale: Should say "f or" not "after."

Individual Response: Based on its evaluation of all public comments and input on the proposed rule, EPA has clarified this language in the final rule. It now reads, “Pre dict, using existing site characterization, monitoring and operational data , and computational modeling, the projected lateral and vertical migration of the carbon dioxide plume and formation fluids in the subsurface from the commencement of injection activities until the plume movement ceases, until pressure

65differentials sufficient to cause th e movement of injected fluids or formation fluids into a USDW are no longer present, or until the end of a fixe d time period as determined by the Director.”

Letter ID: 0259 Comment ID: 24886 Letter Lines: 1592 to 1628

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment: Rule Provision: 146.84(c)(i)

EPA Proposal: (i) Be based on detailed ge ologic data collected to characterize the injection zone, confining zone and any additional zones; and anticipated operating data, including injection pressu res, rates and total volumes over the proposed life of the geologi cal sequestration project;

(ii) Take into account any geologic hete rogeneities, data quality, and their possible impact on model predictions; and

(iii) Consider potential mi gration through faults, fract ures, and ar tificial penetrations.

GWPC Recommendations: (i) Be based on de tailed geologic data collected to characterize the injection zone, confini ng zone; and anticipat ed operating data, including injection pressures, rates a nd total volumes over the duration of injection;

(ii) Take into account relevant geologic heterogeneities, and data quality, and their possible impact on model predictions; and

(iii) Consider potential mi gration through faults, fract ures, and ar tificial penetrations.

Rationale: Suggest deletion of "any additional zones". You do not need to include any additional zones if you use th e current CFR definition of confining zone since it includes multiple zones.

Should be geologic not geological for cons istency with other provisions because geologic sequestration project is defined.

Suggest "duration of injection" instead of "life of the geolog ical sequestration project"

Suggest "relevant" instead of any in (ii)

Insert "and" between "heter ogeneities" and "data"

66Individual Response: EPA agrees that detailed geologic da ta is invaluable to modeling an accurate AoR. The Agency believes that the AoR delineation requirements in 146.84 (c)(1)(i), which specify using "detailed geologic data collected to characterize the injection zone, confining zone and any additional zones; and anticipated operating data...," and (c)(iii) to "consider potential migration thr ough faults, fractures and artific ial penetrations," provide the necessary information needed for appropriate site modeling, subsequent site evaluation, and protection of USDWs from endangerment. EPA a dds that the extensive requirements for data that is to be included in the permit applic ation at 146.82 incorporate these same types of

information. The Director will review the AoR mode ls in the context of th e extensive site data submitted with the permit application. EPA recogni zes that in some inst ances, the Director may require additional types of data to be include d in the AoR delineati on (146.84(c)(1)). Based on its evaluation of all public comm ents and input on the proposed rule and NODA and Request for Comment EPA has made many revisions to the GS Rule. See the final rule and preamble for further discussion on EPA's final approach.

EPA disagrees that only the injection and conf ining zones should be included in AoR modeling of GS sites. EPA believes that the modeling shou ld also take into acc ount the possibility of displaced fluids or brines caused by a lateral and/ or vertical pressure plume, and therefore it may be necessary to include additional zones along with the confining/injection zones to ensure the integrity of the confining zone and ultimat ely protect a USDW from endangerment.

Letter ID: 0259 Comment ID: 24887 Letter Lines: 1630 to 1661

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3400 2.2.2 Corrective Action

Comment: EPA Proposal: (2) Using methods appr oved by the Director, identify all penetrations, including ac tive and abandoned wells and underground mines, in the area of review that may penetrate the c onfining zone. Provide a description of each well’s type, construction, date drilled, location, depth, record of plugging and/or completion, and any additi onal information the Director may require; and

GWPC Recommendations: (2) Using methods approved by the Director, identify all known artificial penetrations into the confining zone, incl uding active and abandoned wells and underground mines, in th e area of review that may penetrate the confining zone. Provide a descripti on of each well’s type, construction, date drilled, location, dept h, record of plugging and/ or completion, and any

additional information the Di rector may require; and

Rationale: Insert "known ar tificial penetrations in to the confining zone"

EPA Proposal: (3) Determine which abandoned wells in the area of review have been plugged (as required by § 146.92) in a ma nner that prevents the movement of

carbon dioxide or associated flui ds that may endanger USDWs

67GWPC Recommendations: (3) Determine which abandoned wells identified in 146.84 (c) (2) have been plugged (a s required by §146.92) in a manner that prevents the movement of carbon dioxide or displaced formation fluids that may endanger

USDWs.

Rationale: Add identified in 146.84 (c) (2)

Remove "area of review" as redundant.

Suggest change "associated fluids" to "d isplaced formation fluids." Associated

fluids is not defined so if EPA means di splaced formation fluids the regulation should just use this term. Otherwise, y ou need to define associated fluids.

Individual Response: EPA is retaining the requirement in 146.84(c)(2) as proposed. EPA agrees with commenters that, for most GS sites, relyi ng on database and other pu blic records searches (i.e., of "known" artificial penetrations) will be sufficient to meet the requirements at §146.84(c)(2). However, the Agency recognizes that there may be situations where additional surveys or research to locate wells may be appr opriate. For example, there may be cases where the Director may determine that ground or airb orne surveys for wells are appropriate, e.g., if

there is reason to believe, ba sed on knowledge of the site or of available data, that the incompleteness of information on known wells could compromise USDW protection from endangerment. In order to preserve the Director's discretion to require an operator to supplement a records search, EPA did not make the suggested change.

EPA clarifies that the term "a ssociated fluids" as proposed in §146.84(c)(3) refers to formation fluids, other injectates, etc that may be present in the subsurface and affect movement of the CO2 plume and/or pressure front. EPA believes this terminology would incorpor ate any fluids in the subsurface that could potentially move through ar tificial penetrations a nd affect USDWs. EPA has revised the language at §146.84(c)(3) to read, "... carbon dioxide or ot her fluids that may endanger USDWs..."

Letter ID: 0259 Comment ID: 24888 Letter Lines: 1663 to 1678

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3460 2.2.2.3 Acceptable corrective action techniques for GS sites (e.g., cements)

Comment: Rule Provision: 146.84(d)

EPA Proposal: (d) Owners or operators of Cl ass VI wells must perform corrective

action on all wells in the area of review th at are determined to need corrective action using methods necessary to prevent th e movement of fluid into or between USDWs including use of corrosion resist ant materials, wh ere appropriate.

68GWPC Recommendations: (d) Owners or operato rs of Class VI wells must perform corrective action using materials suitable for use with carbon dioxide streams, on all wells identified in 146.84(c)(2) that are determined to need corrective

action".

Rationale: Re-write as follows "Owners or operators of Class VI wells must perform corrective action using corrosion re sistant materials, when appropriate, on all wells identified in 146.84(c)(2) that are determined to need corrective

action".

Individual Response: EPA revised the text at §146.84(d) to re quire the use of materials that are "compatible with the carbon dioxide stream." EPA believes this language change addresses

commenters' concerns and is also consiste nt with other language regarding materials requirements in the GS rule.

Letter ID: 0259 Comment ID: 24889 Letter Lines: 1680 to 1687

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3400 2.2.2 Corrective Action

Comment: EPA Proposal: (e) If monitoring data indi cate an endangerment to USDWs, the owner or operator must notify the Director and cease operations as required by §

146.94.

GWPC Recommendations: Delete

Rationale: Why is this needed if 146.94 already specifies th e notification and cessation of injection?

Individual Response: Based on consideration of all public comments and other information, EPA deleted this provision from §146.84. The fina l rule now contains a provision in §146.91(c) that requires the owner or opera tor to report within 24 hours any evidence that the carbon dioxide stream or associated pressure front may cause an endangerment to a USDW. EPA believes this change consolidates reporting requirements in one place and provides additional clarity.

Letter ID: 0259 Comment ID: 24890 Letter Lines: 1689 to 1711

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment: EPA Proposal: (f) At the minimum fixed fr equency, not to exceed 10 years, as specified in the area of review and corre ctive action plan, or when monitoring and operational conditions warrant, owners or operators must:

(1) Reevaluate the area of review in th e same manner specified in paragraph (c)

69(1) of this section;

(2) Identify all wells in the reevaluated area of review that require corrective action in the same manner specified in paragraph (c)(2) of this section;

GWPC Recommendations: (f) As specified in the approved area of review and corrective action plan, or when monitori ng and operational conditions warrant,

owners or operators must

(1) Reevaluate the area of review in th e same manner specified in paragraph (c) (1) of this section;

(2) Identify all wells in the reevaluated area of review that require corrective action in the same manner specified in paragraph (c)(2) of this section;

Rationale: Delete "At the minimum fixe d frequency, not to exceed 10 years".

Insert "approved" before "a rea of review" in (f).

Individual Response: EPA disagrees with the suggested edit, and believes that periodic AoR reevaluation at a set frequency is necessary to ensure protect ion of USDWs from endangerment and address the uncertainties inherent in pred ictive modeling. Periodic AoR reevaluations at §146.84(e) ensure that a deliberate effort is made to verify, based on monitoring and operational data, that the CO2 plume is moving within the subsurface as predicted. EPA believes that less frequent reevaluations may not be sufficient to appropriate ly model plume and pressure front

movement, establish conditions for corrective action, and ensure protection of USDWs from endangerment.

EPA clarifies that if site m onitoring data agrees with the existing AoR delin eation, a model recalibration may not be necessary, and the AoR reevaluation may consist of a demonstration

that the current AoR delineation is ad equate based on site monitoring data.

Letter ID: 0259 Comment ID: 24891 Letter Lines: 1713 to 1731

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3700 2.2.5 Comments on the requirement for an AoR and corrective action plan

Comment: EPA Proposal:(3) Perform corrective acti on on wells requiring corrective action

in the reevaluated area of review in the same manner specified in paragraph (c) (3) of this section; and

(4) Submit an amended area of review and corrective action plan or demonstrate to the Director through monitoring data and modeling results that no amendment to the area of review and corrective action plan is needed.

70GWPC Recommendations: (3) Perform co rrective action on we lls requiring

corrective action in the reev aluated area of review in the same manner specified in paragraph (c)(3) of this section; and

(4) Submit an amended area of review and corrective action plan or demonstrate to the Director through monitoring data a nd modeling results that no change to

the area of review and correc tive action plan is needed.

Rationale: Suggest "change" instead of "a mendment" in (4) because the term amendment is typically c onstrued to mean an offi cial permit modification

process.

Individual Response: EPA disagrees with the suggested change regarding the term

“amendment.” EPA believes that, in some cases an amendment to the AoR and corrective action plan may warrant a permit modification. EP A added text to §144.39(a)(5) that permit modifications, requiring public notice and comment, ar e required if the Director determines that a modification is necessary based on an AoR reevaluation, amendments to any of the project plans, or a review of the testing and monito ring results. EPA made this change because the Agency recognizes that the AoR reevaluation pro cess and any subsequent modifications to the plans may generate significant levels of public interest.

EPA clarifies that if site m onitoring data agrees with the existing AoR delin eation, a model recalibration may not be necessary, and the AoR reevaluation may consist of a demonstration

that the current AoR delineation is ad equate based on site monitoring data.

Letter ID: 0259 Comment ID: 24892 Letter Lines: 1733 to 1747

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment: Rule Provision: 146.84(g)

(g) The emergency and remedial respons e plan (as required by § 146.94) and a demonstration of financial responsibility (as described by § 146.85) must

account for the entire area of review, re gardless of whether or not corrective action in the area of review is phased.

GWPC Recommendations: (g) The emergency a nd remedial response plan (as required by § 146.94) and a demonstration of financ ial responsibility (as described by § 146.85) must account for the entire area of re view [as modified], regardless of

whether or not corrective action in the area of review is phased.

Rationale: Need to add phrase to account for the periodic reevaluations and possible revisions that will be occurri ng. Addition of the term [as modified]

71addresses this concern.

Individual Response: EPA agrees with the commenter and has modified the final rule at §146.84(f) to require the owner or operator to pe riodically review the em ergency and remedial response plan to take into account the most recent AoR. Owners or operators must also periodically update the demonstration of financial responsibility to account for any such changes.

Letter ID: 0259 Comment ID: 24893 Letter Lines: 1749 to 1771

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment: Rule Provision: 146.85

EPA Proposal: 146.85 Financ ial responsibility

(a) The owner or operator must demonstrate and maintain financial responsibility and resources for corrective action (tha t meets the requirements of § 146.84), injection well plugging (that meets the requirements of § 146.92), postinjection site care and site closure (t hat meets the requirements of § 146.93), and emergency and remedial response (tha t meets the requirements of§ 146.94) in a manner prescribed by the Director until:

(1) The Director receives and approves the completed post-injection site care and site closure plan; and

(2) The Director determines that the s ite has reached the end of the postinjection site care period.

GWPC Recommendations: No specific la nguage recommended. See rationale

Rationale: Maintenance of plugging liabili ty until site closure release by the Director is probably not needed once the well has been plugged. Should the owner/ operator be allowed to make a de monstration to the Director for the partial release of other financ ial responsibility elements?

Individual Response: EPA will allow owners or operators to use separate or multiple financial responsibility instruments for different GS activ ities. However, owners or operators must demonstrate adequate financial re sponsibility for all re quired activities, in cluding well plugging, with their permit application, per §146.82(a)(14). In addition, on an annual basis, the owner or operator must adjust the cost estimate for inflatio n, increase or decrease the value of the financial instrument to match the cost estimate, and pr ovide any updated information related to their financial responsibility instrument(s), or at a ny other time deemed appr opriate by the Director. These annual reviews provide a mechanism for revi sing cost estimates up or down to account for changes in the project, includi ng the execution of environmental obligations as phases of a GS

72project are completed. See the final rule and pr eamble for further disc ussion of EPA's final approach to financial responsibility.

Regarding the suggested edit at §146.85(a)(1), EPA clarifies that the owner or operator may be released from a financial instrument when the phase of the project for which the instrument was required is complete and financ ial obligations for the required activity have been met, as specified in §146.85(b)(2).

Letter ID: 0259 Comment ID: 24894 Letter Lines: 1773 to 1791

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment: EPA Proposal: (b) The owner or operator mu st provide to the Director, at a frequency determined by the Director, writte n updates of adjustments to the cost estimate to account for any amendments to the area of revi ew and corrective action plan (§ 146.84), the injection we ll plugging plan (§ 146.92), and the post-injection site care and site closur e plan (§ 146.93).

GWPC Recommendations: (b) The owner or oper ator must provide to the Director, at a frequency determined by the Director, but no more frequently than annually, written updates or adjustments to the co st estimate to account for any changes

to: the area of review and corrective action plan (§146.84), the injection well plugging plan (§146.92), and the post-injecti on site care and site closure plan (§146.93).

Rationale: Does this contemplate bot h upward and downward adjustments?

Suggest "change" instead of amendments.

Clarification on what is meant by "updates or adjustments" woul d be beneficial e.g. what is included, at what frequency etc...

Individual Response: Owners or operators will be required to adjust costs when they are no longer adequate, as spec ified in the GS rule, at §146.85. Thes e baseline estimates can then be updated annually and kept current through input from ongoing dialogue between the owner or operator and the Director. The cost estim ation methodology guidance will also contain instructions on how to adjust cost estimates for inflation to help account for the long-term nature

of GS and will address the need to ad just cost estimates for inflation.

EPA is developing guidance on fina ncial responsibility for GS we lls. The guidance will include a

discussion on how to estimate costs to assist GS well owners or operators, third party insurers or providers of financial instruments, and permitting au thorities in developing estimates of the costs

associated with various GS activities. Th e guidance is available on EPA's website at http://water.epa.gov/type/groundwater /uic/wells_sequestration.cfm.

73EPA did not make the proposed edits, but did extensively revise and clarify the financial responsibility requirements. See the final GS rule and preambl e for additional information on EPA's final approach.

Letter ID: 0259 Comment ID: 24895 Letter Lines: 1793 to 1804

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment: Rule Provision: 146.85(c)

EPA Proposal: (c) The owner or operator mu st notify the Director of adverse financial conditions such as bankruptcy that may affect the ability to carry out injection well plugging a nd post-injection site car e and site closure.

GWPC Recommendations: (c) The owner or operator must notify the Director of adverse financial conditions that may aff ect the ability to carry out injection well plugging and post-injection si te care and site closure.

Rationale: Delete "such as bankruptcy" from (c). Such examples of potential circumstances are unnecessary.

Individual Response: EPA did not make the proposed edits, but did extensively revise and clarify the financial responsibility requirements. EPA believes that the Director must be notified of bankruptcy specifically, among other adverse fina ncial conditions, because it affects the use of financial instrument. See the final GS rule and preamble for additional information on EPA's final approach. Please see the final rule and th e discussion of financia l responsibility in the preamble for additional information.

Letter ID: 0259 Comment ID: 24896 Letter Lines: 1806 to 1824

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment: EPA Proposal: (d) The operator must provide an adjustment of the cost estimate

to the Director if the Director has reason to believe that the original demonstration is no longer adequate to c over the cost of injection well plugging (as required by § 146.92) and post-injecti on site care and site closure (as required by § 146.93).

GWPC Recommendations: (d) The operator must provide an adjustment of the cost

estimate to the Director if the Director has reason to believe that the most

74recent demonstration is no longer adequate to cover the cost of injection well plugging (as required by § 146.92) and post-inje ction site care a nd site closure (as required by § 146.93).

Rationale: The reference should be to the last demonstration not the original

demonstration

This is a one time extraordinary even t. Regular updates are covered by 146.85(b).

Recognize that these will be updated periodically.

Individual Response: EPA agrees that it is important to periodically update cost estimates that support financial responsibility determinations. EPA clarifies th at the GS rule, at §146.85(e) requires the owner or operator to provide annua l updates to the cost es timate to account for any amendments to the AoR and corrective action plan, the injection well plugging plan, and the PISC and site closure plan.

Letter ID: 0259 Comment ID: 24897 Letter Lines: 1826 to 1851

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment: Rule Provision: 146.86

EPA Proposal: 6. Injection well construction requirements

(a) General. The owner or operator must ensure that all Class VI wells are constructed and completed to:

(1) Prevent the movement of fluids in to or between USDWs or into any

unauthorized zones; (2) Permit the use of appropriate tes ting devices and wor kover tools; and (3) Permit continuous monitoring of the annulus space between the injection tubing and long string casing.

GWPC Recommendations: (a) General. The ow ner or operator must ensure that all Class VI wells are constructed and completed to:

(1) Prevent the movement of fluid contai ning any contaminant into USDWs per 40 CFR Part 144.12(a). (2) Permit the use of appropriate tes ting devices and wor kover tools; and (3) Permit continuous monitoring of the annulus space between the injection tubing and long string casing.

75Rationale: Mirror language concerning endangerment standard in (1).

The GWPC suggests re-wording (a)(1) to simp lify and make it cons istent with the

CFR definitions of fluid movement.

Individual Response: EPA believes that protection of USDWs from endangerment and prevention of fluid movement between formations is paramount and believes that the language as proposed meets the non-endangerment standard provided in SDWA and §144.12. Appropriately designed and constructed wells ar e necessary to prevent endange rment 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-operationa l testing of Class VI wells at §§146.86 and

146.87.

Based on its evaluation of all public comment s and input on the proposed rule and NODA and Request for Comment EPA has made many revisions to the GS rule. Please see the final rule and preamble for additional information.

Letter ID: 0259 Comment ID: 24898 Letter Lines: 1853 to 1882

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3860 2.3.3 Well component degradation

Comment: EPA Proposal: (b) Casing and Cementing of Class VI Wells.

(1) Casing and cement or other materials us ed in the construction of each Class

VI well must have sufficient structural st rength and be designed for the life of the geologic sequestration project. All we ll materials must be compatible with fluids with which the materials may be exp ected to come into contact and meet or exceed standards developed for such materials by the American Petroleum Institute, ASTM International, or comp arable standards acceptable to the Director. The casing and cementing program must be designed to prevent the

movement of fluids into or between USDW s. In order to allow the Director to determine and specify casing and cementing requirements, the owner or operator must provide the following information:

GWPC Recommendations: (1) Casing and cem ent or other materials used in the construction of each Class VI well must have sufficient structural strength and be designed for the life of the operating life of the well. All well materials must be compatible with fluids with whic h the materials may be expected to come

into contact and meet or exceed test sta ndards or practices developed for such materials by the American Petroleum Institu te, ASTM International, or comparable standards acceptable to the Director. Th e casing and cementing program must be designed to prevent the movement of fluids into or between USDWs. In order to allow the Director to determine and sp ecify casing and cementing requirements, the owner or operator must provi de the following information:

76Rationale: Suggest substituting "operating life of the well" for "the life of the geologic sequestration project" in (1) The GWPC determined that geologic sequestration project was a nebulous term th at could not be calculated and thus would have no meaning in designin g a casing or cementing program.

IMirror the non endangerment standard.

Individual Response: EPA disagrees that the casing, cement or other materials should only be designed for the period of the injection process, ra ther than the life of the sequestration project. GS projects are anticipated to ha ve long life spans in comparison to other types of deep injection wells. Not only must Class VI wells be able to function safely and properly over the lifespan of the GS project, but they must be constructe d such that USDWs remain protected after well plugging. The requirements at §146.86 will ensure that the well can maintain integrity throughout the proposed life span of the project, including after the injection well is plugged and through post-injection site care period and beyond. While the risk profile of a GS site will decrease following cessation of in jection, EPA believes that Class VI wells must be designed to protect USDWs from endangerment for the life of the project. Furthermore, rigorous casing and cementing help ensure that the Class VI well will not serve as a conduit fo r movement of fluids

associated with future injection operations.

Letter ID: 0259 Comment ID: 24899 Letter Lines: 1884 to 1911

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3860 2.3.3 Well component degradation

Comment: Rule Provision: 146.86(b)(1)

EPA Proposal: (i) Depth to the injection zone; (ii) Injection pressure, exte rnal pressure, internal pre ssure and axial loading; (iii) Hole size; (iv) Size and grade of all casing strings (wall thickness, external diameter, nominal weight, length, joint specific ation and construction material); (v) Corrosiveness of the carbon dioxid e stream, and formation fluids; (vi) Down-hole temperatures; (vii) Lithology of injecti on and confining zones;

GWPC Recommendations: (i) Depth to the injection zone;

(iii) Hole size; (iv) Size and grade of all casing strings (wall thickness, external diameter, nominal weight, length, joint specific ation and construction material); (v) Predicted corrosiveness of the combined carbon dioxide stream and formation

fluids; (vi) Down-hole temperatures and pressures; (vii) Lithology of injecti on and confining zones;

77Rationale: What is meant by external and internal pressure? Recommend deleting (ii).

Insert "and pressures" in (vi)

Cannot measure the corrosiveness of the CO2 stream because it is not corrosive. Only liquids will yield pH measurements.

Individual Response: EPA disagrees with the suggested edits. The internal and external pressure mentioned in §146.86(b)(1)(ii) refers to pressure on the well casing. Internal pressures could be caused by cement or annular fluids; exte rnal pressures could be caused by cementing against the borehole or pressure head from formations.

At §146.86(c)(3)(ii), EPA clarifies that, although corrosiveness does not have a unit of measure, corrosiveness can be technically measured and described. Procedures that can identify corrosion (or the absence of corrosion) in a Class VI well provide valuable operational information that the Director needs to determine appropriate standard s for the tubing and packer. EPA believes that this subpart accounts for all charac teristics of the CO2 that could affect the performance of the tubing and packer, including the chemical content, corrosiveness, temperature, and density.

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

Letter ID: 0259 Comment ID: 24900 Letter Lines: 1910 to 1911

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

Comment: Cannot measure the corrosiveness of the CO2 stream because it is not corrosive. Only liquids will yield pH measurements.

Individual Response: EPA clarifies that, although corro siveness does not have a unit of measure, corrosiveness can be technically measured and described. Procedures that can identify corrosion (or the absence of corrosion) in a Class VI well provide valuable operational

information that the Director needs to determin e appropriate standards for the tubing and packer. As written, the text at §146.86(c)(3)(ii) accounts fo r all characteristics of the CO2 that could affect the performance of the t ubing and packer, including the ch emical content, corrosiveness, temperature, and density.

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.

78Letter ID: 0259 Comment ID: 24901 Letter Lines: 1913 to 1921

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment: EPA Proposal: (viii) Type or grade of cement; and (ix) Quantity, chemical composition, a nd temperature of the carbon dioxide

stream.

GWPC Recommendations: (viii) Type or grade of cement and additives; and (ix) Quantity, chemical composition, a nd temperature of the carbon dioxide

stream.

Rationale: Insert "and additives" in (viii)

Individual Response: EPA agrees with the suggestion that §146.86(b)(1)(viii) be revised to also

address cement additives. In the final GS rule, the subparagraph reads as follows: "Type or grade

of cement and cement additives."

Letter ID: 0259 Comment ID: 24902 Letter Lines: 1923 to 1933

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment: EPA Proposal: (2) Surface casing must exte nd through the base of the lowermost

USDW and be cemented to the surface.

GWPC Recommendations: (2) Surface casing must extend through the base of the lowermost USDW above the injection z one and be cemented to the surface.

Rationale: Insert "above the injection zone" in (2) after "USDW." In some parts of the US the USDW is very deep and this standard may preclude geologic sequestration in these areas. EPA should consider allowing the Director to exercise discretion to approve alternativ e means of achieving continuous cement

around the well in such areas.

Individual Response: EPA disagrees with the suggested edit or that th e surface casing requirements in the GS rule preclude injecti on below deep USDWs. The final GS rule at §146.86(b)(2) requires that surface casing extend th rough the base of the lowermost USDW and be cemented to the surface through the use of a singl e or multiple strings of casing and cement. It does not, however, specify how cementing must 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. EPA notes that there are many potential ways to meet the requirement , such as the use of staged cementing.

EPA adds that protection of USDWs is the pr imary mission and mandate of the UIC program

79and the purpose of all requirements for inject ion wells. Any injection activity must be demonstrated to not endanger USDWs, regardless of their depth, and if such a demonstration cannot be made, then the activity will not be allowed under UIC requirements or the SDWA.

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 requirements. Owners or operators of wells opera ting under injection depth waivers must comply with additional construction require ments to ensure that wells used to inject above or between USDWs are protective. See the discussion of the wa iver approach in the preamble to the final GS

rule for additional information.

Letter ID: 0259 Comment ID: 24903 Letter Lines: 1935 to 1953

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment: EPA Proposal: (3) At least one long string casing, using a sufficient number of centralizers, must extend to the inje ction zone and must be cemented by circulating cement to the surface in one or more stages.

GWPC Recommendations: (3) At least one long string casing, using a sufficient

number of centralizers, which at a mi nimum, would create a cement bond through the confining zone, and which must extend to the injection z one and must be isolated by placing cement and/or other is olation technologies as necessary to provide adequate isolation of the injec tion zone and provide for protection of

USDWs.

Rationale: Cementing to surface is not neces sary to protect USDWS, and may have negative consequences, as follows. Cement to surface would eliminate the ability to monitor pressures in this annulus and would limit flexibility of remedial options. As revised, the propos al would allow for application and development of alternative technologies. See API RP90 for description of riskbased approach for managing situations involving annular casing pressure. Industry experience with CO 2 EOR under the class II progr am demonstrates the effectiveness of existing cementing procedures.

Individual Response: EPA does not believe that the cem enting requirements at §146.86 would prevent monitoring, operation and remediation of Class VI wells. Cementing of deep wells has been performed successfully in the past by owners or operators of Class I hazardous and Class I municipal waste disposal wells. Some of these wells, which must meet the same cementing and casing requirements as Class VI wells, are up to 12,000 feet deep and have been successfully cemented in a manner that maintains integrity an d allows for all required well testing, operation, and remediation (EPA, 2001). See the discussion of Class VI well construction requirements in the preamble to the final GS rule for additi onal information. Additionally, EPA is developing

80guidance on the construction of Class VI wells . This guidance will be available on EPA’s website at http://water.epa.gov/type/gr oundwater/uic/wells_se questration.cfm.

Letter ID: 0259 Comment ID: 24904 Letter Lines: 1955 to 1965

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment: Rule Provision: 146.86(b)

EPA Proposal: (4) Circulation of cement may be accomplished by staging. The Director may approve an alternative me thod of cementing in cases where the

cement cannot be recirculated to the surf ace, provided the owner or operator can demonstrate by using logs that the cement does not allow fluid movement behind

the well bore.

GWPC Recommendations: Delete

Rationale: Same as above

Individual Response: EPA disagrees that the requireme nt should be deleted. Section 146.86(b)(4) of the final rule allows alternate methods of staging the cement, at the Director's discretion, provided the owner or operator can demonstrate using logs that the cement does not

allow fluid movement behind the wellbore.

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: 0259 Comment ID: 24905 Letter Lines: 1967 to 1988

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment: EPA Proposal: (5) Cement and cement additives must be compatible with the carbon

dioxide stream and formati on fluids and of sufficient quality and quantity to maintain integrity over the design life of the geologic sequestration project. The integrity and location of the cement shall be verified using technology capable of evaluating cement quality radially and identifying the location of

channels to ensure that USDWs are not endangered.

GWPC Recommendations: (5) Cement and cemen t additives must be suitable for use

with the carbon dioxide stream and forma tion fluids and of sufficient quality and quantity to maintain integrity over the operating life the well. The

81integrity and location of the cement sha ll be verified using technology capable of evaluating cement quality radially and identifying th e location of channels to ensure that USDWs are not endangered.

Rationale: Experience with CO2 EOR under th e class II program demonstrates the effectiveness of existing cementing mate rials and procedures. Standard API

cements have been used in numerous CO2 EOR operations without adverse consequences. Reference API CO2 EOR report and Carey et al. Bill Carey (SACROC) and Walter Crow (CCP2 - placement and annul ar gap more important than type).

Once the well is plugged, the plug will is olate the other portions of the well from the injected fluids.

Individual Response: EPA clarifies that the requirement at §146.86(b)(5) is that cement and cement additives must be compatible with the CO2 stream and formation fluids and of sufficient quality and quantity to maintain integrity over the design life of th e GS project. The rule does not specify materials to be used; rather, it provides owne rs or operators with the flexibility to choose, as long as the materials used in Class VI wells are compatible w ith fluids with which they may

come into contact and meet or exceed standard s developed for such materials by API or ASTM International, or comparable sta ndards approved by the Director.

EPA recognizes that the oil and gas industry has decades of e xperience injecting CO2 for the purpose of enhanced recovery, and that this practice has led to th e development of many measures that would be appropriate for the design of Class VI wells.

EPA disagrees that the casing, cement or other materials should only be designed for the period of the injection process, rather than the life of the sequestration proj ect. GS projects are anticipated to have long life span s in comparison to other types of deep injection wells. Not only

must Class VI wells be able to function safely and properly over the lifespan of th e GS project, but they must be constructed such that US DWs remain protected after well plugging. The requirements at §146.86 will ensure that the well can maintain integrity throughout the proposed life span of the project, including after the in jection well is plugged and through post-injection site care period and beyond. While the risk profile of a GS site will decrease following cessation of injection, EPA believes that Class VI wells must be desi gned to protect USDWs from endangerment for the life of the project. Furthermore, rigorous casing and cementing help ensure

that the Class VI well will not se rve as a conduit for movement of fluids associated with future injection operations.

Additionally, EPA is developing guidance on the constr uction 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: 0259 Comment ID: 24906 Letter Lines: 1990 to 2022

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3826 2.3.1.3 Packer requirements (seeking comment)

82Comment: Rule Provision: 146.86(c)

EPA Proposal: (c) Tubing and packer.

(1) All owner and operators of Class VI wells must inject fluids through tubing with a packer set at a depth opposite a cemented interval at the location approved by the Director.

(2) In order for the Director to determ ine and specify requirements for tubing and packer, the owner or operator must submit the following information:

(i) Depth of setting; (ii) Characteristics of the carbon di oxide stream (chemical content, corrosiveness, temperature, and density);

GWPC Recommendations: (c ) Tubing and packer.

(1) All owner and operators of Class VI wells must inject fluids through tubing with a packer set at a depth opposite a cemented interval at the location approved by the Director.

(2) In order for the Director to determ ine and specify requirements for tubing and packer, the owner or operator must submit the following information:

(i) Depth of setting; (ii) Composition of the carbon dioxide stream;

Rationale: What does corrosiveness mean? How is it measured?

Cannot measure the corrosiveness of a carbon dioxide stream.

Composition of the cO2 stream is needed to design a tubing and packer system.

The other listed characteristics are not needed.

Individual Response: As written, the text at §146.86(c)(3)(ii) accounts for all characteristics of the CO2 that could affect the performance of the tubing and packer, including the chemical content, corrosiveness, temperature, and de nsity. The suggested revision to refer to CO2 "composition" would be less precise. EPA clarifie s that, although corrosiveness does not have a unit of measure, corrosiveness can be technically measured and describe d. Procedures that can identify corrosion (or the absence of corrosion) in a Class VI well provid e valuable operational

information that the Director needs to determine appropriate standards for the tubing and packer.

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

83Class VI wells. This guidance will be available on EPA’s website at http://water.epa.gov/type/groundwater /uic/wells_sequestration.cfm.

Letter ID: 0259 Comment ID: 24907 Letter Lines: 2024 to 2042

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3826 2.3.1.3 Packer requirements (seeking comment)

Comment: Rule Provision: 146.86(c)(2)

EPA Proposal: (iii) Injection pressure; (iv) Annular pressure; (v) Injection rate (intermittent or c ontinuous) and volume of the carbon dioxide

stream; (vi) Size of casing; and (vii) Tubing tensile, burst, and collapse strengths.

GWPC Recommendations: (iii) Maximum proposed Injection temperat ure and pressure; (iv) Maximum proposed Annular pressure; (v) Maximum proposed Injection rate (inter mittent or continuous) and volume of

the carbon dioxide stream;

Rationale: It is more helpful to know the recommended information.

The GWPC also recommends addition of the term "proposed in (iii), (iv) and (v) as this section relates to an applicatio n and not to actual established permit

conditions

Individual Response: EPA has revised §146.86(c)(3 )(iii) and (iv) to reference the maximum proposed injection pressure and maximum propos ed annular pressure, respectively. EPA has revised §146.86(c)(3)(v) to read "proposed injec tion rate (intermittent or continuous), and

volume and/or mass of the carbon dioxide stream." EPA believes that refere nce to the continuous injection rate would be duplica tive of the maximum rate. EPA believes that considering the maximum injection and annular pressu re would be more protective.

Letter ID: 0259 Comment ID: 24909 Letter Lines: 2270 to 2295

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 4110 2.4.1.1 Injection pressure limitations

Comment: Rule Provision: 146.88

EPA Proposal: 8. Injection we ll operating requirements

(a) Except during stimulation, the owner or operator must ensure that injection

84pressure does not exceed 90 percent of the fracture pressure of the injection zone so as to assure that the inject ion does not initiate new fractures or propagate existing fractures in the inj ection zone. In no case may injection pressure initiate fractures in the confin ing zone(s) or cause the movement of injection or formation fluids that endangers a USDW.

GWPC Recommendations: (a) The owner or operator must comply with a maximum injection pressure limit approved by the Director and specified in the permit. In approving a maximum injection pressure limit, the Director shall consider the results of well tests and, where appropri ate, geomechanical or other studies

that assess the risks of tensile failure and shear failure. The Director shall approve limits that, with a reasonab le degree of certainty, will avoid initiation or propagation of fractures in the confining zone or cause otherwise non-transmissive faults transecting the c onfining zone to become transmissive. In no case may injection pressure cause movement of injection or formation fluids in a manner prohibited by 40 CFR Part 144.12(a).

Rationale: Maintaining the integrity of the confining zone is the critical parameter. We believe establishing a ma ximum pressure based on an arbitrary percentage of injection z one fracture pressure does not address the issue of confining zone integrity in an appropriate way.

Individual Response: EPA notes that because determination of the injection pressure limit is based on the fracture pressure of the injection zo ne, the limit is site-sp ecific and not arbitrary. EPA emphasizes that injection pressure limits ar e important to protect against fracturing of the confining zone, and that the requ irement at §146.88(a) that the pressure in th e injection zone not exceed 90 percent of the fracture pressure provides a margin of safety in the well operation and protects USDWs from endangerment. If the Dire ctor determines, based on a review of the information collected as part of site characterization, th at a lower injection pr essure limitation is appropriate, the Director has the authority to set a lower limit in the operating permit than the

limit established in the rule.

EPA notes that during the site characterization pr ocess, owners or operators must submit data about the geology of the site, as specified at §146.82(a), includ ing data on known or suspected faults and fractures and geomechanical informati on on fractures, stress, du ctility, rock strength, and in situ fluid pressures w ithin the confining zone. The Di rector will use these data to determine appropriate limits on injection.

EPA is developing guidance on site characterization for GS projects to assist owners or operators in meeting the requirements of §146.82 and to assist directors in evaluating permit applications. The guidance will describe recommended approach es for characterizing the regional geology and hydrogeology of a proposed site and performing the necessary geochemical, geomechanical, and geophysical analyses of the injection and confin ing zone. EPA is also developing guidance for primacy agencies that will include recommended a pproaches for evaluating owner or operatorsubmitted data in setting permit conditions. The gu idance will be available on EPA's web site, at http://water.epa.gov/type/groundwater /uic/wells_sequestration.cfm.

85Letter ID: 0259 Comment ID: 24910 Letter Lines: 2297 to 2308

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 4100 2.4.1 Injection parameters

Comment: EPA Proposal: (b) Injection between the outer-most casing protecting USDWs and the well bore is prohibited.

GWPC Recommendations: (b) Injection of the CO2 stream between the outermost casing protecting USDWs and th e well bore is prohibited.

Rationale: Routine injection into zones othe r than the target interval(s) should be prohibited, however, wording of this re quirement is not clear as to which interval is being addressed. An absolu te prohibition on injection may also limit diagnostic options th at could be useful.

Sometimes inject other things to remediate well.

Individual Response: EPA retains the provision as propos ed, and clarifies that injection between the casing and the well bore is prohibited. This is consistent with requirements for other injection well classes.

Letter ID: 0259 Comment ID: 24911 Letter Lines: 2310 to 2335

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 4100 2.4.1 Injection parameters

Comment: EPA Proposal: (c) The owner or operator mu st fill the annulus between the tubing and the long string casing w ith a non-corrosive fluid approved by the Director. The owner or operator must maintain on th e annulus a pressure that exceeds the operating injection pressure, unless the Director determines that such requirement might harm the integrity of the well.

GWPC Recommendations: (c) The owner or operator must fill the annulus between the tubing and the long string casing with a corrosion inhibiti ng fluid approved by the Director. The owner or operator must maintain a positive pressure on the

annulus.

Rationale: Agency and Industry experience with the Class II UIC program does not support this requirement. The standard proposed by EPA is consistent with

neither the risk level related to CO2 nor the specifications needed to monitor the annular space for leakage.

Rule Provision: 146.88(d)

86EPA Proposal: (d) Other than during peri ods of well workover (maintenance) approved by the Director in which the sealed tubing-casing annulus is of necessity disassembled for maintenance or corrective procedures, the owner or operator must maintain mechanical integrity of the injection well at all times.

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

Individual Response: EPA believes that maintaining an annulus pressure that is higher than the injection pressure, as required at §146.88(c), is a ppropriate and will ensure that if there are leaks in the tubing, the annulus fluid will move into th e tubing, rather than the injectate moving out of the tubing and potentially along the outside of the well. EPA believes this requirement is appropriate for Class VI wells given the potential high volumes a nd supercritical nature of the CO2 injectate, potential geomechanical stresses in the wellbore, and the potential for movement

of the CO2 in the event of a mechanical integrity loss.

EPA disagrees that maintaining an annulus pres sure higher than the injection pressure impacts continuous pressure monitoring for internal MI. The purpose of continuous pressure monitoring (to demonstrate internal MI) is to demonstrate that no pressure changes are occurring, because a drop in pressure on the annulus pr ovides an early indicati on that attention is needed to prevent a loss of MI or unacceptable fluid movement. EPA believes that any change in the pressure on the annulus between tubing and long stem casing, regardless of what th e annulus pressure is relative to injection pressure, can indicate a leak.

EPA agrees with the commenter that maintaining mechanical integrity is an essential component of protecting USDWs. The final rule retains a requirement to maintain mechanical integrity at §146.88(d).

Letter ID: 0259 Comment ID: 24912 Letter Lines: 2337 to 2362

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment: Rule Provision: 146.88

EPA Proposal: (e) The owner or operato r must install and use continuous recording devices to monitor: The inj ection pressure; the rate, volume, and temperature of the carbon dioxide str eam; and the pressure on the annulus between the tubing and the long string casi ng and annulus fluid volume; and must install and use alarms and automatic down-hole shut-off systems, designed to alert the operator and shut -in the well when operating parameters such as annulus pressure, injection rate or othe r parameters approved by the Director diverge beyond permitted ranges and/or gradients specified in the permit;

GWPC Recommendations: (e) The owner or ope rator must install and use continuous

87recording devices to monitor: the inje ction pressure; the rate, volume, and temperature of the carbon dioxide stream. The owner or operator must regularly monitor the pressure on the annulus be tween the tubing and the long string casing. The owner or operator must instal l, test and use alarms and automatic shut-off systems, designed to alert th e operator and shut-i n the well when operating parameters such as injection rate, injection pressure, or other parameters approved by the Director di verge beyond ranges a nd/or gradients specified in the permit;

Rationale: Over-pressure protection is be st achieved by ensuring compatibility of the casing/tubing material design strength with the surface injection (compression) system. Down-hole shut-in devices may be appropriate, however, for site-specific situations of unique pot ential impact (such as offshore or near airports), but they should not be mandated for all injection sites.

Individual Response: EPA acknowledges that proper design of the well, including appropriate materials and emplacement of casing and tubing, is essential to proper operation of the well so that USDWs are protected. Such design, however, does not eliminate the possibility of failure, e.g., due to over-pressurization as suggested by th e commenter. EPA believes that a multiplebarrier approach, which includes appropriate well design as required at §146.86, suitable injection pressure limits as required at §146.88(a), and automatic shut-off systems, as required at §146.88(e), is necessary to ensure protection of USDWs from endangerment from the risks

associated with CO2 GS.

After evaluating the risk s and benefits of down-hole shut-off systems and considering additional research, EPA will not require automatic down-ho le 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), re quires that owners or operato rs of onshore Class VI wells

install automatic surface shut-off devices. The ru le affords Director's discretion to mandate

automatic down-hole shut-off devices in onshore situ ations that may warrant their use. However, the Agency believes that offshore Class VI we lls present unique construction and operational conditions, including isolation from shorelines and the need to c onstruct wells th rough the water column and the subsurface, which may delay res ponse time in the event of well difficulties. The rule requires, at §146.88(e)(3), that owners or oper ators of offshore wells w ithin State territorial waters install automatic down-hole shut-off system s. EPA believes that these requirements at §146.88(e) ensure that proper precautions are take n to prevent subsurface fluid movement and ensure protection of USDWs.

While EPA acknowledges that the likelihood of damage to onshore f acilities is lower than that

for off-shore facilities, down-hole shut-off valv es are still commonly used in onshore facilities such as acid gas injection wells and high pressu re, high-temperature wells. While valve failure is a concern, EPA believes that technology has advanced sufficiently to make valve failure a rare occurrence and to appropriately hand le such failure if it occurs. Fo r example, wireline retrievable devices can allow repair or replacement of da maged devices without necessitating pulling the tubing.

88Letter ID: 0259 Comment ID: 24913 Letter Lines: 2364 to 2388

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment: Rule Provision: 146.88

EPA Proposal: (f) If a down-hole automatic shutdown is triggere d or a loss of mechanical integrity is discovered, the owner or operator must immediately investigate and identify as expeditiously as possible the cause of the shutoff. If, upon such investigation, the well a ppears to be lacking mechanical integrity, or if monitoring required u nder paragraph (e) of this section otherwise indicates that the well may be lacking mechanical in tegrity, the owner

or operator must:

GWPC Recommendations: (f) If an automatic shutdown is triggered or a loss of mechanical integrity is discovered, the owner or operator must immediately investigate and identify as expeditious ly as possible the cause. If, upon such investigation, the well appears to be l acking mechanical integrity, or if monitoring required under paragraph (e) of this section otherwise indicates that the well may be lacking mechanical integrity, the owner or operator must:

Rationale: Eliminates requirement for down-hole shutoff device. Although the use of downhole shutoff valves may be needed in some applications, their required use would be less than ideal for many reasons such as the fact that since they are a downhole inst allation, integrity and main tenance of the valves

is difficult. Further the installation of surface valves would allow for more control and provide for visual inspecti on. Since the key is to shut down the injection flow if a parameter is exceed ed, the use of surface valves would be just as effective as downhole valves.

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. The rule requires, at §146. 88(e)(3), that owners or operators of offshore

wells within State territorial waters install auto matic down-hole shut-off systems. Please see the final rule and preamble for additional information on EPA's final approach.

Letter ID: 0259 Comment ID: 24914 Letter Lines: 2390 to 2409

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 4000 2.4 Proposed Injection Well Operat ing Requirements (40 CFR 146.88)

Comment: Rule Provision: 146.88(f)

89EPA Proposal: (1) Immediat ely cease injection; (2) Take all steps reasonably necessary to determine whet her there may have been a release of the injected carbon dioxid e stream into any unauthorized zone; (3) Notify the Director within 24 hours; (4) Restore and demonstrate mechanical integrity to the satisfaction of the Director prior to resuming injection; and (5) Notify the Director when injec tion can be expected to resume.

GWPC Recommendations: Support the proposed EPA language for (1), (2), and (5)

(3) Notify the Director with in 24 hours of discovery; (4) Restore and demonstrate mechanical integrity to the satisfaction of the director as soon as practicable a nd prior to resuming injection.

Rationale: Needs to be reasonable and allow for time following discovery.

It was felt that some timeframe for restoration of mechanical integrity should be added to (4)

Individual Response: The final rule text at §146.88(f) now reads, "If a shutdown (i.e., downhole or at the surface) is triggere d or a loss of mechanical integr ity is discovered." Therefore the notice required at §146.88(f)(3) must be provide d within 24 hours of an automatic shut-off device being triggered or a loss of mechanical integrity being discovered. EPA believes this provision is necessary to ensure timely re sponse to potential USDW endangerment.

Letter ID: 0259 Comment ID: 24915 Letter Lines: 2411 to 2423

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment: Rule Provision: 146.89

EPA Proposal: 9. Mechanical integrity

(a) A Class VI well has mechanical integrity if:

(1) There is no significant leak in the casing, tubing or packer; and (2) There is no significant fluid movement into a USDW through channels adjacent to the injection well bore.

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

90Individual Response: EPA acknowledges the comment and the final rule retains the text at 146.89(a) as proposed. For additional information, please see the discussion of MITs in the final rule preamble.

Letter ID: 0259 Comment ID: 24916 Letter Lines: 2425 to 2440

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment Code: 4720 2.7.2 Operational record keeping and reporting

Comment: EPA Proposal: (b) To evaluate the absen ce of significant l eaks under paragraph (a)(1) of this section, owne rs or operators must, following an initial annulus pressure test, continuously monitor inject ion pressure, rate, injected volumes, and pressure on the annulu s between tubing and long st em casing and annulus fluid volume as specified in § 146.88(e);

GWPC Recommendations: (b) To evaluate the absence of significant leaks under paragraph (a)(1) of this s ection, owners or operators must, following an initial annulus pressure test, continuously monito r and record at least daily injection pressure, rate, injected volumes, and pressure on the annulus between tubing and long stem casing and annulus flui d volume as specified in §146.88 (e);

Rationale: We believe that injection para meters must not only be monitored but should be recorded at least daily. We furt her believe the use of monitoring with digital equipment which records readings on an appropriate frequency should be considered continuous for purposes of this section.

Individual Response: EPA believes that continuous pressure monitoring to demonstrate internal mechanical integrity of Class VI wells require d at §146.89(b) is important, given the potential corrosive impact of CO2 and impurities on well ma terials, the potential geomechanical impacts to well integrity due to CO2 phase changes, and the temperature and pressure effects associated with injecting supercritical CO2. EPA also believes that the technology for continuous monitoring is practicable, available, and is currently in fairly wide use. Class VI injection wells will be equipped with dedicated computer-based continuous pressure monitoring devices (in concert with the shut-off systems required for GS wells), which typically take readings several times per second (i.e., more frequently than daily) and record them electronically in a computer system. 40 CFR §146.91(a)(2) requires that mo nthly averages of the continuous annulus monitoring be reported on a semiannual basis. For additional information, please see the discussion of MITs in the final rule preamble.

Letter ID: 0259 Comment ID: 24917 Letter Lines: 2442 to 2462

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 4540 2.5.2 Proposed external MIT requirements

91Comment Code: 4543 2.5.2.1 MIT procedures and methods for GS (seeking comment)

Comment: Rule Provision: 146.89(c)

EPA Proposal: (c) At least once per year, th e owner or operator must use one of the following methods to determine the absence of significant fluid movement under paragraph (a)(2) of this section:

(1) A tracer survey such as oxygen-activation logging; (2) A temperature or noise log; or (3) A casing inspection log, if required by the Director.

GWPC Recommendations: (c) At least once per year, the owner or operator must confirm the absence of significant fluid m ovement under paragraph (a)(2) of this section using a method acceptable to the Director (e.g. including diagnostic surveys such as oxygen-activation logging or temperature or noise logs).

Delete (1) Delete (2) Delete (3)

Rationale: Revised text supports a perfor mance-based approach and allows the development and use of new technologi es as they become available.

Individual Response: EPA believes that the MITs describe d in §146.89(c) of the rule (e.g., an approved tracer log or temperatur e or noise logs) are effective me thods to demonstrate external MI, provide an important early warning of potenti al problems in the injection well system, and represent standard techniques that have been used successfully by the drilling industry and for the UIC Program for decades. The Agency notes that the regulations do provide the Director flexibility at §146.89(e) to approve th e use of alternative MIT methods.

EPA agrees that the casing inspection log is not an appropriate test to detect fluid movement behind the casing, but clarifies that it is appropriate to be used to determine the presence or absence of corrosion of the long-string casing, and is required if the Director determines that it is necessary based on site-specific information. EPA ha s revised the final GS rule to require that the frequency of the casing insp ection log must be specified in the approved testing and monitoring plan. See §146.89(d).

Letter ID: 0259 Comment ID: 24918 Letter Lines: 2464 to 2478

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 4543 2.5.2.1 MIT procedures and methods for GS (seeking comment)

Comment: EPA Proposal: (d) The Director may require an y other test to evaluate mechanical integrity under paragraph (a )(1) or (a)(2) of this sect ion. Also, the Director

92may allow the use of a test to demonstrat e mechanical integrity other than those listed above with the written approval of the Administrator. To obtain approval, the Director must submit a written request to the Administrator, which must set forth the proposed test and all technical data supporting its use. The Administrator must approve the request if it will reliably demonstrate the mechanical integrity of wells for whic h its use is propose d. Any alternate method approved by the Administrator will be published in the Federal Register and may be used in all States in accord ance with applicable State law unless its use is restricted at the time of approval by the Administrator.

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

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

Letter ID: 0259 Comment ID: 24919 Letter Lines: 2480 to 2492

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 4543 2.5.2.1 MIT procedures and methods for GS (seeking comment)

Comment: Rule Provision: 146.89(e)

EPA Proposal: (e) In conducting and evaluating the tests enumerated in this section or others to be allowed by the Director, the owner or operator and the Director must apply methods and standa rds generally accepted in the industry. When the owner or operator reports the resu lts of mechanical integrity tests to

the Director, he/she shall include a description of the test(s) and the method(s) used. In making his/her eval uation, the Director must review monitoring and other test data submi tted since the previous evaluation.

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

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

Letter ID: 0259 Comment ID: 24920 Letter Lines: 2494 to 2503

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 4543 2.5.2.1 MIT procedures and methods for GS (seeking comment)

Comment: EPA Proposal: (f) The Director may require additional or alternative tests if

93the results presented by the owner or ope rator under paragraph (d) of this section are not satisfactory to the Direct or to demonstrate that there is no significant leak in the ca sing, tubing or packer or significant movement of fluid into or between USDWs resulting from the injection activity as stated in paragraphs (a)(1) and (2) of this section.

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

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

Letter ID: 0259 Comment ID: 24922 Letter Lines: 2505 to 2518

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment: Rule Provision: 146.90

EPA Proposal: 10. Testing and monitoring requirements

The owner or operator of a Class VI well mu st prepare, maintain, and comply with a testing and monitoring plan to verify that the geologic se questration project is operating as permitted and is not endangering USDWs. The testing and monitoring plan must be submitted with the permit application, for Director approval, and must include a description of how the owner or operator will meet the requirements of this section. Test ing and monitoring associated with geologic sequestration projects mu st, at a minimum, include:

GWPC Recommendations: Support the proposed EPA language.

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

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

Letter ID: 0259 Comment ID: 24923 Letter Lines: 2521 to 2540

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

94CFR 146.90)

Comment: Rule Provision: 146.90

EPA Proposal: (a) Analysis of the car bon dioxide stream with sufficient frequency to yield data representati ve of its chemical and physical

characteristics;

(b) Installation and use, except during well workovers as defined in § 146.86(d), of continuous recording devices to monitor injection pressure, rate and volume; the pressure on the annulus between the tubing and the long string casing; and the annulus fluid volume;

GWPC Recommendations: Support the proposed EPA language in (a)

(b) Installation and use, except during well workovers as defined in §146.88(d), of continuous monitoring devices (includi ng digital devices ca pturing periodic data) to monitor injection pressure, rate and volume; and record at least daily the pressure on the annulus between th e tubing and the long string casing;

Rationale: 146.86(d) does not exist; perhap s 146.88(d) is what was apparently

intended.

Individual Response: EPA acknowledges the comment; the fina l rule retains the language in §146.90(a) as proposed. EPA adds that the final GS rule referen ces §146.88(e), as the commenter

suggests.

Regarding §146.90(b), based on its evaluation of all public comments and input on the proposed rule and NODA and Request for Comment EPA has ma de many revisions to the GS rule. See the final rule and preamble for further discussion on EPA's final approach.

Letter ID: 0259 Comment ID: 24924 Letter Lines: 2542 to 2560

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 4630 2.6.3 Corrosion monitoring

Comment: Rule Provision: 146.90

EPA Proposal: (c) Corrosion monitoring of the well materials for loss of mass, thickness, cracking, pitting and other signs of corrosion must be performed on a quarterly basis to ensure that the well components meet the minimum standards for material strength and perfor mance set forth in § 146.86(b) by:

GWPC Recommendations: c) Corrosion monitoring of the well materials for loss of mass, thickness, cracking, pitting and other signs of corrosion must be performed and recorded at least quarterly and may be modified to be less

95frequent as approved by the Director based on construc tion materials, operating conditions, and monitoring history to ensu re that the well co mponents meet the minimum standards for material strength and performance set forth in §146.86(b) by:

Rationale: Allows application of performance based approach.

Rationale: Allows less frequent mon itoring, for example, where corrosion

resistant materials are used.

Individual Response: EPA believes that quarterly corrosion monitoring is appropriate given the potentially corrosive nature of the CO2 stream. CO2 in the presence of water becomes acidic, potentially accelerating corrosion of well material s. The CO2 stream for a GS project may also contain small volumes of impurities that could co ntribute to corrosion. For these reasons, the final rule requires quarterly co rrosion monitoring, at §146.90(c).

Based on its evaluation of all public comment s and input on the proposed rule and NODA and Request for Comment EPA has made many revisions to the GS rule. See the final rule and preamble for further discussi on on EPA's final approach.

Letter ID: 0259 Comment ID: 24925 Letter Lines: 2562 to 2577

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 4630 2.6.3 Corrosion monitoring

Comment: Rule Provision: 146.90(c)

EPA Proposal: (1) Placing coupons of the we ll construction materi als in contact

with the carbon dioxide stream; or (2) Routing the carbon dioxide stream through a loop constructed with the

material used in the well; or (3) Using an alternative met hod approved by the Director;

GWPC Recommendations: (1) Analyzing coupo ns of the well construction materials placed in contact with the carbon dioxide stream; or (2) Routing the carbon dioxide stream through a loop constructed with the material used in the well and inspec ting the materials in the loop; or (3) Using an alternative method, materi als, or time period approved by the

Director;

Rationale: Clarification edits

Individual Response: As described above, EPA believes that quarterly corrosion monitoring is appropriate given the potentially corrosive nature of the CO2 st ream. Based on its evaluation of all public comments and input on the proposed rule and NODA and Request for Comment EPA

96has made many revisions to the GS rule. See the final rule and preamble for further discussion on EPA's final approach.

Letter ID: 0259 Comment ID: 24926 Letter Lines: 2579 to 2613

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 4660 2.6.6 Geochemical monitoring

Comment: Rule Provision: 146.90(d)

EPA Proposal: (d) Periodic monitori ng of the ground water quality and geochemical changes above the confining zone(s) that may be a result of carbon dioxide movement through the confining z one or additional identified zones:

(1) The location and number of monitoring wells must be based on specific information about the geologic sequestrati on project, including injection rate and volume, geology, the presence of artific ial penetrations and other factors;

(2) The monitoring frequency and spatial distribution of monitoring wells must be based on baseline geochemical data th at has been collected under § 146.82(a) (6) and any modeling results in the area of review evaluation required by § 146.84(b);

GWPC Recommendations: (d) Periodic monitoring of reservoir formation fluid quality in a permeable and porous forma tion as near as practicable to the confining zone(s) for geochemical changes that may be a result of carbon dioxide or displaced formation fluid movement:

(1) The location and number of monitoring wells must be based on specific information about the geologic sequestrati on project, including injection rate and volume, geology, the presence of artific ial penetrations and other relevant factors as warranted by a risk-assessment;

(2) The monitoring frequency and spatial distribution of monitoring wells must be based on geological, geochemical and ge ophysical data that ha s been collected under §146.82(d) and any modeling results in the area of review evaluation required by §146.84(b);

Rationale: Drilling monitoring wells should be carefully considered since each well introduces a potential pathway for movement.

[Geochemical data do not have a high degr ee of relevance in selecting monitoring well sites.]

Individual Response: EPA believes that monitoring using we lls in the injection zone, e.g., for pressure monitoring as required at §146.90(g)(1), can be safely performed if the wells are

97constructed to prevent flow be tween the injection zone and USDWs or other layers above the confining zone. Such constructi on technologies exist and have b een used in the oil and gas industry for years. EPA believes th at properly constructed monitoring wells will be a safe way to

obtain the data that is essential to ensure that the injected CO2 remains confined in the injection zone and that pressure changes are not causing movement of formation or other fluids. To mitigate the risk of fluid movement, EPA require s owners and operators to submit a testing and monitoring plan that describes how the owner or operator plans to site and construct monitoring wells. EPA has developed a brief technical pa per on construction of monitoring wells that perforate the confining zone; th is paper can be found in the ru lemaking docket. EPA is also developing guidance on well constr uction that will include reco mmendations for monitoring well construction. The guidance will be available on EPA’s website at http://water.epa.gov/type/groundwat er/uic/wells_se questration.cfm.

Baseline characterization of the site, including the geochemical data and initial modeling, will be highly valuable in selection of monitoring well locations and in refining plans for monitoring frequency. The GS rule stipulates that the m onitoring frequency and spatial distribution of monitoring wells must be based on baseline geoc hemical data that were collected during the

initial site characterization and the area of review evaluation (§146.90(d)(2)). The details of the geochemical monitoring must be based on site -specific information and described in the Director-approved testin g and monitoring plan.

Letter ID: 0259 Comment ID: 24927 Letter Lines: 2615 to 2632

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment: Rule Provision: 146.90

EPA Proposal: (e) A demonstrat ion of external mechanical integrity pursuant to § 146.89(c) at least once per year throu ghout the duration of the geologic sequestration project;

(f) A pressure fall-off test at least once every five years unless more frequent testing is required by the Director based on site specific information;

GWPC Recommendations: (e) A demonstrati on of external mechanical integrity pursuant to §146.89(c) at least once per year until the we ll is plugged;

(f) A pressure fall-off test or other equi valent test that identifies reservoir conditions with respect to flow dynamics at least once every five years unless more frequent testing is required by the Director based on site specific

information;

Rationale: Redundant to section 146.89

Individual Response: Based on its evaluation of all public comments and input on the proposed

98rule and NODA and Request for Comment EPA has ma de many revisions to the GS rule. See the final rule and preamble for further discussion on EPA's final approach.

EPA believes that pressure fall-off testing is necessary for GS wells. Pressure fall-off tests are designed to verify that modeled projections of reservoir pressure decline agree with measured pressure decline profiles. These tests can be us eful in AoR calculations and reevaluations and may also indicate mischaracterization of site ge ology and the presence of leakage pathways. EPA therefore believes that pressure fall-off testing is necessary every five years at a minimum, and the final GS regulation includes this requirement at §146.90(f). Pr essure fall-off tests may be conducted in conjunction with othe r well performance tests (i.e., mech anical integrity testing) to ensure safe and effective operations.

Letter ID: 0259 Comment ID: 24928 Letter Lines: 2634 to 2646

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment: EPA Proposal: (g) Testing and monitoring to track the extent of the carbon dioxide plume and the position of the pre ssure front by either monitoring for pressure changes in the first formation overlying the confining zone or using indirect, geophysical techniques (e.g., seismic, electrical, gravity, or electromagnetic surveys and/or down-hol e carbon dioxide detection tools);

GWPC Recommendations: (g) Testing and m onitoring to track the extent of the carbon dioxide plume and the posi tion of the pressure front.

Rationale: Monitoring outside of the inje ction zone provides little information of value for tracking and monitoring the in jected plume. Examples of how to

test and monitor could be included in the Preamble but need not be included in

the rule itself.

Individual Response: EPA has revised this requirement in the final rule. The final GS regulation, at §146.90(g)(1), requires all GS project owners or opera tors to monitor for pressure changes in the injection zone. EPA believes that pressure monitoring in the injection zone is necessary to track the development and moveme nt of the pressure front and CO2 plume.

Pressure monitoring within the injection zone is necessary because any such monitoring above the confining zone would not de tect movement of the pressure front unless a breach of the confining zone occurs. EPA believes that monitori ng using wells in the inje ction zone (i.e., that penetrate the confining zone) can be safely performed if the wells are constructed to prevent flow between the injection zone a nd USDWs or other layers above the confining zone. Such construction technologies exist and have been us ed 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

99at §146.90(d)) to provide additional verification that no pressure ch anges are occurr ing above the confining zone due to CO2 leakage. Monitoring al so identifies needed re medial actions, provides inputs for AoR reevaluation modeling, and ta rgets additional geochemical and surface monitoring needs. Knowledge of th e location of the CO2 plume and the associated pressure front will assure the public that GS projects are proceeding according to plan, provide sufficient information to the owner or operator and Director, or allow for appropriate actions to address any

indication that USDWs may be endangered.

EPA acknowledges that, at certain sites, there ma y be a need for more or different monitoring schemes (which may include monitoring in the conf ining zone), and adds that it is important to balance the need for adequate monitoring that ensures USDW protection from endangermentagainst too many artificial penetrations which could serve as conduits for fluid migration. Sitespecific testing and monitoring plans should desc ribe the proposed monitoring regime, which must be approved by the Director. Flexibility is also provided re garding how to monitor for the sp ecific data required by the final rule. The testing and monitoring plan is develope d by the owner or operato r in consultation with the Director and is designed to ensure that a detailed, Director-approved document describing how monitoring will be conducted during the lifetime of the project exists. EPA is developing guidance on testing and monitoring to assist owners or operators and Directors in evaluating requirements under §146.90, including proposed monitoring plans. The guidance describes available technologies and reco mmended approaches for implem enting a testing and monitoring plan, including pre-operational geophysical logging and testin g of injection wells, MITs, injection well testing during ope ration, groundwater quali ty monitoring, tracking the CO2 plume and pressure front, and soil gas and surface ai r monitoring which may be required by the UIC Director for specific GS projects. The guidance can be found on EPA’s website at http://water.epa.gov/type/groundwater /uic/wells_sequestration.cfm.

Letter ID: 0259 Comment ID: 24929 Letter Lines: 2648 to 2659

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment: Rule Provision: 146.90

EPA Proposal: (h) At the Di rector’s discretion, surfa ce air monitoring and/or soil gas monitoring to detect movement of carbon dioxide that could endanger a

USDW.

GWPC Recommendations: (h) At the Direct or’s discretion base d on site-specific

conditions and risk-based factors, su rface air monitoring and/or soil gas monitoring to detect movement of car bon dioxide that coul d endanger a USDW.

Rationale: In most situations soil an d air monitoring does not provide an effective method of protecting USDWs.

100Individual Response: As described above, EPA acknowledges that air and soil gas monitoring are subject to site-specific limitations and may not be suitable in all settings as a method to ensure USDW protection. However, EPA does not be lieve that this should entirely preclude their use. The final rule at §146.90(h) retains the allowance for surface air and soil gas monitoring at

the discretion of the Director as a means of identifying leaks that may pose a risk to USDWs and informing emergency notification of a Class VI ow ner or operator and UIC Director in the event of a USDW endangerment, pursuant to requirements at §146.91(c).

Letter ID: 0259 Comment ID: 24930 Letter Lines: 2661 to 2679

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment: Rule Provision: 146.90(h)

EPA Proposal: (1) The testing and monito ring plan must be based on potential

vulnerabilities within the area of review;

(2) The monitoring frequency and spatial distribution of surface air monitoring and/or soil gas monitoring must reflect baseline data and the monitoring plan must include how the proposed monitoring will yield useful information on the area of review delineation and/or comp liance with standards under 40 CFR 144.12;

GWPC Recommendations: (1) The testing and monitoring plan must be based on sitespecific geologic factors, modeling, and risk-assessment within the area of

review;

(2) Agree with EPA language

Rationale: The GWPC feels that the term "potential vulnera bilities" is too nebulous. We suggest replacing this term with the term "site-specific geologic factors, modeling, and risk-assessment."

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

EPA anticipates that the testing and monitoring plan will address site-specific geologic factors, modeling, and risk-assessment. EPA is developing guidance on how best to develop the various required project plans, includi ng the testing and monitoring pl an. The guidance can be found on EPA’s website at http://water.epa.gov/type /groundwater/uic/wells _sequestration.cfm.

Letter ID: 0259 Comment ID: 24931 Letter Lines: 2681 to 2693

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

101Comment Code: 4610 2.6.1 Testing and monitoring plan requirement (seeking comment)

Comment: Rule Provision: 146.90(i)

EPA Proposal: (i) Any additional monito ring, as required by the Director, necessary to support, upgrade, and improve computational modeli ng of the area of review evaluation required under § 146.84(b) and to determine compliance with

standards under 40 CFR 144.12; and

(j) A quality assurance and surveillance plan for all testing and monitoring requirements.

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

Individual Response: EPA acknowledges the comment. The fina l rule retains these provisions as proposed.

Letter ID: 0259 Comment ID: 24932 Letter Lines: 2695 to 2715

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment: Rule Provision: 146.91

11. Reporting requirements.

The owner or operator must, at a minimum, provide the following reports to the Director, for each permitted Class VI well:

(a) Semi-annual reports containing:

(1) Any changes to the physical, chemical and other relevant characteristics of

the carbon dioxide stream from the proposed operating data; (2) Monthly average, maximum and minimum values for injection pressure, flow rate and volume, and annular pressure;

GWPC Recommendations: (a) Semi-annual or at a frequency determined by the Director reports containing:

(1) Any significant change s to the physical, chemi cal and other relevant

characteristics of the carbon dioxide str eam from the proposed operating data;

Rationale: Should be semi-annual unless otherwise determined

102Individual Response: EPA is retaining the semi-annual repo rting requirements as proposed at §146.91(a). These requirements ensure the Direct or has the information needed to take preventive action in a timely manner to prot ect USDWs from endangerment. For additional information, please see the final rule and the prea mble for a discussion of EPA's final approach to recordkeeping and reporting.

Letter ID: 0259 Comment ID: 24933 Letter Lines: 2717 to 2735

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 4720 2.7.2 Operational record keeping and reporting

Comment: Rule Provision: 146.91(a)

EPA Proposal: (3) A description of any ev ent that exceeds operating parameters for annulus pressure or injection pr essure as specified in the permit; (4) A description of any event which triggers a shutdown device required pursuant to § 146.88(e) and the response taken; (5) The monthly volume of the carbon dioxide stream injected over the reporting period and project cumulatively; (6) Monthly annulus flui d volume added; and (7) The results of monitori ng prescribed under § 146.90.

GWPC Recommendations: (3) A description of any event that significantly exceeds operating parameters for annulus pressure or injection pressure as specified in the permit; (4) A description of any event which triggers a shutdown device required pursuant to §146.88(e) and the response taken;

Rationale: EPA should consider some signi ficance threshold on reporting these events, to avoid reporting even ts would be of limited in terest or consequence.

Individual Response: EPA retained this provision as pr oposed. The final rule at §146.91(a)(3) requires reporting of all exceedances of operating parameters. EPA disagrees with the suggestion to report only "significant" exceedances. Making a determination as to whether an exceedance is "significant" is not the purpose of the requirement. EPA believes that the ability of an operator toconsistently meet operating requirements and avoid exceedances provides evidence of a wellmanaged GS project that is in compliance with the Class VI permit. If multiple exceedances

occur, the Director should be aware of such o ccurrences, and that information will aid in his/her

determination of whether these indi cate problems at the site, and what is the appropriate course of action (e.g., a well workover, modification of operating parameters, or imposition of a penalty) to remediate such problem(s).

Letter ID: 0259 Comment ID: 24934 Letter Lines: 2737 to 2750

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

103Comment Code: 4720 2.7.2 Operational record keeping and reporting

Comment Code: 4740 2.7.4 Electronic reporting (seeking comment)

Comment: EPA Proposal: (b) Report, within 30 days the results of:

(1) Periodic tests of mechanical integrity; (2) Any other test of the injection we ll conducted by the permittee if required by the Director; and (3) Any well workover.

(c) Owners or operators must submit reports in an electronic format acceptable

to the Director. At the discretion of the Director, other formats may be accepted.

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

Individual Response: EPA acknowledges the comment. Pleas e see the final rule and the discussion of reporting preamble for additional information on EPA's final rulemaking approach.

EPA believes that electronic formatting is the most appropriate format for submitting Class VI project information to the Director, and that many GS well owners or op erators will have the capability to report electronically.

Letter ID: 0259 Comment ID: 24935 Letter Lines: 2752 to 2766

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 5100 2.8.1 Injection well plugging activ ities (seeking comment) (40 CFR 146.92)

Comment: Rule Provision: 146.92

EPA Proposal: 12. Injection well plugging.

(a) Prior to the well plugging, the owner or operator must flush each Class VI injection well with a buffer fluid, determ ine bottomhole reser voir pressure, and perform a final mechanical integrity test.

GWPC Recommendations: (a) Prior to the we ll plugging, the owner or operator must flush each Class VI injection well with a buffer fluid, determine bottomhole reservoir pressure, and perform a final external mechanical integrity test.

Rationale: Many of the components that woul d be tested by an internal MIT are removed or tested during the plugging pro cess. Consequently, the GWPC suggests including the term internal to the language for clarification.

104Individual Response: EPA agrees that only an external MIT is required, and has modified the GS rule at §146.92(a) to require owners or opera tors to perform a final external mechanical integrity test prior to the well plugging.

Letter ID: 0259 Comment ID: 24936 Letter Lines: 2768 to 2779

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 5100 2.8.1 Injection well plugging activ ities (seeking comment) (40 CFR 146.92)

Comment: Rule Provision: 146.92(b)

EPA Proposal: (b) Well Plugging Plan. The ow ner or operator of a Class VI well must prepare, maintain, and comply w ith a plan that is acceptable to the Director. The requirement to maintain and implement an approved plan is directly enforceable regardless of whethe r the requirement is a condition of the permit. The well plugging plan must be submitted as part of the permit application and must include the following information:

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

Individual Response: EPA acknowledges the commenter’s suppor t; the final rule retains this provision.

Letter ID: 0259 Comment ID: 24937 Letter Lines: 2781 to 2803

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 5100 2.8.1 Injection well plugging activ ities (seeking comment) (40 CFR 146.92)

Comment: EPA Proposal: (1) Appropriate test or measure to determine bottomhole reservoir

pressure; (2) Appropriate testing methods to ensure mechanical integrity as specified in §

146.89; (3) The type and number of plugs to be used; (4) The placement of each plug including th e elevation of the top and bottom of each plug; (5) The type and grade and quantity of material to be used in plugging. The material must be compatible with the carbon dioxide stream; and (6) The method of placement of the plugs.

GWPC Recommendations: Support the proposed EPA language for (1), (3), (4) and

105(6)

(2) Appropriate testing methods to ensure final external mechanical integrity as specified in §146.89(c);

(5) The type and grade and quantity of material to be used in plugging. The

material must be suitable for use wi th the carbon dioxide stream; and

Rationale: Many of the components that woul d be tested by an internal MIT are removed or tested during the plugging pro cess. Consequently, the GWPC suggests adding the term external to th e language for clarification.

Individual Response: Regarding the suggested edit at 146.92(b)(2), EPA agrees that only an external MIT is required, and has modified th e GS rule at §146.92(a) to require owners or operators to perform a final external mechani cal integrity test prior to the well plugging.

Regarding the edit at 146.92(b)(5), EPA believes, considering the pot entially corrosive nature of

CO2 when it is in contact with water, that the re quirement that the material must be compatible with the CO2 stream is appropriate. Th e final rule retains this requirement.

Letter ID: 0259 Comment ID: 24938 Letter Lines: 2805 to 2813

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 4730 2.7.3 Reporting associated with closur e and post-injection site care

Comment Code: 5100 2.8.1 Injection well plugging activ ities (seeking comment) (40 CFR 146.92)

Comment: EPA Proposal: (c) Notice of intent to plug. The owner or operator must notify the Director at least 60 days before pl ugging of a well. At th is time, if any changes have been made to the original well plugging plan, the owner or operator must also provide the revised well pl ugging plan. At the discretion of the

Director, a shorter notice period may be allowed.

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

Individual Response: EPA acknowledges the commenter’s suppor t; the final rule retains this provision.

Letter ID: 0259 Comment ID: 24939 Letter Lines: 2815 to 2830

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 4730 2.7.3 Reporting associated with closur e and post-injection site care

106Comment Code: 5100 2.8.1 Injection well plugging activ ities (seeking comment) (40 CFR 146.92)

Comment: Rule Provision: 146.92(d)

EPA Proposal: (d) Plugging report. Within 60 days after plugging or at the time of the next semi-annual report (whichever occurs earlier) the owner or operator must submit a plugging report to the Direct or. If the semi-annual report is due less than 15 days after completion of plugging, then the report must be submitted within 60 days after plugging. The report must be certified as accurate by the owner or operator and by the person who performed the plugging operation (if other than th e owner or operator.)

GWPC Recommendations: (d) Plugging report. Within 60 days after plugging the owner or operator must submit a plugging report to the Director. The report must be certified as accurate by the owner or operator and by the person who performed the plugging operation (if othe r than the owner or operator.)

Rationale: Simplification

Individual Response: EPA has revised the text at §146.92(d) to reduce confusion. The final rule text reads, "Within 60 days afte r plugging the owner or operator must submit a plugging report to

the Director."

Letter ID: 0259 Comment ID: 24940 Letter Lines: 2832 to 2846

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 5220 2.8.2.1 Post-injection monitoring activities

Comment: Rule Provision: 146.93

EPA Proposal: 13. Post-injection si te care and site closure

(a) The owner or operator of a Class VI we ll must prepare, maintain, and comply with a plan for post-injection site ca re and site closure that meets the requirements of paragraph (a)(2) of this section and is ac ceptable to the

Director.

(1) The owner or operator must submit th e post-injection site care and site closure plan as a part of the permit app lication to be approve d by the Director.

GWPC Recommendations: Support the proposed EPA language

Rationale: Agree with EPA’s rationale

107Individual Response: EPA acknowledges the commenter’s suppor t; the final rule retains this provision.

Letter ID: 0259 Comment ID: 24941 Letter Lines: 2848 to 2859

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 5200 2.8.2 Post injection site care (seeking comment) (40 CFR 146.93)

Comment: EPA Proposal: (2) The post-injection site care and site closure plan must include the following information:

(i) The pressure differential between pre- injection and predicted post-injection pressures in the injection zone; (ii) The predicted position of the carbon dioxide plume and associated pressure

front at site closure as de monstrated in the area of review evaluation required under § 146.84(b);

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

Individual Response: EPA acknowledges the commenter’s suppor t; the final rule retains this provision.

Letter ID: 0259 Comment ID: 24942 Letter Lines: 2861 to 2870

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 5220 2.8.2.1 Post-injection monitoring activities

Comment: Rule Provision: 146.93(a)(2)

(iii) A description of post-injection m onitoring location, methods, and proposed frequency; and (iv) A proposed schedule for submitting post-injection site care monitoring

results to the Director.

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

Individual Response: EPA acknowledges the commenter’s suppor t; the final rule retains this provision.

108Letter ID: 0259 Comment ID: 24943 Letter Lines: 2872 to 2879

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 5200 2.8.2 Post injection site care (seeking comment) (40 CFR 146.93)

Comment: EPA Proposal: (3) Upon cessation of injecti on, owners or operat ors of Class VI wells must either submit an amended post-injection site care and site closure plan or demonstrate to the Director th rough monitoring data a nd modeling results that no amendment to the plan is needed.

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

Individual Response: EPA acknowledges the commenter’s suppor t; the final rule retains this provision.

Letter ID: 0259 Comment ID: 24944 Letter Lines: 2881 to 2887

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 5200 2.8.2 Post injection site care (seeking comment) (40 CFR 146.93)

Comment: EPA Proposal: (4) The owner or operator may modify and resubmit the postinjection site care and site closure plan for the Director’s approval within 30 days of such change.

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

Individual Response: EPA acknowledges the commenter’s suppor t; the final rule retains this provision.

Letter ID: 0259 Comment ID: 24945 Letter Lines: 2889 to 2917

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment Code: 5280 2.8.2.4 USDW non-endangerment demonstrations

Comment: Rule Provision: 146.93(b)

EPA Proposal: (b) The owner or operator shall monitor the site following the cessation of injection to show the pos ition of the carbon dioxide plume and pressure front and demonstrate that USDWs are not being endangered.

109(1) The owner or operator shall continue to conduct monitoring as specified in the Director-approved post-injection site care and site closure plan for at least 50 years following the cessation of injection. At the Director’s discretion, the monitoring will continue until the geologic sequestration project no longer poses an endangerment to USDWs.

GWPC Recommendations: (b) The owner or oper ator shall monitor the site following the cessation of injection.

(1) The owner or operator shall continue to conduct monitoring as specified in the Director-approved post-injection site care and site closure plan until closure is authorized pur suant to 146.93(b)(3).

Rationale: Eliminate the 50 year requirement.

There is no justification for extending completed projects for the presumptive 50 years, and it will be difficult to accep t much shorter demonstration periods with the 50 year presumpti on in the regulations. Defau lt 50-year period defeats

incentives for best site identification and best MMV

Need for site-specific consid erations and use of data

Need achievable and definable standard

Individual Response: EPA agrees that there will be circumst ances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the fi nal GS regulation includes a provi sion that the Director may, at his or her discretion, shorten the post-injection s ite care timeframe if the owner or operator can demonstrate that the GS project does not pose an endangerment to USDW s, as specified in §146.93(b)(2). Such a demonstration will be site-s pecific, and based on pressure monitoring and USDW impacts. Alternatively, the final rule at §146.93(c), also allows the Director to approve an alternative post-injection site care timeframe where an owner or operator can demonstrate during the permitting process that an alternative post-inj ection site care timeframe, other than the 50 year default, is appropriate and ensures non-e ndangerment of USDWs. The demonstration must be based on site-specific information, includi ng the results of site-s pecific computational modeling; the predicted timefram e for pressure decline; the pr edicted rate of carbon dioxide plume migration; site-specific chemical processe s that will result in carbo n dioxide trapping; the predicted rate of carbon dioxide trapping; characterization of the confining zone(s); laboratory analyses or studies to verify the information on trapping; the pr esence of potential conduits for fluid movement and the quality of abandoned we ll plugs within the AoR; the distance between the injection zone and the USDWs above and/or below the injection zone; and any additional site-specific factors determined by the Director . The demonstration must meet the criteria at §146.93(c)(2) for ensuring the quality and accuracy of the data and models on which the

demonstration is based. This demonstration would be submitted as part of the permit application, per §146.82(a)(18), in addition to the PISC and site closure plan required at §146.82(a)(17).

110EPA believes however, that to ensure USDW protection from enda ngerment, a default timeframe for post-injection site care will be necessary in al l but a limited number of cases. This default 50 year post-injection site care ti meframe represents a reasonable and protective monitoring period

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

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

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

Letter ID: 0259 Comment ID: 24946 Letter Lines: 2919 to 2932

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

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

Comment: Rule Provision: 146.93(b)

EPA Proposal: (2) If the owner or operator can demonstrate to the satisfaction of the Director before 50 years, base d on monitoring and other site-specific data, that the geologic sequestration proj ect no longer poses an endangerment to USDWs, the Director may approve an amendm ent to the post-injection site care and site closure plan to reduce the frequenc y of monitoring or may authorize site

closure before the end of the 50-year period.

GWPC Recommendations: (2) The owner or op erator can request a nd demonstrate to

the satisfaction of the Director that th e post-injection site care and site closure plan should be revised to reduce the frequency of monitoring.

Rationale: See above regarding eliminati on of 50-year presumptive time period.

Individual Response: As described above, EPA disagrees that a post-injection site care timeframe of 50 years is excessive for most Class VI wells. However, EPA agrees that there will

be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the du ration of the PISC timeframe by: (1) allowing the

Director discretion to shorten or lengthen the PISC timeframe during the post-injection period based on site-specific data, pursuant to requiremen ts 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 timef rame may be appropriate if it ensures non-endangerment of USDWs pur suant to requireme nts at §146.93(c).

111EPA believes that a default post-injection site car e timeframe of 50 years, with flexibility to adjust the timeframe for a limited number of GS projects during the permitting process where

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

Letter ID: 0259 Comment ID: 24947 Letter Lines: 2934 to 2959

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 5280 2.8.2.4 USDW non-endangerment demonstrations

Comment: EPA Proposal: (3) Prior to authorization fo r site closure, the owner or operator

must submit to the Director a demonstra tion, based on monitoring and other sitespecific data, that the car bon dioxide plume and pressure front have stabilized and that no additional monitoring is n eeded to assure that the geologic sequestration project does not pos e an endangerment to USDWs.

GWPC Recommendations: (3) Prior to authoriz ation for site closur e, the owner or operator must demonstrate to the Dir ector, based on monitoring, other sitespecific data, and modeling that is reasonabl y consistent with site performance, that no additional monitoring is needed to assure that the geologic sequestration project does not and is not expected to pose an endangerment to USDWs. The Director shall approve closure if the owner or operator demonstrates, based on the current understanding of the site, including monito ring data and/or modeling, all of the following: (i) the es timated magnitude and extent of the project footprint (CO2 plume and the ar ea of elevated pre ssure) ; (ii) the

estimated location of the detectable CO2 plume; (iii) that there is no significant leakage of either CO2 or di splaced formation fluids that is endangering USDWs; (iv) that the injected or displaced fluids are not expected to migrate in the future in a manner that encounters a potential leakage pathway into a USDW; (v) that the injection wells at the site completed into or through the injection zone or confining zone are plugged and abandoned in accordance with these requirements; a nd (vi) any remaining projec t monitoring wells at the site are being managed by a person and in a manner acceptable to the Director.

Rationale: The GWPC revised this secti on to establish the performance based criteria for selecting the monitoring period.

Individual Response: EPA disagrees that the rule should specify the criteria for setting the monitoring timeframe. Instead, EPA believes that such determinations are site-specific and should be described in a project specific post-injection site care and site cl osure plan. EPA also believes that periodic reviews and updates, wh ere necessary, to the plan are important to

112ensuring that the site continues to be managed effectively and to determine whether shortening the monitoring timeframe is appropriate.

As described above, EPA agrees th at there will be circumstances where it can be demonstrated in less than 50 years that the plume and pressure front no longe r pose a risk of endangerment to

USDWs. For this reason, the GS ru le offers owners or operators flexibility regard ing the duration of the PISC timeframe by: (1) allowing the Direct or discretion to shorten or lengthen the PISC timeframe during the post-injecti on period based on site-specific da ta, pursuant to requirements at §146.93(b); or (2) affording the Director discretion to allow a Class VI well owner or operator to demonstrate, during the permitting process based on substantial data, that an alternative PISC timeframe may be appropriate if it ensu res non-endangerment of USDWs pursuant to requirements at §146.93(c).

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

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

Letter ID: 0259 Comment ID: 24948 Letter Lines: 2961 to 2968

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

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

Comment: EPA Proposal: (4) If such a demonstrati on cannot be made (i.e., if the carbon dioxide plume and pressure front have not stabilized) after the 50-year period, the owner or operator must submit to the Director a plan to continue postinjection site care.

GWPC Recommendations: Delete

Rationale: No longer necessary if 50 year time period is removed.

Individual Response: As described above, EPA believes that , to ensure USDW protection from endangerment, a default timeframe for post-injecti on site care is necessary in most cases. A 50 year post-injection site care ti meframe represents a reasonable and protective monitoring period

for most GS sites based on a review of res earch studies, industry reports, and existing environmental programs, and ev aluation of public comments.

EPA believes that a 50-year de fault post-injection site care timeframe, as required at §146.93(b)(1), is not overly burdensome, does not ex aggerate the risks associated with GS, is

113consistent with other environmental program s, and sufficiently protects USDWs from endangerment.

Letter ID: 0259 Comment ID: 24949 Letter Lines: 2970 to 2980

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 5300 2.8.3 Site closure activities (40 CFR 146.93)

Comment: Rule Provision: 146.93(c)

EPA Proposal: (c) Notice of intent for site closure. The owner or operator must notify the Director at least 120 days before site closure. At this time, if any changes have been made to the original post-injection site car e and site closure plan, the owner or operator must also provide the revise d plan. At the

discretion of the Director, a shor ter notice period may be allowed.

GWPC Recommendations: No recommendation

Rationale: Need for site-specific co nsiderations and use of data

Individual Response: EPA acknowledges the comment. For additional information on EPA's final regulatory approach, please see the final rule and preamble as well as the rulemaking

docket.

Letter ID: 0259 Comment ID: 24950 Letter Lines: 2982 to 2990

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 5300 2.8.3 Site closure activities (40 CFR 146.93)

Comment: Rule Provision: 146.93(d)

EPA Proposal: (d) After the Director has au thorized site closure, the owner or operator must plug all monitoring wells in a manner which will not allow movement of injection or formati on fluids that endangers a USDW.

GWPC Recommendations: No recommendation

Rationale: Need for site-specific co nsiderations and use of data

Individual Response: EPA acknowledges the comment. For additional information on EPA's final regulatory approach, please see the final rule and preamble as well as the rulemaking

docket.

114Letter ID: 0259 Comment ID: 24951 Letter Lines: 2992 to 3018

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 4730 2.7.3 Reporting associated with closur e and post-injection site care

Comment Code: 5300 2.8.3 Site closure activities (40 CFR 146.93)

Comment: EPA Proposal: (e) Once the Director has aut horized site closure, the owner or operator must submit a site closure report within 90 days that must thereafter be retained at a location designated by th e Director. The report must include:

(1) Documentation of appropriate inj ection and monitoring well plugging as specified in § 146.92 and paragraph (c) of this section. The owner or operator must provide a copy of a survey plat which has been submitted to the local zoning authority designated by the Director. The plat must indicate the location of the injection well relative to permanently surveyed benchmarks. The owner or operator must also submit a copy of the plat to the Regional Administrator of the appropr iate EPA Regional Office;

GWPC Recommendations: (e) Once the Direct or has authorized site closure, the owner or operator must submit a site cl osure report within 90 days after completion of all closure operati ons. The report must include:

(1) Documentation of appropriate inj ection and monitoring well plugging as specified in §146.92 and paragraph (c) of this section. The owner or operator must provide a copy of a survey plat which has been submitted to the local zoning authority designated by the Director. The plat mu st indicate the location of the injection well(s) relative to permanently surveyed benchmarks. The owner or operator must also submit a copy of the plat to the Regional Administrator of the appropriate EPA Regional Office;

Rationale: What is the retention period? Many other programs have a three year

limit for retention of records. EPA is the steward of information at this point of the project, not th e owner or operator.

Individual Response: The GS regulation at §146.93(g) requires the owner or ope rator to record a notation on the deed to the facility property or other similar document examined during a title

search that the land has been used to sequester CO2 on the deed to the facility property at the

time of site closure.

Regarding record retention, EPA has clarified th e recordkeeping requirements in the final GS rule, which includes requirements that we ll plugging reports, as required at §146.92(d), postinjection site care data, as re quired at §146.93(f), and site clos ure reports, as required at §146.93(h), must be kept by the owner or operator fo r ten years after site closure. EPA believes that longer record retention times for GS we lls are appropriate and necessary for the postinjection and site closure period to ensure that data are available to support non-endangerment

115demonstrations and to address any concerns that may arise following site closure. This data will also support EPA's review of project data as part of the adaptive rulemaking approach.

Letter ID: 0259 Comment ID: 24952 Letter Lines: 3020 to 3031

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 4730 2.7.3 Reporting associated with closur e and post-injection site care

Comment Code: 5300 2.8.3 Site closure activities (40 CFR 146.93)

Comment: EPA Proposal: (2) Documentation of appropr iate notification and information to

such State, local and tribal authori ties as have author ity over drilling

activities to enable such State and lo cal authorities to impose appropriate conditions on subsequent drilling activit ies that may penetrate the injection and confining zone(s); and

(3) Records reflecting the nature, composition and volum e of the carbon dioxide

stream.

GWPC Recommendations: No recommendation

Rationale: Need for site-specific co nsiderations and use of data

Individual Response: The GS regulation at §146.93(g) requires the owner or ope rator to record a notation on the deed to the facility property or other similar document examined during a title

search that the land has been used to sequester CO2 on the deed to the facility property at the

time of site closure.

Letter ID: 0259 Comment ID: 24953 Letter Lines: 3033 to 3047

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 4730 2.7.3 Reporting associated with closur e and post-injection site care

Comment Code: 5300 2.8.3 Site closure activities (40 CFR 146.93)

Comment: Rule Provision: 146.93

EPA Proposal: (f) Each owner or operator of a Class VI injection well must

record a notation on the deed to the f acility property or any other document that is normally examined during title se arch that will in perpetuity provide any potential purchaser of the pr operty the following information:

(1) The fact that land has been us ed to sequester carbon dioxide; (2) The name of the State agency, local au thority, and/or tribe with which the survey plat was filed, as well as the address of the Regional Environmental Protection Agency Office to which it was submitted; and

116GWPC Recommendations: No recommendation

Rationale: Need for site-specific co nsiderations and use of data

Individual Response: The GS regulation at §146.93(g) requires the owner or ope rator to record a notation on the deed to the facility property or other similar document examined during a title

search that the land has been used to sequester CO2 on the deed to the facility property at the

time of site closure.

Letter ID: 0259 Comment ID: 24954 Letter Lines: 3049 to 3060

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 4730 2.7.3 Reporting associated with closur e and post-injection site care

Comment Code: 5300 2.8.3 Site closure activities (40 CFR 146.93)

Comment: EPA Proposal: (3) The volume of fluid inject ed, the injection zone or zones into which it was injected, and the peri od over which injection occurred.

(g) The owner or operator must retain fo r three years following site closure, records collected during the post-injection site ca re period. The owner or operator must deliver the records to th e Director at the conclusion of the retention period, and the records must th ereafter be retained at a location designated by the Director for that purpose.

GWPC Recommendations: No recommendation

Rationale: Need for site-specific co nsiderations and use of data

Individual Response: The GS regulation at §146.93(g) requires the owner or ope rator to record a notation on the deed to the facility property or other similar document examined during a title

search that the land has been used to sequester CO2 on the deed to the facility property at the

time of site closure.

Letter ID: 0259 Comment ID: 24956 Letter Lines: 3072 to 3098

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment: Rule Provision: 146.94(b)

(b) If the owner or operator obtains ev idence that the inj ected carbon dioxide stream and associated pressure front ma y cause an endangerment to a USDW, the

owner or operator must:

117(1) Immediately cease injection; (2) Take all steps reasonably necessa ry to identify and characterize any

release; (3) Notify the Director within 24 hours; and (4) Implement the emergency and remedial response plan approved by the Director.

GWPC Recommendations: (b) If the owner or operator obtains evidence that the injected carbon dioxide stream, displaced formation fluids or associated pressure front endangers a USDW , the owner or operator must:

(1) Immediately cease injection; (2) Take all steps reasonably necessa ry to identify and characterize the endangerment posed; (3) Notify the Director or the designa ted representative within 24 hours of becoming aware of the endangerment; and (4) Implement the emergency and remedial response plan approved by the Director.

Rationale: The GWPC felt the notification period needed clarification since it did not specify when the clock began to run for the 24 hour notice period.

Further, it was felt that notification of someone representi ng the Director would also constitute appropriate notice.

Individual Response: After consideration of comments, EPA has finalized the rule language in §146.94(b) as proposed. In the introductory section of §146.94(b), EPA clarifie s that the pressure front, as defined in §146.81, is a zone where the pr essure differential is sufficient to cause the movement of injected fluids or formation flui ds into a USDW. Therefor e, displaced formation fluids are implicitly included in the requirements for §146.94. EPA al so clarifies that owners or operators must take action when the CO2 stream or pressure front may cause endangerment. In order to prevent the endangerment of USDW s, as required under §1421 of the SDWA, EPA expects the owner or operator to act preemptiv ely and not wait until endangerment has occurred. This language is consistent w ith existing UIC requirements fo r other well classes and EPA’s authority under the SDWA.

Regarding changes to the language in §146.94(b)(1), EPA clarifies that the Agency expects that owners or operators take care not to da mage the well when ceasing injection under §146.94(b)(1). At §146.94(b)(2), EPA is maintaini ng the requirement to “characterize the release.” In order to prevent the endangerm ent of USDWs, as re quired under §1421 of the SDWA, EPA expects the owner or operator to act preemptively and not wait until endangerment has occurred. This language is c onsistent with existing UIC requi rements for other well classes and EPA’s authority under the SDWA.

Concerning commenters’ suggestions for §146.94(b)(3 ), EPA clarifies that the 24 hours begins when the owner or operator obtains evidence of possible endangerment. Note that the definition

of the Director in 40 CFR 144.3 includes the Direct or’s authorized repres entative. EPA believes

118the rule language is clear on this requirement.

Letter ID: 0259 Comment ID: 24957 Letter Lines: 3100 to 3113

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

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

Comment: EPA Proposal: (c) The Director may allow th e operator to resume injection prior to remediation if the owner or operato r demonstrates that the injection operation will not endanger USDWs.

(d) The owner or operator must notify the Director and obtain hi s approval prior to conducting any well workover.

GWPC Recommendations: Support the proposed EPA language for (c)

(d) The owner or operator must notify th e Director prior to conducting any well workover in response to any case of endangerment.

Rationale: In critical situations, time sp ent obtaining approval could adversely affect the ability to conduct operations or increase the level of endangerment.

Individual Response: Since proposal, EPA has modified the final regulatory language at §146.94(d) to clarify what constitutes a workover to address a well failure (which invokes remedial actions) and what constitutes a mainte nance-type workover. For maintenance-type workovers (i.e., those that are scheduled in adva nce), the owner or operato r must notify and gain approval from the Director prior to beginning the workover. In th e final GS regulation, EPA has moved this requirement to the reporting requi rements at §146.91(d) to clarify its intent.

Regarding concerns that notifica tion could delay responses, EPA cl arifies that the GS rule, at §146.94(b), describes procedures owners or opera tors must take in emergency situations. Specifically, upon determining that there is a problem with the we ll that may endanger a USDW, the owner or operator must firs t cease injection, then take all steps reasonably necessary to identify and characterize any release, notif y the Director, and implement the approved emergency and remedial response plan, which ma y include a well workover. EPA believes that ceasing injection (which the ow ner or operator would do immediately and before notifying the Director) is the action necessary to prevent or mitigate enda ngerment of USDWs as required

under the SDWA.

Letter ID: 0259 Comment ID: 24964 Letter Lines: 798 to 815

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)

119Comment: Rule Provision: 144.80

EPA Proposal: 11. Section 144.80 is amended by revising the first sentence in paragraph (e) and by adding paragr aph (f)to read as follows:

§ 144.80 What is a Class V injection well? * * * * *

(e) Class V. Injection wells not included in Class I, II, III, IV or VI. * *

*

(f) Class VI. Wells used for geologi c sequestration of carbon dioxide.

GWPC Recommendations: (4) For enhanced r ecovery of oil or natural gas where geologic sequestration is occurring duri ng or in connection with enhanced recovery of oil or natural gas provided (i) there is reasonable expectation of more than insignificant future production volumes or rate s as a result of carbon dioxide injection and (ii) operating pressures are no higher than reasonably necessary to produce such volumes or rates;

Individual Response: EPA disagrees with the suggested cha nges to the rule language; geologic sequestration conducted as part of enhanced recovery operations is considered Class II. Injection where geologic sequestration is the primar y purpose is categorized as Class VI.

Letter ID: 0259 Comment ID: 24965 Letter Lines: 917 to 925

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment: Rule Provision: 146.81 Applicability.

EPA Proposal: (a) This subpart estab lishes criteria and standards for underground injection control programs to regulate Class VI carbon dioxide geologic sequestration injection wells.

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

Individual Response: EPA acknowledges the comment. For additional information on EPA's final regulatory approach, please see the final rule and preamble as well as the rulemaking

docket.

Letter ID: 0259 Comment ID: 24966 Letter Lines: 456 to 471

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

120Comment: EPA Notice Questions: 73 FR 43523

EPA Rule Issue: 48. To gain authority fo r Class VI wells, States, Territories, and Tribes will be required to show that their regulations are at least as stringent as, and may be more stringent than, the proposed minimum Federal requirements (e.g., inspection, operati on, monitoring, and recordkeeping requirements that well owners or operator s must meet). Such Primacy States,

Territories, and Tribes are authorized under Section 1422 of the SDWA. EPA

Notice 43523.

GWPC CO2 Committee Response: Retain curr ent requirement, but recognize that geology varies from state to state and so me modifications may be appropriate

that will result in variations that are not less stringent, but simply adapted

to different circumstances. There shoul d also be some recognition that the beneficial effects of GS may be enhanced by allowing flexibility for adaptation of state requirements.

Individual Response: EPA agrees that it is important to balance flexibility and national consistency. The GS rule sets forth minimum requi rements, tailored to the unique nature of CO2

GS, which must be met in order to ensure USDW protection from 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 met across differing geologic situations.

Letter ID: 0259 Comment ID: 29176 Letter Lines: 2044 to 2081

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3866 2.3.3.3 Logging and testing requirements (40 CFR 146.87)

Comment: Rule Provision: 146.87

EPA Proposal: 7. Logging, sampling, and te sting prior to injection well operation

(a) During the drilling and c onstruction of a Class VI in jection well, the owner

121or operator must run appropria te logs, surveys and tests to determine or verify the depth, thickness, porosity, permeabil ity, and lithology of, and the salinity of any formation fluids in, all releva nt geologic formations to assure

conformance with the in jection well construction requirements under § 146.86, and to establish accurate baseline data against which future measurements may be compared. The owner or operator must s ubmit to the Director a descriptive report prepared by a knowledgeable log an alyst that includes an interpretation of the results of such logs and tests. At a minimum, such logs and tests must

include:

GWPC Recommendations: (a) During the dr illing and constructi on of a Class VI injection well, the owner or operator must run appropr iate logs, surveys and tests to determine or verify the depth, thickness, porosity, permeability, and lithology of, and the salinity of any forma tion fluids in, all relevant geologic

formations to assure conformance w ith the injection well construction requirements under §146.86, and to establish accurate baseline data against which future measurements may be compare d. The owner or operator must submit to the Director a descriptive report prepared by a knowledgeable log analyst that includes an interpretation of the results of such logs and tests. The Director may require such logs and tests as may be needed after taking into account the availability of similar data in the area of the drilling site, the construction plan, and the need for additional information that may arise from time to time as the construction of the well progresse s and these may include the following:

Rationale: In well defined areas, these evaluations are frequently unnecessary.

The director should have discretion to select the appropriate requirements necessary to ensure sufficient baseline da ta and information are available. For example, in an area where a number of we lls are being drilled , the logging of surface hole yields little usef ul additional information.

In particular, this change would allow the Director to reduce the requirements when multiple wells are in stalled for a project.

Individual Response: EPA believes that the logging and testi ng requirements in the GS rule are appropriate and necessary. The requirements at §146.87 stem from existing knowledge and practices in place for other inj ection well classes and within th e oil and gas industry, and are tailored to the special characteris tics of CO2 injection for GS.

EPA is developing guidance on monitoring and tes ting that will describe recommended tests and procedures to assist owners/operators and Di rectors in evaluating the requirements for preoperational logging and testing under §146.87. This guidance will be available on EPA’s website at http://water.epa.gov/type/ground water/uic/wells_sequestration.cfm.

EPA clarifies that §146.87(b) pr ovides some flexibility. EPA notes that §146.87(b) allows information on cores from nearby wells to be submitted if the owner or operator can demonstrate that core retrieval is not po ssible and that cores from nearby wells are representative of

122conditions at the GS well. EPA clarifies that, at a minimum, reports on co res of injection zones and confining zones, and samples of formation fluids must be submitted. Section 146.87(b) gives the Director authority to require the owner or operator to core othe r formations in the borehole if necessary to provide sufficient geologic information to verify that the site is suitable for GS.

Letter ID: 0259 Comment ID: 29177 Letter Lines: 2083 to 2091

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3866 2.3.3.3 Logging and testing requirements (40 CFR 146.87)

Comment: EPA Proposal: (1) Deviation checks duri ng drilling on all holes constructed by drilling a pilot hole which are enlarged by reaming or another method. Such checks must be at sufficiently frequent intervals to determine the location of

the borehole and to assure that vertical avenues for fluid movement in the form of diverging holes are not cr eated during drilling; and

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

Individual Response: EPA acknowledges the comment; the fina l rule retains the requirements for deviation checks required at §146.87(a)(1). EPA adds that the Di rector would have discretion to approve a plan without deviation checks that addresses circumstances where these tests may not be practical or useful, such as those me ntioned by the commenter. EPA encourages owners or operators to discuss these si tuations with the Director when planning the deviation testing.

Letter ID: 0259 Comment ID: 29178 Letter Lines: 2093 to 2099

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3866 2.3.3.3 Logging and testing requirements (40 CFR 146.87)

Comment: Rule Provision: 146.87(a)

EPA Proposal: (2) Before and upon inst allation of the surface casing:

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

Individual Response: EPA acknowledges the comment; the fina l rule retains the requirements for logging and testing prior to and upon installation of surface casing.

Letter ID: 0259 Comment ID: 29179 Letter Lines: 2101 to 2111

123Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3866 2.3.3.3 Logging and testing requirements (40 CFR 146.87)

Comment: EPA Proposal: (i) Resistivity, spontaneous potential, and caliper logs before the casing is installed; and

GWPC Recommendations: (i) Resistivity, sp ontaneous potential, and caliper logs before the casing is installed; and

Rationale: After a few wells are drilled in an area, these evaluations are frequently unnecessary and yield little new information.This is an example of why it is appropriate to make this a discretionary rather than mandatory requirement. The proposed revision to 146.87( a) would give the Director the necessary discretion.

Individual Response: EPA disagrees that the requirements for logs, surveys, and tests are excessive or duplicative. All logs , surveys, and tests listed at §146.87(a) are necessary to verify information about the injection and confining zone s and ensure that the well is being drilled and cased as approved, and has mechanical integrity. EPA notes that the Dire ctor has the discretion at §146.87(a)(5) to approve alternative methods that provide equivalent or better information.

Letter ID: 0259 Comment ID: 29180 Letter Lines: 2113 to 2122

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3866 2.3.3.3 Logging and testing requirements (40 CFR 146.87)

Comment: EPA Proposal: (ii) A cement bond and variab le density log, and a temperature log after the casing is set and cemented.

GWPC Recommendations: (ii) A cement bond and variable density log, and a temperature log after the cas ing is set and cemented.

Rationale: Unusual to run these logs in a surface hole due to uniformity of shallow geology. This is an example of w hy it is appropriate to make this a discretionary rather than mandatory requirement. The proposed revision to 146.87(a) would give the Director the necessary discretion.

Individual Response: As described above, EPA disagrees that the requirements for logs, surveys, and tests are excessive or duplicative. All logs, survey s, and tests listed at §146.87(a) are necessary to verify information about the in jection and confining zones and ensure that the well is being drilled and cased as approved, and has mechanical integrity. EPA notes that the Director has the discretion at §146.87(a)(5) to approve alternative methods that provide equivalent or better information.

EPA clarifies that in the final GS rule, §146.87( a)(2)(ii) reads as follows: "A cement bond and variable density log to evaluate cement quality radially, and a te mperature log after the casing is

124set and cemented."

Letter ID: 0259 Comment ID: 29181 Letter Lines: 2124 to 2128

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3866 2.3.3.3 Logging and testing requirements (40 CFR 146.87)

Comment: EPA Proposal: (3) Before and upon instal lation of the long string casing:

GWPC Recommendations: Support the proposed EPA language.

Rationale: Agree with EPA’s rationale.

Individual Response: EPA acknowledges the comment; the fina l rule retains the requirements for logging and testing prior to and upon installation of the long string casing.

Letter ID: 0259 Comment ID: 29182 Letter Lines: 2130 to 2134

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3866 2.3.3.3 Logging and testing requirements (40 CFR 146.87)

Comment: EPA Proposal: (i) Resistivity, spontaneous potential, porosity , caliper, gamma ray, fracture finder logs, and any other l ogs the Director requires for the given geology before the cas ing is installed; and

GWPC Recommendations: Support the proposed EPA language.

Individual Response: EPA acknowledges the comment; the fina l rule retains the requirements for the logs and tests re quired at §146.87(a)(3).

Letter ID: 0259 Comment ID: 29183 Letter Lines: 2136 to 2146

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3866 2.3.3.3 Logging and testing requirements (40 CFR 146.87)

Comment: EPA Proposal: (ii) A cement bond and variab le density log, and a temperature log after the casing is set and cemented.

GWPC Recommendations: (ii) Cement evalua tion logs after the casing is set and cemented to evaluate cement quality w ith sufficient radial resolution to identify channels or missing cement.

Rationale: Acceptable to specify basic logging requirements, however, special

125logs should not be specified. Any other information from the area should be drawn on. Provides more flexibility to sel ect the appropriate log to demonstrate adequate cement bond.

Individual Response: EPA agrees with the suggested change. In the final GS rule, §146.87(a)(2)(ii) reads as follows: "A cement bond and variable density log to evaluate cement quality radially, and a te mperature log after the ca sing is set and cemented."

EPA believes that a minimum suite of logs and tests is necessary at all GS wells. All logs, surveys, and tests listed at §146.87(a) are necessary to verify information about the injection and confining zones and ensure th at the well is being drilled and cased as approved and has mechanical integrity. EPA adds that, should alternative methods be shown to provide equivalent or better information or if site-specific conditio ns and risk factors dict ate that other logs are necessary, the Director has the discretion at §146.87(a)(5) to requi re further logs and tests if necessary and to approve altern ative methods that provide equi valent or better information.

Letter ID: 0259 Comment ID: 29184 Letter Lines: 2148 to 2175

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3866 2.3.3.3 Logging and testing requirements (40 CFR 146.87)

Comment: EPA Proposal: 146.87(a)(4)

(4) A series of tests designed to dem onstrate the internal and external mechanical integrity of inject ion wells, which may include:

(i) A pressure test w ith liquid or gas; (ii) A tracer survey such as oxygen-activation logging; (iii) A temperature or noise log; (iv) A casing inspecti on log, if required by the Director; and

(5) Any alternative methods that provide equivalent or better information and that are required of and/or approved of by the Director.

GWPC Recommendations: (4) Test(s) design ed to demonstrate the internal and external mechanical integrity of injection wells, which may include:

(i) A pressure test w ith liquid or gas; (ii) Diagnostic tools such as oxygen-activation logging; (iii) A temperature or noise log; and (iv) A casing inspection log.

(5) Accept the EPA language and numbering.

Rationale: Technical and grammatical corrections

126In (iv), "if required by the Director" is unnecessary.

We interpret that (5) applies to 146.87(a)

Individual Response: EPA agrees with the commenter about the wording of the casing inspection log requirement at §146. 87(a)(4) and made the suggested change to improve clarity. In the final regulation, §146.87( a)(4)(iv) does not include th e phrase, “if required by the

Director.”

Letter ID: 0259 Comment ID: 29185 Letter Lines: 2177 to 2195

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3866 2.3.3.3 Logging and testing requirements (40 CFR 146.87)

Comment: Rule provision: 146.87(b)

EPA Proposal: (b) The owner or operator mu st take and submit to the Director

whole cores or sidewall cores of the in jection zone and confining system and formation fluid samples from the injec tion zone(s). The Director may accept cores from nearby wells if the owner or operator can demonstrate that core retrieval is not possible and that such cores are representative of conditions at the well. The Director may require the owner or operator to core other

formations in the borehole.

GWPC Recommendations: (b) The owner or op erator must submit to the Director a report describing whole cores or sidewall cores representa tive of the injection zone and confining system and formati on fluid samples from the injection zone(s). The Director may accept data from cores and fluid samples from nearby wells if the owner or operator can demonstr ate that such data are representative

of conditions in the wellbore.

Rationale: The information required should be sufficient to properly describe the injection and confining zones.

Individual Response: EPA clarifies that it is not the Agency's intent that physical cores be submitted to the Director. In the final GS rule, EPA has revised the first sentence of §146.87(b) to read as follows: "The owner or operator mu st take whole cores or sidewall cores of the injection zone and confining system and formati on fluid samples from the injection zone(s), and must submit to the Director a detailed report pr epared by a log analyst that includes: well log analyses (including well logs), core analyses, and formati on fluid sample information...."

EPA believes that logs and tests must be perf ormed on each well drilled regardless of existing

information about the area to ac count for the complexity of CO 2 injection well construction and the buoyancy of CO2. Existing lit hologic and geologic information may lack the details needed

127for site-specific well design and the geology ne eded to support protection of USDWs from endangerment.

Letter ID: 0259 Comment ID: 29186 Letter Lines: 2197 to 2206

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3866 2.3.3.3 Logging and testing requirements (40 CFR 146.87)

Comment: EPA Proposal: (c) The owner or operator must record the fluid temperature, pH, conductivity, reservoir pressure and the st atic fluid level of the injection zone(s).

GWPC Recommendations: (c) Prior to in jection well operation, the owner or operator must record the formation te mperature, formation fluid pH and conductivity, and reservoi r pressure of the injection zone(s).

Rationale: Technical corrections. Reservoir pressure and static fluid level are redundant parameters.

Individual Response: EPA disagrees that "reservoir pressu re" and "static fluid level" are redundant parameters. Although the st atic fluid level is equal to the bottom hole pressure, this may not always be identical to the reservoir pr essure. Additionally, measuring the static fluid level provides additional assurance that the r eading is accurate (or, provides the needed information in cases where a good reading is no t obtained). In addition, a static fluid level measurement provides information regarding th e proximity to USDWs that need protection

afforded to them.

Letter ID: 0259 Comment ID: 29187 Letter Lines: 2208 to 2224

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3866 2.3.3.3 Logging and testing requirements (40 CFR 146.87)

Comment: EPA Proposal: (d) At a minimum, the ow ner or operator must determine or calculate the following information con cerning the injection and confining zone(s):

(1) Fracture pressure; (2) Other physical and chemical characteristics of the injection and confining

zones; and (3) Physical and chemical characteristic s of the formation fluids in the injection zone.

GWPC Recommendations: Delete all

Rationale: With the exception of calculati ng fracture pressure, the requirements

128of this section appear re dundant to other requiremen ts of prior sections. Recommend moving injection pressure to old (e), now renum bered as (d).

(2) and (3) are also too vague.

Individual Response: EPA believes that the requirement to provide information on the injection and confining zones in §146.87(d) is warranted, and that the rule provides flexibility to account for the variety of geologic conditions that may be encountered at GS sites.

EPA is developing guidance on monitoring and tes ting that will describe recommended tests and procedures to assist owners/operators and Di rectors in evaluating the requirements for preoperational logging and testing under §146.87. This guidance will be available on EPA’s website at http://water.epa.gov/type/ground water/uic/wells_sequestration.cfm.

Letter ID: 0259 Comment ID: 29188 Letter Lines: 2226 to 2249

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3866 2.3.3.3 Logging and testing requirements (40 CFR 146.87)

Comment: EPA Proposal: (e) Upon completion, but prior to operation, the owne r or operator must conduct the following tests to verify hydrogeologic charact eristics of the injection zone:

(1) A pump test; or (2) Injectivity tests.

GWPC Recommendations: (d) At any time prior to injection well operation, the owner or operator must determine fract ure pressures of the injection and confining zones and conduc t tests to verify hydrogeo logic and geomechanical characteristics of the injection zone, e.g., injectivity tests.

Rationale: Allows the use of information such as leak off te sts conducted during the drilling operation.

Delete (1)

It was felt that Geomechan ical properties were at least as important as hydrogeologic characteristics.

The results of a pump test (pumping fluid from the well) has no relevance for an injection well.

If current (d) is deleted as reco mmended, this would become (d)

Individual Response: EPA clarifies that the owner or ope rator has the option of using pump

129tests or injectivity tests depending on which woul d provide the most valuable information based on site-specific conditions. Further, EPA disagree s that pump tests are irrelevant to determining injection zone properties. Depending on the ch aracteristics or depth of knowledge of the confining and injection zone formations, pump test s may be necessary to prove that no hydraulic

connection exists between the injection zone and a USDW.

EPA is developing guidance on monitoring and tes ting that will describe recommended tests and procedures to assist owners/operators and Di rectors in evaluating the requirements for preoperational logging and testing under §146.87. This guidance will be available on EPA’s website at http://water.epa.gov/type/ground water/uic/wells_sequestration.cfm.

Letter ID: 0259 Comment ID: 29189 Letter Lines: 2251 to 2268

Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language

Comment Code: 3866 2.3.3.3 Logging and testing requirements (40 CFR 146.87)

Comment: Rule Provision: 146.87(f)

EPA Proposal: (f) The owner or operator mu st provide the Director with the opportunity to witness all logging and testing by this subpart. The owner or operator must submit a schedule of such act ivities to the Direct or 30 days prior to conducting the first test and submit any changes to the schedule 30 days prior to the next scheduled test.

GWPC Recommendations: (e) The owner or ope rator must provide the Director with the opportunity to witness a ll logging and testing by this subpart. The owner or operator must submit a schedule of such activities to the Di rector upon spudding the well and submit any changes to the sc hedule 48 hours prior to the scheduled

test.

Rationale: The changes reflect the realitie s of flexible rig schedules and are fully consistent with current Cl ass II requirements and practices.

If current (d) is deleted as reco mmended, this would become (e)

Individual Response: EPA disagrees that the 30-day notif ication requirement is unreasonable. The 30-day notification mirrors the current requ irement for logging and testing of new Class I wells, as described in §146.66. Acknowledging the developing nature of CO2 GS, EPA believes that involvement by the permitting authority in each project will provide much needed field data for assurance of USDW protec tion from endangerment and will help update and refine the permitting process. Adequate timing of notification will ensure the Director's ability to be

involved.

130