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 24, 2008

U. S. Environmental Protection Agency Docket ID No. EPA-HQ-OW-2008-0390 Office of Groundwater and Drinking Water (OGWDW)

Mail Code: 2822T 1200 Pennsylvania Ave. NW Washington, DC 20460

RE: Federal Requirements Under the Underground Injection Control (UIC) Program for Carbon Dioxide Geosequestration Wells, Proposed Rule

Dear Docket:

Enclosed are the comments of the American Water Works Association (AWWA) on the proposed requirements for carbon dioxide geosequestration wells under the Underground Injection Control (UIC) Program as published in the July 25 st Federal Register (73 FR 43491). Protection of underground sources of drinking water (USDWs) should be a key priority of any geologic carbon sequestration regulation developed as part of the Underground Injection Control (UIC) Program. AWWA appreciates the opportunity to comment on this proposed regulation, and we have several significant comments that we feel should be addressed in the final regulation.

If you have any questions about these comments, please feel free to contact me or Alan Roberson in our Washington Office.

Yours Sincerely,



## Chapter 5.

Thomas W. Curtis Deputy Executive Director

cc: Ben Grumbles – USEPA OW Cynthia Dougherty – USEPA OGWDW Government Affairs Office 1300 Eye Street NW

Suite 701W Washington, DC 20005

T 202.628.8303

F 202.628.2846

www.awwa.org

Headquarters Office 6666 W. Quincy Avenue

Denver CO 80235

T 303.794.7711

F 303.347.0804 The Authoritative Resource on Safe Water SMPage 2 of 60 EXECUTIVE SUMMARY OF COMMENTS BY THE

AMERICAN WATER WORKS ASSOCIATION ON THE PROPOSED FEDERAL REQUIREMENTS FOR CARBON DIXOIDE GEOLOGIC SEQUESTRATION (GS) WELLS

The American Water Works Association (AWWA) is providing detailed comments on the proposed requirements for GS wells as published in the July 25 th , 2008 Federal Register (73 FR 43491). The following six central issues are addressed in more detail in our comments:

 Protection of underground sources of drinking water (USDWs) should be the highest priority – water should trump everything!

 Prevention of unintended consequences is of utmost importance;

 Injection of carbon dioxide and construction of injection wells should not be allowed in or near sole source aquifers, coal seams, earth-quake prone areas, or above the lowermost USDWs;

 Hydraulic fracturing should not be used at all for GS;

 If USDW water quality is degraded by a GS project, the owner/operator of that projects is responsible for any costs born by drinking water utilities due to increased treatment requirements for that ground water or replacement of lost capacity; and,

 The 10,000 mg/l TDS limit for classifying USDWs for the siting of Class VI wells needs to be revised upward.

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

 Requirement to consult with the state environmental department and affected water utilities to determine which aquifers currently not classified as USDWs might be considered as future drinking water sources;

 Definition of “endangerment” that includes water quality impacts beyond those contaminants with MCLs;

 Addressing liability, treatment costs for remediation, and financial recourse for a water utility if a USDW is degraded due to a GS project;

 Requirement for owner/operators of grandfathered wells to certify that the wells were constructed and cemented with materials appropriate for GS wells;

 Development of a standard computation flow model to delineate the area of review;

 Reevaluation of the area of review annually for the first ten years, and then every five years for the remaining life of the project;

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

 Inclusion of detailed monitoring requirements in the final regulation;

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

 Requirement for mandatory public notification and public hearings for any new permit and any permit revision or renewal, and for a 90-day public comment period

Several issues need more research by EPA and DOE, and the following research needs to be completed prior to issuance of the final regulation:

 Criteria for the determination that the carbon dioxide plume has stabilized;

 The potential for seismic shifts due to subsurface pressure changes;

 The minimum concentration of carbon dioxide in the injection stream; and

 The types of tracers that would be acceptable for GS.Page 3 of 60 INTRODUCTION

The American Water Works Association (AWWA) is an international, nonprofit, scientific and educational society dedicated to the improvement of drinking water quality and supply. Founded in 1881, the Association is the largest organization of water supply professionals in the world. Our 60,000 plus members represent the full spectrum of the drinking water community: treatment plant operators and managers, environmental advocates, engineers, scientists, academicians, and others who hold a genuine interest in water supply and public health. Our membership includes more than 4,700 utilities that supply roughly 80 percent of the nation's drinking water.

AWWA appreciates the opportunity to comment on the proposed requirements for geologic sequestration wells as published in the July 25 th , 2008 Federal Register (73 FR 43491). Protection of underground sources of drinking water (USDWs) should be a key priority of any geologic carbon sequestration regulation developed as part of the Underground Injection Control (UIC) Program.

AWWA has developed detailed comments on the proposed regulation. These comments presented in the following document, and are organized into the following four sections:

 Section 1: General comments on the proposed geologic sequestration regulation

 Section 2: Responses to EPA’s specific requests for comments as provided in the preamble to the proposed regulation

 Section 3: Monitoring guidelines for geologic carbon sequestration projects

 Section 4: Comments on specific parts of the proposed regulation textPage 4 of 60 I. GENERAL COMMENTS

In 2007, approximately 78% of 52,000 community water systems in the United States were supplied by groundwater and these systems served 90.5 million people. In addition, many surface water utilities are currently looking at conjunctive use and/or groundwater development as adaptation measures (supply portfolio diversification/new storage) to combat climate change. Each of these utilities could potentially be impacted by geologic carbon sequestration, simply by the fact that these utilities utilize groundwater resources.

The proposed regulation is a good technical starting point given the evolving state of geologic sequestration; however, the proposed rule has many limitations that could allow for the endangerment of underground sources of drinking water (USDWs). Many of the requirements are based on faith, and not a lot of data, and the drinking water community is being asked trust that geologic sequestration technology will work even though there is very little experience with this technology on a large scale. For example, the requirements for determining the direction of carbon dioxide plume migration, predicting confining layer containment potential, and identifying necessary geo-chemical monitoring are based on modeling exercises, with limited monitoring data to validate these models and limited real-life data to support the requirements. There is the possibility for unintended consequences to occur with geologic sequestration is very real, similar to what was observed with the use of MTBE. MTBE is the fuel additive that was meant to solve an air pollution problem but its use resulted in unanticipated drinking water pollution problems. Carbon dioxide is an energy production/use byproduct that causes air pollution/climate problem but whose mitigation (using geologic sequestration) could cause drinking water contamination and other (supply) problems. EPA needs to draw on the lessons learned from the MTBE situation, and do everything possible to prevent a similar situation from occurring with geologic sequestration. Prevention is the key word here. AWWA will address these issues, as well as some other important concerns, in this section of general comments.

USDW Classification: The best sources of drinking water are already being used by utilities. In many areas, population growth is forcing utilities to look further or to look at more challenging sources. With the potential impacts from climate change, drinking water utilities are facing an even more limited supply of fresh drinking water. As a result, many utilities are turning to more challenging groundwater sources such as those that are very deep or have high salinity concentrations. Additionally, the pumping costs for these deep wells are no longer prohibitive given the lack of sufficient water sources. Some of these new sources could fall outside of the current definition of a USDW, in that the aquifer has a TDS concentration higher than 10,000 ppm. The proposed rule promises protection of USDWs from endangerment, in that the activity does not cause a primary drinking water Maximum Contaminant Level (MCL) to be exceeded in an USDW or affect human health. There are no anti-degradation provisions in the proposed regulation to protect other groundwater supplies, such as those aquifers that are not classified as a USDW but have been, or may be, identified as a future drinking water source. The definition of a USDW was written at a time when many advanced water treatment technologies were generally cost prohibitive, and the general thinking that the high-salinity aquifers would never be utilized as drinking water sources.Page 5 of 60 Technological advances in the area of desalination have reduced many of the treatment costs, making it more and more accessible. Many utilities have no other choice for new water sources. Ever increasing population and water demands have utilities using non-traditional and poorer water sources (see Table 1-1 for examples; note that this is not meant to be a comprehensive list of all desalination plants in the United States).

Table 1-1: Water Utilities with More Challenging Water Sources

Utility Name Water Source Usage TDS Concentrations

El Paso Water Utilities and Ft. Bliss, Texas Hueco Bolson Basin 27.5 mgd 600 to 4,900 mg/l

Tampa Bay Water, Florida Seawater 25 mgd 18,000 – 32,000 mg/L Yuma Desalting Plant,

Arizona Drainage water 22 mgd 3,200 mg/L

Miami-Dade County, Florida Florida Aquifer 17.5 mgd (currently under design) 1,000 – 5,000 mg/L

Temescal Desalter Project,

California Temescal Basin 15 mgd 700 mg/L

City of Abilene, Texas Surface water 8.0 mgd 1,200 mg/L City of Sherman, Texas Surface water 7.5 mgd 900 – 1500 mg/L Southmost Regional Water Authority, Texas Groundwater 6.75 mgd 3,500 mg/L

Lake Granbury SWATS,

Texas Surface water 6.0 mgd 1,800 mg/L

City of Fort Stockton, Texas Groundwater 6.0 mgd 1485 mg/L

Newport News WTP, Virginia Lower and Middle Potomac Aquifers 5.7 mgd 3600 mg/L

Alameda County Water District, California Niles Cone Groundwater

Basin 5.0 mgd with expansion to 10 mgd 1,100 – 2,400 mg/L

Pascagoula, Mississippi Groundwater 4.5 mgd 1,000 mg/L Dare County North WTP,

North Carolina Groundwater 3.0 mgd 4,300 mg/L

Port Hueneme Brackish Water Facility, California Groundwater 3.0 mgd 1,300 mg/L

James City Service Authority, Virginia Middle and Lower Potomac Aquifers 2.5 mgd 1,000 – 2,400 mg/L

Buxton, North Carolina Groundwater 2.0 mgd 13,200 mg/L Cape May, New Jersey Groundwater 2.0 mgd 2,100 mg/L Dare County Cape Hatteras WP, North Carolina Groundwater 2.0 mgd 11,200 mg/L

Las Animas, Colorado Groundwater 1.18 mgd 3,500 mg/L VA Medical Center, Ft. Lyon,

Colorado Groundwater 0.24 mgd 800 mg/L

The use of very deep and/or high salinity groundwater becoming more commonplace is only a matter of time. Therefore, we believe the 10,000 mg/L TDS USDW definition is no longer appropriate. Given that this regulation does not currently extend protection to non-traditional and poorer water sources, AWWA believes that these aquifers may be adversely impacted by this rulemaking. These aquifers, which have not been previously used as a drinking water source, may be in the future, and it is important to make sure that they are adequately protected. AWWA recommends that EPA consider the “green-effect” and that, in many cases, the overallPage 6 of 60 least cost alternative may be to treat brackish groundwater using desalination technology instead of trying to obtain surface water as the drinking water source. While the surface water may be less expensive to treat, if the utility is located in a dry environment, such as Arizona or New Mexico, the pumping costs to transport that water over a large distance may be much larger than the cost to treat a brackish groundwater. EPA should also consider that as technology evolves, utilities will be able to treat a much different set of waters than is currently being treated. Several utilities are using sea water or brackish water as drinking water sources, which would not have been even remotely considered as a viable option 20 years ago, when the TDS limit was originally developed.

Recognizing that it is difficult to extend protection to these aquifers due to the restrictions of the SDWA, AWWA recommends that the regulation be revised to mandate that, during the project planning process, the owner/operators should include state environmental departments as they can provide insight into what aquifers currently (not classified as USDWs) might be considered as future drinking water sources. The stakeholder process should also involve both regional and local planning boards, as well as the local utilities. This process will allow for protection to be extended to the non-traditional aquifers, which will be necessary given the pressures on water resources that the country will be facing in the upcoming century.

USDW Endangerment: AWWA recommends revision to the definition of “endangerment” in the proposed rule. The current definition of endangerment is limited to SDWA UIC definition of 10,000 TDS and to primary MCL contamination. Certain health-effects can be related to concentrations in water of compounds that do not exceed the primary MCL. However, under the current language, these potential contaminants would not be covered with the protections afforded by the SDWA.

EPA should also consider the risk associated with the potential exposure of any contaminants that are released to the surface. While we recognize that a gradual leak may have little impact,the potential of a catastrophic leak is always present. EPA should be mindful during the rulemaking process of not only the risk to drinking water, but also of other potential risks from exposure to other constituents such as pH, lead and copper, iron, hardness, silica and boron. These are compound for which no MCLs have been developed but still impact drinking water quality and increase the necessary treatment costs. There could be potential health impacts due to long-term exposure to contaminant levels below the established MCLs. Also, beneficial uses of groundwater could also be impacted by increases of these compounds in the aquifers. Owners/operators could be in compliance with the regulation, but could be degrading an aquifer by contaminating it with compounds for which MCLs do not exist.

Assignment of Liability: Most importantly, the regulation does not seem to address the liability that would be realized by owners/operators of the geologic sequestration projects if water quality of USDWs is degraded by the operation of their project (even if the impacts are limited to MCLs). AWWA recommends that this issue be addressed in the final regulation, as drinking water utilities may have little financial recourse if the water quality one of their aquifers is degraded due to the operation of a geologic sequestration process. Provisions need to be included in the final rule that would allow the drinking water utility to recoup any costs that are realized due to increased treatment requirements for contaminated ground water or to replace lostPage 7 of 60 capacity. In some cases, utilities may need to install different types of treatment to remove compounds that might not have been present in the water prior to the geologic sequestration project. In other instances, treatment may consist of the addition of more chemicals to facilitate precipitation of the inorganic compounds or the utility may have to backwash membranes more often, resulting in higher energy and other operation and maintenance costs. In any of these cases, the owner/operator of the geologic sequestration project should be required to reimburse the drinking water utility for these incurred costs, and they should also be required to continue such payments for as long as the ground water source remains degraded.

Water utilities should not be penalized for having to develop local sites contaminated by sequestration activities for water supply. In fact they should be encouraged to do so, under the appropriate conditions, as there is no more critical public health issue than the need to provide potable water. In order to meet increasing demands imposed on them by a growing service population, water utilities will need to develop marginal water supplies. However, increased treatment costs due to contamination resulting from sequestration activities should not be borne by the local utility or their customers when national environmental objectives have been met without significant benefit to the local economy.

Should a water utility “lose” an existing or future source of supply due to contamination or inaccessibility resulting from a sequestration project, there will be the issue of financial compensation (for treatment or development of an alternative source). As water resources become scarce, financial compensation for a lost source of supply may not suffice, as local alternatives may not be available. Hence, it will be critical that contingency planning to identify alternatives to the current groundwater supply be a part of the planning activities for the sequestration project, along with a commitment to provide an alternative source of water, should

the need arise.

AWWA also recommends that the company generating the carbon dioxide must maintain sole ownership of the carbon dioxide they generate. This would ensure that liability remains with the original generator in perpetuity; even if the carbon dioxide is commingled with some generated from another facility or if its disposal is managed by another company.

Trespass and Aquifer Displacement: AWWA recommends that the potential for trespass be addressed in the final rule. Carbon dioxide plumes may migrate into a location that a drinking water utility was planning to utilize, possibly for aquifer storage and recovery. What recourse is provided by the proposed regulation in the event that trespass occurs, and damages are realized by the drinking water utility? Also, movement of the pressure front associated with a carbon dioxide plume may cause aquifers to shift in location, potentially moving them out of the jurisdiction of their original utility “owner.” This can be a serious problem in certain portions of the country where ground water resources are limited or conflict, and utilities face intense competition for water rights. AWWA questions if an appropriate recourse will be provided by the sequestration project owner/operator in the event that these water rights issues become a reality for the drinking water utility.

Safe Drinking Water Act Authority: In its February 2008 stakeholders meeting, EPA seemed to imply that it was restricted in what it could regulate and/or require under the SDWA for UICPage 8 of 60 projects to preventing “endangerment of USDW.” AWWA recognizes that EPA’s regulatory authority is limited by the requirements of the SDWA and will be advocating that several portions of the SDWA be amended to better protect the nation’s groundwater resources. Issues that we will be addressing include:

1. The definition of a USDW is provided within the SDWA, which may require amendment if the quality and accessibility groundwater sources is to be protected. We recognize that the 10,000 mg/L TDS limit is very outdated, and that a new upper limit should be established and applied when siting Class VI wells. We hesitate to recommend any specific number at this point in time, given that some drinking water utilities are so stressed for water resources that they are investigating extremely non-traditional water sources with high TDS levels.

2. Endangerment is defined by the SDWA and may need to be redefined to protect beneficial uses. The proposed rule seems to be focused on preventing brine from the carbon dioxide storage formations from reaching USDWs and/or preventing carbon dioxide from contaminating USDWs and causing exceedences of primary MCLs. The protective measures of the proposed rule may not be adequate from a source water and beneficial use protection standpoint as other changes are likely to occur besides exceeding primary MCLs (e.g., increased Fe/Mn, TDS, and lowered pH – all of which have secondary MCLs and possible increase in silica and boron, which do not have MCLs, but have water quality significance). EPA needs to be provided with the regulatory authority to protect against these other types of endangerment, and the SDWA should be modified to allow for these protective measures to be developed.

AWWA recommends that EPA not ignore the potential impacts outside of the scope of the SDWA such as those to air and human health if there is a massive leak. Could there be any conflicts or overlaps with the Clean Air Act or the Clean Water Act? Are other Program Offices within EPA planning on looking at this proposal? This review by other EPA Program Offices would seem to be necessary given the potential impacts that could arise if there is a failure of the confining layer.

Sole Source Aquifers: Several areas of the country rely on sole source aquifers as their drinking water resource. Given the special protective measures already afforded to these aquifers by EPA, AWWA strongly recommends that the final geologic sequestration regulation should restrict project activities in the vicinity of these aquifers. Table 1-2 below presents a list of some of the sole-source aquifers that are located in potential geologic sequestration areas. (Note that this is not meant to be a comprehensive list of all of the sole source aquifers in the United States.)Page 9 of 60 Table 1-2: Sole-Source Aquifers in Potential Geologic Sequestration Areas Aquifer Name Location Potentially Impacted Characteristics
Upper Santa Cruz & Avra Basin Aquifer Arizona Tucson, Green Valley, Catalina Discharges 376,000 acre-feet per year

Fresno County Aquifer California Fresno, Clovis Contains 5.8 million

acre feet of water

Volusia Sole Source Aquifer Florida Ormond Beach, Daytona Beach, New Smyrna Beach and Deland Covers 1,450 sq. mi.

Biscayne Sole Source Aquifer Florida All of Dade County; parts of Broward,

Monroe and Palm Beach Counties Covers 4,000 sq. mi.

Eastern Snake River Plain Aquifer Idaho 300,000 residents of Eastern Idaho Contains 200 to 300

million acre-feet Spokane Valley-Rathdrum Prairie Aquifer Idaho, Washington 700,000 residents of Idaho and Washington Covers 325 sq. mi.

Chicot Aquifer System Louisiana Lafayette, Lake Charles, Crowley Supplies 800 mgd, most for irrigation

Southern Hills Aquifer System Louisiana, Mississippi Baton Rouge, Natchez, McComb Supplies 290 million gallons per day New Jersey Coastal Plain Aquifer System New Jersey Over 3,000,000 residents Over 350 million gal. withdrawn per day Northwest New Jersey Fifteen Basin Aquifer New Jersey,

New York Over 500,000 residents Covers 1,735 square

mile area Espanola Basin Aquifer System New Mexico Sante Fe, Los Alamos, and Española Covers 3,000 sq. mi. Clinton Street Ballpark Aquifer System New York Broome and Tioga Counties 16.25 mgd withdrawn for drinking water

Miami Valley Buried Aquifer Ohio Serves over 1,600,000 residents Provides 200 mgd for drinking water

Edwards Aquifer Texas San Antonia, San Marcos, New

Branfels Discharges 900,000 acre-feet per year

Columbia and YorktownEastover Multiaquifer Virginia Exmore, Olney, Chincoteague Covers 695 sq. mi.

AWWA recommends that EPA prohibit owner/operators from constructing carbon dioxide injection wells in sole source aquifers. Owner/operators should also be prohibited from ever injecting carbon dioxide into a formation that would result in the migration of the carbon dioxide to a point that is under a sole source aquifer. EPA should establish a minimum distance that needs to be provided between the closest geologic sequestration project and the location of any sole source aquifers. AWWA would recommend a 50 mile minimum; however, not being experts on the details of plume migration, AWWA recommends that EPA and DOE perform research on this topic to better assess what the regulatory requirement should be. Including these restrictions in the final geologic sequestration regulation would allow for the protection of drinking water aquifers that, if contaminated by carbon dioxide, could result in very significant and expensive issues for the drinking water utilities.

Water versus Energy: AWWA questions how will geologic sequestration projects will be permitted if there is potential competition for a specific geologic basin between an energy company and a drinking water utility. Water should trump everything. The water sector should be given priority, especially if a drinking water utility has limited or no other options, as they have very limited water and storage resources. It may also be possible that there may not be aPage 10 of 60 single federal and/or state oversight agency that could provide guidance in this arena as the agency would need to have oversight for air, water, environmental, energy, and other sectors. The NEPA process and the state equivalent, such as CEQA in California, will need to be well fleshed out at the outset of the permitting process.

Seismicity: The seismicity requirements in the Area of Review requirements are not very prescriptive. AWWA believes there is too much latitude for interpretation and that the regulation could be applied inconsistently by Directors of different states. AWWA recommends making the language stronger to clarify exactly what is meant by the following requirement (§146.82(d)(3)): “...information on seismic history including the presence and depth of seismic sources and a determination that the seismicity would not interfere with containment.” A geologic sequestration project should be evaluated on the entire risk spectrum using different ranges of seismic activity and distance requirements from active faults to determine if the proposed site is acceptable. EPA should develop guidance that will assist owner/operators in making the appropriate determinations regarding seismic risk for a geologic sequestration project. For example, is there a minimum distance that should be provided between the potential plume footprint and an area of seismic activity? This information is critical as different owner/operators could decide to take on a different level of risk due to their comfort with the financial implications. AWWA does not want to see USDW protection compromised due to faulty assumptions about seismic activity in and around a potential project site.

AWWA recommends that EPA also investigate the need for modeling the potential for seismic shifts due to the changes in subsurface pressures associated with the carbon dioxide injection process. A literature search should be performed to see if either Laurence Berkley National Laboratory or the National Energy Technology Laboratory has developed any information on this topic.

Project Security: AWWA recommends that EPA work with the Department of Transportation and the Department of Homeland Security to ensure the safety and security of geologic sequestration projects. We have concerns about the unintentional or intentional release of stored carbon dioxide and the related control and monitoring systems required, as well as security measures. A requirement for strict monitoring systems during project construction and operation is necessary to ensure that the project is not intentionally sabotaged, as this could result in a

massive leak of carbon dioxide out of the confinement zone and into the environment. EPA should mandate strict monitoring systems be included as part of any geologic sequestration project, not only to ensure the safety of USDWs, but also the safety of those living in the footprint of the project.

Data and Research Needs: AWWA believes that stakeholder access to the necessary data is lacking and will inhibit making informed/transparent decisions on geologic carbon sequestration projects. Stakeholders need better and more accessible data and data reduction tools (i.e., GIS maps). EPA should consider creating an interactive web based data warehouse that would store data and GIS layers on large carbon dioxide emitters, drinking water groundwater basins, seismic/volcanic/geothermal zones, proposed carbon dioxide saline injection basins, etc. and provide the ability to overlay layers. Stakeholders would then have improved abilities toPage 11 of 60 evaluate a proposed geologic sequestration project to determine if they would be impacted by the carbon dioxide plume and/or associated pressure front.

AWWA also recommends that EPA review the following reports that address the potential costs of treating source water that has lowered pH levels and/or increased concentrations of iron, minerals and other potential contaminants.

 AWWA projects:

o Managing Change and Unintended Consequences: Lead and Copper Rule Corrosion Control Treatment (WITAF)

o Regulatory Risk Assessment for Arsenic in Water (WITAF)

o Technology and Cost Review of the Proposed Arsenic Regulation (WITAF)

 AwwaRF projects:

o Adsorbent Treatment Technologies for Arsenic Removal (#2731)

o Demonstration of Emerging Technologies for Arsenic Removal (#2661)

o Implementation of Arsenic Treatment Systems Part 2: Design Considerations, Operation, and Maintenance (#2665)

o Arsenic Removal by Iron-Modified Activated Carbon (#3158)

o Subsurface Treatment For Arsenic Removal--Phases I and II (#3082)

o Characterization and Performance of Filter Media for Manganese Control (#2951)

o Occurrence of Manganese in Drinking Water and Manganese Control (#2863)

o Advanced Processes for Simultaneous Arsenic and Manganese Removal (#2748)

o Occurrence Survey of Boron and Hexavalent Chromium (#2759)

o Integrated Water Treatment: Softening and Ultrafiltration (#2647)

o Enhanced Reverse Osmosis Systems: Intermediate Treatment to Improve Recovery (#4061)

o Membrane Treatment Of Impaired Irrigation Return (#4069)

o Zero Liquid Discharge Desalination of Waters with High Organic Content (#4163)

o Zero Liquid Discharge for Inland Desalination (#3010)

o Comparison of Zinc vs Non-Zinc Corrosion Control for Lead and Copper (#4103)

o Effect of Nitrification on Corrosion in the Distribution System (#4015

The lack of good background data and inappropriate oil and gas well closures reflect inadequate regulatory oversight that can only get worse as regulatory agencies are asked to take on more activities related to climate change. Climate change adaptation and mitigation measures, such as geologic sequestration, may be delayed due to inadequate regulatory agency resources (e.g., number of staff and expertise). EPA needs to support significant research to reduce the uncertainties associated with climate change and afford better long-term planning decisions as water utilities and their customers are likely to feel a disproportionate impact due to anticipated adaptation and mitigation activities. EPA should also work in concert with other federal agencies to spur research into technologies that can convert carbon dioxide into inert or innocuous products.Page 12 of 60 II. RESPONSES TO EPA’S SPECIFIC REQUESTS FOR COMMENT

In this section, we have grouped all of the specific requests for comment provided in the preamble of the proposed regulation into different categories. This allows for AWWA to provide to certain groupings in whole, instead of addressing each request for comment individually.

Category: USDW Location

EPA Request for Comment: EPA is proposing to preclude the injection of CO2 for long-term storage into coal seams where they are above the lowermost USDW. EPA requests comment on this proposed prohibition. EPA Notice 43503.

AWWA Response: AWWA recommends that EPA preclude the injection of carbon dioxide into coal seams located above the lowermost USDWs. First and foremost, AWWA is adamantly opposed to the injection of carbon dioxide into any storage formation not located beneath the lowermost USDW. If a utility ever desired to use the USDW as a water resource, they would have to drill through the carbon dioxide plume, thus creating a pathway for carbon dioxide to potentially migrate out of the confining layer and into nearby aquifers. This could cause contamination of USDWs located above the coal seam, and result in significant remediation activities for a water utility. Second, little research has been conducted to determine the specific impacts that storage of carbon dioxide would have on coal seams. Much of the research that has been performed to date has been on either carbon dioxide storage in saline reservoirs or in depleted oil/gas fields. AWWA recommends that at this point in time, EPA preclude the injection of carbon dioxide into all coal seams, no matter where they are located in the subsurface. This regulation was not designed for coal seams to be used as carbon dioxide storage reservoirs. Therefore, AWWA recommends that any wells constructed for the injection of carbon dioxide into coal seams wells be permitted under the Class V experimental wells until the potential impacts of coal seam carbon dioxide sequestration on USDWs are better

understood.

EPA Request for Comment: EPA is soliciting comment on whether CO2 injection should be allowed into an injection zone above the lowermost USDW, when the Director determines that geologic conditions (e.g., thousands of feet of intervening formations between the injection zone and the overlying and/or underlying USDWs) exist that will prevent fluid movement into adjacent USDWs. EPA Notice 43512.

AWWA Response: As previously stated, AWWA is adamantly opposed to the injection of carbon dioxide into any storage formation not located beneath the lowermost USDW. If a utility ever desired to use the lowermost USDW as a water resource, they would have to drill through the carbon dioxide plume, thus creating a pathway for carbon dioxide to potentially migrate out of the confining layer and into nearby aquifers. This could cause contamination of USDWs located above the storage aquifer, and result in significant remediation activities for a water utility. AWWA recommends that EPA include a section in the final regulation prohibiting the injection of carbon dioxide into any formation located above the lowermost USDW.Page 13 of 60 EPA Request for Comment: EPA specifically seeks comment on the merits of requiring the identification of additional confining and containment zones above the primary (i.e., lowermost) confining zone that could further impede vertical fluid movement and allow for pressure dissipation. EPA Notice 43506.

AWWA Response: AWWA recommends that EPA require owner/operators to identify these additional confining and containment zones as part of the site characterization process. This identification is important to understand the project as a whole, and failing to identify these additional zones results in a very large knowledge gap in the identification of potential mitigation options in the event that a leak occurs from the primary confining layer. Having this information available to regulators and stakeholders would allow for a better understanding of the project as a whole, and would provide for a more informed and comprehensive review process. If certain stakeholders, such as drinking water utilities, were provided with this information, utilities would have a better understanding of a geologic sequestration project with the knowledge that multiple confining layers separated the carbon dioxide injection zone from their USDWs.

EPA Request for Comment: EPA is also requesting comments on whether aquifer exemptions should be allowed for the purpose of Class VI injection, and under what conditions should such aquifer exemptions be approved. EPA Notice 43512.

AWWA Response: AWWA does not support aquifer exemptions for the purposes of Class VI injection projects. Water resources are becoming extremely limited in many parts of the country and many drinking water utilities will be turning to alternative supply sources, including brackish and saline groundwater, as well as deeper USDWs. 40 CFR 146.4 states that:

“An aquifer or a portion thereof which meets the criteria for an underground source of drinking water...may be determined...to be an exempted aquifer if it meets the following criteria: (a) It does not currently serve as a source of drinking water; and (b) It cannot now and will not in the future serve as a source of drinking water because: (1) It is mineral, hydrocarbon or geothermal energy producing, or can be demonstrated by a permit applicant as part of a permit application for a Class II or III operation to contain minerals or hydrocarbons that considering their quantity and location are expected to be commercially producible, (2) It is situated at a depth or location which makes recovery of water for drinking water purposes economically or technologically impractical ; (3) It is so contaminated that it would be economically or technologically impractical to render that water fit for human consumption ; or (4) It is located over a Class III well mining area subject to subsidence or catastrophic collapse; or (c) The total dissolved solids content of the ground water is more than 3,000 and less than 10,000 mg/l and it is not reasonably expected to supply a public water system.”

As previously stated, many drinking water utilities are exploring ground water resources that might not have been previously feasible to access or treat. The underlined portions of the aquifer exemption regulations are problematic as ground water resources that fit these definitions are now being tapped, given that much of the easily accessible and/or treatable ground water has already been utilized or allocated. By allowing for aquifer exemptions in these cases, EPA is precluding their use as a future USDW at a time when the country’s remaining ground waterPage 14 of 60 resources should be aggressively protected. Therefore, AWWA recommends that EPA not allow aquifer exemptions for the purposes of Class VI injection.

EPA Request for Comment: EPA seeks comment on whether the Agency should set a minimum injection depth requirement for CO2 GS, rather than require that such injection take place below

the lowermost USDW. EPA Notice 43512.

AWWA Response: EPA should consider setting a minimum injection depth for geologic carbon sequestration as well as requiring that the injection take place below either the lowermost USDW or the lowermost aquifer that would be used as a drinking water source. AWWA believes this is necessary to ensure that carbon dioxide injected in the supercritical phase remains as such. The IPCC Special Report on Carbon Dioxide Capture and Storage suggested that carbon dioxide should be sequestered depths of at least 800 to 1,000 meters because at these depths, supercritical carbon dioxide has a liquid-like density that provides the potential for efficient utilization of underground storage space in the pores of sedimentary rocks. Providing for a minimum depth for carbon dioxide injection would strengthen the protective measures for USDWs. However, it is important to note that the minimum injection depth should be coupled with the provision that carbon dioxide must be injected below either the lowermost USDW or the lowermost aquifer that could be used as a drinking water source.

Category: Grandfathering Wells/ Enhanced Oil Recovery Wells

EPA Request for Comment: Injection of CO2 for the purposes of enhanced oil and gas recovery (EOR/EGR), as long as any production is occurring, will continue to be permitted under the Class II program. EPA seeks comment on the merits of this approach since owners or operators of some Class II EOR/EGR wells may wish to use wells for the purposes of production and GS prior to the field being completely depleted. EPA Notice 43502.

AWWA Response: AWWA agrees with this approach and supports the continued operation of Class II wells for EOR/EGR as long as they are still producing. However, AWWA recommends that an economic test for oil and gas reservoir “depletion” be used to determine when the Class II well should be transitioned to Class VI, and then operated under the Class VI conditions. One suggestion for determining when the reservoir has been depleted is to determine what the lowest physical amount of production would be. When oil or gas production reaches this point, the owner or operator would be required to plug the production wells and begin the application process for converting the remaining injection wells to Class VI wells. EPA needs to monitor the operation of existing Class II wells to ensure that they are not being operated as carbon sequestration projects, as there are significant differences in the permitting and operation of these two classes. Companies will try to bypass some of the Class VI construction requirements by designing and operating the system as an EOR/EGR project for a few years, and then converting it to a geologic sequestration system.

EPA Request for Comment: EPA seeks comment on the approach to grandfather construction requirements at the Director’s discretion for existing Class I, Class II, and Class V wells seeking to convert to Class VI wells, and whether additional construction requirements would be necessary to prevent endangerment to USDWs from the GS of CO2. EPA Notice 43502.Page 15 of 60 AWWA Response: The construction requirements for the other well classes may not be as stringent as the requirements for Class VI wells. AWWA recommends that in order for wells from the other classes to be used for the injection of carbon dioxide, the wells must have been constructed using methods that are at least or more stringent than the Class VI requirements. Otherwise, as stated previously, it may encourage companies to construct an EOR well under the less strict Class II rules, with the goal of running the operation for a few years and then converting to a carbon sequestration operation.

Certain operating methods for Class II wells may result in conditions that would be unacceptable for geologic sequestration. For example, EOR wells that used saltwater may be deteriorated to a point that would not be acceptable for the injection of carbon dioxide for geologic sequestration. In this case, these wells may have been constructed using different methods and materials that are not compatible with carbon dioxide. AWWA recommends that the owner/operators are required to prove that the grandfathered wells were constructed using corrosion resistant materials, and were cemented along the casing in accordance with the Class VI requirements. The well should be inspected to determine if any interior or exterior corrosion had occurred, and if so, there should be a determination that the well is not acceptable for use as a Class VI well. The review process should also include long-term demonstration by the owner/operator of the performance of the well as a Class II well. This review could provide an indication of continued prevention of USDW contamination. While these are fairly strict requirements, following this process is essential to prevent the contamination of USDWs or other source water aquifers. This should be the ultimate goal of the grandfathering process, not the prevention of additional construction costs for the owner/operator.

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

EPA Notice 43502.

AWWA Response: Grandfathered wells may not have some of the protective measures that are required in the proposed regulation, such as the down-hole shut-off valve. This valve is an important safety mechanism and AWWA believes that a Class VI well should not be permitted for carbon sequestration unless it is constructed with this appurtenance. Also, some of the potentially grandfathered wells may not be constructed in a way that would allow for the mechanical integrity testing requirements that are part of the regulation. AWWA believes that some of the very prescriptive testing and monitoring requirements are necessary, as the grandfathered wells may not have been constructed in a way that would allow for these tests to be carried out. AWWA recommends that EPA include in the final regulation a requirement that the owners/operators of the wells conclusively prove that the grandfathered wells can be operated in compliance with all the other requirements of the proposed regulation or the wells will not be permitted for Class VI operation.

Category: Injection Stream

EPA Request for Comment: By defining “carbon dioxide stream” to exclude hazardous wastes (146.81(d)), EPA’s rule, if finalized, assures that it would apply only to CO2 streams that are notPage 16 of 60 hazardous wastes as defined in 40 CFR Part 261. As a result, EPA’s proposed rule would preclude the injection of hazardous wastes in Class VI injection wells. EPA seeks comment on this approach and other considerations associated with the presence of “impurities” in the CO2

stream. EPA Notice 43503.

AWWA Response: AWWA agrees with EPA’s approach in defining the “carbon dioxide stream” to exclude hazardous wastes. However, AWWA recommends that the final regulation include more specifics on the definition of the required quality of the injection stream and establishing a minimum concentration of carbon dioxide present in the injection stream. This requirement for the injection stream will ensure that the injection of other harmful or undesirable gases is limited. Our initial thoughts on this topic would be that 100% of the injectate must come from a carbon dioxide capture process and the injectate must be at least 98% carbon dioxide. Owner/operators must ensure that the remaining 2% of the injectate is not made up of compounds that would result in the injectate being classified as a hazardous waste. Also, 100% of the injection stream should be required to come from the carbon capture process as to preclude the co-mingling of wastes from other industrial processes in the injection stream as this is not an appropriate use of the Class VI injection wells. As AWWA is not a technical expert on this topic, AWWA recommends that EPA pursue research in association with DOE to develop a standard for the minimum concentration of carbon dioxide in the injection stream.

EPA Request for Comment: Class VI requirements and permits will need to be carefully structured to ensure that they do not “authorize” inappropriate hazardous releases. This would include clarifying if there are potential releases from the well which are outside the scope of the Class VI permit. EPA requests comment on particular situations where this might occur. EPA

notice 43504.

AWWA Response: AWWA agrees with EPA’s assertion that the permits and well requirements need to be carefully structured to prevent “authorized” releases of hazardous substances into subsurface geologic formations. We are not aware of any situations where this might occur, as long as the injectate is properly characterized and is not classified as a hazardous substance. There may be a situation where a release of carbon dioxide from the confining layer might cause the formation of a hazardous substance due to reactions with the surrounding geologic strata. To prevent this problem from occurring, the geologic characteristics of the geologic formations should be evaluated prior to injection for potential interactions with the injectate stream. If there are indications that hazardous substances could be formed, the site should not be considered acceptable for carbon sequestration.

EPA Request for Comment: EPA’s proposal allows Directors’ discretion 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.

AWWA Response: AWWA recommends that EPA require tracers to be injected along with the carbon dioxide stream to provide for a better mechanism of tracking the movement of the carbon dioxide plume. Certain tracers could provide for a better understanding of the plume behavior using non-traditional indicators, such as those that are conservative, easy to measure, non-toxic,Page 17 of 60 and do not degrade into contaminants of concern. These tracers could be easily identified in USDWs, as well as in the vadose zone, where they could be used as an indicator when carbon dioxide soil-gas monitoring proves difficult to interpret. Unfortunately, AWWA can not provide recommendations on specific tracers that could be utilized, and recommends that EPA perform research, in association with DOE, on the types of tracers that would be acceptable for use in carbon sequestration.

Category: Modeling

EPA Request for Comment: EPA proposes that the owners or operators of GS wells be required to delineate the AoR for CO2 GS sites using computational fluid flow models designed for the specific site conditions and injection regime. EPA seeks comment on the use of modeling for

AoR delineation. EPA Notice 43506.

When using a proprietary model, owners or operators should clearly disclose the code assumptions, relevant equations, and scientific basis. EPA seeks comment on allowing the use of proprietary models for GS sites. EPA Notice 43507.

AWWA Response: The proposed rule depends heavily on computer modeling to track the carbon dioxide plume and demonstrate that it is contained within the confining zone. As stated by EPA, some of these models are proprietary and the rule is unclear how or if confirmation of the model results will be provided. Additionally, each of the individual proprietary models can show a different answer to the problem. Owner/operators need to ensure that their basis for the model is static, and that the basis does not change once more details are known about the movement of the plume. For example, the operation of the geologic sequestration system should be adjusted based on modeling results, and the model shouldn’t be revised because the plume is moving in a direction not originally predicted.

AWWA recommends that EPA standardize on one specific model that is transparent and available for outside stakeholders to review, including the public. The other option is for EPA to develop a standard model that would be used for all geologic sequestration projects. If EPA were to develop a standard model, a pilot program should be part of the model development so that the modeling results could be validated with real-life monitoring data. In either case, clearly stating the model assumptions made during model set-up is critical, and these assumptions must be made available to stakeholders when they are reviewing the model results.

Category: Area of Review (AoR)

EPA Request for Comment: EPA seeks comment on requiring the reevaluation of the site AoR on a periodic basis, under what conditions the AoR should be reevaluated, and the appropriateness of a 10-year minimum fixed frequency for AoR reevaluation. EPA Notice

43507.

EPA proposes to allow a phased approach to corrective action but says this may not be appropriate in all situations; therefore EPA is proposing that the Director have the discretion to decide to allow this approach, based on the understanding of relevant geologic and sitePage 18 of 60 conditions. EPA invites public comment on the merits and frequency of reevaluation of the AoR as well as the phased corrective action approach for GS wells. EPA Notice 43508.

AWWA Response: AWWA recommends that the area of review be reevaluated more frequently than suggested by EPA in the proposed regulation. AWWA recommends that the AoR be reevaluated annually for the first ten years of the project, and then every five years for the remaining operating period of the project. However, criteria should be established to trigger a shorter review period (based on a risk management approach) any time during the five-year time periods. For example, reevaluation of the AoR could be triggered by a shift in plume direction or sudden change in plume size or pressure. The local drinking water utilities, commissions, and planning boards need to be included in the AoR review process in the event that one of their drinking water sources becomes threatened due to a change in plume direction or behavior. Public involvement also needs to be a mandatory part of the AoR reevaluation process

AWWA recommends that a phased corrective action plan be developed as a result of the AoR reevaluation. This would prevent owner/operators from performing unnecessary work in the event that the plume migrates in a different direction than originally predicted. However, AWWA recommends that the required corrective actions be completed at least two years beforethe plume is expected to reach the specific location. Corrective actions should include reentering and replugging old or abandoned wells that have not been certified to be closed in accordance with the sequestration requirements. Also, in the case where old wells were plugged with cement that is not compatible with carbon dioxide, these wells should be re-entered and replugged. Finally, old wells for which no records exist should be re-entered and replugged to ensure that a pathway for carbon dioxide to escape is not provided.

One issue that EPA needs to consider in the final regulation is the potential cost differential for either performing all of the necessary corrective actions immediately or by phasing them in over time. If the corrective actions are phased in, EPA needs to require that the owner/operator provide financial assurance that the corrective action measures will still be performed even if the company goes out of business and the carbon dioxide plume continues to migrate.

Category: Permit Life

EPA Request for Comment: EPA proposes that Class VI injection well permits would be issued for the operating life of the GS project including the post-injection site care period. EPA seeks comment on the merits of this approach. EPA Notice 43523.

AWWA Response: AWWA does not support issuing an operating permit for the life of the sequestration site. AWWA recommends issuing a lifetime operating permit for the coal plant, but with a separate and renewable permit for the operation of the geologic sequestration process. Much like the wastewater treatment plants and NPDES permits go through a permit review process every five years, AWWA recommends that this same process be used for operating permits for geologic sequestration processes. For water and wastewater treatment plants, the operating permit is issued at the start of operation and the plant must renew it every five years. This allows for the expansion of plant flow, and changes in required effluent criteria due to regulation modifications. Much as water and wastewater plants are required to keep up withPage 19 of 60 available technology, carbon sequestration systems should be required to apply BACT when it is feasible to incorporate it into the treatment process. Owner/operators should also be required to periodically re-evaluate their injectate stream for any emerging contaminants, and remove them if required. If wastewater treatment plants can be constructed and operating using this type of process, then a sequestration operation should be permitted in the same manner. Process changes are part of standard business operation in that regulations become more stringent, and processes become more efficient, and the owner/operators should be required to adapt to these changes through the permit renewal process.

AWWA recommends that the application process include a review of the site operations to see if any instances of unsafe operation or changes in regulation would require a change in the plant operation. If a problem were detected, the permit wouldn’t be immediately revoked, but the operator would be given the chance to rectify the situation so that the permit could be reissued. An owner/operator should consider the financial implications of this requirement and plan accordingly as the process will require a certain level of effort every five years to execute. AWWA recommends that the permit review process be aligned with the process used for review and renewal of NPDES permits. This would allow for all of the permit activities to be consolidated into one reapplication effort every five years.

The capacity of the various state agencies to deal with the five year permit review process is an issue that needs to be recognized. Some states that are already stressed for resources could be overwhelmed with this additional task. However, AWWA believes that this permit requirement should not be sacrificed because the states might be resource stressed. Therefore, the federal government should consider allocating enough money to the state programs to adequate staff their sequestration permit division

Group: Well Construction

EPA Request for Comment: EPA seeks comment regarding requirements for degradationresistant well construction materials, such as acid-resistant cements and corrosion resistant casing. EPA Notice 43510.

EPA seeks comment on the merits of requiring down-hole shut-off valves in GS wells. EPA

Notice 43511.

AWWA Response: AWWA recommends that injection wells be constructed from degradationresistant materials to prevent carbon dioxide from escaping from a portion of the injection well that may have been compromised due to non-compatible materials. AWWA also recommends that down-hole shut-off valves be required for all injection wells. These valves can be a first line of defense against contamination of USDWs due to faulty injection practices. Further research is needed by both EPA and DOE to identify specific construction methods that would prevent degradation of the well and the carbon sequestration site. AWWA recommends the creation of a certification program that would be used to guarantee that existing or newly developed construction methods are approved for use with geologic sequestration.Page 20 of 60 Category: Hydraulic Fracturing

EPA Request for Comment: EPA is requesting comment on the extent and scope to which hydraulic fracturing should be allowed during GS injection, and whether the use of fracturing for the purposes of well stimulation is appropriate. EPA Notice 43511.

AWWA Response: Hydraulic fracturing during carbon dioxide injection has the potential to serious compromise the confining layer and AWWA recommends that this practice should not be allowed as part of the injection process. The objective of characterizing the injection and confining zones is to find a location that is free from faults, penetrations or other physical methods by which carbon dioxide could escape. Hydraulic fracturing creates fractures in the injection zone, and possibly the confining layer, which would allow for a pathway by which carbon dioxide could migrate into USDWs. Therefore, AWWA recommends that this process not be utilized at all in geologic carbon sequestration.

Category: Monitoring

EPA Request for Comment: EPA’s proposal would require owners or operators of Class VI GS projects to monitor internal mechanical integrity of their injection wells by continuously monitoring injection pressure, flow rate, and injected volumes, as well as the annular pressure and fluid volume to assure that no anomalies occur that may indicate an internal leak. EPA requests comment on the practicability of this requirement. EPA Notice 43513.

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

43514.

EPA seeks comment on the requirement for monitoring of GS sites for the purpose of tracking the location of the CO2 plume and associated pressure front over time. EPA Notice 43514

EPA’s proposal would require that owners or operators perform a pressure fall-off test at least once every five years. EPA seeks comment on the use and frequency of pressure fall-off testing

for GS wells. EPA Notice 43515.

Specifically, EPA seeks comment regarding the usefulness of indirect geophysical monitoring and surface air and soil gas monitoring. In addition, EPA seeks comment regarding the use of a Director-approved monitoring plan for GS sites. EPA Notice 43517.

AWWA Response: Detailed monitoring guidelines were developed as part of a joint research project by AwwaRF and AWWA. These guidelines are provided in Section III of these comments and EPA should include the named tests and frequencies in the final regulation to ensure that protection of USDWs is consistent across all geologic sequestration projects. Based upon these requirements, owner/operators would develop testing and monitoring plans, which should be reviewed and updated at the same time as the re-evaluation of the Area of Review. The costs associated with monitoring of a sequestration project should not be a major consideration when determining the types and frequency of required monitoring. The goal of thePage 21 of 60 monitoring requirements should be on preventing degradation of USDWs, not minimizing the cost to the owner/operator.

AWWA strongly recommends both that both internal and external mechanical integrity testing should be required to prevent leakage of carbon dioxide from the injection well. Monitoring of the plume and pressure front over time is absolutely required as part of the system operation and a project shouldn’t even be considered unless this monitoring is included. All of the monitoring requirements should be put forth in a monitoring plan, which should be reviewed and approved by the Director prior to the start of the project. This plan should be re-evaluated every five years during the permit review, and should be updated by the owner/operator based on any changes in operation or performance of the carbon dioxide plume.

Pressure fall-off testing should definitely be required however the five year length between testing is too long. This should be performed on an annual basis as part of the annual reporting requirements

Surface air and soil gas monitoring should be required however, baseline soil carbon dioxide levels should be determined prior to the start of monitoring. Testing for other compounds such as tracers that may included as part of the carbon dioxide injectate stream should also be considered in the development of the monitoring plan.

Category: Required Project Plans

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

AWWA Response: The requirement for the development of plans for monitoring, AoR, and post-injection site care is necessary and is a very important part of the permit process. The information will provide outside stakeholders with a much better idea of how the project will proceed and can help to assure them that the owner/operator has a clear vision for the life of the project. AWWA recommends that these plans be reviewed at the same time that the area of review is reevaluated. During this review, the plans should be updated based on any operational changes since the last project review period and submitted to the Director for approval. AWWA recommends that a review occur every year for the first ten years of the project, and then should be reviewed every five years until injection ceases.

EPA Request for Comment: EPA seeks comment on the frequency of all proposed reporting requirements. EPA Notice 43517

AWWA Response: AWWA recommends that the owner/operators of a Class VI well provide a monthly operating report to the Director instead of the semi-annual report as proposed. The operating information for the geologic sequestration project is extremely important and needs to be reviewed at a frequency by the regulatory agency to ensure problems are identified and addressed in a timely manner. For example, based on the proposed regulation, data collected on July 1, 2008 would not be seen by the regulatory agency before January 15, 2009, if the operator is allowed 15 days to submit the report. This would allow for very little time to correct anyPage 22 of 60 potential issues in the operation of the project. We have provided example monthly reporting sheets that were developed as part of the AwwaRF project in Section III of our comments, and these reports are similar to the monthly reporting sheets used by water and wastewater treatment plants. Given the potential scale of carbon sequestration and the need to protect groundwater resources, a requirement for monthly operating reports is reasonable.

With respect to the requirement for recordkeeping, AWWA recommends that the one-year holding requirement for the plugging and abandonment report be extended. This is an extremely important report, and the owner/operator must be required to keep this report on file for a minimum of 10 years following the closure of the project site.

EPA Request for Comment: EPA seeks comment on the requirement for electronic reporting in its proposed rule. EPA Notice 43518.

AWWA Response: AWWA agrees with the electronic reporting requirements include as part of the proposed regulation. Electronic reporting allows for easier tracking of the operating data to observe any trends that might indicate potential contamination of a USDW. EPA should consider the infrastructure that will be required to collect information prior to publishing the first report and develop a model reporting plan for owner/operators to use when submitting data to state agencies.

EPA Request for Comment: In addition to the above recordkeeping and reporting requirements, EPA considered a requirement for owners or operators of GS sites to provide an annual report during the lifetime of the project, including the post-injection period, regarding the GS operation. Although EPA has not included a requirement for this report in its proposal, EPA seeks comment regarding the necessity for such an annual report. EPA Notice 43518.

AWWA Response: AWWA recommends that an annual reporting requirement be included in the proposed regulation. This report should summarize the operation of the system including standard operating criteria, information on well operation, details of plume movement, and any details on major changes in well operation. It should be similar to the Consumer Confidence Reports (CCR) that drinking water utilities must develop and it should be mailed or emailed to all relevant stakeholders. EPA should develop requirements for the report similar to those required for the CCR because the annual report should be developed by someone one of the team members involved in the operation of the geologic sequestration project.

Category: Post-Injection

EPA Request for Comment: EPA requests comment on the proposed use of a tentative 50-year fixed timeframe that could be modified at the Director’s discretion based on monitoring and modeling data. EPA Notice 43519.

EPA is requesting comments on the proposed requirements for well plugging, post-injection site care, and site closure, including the proposed requirements for the post-injection time period.

EPA Notice 43520.Page 23 of 60 AWWA Response: AWWA recommends that the time period for post-injection site care be set at a minimum of 50-years and that the Director not be given any discretion to shorten this time period. After this 50-year period, the operator must continue to monitor until such time as they can demonstrate that the plume has stabilized and that it does not present any potential danger to USDWs or other potential sources of drinking water. This requirement is not overly prescriptive or burdensome given the information available on the long-term behavior of carbon dioxide plumes. This time period is necessary to monitor the site for changes that may occur over a longer amount of time, such as gradual leakages, fault movement, or sudden seismic shifts. After this time period, the owner/operator may apply to the Director for a modification or termination of the monitoring requirements.

AWWA has observed that the proposed regulation is lacking in details on the requirements to demonstrate that the carbon dioxide plume has stabilized. For example, the proposal does not include requirements that the plume pressure must be constant for a certain number of years or that the plume has not migrated for a set period of time. Since AWWA does not claim to be experts on the behavior of carbon dioxide plumes and can not provide recommendations on this topic, AWWA recommends that EPA should engage in research on determining exactly what these criteria should be. For example, when referencing lack of plume movement, what should the trigger time period be (no movement of plume for 10, 15, 20 or more years??). AWWA recommends that EPA clarify what is an acceptable frequency for a lack of change in the plume characteristics and also needs to clarify plume stabilization as this issue could be interpreted differently by different states. Guidance should be prepared by EPA on this topic so that there is consistent application of this requirement across all sequestration projects. A performance based system could also be developed that would require the operator to meet certain criteria to prove that the plume has stabilized. This could be used to justify the closing of the site after the 50-year period of post-injection site care has elapsed. This would allow for a process where long-term monitoring decisions are made in response to the specific characteristics of each project.

AWWA believes that the proposed post-injection site care requirements have been established to prevent endangerment to USDWs. Carbon dioxide can potentially leak from the confining layer into other aquifers that, while not classified as USDWs, may still be considered drinking water sources in some areas of the county. EPA should also consider including requirements inthe regulation to address the potential for endangerment of these aquifers during the postinjection period. Monitoring requirements should be extended to cover these aquifers, and the post-injection site care plan should include provisions for the protection of aquifers that are not classified as USDWs, but are still considered a future drinking water source.

Category: Financial

EPA Request for Comment: Because of the possibility that the owner or operator may face financial distress prior to the trust being fully funded, EPA is considering a guidance approach that would recommend adopting a pay in period of three years for GS projects, consistent with other similar programs in the Agency. EPA Notice 43521.Page 24 of 60 EPA is assessing whether 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.

EPA is requesting comments on whether financial responsibility mechanisms to be recommended in EPA guidance should be adjusted in the manner described, whether additional instruments should be included, and whether other adjustments to the financial responsibility mechanisms should be considered, all subject to EPA’s authority under the SDWA. EPA Notice

43522.

AWWA Response: AWWA has several major concerns regarding owner/operator financial assurance and liability. Our primary concern is that the liability mechanism that would be triggered when the confining zone fails and carbon dioxide escapes has not been identified. Would this incident trigger CERCLA requirements if groundwater is degraded? AWWA recommends that the liability requirements and financial mechanisms that were used to address MTBE contamination be applied to any USDW degradation from carbon sequestration activities. The definition of a “corrective action” does not provide any protection for aquifers that are contaminated by the carbon sequestration process. The definition as provided in the proposed rule states that corrective action is “...the use of Director approved methods to assure that wells within the area of review do not serve as conduits for the movement of fluids into underground sources of drinking water (USDW).” Note that this definition does not address “fixing” the impact to USDW. What is unclear to AWWA is if the geologic sequestration process does endanger groundwater aquifers, whether the owners/operators have any financial liability in restoring water quality (e.g., paying for extra treatment costs incurred by water utilities or other groundwater users), as the corrective action seems to focus on fixing injection wells and/or the confining layer.

The question remains regarding what an owner/operator’s total liability would be outside of the USDW contamination. The potential exists for contamination of other ground water aquifers, such as those that are not classified as USDWs but are used as a drinking water sources, and it is extremely important that the liability requirements are extended to these aquifers. The cost to remediate any degradation can be extremely high. Depending on the scope and location of the degradation, examples of potential costs that might be incurred by a drinking water utility include the installation of advanced water treatment technologies and/or development of alternative water sources. The responsibility for these costs must be assumed by the owner/operator in the event of a failure of the geologic sequestration process.

AWWA believes that the time limit for financial responsibility in the proposed regulation may be too long for most insurance agencies, which may trigger the need for the development of a trust fund or for owner/operators to use a self-insurance mechanism. If the trust fund is the desired method, EPA should require that companies constantly add to the fund, even if it appears that the fund is fully funded. In addition to the initial pay in period of three years, owner/operators should be required to pay in any additional amount identified during the five-year reviews for the area of review and corrective action plan, injection well plugging plan, the post-injection site care and site closure plan, and the emergency and remedial response plan. This additional pay in is required so that we don’t have a repeat of the funding stoppage with the Superfund program.Page 25 of 60 AWWA questions whether it would be acceptable for energy companies and owner/operators to bond projects as a way to demonstrate financial assurance. AWWA recommends that EPA develop formal technical, managerial, and financial requirements for carbon sequestration projects that owner/operators must meet and maintain. This should be tied to the permitting process as these requirements must be demonstrated prior to the operating permit being issued. Demonstrating ongoing technical, managerial, and financial capabilities would be an important component of the five-year permitting review process that AWWA is recommending.

With respect to the required financial mechanisms, AWWA would like to leave the door open for establishing financial mechanisms on a project by project basis. The rulemaking should not prescribe or preclude particular financial instruments as the issue of financial assurance is very complex. Other funding models could be developed, and it may be that Moodys or Standards and Poors will see this as a potential opportunity. Many significant financial details remain that must be addressed before any guidance or regulation is issued on this topic. As an example, the issue of long-term liability still has not been resolved. Who is ultimately responsible for ownership of the injection wells and the carbon dioxide plume after the post-closure period has ended? Does the liability transfer to whoever manages the trust fund (in that particular financial assurance mechanism)?

AWWA would also like to see the issue of long-term liability resolved. EPA’s proposed geologic carbon sequestration rule is not able to address financial responsibility of the sequestration site after the formal period of post-injection site care has ended (default of 50 year length). Recognizing that EPA does not have the power to assign responsibility after this period of time has expired, AWWA recommends that EPA work with the appropriate stakeholders to develop legislation that will address the issue of who has to assume financial responsibility of the sequestration site after the site closure requirements have been fulfilled. AWWA anticipates that this legislation would provide for a means by which drinking water utilities could recover any costs incurred as a result of USDW contamination by geologic carbon sequestration activities. AWWA also recommends that EPA work with the appropriate stakeholders to develop comprehensive climate change legislation with the goal of protecting water systems, and their customers, from loss of water supply or unplanned major financial burdens. Everyone needs to apply the lessons learned from MTBE contamination to prevent unintended consequences from developing with geologic sequestration wells.

Category: State Capacity

EPA Request for Comment: EPA seeks comment on any aspects of the ongoing State efforts to regulate the GS of CO2 and how these efforts might be used to better inform a final Federal rulemaking. EPA Notice 43497.

AWWA Response: From our perspective, EPA’s proposed rule appears to be focused on preventing brine from formations where carbon dioxide was stored from reaching USDWs and/or from preventing carbon dioxide that reaches USDWs from causing primary MCLs to be exceeded. This focus may not be adequate from the standpoint of protecting source water and beneficial use aquifers from detrimental changes in water quality other than the exceedance ofPage 26 of 60 primary MCLs. Other water quality impacts could be observed such as increased concentrations of iron, manganese and TDS, as well as lowered pH, all of which have secondary MCLs. Increases in the concentrations of silica and boron, which do not currently have MCLs but can significantly degrade water quality, are also likely to occur.

This past year, the State of Washington adopted carbon sequestration regulations which AWWA recommends that EPA review and incorporate some of the language into the final regulation. The Washington regulations require that the owner or operator must demonstrate that the “design and construction standards of all facility structures and wells are sufficient to prevent migration of carbon dioxide or nonpotable water that will degrade water quality or impact beneficial uses outside the geologic containment system.” The language in this regulation provides protection mechanisms for groundwater sources that may not be used as USDWs but have other beneficial uses, such use as industrial applications or agriculture. Given the stresses that the drinking water industry is facing with respect to water resources, AWWA recommends that the monitoring requirements in the final rule be extended to protect against aquifer contamination beyond that which is associated with compounds that have primary MCLs.

EPA Request for Comment: EPA is seeking comment on the merits and possible disadvantages of allowing primacy approval for Class VI wells independent of other well classes. EPA Notice

43523.

AWWA Response: AWWA recommends that a state be able to administer only Class VI well permits, if they so desire. The Class VI well program is a very specialized class, which has major differences from all the other well classes. A state that decides to apply for primacy of the Class VI wells only would be able to specialize in this well class, and could develop and execute a very detailed program. The state would have an advantage in that the state staff would be very familiar with the regional geology, water resources and business operations in the areas proposed for geologic sequestration. One disadvantage could be seen if the applying state had never held primacy for any of the other classes of wells. Since this is a fairly specialized class, there could be some logistical issues in the beginning stages of the state administering the program. However, AWWA believes that these issues could be addressed through consultation with either the federal EPA offices, or in discussions with other states that are administering the Class VI program. In our opinion, the benefits associated with state primacy, such as a more in depth knowledge of the state geology, operations and politics far outweighs any minor implementation issues that might be associated with a state having primacy approval for only Class VI wells.

Other AWWA Comments Related to State Primacy and Capacity: When EPA allows states to obtain primacy for the Class VI wells and develop their own regulations for geologic sequestration, these regulations must be developed in accordance with Section 1422 of the SDWA instead of Section 1425. The language in Section 1422 mandates that state requirements for geologic sequestration be as stringent as federal requirements. By comparison, the language in Section 1425 mandates that the state requirements represent an “effective” program to prevent injection which endangers drinking water sources. The language in Section 1425 leaves too much room for interpretation, and could result in varying degrees of protection of USDWs across the country. Given the current strain on our groundwater resources in some areas of the UnitedPage 27 of 60 States, AWWA recommends that EPA ensure state regulations provide at least the same level of protection as the federal regulations.

AWWA recognizes that the SDWA currently provides for a $16 million statuary limit for federal support to states to enact and enforce the Act. Given that state primacy agencies are already resource limited and are inadequately funded to cover existing oversight responsibilities, AWWA anticipates that this regulation could place an even larger burden on them. Geologic carbon sequestration will require new resources, and in addition, staff with very specialized expertise in areas such as groundwater, wells, geochemistry, and underground injection. Inadequate resources and staff capabilities will result in delayed permit reviews/approvals and/or rushed and poor decision making. AWWA recognizes the funding limitation for the state primacy programs and this is an issue that Congress would have address either through a modification of the SDWA or by a revenue set-aside as part of a future "cap and trade" program. As a result, AWWA recommends that EPA consider the potential burden on state programs when finalizing the regulation and look for ways to streamline the process without sacrificing the protective measures of the regulation.

Category: Public Participation

EPA Request for Comment: EPA requests comment on adopting the existing requirements for public participation at 40 CFR Part 25 and 40 CFR Part 124 and whether additional requirements should be included to reflect the availability of new tools for disseminating and gathering information. Such tools include cable networks, the Internet, and other new technology. EPA

Notice 43523.

AWWA Response: 40 CFR 124 does not include a requirement for public notification when a request is made to modify, revoke and/or reissue an operating permit for a geologic sequestration project. It also does not provide for mandatory public hearings, as the regulations states that it is up to the discretion of the Director unless a hearing is specifically requested by a stakeholder. AWWA disagrees the omission of with these requirements and recommends that both of these activities be recognized as mandatory during the permit development, review, and approval processes for geologic sequestration projects.

Most of the geologic sequestration projects will be located in rural areas where the local water utility is very small with limited staffing and funding resources. While these utilities may be impacted by the projects, they may not have the technical ability to adequately participate in a project review. Therefore, AWWA recommends that as part of the public participation requirements, owner/operators should be required to notify and involve national and state drinking water organizations as well as the local water utilities. This would allow the local utility to be supported technically by the staff of the national organization, which can provide technical expertise in drinking water issues related to carbon sequestration.

Each project should be required to establish public advisory groups, such as those created for some of the regional carbon sequestration partnership projects. Owner/operators need to ensure they identify stakeholders groups from water sector, such as rural water associations,Page 28 of 60 groundwater associations, and drinking water utility associations. These groups would be involved in the project from the beginning and provide the stakeholder voice for the project.

AWWA recommends that the public comment period for the permit review process be extended in the final regulation. Due to the technical nature of the geologic sequestration process, AWWA recommends that the comment period be extended from 30 days to 90 days. A 30 day comment period does not provide enough time for outside groups to obtain the permit, perform a detailed technical review and generate comments. Extending the comment period for 90 days allows the stakeholders to perform a much more comprehensive review of the project.

The issue of environmental justice must be appropriately considered when involving the public in geologic sequestration projects. Consideration should be given to ensure that certain populations aren’t repeatedly subjected to the problems that may arise from the sequestration projects. It is also necessary to remember that not everyone has access to the same media outlets. When an owner/operator is advertising public hearings or comment periods, they should be required to utilize all forms of media, including the newspaper, radio, television and internet. The general public has a wide range of media-viewing habits, and many have moved away from

some of the more traditional communication methods.

Category: Cost Analysis

EPA Request for Comment: The Agency assumes three monitoring wells per injection well for the purpose of estimating national costs; however, the Agency recognizes that operators and primacy agency Directors may choose more or fewer monitoring wells depending on project site characteristics. Because the monitoring wells and associated costs represent a significant component of the Cost Analysis, the Agency acknowledges that this factor may be significant in the overall uncertainty of the Cost Analysis. EPA requests comment on whether three monitoring wells per injection well is an appropriate costing assumption. EPA Notice 43527.

AWWA Response: AWWA does not agree with the assumption to use three monitoring wells per injection well as the standard for the cost analysis. This number seems very low given the amount of area that would be covered by one injection well. Requiring three monitoring wells for an injection well that might be associated with a carbon dioxide plume stretching for over a mile seems like a drastic underestimate of the necessary monitoring. AWWA recommends that the requirement be based more on the projected plume performance and the potential interactions with USDWs or other important geologic formations.

Other cost estimates have indicated that, in the overall cost of the project, monitoring is a very small percentage of the total project cost as compared to those associated with the capture and transport processes. This conclusion is contrary to EPA’s cost estimate, and AWWA is concerned that the EPA’s high cost numbers for monitoring may be used to attempt to reduce the monitoring requirements and lower the overall project cost. AWWA recommends that the cost estimate be revised at a later date based upon data that becomes available from the DOE pilot projects. These projects might identify additional well construction costs, as well as be able to provide a better understanding of how the cost of monitoring compares to the rest of the project.Page 29 of 60 III. MONITORING GUIDELINES FOR GEOLOGIC CARBON SEQUESTRATION

PROJECTS

This monitoring guideline has been designed to aid in the development of project specific monitoring plans designed to reduce risk and uncertainty and demonstrate compliance throughout the project life cycle including site characterization, operation and closure.

This guideline was developed as part of the American Water Works Association Research Foundation Project No. 4203, which was partially funded by the American Water Works Association. Information included in this monitoring guideline was obtained from the combined experience of the consultants and these primary sources:

1) EPA’s proposed requirements under the underground injection control program from carbon dioxide geologic sequestration (EPA, 2008); 2) EPA’s guidance on systematic planning using the data quality objective process (EPA, 2006); and, 3) The International Panel on Climate Change special report on carbon dioxide capture and storage (IPCC, 2005).

1.0 CHARACTERIZATION

During the characterization phase of a Geologic Carbon Sequestration (GCS) project, measurements should be collected to establish a baseline for comparison with monitoring measurements made during the injection and post-injection phases. The data collected about these background conditions should characterize not only the injection formation but also the confining unit(s), horizons above the injection zone and below the lowermost USDW above the injection zone, and other USDWs encountered. Data collected about each formation should

include:

 Thickness

 Lateral extent

 Porosity

 Permeability

 Mineralogy

 Geochemistry (including analyses for all EPA Primary and Secondary drinking water constituents, and other constituents of interest)

To anticipate potential leakage pathways from the injection formation into any USDWs, the following additional data should be collected about the confining unit(s):

 Existing faults and fractures

 Discontinuities and pinch-outs

 Existing manmade penetrations

 Potentially seismically active zones

 Rock stress

 Rock strengthPage 30 of 60 Furthermore, the vadose zone and surface gas compositions should be characterized sufficiently such that natural temporal changes in these compositions can be differentiated from any future changes due CO 2 leakage.

Background water samples are to be obtained from all monitor zones and the injection zone. Prior to sampling, the horizons are to be fully and properly developed. After development, a minimum of three well volumes is to be purged before samples are collected. The samples are to be analyzed for a variety of constituents to establish the "natural" or background quality of the water. The analysis is to include USEPA Primary and Secondary drinking water Standards, Unregulated Organic Contaminants and other groundwater monitoring parameters (e.g., silica and boron).

2.0 MONITORING PLAN

The owner/operator of a GCS project should prepare a monitoring plan prior to the start of injection. The plan should be created using the baseline characterization data in order to choose the most effective monitoring technologies and monitoring locations. The monitoring plan

should:

 Be designed to minimize risk to USDWs

 Include both operational and environmental monitoring

 Describe the specific monitoring technologies to be used and how they will be effective

 Include the timing of sampling and monitoring

 Include sample data recording forms (examples attached)

 Include how the monitoring data will be used to update site models and how the updated models will be used to update the monitoring plan

 Be designed to demonstrate compliance with standards or “triggers”

The plan should be developed following EPA’s Guidance on Systematic Planning Using the Data Quality Objective (DQO) Process (EPA, 2006). Figure 2-1 illustrates that the DQO process is a series of logical steps that guides managers and staff to a plan for the resource-effectiveacquisition of environmental data. It is both flexible and iterative, and applies to both decisionmaking (e.g., compliance / non-compliance with a standard) and estimation (e.g., ascertaining the mean concentration level of a contaminant). Each step defines criteria that will be used to establish the final data collection design. The first five steps are primarily focused on identifying qualitative criteria, such as:

 Nature of the problem that has initiated the project and a conceptual model of the environmental hazard to be investigated;

 Decisions or estimates that need to be made and the order of priority for resolving them;

 Yype of data needed; and

 Analytic approach or decision rule that defines the logic for how the data will be used to draw conclusions from the project findings.Page 31 of 60 The sixth step establishes acceptable quantitative criteria on the quality and quantity of the data to be collected, relative to the ultimate use of the data. These criteria are known as performance or acceptance criteria, or DQOs. In the seventh step of the DQO Process, a data collection design is developed that will generate data meeting the quantitative and qualitative criteria specified at the end of Step 6.

The site model and risk models should be updated as frequently as new data is collected about the plume. Based on these updated models and the performance of the site, the monitoring plan should also be updated and the monitoring operations should be adapted as necessary.Page 32 of 60 Figure 2-1: The Data Quality Objective Process (EPA, 2006)Page 33 of 60 3.0 MONITORING DATA

The following recommendations should be carried out conscientiously to ensure successful operation of the well:

 Monitor well pressure is to be continuously monitored

 Injection wellhead pressure is to be continuously monitored

 Flow to the injection well is to be continuously monitored

 Monitor well water quality is to be monitored weekly

 Injection well injectivity tests are to be performed monthly

 Injection stream parameters are to be monitored weekly

 A complete analysis of the injection stream is to be performed annually

 Injection well mechanical integrity tests are to be performed annually

When the injection well is operational, a variety of data will be collected during both the initial testing and long-term operation of the injection well system. It is essential that the performance data collection begin upon operational startup to establish baseline information that serves for future data comparison and performance analyses.

3.1 Injection Formation Analysis

During site characterization and during startup testing, samples from the injection formation are be collected and analyzed for pH, alkalinity, TDS/EC, major cations and anions, trace metals, dissolved organic carbon, total organic carbon, silica and boron. The suggested water quality analyses are listed in Table 3.1-1.Page 34 of 60 Table 3.1-1: Suggested Annual Water Quality Analyses of the Injection Formation

General Constituents Trace Metals
pH Aluminum
Alkalinity Antimony

TDS/EC Arsenic

Calcium Asbestos
Magnesium Barium

Potassium Beryllium

Sodium Cadmium

Bicarbonate Chromium

Chloride Copper

Sulfate Copper

Other Constituents Cyanide

Nitrate Fluoride
Dissolved organic carbon Iron
Total organic carbon Lead

Silica Manganese

Boron Mercury

Sulfide Nickel

Selenium

Silver

Sulfate

Thallium

Zinc

3.2 Injection Well Data Collection

The owner/operator must provide operational monitoring during the injection period to ensure that the physical and chemical properties of the injected CO 2 stream are measured and recorded. Beginning with the start of injection, injection records should be maintained to evaluate injection well performance.

The pressure at the injection wellheads is to be continuously monitored and recorded. Daily average, maximum and minimum pressures are to be reported monthly. The internal and external integrity of the well and the injection pressure must also be monitored to ensure that the confining properties of the well and the project are maintained.

The flow rate into the injection well is to be continuously monitored and recorded. Daily average, maximum, and minimum flow rates, as well as the total volume of fluid pumped into the well are to be reported on a monthly basis.Page 35 of 60 All pressure gauges, flow meters, chart recorders and any other equipment associated with the injection well monitoring system are to be calibrated on a semiannual basis using standard engineering methods

The physical injection well performance characteristics to be recorded include:

Flow Rate Parameters

 average daily flow rate to injection well as measured from flow meter

 daily maximum sustained (15 minutes minimum) flow rate to injection well

 daily minimum sustained (15 minutes minimum) flow rate to injection well

 monthly average of the daily flow rates to injection well

 monthly maximum (peak hour) flow rate to injection well

 monthly minimum flow rate to injection well

Volumetric parameters

 total daily effluent to injection well from as measured from totalizer

 total monthly flow volume to injection well

 monthly average of the daily flow volumes to injection well

 monthly maximum of the daily flow volumes to injection well

 monthly minimum of the daily flow volumes to injection well

Wellhead pressure parameters

 daily average injection pressure at injection well (psig)

 daily maximum sustained (15 minutes minimum) injection pressure at injection well (psig)

 daily minimum sustained (15 minutes minimum) injection pressure at injection well (psig)

 monthly average injection pressure at injection well (psig)

 monthly maximum sustained injection pressure at injection well (psig)

 monthly minimum sustained injection pressure at injection well (psig)

 monthly wellhead pressure with no flow (shut-in pressure, psig)

Annulus pressure parameters

 daily average annular pressure at injection well (psig)

 daily maximum annular pressure at injection well (psig)

 daily minimum annular pressure at injection well (psig)

 monthly average annular pressure at injection well (psig)

 monthly maximum annular pressure at injection well (psig)

 monthly minimum annular pressure at injection well (psig)

The monitoring equipment should be designed so that manual backup capability to monitor pressure will be provided for systems utilizing automatic and continuous recording devices.Page 36 of 60 3.3 Monitor Well Data Collection

Water quality should be monitored in the first porous zone above the primary confining unit, within and near the base of the lowermost USDW above the injection zone, and in any other USDWs that may be affected by CO 2 injection as determined during risk assessment.

The purpose of monitor zone data collection is to detect changes in water quality attributable to the injection fluids into the nearby injection well. To collect the water quality samples, the monitor wells will be equipped with sampling pumps. Prior to collecting water samples for analysis, at least three well volumes have to be pumped from the monitor zones. In addition to collection of samples for analysis of constituents listed on Table 1, monitoring well water quality is to be monitored through weekly and monthly samples during system startup for a smaller suite of constituents. Once startup testing has been completed, it may be feasible to decrease the sampling frequency. Samples are to be collected and analyzed weekly, monthly, and annually

are shown in Table 3.3-1.

Table 3.3-1: Water Quality Monitoring

Parameters Reporting Frequency
Specific Co nductivity (μmhos/cm) Weekly
Total Dissolved Solids (mg/L) Weekly
pH (std. units) Weekly
Chloride (mg/L) Weekly
Sulfate (mg/L) Weekly
Field Temperature (°C) Weekly
Ammonia (mg/l) Weekly
Total Kjeldahl Nitrogen (TKN) (mg/L) Weekly
Alkalinity (mg/L) Weekly
Sulfide (mg/L) Weekly
Mercury (mg/L) Monthly
Lead (mg/L) Monthly
Sodium (mg/L) Monthly
Calcium (mg/L) Monthly
Potassium (mg/L) Monthly
Magnesium (mg/L) Monthly
Iron (mg/L) Monthly
Bicarbonate (mg/L) Monthly

Silica Annually

Boron Annually
Gross Alpha Activity Annually

Once startup testing has been completed, it may be feasible to decrease the sampling frequency.Page 37 of 60 These data should be presented on time-series plots so that temporal trends are easily observed. If increases in dissolved organic or total organic carbon are observed, more detailed sampling should be performed to characterize the nature and extent of contamination.

The pressure in each monitor well is to be continuously monitored and recorded relative to feet NGVD or in psi. Pressures are to be reported as follows.

 daily maximum pressure or water level (as appropriate)

 daily minimum pressure or water level (as appropriate)

 daily average pressure or water level (as appropriate)

 monthly maximum pressure or water level (as appropriate)

 monthly minimum pressure or water level (as appropriate)

 monthly average pressure or water level (as appropriate)

3.4 Injectivity Testing

Periodic determination of the injectivity of a well is used as a measure of the efficiency of a well. An injectivity test involves injecting fluid into a well at three (or more) injection rates and recording the injection pressure for each rate. The shut-in pressure of the injection well is to be measured before each different injection rate. The injectivity is calculated by dividing the injection rate by the required injection pressure (wellhead injection pressure minus shut-in wellhead pressure). The result is expressed as gallons per minute per pounds per square inch (gpm/psi). Factors affecting the injection wellhead pressure are a function of:

 The density differential between the injected fluid and the formation water in the injection zone

 The friction loss in the casing

 The bottom hole pressure (injection zone transmissivity)

The density differential is fairly constant as long as the temperature and density of the injection and formation fluids remain constant. Friction loss in the casing and bottom hole pressure can vary as a result of changes in the flow rate, the physical condition of the injection zone and the physical condition of the pipe. In general, pressure builds up slowly with time (for a given pumping rate) as the casing "ages". Similarly, plugging of an injection zone can cause a gradual pressure build-up over time. Testing should be conducted quarterly for the life of the well. The testing rates for injectivity testing should be established as soon as the well is put into operation. The testing procedure should be chosen so that it is easily repeatable.Page 38 of 60 4.0 WELL INTEGRITY MONITORING

The integrity of the injection well must be monitored to ensure that the well does not become a conduit for fluid movement that could endanger USDWs. An injection well has mechanical integrity when there is no leak in the casing and no fluid movement into the underground source of drinking water through channels adjacent to the well bore. Mechanical integrity testing includes a pressure test, a radioactive tracer survey, a high-resolution temperature log and a television survey. This testing will be used, along with the monitoring data of the monitor zones, to demonstrate the absence of fluid movement above the injection zone. The injection wells are to be tested for mechanical integrity annually.

The internal mechanical integrity must be monitored to ensure that no fluids can move from the well into any formation other than the injection formation. The external mechanical integrity must be monitored to ensure that there is no significant movement of fluids between formations.

The owner/operator must perform an internal mechanical integrity test (e.g. an annular pressure test) prior to the start of injection. Such a test must also be performed prior to the restart of injection after removing the injection tubing for a workover or any other activity. Although the owner/operator must continuously monitor the pressure in the fluid- filled annulus between the long string casing and the injection tubing to ensure that there is no leak, an annual pressure test should also be conducted. A pressure gauge with a maximum of 1 psi increments that is accurate to one quarter of 1 percent of full-scale deflection will be mounted on the temporary wellhead. The gauge will have previously been calibrated. Calibration will have been conducted on the gauge within a period of three months prior to the date of use. The annular space will be pressurized to 150 percent of the design maximum injection pressure. Pressure readings will be recorded every 5 minutes for a 1-hour period. The pressure must not vary by more than 5 percent during the 1-hour testing period.

The internal integrity of the well should also be verified by corrosion monitoring of the injection tubing. This can be accomplished by comparing a baseline measurement with subsequent annual monitoring measurements made using corrosion logging tools. If the components of the injection stream warrant, the owner/operator should perform quarterly monitoring of the internal well materials for corrosion, change in mass, and change in thickness. This may be done by placing representative samples of the material in contact with the injection stream.

The external mechanical integrity of the well must be regularly monitored to ensure that it does not allow leakage of fluids between formations that could endanger USDWs. The external mechanical integrity of the well must be tested annually using logs or surveys capable of detecting fluid movement between the long string casing and the adjacent formation(s). Such logs and surveys include:

 Tracer surveys

 Oxygen activation logs

 Noise logs

 Temperature logs.Page 39 of 60 Prior to the start of injection, and every 5 years after injection, the owner/operator must evaluate the quality of the cement around the long string casing. This can be done using a technology that is capable of radially mapping the cement and casing to look for changes in the cement quality and potential leakage pathways.

As part of the testing report the data for the injection wells and monitor wells for the previous 12 months will be summarized in tabular and graphical format and interpreted.

4.1 Environmental Monitoring

The owner/operator must perform environmental monitoring during the injection phase of the project to delineate the AoR. Environmental monitoring should therefore provide information about the boundary of the CO 2 plume and the associated pressure front created by injection. Resources within the AoR, like minerals and USDWs, must also be monitored to ensure that they are not endangered by leakage of the injected CO 2 or migration of formation fluids.

Plume and Pressure Front Monitoring The separate-phase CO 2 plume and associated zone of increased pressure must be monitored to determine its location throughout the injection and post-injection phases of the CCS project. The

first measurements to delineate the CO 2 plume and the extent of the pressure front should be conducted within one year after the start of injection. Following the first measurements, monitoring should occur on a timeframe determined to be appropriate based upon the initial characterization and modeling, with a minimum of every 3 months during operational injection. The technologies used to delineate both the CO 2 plume and the pressure front must be of sufficient resolution to visualize the maximum extent of the plume in three dimensions.

Soil Gas and Surface Air Monitoring Monitoring of gases in the vadose zone and at the surface is not generally expected to be an effective method for determining potential endangerment of USDWs. However, a leak detected at the surface will provide a potential indication that a leak into a USDW has already occurredand may need to be remediated. In particular, gas monitoring should be implemented in highrisk zones where characterization and modeling data indicate that it could be useful.

5.0 POST-INJECTION MONITORING

The owner/operator must sustain the environmental monitoring during the post-injection phase of the project. This monitoring should be a continuation of the environmental monitoring that occurred during the injection phase, and it should provide information about the boundary of the

CO 2 plume and the associated pressure front created by the injection. Resources within the AOR, like minerals and USDWs, must also continue to be monitored to ensure that they are not endangered by leakage of the injected CO 2 or formation fluids. The post-injection monitoring should be performed on an annual basis.

The separate-phase CO 2 plume and associated zone of increased pressure must continue to be monitored to determine its location throughout the post-injection phase of the CCS project.

Measurements to delineate the CO 2 plume and identify the extent of the pressure front shouldPage 40 of 60 continue to be conducted on a timeframe established based on the operational phase monitoring and modeling.

Water quality should continue to be monitored in the first porous zone above the primary confining unit, in the lowermost USDW above the injection zone, and in any other USDWs that may be affected by CO 2 injection. Monitoring of vadose zone and surface gases should continue and/or be implemented based on the locations where site characterization and modeling indicate it would be useful, particularly in high-risk areas.

5.1 Criteria for Cessation of Monitoring

The decision to halt monitoring should be based on the determination of an acceptably low risk of endangerment to USDWs. This determination may be made when site monitoring data and modeling indicate that the following have occurred:

 The pressure due to injection has dissipated

 The separate-phase CO 2 plume has stabilized

 The separate-phase CO 2 plume is reasonably expected not to encounter a pathway that will create a significant risk of leakage.

Once the risk of endangering USDWs is determined to be acceptably low, the project director may approve the cessation of monitoring.

6.0 REFERENCES

Environmental Protection Agency, 2008. Proposed Requirements under the Underground Injection Control Program from Carbon Dioxide Geologic Sequestration. July, 2008.

Environmental Protection Agency, 2005. Guidance on Systematic Planning using the Data Quality Objective Process. EPA QA/G-4. February, 2005.

IPCC (International Panel on Climate Change), 2005. Special Report on Carbon Dioxide Capture and Storage.Page 41 of 60 

## ATTACHMENTS

FOR

SECTION IIIPage 42 of 60 Example Sample Data Recording Form - Monthly Injection Well Report

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Daily Injection Pressure Injection Flow Inj Vol Weekly Monthly

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GPM Gallons Cl mg/L NH3 mg/L TKN mg/L Sulfide mg/L pH Sulfate mg/L TDS mg/L Cond

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C Alkalinity Mg/L Hg Mg/L Pb Mg/L Ca mg/L Mg mg/L Fe Mg/L Bicarb Mg/L G Alpha pCi/L C 13 pCi/L C 14 pCi/L

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MONTHLY REPORT DATE

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UIC PERMIT NUMBER LEAD OPERATOR

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TEMPERATURE WATERPage 45 of 60 Example Sample Data Recording Form - Monthly Injection Well Report

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- Monthly Monitor ing Well Report

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mmhos SO4 mg/L G Alpha pCi/L Rs

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mmhos SO4 mg/L G Alpha pCi/L Rs

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AVGPage 47 of 60 IV. COMMENTS ON RULE TEXT

Part 144.6(f): Would “lowermost USDW” include formations that are not USDW’s at the point of injection but become USDW’s within the extent of the expected area of influence of the injection plume? AWWA recommends that these types of formations be included within the definition of USDW based on the ability of carbon dioxide to easily migrate within the confines of an aquifer.

Part 144.36(a): The geologic sequestration of carbon dioxide is not a fully proven technology and much is unknown about the long-term impacts, and potential unintended consequences of such injection. As previously stated, AWWA believes it would be prudent to limit the life of the Class VI permit so that necessary adjustments to the permit can be made as needed, with the opportunity for public comment. This will also establish a process for obtaining updated information on the injection operation. We would recommend a permit life of no more than 5 years. Therefore, AWWA recommends revising this part to read:

Permits for Class I and V wells shall be effective for a fixed term not to exceed 10 years. UIC Permits for Class II and III shall be issued for a period up to the operating life of the facility. Permits for Class VI wells shall be effective for a fixed term not to exceed 5 years.

Part 146.5(f): There is the possibility that some of the geologic sequestration activities

will occur in areas where there are no USDWs located in the area of review. These wells should still be permitted as Class VI wells, and AWWA recommends revising the Class VI definition to:

(f) Class VI. Wells used for geologic sequestration of carbon dioxide in the following applications: 1. Where carbon dioxide is injected below the lowermost formation containing a USDW; and, 2. Where carbon dioxide is injected in formations where no USDWs exist within the zone of elevated pressure associated with the injection well. Wells used for the geologic storage of carbon dioxide in formations above the lowermost USDW are prohibited.

This definition would capture all wells associated with geologic carbon sequestration activities whether or not a USDW was present in the projected footprint of the project.

Part 146.81 AWWA recommends defining the quality of the injection stream and establishing a minimum concentration of carbon dioxide. This requirement for the injection stream will ensure that the injection of otherPage 48 of 60 harmful or undesirable gases is limited. Our initial thoughts on this topic would be that 100% of the injectate must come from a carbon dioxide capture process and the injectate must be at least 98% carbon dioxide. Owner/operators must ensure that the remaining 2% of the injectate is not made up of compounds that would result in the injectate being classified as a hazardous waste. As AWWA is not an expert on this topic, we would suggest that EPA pursue research in association with DOE to develop a standard for the minimum concentration of carbon dioxide in the injection

stream.

Part 146.81(c) Specific benchmarks should be established to demonstrate that USDWs will not be endangered if the well is exempted from the casing and cementing requirements provided in Parts 146.86(b) and 146.87(a)(1) through (3). This will provide for a consistent application of this requirement across each permitting agency.

Part 146.81(d) AWWA recommends revising the definition of “pressure front” to read:

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 through an injection zone, and/or confining zone, and into a USDW.

Part 146.81(d) AWWA recommends revising the definition of “transmissive fault or

fracture” to read:

Transmissive fault or fracture means a fault, fracture or other discontinuity that has sufficient permeability and vertical extent to allow

fluids to move between formations.

Part 146.82(b) AWWA recommends revising the second to the last sentence to read:

The map should also show faults and other major geologic discontinuities

, if known or suspected.

Part 146.82(b) AWWA recommends that the last sentence be deleted from this part. Owner/operators should be required to go beyond the data available in the public record to identify some of the features listed in this requirement. For example, the owner/operator should be required to do its due diligence to identify all abandoned wells, plugged wells or old boreholes in the area of review. While public records may be a good starting point for the identification of these features, given the fact that some of the existing wells could be decades old, it is hard to believe that records would exist for every one of them. EPA should mandate that owner/operators use wellPage 49 of 60 identification technology to locate any existing wells that are not listed in the public record.

AWWA recommends revising this part to read:

A surface map showing the injection well(s) for which a permit is sought and the applicable area of review. Within the area of review, the map must show the number, or name and location of all injection wells, producing wells, abandoned wells, plugged wells or dry holes, deep stratigraphic boreholes, State or EPA approved subsurface cleanup sites, surface bodies of water, springs, mines (surface and subsurface), quarries, water wells and other pertinent surface features including structures intended for human occupancy and roads. The map should also show faults, if known or suspected. The owner or operator must include all information available in the public record, as well as conducting independent site investigations to locate any of the above features that may not be identified in the public record.

Part 146.82 (c) AWWA recommends revising this part to read:

A map delineating the area of review based upon modeling, using all available data including data obtained during geophysical logging and testing of the well and the formation as required by paragraphs (l), (r), and (s) of this section.

Part 146.82(d)(1) AWWA recommends revising this part to read:

Isopach maps of the area of review , including the proposed injection and confining zone(s), a structural contour map hung on the top of the proposed injection zone, and at least two geologic cross sections of the area of review showing the geologic formations from the surface to total depth

.

Part 146.82(d)(2) AWWA recommends revising this part to read:

Location, orientation, and properties of known or suspected subsurface faults, fractures, and other discontinuities that may transect the confining zone(s) in the area of review and a determination that they would not

interfere with containment.

Part 146.82(d)(3) AWWA recommends revising this part to read:

Information on the seismic history within the proposed area of review including presence and depth of seismic sources, knowledge of previous seismic events and history of these events , and a determination that the seismicity would not interfere with containment.Page 50 of 60 Part 146.82(d)(4) AWWA recommends revising this part to read:

A spreadsheet with data on the depth, areal extent, thickness, mineralogy, porosity, permeability, capillary and reservoir pressure of the injection and confining zone(s) within the area of review ; including any geologic/facies changes based upon field data which may include geologic cores, outcrop data, seismic surveys, well logs, and names and lithologic descriptions.

Part 146.82(d)(5) AWWA recommends revising this part to read:

Geomechanical information on fractures, stress, ductility, rock strength, and in situ fluid pressures on the injection and confining zones within the area of review.

Part 146.82(e) AWWA recommends revising the first sentence to read:

A spreadsheet of all wells and other artificial penetrations within the area of review which penetrate the injection or confining zone(s).

Part 146.82(f) AWWA recommends revising this part to read:

Potentiometric (water level) surface maps and stratigraphic cross sections indicating the general vertical and lateral limits of all USDWs including existing aquifers not meeting the definition of a USDW that are either currently being utilized as private or public water supplies or are identified as a future water supply, water wells and springs within the area of review, their positions relative to the injection zone(s) and the direction and velocity of water movement. At least two geologic cross sections showing the thickness and general vertical and lateral limits of all USDWs within the area of review.

Part 146.82(g) This part should provide a list of the formations for which baseline geochemical data should be obtained. AWWA recommends revising this part to read:

Collection of baseline geochemical data on the subsurface formations, including all USDWs in the area of review. At a minimum, geochemical data should be provided for the injection formation, the confining zone immediately above the injection zone, the nearest adjacent porous and permeable formation to the confining zone, all USDWs in the area of review including existing aquifers not meeting the definition of a USDW that are either currently being utilized as private or public water supplies or are identified as a future water supply , as well as for any additional formations as required by the Director.Page 51 of 60 Part 146.82(h)(1) AWWA recommends revising this part to read:

Average and maximum daily injection rate and volume of the carbon

dioxide stream.

Part 146.82(h)(2) AWWA recommends revising this part to read:

Average and maximum surface injection pressure;

Part 146.82(k) AWWA recommends revising this part to read:

Proposed stimulation program and a determination that stimulation will

not interfere with or breach the confining layer

.

Part 146.82(n) AWWA recommends revising this part to read:

Engineering drawings of the surface and subsurface construction details of the system, including design features for surge control and water hammer protection, including the following:

(i) Record drawings, based upon inspections by the engineer of record or persons under his direct supervision, with al deviations noted; (ii) Copies of the mill certificates of all casings used in the construction of the well; (iii) Certification of completion submitted by the engineer of record; (iv) An operation manual including emergency procedures; (v) Proposed monitoring program and data to be submitted; (vi) Proof that the existence of the well and any associated monitoring wells have been recorded with the permanent warranty deed or other instrument of conveyance as a two page proviso or addendum that contains certification of the locations of the wells (by metes and bounds) and a detailed sketch of the parcel that shows the location of the well. The location shall be measured by a certified land surveyor, and shall contain the surveyor's signature, registration number, official seal, and the following statement: "I hereby certify that this survey was made under my responsible direction and supervision, and is a correct representation of the land surveyed."

Part 146.82(q) As the Director should approve the corrective action plan prior to any activities taking place within the area of review, AWWA recommends revising this part to read:

The plan for corrective action on artificial penetrations within the area of

review and the status of any correction actions, if previously approved by

the Director

.Page 52 of 60 Part 146.82(s) As the well should not yet be constructed when the owner/operator applies for the permit, the demonstration of mechanical integrity should not have occurred yet. Therefore, AWWA recommends revising this part to read:

The proposed demonstration method for mechanical integrity pursuant to §146.89.

Part 146.82(v) As monitoring wells may also have to be plugged, AWWA recommends revising this part to read:

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

Part 146.83(a)(1) AWWA recommends revising this part to read:

An injection zone of sufficient areal extent, thickness, porosity, and permeability to receive the total anticipated volume of the carbon dioxide

stream, and at a depth with sufficient overburden pressure to keep the carbon dioxide stream as a supercritical fluid

.

Part 146.83(a)(2) AWWA recommends revising this part to read:

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 formation fluids and allow injection at proposed maximum pressures and volumes without initiating or propagating

fractures in the injection and confining zone(s).

Part 146.83(b) This part of the rule should a requirement, not an option that can be requested at the discretion of the Director. While it is possible that a site with a single confining can provide storage integrity, AWWA recommends that additional confining layers at the site be characterized to get a better estimate of leakage risk to USDWs and possibly identify additional monitoring zones. It is important to know if these zones exist, and to have adequately documented their characteristics, to evaluate and demonstrate the possibility of secondary containment. AWWA recommends revising this part to read:

Owners or operators of Class VI wells must identify and characterize additional zones that will impede vertical fluid movement, are free of faults, fractures or other discontinuities that may interfere with containment, allow for pressure dissipation, and provide additional opportunities for monitoring, mitigation and remediation.

Part 146.84 It is important to note that the carbon dioxide plume will never cease moving. Even deep formations have a natural flow gradient, and it isPage 53 of 60 likely that there will always be some movement due to changes in density gradients and diffusion. This should be considered when defining the AoR for each project.

Part 146.84(c)(1)(iii) AWWA recommends revising this part to read:

Consider potential migration through faults, fractures, other

discontinuities and artificial penetrations.

Part 146.84(c)(2) AWWA recommends revising the first sentence to read:

Using methods approved by the Director, identify all penetrations, including active and abandoned wells and underground mines, in the area of review that may penetrate any portion of the confining zone.

Part 146.84(d) AWWA recommends revising this part to read:

Owners or operators of Class VI wells must perform corrective action on

all wells and other artificial penetrations in the area of review that are determined to need corrective action using methods necessary to prevent

the movement of fluid into or between USDWs and between the injection zones(s) and USDWs, including use of corrosion resistant materials, where appropriate.

Part 146.84(d) Based upon our comments in the previous section of this document, AWWA recommends revising this part to read:

At the minimum fixed frequency, not to exceed one (1) year for the first ten (10) years of the operation of the carbon sequestration project and not to exceed five (5) years after the first ten year time period , as specified in

the approved area of review and corrective action plan, or when monitoring and operational conditions warrant, owners or operators must:

Part 146.85(b) AWWA believes that potential changes in the size of the area of review require that all site plans be reevaluated at the same frequency as the area of review. Therefore, AWWA recommends revising this part to read:

The owner or operator must provide to the Director, at the same frequency
as the AOR reevaluation, written updates of adjustments to the cost estimate to account for any amendments to the area of review and corrective action plan (§146.84), the testing and monitoring plan (§146.90), the injection well plugging plan (§146.92), the post-injection site care and site closure plan (§146.93), and the emergency and remedial response plan (§146.94).Page 54 of 60 Part 146.86(b)(1) AWWA recommends revising the second to the last sentence to read:

The casing and cementing program must be designed to prevent the

movement of fluids into or between USDWs and between the injection zone(s) and USDWs

.

Part 146.86(b)(1)(i) AWWA recommends revising this part to read:

Depth to the injection zone and overburden pressures in the injection

zone

.

Part 146.86(b)(1)(v) The corrosiveness evaluation should include the possible combining of the carbon dioxide stream and the injection zone water, which has a higher potential to corrode than the carbon dioxide alone. AWWA recommends revising this part to read:

Corrosiveness, chemical compatibility and reactivityof the carbon dioxide

stream and the formation fluids located within the injection zone

.

Part 146.86(b)(1)(viii)AWWA recommends revising this part to read:

Type or grade of cement and chemical compatibility and reactivity of cement and formation fluids located within the injection zone

.

Part 146.87(b) AWWA suggests that submittal of the cores to the Director is not very practical. The requirement should be rewritten to state that the Director should be provided with a summary report describing the cores and the test results. The operator should be required to first submit a coring plan to the Director listing the intervals to be cored, the coring procedures, the tests to be conducted and proposed storage of the core for review and consideration of approval by the Director. A core report, including the test results, geomechanical characteristics, and values calculated from the testing, such as fracture gradient, should be submitted to the Director. The owner/operator should make the cores available for inspection by the Director upon the request. AWWA recommends revising this part to read:

The owner or operator must submit to the Director a report describing

whole cores or sidewall cores representative of the injection zone and confining system and formation 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 demonstrate that such data are representative of conditions at the well. The Director may require the owner or operator to core other formations in the borehole to acquire more information on the subsurface geologic characteristics

.Page 55 of 60 Part 146.88(a) AWWA is concerned that the limitation on injection pressure to 90% of the fracture pressure is not stringent enough. We heard it stated at the public hearing in Denver that fracturing of the injection formation can occur when injection pressures are below 90% of the fracture pressure. It is important to consider that injection pressure limitations need to take account of the possibility that, under certain conditions, faults can be re-activated even if injection pressures are kept below the level necessary to create new fractures or propagate existing fractures. Therefore, the regulation should provide for the injection pressure to be calculated based on the site geology, hydrogeology and geomechanics, in combination with the injection pressure limitation. Injection pressures and rates should be determined by well tests and geomechancial studies, taking into account both formation fracture pressure and formation parting pressure. However, due to the amount of uncertainty associated with this topic, AWWA recommends that EPA research their proposed limitation in more detail to determine the best method for preventing possible contamination of USDWs. Therefore, we recommend revising this part to read:

The owner or operator must ensure that injection pressure and rates remain within limits established by permit. Such permit limitations shall be based on well tests and geomechanical studies, including assessments of both the fracture pressure of the confining zone and the parting pressure of the confining zone. In no case may injection pressure initiateor propagate fractures in the confining zone, cause otherwise nontransmissive faults transecting the confining zone to become transmissive, otherwise degrade the integrity of the confining zone, or cause the movement of injection or formation fluids that endangers a USDW.

Part 146.88(b) AWWA recommends revising this part to read:

Injection of the carbon dioxide stream between the outermost casing protecting USDWs and the well bore is prohibited.

Part 146.88(d) AWWA recommends that the final rule require mandatory implementation of a Supervisory Control and Data Acquisition (SCADA) system as part of the geologic carbon sequestration system. This system would allow for continuous monitoring and storage of the data associated with the operation of the injection well. Owner/operators would be able to review data trends and detect anomalies or potential problems before they occur. This SCADA system should also be tied to a carbon dioxide detector to

alarm and shut off the well in the event that carbon dioxide is detected above a pre-set level.Page 56 of 60 Part 146.89(f) AWWA recommends revising this part to read:

The Director may require additional or alternative tests if the results presented by the owner or operator under paragraph (d) of this section are not satisfactory to the Director to demonstrate that there is no significant leak in the casing, tubing or packer or significant movement of fluid into or between USDWs, or between the injection zone(s) and USDWs

, resulting from the injection activity as stated in paragraphs (a)(1) and (2)

of this section.

Part 146.90 AWWA recommends revising this part to read:

The owner or operator of a Class VI well must prepare, maintain, and comply with a testing and monitoring plan to verify that the geologic sequestration 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. The testing and monitoring plan must be reviewed and updated, as necessary, on the same schedule as the update to the Area of Review.

Part 146.90(d) AWWA recommends revising this part to read:

Periodic monitoring of the ground water quality and geochemical changes within (if wells can be installed without adversely affecting the integrity of the confining zone) and above the confining zone(s) that may be a result of carbon dioxide movement through the confining zone or additional

identified zones:

Part 146.90(d)(1) AWWA recommends revising this part to read:

The location and number of monitoring wells must be based on specific information about the geologic sequestration project, including injection rate and volume, geology, the presence of natural discontinuities and artificial penetrations and other factors.

Part 146.90(g) AWWA recommends revising this part to read:

Testing and monitoring to track the extent of the carbon dioxide plume and the position of the pressure front by either monitoring for pressure changes in the confining zone, in the first formation overlying the confining zone or using indirect, geophysical techniques (e.g., seismic, electrical, gravity, or electromagnetic surveys and/or down-hole carbon dioxide detection tools);Page 57 of 60 Part 146.90(h)(1) AWWA recommends revising this part to read:

The testing and monitoring plan must be based on site-specific geologic factors, modeling, and a risk-assessment of potential vulnerabilities within the area of review;

Part 146.91(11)(a) AWWA believes that the reporting frequency should be on a monthly basis, similar to what water and wastewater treatment plants have to do. The operating information for the geologic sequestration project is extremely important and needs to be reviewed at a frequency by the regulatory agency to ensure problems are identified and addressed in a timely manner. For example, with the way the regulation is currently structured, data collected on July 1, 2008 would not be seen by the regulatory agency before January 15, 2009, if the operator is allowed 15 days to submit the report. This would allow for very little time to correct any potential issues in the operation of the project. As such, AWWA recommends revising this part to read:

Monthly reports, due on the 15 th day of each month for the previous
month’s activities, containing:

Part 146.92(b) As previously stated AWWA believes that potential changes in the size of the area of review require that all site plans be reevaluated at the same frequency as the area of review. Therefore, AWWA recommends revising this part to read:

Well Plugging Plan. The owner or operator of a Class VI well must prepare, maintain, and comply with a plan that is acceptable to the

Director. The plan must be reviewed and revised by the owner or operator, and submitted to the Director for approval, at the same frequency and time as the AOR reevaluation. The requirement to maintain and implement an approved plan is directly enforceable regardless of whether the requirement is a condition of the permit. The well plugging plan must be submitted as part of the permit application and must include the following information:

Part 146.92(b)(5) AWWA recommends revising this part to read:

The type and grade and quantity of material to be used in plugging. The material must be compatible with the carbon dioxide stream and preinjection formation conditions ; andPage 58 of 60 Part 146.93(a) As previously stated AWWA believes that potential changes in the size of the area of review require that all site plans be reevaluated at the same frequency as the area of review. Therefore, AWWA recommends revising this part to read:

The owner or operator of a Class VI well must prepare, maintain, and comply with a plan for post-injection site care and site closure that meets the requirements of paragraph (a)(2) of this section and is acceptable to the

Director. The plan must be reviewed and revised by the owner or operator, and submitted to the Director for approval, at the same frequency and time as the AOR reevaluation.

Part 146.93(b)(2) AWWA recommends that there should be a minimum 50 year postinjection monitoring period for all carbon sequestration projects. This time period is necessary to monitor the site for changes that may occur over a longer amount of time, such as gradual leakages, or sudden seismic shifts. After this time period, the owner/operator may apply to the Director for a modification or termination of the monitoring requirements. AWWA recommends revising this part to read:

If, after the 50-year post-injection monitoring period , the owner or operator can demonstrate to the satisfaction of the Director, based on monitoring and other site-specific data, that the geologic sequestration project no longer poses an endangerment to USDWs, the Director may approve an amendment to the post-injection site care and site closure plan to reduce the frequency of monitoring or may authorize site closure before the end of the 50-year period.

Part 146.93(b)(3) When addressing plume stabilization in association with site closure, it is important to realize that the carbon dioxide plume will never be completely stable. The carbon dioxide plume will continue to move by a combination of methods including density differences, natural formation flow gradients and diffusion. AWWA recommends that EPA engage in research to provide specific criteria on what exactly it would mean for the plume to have stabilized. If left up to the discretion of the various Directors, stabilization could be defined in many different ways. In order to have a consistent application of this part of the regulation, EPA should define the specific situations in which the plume could be considered “stable.” AWWA recommends revising this part to read:

Prior to authorization for site closure, the owner or operator must demonstrate to the Director, based on monitoring and other site-specific data that no additional monitoring is needed to assure that the geologic sequestration project does not pose an endangerment to USDWs. The demonstration must demonstrate all of the following:Page 59 of 60 (i) the estimated magnitude and extent of the project footprint (CO2 plume and the area of elevated pressure) based on measurements and modeling; (ii) that CO2 movement and pressure changes match model predictions, (iii) the estimated location of the detectable CO2 plume based on measurement and modeling (measuring magnitude of saturation within the plume or mapping the edge of it); (iv) that there is no evidence of significant leakage of either CO2 or displaced formation fluids that endanger USDWs; (v) that the CO2 plume and displaced formation fluid are not expected to migrate in the future in a manner that encounters a potential leakage pathway; (vi) that the injection wells at the site completed into or through the injection zone or confining zone are properly plugged and
abandoned; and, (vii) any remaining project monitoring wells at the site are being managed by a person and in a manner acceptable to the Director.

Part 146.93(c) AWWA recommends that this part of the rule needs to include a directive that the Director needs to provide approval for site closure prior to implementation of the site-closure plan. AWWA recommends revising this part to read:

Notice of intent for site closure. The owner or operator must notify the Director at least 120 days before site closure. At this time, if any changes have been made to the original post-injection site care and site closure plan, the owner or operator must also provide the revised plan. The Director must provide approval for site closure prior to the implementation of the site closure plan. At the discretion of the Director, a shorter notice period may be allowed.

Part 146.93(d) There may be cases where the Director would want some of the monitoring wells to remain in service after site closure. While this may not be the case for all projects, for some of the earlier sites, the Director may want to continue minimal monitoring to continue to verify that the plume characteristics have remained stable.Page 60 of 60 Part 146.94(a) It is important that the emergency and remedial response plan is reviewed and updated on the same schedule as the area of review update. Changes

in the area of review could affect the actions that would need to be taken in the event of an emergency. AWWA recommends revising this part to

read:

As part of the permit application, the owner or operator must provide the Director with an emergency and remedial response plan that describes actions to be taken to address movement of the injection or formation fluids that may cause an endangerment to a USDW during construction, operation, closure and post-closure periods. The emergency and remedial response plan must be reviewed and updated, as necessary, on the same schedule as the update to the Area of Review.Letter ID: 0181

Commenter: Thomas Curtis Organization: American Wate r Works Association (AWWA)

Letter ID: 0181 Comment ID: 23643 Letter Lines: 81 to 83

Comment Code: 1200 1.1 General comments about the rulemaking

Comment: - Protection of underground sources of dr inking water (USDWs) should be the highest priority - water should trump everything! - Prevention of unintended conseque nces is of utmost importance;

Individual Response: EPA agrees that protecting USDWs is a high priority. The purpose of the GS regulation is to ensure consistency in permitting underground inje ction of CO2 at GS operations across the United States and provide requirements to prevent endangerment of USDWs in anticipation of the eventual use of GS to reduce CO2 emissions. Please see the remainder of EPA's responses to this comment for further details. 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: 0181 Comment ID: 23644 Letter Lines: 84 to 86

Comment Code: 2100 1.6 Target Geologic Formations for GS

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

USDW

Comment: - Injection of carbon dioxide and construc tion of injection wells should not be allowed in or near sole source aquifers, coal seams, earth-qua ke prone areas, or above the lowermost USDWs;

Individual Response: EPA clarifies that the GS rule does not preclude injection into any nonUSDWs non-USDW formations, provi ded the site-suitability requi rements in the GS rule are met. The purpose of the GS rule is to ensure protection of USDWs from endangerment, and the rule requires that owners or operators demonstrat e that wells are sited in suitable systems with geologic formations to receive and confine inje cted CO2, required at §146.83 of the GS rule. If an owner or operator can demonstrat e to the Director's satisfaction th at GS in coal seams, basalts, salt domes, or shales can be accomplished in a ma nner that protects USDW s and meets all of the requirements of the GS rule, the project may be permitted as a Class VI well.

In response to the comment that GS should not be allowed in areas with high-risk for a seismic event, EPA clarifies that the GS rule does not allow GS to be performed in seismically active areas and requires that operators must submit information about the seismic history of and seismic sources near a proposed GS site, as re quired at §146.82( a)(3)(v). This information, along with other required submissions, will be eval uated by the Director, who will determine the suitability of a potential project site for GS.

1Additionally, the GS rule, at 146.82(a)(5) requires prospective ow ners or operators to submit information on all USDWs, which would include so le source aquifers within the AoR. Based on

that information the Director must consider the potential impact of the GS project on all USDWs, including any sole source aquifers when determ ining whether GS is acceptable at a given site.

EPA clarifies that a state’s Cla ss VI primacy program may be more stringent then the federal requirements. For example, a state has the disc retion to ban GS projects from taking place in formations or areas that affect sole source aquifers. EPA anticipates that state permitting authorities are in the best position to make determinations about the appropriateness of a particular site based on all available inform ation, including drinking water supply needs.

As described above, the Agency believes that there are limited circumstances where injection above the lowermost USDW can be performed in a manner that protects USDWs, as long as appropriate protections are in place. The final GS rule at §146.95 establishes a process by which owners or operators can seek a waiver of the Cl ass VI injection depth requirements for injection

into non-USDW formations above and/or between USDWs.

Letter ID: 0181 Comment ID: 23645 Letter Lines: 87 to 87

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

Comment: - Hydraulic fracturing should not be used at all for GS;

Individual Response: EPA emphasizes that fracturing of th e confining zone during injection and/or stimulation is prohibited, as specified at §146.88(a). However, EPA believes there are some circumstances where fracturing of the injec tion zone is acceptable, provided the integrity of the confining system remains unaffected. The final rule allows the use of hydraulic fracturing at GS sites, where approved by the Director. Hydrau lic fracturing is one of several stimulation technologies available to improve we llbore and formation injectivity.

EPA clarifies that all stimula tion, including hydraulic fracturing, must be approved by the Director. Owners or operators must submit a propos ed stimulation program as part of the permit application under §146.82(a)(9); the plan must demonstrate that a ny stimulation act ivities will not compromise the integrity of the confining zone. The Director will evaluate the owner or operator's proposed stimulation plan in the cont ext of all information about the site, and the owner or operator must perform stimulation only as approved.

The final rule at §146.91(d)(2) also requires that the owner or operator notify the Director 30 days before performing stimulation during the operational phase of a GS project; this will provide an additional opportunity for the Director to review the owner or operator's plans for

stimulation and add other requirements as needed.

Letter ID: 0181 Comment ID: 23646 Letter Lines: 88 to 91

2Comment Code: 1200 1.1 General comments about the rulemaking

Comment: - If USDW water quality is degraded by a GS project, th e owner/operator of that projects is responsible for any costs bo rn by drinking water utilities due to increased treatment requirements for that ground water or replacement of lost capacity; and,

Individual Response: As described above, EPA clarifies that the purpose of the GS regulation is to ensure consistency in permitting underground injection of CO2 at GS operations across the United States and provide requirements to prev ent endangerment of USDWs in anticipation of

the eventual use of GS to reduce CO2 emissions.

Letter ID: 0181 Comment ID: 23647 Letter Lines: 92 to 93

Comment Code: 1220 1.1.1.1 Terminology and definitions

Comment Code: 4400 2.4.4.3 Allowing injection above or between USDWs (seeking comment)

Comment: - The 10,000 mg/l TDS limit for classifying USDWs for the siting of Class VI wells needs to be revised upward.

Individual Response: EPA is not changing the USDW definition; changing the definition of a USDW is outside the scope of the GS rulemaki ng. 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: 0181 Comment ID: 23648 Letter Lines: 95 to 100

Comment Code: 1200 1.1 General comments about the rulemaking

Comment: In its comments, AWWA makes several r ecommendations for the following specific

items to be included in the final regulation:

- Requirement to consult with the state environmental department and affected water utilities to determine which aquife rs currently not classified as USDWs might be considered as future drinking water sources;

Individual Response: As part of the UIC permit review process in 40 CFR §124, the UIC Program Director is required to notify certain stakeholders of any public hearings and the availability of the draft perm it. EPA has added a requirement at §124.10(c)(1)(xi) that state and local oil and gas regulatory agencies and stat e agencies regulating mineral exploration and recovery, the PWSS Program Director, and all agen cies that oversee injection wells in the state must be notified as part of the public notice process for a Class VI permit. For additional information on EPA's final regulatory approach, pl ease see the final rule and preamble as well as the rulemaking docket.

3Letter ID: 0181 Comment ID: 23649 Letter Lines: 95 to 96 ; 101 to 102

Comment Code: 1220 1.1.1.1 Terminology and definitions

Comment: In its comments, AWWA makes several r ecommendations for the following specific

items to be included in the final regulation:

- Definition of "endangerment" that incl udes water quality impacts beyond those contaminants with MCLs;

Individual Response: EPA disagrees that endangerment should be defined in the context of the Class VI GS rule. Rather, the Ag ency clarifies that the purpose of the Cl ass VI GS regulation, promulgated under authority of the SDWA, is to ensure that, where GS is deployed, it is conducted in a manner that protect s USDWs from endangerment.

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: 0181 Comment ID: 23650 Letter Lines: 95 to 96 ; 103 to 104

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

Comment: In its comments, AWWA makes several r ecommendations for the following specific

items to be included in the final regulation:

- Addressing liability, treatment costs fo r remediation, and financial recourse for a water utility if a USDW is degraded due to a GS project;

Individual Response: The goal of financial responsibility is to ensure that financial resources are available to prevent endangerment of USDWs from improper plugging, remediation, and management of wells in the event that the owne r or operator experiences financial difficulties. As such, owners or operators must demonstrate financial responsibility for, among other things, any needed emergency and remedial respons e actions that are necessary to mitigate endangerment of USDWs. Furthermore, the financ ial responsibility provis ions provided the final GS rule are intended to ensure the owner or ope rator will be held liable for remediating or correcting any endangerment of USDWs via their demonstrated financial instrument up through site closure. For example, if during the life of the GS project (up until site closure) a Class VI well leaks, which results in endangerment of a USDW, the primacy State of other 3rd party beneficiary can call upon that fi nancial instrument to pay for remediation or corrective action. EPA wants to clarify that the Agency can never be the beneficiary of the financial instrument used to meet §146.95 due to limitations under the Miscellaneous Receipts Act. See the final rule and preamble for further discussion of EPA's final approach to financial responsibility for Class

VI wells.

4Letter ID: 0181 Comment ID: 23651 Letter Lines: 95 to 96 ; 105 to 106

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

Comment: In its comments, AWWA makes several r ecommendations for the following specific

items to be included in the final regulation:

- Requirement for owner/operators of gra ndfathered wells to certify that the

wells were constructed and cemented with materials appropri ate for GS wells;

Individual Response: EPA agrees that a cautious approach to grandfathering is appropriate, particularly given that the convert ed well will be used for a substa ntially different process, which involves increased reservoir pre ssures associated with large volumes of stored CO2 and the corrosivity of CO2 in the presence of water. Th e final GS rule provides for the construction of these wells to be grandfathered (per 146.81(c)). EPA has included a requirement in the final GS rule that owners or operators seeking to c onvert existing wells for long term storage must demonstrate to the Director that the grandfathe red wells were engineered and constructed meet the requirements at §146.86(a) and ensure prot ection of USDWs, in lieu of requirements at §146.86(b) and §146.87(a).

Letter ID: 0181 Comment ID: 23652 Letter Lines: 95 to 96 ; 107 to 108

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

Comment: In its comments, AWWA makes several r ecommendations for the following specific

items to be included in the final regulation:

- Development of a standard computation flow model to delin eate the area of review;

Individual Response: EPA believes that operators should have the flexibility to select models with which they are familiar and that are most appropriate to the site conditions and available data types and amounts. EPA also recognizes that a standardized model for AoR delineations could be effective as long as the model accounts for the expected variations in site conditions, and adds that a state or regional UIC Director has the discretion to select one standa rd model if it took site-specific variat ions into account.

EPA does not envision that members of the public would evaluate the AoR delineation models themselves. The models and their inputs will, by necessity, entail an extensive amount of technical information that may not be easily unde rstood by the public. EPA believes that it is the Director's responsibility, as a steward of public health and the environment, to review models, model inputs, and results and to determine whether the model is appropriate for predicting the AoR, and to distribute information that may be easily understood by the public (e.g., in the form of a fact sheet). However, the models mu st be made available to the public.

5Letter ID: 0181 Comment ID: 23653 Letter Lines: 95 to 96 ; 109 to 110

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

Comment: In its comments, AWWA makes several r ecommendations for the following specific

items to be included in the final regulation:

- Reevaluation of the area of review annually for the fi rst ten years, and then every five years for the rema ining life of the project;

Individual Response: EPA agrees with commenters that reevaluations of the AoR every ten years may not be sufficient to appropriately model plume and pressure front movement, establish conditions for corrective action, and ensure prot ection of USDWs from endangerment. For these reasons, the Agency changed the minimum freq uency for the AoR reevaluation at §146.84(e) from 10 years to at least every 5 years in the final GS rule. EPA belie ves that this revised frequency addresses commenters' concerns about the inherent uncertainties in modeling CO2 movement, the emerging nature of GS technology, risk-based targeting of monitoring activities, and the unique nature of CO2 GS. In addition, the Director has discre tion to require more frequent AoR reevaluation if he or she has reason to believe, based on site-specific information, that a five-year reevaluation schedule is not sufficiently protective of USDWs.

Letter ID: 0181 Comment ID: 23654 Letter Lines: 95 to 96 ; 111 to 112

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 comment)

Comment: In its comments, AWWA makes several r ecommendations for the following specific

items to be included in the final regulation:

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

Individual Response: EPA believes that permitting under the UIC Program is an essential element for ensuring that GS projects are opera ted in a manner that protects USDWs from endangerment. The UIC Program establishes minimum federal requirements for owners or operators of GS wells; and, States may choose to de velop requirements that are as stringent as or more stringent than the minimum federal requireme nts. This affords states the flexibility to implement the program while ensuring that USDWs are protected from endangerment. If a State does not develop UIC Program requirements for Class VI wells, EPA implements the program in those states. The Agency clarifie s that all owners or operators of Class VI wells must comply with the requirements under Subpart H of 146 in order to inject CO2 for GS through a Class VI well. A UIC injection well permit application is separate from other permitting activities (i.e., coal plant permitting).

6EPA believes that the extensive requirements for geologic site char acterization (at §146.82), AoR evaluation (§146.84), and testing of the we ll during drilling (§146.87) are appropriate to ensure that permitting authorities have the necessary information to evaluate whether a specific site will allow safe injection of CO2. EPA adds th at submittal and review of monitoring data (as required at §146.90) and the AoR reevaluation pr ocess (§146.84(e)) will provide an opportunity for an ongoing review of the site and a dialogue between the Dir ector and the owner or operator to ensure that the project is being oper ated in a manner that protects USDWs from endangerment.

EPA is developing a number of technical guid ances and implementation materials to assist owners or operators and Directors in the pe rmitting process. These guidances will provide recommendations regarding performing many of the activities necessary for applying for a permit, including developing all required plans and conducting site charact erizations that meet the requirements of §146.82. These guidan ces can be found on EPA’s website at http://water.epa.gov/type/groundwat er/uic/wells_se questration.cfm.

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

discretion of the Director.

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

Letter ID: 0181 Comment ID: 23655 Letter Lines: 95 to 96 ; 113 to 113

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

Comment: In its comments, AWWA makes several r ecommendations for the following specific

items to be included in the final regulation:

- Inclusion of detailed monitoring requi rements in the final regulation;

Individual Response: EPA disagrees that the rule should specify the monitoring techniques for all GS sites. EPA believes that flexibility is important in developing and implementing a monitoring plan that is appropr iately tailored for a specific GS site. The purpose of the requirement at §146.90 to develop site-specific testi ng and monitoring plans is to ensure that the monitoring performed at a site is appropriate for site operat ional conditions and the geologic setting. EPA believes that this is the best approach for addressi ng potential risks at GS sites. These flexible provisions in the monitoring requirements for Class VI wells enable the owner or

7operator to tailor monitoring programs to the speci fic needs of each project in consultation with

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 pressure front, a nd soil gas and surface air monitoring which may be required by the UIC Director for specific GS projects. Th e guidance can be found on EPA’s website at http://water.epa.gov/type/groundwater/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.

Letter ID: 0181 Comment ID: 23656 Letter Lines: 95 to 96 ; 114 to 115

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 comment)

Comment: In its comments, AWWA makes several r ecommendations for the following specific

items to be included in the final regulation:

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

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

Letter ID: 0181 Comment ID: 23657 Letter Lines: 95 to 96 ; 116 to 118

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

8Comment: In its comments, AWWA makes several r ecommendations for the following specific

items to be included in the final regulation:

- Requirement for mandatory public notific ation and public hearings for any new permit and any permit revision or renewa l, and for a 90-day public comment period

Individual Response: EPA disagrees that a 90-day comment period should be required for all GS projects. EPA believes that the existing public comment period requirements at §124.10, which require a minimum 30-day comment period for draft permits, and which require public notice for most permit modifications, are appropr iate for GS projects. The Agency does not believe it is appropriate to impos e longer time frames if they are unnecessary, but supports the Directors' discretion and authority under §124.10 to extend the public comment period if he or

she determines that such an extension is warrant ed. Circumstances that ma y affect a Director's determination may include the level of public intere st in a GS project, specific permit details, or project-specific considerations.

EPA also disagrees that public hearings should be mandatory for all GS permits, in order to account for the possibility that, if the public does not express an in terest in a hearing, holding one

would not be useful. 40 CFR 124.12 requires the Director to hold public heari ngs if there is a significant degree of interest in a draft permit. EPA expects that publ ic hearings will be requested and held for many GS projects, due to the expect ed level of public intere st in GS projects.

Letter ID: 0181 Comment ID: 23658 Letter Lines: 120 to 125

Comment Code: 1510 1.2.2.3 Need for additional study

Comment: Several issues need more research by EPA and DOE, and the following research needs to be completed prior to issuance of the final regulation:

- Criteria for the determination that the carbon dioxide plume has stabilized; - The potential for seismic shifts due to subsurface pressure changes;

- The minimum concentration of carbon di oxide in the injection stream; and - The types of tracers that would be acceptable for GS.

Individual Response: EPA agrees that continued research w ill be integral to development of GS technology, but disagrees that th e Agency should wait for all cu rrent field research to be complete before finalizing the GS rule. The Ag ency believes that es tablishing a regulatory framework for the future development and depl oyment of CCS technolo gy provides a framework for injecting CO2 so that the activity does not result in endanger ment of USDWs.

To protect USDWs from endangerment and meet the potentially fast pace of GS deployment, EPA is using an adaptive approach to regula ting CO2 injection for GS. The Agency plans to collect and review data every six years on GS projects to dete rmine whether the appropriate amount and types of information and appropria te documentation are being collected, and to determine if modifications to the requiremen ts are appropriate or necessary. An adaptive

9approach will allow regulatory development to pr oceed in time to meet the current and future demands for Class VI permits, while EPA continues to gather data from pilot projects and other

research as it becomes available.

Letter ID: 0181 Comment ID: 23659 Letter Lines: 139 to 143

Comment Code: 1200 1.1 General comments about the rulemaking

Comment: AWWA appreciates the opportunity to co mment on the proposed requirements for geologic sequestration wells as publis hed in the July 25th, 2008 Federal Register (73 FR 43491). Protection of underground sources of drinking water (USDWs) should be a key priority of any geologic carbon seque stration regulation developed as part of the Undergroun d Injection Control (UIC) Program.

Individual Response: EPA agrees that protecting USDWs is a high priority. The purpose of the GS regulation is to ensure consistency in permitting underground inje ction of CO2 at GS operations across the United States and provide requirements to prevent endangerment of USDWs in anticipation of the eventual use of GS to reduce CO2 emissions. Please see the remainder of EPA's responses to this comment for further details. 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: 0181 Comment ID: 23660 Letter Lines: 156 to 187

Comment Code: 1200 1.1 General comments about the rulemaking

Comment: I. GENERAL COMMENTS

In 2007, approximately 78% of 52,000 community water systems in the United States were supplied by groundwater a nd these systems served 90.5 million people. In addition, many surface water utilities are currently looking at conjunctive use and/or gr oundwater development as ad aptation measures (supply portfolio diversification/new storage) to combat climate change. Each of these utilities could potentially be impacted by geologic carbon sequestration, simply by the fact that these utilities utilize groundwater resources.

The proposed regulation is a good technical starting point gi ven the evolving state of geologic sequestration; however, th e proposed rule has many limitations that could allow for the endangerment of underground sources of drinking water (USDWs). Many of the requirements are base d on faith, and not a lot of data, and the drinking water community is being as ked trust that geologic sequestration technology will work even though there is very little experience with this technology on a large scale. For example, the requireme nts for determining the direction of carbon dioxide plume migration, predicting c onfining layer containment potential, and identifying n ecessary geo-chemical monitoring are

10based on modeling exercises, with limite d monitoring data to validate these models and limited real-life data to support the requirement s. There is the possibility for unintended consequences to occur with geologic sequestration is very real, similar to what was observed w ith the use of MTBE. MTBE is the fuel

additive that was meant to solve an ai r pollution problem but its use resulted in unanticipated drinking water pollution problems. Carbon dioxi de is an energy production/use byproduct that causes air po llution/climate problem but whose mitigation (using geologic sequestration) could cause drinking water contamination and other (supply) problems. EPA needs to draw on the lessons learned from the MTBE situation, and do ev erything possible to prevent a similar situation from occurring with geologic se questration. Prevention is the key word here. AWWA will address these issues, as well as some other important concerns, in this section of general comments.

Individual Response: EPA disagrees that GS is analogous to the MTBE situation. EPA believes that large scale GS can be done sa fely. The final rule is based on th e most recent GS-related data, information, and scientific research available. EP A intends to continue to collect data on GS and to incorporate such data as it implements its ad aptive approach to GS rulemaking to incorporate new research, data, and information about GS. An adaptive approach provides Class VI owners or operators the flexibility to use and apply newly developed tec hnologies for GS as they become

available in the future.

The GS regulation builds upon the long-standing, protective regulatory framework of the UIC program, which has been regulating the injecti on of fluids for decades. The GS regulation enhances this existing framework with tailored re quirements for Class VI GS wells to address the unique nature of large scale GS of CO2. Thes e protective requirements include extensive geologic testing, detailed computational modeli ng of the AoR and periodic re-evaluations, detailed requirements for monitoring and tr acking the CO2 plume and pressure front, and extended post-injection mon itoring and site care.

Letter ID: 0181 Comment ID: 23661 Letter Lines: 189 to 357

Comment Code: 1220 1.1.1.1 Terminology and definitions

Comment Code: 4400 2.4.4.3 Allowing injection above or between USDWs (seeking comment)

Comment: USDW Classification: The best sources of drinking water are already being used by utilities. In many area s, population growth is fo rcing utilities to look

further or to look at more challenging sources. With the potential impacts from climate change, drinking water utilities are facing an even more limited supply of fresh drinking water. As a result, many utilities are turning to more challenging groundwater sources such as thos e that are very d eep or have high salinity concentrations. Additionally, th e pumping costs for these deep wells are no longer prohibitive gi ven the lack of sufficient water sources. Some of

these new sources could fall outside of the current de finition of a USDW, in that the aquifer has a TDS concentrat ion higher than 10,000 ppm. The proposed rule promises protection of USDWs from e ndangerment, in that the activity does

11not cause a primary drinking water Maxi mum Contaminant Level (MCL) to be

exceeded in an USDW or affect human health. Ther e are no anti-degradation provisions in the proposed regulation to protect other groundw ater supplies, such as those aquifers that are not classi fied as a USDW but have been, or may be, identified as a future drinking water source. The definition of a USDW was written at a time when many advanced water treatment technologies were generally cost prohibitive, and the ge neral thinking that the high- salinity aquifers would never be utilized as drinking water sources.

Technological advances in the area of de salination have reduced many of the treatment costs, making it more and more accessible. Many utilities have no

other choice for new water sources. Ever increasing population and water demands have utilities using non-traditional and poor er water sources (see Table 1-1 for examples; note that this is not meant to be a comprehensive list of all desalination plants in the United States).

Table 1-1: Water Utilities with More Challenging Water Sources

[The information below was originally pres ented as a table. See Docket PDF EPAHQ-OW-2008-0390-0181 to see a copy of the original table.]

Utility Name: El Paso Water U tilities and Ft.Bliss, Texas

Water Source: Hueco Bolson Basin Usage: 27.5 mgd

TDS Concentrations : 600 to 4,900 mg/l

Utility Name: Tampa Bay Water, Florida

Water Source: Seawater Usage: 25 mgd

TDS Concentrations : 18,000 - 32,000 mg/L

Utility Name: Yuma Desalting Plant, Arizona Water Source: Drainage water Usage: 22 mgd

TDS Concentrati ons: 3,200 mg/L

Utility Name: Miami-Dade County, Florida Water Source: Florida Aquifer Usage: 17.5 mgd (curre ntly under design) TDS Concentrations: 1,000 - 5,000 mg/L

Utility Name: Temescal Desalter Project, California

Water Source: Temescal Basin Usage: 15 mgd

TDS Concentrati ons: 700 mg/L

12Utility Name: City of Abilene, Texas

Water Source: Surface water Usage: 8.0 mgd

TDS Concentrati ons: 1,200 mg/L

Utility Name: City of Sherman, Texas

Water Source: Surface water Usage: 7.5 mgd TDS Concentrations: 900 - 1500 mg/L

Utility Name: Southmost Regional Water Authority, Texas

Water Source: Groundwater Usage: 6.75 mgd

TDS Concentrati ons: 3,500 mg/L

Utility Name: Lake Granbury SWATS,Texas

Water Source: Surface water Usage: 6.0 mgd

TDS Concentrati ons: 1,800 mg/L

Utility Name: City of Fort Stockton, Texas

Water Source: Groundwater Usage: 6.0 mgd

TDS Concentrati ons: 1485 mg/L

Utility Name: Newport News WTP, Virginia Water Source: Lower and Middle Potomac Aquifers Usage: 5.7 mgd

TDS Concentrati ons: 3600 mg/L

Utility Name: Alameda County Water District, California

Water Source: Niles Cone Groundwater Basin Usage: 5.0 mgd with expansion to 10 mgd TDS Concentrations: 1,100 - 2,400 mg/L

Utility Name: Pascagoula, Mississippi

Water Source: Groundwater Usage: 4.5 mgd

TDS Concentrati ons: 1,000 mg/L

Utility Name: Dare County North WTP, North Carolina

Water Source: Groundwater Usage: 3.0 mgd

TDS Concentrati ons: 4,300 mg/L

13Utility Name: Port Hueneme Brackish Water Facility, California

Water Source: Groundwater Usage: 3.0 mgd

TDS Concentrati ons: 1,300 mg/L

Utility Name: James City Service Authority, Virginia

Water Source: Middle and Lower Potomac Aquifers Usage: 2.5 mgd TDS Concentrations: 1,000 - 2,400 mg/L

Utility Name: Buxton, North Carolina

Water Source: Groundwater Usage: 2.0 mgd

TDS Concentrati ons: 13,200 mg/L

Utility Name: Cape May, New Jersey

Water Source: Groundwater Usage: 2.0 mgd

TDS Concentrati ons: 2,100 mg/L

Utility Name: Dare County Cape Hatteras WP, North Carolina

Water Source: Groundwater Usage: 2.0 mgd

TDS Concentrati ons: 11,200 mg/L

Utility Name: Las Animas, Colorado

Water Source: Groundwater Usage: 1.18 mgd

TDS Concentrati ons: 3,500 mg/L

Utility Name: VA Medical Ce nter, Ft. Lyon, Colorado

Water Source: Groundwater Usage: 0.24 mgd

TDS Concentrati ons: 800 mg/L

The use of very deep and/or high salin ity groundwater becoming more commonplace is only a matter of time. Therefore, we believe the 10,000 mg/L TDS USDW definition is no longer appropriate. Give n that this regulation does not currently extend protection to non-traditional and poorer water sources, AWWA believes that these aquifers may be adve rsely impacted by this rulemaking. These aquifers, which have not been previously used as a drinking water source, may be in the future, and it is important to ma ke sure that they are adequately protected. AWWA recommends that EPA cons ider the "green-effect" and that, in many cases, the overall least cost alte rnative may be to treat brackish groundwater using desalination technology instead of trying to obtain surface

14water as the drinking water source. While the surface water may be less expensive to treat, if the utility is lo cated in a dry environment, such as Arizona or New Mexico, the pumping costs to transport that water over a large distance may be much larger than the co st to treat a bracki sh groundwater. EPA

should also consider that as technology evolves, utilitie s will be able to treat

a much different set of waters than is currently being treated. Several utilities are using sea water or brackish water as drinking wate r sources, which would not have been even remotely cons idered as a viable option 20 years ago, when the TDS limit was originally developed.

Recognizing that it is difficult to extend protection to these aquifers due to

the restrictions of the SDWA , AWWA recommends that the regulation be revised to mandate that, during the project planning process, the owner/operators should include state environmental departments as they can provide in sight into what aquifers currently (not classified as US DWs) might be consid ered as future drinking water sources. The stakeholde r process should also involve both regional and local planning boards, as well as the local utilities. This process will allow for protection to be extended to the non-traditional aquifers, which will be necessary given the pressures on water resources that the country will be facing in the upcoming century.

Individual Response: As described above, EPA is not cha nging the USDW definition; changing

the definition of a USDW is out side 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: 0181 Comment ID: 23662 Letter Lines: 359 to 364

Comment Code: 1220 1.1.1.1 Terminology and definitions

Comment Code: 1610 1.3.1 Risks to USDWs

Comment Code: 4400 2.4.4.3 Allowing injection above or between USDWs (seeking comment)

Comment: USDW Endangerment: AWWA recommends revision to the definition of "endangerment" in the proposed rule. The current definiti on of endangerment is limited to SDWA UIC definition of 10,000 TDS and to primar y MCL contamination. Certain healtheffects can be related to concentrations in water of compounds that do not exceed the primary MCL. However, under the current language, these potential

contaminants would not be covered with the protections afforded by the SDWA.

Individual Response: The Agency acknowledges commenter concerns about water resources and future water resource availability. Howeve r, modifying the definition of a USDW or “endangerment” is outside the scope of the GS rulemaking. USDWs are defined as aquifers currently being used as sources of drinking water or those ca pable of supplying a public water system and they have a total dissolved solids (TDS) content of 10,000 milligrams per liter or less as specified in §144.3. EPA adds that concerns about contaminants with health effects even at

15concentrations below the maximum contaminant leve l should be addressed as part of the review process for the national primary drinking water re gulations; such concerns are outside the scope of this rulemaking. Please note that the defi nition of “endangerment” has been defined by Congress at SDWA §1421(d)(1)(2).

The primary goal of the UIC Program under the SDWA is to protect USDWs from endangerment in order to ensure a reliable supply of drinking water for the American public. The GS rule, as part of the UIC program regulations, continues the program’s mandate of ensuring the protection of USDWs. EPA expects the ta ilored permitting, siting, construction, operation, monitoring, and post-injection site care requirements in the GS rule to prevent leakage from injection formations and protect USDWs.

Letter ID: 0181 Comment ID: 23663 Letter Lines: 366 to 378

Comment Code: 1610 1.3.1 Risks to USDWs

Comment Code: 1650 1.3.5 Human health impacts

Comment: EPA should also consider the risk associ ated with the potentia l exposure of any

contaminants that are released to the su rface. While we recognize that a gradual leak may have little impact, the potentia l of a catastrophic leak is always present. EPA should be mindful during th e rulemaking process of not only the risk to drinking water, but also of othe r potential risks from exposure to other constituents such as pH, lead and co pper, iron, hardness, silica and boron. These are compound for which no MCLs have been developed but still impact drinking water quality and increase the n ecessary treatment costs. There could be potential health impacts due to long- term exposure to contaminant levels below the established MCLs. Also, benefici al uses of groundwater could also be impacted by increases of these compounds in the aquifers. Owners/operators could be in compliance with the regulation, but could be de grading an aquifer by contaminating it with compounds fo r which MCLs do not exist.

Individual Response: EPA acknowledges that there are pote ntial risks associated with GS, including the potential for leakage of CO2 into USDWs, which could re sult in the mobilization of substances that could pose threats to USDWs or human health or could increase treatment costs. The purpose of the Class VI requirements is to minimize and mitigate potential/identified risks through proper site ch aracterization, well construction, operation, monitoring, postinjection site care, and site cl osure. The mandate of the UIC Program, and the GS rule, is to protect USDWs from endangerment that may be caused by underground in jection. The GS rule accomplishes this through requirements tailored to address the unique nature of GS, including the large volumes of CO2 injected, its buoyancy and potential corrosivity in the presence of water, and impurities in the CO2 stream. Many of these requirements specifically address the potential for mobilized substances to affect USDWs. The GS rule is concerned with the migration of CO2 and displacement of native fluids that may result in endangerment of USDWs.

16For example, the owner or operator must submit da ta about the site, including information on the porosity, permeability, mineralogy, and geochemistry of the targeted injection and confining zones. Operators must also present informati on on the compatibility of the CO2 stream with fluids in the injection zone and minerals in both the injection and confining zones as specified in §146.82(c)(3). The data will help identify potential geochemical reactions between the injected CO2 and the host geologic formations, which coul d result in the plugging of pore spaces or the dissolution of formation minerals. During injection operations, operato rs must extensively monitor ground water quality to provide early de tection of any unacceptable movement of fluids or impurities in the subsurface as specified in §146.90. Operators must develop and follow an emergency and remedial response plan to addres s any adverse effects a ssociated with the GS operation as specified in §146.94 and provide financial responsibil ity to address contamination as specified in §146.85.

Recent research has focused on addressing this concern. EPA is funding research at the Lawrence Berkeley National Laboratory (LBNL) on potential USDW impacts associated with mobilization of trace elements. In the August 31, 2009, Notice of Data Availability and Request for Comment (74 FR 44802), EPA published the results of the study, which evaluated the potential for GS to cause changes in ground wa ter 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). In th e study, LBNL estimated the amount of trace elements from native mineral sp ecies that could poten tially be mobilized by

the intrusion of CO2 and the potential ground water concentrati ons that coul d result, to determine the potential for drinking water standa rds to be exceeded. Results from this model simulation suggest that if CO2 were to leak into a shallow aquife r, the potential for mobilization of lead and arsenic could be enhanced, causing increases in the concentration of these trace elements in ground water. The Agency continues to monitor research related to CO2 confinement, potential for CO2 leakage, and mobilization of trace elements.

EPA adds that concerns about contaminants that cause health effects but do not have maximum contaminant levels should be addressed as part of the review process for the national primary drinking water regulations; such concerns are outside the scope of this rulemaking. EPA has also examined potential methods for conducting treatment of water affected by a CO2 leak; this study is presented in the final rulemaking docket.

Letter ID: 0181 Comment ID: 23664 Letter Lines: 380 to 420

Comment Code: 1310 1.1.2.4 Comments on other "out of scope" issues, e.g., pore space ownership

Comment Code: 1610 1.3.1 Risks to USDWs

Comment: Assignment of Liability: Most importan tly, the regulation does not seem to address the liability that would be realiz ed by owners/operators of the geologic sequestration projects if water quality of USDWs is de graded by the operation of their project (even if the impacts are limited to MCLs). AWWA recommends that

this issue be addressed in the final re gulation, as drinking water utilities may

have little financial recour se if the water quality one of their aquifers is

17degraded due to the operation of a ge ologic sequestration process. Provisions

need to be included in the final rule that would allow the drinking water utility to recoup any cost s that are realized due to increased treatment requirements for contaminated ground water or to replace lost ca pacity. In some cases, utilities may need to install diffe rent types of treatment to remove compounds that might not have been presen t in the water prior to the geologic sequestration project. In other instances , treatment may consist of the addition of more chemicals to facilitate precip itation of the inorgani c compounds or the utility may have to backwash membranes more often, resulting in higher energy and other operation and maintenance co sts. In any of these cases, the owner/operator of the geologic sequestra tion project should be required to reimburse the drinking water utility for these incurred costs, and they should also be required to continue such pa yments for as long as the ground water source remains degraded.

Water utilities should not be penalized for having to develop local sites contaminated by sequestration activities for water supply. In fact they should be encouraged to do so, under the appropriate conditions, as there is no more critical public health issue than the need to provide potable water. In order to meet increasing demands imposed on them by a growing servi ce population, water utilities will need to develop marginal water supplies. However, increased

treatment costs due to contamination re sulting from sequestration activities should not be borne by the local utilit y or their customers when national environmental objectives have been met w ithout significant benefit to the local

economy.

Should a water utility "lose" an existing or future source of supply due to

contamination or inaccessibi lity resulting from a sequestration project, there will be the issue of financial compensation (for treatment or development of an alternative source). As water resources become scarce, financial compensation for a lost source of supply may not suffice, as local alternatives may not be available. Hence, it will be critical that contingency planning to identify

alternatives to the curre nt groundwater supply be a part of the planning activities for the sequestration project, al ong with a commitment to provide an alternative source of water, should the need arise.

Individual Response: EPA agrees that owners or operators of Class VI wells must ensure that resources are available to prevent enda ngerment of USDWs from improper plugging, remediation, and management of wells. For this reason, the GS rule requires that owners or operators demonstrate a nd maintain financial responsibility for corrective action on wells in the AoR, injection well plugging, post- injection site care and site closure, and emergency and remedial response at GS sites as specified in §146.85. In the event of contamination or other adverse event to the USDW during the life of the project, the financial instrument(s), such as insurance, bonds, etc., rather than public m onies, would cover necessary response actions. EPA clarifies that it is the owner or operator of the well who will be required to demonstrate financial responsibility, not the generato r of the CO2, consistent with EPA’s authority under SDWA.

18Furthermore, EPA notes that tort and other reme dies will continue to be available after site

closure. Other Federal environmental stat utes, e.g. Clean Air Act, 42 U.S.C. §§7401-7671; CERCLA, 42 U.S.C. §9601-9675; and RCRA, 42 U.S.C. §6901-6992, potentially apply as well to the risks created by the long- term storage of CO2. EPA has also examined potential methods for conducting treatment of water affected by a CO 2 leak; this study is presented in the final rulemaking docket.

EPA clarifies that long-term liability beyond the life of the project (after s ite closure) is beyond the scope of the GS rulemaking. Please see the final rule and the discussion of financial responsibility and long-term liability in the preamble for additional information.

EPA adds that Class VI well owne rs and operators must site, cons truct, operate, monitor, and close their wells in a manner that protects USDW s, and Class VI permits will set forth rigorous technical requirements to ensure careful planning, operation, and cl osure of GS projects. Failure to meet these requirements would be considered a violation of th e permit and would be subject to applicable civil, criminal, or admi nistrative penalties under SDWA §1423.

Letter ID: 0181 Comment ID: 23665 Letter Lines: 422 to 426

Comment Code: 1310 1.1.2.4 Comments on other "out of scope" issues, e.g., pore space ownership

Comment: AWWA also recommends th at the company generating the carbon dioxide must maintain sole ownership of the carbon dioxi de they generate. This would ensure that liability remains with the original generator in perpetu ity; even if the carbon dioxide is commingled with some gene rated from another facility or if its disposal is managed by another company.

Individual Response: EPA clarifies that the final Class VI GS rule applies to owners or operators of wells that will be used to injectCO2 into the subsurface for the purpose of longterm storage, and not the generator of the CO2. Any issues related to "o wnership" of generated CO2 are outside the scope of the Class VI GS rulemaking. Rather, the purpose of the Class VI GS rule is to ensure consistency in permitting underground injection of CO2 at GS operations across the United States and pr ovide requirements to prevent endangerment of USDWs in anticipation of the eventual use of GS to reduce CO2 emissions.

Letter ID: 0181 Comment ID: 23666 Letter Lines: 428 to 440

Comment Code: 1610 1.3.1 Risks to USDWs

Comment Code: 1616 1.3.1.3 Fluid movement

Comment: Trespass and Aquifer Displacement: AWWA recommends that the potential for trespass be addressed in the final rule. Carbon dioxide plumes may migrate into a location that a drinking water utility was planning to utilize, possibly for aquifer storage and recovery. What r ecourse is provided by the proposed

19regulation in the event that trespass occurs, and damages are realized by the drinking water utility? Also, movement of the pressure front associated with a carbon dioxide plume may cause aquifers to shift in location, potentially moving them out of the juri sdiction of their original util ity "owner." This can be a serious problem in certain portions of th e country where ground water resources are limited or conflict, and utilities face intense competition for water rights. AWWA questions if an appropria te recourse will be provided by the sequestration project owner/operator in the event that these water rights issues become a reality for the drinking water utility.

Individual Response: EPA clarifies that owners and operators must perform extensive site characterization and modeling of the AoR to dete rmine the extent of the CO2 plume prior to approving a GS project. The financial responsib ility requirements at§146.84 require owners and operators to demonstrate and maintain resources to address emergency and remedial response to adverse events that may occur associated with GS. This would include im pacts to drinking water

utilities associated with fluid displacement.

Letter ID: 0181 Comment ID: 23667 Letter Lines: 442 to 469

Comment Code: 1220 1.1.1.1 Terminology and definitions

Comment Code: 4400 2.4.4.3 Allowing injection above or between USDWs (seeking comment)

Comment: Safe Drinking Water Act Aut hority: In its February 2008 stakeholders meeting, EPA seemed to imply that it was restrict ed in what it coul d regulate and/or require under the SDWA for UIC projects to preventing "endangerm ent of USDW." AWWA recognizes that EPA’s regulatory authority is lim ited by the requirements of the SDWA and will be advocating that several portions of the SDWA be amended to better protect the nation’s groundwate r resources. Issues that we will be addressing include:

1. The definition of a USDW is provided within the SDWA, which may require amendment if the quality and accessibili ty groundwater sources is to be protected. We recognize th at the 10,000 mg/L TDS limit is very outdated, and that a new upper limit should be establis hed and applied when siting Class VI

wells. We hesitate to recomm end any specific number at th is point in time, given that some drinking water utilities are so stressed for water resources that they are investigating extremely non-traditional water sources with high TDS levels.

2. Endangerment is defined by the SDWA and may need to be redefined to protect beneficial uses. The proposed rule seems to be focused on preventing brine from the carbon dioxide storage formations fr om reaching USDWs and/or preventing carbon dioxide from contaminating USDWs and causing exceedences of primary MCLs. The protective measures of the proposed ru le may not be adequate from a source water and beneficial use pr otection standpoint as othe r changes are likely to occur besides exceeding primary MCLs (e.g., increased Fe/Mn, TDS, and lowered pH - all of which have secondary MCLs a nd possible increase in silica and boron,

20which do not have MCLs, but have water quality significance). EPA needs to be provided with the regulatory authority to protect against thes e other types of endangerment, and the SDWA should be modified to allow for these protective measures to be developed.

Individual Response: As described above, EPA is not cha nging the USDW definition; changing

the definition of a USDW is out side 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: 0181 Comment ID: 23668 Letter Lines: 471 to 477

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

Comment: AWWA recommends that EPA not ignore the potential impacts outside of the scope

of the SDWA such as those to air and hu man health if there is a massive leak. Could there be any conflicts or overlaps with the Clean Air Act or the Clean Water Act? Are other Program Offices w ithin EPA planning on looking at this proposal? This review by other EPA Program Offices would seem to be necessary given the potential impacts that could arise if there is a failure of the confining layer.

Individual Response: EPA acknowledges that there are potent ial risks associated with GS. The purpose of the Class VI requirements is to minimize and mitigate potential/identified risks through proper site characterization, well cons truction, operation, monitoring, post-injection site care, and site closure and to en sure protection of USDWs. EPA be lieves that the measures in the GS rule that directly mitigate the possibility of CO2 leakage out of the injection zone will also indirectly mitigate the risks to receptors mentioned by the commenters, including fresh water, wildlife, ecosystems, and agriculture.

EPA acknowledges that GS falls within the br oader context of CCS and acknowledges that regulatory clarity is essential for enabling GS to move forward in a manner that protects human health and the environment. The Agency is working to identify areas related to GS that could be

addressed under other statutes to ensure that GS is conducted in a manner that is protective of human health and the environment. Additionally, th e Agency is and will c ontinue to coordinate internally and with ot her Federal agencies involved in GS and CCS, including the Minerals Management Service, Bureau of Land Management , and the United States Geological Survey, to promote consistency in existing and future GS initiatives.

Letter ID: 0181 Comment ID: 23669 Letter Lines: 479 to 567

Comment Code: 1610 1.3.1 Risks to USDWs

Comment: Sole Source Aquifers: Severa l areas of the country rely on sole source aquifers as their drinking water resource. Given th e special protective measures already

21afforded to these aquifers by EPA, AW WA strongly recommends that the final geologic sequestration regulation should restrict project activities in the vicinity of these aquifers. Table 1-2 below presents a list of some of the solesource aquifers that are located in po tential geologic sequestration areas. (Note that this is not meant to be a comprehensive list of all of the sole source aquifers in the United States.)

Table 1-2: Sole-Source A quifers in Potential Geol ogic Sequestration Areas

[The information below was originally pres ented as a table. See Docket PDF EPAHQ-OW-2008-0390-0181 to see a copy of the original table.]

Aquifer Name: Upper Santa Cr uz & Avra Basin Aquifer

Location: Arizona Potentially Impacted: Tucs on, Green Valley, Catalina Characteristics: Discharges 376,000 acre-feet per year

Aquifer Name: Fresno County Aquifer

Location: California Potentially Impacted: Fresno, Clovis

Characteristics: Contains 5.8 million acre feet of water

Aquifer Name: Volusia Sole Source Aquifer

Location: Florida Potentially Impacted: Ormond Beach, Daytona Beach, New Smyrna Beach and Deland Characteristics: Covers 1,450 sq. mi.

Aquifer Name: Biscayne Sole Source Aquifer

Location: Florida Potentially Impacted: All of Dade County; parts of Broward, Monroe and Palm

Beach Counties Characteristics: Covers 4,000 sq. mi.

Aquifer Name: Eastern Snak e River Plain Aquifer

Location: Idaho Potentially Impacted: 300,000 re sidents of Eastern Idaho

Characteristics: Contains 200 to 300 million acre-feet

Aquifer Name: Spokane Valley-Rathdrum Prairie Aquifer Location: Idaho, Washington Potentially Impacted: 700,000 reside nts of Idaho and Washington Characteristics: Covers 325 sq. mi.

Aquifer Name: Chicot Aquifer System

Location: Louisiana Potentially Impacted: Lafayette, Lake Charles, Crowley

22Characteristics: Supplies 800 mgd, most for irrigation

Aquifer Name: Southern Hills Aquifer System Location: Louisiana, Mississippi Potentially Impacted: Baton Rouge, Natchez, McComb Characteristics: Supplies 290 million gallons per day

Aquifer Name: New Jersey Coastal Plain Aquifer System Location: New Jersey Potentially Impacted: Over 3,000,000 residents

Characteristics: Over 350 milli on gal. withdrawn per day

Aquifer Name: Northwest New Je rsey Fifteen Basin Aquifer Location: New Jersey, New York Potentially Impacted: Over 500,000 residents

Characteristics: Covers 1,735 square mile area

Aquifer Name: Espanola Basin Aquifer System

Location: New Mexico Potentially Impacted: Sante Fe , Los Alamos, and Española Characteristics: Covers 3,000 sq. mi.

Aquifer Name: Clinton Street Ballpark Aquifer System

Location: New York Potentially Impacted: Broome and Tioga Counties Characteristics: 16.25 mgd withdrawn for drinking water

Aquifer Name: Miami Valley Buried Aquifer

Location: Ohio Potentially Impacted: Serv es over 1,600,000 residents

Characteristics: Provides 200 mgd for drinking water

Aquifer Name: Edwards Aquifer

Location: Texas Potentially Impacted: San Antoni a, San Marcos, New Branfels Characteristics: Discharges 900,000 acre-feet per year

Aquifer Name: Columbia and York town- Eastover Multiaquifer Location: Virginia Potentially Impacted: Exmore, Olney, Chincoteague Characteristics: Covers 695 sq. mi.

Individual Response: The GS rule, at §146.82(a)(5) requires pr ospective owners or operators to submit information on all USDWs (which would in clude sole source aquifers) within the AoR. The GS rule also requires operators to submit extensive information about the site, including the geologic characteristics of the in jection and confining zones, to demonstrate that the injected

23CO2 will remain within the target formation. The Director must consider this information when determining whether GS is acceptable at a given site. EPA expects that this determination will include consideration of potenti al impacts of the GS project on any sole source aquifers.

EPA agrees that, in many cases, UIC Directors will have extensive knowledge of which areas are suitable for GS, but clarifies that it is the res ponsibility of Class VI permit applicants to demonstrate the suitability of a particular site or formation. It is the respon sibility of the Director

to evaluate the information collected and s ubmitted by the owner or operator to determine whether a permit for GS at the site is appropriate.

Letter ID: 0181 Comment ID: 23670 Letter Lines: 570 to 582

Comment Code: 1610 1.3.1 Risks to USDWs

Comment Code: 1810 1.4.1 Research on identify ing risks to USDWs

Comment: AWWA recommends that EPA prohibit ow ner/operators from constructing carbon dioxide injection wells in sole source a quifers. Owner/operators should also be prohibited from ever injecting carbon dioxi de into a formation that would result in the migration of the carbon dioxide to a point that is und er a sole source aquifer. EPA should establish a minimum distance that needs to be provided between the closest geologic sequestration project and the location of any sole source aquifers. AWWA would recommend a 50 mile minimum; however, not being experts on the details of plume migrati on, AWWA recommends that EPA and DOE perform research on this topic to better assess what the regul atory requirement should be. Including these restrictions in the final geologic sequestration regulation would allow for the protection of drinking water aquifers that, if contaminated by carbon dioxide, could result in very significant and expensive issues for the drinking water utilities.

Individual Response: EPA believes that the extensive site characterization requirements for GS projects in the final rule are pr otective of USDWs, including sole source aquifers. The GS rule, at §146.82(a)(5) requires prospective owners or op erators to submit information on all USDWs, which would include sole source aq uifers within the AoR. The GS rule also requires operators to submit extensive information about the site, in cluding the geologic characteristics of the injection and confining zones, to demonstrate that the injected CO2 will re main within the target

formation. The Director must consider this in formation and the potential impact of the GS project on any sole source aquifers when determin ing whether GS is accepta ble at a given site.

EPA agrees that, in many cases, UIC Directors will have extensive knowledge of which areas are suitable for GS, but clarifies that it is the res ponsibility of Class VI permit applicants to demonstrate the suitability of a particular site or formation. It is the respon sibility of the Director

to evaluate the information collected and s ubmitted by the owner or operator to determine whether a permit for GS at the site is appropriate.

EPA is tracking other recent research on GS and USDW prot ection including the following studies (which are available in the docket for the rulemaking):

24• Smyth et al. (2008) reviewed modeling and laboratory experi ments and field results from groundwater studies conducted at SA CROC, an ER site in west Te xas where tens of millions of tons of CO2 have been injected for over 30 years. • Zheng et al. (2008) used more than 38,000 groundwater quality analyses from aquifers throughout the US to perform reactive transpor t modeling of groundwater quality after the

intrusion of CO2. The model simu lations indicate that aquifers containing more carbonate and clay minerals are less vulnerable to CO2 intr usion, and that, while under certain conditions CO2 can potentially mobilize metals pr esent in the aquifer, mobilized amounts of the metals are always below health-based limits. • Kharaka et al. (2009) conducted CO2 injectio n field tests in Montana and reported that shallowly injected CO2 can aff ect the chemistry of shallow gr oundwater by decreasing pH and mobilizing rock and soil ions. • Nicot (2008) modeled an injection roughly equiva lent to 50 Mt CO2/year for 50 years in an area that is hydrologically similar to the Gulf Coast Basin. Model results indicate an average water table rise of approximately 1 meter with a minor increase in stream baseflow and a larger increase in ground water evapotranspiration.

ORD's National Center for Environmental Resear ch awarded six Science To Achieve Results (STAR) grants in the Fall of 2009 to recipients from major univers ities and institutions within the scope of the "Integrated Design, Modeling and Monitoring of Geologic Sequestration of Anthropogenic Carbon Dioxide to Safeguard Sources of Drinking Water" research area. These projects, which started in late 2009, include thes e lead institutions with specific topics of investigation: Clemson Universi ty will study potential impacts to drinking water aquifers of CO2-rich dissolved brines; the University of Illinois-Urbana will conduc t research related to reducing hydrologic and geochemical uncertainties associated with CO2 sequestration in deep, saline reservoirs; the University of Texas at Austin will assess appropriate monitoring approaches at geologic sequestration sites; the University of Utah will integrate design, monitoring, and modeling of GS to assist in developing a practical methodology for characterizing risks to USDWs; Columbia University will conduct laboratory experiments on shallow aquifer systems to improve understanding of geochemical and micr obiological reactions under low pH/high CO2 stress; and Princeton Univ ersity will develop a set of computational

tools to model CO2 and brine movement associated with GS.

Letter ID: 0181 Comment ID: 23671 Letter Lines: 584 to 594

Comment Code: 1610 1.3.1 Risks to USDWs

Comment: Water versus Energy: AWWA questions how will geologic sequestration projects will be permitted if there is potentia l competition for a specific geologic basin between an energy company and a dr inking water utility. Water should trump everything. The water sector should be gi ven priority, especia lly if a drinking water utility has limited or no other opti ons, as they have very limited water and storage resources. It may also be po ssible that there may not be a single federal and/or state oversight agency that could provide guidance in this arena

25as the agency would need to have over sight for air, water, environmental, energy, and other sectors. The NEPA proce ss and the state equivalent, such as CEQA in California, will need to be we ll fleshed out at the outset of the permitting process.

Individual Response: The Agency agrees that drinking wa ter is an important resource that needs protection. The primary goal of the UIC Program under the SDWA is to protect USDWs from endangerment. It is outside the scope of th is rulemaking or EPA’s authority to provide the water sector any type of priority over stor age areas. Consistent with SDWA §1422, the UIC program provides that no undergroun d injection shall be authorized if it results in the movement of fluid containing any contaminan t into USDWs, if the presence of that contaminant may cause a violation of any primary drinking water regulat ion or may adversely affect the health of persons as specified in §144.12.

EPA has added a requirement at 40 CFR 124.10(c )(1)(xi) that state and local oil and gas regulatory agencies and state agencies regulatin g mineral exploration an d recovery, the PWSS program director, and all agencies that oversee in jection wells in the state must be notified as part of the public notice pro cess for a Class VI permit.

Letter ID: 0181 Comment ID: 23672 Letter Lines: 596 to 619

Comment Code: 1620 1.3.2 Induced seismicity

Comment: Seismicity: The seismicity requirements in the Area of Review requirements are not very prescriptive. AWWA believes there is too much latitude for interpretation and that the regulation could be applied inconsistently by

Directors of different stat es. AWWA recommends making the language stronger to clarify exactly what is meant by th e following requirement (§146.82(d)(3)): "...information on seismic history includi ng the presence and depth of seismic

sources and a determination that the se ismicity would not interfere with containment." A geologic sequestration proj ect should be evalua ted on the entire risk spectrum using different range s of seismic activity and distance requirements from active faults to determin e if the proposed site is acceptable. EPA should develop guidance that will a ssist owner/operators in making the appropriate determinations regarding seis mic risk for a geologic sequestration project. For example, is there a mini mum distance that should be provided between the potential plume footprint a nd an area of seis mic activity? This

information is critical as different owner/operators coul d decide to take on a

different level of risk due to their co mfort with the financial implications. AWWA does not want to see USDW protection compromised due to faulty assumptions about seismic activity in and ar ound a potential project site.

AWWA recommends that EPA also investig ate the need for modeling the potential for seismic shifts due to the changes in subsurface pressures associated with the carbon dioxide injection process. A litera ture search should be performed to see if either Laurence Berkley Nation al Laboratory or the National Energy

26Technology Laboratory has developed a ny information on this topic.

Individual Response: EPA believes that decisions about seis mic risk should be made on a sitespecific basis. The Class VI requirements are desi gned to ensure that, where GS is employed, it is done in a manner that protects USDWs from endangerment. These requirements include site characterization during which owners or operato rs must submit information about the seismic history of and seismic sources near a proposed GS site, as well as data on known or suspected faults in the AoR, geomechanical information on fr actures, stress, ductility, rock strength, and in situ fluid pressures within the confining zone as specified in §146.82(a)(3). This information is evaluated by the Director in conjunction with information about well construction, operation, monitoring, post-injec tion site care, and other site-specific information. The Director determines the suitability of a potential project site fo r GS. Sites with the potential for reopening or

reactivation of faults or un acceptable seismic risk that co uld otherwise interfere with

containment would not be suitable for GS sites–as owners or operators se eking to inject CO2 for

GS at such sites would not be able to dem onstrate USDW protection from endangerment.

The final rule also contains operational requ irements to ensure US DW protection including injection pressure limitations. During injection, the pressure in the injection zone must not exceed 90 percent of fracture pressure of the injection zone as specified in §146.88(a). This requirement is intended to prevent the opening of fractures or faults th rough over pressurization of the injection zone. EPA adds that these requ irements are based on extensive study and review

of scientific literature and la boratory and field experience.

EPA clarifies that the rule doe s not contain any specific require ments describing "seismically appropriate" areas, and does not believe this is appropriate for all sites. EPA believes such determinations should be made on a site-specific ba sis. If such information is available, and the

Director determines it to be relevant to the site characterization, it is in their authority to require detailed evaluations. However, EPA disagrees th at this should be a requirement for all GS projects. In many cases, UIC Directors will ha ve extensive knowledge of which areas are suitable for GS, but clarifies that it is the res ponsibility of Class VI permit applicants to demonstrate the suitability of a particular site or formation. It is the respon sibility of the Director

to evaluate the information collected and s ubmitted by the owner or operator to determine whether a permit for GS at the site is appropriate.

To support consistent interpretation and applic ation of the safeguards related to induced seismicity in the GS rule, EPA is developing guid ance on site characterizati on for GS projects to assist owners or operators and Directors in evaluating permit requirements and applications under §146.82. The guidance provides recommendati ons to owners or operators regarding information to support characterizing the re gional geology and hydroge ology of a proposed GS site as well as how to perform the necessa ry geochemical, geomechanical, and geophysical analyses of the injection and confining zone. EP A expects that this guidance will assist permit writers/UIC Directors in making an objectiv e decision about requiring additional confining layers. The guidance can be found on EPA’s website at http://water.epa.gov/type/groundwater /uic/wells_sequestration.cfm.

27Letter ID: 0181 Comment ID: 23674 Letter Lines: 621 to 632

Comment Code: 1310 1.1.2.4 Comments on other "out of scope" issues, e.g., pore space ownership

Comment: Project Security: AWWA recommends that EPA work with the Department of Transportation and the Department of Homela nd Security to ensu re the safety and security of geologic sequestration proj ects. We have concerns about the

unintentional or inte ntional release of stored ca rbon dioxide and the related control and monitoring systems required, as well as security measures. A requirement for strict monitoring syst ems during project construction and operation is necessary to ensure that the project is not intentionally sabotaged, as this could result in a ma ssive leak of carbon dioxide out of the

confinement zone and into the environmen t. EPA should mandate strict monitoring systems be included as part of any geol ogic sequestration proj ect, not only to ensure the safety of USDWs, but also the safety of those living in the footprint of the project.

Individual Response: EPA clarifies that pipelines and CO2 transport are outside the scope of the Class VI GS rulemaking. The Class VI GS regulation is being promulgated under authority of the Safe Drinking Water Act. The purpose of the Class VI GS rule is to ensure consistency in permitting underground injection of CO2 at GS operations across the United States and provide requirements to prevent endangerment of USDWs in anticipation of the eventual use of GS to

reduce CO2 emissions.

Regarding the comment on ensuring the safety and security of GS projects related to

unintentional or inte ntional release of stored CO2, EPA clarifies that th e purpose of the Class VI GS rule is to ensure that where GS technologies are deployed, GS is performed in a manner that protects USDWs from endangerment. EPA agrees that testing and monitoring are important aspects of ensuring USDW protection, and the Cl ass VI GS rule requires that owners or operators develop and implement a testing and m onitoring plan. See the fi nal rule and preamble discussion of testing and monitoring requi rements for additional information.

Letter ID: 0181 Comment ID: 23675 Letter Lines: 634 to 644

Comment Code: 1910 1.4.4 Stakeholder outreach

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

Comment: Data and Research Needs: AWWA believes that stakeholder access to the necessary data is lacking and will inhibit maki ng informed/transparent decisions on geologic carbon sequestration projects. Stak eholders need better and more accessible data and data reduction tools (i .e., GIS maps). EPA should consider creating an interactive web based data warehouse that w ould store data and GIS layers on large carbon dioxide emitters, drinking water groundwater basins, seismic/volcanic/geothermal zones, pr oposed carbon dioxide saline injection basins, etc. and provide the ability to overlay layers. Stakeholders would then

28have improved abilities to evaluate a pr oposed geologic sequestration project to determine if they would be impacted by the carbon dioxide plume and/or associated pressure front.

Individual Response: EPA notes that the full results of the regional ca rbon sequestration partnership pilot projects will be available to the public once the projects are complete (the results of Phase II of these projects are currentl y available). Results of other research sponsored by EPA and DOE are available in the GS rulemaking docket as it is complete.

EPA agrees that all information presented to the public must be clea r, understandable, and

available. In addition to re quiring public notice of all dr aft permits under §124.10(a)(1)(ii), stakeholders may request copies of the draft permit and the pe rmit application during the draft permit comment period; the application include s data on the geology of the injection and confining zones which are likely to be used as inputs for modeling. However, it is likely that information submitted in support of a permit in its original form (e.g., modeling inputs) may be extremely technical and not easily understood by a lay audience. Permitting authorities are required under §124.8 to produce a fact sheet whic h typically summarizes relevant information for the public in a much more understandable format than the supporting data in a permit application. The fact sheet describes the draft permit conditions, procedures to determine the final decision on the permit, any procedures to request a hearing, and pr ocedures that may be available for additional public participation in the final permitting decision. EPA will encourage permitting authorities and operators to pres ent all modeling data to the public.

EPA has no plans to create a web-based GIS data base, due to the sheer volume of information required and variety in GIS software products available by potential users.

Information about specific GS projects would be available from permitting authorities as part of

the administrative record associated with each permit. EPA will encourage (but not require) that

this information be available online.

Letter ID: 0181 Comment ID: 23676 Letter Lines: 646 to 674

Comment Code: 1840 1.4.1.3 Other research

Comment: AWWA also recommends that EPA review the following reports that address the potential costs of treating source water that has lowered pH levels and/or increased concentrations of iron, minera ls and other potential contaminants.

- AWWA projects: o Managing Change and Unintended Conseque nces: Lead and Copper Rule Corrosion Control Treatment (WITAF) o Regulatory Risk Assessment fo r Arsenic in Water (WITAF) o Technology and Cost Review of the Proposed Arsenic Regulation (WITAF)

- AwwaRF projects:

29o Adsorbent Treatment Technologies for Arsenic Removal (#2731) o Demonstration of Emerging Technologi es for Arsenic Removal (#2661) o Implementation of Arsenic Treatment Sy stems Part 2: Design Considerations, Operation, and Maintenance (#2665) o Arsenic Removal by Iron-Modified Activated Carbon (#3158)

o Subsurface Treatment For Arsenic Removal--Phases I and II (#3082)

o Characterization and Performance of F ilter Media for Manganese Control (#2951) o Occurrence of Manganese in Drinking Water and Manganese Control (#2863)

o Advanced Processes for Simultaneous Arsenic and Manganese Removal (#2748) o Occurrence Survey of Boron and Hexavalent Chromium (#2759) o Integrated Water Treatment: Soft ening and Ultrafiltration (#2647) o Enhanced Reverse Osmosis Systems: Interm ediate Treatment to Improve Recovery (#4061) o Membrane Treatment Of Impaired Irrigation Return (#4069) o Zero Liquid Discharge Desalination of Wa ters with High Organic Content (#4163) o Zero Liquid Discharge for Inland Desalination (#3010) o Comparison of Zinc vs Non-Zinc Corrosion Control for Lead and Copper (#4103)

o Effect of Nitrification on Corrosion in the Distribution System (#4015

Individual Response: EPA acknowledges that there are pote ntial risks associated with GS including the potential for leakage of CO2 into USDWs which may result in the mobilization of substances that could endanger USDWs or affect drinking water supplies and increase treatment

costs. Recent research has focused on addressing this concern. EPA is funding research at the Lawrence Berkeley National Laboratory (LBNL) on potential USDW impacts associated with mobilization of trace elements. In the August 31, 2009, Notice of Data Availability and Request for Comment (74 FR 44802), EPA published the results of the study, which evaluated the potential for GS to cause changes in ground wa ter 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). In th e study, LBNL estimated the amount of trace elements from native mineral sp ecies that could poten tially be mobilized by

the intrusion of CO2 and the potential ground water concentrati ons that coul d result, to determine the potential for drinking water standa rds to be exceeded. Results from this model simulation suggest that if CO2 were to leak into a shallow aquife r, the potential for mobilization of lead and arsenic could be enhanced, causing increases in the concentration of these trace elements in ground water. The Agency continues to monitor research related to CO2 confinement, potential for CO2 leakage, and mo bilization of trace elements. EPA 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 clarifies that the purpose of the Class VI requirements is to minimize and mitigate potential/identified risks through proper site characterization, well construction, operation, monitoring, post-injection site care, and site closure. Th e rule at §146.82 requires owners or operators to submit extensive data about a proposed GS site in order to eliminate sites with potential for unacceptable fluid movement that could endanger USDWs. Operators must also develop and follow an emergency and remedial response plan to address any adverse effects associated with the GS operation at §146.94) and maintain financial responsibility to address

30contamination under §146.85.

Letter ID: 0181 Comment ID: 23677 Letter Lines: 676 to 687

Comment Code: 1840 1.4.1.3 Other research

Comment: The lack of good background data and ina ppropriate oil and gas well closures reflect inadequate regulator y oversight that can only get worse as regulatory agencies are asked to take on more activiti es related to climate change. Climate change adaptation and mitigation measures, such as geologic sequestration, may be delayed due to inadequate regulatory ag ency resources (e.g., number of staff and expertise). EPA needs to support significant research to reduce the

uncertainties associated with climate change and afford better long-term planning decisions as water utilities and their customer s are likely to feel a disproportionate impact due to anticipate d adaptation and miti gation activities.

EPA should also work in concert with othe r federal agencies to spur research into technologies that can convert ca rbon dioxide into inert or innocuous products.

Individual Response: EPA acknowledges that there may be technical and administrative challenges including resource concerns , and will work closely with the states to assist them in resolving funding issues or acquiri ng the resources, personnel, and training needed to address the unique technical challenges associated with GS . Please see EPA's guidance for primacy agencies on implementing the GS rule, which w ill be available on EPA’s website at http://water.epa.gov/type/groundwat er/uic/wells_se questration.cfm.

While developing the GS regulation, EPA evaluate d relevant GS research , including projects conducted by the seven regional carbon seque stration partnerships funded by the U.S. Department of Energy (DOE) and coordina ted through the National Energy Technology Laboratory (NETL), and several international pr ojects. Additionally, EP A's Office of Water

continues to fund research at the Lawrence Berk eley National Laboratory examining the effects of CO2 interaction on ground water aquifers an d any potential mobilization of trace elements that may occur. EPA is communicating with other research organizations and academic institutions including, among others, Princet on University, Massachusetts Institute of Technology, and Montana State University, wher e specific research on geologic sequestration, injection well materials, and CO2 monitoring tech niques is in progress. EPA is also working with DOE, USGS, and others to identify tools and training techniques th at will provide GS permitting assistance and technical expertise as appropriate. Additionally, EPA's Office of Research and Development (ORD) is undertaking multiple research efforts on GS. Topics of research include bolstering di fferent default thermodynamic databases to include more comprehensive information on aqueous complexes and solid-phases that contain

carbonate/bicarbonate an d toxic elements for which EPA has a listed MCL (maximum concentration level) for safe drinking water.

ORD's National Center for Environmental Research (NCER) awarded six Science To Achieve

31Results (STAR) grants in the Fall of 2009 to re cipients from major universities and institutions within the scope of the "Integrated Design, Modeling and Mon itoring of Geologic Sequestration of Anthropogenic Carbon Dioxide to Safeguard S ources of Drinking Water" research area. These projects, which started in late 2009, include thes e lead institutions with specific topics of investigation: Clemson Universi ty will study potential impacts to drinking water aquifers of CO2-rich dissolved brines; the University of Illinois-Urbana will conduc t research related to reducing hydrologic and geochemical uncertainties associated with CO2 sequestration in deep, saline reservoirs; the University of Texas at Austin will assess appropriate monitoring approaches at geologic sequestration sites; the University of Utah will integrate design, monitoring, and modeling of GS to assist in developing a practical methodology for characterizing risks to USDWs; Columbia University will conduct laboratory experiments on shallow aquifer systems to improve understanding of geochemical and micr obiological reactions under low pH/high CO2 stress; and Princeton Univ ersity will develop a set of computational

tools to model CO2 and brine movement associated with GS.

EPA is using an adaptive approach to re gulating GS under the UIC Program. Even after finalization of the GS regulation, the Agency plan s to collect and review data every six years on GS projects to determine whether the appropr iate 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: 0181 Comment ID: 23678 Letter Lines: 697 to 721

Comment Code: 2166 1.6.3.2 Comments opposing injection into unmineable coal seams

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

USDW

Comment: Category: USDW Location

EPA Request for Comment: EPA is proposing to preclude the inje ction of CO2 for long-term storage into coal seams where they are above the lo wermost USDW. EPA requests comment on this propos ed prohibition. EPA Notice 43503.

AWWA Response: AWWA recomme nds that EPA preclude the inje ction of carbon dioxide

into coal seams located above the lowermos t USDWs. First and foremost, AWWA is adamantly opposed to the injection of car bon dioxide into any storage formation

not located beneath the lowermost USDW. If a utility ever desired to use the USDW as a water resource, they would have to drill through the carbon dioxide plume, thus creating a pathway for carbon dioxide to potentiall y migrate out of the confining layer and into nearby aquifers. This coul d cause contamination of USDWs located above the coal seam, and result in significant remediation activities for a water utility. Second, litt le research has been conducted to determine the specific impact s that storage of carbon dioxi de would have on coal

seams. Much of the research that has been performed to date has been on either carbon dioxide storage in salin e reservoirs or in deplet ed oil/gas fields. AWWA

32recommends that at this point in time, EPA preclude the injection of carbon dioxide into all coal seams, no matter wher e they are located in the subsurface. This regulation was not designed for coal seams to be used as carbon dioxide storage reservoirs. Therefor e, AWWA recommends that any wells constructed for the injection of carbon dioxide into coal seams wells be permitted under the Class V experimental wells until the pot ential impacts of coal seam carbon dioxide sequestration on US DWs are better understood.

Individual Response: The final GS rule does not preclude in jection into unmineable coal seams (or any non-USDW formation type) provided owners or operators can demonstrate that GS can be performed in a manner that protects US DWs from endangerment as required under today’s

final rule.

EPA recognizes that GS in unmineable coal seam s has been the subject of less research than saline formations or depleted oi l and gas reservoirs. However, EPA has examined select field projects involving injection into unmineable co al seams, including the Pump Canyon Site, near Archuleta, New Mexico. In the Notice of Data Availability and Reque st for Comment, EPA described research at the Pump Canyon site where the Southwes t Partnership is studying CO2 injection into deep, unmineable coal seams and pe rforming a "seal analysis" of the ability of the

Kirtland Formation to act as a barrier to the m ovement of CO2 or othe r reservoir fluids. EPA continues to follow this projec t, recently completed projects, and ongoing GS projects injecting

into unmineable coal seams. Other coal seam in jection projects are underway through the RCSPs in the Illinois Basin, Black Warrior Basin, and Central Appalachian Basin.

EPA acknowledges that there may be risks associated with GS into coal seams. For this reason, the Agency is using an adaptive approach to regu late GS injection. The Ag ency anticipates that in the near-term, most GS in unmineable coal seams will continue to be experimental. Such projects may be permitted as Class V experi mental technology wells if they are of an experimental nature (i.e., to test GS technologi es and collect data).EPA will collect and review project data on early GS projects , including those that inject into various formation types, to determine whether the appropriate amount and t ypes of information and documentation are being collected. EPA plans, every six years, to collect and review data on GS projects to determine whether the appropriate amount and types of information and appropriate documentation are being collected, and to determine if modificatio ns to the requirements are appropriate or

necessary.

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

the final rule.

Letter ID: 0181 Comment ID: 23679 Letter Lines: 723 to 739

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

USDW

33Comment: EPA Request for Comment: EPA is soliciti ng comment on whether CO2 injection should be allowed into an injection zone above the lowermost USDW, when the Director determines that geologic cond itions (e.g., thousands of feet of intervening formations between the inj ection zone and the overlying and/or underlying USDWs) exist that will prevent fluid movement into adjacent USDWs.

EPA Notice 43512.

AWWA Response: As previously stated, AWWA is adamantly opposed to the injection of carbon dioxide into any storage forma tion not located beneath the lowermost USDW. If a utility ever desi red to use the lowermost USDW as a water resource, they would have to dril l through the carbon dioxide pl ume, thus creating a pathway for carbon dioxide to potentially mi grate out of the co nfining layer and into nearby aquifers. This could cause c ontamination of USDWs located above the storage aquifer, and result in significa nt remediation activities for a water utility. AWWA recommends that EPA incl ude a section in the final regulation prohibiting the injection of carbon dioxide into any form ation located above the

lowermost USDW.

Individual Response: As described above, EPA agrees that protecti ng USDWs from endangerment must be a top priority. The Agency believes that there are limited circumstances where injection above the lowermost USDW can be performed in a manner that protects USDWs, as long as appropriate protections are in place. The final GS rule at §146.95 establishes a process by which owners or operators can se ek a waiver of the Class VI injection depth requirements for injection into non-USDW fo rmations above and/or between USDWs.

EPA believes that the requirements at §146.95 w ill ensure USDW protection while providing flexibility to UIC Program Dir ectors and owners or operators who undertake CO2 injection for GS. EPA’s approach to addressi ng injection depth vari ability through a waiver process responds

to concerns about future drinki ng water resource availability and the need to ensure that high quality water remains available in sufficient qua ntities to supply drinking water needs. For additional information on the waiver approach, pleas e see the final rule and preamble, as well as EPA's responses to comments on the Notice of Data Availability and Request for Comment.

Letter ID: 0181 Comment ID: 23680 Letter Lines: 741 to 758

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

Comment: EPA Request for Comment: EPA specifically seeks comment on the merits of requiring the identification of additional confining and containment zones above the primary (i.e., lowermost) confining zone that could further impede vertical fluid movement and allow for pre ssure dissipation. EPA Notice 43506.

AWWA Response: AWWA recomm ends that EPA require owne r/operators to identify these additional confining and contai nment zones as part of the site

34characterization process. This identifi cation is important to understand the project as a whole, and failing to iden tify these additional zones results in a very large knowledge gap in the identification of poten tial mitigation options

in the event that a leak occurs from th e primary confining layer. Having this information available to regulators and st akeholders would allow for a better understanding of the project as a whole, and would provide for a more informed and comprehensive review process. If cer tain stakeholders, such as drinking water utilities, were provided with this information, utilities would have a better understanding of a geologic sequestrati on project with th e knowledge that multiple confining layers separated the car bon dioxide injection zone from their

USDWs.

Individual Response: EPA agrees with the commenter that, in some situations, the presence of additional confining and containment zones above the primary (i.e., lowermost) confining zone can improve USDW protection from endangermen t. EPA disagrees that secondary confining zones are required at all sites, e.g., where a prim ary confining zone that free of transmissive

faults or fractures and of suffi cient areal extent and integrity to contain the injected carbon dioxide stream and displaced formation fluids and allow injection at proposed maximum pressures and volumes without in itiating or propagating fractures in the confini ng zone(s) (per §146.83(a)) is demonstrated to be present. The final regulation retains the requirement at §146.83(b) which affords the Director discretion to require owners or operators to identify and

characterize additional zones.

Letter ID: 0181 Comment ID: 23681 Letter Lines: 760 to 796

Comment Code: 4470 2.4.4.4.2 Comments opposing aquifer exemptions in all cases

Comment: EPA Request for Comment: EPA is also requesting 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.

AWWA Response: AWWA does not support aquifer exemptions for the purposes of Class VI injection projects. Water resour ces are becoming extremely limited in many parts of the country and many drinki ng water utilities will be turning to alternative supply sources, including br ackish and saline gro undwater, as well as deeper USDWs. 40 CFR 146.4 states that:

"An aquifer or a portion thereof which m eets the criteria for an underground source of drinking water...may be determin ed...to be an exempted aquifer if it meets the following criteria: (a) It does not currently serve as a source of drinking water; and (b) It cannot now a nd will not in the future serve as a source of drinking water becau se: (1) It is mineral, hydrocarbon or geothermal energy producing, or can be demonstrated by a permit applicant as part of a permit application for a Class II or III operation to contain minerals or hydrocarbons that considering their quantity and location are expected to be commercially producible, (2) It is situated at a depth or location which makes

35recovery of water for drinking water pur poses economically or technologically impractical; (3) It is so contaminated that it would be economically or technologically impractical to render that water fit for human consumption; or (4) It is located over a Class III well mining area subject to subsidence or catastrophic collapse; or (c) The total dissolved solids content of the ground water is more than 3,000 and less than 10,000 mg/l and it is not reasonably expected to supply a public water system."

As previously stated, many drinking wate r utilities are exploring ground water resources that might not have been previ ously feasible to access or treat. The underlined portions of the aquifer exem ption regulations are problematic as ground water resources that fit these de finitions are now being tapped, given that much of the easily accessible and/ or treatable ground water has already been utilized or allocated. By allowing fo r aquifer exemptions in these cases, EPA is precluding their use as a future USDW at a time when the country’s remaining ground water resources should be aggressively protected. Therefore, AWWA recommends that EPA not allow aquife r exemptions for the purposes of Class VI injection.

Individual Response: EPA believes that there are limited circumstances where aquifer exemptions for GS may be warranted, and the final GS rule allows for the expansion of the areal extent of existing aquifer exemptions for Cl ass II EOR/EGR wells tran sitioning 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.

If an owner or operator applies for a Class VI permit to inject CO2 into a previously exempted aquifer (non-USDW) that is lo cated above and/or between USDW s, the permit applicant must also apply for a waiver of the injection depth re quirements pursuant to §146.95 to ensure that if a waiver is granted, USDWs above and below the inje ction zone are protected from endangerment.

The Agency developed the waiver process to ad dress comments and conc erns about current and future drinking water resources and the use of cl imate mitigation technology at appropriate sites. The aquifer exemption requirements in the final ru le provide flexibility and afford owners or operators an opportunity to asse ss and select a suitable GS si te while also preserving USDWs (i.e., formations/aquifers afforded SDWA protec tion). 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 fi nal GS rule. EPA agrees with the commenter's concerns about USDW preservation and protection and believes that , in most cases, the injection depth waiver is a more appropriate option than aquifer exemptions for Class VI injection, and that aquifer exemption expansions for GS should be granted in limited circumstances.

EPA agrees that future water resources needs ar e an important consideration, and believes that the injection depth waiver process at §146.95 res ponds to concerns about future drinking water resource availability and the need to ensure high quality water remains available in sufficient quantities to supply drinking wa ter supply needs. For additional information on the waiver

36approach and aquifer exemptions for Class VI we lls, 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.

Letter ID: 0181 Comment ID: 23682 Letter Lines: 798 to 815

Comment Code: 4342 2.4.4.2.1 Comments in favor of setti ng a minimum injection depth

Comment: EPA Request for Comment: EPA seeks comment on whether the Agency should set

a minimum injection depth requirement for CO2 GS, rather than require that such injection take place below the lowermost USDW. EPA Notice 43512.

AWWA Response: EPA should consider se tting a minimum injection depth for geologic carbon sequestration as well as re quiring that the in jection take place

below either the lowermost USDW or the lowe rmost aquifer that would be used as a drinking water source. AWWA believes this is necessary to ensure that carbon dioxide injected in the s upercritical phase remains as such. The IPCC Special Report on Carbon Dioxide Capture and St orage suggested that carbon dioxide should be sequestered depths of at leas t 800 to 1,000 meters because at these depths, supercritical carbon dioxide has a liquid-like density that provides the potential for efficient utilization of u nderground storage space in the pores of sedimentary rocks. Providing for a minimu m depth for carbon dioxide injection would strengthen the protective measures fo r USDWs. However, it is important to note that the minimum injection depth shoul d be coupled with the provision that carbon dioxide must be injected below either the lowermost USDW or the lowermost aquifer that could be used as a drinking water source.

Individual Response: EPA disagrees that it is necessary to set a minimum 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 agrees that protecting USDWs from endange rment must be a top priority. The Agency

believes that there are limited circumstances wh ere injection above the lowermost USDW can be performed in a manner that protects USDWs, as l ong as appropriate protections are in place. The final GS rule at §146.95 establishe s a process by which owners or operators can seek a waiver of the Class VI injection depth 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 conjunction with the permit applica tion submission) to dem onstrate that injection

of CO2 into a non-USDW that is above or be tween USDWs can be done in a manner that is protective of USDWs. It estab lishes: 1) requirements specifyi ng information that owners or operators must submit, and Dir ectors must consider, in consul tation with PWSS Directors; 2)

37procedures for public notice of a waiver application and for Director-Regional Administrator communication; 3) the waiver i ssuance process; and, 4) additiona l requirements that apply to owners or operators of Class VI wells granted a waiver of the injection depth requirements to ensure USDW protection above a nd below the injection zone.

Letter ID: 0181 Comment ID: 23683 Letter Lines: 817 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: Category: Grandfathering Wells/ Enhanced Oil Recovery Wells

EPA Request for Comment: Injection of CO2 for the purposes of enhanced oil and gas recovery (EOR/EGR), as long as any production is occurring, will continue to be permitted under the Class II program. EPA seeks comment on the merits of this approach since owners or operators of some Class II EOR/EGR wells may wish to use wells for the purposes of production and GS prior to the field being completely depleted. EPA Notice 43502.

AWWA Response: AWWA agrees with this approach and suppor ts the continued operation of Class II wells for EOR/EGR as long as they are still producing. However, AWWA recommends that an econom ic test for oil and gas reservoir "depletion" be used to determine when the Class II well should be transitioned to Class VI, and then operated under the Class VI conditions. One suggestion for determining when the reservoir has been depl eted is to determine what the lowest physical amount of production would be. When oil or gas production reaches this point, the owner or operator would be re quired to plug the production wells and begin the application process for conver ting the remaining injection wells to Class VI wells. EPA needs to monitor the operation of existing Class II wells to ensure that they are not being operated as carbon sequestration projects, as there are significant differences in the permitting and operation of these two classes. Companies will try to bypass some of the Class VI construction requirements by designing and operating the sy stem as an EOR/EGR project for a few years, and then converting it to a geologic sequestration system.

Individual Response: EPA agrees that the nature and risk s of CO2 injection for long term storage is different from Class II CO2 injection for EOR, and that tailored requirements for GS wells are appropriate and necessa ry to protect USDWs from endangerment. For this reason, the Agency tailored UIC requirements for Class VI wells that address the general risks deep injection may pose to USDWs and specifically addr ess the unique nature of CO2 GS (i.e., very large volumes, very long time-periods, and reservoir pressure conditions).

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

38USDWs 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 perm its from Class II to Class VI. The guidance will assist Directors in determining whether an injection project should be transitioned from Class II where the primary purpose is oil and gas production to Class VI where the primary purpose is long-term storage of large volumes of CO2. The gu idance describes the recommended methods the Director may use to evaluate change s in risk to USDWs from projects, and how the Director may determine whether a project should be regulated within th e Class II or Class VI UIC program. This guidance will be available on EPA’s website at http://water.epa.gov/type/groundwat er/uic/wells_sequest ration.cfm. For more information, please

see the discussion on transition of Class II well s in the preamble to the final GS rule.

Letter ID: 0181 Comment ID: 23684 Letter Lines: 842 to 874

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

Comment: EPA Request for Comment: EPA seeks comm ent on the approach to grandfather construction requirements at the Director ’s discretion for existing Class I, Class II, and Class V wells seeking to c onvert to Class VI wells, and whether additional construction require ments would be necessary to prevent endangerment

to USDWs from the GS of CO2. EPA Notice 43502.

AWWA Response: The construc tion requirements for the other well classes may not be as stringent as the requirements for Cl ass VI wells. AWWA recommends that in

order for wells from the other classes to be used for the injection of carbon dioxide, the wells must have been construc ted using methods that are at least or more stringent than the Cla ss VI requirements. Otherwise, as stated previously, it may encourage companies to construct an EOR well under the less strict Class II rules, with the goal of running the operation for a few years and then converting to a carbon se questration operation.

Certain operating methods for Class II well s may result in conditions that would be unacceptable for geologic sequestration. For example, EOR wells that used saltwater may be deteriorated to a point that would not be acceptable for the injection of carbon dioxide for geologic sequestration. In this case, these wells may have been constructed using di fferent methods and ma terials that are not compatible with carbon dioxide. AWWA re commends that the owner/operators are required to prove that the grandfathered wells were constructed using corrosion resistant materials, and were cemented along the casing in ac cordance with the Class VI requirements. The well should be inspected to determin e if any interior or exterior corrosion had occurred, and if so, there should be a determination that the well is not acceptable for use as a Class VI well. The review process should also include long-term demonstr ation by the owner/operator of the performance of the well as a Class II we ll. This review could provide an indication of continued prevention of USDW contamination. While these are fairly

39strict requirements, following this pr ocess is essential to prevent the

contamination of USDWs or other source water aquifers. This should be the ultimate goal of the grandfathering process, not the prevention of additional construction costs for the owner/operator.

Individual Response: As described above, EPA agrees that a cautious approach to grandfathering is appropriate, particularly gi ven that the converted well will be used for a substantially different process, which involves increased reservoir pressures associated with large volumes of stored CO2 and the corrosivity of CO2 in the presence of water. The final GS rule provides for the construction of these wells to be grandfathered (per 146.81(c)). EPA has included a requirement in the final GS rule that owners or operators seeking to convert existing wells for long term storage must demonstrate to the Director that the grandfathered wells were engineered and constructed meet the require ments at §146.86(a) and en sure protection of USDWs, in lieu of requirements at §146.86( b) and §146.87(a). EPA clarifies that only the construction requirements are grandfathered and th at all other Class VI requirements (reporting, monitoring, mechnical integrity testing, etc.) must be met following a determination under §146.81(c).

Letter ID: 0181 Comment ID: 23685 Letter Lines: 880 to 884

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

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

Comment: AWWA Response: Grandfathered wells ma y not have some of the protective

measures that are required in the proposed regu lation, such as the down-hole shut-off valve. This valve is an important safe ty mechanism and AWWA believes that a Class VI well should not be permitted fo r carbon sequestration unless it is constructed with this appurte nance. Also, some of the potentially grandfathered

Individual Response: EPA believes that some wells can be re-permitted for use as Class VI wells and safely operated, even if down-hole sh ut-off systems cannot be installed. EPA will not require automatic down-hole shut-off devices for ons hore Class VI wells since it is not necessary in all cases to ensure protection of USDWs fr om endangerment. Instead, the final rule, at §146.88(e)(2), requires that owners or operators of onshore Class VI we lls install automatic

surface shut-off devices. The rule affords Director 's discretion to mandate automatic down-hole shut-off devices in onshore situations that may wa rrant their use. However, the Agency believes

that offshore Class VI wells present unique construction and operational conditions, including

isolation from shorelines and the need to c onstruct wells through the water column and the subsurface, which may delay response time in the event of well difficulties. The rule requires, at §146.88(e)(3), that owners or operators of offshore wells within State terr itorial waters install automatic down-hole shut-off systems. EPA beli eves that these requirements at §146.88(e) ensure that proper precautions are taken to pr event subsurface fluid movement and ensure protection of USDWs.

The final GS regulation requires at §146.81(c) that owners or ope rators seeking to grandfather

40existing Class I, II, or V wells for GS demonstrat e that grandfathered wells were engineered and constructed to meet the requirements at §146.86(a) and ensure protection of USDWs, in lieu of requirements at §§146.86(b) and 146.87(a). In additi on, these grandfathered wells would still be required to meet the other requirements of the GS regulation (e.g., operating, monitoring, MIT, well plugging, and post-inject ion site care and site closure requirements).

Letter ID: 0181 Comment ID: 23686 Letter Lines: 884 to 893

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

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

Comment: constructed with this appurte nance. Also, some of the potentially grandfathered wells may not be constructed in a way that would allow for the mechanical integrity testing requirements that are pa rt of the regulation. AWWA believes that some of the very prescriptive te sting and monitoring requirements are necessary, as the grandfathered wells may not have been constructed in a way

that would allow for these tests to be carried out. AWWA recommends that EPA include in the final regula tion a requirement that the owners/operators of the wells conclusively prove that the gra ndfathered wells can be operated in compliance with all the other requirement s of the proposed regulation or the wells will not be permitted for Class VI operation.

Individual Response: EPA agrees with the commenter regarding the need for MITs; the final rule requires both internal and external mechanical integrity testing. Mechanical integrity testing

is one of the cornerstones of the existi ng EPA UIC program. MIT requirements at §146.89 ensure protection of USDWs from endangerment and provide an important early warning of potential problems in the injection well. Routine mechanical integrity testing of injection wells provides data that enables the identification a nd remediation of well integrity problems before they lead to leakage and/or endangerment of USDWs.

EPA agrees that a cautious approach to grandfathe ring is appropriate, partic ularly given that the converted well will be used for a substantially diff erent process. The final GS rule provides for the construction of these wells to be gra ndfathered (per 146.81(c)). EPA has included a requirement in the final GS rule that owners or operators seeking to c onvert existing wells for long term storage must demonstrate to the Director that the grandfathered wells were engineered and constructed meet the requirements at §146.86(a) and ensure protection of USDWs, in lieu of requirements at §146.86(b) and §146.87(a). EPA clarif ies that only the cons truction requirements are grandfathered and th at all other Class VI requirements (reporting, monitoring, mechanical integrity testing, etc.) must be met fo llowing a determination under §146.81(c).

EPA adds that following re-permitting as Class VI wells, these projects would be subject to the requirements of the final GS rule, including MIT, monitoring, opera tional, reporting, plugging, and post-injection site care a nd site closure requirements. S ee the discussion of EPA's final regulatory approach in the preamble to the GS ru le for additional detail on these requirements.

41Letter ID: 0181 Comment ID: 23687 Letter Lines: 895 to 921

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

Comment: Category: Injection Stream

EPA Request for Comment: By defining "carbon dioxide stream" to exclude hazardous wastes (146.81(d)), EPA’s rule, if finalized, assures that it would apply only to CO2 streams th at are not hazardous wastes as defined in 40 CFR Part 261. As a result, EPA’s proposed ru le would preclude th e injection of hazardous wastes in Class VI injection we lls. EPA seeks comment on this approach

and other considerations associated with the presence of "impurities" in the CO2

stream. EPA Notice 43503.

AWWA Response: AWWA agrees with EPA’s approach in defining the "carbon dioxide

stream" to exclude hazardous wastes. Howe ver, AWWA recommends that the final regulation include more specifics on the de finition of the re quired quality of the injection stream and establishing a mi nimum concentration of carbon dioxide present in the injection stream. This re quirement for the injection stream will ensure that the injection of other harm ful or undesirable gases is limited. Our initial thoughts on this topi c would be that 100% of th e injectate must come from a carbon dioxide capture process and the injectate must be at least 98% carbon dioxide. Owner/operators must ensu re that the remaining 2% of the injectate is not made up of compounds that would result in th e injectate being classified as a hazardous waste. Also, 100% of the injection stream should be required to come from the carbon capture pr ocess as to preclude the co-mingling of wastes from other industrial processes in the injection stream as this is not an appropriate use of the Class VI injec tion wells. As AWWA is not a technical expert on this topic, AWWA recommends th at EPA pursue research in association with DOE to develop a standard for the minimum concentration of carbon dioxide in the injection stream.

Individual Response: EPA understands that many CO2 str eams may be relatively pure, and

research indicates that the estimated amounts of impurities in a CO2 stream are likely to be low. However, these estimates are based on limited in formation, and uncertainties remain about the expected concentrations of impurities from the va rious types of CO2 streams. The concentrations

of minor and trace elements in CO2 streams for GS projects are likely to vary by facility, coal composition, plant operating conditions, and pollution removal technologies.

The GS rule does not set generic purity standa rds for CO2 injectate streams (e.g., a percent CO2). Instead, the GS rule addresses the quality and quantity of impurities by requiring owners or operators to submit information on the sour ce of the CO2 and its physical and chemical properties. Specifically, the GS rule requires the owner or operator to subm it data about the site, including an analysis of the chemical and physical characteristics of the CO2 stream, as required at §146.82(a)(7)(iv), and information on the compatib ility of the CO2 stream with fluids in the

42injection zone and minerals in both the injection and the confini ng zones and the materials used to construct the well, per §146.82(c)(3). This info rmation can help the Director determine the potential for geochemical 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: 0181 Comment ID: 23688 Letter Lines: 923 to 941

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

Comment: EPA Request for Comment: Class VI requirements and permits will need to be carefully structured to ensure that they do not "authori ze" inappropriate

hazardous releases. This would include clarifying if there are potential releases from the well which are outside the scope of the Class VI permit. EPA requests comment on particular situations where this might occur. EPA notice

43504.

AWWA Response: AWWA agrees with EPA’ s assertion that the permits and well requirements need to be carefully structur ed to prevent "authorized" releases of hazardous substances into subsurface geol ogic formations. We are not aware of any situations where this might occur, as long as the inj ectate is properly

characterized and is not classified as a hazardous substance. There may be a

situation where a release of carbon dioxide from the conf ining layer might cause

the formation of a hazardous substance due to reactions with the surrounding geologic strata. To prevent this pr oblem from occurring, the geologic characteristics of the geologic forma tions should be evaluated prior to injection for potential interactions with the injectate str eam. If there are

indications that hazardous substances coul d be formed, the site should not be considered acceptable for carbon sequestration.

Individual Response: EPA agrees that proper siting, operation, and monitoring are important for protecting USDWs from endangerment. In add ition, the UIC program Director has authority under SDWA §1423 to address potential complian ce issues (e.g., potential releases that may endanger USDWs) resulting from injection viola tions in the unlikely event that a remedial response is necessary. Although EPA anticipates that the need for emergenc y or remedial actions at GS sites will be rare, the GS rule requires, at §146.94, that emergency and remedial response plans be developed and updated to address such events and that owners or operators demonstrate

that financial resources are set aside to implement the plans if necessary, per §146.85.

EPA clarifies that, while the Administrator re serves the right to promulgate regulations designating additional substances as hazardous under §102 of CERCLA, EPA intends to avoid any potential overlap of SDWA and CERCLA authority through its comprehensive Class VI requirements.

CO2 itself is not listed as a hazardous substan ce under CERCLA; however, the CO2 stream may contain a listed hazardous substance (such as mercury) or may mobilize substances in the

43subsurface that could react with ground water to produce listed hazardous substances (such as sulfuric acid). Whether such substances may result in CERCLA liability from a sequestration facility depends entirely on th e composition of the specific CO2 stream and the environmental media in which it is stored (e.g., soil or gr ound water). CERCLA exempts from liability, under CERCLA section 107, 42 U.S.C. 9607, certain “feder ally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential releases from the we ll which are outside the scope of the Class VI permit.

Letter ID: 0181 Comment ID: 23689 Letter Lines: 943 to 958

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

Comment: EPA Request for Comment: EPA’s proposal allo ws Directors’ disc retion 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 ope rations, and any potential impact of tracers on human health or ecosystems as they relate to USDWs. EPA Notice 43513.

AWWA Response: AWWA recomm ends that EPA require trac ers to be injected along with the carbon dioxide stream to provide for a better mechanism of tracking the movement of the carbon dioxide plume. Cert ain tracers could provi de for a better understanding of the plume behavior usi ng non-traditional indicators, such as those that are conservative, easy to meas ure, non-toxic, and do not degrade into

contaminants of concern. These tracers coul d be easily identified in USDWs, as well as in the vadose zone, wh ere they could be used as an indicator when carbon dioxide soil-gas monitoring proves difficu lt to interpret. Unfortunately, AWWA can not provide recommendations on specifi c tracers that could be utilized, and recommends that EPA perform research, in association with DOE, on the types of tracers that would be acceptable for use in carbon sequestration.

Individual Response: EPA agrees that tracers can be useful tools for monitoring GS projects. EPA also acknowledges that tracers can also be used to identify (i.e., tag) injections by time, producer, or location, but clarifies that any requirement for the use of tracers at GS sites would be for the purpose of identifying potential e ndangerment to USDWs as a result of CO2 movement from the injection zone.

However, EPA does not believe that tracer use is appropriate in all situations. For this reason, EPA does not require the use of tr acers at all GS sites; however, the Director has discretion to require their use 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 operato r and approved by the Director.

EPA adds that the other aspects of the extens ive monitoring required at GS sites, including monitoring of the well system, tr acking of the CO2 plume and pr essure front, and geochemical monitoring, will also detect leak s and track the CO2 plume.

44EPA will continue to track research related to tr acer use, and 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: 0181 Comment ID: 23690 Letter Lines: 960 to 991

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

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

Comment: Category: Modeling

EPA Request for Comment: EPA proposes that the owners or operato rs of GS wells be required to delineate the AoR for CO2 GS sites using computational fluid flow models designed for the specific site condi tions and injection regime. EPA seeks comment on the use of modeling fo r AoR delineation. EPA Notice 43506.

When using a proprietary model, owners or operators should cl early disclose the code assumptions, relevant equations, and scientific basis. EPA seeks comment on allowing the use of proprietary mode ls for GS sites. EPA Notice 43507.

AWWA Response: The proposed rule depends heavily on computer modeling to track the carbon dioxide plume and demonstrate that it is contai ned within the confining zone. As stated by EPA, some of these models are pr oprietary and the

rule is unclear how or if confirmation of the model results will be provided. Additionally, each of the individual propr ietary models can show a different answer to the problem. Owner/operators need to ensure that their basis for the model is static, and that the basis does not change once more details are known about the movement of the plume. For example, the operation of the geologic sequestration system should be adjusted based on modeling results, and the model shouldn't be revised because the plume is moving in a directio n not originally predicted.

AWWA recommends that EPA standardize on one specific model that is transparent and available for outside stakeholders to review, including the public. The other option is for EPA to develop a standa rd model that would be used for all geologic sequestration projects. If EPA we re to develop a standard model, a pilot program should be part of the m odel development so that the modeling

results could be validated with real- life monitoring data. In either case, clearly stating the model assumptions made during model set-up is critical, and these assumptions must be made available to stakeholders when they are reviewing

the model results.

Individual Response: The final rule does not require use of a standardized model. As described above, EPA believes that operators should have the flexibility to select models with which they

45are familiar and that are most appropriate to th e site conditions and available data types and amounts. EPA also recognizes that a standardized model for AoR delineations could be effective as long as the model accounts for the expected varia tions in site conditions, and adds that a state or regional UIC Dir ector could select one standard model if it took site-specific variations into

account.

EPA does not envision that members of the public will evaluate the AoR delineation models themselves. The models and their inputs will, by necessity, entail an extensive amount of technical information that may not be easily unde rstood by the public. EPA believes that it is the Director's responsibility, as a steward of public health and the environment, to review models, model inputs, and results and to determine whether the model is appropriate for predicting the AoR, and to distribute information that may be easily understood by the public (e.g., in the form of a fact sheet). EPA adds that its Confiden tial Business Information requirements at 40 CFR 144.5 will apply to the use of proprietary models.

Letter ID: 0181 Comment ID: 23691 Letter Lines: 993 to 1018

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

Comment: Category: Area of Review (AoR)

EPA Request for Comment: EPA seeks commen t on requiring the re evaluation of the site AoR on a periodic basis, under what conditions the AoR should be reevaluated, and the appropriateness of a 10-year minimum fixed frequency for

AoR reevaluation. EPA Notice 43507.

EPA proposes to allow a phased approach to corrective action but says this may not be appropriate in all situations; therefore EPA is proposing that the

Director have the discretion to decide to allow this approach, based on the understanding of relevant geologic a nd site conditions. EPA invites public comment on the merits and frequency of r eevaluation of the AoR as well as the phased corrective action approach for GS wells. EPA Notice 43508.

AWWA Response: AWWA recomm ends that the area of review be reevaluated more frequently than suggested by EPA in th e proposed regulation. AWWA recommends that the AoR be reevaluated annually for th e first ten years of the project, and then every five years for the remain ing operating period of the project. However, criteria should be established to trigger a shorter review period (based on a risk management approach) any time during the five-year time periods. For example, reevaluation of the AoR could be triggered by a shift in plume direction or sudden change in plum e size or pressure. The local drinking water utilities, commissions, and planning boa rds need to be included in the AoR review process in the even t that one of their drinki ng water sources becomes threatened due to a change in plume dire ction or behavior. Pu blic involvement also needs to be a mandatory part of the AoR reevaluation process

46Individual Response: EPA agrees with commenters that reevaluations of the AoR every ten years may not be sufficient to appropriately model plume and pressure front movement, establish conditions for corrective action, and ensure prot ection of USDWs from endangerment. For these reasons, the Agency changed the minimum freq uency for the AoR reevaluation at §146.84(e) from 10 years to at least every 5 years in the final GS rule. EPA believes that this revised frequency addresses commenters' concerns about the inherent uncertainties in modeling CO2 movement, the emerging nature of GS technology, risk-based targeting of monitoring activities, and the unique nature of CO2 GS. In addition, the Director has discre tion to require more frequent AoR reevaluation if he or she has reason to believe, based on site-specific information, that a five-year reevaluation schedule is not sufficiently protective of USDWs.

Letter ID: 0181 Comment ID: 23692 Letter Lines: 1020 to 1039

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

Comment: AWWA recommends that a phased corrective ac tion plan be developed as a result of the AoR reevaluation. This would prevent owner/operators from performing unnecessary work in the event that the pl ume migrates in a different direction than originally predicted. However, AWWA recommends that the required corrective actions be completed at least two years be fore the plume is expected to reach the specific location. Corrective actio ns should include reentering and replugging old or abandoned we lls that have not been cer tified to be closed in accordance with the sequestr ation requirements. Also, in the case where old wells were plugged with cement that is not compatible with carbon dioxide, these wells should be re-entered and replug ged. Finally, old wells for which no

records exist should be re-entered and re plugged to ensure that a pathway for carbon dioxide to escape is not provided.

One issue that EPA needs to consider in the final regulation is the potential cost differential for either performing all of the necessary corrective actions immediately or by phasing them in over time. If the corrective actions are phased in, EPA needs to require that the owner/operator pr ovide financial

assurance that the corrective action measur es will still be performed even if the company goes out of business and the carbon dioxide plume continues to migrate.

Individual Response: EPA believes that the phased corrective action approach is appropriate for GS projects, and retained it at §146.84(b)(2)(iv) in the final GS regulat ion. EPA believes that phased corrective action may provide many benefits to a project including, but not limited to, spreading the burden of cost, avoi ding delays in project start- up, allowing for use of future, improved corrective action techniqu es and addressing unanticipated changes in the movement of the CO2 plume or pressure front.

EPA agrees with the commenter that phased co rrective action must account for any changes in the AoR, as demonstrated through a reevaluation or other site-specific da ta. For this reason, the

47final rule includes provisions that owners or operators review and update the AoR and corrective action plan throughout the life of the project, as specified in §146.84(c). These reviews must be performed within one year of an AoR reeval uation, following any significant changes to the facility (e.g., the additio n of monitoring or injection wells), or when required by the Director.

EPA also agrees that corrective action techni ques must be appropr iate for CO2 GS. All corrective action performed under §146.84(d) must be appropriat e to the GS site and the injectate/formation fluid chemistry to ensure that the well does not allow CO2 or other fluids to move into or endanger USDWs.

Regarding financial responsibility for corrective action, EPA clarifies that th e owner or operator
must demonstrate and maintain financial res ponsibility for all need ed corrective action, regardless of whether it is to be phased. EPA is developing guidance on financial responsibility that will discuss approaches to how best to esti mate appropriate costs for all required activities. The guidance will be available on EPA's web site, at http://water.epa.gov/type/groundwat er/uic/wells_se questration.cfm.

Letter ID: 0181 Comment ID: 23693 Letter Lines: 1041 to 1087

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

Comment: Category: Permit Life

EPA Request for Comment: EPA proposes that Class VI injection well permits would be issued for the operating life of the GS project including the post-injection site care period. EPA seeks comment on the merits of this approach. EPA Notice

43523.

AWWA Response: AWWA does no t support issuing an operating permit for the life of the sequestration site. AWWA recommends issuing a lifetime operating permit for the coal plant, but with a separate and renewable permit for the operation of the geologic sequestration process. Much like the wastewater treatment plants and NPDES permits go through a permit review process every five years, AWWA recommends that this same process be used for operating permits for geologic sequestration processes. For water an d wastewater treatment plants, the operating permit is issued at the start of operation and the plant must renew it every five years. This allows for the e xpansion of plant flow, and changes in required effluent criteria due to regula tion modifications. Much as water and wastewater plants are required to ke ep up with available technology, carbon sequestration systems should be required to apply BACT when it is feasible to incorporate it into the treatment pro cess. Owner/operators should also be required to periodically re-evaluate th eir injectate stream for any emerging contaminants, and remove them if required. If wastewater treatment plants can be constructed and operating usi ng this type of process, then a sequestration

48operation should be permitted in the same manner. Process changes are part of standard business operation in that regul ations become more stringent, and processes become more efficient, and the owner/operators should be required to adapt to these changes through the permit renewal process.

AWWA recommends that the application process include a review of the site operations to see if any instances of uns afe operation or chan ges in regulation would require a change in the plant oper ation. If a problem we re detected, the permit wouldn't be immediately revoked, but the operator would be given the chance to rectify the situation so that the permit could be reissued. An owner/operator should consider the financia l implications of this requirement and plan accordingly as the process will re quire a certain level of effort every five years to execute. AWWA recommends that the permit review process be aligned with the process used for review and rene wal of NPDES permits. This would allow for all of the permit activities to be consolidated into one reapplication effort every five years.

The capacity of the various state agencies to deal with the five year permit review process is an issue that needs to be recognized. Some states that are already stressed for resources could be overwhelmed with this additional task. However, AWWA believes that this permit requirement should not be sacrificed because the states might be resource stre ssed. Therefore, the federal government should consider allocating enough money to the state programs to adequate staff their sequestration permit division

Individual Response: The final rule maintains the lifetime permit provision and clarifies that the permit extends through the post-injection site car e period (144.36(a)). However, it also adds a requirement that the Director re view each Class VI permit at l east every 5 years to determine whether it should be modified, revoked and reissu ed, terminated or a minor modification made as provided in §§144.39, 144.40, or 144.41. The Director’s re view will be informed by the owners’ or operators’ iterative reevalua tion of the project. Specifical ly, the final rule includes a requirement that the AoR be reevaluated at least every five years, and also requires owners or operators to review and update the AoR and corrective action pl an, the testing and monitoring plan, and the emergency and remedial response plan throughout the life of the project (146.84(e), 146.90(j), and 146.94(d)). They must identify necessary amendments or demonstrate to the Director that no amendment is needed. In no case can reviews occur less often than once every five years. The iterative process and subseque nt plan reevaluations ensure that time and resources are committed to the most critical aspects of the permit in preventing endangerment to

USDWs.

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

49EPA believes that these changes will address many comments in support of permit renewal. Additionally, the reevaluation pro cess could be aligned with i ssuance of other environmental permits associated with the facility, provided the minimum reevaluation frequency requirements

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

EPA adds that, in addition to the requirement that the Director review the permit at least every 5 years, as part of existing requi rements at 40 CFR 144.39, the Director has the authority to revise the permit if project operations change or if the director believes based on monitoring or operational data that the project may endanger US DWs. EPA also added te xt to 144.39(a)(5) that says permit modifications may be required if th e Director determines that a modification is necessary based on an AoR reevaluation, amendments to any of the project plans, or a review of the testing and monitoring results. The Direct or may also choose to require minor permit modifications under 40 CFR 144.41, depending on the extent of the plan amendment.

EPA acknowledges that states and other commente rs are concerned about resource availability for GS. The Agency will work closely with stat es to assist them in acquiring the resources, personnel, and training needed to address the uni que challenges associated with GS. The Agency is developing guidance materials and plans to conduct on-line and in-person training for States

and Tribes to enhance national unde rstanding of the specific require ments in the GS rule and to support primacy application development and ev entual implementation of the GS rule.

The Agency plans to collect and review data on GS projects every six years to determine whether the appropriate amount and types of information and appropriate documentation are being collected, and to determine if modifications to the requirements are appropr iate or necessary to ensure the protection of US DWs from endangerment.

Letter ID: 0181 Comment ID: 23694 Letter Lines: 1089 to 1108

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

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

Comment: Group: Well Construction

EPA Request for Comment: EPA seeks co mment regarding requirements for degradation-resistant well construction materials, such as acid-resistant

cements and corrosion resist ant casing. EPA Notice 43510.

EPA seeks comment on the merits of requi ring down-hole shut-off valves in GS

wells. EPA Notice 43511.

AWWA Response: AWWA recomm ends that injection wells be constructed from

50degradation-resistant materials to preven t carbon dioxide from escaping from a portion of the injection well that may have been compromised due to noncompatible materials. AWWA also recomme nds that down-hole shut-off valves be required for all injection wells. These va lves can be a first line of defense against contamination of USDWs due to faulty injection pr actices. Further research is needed by both EPA and DOE to identify specific construction methods that would prevent degradation of the well and the carbon sequestration site.

AWWA recommends the creation of a certific ation program that would be used to guarantee that existing or newly develope d construction methods are approved for use with geologic sequestration.

Individual Response: EPA agrees that the use of non-co mpatible materials can result in degradation and failure of the well and could ultimately endanger a USDW. Under §146.86(b)(1), casings and cement and other material s used must have sufficient strength and be designed for the life of the sequestration project. Further, materials must meet standards listed in the rule and be compatible with fluids with wh ich the materials may be expected to come into contact. Therefore, some well materials may need to be acid-resistant and some may not if they

do not come in contact with the CO2 stream or other corrosive fluids and if approved by the

Director.

EPA disagrees that the rule should contain a construction me thod certification program. EPA believes that the prescribed construction requirements for Class VI wells are sufficient to protect USDWs from endangerment. EPA adds that the requirement at §146.86(b)(1) that materials must meet or exceed standards developed by the Amer ican Petroleum Institute, ASTM International, or comparable standards acceptable to the Direct or invokes the expertise of these bodies without

the added burden of a certification program.

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/groundwat er/uic/wells_se questration.cfm.

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 such devices are not necessary in all cases to ensure protection of USDWs from endangerment. Instead, the final rule, at §146.88(e)(2 ), requires that owne rs or operators of

onshore Class VI wells install automatic surface shut-off devices. The rule affords Directors

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

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

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

51Letter ID: 0181 Comment ID: 23695 Letter Lines: 1110 to 1126

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

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

Comment: Category: Hydraulic Fracturing

EPA Request for Comment: EPA is requesti ng comment on the extent and scope to hich hydraulic fracturing should be allo wed during GS injection, and whether the use of fracturing for the purposes of well stimulation is appropriate. EPA

Notice 43511.

AWWA Response: Hydraulic fracturing dur ing carbon dioxide in jection has the potential to serious compromise the conf ining layer and AWWA recommends that this practice should not be allowed as part of the injection process. The objective of characterizing the injecti on and confining zones is to find a location that is free from faults, penetrations or other physical methods by

which carbon dioxide could es cape. Hydraulic fracturing cr eates fractures in the injection zone, and possibly the confin ing layer, which would allow for a pathway by which carbon dioxide could migr ate into USDWs. Therefore, AWWA recommends that this process not be utilized at all in geologic carbon sequestration.

Individual Response: EPA emphasizes that fracturing of th e confining zone during injection and/or stimulation is prohibited, as specified at §146.88(a). However, as described above, EPA believes there may be some circumstances wher e fracturing of the injection zone may be acceptable, provided the integrity of the confin ing system remains unaffected. The final rule allows the use of hydraulic fracturing at GS sites, where approved by the Director. Hydraulic fracturing is one of several stim ulation technologies av ailable to improve wellbore and formation injectivity.

Letter ID: 0181 Comment ID: 23696 Letter Lines: 1128 to 1170

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

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

Comment: Category: Monitoring

EPA Request for Comment: EPA’s proposal w ould require owners or operators of Class VI GS projects to monitor internal mechanical integrity of their injection wells by continuously monitoring injection pressure, flow rate, and injected volumes, as well as the annular pressure and fluid volume to assure that no anomalies occur that may indicate an in ternal leak. EPA requests comment on the

52practicability of this requirement. EPA Notice 43513.

EPA seeks comment on the appropriate frequenc y of internal and external MITs for GS injection wells, the appropriate type s of MITs, and how to optimize MIT

methods for GS. EPA Notice 43514.

EPA seeks comment on the requirement for monitoring of GS sites for the purpose of tracking the location of the CO2 plume and associat ed pressure front over

time. EPA Notice 43514

EPA’s proposal would require that owners or operators perform a pressure falloff test at least once every five year s. EPA seeks comment on the use and frequency of pressure fall-off te sting for GS wells. EPA Notice 43515.

Specifically, EPA seeks comment regarding the usefulness of i ndirect geophysical monitoring and surface air and soil gas monitoring. In addition, EPA seeks comment regarding the use of a Director-a pproved monitoring plan for GS sites.

EPA Notice 43517.

AWWA Response: Detailed monitoring guideline s were developed as part of a joint research project by AwwaRF and AWWA. Thes e guidelines are prov ided in Section

III of these comments and EPA should include the named tests and frequencies in the final regulation to ensure that protect ion of USDWs is consistent across all geologic sequestration projects. Based upon these requirements, owner/operators would develop testing and monitoring plan s, which should be reviewed and updated

at the same time as the re-evaluati on of the Area of Re view. The costs associated with monitoring of a sequest ration project should not be a major consideration when determining the type s and frequency of required monitoring. The goal of the monitoring requirements s hould be on preventing degradation of USDWs, not minimizing the cost to the owner/operator.

AWWA strongly recommends both that both internal and external mechanical integrity testing should be required to pr event leakage of carbon dioxide from the injection well. Monitoring of the pl ume and pressure front over time is absolutely required as part of the syst em operation and a project shouldn't even be considered unless this monitoring is included. All of the monitoring

Individual Response: EPA agrees with the commenter; the final rule requires both internal and external mechanical integrity testing. Mechanical integrity testing is one of the cornerstones of the existing EPA UIC program. MIT requirement s at §146.89 ensure protection of USDWs from endangerment and provide an important early wa rning of potential proble ms in the injection well. Routine mechanical integrity testing of injection wells provides data that enables the identification and remediation of well integrity problems before they l ead to leakage and/or endangerment of USDWs.

The GS rule's requirements for MITs encompa ss many of the same tests mentioned in the

53AwwaRF and AWWA monitoring guid elines, including an approved tracer log, or noise logs and temperature logs. EPA believes that the MITs described in the rule at §146.89(c) are effective methods to demonstrate external MI. They ha ve been used successfully by injection well operators for decades and provide an important early warning of potential problems in the injection well system. While the oxygen activation l og is not explicitly re quired in the rule, the regulations do provide flexibility at §146.89(e) to allow the Direct or to require additional test methods or, with the approval of the Administra tor, to approve the use of alternative MIT

methods. These additional methods could include the annual pressure test recommended in the AwwaRF/AWWA guidelines. The specific MITs required prior to start-up of injection or at well

workovers would be identified in the permit by the Director. For additional information, please see the discussion of MITs in the final rule preamble.

As stated above, EPA disagrees th at the rule should specify the monitoring techniques for all GS

sites.

EPA agrees that tracking the plume and the pos ition of the pressure front during injection operations and the post-injection si te care period will provide important data for determining that the injectate is confined within the target formation, as well as for evaluating any risks within the AoR. EPA also agrees with the commenter that data collected during site characterization (such as baseline geochemistry, pre-in jection reservoir pressure, etc.) are appropriate to ensure that there is a baseline with which to compar e GS operation and post-injection data.

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 recommended approaches for implementing a testing and monitoring plan, including pre-operational geophysical logging and testing of injecti on wells, MITs, injection well testing during operation, groundwater quality monitoring, tracking the CO2 plume and pressure front, and soil gas and surface air monitoring wh ich 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/groundwat er/uic/wells_sequestration.cfm. In addition, in January 2009, DOE published a best practices manual entitled "Monitoring, Verificat ion, and Accounting of CO2 Stored in Deep Geologic Formations" (DOE/NETL-311/081508); this manual is included in

the docket for the final GS rule.

EPA also agrees that periodic updates to the plan are appropriate. EPA clarif ies that the final GS regulation includes a requirement th at the AoR be reevaluated ever y 5 years, and it specifies at §146.90(j) that the operator revise the testing and monitoring plan to incorporate the results of

the most recent AoR reevaluation and recent operational and monitoring data.

EPA clarifies that cost -benefit analyses are not used to determine the most appropriate monitoring technologies, location, or frequency. Instead, the Agency believes that the flexibility afforded the owner or operator at §146.90 to de velop a testing and monitoring plan tailored to site-specific characteristics is appropriate for GS.

Letter ID: 0181 Comment ID: 23697 Letter Lines: 1170 to 1175

54Comment Code: 4610 2.6.1 Testing and monitoring plan requirement (seeking comment)

Comment: be considered unless this monitoring is included. All of the monitoring requirements should be put forth in a mon itoring plan, which should be reviewed and approved by the Director prior to the start of the project. This plan should be re-evaluated every five years during the permit review, and should be updated by the owner/operator based on any changes in operation or performance of the carbon dioxide plume.

Individual Response: EPA agrees with commenters that developing and following testing and monitoring plans is an important pa rt of assuring that a GS projec t is operating properly and is crucial for the early detection of potential enda ngerment to USDWs. EPA also agrees that periodic updates to the plan are appropriate. EP A clarifies that the fina l GS regulation includes a requirement that the AoR be reevaluated at least every 5 years, and it speci fies at §146.90(j) that the operator revise the testing and monitoring plan to incorporate the results of the most recent AoR reevaluation and recent operational and mo nitoring data. EPA is developing guidance on how best to develop the various required project plans, including the testing and monitoring plan. The guidance can be found on EPA’s website at http://water.epa.gov/type/groundwater /uic/wells_sequestration.cfm.

Letter ID: 0181 Comment ID: 23698 Letter Lines: 1176 to 1179

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

Comment: Pressure fall-off testing should definitely be required however the five year length between testing is too long. This should be performed on an annual basis as part of the annual reporting requirements

Individual Response: EPA believes that a frequency of at least once every five years, as specified at §146.90(f), is an appropr iate interval for pressure fall- off testing (particularly given the suite of tests operators will perform on the well and the site). EPA clarifies that the Director may require more frequent pressure fall-off tests at a specific proj ect, if necessary based on sitespecific circumstances. Pressure fall-off tests ma y be conducted in conjunction with other well performance tests (i.e., mechanical integrity testing) to ensure sa fe and effective operations. All monitoring data collected, including information from pressure fall-off tests, will be incorporated

in AoR reevaluations conducted at least every five years.

Letter ID: 0181 Comment ID: 23699 Letter Lines: 1181 to 1185

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

Comment: Surface air and soil gas mon itoring should be required however, baseline soil

carbon dioxide levels should be determined prior to the start of monitoring.

55Testing for other compounds such as tracer s that may included as part of the carbon dioxide injectate stream should also be considered in the development of the monitoring plan.

Individual Response: EPA agrees that surface air and soil gas monitoring, when coupled with subsurface monitoring, may be appr opriate at some GS projects to ensure USDW protection. In the final rule, at §146.90(h), the decision to require such monitoring rests w ith 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 operat or and UIC Director in the ev ent of a USDW endangerment, pursuant to requirements at §146.91(c). The Agency agrees with the comm enter that, if air and soil gas monitoring is performed, baseline

soil CO2 levels need to be determined befo re monitoring. This would be considered and described in the site-specific testing and monitoring plan.

Letter ID: 0181 Comment ID: 23700 Letter Lines: 1187 to 1203

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

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

Comment: Category: Required Project Plans

EPA Request for Comment: EPA seeks comment on the merits of requiring plans for monitoring, AoR, and post-inj ection site care as part of a permit application.

EPA Notice 43517.

AWWA Response: The requirement for the de velopment of plans for monitoring, AoR, and post-injection site care is necessary and is a very important part of the permit process. The information will provide outside stakeholders with a much better idea of how the project will proceed and can help to assure them that the owner/operator has a clear vision for the li fe of the project. AWWA recommends that these plans be reviewed at the sa me time that the area of review is reevaluated. During this review, the plans should be updated based on any operational changes since the last project review period and submitted to the Director for approval. AWWA recommends th at a review occur every year for the first ten years of the proj ect, and then should be revi ewed every five years until injection ceases.

Individual Response: EPA agrees with the commenter. Own ers or operators are required to submit an AoR and corrective action plan, a testi ng and monitoring plan, and a post-injection site care and site closure plan as part of the perm it application, as specified in §146.82(a), to outline how these activities will be performed a nd how non-endangerment of USDWs will be demonstrated throughout the operati onal and post-injection site care periods. EPA is developing guidance on how best to develop the various required project pl ans, including the testing and monitoring plan. The guidance can be found on EPA’s website at http://water.epa.gov/type/groundwater /uic/wells_sequestration.cfm.

56The GS rule also requires owners or operato rs to review and update the AoR and corrective action plan and the testing and monitoring plan th roughout the life of the proj ect, as described at §146.84(c) and §146.90(j). The rule requires at §146.90(j) that the operator revise the testing and monitoring plan to incorporate the results of the most recen t AoR reevaluation and recent operational and monitoring data. Owners or oper ators must review ea ch plan and identify necessary amendments to the plan or demonstrat e to the Director that no amendment is needed. These reviews must be performed within one year of an AoR reevaluation, following any significant changes to the facility (e.g., the additi on of monitoring or injection wells), or when required by the Director. In no case can reviews occur less often than once every five years. This review frequency is appropriate to ensure that reviews of the plans are conducted on a defined schedule or when there is a change in the AoR or significant change, while adding little burden if an AoR reevaluation confirms that the plans are appropriate as written. Se e the preamble sections on the plans for additional information.

EPA is not requiring formal periodic review a nd updates to the PISC a nd site closure plan throughout the injection phase as with the AoR r eevaluation that is requ ired at least every 5 years. EPA does not expect that changes to th is plan would be implemented until injection operations cease. EPA is requiring that upon the cessation of injection, the owner or operator submit an amended post-injection site care and site closure plan or demonstrate to the Director that no changes to the original post-injection site care and site closure plan are necessary, as specified in §146.93(a)(3). EPA envi sions that owners or operat ors would take into account similar considerations that guide updates to other pr oject plans, e.g., monitoring and operational

data and results of AoR reevaluations.

EPA has also added a new provision at §144.39(a)(5 ) identifying the basis for a modification, revocation, or reissuance of a Class VI permit when ever the Director determines that a change in the permit is necessary based on an amended AoR and corrective action plan, testing and monitoring plan, injection well pl ugging plan, post-injection site care and site closure plan, or emergency and remedial response plan is necessary.

Letter ID: 0181 Comment ID: 23701 Letter Lines: 1205 to 1222

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

Comment: EPA Request for Comment: EPA seeks comm ent on the frequency of all proposed reporting requirements. EPA Notice 43517

AWWA Response: AWWA recomm ends that the owner/operat ors of a Class VI well provide a monthly operating report to the Director instead of the semi-annual report as proposed. The operating inform ation for the geologic sequestration project is extremely important and needs to be reviewed at a frequency by the regulatory agency to ensure problems are identified and addressed in a timely manner. For example, based on the proposed regulation, data collected on July 1, 2008 would not be seen by the regulatory agency before January 15, 2009, if the operator is allowed 15 days to submit th e report. This would allow for very little time to correct any potential issues in the operation of the project. We

57have provided example monthly reporting sheets that were devel oped as part of the AwwaRF project in Section III of our co mments, and these reports are similar to the monthly reporting sheets used by wa ter and wastewater treatment plants. Given the potential scale of carbon seque stration and the need to protect groundwater resources, a requirement for monthly operating reports is

reasonable.

Individual Response: The final rule remains unchanged from the proposal and requires semiannual reporting of monthly average, maximum and minimum values for injection pressure, flow rate and volume, annular pressure, and monthl y annulus fluid volume added at §146.91(a). EPA believes that monthly reporting of routine operational data and monitoring results would provide no additional protection of USDW s from endangerment. EPA adds , at §146.91(c), that it has included in the final rule a requirement that ope rators must report with in 24 hours of any event that may endanger USDWs. EPA notes that states seeking primacy for Class VI wells are free to require more frequent reporting.

EPA reviewed the sample reporting form s submitted by AWWA (EPA-HQ-OW-2008-0390- 0181). The Agency will refer to these as it pr epares guidance for comp lying with the reporting requirements. However, EPA notes that mo st reporting will be done electronically.

Letter ID: 0181 Comment ID: 23702 Letter Lines: 1224 to 1228

Comment Code: 4730 2.7.3 Reporting associated with closur e and post-injection site care

Comment: With respect to the requirement for r ecordkeeping, AWWA recommends that the

oneyear holding requirement for the plugging and abandonment report be extended. This is an extremely important report, a nd the owner/operator must be required to keep this report on file for a minimu m of 10 years following the closure of the project site.

Individual Response: EPA is requiring that data collected during the post-injection phase be retained throughout the post-inj ection site care timeframe and for ten years following site closure. EPA agrees that well plugging reports shoul d be retained for longer than one year. EPA has clarified the recordkeeping requirements in the final GS rule, which includes requirements that well plugging reports, as required at §146.92(d), post-injection site care data, as required at §146.93(f), and site closure reports, as required at §146.93(h), be ke pt for ten years after site

closure.

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

58Letter ID: 0181 Comment ID: 23703 Letter Lines: 1230 to 1239

Comment Code: 4740 2.7.4 Electronic reporting (seeking comment)

Comment: EPA Request for Comment: EPA seeks comment on the requirement for electronic reporting in its proposed rule. EPA Notice 43518.

AWWA Response: AWWA agrees with the elec tronic reporting requir ements include as part of the proposed regulation. Electroni c reporting allows for easier tracking of the operating data to observe any tr ends that might in dicate potential

contamination of a USDW. EPA should consid er the infrastructure that will be required to collect information prior to publishing the first report and develop a model reporting plan for owner/operators to use when submitting data to state agencies.

Individual Response: EPA believes that electronic formatting is the most appropriate format for submitting Class VI project information to the Director, and based on comments received on the proposed rule, the majority of Class VI well owners or operators will have the capability to report electronically, and re quires this at §146.91(e).

EPA is developing guidance for states that describes the recordkeeping, reporting, and additional data management needs associated with GS act ivities and provides recommended guidelines on the types of data to be collected for tracki ng GS projects, reporti ng to EPA for compliance tracking, and transfer of data to EPA's GS data system. The recordkeeping and reporting guidance will be available on EPA's web site, at http://water.epa.gov/type/groundwater /uic/wells_sequestration.cfm.

Letter ID: 0181 Comment ID: 23704 Letter Lines: 1241 to 1257

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

Comment: EPA Request for Comment: In addition to the above recordkeep ing 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.

AWWA Response: AWWA recomme nds that an annual reporti ng requirement be included n the proposed regulation. This report should summarize the operation of the system including standard operating cr iteria, information on well operation, details of plume movement, and any deta ils on major changes in well operation.

It should be similar to the Consumer Confidence Reports (CCR) that drinking water utilities must develop and it should be mailed or emailed to all relevant stakeholders. EPA should develop requireme nts for the report similar to those required for the CCR because the annual re port should be deve loped by someone

59one of the team members involved in th e operation of the geologic sequestration project.

Individual Response: Individual Response: The final GS regulation retains the semi-annual reporting requirements as proposed and does not include a requirement for an annual report. Instead, EPA believes that peri odic reevaluation of the AoR, as required at §146.84(e), along with any revisions to the required plans that may be necessary based on the AoR reevaluation, will promote an ongoing relationship between the permitting authority and th e owner or operator. The final GS rule, at §§146.84(c), 146.90(j), an d 146.94(d), requires owners or operators to review and update the AoR and co rrective action plan, the testi ng 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.

EPA also encourages and expects owners and op erators to share monitoring and operating data with the public voluntarily (e .g., through the Internet. Providing the public with information throughout the GS project will he lp clear up and avoid public misp erceptions about the nature and safety of GS. For additional information, plea se see the final rule and the preamble for a discussion of EPA's final approach to recordkeeping and reporting.

Letter ID: 0181 Comment ID: 23705 Letter Lines: 1259 to 1280

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

Comment: Category: Post-Injection

EPA Request for Comment: EPA requests comme nt on the proposed use of a tentative 50-year fixed timeframe that could be m odified at the Dir ector’s discretion based on monitoring and modeling data. EPA Notice 43519.

EPA is requesting comments on the proposed requirements for well plugging, postinjection site care, and site closure, including the proposed requirements for the post-injection time period. EPA Notice 43520.

AWWA Response: AWWA recomm ends that the time period fo r post-injection site care be set at a minimum of 50-years and th at the Director not be given any

discretion to shorten this time period. After this 50-year period, the operator

must continue to monitor until such time as they can demonstrate that the plume has stabilized and that it does not pres ent any potential danger to USDWs or other potential sources of drinking wate r. This requirement is not overly prescriptive or burdensome given the in formation available on the long-term behavior of carbon dioxide plumes. This tim e period is necessary to monitor the site for changes that may occur over a longer amount of time, such as gradual

60leakages, fault movement, or sudden seismi c shifts. After this time period, the owner/operator may apply to the Director for a modification or termination of the monitoring requirements.

Individual Response: EPA agrees that a 50 year post-injec tion site care timeframe represents a reasonable and protective post-in jection site monitoring periodfor most GS projects and available data, including data submitted by commenters, do not support a different default

timeframe. EPA bases this on a review of res earch studies, industry reports, and existing environmental programs, and evaluation of public comments. Furthermore, EPA believes that a 50-year default post-injection site care timeframe is not overly burdensome, does not exaggerate the risks associated with GS, is consistent with other environmental programs, and sufficiently protects USDWs from endangerment. For this re ason, the final GS regulation retains the 50 year post-injection site car e timeframe, as specified in §146.93(b)(1).

However, EPA disagrees that a 50 year post-injection s ite care timeframe should be an absolute minimum. Rather, EPA believes, as some commenters suggest, that there will be circumstances

where it can be demonstrated in less than 50 years that the plum e and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-injecti on period based on site-specific data, pursuant to requirements at §146.93(b); or (2) affording the Director discretion to allow a Class VI well owner or operator to demons trate, during the permitting process based on substantial data, that an alternative PISC tim eframe may be appropria te if it ensures nonendangerment 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: 0181 Comment ID: 23706 Letter Lines: 1282 to 1312

Comment Code: 5220 2.8.2.1 Post-injection monitoring activities

Comment Code: 5280 2.8.2.4 USDW non-endangerment demonstrations

Comment: AWWA has observed that the proposed regul ation is lacking in details on the requirements to demonstrate that the car bon dioxide plume has stabilized. For example, the proposal does not include requi rements that the plume pressure must be constant for a certain number of years or that the plume has not migrated for a set period of time. Since AWWA does not cl aim to be experts on the behavior of carbon dioxide plumes and can not provide recommendations on this topic, AWWA

61recommends that EPA should engage in rese arch on determining exactly what these criteria should be. For example, when re ferencing lack of plume movement, what should the trigger time period be (no move ment of plume for 10, 15, 20 or more years??). AWWA recommends that EPA clarif y what is an acceptable frequency for a lack of change in the plume characteris tics and also needs to clarify plume

stabilization as this issue could be interpreted differently by different states. Guidance should be prepared by EP A on this topic so that there is consistent application of this requireme nt across all sequestration projects. A performance based system could also be de veloped that would require the operator to meet certain criteria to prove that th e plume has stabilized. This could be used to justify the closing of the s ite after the 50-yearperiod of postinjection site care has elapsed. This would allow for a process where long-term monitoring decisions are made in respons e to the specific ch aracteristics of each project.

AWWA believes that the proposed post-injec tion site care requirements have been established to prevent endangerment to USDWs. Carbon dioxid e can potentially leak from the confining layer into other aquifers that, while not classified as USDWs, may still be consid ered drinking water sources in some areas of the county. EPA should also consider includi ng requirements in the regulation to address the potential for endangerment of these aquifers during the postinjection period. Monitoring requirements should be extended to cover these aquifers, and the post-injection site care plan should include provisions for the protection of aquifers that are not classified as USDWs, but are still considered a future drinking water source.

Individual Response: EPA acknowledges that many site-sp ecific factors will influence the determination of when the CO2 plume and pressu re front no longer pose a risk of endangerment

to USDWs. It is for this reason that EPA believe s that individual UIC Dir ectors, in consultation with operators, will be in the best position to determine whether additional post-injection site care is needed. EPA expects this decision to be made based on relevant site data and in consultation with all potentia lly impacted parties.

EPA is developing guidance to assist owners or operators in evaluating well plugging, postinjection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating propo sed well plugging plans a nd post-injection site care and site closure plans under §146.92 a nd §146.93. The guidance describes recommended approaches for how an owner or operator coul d plug injection and m onitoring wells; perform post-injection monitoring; demonstrate the appropriateness of an alternative post-injection site care time frame; demonstrate non endangerment; and perform site closure activities. The guidance will be available at http://water.epa.gov/t ype/groundwater/uic/wells_sequestration.cfm.

EPA has conducted research regard ing stabilization timef rames. As described in the preamble to the proposed rule, in determining the post-in jection site care-timef rame for the proposed regulation, EPA reviewed industry reports, exis ting environmental programs, and initial GS research studies. EPA provided a synthesis of pe rtinent results from GS modeling studies in the

62preamble to the proposed regulation. Further expl anation of this analysis was included in an EPA-prepared background document that is available in the federal docket, titled "Computational Modeling of Unde rground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underg round Sources of Drinking Water." Based on review of these studies, modeling results indicate that the CO2 plume stabilization may occur on the timeframe of 10-100 years after the cessati on of injection. EPA be lieves that a 50-year default post-injection site care timeframe is a reasonable midpoint for most GS projects and available data, including data submitted by commenters, do not support a different default timeframe, and has retained this in the final regu lation. EPA will continue research in this area and plans, every six years, to collect and review data on GS projects to determine whether the appropriate amount and types of information a nd appropriate documentation are being collected,

and to determine if modifications to the requirements are appropriate or necessary.

Letter ID: 0181 Comment ID: 23707 Letter Lines: 1314 to 1375

Comment Code: 1310 1.1.2.4 Comments on other "out of scope" issues, e.g., pore space ownership

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

Comment: Category: Financial

EPA Request for Comment: Because of the po ssibility that the owner or operator may face financial distress prior to th e trust being fully funded, EPA is considering a guidance appro ach that would recommend adop ting a pay in period of three years for GS projects, consistent with other similar programs in the Agency. EPA Notice 43521.

EPA is assessing whether to provide guida nce on the use of insurance providers and, if so, whether to update eligibility requirements fo r insurers for GS wells

consistent with other current Federa l agency practices. EPA Notice 43521.

EPA is requesting comments on whether financial responsibility mechanisms to be recommended in EPA guidance should be ad justed in the manner described, whether additional instruments should be included, and whether other adjustments to the financial responsibility mechanisms should be considered, all subject to EPA’s authority under the SDWA. EPA Notice 43522.

AWWA Response: AWWA has several majo r concerns regarding owner/operator financial assurance and liability. Our pr imary concern is that the liability mechanism that would be triggered when the confining zone fails and carbon dioxide escapes has not been identified. Would this incident trigger CERCLA requirements if groundwater is degraded? AWWA recommends that the liability requirements and financial mechanisms that were used to address MTBE contamination be applied to any USDW degradation from carbon sequestration

63activities. The definition of a "co rrective action" does not provide any protection for aquifers that are c ontaminated by the carbon sequestration process. The definition as provided in th e proposed rule states that corrective action is "...the use of Director approved methods to assure that wells within

the area of review do not se rve as conduits for the movement of fluids into underground sources of drinking water (USD W)." Note that this definition does not address "fixing" the imp act to USDW. What is unclear to AWWA is if the geologic sequestration process does endange r groundwater aquife rs, whether the owners/operators have any financial liab ility in restoring water quality (e.g., paying for extra treatment costs incu rred by water utilities or other groundwater users), as the corrective action seems to focus on fixing injection wells and/or the confining layer.

The question remains regarding what an owne r/operator’s total li ability would be

outside of the USDW contamination. The potential exists for contamination of other ground water aquifers, such as those that are not classified as USDWs but are used as a drinking water sources, a nd it is extremely important that the liability requirements are extended to thes e aquifers. The cost to remediate any degradation can be extremely high. Depe nding on the scope and location of the degradation, examples of potential cost s that might be incurred by a drinking water utility include the installation of advanced water treatment technologies and/or development of alternative wate r sources. The responsibility for these costs must be assumed by the owner/opera tor in the event of a failure of the geologic sequestration process.

AWWA believes that the time limit for fina ncial responsibility in the proposed regulation may be too long for most insu rance agencies, whic h may trigger the need for the development of a trust fund or for owner/operators to use a selfinsurance mechanism. If the trust fund is the desired method, EPA should require that companies constantly add to the f und, even if it appears that the fund is fully funded. In addition to the initia l pay in period of three years, owner/operators should be required to pa y in any additional amount identified during the five-year reviews for the area of review and corre ctive action plan, injection well plugging pla n, the post-injection site care and site closure plan, and the emergency and remedial response plan. This additional pay in is required so that we don't have a repe at of the funding stoppage with the Superfund program.

Individual Response: The goal of financial responsibility is to ensure that financial resources are available to prevent endangerment of USDWs from improper plugging, remediation, and management of wells in the event that the owne r or operator experiences financial difficulties. As such, owners or operators must demonstrate financial responsibility for, among other things, any needed emergency and remedial respons e actions that are necessary to mitigate endangerment or potential endangerment of USDWs. See the final rule and preamble for further discussion of EPA's final approach to financial responsibility.

64EPA clarifies that, while the co mmenter accurately defines corrective action for wells in the AoR, this term does not refer to actions needed to address endangerment in the UIC program regulations. EPA clarifies that th e intent of the emergency and remedial response requirements at §146.94 is that if the owner or operator obtains any evidence that USDWs may be endangered, he or she must cease injection, take all steps reasonably necessary to identify and characterize any release, notify the Director, and implement the approved emergency and remedial response plan, per §146.94(b).

EPA disagrees that GS is analogous to the MTBE situation. EPA believes th at large scale GS can be done safely. The GS regulation builds upon the long-standing, protective regulatory framework of the UIC program, which has been re gulating the injection of fluids for decades. The GS regulation enhances this existing framewor k with tailored requirements for Class VI GS wells to address the unique nature of large scale GS of CO2. These protective requirements include extensive geologic tes ting, detailed computational modeling of the AoR and periodic reevaluations, detailed requirements for monitori ng and tracking the CO2 plume and pressure front, and extended post-injecti on monitoring and site care.

Letter ID: 0181 Comment ID: 23708 Letter Lines: 1377 to 1385

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

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

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

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

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

include a discussion on how best to estimate costs to assist GS well owners or operators, third party insurers or providers of financial inst ruments, and permitting authorities in developing

estimates of the costs associated with various GS activities. This guidance will be available on EPA's website at http://wat er.epa.gov/type/groundwater/ui c/wells_sequestration.cfm.

65Letter ID: 0181 Comment ID: 23709 Letter Lines: 1387 to 1392

Comment Code: 5434 2.9.1.2 Need for additional instruments (seeking comment)

Comment: With respect to the required financial m echanisms, AWWA would like to leave the door open for establishing financial mech anisms on a project by project basis. The rulemaking should not prescribe or prec lude particular fina ncial instruments

as the issue of financial assurance is very complex. Other funding models could be developed, and it may be that Moodys or Standards and Poors will see this as a potential opportunity. Many significant fina ncial details remain that must be

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.

Letter ID: 0181 Comment ID: 23710 Letter Lines: 1392 to 1398

Comment Code: 5460 2.9.2 Comments on transfer of lia bility for long-term care

Comment: a potential opportunity. Many significant fina ncial details remain that must be addressed before any guidance or regulati on is issued on this topic. As an example, the issue of long-term liability still has not been resolved. Who is ultimately responsible for ownership of the injection wells and the carbon dioxide plume after the post-closure pe riod has ended? Does the liability transfer to whoever manages the trust fund (in that particular financial assurance mechanism)?

Individual Response: Under the final GS rule, once an owne r or operator has met all regulatory requirements under Part 146 for Class VI wells and the Director has approved site closure pursuant to requirements at §146.93, the owner or opera tor 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.

66Under §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 SDWA or other legal liability for Class VI wells to the State or federal government or a third-party fund. See the final rule preamble for further discussion of EPA's final approach.

Letter ID: 0181 Comment ID: 23711 Letter Lines: 1400 to 1416

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

Comment Code: 5460 2.9.2 Comments on transfer of lia bility for long-term care

Comment: AWWA would also like to s ee the issue of long-term lia bility resolved. EPA’s proposed geologic carbon sequestration rule is not able to address financial responsibility of the seque stration site after the fo rmal period of postinjection site care has ended (default of 50 year length). R ecognizing that EPA does not have the power to assign respons ibility after this period of time has expired, AWWA recommends that EPA work w ith the appropriate stakeholders to develop legislation that will address the issue of who has to assume financial responsibility of the seque stration site after the s ite closure requirements have been fulfilled. AWWA anticipates that this legislation would provide for a means by which drinking water utilities could recover any costs incurred as a result of USDW contamination by geologi c carbon sequestration activities. AWWA

also recommends that EPA work with th e appropriate stakehol ders to develop comprehensive climate change legislati on with the goal of protecting water systems, and their customers, from lo ss of water supply or unplanned major financial burdens. Everyone needs to apply the lessons learned from MTBE contamination to prevent unintended conse quences from developing with geologic sequestration wells.

Individual Response: EPA is working to create a nationally consistent financial responsibility regime for GS projects within its authorit y under the SDWA while providing permitting authorities an appropriate level of flexibility. The goa l of financial responsibility is to ensure that financial resources are available to preven t endangerment of USDW s from improper plugging, remediation, and management of wells in the event that the owner or operator experiences financial difficulties, thereby preventing costs from spilling over to the public. EPA believes that

67the general authorities provided under SDWA in clude the authority to set federal minimum requirements for financial responsibility to ensure that resources are available to protect USDWs throughout the life of the GS project. However, th is authority does not ex tend to release owners or operators from long-term res ponsibility of other environmental statutes, such as CERCLA, for potential impacts to USDWs afte r the PISC period has ended, or for the potential economic costs associated with activities with impacts unrelated to USDWs (e.g., risks to air, or ecosystems).

Comments related to comprehensive climate cha nge legislation is outside the scope of this rulemaking.

Under the final GS rule, once an owner or ope rator has met all regulatory requirements under

Part 146 for Class VI wells and th e Director has approved site cl osure pursuant to requirements at §146.93, the owner or operator will generally no longer be subject to enforcement for regulatory noncompliance. Furthermore, thei r financial instrument as required under §146.85 will be released if it was not used. However, ev en if a site closure is approved under §146.93, an owner or operator may be held liable for re gulatory noncompliance (inc luding violation of 40 CFR 144.12) in certain circumstances. For example, an owner or operator may be held liable for regulatory noncompliance even after site clos ure was approved if the Director relied on erroneous information (e.g., erroneous modeling data) provided 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 SDWA or other legal liability for Class VI wells to the State or federal government or a third-party fund. See the final rule preamble for further discussion of EPA's final approach to financial responsibility for Class VI wells.

As described above, EPA disagrees that GS is analogous to the MTBE situation.

Letter ID: 0181 Comment ID: 23712 Letter Lines: 1418 to 1448

Comment Code: 1530 1.2.3.1 State regulatory effort s on GS (seeking comment)

Comment Code: 1650 1.3.5 Human health impacts

68Comment: Category: State Capacity

EPA Request for Comment: EPA seeks commen t on any aspects of the ongoing State efforts to regulate the GS of CO2 and how these efforts might be used to better inform a final Federal rulemaking. EPA Notice 43497.

AWWA Response: From our perspective, EPA’ s proposed rule appears to be focused on preventing brine from formations wh ere carbon dioxide was stored from reaching USDWs and/or from preventing ca rbon dioxide that reaches USDWs from causing primary MCLs to be exceeded. This focus may not be adequate from the standpoint of protecting s ource water and beneficial use aquifers from detrimental changes in water quality other than the exceedance of primary MCLs. Other water quality impacts could be obser ved such as increased concentrations of iron, manganese and TDS, as well as lo wered pH, all of which have secondary

MCLs. Increases in the concentratio ns of silica and boron, which do not currently have MCLs but can significantly degrade water quality, are also likely

to occur.

This past year, the State of Washington adopted carbon sequest ration regulations

which AWWA recommends that EPA review a nd incorporate some of the language into the final regulation. The Washington regul ations require that the owner or operator must demonstrate that the "des ign and construction standards of all facility structures and wells are suffi cient to prevent migration of carbon dioxide or nonpotable water that will degrade water quality or impact beneficial uses outside the geologic containment sy stem." The language in this regulation provides protection mechanisms for groundwater sources that may not be used as USDWs but have other beneficial uses, su ch use as industrial applications or agriculture. Given the stresse s that the drinking water industry is facing with respect to water resources, AWWA recomme nds that the monitoring requirements in the final rule be extended to protect ag ainst aquifer contamination beyond that which is associated with compounds that have primary MCLs.

Individual Response: EPA recognizes the complexity and im portance of states' approaches to managing GS and is aware that states are current ly in various stages of developing statutory frameworks, regulations, workgroups , technical guidance, and stra tegies for addressing CCS and

GS.

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

for the GS rule.

EPA clarifies that the UIC program’s author ity applies to protec tion of USDWs from

69endangerment. SDWA §1421(d)(2) states that “underground injection en dangers drinking water sources if such injection may result in the pr esence in underground water which supplies or can reasonably be expected to supply any public wa ter system of any contaminant, and if the presence of such contaminant may result in su ch system’s not complying with any primary drinking water regulation or may otherwise adversely affect the h ealth of person.” EPA disagrees that the GS rule is only focused on MCL contam ination as it relates to endangerment; rather the

rule also focuses on “adverse effects on the heal th of person[s].” This does not necessarily require a showing of non-co mpliance with an MCL.

EPA clarifies that the UIC regulations apply only to underground injectio n wells and injection activities, and not to "facility structures” th at are not considered to be wells under §144.3.

Under §146.94, if the owner or operator obtains ev idence that injection may cause endangerment to a USDW, he or she must stop injection and implement the emergency and remedial response plan for that well. With proper site selection, the final, tailored, Class VI requirements address the large volumes of CO2 injected, its buoyancy, pot ential corrosivity in the presence of water, and potential impurities in the CO2 stream. In addition, the tailored permitting, siting, construction, operation, monitoring, and post-injection site care re quirements in the GS rule are intended to prevent leakage from injec tion formations and protect USDWs.

Letter ID: 0181 Comment ID: 23713 Letter Lines: 1450 to 1470

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

Comment: EPA Request for Comment: 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.

AWWA Response: AWWA r ecommends that a state be able to administer only Class VI well permits, if they so desire. The Class VI well program is a very specialized class, which has major differences from a ll the other well classes. A state that decides to apply for primacy of the Cl ass VI wells only would be able to specialize in this well class, and coul d develop and execute a very detailed program. The state would have an advantage in that the state st aff would be very familiar with the regional geology, water resources and business operations in the areas proposed for geologic sequestrati on. One disadvantage could be seen if the applying state had never held primacy for any of the other classes of wells. Since this is a fairly specialized class, there could be some logistical issues in the beginning stages of the state ad ministering the program. However, AWWA

believes that these issues could be addr essed through consultation with either the federal EPA offices, or in discus sions with other states that are administering the Class VI program. In our opinion, the benefits associated with state primacy, such as a more in depth knowledge of the state geology, operations and politics far outweighs any minor implementation issues that might be associated with a state having prim acy approval for only Class VI wells.

70Individual 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.

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

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

EPA agrees that states without primacy for ot her injection well classes may encounter some logistical challenges while developing a ne w Class VI primacy program. EPA is developing guidance that describes, for States, the proce ss of applying for and receiving primacy for GS

Class VI wells under Section 1422 of SDWA. The manual will also provide tools designed to assist States with the development of thei r primacy application and UIC Directors with evaluating permit application informati on. The guidance will be available at http://water.epa.gov/type/groundwat er/uic/wells_se questration.cfm.

EPA also encourages States, Tribes, and Territori es to consult with their EPA Region or other States, Tribes, and Territories administering the Class VI program for guidance as they begin the

71primacy application process and devel op a UIC program for Class VI wells.

Letter ID: 0181 Comment ID: 23714 Letter Lines: 1472 to 1500

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

Comment: Other AWWA Comments Related to State Pr imacy and Capacity: When EPA allows states to obtain primacy for the Cl ass VI wells and develop their own regulations for geologic se questration, these regulations must be developed in

accordance with Section 1422 of the SDWA instead of Section 1425. The language in Section 1422 mandates that state requi rements for geologic sequestration be as stringent as federal re quirements. By comparison, the language in Section

1425 mandates that the state requirements represent an "effective" program to prevent injection which endangers dri nking water sources. The language in

Section 1425 leaves too much room fo r interpretation, and could result in varying degrees of protection of USDWs across the country. Given the current strain on our groundwater resources in some areas of the United States, AWWA recommends that EPA ensure state regulati ons provide at least the same level of protection as the federal regulations.

AWWA recognizes that the SDWA currently provides for a $16 million statuary limit for federal support to states to en act and enforce the Act. Given that state primacy agencies are already resour ce limited and are inadequately funded to cover existing oversight responsibilities, AWWA an ticipates that this regulation could place an even larg er burden on them. Geologic carbon sequestration will require new resources , and in addition, staff with very specialized expertise in areas such as groundwater, wells, geochemistry, and underground injection. Inadequa te resources and staff cap abilities will result in delayed permit reviews/approvals and/or rushed and poor decision making. AWWA recognizes the funding limitation for the state primacy programs and this is an issue that Congress would have address ei ther through a modification of the SDWA or by a revenue set-aside as part of a future "cap and trade" program. As a result, AWWA recommends that EPA consider the potential burden on state programs when finalizing the regulation and look for ways to streamline the process without sacrificing th e protective measures of the regulation.

Individual Response: EPA clarifies that primacy for Cla ss II and primacy for Class VI are different. While there are many similarities be tween CO2-ER injection and GS, CO2 injection for the purpose of GS is not explicitly author ized under section 1425 of the SDWA; therefore GS of CO2 is regulated under Section 1422. In orde r for States, Tribes, or Territories to obtain Primacy for Class VI wells (und er Section 1422 of the SDWA) they must demonstrate that they have requirements that are at least as stringen t as the federal Class VI requirements; have the authority to inspect and assess construction a nd operation of the wells as well as have the necessary legal authorities to take administrative, civil and criminal enforcement actions required by the SDWA under §1423, impose criminal, civil, and administrative penalties on owners and

72operators for non-compliance with regul atory requirements; and demonstrate sufficient/appropriate technical capacity (e.g., personnel, infrastruc ture, and technical expertise) to implement their Class VI program.

However, EPA acknowledges the expertise of st ate oil and gas agencies, which have been regulating Class II wells for decades. These ag encies already understand many of the issues pertaining to Class VI wells, wh ich should facilitate the adopti on of Class VI primacy programs

in states with Class II wells.

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.

EPA adds that the GS rule does not address “cap and trade.” Cap and trad e is outside the scope of this rulemaking; the purpose of the GS rule is to ensure that injection of CO2 for GS is conducted in a manner that is protective of USDWs.

Letter ID: 0181 Comment ID: 23715 Letter Lines: 1502 to 1517

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

Comment: Category: Public Participation

EPA Request for Comment: EPA requests comment on adopting the existing requirements for public participation at 40 CFR Part 25 and 40 CFR Part 124 and whether additional requirements should be included to reflect the availability of new tools for disseminating and gather ing information. Such tools include cable networks, the Internet, and ot her new technology. EPA Notice 43523.

AWWA Response: 40 CFR 124 does not include a requirement for pub lic notification when a request is made to modify, revoke and/or reissue an operating permit for a geologic sequestration project. It also does not provide for mandatory public hearings, as the regulations states th at it is up to the discretion of the Director unless a hearing is specifica lly requested by a stakeholder. AWWA disagrees the omission of with these re quirements and recommends that both of these activities be recognized as manda tory during the permit development, review, and approval processes for geologic sequestration projects.

73Individual Response: EPA disagrees that the requireme nts at 40 CFR Parts 25 and 124 are inadequate for GS projects. Thes e public participati on requirements have been effective for the

other UIC well classes. EPA believes that these requirements can help avoid public misperceptions about the nature and safety of GS projects and address the public's concerns about the project. EPA notes that public notice is required when a dr aft permit is issued including when existing permits are modified (except for minor modifications ). See §124.10(a) Public notice is also required when a permit is re voked or reissued. See §124.5(c)). Although public hearings are not mandatory, EPA expects that public hearings will be requested and necessary due to the expected level of public interest in GS projects. See §124.12. The commenter is correct that public notic e is not required when a request for modification, revocation and

reissuance and termination of a permit is made, however, EPA believes the public notice required when the draft is issued is appropriate for GS wells.

EPA recognizes that the AoR reev aluation process may generate significant levels of public interest. EPA added text to §144.39(a)(5) that pe rmit modifications woul d be required if the

Director determines that a modification is nece ssary based on an AoR reevaluation, amendments to any of the project plans, or a review of the testing and monitoring resu lts. EPA notes that any permit modifications, except for minor modifi cations under 40 CFR 144.41, would invoke the public notification procedures of 40 CFR Part 124.

EPA disagrees that public hearings should be ma ndatory for all GS permits, in order to account for the possibility that, if the public does not e xpress an interest in a hearing, holding one would not be useful. 40 CFR 124.12(a) re quires the Director to hold pub lic hearings if there is a significant degree of interest in a draft permit. EPA expects that publ ic hearings will be requested and held for many GS projects, due to the expect ed level of public intere st in GS projects.

Letter ID: 0181 Comment ID: 23716 Letter Lines: 1519 to 1554

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

Comment: Most of the geologic sequestration project s will be located in rural areas where the local water utility is very small with limited staffing and funding resources. While these utilities may be impacted by the projects, they may not have the technical ability to adequate ly participate in a project review. Therefore, AWWA recommends that as part of the public participation requirements, owner/operators should be required to notify a nd involve national and state drinking water organizations as well as the local water utilities.

This would allow the local utility to be supported tec hnically by the staff of the national organization, which can provi de technical expert ise in drinking

water issues related to carbon sequestration.

Each project should be required to esta blish public advisory groups, such as those created for some of the regi onal carbon sequestration partnership projects. Owner/operators need to ensure they identify stakehol ders groups from

74water sector, such as rura l water associations, groundw ater associations, and drinking water utility associations. Th ese groups would be involved in the project from the beginning and provide the stakeholder voice for the project.

AWWA recommends that the public comment period for the permit review process be extended in the final regulation. Due to the technical nature of the geologic sequestration process, AWWA recommends th at the comment period be extended from 30 days to 90 days. A 30 day comment pe riod does not provide enough time for outside groups to obtain the permit, pe rform a detailed technical review and generate comments. Extending the comm ent period for 90 days allows the stakeholders to perform a much more co mprehensive review of the project.

The issue of environmental justice must be appropriately considered when involving the public in geologi c sequestration projects. C onsideration should be given to ensure that certain populations aren't repeatedly subjected to the problems that may arise from the sequestrati on projects. It is also necessary to remember that not everyone has access to the same media outlets. When an owner/operator is advertisi ng public hearings or comment periods, they should be required to utilize all forms of medi a, including the newspaper, radio,

television and internet. The general public has a wide range of media-viewing habits, and many have moved away from so me of the more traditional communication

methods.

Individual Response: EPA recognizes that there may be local public interest in GS projects, and

notes that the Director has the authority to include local governments in the public participation process as necessary. The exis ting public particip ation requirements for UIC permits at §124.10(c)(1)(x)(A) require notification "to any unit of local government having jurisdiction over the area where the facility is proposed to be located." In addition, the final rule adds a requirement that the director of the State Pub lic Water System Supervision program be notified. See §124.10(c)(1)(xi). EPA anticipates that this st ate director will notify public water systems

within the area of review and will make thei r own evaluation of the proposed project.

EPA anticipates that drinking water associations a nd local water utilities w ill express interest in and be notified of draft permits and public he arings as required under §124.10(c)(1)(ix) and 40 CFR Part 25.5 (where EPA is providing public information) which requires the permitting authority to notify all interested parties.

EPA disagrees that a 90-day comment period sh ould be required for all GS projects. EPA believes that the existing public comment period requirements at 40 CFR 124.10, which require a minimum 30-day comment period for draft permits, are appropriate for GS projects. The Agency does not believe it is appropria te to impose longer time frames if they are unnecessary, but supports the Directors' discretion and aut hority under §124.10 to exte nd the public comment period if he or she determines that such an exte nsion is warranted. Circumstances that may affect a Director's determination may include the level of public interest in a GS project, specific permit details, or project-specific considerations.

75Regarding the suggestion to form advisory groups, EPA clarifies that such advisory groups could participate in the public proce ss associated with any GS proj ect, although such groups are not necessary for the public to engage the agency about any GS project.

EPA agrees that environmental justice is an im portant concern. The Agency has determined that the GS rule will not have disproportionately hi gh and adverse human health or environmental effects on minority or low-income populations because it increases the level of environmental protection for all affected populations. Please se e the discussion of Environmental Justice and Executive Order 12898 in the preamble to the final GS rule. The rule does not require that GS be undertaken; but does require that if it is undertak en, operators will conduct the activity in such a way as to protect USDWs from endangerment cause d by CO2. Additionally, this rule will ensure that all areas of the United States are subject to the same minimum Federal requirements for protection of USDWs from endangerment from GS . EPA's primacy implementation materials for UIC Directors place emphasis on considering the potential impact of any GS permits on communities (such as minority and low income popul ations) when evaluating Class VI injection well permit applications, as well as provides s uggestions and tools for targeted outreach to ensure more meaningful public input and partic ipation from the most affected communities during the permit evaluation and approval process.

Letter ID: 0181 Comment ID: 23717 Letter Lines: 1556 to 1586

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

Comment: Category: Cost Analysis

EPA Request for Comment: The Agency assume s three monitoring wells per injection well for the purpose of estimating nati onal costs; however, the Agency recognizes that operators and primacy agency Directors may choose more or fewer monitoring wells depending on project site characteristics. Because the monitoring wells and associated costs repr esent a significant component of the Cost Analysis, the Agency acknowledges that this factor may be significant in the overall uncertainty of the Cost Anal ysis. EPA requests comment on whether three monitoring wells per injection well is an appropriate costing assumption.

EPA Notice 43527.

AWWA Response: AWWA does not agree with the assumption to use three monitoring wells per injection well as the standard for the cost analysis. This number seems very low given the amount of area th at would be covere d by one injection well. Requiring three monitoring wells for an injection well that might be associated with a carbon dioxide plume st retching for over a mile seems like a

drastic underestimate of the necessary monitoring. AWWA recommends that the requirement be based more on the projected plume performance and the potential

interactions with USDWs or othe r important geologic formations.

76Other cost estimates have i ndicated that, in the overal l cost of the project, monitoring is a very small percentage of the total project cost as compared to those associated with the capture and tran sport processes. This conclusion is contrary to EPA’s cost estimate, and AWWA is concerned that the EPA’s high cost numbers for monitoring may be used to attempt to reduce the monitoring requirements and lower the overall project co st. AWWA recommends that the cost

estimate be revised at a later date base d upon data that becomes available from the DOE pilot projects. These projec ts might identify additional well construction costs, as well as be able to provide a better understanding of how the cost of monitoring compares to the rest of the project.

Individual Response: EPA agrees that the number of mon itoring 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).

In response to the concern that EPA will change its monitoring requirements to save costs, EPA clarifies that the number of monitoring wells in the cost analysis is an assumption developed for the purpose of the cost analysis only. The Agency is not specifying in the GS Rule the number of monitoring wells required at a GS site and clarifies that the ex act number of monitoring wells at a particular GS project will be determined ba sed on site-specific information and will be appropriate to ensure protecti on of USDWs from endangerment. For additional information on EPA's final regulatory approach, including testin g and monitoring requirements, 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

77number 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: 0181 Comment ID: 23718 Letter Lines: 1594 to 1600

Comment Code: 1220 1.1.1.1 Terminology and definitions

Comment Code: 4400 2.4.4.3 Allowing injection above or between USDWs (seeking comment)

Comment: IV. COMMENTS ON RULE TEXT

Part 144.6(f): Would "lowermost USDW" include formations that are not USDW’s at the point of injection but become USDW’s within the extent of the expected area of influence of the injection plume? AWWA recommends that these types of

formations be included within the defin ition of USDW based on the ability of carbon dioxide to easily mi grate within the confin es of an aquifer.

Individual Response: EPA clarifies that the GS rule (and all of the UIC regulations) requires the protection of all USDWs in the AoR of an injecti on activity. As part of th e site characterization process and during AoR delineation, owners or operators must identify all USDW s within the AoR, model the full extent of the CO2 plume, and demonstrate that all USDWs within the AoR are protected from endangerment. This would in clude USDWs that are laterally connected to non-USDWs, as suggested by the commenter.

Letter ID: 0181 Comment ID: 23719 Letter Lines: 1602 to 1614

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

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

Comment: Part 144.36(a): The geologic sequestration of carbon dioxide is not a fully proven technology and much is unknown about th e long-term impacts, and potential unintended consequences of such injecti on. As previously stat ed, AWWA believes it would be prudent to lim it the life of the Class VI permit so that necessary adjustments to the permit can be made as needed, with the oppor tunity for public comment. This will also establish a process for obtaining updated information on the injection operation. We would recomm end a permit life of no more than 5 years. Therefore, AWWA recommends revising this part to read:

Permits for Class I and V wells shall be effective for a fixed term not to exceed 10 years. UIC Permits for Class II and III shall be issued for a period up to the operating life of the facility . Permits for Class VI wells shall be effective for a fixed term not to exceed 5 years.

Individual Response: The final rule maintains the lifetime permit provision and clarifies that the permit extends through the post-injection site car e period (144.36(a)). However, it also adds a

78requirement that the Director re view each Class VI permit at l east every 5 years to determine whether it should be modified, revoked and reissu ed, terminated or a minor modification made as provided in §§144.39, 144.40, or 144.41. The Director’s re view will be informed by the owners’ or operators’ iterative reevaluati on of the GS project. Specifica lly, the final rule includes a requirement that the AoR be reevaluated at least every five years, and also requires owners or operators to review and update the AoR and corrective action pl an, the testing and monitoring plan, and the emergency and remedial response plan throughout the life of the project (146.84(e), 146.90(j), and 146.94(d)). Owners or operators must review each plan and identify necessary

amendments or demonstrate to the Director that no amendment is needed. In no case can reviews occur less often than once every five years. The iterative process and subsequent plan

reevaluations ensure that time and resources are committed to the most critical aspects of the permit in preventing enda ngerment to USDWs.

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

Letter ID: 0181 Comment ID: 23720 Letter Lines: 1616 to 1633

Comment Code: 1220 1.1.1.1 Terminology and definitions

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

Comment Code: 4400 2.4.4.3 Allowing injection above or between USDWs (seeking comment)

Comment: Part 146.5(f): There is the possibility that some of the geologic sequestration

activities will occur in areas where there are no USDWs located in the area of review. These wells should still be permitted as Class VI wells, and AWWA recommends revising the Cl ass VI definition to:

(f) Class VI. Wells used for geologic se questration of carbon dioxide in the following applications: 1. Where carbon dioxide is injected belo w the lowermost formation containing a USDW; and, 2. Where carbon dioxide is injected in fo rmations where no USDWs exist within the zone of elevated pressure asso ciated with the injection well.

Wells used for the geologic storage of carbon dioxide in formations above the lowermost USDW are prohibited.

This definition would capture all well s associated with geologic carbon sequestration activities whether or not a USDW was present in the projected footprint of the project.

Individual Response: In the final rule EPA will allow injection into non-USDWs above or

79between the lowermost USDW where owners or ope rators can demonstrate that such injection can be performed in a manner th at protects USDWs from endangerm ent, as long as appropriate protections are in place.

EPA adds that, in the final rule at §144.6 (f), Cl ass VI wells are defined as wells that are not experimental in nature that are used for geol ogic sequestration 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 recovery or enhanced gas rec overy aquifer exemption pursuant to §§146.4 of this chapter and 144.7(d).

Letter ID: 0181 Comment ID: 23721 Letter Lines: 1635 to 1645

Comment Code: 1220 1.1.1.1 Terminology and definitions

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

Comment: Part 146.81 AWWA recommends defining the qu ality of the injection stream and establishing a minimum concen tration of carbon dioxide. This requirement for the injection stream will ensure that the in jection of other harm ful or undesirable gases is limited. Our initial thoughts on this topic would be that 100% of the injectate must come from a carbon dioxide capture process and the injectate must be at least 98% carbon dioxide. Owner/operato rs must ensure that the remaining 2% of the injectate is not made up of compounds th at would result in the injectate being classified as a hazardous waste. As AWWA is not an expert on this topic, we would suggest that EPA pursu e research in association with DOE to develop a standard for the minimum c oncentration of carbon dioxide in the injection stream.

Individual Response: As described above, the GS rule does not set generic purity standards for CO2 injectate streams (e.g., a percent CO2). The fi nal GS rule retains th e definition of a CO2 stream as proposed.

Letter ID: 0181 Comment ID: 23722 Letter Lines: 1647 to 1651

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

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

Comment: Part 146.81(c) Specific benchmarks should be established to demonstrate that USDWs will not be endangered if the well is exempted from the casing and cementing requirements provided in Part s 146.86(b) and 146.87(a )(1) through (3). This will provide for a consistent application of this requirement across each permitting agency.

80Individual Response: EPA believes that, given the range of types of existing wells that may be candidates for conversion, flexibil ity is appropriate regarding c onversion of Class I, II, or V wells for GS, provided it can be demonstrated to the Director's satisfaction that the converted well can conduct Class VI operations in a manne r that does not endanger USDWs. The final GS rule, at §146.81(c), allows the construction of these wells to be grandfathered, provided the owner or operator can demonstrate to the Director that the wells were en gineered and constructed to meet the requirements at §146.86(a) and ensure protection of USDWs, in lieu of requirements at §146.86(b) and §146.87(a).

EPA is developing guidance documents that will support UIC Directors in evaluating whether grandfathering specific wells is appropriate. For example, primacy guidance for primacy agencies will describe areas of Directo r’s discretion and reco mmended procedures and considerations for exercising that discretion. EPA is also developing guidance on construction of Class VI wells. The guidances will be available on EPA's web site at http://water.epa.gov/type/groundwater /uic/wells_sequestration.cfm.

Letter ID: 0181 Comment ID: 23723 Letter Lines: 1653 to 1668

Comment Code: 1220 1.1.1.1 Terminology and definitions

Comment: Part 146.81(d) AWWA recommends revising th e definition of "pressure front" to

read:

Pressure front means the zone of elevat ed pressure that is created by the injection of carbon dioxide into the s ubsurface. For the purposes of this subpart, the pressure front of a carbon di oxide plume refers to a zone where there is a pressure differential sufficien t to cause the movement of injected fluids or formation fluids through an inje ction zone, and/or confining zone, and

into a USDW.

Part 146.81(d) AWWA recommends revising the definition of "transmissible fault or

fracture" to read:

transmissible fault or fracture means a fault, fracture or other discontinuity that has sufficient permeability and verti cal extent to allow fluids to move

between formations.

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 created 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.”

The final definition of transmissive fault or fracture at §146.81(d) is unchanged and reads as follows: “[A] fault or fracture that has sufficient permeability and vertical extent to allow fluids

81to move between formations.” EPA adds that it changed the text at §146. 84(c)(1)(ii) to include “other discontinuity” to address concern regarding the pot ential for migration of CO2 at GS sites. It reads as follows: "Take into account any geol ogic heterogeneities, other discontinuities, data quality, and their possible im pact on model predictions."

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: 0181 Comment ID: 23724 Letter Lines: 1670 to 1673

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: Part 146.82(b) AWWA recommends revising the second to the last sentence to read:

The map should also show faults and othe r major geologic discontinuities, if known or suspected.

Individual Response: Based on its evaluation of all public comments and input on the proposed rule and the NODA and Request for Comment EP A has made many revisions to the GS rule. Please see the final rule and preamble for additional information.

Letter ID: 0181 Comment ID: 23725 Letter Lines: 1675 to 1698

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: Part 146.82(b) AWWA recommends that the last sentence be delete d from this part. Owner/operators should be required to go beyond the data available in the public record to identify some of the features lis ted in this requirement. For example, the owner/operator should be required to do its due diligence to identify all abandoned wells, plugged wells or old boreh oles in the area of review. While public records may be a good starting point for the identification of these features, given the fact that some of the existing wells could be decades old,

it is hard to believe that records would exist for every one of them. EPA should mandate that owner/operators use well id entification technology to locate any existing wells that are not listed in the public record.

AWWA recommends revising this part to read:

A surface map showing the injection well(s) for which a permit is sought and the applicable area of review. Within the ar ea of review, the map must show the number, or name and location of all in jection wells, producing wells, abandoned wells, plugged wells or dry holes, deep stratigraphic borehol es, State or EPA

82approved subsurface cleanup sites, surface bodies of water, springs, mines (surface and subsurface), quarries, wate r wells and other pertinent surface features including structures intended for human occupancy and roads. The map should also show faults, if known or su spected. The owner or operator must

include all information available in th e public record, as well as conducting independent site investigati ons to locate any of the above features that may not

be identified in the public record.

Individual Response: EPA believes that a determination about whether data/information is outside or within the public reco rd will be site-specific, and ba sed on knowledge of the site, data availability, and data quality. For instance, in meeting the requirement to tabulate information on wells in the AoR, the Director has the discretion to require the owner or operator to supplement a data records search, including re quiring ground or airborne surveys for wells, if there is reason to believe, based on knowledge of the site or of avai lable data bases, that the incompleteness of available information could compromise USDW protection from endangerment.

Letter ID: 0181 Comment ID: 23726 Letter Lines: 1700 to 1704

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: Part 146.82 (c) AWWA recommends re vising this part to read:

A map delineating the area of review ba sed upon modeling, using all available data including data obtained during geophys ical logging and test ing of the well and the formation as required by paragra phs (l), (r), and (s) of this section.

Individual Response: EPA clarifies that the map of the AoR must reflect the model inputs, including the extensive geologic information, data collecte d during the site characterization process (e.g., information about artificial penetrations), and an ticipated operating parameters (e.g., injection rates) submitted with the permit application under 146.82. EPA adds that the final rule, at §146.82(c)(1), requires that the final area of review be “based on modeling, using data obtained during logging a nd testing of the well and the formation...”

Letter ID: 0181 Comment ID: 23727 Letter Lines: 1706 to 1824

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: Part 146.82(d)(1) AWWA recommends revising this part to read:

Isopach maps of the area of review, including the proposed injection and confining zone(s), a structural contou r map hung on the top of the proposed injection zone, and at leas t two geologic cross sections of the area of review showing the geologic formations fr om the surface to total depth.

83Part 146.82(d)(2) AWWA recommends revising this part to read:

Location, orientation, and properties of known or suspected subsurface faults, fractures, and other discontinuities that ma y transect the confining zone(s) in

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

containment.

Part 146.82(d)(3) AWWA recommends revising this part to read:

Information on the seismic history within th e proposed area of review including presence and depth of seismic sources, know ledge of previous seismic events and history of these events, a nd a determination that the seismicity would not

interfere with containment.

Part 146.82(d)(4) AWWA recommends revising this part to read:

A spreadsheet with data on the depth, areal extent, thickness, mineralogy, porosity, permeability, capillary and reservoir pressure of the injection and confining zone(s) within the area of review; includ ing any geologic/facies changes based upon field data which may in clude geologic cores, outcrop data, seismic surveys, well logs, and name s and lithologic descriptions.

Part 146.82(d)(5) AWWA recommends revising this part to read:

Geomechanical information on fractures, stre ss, ductility, rock strength, and in situ fluid pressures on the injection a nd confining zones within the area of

review.

Part 146.82(e) AWWA recommends revisi ng the first sentence to read:

A spreadsheet of all wells and other artificial penetrations within the area of review which penetrate the inje ction or confining zone(s).

Part 146.82(f) AWWA recommends re vising this part to read:

Potentiometric (water level) surface ma ps and stratigraphic cross sections indicating the genera l vertical and lateral limits of all USDWs including existing aquifers not meeting the definition of a USDW that are either currently being utilized as private or public water supplies or are identif ied as a future water supply, water wells and springs within the area of review, their positions relative to the injection zone(s) and th e direction and velo city of water movement. At least two geol ogic cross sections showing the thickness and general

vertical and lateral limits of all USDWs within the area of review.

Part 146.82(g) This part should provide a list of the formations for which

84baseline geochemical data should be obtained. AWWA reco mmends revising this part

to read:

Collection of baseline geochemical data on the subsurface formations, including

all USDWs in the area of review. At a mi nimum, geochemical data should be provided for the injection formation, the confining zone immediately above the injection zone, the nearest adjacent porous and permeable formation to the confining zone, all USDWs in the area of review including existing aquifers not meeting the definition of a USDW that ar e either currently being utilized as private or public water supplies or are id entified as a future water supply, as well as for any additional formati ons as required by the Director.

Part 146.82(h)(1) AWWA recommends revising this part to read:

Average and maximum daily injection ra te and volume of the carbon dioxide

stream.

Part 146.82(h)(2) AWWA recommends revising this part to read:

Average and maximum surf ace injection pressure;

Part 146.82(k) AWWA recommends re vising this part to read:

Proposed stimulation program and a determ ination that stim ulation will not interfere with or breach the confining layer.

Part 146.82(n) AWWA recommends re vising this part to read:

Engineering drawings of the surface and subsurface construction details of the system, including design features for su rge control and water hammer protection, including the following:

(i) Record drawings, based upon inspections by the engineer of record or persons under his direct supervision, w ith al deviations noted; (ii) Copies of the mill certificates of all casings used in the construction of the well; (iii) Certification of completion submitted by the engineer of record; (iv) An operation manual incl uding emergency procedures; (v) Proposed monitoring program and data to be submitted; (vi) Proof that the existence of the we ll and any associated monitoring wells have been recorded with the permanent warranty deed or other instrument of conveyance as a two page proviso or adde ndum that contains certification of the locations of the wells (by metes and bounds) and a detailed sketch of the parcel that shows the location of the well. The location shall be measured by a certified land surveyor, and shall contain the surveyor's signature, registration number, offici al seal, and the followi ng statement: "I hereby

85certify that this survey was made under my responsible direction and supervision, and is a correct repres entation of the land surveyed."

Part 146.82(q) As the Director should appr ove the corrective ac tion plan prior to any activities taking place within th e area of review, AWWA recommends revising this part to read:

The plan for corrective action on artificia l penetrations within the area of review and the status of any correction actions, if previously approved by the

Director.

Part 146.82(s) As the well should not yet be constructed when the owner/operator applies for the permit, the demonstration of mechanical integrity should not have occurred yet. Therefore, AWWA reco mmends revising this part to read:

The proposed demonstration method for m echanical integrity pursuant to §146.89.

Part 146.82(v) As monitoring wells may also have to be plugged, AWWA recommends revising this part to read:

Proposed injection and monitoring well(s) plugging plan re quired by §146.92(b).

Individual Response: EPA disagrees that the suggested revisions are necessary. While EPA acknowledges and agrees with the importance of many of the specific items the commenter suggests adding to the text, the Agency believes that it is important to a llow some flexibility to address the varied and site-speci fic conditions at GS sites. EPA anticipates that the iterative process by which owners or operators submit and Directors review geologic and other information to support the permit application wi ll promote the most effective approach to addressing USDW endangerment. EPA adds that if the Director believes that additional information is needed to support a determination about the suitability of a proposed site, it is

within his/her author ity to request it.

EPA notes that the final rule does include refe rence to capillary pre ssure in §146.82(a)(3)(iii), “Data on the depth, areal extent, thickness, mi neralogy, porosity, permeab ility, and capillary pressure of the injection and confining zone(s); including geol ogy/facies changes based on field data which may include geologic cores, outcrop data, seismic surv eys, well logs, and names and lithologic descriptions.”

EPA agrees that not all of the information listed at §146.82 of the proposed regulation will be available at the time the owner or operator deve lops their initia l permit application. In response to comments and based on an evaluation of the proposed requirements at §146.82, the Agency revised this subpart so that the final regulation specifies separate requirements for information to be submitted with the permit application and be fore 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)).

EPA is developing guidance on site characterization for GS projects to assist owners or operators

86and Directors in evaluating permit requirements 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/gr oundwater/uic/wells_sequestration.cfm.

Letter ID: 0181 Comment ID: 23728 Letter Lines: 1826 to 1831

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: Part 146.83(a)(1) AWWA recommends revising this part to read:

An injection zone of sufficient ar eal extent, thickne ss, porosity, and permeability to receive the total antic ipated volume of the carbon dioxide stream, and at a depth with sufficient ove rburden pressure to keep the carbon dioxide stream as a supercritical fluid.

Individual Response: EPA disagrees that the GS rule should require that the CO2 remain in a supercritical state. EPA believes that, in many cases CO2 will be injected at depths where it will remain supercritical. However, th e final rule does not require that it remain in a supercritical state once it is injected; nor doe s the rule preclude the injectio n of gaseous CO2 into shallower non-USDWs provided that the owne r or operator meets the Class VI requirements and ensures protection of USDWs from endangerment.

Letter ID: 0181 Comment ID: 23729 Letter Lines: 1841 to 1854

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: Part 146.83(b) This part of the rule shoul d a requirement, notan option that can be requested at the discretion of th e Director. While it is possible that a site with a single confining can provide st orage integrity, AWWA recommends that additional confining layers at the site be characterized to get a better estimate of leakage risk to USDWs and possibly identify additional monitoring zones. It is important to know if these zones exist, and to have adequately documented their characteristics, to eval uate and demonstrate the possibility of secondary containment. AWWA recomme nds revising this part to read:

Owners or operators of Class VI wells mu st identify and char acterize additional zones that will impede vertical fluid move ment, are free of faults, fractures or

other discontinuities that ma y interfere with containment, allow for pressure dissipation, and provide additional opport unities for monitori ng, mitigation and

87remediation.

Individual Response: EPA agrees with the commenter that, in some situations, the presence of additional confining and containment zones above the primary (i.e., lowermost) confining zone can improve USDW protection from endangermen t. EPA disagrees that secondary confining zones are required at all sites, e.g., where a prim ary confining zone that free of transmissive

faults or fractures and of suffi cient areal extent and integrity to contain the injected carbon dioxide stream and displaced formation fluids and allow injection at proposed maximum pressures and volumes without in itiating or propagating fractures in the confini ng zone(s) (per §146.83(a)) is demonstrated to be present. The final regulation retains the requirement at §146.83(b) which affords the Director discretion to require owners or operators to identify and

characterize additional zones.

Letter ID: 0181 Comment ID: 23730 Letter Lines: 1856 to 1860

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: Part 146.84 It is important to note that the carbon dioxide plume will never cease moving. Even deep formations have a natural flow gradient, and it is likely that there will always be some movement due to changes in density gradients and diffusion. This should be c onsidered when defining the AoR for each project.

Individual Response: EPA agrees with the commenter that there may be cases where movement of the CO2 plume will never cease due to gradient, diffusion, and density gradients, but disagrees that the AoR definition at 146.84( a) should describe a never-e nding timeframe of CO2 plume movement. The GS regulation recognizes that pl ume movement may stabilize to a point where movement of the CO2 plume slows or pressures in the injection zone sufficiently decline to the point that they no longer pose an endangerment to USDWs, although movement does not completely cease. EPA believes that in all cases, th ese criteria will be met at some point after the cessation of injection. As discu ssed in the preamble to the proposed GS regulation and the associated background document "Computational Modeling of Underground Injection of Carbon

Dioxide for Determination of Area-of-Review a nd Potential Risk to Underground Sources of Drinking Water" (cited in the proposed rule pr eamble as USEPA, 2008d), research has shown that CO2 may continue to migrate for a period of time after injection ceases.

For this reason, the GS regulation does not sp ecify a timeframe over which the AoR delineation model should run. Rather, the model should be us ed to predict the ultimate plume movement up to the point the plume movement ceases or pressure s in the injection zone sufficiently decline to the point that they no longer pose an endangerment to USDWs.

EPA believes that an iterative pr ocess of AoR reevaluation is appr opriate to verify that the CO2 plume and pressure front are moving through the s ubsurface as predicted, verify the accuracy of the delineation model (or identif y needed changes), and refine testing and monitoring activities to ensure that USDWs are protected from enda ngerment and that there would be adequate

88warning of potential problems at the site befo re any endangerment could occur. EPA adds that the requirement at 146.93(b) for post-injection site care further ensures that any continued movement of the CO2 plume and pressure front will be addressed until it can be demonstrated that the GS operation no longer poses an endangerment risk to USDWs.

Letter ID: 0181 Comment ID: 23731 Letter Lines: 1862 to 1865

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: Part 146.84(c)(1)(iii) AWWA recommends revising this pa rt to read:

Consider potential migra tion through faults, fractur es, other discontinuities and artificial penetrations.

Individual Response: EPA did not change 146.84(c)(1)(iii) but instead changed the text at 146.84(c)(1)(ii) to read as follows: "Take into account any geologic heterogeneities, other discontinuities, data quality, and their possible impact on model pred ictions" to address the water

association commenter's concern regarding the potential for migr ation of CO2 at GS sites.

Letter ID: 0181 Comment ID: 23732 Letter Lines: 1867 to 1871

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

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

Comment: Part 146.84(c)(2) AWWA recommends revi sing the first sentence to read:

Using methods approved by the Director, id entify all penetrations, including active and abandoned wells and underground mine s, in the area of review that may penetrate any portion of the confining zone.

Individual Response: EPA clarifies that the mapping and cross sections required to be submitted under 146.82(a)(3) will define the limits of the confining zone, which would be

accounted for in the AoR delineation and correc tive action evaluation re quired at 146.84(c). EPA adds that owners or operators must also, under 146.82(a)(2), submit a map of the AoR that shows all injection wells, producing wells, abandone d wells, plugged wells or dry holes, deep stratigraphic boreholes, State or EPA approved subsurface cleanup sites, surface bodies of water, springs, mines (surface and subsurface), quarries, water wells and other pertinent surface features including structures intended for human occ upancy and roads. EPA believes that these requirements address the commenter's concerns.

EPA adds that any well that penetrates the conf ining zone, even if it doe s not extend all the way through the confining formation, is to be included in the tabulation. EPA is issuing guidance on

89how to identify all wells that require co rrective action. The guidance describes EPA's recommended approaches for the data to be c onsidered in an initial 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 _sequestration.cfm.

Letter ID: 0181 Comment ID: 23733 Letter Lines: 1881 to 1888

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: Part 146.84(d) Based upon our comments in the previous section of this document, AWWA recommends revising this part to read:

At the minimum fixed frequency, not to ex ceed one (1) year for the first ten (10) years of the operation of the car bon sequestration proj ect and not to exceed five (5) years after the first ten year time period, as specified in the approved area of review and corrective action plan, or when monitoring and operational conditions warrant, ow ners or operators must:

Individual Response: EPA agrees with commenters that reevaluations of the AoR every ten years may not be sufficient to appropriately model plume and pressure front movement, establish conditions for corrective action, and ensure prot ection of USDWs from endangerment. For these reasons, the Agency changed the minimum freq uency for the AoR reevaluation at §146.84(e) from 10 years to at least every 5 years in the final GS rule. EPA belie ves that this revised frequency addresses commenters' concerns about the inherent uncertainties in modeling CO2 movement, the emerging nature of GS technology, risk-based targeting of monitoring activities, and the unique nature of CO2 GS. In addition, the Director has discre tion to require more frequent AoR reevaluation if he or she has reason to believe, based on site-specific information, that a five-year reevaluation schedule is not sufficiently protective of USDWs.

Letter ID: 0181 Comment ID: 23734 Letter Lines: 1890 to 1899

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: Part 146.85(b) AWWA believes that potential changes in the si ze of the area of review require that all site plans be re evaluated at the same frequency as the area of review. Therefore, AWWA recomm ends revising this part to read:

The owner or operator must provide to the Director, at the same frequency as the AOR reevaluation, written updates of adjustme nts to the cost estimate to account for any amendments to the area of revi ew and corrective ac tion plan (§146.84),

90the testing and monitoring plan (§14 6.90), the injection well plugging plan (§146.92), the post-injection site care and site closure plan (§146.93), and the emergency and remedial response plan (§146.94).

Individual Response: EPA agrees that it is important to periodically update cost estimates that support financial responsibility determinations. The final GS rule, at §146.85(c), requires the owner or operator to provide updates to the cost estimate within 60 days of 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. Owners or operators must also adjust the estimates for inflation annually under §146.85(c)(2). EPA adds that the Director can also require the owner or operator to provide an adjustment of the cost estimate if the Director determines that the original demonstration is no l onger adequate, as specified at §146.85(e).

Letter ID: 0181 Comment ID: 23735 Letter Lines: 1901 to 1905

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: Part 146.86(b)(1) AWWA recommends revising the second to the last sentence to

read:

The casing and cementing program must be designed to prevent the movement of fluids into or between USDWs and between the injection zone(s) and USDWs.

Individual Response: EPA believes that the existing language as written ensures the prohibition of fluid movement between the injection zone and any USDW and the suggested change is unnecessary. Based on its evaluati on of all public comments and i nput 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: 0181 Comment ID: 23736 Letter Lines: 1911 to 1917

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

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

Comment: Part 146.86(b)(1)(v) The corrosiveness eval uation should include the possible combining of the carbon dioxide stream and the injection zone water, which has a higher potential to corrode than the carbon dioxid e alone. AWWA recommends revising this part to read:

Corrosiveness, chemical compatibility and reactivity of th e carbon dioxide

stream and the formation fluids lo cated within the injection zone.

91Individual Response: EPA clarifies that reference to co rrosiveness of the CO2 stream in §146.86 refers to the potential for CO2 to be corros ive in the presence of water or formation fluids. EPA believes that the risk of creating acidic fluids that could come in contact with well materials and cements is addressed by the construction requirement s in §146.86 to ensure protection of USDWs from endangerment.

Letter ID: 0181 Comment ID: 23737 Letter Lines: 1919 to 1922

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: Part 146.86(b)(1)(viii)AWWA recommends revising this pa rt to read:

Type or grade of cement and chemical co mpatibility and reactivity of cement and

formation fluids located w ithin the injection zone.

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. Please

see the final rule and the disc ussion of financial responsibilit y in the preamble for additional

information.

Letter ID: 0181 Comment ID: 23738 Letter Lines: 1924 to 1943

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: Part 146.87(b) AWWA suggests that submittal of the cores to the Director is not very practical. The requirement should be rewritten to state th at the Director should be provided with a summary repor t describing the cores and the test results. The operator should be required to first submit a coring plan to the Director listing the intervals to be core d, the coring procedures, the tests to be conducted and proposed stor age of the core for review and consideration of approval by the Director. A core repo rt, including the test results, geomechanical characteristics, and values calculated from the testing, such as fracture gradient, should be submitted to the Director. The owner/operator should make the cores available for insp ection by the Director upon the request. AWWA recommends revising this part to read:

The owner or operator must submit to th e Director a report describing whole cores or sidewall cores representative of the injection zone and confining system and formation 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 demonstrate that such data are representative of conditions at the well. The Director may require the owner or operator to core other formations in the borehole to acquire more info rmation on the subsurface geologic

92characteristics.

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 formation fluid sample information...."

Letter ID: 0181 Comment ID: 23739 Letter Lines: 1945 to 1970

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: Part 146.88(a) AWWA is concer ned that the limitation on injection pressure to 90% of the fracture pressure is not stri ngent enough. We heard it stated at the public hearing in Denver that fracturing of the injection fo rmation can occur when injection pressures are below 90% of the fracture pressure. It is important to consider that injection pressure lim itations need to take account of the possibility that, under certain conditions, fa ults can be re-activated even if injection pressures are kept below the le vel necessary to create new fractures or propagate existing fractures. Therefor e, the regulation should provide for the injection pressure to be calculate d based on the site geology, hydrogeology and geomechanics, in combination with the injection pr essure limitation. Injection pressures and rates should be determined by well tests and geomechancial studies, taking into account both formation fracture pressure and formation parting pressure. However, due to the amount of uncertainty associated with this topic, AWWA recommends that EPA research their proposed limitation in

more detail to determine the best met hod for preventing possible contamination of USDWs. Therefore, we recommend revising this part to read:

The owner or operator must ensure that injection pressure and rates remain within limits established by permit. Such permit limitations shall be based on well tests and geomechanical studies, incl uding assessments of both the fracture pressure of the confining zone and the pa rting pressure of th e confining zone. In no case may injection pressure initiate or propagate fractures in the confining zone, cause otherwise non-tra nsmissive faults transecting the confining zone to become transmissible, otherwise degrade the integrity of the confining zone, or cause the movement of injection or formation fluids that endangers a USDW.

Individual Response: EPA agrees that the operator must remain within limits established by the Class VI permit. EPA clarifies that the owner or operator is required in §146.82(a)(7) to propose a maximum injection pressure as part of the pe rmit application. The propos ed injection pressure will be evaluated by the Director based on site-specific conditions, and be informed by data on the injection zone. During injection, the pressu re in the injection zone must not exceed 90

93percent of the fracture pressure of the injec tion zone, as specified at §146.88(a). The fracture pressure (and, therefore, the injection pre ssure) are based on site -specific geologic and geomechanical data collected du ring the site characterization process required at §146.82. If, based on this information, a lower pressure lim itation is appropriate, the Director has the authority to set a lower limit in the operating permit.

In response to the concern about reopening of faults at lower pressures than 90 percent of fracture pressure, EPA believes that the requireme nt for the owner or operator to submit data on known or suspected faults and fractures and inform ation on the seismic history of the site will inform the determination of an appropriate pressu re limitation in the permit. Any sites with the potential for reopening or reactivation of faults or unacceptable seismic risk that could otherwise interfere with containment will not be permitted as GS sites.

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.

Letter ID: 0181 Comment ID: 23740 Letter Lines: 1972 to 1975

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: Part 146.88(b) AWWA recommends re vising this part to read:

Injection of the carbon dioxi de stream between the out ermost casing protecting USDWs and the well bore is prohibited.

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 in the UIC program.

Letter ID: 0181 Comment ID: 23741 Letter Lines: 1977 to 1984

Comment Code: 4000 2.4 Proposed Injection Well Operat ing Requirements (40 CFR 146.88)

Comment: Part 146.88(d) AWWA recommends that the final rule require mandatory implementation of a Supervisory Control a nd Data Acquisition (SCADA) system as part of the geologic carbon sequestration system. This system would allow for continuous monitoring and stor age of the data associated with the operation of the injection well. Owner/operators would be able to review data trends and

94detect anomalies or potential problems be fore they occur. This SCADA system

should also be tied to a carbon dioxide de tector to alarm and shut off the well

in the event that carbon dioxide is detected above a pre-set level.

Individual Response: To meet the requirements at §146.88(e), Class VI wells will be equipped with some type of continuous computer-based monitoring device that will be connected to alarms and the shut-off system. EPA does not beli eve it is necessary to specify what type of equipment is to be used to trigger the shut-off system. Instead, the regula tion allows the owner or operator some flexibility in deciding what equipm ent and alarms should be installed to allow site specific flexibility and to make use of improvements in technology. EPA believes that the technology for continuous monitoring is available and is currently in fairly wide use. The combination of computer-driven continuous pressure monitoring li nked to an automatic injection shut-off provides maximum protection of USDWs from endangerment and provides the earliest warning to owners or operators that well repairs need to be performed.

Letter ID: 0181 Comment ID: 23742 Letter Lines: 1986 to 1993

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: Part 146.89(f) AWWA recommends re vising this part to read:

The Director may require additional or alternative tests if the results presented by the owner or operator under paragraph (d) of this section are not satisfactory to the Director to demonstrat e that there is no significant leak in the casing, tubing or packer or significant movement of fluid into or between USDWs, or between the inje ction zone(s) and USDWs, re sulting from the injection activity as stated in paragraphs (a)(1) and (2) of this section.

Individual Response: EPA clarifies that the regulations at §146.89(e) allow the Director to require additional methods or, with the Administrator's approval, to approve the use of alternative MIT methods based on specific in formation about the site or the well.

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

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

95Letter ID: 0181 Comment ID: 23743 Letter Lines: 1995 to 2004

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: Part 146.90 AWWA recommends revi sing this part to read:

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. The testing and monitoring plan must be reviewed and updated, as necessary, on the same schedule as the update to the

Area of Review.

Individual Response: EPA agrees that periodic updates to the plan are appropriate. EPA clarifies that the final GS regul ation includes a requirement that the AoR be reevaluated at least every 5 years, and it specifies at §146.90(j) that the operator re vise the testing and monitoring plan to incorporate the results of the most recent AoR reeval uation and recent operational and monitoring data. Based on its eval uation of all public comments a nd input on the proposed rule and NODA and Request for Comment EPA has made many revisions to the GS rule. See the final rule and preamble for further discussion on EPA's final approach.

EPA agrees with commenters that developing 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: 0181 Comment ID: 23744 Letter Lines: 2020 to 2026

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

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

Comment: Part 146.90(g) AWWA recommends re vising this part to read:

Testing and monitoring to track the exte nt of the carbon dioxide plume and the position of the pressure front by either m onitoring for pressure changes in the confining zone, 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);

Individual Response: EPA has revised the final GS regulat ion, at §146.90(g)(1), to require all GS project owners or operators to monitor for pressure changes in the injection zone. EPA believes that pressure monitoring in the injection zone is necessary to tr ack the development and movement of the pressure front and CO2 plume. Pr essure monitoring within the injection zone is

96necessary because any such monitoring above the confining zone would not detect movement of the pressure front unless a breach of the confin ing zone occurs. EPA believes that monitoring using wells in the injection zone (i.e., that penetrate the confini ng zone) can be safely performed if the wells are constructed to prevent flow between the injection z one and USDWs or other layers above the confining zone. Such construction technologies exis t and have been used in the oil and gas industry for years. EPA believes that the benefits of monitoring in the injection formation outweigh the manageable risk of thos e monitoring wells serving as conduits for fluid movement. EPA adds that owners or operato rs may consider and Directors may require performing additional pressure monitoring in wells that are above the confining zone (e.g., in the same wells used to perform ground water qualit y monitoring required at §146.90(d)) to provide additional verification that no pr essure changes are occurring above the conf ining zone due to CO2 leakage. Monitoring also identifies n eeded remedial actions, provides inputs for AoR reevaluation modeling, and targets additiona l geochemical and surface monitoring needs. Knowledge of the location of the CO2 plume and the associated pressure front will assure the public that GS projects are proceeding according to plan, provide sufficient information to the owner or operator and Director, or allow for a ppropriate actions to addr ess any indication that USDWs may be endangered.

In addition, §146.90(g)(2) requires owners or oper ators to track the position of the CO2 plume using indirect methods (e.g., seismic, electri cal, gravity, or electromagnetic surveys and/or down-hole CO2 detection tools), un less the Director determines based on site-specific geology,

that such methods ar e not appropriate.

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

Letter ID: 0181 Comment ID: 23745 Letter Lines: 2028 to 2032

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

97Comment Code: 4610 2.6.1 Testing and monitoring plan requirement (seeking comment)

Comment: Part 146.90(h)(1) AWWA recommends revising this part to read:

The testing and monitoring plan must be based on site-specific geologic factors, modeling, and a risk-assessmen t of potential vulnerabili ties within the area of review;

Individual Response: As described above, EPA agrees that periodic updates to the plan are appropriate, and the final GS re gulation includes a requirement that the AoR be reevaluated at least every 5 years, and it sp ecifies at §146.90(j) that the oper ator revise the testing and monitoring plan to incorporate the results of the most recen t AoR reevaluation and recent operational and monitoring data. Based on its eval uation of all public comments and input on the proposed rule and NODA and Request for Commen t EPA has made many revisions to the GS rule. See the final rule and preamble for fu rther discussion on EPA's final approach.

Letter ID: 0181 Comment ID: 23746 Letter Lines: 2034 to 2046

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: Part 146.91(11)(a) AWWA believes that th e reporting frequency should be on a monthly basis, similar to what water and wastewater treatment plants have to do. The operating information for the geologi c sequestration project is extremely important and needs to be reviewed at a frequency by the regulatory agency to ensure problems are identified and addre ssed in a timely manner. For example, with the way the regulation is currently structured, data co llected on July 1, 2008 would not be seen by the regulatory agency before January 15, 2009, if the operator is allowed 15 days to submit th e report. This would allow for very little time to correct any potential issues in the operation of the project. As such, AWWA recommends revi sing this part to read:

Monthly reports, due on the 15th day of each month for the previous month’s activities, containing:

Individual Response: As described above, the final rule remains unchanged from the proposal and requires semi-annual reporting of monthly average, maximum and minimum values for injection pressure, flow rate and volume, annul ar pressure, and monthl y annulus fluid volume added at §146.91(a). EPA believes that monthl y reporting of routine operational data and monitoring results would provide no additional protection of USDWs from endangerment.

For additional information, please see the final rule and the preamble fo r a discussion of EPA's final approach to reco rdkeeping and reporting.

98Letter ID: 0181 Comment ID: 23747 Letter Lines: 2048 to 2060

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: Part 146.92(b) As previously stated AWWA believes that potential changes in the

size of the area of review require that all site plan s be reevaluated at the same frequency as the area of review. Ther efore, AWWA recomme nds revising this part to read:

Well Plugging Plan. The owner or operator of a Class VI well must prepare, maintain, and comply with a plan that is acceptable to the Director. The plan must be reviewed and revised by the ow ner or operator, and submitted to the Director for approval, at the same frequency and time as the AOR reevaluation. The requirement to maintain and implem ent an approved plan is directly enforceable regardless of whether the requi rement 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:

Individual Response: EPA agrees that developing, maintaining, and implementing an injection well plugging plan is important to assuring that GS wells are plugged in a manner that will

ensure that the well will not serve as a conduit for CO2 leak age preventing endangerment of

USDWs.

EPA disagrees with the suggested change, howev er. The final rule requirement at §146.92(c) for the owner or operator to notify the Director of any changes to the injection well plugging plan at least 60 days before plugging the well will allow the owner or opera tor (through communication with the Director) to address any issues associat ed with the initial well plugging plan submitted with the permit application. EPA is not requiri ng formal periodic review and updates to the injection well plugging plan thr oughout the injection phase. EPA doe s not expect that changes to this plan would be implemented until injection op erations cease. EPA envi sions that owners or operators will take into account similar considerations that guide updates to other project plans, e.g., monitoring and operational data and results of AoR reevaluations.

EPA clarifies that the owner or operator's injectio n well plugging plan will be incorporated as a condition of their UIC permit and is therefore en forceable; failure to follow the approved plan would be considered a violation of the permit and would be subject to appl icable civil, criminal, or administrative penaltie s under §1423 of the SDWA.

Letter ID: 0181 Comment ID: 23748 Letter Lines: 2068 to 2077

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)

99Comment: Part 146.93(a) As previously stated AWWA believes that potential changes in the

size of the area of review require that all site plan s be reevaluated at the same frequency as the area of review. Ther efore, AWWA recomme nds revising this part to read:

The owner or operator of a Class VI well mu st prepare, maintain, and comply with a plan for post-injection site care and s ite closure that meets the requirements of paragraph (a)(2) of this section and is acceptable to the Di rector. The plan must be reviewed and revised by the ow ner or operator, and submitted to the Director for approval, at the same frequency and time as the AOR reevaluation.

Individual Response: As described above, the final rule requires review and revision of the post-injection and site care cl osure plan when injection ceases, as described in §146.93(a)(3). EPA is not requiring formal periodic review a nd updates to the PISC a nd site closure plan throughout the injection phase. EPA does not exp ect that changes to this plan would be implemented until injection operations cease. Se e the final rule and preamble for further discussion on EPA's final approach.

Letter ID: 0181 Comment ID: 23749 Letter Lines: 2094 to 2125

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: Part 146.93(b)(3) When addressing plume stab ilization in association with site closure, it is important to realize that the carbon dioxide plume will never be completely stable. The carbon dioxide plume will continue to move by a combination of methods including density differences, natural formation flow gradients and diffusion. AWWA recommends that EPA engage in research to provide specific criteria on what exactly it would mean for the plume to have stabilized. If left up to th e discretion of the various Directors, stabilization could be defined in many different ways . In order to have a consistent application of this part of the regul ation, EPA should define the specific situations in which the plume could be considered "stable." AWWA recommends revising this part to read:

Prior to authorization for site closure, the owner or operator must demonstrate to the Director, based on monitoring a nd other site-specific data that no additional monitoring is needed to as sure that the geologic sequestration project does not pose an endangerment to USDWs. The demonstration must demonstrate all of the following:

(i) the estimated magnitude and extent of the project footprint (CO2 plume and the area of elevated pressure) base d on measurements and modeling; (ii) that CO2 movement and pressure changes match model predictions, (iii) the estimated location of the det ectable CO2 plume based on measurement and modeling (measuring magnitude of satura tion within the plume or mapping the

100edge of it); (iv) that there is no evidence of significan t leakage of either CO2 or displaced formation fluids that endanger USDWs; (v) that the CO2 plume and di splaced formation fluid are not expected to migrate in the future in a manner that encounters a potential leakage pathway; (vi) that the injection wells at the site completed into or through the injection zone or confining zone ar e properly plugged and abandoned; and, (vii) any remaining project monitoring wells at the site are being managed by a person and in a manner acceptable to the Director.

Individual Response: EPA acknowledges that many site-sp ecific factors will influence the determination of when the CO2 plume and pressu re front no longer pose a risk of endangerment

to USDWs. It is for this reason that EPA believe s that individual UIC Dir ectors, in consultation with operators, will be in the best position to determine whether additional post-injection site care is needed. EPA expects this decision to be made based on relevant site data and in consultation with all potentia lly impacted parties.

EPA agrees that a complete cessa tion of plume movement may not occur at some sites for long time periods due to density differences, natura l formation flow grad ients and diffusion. EPA clarifies that a complete cessati on of plume movement is not requi red, only a demonstration that the plume and pressure front no longer pos e a risk of endangerment to USDWs.

EPA is developing guidance to assist owners or operators in evaluating well plugging, postinjection site care, and site closure requirements of §146.92 and §146.93. Additionally, the guidance will assist Directors in evaluating propo sed well plugging plans a nd post-injection site care and site closure plans under §146.92 a nd §146.93. The guidance describes recommended approaches for how an owner or operator coul d plug injection and m onitoring wells; perform post-injection monitoring; dem onstrate non endangerment; and perf orm site closure activities. The guidance will be available at http://water.epa.gov/type/groundwater /uic/wells_sequestration.cfm.

Letter ID: 0181 Comment ID: 23750 Letter Lines: 2140 to 2144

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

Comment Code: 5300 2.8.3 Site closure activities (40 CFR 146.93)

Comment: Part 146.93(d) There may be cases where th e Director would want some of the monitoring wells to remain in service afte r site closure. While this may not be the case for all projects, for some of the earlier sites, the Director may want to continue minimal monitoring to c ontinue to verify that the plume

characteristics have remained stable.

Individual Response: EPA clarifies that the owner or opera tor must conduct post-injection site care that is consistent with the approved PISC plan or for the durat ion of the alternative timeframe approved by the Director pursu ant to requirements in §146.93(c), until a

demonstration can be made to th e satisfaction of the Di rector that the plum e and pressure front

101no longer pose a risk of endangerment to USDWs. After this determination is made, site closure is approved and the post-injection site care pe riod would end, as specified in §146.93 (b)(1).

If, however, there is reason to believe that additi onal minimal monitoring is necessary to verify that the plume characteristics have remained stab le, this would be considered post-injection site care monitoring. If a reduction in monitoring fr equency or methods is appropriate (i.e., an additional year or so of veri fication of the non-endangerment de monstration), the Director has discretion to authorize an amendment to the post-inje ction site care and site closure plan. This is consistent with the requ irements at §146.93(b)(2).

Letter ID: 0181 Comment ID: 23751 Letter Lines: 2146 to 2156

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: Part 146.94(a) It is importan t that the emergency and remedial response plan is reviewed and updated on the same schedule as the area of review update. Changes

in the area of review could affect the ac tions that would need to be taken in the event of an emergency. AWWA recomm ends revising this part to read:

As part of the permit application, the owner or operator must provide the Director with an emergency and remedial re sponse plan that de scribes actions to be taken to address movement of the injection or formation fluids that may cause an endangerment to a USDW during cons truction, operation, cl osure and postclosure periods. The emergency and remedial response plan must be reviewed and updated, as necessary, on the same schedule as the update to the Area of Review.

Individual Response: EPA has added a requirement at §146.94(d) that owners or operators must review their emergency and remedial response pl an within one year of an AoR reevaluation required under §146.84 or following significant changes to the facility. Subsequently, owners or operators must submit an amended plan or demons trate to the Director that no amendment to the plan is needed based on the AoR reevaluation or any significant changes made to the facility.

Letter ID: 0181 Comment ID: 24332 Letter Lines: 2006 to 2011

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

Comment Code: 4660 2.6.6 Geochemical monitoring

Comment: Part 146.90(d) AWWA recommends re vising this part to read:

Periodic monitoring of the ground water qual ity and geochemical changes within (if wells can be installed without adversely affecti ng the integrity of the

102confining zone) and above the confining z one(s) that may be a result of carbon dioxide movement through the confining z one or additional identified zones:

Individual Response: EPA clarifies that §146.90( d) requires geochemical monitoring above the confining zone. To mitigate the risk of fluid movement, EPA requires owners and operators to submit a testing and monitoring plan that describe s how the owner or operator plans to site and construct monitoring wells.

EPA believes that monitoring using wells in the injection zone, e.g., for pressure monitoring as required at §146.90(g)(1), can be safely performed if the wells are constructed to prevent flow between the injection zone 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 properly constructed monitoring wells will be a safe way to obtain the data that is essential to ensure that the inje cted 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 requires 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 is 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. EPA is developing guidance on testing and mon itoring to assist owne rs or operators and Directors in evaluating requi rements under §146.90, including pr oposed monitoring plans. The guidance describes available technologies a nd recommended approaches for implementing a testing and monitoring plan, including pre-ope rational geophysical l ogging and testing of injection wells, MITs, injecti on well testing during operation, groundwater quality monitoring, tracking the CO2 plume and pressure front, a nd soil gas and surface air monitoring which may be required by the UIC Director for specific GS projects. Th e guidance can be found on EPA’s website at http://water.epa.gov/type/gr oundwater/uic/wells_se questration.cfm.

Letter ID: 0181 Comment ID: 24339 Letter Lines: 2013 to 2018

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: Part 146.90(d)(1) AWWA recommends revising this part to read:

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 natu ral discontinuities and artificial penetrations and other factors.

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.

103EPA's guidance on testing and monitoring will provide guidance on monitoring well placement. The guidance can be found on EPA’s website at http://water.epa.gov/type/groundwater /uic/wells_sequestration.cfm.

Letter ID: 0181 Comment ID: 24371 Letter Lines: 2062 to 2066

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: Part 146.92(b)(5) AWWA recommends revising this part to read:

The type and grade and quantity of material to be used in plugging. The material must be compatible with the carbon dioxi de stream and pre-in jection formation conditions; and

Individual Response: EPA believes, considering the potentia lly corrosive nature of CO2 when it is in contact with water, that the requirement that the material must be compatible with the CO2 stream is appropriate. The final rule retains this requirement.

Letter ID: 0181 Comment ID: 24372 Letter Lines: 2079 to 2092

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: Part 146.93(b)(2) AWWA recommends that there should be a minimum 50 year

postinjection monitoring period for all car bon sequestration projects. This time period is necessary to monitor the site for changes that may occur over a longer amount of time, such as gradual leakages, or sudden seismic shifts. After this time period, the owner/operator may apply to the Director for a modification or termination of the monitoring requirements . AWWA recommends revising this part

to read:

If, after the 50-year post- injection monitoring period, the owner or operator

can demonstrate to the sa tisfaction of the Director , based on monitoring and other site-specific data, that the ge ologic sequestration project no longer poses an endangerment to USDWs, the Dire ctor may approve an amendment to the post-injection site care and site closur e plan to reduce the frequency of monitoring or may authorize site closure before the end of the 50-year period.

Individual Response: As described above, EPA agrees wi th commenters that a 50 year postinjection site care timeframe represents a reasonable and protective post-injection site monitoring period in most cases and available data, includ ing data submitted by commenters, do not support

a different default timeframe. EPA bases this on a review of research st udies, industry reports,

104and existing environmental programs, and eval uation of public comments. Furthermore, EPA believes that a 50-year default post-injection si te care timeframe is not overly burdensome, does not exaggerate the risks associated with GS, is consistent with other environmental programs, and sufficiently protects USDWs from endangerm ent. For this reason, the final GS regulation retains the 50 year post-injection site car e timeframe, as specifi ed in §146.93(b)(1).

However, EPA disagrees that a 50 year post-injection s ite care timeframe should be an absolute minimum. Rather, EPA believes, as some commenters suggest, that there will be circumstances

where it can be demonstrated in less than 50 years that the plum e and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion to shorten or lengthen the PISC timeframe during the post-injecti on period based on site-specific data, pursuant to requirements at §146.93(b); or (2) affording the Director discretion to allow a Class VI well owner or operator to demons trate, during the permitting process based on substantial data, that an alternative PISC tim eframe may be appropria te if it ensures nonendangerment of USDWs pursuant to requirements at §146.93(c).

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

comments.

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: 0181 Comment ID: 24373 Letter Lines: 2127 to 2138

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: Part 146.93(c) AWWA recommends that this part of the rule needs to include a directive that the Director needs to provi de approval for site closure prior to implementation of the site-closure plan. A WWA recommends revisi ng this part to

read:

Notice of intent for site closure. Th e owner or operator must notify the Director at least 120 days be fore site closure. At th is time, if any changes have been made to the original post-inj ection site care and site closure plan,

105the owner or operator must also provide the revised plan. Th e Director must provide approval for site closure prior to the implementation of the site closure plan. At the discre tion of the Director, a shor ter notice period may be

allowed.

Individual Response: EPA considers the combination of the Director's evaluation of the data submitted to support a demonstration of non-endangerment of USDWs, as specified in §146.93(b)(3), and the Director's recei pt of and agreement with the no tification of intent for site

closure as confirmation that GS site closure can proceed.

Letter ID: 0181 Comment ID: 24374 Letter Lines: 1720 to 1725

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: Part 146.82(d)(3) AWWA recommends revising this part to read:

Information on the seismic history within th e proposed area of review including presence and depth of seismic sources, know ledge of previous seismic events and history of these events, a nd a determination that the seismicity would not

interfere with containment.

Individual Response: EPA agrees that consideration of local and regional seismicity is important. This information is required fo r GS projects at §146.82(a)(3)(v). The site characterization provisions in the GS rule also require the owner or operator to submit data on known or suspected faults in the AoR (§146.82(a)(3 )(ii)). Beyond the AoR (the specific project area) EPA notes that the site characterization requires a revi ew of the local and regional geology,

and detailed review of any known or potential seismically ac tive terrain in the vicinity of a proposed GS site would certainly be re quired in a GS site characterization.

Letter ID: 0181 Comment ID: 24375 Letter Lines: 1873 to 1879

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

Comment Code: 3420 2.2.2.1 Scope of the inventory pr ocess (e.g., reliance on publicly available information, depth of wells)

Comment: Part 146.84(d) AWWA recommends re vising this part to read:

Owners or operators of Class VI wells must perform corrective action on all wells and other artificial penetrations in the area of review that are

determined to need corrective action us ing methods necessary to prevent the

movement of fluid into or between USDWs and between the injection zones(s) and USDWs, including use of corrosion resist ant materials, where appropriate.

Individual Response: EPA revised the text at §146.84(d) to re quire the use of materials that are

106"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. EPA believes that meeting the requi rement for preventing

"movement of fluid into or between USDWs" w ill prevent movement between the injection zone and USDWs; therefore, it did not make the suggested change.

Letter ID: 0181 Comment ID: 24376 Letter Lines: 1907 to 1909

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: Part 146.86(b)(1)(i) AWWA recommends revising this part to read:

Depth to the injection zone and overbur den pressures in the injection zone.

Individual Response: EPA believes that the requirement in 146.86(b)(ii) to report the external pressure provides the same information as the requested change. Based on its evaluation of all public comments and input on the proposed rule and NODA and Request for Comment EPA has made many revisions to the GS rule. Please see the final rule and preamble for additional

information.

Letter ID: 0181 Comment ID: 24377 Letter Lines: 1833 to 1839

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: Part 146.83(a)(2) AWWA recommends revising this part to read:

A confining zone(s) that is free of tran smissible faults or fractures and of sufficient areal extent and integrity to contain the injected carbon dioxide stream and displaced formation fluids a nd allow injection at proposed maximum pressures and volumes without initiati ng or propagating fr actures in the injection and confining zone(s).

Individual Response: EPA acknowledges the importance of se lecting GS sites with confining

zones that are free of transmissive faults and fract ures but disagrees that the rule should prohibit fracturing within the injection zone. EPA believe s that, in some circumstances, fracturing is necessary (i.e., in association w ith an approved for stimulation program to improve wellbore and formation injectivity). EPA clarifies that all stim ulation for GS must be approved by the Director pursuant to requirements at §146.91.

Letter ID: 0181 Comment ID: 25061 Letter Lines: 1364 to 1375

107Comment Code: 5432 2.9.1.1 Need to adjust financial responsibility mechanisms (seeking comment)

Comment: AWWA believes that the time limit for fina ncial responsibility in the proposed regulation may be too long for most insu rance agencies, which may trigger the need for the development of a trust fund or for owner/operators to use a selfinsurance mechanism. If the trust fund is the desired method, EPA should require that companies constantly add to the f und, even if it appears that the fund is fully funded. In addition to the initia l pay in period of three years, owner/operators should be required to pa y in any additional amount identified during the five-year reviews for the area of review and corre ctive action plan, injection well plugging pla n, the post-injection site care and site closure plan, and the emergency and remedial response plan. This additional pay in is required so that we don't have a repe at of the funding stoppage with the Superfund program.

Individual Response: EPA acknowledges that there may be several possible approaches to setting pay-in periods for trust funds. However, EPA emphasizes that regardless of the use or duration of a pay-in period, the value of the trus t must ultimately be equal to the cost estimate. The final rule requires that the Director approve the use and length of pay-in periods. EPA is developing guidance (available 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.

The final GS rule, at §146.85(c), requires the owne r or operator to provide adjustments 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. Owners or operators must also adjust the estimates for inflation annually under §146.85(c)(2). EPA adds that the Director can also require the owner or operator to provide an adjustment of the cost estimate if the Director determines that the original demonstration is no longer adequate, as spec ified at §146.85(e). Any adjustment to the cost estimate would require the owner or operator to adjust the funded amount of any financial responsibility instruments, as required at §146.85(c)(4).

Under SDWA, EPA has the general authority to set financial responsibility requirements for injection well owners or operators to ensure th at adequate resources are available to protect USDWs throughout the life of the GS project. However, this au thority does not extend to allowing the Agency to create a financial instru ment with EPA as the trustee, due to the

restrictions of the Miscellane ous Receipts Act (MRA). The MRA requires that EPA deposit the

funds it receives for the use of the Government into the Treasury, therefore funds would not necessarily be available for GS financial responsibility.

108109 Additionally, EPA does not have authority under SDWA to establis h a trust fund for purposes of financial responsibility for Class VI projects. The Agency clarifie s that the trust funds that are addressed as financial responsibility instruments on the GS rule are set up by individual owners or operators and are different from a national-le vel trust described by th e commenters that would cover large numbers of GS projects.