### 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.

# Gasification Technologies Council

4301 North Fairfax Drive, Suite 300 Arlington, VA 22203 Ph (703) 276-0110 Fx (703) 276-0141 Email jchildress@gasification .org

Water Docket, Environmental Protection Agency Mailcode : 2822T, 1200 Pennsylvania Ave ., NW ., Washington, DC 20460 RE : EPA Docket EPA-HQ-OW-2008-0390 FRL-8695-3 Dear Sir : 

# __ n Fr
. 0 120 0 8

The Gasification Technologies Council (GTC) is pleased to provide its comments on EPA's Proposed Rule for Geologic Storage of COZ (Docket EPA-HQ-OW-2008-0390 FRL-8695-3) 73 F .R

. 43492 (July 25, 2008)

. GTC represents 80 companies involved in the development, licensing, and use of gasification technologies

. The GTC's mission is to promote a better understanding of how gasification can provide the power, chemical and refining industries with economically competitive and environmentally conscious technology options to produce electricity, fuels, and chemicals

. Our members represent 95% of the world's gasification capacity Gasfication is an important technology for the conversion of coal, biomass, petroleum coke, municipal solid waste (MSW) and other carbonaceous feedstocks to power, chemicals, fertilizers and cleaner fuels

. With gasification, COZ can be captured using commercially available technologies

. Due to its inherent carbon capture capability, gasification can serve a major role in Carbon Capture and Storage (CCS) projects

. GTC's interest in EPA's proposed regulation derives from the importance of CCS to achieving future goals of COZ emissions reduction while using secure and indigenous resources to meet our growing national need for chemicals, fertilizers, liquid fuels, hydrogen, and electricity

. EPA is commended for taking this action that begins the process of providing regulatory clarity to a complex and important topic

. In its decision process, EPA needs to consider the importance of CCS to the success of the nation's overall climate change, energy independence and economic growth strategies

. Any rule for geologic storage of C02 needs to provide an unambiguous framework that promotes the development and deployment of CCS while protecting the environment

. Also, given the current state of experience in geologic sequestration, any prescription needs to be flexible and adaptive

. In addition to regulatory clarity, climate change policy will be needed to define a value for COZ in order to drive deployment of CCS

. After policy, cost will determine how quickly and widely CCS can be deployed

. Currently, the value of COZ is principally limited to its use in Enhanced Oil Recovery (EOR)

. The cost of CCS needs to be reduced

Page 1 of 16by implementing requirements that are necessary and sufficient while not compromising

the protection of drinking water
. These are our principal concerns with the draft regulation : 1

. EPA needs to categorically exclude COZ specifically intended for geologic storage from the definition of RCRA hazardous waste

. 2

. EPA must emphatically conclude that COZ containing trace contaminants does not open any regulatory pathways to subjecting a geological storage site to Superfund liability

. 3

. CLASS VI (Underground Injection Control (UIC) permits need to identify the potential for hazardous substances that might be generated in geologic formations after facility decommissioning and well closure so that should releases occur, they would be federally-permitted

. 4

. Secondary confinement/containment should not be required

. 5

. COZ injection should not be restricted only to formations below the lowermost underground source of drinking water

. 6

. EPA needs to clarify how to demonstrate financial responsibility ; the proposed regulation leaves too much discretion to the Director

. 7

. EPA should not adopt a pay-in period of three years
. 8

. The period of post-injection site management should be performance-based and not be arbitrarily set at 50 years
. . 9

. EPA should increase its state stakeholder effort towards uniformity of technical requirements ; disparate requirements and processes will increase the time, cost, and complexity of projects

. 10

. EPA should not stigmatize geological storage of COZ such as can be inferred by having requirements for Class VI wells that are more restrictive than for Class II wells

. 11

. Requirements for conversion of any well to a Class VI well should be site and risk dependent

. 12

. EPA's implied 2017 date for completion of the final UIC regulations is too late to provide regulatory clarity faced by CCS project developers today

. These are the details supporting these concerns and recommendations : Discussion #1 : Potential Applicability of CFR 40 Part 261 (RCRA)

. (Ref : page 43503, Section 1) In the preamble to the ANPR, EPA poses the question of whether injected COZ might be considered a RCRA hazardous waste, but does not answer the question

. Any ambiguity concerning the applicability of complex and expensive regulatory regimes such as RCRA and CERCLA will be a major disincentive to the development and deployment of CCS

. Regulatory clarity and certainty are critical to companies facing multi-billion dollar investment decisions regarding gasification facilities and COZ sequestration projects

.
Page 2 of 16EPA should explicitly address these issues in the final rule and not leave open any

implication that RCRA and CERCLA may or may not apply to CCS

. The presence of low levels of hazardous contaminants in COZ as a result of the carbon capture process should not limit the storage of the COZ using Class VI wells, especially taking into account the diminimus risk of exposure associated with the disposition of C02 into deep geological formations under the stringent controls required by this proposed regulation

. We strongly recommend that EPA provide a categorical exclusion in this rulemaking, that CO2 streams that are specifically intended to be stored in geologic structures are not RCRA hazardous wastes

. Such an exclusion would be analogous to the provision of 40 CFR §261 .4(b)(5), which excludes drilling fluids, produced waters, and other wastes associated with the development, or production of crude oil, natural gas or geothermal energy, and therefore can be injected into Class II wells

. In terms of its approach, we recommend that EPA consider captured C02 -- inclusive of transport, the injection facility and within injection wells -- as material that constitutes a stream that is contained within a process and therefore, not a solid waste

. Within this scope, protection of health and the environment will be provided by controls required under other regulatory domains such as OSHA and NESHAPS

. For purposes of evaluating the potential RCRA status of the captured COZ that may be injected in Class VI wells, the C02 streams trigger none of the RCRA hazardous waste criteria

. Specifically, captured C02 is not a "listed" hazardous waste as set forth in 40 C .F .R

. §261 .31 - .35, nor is it "characteristically" hazardous pursuant to 40 C .F .R

. § 261 .20 - .24

. It is neither "ignitable" nor "corrosive", and the TCLP test used to determine whether a waste is characteristically "toxic" cannot be used on the supercritical liquid C02 stream

. In any event, the level of trace contaminants in the COZ is so low that TCLP levels are not even approached when measured on an absolute concentration basis

. Next, the COZ stream is not "reactive," since the injected COZ stream will not generate toxic gases in a quantity sufficient to present a danger to human health or the environment

. For example, the levels of hydrogen sulfide likely to be present in the COZ stream (generally less than 0 .3%) are an order of magnitude less than those typically present in the "acid gas" that is widely injected into Class 11 underground injection wells in the U

.S ., which have an average hydrogen sulfide concentration of approximately 40%

. See Kleweki (Cadmus Group), Kobelski (U .S

. EPA), Karimjee (U .S

. EPA), and Sham (Cadmus Group) : Acid Gas Injection In The United States (Presentation on May 8, 2006 at the Fifth Annual Conference On Carbon Capture & Sequestration)

. U .S

. EPA continues to encourage the underground injection of "acid gas" streams, recently including such a requirement in a proposed consent decree that would resolve an enforcement case brought under the Clean Air Act

. U .S

. v
. Merit Energy Company, Civil Action No

. 1 :08-CV-917 (W .D

. Mich .), proposed Consent Decree lodged on September 30, 2008 (73 Fed

. Reg

. 58267 (Oct

. 6, 2008) (U .S

. EPA's October 1, 2008 press release in this matter stated that the underground injection of the acid gas would result in "zero sulfur dioxide emissions .") EPA should take into account the specific disposition of the C02 that the ruling is focused on (i .e ., deep underground storage)

. A well permitted under this rule will be protective of underground sources of drinking water

. The minimum depth of injection required to maintain COZ in a supercritical state is approximately 2,500 feet

. This, in
Page 3 of 16conjunction with the controls and safeguards required by this rule throughout the

injection and post-injection period, will ensure that COZ injected into a Class VI well poses de minimus risk

. There is very little likelihood for hazardous constituents to be released where they would pose a risk to human health or the environment

. (See, e .g ., Final Risk Assessment for the FutureGen Project Environmental Impact Statement, DOE, April, 2007) Finally, much higher HZS levels than will be used in CCS have been successfully and safely used for EOR injection with Class II wells

. For example, in Canada, there are 45 ongoing projects where high levels (uV to 68%) of HZS in COZ are being injected into saline aquifers or producing oilfields 'Z'3 for disposal purposes
. These combined gas streams of HZS and COZ are commonly referred to as acid gas and originate from purification of sour natural gas, are highly toxic and in some cases of high concentration, flammable

. These projects have been studied in detail and their success is well documented 3,4

. In addition, there have never been any significant safety incidents reported, since the start of the first injection of acid gas into a depleted oil reservoir on the outskirts of the city of Edmonton, Alberta in the early 1990's

. Nor have there ever been any reports of leakage of H2S from these operations4

. Accordingly, EPA has sufficient information now to conclude that captured COZ streams are not RCRA hazardous wastes and do not pose greater risks that many streams than are already being routinely injected in Class II and other UIC wells as non-hazardous wastes

. Indeed, to conclude otherwise would create the nonsensical result of suggesting that sequestering a material in deep geological formations poses more hazards than emitting it into the air

. It is very important that EPA make this determination as soon as possible to remove the implication that CCS might be subject to RCRA regulation, an implication that would be extremely damaging to the future of CCS, and to the goal of significantly reducing the carbon footprint of the nation's energy sector

. Concern #2 : Scope of Class VI Permits and the Potential Applicability of Superfund to CCS

. (Ref page 43503, Section J) EPA raises, but does not answer, the question of whether the underground injection of COZ might trigger Superfund and associated natural resource damages liabilities, and appears to suggest that Class VI permits might be written to allow future Superfund liability associated with CCS

. EPA must emphatically conclude that C02 containing trace contaminants does not open any regulatory pathways for subjecting a geological storage site to Superfund liability

. As with RCRA, any ambiguity on applicability of CERCLA will be potentially fatal to the development and deployment of CCS

. It is highly unlikely that CCS will be implemented on a meaningful scale if there is a possibility that CCS might trigger Superfund

. CERCLA expressly excludes from Superfund liability "federally permitted releases ." Further, "any injection of fluids authorized under the Federal underground injection control programs or State programs submitted for Federal approval

. . . pursuant to part C of the Safe Drinking Water Act" are "federally permitted releases ." 42 U .S .C

. § 9601(10)(G) (CERCLA Section 101(10)(G))

. Therefore, any captured C02 stream that is injected in a Class VI well pursuant to a Federal or State permit is a "federally permitted release" and not subject to Superfund liability (including natural resource damages)

. It
Page 4 of 16would be inconsistent with existing practice in the UIC program, impractical, and fatal to

the future of CCS to limit Class VI permits solely to the COZ portion of the stream and explicitly exclude any trace contaminants

. By its inherent nature, gasification will provide a stream of >90% COZ having extremely low levels of both organic and inorganic hazardous air pollutants (HAPS)

. There are several mechanisms that provide this : 1) destruction of organic HAPS within a gasifier due to the extreme (-2,500 °F) gasification temperature, 2) removal of inorganic content in the melting and slagging process, 3) particulate scrubbing or filtration, 4) activated carbon beds to remove mercury and other condensed metals ;, and finally 5) cooling followed by acid gas scrubbing

. The combination of these HAP reductions is very effective

. As a point of reference, the total inorganic HAPS that would be injected with captured COZ from an IGCC or gasification process over 30 years of CCS operation will be at least an order-of-magnitude lower than the annual limits (both total and individual components) of NSPS

. Concern #3 : Potential releases from the well which are outside the scope of the Class VI permit

. (Ref : page 43504, Section J) Class VI UIC permits must also be carefully written to identify and address the potential post-injection releases of hazardous substances, or the generation of hazardous substances from the chemical interaction of the COZ with the geological storage formation (e .g
. - leaching of metals) so that they would be federally permitted releases

. If the potential release or generation of such hazardous substances is viewed as beyond the scope of Class VI permits, CCS sites could be subjected to the threat of long-term Superfund liability, a threat that could be fatal to the viability of CCS

. With respect to releases from the well itself, the primary source of such releases could occur during injection operation through failure of well seals, flanges and gaskets, piping breaches, liners, valve packing and other mechanical components or failure to follow operational and safety procedures

. Such releases will likely be confined to the injection period

. During operation and the measurement, monitoring, and validation (MMV) period, the injection facility (metering, distribution and injection systems), should be classified as a production facility where industrial safety standards, design and operating procedures (e .g ., - HAZOPS reviews) will apply

. Appropriate regulation will be derived from permits under the Clean Air Act that are issued to the facility along with protection of operating personal as required by OSHA

. Concern #4 : Requirement for secondary confinement/containment

. (Ref

. page 43505, 1- Proposed Geologic Siting Requirements) The proposal would provide the Director the discretion to require the owner or operator to identify and characterize additional confining and containment zones above the primary (i .e ., lowermost) confining zone that could further impede vertical fluid movement and allow for pressure and dissipation

. Secondary containment (multiple confining structures) should not be required to prevent leakage of C02

. If required, this will prevent geologic storage in certain but important geographic regions

. It also raises doubt concerning procedures and protocols to characterize and validate safe geologic storage formations and containment where there is not secondary containment

. Under the

Page 5 of 16proposed rule, there are measures that provide adequate assurance of formation integrity

and require operators to demonstrate that their project will not endanger underground sources of drinking water (USDWs)

. If a secondary containment is present, it will be detected during site characterization and risk assessment

. Such a special case could be analyzed to evaluate the potential risks to USDWs and to develop additional evaluation criteria to be applied to permit geological storage without going through the aquifer exemption process
. Concern #5 : Restriction of injection to formations below the lowermost underground source of drinking water or USDW

. (Ref page 43512, 3

. Proposed Injection Well Construction Requirements) This requirement is not necessary for the protection of USDWs

. It is in-fact overly restrictive and will eliminate many suitable and safe geologic formations for C02 sequestration or permanent storage

. It will also render geological storage impractical (pumping power and well costs) for states in the western United States where the drinking water aquifers are many thousands of feet deep and well isolated from overlying regions

. Also, industry has demonstrated that it can operate COZ injection wells for EOR without endangering USDWs that are located below the injection zone (e .g ., the Salt Creek EOR project in Wyoming, having a USDW below the injection zone)

. Concern #6 Demonstration of financial responsibility

. (Ref : page 43520, 9

. Proposed Financial Responsibility and Long-Term Care Requirements) EPA needs to provide clarifying guidance on how to demonstrate financial responsibility

. The proposed regulation leaves too much to the discretion of the Director

. Such openended requirements will effectively discourage carbon capture projects and the development of financial pro formas

. Of particular concern are those assurances necessary to cover the costs of potential long-term stewardship or the potential to have to perform remediation at sites that have been previously certified as closed

. This uncertainty may increase the perceived risk exposure to levels that serve as a barrier to investment

. A potential approach to share risk and overcome this barrier is the Interstate Oil and Gas Compact Commission (IOGCC)5 proposal for an industry-funded and stateadministered trust fund to provide the stewardship during the Post-Closure Period

. The trust would be funded through an injection fee assessed to the site operator and calculated on a per-ton basis, at the point of custody transfer of the C02 from the generator to the site operator

. Concern #7

. EPA is considering a guidance approach that would recommend adonting a pay in period of three years for GS projects consistent with other similar programs in the Agency

. (Ref : page 43521, Sec

. 9

. Proposed Financial Responsibility and Long-Term Care Requirements, Pay-in period for trustfunds) We strongly urge that the EPA not adopt this approach

. CCS projects will be subject to their highest financial strain in the first several years of operation

. During this period, commissioning, systems integration and debugging of mechanical and process systems will need to be completed with potential loss of plant operation, production and revenue
. Projects will likely be burdened with additional initial capital coverage of an already

Page 6 of 16expensive facility to contend with an accelerated payment

. We therefore recommend that

any payment schedule be based on a per-ton fee over an amortization period equal to the expected operational life of the project and in a framework as recommended by the IOGCC (ref- Concern #6)

. Concern #8 : The owner or operator shall continue to conduct monitoring as specified in the Director-approved post-injection site care and site closure plan for at least 50 years following the cessation of injection

. At the Director's discretion, the monitoring will continue until the geologic sequestration project no longer poses an endangerment to USDWs

. (Ref : page 43519, Sec

. 8

. Post-Injection Site Care Timeframe) The time required for post-injection site management should not be arbitrarily set at 50 years
. Criteria for defining the time for post-injection management should be performance based and site specific

. The choice of 50 years is arbitrary and does not take into account the data and knowledge and modeling verification obtained over a preceding operating and injection period of years and likely decades

. The maximumpost-injection monitoring period should be defined on reasonable but quantitative, performance-based metrics - for example, that the validated model predicts that 95% of the plume is or will be trapped and that a sensitivity analysis predicts a comfortable margin of safety to minimize approach to any USDWs, thus preventing potential endangerment

. Concern #9: On-going state efforts to regulate GS

. (Ref : page 43497, Sec

. C

. Who Implements the UIC Program?) Although we recognize that state primacy is integral to the UIC program, we strongly recommend that EPA drive its state stakeholder activities towards the goal of unanimity and uniformity of technical requirements

. Disparate requirements and processes will increase cost, delay, and complexity and make the permitting process less predictable

. Individual states should not develop regulations that are substantially more restrictive or prescriptive than that required by the EPA

. Many states will also not have technical resources that are comparable to that of the US EPA

. EPA's stakeholder technical workshops had good representation from the EPA regions, but it appears that many states have not yet been engaged

. To avoid this and the problems from a patchwork of permitting regulations, EPA should carefully but quickly consider and integrate input from a majority of state environmental protection and conservation and natural resource offices

. Concern #10 : Continuation of Class II for EOR

. (Ref : page 43502, Sec

. G) By proposing different and more restrictive requirements for Class VI wells, EPA will create economic or operational barriers that prevent a seamless transition from EOR and storage operations to wholly storage operations

. EOR can make a significant contribution to offset the cost of early CCS demonstration projects

. For example, EOR can contribute to the investment in pipeline infrastructure helping to enable pure CCS operations

. Also, COZ storage operations may continue after EOR has ceased, thus reducing the cost of storage, site characterization and development

. These benefits should be viewed as especially significant in light of the difficulties in securing sufficient funds to initially deploy CCS

. EOR projects could quite feasibly bring CCS deployment forward by many

Page 7 of 16years as a considerable quantity of COZ remains underground during such operations

.

This will reduce the number of target formations where COZ could be stored

. Concern #11 : Grandfathering of construction requirements at the Director's discretion for existing Class 1, Class 11, 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 CO,

. (Ref

. page 43497, Sec

. G) ~ Requirements for conversion of any well to a Class VI well should be site and risk dependent

. EPA should consider expanding grandfathering scope to more than construction requirements and not a-priori require that all other permitting requirements be redone

. Existing permit holders should be allowed to provide data on the experience and characteristics of their site demonstrating that it is suitable for long-term storage of carbon dioxide without endangering underground sources of drinking water

. This could be more acceptable with an end date for grandfathering wells (e .g ., - operational before 2012)

. Concern #12 : EPA's schedule for promulgation of its proposed UIC regulation (Page 43499 Sec

. E3) We reference the following statement from the preamble section of the proposed rule : "During the Deployment Phase (2008-2017), the [RCSP] partnerships will conduct large volume carbon storage tests to demonstrate that large-scale COZ injection and storage can be achieved safely and economically

. EPA will use the data collected from these projects to support decisions in the final GS rule ." This statement suggests that a final GS rule may not be issued until 2017

. We believe that this is too late to clear the regulatory uncertainty that CCS project developers are facing today

. If this reflects EPA's intention, we recommend that EPA abandon a prescriptive approach and instead, favor general and performance-based requirements until these demonstration tests are completed

. Other concerns expressed by our membership and recommendations for improvement of the proposed rulemaking are given in Appendix A

. Should the EPA have further questions, please fell free to contact me
.

James Childress Executive Director ;Gasification Technologies Council

Page 8 of 16References

' Keushnig, H

. (1995) ; Hydrogen sulfide - if you don't like it, put it back

. J

. Canadian Petroleum Technology

. 34 : 18-20

. 2 Longworth, H

.L ., G .C

. Dunn, M

. Semchuck (1996) ; Underground disposal of acid gas in Alberta, Canada : Regulatory concerns and case histories

. SPE 35584

. pg 181-192

. 3 Bachu, S ., K

. Haug (2005) In situ characteristics of acid-gas injection operations in the Alberta Basin, Western Canada : Demonstration of C02 geological storage

. in Carbon Dioxide for Storage in Deep Geological Formations

. Vol

. 3

. ed

. D.C

. Thomas, S .M

. Benson

. Elsevier Ltd

. pg 867-876

. 4 Bachu, S ., W

.D

. Gunter ; Overview of Acid-Gas Injection Operations in Western Canada

. In Proceedings of 7th International Conference on Greenhouse Gas Control Technologies

. Volume 1 : Peer-Reviewed Papers and Plenary Presentations (E .S

. Rubin, D .W

. Keith and C.F

. Gilboy, ed .), IEA Greenhouse Gas Programme, Cheltenham, UK, 2005

. 5 The Interstate Oil and Gas Compact Commission Task Force on Carbon Capture and Geologic Storage, Storage of Carbon Dioxide in Geologic Structures - A Legal and Regulatory Guide for States and Provinces , September 25, 2007

Page 9 of 160
C"

. 0 U

0 U 0 b U U

O,O
ti4 ti4 O U 0) O

0) -

. ,
`'N o 0

. ~ "tt L, o p

U O i -IZ C,

, v Z~ o 0

o 3 o o

a O U

o W

p , .

.~ ^O
`° 41- U U ~ .~ ~ o o

, U ~ ~ ' y ~ ~ '~ .O cd 'v su , ~ ~ ~, ~- ~ 3 =

. o ~ 's ~~ "~ N ~' ~n 3

cd r 03

. rz Q,

14) (Z CL, Z~

. ~ O ~ o U) Z 44 U

- ~ ,~ ° o ('0 b

.

41, 3 o ~~ a ~ ~ ~ o o ~ .

° ~ `~ ~ .~^o ; ~¢ w U p ~ s R

rz o 0 Z- cr O U ~ y LC ,,, . ~ O

~ ~ U

. b4 ~ U O c~S ~ S` A~ ~ U CZS 7~ E~ 4 -b o ~ s ~ ~ ~ . 0 4, zs o ~ti ~' 3 ~~ q o~~ o
.~ o ~ sy~ ~ ~ ~ o?e
a C7 °' ° ' ~ ~C ~° a~° ' ~ .

o ~ ° on ~ ~ ~ ~ o o
~ . . o -~ o

O p~ ~ U ~ Q

. o ti ° ~U ;ti_ O ~51" cC

~ . 44"-~
. O
U

~ '~

. U c~ U ~ p O ~ ~ .--, +' U U '~+ ~ ~

V O

.~ U z ~ p ,1~

.

_ ~A In - - U ~ 'CS

b4 ~o c3 f~ p
. Z :
_ ~ . b4

Sz

. C) ;z O

~ ~ 'b"

y U sy 3 ~ 110, v)

. ,~U + r'1
.N

CIO o

o ~ p> U " _O

. O'~O

x N O

"

~, 4> O ~ . C~ O

. O

U p~ N bq ~ N

' O

+~ N U

. o s° ~ q

k

O N_ 4~O

.

O 'w ~ U -d ,0 o ,C) o i

° O ~ O y ° > ~ '~ a~ Q

. O Q ., 

### ~c t
0 Z c~, U ~ " ~ bA

p

.~ .~ ~ ~ O G) o ~ o r+

:, '~, o 0 cd ~ O ~

. vi U

U y N p .-+ sn,

. on (1) m ' 7r j O"C ~~ ^

.

p~ ~ 'b U f~ 'C 3 0 71~

~, C8 .v~~ .~ E '~,~ y }' G~ U y

U ~ O ° ~ 3 ~ _a U 'r'~ cd U U cC Q

. 'O ~ O U ~ cj s ., y ~

. c~ cf-, y .,
.~ En = o ^C ~ `~' ~ U _,,
O

~ c~C O U 3 .~, o ~ 3 4, ' - 'b " t : ; O
O o
. o ~ ct .¢"'~ ~ p c~d U

U U C4--4 V) E 

### En CA

~:) = = = U .~ V U s .U

b~A .3- ~ p 't -d'C G~4

~ G~ pA
.

' v~ N b s .U

. :'a ~ ~ ~ O p o ~ 3 O 

### U-

~ C~3 ~ v 'Z3 , O

o o

.~ O O

p> p

O ~ C3 q , b~4

O O ? N
O

. ti4 " O

.

N v 'Zs

. s

~v '~ o ~S v ~ U

U O Y O'"p

c O

U (j U U O' " o ,o

U .U c'a 

### q
0

O U
O U

O

N N

b0

.

U

i O U ; U U O U
U U O



### 00 F,) b U a .D

03

3

N

U >

.

._~

O

U 3

. N

a~)

.

O ti)

U

o 

### Q CZ

U U? O

. .
U bq O N

U S~

.~ .

O O

O ti U O O N U ~ti O O v O ^~ b-0 ~

, b-0 +~

. i o ? O ' ,O O

U 0) + .,

. o

O N

O O G~

. .~

U

0 U U
U N bA

. U O O U

O o 3 ~ o > o 

## ;

, .o o t
. . "

. . O ~ O

r
. as

. O y

. .' .O ~ ~ b~U

c~ O

.

"

. . o ~ 3

on .~

.
U U ~ `~ '~ y " bA
3 0 

## 3 N ~' .~ .O O O O "fl Or

K ~ O O v o IZL) o \

4~ 0) v N O O U

~4 O o

v

b4 N

" O ,U

O N i ~ p4
N U bq "° ~ ° ° x .o

'~ O O

~ bq 0 cz U
s .~ . U O ~ >, U .~ ._O " ~,' O Cn

to ~ Q

. cd Q , i

. . " = bA A C/~ ~ ' "" 40

. ~ '~= cC N '~U, Q
. .4 : O ~ 'C ' U 50 ~I--I U ~ ~ C-0
~ ~ o N o
. O o~4U-
. o ° 4 .'~ o cd a
. o C13

.~ O U Q

" 'C cd f-' 3 O y N .r ., .r O p
. 12

U U cl) C p
. O ~, ~ CS cd ~ cCl

~ v~ cio

p p cc " 3 '~ 0 3 '°

ti

. u O O ~ O

O

. cc 

## °~o~ Q cu



## ~~~

. ~j >, p

., o 03 o v o c~ bA ~

7~ bo U ~ ~ e O ~ Z 7

-- U ~ - ° 3 Zs

. o
" ~ . .~ +cn U U ~ . cd ,~ ~ c~d ~ .fl

Q

. ~'"Q ~ " ~ ~ .~ ~ ' ~ `~ y ~ v j

z 73 ~ U p
. C U

, , U > ~ N ,~ cn ~ v GO ~ ~ o o ~ ~ ~' ~ ~ .° o o '~ m `

.4z : m 

## '° ~ ; ~ ° N o ~~'° 03° a U = Q, d E- 'r- -0 ? o-d in

. U U ~ ~ ~ U

U ~ " ~ +' ~ c~ ' " . . cd U O O U ' . .

.

'O U i Oo
O

0 O
N O

v O ,Z,

. U ~ ti bq h

.

" VI Y

O

o

O

. O

O O

o ,o 0

o ° o .~ o

a Q 0

t I >1

. o °

A .,

o

.

. 0 ~ r~ ~

~ O ` .1, ~

U N '

O U U ' 't3 t, ° U

_ >, DC "
N G~ ~ ~-U, ct

U

60 ? O
o 7~ ~ cb

O
'C ~ ¢

~ 'tS ~ O

~ U °U U N " > ~ _y

on ,~ ~ a~

to U C) ~ a~ ,~ ° o

o °

. "U w ~a>, cd y
_ U Q ., o
-~ b N U

W

0

.i O

N

. 0
0

0

W N

O

. .,
cC >

~ . w

bA

. 0 a

U

. ; O Q

. U

U U

0

0

. O a b

v

W _Ln

O

. N

ti
O

11 0


## .

O U O

0 s 0

0

W b °

. 0 ¢
.

03

O

U

. ; O Q
. .

.

O
O U
bA

. cIi

~. .b
142

- .0 a U U

p O U

N ~ o 3 o .° b ;

0

o O U CIO 0

0

O U O 0 U ~s W

O
O N ?,

O p> Z

O ?

0> ~'

Y

o

o
o ? W 0

N

.

.

° U

> U O U

0 0

. a °
0

~ .

0 0

v

.

I O O

U

w b0

U

~o v 's O
~° W

o

. p> i

U

w

~1, O O ,

o a, o

o v o

U W O

c°

3 N O

U N

. U N O

.
U ^C O O
i

. ., O

H

. ., N O

~U U U O U ° U U

U O e-, W O °
~ .o

.

a~ ° Q
. . 

### U

. . - ,3 p

~ . U

. H HV

N

. v

C3 O O N .O W

O N

. x O

v O

N h W O

.

O

N
O

U

blo

U

`ti Iz

i ~ . W

.

N N

N

O >

. ., O

. . . ~,

. 64 U ~ .S"

. O Z*"' Ln cd b,U O

y p
. SJ

.

O C3 , c~ U > 

### 03 cri C3 .T, ~ ~ +' S .U
. ~

~ ., 3 p, a4 '~

O ~ U
N ~ ~ ~ V O O

O O Qn rn ~4i O c~ ^' " ' ~ `3 ""

'd U O p .0

. O O O to
" U U

.

.

. °' ° 3 ti o a~ CZ

O :Z O ;t U~ ,O U cQ rp .~ ~ ~ .O U 4~ p c~S W

r~
4 : O ~n ; :s ~ ~ Cl~

.~ ~ 4QJ

., . o
.~ d ~, `ti ° ~ -o 

### 44 +-~' U ~O ° Ln W

. w ~ E-~ i

G

N

i

O .U
M a v o

N

O h O co °' o '~ p) 4) O

w O

.

h U W U U

O w O Q

. U W

z W W W ~ W W CIS U O U ~ V v

" 

### CA z

-a cn
. O b0 h ti 

### Cl Z : U V y p '~ O 

### .

N bUD w 4Z -rz O c~ ; '~ z C blo 0 G1 C~3 ~ ~ o ~o ° y

o ~ ~ o °~° 0

ci U c~ ~ O cts ~ .

.C s,° ~ q~ ~ b4 0 Q ~ O ~ + Y

'C o" + ~

. s.~

" Y~ ~ o

O cn z C46)

m c,

. Qn O ~ . O ~ s
. . ~ ~ ~ fy, ~ O ' O ti ~ W 5~ ., ~ b4 b4 > ~ ~ y

. .US"

. ~ 'L7 Ln +~ b -o ~ ~ °sy ~ q ~ ~ tio bq

cn U 'G on d W ~ ~ ~' W o O W V) 03 p
. 14

lfl

~+- O

v an n
.cd G~ ~ .--~ cd h ° cl
.S", ~ ' ~ 3 'C bq .' %) C3
O p ~ ti ~ Ct O 4 

### ~4~ .,~ .~ >

++ ts
. ~ ~ s . . U w

. U p~ h U O bA O ~ ^~ U Os

. ., p .~ U U ~ U ~ U
.U

> .cn N cd v~ Or $y

. U

. C) Z

cd Q G cl C)

w _O

. .O p cd ° ~ O

~ cn U > . 03 M

N p U + . .
O r
. . .4cd, ~

. cn O cn N O

~ O ~ o 'Z3 ~ os ~D o ~ o p ? o~ U ~ N :4 o

a a' ~ p v' ~ ~ O
s-p
. >, ~ ~> ~~ ~ ~° ~ i cC O
U ~ O ~ ~, pp U O cn 4213 v~ .~ O ~ y ~ ~ O

° b~p ~ p a> >, .



### °o o b4 _~ cn ~ '~0) p ' un c~d .y

.

.O U ~ U v~ ~ ~ ° o > W ~ v

0

.

0 O O O
bA U bA~ o

03

.

U

U

O .ct N

S~

. '0 O V
U W a~ y

O U o 

## x

o
o U

W

N h O O

i 0 U 0 U 3 ° O p
. bA y O .o o °

O ~ 4
0j) m

.~ .p 0

O



### >~ .o a~ a~

3b~'" W U

U
U

U

~ .

N

U H
o

O U

U O U U >

U >

. ~ . ~ ., u °o~

. ~°
O U y O p

~ . U U o
O p

a ° W b

"C3 C U o 0 U N v

. U

b4

O U

U
W

O O

0
z

N

. i

v 0 h
Q W

O 

## Q v

W
Y 0

0 v ~o

. o a~ o x .b L.zr ~

.~ .~ O cd cn a~ °'

N ~ N O U c~d O
U

. 

## .

. U ,~ O .fl O Sy

.~ bA O .~ U .O bA ~ U o 0 0,

N "p O
O O bq

Ln o ° ° o

.~ o

o>

U Q,

, .d Gj O cd '~ o ~ ° o

U

~ . O U p °We

p U ~ N 14) p ~ o ~O 4 ; ¢ t~ ~ s~ W ~ ~C Q a~~ o 0

.

o 3 ~,~ ~ti or-l ., <+ . .~ R ~ ~o Ao
.0 O .° ~ ~ U o ,~ ~ ~ `a

o ~C " ~ o' o v rn

~ bo .z o 0
,~ 04 L $M

. Ct o ~ ~ ~ ~ ~ ~ o ~ W ,cl ~ U +Z u a~ ° ,M ~ 4

. ~ o ? ° o, R o ° q' R ' bD .~? _~ cd zz -C3 R ~ ti4 U ~ c~d p " ti '" ,~ , .~ ° x p O M bn_~, o 0 0 ~ o

~ ' cd v -

° U 14) p U U ~ p i U -S-'

. s .~,

. rxn ~ o C-11 ° '

~ cd ~ o z

~ .o ti IZ o ° o `ti

. " ^" 'L3

~ .fl V1

~ o .°

U o Q O ~ ^C

. V)

°R 3

> U O

361 R c~ v o C) U

° " O C ~ .Cd

ct3 c~ a~
,b O S U ~ 3 03 U s
. O .~ 0

4

. o O ° C+ :4 y ~ a~ o Q '~s CIS 'C U

bA y U U o o d

. . oA°d

W

~; u
. ~, U o 0

. f~

. O U := G~ "



### . u -o m ° cC u 3'~ o 

### -oa~

p

° U ~ cz U

~s ~ o o

o

h
O

.
s o

o i o R~ o

h °

o
' o

o ~ ~ o 0 o h O Cq

4) C4 M


### z 4, o

o ~W s

0 °z 'cZ C p ~ p o O R W Gi s > ~ ~ -- ~ .o O

03 ° c~

. U U ~O N
.

O O p o +~ N
U Vz ~) .~ .' O 0 U
U W o .~ ~ ~ w >,

. o ~c ~3

CIO Ln

° ~ ° o~ '~ 3

%) ;t 0

~w ~"D^~ ~ u o ° ~ ~ ~, r+ i .?, x W

o `~'~ p ~ V 4z o ~, -°

)

°

.--~ U ZZ : «i U ' rz '~ '~ ^G b~A
c,~ a " 3 >

o 

### o s rz c, 3 y u -Z 

### r~,) o 4, ° ~ 4>

° ~ s .q)

.

V ~ -C

.) M O `n ~ :'d ° °' t4- :4 u

o~ p u ~ w ~n r4) ° ,b ~ ~ ~-+ O
° '3 " " ti o~ ¢, ~~ Rd, °, R ~ y a
. o d a~ W ti ~ w su,

### Letter ID: 0158 Commenter: James Childress Organization: Gasification Technologies Council (GTC) Letter ID: 0158 Comment ID: 23754 Letter Lines: 50 to 57 Comment Code: 1250 1.1.1.4 Flexibility is needed (p erformance-based standards) Comment Code: 1410 1.2.1 Comments in support of EPA/rulemaking Comment: EPA is commended for taking this action that begins the process of providing regulatory clarity to a complex and important topic. In its decision process, EPA needs to consider the importance of CCS to the success of the nation's overall climate change, energy independen ce and economic growth strategies. Any rule for geologic storage of CO2 needs to provide an unambiguous framework that promotes the development and deployment of CCS while protecting the environment. Also, given the current state of expe rience in geologic sequestration, any prescription needs to be flexible and adaptive. Individual Response: While EPA agrees with commenters that a stable, predic table, nationally consistent, and workable regulatory framework is important, EPA stresses that the focus of the GS rule is to ensure that, where GS is deploye d, it is conducted in a manner that protects USDWs from endangerment. EPA agrees that an adaptive and flexible approach is appropriate. To protect USDWs from endangerment and meet the potentially fast pace of GS deployment, EPA is using an adaptive approach to regulating CO2 injection for GS. The Agency plans to collect and review data every six years on GS projects to dete rmine whether the appropriate am ount and types of information and appropriate documentation are being collecte d, and to determine if modifications to the requirements are appropriate or necessary. An adaptive approach will allow regulatory development to proceed in time to meet the current and future demands for Class VI permits while EPA continues to gather data from p ilot projects and other re search as it becomes available.

Letter ID: 0158 Comment ID: 23755 Letter Lines: 59 to 104 Comment Code: 1380 1.1.3.6 Deployment of GS Comment: In addition to regulatory clarity, climat e change policy will be needed to define a value for CO2 in order to driv e deployment of CCS. After policy, cost will determine how quickly and widely CCS can be deployed. Currently, the value of CO2 is principally limited to its use in Enhanced Oil Recovery (EOR). The cost of CCS needs to be reduced by imple menting requirements that are necessary and sufficient while not compromising the pr otection of drinking water. These are our principal concerns withthe draft regulation:

1

### 1 . EPA needs to categorically exclude CO2 specifically intended for geologic storage from the definition of RCRA hazardous waste. 2. EPA must emphatically conclude that CO2 containing trace contaminants does not open any regulatory pathways to subj ecting a geological st orage site to Superfund liability. 3. CLASS VI (Underground Inje ction Control (UIC) permits need to identify the potential for hazardous substances that might be generated in geologic formations after facility decommissioni ng and well closure so that should releases occur, they would be federally-permitted. 4. Secondary confinement/containment should not be required. 5. CO2 injection should not be restricted only to formations below the lowermost underground source of drinking water. 6. EPA needs to clarify how to demons trate financial responsibility; the proposed regulation leaves too muchdiscretion to the Director. 7. EPA should not adopt a pay- in period of three years. 8. The period of post-injection site mana gement should be performance-based and not be arbitrarily se t at 50 years. . 9. EPA should increase its state stake holder effort towards uniformity of technical requirements; disparate require ments and processes will increase the time, cost, and complexity of projects. 10. EPA should not stigmatize geological stor age of CO2 such as can be inferred by having requirements for Class VI wells that are more restrictive than for Class II wells. 11 . Requirements for conversion of any we ll to a Class VI we ll should be site and risk dependent. 12. EPA's implied 2017 date for completion of the final UIC regulations is too late to provide regulatory clarity face d by CCS project developers today. Individual Response: The purpose of the Class VI GS regulat ion 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. The UIC program’s author ity under SDWA is focused on ensuring that GS projects are sited, constructed, operated, monitored, and closed in a manner that is protective of USDWs. EPA adds that setting a value for CO2 (i .e., a price per ton) is outside of the scope of the Class VI GS rulemaking.

2

### EPA acknowledges that GS falls within the broade r context of CCS and the need for regulatory clarity to ensure that USDWs are protected from endangerment. In develo ping the final GS rule, the Office of Water coordinated with other Agency program offices and across federal agencies (e.g., with the Department of Energy; United Stat es Geological Survey; Bureau of Ocean Energy Management, Regulation, and Enforcement, formerly the Minerals Management Service; Bureau of Land Management). The Agency continues to eval uate areas of potential applicability of other Federal environmental statutes including, but not limited to: the Clean Air Act; the Resource Conservation and Recovery Act; the Comprehe nsive Environmental Response, Compensation, and Liability Act; and the Marine Protection, Resear ch and Sanctuaries Act to various aspects of GS and CCS. The Agency will continue to coordinate on GS and CCS related issues to minimize redundancy and maximize efficiencies for owners or operators. For additional information, please see the discussion entitle d "How Does This Rulemaking Relate to Other Federal Authorities and GS and CCS Activities?" in the preamble to the final GS rule. Please see the remainder of EPA's responses to th is comment for further details. For additional information on EPA's final regulatory approach, pl ease see the final rule and preamble as well as the rulemaking docket.

Letter ID: 0158 Comment ID: 23756 Letter Lines: 110 to 204 ; 424 to 440 Comment Code: 1630 1.3.3 RCRA/hazardous waste i ssues (seeking comment) Comment: #1: Potential Applicability of CFR40 Part 261 (RCRA). (Ref: page 43503, Section 1) In the preamble to the ANPR, EPA poses the question of whether injected CO2 might be considered a RCRA hazardous wast e, but does not answer the question. Any ambiguity concerning the applicability of complex and e xpensive regulatory regimes such as RCRA and CERCLA will be a major disincentive to the development and deployment of CCS. Regulatory clar ity and certainty ar e critical to companies facing multi-billion dollar investment decisions regarding gasification facilities and CO 2 sequestration projects. EPA should explicitly addre ss these issues in the fina l rule and not leave open any implication that RCRA and CERCLA may or may not apply to CCS. The presence of low levels of hazardous contaminants in CO2 as a result of the carbon capture process should not limit the storage of th e CO2 using Class VI wells, especially taking into account the di minimus risk of exposure associated with the disposition of CO2 into deep geological formations unde r the stringent controls required by this proposed regulation. We strongly recommend that EPA provide a categorical exclusion in this rulemaking, th at CO2 streams that are specifically intended to be stored in geologic struct ures are not RCRA hazardous wastes. Such an exclusion would be analogous to th e provision of40 CFR §261.4(b)(5), which excludes drilling fluids, produced waters, and other wastes associated with the development, or production of crude oil, natural gas or geothermal energy, and
3

### therefore can be injected into Class II wells. In terms of its approach, we recommend that EPA consider captured CO2 -- inclusive of transport, the injection f acility and within injection wells --as material that constitutes a stream that is contained within a process and therefore, not a solid waste. Within th is scope, protection of health and the environment will be provided by controls required under other regulatory domains such as OSHA and NESHAPS. For purposes of evaluating the potential RCRAstatus of the captured CO2 that maybe injected in Class VI wells, the CO2 streams trigger none of the RCRA hazardous waste criteria. Specifically, captured CO2 is not a "listed" hazardous waste as set forth in 40 C.F.R. §261.31 -.35, nor is it "characteristically" hazardous pursuant to 40 C.F.R. § 261 .20 -.24. It is neither "ignitable" nor "corrosive", and the TCLP test usedto determine whether a waste is characteristically "toxic" cannot be used on the supercritical liquid CO2 stream. In any event, the level of trace contaminants in the CO2 is so low that TCLP levels are not even approached whenmeasured on an absolute concentration basis. Next, the CO2 stream is not "reactive," since the injected CO2 stream will not generate toxic gases in a quantity suffi cient to present a danger to human health or the environment. For example, the levels of hydrogen sulfide likely to be present in the CO2 stream (genera lly less than 0.3%) ar e an order of magnitude less than those typically present in the "acid gas" that is widely injected into Class II under ground injection wells in th e U.S., which have an average hydrogen sulfide concentration of approximately 40%. See Kleweki (Cadmus Group), Kobelski (U.S . EPA), Karimjee (U.S . EPA), and Sham (Cadmus Group): Acid Gas Injection In The United States (P resentation on May8, 2006 at the Fifth Annual Conference On Carbon Capture & Se questration). U.S. EPA continues to encourage the underground injection of " acid gas" streams, recently including such a requirement in a proposed cons ent decree that would resolve an enforcement case brought under the Clean Air Act. U.S. v. Merit Energy Company, Civil Action No. 1:08-CV-917 (W.D. Mic h.), proposed Consent Decree lodged on September 30, 2008 (73 Fed. Reg. 58267 (Oct. 6, 2008) (U.S . EPA's October 1, 2008 press release in this matter stated that the underground injection of the acid gas would result in "zero sulfur dioxide emissions.") EPA should take into account the specific disposition of the CO2 that the ruling is focused on (i.e., deep underground stor age). A well permitted under this rule will be protective of underground sources of drinking water. The minimum depth of injection required to maintain CO2 in a supercritical state is approximately 2,500 feet. This, in conjunction with th e controls and safeguards required by this rule throughout the injection and pos t-injection period, will ensure that CO2 injected into a Class VI well poses de minimus risk. There is very little likelihood for hazardous consti tuents to be released where they would pose a

4

### risk to human health or the environment. (See, e.g., Final Risk Assessment for the FutureGen Project Environmental Im pact Statement, DOE, April, 2007) Finally, much higher H2S levels than will be used in CCS have been successfully and safely used for EOR injection with Cl ass II wells. For example, in Canada, there are 45 ongoing projects where high leve ls (up to 68%) of H2S in CO2 are being injected into saline aquifers or producing oilfields [ 1,2,3] for disposal purposes. These combined gas streams of H2 S and CO2 are commonly referred to as acid gas and originate from pur ification of sour natural gas, are highly toxic and in some cases of high concentration, flammable. These projects have been studied in detail and their success is well documented [3,4]. In addition, there have never been any significant safety incidents reported, since the start of the first injection of acid gas into a de pleted oil reservoir on the outskirts of the city of Edmonton, Alberta in the early 1990's. Nor have there ever been any reports of leakage ofH2S from these operations[4]. Accordingly, EPA has sufficient informati on now to conclude that captured CO2 streams are not RCRA hazardous wastes and do not pose greater risks that many streams than are already being routinely injected in Class II and other UIC wells as non-hazardous wastes. Indeed, to conclude otherwise would create the nonsensical result of suggesting that sequest ering a material in deep geological formations poses more hazards than em itting it into the air. It is very important that EPA make this determina tion as soon as possible to remove the implication that CCS might be subject to RCRA regulation, an implication that would be extremely damaging to the fu ture of CCS, and to the goal of significantly reducing the carbon footprint of the nation's energy sector. 1. Keushnig, H. (1995); Hydrogen sulfide - if you don't like it, put it back. J. Canadian Petroleum Technology. 34: 18-20. 2 Longworth, H.L., G.C . Dunn, M. Semchuc k (1996); Underground disposal of acid gas in Alberta, Canada: Regulatory c oncerns and case histories. SPE 35584. pg 181-192. 3 Bachu, S., K. Haug (2005) In situ ch aracteristics of aci d-gas injection operations in the Alberta Basin, Western Canada: Demonstration of CO2 geological storage. in Carbon Dioxide for Storage inDeep Geological Formations. Vol. 3. ed. D.C. Thomas, S.M. Benson. Elsevier Ltd. pg 867-876. 4 Bachu, S., W.D. Gunter; Overview of Acid -Gas Injection Operations in Western Canada. In Proceedings of 7th Interna tional Conference on Gr eenhouse Gas Control Technologies. Volume 1 : Peer-Reviewed Pape rs and Plenary Presentations (E.S . Rubin, D.W. Keith and C.F. Gilboy, ed.), IEA Greenhouse Gas Programme, Cheltenham, UK, 2005. Individual Response: EPA received many comments regardi ng the applicability of the RCRA

5

### regulations and statute to CO2 streams that are geologically seque stered under the final Class VI UIC well requirements. As a result, EPA has deci ded to initiate a sepa rate proposed rulemaking specifically to examine the issue of RCRA appl icability to CO2 streams being geologically sequestered, including the possible option of a conditional exemption from the RCRA requirements for CO2 GS in Class VI wells. EPA will consider these comments as part of its development of that proposal. The Agency will consider issues pa rticular to RCRA in the context of that separate rulemaking, and recommends that the commenter read that proposed rule when it is published. The Agency notes that comment ers who wish to submit comments on the RCRA proposal will need to do so during the comment pe riod for that rule. Finall y, EPA also notes that the final GS rule, which adds ne w regulations for Class VI wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA regulations. 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 subsurface 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: 0158 Comment ID: 23757 Letter Lines: 206 to 243 Comment Code: 1640 1.3.4 CERCLA issues (seeking comment) Comment: Concern #2: Scope of Class VI Permits and the Potential Applicability of Superfund to CCS. (Ref page 43503, Section J) EPA raises, but does not answer, the question of whether the underground injection of CO2 might tri gger Superfund and associated natural resource damages liabilities, and appears to suggest that Class VI permits might be written to allow future Superfund liability associat ed with CCS. EPA must emphatically conclude that CO2 containing trace contam inants does not open any regulatory pathways for subjecting a geological stor age site to Superf und liability. As with RCRA, any ambiguity on applicability of CERCLA will be potentially fatal to the development and deployment of CCS. It is highly unlikely that CCS will be implemented on a meaningful scale if th ere is a possibility that CCS might trigger Superfund. CERCLA expressly excludes from Supe rfund liability "fed erally permitted releases." Further, "any injection of fluids authorized under the Federal underground injection control programs or State programs submitted for Federal approval . . . pursuant to part C of the Sa fe Drinking Water Act" are "federally permitted releases." 42 U.S.C. § 9601(10 )(G) (CERCLA Section 101(10) (G)).
6

### Therefore, any captured CO2 stream that is injected in a Class VI well pursuant to a Federal or State permit is a "feder ally permitted release" and not subject to Superfund liability (including natura l resource damages). It would be inconsistent with existing practice in th e UIC program, impractical, and fatal to the future of CCS to limit Class VI permits solely to th e CO2 portion of the stream and explicitly exclude any trace contaminants. By its inherent nature, ga sification will provide a str eam of >90% CO2 having extremely low levels of both organic and inorganic hazardous air pollutants (HAPS). There are several mechanisms that provide this : 1) destruction of organic HAPS within a gasifier due to the extreme (~2,500 °F) gasification temperature, 2) removal of inorgani c content in the melting and slagging process, 3) particulate scrubbing or fi ltration, 4) activated carbon beds to remove mercury and other condensed metals ;, and finally 5) cooling followed by acid gas scrubbing. The combination of thes e HAP reductions is very effective. As a point of reference, the total inorganic HAPS that would be injected with captured CO2 from an IGCC or gasificati on process over 30 years of CCS operation will be at least an order-of-magnitude lower than the annual limits (both total and individual components) of NSPS. Individual Response: The Agency thanks the commenter for their detailed comments regarding the scope and possible impacts of CERCLA liability on CCS activities, and in particular comments related to the CERCLA exemption for federally-permitted releases. EPA notes that the GS rule is not promulgated under CERCLA, therefore the applicability of th at statute will not be determined under the SDWA or the terms of the GS rule, but rather according to the CERCLA statute itself and any implementing regul ations that may apply. To the extent the commenter is seeking interpreta tions of RCRA or CERCLA, suchinterpretations are beyond the scope of this rulemaking. EPA recognizes that many CO2 streams may be relatively pure, and research indicates that the estimated amounts of impurities in a CO2 stream are likely to be lo w. However, the GS rule does not set generic purity standards for CO2 injectat e streams (e.g., a percent CO2). Instead, the GS rule addresses the quality and quantity of impur ities by requiring owners or operators to submit information on the source of the CO2 and its physical and chemical properties. Specifically, the GS rule requires the owner or ope rator to submit data about the site , including an analysis of the chemical and physical characteristics of the CO 2 stream, as required at §146.82(a)(7)(iv), and information on the compatibility of the CO2 stream with fluids in the injection zone and minerals in both the injection and the confining zones and the materials used to construct the well, per §146.82(c)(3). This information can help the Director determine the pote ntial for geochemical reactions between the injectate (CO2) and the host geologic formations, whic h could result in the plugging of pore spaces or the disso lution of formation minerals.

Letter ID: 0158 Comment ID: 23758 Letter Lines: 245 to 267 Comment Code: 1640 1.3.4 CERCLA issues (seeking comment)

7

### Comment: Concern #3: Potential releases from the well which are outside the scope of the Class VI permit. (Ref: page 43504, Section J) Class VI UIC permits must also be carefu lly written to identify and address the potential post-injection releases of hazar dous substances, or the generation of hazardous substances from the chemical interaction of the CO2 with the geological storage formation (e.g. -leaching of metals) so that they would be federally permitted releases. If the potential release or generation of such hazardous substances is viewed as beyond the scope of Class VI permits, CCS sites could be subjected to the thr eat of long-term Superfund liability, a threat that could be fatal to the viability of CCS. With respect to releases from the well itself, the primary source of such releases could occur duri ng injection operation through failure of well seals, flanges and gaskets, piping breaches, liners, valve packing and other mechanical components or failure to follow operational and safety procedures. Such releases will likely be confined to the injection period. During operation and the measurement, monitoring, and validation (MMV) period, the inje ction facility (metering, distribution and injection sy stems), should be classified as a production facility where industrial safe ty standards, design and operating procedures (e.g., -HAZOPS reviews) will apply. Appropriate regulation will be derived from permits under the Clean Air Ac t that are issued to the facility along with protection of operating personal as required by OSHA. Individual Response: Again, the Agency thanks the comment er for their detailed comments regarding the scope and possible impacts of CERCLA liabilityon CCS activities, and in particular comments related to the CERCLA exemption for federally-permitted releases. EPA notes that the GS rule is not promulgated unde r CERCLA, therefore the applicability of that statute will not be determined under the SDWA or the terms of the GS rule, but rather according to the CERCLA statute itself and any implementing regulations that may apply. Additionally, comments related to permitting under the CAA are outside the scope of this rulemaking.

Letter ID: 0158 Comment ID: 23759 Letter Lines: 269 to 287 Comment Code: 3120 2.1.2 Need to identify additional confining and containment zones (seeking comment) Comment: Concern #4: Requirement for secondary confinement/containment. (Ref. page 43505, 1Proposed Geologic S iting Requirements) The proposal would provide the Director th e discretion to require the owner or operator to identify and characterize addi tional confining and containment zones above the primary (i.e., lowermost) confin ing zone that could further impede vertical fluid movement and allow fo r pressure and dissipation. Secondary containment (multiple confining structures ) should not be required to prevent leakage of CO2. If required, this will pr event geologic storage in certain but
8

### important geographic regions. It also ra ises doubt concerning procedures and protocols to characterize and validate sa fe geologic storage formations and containment where there is not secondary containment. Under the proposed rule, there are measures that provide adequate assurance of formation integrity and require operators to demonstrate th at their project will not endanger underground sources of drinking water (USD Ws). If a secondary containment is present, it will be detected during site characterization and risk assessment. Such a special case could be analyzed to evaluate the potential risks to USDWs and to develop additional evaluation criteria to be applied to permit geological storage without going through the aquifer exemption process. Individual Response: EPA retains the requirement to iden tify additional containment/confining zones, if required by the Di rector, as proposed (§146.83(b)). EPA acknowledges that such additional zones may not be needed in all circumst ances, and clarifies that this requirement is at the Director's discretion, based on his or her understanding of a part icular site. EPA believes that, in some situations, the presence of additional confining and containment zones above the primary (i.e., lowermost) confining zone canimprove USDW protecti on. These layers could further impede vertical fluid movement and al low for pressure dissipation, and also provide additional sites for monitoring, mitigation, and re mediation. The Agency's decision is supported by commenters representing states, water associati ons, and an electric utility who assert that these requirements promote a flexible, risk-base d, site-specific approach to characterizing and permitting a site for GS projects, and are intende d to improve understanding of the project as a whole and promote better modeling of the site.

Letter ID: 0158 Comment ID: 23760 Letter Lines: 289 to 301 Comment Code: 4324 2.4.4.1.2 Comments opposed to requiring injection below the lowermost USDW Comment: Concern #5: Restriction of injection to formations below the lowermost underground source of drinking water or USDW. (Ref page 43512, 3. Proposed Injection Well Construction Requirements) This requirement is not necessary for th e protection of USDWs. It is in-fact overly restrictive and will eliminate many suitable and safe geologic formations for CO2 sequestration or permanent storag e. It will also re nder geological storage impractical (pumping power and well costs) for states in the western United States where the drinking water aqui fers are many thousands of feet deep and well isolated from overlying regions. Also, industry has demonstrated that it can operate CO2 injection wells for EO R without endangering USDWs that are located below the injection zone (e.g., the Salt Creek EOR project in Wyoming, having a USDW below the injection zone). Individual Response: EPA acknowledges that there are lim ited circumstances where injection above the lowermost USDW can be performe d in a manner that protects USDWs from endangerment, as long as appropriate protections are in place. The final GS rule at §146.95
9

### establishes a process by which owne rs or operators can seek a waiv er of the Class VI injection depth requirements for injecti on into non-USDW formations above and/or between USDWs. It establishes: 1) requirements spec ifying information that owners or operators must submit, and Directors must consider, in consultation with PW SS Directors; 2) procedures for public notice of a waiver application and for Director-Regiona l Administrator communicat ion; 3) the waiver issuance process; and, 4) additiona l requirements that apply to owne rs or operators of Class VI wells granted a waiver of the in jection depth requirements to en sure USDW protection above and below the injection zone. While the Agency acknowledges the experience gained by the oil and gas industry and other injection activities, EPA identified unique cha llenges posed by large-scale GS including large injection volumes, the relative buoyancy of CO2, its corrosivity in the presence of water, the potential presence of impurities in captured CO2, and its mobility within subsurface geologic formations that warrant the tailored approach in the GS rule. Furthermore, the Agency believes that wells that inject into non-USDW formations above and be tween USDWs presents additional challenges that warrant a dditional requirements. For additional information on the waiver approa ch, please see the final rule and preamble, as well as EPA's responses to comments on the No tice of Data Availability and Request for Comment.

Letter ID: 0158 Comment ID: 23761 Letter Lines: 303 to 319 ; 442 to 444 Comment Code: 5430 2.9.1 Comments on proposed financia l responsibility requirements (40 CFR 146.85) Comment Code: 5432 2.9.1.1 Need to adjust financial responsibility mechanisms (seeking comment) Comment: Concern #6 Demonstration of financia l responsibility. (R ef: page 43520, 9. Proposed Financial Responsibility and Long-Term Care Requirements) EPA needs to provide clarifying guidan ce on how to demonstrate financial responsibility. The proposed re gulation leaves too much to the discretion of the Director. Such open-ended requirements will effectively discourage carbon capture projects and the development of financial pro formas. Of particular concern are those assurances necessary to cover the costs of po tential long-term stewardship or the potential to have to perform remediation at sites that have been previously certified as closed. This uncertainty may increase the perceived risk exposure to levels that serve as a barrier to invest ment. A potential approach to share risk and overcome this barrier is the Interstate Oil and Gas Compact Commission (IOGCC)[5 ] proposal for an industry-funded and stateadministered trust fund to provide the stewardship during the Post-Closure Period. The trust would be funded through aninjection fee asse ssed to the site operator and calculated on a per-ton basis, at the point of custody transfer of the CO2 from the generator to the site operator.

10

### 5 The Interstate Oil and Gas Compact Comm ission Task Force on Carbon Capture and Geologic Storage, Storage of Carbon Dioxide in Geologic Structur es -A Legal and Regulatory Guide for States and Provinces, September 25, 2007 Individual Response: EPA believes that minimum financia l responsibility requirements are necessary to hold well owners or operators accountable for the safe operation, site closure, and post-injection site care of wells while protec ting USDWs and avoiding extra public expense. EPA anticipates that the availabi lity of a variety of financial responsibility providers and thirdparty GS financial instruments will grow in response to demand for GS technology. EPA believes that the financial responsibility requ irements provided in the final rule do not leave too much discretion to the Direct or. Owners or operators may choos e from a variety of financial instruments to meet their financial responsib ility obligations under the rule, provided the Director determines that the operator's propos ed financial responsibil ity demonstration is adequate to protect USDWs from endangerment throughout the life of the project. The final GS rule specifies at §146.85(a)(1) the permitted types of financial responsibility instruments. See the final rule and preamble for further discussion of EPA's final approach to financial responsibility. EPA is developing guidance on financial responsibility for GS wells that will provide information about the appropriateness of various financial instruments. The guidance will be available on EPA's website at http://water.epa.gov/type/groundwat er/uic/wells_sequest ration.cfm. This guidance will consider the recommendations in the Office of the Insp ector General report on fi nancial assurance and will include recommendations to help permitting authorities determine whether an owner or operator's plan for financial responsibility is adequate. Under SDWA, EPA has the general authority to set financial responsibility requirements for injection well owners or operators . However, this authority does not extend to allowing the Agency to create a financial instrument with EPA as the trustee, due to the restrictions of the Miscellaneous Receipts Act (MRA). The MRA re quires 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. Addi tionally, EPA does not have authority under SDWA to establish a trust fund for purposes of financial responsibility for Class VI projects. The Agency clarifies that the trust funds that are addr essed as financial respon sibility instruments in the GS rule are set up by indivi dual owners or operators and ar e different from a national-level trust described by the commenters that woul d cover large number s of GS projects. Under SDWA authority, owners or operators of injection well s must ensure protection of USDWs from endangerment and are subject to liab ility for enforcement under the Act. The final rule requires that an owner or operator conduct monitoring as specified in the Director-approved PISC and site closure plan following the cessation of injection until he or she can demonstrate to the Director that the geologic sequestration project no longer pose s an endangerment to USDWs. For additional information about the PISC and site closure requirements, see the preamble to the final GS rule. Once an owner or operator has met all regulator y requirements under Part 146 for Class VI wells

11

### and the site closure has been approved pursu ant to requirements at §146.93, he or she will generally no longer be subject to enforcement for regulatory nonc ompliance. Furthermore, the financial instrument required under §146.85 will be released if it has not been used. However, even if site closure is approved under §146.93, an owner or operator may be held liable for regulatory noncompliance (includi ng violation of 40 CFR 144.12) in certain circumstances, for example if the Director relied on erroneous information provided by the owner or operator when approving site closure. Additionally, an owner or operator may always be subject to any action the Administrator deems necessary to protect the health of persons under §1431 of the SD WA after site closure if there is unanticipated migration towards or into a US DW that causes or threatens imminent and substantial endangerment to public health. The action may include issuing administrative orders or commencing a civil action for appropriate relief. If the owner or operator fails to comply with the order, he or she may be subj ect to a civil penalty for each day in which such violation occurs or failure to comply continues. The Agency clarifies that Class VI well permits may be transferred to another owner or operator pursuant to §144.38 whereby generally all other regulatory re sponsibilities are transferred to that new owner and operator, includ ing all potential liabilities a ssociated with meeting the requirements of that permit. 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: 0158 Comment ID: 23762 Letter Lines: 321 to 335 ; 442 to 444 Comment Code: 5432 2.9.1.1 Need to adjust financial responsibility mechanisms (seeking comment) Comment: Concern #7. EPA is considering a guidance approach that would recommend adopting a pay in period of three years for GS pr ojects consistent with other similar programs in the Agency. (Ref: page 43521, Sec. 9. Proposed Financial Responsibility and Long-Term Care Require ments, Pay-in period for trust funds) We strongly urge that the EPA not adopt this approach. CCS pr ojects will be subject to their highest financial strain in the first several years of operation. During this period, commissioning, systems integration and debugging of mechanical and process systems will n eed to be completed with potential loss of plant operation, production and revenue. Projects will likely be burdened with additional initial capital coverage of an already expensive facility to contend with an accelerated payment. We therefore recommend that any payment

12

### schedule be based on a per-ton fee over anamortization period equal to the expected operational life of the project and in a framework as recommended by the IOGCC (ref-Concern #6). 5 The Interstate Oil and Gas Compact Comm ission Task Force on Carbon Capture and Geologic Storage, Storage of Carbon Dioxide in Geologic Structur es -A Legal and Regulatory Guide for States and Provinces, September 25, 2007 Individual Response: EPA acknowledges that there may be several possible approaches to setting pay-in periods for trust funds. The final rule requires that the Di rector approve the use and length of pay-in periods EPA is devel oping 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 guidance will discuss pay-inperiods and provide guidance for Directors to use in determining an appropriate pay-in period so that the financial benefits to the owner or opera tor of a longer pay-in period ar e balanced with the increased financial risk to the public. EPA adds that ow ners or operators may choose from a variety of financial instruments to meet thei r financial responsibility needs.

Letter ID: 0158 Comment ID: 23763 Letter Lines: 337 to 353 Comment Code: 5240 2.8.2.2 Post injection timeframe (seeking comment) Comment: Concern #8: The owner or operator shall continue to conduct monitoring as specified in the Director- approved post -injection site care and site closure plan for at least 50 years following the cessation of in jection. At the Director's discretion, the monitoring will continue until the geologic sequestration project no longer poses an endangerment to USDWs. (Ref: page 43519, Sec. 8. Post-Injection Site Care Timeframe) The time required for post-injection site management should not be arbitrarily set at 50 years. Criteria for defining the time for post-injection management should be performance based and site specific. The choice of 50 years is arbitrary and does not take into account the data and knowledge and modeling verification obtained over a preceding operating and injection period of years and likely decades. The maximum post-inj ection monitoring period should be defined on reasonable but quantitative, perf ormance-based metrics - for example, that the validated model predicts that 95% of the plume is or will be trapped and that a sensitivity analysis predicts a comfortable margin of safety to minimize approach to any USDWs, thus preventing potential endangerment. Individual Response: EPA agrees that there will be circumst ances where it can be demonstrated in less than 50 years that the plume and pressure front no longer pose a risk of endangerment to USDWs. For this reason, the final GS regulation o ffers owners or operators flexibility regarding the duration of the PISC timefra me by: (1) allowing the Direct or discretion to shorten or lengthen the PISC timeframe during the PISC pe riod based on site-specific data, pursuant to
13

### requirements at §146.93(b); or (2) affording the Director discretion to allow a Class VI well owner or operator to demonstrate, based on substantial data during the permitting process, that an alternative PISC timeframe may be appropria te if it ensures non- endangerment of USDWs pursuant to requirements at §146.93(c). EPA believes that a default post-injection site car e timeframe of 50 years, with flexibility to adjust the timeframe for a limited number of GS projects during the permitting process where substantial data exists to demonstrate that analternative 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. EPA believes however, that to ensure USDW protection from endangerment, a default timeframe for post-injection site care is necessary in mo st cases. A 50 year post-injection site care timeframe represents a reasonabl e and protective monitoring period for most GS sites based on a review of research studies, industry reports, and existing environmental programs, and evaluation of public comments. EPA disagrees that a post-injection site care timeframe of 50 years is excessive in most cases or arbitrary. EPA proposed a default post-injection site care timeframe of 50 years based on a review of research studies, indus try reports, and existing environm ental programs. This analysis was included in an EPA-prepared background docume nt that is available in the federal docket, titled "Computational Modeling of Underground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water." EPA assessed various default timeframes based on additional review of research studies and evaluation of public comments. While numerous commenters suggested th at EPA shorten the monitoring timeframe, none of the commenters provided sufficie nt data or other evidence to warrant a change in the proposed timeframe. Wh ile the 10- or 30-year timeframe suggested by some of these commenters may be within the ti meframe suggested in some studies, EPA believes that the potential risks of endangering USDWs w ill likely not decline within these timeframes and available data, including data submitted by commenters, do not support a different default timeframe. However, EPA recognizes that alte rnative timeframes may be appropriate under limited, specific circumstances, which is why EPA is providing the Director discretion to approve an alternative post-inj ection site care timeframe as l ong as the owner or operator can meet the requirements provided at §146.93(c).

Letter ID: 0158 Comment ID: 23764 Letter Lines: 355 to 370 Comment Code: 5600 2.11 Comments related to UIC Program primacy for Class VI wells Comment: Concern #9: On-going state efforts to re gulate GS. (Ref: page 43497, Sec. C. Who Implements the UIC Program?) Although we recognize that state primacy is integral to the UIC program, we strongly recommend that EPA drive its state stakeholde r activities towards the

14

### goal of unanimity and uniformity of technical requirements. Disparate requirements and processes will increase cost, delay, and complexity and make the permitting process less predictable. In dividual states should not develop regulations that are substantially more re strictive or prescriptive than that required by the EPA. Many states will also not have technical resources that are comparable to that of the US EPA. EPA' s stakeholder technical workshops had good representation from the EPA regions, but it appears that many states have not yet been engaged. To avoid this and the problems from a patchwork of permitting regulations, EPA should carefully but quicklyconsider and integrate input from a majority of state environmental pr otection and conservation and natural resource offices. Individual Response: EPA recognizes the importance of cons istency in state regulations. Under Section 1421 of the SDWA, EPA is responsible for the development of minimum federal requirements for underground injection wells to ensure protection of USDWs from endangerment. In order to receive primacy th e States, Tribes, and Territories must then demonstrate that their programs are at least as stringent as the minimu m Federal requirements, which helps to ensure consistency between Stat e UIC programs. The Agen cy acknowledges that Section 1422 of the SDWA provides that St ates, Tribes and Terri tories may develop requirements that are more stringent than the fe deral requirements –for Class VI GS and other UIC well classes. Furthermore, EPA believes that it is appropriate to allow Director's disc retion, given the variety of geologic settings even within each State inwhich GS will be applied. The Agency believes that the GS rule balances the need for these s ite-specific decisions withthe need for minimum standards to ensure national consistency. When a State applies for Class VI Primacy, it must demonstrate that it has sufficient and appropriate technical capacity (e.g., personnel, infrastructure, techni cal expertise) to implement a Class VI program that meets EPA's minimu m requirements. EPA is developing guidance materials and plans to conduct on- line and in-person training for St ates, Tribes, and Territories that describe the process of applying for and receiving prim ary enforcement responsibility (primacy) for GS Class VI wells under Secti on 1422 of SDWA, as well as the technical and administrative issues on developi ng GS regulations that are the equivalent of minimum federal criteria and requirements. The guidance will be available at http://water.epa.gov/type/groundwater /uic/wells_sequestration.cfm.

Letter ID: 0158 Comment ID: 23765 Letter Lines: 372 to 385 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: Concern #10: Continuation of Class II fo r EOR. (Ref: page 43502, Sec. G) By proposing different and mo re restrictive requirements for Class VI wells, EPA will create economic or operational barrier s that prevent a seamless transition
15

### from EOR and storage operations to who lly storage operations. EOR can make a significant contribution to offset the cost of early CCS demons tration projects. For example, EOR can contribute to the investment in pipeline infrastructure helping to enable pure CCS operations. Als o, CO2 storage operations may continue after EOR has ceased, thus reducing the cost of storage, site characterization and development. These benefits should be viewed as especially significant in light of the difficulties in securing suffi cient funds to initially deploy CCS. EOR projects could quite feasibly bring CCS deployment forward by many years as a considerable quantity of CO2 remains underground during such operations. This will reduce the number of target formations where CO2 could be stored. Individual Response: In response to the comment that es tablishing a new well class will create economic and operational barriers, EP A clarifies that the purpose of the GS rule is to ensure protection of USDWs from endangerment. The Ag ency believes that establishing a regulatory framework for the future development and deployment of CCS tec hnology may provide the regulatory and jurisdicti onal certainty needed to foster development and deployment of CCS while ensuring USDW protection. However, this is not the purpose of th e rule and the comment is outside the scope of the rulemaking. Regarding the comment that Class VI requirement s will reduce the number of available target formations where CO2 can be stored, EPA reiterate s that the regulation is meant to ensure that proposed sites are suitable for sa fely injecting, and confining CO 2, and avoid sites not suited for GS. EPA notes the final GS rule contains a pr ovision at §146.95 for owne rs or operators the ability to apply for waivers from the requirement that injection takes place below the lowermost USDW. EPA believes this waiver provision will reduce potential limitations on the re-permitting of Class II wells as Class VI wells, provided they meet the requirements at §146.95 while still protecting USDWs from endangerment.

Letter ID: 0158 Comment ID: 23766 Letter Lines: 387 to 400 Comment Code: 2060 1.5.3 Comments on grandfathering of existing wells (seeking comment) Comment: Concern #11 : Grandfathering of construc tion requirements at the Director's discretion for existing Class I, Class II, and Class V we lls seeking to convert to Class VI wells and whether additiona l construction requirements would be necessary to Prevent endangerment to US DWs from the GS ofCO2. (Ref. page 43497, Sec. G) Requirements for conversion of any well to a Class VI well should be site and risk dependent. EPA should consider expanding grandfathering scope to more than construction requirements and not a-priori require that all other permitting requirements be redone. Existing permit hol ders should be allowed to provide data on the experience and characteristics of their site demonstrating that it is suitable for long-term storage of carbon dioxide without endangering underground sources of drinking water. This could be more acceptable with an end date for grandfathering wells (e.g., -operational before 2012).
16

### Individual Response: EPA agrees that many Class I, Cl ass II, and Class V experimental technology wells are designed and constructed to withstand exposure to CO2. The final GS rule provides for the construction of these wells to be grandfathered per §146.81(c), 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 clarifies that only the construction requirements are grandfathered and that all other Class VI requirements (reporting, monitoring, mechanical integrity testing, etc.) must be met fo llowing a determination under §146.81(c). EPA disagrees with commenters who suggest th at other requirements (e.g., MITs, siting, monitoring, operational, and AoR requirements) should also be grandfathered. Following repermitting of the project as GS, many of the uniqu e factors of GS sites (e.g., increased reservoir pressures associated with large volumes of st ored CO2 and the corrosivity of CO2 in the presence of water) will result in an increased risk profile, warrant ing the specific requirements in the final GS rule. Therefore, following re-permitti ng as Class VI wells, these projects would be subject to the operational, MIT, monitoring, reporting, plugging, and post-injection site care and site closure requirements in the final GS rule . See the discussion of EPA's final regulatory approach in the preamble to the GS rule for additional detail on these requirements.

Letter ID: 0158 Comment ID: 23767 Letter Lines: 402 to 415 Comment Code: 1200 1.1 General comments about the rulemaking Comment: Concern #12: EPA's schedule for promulgation of its proposed UIC regulation (Page 43499 Sec. E3) We reference the following statement from the preamble section of the proposed rule : "During the Deployment Phase ( 2008-2017), the [RCSP] partnerships will conduct large volume carbon storage tests to demonstrate that large-scale CO2 injection and storage can be achieved sa fely and economically. EPA will use the data collected from these projects to s upport decisions in the final GS rule." This statement suggests that a final GS rule may not be issued until 2017. We believe that this is too late to clear the regulatory uncertainty that CCS project developers are fa cing today. If this reflects EPA's intention, we recommend that EPA abandon a prescriptive approach and instead, favor general and performance- based requirements until these demonstration tests are completed. Individual Response: EPA believes that sufficient data have been collected to inform the final GS rule. Nevertheless, EPA anticipates that future experimental and full-scale projects will continue to inform the technology, and is theref ore using an adaptive rulemaking approach. EPA plans, every six years, to colle ct and review data on GS pr ojects to determine whether the appropriate amount and types of information a nd appropriate documentation are being collected, and to determine if modifications to the re quirements are appropr iate or necessary.

17

### Letter ID: 0158 Comment ID: 23768 Letter Lines: 448 to 457 Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language Comment: §146.81 Applicability. (b) "This subpart applie s to wells used to inject carbon dioxide specifically for the purpose of geologic sequestration, i.e., the longterm containment of a gaseous, liquid or supercritical carbon dioxide stream in subsurface geologic formations." We recommend striking out "gaseous, li quid or supercritical carbon dioxide stream" and replacing with "gaseous, li quid, supercritical or co-mixed carbon dioxide stream" This change will allow fo r injection of carbon dioxide that is pre-dissolved with water to prevent phas e separation in the in jection zone or with inclusion of flow or pumping enhancement components. Individual Response: EPA disagrees with the suggested change. EPA believes that this paragraph, along with the definition of a CO2 stream at §146.81(d), appropriately convey the allowable injection activities that may be perm itted as Class VI. For additional information on EPA's final regulatory approach, please see the fi nal rule and preamble as well as the rulemaking docket.

Letter ID: 0158 Comment ID: 23769 Letter Lines: 460 to 474 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: 146.82 Required Class VI permit information. (b) "A map showi ng the injection well(s) for which a permit is sought and th e 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 f eatures including structures intended for human occupancy and roads. The map should also show faults, if known or suspected. Only information of public reco rd is required to be included on this map; " The note that "only information of public record is required to be included on this map" may leave out deep oil and ga s wells, particularly older wells. The presence of such non-public but "known " information may be eligible for inclusion as "known" under 144.55(a). Individual Response: EPA believes that a determination about whether or what information may be necessary (for a specific GS project) is outside of the public record will be site-specific and based on knowledge of the site, data availab ility, and data quality. Fo r instance, in meeting
18

### the requirement to tabulate information on wells inthe AoR, the Director has the discretion to require the owner or operator to supplement a data records search if ther e is reason to believe that the incompleteness of available information could compromise USDW protection from endangerment.

Letter ID: 0158 Comment ID: 23770 Letter Lines: 477 to 489 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: §146.82 Required Class VI permit informati on (e) "A tabulation of all wells within the area of review which penetrat e the injection or c onfining zone(s). Such data must include a description of each well's type, construction, date drilled, location, depth, r ecord of plugging and/or completion, and any additional information the Director may require; - We recommend striking out "all wells" and replacing with "all known wells". Requiring that all wells or other artificial penetrations into injection or confining zones within the AoR be id entified and information on depth and closure be provided can be costly and sometimes accurate information is difficult to obtain for older wells w ithin the AoR. EPA's assistance in obtaining and storing this information would be helpful to CCS operators. Individual Response: The Agency believes that the requireme nt to provide a tabulation of wells and geologic information (at §146.82(a)), along with a description of each well's type, construction, date drilled, location, depth, record of plugging and/or completion will appropriately inform a determination of the risk associated with wells in the AoR. EPA believes that it is important to have information on all wells in the AoR.

Letter ID: 0158 Comment ID: 23771 Letter Lines: 492 to 512 Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language Comment Code: 3330 2.2.1.3 Applicability /adequacy of computational models (seeking comment) Comment: §146.84 Area of review and corrective action. (c) (1) "Predict, using computational modeling, the projected late ral and vertical migration of the carbon dioxide plume and formation fluids in the subsurface from the commencement of injection activities until the plume m ovement ceases, pressure differentials sufficient to cause the moveme nt of injected fluids or formation fluids into a USDW are no longer presen t, or after a fixed time period as determined by the Director." We recommend striking out "P redict, using computationa l modeling, the protected

19

### lateral and vertical migration of the carbon dioxide plume" and replacing with "Using computational modeling, provide prot ected potential ranges of lateral and vertical migration of the carbon diox ide plume" The use of multiphase groundwater flow and transport models is to predict the composition and movement of each phase state (e.g., liquid, gas ,supe rcritical fluid) of CO2 in the subsurface, as well as fluid pressures, to define the AoR. One of the concerns with the use of such complex models is that the site may not be fully characterized with respect to hydro-g eologic properties. There may be significant uncertainty in one or mo re hydraulic processes/parameters. Therefore, it is possible to obtain a wide-range of mode l outcomes from different model parameters. The uncertainty in model parameters and sensitivity of model results to parameter selection should be addressed. Individual Response: EPA has clarified this language in the final rule. It now reads, “Predict, using existing site character ization, monitoring and operati onal data, and computational modeling, the projected lateral and vertical migr ation of the carbon dioxide plume and formation fluids in the subsurface from the commence ment of injection ac tivities until the plume movement ceases, until pressure diffe rentials sufficient to cause the movement of injected fluids or formation fluids into a USDW are no longer pres ent, or until the end of a fixed time period as determined by the Director.” EPA agrees that modeling results are prone to varied degrees of uncertainty. As discussed in the preamble to the proposed GS regulation and the associated background document "Computational Modeling of Unde rground Injection of Carbon Dioxide for Determination of Area-of-Review and Potential Risk to Underground Sources of Drinking Water" (cited in the proposed rule preamble as USEPA, 2008d), model predictions depend larg ely on the values of key parameters. Often these parameter values are estimated or averaged from several data sources. EPA also agrees that sensitivity anal yses and "worst case scenario" modeling runs should be presented by the owner or operator and evaluated by the Direct or. If during the permit review, the Director determines that modeling results are too wide-rang ing, further information will be required of the owner or operator. EPA clarifies that models are to ols to help predict the movementof a CO2 plume over long time frames. However, EPA recognizes that it cannot be expected that modeling something as complex as a CO2 plume can be done with comple te certainty; therefore EPA is also requiring that the AoR be reevaluated to verify the CO2 plume is moving as predicted and to allow for model calibration and necessary revisions to the required GS project plans (e.g., AoR and corrective action, test ing and monitoring, injection well plugging, post-injection site care and site closure, and emergency and reme dial response). EPA believes th at near-term predictions (e.g., over the subsequent 5 years) will have the high est degree of certainty. Periodic model calibration will allow refinement to the AoR delineation based on real-world conditions and operating data and monitoring results, and thus increase confiden ce in the modeled predictions. EPA adds that the final GS regulation includes a requirement at §146.84(e) that th e AoR be reevaluated at least every 5 years (an adjustment from the ten year interval in the proposal), which should further address the commenters' concerns regarding model uncertainty.

20

### Letter ID: 0158 Comment ID: 23772 Letter Lines: 515 to 531 Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language Comment Code: 3440 2.2.2.2 Evaluation of wells in the AoR (e.g., types of data to be reviewed) Comment: §146.84 Area of review and corrective acti on. (c) (2) "Using methods approved by the Director, identify all penetrations , including active and abandoned wells and underground mines, in the area of revi ew that may penetrate the confining zone. Provide a description of each well' s type, construction, date drilled, location, depth, record of plugging and/ or completion, and any additional information the Director may require; and ..." We recommend striking out "approved" and replacing with "prescribed". We recommend deleting the second sentence and replacing with "Where such information is available or can be ob tained, provide a description of each well's type, construction, date drille d, location depth record of plugging and/or completion and any additional inform ation prescribed by the director and ..." Acceptable methods for identifying deep wells into confining zones within the AoR should be prescribed by the EPA as part of the regulation. Accurate information is difficult to obtain for olde r wells within the AoR. Examples of other information that coul d be required by the Dir ector should be clearly stated. Individual Response: EPA is retaining the language in §146.84(c)(2) as proposed. Based on its evaluation of all public comments and input on the proposed rule and NODA and Request for Comment, EPA has made many other revisions to the GS Rule. See the final rule and preamble for further discussion on EPA's final approach. EPA acknowledges that public records may not contai n data on every artifici al penetration in the AoR (or all of the data on each well that is require d for the tabulation), part icularly in areas with many older wells. However, the Agency recognizes that there may be situations where additional surveys or research to locate information on we lls may be appropriate. For example, there may be cases where the Director may determine th at ground or airborne surveys for wells are appropriate, e.g., if there is re ason to believe that the incomp leteness of information on known wells could compromise USDW protection from endangerment. In order to preserve the Director's discretion to require an operator to supplement a records search, EPA did not make the suggested change. EPA adds that all correctiv e action must be performed pursuant to the approved AoR and corrective action plan, which a ffords the Director the discretion to require any additional information needed (including inform ation that may not be publically available) to ensure that all necessary corrective action is performed. 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 reevaluations. The guidance will be available on EPA's web site, at http://water.epa.gov/type/g roundwater/uic/wells_s equestration.cfm

21

### Letter ID: 0158 Comment ID: 23773 Letter Lines: 534 to 538 Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language Comment Code: 3822 2.3.1.1 Depth of surface casing (seeking comment) Comment: §146.86 Injection well construction requireme nts. (b) (2) "Surface casing must extend through the base of the lowermost USDW and be cemented to the surface. " We recommend striking out this requirem ent in its entirety. This will be prohibitively expensive in deep wells, and may not be necessary at all sites. Individual Response: EPA disagrees that protecting deep USDWs underlying multiple, more shallow USDWs is unnecessary. Protection of USDWs, regardless of their depth or stratigraphic location, is the primary mission and mandate of the UIC program—as specified by Congress in the SDWA—and the purpose of all requirements fo r injection wells. Any injection activity must be demonstrated to not endanger USDWs, regardle ss of their depth, and if such a demonstration cannot be made, then the activity will not be allowed under UIC requirements or the SDWA. Water agencies commenting on the proposed rule noted that diminishing water supplies are requiring water utilities to use deeper and more saline sources, and the SDWA mandates EPA to set regulations that protec t USDWs from endangerment. The final GS rule at §146.86(b)(2) requires that surface casing extend through the base of the lowermost USDW and be cemented to the surface through the use of a single string or multiple strings of casing and cement. It does not, however, specify how cementing must be accomplished, and it allows the owner or operator to propose alternate methods that provide a sufficient amount of cement to meet the standard that USDWs are protected from endangerment. EPA notes that there are many potential ways to meetthe requirement, such as the use of staged cementing. EPA recognizes concerns regardi ng construction of Class VI wells where the lowermost USDW is very deep. To further address comments on d eep injection wells, the final GS rule at §146.95 includes requirements for owners or operators that seek a waiver of the injection depth requirements. Owners or operators of wells opera ting under injection depth waivers must comply with additional construction require ments to ensure that wells used to inject above or between USDWs are protective. See the discussion of the wa iver approach in the preamble to the final GS rule for additional information.

Letter ID: 0158 Comment ID: 23774 Letter Lines: 541 to 550 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 Code: 4660 2.6.6 Geochemical monitoring Comment: §146.90 Testing and monitoring requirements . (d) Periodic monitoring of the ground water quality and geochemical change s above the confini ng zone(s) that may be a result of carbon dioxide movement through the confining zone or

22

### additional identified zones: We recommend changing to "Periodic m onitoring of the ground water quality and geochemical changes between the confining zone(s) and the USDW that may be a result of carbon dioxide movement thr ough the confining zone or additional identified zones:" This rewording is c onsistent with allowing for injection either above or below USDWs Individual Response: EPA disagrees that the GS rule should specify the zones to be monitored. EPA clarifies that §146.90(d) re quires periodic monitoring of the ground water quality and geochemical changes above the confining zone(s). EPA clarifies that this monitoring requirement does not include the confining layer itself. Monitoring above the confining layer will provide an indication of upward movement of CO2 that might endanger a USDW. The exact number of formations to be tested will, however, be based on site-specific characteristics and vulnerabilities and described in the Director-appr oved testing and monitoring plan. 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 and 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, and 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_sequestration.cfm. In the final GS rule, owners or operators grante d injection depth waivers are subject to additional requirements at §146.95(f)(3) to monitor above and be low the injection zone in order to ensure protection of USDWs underlying and overlying the injection z one during both well operation and the post-injection site care period. For additional information on the waiver approa ch, please see the final rule and preamble, as well as EPA's responses to comments on the No tice of Data Availability and Request for Comment.

Letter ID: 0158 Comment ID: 23775 Letter Lines: 553 to 569 Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language Comment Code: 4650 2.6.5 CO2 plume and pressure fr ont tracking (seeking comment) Comment: §146.90 Testing and monitoring requirements . (g) "Testing and monitoring to track the extent of the carbon dioxide pl ume and the position of the pressure front by either monitoring for pressure changes in the first formation overlying the confining zone or using indirect, geophysical techniques (e.g., seismic, electrical, gravity, or electromagnetic surveys and/or down-hole carbon dioxide detection tools); -

23

### We recommend deletion of this requirement in its entirety and replacing with "Testing and monitoring to track the ex tent of the carbon dioxide plume." Tracking the precise position of a moving pressure front will require a large number of expensive and deeply locate d probes. A limited number of pressure monitors that can provide information on pressures affecting the confinement layers are more valuable. The Proposed Rule also requires well ow ners to monitor periodically groundwater qua lity and geochemical changes above the confining zone. The requirements for such deep m onitor wells could be costly. Requiring both pressure and geochemical monitoring wi ll be costly and provide questionable additional information or warning. Individual Response: EPA maintains that plume tracking and pressure monitoring are key components of monitoring at GS sites. A ri gorous plume tracking and pressure monitoring scheme, such as one that meets the requireme nts at §146.90(g), is imperative for ensuring that the CO2 plume is contained w ithin the injection zone. The final rule (at §146.90(g)) requi res owners or operators to pe rform monitoring to track the extent of the CO2 plume and pressure front. The owner or operator must use direct methods to monitor for pressure changes in the injection zone. Indirect methods (e.g., seismic, electrical, gravity, or electromagnetic surveys and/or down- hole CO2 detection tool s) are also required unless the Director determines, based on site-s pecific geology, that such methods are not appropriate Pressure monitoring in the injection zone is nece ssary to track the develo pment and movement of the pressure front and CO2 plume. When combin ed with information on temperature, pressure data provide an indication of the phase (e.g., gas, supercritical) and distri bution of the injected CO2 (73 FR 43515). Monitoring can also identify n eeded remedial actions, provide inputs for AoR reevaluation modeling, evaluate predictions of plume movement, and target additional geochemical and surface monitoring needs. EPA recognizes that installation of monitoring wells entails additional resources. However, the Agency believes that such monitoring is necessaryto ensure that GS projects are appropriately operated and monitored and to protect USDWs fro m endangerment. EPA be lieves that pressure monitoring in the injection zone is necessary to track the de velopment and movement of the pressure front and CO2 plume. Monitoring can al so identify needed remedial actions, provide inputs for AoR reevaluation modeling, evaluate predictions of plume movement, and target additional geochemical and surface monitoring n eeds. Knowledge of the location of the CO2 plume and the associated pressure front will a ssure the public that GS projects are proceeding according to plan, provide sufficient information to the owner or operator and Director, or allow for appropriate actions to address any i ndication that USDWs may be endangered. The combination of site characterization and pr edictive modeling will help guide the siting of monitoring wells and enable ope rators to optimize the numbe r and position of wells. The Director-approved testing and monitoring plan will describe the use and installation of monitoring wells at the site.

24

### EPA acknowledges the commenters' concern about the cost of pressure monitoring. However, EPA believes that this monitoring is essential for protection of USDWs at GS sites Although a significant cost in absolute terms, monitoring costs are expected to be a small fraction of site operating costs, according to EPA's cost analysis for the GS rulemaking (which is available in the docket).

Letter ID: 0158 Comment ID: 23776 Letter Lines: 572 to 585 Comment Code: 1240 1.1.1.3 Suggested changes/ed its to rule language Comment Code: 4670 2.6.7 Surface air monitoring and/or soil gas monitoring (seeking comment) Comment: §146.90 Testing and monitoring requirements. (71) "At the Director's discretion, surface air monitoring and/or soil gas mon itoring to detect movement of carbon dioxide that could e ndanger a USDW. " We recommend deletion of this requirement in its entirety. While this requirement may be suitable for determin ing potential air leakage relevant to monitoring of CO2 in a greenhouse gas polic y context, this requirement does not provide any additional protect ion to migration to USDW as surface breakthrough will only occur well after the deep-surface migration of CO2 to a USDW. Surface monitoring to detect CO2 has high uncertainty and seasonal variability that is likely to result in many false positives and operational distra ctions. Seismic methods of tracking the CO2 plume are more effective than soil gas monitoring of CO2, which is affected by many other f actors and thus is highly variable.
Individual Response: EPA acknowledges that surface air and soil gas measurements are subject to variability and may not be suitable in all settings as a method to ensure USDW protection. However, EPA does not believe that this should en tirely preclude their use. The decision to use surface monitoring and the selecti on of monitoring methods will be site-specific (e.g., may be influenced by geology, injection depth, and operational conditions) and must be based on potential risks to USDWs within the AoR. The Agency believes that surface air and soil gas monitoring, when coupled with subsurface monitori ng, may be appropriate at some GS projects to ensure USDW protection. The final rule at §146.90(h) retains the allowance for surface air and soil gas monitoring at the discretion of the Director as a means of identif ying leaks that may pose a risk to USDWs and informing emergency notification of a Class VI owner or operator and UIC Director in the event of a USDW endangerment, pursu ant to requirements at §146.91(c). EPA cl arifies that the decision to use surface monitoring and the selecti on of monitoring methods will be site-specific (e.g., may be influenced by geology, injection depth, and operational conditions) and must be based on potential risks to USDWs within the AoR.

25

### Letter ID: 0158 Comment ID: 23777 Letter Lines: 587 to 601 Comment Code: 1220 1.1.1.1 Terminology and definitions Comment Code: 5300 2.8.3 Site closure activities (40 CFR 146.93) Comment: §146.93 Post-injection site care and site cl osure (b)(3) "Prior to authorization for site closure, the owner or operator must submit to the Director a demonstration, based on monitoring and othe r site-specific data , that the carbon dioxide plume and pressure front have stabilized and th at no additional monitoring is needed to assure that the geologic sequestration project does not pose an endangerment to USDWs." Clarification of the term "stabilized" is needed. We recommend that the term "stabilized" does not necessarily mean th e plume and pressure front are no longer moving, but that the rate and dire ction as defined by confinement zones no longer place an USDW at risk. Long-term monitoring should have an "end point" defined. Often termed an "exit strategy", this is a key point that is agreed upon by all parties about what is a "stabl e condition". Monitoring data includes a prescribed amount of error, thus statisti cs or other analyses may be required to define a "stable condition". 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 and post-injection site care and site closure plans under §146.92 and §146.93. The guidance describes recommended approaches for how an owner or operator 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: 0158 Comment ID: 23778 Letter Lines: 605 to 609 Comment Code: 3350 2.2.1.5 Use of proprietary models for GS sites (seeking comment)

26

### Comment: EPA seeks comment on allowing the use of pr oprietary models for GS sites. EPA Notice 68. Proprietary models should be acceptable provided that supporting data for validation are submitted. Individual Response: EPA agrees with commenters that av ailable proprietary models may meet the complex needs for calculating the AoRs of GS sites, and shar es their concern about the need to evaluate the inputs and assumptions used. EP A will allow the use of proprietary models in meeting the requirements for the GS regulation, as long as GS well operators using a proprietary model clearly disclose, to the Director's satisf action, the code assumptions, relevant equations, and scientific basis. EPA adds that its Confid ential Business Information requirements at 40 CFR 144.5 will apply to the use of proprietary models.

Letter ID: 0158 Comment ID: 23779 Letter Lines: 612 to 617 Comment Code: 3330 2.2.1.3 Applicability /adequacy of computational models (seeking comment) Comment: EPA seeks comment on the applicability of computational fluid flow models for delineating the AoR of GS sites. EPA Notice 69. Computational fluid flow models should be permitted for delineating the AoR of GS sites provided also that data are provided supporting their validation in similar complex structures and flow regimes Individual Response: EPA agrees that a detailed geologic a ssessment is essential to evaluating the presence and adequacy of a proposed site to receive and confine the CO2. EPA encourages owners and operators to submit (and Directors to review) any available data on the site, such as seismic or off-set well data. The AoR and co rrective action plan required at §146.84(b)must describe the site characterization data on which the model will be based. The Director has discretion to require the us e of existing data if it is not init ially included. Furthermore, the owner or operator's testing and monitori ng plan required at §146.90 should provide for site-specific data (which may include seismic and direct measuremen ts) that can be used to inform updates to the model and support AoR reevaluations. The Agency believes that predicting the comp lex multiphase buoyant flow of the CO2, coinjectates, and compounds that may be mobilized due to injection require s the sophistication of computational models. Models can predict CO2 fate and transport, as well as changes in formation pressure, in three dimens ions, as a function of time in or der to delineate the subsurface storage site and the AoR. Models can account fo r site-specific and pred icted operating conditions as well as geologic heterogeneitie s and potential migration through faults, fractures, and artificial penetrations. EPA clarifies that the model i nputs must include actual geologic information, data collected during the site characterization process (e.g., information about artificial penetrations), and
27

### anticipated operating parameters (e.g., injection rates) submitted with the permit application under §146.82. Models will be revised and recalibr ated during subsequent AoR reevaluations, which must account for all availa ble monitoring and operational data, as required at §146.84(e).

Letter ID: 0158 Comment ID: 23780 Letter Lines: 620 to 626 Comment Code: 3530 2.2.3.1 AoR reevaluation fre quency (seeking comment) Comment: EPA seeks comment on requiring the reevalua tion of the site AoR on a periodic basis, under what conditions the Ao R should be reevaluated, and the appropriateness of a 10-year minimum fixe d frequency for AoR reevaluation. EPA Notice 72. 10 years is a reasonable period of time to reevaluate the site AoR during injection. Individual Response: Based on evaluation of the public comments on this topic, EPA has changed the minimum frequency for the AoR reev aluation at §146.84(e) from 10 years to at least every 5 years. EPA believes that this revised fre quency addresses concerns raised by commenters representing water associations, an energy co mpany, associations, industries, states, and environmental groups about the inherent uncerta inties in modeling CO2 movement, the emerging nature of GS technology, risk-based targeting of monitoring activities, an d the unique nature of CO2 GS. The 5-year reevaluation frequency, particularly during early stages of GS deployment, will also support EPA's adaptive approach to the GS rule making. EPA is using an adaptive approach to regulating GS. The Agency plans, every six years, to collect and review data on GS projects to determine whether the appropriate amount and types of information and appropriate documentation are being collected, and to determ ine if modifications to the requirements are appropriate or necessary.

Letter ID: 0158 Comment ID: 23781 Letter Lines: 629 to 636 Comment Code: 3820 2.3.1 Well construction procedures Comment: EPA seeks comment on the proposed GS well requirements for depth of surface casing, the cementing of long-string casing and construction witha packer set opposite a cemented interval. EPA Notice 78. The requirements for construction of the proposed Class VI CO2 injection wells should be similar to the Class II wells us ed for EOR. This will expedite the transition of EOR projects to CCS projects. This requirement also unnecessarily stigmatizes CO2. Individual Response: EPA recognizes that many early GS pr ojects will be in depleting or

28

### depleted oil and gas fields and that grandfatheri ng of wells used for ER, where appropriate and protective, can facilitate the transition from ER to GS. However, EPA believes that injection for the prim ary purpose of long term storage is sufficiently different from Class II ER operations and warrant s tailored requirements for Class VI wells at §146.86. For example, the volume of CO2 anticipated to be injected in Class VI wells is significantly greater than for Class II wells. Reser voir pressure conditions will also be different, with Class VI injection opera tions involving large volumes of CO2 and likely having higher pressures within their storage formations than Class II ER projects. The final Class VI regulations re quire that any owner or operato r injecting CO2 for the primary purpose of long term storage obtain a Class VI pe rmit with some special consideration for the fact that they are transitioning from a well not or iginally designed to meet Class VI requirements. The Director has the authority to determine at wh at point a Class VI permit is required for those projects that are transitioning from the primar y purpose of EOR to long term storage of CO2. The final regulation provides a set of technical factors for the Direct or to evaluate in making this determination, at §144.19. EPA believes that this approach provides su fficient protection of USDWs when there is an increased risk to USDWs as compared to traditi onal Class II operations while allowing for site-specific flexibility. The final GS rule, at §146.81(c), allows the co nstruction of ER wells to be grandfathered, provided the owner or operator candemonstrate to the Director that the wells were engineered and constructed to meet the requirements at §146. 86(a) and ensure protec tion of USDWs, in lieu of requirements at §146.86(b) and §146.87(a). Only the cemented-in-place construction requirements will be grandfathered under the fi nal GS rule; following conversion, these wells will be permitted as Class VI wells and be subj ect to the operational, MIT, monitoring, reporting, plugging, and post-injection site ca re and site closure requiremen ts in the final GS rule. EPA is developing guidance on transitioning from Class II to Class VI. The guidance will assist Directors and owner/operators in evaluating where a project may fit within a Class II to Class VI transition. The guidance describes the methods ava ilable for the Director to determine the risk posed to USDWs from a GS/ER project, and how th e Director may determine if a project should be regulated by a Class II or Class VI UIC program. The guidance will be available on EPA's web site, at http://water.epa.gov/type/g roundwater/uic/wells _sequestration.cfm. EPA disagrees that the constr uction requirements for Class VI wells will stigmatize CO2 GS. Although the requirements are based on the existing regulatory framework for deep wells, including Class I wells, EPA believes that GS is sufficiently differentfrom other injection operations to warrant the tailored requirements for Class VI wells at §146.86.

Letter ID: 0158 Comment ID: 23782 Letter Lines: 639 to 645 Comment Code: 3840 2.3.2 Horizontal well drilling techniques (seeking comment) Comment: EPA seeks comment on the merits of horiz ontal well drilling t echniques for GS wells and the applicability of well constructi on requirements discussed in this
29

### proposal. EPA Notice 80. Horizontal wells should be permitted for in jection of CO2. The use of horizontal wells may minimize the number of wells re quired for injection. A reduced number of wells will reduce both cost and may also reduce potential leakage paths. Individual Response: In the final rule, EPA allows the use of horizontal wells at GS projects. In the proposed rule, EPA sought comment on the appr opriateness of horizonta l drilling techniques for Class VI wells, and commenters representing energy companies, el ectric utilities, the oil and gas industry, CCS associations, states, and the public, unanimously suppo rted the concept and provided many reasons why horizonta l wells could be beneficial at GS sites. Based on an evaluation of these comments and additional research by EPA, the Agency has concluded that horizontal wells that are properly constructed, logged, and tested for mechanical integrity (i.e., to meet the requirements of the GS rule) can ensure the protection of USDW s from endangerment.

Letter ID: 0158 Comment ID: 23783 Letter Lines: 648 to 657 Comment Code: 4120 2.4.1.2 Allowing hydraulic fracturing during GS (seeking comment) 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 85. Fracturing of GS formations should be permitted, provided confining structures are not negatively impacted and fracturi ng is limited to the injection zone. Exclusion of fracturing of storage form ations would often require unnecessary drilling of new injection wells. The oil industry has sufficient experience in using fracturing technology to avoid negatively impacti ng confining structures (e.g., caprock). Individual Response: EPA recognizes that there may be well completions which require intermittent treatments that include stimulation to improve wellbore injectivity. Stimulation of the injection zone during a well workover will be permissible, if approved by the Director (operators seeking to use stimul ation must submit the proposed stimulation program as part of the permit application under §146.82(a)(9) where in jection pressure limits will be set). EPA has also added a requirement that owners or operators notify the Director in advance of any planned stimulation activities, as speci fied at §146.91(d). During injection, the injection pressure must not exceed 90 percent of the fracture pressure, as specified in §146.88(a). EPA clarifies that the injection pressure limit at §146.88(a) applies only to the period of injectio n, not well stimulation.

Letter ID: 0158 Comment ID: 23784 Letter Lines: 660 to 667 Comment Code: 4344 2.4.4.2.2 Comments opposed to setting a minimum injection depth Comment: EPA seeks comment on whether the Agency should set a minimum injection depth

30

### requirement for CO2 GS, rather than require that such injection take place below the lowermost USDW. EPA Notice 93. EPA should neither require injection belo w the lowermost USDW nor alternately require a minimum depth requirement as ge ologic structures ar e likely to be encountered that provide for secure and sa fe storage. Examples of such storage that should be acceptable are domes and caverns. Individual Response: EPA agrees that it is notappropriate to set a mi nimum injection depth for GS projects and the Agency believes that a determ ination of site-suitabili ty for GS (i.e., that subsurface formations will receiv e and confine injected CO2) s hould be made on a site-specific basis. The GS rule, at §146.82, requires the owne r or operator to provide extensive site- and project-specific information to the Director to demonstrate that the site meets the minimum site criteria at §146.83, that the CO2 will be contai ned within the injection formation, and that USDWs will be protected from endangerment. EPA acknowledges that there are limited circum stances where injectio n above the lowermost USDW can be performed in a manner that protec ts USDWs, as long as appropriate protections are in place. The final GS rule at §146.95 establis hes a process by which owners or operators can seek a waiver of the Class VI injection de pth requirements for in jection into non-USDW formations above and/or between USDWs. The waiver approach requires the submission of extensive, site-specific information (in conjunc tion with the permit appl ication submission) to demonstrate that injection of CO2 into a non-US DW that is above or between USDWs can be done in a manner that is protective of USDWs. Th e requirements are designed to ensure that the owner or operator, the Director, and the Regional Administrator cons ider, on a site specific basis, the implications, benefits, and challenges associat ed with GS and ensuring water availability and USDW protection. For additional information on the waiver approach, please see the final rule and preamble, as well as EPA's responses to comments on the Notice of Data Availability and Request for Comment.

Letter ID: 0158 Comment ID: 23785 Letter Lines: 670 to 676 Comment Code: 4490 2.4.5 Use of tracers and potential impact on human health or ecosystems (seeking comment) Comment: EPA's proposal allows Directors' discre tion on whether to require the use of tracers, and if so, what types of tr acers. 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 95. Tracers should be permitted, but not require d. They are commonly and safely used in the oil and gas industry. Individual Response: EPA agrees that tracer use is not ap propriate in all situations. For this reason, EPA does not require the use of tracers at all GS sites; however, the Director has discretion to require their use if he/she determines that th e use of tracers could improve
31

### monitoring of the site and enhance USDW prot ection from endangerment. The rule will also allow their use if proposed by the owner or operator and approved by the Director.

Letter ID: 0158 Comment ID: 23786 Letter Lines: 679 to 694 Comment Code: 4670 2.6.7 Surface air monitoring and/or soil gas monitoring (seeking comment) Comment: EPA seeks comment on the appropriate amountand types of monitoring that should be conducted at a GS site. Specificall y. EPA seeks comment regarding the usefulness of indirect geophysical monitoring and surface air and soil gas monitoring. In addition, EPA seeks commen t regarding the use of a Directorapproved monitoring plan for GS sites. EPA Notice 111 Surface air and soil gas mon itoring are not useful. Seis mic methods of tracking the CO2 plume are more effective than soil gas monitoring of CO2, which is affected by many other factors and thus is highly variable. Surface breakthrough represents an "after-the-fact" event. While this requirement may be suitable for determining potential air CO2 leakage re levant to monitori ng of CO2 in a GHG context, this requirement does not pr ovide any additional protection to migration to USDW as surface CO2 breakthrough will only occur well after the deep-surface migration of CO2 to a USDW . Surface monitoring to detect CO2 has high uncertainty and seasonal variability that is likely to result in many false positives, operational distractions and unduly raise public concern. Individual Response: EPA clarifies that subsurface geochemi cal and pressure monitoring in the subsurface formations are the first line of m onitoring that would allow detection of potential endangerment to USDWs from GS ac tivities (this is required at al l GS sites, as described at §146.90(d)). The Agency also believes that surf ace air and soil gas monitoring, when coupled with subsurface monitoring, may be appropriate at some GS projects to ensure USDW protection. EPA clarifies that surfac e air and soil gas monitoring are not required at all GS sites. However, the GS rule at §146.90(h) gives th e Director discretion to require surface air and/or soil gas monitoring as a means of iden tifying leaks that may pose a risk to USDWs and informing emergency notification of a Class VI owner or operator and UIC Director in the event of a USDW endangerment, pursuant to requirements at §146.91(c). EPA clarifies that the decision to use surface monitoring and the se lection of monitoring methods will be site-specific (e.g., may be influenced by geology, injection depth, and operational conditions) and must be based on potential risks to USDWs within the AoR. EPA acknowledges that air and so il gas monitoring are subject to variability and may not be suitable in all settings as a method to ensure USDW protection. However, EPA does not believe that this should entirely preclude their use. The decision to use surface monitoring and the selection of monitoring methods will be site-specific (e.g., may be influenced by geology,

32

### injection depth, and operational conditions) and must be based on poten tial risks to USDWs within the AoR.

Letter ID: 0158 Comment ID: 23787 Letter Lines: 697 to 708 Comment Code: 4710 2.7.1 Proposed submissions required for permit applications (seeking comment) Comment: EPA is proposing that permit applications for GS sites include several plans not currently required under existing UIC re gulations. These plans include a monitoring and testing plan, an AoR and corrective action plan, and a postinjection site care and site closure plan. EPA seeks comment on the merits of requiring plans for monitoring, AoR, and post- injection site care as part of a permit application. EPA Notice 112. We believe that requiring a monitoring pl an is reasonable. However, the EPA should develop such requirements withrecognition of a di stinct end to operations and monitoring following cl osure, and consider specific representations and codicils that r ecognize an end of "in-perpetuity" responsibility for the operator or owner. Individual Response: EPA clarifies that the owner or operator's approved testing and monitoring plan and post-in jection site care and site closure plan will be incorporated as a condition of the Class VI permit. Class VI well operators will be require d to perform monitoring pursuant to the plans throughout the life of the facility (i.e., the dur ation of the Class VI permit). EPA adds that §146.93(b) requires operators to pe rform post-injection site monitoring until it can be demonstrated that the CO2 and pressure fr ont no longer pose a risk of endangerment to USDWs. EPA notes that the post-injection monito ring may be different from monitoring that occurs during the operational phase. Once this de monstration is made, site closure may be authorized and monitoring is no longer required. EPA adds thatowners or operators must maintain financial responsibility unti l site closure has been authorized. Please see the final rule and preamble, includi ng the discussion of post-injection site care monitoring and financial responsibil ity for additional information.

Letter ID: 0158 Comment ID: 23788 Letter Lines: 711 to 716 Comment Code: 4740 2.7.4 Electronic reporting (seeking comment) Comment: EPA seeks comment on the requirement for electronic reporting in its proposed rule. EPA Notice 115, We recommend that EPA allow electronic re porting as an alternative to hardcopy submittals. The benefits are speed, efficiency, reduced cost and burden of paperwork, ease of document retrieval, public access, search and storage.

33

### Individual Response: EPA believes that electronic formatting is the most appropriate format for submitting Class VI project information to the Di rector, and that, based on comments received on the proposed rule, the majority of Class VI we ll owners or operators wi ll have the capability to report electronically, and requires this at §146.91(e). EPA is developing guidance for states that describes the recordkeeping, reporting, and additional data management needs associated with GS 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: 0158 Comment ID: 23789 Letter Lines: 719 to 726 Comment Code: 4750 2.7.5 Comments on the merit of a nnual reports (seeking comment) Comment: Although EPA has not included a requirement for this report in its proposal, EPA seeks comment regarding the necessity for such an annual report. EPA Notice 115. While reports on status are worthwhile, ac tivity and changes in status are not going to be significant on an annual basis. Following a report after the first year of operation to ensure that requirem ents for later reporting are being met, once every 10 years coincident with th e periods for AoR review should be adequate. Individual Response: The final GS regulation retains the reporting requirements as proposed, which does not include a requirement for an annu al report. Instead, EPA believes that periodic reevaluation of the AoR, as re quired at §146.84(e), along with any re visions to the required plans that may be necessary based on the AoR reevaluation, will promote an ongoing relationship between the permitting authority and the owner or operator. The final GS rule, at §§146.84(c), 146.90(j), and 146.94(d), requires owners or oper ators to review and update the AoR and corrective action plan, the testi ng and monitoring plan, and the emergency and remedial response plan throughout the life of the project. Owners or operators mu st review each 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 cas e can reviews occur less often than once every five years. For additional information, please see the final rule an d the preamble for a discussion of EPA's final approach to recordk eeping and reporting. While the Agency recognizes some concerns expressed by commenters about the burden associated with an annual report, the Agency 's decision to retain the semi-annual reporting requirement at §146.91(a) is because the semi-annua l report in conjunction with the continued dialogue associated with AoR r eevaluations and periodic updates to the plans is a preferred approach to an annual report.
34

### EPA encourages and expects owners and operators to share monitoring and operating data with the public voluntarily (e.g., through the Inte rnet), however. Providing the public with information throughout the Class VI project will help clear up and avoid public misperceptions about the nature and safety of GS.

Letter ID: 0158 Comment ID: 23790 Letter Lines: 729 to 742 Comment Code: 5260 2.8.2.3 Adjusting the post-injecti on timeframe (seeking comment) Comment: In addition, EPA seeks comment on whether the Director should be allowed to shorten the timeframe based on performan ce information, and whether EPA should require a shorter or longer post injec tion period if data suggests the time frame should be adjusted. EPA Notice 125-26. EPA should allow the Director to shorte n the timeframe based on performance information. However, an open-ended time period results in a high degree of uncertainty regarding cost exposure to a project developer. It also leaves a site open to future liability from "r eopeners" by the regulatory community. To avoid this latter scenario, a maximum monitoring period should be defined in terms of clear, performance-based risk metr ics - for example, that the validated model predicts that 95% of the plume is or will be trapped and that a sensitivity analysis predicts a comfortabl e margin of safety and diminimus risk of endangerment to any USDWs. Individual Response: EPA disagrees that the Director shouldnot have discretion to shorten or lengthen the post-injection site care monitoring period or that it create s a “high degree of uncertainty regarding cost exposure.” Because of th e variety of site-specific circumstances at GS sites, EPA believes that individual UIC Directors, in consultation with operators, will be in the best position to determine whether additional post-injection site care monitoring is needed (or whether the timeframe may be shortened), based on the circumstances of a particular project. EPA expects this decision to be made based on re levant site data and in consultation with all potentially impacted parties to ensure USDW protection. EPA recognizes that there are chal lenges associated with assuring funding for activities that will occur far in the future. However, the Agency be lieves that operators must demonstrate that financial resources are available to plug the inje ction well and provide po st-injection care at the point in time that the first CO2 is injected. EP A also recognizes the conc erns associated with assuring financial responsibility for the long tim e frames over which post-injection site care will be conducted. EPA is developing guidance on financ ial responsibility to assist owners or operators in evaluating the requi rements of §146.85 and to assist Directors in evaluating financial responsibility demonstrations. The guidance descri bes the types of financial mechanisms that operators may choose to use when evaluating th e financial responsibility requirements for GS wells and it will also include a section on how to estimate costs to support accurate financial responsibility demonstrations. The guidance will be available at http://water.epa.gov/type/groundwater /uic/wells_sequestration.cfm.
35

### Letter ID: 0158 Comment ID: 23791 Letter Lines: 745 to 761 Comment Code: 5432 2.9.1.1 Need to adjust financial responsibility mechanisms (seeking comment) Comment: Current UIC regulations for Class I hazar dous waste injection allow for the use of insurance for purposes of demonstrat ing financial respons ibility. However, insurance was not included as part of the guidance provided for Class II injection because this insurance mechanism was and still is, rarely used for the purpose of demonstrating financial assurance for injection wells. EPA is assessing whether to provide guidance on th e use of insurance providers and, if so, whether to update eligibility requir ements for insurers for GS wells consistent with other current Fede ral agency practices. EPA Notice 131. The role of insurance needs to be define d and especially, what is being insured and for what events and risks. We interp ret this as being limited to insurance related to decommissioning, plugging of we lls and closure of the site. Such costs and insurance coverage may change as additional wells are needed or the scope of the AoR changes. Absent of Fe deral or state assumption of long term liability, and regulatory clar ity on the inapplicability of CERCLA, and events and their mitigation, it will be difficult fo r insurers to provide coverage for any more than a limited scope. Individual Response: EPA clarifies that owners or operato rs must demonstrate and maintain financial responsibility for corr ective action on wells in the AoR, injection well plugging, PISC and site closure, and emergency and remedial response for Class VI wells, as specified at §146.85(a). Owners or operators may choose a combination of instruments, including insurance, for various GS activities for purposes of meeting their regulatory ob ligations under §146.85. EPA agrees that it is important for insurance te rms to be clear and for that reason requires owners or operators to reassess the needs for cove rage when there are changes at the site. The GS regulation, at §146.85(c), requires the owner or oper ator to provide annual updates to the cost estimate to account for any amendments to the AoR and corrective action plan, the injection well plugging plan, the PISC and site closure plan, and the emergency and remedial response plan. Furthermore, EPA is developing guidance that de scribes the types of fi nancial instruments, including insurance, that owne rs or operators can use to meet financial responsibility requirements for Class VI wells. The gui dance (available on EPA's website at http://water.epa.gov/type/groundwat er/uic/wells_sequestration.cfm) will include considerations of how to evaluate the appropriateness of a specific financial responsibility instrument for a project.

Letter ID: 0158 Comment ID: 23792 Letter Lines: 764 to 774 Comment Code: 5430 2.9.1 Comments on proposed financia l responsibility requirements (40
36

### CFR 146.85) Comment: EPA is assessing whether a financial rati ngs threshold for all companies using a self-guarantee, similar to those used by other Federal agencies, is appropriate. The Agency also is considering what cons titutes an appropriate financial rating threshold, and whether a financial rati ng greater than BBB or Baa (i.e., the current rating threshold es tablished under the UIC regul ations) is appropriate for GS wells. EPA Notice 133. Allowing for self-insurance definitely will be helpful to provide another avenue for CCS projects to be deployed. However, as we've experienced in the recent economic crisis, there are no guarantees of financial continuity for either insurers or other economic entities. Individual Response: EPA believes that the GS rule provides a flexible approach for financial responsibility. Under the final GS rule owners or operators have the flexib ility to choose from a variety of financial instruments to meet their financial responsibilityobligations. Owners or operators may use one or multiple financial responsibility instruments for well plugging and PISC (§146.85(a)(6)). However EPA will not allo w for a separate financial responsibility demonstration for well plugging and PISC (i.e., a demonstration submitted prior to well plugging and the beginning of the post-injec tion site care period rather than with the permit application). A demonstration of financial responsibility for all ph ases of the GS project will be required prior to the issuance of a Class VI permit (§146.85(a)(5)(i)). EPA is developing guidance that describes the types of financia l instruments, including self insurance, which owners or operators may c hoose to use to meet financial responsibility requirements for Class VI wells. EPA recognizes th at there are some concerns about the use of self insurance, including those mentioned by the commenters. The financial responsibility guidance will include consideratio ns for Directors regarding how to evaluate the appropriateness of a specific financial responsibil ity instrument for a given project , such as potential concerns regarding companies with relatively small capitalizat ion or the experiences of states in approving self-insurance instruments. The guidan ce is available on EPA's website at http://water.epa.gov/type/groundwater /uic/wells_sequestration.cfm. EPA acknowledges the commenter's concern regard ing the current economic crisis, but notes that such unpredictable events are outside of the scope of this rulemaking and the Agency's control or authority.

Letter ID: 0158 Comment ID: 23793 Letter Lines: 777 to 785 Comment Code: 5460 2.9.2 Comments on transfer of lia bility for long-term care Comment: 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
37

### 38 authority under the SDWA. EPA Notice 133. EPA needs to consider and define how it will deal with and allow transfer of financial responsibility be tween private entities and also potentially to Federal agencies or other sovereign enti ties such as states or commonwealths. 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 operator will generally no longer be subject to enforcement for regulatory noncompliance. Furtherm ore, their financial instrument as required under §146.85 will be released if it was not used. However, even if a site closure is approved under §146.93, an owner or operator may be held liable for regulatory noncompliance (including violation of 40 CFR 144.12) in ce rtain circumstances. For example, an owner or operator may be held liable for regulatory noncompliance even afte r site closure was approved if the Director relied on erroneous information (e.g., erroneous modeling data) provid ed by the owner or operator when approving site closure. Separate from EPA’s authority to enforce regul atory compliance, an owner or operator may be subject to a §1431 response orde r even after proper site cl osure is approved under §146.93. Under §1431 the Administrator may require an owner or operator to take necessary response measures if he or she receives information that a contaminant is present or is likely to enter a public water system or an USDW, which may pres ent an imminent and s ubstantial endangerment to the health of persons, and the appropriate Stat e and local authorities have 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 owner or operator of a Class VI well. If the owner or operator fails to comply with the order, they may be subject to a civil penalty for each day in which such violation occurs or failure to comply continues. 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. Please note that EPA does not have authority under SDWA 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.