1.3 –  Responses to Public Comments on Risk Associated with GS

This file contains responses to public comments on the risk associated with geologic

sequestration (comment codes 1600 to 1680).  This section includes comments on risks

to drinking water, induced seismicity, RCRA/CERCLA issues, and health effects.

The table below presents all of the EPA‐assigned comment codes that are included in

this section of the comment and response summary.  Use the bookmarks in the PDF to

move among the comment codes.   

Topics included in this summary and associated comment codes

Topic Code

1.3 Risk Associated with CO2 GS 1600

1.3.1 Risks to USDWs 1610

1.3.1.1 Leaching and mobilization of contaminants; reactions in injection zone 1612

1.3.1.2 Impurities in captured CO2; purity standards for CO2 1614

1.3.1.3 Fluid movement 1616

1.3.1.4 Impacts on drinking water treatment (No comments were submitted for this topic.) 1618

1.3.2 Induced seismicity 1620

1.3.3 RCRA/hazardous waste issues   1630

1.3.4 CERCLA issues   1640

1.3.5 Human health impacts 1650

1.3.5.1 Concerns about Lake Nyos and Mammoth Mountain‐type events 1655

1.3.6 Ecosystem impacts (soil, air, surface water) 1660

1.3.7 Other/miscellaneous risks 1670

1.3.8 Don't overstate risk, don't stigmatize CO2 1680

Every comment on these topic areas and the associated response is included in this

summary; there is some repetition where multiple commenters made the same

comment.

Responses to letters from individual commenters or organizations are also available in

the rulemaking docket.

  
Comment Code: 1600 1.3 Risk Associated with CO2 GS 

Individual Comments

Commenter Name: Anonymous Letter ID: 0101

Comment ID: 21937

Comment: i believe this is a dangerous solution to the issue of too much carbon. 

i believe we need to deal with this issue by making sure we produce less of this 

toxic substance. this is not the way to go. it is expensive and it is dangerous. 

we need conservation to step in first as a preventative. 

Response: EPA recognizes that injecting large volumes of CO2 for GS poses unique challenges that,

if not properly managed, could endanger drinking water sources and have other adverse impacts.

However, the final, tailored, Class VI requirements address the large volumes of CO2 injected, its

buoyancy, potential corrosivity in the presence of water, and potential impurities in the CO2 stream.

In addition, EPA expects the tailored permitting, siting, construction, operation, monitoring, and

post-injection site care requirements in the GS rule to prevent leakage from injection formations and

protect USDWs. EPA acknowledges the comment on reduction of carbon emissions. These

comments are outside the scope of the UIC Program’s authority under the GS rulemaking.

EPA has estimated the costs of complying with the GS rule requirements; these are presented in the

Cost Analysis, which is available in the rulemaking docket.

Commenter Name: B. Sachau Letter ID: 0105

Comment ID: 21939

Other EPA Comment Codes and Descriptions: 1340 1.1.3.2 Oppose use of GS in general 

Comment: i elieve these wells are extremely dangerous. it would be far better to 

see that less carbon dioxide is formed. i see little to no effort in that regard 

and ask for more effort on that. these wells are an accident waiting to happen. 

look at how the army orps of engineers built the leveees in new orleans - that 

is an indication of the quality of construction that can happen in the usa. 

Response: EPA recognizes that injecting large volumes of CO2 for GS poses unique challenges that,

if not properly managed, could endanger drinking water sources and have other adverse impacts.

However, the final, tailored, Class VI requirements address the large volumes of CO2 injected, its

buoyancy, potential corrosivity in the presence of water, and potential impurities in the CO2 stream.

In addition, EPA expects the tailored permitting, siting, construction, operation, monitoring, and

post-injection site care requirements in the GS rule to prevent leakage from injection formations and

protect USDWs. EPA acknowledges the comment on reduction of carbon emissions. This comment

is outside the scope of the UIC Program’s authority under the GS rulemaking.

Commenter Name: Nancy LaPlaca Letter ID: 0115

Commenter Organization: Bardwell Consulting Comment ID: 22047

Other EPA Comment Codes and Descriptions: 1620 1.3.2 Induced seismicity 

Comment: Here are the problems with underground injection of CO2: - it's risky: who will 

bear the risk of leakage? - CO2 is heavier than air and displaces air - couple 

incidents in Africa (one in Cameroon) in late 1980's where large "cloud" of CO2 

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was released and suffocated 1800 people and 1100 head of cattle. - liquid CO2 is 

very corrosive - injecting CO2 can induce seismic activity 

Response: The final, tailored, Class VI requirements address the large volumes of CO2 injected, its

buoyancy, potential corrosivity in the presence of water, and potential impurities in the CO2 stream.

In addition, EPA expects the tailored permitting, siting, construction, operation, monitoring, and

post-injection site care requirements in the GS rule to prevent leakage from injection formations and

protect USDWs.

Regarding the cost of responding to leaks, the GS rule requires that owners or operators demonstrate

and maintain financial responsibility for corrective action on wells in the AoR, injection well

plugging, post-injection site care and site closure, and emergency and remedial response at GS sites

as specified in §146.85. In the event of contamination or other adverse event to a USDW associated

with GS, the financial instrument(s), such as insurance, bonds, etc., rather than public monies, would

cover necessary response actions. 

EPA disagrees that the CO2 releases at Lake Nyos is a valid analogue for GS. GS sites have little in

common with the physical setting or mechanism that resulted in the release of naturally-occurring

CO2 trapped at the bottom of Lake Nyos, a stratified tropical lake that suddenly overturned through a

process known as "limnic eruption." No injection was associated with this event, and this site would

not have been considered sufficiently geologically stable to be issued a Class VI permit based on the

rigorous site characterization requirements at §146.82 (e.g., including lack of confining units).

GS takes places thousands of feet below the Earth’s surface within porous spaces in deep rock

formations. CO2 is injected for GS through technically engineered wells with multiple barriers

designed to isolate the injectate in the well and protect formations outside the well materials. The

injected CO2 is stored in geologic formations underneath confining layers of rock that act as natural

barriers to leakage. It is unlikely that CO2 would escape from a GS site that is properly

characterized, operated, monitored, and closed. During the site selection process, operators of Class

VI wells identify and evaluate the appropriateness of a site for GS of CO2. The evaluation includes

the identification of surface and subsurface features such as deep stratified lakes and other naturally

occurring pockets of CO2. Furthermore, during GS operation, injection pressures and formation

conditions are monitored to avoid overpressuring the storage formation.

EPA acknowledges that induced seismicity is a risk that may be associated with GS but maintains

that the risk is low (IPCC, 2005). The GS rule contains several requirements to address seismic risk.

First, as part of the site characterization process, owners or operators must submit information about

the seismic history of and seismic sources near a proposed GS site, data on known or suspected

faults in the AoR, geomechanical information on fractures, stress, ductility, rock strength, and in situ

fluid pressures within the confining zone as specified in §146.82(a)(3). This information is evaluated

by the Director, who determines the suitability of a potential project site for GS. Any sites with the

potential for reopening or reactivation of faults or unacceptable seismic risk that could otherwise

interfere with containment will not be permitted as GS sites. During injection, the pressure in the

injection zone must not exceed 90 percent of the fracture pressure of the injection zone as specified

in §146.88(a); this requirement is intended to prevent the opening of fractures or faults through over

pressurization of the injection zone.

Commenter Name: John Stormon Letter ID: 0123

Commenter Organization: Washington State Dept. of Ecology Comment ID: 22998

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Other EPA Comment Codes and Descriptions: 2046 1.5.2.3 Continuing to classify CO2 injection

for EOR/EGR as Class II/ dividing line between Class II and Class VI (seeking comment) 

Comment: Risk: Geologic Sequestration is not the same as Enhanced Oil Recovery (EOR) and 

needs to have much high standards than EOR activities have had to date. 

Protecting USDW is the most important aspect of the UIC program for the geologic 

sequestration of carbon dioxide. Although limited experience has been gained by 

the oil and gas industry injecting CO2 into proven structural traps for EOR, 

this experience has limited carry over to broader strategies for geologic 

sequestration. Geologic sequestration, unlike EOR, is being considered in basins 

without proven oil and gas capture and holding reservoirs. Even where exhausted 

oil and gas reservoirs are being considered for geologic sequestration, the 

amount of carbon dioxide to be injected is far greater than used for EOR and the 

goals of the injection are different. There is an unknown, likely large, level 

of risk associated with large geologic sequestration projects. The regulatory 

standards for site selection, site characterization and ongoing monitoring 

should be kept high to help ensure that the worst case scenarios are never 

realized. 

Response: EPA agrees that the nature and risks of CO2 injection for long-term storage are different

from Class II CO2 injection for ER, and that tailored requirements for GS wells are necessary to

protect USDWs from endangerment. For this reason, the Agency tailored UIC requirements for Class

VI wells that address the general risks deep injection may pose to USDWs and specifically address

the unique nature of CO2 GS (i.e., very large volumes, very long time-periods, and reservoir

pressure conditions). 

EPA recognizes that injecting large volumes of CO2 for GS poses unique challenges that, if not

properly managed, could endanger drinking water sources or have other adverse impacts. Although

EPA believes that a lot can be learned from the EOR experience, EPA agrees that caution is

warranted and has, as a result, developed a new well class with requirements tailored to address the

unique challenges posed by GS and potential risks associated with long-term injection of CO2. For

example, these requirements include the tailored AoR delineation process per §146.84, monitoring

that is appropriate to GS projects per §146.90, and extended post-injection site care per §146.93. 

As part of its adaptive rulemaking approach, the Agency plans, every six years, to collect and review

data on GS projects to determine whether the appropriate amount and types of information and

appropriate documentation are being collected, and to determine if modifications to the requirements

are appropriate or necessary.

Commenter Name: Sam Kitto Letter ID: 0126

Commenter Organization: National Tribal Air Association Comment ID: 23048

Other EPA Comment Codes and Descriptions: 1930 1.4.4.2 Consultations with State, Tribal, and

local Associations (e.g., GWPC, IOGCC) 

Comment: As will be noted further in our comments, the EPA failed to adequately consult 

with Indian tribes on the GS rule. If the Agency had properly consulted, many 

tribes might have communicated that the lands on which they live are highly 

diverse and environmentally sensitive. As such, geologic sequestration conducted 

on or near these lands requires extra due diligence to ensure the safety of 

tribes and their environments. Every effort to mitigate the environmental 

impacts of geologic sequestration, even beyond impacts to USDWs, must be taken 

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by the EPA. 

The NTAA therefore recommends that the EPA provide specifics on how it will help 

protect Indian tribes and their lands from the environmental impacts of geologic 

sequestration, even impacts beyond those to USDWs. 

Response: EPA clarifies that regulating environmental impacts beyond impacts of endangerment to

USDWs is beyond the scope of EPA’s authority under the Safe Drinking Water Act and outside the

scope of this rulemaking. However, EPA believes that the GS rule, properly implemented, will

protect USDWs and the overlying land from endangerment.

Throughout the GS rulemaking, EPA has promoted a transparent stakeholder process to ensure that

all stakeholders understood the rulemaking elements and that viewpoints and suggestions for rule

modifications were recorded. EPA, with support from the American Indian Environmental Office

(AIEO), engaged and consulted Tribes early in the rulemaking process, and continued to update

Tribal representatives as appropriate. Additionally, the Agency provided tribes with the contact

information for EPA managers in order to facilitate communication throughout the rulemaking

process. 

In April 2008, prior to publication of the proposed GS rule, the Agency sent background information

about the proposed rulemaking to all federally recognized American Indian tribes. In addition, EPA

communicated with the National Tribal Caucus of the National Operations Committee (NTC) and

the National Tribal Water Council (NTWC) to encourage participation in a dedicated consultation on

the rulemaking. On April 24, 2008, the Agency held a conference call with all interested tribal

representatives; a summary is included in the rulemaking docket. Additionally, an EPA

representative presented information on GS and the GS regulatory framework at the National Tribal

Council on Environmental Management (NTCEM) Meeting in Billings, Montana, in June 2008. In

September 2008, during the proposed rule public comment period, EPA held two public hearings at

which tribes were represented. 

Throughout 2009 and 2010, more recent updates on the GS rulemaking were presented to tribal

representatives through regularly scheduled calls with the NTWC, State and Tribal Climate Change

Council (STC3), and the National Tribal Caucus. Representatives had the opportunity to ask EPA

managers questions related to the rulemaking elements and finalization schedule. EPA believes that

all of the actions undertaken were conducted to support an open and transparent rulemaking process

in accordance with Executive Order 13175 and Agency recommendations. 

EPA clarifies that following publication of the proposed rule in July 2008, the Fort Peck Assiniboine

and Sioux Tribes and the Navajo Nation received UIC Program primacy for the Class II program

under §1425 of the SDWA. EPA recognizes those tribes as co-regulators and remains committed to

ensuring that co-regulators are informed on and have an opportunity to engage with EPA on the GS

rule. To further ensure coordination and communication regarding the GS rule, EPA hosted a

conference call specifically for the Fort Peck Assiniboine and Sioux Tribes, as well as the Navajo

Nation, UIC Program Directors in February 2010. EPA representatives presented the history of the

rulemaking, the current schedule for finalization of the rule, and the statutory differences in applying

for primacy for the proposed Class VI program versus applying for primacy for the Class II program.

A summary of the call is included in the docket for the GS rulemaking.

The Agency is currently reviewing its tribal consultation policies and procedures in accordance with

the President's directive of November 5, 2009. When that review is final, there will be more

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clarification from EPA on tribal consultation during program implementation.

In response to the comment that "extra due diligence" should be required on Tribal lands, EPA

clarifies that the Class VI GS rule requirements are protective and apply to all USDWs. EPA clarifies

that States, Tribes, and Territories that seek primacy for the Class VI program may adopt

requirements that are more stringent than the minimum federal requirements in the GS rule.

Commenter Name: Emily Rochon Letter ID: 0129

Commenter Organization: Greenpeace International Comment ID: 23065

Comment: trapping mechanisms depends on the "migration rate of the CO2, which itself is 

highly dependent on the rock and fluid properties and geological characteristics 

of each site".[FN8 8 Bradshaw, J et al., 2007. CO2 storage capacity estimation: 

Issues and development of standards, International Journal of Greenhouse Gas 

Control 1, 2007, pp. 62-68.] This means that each storage site would need to 

undergo detailed characterizations both to determine suitability, as well as to 

assess the likelihood of leakage. As long as CO2 is present in geological 

formations, there is a risk of leakage -- it can migrate laterally or upwards to 

the surface. Undetected fractures in cap rocks or those created by injecting CO2 

at too high a pressure can provide another avenue for CO2 to escape. Improper 

design and construction of wells can also create opportunities for leakage.[FN9 

9 Massachusetts Institute of Technology (MIT), 2007. The Future of Coal, MIT, 

Boston 2007, .] The implications 

for climate mitigation as well as the other environmental and public health 

risks make leakage a serious concern. 

Response: EPA recognizes that injecting large volumes of CO2 for GS poses unique challenges that,

if not properly managed, could endanger drinking water sources and have other adverse impacts.

However, the final, tailored, Class VI requirements address the large volumes of CO2 injected, its

buoyancy, potential corrosivity in the presence of water, and potential impurities in the CO2 stream.

In addition, EPA expects the tailored permitting, siting, construction, operation, monitoring, and

post-injection site care requirements in the GS rule to prevent leakage from injection formations and

protect USDWs.

EPA believes that building upon the existing UIC requirements (e.g., Class I and Class II well

requirements) to develop the Class VI GS regulation provides a foundation for protecting USDWs

that is based on successful field experience and lessons learned about CO2 injection in other

applications. Class I well owners or operators have experience with site characterization, well

construction, and monitoring procedures and technologies that are applicable to Class VI wells. Class

II ER well operators have experience with managing the unique properties of CO2. To successfully

flood a hydrocarbon field with CO2 during an ER operation, the behavior of injected CO2 must be

well understood. For example, at the Weyburn CO2-ER project in Saskatchewan, the distribution,

phase, and interaction of injected fluids with native fluids were modeled and monitored to ensure

maximum recovery (of CO2) and target circulation in a thin subsurface formation (Wilson and

Monea, 2004). 

The Agency clarifies that, under SDWA, EPA does not have the authority to directly regulate air

emissions via CO2 leakage to the surface and comments related to such issues are outside the scope

of this rulemaking. However, the GS rule requires that CO2 injected for GS remain confined in the

injection zone. Leakage outside of the injection zone as defined in a Class VI permit, which may be

5
evidenced by leakage to the surface, would be a permit violation if a USDW is endangered.

Commenter Name: Emily Rochon Letter ID: 0129

Commenter Organization: Greenpeace International Comment ID: 23067

Comment: Either way, even a tiny rate of leakage could undermine any putative climate 

benefit of CCS. A leakage rate of just 1% on 600 Gt of stored carbon (2160 Gt 

CO2 or about 100 years’ worth of CO2 emissions from fossil fuels), could release 

as much as 6Gt of carbon (21.6 Gt CO2) per year back into the atmosphere. This 

is roughly equivalent to current total global CO2 emissions from fossil 

fuels.[FN14 14 Azar, C et al, 2006, Carbon Capture and Storage from Fossil Fuels 

and Biomass--Costs and Potential Role in Stabilizing the Atmosphere, Climactic 

Change vol. 74, 2006, pp. 47-79.] 

Response: EPA recognizes that injecting large volumes of CO2 for GS poses unique challenges that,

if not properly managed, could endanger drinking water sources and have other adverse impacts.

However, the final, tailored, Class VI requirements address the large volumes of CO2 injected, its

buoyancy, potential corrosivity in the presence of water, and potential impurities in the CO2 stream.

In addition, EPA expects the tailored permitting, siting, construction, operation, monitoring, and

post-injection site care requirements in the GS rule to prevent leakage from injection formations and

protect USDWs. The Agency clarifies that, under SDWA, EPA does not have the authority to

directly regulate air emissions via CO2 leakage to the surface. However, the GS rule requires that

CO2 injected for GS remain confined in the injection zone. Leakage outside of the injection zone as

defined in a Class VI permit, which may be evidenced by leakage to the surface, would be a permit

violation if a USDW is endangered.

EPA believes that building upon the existing UIC requirements (e.g., Class I and Class II well

requirements) to develop the Class VI GS regulation provides a foundation for protecting USDWs

based on success, field experience, and lessons learned about CO2 injection in other applications.

Class I well owners or operators have experience with site characterization, well construction, and

monitoring procedures and technologies that are applicable to Class VI wells. Class II ER well

operators have experience with managing the unique properties of CO2. To successfully flood a

hydrocarbon field with CO2 during an ER operation, the behavior of injected CO2 must be well

understood. At the Weyburn CO2-ER project in Saskatchewan, the distribution, phase, and

interaction of injected fluids with native fluids were modeled and monitored to ensure maximum

recovery (of CO2) and target circulation in a thin subsurface formation (Wilson and Monea, 2004).

Commenter Name: Dawn A. Thorne Letter ID:

0134

Commenter Organization: University of Utah Energy and Geoscience Institute on

behalf of the Southwest Regional Partnership

Comment

ID: 21653

Other EPA Comment Codes and Descriptions: 1250 1.1.1.4 Flexibility is needed (performancebased standards) 

Comment: 1.) The SWP would like to recommend a risk-based approach to the siting 

requirements, Area of Review (AoR), monitoring requirements, site-closure 

requirements, and the grandfather clause. The EPA notes in several places within 

the proposed rule that each GS site is unique with respect to physical and 

chemical properties. As such, the SWP recommends that the EPA adopt a 

risk/performance-based approach for each site. Reasoning for this recommendation 

as it relates to specific aspects of the proposed rule are outlined by relevant 

6
sections: 

Response: EPA has taken a regulatory approach that promotes USDW protection, incorporates

flexibility or permitting authority discretion when appropriate, seeks to limit burden on owners or

operators and permitting agencies, and provides a foundation for national consistency in permitting

of GS projects. Under the final rule, many of the permit requirements must be established through

site-specific plans (e.g., AoR and corrective action plan, testing and monitoring plan, etc.) developed

by the owner or operator and approved by the Director. Consequently EPA expects that owners or

operators will consult with the Director as they develop, implement, and update these plans.

Additionally, the Director has the discretion to approve alternatives to the requirements in some

cases. For example, the Director may in certain situations modify the length of the post-injection site

care period or approve an alternative post-injection site care timeframe as part of the permitting

process under §146.93, allow the use of alternate methods for mechanical integrity testing (if

approved by EPA) under §146.89, and waive the requirement that wells be designed to inject below

the lowermost USDW under §146.95.

Commenter Name: Theresa Pugh Letter ID: 0169

Commenter Organization: American Public Power Association Comment ID: 23380

Comment: 8. "Acts of God" such as CO2 or other substances released from seismic events 

where seismic events could not have been reasonably anticipated by experts 

should not have liability attached to the owner/operator or other parties if the 

parties acted in a responsible way and could not have reasonably anticipated a 

fault or seismic risk. 

Response: Under the final GS rule, once an owner 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. Furthermore, 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

certain circumstances. For example, an owner or operator may be held liable for regulatory

noncompliance even after site closure was approved if the Director relied on erroneous information

(e.g., erroneous modeling data) provided by the owner or operator when approving site closure. 

Separate from EPA’s authority to enforce regulatory compliance, an owner or operator may be

subject to a §1431 response order even after proper site closure 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 present an imminent and substantial endangerment to the health of

persons, and the appropriate State and local authorities have not acted to protect the health of such

persons. The action may include issuing administrative 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 operator may remain liable under tort and other remedies,

or under other federal statutes including, 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

7
third-party fund. See the final rule preamble for further discussion of EPA's final approach.

EPA adds that the GS rule contains several permit requirements (i.e., related to proper siting and

operation of the well) to address seismic risk that should mitigate the chances of such events.

Commenter Name: Quinlan J. Shea Letter ID: 0177

Commenter Organization: Edison Electric Institute Comment ID: 23565

Comment: ii. Appropriate characterization of potential risks. Similarly, any regulation 

should be based upon an accurate characterization of the potential risks posed 

by GS of CO2 and be tailored accordingly to address those potential risks, not 

only to ensure appropriate protection of underground sources of drinking water 

(USDW), but also to avoid unnecessary regulations that may hamper CCS projects 

from going forward or call into question the general safety of CO2 storage. 

Response: EPA agrees that risk is an important aspect of setting requirements for GS, and expects

that the tailored permitting, siting, construction, operation, monitoring, and post-injection site care

requirements in the GS rule will prevent leakage from injection formations and protect USDWs.

EPA does not believe that the GS regulation stigmatizes CO2 injection or that it mischaracterizes any

potential risks. EPA believes that injecting large volumes of CO2 for GS poses unique challenges

that, if not properly managed, could endanger drinking water sources and have other adverse

impacts. However, the final, tailored, Class VI requirements address the large volumes of CO2

injected, its buoyancy, potential corrosivity in the presence of water, and potential impurities in the

CO2 stream.

EPA believes that building upon the existing UIC requirements (e.g., Class I and Class II well

requirements) to develop the Class VI GS regulation provides a foundation for protecting USDWs

based on successful field experience, and lessons learned about CO2 injection in other applications.

Class I well owners or operators have experience with site characterization, well construction, and

monitoring procedures and technologies that are applicable to Class VI wells. Class II ER well

operators have experience with managing the unique properties of CO2. To successfully flood a

hydrocarbon field with CO2 during an ER operation, the behavior of injected CO2 must be well

understood. At the Weyburn CO2-ER project in Saskatchewan, the distribution, phase, and

interaction of injected fluids with native fluids were modeled and monitored to ensure maximum

recovery (of CO2) and target circulation in a thin subsurface formation (Wilson and Monea, 2004). 

EPA clarifies that the GS rule does not promote GS. The focus of the GS rule is to ensure that,

where GS is deployed, it is conducted in a manner that is protective of USDWs.

Commenter Name: Frederick R. Eames Letter ID: 0178

Commenter Organization: CCS Alliance Comment ID: 23809

Comment: C. VIEW OF GS RISKS AND HAZARDS 

The CCS Alliance concurs with the Agency's identification of the risks and 

hazards, to the extent these are understood and can be reasonably predicted, 

that likely are posed by underground injection. The U.S. oil and gas industry, 

as EPA has pointed out. has had decades of experience drilling through highly 

pressurized formations and injecting significant amounts of CO2 for purposes of 

enhanced recovery. The Agency rightly notes that CO2 has been successfully 

8
injected on much larger scale at several sites outside the United States. 

However, broad scale, large CCS injections pose new considerations, and CCS 

requires site-specific review. 

Response: EPA recognizes that industry has decades of experience with well construction and

operation. For example, the oil and gas industry has experience drilling and cementing wells in very

deep formations, in a variety of environments (e.g., high-pressure and low-pressure formations), and

for a variety of uses (e.g., injection, oil and gas production, monitoring). EPA believes that this

experience has led to the development of well materials and construction and operating procedures

that are applicable to Class VI wells.

EPA has taken a regulatory approach that promotes USDW protection, incorporates flexibility or the

discretion of the permitting authority when appropriate, seeks to limit burden on owners or operators

and permitting agencies, and provides a foundation for national consistency in permitting of GS

projects. For example, under the final rule, many of the permit requirements must be established

through site-specific plans (e.g., AoR and corrective action plan, testing and monitoring plan, etc.)

developed by the owner or operator and approved by the Director. Consequently EPA expects that

owners or operators will consult with the Director as they develop, implement, and update these

plans. Additionally, the Director has the discretion to approve alternatives to the requirements in

some cases. For example, the Director may in certain situations modify the length of the postinjection site care period under §146.93, allow the use of alternate methods for mechanical integrity

testing (if approved by EPA) under §146.89, and waive the requirement that wells be designed to

inject below the lowermost USDW under §146.95.

Commenter Name: Frederick R. Eames Letter ID: 0178

Commenter Organization: CCS Alliance Comment ID: 23817

Comment: D. INSUFFICIENT RECOGNITION OF LIKELIHOOD OF TECHNICAL

ADVANCES 

CO2 injection has been successfully utilized in the EOR process for decades. As 

such, even though CCS technology has not been widely deployed, the technology 

and industry knowledge are nevertheless presently sufficient to commence CCS 

activities. However, significant advances in technology and understanding are 

likely to be made in the future. The Proposed Rule fails to fully recognize or 

otherwise take into account that technology and the state of knowledge almost 

certainly will improve and continue to evolve. EPA, therefore, should better 

reflect that as technology and understanding improves, the risks associated with 

CCS will be reduced and the ability to mitigate remaining risks will be 

improved. 

Response: EPA recognizes that technologies will evolve and improve over time, and for these

reasons, the Agency is using an adaptive approach to regulate GS injection. 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 determine if

modifications to the requirements are appropriate or necessary.

Commenter Name: Frederick R. Eames Letter ID: 0178

Commenter Organization: CCS Alliance Comment ID: 23825

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Other EPA Comment Codes and Descriptions: 5400 2.9 Proposed Financial Responsibility and

Long-Term Care Requirements 

Comment: C. WHAT MARKET PARTICIPANTS SAY ABOUT RISK 

The framework for approaching the commercial risk in the development and 

deployment of coal-based projects with CCS is demonstrated by the following 

chart: 

For Development of Coal Based Charts with CCS Approach to Commercial Risk 

Framework [Please see Comment Pdf for Graphic, pg. 20] 

The CCS Alliance has evaluated technical, market, and policy risks associated 

with CCS deployment. On behalf of the CCS Alliance, Andrew Paterson of Econergy 

International interviewed dozens of market participants earlier this year, 

including project developers, utilities, technology vendors, risk managers, and 

financial providers to assess which risks were considered most likely to occur, 

and which, if they occurred, would be considered to have the greatest impact to 

the project. 

The results can be viewed graphically in a Cartesian coordinate analysis, as follows: 

Which Risks Matter? Which Will the Market Handle? Probability vs. Impact [Please 

see Comment Pdf for Graphic, pg. 21] 

The CCS Alliance analysis confirms that market participants concur with the view 

of the Intergovernmental Panel on Climate Change ("IPCC") that physical risks 

such as an operating accident or geologic sequestration site failure are low 

probability, high impact risks.[FN16] However, they view as higher probability the 

risk of policy failure. 

[FNl6] IPCC, Special Report on Carbon Dioxide Capture and Storage (2005). IPCC 

report states that there is only a one percent chance that CO2 would escape into 

the atmosphere in 100 years. 

In the CCS Alliance Risk Study, the highest rated risks for companies and 

investors considering investment in projects with CCS were focused on: 

- Higher capital costs for capture, compression, transport, injection and 

storage. 

- Uncertainty about the extent and timing of legislation and regulations for 

carbon emission constraints - in other words, a regulatory basis for pursuing 

CCS at all. 

- Unclear rules at the federal and state level for CCS injection (which the UIC 

Proposed Rule is seeking to address), creating some uncertainty about specific 

liabilities. 

- Lack of clarity about long-term ultimate liability for CO2 leakage after 

injection and storage for some commercially relevant time period (e.g., 10 to 30 

10
years). The Proposed Rule also seeks to address this issue. 

- Electricity (or fuel) prices - in the regional market or set by state utility 

commissions - which are too low to cover costs for CCS. 

Some mechanisms, as either subsidies or for risk transfer, exist to address 

these issues, but as depicted in the table below, they are concentrated in the 

area of either reducing capital costs and other CCS related expenses, or in 

dealing with electricity rates and adjusting revenues in some manner. Subsidies 

to cover higher costs include: federal grants for new facilities, tax credits, 

and state grants. Other mechanisms, such as a federal loan guarantee (Section 

1703 of EPAct 2005) or rate-basing a plant with CCS, remove substantial risk for 

capital recovery by providing alternative recovery or prevention of default. 

Mechanisms (vs. Capital Risks) -- [Please see Comment Pdf for Graphic, pg. 23] 

Because substantial exposure to some critical risks remains, additional 

mechanisms and regulatory clarification are needed to garner the scale of 

investment and capital recovery needed for commercial entities to deploy major 

facilities with CCS. As summarized in the table above, clarifying injection and 

transport rules clearly help, and can be coordinated with private insurance, 

trust funds or bonding, and state revolving funds. Additionally, some clarity on 

carbon emission regulations would eventually enhance the value of assets with 

CCS, and help attract capital for construction in the first place. Without 

capital investment, no CCS will be implemented because it is an inherently 

capital-intensive activity primarily involving facilities costing more than $1 

billion. 

But, there is no private instrument that can bear "indefinite, long-term 

liability" for leakage from CCS sites because commercial enterprise carries a 

finite horizon for investment. The EPA UIC program does wield a regulatory 

incentive, though, in negotiating or retaining some flexibility on the point 

(e.g., 10 years versus 50 years) at which liability for long-term leakage is 

assumed by the federal holder after injection. 

Results of the CCS Alliance Risk Study are summarized in the following chart. 

Note that in addition to the concern noted earlier about state CCS regulations 

and liability policies, one of the issues scoring the highest risk factor is 

that EPA regulations on underground injection of CO2 and liability fail to offer 

clarity for financing. Lack of clarity could prove to be a "showstopper." EPA 

should do its utmost to use its statutory authority to reduce this risk through 

this rulemaking. 

Far Deployment of Coal-based Projects with CCS Risk Study: Technical, Policy, 

Market Risks -- [Please see Comment Pdf for Graphic, pg. 24] 

This information is buttressed by the recently published findings of the 

Government Accountability Office ("GAO") which, in part, concludes that 

regulatory and legal uncertainties, including questions about liability 

concerning CO2 leakage and ownership, are primary barriers to CCS 

11
deployment.[FN17] 

[FN17] GOVERNMENT ACCOUNTABILITY OFFICE. GAO-OX-1080, CLIMATE CHANGE:

FEDERAL. 

ACTIONS WILL GREATLY AFFECT THE VIABILITY OF CARBON CAPTURE AND

STORAGE AS A KEY 

MITIGATION OPTION (2008). 

Response: EPA acknowledges the comment on market risk. This comment is outside the scope of

the UIC Program’s authority under the GS rulemaking. However, EPA clarifies that the final rule, at

§146.85, provides more detailed requirements on financial responsibility for risks associated with

injection.

Commenter Name: Scott Davis Letter ID: 0187

Commenter Organization: Arizona Public Service Company Comment ID: 25222

Comment: - The final rule must ensure protection of underground sources of drinking 

water, but not be overly burdensome or subject CO2 sequestration operations to 

unnecessarily more stringent regulation than is warranted based upon the risks. 

Response: The GS rule balances the need for site-specific decisions with the need for minimum

standards to ensure national consistency and USDW protection from endangerment, while also

ensuring that states have the data they need to make permitting decisions.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190

Commenter Organization: Carbon Sequestration Council Comment ID: 24317

Comment: Unfortunately, the proposed rule does not seem to reflect an adequate 

appreciation of the demonstrated strength and experience of the UIC program. 

Instead the proposal appears to be based on an exaggerated assessment of the 

risks and challenges involved in CO2 injection; as a result the proposed rule 

would impose requirements that are substantially more elaborate, burdensome and 

prescriptive than necessary to protect human health and the environment. Because 

such requirements would impose regulatory burdens that are disproportionate to 

any environmental benefits they might provide, they would do more to impede and 

deter GS than to facilitate its responsible use. 

Response: EPA acknowledges that industry has decades of experience with well construction and

operation. For example, the oil and gas industry has experience drilling and cementing wells in very

deep formations, in a variety of environments (e.g., high-pressure and low-pressure formations), and

for a variety of uses (e.g., injection, oil and gas production, monitoring). EPA believes that this

experience has led to the development of well materials and construction and operating procedures

that are applicable to Class VI wells.

EPA disagrees that the GS requirements are excessive or are based on an exaggerated assessment of

risks and challenges involved in CO2 injection. The Agency believes that injecting large volumes of

CO2 for GS poses unique challenges that, if not properly managed, could endanger drinking water

sources or have other adverse impacts. EPA believes that caution is warranted and has, as a result,

developed a new well class with requirements tailored to address the unique challenges posed by GS

and potential risks associated with long-term injection of CO2. These requirements include the

12
tailored AoR delineation process per §146.84, monitoring that is appropriate to GS projects per

§146.90, and extended post-injection site care per §146.93. 

As part of its adaptive rulemaking approach, The Agency plans, every six years, to collect and

review data on GS projects to determine whether the appropriate amount and types of information

and appropriate documentation are being collected, and to determine if modifications to the

requirements are appropriate or necessary.

EPA clarifies that the GS rule does not promote GS in specific settings, nor does it limit injection

activities to any specific type of formation, geographic region, or depth. The focus of the GS rule is

to ensure that, where GS is deployed, it is conducted in a manner that is protective of USDWs.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190

Commenter Organization: Carbon Sequestration Council Comment ID: 24326

Other EPA Comment Codes and Descriptions: 1200 1.1 General comments about the rulemaking 

Comment: E. EPA Should Ensure that the Regulations for GS Are Not More Stringent or 

Prescriptive than Necessary to Protect USDWs. 

EPA has recognized that it has two goals for the proposed rules for geologic 

storage of carbon dioxide: the protection of underground sources of drinking 

water [FN2/] and the promotion of the development of carbon capture and 

storage.[FN3/] EPA Administrator Stephen Johnson noted when he announced the 

proposal that ""[t]oday's proposal paves the way for technologies that would 

protect public health and help reduce the effects of climate change. With proper 

site selection and management, geologic sequestration could play a major role in 

reducing emissions of carbon dioxide into the atmosphere."[FN4/] We urge EPA to 

keep both of these goals in mind and to work to ensure that the regulatory 

regime that is ultimately adopted is designed to facilitate - not delay or 

discourage - the successful commercial-scale development of carbon capture and 

storage. The potential emissions benefits of commercial-scale carbon storage are 

too large and too important to ignore in the context of these regulations. 

[FN2/: 73 Fed. Reg 43492 (July 25, 2008) ("It proposes a new class of well and 

minimum technical criteria for the geologic site characterization, fluid 

movement, area of review (AoR) and corrective action, well construction, 

operation, mechanical integrity testing, monitoring, well plugging, postinjection site care, and site closure for the purposes of protecting underground 

sources of drinking water (USDWs).").] 

[FN3/: EPA Press Release, "EPA Lays Groundwork for Promising Technologies to 

Help Mitigate Climate Change" (July 15, 2008), 

http://www.epa.gov/safewater/uic/wells_sequestration.html ("EPA is proposing a 

rule that supports promising technologies to prevent industrial emissions of 

carbon dioxide. Secure, long-term underground storage of the greenhouse gas is 

one way scientific innovation could lessen the effects of climate change. . . . 

Carbon capture and storage is part of a portfolio of technologies available to 

reduce greenhouse gas emissions. EPA is coordinating with the Department of 

Energy on carbon sequestration research and development."); EPA Press Release, 

"EPA To Develop Regulations for Geologic Sequestration of Carbon Dioxide" 

(October 7, 2007) Id.] 

13
[FN4/: EPA Press Release (July 15, 2008).] 

Unfortunately, in its effort to ensure protection of USDWs, EPA has exhibited a 

zeal that could materially impede, overburden, and effectively stigmatize GS. 

The preamble to the proposed rule repeatedly overstates the risks posed by CO2 

injection while systematically understating the extent of knowledge and 

experience industry and regulators have gained through decades of practical 

experience with a wide range of injection well operations. As a result, the 

preamble presents an exhaustive review of every imaginable risk with respect to 

CO2 injection, but fails to disclose that many of these theoretical risks relate 

to implausible scenarios or concerns that - based on decades of robust 

operational and regulatory experience - are well understood and relatively easy 

to address. The scale of GS operations will certainly be larger than many 

previous CO2 injection operations, but it is not as though we do not have 

extensive experience with CO2 injection or that there is any fundamental lack of 

understanding about what happens when CO2 is injected underground. After all, 

there are already thousands of existing CO2 injection wells in operation that 

have injected hundreds of millions of tons of CO2 largely without incident. 

Rather than provide appropriate context for the development of Class VI 

regulations, however, the proposed rule gives the impression that GS is an 

adventure into entirely uncharted seas. The proposed rule - having started by 

framing the issues in this way - then employs a regulatory approach that errs on 

the side of including excessively prescriptive, overly-burdensome, and often 

redundant requirements. 

Response: EPA disagrees that the GS requirements are excessive. The Agency believes that injecting

large volumes of CO2 for GS poses unique challenges that, if not properly managed, could endanger

drinking water sources or have other adverse impacts. EPA believes that caution is warranted and

has, as a result, developed a new well class with requirements tailored to address the unique

challenges posed by GS and potential risks associated with long-term injection of CO2. These

requirements include the tailored AoR delineation process per §146.84, monitoring that is

appropriate to GS projects per §146.90, and extended post-injection site care per §146.93. 

EPA acknowledges that industry has decades of experience with well construction and operation.

For example, the oil and gas industry has experience drilling and cementing wells in very deep

formations, in a variety of environments (e.g., high-pressure and low-pressure formations), and for a

variety of uses (e.g., injection, oil and gas production, monitoring). EPA believes that this experience

has led to the development of well materials and construction and operating procedures that are

applicable to Class VI wells.

As part of its adaptive rulemaking approach, 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 determine if modifications to the requirements

are appropriate or necessary.

EPA clarifies that the GS rule does not promote GS in specific settings, nor does it limit injection

activities to any specific type of formation, geographic region, or depth. The focus of the GS rule is

to ensure that, where GS is deployed, it is conducted in a manner that is protective of USDWs.

14
Commenter Name: Robert F. Van Voorhees Letter ID: 0190

Commenter Organization: Carbon Sequestration Council Comment ID: 24327

Other EPA Comment Codes and Descriptions: 1200 1.1 General comments about the rulemaking 

Comment: 1. The Proposed Class VI Requirements Are Far More Burdensome than Necessary to 

Protect USDWs. 

As the preamble acknowledges, the actual human health and ecological risks 

associated with GS are relatively remote and can be addressed effectively 

through measures implemented to protect USDWs. 73 Fed. Reg. at 43497-98. 

Unfortunately, having started with an exaggerated sense of the risks involved 

and an inadequate recognition of the value of existing regulatory and 

operational experience relevant to CO2 injection, the proposed rule seems to 

proceed from the premise that the most strict UIC regulations in existence - 

those for hazardous waste injection - should serve as the starting point for the 

development of the Class VI regulations. This is not a logical or appropriate 

regulatory approach, because CO2 - which is found in abundance both in ambient 

air and in the subsurface - is nothing like hazardous waste and plainly does not 

warrant the same level of regulation. In fact, the principal issues with respect 

to CO2 injection for GS relate primarily to the mobility of CO2 and the sheer 

magnitude of the injection operations involved; these are not issues that the 

requirements for hazardous waste injection are particularly well suited to 

address. 

The more logical starting point for development of the Class VI regulations is 

the Class II regulations. As the proposed rule recognizes, CO2 injection 

operations have been conducted pursuant to the Class II regulations for many 

years, and experience with thousands of wells injecting hundreds of millions of 

tons of CO2 demonstrates that the Class II regulations - as applied to CO2 

injection - are adequate to protect USDWs. This is certainly true with respect 

to the basic construction, operating, monitoring, and mechanical integrity 

testing requirements for injection wells; after all, what "works" in terms of 

the construction and operation of a CO2 injection well does not depend on the 

purpose for which CO2 is being injected. Accordingly, there is no reason why the 

Class VI requirements addressing issues such as well construction and mechanical 

integrity testing should be any different than the Class II requirements. 

Unfortunately, the proposed Class VI requirements are far more stringent than 

the Class II requirements, a fact that creates a need to "grandfather" Class II 

CO2 injection wells that remain in service for GS purposes after EOR/EGR 

operations cease. Rather than resembling the Class II requirements, the proposed 

Class VI requirements are as stringent as those for hazardous waste injection in 

most respects. Indeed, many of the construction, mechanical integrity, 

monitoring and financial assurance requirements proposed for Class VI wells are 

even more comprehensive and more strict than those for hazardous waste injection 

wells. While some of these more burdensome requirements are legitimately related 

to concerns about the mobility of CO2 or the anticipated scale of GS operations, 

many - as discussed in Part III of these comments - are not. 

Response: EPA disagrees that the GS requirements are excessive or are based on exaggerated risks;

the Agency believes that injecting large volumes of CO2 for GS poses unique challenges that, if not

15
properly managed, could endanger drinking water sources or have other adverse impacts. EPA

believes that caution is warranted and has, as a result, developed a new well class with requirements

tailored to address the unique challenges posed by GS and potential risks associated with long-term

injection of CO2. These requirements include the tailored AoR delineation process per §146.84,

monitoring that is appropriate to GS projects per §146.90, and extended post-injection site care per

§146.93. 

EPA believes that the nature of CO2 injection for long-term storage is different from Class II CO2

injection for ER, and that tailored requirements for Class VI wells are appropriate and necessary to

protect USDWs from endangerment. For this reason, the Agency tailored UIC requirements for Class

VI wells that address the general risks deep injection may pose to USDWs and specifically address

the unique nature of CO2 GS (i.e., very large volumes, very long time-periods, and reservoir

pressure conditions).

Commenter Name: Brad Castleberry Letter ID: 0203

Commenter Organization: Water Environment Association of Texas (WEAT)Comment ID: 22178

Comment: These comments are submitted on behalf of the Water Environment Association of 

Texas ("WEAT"). Specifically, these comments are submitted in response to the 

above-referenced rulemaking in an effort to urge caution and careful 

consideration before adoption of the proposed regulations. We urge this caution 

in the interest of protecting drinking water sources and groundwater quality. 

WEAT is a non-profit technical trade organization comprised of a number of 

utilities, industries, and individuals in the State of Texas. WEAT's members 

strive to promote sound science, education, and environmental stewardship. There 

are a number of activities in the proposed regulations that could impact 

groundwater quality as well as public drinking water sources. Careful 

Response: EPA believes that injecting large volumes of CO2 for GS poses unique challenges that, if

not properly managed, could endanger drinking water sources or have other adverse impacts. EPA

believes that caution is warranted and has, as a result, developed a new well class with requirements

tailored to address the unique challenges posed by GS and potential risks associated long-term

injection of CO2.

Commenter Name: Diane VanDe Hei Letter ID: 0213

Commenter Organization: Association of Metropolitan Water Agencies

(AMWA)

Comment ID:

22920

Comment: sequestration sites. EPA’s rule and any financial incentives put forth by other 

branches of government must avoid the manifestation of long-term risks from 

adverse site selection or design due to moral hazard. Moral hazard is the 

possibility that a party insulated from risk may behave differently from the way 

it would behave if it were fully exposed to the risk. A potential owner/operator 

of a CCS site that has liability immunity for example, may have a tendency to 

act less carefully than it otherwise would, leaving another party to bear some 

responsibility for the consequences of those actions. 

Response: EPA clarifies that the GS rule does not insulate owners or operators from risk. The GS

rule requires that owners or operators demonstrate and maintain financial responsibility for corrective

16
action on wells in the AoR, injection well plugging, post-injection site care and site closure, and

emergency and remedial response at GS sites, as specified in §146.85. In the event of contamination

or other adverse event that endangers a USDW during the life of the project, the financial

instrument(s), such as insurance, bonds, etc., rather than public monies, would cover necessary

response actions to remediate the USDW. EPA clarifies that it is the owner or operator of the well

who will be required to demonstrate financial responsibility, not the generator of the CO2, consistent

with EPA’s authority under SDWA. Furthermore, EPA notes that tort and other remedies will

continue to be available after site closure. Other Federal environmental statutes, e.g. Clean Air Act,

42 U.S.C. §§7401-7671; CERCLA, 42 U.S.C. §9601-9675; and RCRA, 42 U.S.C. §6901-6992,

potentially apply as well to the risks created by the long-term storage of CO2.

EPA adds that Class VI well owners and operators must site, construct, operate, monitor, and close

their wells in a manner that protects USDWs, and Class VI permits will set forth rigorous technical

requirements to ensure careful planning, operation, and closure of GS projects. Failure to meet these

requirements would be considered a violation of the permit and would be subject to applicable civil,

criminal, or administrative penalties under SDWA §1423. The comment regarding financial

incentives put forward by other federal agencies is outside the scope of this rulemaking.

Commenter Name: Diane VanDe Hei Letter ID: 0213

Commenter Organization: Association of Metropolitan Water Agencies

(AMWA)

Comment ID:

22934

Other EPA Comment Codes and Descriptions: 1510 1.2.2.3 Need for additional study 

Comment: o Before any CO2 geosequestration projects are fully deployed, more research is 

needed to allow EPA and/or DOE to develop a risk assessment for the technology, 

taking into account risks to USDWs. 

o The effectiveness of available risk management methods must be demonstrated. 

This is also recommended by the IPCC in its Summary for Policymakers. 

Response: As described above, EPA agrees that continued research in all GS associated fields will

be integral to development of GS technology. EPA is using an adaptive approach to regulating GS

under the UIC Program. Even after finalization of the GS regulation, the Agency plans to collect and

review data every six years on GS projects to determine whether the appropriate amount and types of

information and appropriate documentation are being collected, and to determine if modifications to

the requirements are appropriate or necessary.

EPA believes that the GS rule requirements are tailored to address the unique challenges posed by

GS and the potential risks associated with the long-term injection of CO2. These requirements

include the tailored AoR delineation process per §146.84, monitoring that is appropriate to GS

projects per §146.90, and extended post-injection site care per §146.93.

Commenter Name: Kristin Henry Letter ID: 0242

Commenter Organization: Sierra Environmental Law Program, Sierra Club Comment ID: 23318

Other EPA Comment Codes and Descriptions: 5400 2.9 Proposed Financial Responsibility and

Long-Term Care Requirements 

Comment: II. The EPA should create a liability scheme for the CCS program. 

There is a long list of potential risks associated with CO2 injection and 

17
sequestration. Most prominently for purposes of the proposed rule, injected CO2 

could cause groundwater contamination by leaking into potable aquifers or 

causing saline intrusion.[FN15] 

When CO2 is injected underground it will naturally migrate through the pore 

space. This natural migration could lead CO2 to travel upward throughout the 

reservoir into undetected or abandoned portions of the reservoir, or into 

portions of the reservoir not owned by the operator, resulting in potential 

liability for subsurface trespass.[FN16] 

Surface leakage out of the storage formation through faults and fractures may 

lead to other types of potential liability. It could endanger human health by 

leaking into indoor air and basements.[FN17] Although unlikely, a large surface 

release could pose health risks to humans, in the form of asphyxiation or the 

other effects from prolonged exposure to high concentrations of CO2.[FN18] Such 

other effects include difficulty breathing, loss of consciousness, and death. In 

addition, CO2 seepage could harm flora and fauna, and could potentially ruin 

nearby ecosystems and agriculture.[FN19] CO2 also could make sources of oil and gas 

unattainable, create pressure changes causing ground heave, and even trigger 

seismic events.[FN20] 

[FN15: Wilson et al., World Resources Institute Issue Brief, Liability and 

Financial Responsibility Frameworks for Carbon Capture and Sequestration at 3 

(Dec. 2007).] 

[FN16: Id. at 2.] 

[FN17: Id. at 3; see also IPCC CCS 5.7.7.] 

[FN18: Id. at 3.] 

[FN19: Id.] 

[FN20: Id.] 

Given the potential impacts to the environment, public health, and private 

property, the proposed rule’s approach of ignoring liability issues is improper. 

Large-scale CO2 sequestration should not begin until liability is definitively 

determined. EPA should thus revise the regulations and adopt a liability scheme 

that encompasses the "polluters pay" principle. 

The polluters pay principle derives from the fundamental, fair, and logical 

proposition that the party responsible for producing pollution should also be 

responsible for paying for any damage to the natural environment. Utilizing the 

polluters pay principle provides an incentive for owners, operators and CO2 

generators to use precaution in their operations. Potentially liable parties 

have an incentive to avoid risk and damage, which often manifests in parties 

undertaking additional investment in research and development to improve 

knowledge and technologies. 

The EPA should revise the regulations to impose joint and several liability on 

Class VI well owners and operators and the generator of the injected CO2 for 

contamination of underground sources of drinking water, property damage, 

personal injury or any other injury arising from the injection. In addition, 

the EPA should require that an operator has complete liability coverage from a 

18
private insurance company before commencing injection. "Pollution legal 

liability insurance" coverage protects the insured party from claims arising 

from unknown conditions or problems, such as property damage or public health 

impacts from CO2 leakage. 

Response: EPA believes that the GS rule requirements appropriately address the risk associated with

long-term storage of CO2. EPA agrees that caution is warranted and has, as a result, developed a

new well class with requirements tailored to address the unique challenges posed by GS and

potential risks associated long-term injection of CO2. These requirements include the tailored AoR

delineation process per §146.84, monitoring that is appropriate to GS projects per §146.90, and

extended post-injection site care per §146.93. Failure to meet these requirements would be

considered a violation of the permit and would be subject to applicable civil, criminal, or

administrative penalties under SDWA §1423.

EPA agrees that owners or operators of Class VI wells must ensure that resources are available to

prevent endangerment of USDWs from improper plugging, remediation, and management of wells.

For this reason, the GS rule requires that owners or operators demonstrate and maintain financial

responsibility for corrective action on wells in the AoR, injection well plugging, post-injection site

care and site closure, and emergency and remedial response at GS sites as specified in §146.85. EPA

clarifies that this demonstration must be made before injection can begin. In the event of

contamination or other adverse event that endangers a USDW during the life of the project, the

financial instrument(s), such as insurance, bonds, etc., rather than public monies, would cover

necessary response actions to remediate the USDW. EPA clarifies that it is the owner or operator of

the well who will be required to demonstrate financial responsibility, not the generator of the CO2,

consistent with EPA’s authority under SDWA. Furthermore, EPA notes that tort and other remedies

will continue to be available after site closure. Other Federal environmental statutes, e.g. Clean Air

Act, 42 U.S.C. §§7401-7671; CERCLA, 42 U.S.C. §9601-9675; and RCRA, 42 U.S.C. §6901-6992,

potentially apply as well to the risks created by the long-term storage of CO2.

EPA disagrees that the GS rule ignores liability issues but is working within the confines of its

statutory authority under the SDWA. EPA notes that comments regarding liability for contamination

of the environment outside of endangerment of USDWs (e.g., CO2 leakage into basements, harm to

flora and fauna, etc.) are outside of EPA’s authority under the SDWA and are therefore outside the

scope of this rulemaking.

Commenter Name: Mary Munn Letter ID: 0273

Commenter Organization: Fond du Lac Reservation Comment ID: 24084

Comment: Even as this proposed rule is being considered, the EPA is soliciting 

"applications to conduct research to support the development of sound risk 

management strategies for the underground injection of anthropogenic carbon 

dioxide (CO2)" (accessed online October 6 2008 

http://es.epa.gov/ncer/rfa/2008/2008_star_gsc02.html). The technology for GS of 

CO2 is not yet available or known to be safe. 

Response: EPA believes that sufficient data and experience currently exist to develop regulations for

Class VI wells. The GS rulemaking builds upon decades of knowledge about safe injection practices

regulated by the UIC Program. While developing the GS regulation, EPA has evaluated relevant GS

research, including projects conducted by the seven Regional Carbon Sequestration Partnerships

(RCSPs) funded by DOE and coordinated through the National Energy Technology Laboratory

19
(NETL), and several international projects. 

Several large-scale pilot projects are currently underway worldwide to test the appropriateness and

efficacy of various technologies to characterize sites, ensure proper well construction and operation,

and monitor injection activities and CO2 plume and pressure front distribution. EPA is tracking

international GS efforts and is aware of four commercial-scale projects that are currently in

operation: the Sleipner Project in the Norwegian North Sea (operating since 1996); the Weyburn ER

project in Saskatchewan, Canada (since 2000); the In Salah Gas Project in Algeria (since 2004); and

Snohvit, also in offshore Norway in the Barents Sea (since 2008). Other projects EPA is tracking

include Gorgon and Otway (in Australia); Ketzin (in Germany); Lacq (in France); and CarbFix (in

Iceland). 

Activities at Weyburn, In Salah, Sleipner, and the RCSP sites have been supervised by leading

industry scientists and practitioners. Activities at Weyburn have also been peer-reviewed by the

IEA-GHG Programme, an international collaborative research program that includes the European

Commission and OPEC as members. EPA has considered the results of these pilot projects and data

from RCSPs in developing the GS rule. 

As the commenter notes, EPA continues to research GS and associated technologies. EPA will use

any knowledge gained through this research to inform its adaptive rulemaking approach. 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 determine if modifications to the requirements are appropriate or necessary.

Commenter Name: Becki Clayborn Letter ID: 0509

Commenter Organization: Sierra Club Comment ID: 21203

Comment: So we respectfully urge the U.S. EPA to not look at this in a piecemeal way, but 

to really look at it in a holistic way. How are we going to keep this out of the 

atmosphere? How are we going to make sure that companies, the applicants that 

are getting into this project know that they have to keep it in the ground? How 

do we mitigate if it doesn't stay in the ground? 

Obviously, we brought up some of our concerns on a local level for the Sierra 

Club, what happens in the local areas if it does contaminate wells, if it does 

leak out of an old well that's not been properly capped? 

Response: EPA acknowledges that GS falls within the broader context of CCS and acknowledges

that regulatory clarity is essential for enabling GS to move forward in a manner that protects human

health and the environment. The Agency is working to identify areas related to GS that could be

addressed under other statutes to ensure that GS is conducted in a manner that is protective of human

health and the environment. Additionally, the Agency is and will continue to coordinate internally

and with other Federal agencies involved in GS and CCS, including the Minerals Management

Service, Bureau of Land Management, and the United States Geological Survey, to promote

consistency in existing and future GS initiatives.

EPA acknowledges that there are potential risks associated with GS including the potential that CO2

injection for GS could cause fluid movement, which can endanger USDWs. The purpose of the Class

VI requirements is to minimize and mitigate potential/identified risks through proper site

characterization, well construction, operation, monitoring, post-injection site care, and site closure.

20
Suitable GS sites must have confining zones that are free of transmissive faults or fractures and are

of sufficient areal extent and integrity to contain the injected CO2 stream and displaced formation

fluids. The formations must allow injection at proposed maximum pressures and volumes without

initiating or propagating fractures in the confining zone(s), as required at §146.83(a)(2). 

The GS rule requires owners or operators to submit extensive data about a proposed GS site to

identify (and eliminate) sites with a potential for unacceptable fluid movement. Information to be

submitted and evaluated at §146.82 includes data on the porosity, permeability, and other

information regarding the suitability of the confining zone; the location of any known or suspected

faults; subsurface geochemistry; and the location of, depth of, and other information regarding any

perforations that may extend into the confining zone. EPA believes that this information, in

conjunction with AoR modeling required at §146.84, will help identify the potential for brine

migration as a result of pressure displacement. Based on this information, the Director and the owner

or operator can identify ways to mitigate this risk prior to injection, or, if necessary, the Director can

deny the permit application. During injection operations, operators must extensively monitor ground

water quality and pressure changes to provide early detection of any unacceptable movement of

fluids or impurities in the subsurface as specified in §146.90. 

EPA clarifies that owners or operators must also develop and follow an emergency and remedial

response plan to address movement of the injection or formation fluids that may cause an

endangerment to a USDW during construction, operation, and post-injection site care periods as

specified in §146.94 and maintain financial responsibility to address contamination as specified in

§146.85. 

EPA adds that mitigation of CO2 emissions is outside the scope of the GS rulemaking.

Commenter Name: Leslie Glustrome Letter ID: 0527

Comment ID: 21408

Comment: Secondly, what I would like to do is remind everyone that carbon dioxide is what 

you might call a rock of a molecule. Once you have carbon and oxidize it fully 

at four bonds oxygen, you have created the molecule that is the foundation of 

all life on this planet. It is, in a sense, by nature's design, a molecule that 

does not go away. Climate scientists tell us that we will be dealing with the 

climate science, climate change and warming of the planet for thousands of years 

after we stabilize CO2 levels in the atmosphere. This is not something to play 

around with. This is not something to take lightly. This is not something to 

assume that somehow the guys in the suits have it figured out because we had a 

very clear demonstration that that is not the case very recently. 

Carbon dioxide by nature is a gas. It is as the waterworks association person 

has reminded us, corrosive. It is an acid forming gas, tenth grade chemistry 

reminds us of that. Carbon dioxide and water forms carbonic acid. When you are 

creating large amounts of carbon dioxide, you will be getting large amounts of 

carbonic acid and to state it very scientifically, when you make large amounts 

of carbonic acid, we can expect it to acidify the crap out of everything that it 

comes into contact with. That means that you change the carbonate cycle and you 

start to liberate iron and manganese and arsenic and all, many other metals, so 

this is not something to somehow think that -- this is just a high level 

injection experiment. We are talking about massive volumes of something that is 

21
very different than something that we have. 

Response: EPA acknowledges that there are potential risks associated with GS, including the

potential that CO2 injection for GS may result in leaching of subsurface materials that could

mobilize contaminants or compromise pore space, and therefore injectivity. The purpose of the Class

VI requirements is to minimize and mitigate potential/identified risks through proper site

characterization, well construction, operation, monitoring, post-injection site care, and site closure.

To ensure USDW protection and mitigate risks, the GS regulation requires the owner or operator of

a Class VI well to submit data about the site (during the site characterization process), including

information on the porosity, permeability, mineralogy, and geochemistry of the injection and

confining zones, along with information on the compatibility of the CO2 stream with fluids in the

injection zone and minerals in both the injection and confining zones as specified in §146.82. This

data will help identify potential geochemical reactions that may occur between the injected CO2 and

the host geologic formation. Identification of potential reactions prior to injection would address

concerns that formation of carbonic acid could dissolve potential limestone creating karst features. 

During injection operations, operators must extensively monitor ground water quality to provide

early detection of any unacceptable movement of fluids or impurities in the subsurface as specified

in §146.90. Operators must develop and follow an emergency and remedial response plan to address

movement of the injection or formation fluids that may cause an endangerment to a USDW during

construction, operation, and post-injection site care periods, including contamination as specified in

§146.94, and provide financial responsibility to address contamination as specified in §146.85. 

In response to comments regarding the mobilization of constituents, EPA is funding research at the

Lawrence Berkeley National Laboratory (LBNL) on potential USDW impacts associated with

mobilization of trace elements. In the August 31, 2009, NODA and Request for Comment (74 FR

44802), EPA published the results of the study, which evaluated the potential for GS to cause

changes in ground water quality as a result of CO2 leakage and subsequent mobilization of trace

elements such as arsenic, barium, cadmium, mercury, lead, antimony, selenium, zinc, and uranium

(Birkholzer et al., 2008a). In the study, LBNL estimated the amount of trace elements from native

mineral species that could potentially be mobilized by the intrusion of CO2 and the potential ground

water concentrations that could result, to determine the potential for drinking water standards to be

exceeded. Results from this model simulation suggest that if CO2 were to leak into a shallow

aquifer, the potential for mobilization of lead and arsenic could be enhanced, causing increases in the

concentration of these trace elements in ground water. The Agency continues to monitor research

related to CO2 confinement, potential for CO2 leakage, and mobilization of trace elements. EPA

adds that the GS rule focuses on protection of USDWs from endangerment; impacts on the carbon

cycle are outside of the scope of the UIC rulemaking.

Commenter Name: Barbara Massoner Letter ID: 0531

Commenter Organization: Legacy Economy Comment ID: 21443

Comment: Coal and gas have powered our economy for the past century. This however is a 

new century and it requires new regulations and those regulations must include 

externalities which we have not included in the past. Only by including 

externalities can regulations provide a level playing field for all involved. 

And externalities in this case are not CO2's, but they also are as Cynthia Lane 

pointed out with AWWA, a test that includes CCWs, that is coal combustion 

wastes. And those externalities are very important as they would include 

chemicals such as mercury, lead, cadmium, selenium and a list of other toxins. 

22
Response: EPA clarifies that the GS rule focuses on protection of USDWs from endangerment;

therefore coal combustion wastes and other externalities the commenter mentions are outside of the

scope of the UIC rulemaking.

Comment Code: 1610 1.3.1 Risks to USDWs 

Individual Comments

Commenter Name: Leslie Savage Letter ID: 0122

Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24740

Comment: In nearly every instance where EPA indicates that additional safe-guards are 

necessary, it cites as the reason the chemical characteristics of the CO2 stream 

to be injected and the interaction of the CO2 stream with formation waters and 

strata, the buoyant nature of CO2, and the pressure increases caused by 

injection of very large volumes of CO2. However, buoyancy and chemical 

characteristics of CO2 have been successfully addressed in enhanced recovery 

injection projects using CO2 under the Class II UIC program. Pressure increases 

can be handled by selecting formations that have been depleted and have reduced 

pressures. In those formations for which the pressure has not been reduced as a 

result of production or other activity, the issue of the pressure increase 

resulting from injection of large amounts of CO2 can be addressed by limiting 

the surface injection pressure and adequate monitoring. 

Response: As stated above, EPA acknowledges that industry has decades of experience in

addressing many of the issues present in GS operations. However, EPA reasonably believes that

injecting large volumes of CO2 for GS poses unique challenges that, if not properly managed, could

endanger drinking water sources or have other adverse impacts. EPA believes that caution is

warranted and has, as a result, developed a new well class with requirements tailored to address the

unique challenges posed by GS and potential risks associated long-term injection of CO2. These

requirements include the tailored AoR delineation process per §146.84, monitoring that is

appropriate to GS projects per §146.90, and extended post-injection site care per §146.93.

Commenter Name: John Hanger Letter ID: 0130

Commenter Organization: Pennsylvania Dept. of Env. Protection Comment ID: 21500

Comment: Both DEP and DCNR are interested in the greenhouse gas reduction opportunities 

that responsible carbon capture and storage may present. However, these 

opportunities should be approached with a clear understanding of the potential 

risks and must only be pursued with the best tools-in-hand to mitigate such 

risks. The DEP and DCNR believe that EPA’s proposed rule represents a solid 

effort to categorize and prevent some of the potential risks to underground 

sources of drinking water (USDW) that are associated with carbon capture and 

storage. The DEP and DCNR appreciate the opportunity to comment on this 

proposed rule. 

Response: EPA acknowledges the commenter’s support and agrees that injecting large volumes of

CO2 for GS poses unique challenges that, if not properly managed, could endanger drinking water

23
sources and have other adverse impacts. However, the final, tailored, Class VI requirements address

the large volumes of CO2 injected, its buoyancy, potential corrosivity in the presence of water, and

potential impurities in the CO2 stream. In addition, EPA expects the tailored permitting, siting,

construction, operation, monitoring, and post-injection site care requirements in the GS rule to

prevent leakage from injection formations and protect USDWs.

Commenter Name: Bonnie Lovelace Letter ID: 0152

Commenter Organization: Montana Department of Environmental Quality

(MDEQ)

Comment ID:

22106

Other EPA Comment Codes and Descriptions: 3200 2.2 Proposed Area of Review and Corrective

Action Requirements (40 CFR 146.84) 

Comment: 6. EPA appears to be limiting its protection of waters to only those 

used/potentially used for public water supplies. It should be made clear that 

private use or fewer numbers of uses than those qualifying as public water 

supplies within the aquifer are also to be protected. The requirements to 

identify all perforations into the USDW should also require identification of 

all perforations and water uses (springs) within the Area of Review. These sites, 

then, should be included in all analyses and modeling. 

Response: EPA disagrees that only aquifers currently providing public water supplies will be

protected by the GS regulation. The UIC regulations, promulgated under Section 1421(d)(2) of the

SDWA, including the Class VI regulations, require that injection operations protect against

endangerment for drinking water sources if such injection may result in 1) non-compliance with

national primary drinking water regulations or 2) may otherwise adversely affect the health of

persons in USDWs which supply or can reasonably be expected to supply any public water system.

The definition of a USDW is based on the total dissolved solids content, not the users of the supply

(i.e., public versus private). The applicable portion of the definition of USDW reads: "...an aquifer or

any portion of an aquifer that contains fewer than 10,000 mg/l total dissolved solids and is not an

exempted aquifer," as defined at 144.3. Aquifers supplying private wells that may reasonably be

expected to supply any public water system and meeting these criteria are considered USDWs that

warrant protection from endangerment by GS operations.

Commenter Name: Theresa Pugh Letter ID: 0169

Commenter Organization: American Public Power Association Comment ID: 23382

Other EPA Comment Codes and Descriptions: 1330 1.1.3.1 Support use of GS in general 

Comment: Geologic sequestration into all geologic formations must be considered by 

electric utilities in their long-term plans for future fossil-fuel electricity 

generation while also weighing the need to protect public drinking water 

supplies. Protection of drinking water supplies, for some communities, may mean 

that inadequate surface water supplies may require that the city (or private 

utility) may require usage of groundwater in future years which may not appear 

to be "drinkable" under today’s presumed costs and technological (pump and treat 

or desalination) limitations. Our colleagues in the municipal drinking water 

operations remind us that Americans are currently drinking water which, in many 

locations, was undrinkable only 5-10 years ago. While most American cities in 

the east provide drinking water made up largely of surface water, more than 90% 

of all drinking water systems (private and public) use some amount of 

groundwater to make up for shortages. Acknowledging this does not mean that 

24
geosequestration should not be allowed. It simply requires common sense decision 

making at the local and regional level by power plants and the state directors 

as to the best placement of geosequestration plants or off-site injection 

formations. 

Response: The Agency acknowledges commenter concerns about water resources and future water

resource availability. The primary goal of the UIC Program under the SDWA is to protect USDWs

from endangerment in order to ensure a reliable supply of drinking water for the American public.

The GS rule, as part of the UIC program regulations, continues the program’s mandate and mission

of ensuring the protection of USDWs. EPA expects the tailored permitting, siting, construction,

operation, monitoring, and post-injection site care requirements in the GS rule to prevent leakage

from injection formations and protect USDWs.

Commenter Name: Theresa Pugh Letter ID: 0169

Commenter Organization: American Public Power Association Comment ID: 23385

Other EPA Comment Codes and Descriptions: 1850 1.4.2 CO2 GS Field Research 

Comment: APPA strongly supports private and DOE/NETL geologic sequestration demonstration 

projects to tell us more about the technical viability of the separation 

technology and the scaling up of geologic sequestration. Further, these projects 

must also support any geosequestration or GS research projects that would better 

enable us to know more about the USDWs and protection of that critical resource. 

The "location is everything" is a critical presumption for the reader of our 

comments on the proposed UIC rule. In some locations geosequestration will be an 

optimal technology that makes sense for those future coal plants. In other 

locations, the type of rock, the lack of trapping mechanisms or proximity to 

underground faults, seismic risks or other 

Response: As described above, EPA is tracking continuing research on CCS conducted by other

federal agencies.

EPA agrees that further research will assist with the transition to commercial-scale GS. As part of its

adaptive rulemaking approach, 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 determine if modifications to the requirements are

appropriate or necessary.

While developing the GS regulation, EPA evaluated relevant GS research, including projects

conducted by the seven Regional Carbon Sequestration Partnerships funded by DOE and coordinated

through the National Energy Technology Laboratory (NETL), and several international projects.

EPA published a Notice of Data Availability and Request for Comment (NODA) on August 31,

2009 (74 FR 44802), in which the Agency presented the results of research at three DOE partnership

sites (in Escatawpa, Mississippi; the Aneth Field in Paradox Basin, southeast Utah; and the Pump

Canyon Site, New Mexico). 

In the NODA and Request for Comment, EPA described two modeling studies by the Lawrence

Berkeley National Laboratory on the potential effects of CO2 injection on ground water and

surrounding formations to determine the potential for impacts on USDWs and human health in the

event that a GS project is not properly sited, operated, or managed. In one study, LBNL used a

comprehensive computational model to evaluate the potential impact of CO2 leaking from deep GS

25
sites on the concentrations of trace elements in USDWs (Birkholzer et al., 2008a). In the other,

LBNL studied a hypothetical, future scenario of GS in a sedimentary basin to demonstrate the

potential for basin-scale hydrologic impacts of CO2 storage (Birkholzer et al., 2008b). EPA has also

examined potential methods for conducting treatment of water affected by a CO2 leak; this study is

presented in the final rulemaking docket. 

EPA continues to fund research in this area. In December 2009, EPA awarded a STAR grant to

Clemson University to investigate the potential for GS to affect USDWs. The research will involve

laboratory experiments and modeling simulations to investigate the fate of dissolved CO2 in

underground geologic formations and to determine possible risks associated with the dissolution of

CO2 in underground aquifers. Other projects funded by the STAR grants include: the University of

Illinois-Urbana will conduct research related to reducing hydrologic and geochemical uncertainties

associated with CO2 sequestration in deep, saline reservoirs; the University of Texas at Austin will

assess appropriate monitoring approaches at geologic sequestration sites; the University of Utah will

integrate design, monitoring, and modeling of GS to assist in developing a practical methodology for

characterizing risks to USDWs; Columbia University will conduct laboratory experiments on shallow

aquifer systems to improve our understanding of geochemical and microbiological reactions under

low ph/high CO2 stress; and Princeton University will develop a set of computational tools to model

CO2 and brine movement associated with GS.

Commenter Name: Theresa Pugh Letter ID: 0169

Commenter Organization: American Public Power Association Comment ID: 23387

Other EPA Comment Codes and Descriptions: 1330 1.1.3.1 Support use of GS in general; 1800

1.4 Scientific Background/Informing the Proposal 

Comment: Our comments here should not deny the viability of CCS in some subsurface 

locations nor be read as APPA’s view that geologic sequestration works in all 

geologic locations or for all power plants. There is a great deal that we do not 

yet know about the wide variety of geologic formations to know that there are no 

risks to USDWs or that we could identify specifically what those risks might be. 

APPA hopes that on-going private and public research in the United States, 

Canada, Australia, and Europe will affirm that there are no risks to drinking 

water supplies or that the risks are so truly negligible that there is no reason 

to hesitate to use this technology. But we cannot presume that there are no 

risks simply based upon the commercial and technical success in CO2 recycling in 

Class II injection locations that are managed as production fields. It has been 

presumed that because the CO2 injections began in the Permian Basin of West 

Texas in the late 1970s that the CO2 from those tertiary recovery fields (for 

oil or gas) is actually still in the formation. In most cases the CO2 was 

recycled and used in different production operations. Even if the CO2 was 

injected 25-35 years ago, the CO2 may not still reside or remain in storage 

there. Because we have not seen large storage fields where the CO2 was stored 

for 10-30 years on a sustained basis, there is not as much known about the 

geologic formations, the adequacy of holding capacity and subsurface impacts as 

we would like to know. Also, in many cases, those oil or gas production fields 

are regulated differently than a newly established long-term GS formation would 

be regulated if it were owned/operated by a power company. 

Response: EPA agrees with the commenter that the risks involved in GS projects are different than

the risks associated with Class II activities. EPA believes that GS is sufficiently distinct from Class

26
II ER operations to warrant the tailored requirements in the GS regulation. For example, the volume

of CO2 anticipated to be injected in Class VI wells is significantly greater than for Class II wells.

Reservoir pressure conditions will be different, with Class VI injection operations involving large

volumes of CO2 and likely having higher pressures within their storage formations than Class II ER

projects. Therefore, Class VI GS reservoir pressures will increase more in comparison to Class II ER

during the injection phase of the GS project.

EPA continues to research and collect data on CO2 storage and containment. EPA is tracking

operations at the DOE GS pilot projects and will review data on all aspects of those operations, from

well construction and injection to long-term plume fate and transport and monitoring of

containment, as the data become available. In addition to the information cited in the preamble to the

proposed rule, EPA published a Notice of Data Availability and Request for Comment on August

31, 2009 (74 FR 44802), in which the Agency described the results of research at three DOE

partnership sites: the Escatawpa, Mississippi project; the Aneth Field project in Paradox Basin,

Southeast Utah; and the Pump Canyon Site, New Mexico. Please also see the research described in

the above response.

As part of its adaptive rulemaking approach, 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 determine if modifications to the requirements

are appropriate or necessary.

Commenter Name: Theresa Pugh Letter ID: 0169

Commenter Organization: American Public Power Association Comment ID: 23397

Comment: We agree with EPA that the appropriate standard underlying technical 

requirements for CO2 GS wells should be the protection of underground sources of 

drinking water ("USDWs"). Even though it is difficult to know at this point what 

methods or technology will be developed for injection and long-term storage of 

CO2 in a manner that is protective of USDWs –we know intuitively that sole 

source aquifers and some high risks seismic locations should be ineligible. 

Proximity to Class IV wells might also be inappropriate (although those wells 

are very rare) because of their contents. In areas where there has been a 

history of Class I or Class II leakage or USDW contamination problems the state 

directors should have full discretion to take those locations off the table for 

injection for long-term storage. APPA assumes that state directors will know 

best which geologic locations should be unsuitable or ineligible. But, we 

acknowledge that there are some risks not worth taking. Sole source aquifers are 

just not worth the risk for CO2 injection no matter how noble the goal of CO2 

reductions might be. There are perhaps 10-15 sole source aquifers in the United 

States so APPA does not believe that removing these locations restricts the 

available geology storage in any significant way on a national basis. 

In some cases, those power plants might need to be coal or gas with other carbon 

dioxide mitigation strategies such as the purchase of renewable credits or other 

measures that are outside the scope of this rule. APPA does not suggest that 

coal plants cannot be built near sole source aquifers since sequestration could 

be conducted off-site if the infrastructure for moving the CO2 is in place or 

would be in place within a reasonable date after start up of the new power 

plant. 

27
Response: EPA agrees that certain aspects of a site (e.g., the presence of seismic sources or solesource aquifers) may make it unsuitable for GS. For this reason, owners and operators must submit

extensive information about the proposed site in their permit applications, which the UIC Director

must consider under §146.82 before issuing a Class VI permit. For example, the GS rule, at

§146.82(a)(5) requires prospective owners or operators to submit information on all USDWs (which

would include sole source aquifers) within the AoR. The GS rule also requires operators to submit

extensive information about the site, including the geologic characteristics of the injection and

confining zones, to demonstrate that the injected CO2 will remain within the target formation. The

Director must consider this information when determining whether GS is acceptable at a given site.

EPA expects that this determination will include consideration of potential impacts of the GS project

on any sole source aquifers.

In many cases, UIC Directors have extensive knowledge of which areas are suitable for GS, but

clarifies that it is the responsibility of Class VI permit applicants to demonstrate the suitability of a

particular site or formation. It is the responsibility of the Director to evaluate the information

collected and submitted by the owner or operator to determine whether a permit for GS at the site is

appropriate. 

EPA is developing guidance for permitting authorities. This guidance will be available on EPA’s

website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Thomas Curtis Letter ID: 0181

Commenter Organization: American Water Works Association (AWWA) Comment ID: 23662

Other EPA Comment Codes and Descriptions: 1220 1.1.1.1 Terminology and definitions; 4400

2.4.4.3 Allowing injection above or between USDWs (seeking comment) 

Comment: USDW Endangerment: AWWA recommends revision to the definition of

"endangerment" 

in the proposed rule. The current definition of endangerment is limited to SDWA 

UIC definition of 10,000 TDS and to primary MCL contamination. Certain healtheffects can be related to concentrations in water of compounds that do not 

exceed the primary MCL. However, under the current language, these potential 

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

Response: The Agency acknowledges commenter concerns about water resources and future water

resource availability. However, modifying the definition of a USDW or “endangerment” is outside

the scope of the GS rulemaking. USDWs are defined as aquifers currently being used as sources of

drinking water or those capable of supplying a public water system and they have a total dissolved

solids (TDS) content of 10,000 milligrams per liter or less as specified in §144.3. EPA adds that

concerns about contaminants with health effects even at concentrations below the maximum

contaminant level should be addressed as part of the review process for the national primary

drinking water regulations; such concerns are outside the scope of this rulemaking. Please note that

the definition of “endangerment” has been defined by Congress at SDWA §1421(d)(1)(2). 

The primary goal of the UIC Program under the SDWA is to protect USDWs from endangerment in

order to ensure a reliable supply of drinking water for the American public. The GS rule, as part of

the UIC program regulations, continues the program’s mandate of ensuring the protection of

USDWs. EPA expects the tailored permitting, siting, construction, operation, monitoring, and postinjection site care requirements in the GS rule to prevent leakage from injection formations and

28
protect USDWs.

Commenter Name: Thomas Curtis Letter ID: 0181

Commenter Organization: American Water Works Association (AWWA) Comment ID: 23663

Other EPA Comment Codes and Descriptions: 1650 1.3.5 Human health impacts 

Comment: EPA should also consider the risk associated with the potential exposure of any 

contaminants that are released to the surface. While we recognize that a gradual 

leak may have little impact, the potential of a catastrophic leak is always 

present. EPA should be mindful during the rulemaking process of not only the 

risk to drinking water, but also of other potential risks from exposure to other 

constituents such as pH, lead and copper, iron, hardness, silica and boron. 

These are compound for which no MCLs have been developed but still impact 

drinking water quality and increase the necessary treatment costs. There could 

be potential health impacts due to long-term exposure to contaminant levels 

below the established MCLs. Also, beneficial uses of groundwater could also be 

impacted by increases of these compounds in the aquifers. Owners/operators could 

be in compliance with the regulation, but could be degrading an aquifer by 

contaminating it with compounds for which MCLs do not exist. 

Response: EPA acknowledges that there are potential risks associated with GS, including the

potential for leakage of CO2 into USDWs, which could result in the mobilization of substances that

could pose threats to USDWs or human health or could increase treatment costs. The purpose of the

Class VI requirements is to minimize and mitigate potential/identified risks through proper site

characterization, well construction, operation, monitoring, post-injection site care, and site closure.

The mandate of the UIC Program, and the GS rule, is to protect USDWs from endangerment that

may be caused by underground injection. The GS rule accomplishes this through requirements

tailored to address the unique nature of GS, including the large volumes of CO2 injected, its

buoyancy and potential corrosivity in the presence of water, and impurities in the CO2 stream. Many

of these requirements specifically address the potential for mobilized substances to affect USDWs.

The GS rule is concerned with the migration of CO2 and displacement of native fluids that may

result in endangerment of USDWs.

For example, the owner or operator must submit data about the site, including information on the

porosity, permeability, mineralogy, and geochemistry of the targeted injection and confining zones.

Operators must also present information on the compatibility of the CO2 stream with fluids in the

injection zone and minerals in both the injection and confining zones as specified in §146.82(c)(3).

The data will help identify potential geochemical reactions between the injected CO2 and the host

geologic formations, which could result in the plugging of pore spaces or the dissolution of

formation minerals. During injection operations, operators must extensively monitor ground water

quality to provide early detection of any unacceptable movement of fluids or impurities in the

subsurface as specified in §146.90. Operators must develop and follow an emergency and remedial

response plan to address any adverse effects associated with the GS operation as specified in §146.94

and provide financial responsibility to address contamination as specified in §146.85. 

Recent research has focused on addressing this concern. EPA is funding research at the Lawrence

Berkeley National Laboratory (LBNL) on potential USDW impacts associated with mobilization of

trace elements. In the August 31, 2009, Notice of Data Availability and Request for Comment (74

FR 44802), EPA published the results of the study, which evaluated the potential for GS to cause

29
changes in ground water quality as a result of CO2 leakage and subsequent mobilization of trace

elements such as arsenic, barium, cadmium, mercury, lead, antimony, selenium, zinc, and uranium

(Birkholzer et al., 2008a). In the study, LBNL estimated the amount of trace elements from native

mineral species that could potentially be mobilized by the intrusion of CO2 and the potential ground

water concentrations that could result, to determine the potential for drinking water standards to be

exceeded. Results from this model simulation suggest that if CO2 were to leak into a shallow

aquifer, the potential for mobilization of lead and arsenic could be enhanced, causing increases in the

concentration of these trace elements in ground water. The Agency continues to monitor research

related to CO2 confinement, potential for CO2 leakage, and mobilization of trace elements. 

EPA adds that concerns about contaminants that cause health effects but do not have maximum

contaminant levels should be addressed as part of the review process for the national primary

drinking water regulations; such concerns are outside the scope of this rulemaking. EPA has also

examined potential methods for conducting treatment of water affected by a CO2 leak; this study is

presented in the final rulemaking docket.

Commenter Name: Thomas Curtis Letter ID: 0181

Commenter Organization: American Water Works Association (AWWA) Comment ID: 23664

Other EPA Comment Codes and Descriptions: 1310 1.1.2.4 Comments on other "out of scope"

issues, e.g., pore space ownership 

Comment: Assignment of Liability: Most importantly, the regulation does not seem to 

address the liability that would be realized by owners/operators of the geologic 

sequestration projects if water quality of USDWs is degraded by the operation of 

their project (even if the impacts are limited to MCLs). AWWA recommends that 

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

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

degraded due to the operation of a geologic sequestration process. Provisions 

need to be included in the final rule that would allow the drinking water 

utility to recoup any costs that are realized due to increased treatment 

requirements for contaminated ground water or to replace lost capacity. In some 

cases, utilities may need to install different types of treatment to remove 

compounds that might not have been present in the water prior to the geologic 

sequestration project. In other instances, treatment may consist of the addition 

of more chemicals to facilitate precipitation of the inorganic compounds or the 

utility may have to backwash membranes more often, resulting in higher energy 

and other operation and maintenance costs. In any of these cases, the 

owner/operator of the geologic sequestration project should be required to 

reimburse the drinking water utility for these incurred costs, and they should 

also be required to continue such payments for as long as the ground water 

source remains degraded. 

Water utilities should not be penalized for having to develop local sites 

contaminated by sequestration activities for water supply. In fact they should 

be encouraged to do so, under the appropriate conditions, as there is no more 

critical public health issue than the need to provide potable water. In order to 

meet increasing demands imposed on them by a growing service population, water 

utilities will need to develop marginal water supplies. However, increased 

treatment costs due to contamination resulting from sequestration activities 

should not be borne by the local utility or their customers when national 

30
environmental objectives have been met without significant benefit to the local 

economy. 

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

contamination or inaccessibility resulting from a sequestration project, there 

will be the issue of financial compensation (for treatment or development of an 

alternative source). As water resources become scarce, financial compensation 

for a lost source of supply may not suffice, as local alternatives may not be 

available. Hence, it will be critical that contingency planning to identify 

alternatives to the current groundwater supply be a part of the planning 

activities for the sequestration project, along with a commitment to provide an 

alternative source of water, should the need arise. 

Response: EPA agrees that owners or operators of Class VI wells must ensure that resources are

available to prevent endangerment of USDWs from improper plugging, remediation, and

management of wells. For this reason, the GS rule requires that owners or operators demonstrate and

maintain financial responsibility for corrective action on wells in the AoR, injection well plugging,

post-injection site care and site closure, and emergency and remedial response at GS sites as

specified in §146.85. In the event of contamination or other adverse event to the USDW during the

life of the project, the financial instrument(s), such as insurance, bonds, etc., rather than public

monies, would cover necessary response actions. EPA clarifies that it is the owner or operator of the

well who will be required to demonstrate financial responsibility, not the generator of the CO2,

consistent with EPA’s authority under SDWA. Furthermore, EPA notes that tort and other remedies

will continue to be available after site closure. Other Federal environmental statutes, e.g. Clean Air

Act, 42 U.S.C. §§7401-7671; CERCLA, 42 U.S.C. §9601-9675; and RCRA, 42 U.S.C. §6901-6992,

potentially apply as well to the risks created by the long-term storage of CO2. EPA has also

examined potential methods for conducting treatment of water affected by a CO2 leak; this study is

presented in the final rulemaking docket.

EPA clarifies that long-term liability beyond the life of the project (after site closure) is beyond the

scope of the GS rulemaking. Please see the final rule and the discussion of financial responsibility

and long-term liability in the preamble for additional information.

EPA adds that Class VI well owners and operators must site, construct, operate, monitor, and close

their wells in a manner that protects USDWs, and Class VI permits will set forth rigorous technical

requirements to ensure careful planning, operation, and closure of GS projects. Failure to meet these

requirements would be considered a violation of the permit and would be subject to applicable civil,

criminal, or administrative penalties under SDWA §1423.

Commenter Name: Thomas Curtis Letter ID: 0181

Commenter Organization: American Water Works Association (AWWA) Comment ID: 23666

Other EPA Comment Codes and Descriptions: 1616 1.3.1.3 Fluid movement 

Comment: Trespass and Aquifer Displacement: AWWA recommends that the potential for 

trespass be addressed in the final rule. Carbon dioxide plumes may migrate into 

a location that a drinking water utility was planning to utilize, possibly for 

aquifer storage and recovery. What recourse is provided by the proposed 

regulation in the event that trespass occurs, and damages are realized by the 

drinking water utility? Also, movement of the pressure front associated with a 

carbon dioxide plume may cause aquifers to shift in location, potentially moving 

31
them out of the jurisdiction of their original utility "owner." This can be a 

serious problem in certain portions of the country where ground water resources 

are limited or conflict, and utilities face intense competition for water 

rights. AWWA questions if an appropriate recourse will be provided by the 

sequestration project owner/operator in the event that these water rights issues 

become a reality for the drinking water utility. 

Response: EPA clarifies that owners and operators must perform extensive site characterization and

modeling of the AoR to determine the extent of the CO2 plume prior to approving a GS project. The

financial responsibility requirements at§146.84 require owners and operators to demonstrate and

maintain resources to address emergency and remedial response to adverse events that may occur

associated with GS. This would include impacts to drinking water utilities associated with fluid

displacement.

Commenter Name: Thomas Curtis Letter ID: 0181

Commenter Organization: American Water Works Association (AWWA) Comment ID: 23669

Comment: Sole Source Aquifers: Several areas of the country rely on sole source aquifers 

as their drinking water resource. Given the special protective measures already 

afforded to these aquifers by EPA, AWWA strongly recommends that the final 

geologic sequestration regulation should restrict project activities in the 

vicinity of these aquifers. Table 1-2 below presents a list of some of the solesource aquifers that are located in potential geologic sequestration areas. 

(Note that this is not meant to be a comprehensive list of all of the sole 

source aquifers in the United States.) 

Table 1-2: Sole-Source Aquifers in Potential Geologic Sequestration Areas 

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

Aquifer Name: Upper Santa Cruz & Avra Basin Aquifer 

Location: Arizona 

Potentially Impacted: Tucson, Green Valley, Catalina 

Characteristics: Discharges 376,000 acre-feet per year 

Aquifer Name: Fresno County Aquifer 

Location: California 

Potentially Impacted: Fresno, Clovis 

Characteristics: Contains 5.8 million acre feet of water 

Aquifer Name: Volusia Sole Source Aquifer 

Location: Florida 

Potentially Impacted: Ormond Beach, Daytona Beach, New Smyrna Beach and Deland 

Characteristics: Covers 1,450 sq. mi. 

Aquifer Name: Biscayne Sole Source Aquifer 

Location: Florida 

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

Beach Counties 

32
Characteristics: Covers 4,000 sq. mi. 

Aquifer Name: Eastern Snake River Plain Aquifer 

Location: Idaho 

Potentially Impacted: 300,000 residents of Eastern Idaho 

Characteristics: Contains 200 to 300 million acre-feet 

Aquifer Name: Spokane Valley-Rathdrum Prairie Aquifer 

Location: Idaho, Washington 

Potentially Impacted: 700,000 residents of Idaho and Washington 

Characteristics: Covers 325 sq. mi. 

Aquifer Name: Chicot Aquifer System 

Location: Louisiana 

Potentially Impacted: Lafayette, Lake Charles, Crowley 

Characteristics: Supplies 800 mgd, most for irrigation 

Aquifer Name: Southern Hills Aquifer System 

Location: Louisiana, Mississippi 

Potentially Impacted: Baton Rouge, Natchez, McComb 

Characteristics: Supplies 290 million gallons per day 

Aquifer Name: New Jersey Coastal Plain Aquifer System 

Location: New Jersey 

Potentially Impacted: Over 3,000,000 residents 

Characteristics: Over 350 million gal. withdrawn per day 

Aquifer Name: Northwest New Jersey Fifteen Basin Aquifer 

Location: New Jersey, New York 

Potentially Impacted: Over 500,000 residents 

Characteristics: Covers 1,735 square mile area 

Aquifer Name: Espanola Basin Aquifer System 

Location: New Mexico 

Potentially Impacted: Sante Fe, Los Alamos, and Española 

Characteristics: Covers 3,000 sq. mi. 

Aquifer Name: Clinton Street Ballpark Aquifer System 

Location: New York 

Potentially Impacted: Broome and Tioga Counties 

Characteristics: 16.25 mgd withdrawn for drinking water 

Aquifer Name: Miami Valley Buried Aquifer 

Location: Ohio 

Potentially Impacted: Serves over 1,600,000 residents 

Characteristics: Provides 200 mgd for drinking water 

Aquifer Name: Edwards Aquifer 

Location: Texas 

Potentially Impacted: San Antonia, San Marcos, New Branfels 

33
Characteristics: Discharges 900,000 acre-feet per year 

Aquifer Name: Columbia and Yorktown- Eastover Multiaquifer 

Location: Virginia 

Potentially Impacted: Exmore, Olney, Chincoteague 

Characteristics: Covers 695 sq. mi. 

Response: The GS rule, at §146.82(a)(5) requires prospective owners or operators to submit

information on all USDWs (which would include sole source aquifers) within the AoR. The GS rule

also requires operators to submit extensive information about the site, including the geologic

characteristics of the injection and confining zones, to demonstrate that the injected CO2 will remain

within the target formation. The Director must consider this information when determining whether

GS is acceptable at a given site. EPA expects that this determination will include consideration of

potential impacts of the GS project on any sole source aquifers.

EPA agrees that, in many cases, UIC Directors will have extensive knowledge of which areas are

suitable for GS, but clarifies that it is the responsibility of Class VI permit applicants to demonstrate

the suitability of a particular site or formation. It is the responsibility of the Director to evaluate the

information collected and submitted by the owner or operator to determine whether a permit for GS

at the site is appropriate.

Commenter Name: Thomas Curtis Letter ID: 0181

Commenter Organization: American Water Works Association (AWWA) Comment ID: 23670

Other EPA Comment Codes and Descriptions: 1810 1.4.1 Research on identifying risks to

USDWs 

Comment: AWWA recommends that EPA prohibit owner/operators from constructing carbon 

dioxide injection wells in sole source aquifers. Owner/operators should also be 

prohibited from ever injecting carbon dioxide into a formation that would result 

in the migration of the carbon dioxide to a point that is under a sole source 

aquifer. EPA should establish a minimum distance that needs to be provided 

between the closest geologic sequestration project and the location of any sole 

source aquifers. AWWA would recommend a 50 mile minimum; however, not being 

experts on the details of plume migration, AWWA recommends that EPA and DOE 

perform research on this topic to better assess what the regulatory requirement 

should be. Including these restrictions in the final geologic sequestration 

regulation would allow for the protection of drinking water aquifers that, if 

contaminated by carbon dioxide, could result in very significant and expensive 

issues for the drinking water utilities. 

Response: EPA believes that the extensive site characterization requirements for GS projects in the

final rule are protective of USDWs, including sole source aquifers. The GS rule, at §146.82(a)(5)

requires prospective owners or operators to submit information on all USDWs, which would include

sole source aquifers within the AoR. The GS rule also requires operators to submit extensive

information about the site, including the geologic characteristics of the injection and confining

zones, to demonstrate that the injected CO2 will remain within the target formation. The Director

must consider this information and the potential impact of the GS project on any sole source aquifers

when determining whether GS is acceptable at a given site. 

EPA agrees that, in many cases, UIC Directors will have extensive knowledge of which areas are

34
suitable for GS, but clarifies that it is the responsibility of Class VI permit applicants to demonstrate

the suitability of a particular site or formation. It is the responsibility of the Director to evaluate the

information collected and submitted by the owner or operator to determine whether a permit for GS

at the site is appropriate.

EPA is tracking other recent research on GS and USDW protection including the following studies

(which are available in the docket for the rulemaking):

• Smyth et al. (2008) reviewed modeling and laboratory experiments and field results from

groundwater studies conducted at SACROC, an ER site in west Texas where tens of millions of tons

of CO2 have been injected for over 30 years.

• Zheng et al. (2008) used more than 38,000 groundwater quality analyses from aquifers throughout

the US to perform reactive transport modeling of groundwater quality after the intrusion of CO2. The

model simulations indicate that aquifers containing more carbonate and clay minerals are less

vulnerable to CO2 intrusion, and that, while under certain conditions CO2 can potentially mobilize

metals present in the aquifer, mobilized amounts of the metals are always below health-based limits.

• Kharaka et al. (2009) conducted CO2 injection field tests in Montana and reported that shallowly

injected CO2 can affect the chemistry of shallow groundwater by decreasing pH and mobilizing rock

and soil ions. 

• Nicot (2008) modeled an injection roughly equivalent to 50 Mt CO2/year for 50 years in an area

that is hydrologically similar to the Gulf Coast Basin. Model results indicate an average water table

rise of approximately 1 meter with a minor increase in stream baseflow and a larger increase in

ground water evapotranspiration. 

ORD's National Center for Environmental Research awarded six Science To Achieve Results

(STAR) grants in the Fall of 2009 to recipients from major universities and institutions within the

scope of the "Integrated Design, Modeling and Monitoring of Geologic Sequestration of

Anthropogenic Carbon Dioxide to Safeguard Sources of Drinking Water" research area. These

projects, which started in late 2009, include these lead institutions with specific topics of

investigation: Clemson University will study potential impacts to drinking water aquifers of CO2-

rich dissolved brines; the University of Illinois-Urbana will conduct research related to reducing

hydrologic and geochemical uncertainties associated with CO2 sequestration in deep, saline

reservoirs; the University of Texas at Austin will assess appropriate monitoring approaches at

geologic sequestration sites; the University of Utah will integrate design, monitoring, and modeling

of GS to assist in developing a practical methodology for characterizing risks to USDWs; Columbia

University will conduct laboratory experiments on shallow aquifer systems to improve understanding

of geochemical and microbiological reactions under low pH/high CO2 stress; and Princeton

University will develop a set of computational tools to model CO2 and brine movement associated

with GS.

Commenter Name: Thomas Curtis Letter ID: 0181

Commenter Organization: American Water Works Association (AWWA) Comment ID: 23671

Comment: Water versus Energy: AWWA questions how will geologic sequestration projects 

will be permitted if there is potential competition for a specific geologic 

basin between an energy company and a drinking water utility. Water should trump 

everything. The water sector should be given priority, especially if a drinking 

water utility has limited or no other options, as they have very limited water 

and storage resources. It may also be possible that there may not be a single 

federal and/or state oversight agency that could provide guidance in this arena 

35
as the agency would need to have oversight for air, water, environmental, 

energy, and other sectors. The NEPA process and the state equivalent, such as 

CEQA in California, will need to be well fleshed out at the outset of the 

permitting process. 

Response: The Agency agrees that drinking water is an important resource that needs protection.

The primary goal of the UIC Program under the SDWA is to protect USDWs from endangerment. It

is outside the scope of this rulemaking or EPA’s authority to provide the water sector any type of

priority over storage areas. Consistent with SDWA §1422, the UIC program provides that no

underground injection shall be authorized if it results in the movement of fluid containing any

contaminant into USDWs, if the presence of that contaminant may cause a violation of any primary

drinking water regulation or may adversely affect the health of persons as specified in §144.12. 

EPA has added a requirement at 40 CFR 124.10(c)(1)(xi) that state and local oil and gas regulatory

agencies and state agencies regulating mineral exploration and recovery, the PWSS program director,

and all agencies that oversee injection wells in the state must be notified as part of the public notice

process for a Class VI permit.

Commenter Name: Daniel Plath Letter ID: 0188

Commenter Organization: NiSource, Inc. Comment ID: 25229

Other EPA Comment Codes and Descriptions: 3400 2.2.2 Corrective Action; 3800 2.3 Proposed

Injection Well Construction Requirements (40 CFR 146.86); 5100 2.8.1 Injection well plugging

activities (seeking comment) (40 CFR 146.92) 

Comment: aspects. The following points summarize four primary lessons learned through 

operation of natural gas storage that would be applicable to GS: 

1. History has shown that the one component in the system that has caused the 

most safety issues is the wells; specifically the operator's wells, plugged and 

abandoned (P&A) wells and third party operating wells (e.g. oil and gas 

production wells). The casing and cement in the storage well is the "first line 

of defense" in the containment of high pressure gas and a properly designed, 

constructed and maintained well is critical. Even after several decades of 

operations over a four State area, NiSource subsidiaries have never experienced 

loss of containment from cap rock leakage, migration up faults, re-activation of 

faults, earthquakes, or the other potential leakage pathways that EPA discusses 

in the Proposed Rule. While history will ultimately reveal the root causes of 

future problems, if any, with GS, NiSource submits that the predominant cause 

will likely be identified as being related to an active well, abandoned well or 

third party well if not properly addressed in the Final Rule. This is based on 

the belief that the rigorous site selection process will preclude the other 

sites that would have had other issues, e.g. cap rock leakage, from even being 

activated in the first place. 

Response: EPA agrees that proper site characterization should minimize leakage through faults,

breaks in the seal of the confining layer, and other geologic pathways. EPA believes that the

construction, operating, and monitoring requirements in the GS rule will prevent leakage from

occurring through active wells. Appropriately designed and constructed wells are necessary to

prevent endangerment to USDWs and maintain integrity of the well throughout the lifetime of a GS

project. This is the foundation of the requirements for construction and pre-operational testing of

36
Class VI wells at §§146.86 and 146.87. 

EPA also agrees that the AoR and corrective action process should identify both abandoned wells

and third party wells that could serve as leakage pathways. The UIC Program's long-standing

approach to corrective action, tailored to the potential corrosivity of and impurities in the CO2

stream, can address the potential risk associated with improperly plugged wells in the AoR.

EPA notes that the final rule, at 40 CFR §124.10(c)(1)(xi), requires the notification of state oil and

gas agencies, state mineral exploration agencies, and state public water supply supervision directors

about the availability of the draft permit . EPA expects that such notification can help with further

identifying wells in the area of review.

Commenter Name: John R. Baza Letter ID: 0193

Commenter Organization: Utah Division of Oil, Gas, and Mining Comment ID: 23908

Comment: Protection of Underground Sources of Drinking Water ("USDW") 

As with all underground injection, protection of USDWs should be the major focus 

of the rules. Protection is accomplished through containment of the CO2 stream 

through proper site selection and characterization of the geologic formation 

that is to be used for injection, along with sound construction of the injection 

wells and adequate monitoring practices. 

Response: The Agency agrees that drinking water is an important resource that needs protection.

The primary goal of the UIC Program under the SDWA is to protect USDWs from endangerment.

Consistent with SDWA §1422 the UIC program provides that no underground injection shall be

authorized if it results in the movement of fluid containing any contaminant into USDWs, if the

presence of that contaminant may cause a violation of any primary drinking water regulation or may

adversely affect the health of persons as specified in §144.12. 

EPA recognizes that injecting large volumes of CO2 for GS poses unique challenges that, if not

properly managed, could endanger drinking water sources and have other adverse impacts. However,

with proper site selection, the final, tailored, Class VI requirements address the large volumes of

CO2 injected, its buoyancy, potential corrosivity in the presence of water, and potential impurities in

the CO2 stream. In addition, the tailored permitting, siting, construction, operation, monitoring, and

post-injection site care requirements in the GS rule are intended to prevent leakage from injection

formations and protect USDWs.

Commenter Name: Andy Horn Letter ID: 0196

Commenter Organization: Colorado Ground Water Association (CGWA) Comment ID: 23920

Comment: While a promising technology for mitigation of CO2 emissions, geologic storage 

(GS) of CO2 also has the potential to impact underground Sources drinking waters 

(USDWs). Even though deep injection of CO2 has been used for over 20 years to 

enhance oil and gas recovery and provides a foundation for large-scale use of 

geologic storage (GS), nothing on the scale of the proposed projects has been 

implemented. Full-scale projects have the potential to impact an area within a 

50-mile radius of the injection well site. 

Much of Colorado receives approximately 15 to 20 inches of precipitation yearly, 

37
water resources are currently stressed, and significant population increases are 

expected in the coming decades. Large portions of Colorado’s population rely on 

USDWs and a significant portion of Colorado’s agricultural economy relies on the 

freshwater aquifers for crop irrigation. The CGWA has concerns about the 

proposed CO2 GS rule, which will govern not only the injection wells needed for 

GS but also the siting, operation, monitoring, closure of GS projects and could 

also govern the post-closure liability of GS project operators. These projects 

will be implemented on a scale for which there is no analog and will have the 

potential to impair major water resources in the State of Colorado and elsewhere 

if the projects are mismanaged. 

Response: The Agency agrees that drinking water is an important resource that needs to be

protected. The primary goal of the UIC Program under the SDWA is to protect USDWs from

endangerment. Consistent with SDWA §1422 the UIC program provides that no injection shall be

authorized if it results in the movement of fluid containing any contaminant into USDWs, if the

presence of that contaminant may cause a violation of any primary drinking water regulation or may

adversely affect the health of persons as specified in §144.12.

The GS regulation builds upon the long-standing protective framework of the UIC Program, which

has been regulating the injection of billions of gallons of fluids for decades. The GS regulation

enhances this framework with requirements that are tailored to address the unique issues associated

with 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. These additional protective requirements include more extensive

geologic testing for site characterization, detailed computational modeling of the AoR and periodic

re-evaluations, detailed requirements for monitoring and tracking the CO2 plume and pressure front,

and extended post-injection monitoring and site care. EPA expects the tailored permitting, siting,

construction, operation, monitoring, and post-injection site care requirements in the GS rule will

prevent leakage from injection formations and protect USDWs.

Commenter Name: Andy Horn Letter ID: 0196

Commenter Organization: Colorado Ground Water Association (CGWA) Comment ID: 23921

Other EPA Comment Codes and Descriptions: 2100 1.6 Target Geologic Formations for GS 

Comment: Issue 1. The proposed regulation has no mechanism for the respective State 

authority in each state responsible for administration of water resources to 

remove certain groundwater basins and/or zones with important aquifers from 

consideration as sequestration repositories. 

One of the CGWA’s concerns is the siting of CO2 sequestration projects in major 

sedimentary rock aquifers, near, or in strata underlying major sedimentary rock 

aquifers such as those which are the primary source of drinking or irrigation 

water for large segments of the population or agricultural community. Due to 

uncertainties in the effectiveness of GS at the project-scales being considered, 

siting of GS reservoirs in strata underlying "sole-source" or other "important" 

USDWs, should be avoided, at least until large scale experience validates this 

methodology. Examples of such aquifers include the Denver Basin Aquifers and 

the aquifers of the San Luis Valley. Additional examples of aquifers which may 

be subject to degradation by displaced brines include the alluvial aquifers of 

the South Platte and Arkansas River Valley where they are in contact with the 

38
subcrops of strata which could be used as GS reservoirs. Colorado’s reliance in 

many locations on deep bedrock aquifers should remove potential GS reservoirs 

from consideration due to the potential for degradation either by migration of 

CO2 or displacement of CO2 reservoir brines into fresh water aquifers. 

Response: The Agency agrees that drinking water is an important resource that needs to be

protected. The primary goal of the UIC Program under the SDWA is to protect USDWs from

endangerment. Consistent with SDWA §1422 the UIC program provides that no injection shall be

authorized if it results in the movement of fluid containing any contaminant into USDWs, if the

presence of that contaminant may cause a violation of any primary drinking water regulation or may

adversely affect the health of persons as specified in §144.12.

The GS rule, at §146.82(a)(5), requires prospective owners or operators to submit information on all

USDWs within the AoR. EPA expects that this information will include identification of any sole

source aquifers. The GS rule also requires operators to submit extensive information about the site,

including the geologic characteristics of the injection and confining zones, to demonstrate that the

injected CO2 will remain within the target formation. The Director must consider this information

when determining whether GS is acceptable at a given site. EPA expects that during this evaluation

the Director will consider the potential impact of the GS project on any sole source aquifers.

Additionally, EPA has added a requirement at 40 CFR 124.10(c)(1)(xi) that requires state and local

oil and gas regulatory agencies and state agencies regulating mineral exploration and recovery, the

PWSS program director, and all agencies that oversee injection wells in the state be notified as part

of the public notice process for a Class VI permit.

EPA anticipates that state permitting authorities are in the best position to make determinations about

the appropriateness of a particular site based on all available information, including drinking water

supply needs. EPA clarifies that a state’s Class VI primacy program may be more stringent then the

federal requirements. For example, a state has the discretion to ban GS projects from taking place in

formations or areas that affect sole source aquifers. 

EPA agrees that, in many cases, UIC Directors will have extensive knowledge of which areas are

suitable for GS, but clarifies that it is the responsibility of Class VI permit applicants to demonstrate

the suitability of a particular site or formation. It is the responsibility of the Director to evaluate the

information collected and submitted by the owner or operator to determine whether a permit for GS

at the site is appropriate.

Commenter Name: Andy Horn Letter ID: 0196

Commenter Organization: Colorado Ground Water Association (CGWA) Comment ID: 23923

Other EPA Comment Codes and Descriptions: 1220 1.1.1.1 Terminology and definitions; 1240

1.1.1.3 Suggested changes/edits to rule language; 4400 2.4.4.3 Allowing injection above or between

USDWs (seeking comment) 

Comment: Issue 3. The proposed regulation currently defines USDWs as zones that contain 

groundwater with a total dissolved solids (TDS) concentration of less than 

10,000 mg/L. This limit should be revised to consider geologic strata with water 

containing higher TDS concentrations, because these zones may be economic in the 

future. 

The technology for treating high TDS water for use in water supply is improving 

rapidly, and these high TDS aquifer zones may be needed in the future. In areas 

39
with limited water resources water providers are beginning to turn to 

groundwater sources containing in excess of 10,000 mg/L TDS (Sengebush 2008). 

It is already conceivable that in the near future sources with up to 

approximately 20,000 mg/L TDS will be considered viable as water treatment 

technology advances making such water sources economical. To protect 

groundwater resources which may be economical in the foreseeable future the rule 

should evaluate the potential that currently marginal groundwater sources will 

be usable. The repository zones should be limited to strata containing very high 

TDS concentrations that siting studies and public input indicate are not likely 

to be useable in the future, as use of a zone for CO2 sequestration will likely 

preclude recovery and use of the groundwater resource in the future. 

Sengebush, R. M. 2008, INTERA, Inc. Deep Brackish Water Considered for New 

Mexico Development. Southwest Hydrology, March/April 2008, p. 8. Available from 

http://www.swhydro.arizona.edu/archive/V7_N2/dept-ontheground.pdf. 

Response: The Agency acknowledges the commenter’s concerns about water resources and future

water resource availability. However, modifying the definition of a USDW is outside the scope of

the GS rulemaking. USDWs are defined as aquifers currently being used as sources of drinking

water or those capable of supplying a public water system, with a total dissolved solids (TDS)

content of 10,000 milligrams per liter or less, as specified in §144.3. 

The primary goal of the UIC Program under the SDWA is to protect USDWs from endangerment in

order to ensure a reliable supply of drinking water for the American public. The GS rule, as part of

the UIC program regulations implementing the SDWA, continues the program’s mandate of

ensuring the protection of USDWs. EPA expects that the tailored permitting, siting, construction,

operation, monitoring, and post-injection site care requirements in the GS rule will prevent leakage

from injection formations and protect USDWs.

EPA recognizes that there is increasing demand for water resources and that technology

improvements may make high TDS aquifers viable drinking water sources. EPA believes these

potential resources should be considered when injection depth waivers are sought. Therefore, the

final GS rule at §146.95(b) requires the Director to consider these issues in determining whether an

injection depth waiver is appropriate. Specifically, the Director must consider whether alternative

injection sites are available; community needs, demands, and supply from drinking water resources;

planned needs, potential and/or future use of USDWs and non-USDWs in the area; and a plan for

securing alternative resources or treating USDW formation waters in the event of contamination

related to the Class VI injection activity. 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.

Commenter Name: Chris M. Hobson Letter ID: 0201

Commenter Organization: Southern Company Comment ID: 22155

Other EPA Comment Codes and Descriptions: 1250 1.1.1.4 Flexibility is needed (performancebased standards) 

Comment: Southern Company agrees that the appropriate standard underlying the technical 

requirements to be applied to Class VI wells should be the protection of 

underground sources of drinking water ("USDWs"). See id. at 43497. With this 

standard in mind, it is imperative that EPA fashion the Final Rule with 

40
sufficient flexibility to meet two primary goals: first, adequately addressing 

the varied geologic conditions of different CO2 GS sites; second, ensuring 

adaptability as industry and regulators gain experience with and information 

regarding CO2 GS. It is important that the Final Rule not exclude the existing 

experience and knowledge gained from current CO2 injection and GS demonstration 

projects. To encourage use of this information, Southern Company supports 

facilitated GS in oil and gas reservoirs with the protection of USDWs and the 

transition of Class II and Class V C02 injection operations to GS. The Final 

Rule should establish a regulatory framework built around the standard of 

protecting USDWs while allowing Directors to issue permits with site-specific 

requirements. An emphasis on site selection, site characterization, and careful 

permit-writing will further strengthen a regulatory scheme that will provide 

protection of USDWs while maximizing the beneficial environmental and economic 

impacts of carbon sequestration. 

Response: EPA notes that the final rule does allow owners or operators flexibility. EPA has taken a

regulatory approach that promotes USDW protection, incorporates flexibility or the discretion of the

permitting authority when appropriate, seeks to limit burden on owners or operators and permitting

agencies, and provides a foundation for national consistency in permitting of GS projects. Many

Class VI permit requirements must be established through site-specific plans developed by the owner

or operator and approved by the Director. Consequently, EPA anticipates that owners or operators

will consult with the Director as they develop, implement, and update these plans. In addition, the

final rule affords the Director flexibility to approve alternatives to the requirements in some cases.

For example, the Director may in certain situations modify the length of the post-injection site care

period or approve an alternative post-injection site care timeframe as part of the permitting process

under §146.93, allow the use of alternate methods for mechanical integrity testing (if approved by

EPA), and waive the requirement that wells be designed to inject below the lowermost USDW.

EPA recognizes that technologies will evolve and improve over time, and for these reasons, the

Agency is using an adaptive approach to regulate GS injection. 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 determine if modifications to

the requirements are appropriate or necessary.

EPA is allowing the construction of Class II and V wells to be re-permitted as Class VI wells

pursuant to §146.81(c), provided the owner or operator can demonstrate to the Director that the wells

were engineered and constructed to meet the requirements at §146.86(a) and ensure protection of

USDWs, in lieu of requirements at §146.86(b) and §146.87(a). EPA believes that allowing for

grandfathering of select construction requirements, if approved by the Director, will ease the

transition to Class VI from an existing ER project while protecting USDWs from endangerment. 

EPA clarifies that the GS rule does not promote GS in specific settings, nor does it limit injection

activities to any specific type of formation, geographic region, or depth. The focus of the GS rule is

to ensure that, where GS is deployed, it is conducted in a manner that is protective of USDWs.

Commenter Name: Thomas Curtis Letter ID: 0204

Commenter Organization: American Water Works Association (AWWA) Comment ID: 22180

Comment: - Protection of underground sources of drinking water (USDWs) should be the 

highest priority - "water should trump everything!" 

41
Response: The Agency agrees that drinking water is an important resource to protect. The primary

goal of the UIC Program under the SDWA is to protect USDWs from endangerment. Consistent

with SDWA §1422, the UIC program provides that no injection shall be authorized if it results in the

movement of fluid containing any contaminant into USDWs, if the presence of that contaminant may

cause a violation of any primary drinking water regulation or may adversely affect the health of

persons as specified in §144.12. It is outside the scope of this rulemaking or EPA’s authority to

provide the water sector any type of priority over storage areas.

The GS rule, as part of the UIC program regulations, continues the Program’s mandate under the

SDWA of ensuring the protection of USDWs from endangerment. EPA expects that the tailored

permitting, siting, construction, operation, monitoring, and post-injection site care requirements in

the GS rule will prevent leakage from injection formations and protect USDWs.

Commenter Name: Thomas Curtis Letter ID: 0204

Commenter Organization: American Water Works Association (AWWA) Comment ID: 22183

Other EPA Comment Codes and Descriptions: 4320 2.4.4.1 Injection beneath the lowermost

formation containing a USDW 

Comment: - The protection of the lowermost USDWs is of critical importance, and the 

location of these USDWs should be the primary factor in determining if a 

geosequestration project can be located in the same area. 

Response: The Agency agrees that drinking water is an important resource to protect. The primary

goal of the UIC Program under the SDWA is to protect USDWs from endangerment. Consistent

with SDWA §1422, the UIC program provides that no injection shall be authorized if it results in the

movement of fluid containing any contaminant into USDWs, if the presence of that contaminant may

cause a violation of any primary drinking water regulation or may adversely affect the health of

persons as specified in §144.12.

The GS rule requires operators to submit extensive information about the site, including the geologic

characteristics of the injection and confining zones, to demonstrate that the injected CO2 will remain

within the target formation. The Director must consider this information and the potential impact of

the GS project on any USDWs when determining whether GS is acceptable at a given site. 

In many cases, UIC Directors will have extensive knowledge of which areas are suitable for GS, but

clarifies that it is the responsibility of Class VI permit applicants to demonstrate the suitability of a

particular site or formation. It is the responsibility of the Director to evaluate the information

collected and submitted by the owner or operator to determine whether a permit for GS at the site is

appropriate.

EPA agrees that protecting USDWs from endangerment must be a top priority. The Agency believes

that there are limited circumstances where injection above the lowermost USDW can be performed

in a manner that protects USDWs, as long as appropriate protections are in place. The final GS rule

at §146.95 establishes a process by which owners or operators can seek a waiver of the Class VI

injection depth requirements for injection into non-USDW formations above and/or between

USDWs. The waiver approach requires the submission of extensive, site-specific information (in

conjunction with the permit application submission) to demonstrate that injection of CO2 into a nonUSDW that is above or between USDWs can be done in a manner that is protective of USDWs. It

establishes: 1) requirements specifying information that owners or operators must submit, and

42
Directors must consider, in consultation with PWSS Directors; 2) procedures for public notice of a

waiver application and for Director-Regional Administrator communication; 3) the waiver issuance

process; and, 4) additional requirements that apply to owners or operators of Class VI wells granted

a waiver of the injection depth requirements to ensure USDW protection above and below the

injection zone. 

EPA believes that the requirements at §146.95 will ensure USDW protection while providing

flexibility to UIC Program Directors and owners or operators who undertake CO2 injection for GS.

The Agency believes this approach: 1) responds to concerns about local and regional geologic

storage capacity limitations imposed by the proposed injection depth requirements; 2) allows for a

more site-specific assessment of injection depth for GS projects; 3) accommodates injection into

different formation types; 4) allows for injection of CO2 for GS into non-USDWs above and/or

between USDWs when appropriate and where it can be demonstrated that USDWs will be protected;

and 5) responds to concerns about the use of aquifer exemptions for GS. Finally, EPA’s approach to

addressing injection depth variability through a waiver process responds to concerns about future

drinking water resource availability and the need to ensure that high quality water remains available

in sufficient quantities to supply drinking water needs. 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.

Commenter Name: Thomas Curtis Letter ID: 0204

Commenter Organization: American Water Works Association (AWWA) Comment ID: 22187

Other EPA Comment Codes and Descriptions: 1510 1.2.2.3 Need for additional study 

Comment: - It is not realistic to presume that we know enough about carbon separation or 

geosequestration to draw the conclusion that all new power plants with these new 

technologies would be carbon neutral in the first few decades of operation. 

- More research is needed to answer USDW protection and technical questions 

related to feasibility, infrastructure and reliability. This research includes 

the work from the U.S. Geological Survey and other agencies. 

Response: The effectiveness of various climate change mitigation technologies, including carbon

capture, is beyond the scope of this rulemaking. EPA clarifies that the purpose of the GS regulation

is to assure that, where deployed, GS is conducted in a manner that protects USDWs from

endangerment. As described above, EPA agrees that continued research in all GS associated fields

will be integral to development of GS technology. 

Commenter Name: Diane VanDe Hei Letter ID: 0206

Commenter Organization: Association of Metropolitan Water Agencies

(AMWA)

Comment ID:

22207

Comment: - Protection of drinking water sources and potential future underground sources 

of drinking water (USDW) is paramount. As a result AMWA and AWWA recommend that: 

o The permitting of large-scale geosequestration projects be delayed until 

information about Department of Energy (DOE) pilot projects and the effects of 

carbon sequestration on the subsurface and USDW can be collected and analyzed. 

We are concerned about the potential for carbon capture and storage (CCS) 

projects to result in unintended, and possibly harmful, consequences to sources 

43
of drinking water. Much of the work in CCS arena is still in pilot or pre-pilot 

phase at several magnitudes of scale smaller than the sort of projects 

envisioned under this proposal. 

Response: EPA believes that sufficient data and experience currently exist to develop regulations

under the UIC program for Class VI wells. The GS rulemaking builds upon decades of knowledge

about safe underground injection practices regulated by the UIC Program. While developing the GS

regulations, EPA has evaluated relevant GS research, including projects conducted by the seven

Regional Carbon Sequestration Partnerships (RCSPs) funded by DOE and coordinated through the

National Energy Technology Laboratory (NETL), and several international projects. 

Several large-scale pilot projects are currently underway worldwide to test the appropriateness and

efficacy of various technologies to characterize sites, ensure proper well construction and operation,

and monitor injection activities and CO2 plume and pressure front distribution. EPA is tracking

international GS efforts and is aware of four commercial-scale projects that are currently in

operation: the Sleipner Project in the Norwegian North Sea (operating since 1996); the Weyburn ER

project in Saskatchewan, Canada (since 2000); the In Salah Gas Project in Algeria (since 2004); and

Snohvit, also in offshore Norway in the Barents Sea (since 2008). Other projects EPA is tracking

include Gorgon and Otway (in Australia); Ketzin (in Germany); Lacq (in France); and CarbFix (in

Iceland). 

Activities at Weyburn, In Salah, Sleipner, and the RCSP sites have been supervised by leading

industry scientists and practitioners. Activities at Weyburn have also been peer-reviewed by the

IEA-GHG Programme, an international collaborative research program that includes the European

Commission and OPEC as members. EPA has considered the results of these pilot projects and data

from RCSPs in developing the GS rule. 

EPA recognizes that technologies will evolve and improve over time, and for these reasons, the

Agency is using an adaptive approach to regulate GS injection. 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 determine if modifications to

the requirements are appropriate or necessary.

Commenter Name: Diane VanDe Hei Letter ID: 0206

Commenter Organization: Association of Metropolitan Water Agencies

(AMWA)

Comment ID:

22209

Other EPA Comment Codes and Descriptions: 1310 1.1.2.4 Comments on other "out of scope"

issues, e.g., pore space ownership; 3100 2.1 Proposed Geologic Siting Requirements (40 CFR

146.83) 

Comment: - The USDW classification must be reconsidered when siting Class VI wells. The 

best sources of drinking water are already being used by utilities. Coupled with 

challenges resulting from climactic changes, population growth and land 

development, many utilities are turning to more challenging groundwater sources 

such as those that are very deep or have high salinity concentrations, also 

because the pumping costs for these deep wells are no longer prohibitive given 

the lack of sufficient water elsewhere. Some of these new sources could fall 

outside of the current definition of a USDW, in that the aquifer has a TDS 

concentration higher than 10,000 ppm. EPA’s proposed rule promises protection of 

USDWs from endangerment yet there are no anti-degradation provisions in the 

44
proposed regulation to protect other groundwater supplies, such as those 

aquifers that are not classified as a USDW but have been, or may be, identified 

as a future drinking water source. The TDS criterion was written at a time when 

many advanced water treatment technologies were generally cost prohibitive. In 

light of the changes in the hydrological and technological landscape, we 

recommend that EPA reexamine the classification of USDWs based on TDS when 

considering the siting of Class VI geosequestration wells. The potential need to 

use saline aquifers for potable supply, particularly in water-stressed areas, 

should take precedence over the sequestration of carbon dioxide there. 

Response: The Agency acknowledges commenter concerns about water resources and future water

resource availability. However, modifying the definition of a USDW is outside the scope of the GS

rulemaking. USDWs are defined as aquifers currently being used as sources of drinking water or

those capable of supplying a public water system and they have a total dissolved solids (TDS)

content of 10,000 milligrams per liter or less (§144.3). 

The primary goal of the UIC Program under the SDWA is to protect USDWs in order to ensure a

reliable supply of drinking water for the American public. The GS rule, as part of the UIC program

regulations, continues the program’s tradition of ensuring the protection of USDWs. The permitting,

siting, construction, operation, monitoring, and post-injection site care requirements in the GS rule

built on a long-standing protective regulatory framework, tailored to the unique characteristics of

CO2 GS.

Commenter Name: Diane VanDe Hei Letter ID: 0206

Commenter Organization: Association of Metropolitan Water Agencies

(AMWA)

Comment ID:

22215

Other EPA Comment Codes and Descriptions: 1410 1.2.1 Comments in support of

EPA/rulemaking 

Comment: AWWA and AMWA appreciate the opportunity to comment on EPA’s proposal. The 

proposed regulation is a good technical starting point given the need to have a 

federal standard to guide permit writers. However, the technology is still in 

its infancy and as a result we urge EPA to exercise caution and to ensure the 

protection of USDWs and future USDWs from harmful unintended consequences. 

Response: As described above, EPA recognizes that injecting large volumes of CO2 for GS poses

unique challenges that, if not properly managed, could endanger drinking water sources or have other

adverse impacts. EPA agrees that caution is warranted and has, as a result, developed a new well

class with requirements tailored to address the unique challenges posed by GS and potential risks

associated long-term injection of CO2. These requirements include the tailored AoR delineation

process per §146.84, monitoring that is appropriate to GS projects per §146.90, and extended postinjection site care per §146.93. 

As part of its adaptive rulemaking approach, The Agency plans, every six years, to collect and

review data on GS projects to determine whether the appropriate amount and types of information

and documentation are being collected, and to determine if modifications to the requirements are

necessary.

Also, as EPA noted above the Agency believes that sufficient data and experience currently exist to

develop regulations for Class VI wells. EPA has considered the results of past research in developing

45
the GS rule.

Commenter Name: Diane VanDe Hei Letter ID: 0213

Commenter Organization: Association of Metropolitan Water Agencies

(AMWA)

Comment ID:

22914

Comment: The Association of Metropolitan Water Agencies (AMWA) appreciates the 

opportunity to comment on the proposed rule for permitting the geological 

sequestration of carbon dioxide. AMWA recognizes the importance of reducing 

carbon dioxide emissions to mitigate climate change impacts. Our member 

utilities across the country are engaged in efforts to reduce their carbon 

footprint and greenhouse gas emissions in a myriad of ways -- from increased 

efficiency to green power projects. However, protecting our nation’s water 

supply from potential negative impacts of the development of carbon 

sequestration projects is paramount. 

sequestration is currently very limited. Carbon sequestration is still largely 

untested and prudence is necessary to avoid any unintended consequences that 

could have long-term effects on underground sources of drinking water (USDWs). 

Response: EPA believes that sufficient data and experience currently exist to develop regulations for

Class VI wells. The GS rulemaking builds upon decades of knowledge about safe injection practices

regulated by the UIC Program. While developing the GS regulation, EPA has evaluated relevant GS

research, including projects conducted by the seven Regional Carbon Sequestration Partnerships

(RCSPs) funded by DOE and coordinated through the National Energy Technology Laboratory

(NETL), and several international projects.

Commenter Name: Diane VanDe Hei Letter ID: 0213

Commenter Organization: Association of Metropolitan Water Agencies

(AMWA)

Comment ID:

22916

Comment: efficiency to green power projects. However, protecting our nation’s water 

supply from potential negative impacts of the development of carbon 

sequestration projects is paramount. 

Response: EPA recognizes that injecting large volumes of CO2 for GS poses unique challenges that,

if not properly managed, could endanger drinking water sources or have other adverse impacts. EPA

agrees that caution is warranted and has, as a result, developed a new well class with requirements

tailored to address the unique challenges posed by GS and potential risks associated long-term

injection of CO2. These requirements include the tailored AoR delineation process per §146.84,

monitoring that is appropriate to GS projects per §146.90, and extended post-injection site care per

§146.93.

Commenter Name: Diane VanDe Hei Letter ID: 0213

Commenter Organization: Association of Metropolitan Water Agencies

(AMWA)

Comment ID:

22918

Other EPA Comment Codes and Descriptions: 1510 1.2.2.3 Need for additional study 

Comment: Therefore, AMWA recommends that the final regulation take a phased approach and 

prohibit the construction of CO2 sequestration wells in the following types of 

aquifers until more is known about the risks of CO2 sequestration to USDWs as a 

46
result of the effects and dynamics of the fluid in the subsurface: 

1. Aquifers currently used for potable water supply today, or 

2. Aquifers where it can be demonstrated that the aquifer will be used for 

potable supply in the future. AMWA is not trying to block carbon sequestration 

but believes that unintended consequences to the nation's water supply can be 

avoided by initially prohibiting the construction of CO2 wells in any aquifer 

for potable supply, and by waiting to construct sequestration wells through any 

USDW until there is a better understanding of the effects of carbon 

sequestration on the dynamics of the subsurface geology and geochemistry. EPA 

should then revisit this exclusion once the potential risk factors and 

unintended consequences to USDWs are better understood. 

Response: EPA clarifies that the final regulation does not allow injection of carbon dioxide into

USDWs. USDWs include both currently used sources and sources that may be used in the future.

Under §144.3 a USDW is defined as an aquifer or portion of an aquifer that supplies any public

water system or that contains a sufficient quantity of ground water to supply a public water system,

and currently supplies drinking water for human consumption, or that contains fewer than 10,000

mg/L total dissolved solids and is not an exempted aquifer. The GS rule requires injection below the

lowermost USDW, unless the owner or operator obtains a waiver from this requirement, in which

case injection may occur into non-USDWs that lie above or between USDWs, provided the

requirements at §146.95 are met. The final rule also allows for the expansion of the areal extent of

existing aquifer exemptions for Class II EOR/EGR wells transitioning to Class VI injection for GS

pursuant to requirements at §§146.4 and 144.7(d). Please see the discussion of "Class VI Injection

Depth Waivers and Use of Aquifer Exemptions for GS" in the preamble to the final rule for

additional information. 

The Agency acknowledges the commenter’s concerns about water resources and future water

resource availability. The primary goal of the UIC Program under the SDWA is to protect USDWs

from endangerment. Consistent with SDWA §1422, the UIC program provides that no injection shall

be authorized if it results in the movement of fluid containing any contaminant into USDWs, if the

presence of that contaminant may cause a violation of any primary drinking water regulation or may

adversely affect the health of persons as specified in §144.12.

The GS rule, as part of the UIC program regulations, continues the Program’s mandate under the

SDWA of ensuring the protection of USDWs from endangerment. EPA expects that the tailored

permitting, siting, construction, operation, monitoring, and post-injection site care requirements in

the GS rule will prevent leakage from injection formations and protect USDWs.

Commenter Name: Diane VanDe Hei Letter ID: 0213

Commenter Organization: Association of Metropolitan Water Agencies

(AMWA)

Comment ID:

22924

Other EPA Comment Codes and Descriptions: 1510 1.2.2.3 Need for additional study 

Comment: Protection of drinking water sources is our primary concern. AMWA is concerned 

about the potential for CCS projects to result in unintended, and possibly 

harmful, consequences to sources of drinking water. Much of the work in the CCS 

arena is still in pilot or pre-pilot phase. AMWA cautions against the permitting 

of large scale CCS projects until protection of potable or potentially potable 

47
aquifers can be established as a primary concern, and information about DOE 

pilot projects and the effects of carbon sequestration on the subsurface and 

USDW can be collected and analyzed. 

Response: As described above, EPA believes that sufficient data and experience currently exist to

develop regulations for Class VI wells. While developing the GS regulation, EPA evaluated relevant

GS research, including projects conducted by the seven Regional Carbon Sequestration Partnerships

(RCSPs) funded by DOE and coordinated through the National Energy Technology Laboratory

(NETL), and several international projects. 

EPA agrees that continued research will be integral to development of GS technology, but disagrees

that the Agency should wait for all current field research to be complete before finalizing the GS

rule. The Agency believes that establishing a regulatory framework for the future development and

deployment of CCS technology provides a framework for injecting CO2 so that the activity does not

result in endangerment of USDWs. 

EPA believes that the UIC Program, under the authority of the SDWA, provides a strong framework

for regulating injection of CO2 for GS and adds that the GS regulation tailors the UIC requirements

to address the unique issues associated with large-scale GS including large injection volumes, the

relative buoyancy of CO2, its corrosivity in the presence of water, the potential presence of

impurities in captured CO2, and its mobility within subsurface geologic formations.

Commenter Name: Diane VanDe Hei Letter ID: 0213

Commenter Organization: Association of Metropolitan Water Agencies

(AMWA)

Comment ID:

22954

Comment: water, CO2 and bedrock formations. Above all, drinking water needs should be 

considered paramount and EPA should consider the future drinking water needs of 

the country in light of climate change. EPA’s final rule should protect current 

and future USDWs from unintended consequences of CO2 geosequestration and moral 

hazard. 

Response: As described above, The Agency agrees that drinking water is an important resource to

protect. The primary goal of the UIC Program under the SDWA is to protect USDWs from

endangerment. Consistent with SDWA §1422, the UIC program provides that no injection shall be

authorized if it results in the movement of fluid containing any contaminant into USDWs, if the

presence of that contaminant may cause a violation of any primary drinking water regulation or may

adversely affect the health of persons as specified in §144.12.

The GS rule, as part of the UIC program regulations, continues the Program’s mandate under the

SDWA of ensuring the protection of USDWs from endangerment. EPA expects that the tailored

permitting, siting, construction, operation, monitoring, and post-injection site care requirements in

the GS rule will prevent leakage from injection formations and protect USDWs.

Commenter Name: Randy Joseph Letter ID: 0240

Commenter Organization: Western Organization of Resource Councils Comment ID: 23218

Comment: 1) Water: As you are aware, drinking water supplies are at potential risk of 

contamination from CO2 and any other hazardous materials that are injected 

during geologic sequestration. All areas where geologic sequestration will occur 

48
at important to the local people and economies as agricultural land, wildlife 

habitat, residential land, or for countless other reasons - all of which rely on 

clean water supplies. Thus, we urge EPA to take all steps necessary to protect 

this irreplaceable resource at all sites where geologic sequestration occurs. 

Response: The Agency agrees that drinking water is an important resource to protect. The primary

goal of the UIC Program under the SDWA is to protect USDWs from endangerment. Consistent

with SDWA §1422, the UIC program provides that no injection shall be authorized if it results in the

movement of fluid containing any contaminant into USDWs, if the presence of that contaminant may

cause a violation of any primary drinking water regulation or may adversely affect the health of

persons as specified in §144.12.

The GS rule, as part of the UIC program regulations, continues the Program’s mandate under the

SDWA of ensuring the protection of USDWs from endangerment. EPA expects the tailored

permitting, siting, construction, operation, monitoring, and post-injection site care requirements in

the GS rule to prevent leakage from injection formations and protect USDWs.

Commenter Name: Mic Stewart Letter ID: 0279

Commenter Organization: Metropolitan Water District of Southern CaliforniaComment ID: 24093

Comment: 43492). This potential practice to mitigate the effects of greenhouse gas 

emissions raises the concern of potential contamination to underground sources of 

drinking water, particularly sole-source aquifers. Other concerns include 

Response: The Agency agrees that drinking water is an important resource to protect. The primary

goal of the UIC Program under the SDWA is to protect USDWs from endangerment. Consistent

with SDWA §1422, the UIC program provides that no injection shall be authorized if it results in the

movement of fluid containing any contaminant into USDWs, if the presence of that contaminant may

cause a violation of any primary drinking water regulation or may adversely affect the health of

persons as specified in §144.12.

The GS rule, as part of the UIC program regulations, continues the Program’s mandate under the

SDWA of ensuring the protection of USDWs from endangerment. EPA expects that the tailored

permitting, siting, construction, operation, monitoring, and post-injection site care requirements in

the GS rule to prevent leakage from injection formations and protect USDWs.

The GS rule, at §146.82(a)(5) requires prospective owners or operators to submit information on all

USDWs within the AoR. EPA expects that this information will include identification of any sole

source aquifers. The GS rule also requires operators to submit extensive information about the site,

including the geologic characteristics of the injection and confining zones, to demonstrate that the

injected CO2 will remain within the target formation. The Director must consider this information

when determining whether GS is acceptable at a given site. EPA expects that during this evaluation

the Director will consider the potential impact of the GS project on any sole source aquifers.

Commenter Name: Mic Stewart Letter ID: 0279

Commenter Organization: Metropolitan Water District of Southern CaliforniaComment ID: 24095

Comment: Project utilizing water from the San Joaquin Sacramento River Bay Delta. While 

Metropolitan does not own or operate groundwater wells as part of its water 

supply operation, approximately 37% of the annual retail demands for water in our 

49
service area depend on local and regional groundwater supplies. Metropolitan and 

other agencies store surplus water in various groundwater basins throughout 

California for use during dry years. Metropolitan and the agencies it serves 

depend heavily on the viability of these important groundwater basins to produce 

the balance of regional supply needs. 

We would specifically ask that EPA not implement any geologic sequestration 

pilot program in a groundwater basin that is the sole source of supply for an 

urban area. Unproven commercial-scale geologic carbon sequestration technology 

may pose unintended impacts on groundwater basins and potentially compromise 

both water quality and water supply. 

The American Water Works Association (AWWA) has provided testimony and extensive 

written comment of this proposed regulation. The new class of injection well 

proposed under this rule specifically for injecting CO2 into deep, underground 

geologic formations is a source of primary concern for AWWA because of the 

potential contamination of underground sources of drinking water, particularly 

sole source aquifers, and the unintended, possibly harmful, consequences. 

Metropolitan shares this concern and joins with AWWA in the call to mitigate 

these concerns prior to any final rulemaking. 

While Metropolitan and the drinking water industry support meaningful efforts to 

reduce greenhouse gas emissions, it is our hope that any gain in these 

reductions does not come at the expense of vital drinking water supplies. 

Response: The Agency agrees that drinking water is an important resource to protect. The primary

goal of the UIC Program under the SDWA is to protect USDWs from endangerment. Consistent

with §1422, the UIC program provides that no injection shall be authorized if it results in the

movement of fluid containing any contaminant into USDWs, if the presence of that contaminant may

cause a violation of any primary drinking water regulation or may adversely affect the health of

persons as specified in §144.12.

The GS rule, as part of the UIC program regulations, continues the Program’s mandate under the

SDWA of ensuring the protection of USDWs from endangerment. EPA expects that the tailored

permitting, siting, construction, operation, monitoring, and post-injection site care requirements in

the GS rule will prevent leakage from injection formations and protect USDWs.

The GS rule, at §146.82(a)(5) requires prospective owners or operators to submit information on all

USDWs within the AoR. EPA expects that this information will include identification of any sole

source aquifers. The GS rule also requires operators to submit extensive information about the site,

including the geologic characteristics of the injection and confining zones, to demonstrate that the

injected CO2 will remain within the target formation. The Director must consider this information

when determining whether GS is acceptable at a given site. EPA expects that during this evaluation

the Director will consider the potential impact of the GS project on any sole source aquifers.

EPA recognizes that injecting large volumes of CO2 for GS poses unique challenges and risks that,

if not properly managed, could endanger drinking water sources or have other adverse impacts. EPA

agrees that caution is warranted and has, as a result, developed a new well class with requirements

tailored to address the unique challenges posed by GS and potential risks associated long-term

injection of CO2. These requirements include the tailored AoR delineation process per §146.84,

50
monitoring that is appropriate to GS projects per §146.90, and extended post-injection site care per

§146.93.

Commenter Name: Cynthia Lane Letter ID: 0528

Commenter Organization: American Water Works Association (AWWA) Comment ID: 21381

Comment: Our overarching concern regarding geologic carbon sequestration is the potential 

contamination of underground sources of drinking water from injection activities 

and the potential for other unintended and potential, possibly harmful 

consequences. 

AWWA is particularly concerned about the potential for contamination of sole 

source aquifers and suggests that these aquifers be provided special protective 

measures in the proposed rule. We also support the portion of the rule that 

Response: The Agency agrees that drinking water is an important resource to protect. The primary

goal of the UIC Program under the SDWA is to protect USDWs from endangerment. Consistent

with §1422, the UIC program provides that no injection shall be authorized if it results in the

movement of fluid containing any contaminant into USDWs, if the presence of that contaminant may

cause a violation of any primary drinking water regulation or may adversely affect the health of

persons as specified in §144.12.

The GS rule, as part of the UIC program regulations, continues the Program’s mandate under the

SDWA of ensuring the protection of USDWs from endangerment. EPA expects that the tailored

permitting, siting, construction, operation, monitoring, and post-injection site care requirements in

the GS rule to prevent leakage from injection formations and protect USDWs.

The GS rule, at §146.82(a)(5) requires prospective owners or operators to submit information on all

USDWs within the AoR. EPA expects that this information will include identification of any sole

source aquifers. The GS rule also requires operators to submit extensive information about the site,

including the geologic characteristics of the injection and confining zones, to demonstrate that the

injected CO2 will remain within the target formation. The Director must consider this information

when determining whether GS is acceptable at a given site. EPA expects that during this evaluation

the Director will consider the potential impact of the GS project on any sole source aquifers.

EPA agrees that, in many cases, UIC Directors will have extensive knowledge of which areas are

suitable for GS, but clarifies that it is the responsibility of Class VI permit applicants to demonstrate

the suitability of a particular site or formation. It is the responsibility of the Director to evaluate the

information collected and submitted by the owner or operator to determine whether a permit for GS

at the site is appropriate.

Commenter Name: Cynthia Lane Letter ID: 0528

Commenter Organization: American Water Works Association (AWWA) Comment ID: 21383

Other EPA Comment Codes and Descriptions: 4324 2.4.4.1.2 Comments opposed to requiring

injection below the lowermost USDW 

Comment: As the demand for water increases during the upcoming century and changes in 

climate impact traditional water supplies, water utilities will look for new 

sources of drinking water. It is likely that as a result of these changes, there 

will be a greater reliance on ground water for both new supplies and conjunctive 

51
use. The possibility exists that utilities might want to use some of these 

injection site aquifers as new potable sources. In fact, in several communities 

across the country, brackish waters that are previously considered to be 

unusable because they are above ten thousand TDS are now being used as drinking 

water sources. 

As desalination technology advances, the brackish water sources are treated to 

EPA drinking water standards and provided to water utility customers. As this 

technology improves, even more saline water may be used in the future therefore 

AWWA suggest that the selection standards for potential injection aquifers and 

for USDW's be reviewed and revised to prevent contamination of aquifers that may 

be considered viable sources of drinking water in the near future. 

Response: The Agency acknowledges the commenter’s concerns about water resources and future

water resource availability. However, modifying the definition of a USDW is outside the scope of

the GS rulemaking. USDWs are defined as aquifers currently being used as sources of drinking

water or those capable of supplying a public water system, with a total dissolved solids (TDS)

content of 10,000 milligrams per liter or less as specified in §144.3. 

The primary goal of the UIC Program under the SDWA is to protect USDWs from endangerment in

order to ensure a reliable supply of drinking water for the American public. The GS rule, as part of

the UIC program regulations, continues the program’s tradition of ensuring the protection of

USDWs. EPA expects that the tailored permitting, siting, construction, operation, monitoring, and

post-injection site care requirements in the GS rule will prevent leakage from injection formations

and protect USDWs.

As described above, EPA agrees that protecting USDWs from endangerment must be a top priority.

The Agency believes that there are limited circumstances where injection above the lowermost

USDW can be performed in a manner that protects USDWs, as long as appropriate protections are in

place. The final GS rule at §146.95 establishes a process by which owners or operators can seek a

waiver of the Class VI injection depth requirements for injection into non-USDW formations above

and/or between USDWs.

Commenter Name: Cynthia Lane Letter ID: 0528

Commenter Organization: American Water Works Association (AWWA) Comment ID: 21384

Comment: Owner/operators should be required to involve local planning departments and 

water utilities to determine if any of our subsurface aquifers may be used as 

drinking water source in the future. 

Water chemistry in the underground setting is complex and AWWA has several 

technical concerns regarding the potential for carbon sequestration to 

contaminate USDWs. Preventing degradation of water should not just be limited to 

contaminants with established maximum contaminant levels, but should also 

include other constituents whose presence may either make ground water more 

difficult to treat or impact the beneficial uses of at ground water. 

Several references on geologic carbon sequestration discussed changes in the 

carbonate cycle resulting in lowered pH conditions and the release of iron, 

manganese, arsenic and possibly other inorganics into groundwater surrounding 

52
the injection zone. 

Response: EPA clarifies that existing regulations under 40 CFR 124.10(c)(1)(x) require the

notification of local governments with jurisdiction over the area where the Class VI well is proposed

to be located when the draft permit is available for public comment. In addition, EPA has added a

requirement at §124.10(c)(1)(xi) that the PWSS program director, among other agencies, must be

notified as part of the public notice process for a Class VI permit. EPA expects that the PWSS

director will inform PWSs in the area of review about the proposed GS project. 

EPA acknowledges that there are potential risks associated with GS, including the potential that CO2

injection for GS may result in leaching of subsurface materials that could mobilize contaminants or

compromise pore space, and therefore injectivity. The purpose of the Class VI requirements is to

minimize and mitigate potential/identified risks through proper site characterization, well

construction, operation, monitoring, post-injection site care, and site closure. To ensure USDW

protection and mitigate risks, the GS regulation requires the owner or operator of a Class VI well to

submit data about the site (during the site characterization process), including information on the

porosity, permeability, mineralogy, and geochemistry of the injection and confining zones, along

with information on the compatibility of the CO2 stream with fluids in the injection zone and

minerals in both the injection and confining zones as specified in §146.82. This data will help

identify potential geochemical reactions that may occur between the injected CO2 and the host

geologic formation. Identification of potential reactions prior to injection would address concerns

that formation of carbonic acid could dissolve potential limestone creating karst features. 

During injection operations, operators must extensively monitor ground water quality to provide

early detection of any unacceptable movement of fluids or impurities in the subsurface as specified

in §146.90. Operators must develop and follow an emergency and remedial response plan to address

any adverse effects associated with the GS operation, including contamination as specified in

§146.94, and provide financial responsibility to address contamination as specified in §146.85.

Commenter Name: Dag Nummedal Letter ID: 0533

Commenter Organization: Colorado Energy Resource Institute Comment ID: 21477

Comment: What happens when you put CO2 into the subsurface. One is that when you are 

pumping the large quantities of CO2 that we will be looking at, there are 

formations that will be deformed. They are deformed both by hydrological, by 

thermal and by chemical disturbances from injected CO2. In turn, this for those 

who are reading, I am reading the second paragraph, in turn this deformation 

probably will have a profound effect both on the hydro mechanical and the 

transport response of the injected fluid itself. And of course, fractures are 

particularly important in the subsurface because they are already are in the 

conduit, but they are in the pipeline that work, that carry fluids through the 

rocks. So for that reason we do not have focus a lot of research and very little 

has been done on this yet, to really get an understanding of the distribution 

properties and response of both the natural and induced fractures. How do they 

respond to fluid pressure? To the temperature changes? To the mineralogical 

changes? We can both dissolve minerals in the fluid in the subsurface and you 

can re-precipitate others. This will change the injectivity of CO2. 

Also many fractures create new fresh surfaces and guess what? When you create a 

new fresh surface, that surface is typically chemically very reactive, much more 

53
so than an old rock surface that has been weathered on the surface so 

understanding -- what is called the reactive transport modeling in the technical 

lingo, is basically understanding how the chemistry over fluid moving past this 

reactive surfaces. They change the mineral assemblage and in turn start growing 

crystals or dissolving crystals and changing activity. 

To this, of course, then in the long run they change the mobility of fluids at 

least the mobility of CO2 and where it is trapped and how much we are trapping 

in the subsurface. We are going about this with a combination of flow modeling 

laboratory work and we are starting the project building on what we believe are 

the two most advanced numerical modeling codes in the world today developed by a 

partner in this, and our partners are the Livermore National Lab in Livermore, 

California and the Lawrence Berkeley lab on the Berkeley campus. These labs have 

Response: EPA acknowledges that injection of large volumes of CO2 into the subsurface poses

potential risks associated with fluid movement, deformation in the subsurface, and the potential for

leakage of CO2 into USDWs, which could result in the mobilization of substances that could pose

threats to human health by endangering USDWs. 

The purpose of the Class VI requirements is to minimize and mitigate potential/identified risks

through proper site characterization, computational AoR modeling that accounts for the multiphase

flow of CO2 and native fluids, well construction, operation, monitoring, post-injection site care, and

site closure. The mandate of the UIC Program under the SDWA, and the GS rule, is to protect public

health by ensuring the protection of USDWs from endangerment. The GS rule accomplishes this

through requirements tailored to address the unique nature of GS, including the large volumes of

CO2 injected, its buoyancy and potential corrosivity in the presence of water, and impurities in the

CO2 stream. Many of these requirements specifically address the potential for mobilized substances

to affect USDWs. 

For example, the owner or operator must submit data about the site, including information on the

porosity, permeability, mineralogy, and geochemistry of the targeted injection and confining zones.

Operators must also present information on the compatibility of the CO2 stream with fluids in the

injection zone and minerals in both the injection and confining zones as specified at §146.82(c)(3).

The data can help identify potential geochemical reactions between the injected CO2 and the host

geologic formations, which could result in the plugging of pore spaces or the dissolution of

formation minerals. During injection operations, operators must extensively monitor ground water

quality to provide early detection of any unacceptable movement of fluids or impurities in the

subsurface as specified in §146.90. Operators must develop and follow an emergency and remedial

response plan to address any adverse effects associated with the GS operation as specified in §146.94

and provide financial responsibility to address contamination as specified in §146.85.

Commenter Name: Dag Nummedal Letter ID: 0533

Commenter Organization: Colorado Energy Resource Institute Comment ID: 21480

Other EPA Comment Codes and Descriptions: 1960 1.4.4.5 Consultations with NGOs, e.g.,

environmental and citizens groups 

Comment: But according to your point number seven in the handout for today's meeting, 

where you talk about EPA has an upstanding history of working with academic 

community and the national labs to answer basic science questions and I am 

delighted to see that and I know that in fact. I have been dealing with EPA for 

54
a long time too and I am very pleased that in fact, the labs that you are 

mentioning are mostly the same ones that we believe are the leadership precision 

in this research. You do mention the Lawrence lab. You mention the Pacific 

Northwest labs you are working through, but not formally in this particular 

proposal and you have mentioned little more, but of course [indecipherable] 

strength in the carbon sequestration [indecipherable]. 

Then you mention the regional carbon sequestration partnerships in Colorado is 

member of the southwest partnership headed up by Brian McPherson. Started out in 

New Mexico [indecipherable]. Brian is now at the University of Utah and close 

friend of all of ours. So I have a very close interaction with that partnership 

and also the Big Sky partnership in Montana, in the Great Plains. Now where our 

research already is different and will continue to differ from the partnership 

is that we are not trying to focus on kind of a regional assessment on what 

particular methodology works where which is very much part of the partnership 

and of course, we need that. But instead we want to sit back and look at a much 

more fundamental geomechanical, geomicrobiological and geochemical reactions in 

the subsurface in any kind of rock and we will limit [indecipherable] submitted 

if it gets funded. Get samples and data from these three partnerships that I 

mentioned, so that the research will be tied to the specific environments in the 

Rocky Mountains very likely to store CO2. 

So I think that is -- oh I mentioned the Sleipner project which of course is 

well known. Because Sleipner I attached some CO2 emissions back in 1995 and 

1996. I have mailed it and advantageous for [indecipherable] business 

perspective start sequestering CO2 and I learned a great deal in the process 

about it, so becoming a leader provider on the carbon sequestration expertise 

and technology. The and I have been working with Stockholm for a long time as 

you can tell from my accent, I did not grow up in Louisiana, some people think. 

Response: While developing the GS regulation, EPA evaluated relevant GS research, including

projects conducted by the seven regional carbon sequestration partnerships funded by the U.S.

Department of Energy (DOE) and coordinated through the National Energy Technology Laboratory

(NETL), and several international projects, including Sleipner. A paper summarizing EPA's research

on international GS projects and legislation is in the rulemaking docket. Additionally, EPA's Office

of Water continues to fund research at the Lawrence Berkeley National Laboratory examining the

effects of CO2 interaction on ground water aquifers and any potential mobilization of trace elements

that may occur. EPA is communicating with other research organizations and academic institutions

including, among others, Princeton University, Massachusetts Institute of Technology, and Montana

State University, where specific research on geologic sequestration, injection well materials, and

CO2 monitoring techniques is in progress. EPA is also working with DOE, USGS, and others to

identify tools and training techniques that will provide GS permitting assistance and technical

expertise as appropriate. Additionally, EPA's Office of Research and Development (ORD) is

undertaking multiple research efforts on GS. Topics of research include bolstering different default

thermodynamic databases to include more comprehensive information on aqueous complexes and

solid-phases that contain carbonate/bicarbonate and toxic elements for which EPA has a listed MCL

(maximum concentration level) for safe drinking water. 

EPA is using an adaptive approach to regulating GS under the UIC Program. Even after finalization

of the GS regulation, the Agency will, every six years, collect and review data on GS projects to

55
determine whether the appropriate amount and types of information and appropriate documentation

are being collected, and to determine if modifications to the requirements are appropriate or

necessary.

EPA agrees that research into GS is important and confirms that, as the commenter notes, the final

GS rule was informed by research at LBNL, Pacific Northwest laboratories, the RCSPs, and

international GS research. EPA continues to fund research on GS. As part of its adaptive rulemaking

approach, EPA will continue to review available research on fluid movement. 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

determine if modifications to the requirements are appropriate or necessary.

Commenter Name: George Peridas Letter ID: 0534

Commenter Organization: Natural Resources Defense Council (NRDC) Comment ID: 21464

Comment: I would like to mention since there is talk of contamination of groundwater that 

we need to be careful to distinguish risks from hazards. A hazard is something 

that can potentially go wrong. A risk involves the probability of it. What we 

really need to do is take a good look at which of these hazards are linked to 

what probabilities and to what extent they amount in. I do believe that in the 

case of sequestration, we can effectively manage a lot of those risks. 

Response: EPA recognizes that injecting large volumes of CO2 for GS poses unique challenges that,

if not properly managed, could endanger drinking water sources and have other adverse impacts.

However, the final, tailored, Class VI requirements address the large volumes of CO2 injected, its

buoyancy, potential corrosivity in the presence of water, and potential impurities in the CO2 stream.

In addition, EPA expects the tailored permitting, siting, construction, operation, monitoring, and

post-injection site care requirements in the GS rule to prevent leakage from injection formations and

protect USDWs.

EPA believes that building upon the existing UIC requirements (e.g., Class I and Class II well

requirements) to develop the Class VI GS regulations provides a protective foundation for ensuring

protection of USDWs based on successful field experience, and lessons learned about CO2 injection

in other applications.

Commenter Name: Talib Syed Letter ID: 0537

Comment ID: 21475

Comment: One other concern that I have is of you know, again the safety of underground 

water sources. So the design of the well and the operation because when, when 

you are dealing with CO2, it is very important that you be aware of the phase 

behavior of CO2. We are all aware that CO2 could be in a liquid phase, in a 

supercritical gaseous phase, it could be a supercritical gas or a solid, 

etcetera and that is why the critical temperature, critical pressure comes in. 

So a requirement that you always operate at a certain depth where you are above 

the critical temperature, you are above the critical pressure becomes important 

because otherwise you are going to have unintended consequences. Particularly 

what you have got to watch out for is a catastrophic release. Small releases, 

okay you can manage it, but if you have got a catastrophic release, then 

everything you know, comes to naught. 

56
Response: EPA recognizes that all phases of CO2 must be considered in determining the suitability

of GS projects. Under §146.84, the owner or operator must delineate the area of review for Class VI

wells using computational modeling that accounts for the physical and chemical properties of all

phases of the injected CO2 stream. Modeling must be based on available site characterization,

monitoring, and operational data. The definition of the AoR in the proposed rule accounted for the

varying physical and chemical properties of the CO2 including free-phase and water-dissolved CO2.

GS takes place thousands of feet below the Earth’s surface within porous spaces in deep rock

formations. CO2 is injected for GS through technically engineered wells with multiple barriers

designed to isolate the injectate in the well and protect formations outside the well materials. The

injected CO2 is stored in geologic formations underneath confining layers of rock that act as natural

barriers to leakage. It is unlikely that CO2 will escape from a GS site that is properly sited, operated,

monitored, and closed. During the site selection process under §146.83, operators of Class VI wells

identify and evaluate the appropriateness of a site for GS of CO2. The evaluation includes the

identification of surface and subsurface features such as deep stratified lakes and other naturally

occurring pockets of CO2. Furthermore, during GS operation, injection pressures and formation

conditions are monitored to avoid overpressuring the storage formation.

Comment Code: 1612 1.3.1.1 Leaching and mobilization of contaminants; reactions in injection

zone 

Individual Comments

Commenter Name: Herbert Skolnick, Ph.D. Letter ID: 0110

Commenter Organization: Group Against Smog and Pollution, Inc. (GASP) Comment ID: 22036

Comment: Potential for Adverse Chemical Reactions: 

The corrosive nature of carbon dioxide in the presence of water was noted 

several times during the work sessions conducted during the late-February CO2 

sequestration meetings. [FN1: U.S. ENVIRONMENTAL PROTECTION AGENCY, Proposed UIC 

Regulations for Geologic Sequestration of Carbon Dioxide, Feb. 26-27, 2008.] 

Chemical reactions between the injected carbon dioxide and the pore water in the 

host rock should be expected, resulting in solution and redeposition of host 

mineral material and loss of pore volume. 

For thirty years, the reviewer worked as a geologist for Gulf Oil studying and 

analyzing thousands of surface and subsurface samples of sandstones and 

quartzite rocks 

from different parts of the world. Siliceous overgrowths on the quartz grains 

making up these rocks were common and in some instances resulted in the total 

loss of pore volume. The overgrowths ranged from amorphous silica, various 

cherts, cryptocrystalline quartz to quartz deposited in crystalline continuity 

with the host grains. [FN 2: Skolnick. H., The Quartzite Problem, JOUR. SED. 

PET. V.35, p.12-22 (1965), (The most extreme observed example was a core from 

57
Peru in which all of the pore volume was filled with the mineral pyrite)] Thus 

when the presence of silica is suspected in a CO2 stream,[FN 3: For instance, 

CO2 derived from the combustion of coal may contain significant levels of silica 

due to the presence of fly ash in the waste stream.] silica content should be 

determined prior to sequestration - particularly where storage in sandstone or 

quartzite formations is contemplated. 

Response: EPA acknowledges that there are potential risks associated with GS, including the

potential for leakage of CO2 into USDWs, which could result in the mobilization of substances that

could pose threats to human health by endangering USDWs. The purpose of the Class VI

requirements is to minimize and mitigate potential/identified risks through proper site

characterization, well construction, operation, monitoring, post-injection site care, and site closure.

The mandate of the UIC Program under the SDWA is to protect public health by ensuring the

protection of USDWs from endangerment. The GS rule accomplishes this through requirements

tailored to address the unique nature of GS, including the large volumes of CO2 injected, its

buoyancy and potential corrosivity in the presence of water, and impurities in the CO2 stream. Many

of these requirements specifically address the potential for mobilized substances to affect USDWs. 

For example, the owner or operator must submit data about the site, including information on the

porosity, permeability, mineralogy, and geochemistry of the targeted injection and confining zones.

Operators must also present information on the compatibility of the CO2 stream with fluids in the

injection zone and minerals in both the injection and confining zones as specified at §146.82(c)(3).

The data can help identify potential geochemical reactions between the injected CO2 and the host

geologic formations, which could result in the plugging of pore spaces or the dissolution of

formation minerals. During injection operations, operators must extensively monitor ground water

quality to provide early detection of any unacceptable movement of fluids or impurities in the

subsurface as specified in §146.90. Operators must develop and follow an emergency and remedial

response plan to address any adverse effects associated with the GS operation as specified in §146.94

and provide financial responsibility to address contamination as specified in §146.85.

Commenter Name: Emily Rochon Letter ID: 0129

Commenter Organization: Greenpeace International Comment ID: 23063

Comment: Leaking carbon dioxide from underground storage sites could also contaminate 

fresh water reservoirs rendering them unfit for human consumption, especially if 

other contaminants -- e.g. mobilized (toxic) metals like sulfates, or chloride 

-- reach dangerous levels. If options are considered where CO2 is to be stored 

in saline formations then the consequences of the displacement of in-situ saline 

waters (brines) must be considered. The displaced brines migrate, possibly 

Response: EPA acknowledges that there are potential risks associated with GS including the

potential for leakage of CO2 into USDWs which may result in the mobilization of substances that

could endanger USDWs. The purpose of the Class VI requirements is to minimize and mitigate

potential/identified risks through proper site characterization, well construction, operation,

monitoring, post-injection site care, and site closure. The rule at §146.82 requires owners or

operators to submit extensive data about a proposed GS site to identify (and eliminate) sites with

potential for unacceptable fluid movement. EPA believes that this information, in conjunction with

AoR modeling required at §146.84, will help identify the potential for brine migration as a result of

pressure displacement. Subsequently, the Director and owner or operator can identify ways to

mitigate this risk prior to injection or, if necessary, the Director can deny an injection permit. During

injection operations, operators must extensively monitor ground water quality and pressure changes

58
to provide early detection of any unacceptable movement of fluids or impurities in the subsurface as

specified in §146.90. Operators must also develop and follow an emergency and remedial response

plan to address any adverse effects associated with the GS operation as specified in §146.94 and

maintain financial responsibility to address contamination as specified in §146.85. 

EPA has funded research from the Lawrence Berkeley National Laboratory using models covering a

range of USDW fluid and host reservoir properties (based upon 38,000 groundwater samples)

indicating that, although leakage of CO2 into a USDW could result in the increase of certain trace

element concentrations, including arsenic and lead, rarely exceeding EPA drinking water standards

(Birkholzer et al., 2008). EPA has also examined potential methods for conducting treatment of

water affected by a CO2 leak; this study is presented in the final rulemaking docket.

Commenter Name: James Dooley Letter ID: 0156

Commenter Organization: Joint Global Change Research Institute, Pacific

Northwest National Laboratory

Comment ID:

22673

Comment: - Page 43497 under "What are the risks associated with CO2 GS?" I do not see 

any reason to include the modifier "likely" in the first sentence of "Potential 

USDW Impacts." Under what set of circumstances would CO2 injected into a waterbearing deep geologic formation not come into contact with formation waters? 

Delete "likely" from this sentence. It does not help readers understand CCS or 

how EPA will regulate CO2 storage. 

Response: EPA acknowledges that there are potential risks associated with GS, including the

potential that CO2 injection for GS may result in leaching of subsurface materials that could

mobilize contaminants or compromise pore space, and therefore injectivity. The purpose of the Class

VI requirements is to minimize and mitigate potential/identified risks through proper site

characterization, well construction, operation, monitoring, post-injection site care, and site closure.

To ensure USDW protection and mitigate risks, the GS regulation requires the owner or operator of

a Class VI well to submit data about the site (during the site characterization process), including

information on the porosity, permeability, mineralogy, and geochemistry of the injection and

confining zones, along with information on the compatibility of the CO2 stream with fluids in the

injection zone and minerals in both the injection and confining zones as specified in §146.82. This

data can help identify potential geochemical reactions that may occur between the injected CO2 and

the host geologic formation. Identification of potential reactions prior to injection would address

concerns that formation of carbonic acid could dissolve potential limestone creating karst features. 

During injection operations, operators must extensively monitor ground water quality to provide

early detection of any unacceptable movement of fluids or impurities in the subsurface as specified

in §146.90. Operators must develop and follow an emergency and remedial response plan to address

any adverse effects associated with the GS operation, including contamination as specified in

§146.94, and provide financial responsibility to address contamination as specified in §146.85.

Commenter Name: Mark Singer Letter ID: 0504

Commenter Organization: Green America Project, LLC Comment ID: 21248

Comment: Now, it's obvious that bad things can happen if this goes wrong. CO2 can 

interact chemically with lime right at the injection site even without it, you 

know, moving around, even without it escaping through the well initially. This 

could create carbonic acid, reacting CO2 with water. This could dissolve 

59
limestone or other susceptible rock and underground, underground karst region 

could be created. This could cause a collapsed area due to reduced subjacent 

support. 

The EPA was handling, was, I'm sorry. The EPA participated in the National 

Carbon Sequestration Atlas. And according to the National Atlas, there's a 

section there on engineering aspects of karsts. According to the National Atlas, 

karst lithology already poses problems in many areas of the United States. 

Now, in the EPA's Federal Register publication they call carbonic acid a weak 

acid. This is a, this is a, when we say, weak acid, it's a technical term, it 

has to do with the acid's intrinsic reactivity as compared to other types of 

acids. But it does not take into the account the issue of concentration of the 

carbonic acid. 

The carbonic, the weathering that we see in underground caves is the result of 

atmospheric CO2 dissolving in water and then that attacks the rock and carves 

out all these wonderful caves and such, and also causes many areas where 

subsidence occurs because the subjacent support has been undermined. 

But the percentage of CO2 in the atmosphere is way below one percent, and here 

we're talking about 100 percent CO2 and putting that down by the water source. 

So even though it's in a technical sense a weak acid its concentration will be 

much higher. This concentrated carbonic acid would chemically attack susceptible 

rock, much more fiercely than naturally occurring processes, you'd have karsts 

on steroids. 

Response: EPA acknowledges that there are potential risks associated with GS, including the

potential that CO2 injection for GS may result in leaching of subsurface materials that could

mobilize contaminants or compromise pore space, and therefore injectivity, which may result in

USDW endangerment. The purpose of the Class VI requirements is to minimize and mitigate

potential/identified risks through proper site characterization, well construction, operation,

monitoring, post-injection site care, and site closure. To ensure USDW protection and mitigate risks,

the GS regulation requires the owner or operator of a Class VI well to submit data about the site

(during the site characterization process), including information on the porosity, permeability,

mineralogy, and geochemistry of the injection and confining zones, along with information on the

compatibility of the CO2 stream with fluids in the injection zone and minerals in both the injection

and confining zones as specified in §146.82. This data can help identify potential geochemical

reactions that may occur between the injected CO2 and the host geologic formation. Identification of

potential reactions prior to injection would address concerns that formation of carbonic acid could

dissolve potential limestone creating karst features. 

During injection operations, operators must extensively monitor ground water quality to provide

early detection of any unacceptable movement of fluids or impurities in the subsurface as specified

in §146.90. Operators must develop and follow an emergency and remedial response plan to address

any adverse effects associated with the GS operation, including contamination as specified in

§146.94, and provide financial responsibility to address contamination as specified in §146.85.

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

60
Individual Comments

Commenter Name: Michael H. Cochran Letter ID:

0108

Commenter Organization: Bureau of Water, Division of Environment, Kansas

Department of Health & Environment (KDHE)

Comment

ID: 21960

Comment: 144.81: The quality of the injection stream in regards to a minimum 

concentration of CO2 should be established to ensure that it is actually a CO2 

sequestration project and to limit the injection of other harmful or undesirable 

gases. 

Response: The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a

percent CO2). Instead, the GS rule addresses the quality and quantity of impurities by requiring

owners or operators to submit information on the source of the CO2 and its physical and chemical

properties. Specifically, the GS rule requires the owner or operator to submit data about the site,

including an analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the 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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals. 

Since the GS rule, at §146.81(d), prohibits the injection of CO2 streams that meet the definition of a

hazardous waste under 40 CFR part 261, injection of a CO2 stream that is determined to be a

hazardous waste may only occur in a Class I hazardous waste injection well.

Commenter Name: Elizabeth Lokey Letter ID: 0112

Commenter Organization: Camco International Comment ID: 22046

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: Currently, the proposed rule (EPA-HQ-OW-2008-0390) defines CO2 that can 

be injected under a class VI designation as the following: 

"CO2 that has been captured from an emission source (e.g. power plant), 

plus incidental associated substances derived from the source materials and the 

capture process, and any substances added to the stream to enable or improve the 

injection process. This subpart does not apply to any carbon dioxide stream that 

meets the definition of a hazardous waste under 40 CFR Part 261." 

This definition is vague and needs clarification in terms of the percentage of 

CO2 in a given volume of gas to allow the CO2 to qualify for this injection 

permit. Otherwise, entire stack emissions or chemicals used in the separation 

process could end up being transported and injected. This could have unintended 

consequences on the reservoirs where the CO2 is stored as minerals could be 

dissolved and allow plumes to spread. 

Response: The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a

61
percent CO2). Instead, the GS rule addresses the quality and quantity of impurities by requiring

owners or operators to submit information on the source of the CO2 and its physical and chemical

properties. Specifically, the GS rule requires the owner or operator to submit data about the site,

including an analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the 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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals. 

EPA understands 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 low. However, these estimates are

based on limited information, and uncertainties remain about the expected concentrations of

impurities from the various types of CO2 streams. The concentrations of minor and trace elements in

CO2 streams for GS projects are likely to vary by facility, coal composition, plant operating

conditions, and pollution removal technologies. EPA clarifies that the GS rule does not apply to

capture technologies.

Commenter Name: Doug Louis Letter ID: 0121

Commenter Organization: Kansas Corporation Commission Comment ID: 22075

Comment: Rules that apply to impurities of the CO2 injectate should be further discussed, 

determined and defined for permitting certainty. 

Response: 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 low. However, these

estimates are based on limited information, and uncertainties remain about the expected

concentrations of impurities from the various types of CO2 streams. The concentrations of minor

and trace elements in CO2 streams for GS projects are likely to vary by facility, coal composition,

plant operating conditions, and pollution removal technologies. 

The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a percent CO2).

Instead, the GS rule addresses the quality and quantity of impurities by requiring owners or operators

to submit information on the source of the CO2 and its physical and chemical properties.

Specifically, the GS rule requires the owner or operator to submit data about the site, including an

analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the 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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals. 

Since the GS rule, at §146.81(d), prohibits the injection of CO2 streams that meet the definition of a

hazardous waste under 40 CFR part 261, injection of a CO2 stream that is determined to be a

hazardous waste may only occur in a Class I hazardous waste injection well.

Commenter Name: John Stormon Letter ID: 0123

Commenter Organization: Washington State Dept. of Ecology Comment ID: 23010

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

62
non-CO2 waste streams. One of the most disturbing aspects of the proposed 

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

the contaminants would make the CO2 a hazardous waste. Injected gases may not 

qualify as a hazardous waste under current standards. It appears that the 

proposed rules would allow a facility to import waste materials to add to the 

CO2 and be injected as a cheap disposal option; this should be prevented. 

Washington State prohibits the injection non-CO2 contaminants if technology is 

available for their removal; Washington also prohibits the use of underground 

injection for most waste disposal. An alternative option would be to allow nonCO2 contaminants only as specifically addressed in a facility's permit and a 

statement that the non-CO2 contaminants must be by-products of the CO2 stream 

and may not be imported for disposal by injection with the CO2. 

Response: The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a

percent CO2). Instead, the GS rule addresses the quality and quantity of impurities by requiring

owners or operators to submit information on the source of the CO2 and its physical and chemical

properties. Specifically, the GS rule requires the owner or operator to submit data about the site,

including an analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the 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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals.

Commenter Name: Sam Kitto Letter ID: 0126

Commenter Organization: National Tribal Air Association Comment ID: 23044

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: Hazardous Substances With respect to hazardous substances, the GS rule would 

prohibit the injection of these substances in Class VI injection wells (e.g., 

specific to geologic sequestration), but the EPA offers no means for removing 

hazardous impurities such as hydrogen sulfide and mercury which are often found 

in CO2 streams, the types that would be sequestered as a result of the rule. In 

the rule, the Agency instead focuses on what is considered a hazardous substance 

under the Comprehensive Environmental Response, Compensation, and Liability Act, 

also known as CERCLA or Superfund; and the potential liability to owners and 

operators of geologic sequestration operations for injection of CO2 and 

associated hazardous substances. 

Indeed, liability is an important matter that needs to be addressed upfront, 

particularly since some Indian tribes and their citizens may one day be engaged 

in geologic sequestration. The EPA must not forget, however, that a primary 

purpose of the GS rule is to prevent endangerment to underground sources of 

drinking water (USDWs). As such, every effort should be made by the Agency to 

ensure that hazardous substances, at any level, do not find their way into USDWs 

so as to best protect human health and the environment from the harmful impacts 

of these substances. 

The NTAA therefore recommends that the EPA clearly communicate how it will 

address hazardous impurities often found in CO2 streams, specifically how such 

63
impurities will be removed or their impacts mitigated so as not to endanger 

USDWs. 

Response: EPA agrees that protecting USDWs from endangerment is the primary purpose of the GS

rule, and that the purpose of the tailored requirements in the GS rule is to ensure that GS projects are

permitted sited, constructed, operated, and closed in a manner that avoids releases of CO2 into

USDWs.

The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a percent CO2).

Instead, the GS rule addresses the quality and quantity of impurities by requiring owners or operators

to submit information on the source of the CO2 and its physical and chemical properties.

Specifically, the GS rule requires the owner or operator to submit data about the site, including an

analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the 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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals. 

Because the GS rule, at §146.81(d), prohibits the injection of CO2 streams that meet the definition of

a hazardous waste under 40 CFR part 261, injection of a CO2 stream that is determined to be a

hazardous waste may only occur in a Class I hazardous waste injection well. 

EPA supports the use of CO2 capture technologies that minimize impurities in the CO2 stream, but

clarifies that the GS rule does not address the development or regulation of capture technologies or

technologies for removing impurities from CO2.

EPA is promulgating the GS rule under the authority of the SDWA. To the extent the commenter is

seeking interpretations of RCRA or CERCLA, such interpretations are beyond the scope of this

rulemaking.

Commenter Name: Emily Rochon Letter ID: 0129

Commenter Organization: Greenpeace International Comment ID: 23071

Comment: Our principle concern with this proposed regulation is a lack of specificity on 

the required purity of CO2 being injected underground. Sequestering less pure 

CO2 would be less expensive but could also affect the sealing performance of a 

caprock, increasing the risk of leakage and environmental.[FN15 15 Abanades, J C 

et al., 2005. Summary for Policymakers in IPCC Special Report on Carbon Dioxide 

Capture and Storage, B. Metz et al., Editors. 2005, Cambridge University Press: 

Cambridge, U.K.] The evaluation of existing literature shows that the main 

impurity -- sulfur dioxide, SO2 - dissolved in water creates a far stronger acid 

than does dissolution of CO2. Creation of additional leakage pathways may be 

induced. Mobilization of metals in minerals or soil of the sub-sea bed may be 

higher, leading to a greater risk of hazardous levels of trace metals.[FN16 16 

Pruess K., Xu T., Apps J., Garcia J. (2003): Numerical modeling of aquifer 

disposal of CO2. SPE Journal, 49-60] Current research has proven that it is 

critical that any CO2 stream injected into underground reservoirs is at least at 

99% purity to minimize risks of acidification and mobilization of toxic metals 

into drinking water and the soil.[FN17 17 Knauss K., Johnson J., Steefel C. 

64
(2005): Evaluation of the impact of CO2, co-contaminant gas, aqueous fluid and 

reservoir rock interactions on the geologic sequestration of CO2. Chem.Geol. 

217, 339-350] 

Response: The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a

percent CO2). Instead, the GS rule addresses the quality and quantity of impurities by requiring

owners or operators to submit information on the source of the CO2 and its physical and chemical

properties. Specifically, the GS rule requires the owner or operator to submit data about the site,

including an analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the 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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals. 

Since the GS rule, at §146.81(d), prohibits the injection of CO2 streams that meet the definition of a

hazardous waste under 40 CFR part 261, injection of a CO2 stream that is determined to be a

hazardous waste may only occur in a Class I hazardous waste injection well.

Commenter Name: John Hanger Letter ID: 0130

Commenter Organization: Pennsylvania Dept. of Env. Protection Comment ID: 21520

Comment: Definition of Carbon Dioxide Stream 

-EPA should specify a CO2 purity requirement to prevent the inclusion of 

contaminants (example: hydrogen sulfide, sulfurous and nitrous oxides), the 

inclusion of which would not classify the CO2 stream as a hazardous 

waste/substance but could potentially endanger USDW and/or enhance 

corrosiveness. DEP understands that this subpart does not apply to a CO2 stream 

that meets the definition of a hazardous waste under 40 CFR Part 261. 

Response: EPA understands 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 low. However, these

estimates are based on limited information, and uncertainties remain about the expected

concentrations of impurities from the various types of CO2 streams. The concentrations of minor

and trace elements in CO2 streams for GS projects are likely to vary by facility, coal composition,

plant operating conditions, and pollution removal technologies. 

The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a percent CO2).

Instead, the GS rule addresses the quality and quantity of impurities by requiring owners or operators

to submit information on the source of the CO2 and its physical and chemical properties.

Specifically, the GS rule requires the owner or operator to submit data about the site, including an

analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the 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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals. 

Since the GS rule, at §146.81(d), prohibits CO2 streams that meet the definition of a hazardous

65
waste under 40 CFR part 261, injection of a CO2 stream that is determined to be a hazardous waste

may only occur in a Class I hazardous waste injection well.

Commenter Name: Patrick Nugent Letter ID: 0143

Commenter Organization: Texas Pipeline Association (TPA) Comment ID: 23139

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: 6. Incidental waste streams in the carbon dioxide stream should not cause 

the stream to be characterized as a hazardous waste or hazardous substance. As 

EPA has pointed out, the carbon dioxide stream may have pollutants in it that 

could cause the waste stream to be classified as a hazardous waste. For example. 

the carbon dioxide stream captured from a power plant may include emissions of 

mercury, a hazardous substance. A carbon dioxide stream captured from a gas 

processing plant may have emissions of nitrous oxides or hydrogen sulfides. The 

incidental presence of these waste streams in a carbon dioxide stream should not 

cause the entire carbon dioxide stream to be classified as a hazardous waste or 

a waste. The proposed regulations do not specify content or constituent 

concentration requirements. They merely state that "[t]his subpart does not 

apply to any carbon dioxide stream that meets the definition of a hazardous 

waste under 40 CFR part 261." Proposed § 146.81(d). TPA urges EPA to establish a 

content percentage or constituent concentration of a pollutant in the carbon 

dioxide stream before the stream is declared a hazardous waste, or some other 

methodology that would promote the goals of this program without compromising 

environmental protection. The cost of removing the offending constituents or 

pollutants could defeat the economic viability of the carbon sequestration 

project, generate additional detrimental air emissions through the removal 

process and in the end be counter-productive as the best longterm disposal 

option for the pollutant may be to sequester it in a deep well. In short, such 

specifications might restrict the amount or kinds of greenhouse gas fluids that 

could be stored through geologic sequestration technology and may defeat the 

program in its entirety. 

Response: 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 low. However, these

estimates are based on limited information, and uncertainties remain about the expected

concentrations of impurities from the various types of CO2 streams. The concentrations of minor

and trace elements in CO2 streams for GS projects are likely to vary by facility, coal composition,

plant operating conditions, and pollution removal technologies. 

The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a percent CO2).

Instead, the GS rule addresses the quality and quantity of impurities by requiring owners or operators

to submit information on the source of the CO2 and its physical and chemical properties.

Specifically, the GS rule requires the owner or operator to submit data about the site, including an

analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the 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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals. 

66
EPA received many comments regarding the applicability of the RCRA regulations and statute to

CO2 streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: William Kovacs Letter ID: 0148

Commenter Organization: U.S. Chamber of Commerce Comment ID: 21766

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: The issue becomes even more acute when you consider that EPA has already 

declined to address the very basic question of how to classify the CO2 stream if 

trace amounts of hazardous constituents get in it prior to injection: 

Because the types of impurities and their concentrations in the CO2 stream are 

likely to vary by facility, coal composition, plant operating conditions, and 

pollution removal technologies, EPA cannot make a categorical determination as 

to whether injected CO2 is hazardous under RCRA. [FN8 Federal Register, Vol. 73 

Fed. Reg. No. 144, pg. 43493 (July 25, 2008)] 

Instead, EPA advocates making determinations about the hazardous classification 

of injected CO2 on a case-by-case basis. In essence, EPA is saying that 

hazardous constituents could be present in the injected CO2 stream, and if they 

are, then it will be treated as hazardous. This approach provides little 

guidance to industry, particularly facility owners and operators who are 

required to characterize their CO2 stream as part of their initial permit 

application. 

Response: EPA agrees that any requirements applicable to CO2 injectate should be clearly identified

to the public and to the regulated community. EPA received many comments regarding the

applicability of the RCRA regulations and statute to CO2 streams that are geologically sequestered

under the final Class VI UIC well requirements. As a result, EPA has decided to initiate a separate

proposed rulemaking specifically to examine the issue of RCRA applicability 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 particular 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 commenters who wish to submit comments on the RCRA proposal

will need to do so during the comment period for that rule. Finally, EPA also notes that the final GS

rule, which adds new regulations for Class VI wells under the Safe Drinking Water Act (SDWA), is

not making any changes to the RCRA regulations. The existing RCRA hazardous waste

67
characterization regulations apply to evaluations of CO2 streams, and those regulations define which

RCRA solid wastes are regulated as RCRA hazardous wastes – it is not EPA’s position that the

presence of any levels of impurities would necessarily render a CO2 stream a hazardous waste,

without reference to those regulations.

Commenter Name: James Dooley Letter ID: 0156

Commenter Organization: Joint Global Change Research Institute, Pacific

Northwest National Laboratory

Comment ID:

22632

Other EPA Comment Codes and Descriptions: 1220 1.1.1.1 Terminology and definitions 

Comment: The issue of how pure the "CO2 stream" needs to be and whether trace or more 

significant quantities of other gases or liquids can be injected into a Class VI 

well is a critical issue that will influence the overall economics of CCS and 

could impact the safety and efficacy of GS. Greater clarity on this issue 

(while still allowing for some site-specific flexibility) would help the 

business community better understand what the cost of using CCS will be. The 

USEPA is encouraged to continue trying to narrow the definition of the "CO2 

stream" in subsequent versions of the draft rule. While this is a difficult 

issue and there is no obvious "correct answer", USEPA is encouraged to continue 

research and dialogues with various stakeholders to see if a narrower definition 

of what degree of co-injection is allowable for a Class VI well. It is possible 

that it could take many years maybe even decades to finalize this but it is 

important to begin pursuing it now. 

Response: EPA understands 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 low. However, these

estimates are based on limited information, and uncertainties remain about the expected

concentrations of impurities from the various types of CO2 streams. The concentrations of minor

and trace elements in CO2 streams for GS projects are likely to vary by facility, coal composition,

plant operating conditions, and pollution removal technologies. 

The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a percent CO2).

Instead, the GS rule addresses the quality and quantity of impurities by requiring owners or operators

to submit information on the source of the CO2 and its physical and chemical properties.

Specifically, the GS rule requires the owner or operator to submit data about the site, including an

analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the 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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals.

Commenter Name: Kyle Isakower Letter ID: 0170

Commenter Organization: American Petroleum Institute Comment ID: 24219

Comment: Rule Provisions: 146.81(b), 146.81(d) 

EPA Preamble Question: 7. By defining "carbon dioxide stream" to exclude 

hazardous wastes (146.81(d)), EPA’s rule, if finalized, assures that it would 

apply only to CO2 streams that are not hazardous wastes as defined in 40 CFR 

Part 261. As a result, EPA’s proposed rule would preclude the injection of 

68
hazardous wastes in Class VI injection wells. EPA seeks comment on this approach 

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

stream. EPA Notice 43503. 

API Response: API agrees with the concept that Class VI wells should not be 

injecting hazardous wastes but is proposing some modifications to EPA’s 

definition of CO2 stream in the rule. The modifications reflect the fact that 

the source of CO2 should not be a factor in the context of defining the CO2 

stream. The rule applies to the injection of CO2 and should not address the 

origins of the materials since that is beyond the scope of this regulation. The 

original text would have precluded injection of CO2 from some sources. The 

question of how CO2 should be accounted for, and from what sources, in a GHG 

management and accounting system is beyond the scope of this regulation. 

Response: EPA agrees; the GS regulation applies to injection of CO2 for the purpose of GS,

regardless of the source of the CO2. It is beyond the scope of the GS rule and the UIC Program’s

authority to require or set standards for upstream generators of CO2 or purification facilities. For

purposes of GS, the UIC program’s authority under the SDWA is limited to ensuring that GS

projects are sited, constructed, operated, and closed in a manner that protects USDWs. Although the

GS regulation does not apply to the source of CO2 streams, the GS rule, at §146.82(a)(7)(iv),

requires the owner or operator to submit data about the site, including an analysis of the chemical

and physical characteristics of the CO2 stream because the concentrations of minor and trace

elements in CO2 streams for GS projects are likely to vary by facility, coal composition, plant

operating conditions, and pollution removal technologies.

Commenter Name: Thomas Curtis Letter ID: 0181

Commenter Organization: American Water Works Association (AWWA) Comment ID: 23687

Comment: Category: Injection Stream 

EPA Request for Comment: By defining "carbon dioxide stream" to exclude 

hazardous wastes (146.81(d)), EPA’s rule, if finalized, assures that it would 

apply only to CO2 streams that are not hazardous wastes as defined in 40 CFR 

Part 261. As a result, EPA’s proposed rule would preclude the injection of 

hazardous wastes in Class VI injection wells. EPA seeks comment on this approach 

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

stream. EPA Notice 43503. 

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

stream" to exclude hazardous wastes. However, AWWA recommends that the final 

regulation include more specifics on the definition of the required quality of 

the injection stream and establishing a minimum concentration of carbon dioxide 

present in the injection stream. This requirement for the injection stream will 

ensure that the injection of other harmful or undesirable gases is limited. Our 

initial thoughts on this topic would be that 100% of the injectate must come 

from a carbon dioxide capture process and the injectate must be at least 98% 

carbon dioxide. Owner/operators must ensure that the remaining 2% of the 

injectate is not made up of compounds that would result in the injectate being 

classified as a hazardous waste. Also, 100% of the injection stream should be 

required to come from the carbon capture process as to preclude the co-mingling 

69
of wastes from other industrial processes in the injection stream as this is not 

an appropriate use of the Class VI injection wells. As AWWA is not a technical 

expert on this topic, AWWA recommends that EPA pursue research in association 

with DOE to develop a standard for the minimum concentration of carbon dioxide 

in the injection stream. 

Response: EPA understands 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 low. However, these

estimates are based on limited information, and uncertainties remain about the expected

concentrations of impurities from the various types of CO2 streams. The concentrations of minor

and trace elements in CO2 streams for GS projects are likely to vary by facility, coal composition,

plant operating conditions, and pollution removal technologies. 

The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a percent CO2).

Instead, the GS rule addresses the quality and quantity of impurities by requiring owners or operators

to submit information on the source of the CO2 and its physical and chemical properties.

Specifically, the GS rule requires the owner or operator to submit data about the site, including an

analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the 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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals.

Commenter Name: Thomas Curtis Letter ID: 0181

Commenter Organization: American Water Works Association (AWWA) Comment ID: 23721

Other EPA Comment Codes and Descriptions: 1220 1.1.1.1 Terminology and definitions 

Comment: Part 146.81 AWWA recommends defining the quality of the injection stream and 

establishing a minimum concentration of carbon dioxide. This requirement for the 

injection stream will ensure that the injection of other harmful or undesirable 

gases is limited. Our initial thoughts on this topic would be that 100% of the 

injectate must come from a carbon dioxide capture process and the injectate must 

be at least 98% carbon dioxide. Owner/operators must ensure that the remaining 

2% of the injectate is not made up of compounds that would result in the 

injectate being classified as a hazardous waste. As AWWA is not an expert on 

this topic, we would suggest that EPA pursue research in association with DOE to 

develop a standard for the minimum concentration of carbon dioxide in the 

injection stream. 

Response: As described above, the GS rule does not set generic purity standards for CO2 injectate

streams (e.g., a percent CO2). The final GS rule retains the definition of a CO2 stream as proposed.

Commenter Name: Wendy Jacobs Letter ID: 0183

Commenter Organization: Harvard Law School Environmental Law and Policy

Center

Comment ID:

25156

Other EPA Comment Codes and Descriptions: 5400 2.9 Proposed Financial Responsibility and

Long-Term Care Requirements 

Comment: For instance, EPA has recognized that "co-contaminants in the CO2 stream could

70
endanger a USDW if the injectate migrates into a USDW." 73 Fed. Reg. at 43,497.

The "types of impurities and their concentrations in the CO2 stream are likely

to vary by facility, coal composition, plant operating conditions, and pollution

removal technologies." Id. at 43,503. Yet the proposed regulation’s current

standard for stream purity is loosely defined. The proposed regulation allows

injection of a stream with "incidental associated substances derived from the

source materials and the capture process, and any substances added to the stream

to enable or improve the injection process." Id. at 43,535 (proposed 40 CFR §

146.81(d) (definition of "carbon dioxide stream")). By regulating CO2

generators and CO2 stream treatment (purification) facilities directly, EPA

could reduce the likelihood that a contaminated CO2 stream would be injected

into a GS well and thereby reduce the likelihood that such contaminants would

endanger a USDW.[FN12] EPA should therefore consider setting specific requirements

for the maximum concentrations of "incidental substances" in injected CO2

streams to reduce the uncertainty about the proper level of treatment required.

By imposing financial assurance requirements on those parties, EPA could also

reduce the likelihood that costs and damages arising from such contamination

would go unpaid, for example, if such costs exceeded the security posted by the

owner or operator. Regulatory oversight would make these firms "more likely to

undertake operating decisions that consider environmental (and remediation)

costs." WRI ISSUE BRIEF at 6.

Response: EPA clarifies that the financial responsibility requirements in the GS rule apply to owners

or operators of Class VI wells, and not to the generator of the CO2. The goal of financial

responsibility is to ensure that financial resources are available to prevent endangerment of USDWs

from improper plugging, remediation, and management of wells in the event that the owner or

operator experiences financial difficulties. See the final rule and preamble for further discussion of

EPA's final approach to financial responsibility.

Furthermore, comments related to the need to regulate CO2 generators and CO2 stream treatment

facilities are outside the scope of this rulemaking. 

The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a percent CO2).

Instead, the GS rule addresses the quality and quantity of impurities by requiring owners or operators

to submit information on the source of the CO2 and its physical and chemical properties.

Specifically, the GS rule requires the owner or operator to submit data about the site, including an

analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the 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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190

Commenter Organization: Carbon Sequestration Council Comment ID: 24512

Comment: Rule Provisions or Federal Register Cite: 146.81(b), 146.81(d) 

EPA Preamble Question: 7. By defining "carbon dioxide stream" to exclude 

hazardous wastes (146.81(d)), EPA’s rule, if finalized, assures that it would 

apply only to CO2 streams that are not hazardous wastes as defined in 40 CFR 

71
Part 261. As a result, EPA’s proposed rule would preclude the injection of 

hazardous wastes in Class VI injection wells. EPA seeks comment on this approach 

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

stream. EPA Notice 43503. 

CSC Response: CSC agrees with the concept that Class VI wells should not be 

injecting hazardous wastes, but there are believed to be few, if any, 

circumstances under which RCRA hazardous waste provisions would apply to CO2 

streams. Current capture technologies under development are not likely to 

produce a CO2 stream that would ever meet the definition of hazardous waste 

under 40 CFR 261. These CO2 capture technologies will yield a relatively pure 

CO2 stream, one that is unlikely to contain sufficient hazardous constituents to 

qualify as hazardous under any circumstances. To begin with, those CO2 streams 

will constitute uncontained gas that is not even a solid waste under RCRA. 

Moreover, the captured supercritical streams will not be susceptible to normal 

RCRA testing protocols because of the physical characteristics of supercritical 

CO2. 

In addition, we are proposing some modifications to EPA’s definition of CO2 

stream in the rule. The modifications reflect the fact that the source of CO2 

should not be a factor in the context of defining the CO2 stream. The rule 

applies to the injection of CO2 and should not address the origins of the 

materials since that is beyond the scope of this regulation. The original text 

would have precluded injection of CO2 from some sources. The question of how CO2 

should be accounted for, and from what sources, in a GHG management and 

accounting system is beyond the scope of this regulation. 

More to the issue of "impurities", CSC objects to any mandated purity standards 

for CO2. The inclusion of impurities in stored CO2 should not be arbitrarily 

prohibited; however, it is recognized that the presence of those impurities at 

sufficient concentrations may trigger the applicability of other statutory 

limits or requirements. Determining the type and levels of impurities in the CO2 

stream is " absent a compelling public or environmental health risk " best left 

to contractual negotiations between parties in a CCS value chain as opposed to 

an arbitrary regulatory determination. The contracting parties are best able to 

evaluate the types of impurities, their compatibility with the reservoir and 

equipment, and determine the acceptable levels of those impurities in the stored 

CO2. If there were ever any overriding public interest in limiting either the 

type or level of contaminants, principles of cost-effectiveness and riskmanagement should guide the decision making process. 

Response: EPA understands 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 low. However, these

estimates are based on limited information, and uncertainties remain about the expected

concentrations of impurities from the various types of CO2 streams. The concentrations of minor

and trace elements in CO2 streams for GS projects are likely to vary by facility, coal composition,

plant operating conditions, and pollution removal technologies. 

The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a percent CO2).

Instead, the GS rule addresses the quality and quantity of impurities by requiring owners or operators

72
to submit information on the source of the CO2 and its physical and chemical properties.

Specifically, the GS rule requires the owner or operator to submit data about the site, including an

analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the 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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals. 

Since the GS rule, at §146.81(d), prohibits CO2 streams that meet the definition of a hazardous

waste under 40 CFR part 261, injection of a CO2 stream that is determined to be a hazardous waste

may only occur in a Class I hazardous waste injection well.

Commenter Name: Craig R. Walters Letter ID: 0200

Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24574

Comment: Rule Provisions: 146.81(b), 146.81(d) 

EPA Rule Issue: 7. By defining "carbon dioxide stream" to exclude hazardous 

wastes (146.81(d)), EPA’s rule, if finalized, assures that it would apply only 

to CO2 streams that are not hazardous wastes as defined in 40 CFR Part 261. As a 

result, EPA’s proposed rule would preclude the injection of hazardous wastes in 

Class VI injection wells. EPA seeks comment on this approach and other 

considerations associated with the presence of "impurities" in the CO2 stream. 

EPA Notice 43503. 

Anadarko Petroleum Corporation (APC) Response: APC agrees with the concept that 

Class VI wells should not be injecting hazardous wastes but is proposing some 

modifications to EPA’s definition of CO2 stream in the rule. The modifications 

reflect the fact that the source of CO2 should not be a factor in the context of 

defining the CO2 stream. The rule applies to the injection of CO2 and should not 

address the origins of the materials since that is beyond the scope of this 

regulation. The original text would have precluded injection of CO2 from some 

sources. The question of how CO2 should be accounted for in a GHG management and 

accounting system is beyond the scope of this regulation. 

More to the issue of "impurities", APC objects to any mandated purity standards 

for CO2. The inclusion of impurities in stored CO2 should not be arbitrarily 

prohibited; however, it is recognized that the presence of those impurities at 

sufficient concentrations may trigger the applicability of other statutory 

limits or requirements. Determining the type and levels of impurities in the CO2 

stream is " absent a compelling public or environmental health risk " best left 

to contractual negotiations between partners in a CCS value chain as opposed to 

an arbitrary regulatory determination. The contracting parties are best able to 

evaluate the types of impurities, their compatibility with the reservoir and 

equipment, and determine the acceptable levels of those impurities in the stored 

CO2. To the extent that there is an overriding public interest in limiting 

either the type or level of contaminants, principles of cost-effectiveness and 

risk-management should guide the decision making process. 

Response: EPA understands that many CO2 streams may be relatively pure, and research indicates

73
that the estimated amounts of impurities in a CO2 stream are likely to be low. However, these

estimates are based on limited information, and uncertainties remain about the expected

concentrations of impurities from the various types of CO2 streams. The concentrations of minor

and trace elements in CO2 streams for GS projects are likely to vary by facility, coal composition,

plant operating conditions, and pollution removal technologies. 

The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a percent CO2).

Instead, the GS rule addresses the quality and quantity of impurities by requiring owners or operators

to submit information on the source of the CO2 and its physical and chemical properties.

Specifically, the GS rule requires the owner or operator to submit data about the site, including an

analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the 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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals. 

Since the GS rule, at §146.81(d), prohibits CO2 streams that meet the definition of a hazardous

waste under 40 CFR part 261, injection of a CO2 stream that is determined to be a hazardous waste

may only occur in a Class I hazardous waste injection well.

Commenter Name: Chris M. Hobson Letter ID: 0201

Commenter Organization: Southern Company Comment ID: 22157

Other EPA Comment Codes and Descriptions: 2020 1.5.1 Support Class VI designation 

Comment: Classification of CO2 GS Wells and Interaction with Other Regulatory Regimes 

Southern Company supports EPA's approach of creating a new category of wells 

under the UIC program for the long-term sequestration of C02. Id. at 43502. The 

new Class VI designation is appropriate for the injection of CO2 streams 

captured from an emission source, including incidental associated substances 

derived from source materials and the capture process, as well as substances 

added to the stream to facilitate the injection process. As EPA observes, the 

addition of such substances may sometimes prove a necessary step in the 

injection process. See id. at 43493. Accordingly, the removal of these 

incidental associated substances should only be required as necessary to avoid 

interference with capture, transportation, injection and containment of CO2 

streams. 

Response: EPA agrees that tailored requirements for Class VI wells are necessary to address the

unique nature of injecting large volumes of CO2 and to ensure that USDWs are protected from

endangerment. The GS rule contains tailored requirements for the permitting, geologic site

characterization, AoR and corrective action, well construction, operation, mechanical integrity

testing, monitoring, well plugging, post-injection site care, and site closure of GS wells that directly

address issues unique to the nature of large-scale CO2 injection for GS.

Commenter Name: Richard Guinn Letter ID: 0210

Commenter Organization: Eastman Chemical Company Comment ID: 22707

Comment: By its inherent nature, gasification will provide a stream of >90% CO2 having 

74
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 oF) 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 CO2 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. 

Response: 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 low. However, these

estimates are based on limited information, and uncertainties remain about the expected

concentrations of impurities from the various types of CO2 streams. The concentrations of minor

and trace elements in CO2 streams for GS projects are likely to vary by facility, coal composition,

plant operating conditions, and pollution removal technologies. 

The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a percent CO2).

Instead, the GS rule addresses the quality and quantity of impurities by requiring owners or operators

to submit information on the source of the CO2 and its physical and chemical properties.

Specifically, the GS rule requires the owner or operator to submit data about the site, including an

analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the 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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals.

Commenter Name: Jonathon Palm Letter ID: 0222

Commenter Organization: Nevada Division of Environmental Protection, Bureau

of Water Pollution Control

Comment ID:

21641

Other EPA Comment Codes and Descriptions: 1616 1.3.1.3 Fluid movement 

Comment: 2. The fluid to be injected into the ground may contain pollutants carried with 

the CO2 that potentially could enter a drinking water source. This follows from 

the first bullet above. Gases could be injected into a confined space with 

insufficient capacity for the volume of gas to be injected. Pressure would build 

up as more gas is pumped in, forcing a breach in the reservoir. Pollutants could 

escape and migrate into a source of drinking water. 

Response: EPA acknowledges that there are potential risks associated with GS, including the

potential that CO2 injection for GS may result in leaching of subsurface materials that could

mobilize contaminants or compromise pore space and endanger USDWs. The purpose of the Class

VI requirements is to minimize and mitigate potential/identified risks through proper site

characterization, well construction, operation, monitoring, post-injection site care, and site closure.

To ensure USDW protection and mitigate risks, the GS regulation requires the owner or operator of

a Class VI well to submit data about the site (during the site characterization process), including

information on the porosity, permeability, mineralogy, and geochemistry of the injection and

75
confining zones, along with information on the compatibility of the CO2 stream with fluids in the

injection zone and minerals in both the injection and confining zones as specified in §146.82. This

data can help identify potential geochemical reactions that may occur between the injected CO2 and

the host geologic formation, as well as help determine the capacity of the proposed injection

formation. EPA adds that computational AoR modeling, required at §146.84, must account for the

physical properties of the receiving formation (based on the collected data described above) and the

properties of the CO2, e.g., injection volumes and rates. Identification of potential reactions prior to

injection would address concerns that formation of carbonic acid could dissolve potential limestone

creating karst features. 

During injection operations, operators must extensively monitor ground water quality to provide

early detection of any unacceptable movement of fluids or impurities in the subsurface as specified

in §146.90. Operators must develop and follow an emergency and remedial response plan to address

any adverse effects associated with the GS operation, including contamination as specified in

§146.94, and provide financial responsibility to address contamination as specified in §146.85.

Commenter Name: Ben Yamagata Letter ID: 0227

Commenter Organization: Coal Utilization Research Council Comment ID: 21782

Comment: Other areas of uncertainty in the proposed rule include: 

-The unresolved issue of how much non-CO2 material may be present before 

exceeding the limit for a "Carbon dioxide stream" (§146.81(d)). 

Response: 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 low. However, these

estimates are based on limited information, and uncertainties remain about the expected

concentrations of impurities from the various types of CO2 streams. The concentrations of minor

and trace elements in CO2 streams for GS projects are likely to vary by facility, coal composition,

plant operating conditions, and pollution removal technologies. 

The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a percent CO2).

Instead, the GS rule addresses the quality and quantity of impurities by requiring owners or operators

to submit information on the source of the CO2 and its physical and chemical properties.

Specifically, the GS rule requires the owner or operator to submit data about the site, including an

analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the 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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals. 

Since the GS rule, at §146.81(d), prohibits CO2 streams that meet the definition of a hazardous

waste under 40 CFR part 261, injection of a CO2 stream that is determined to be a hazardous waste

may only occur in a Class I hazardous waste injection well.

Commenter Name: Neeraj Gupta Letter ID: 0229

Commenter Organization: Battelle Energy Technology (BET) Comment ID: 21827

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

76
comment) 

Comment: Page 54 CO2 Composition Requirements and Hazardous Waste under RCRA- While we 

agree some chemical impurities may cause CO2 to be designated hazardous waste, 

there must be more clear guidance on this issue. In the MRCSP tests, each 

regulatory agency had different requirements on this issue injectate composition 

and analysis, even for commercial CO2. One agency required injection to cease if 

the injectate was above any maximum contaminant level (MCL) for groundwater, 

which is a large list of chemicals. Another state agency asked for some 

technically infeasible analyses on the CO2 stream (pH, Fluouride, Mercury). 

Some impurities like H2S and hydrocarbons are naturally occurring in most deep 

saline formations anyway, so we would discourage setting limits on these items. 

Another significant aspect is the composition of CO2 derived from various 

industrial, power generation, and capture processes. All of these are likely to 

result in minor differences in chemical compositions. In most cases the 

concentration of hazardous impurities is likely to be very low. The incremental 

environmental impact of these minor or trace impurities in deep formations that 

already have brine and will have CO2 must be demonstrated before these are 

excluded from the Class VI injection wells. EPA is encouraged to evaluate the 

range of potential impurities from various streams, their environmental impact 

if any, and provide more specific guidance on this topic. The evaluation should 

also assess how many of the GS projects could become infeasible due to this 

requirement. Finally, EPA should clarify whether CO2 streams with RCRA level of 

impurities can be injected under Class I permits. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations 

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 low. However, these estimates are

based on limited information, and uncertainties remain about the expected concentrations of

impurities from the various types of CO2 streams. The concentrations of minor and trace elements in

CO2 streams for GS projects are likely to vary by facility, coal composition, plant operating

conditions, and pollution removal technologies. 

The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a percent CO2).

Instead, the GS rule addresses the quality and quantity of impurities by requiring owners or operators

to submit information on the source of the CO2 and its physical and chemical properties.

Specifically, the GS rule requires the owner or operator to submit data about the site, including an

analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the compatibility of the CO2 stream with fluids in the

77
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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals. 

Since the GS rule, at §146.81(d), prohibits the injection of CO2 streams that meet the definition of a

hazardous waste under 40 CFR part 261, injection of a CO2 stream that is determined to be a

hazardous waste may only occur in a Class I hazardous waste injection well.

Commenter Name: Philip Papadeas Letter ID: 0238

Commenter Organization: Sandia Technologies, LLC Comment ID: 23344

Comment: A sub-category of wells may be considered for pure long-term disposal, without 

having to consider recovery of the injectate, and later purification, etc. The 

direct line from stack gas to geologic reservoir should be considered as the 

total injectate, and if adequate well and surface materials are present then 

there should be no problem to dispose of the scrubber effluent, or gases direct 

into suitable geologic formations. 

Response: The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a

percent CO2). Instead, the GS rule addresses the quality and quantity of impurities by requiring

owners or operators to submit information on the source of the CO2 and its physical and chemical

properties. Specifically, the GS rule requires the owner or operator to submit data about the site,

including an analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the 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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals.

EPA clarifies that the GS rule applies only to wells injecting CO2 for the purpose of long-term

storage. 

Commenter Name: Mark Bohrer Letter ID: 0241

Commenter Organization: North Dakota Industrial Commission Comment ID: 23228

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: 7. By defining "carbon dioxide stream" to exclude hazardous wastes (146.81(d)), 

EPA’s rule, if finalized, assures that it would apply only to CO2 streams that 

are not hazardous wastes as defined in 40 CFR Part 261. As a result, EPA’s 

proposed rule would preclude the injection of hazardous wastes in Class VI 

injection wells. EPA seeks comment on this approach and other considerations 

associated with the presence of "impurities" in the CO2 stream. EPA Notice 

43503. 

The presence of certain hazardous wastes should not preclude the overall carbon 

dioxide stream from injection into a sequestration zone. The process of 

removing the carbon dioxide and making it suitable for transportation and 

injection should render it relatively pure. The presence of impurities can be 

78
dealt with at a specific source and the overall waste stream certified for 

injection. If the well construction and geologic setting is suitable to confine 

the carbon dioxide stream and prevent its migration into a USDW, then certain 

impurities and/or hazardous wastes should be allowed. 

Response: 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 low. However, these

estimates are based on limited information, and uncertainties remain about the expected

concentrations of impurities from the various types of CO2 streams. The concentrations of minor

and trace elements in CO2 streams for GS projects are likely to vary by facility, coal composition,

plant operating conditions, and pollution removal technologies. For this reason, the GS rule requires

the owner or operator to submit data about the site, including an analysis of the chemical and

physical characteristics of the CO2 stream, as required at §146.82(a)(7)(iv), and information on the

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 potential for geochemical reactions between the

injectate (CO2) and the host geologic formations, which could result in the plugging of pore spaces

or the dissolution of formation minerals. 

EPA received many comments regarding the applicability of the RCRA regulations and statute to

CO2 streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: Michel Paque Letter ID: 0259

Commenter Organization: Ground Water Protection Council Comment ID: 24813

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: EPA Notice Questions: 73 FR 43504 

EPA Rule Issue: 9. EPA also requests comment on other considerations associated 

with the presence of impurities in the CO2 stream related to CERCLA. EPA Notice 

43504. 

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

stream that would defeat capture, compression, transport or GS, and these can be 

addressed through the use of special materials in many cases. The focus should 

be on compatibility rather than on any need for purification. 

Response: The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a

percent CO2). Instead, the GS rule addresses the quality and quantity of impurities by requiring

owners or operators to submit information on the source of the CO2 and its physical and chemical

79
properties. Specifically, the GS rule requires the owner or operator to submit data about the site,

including an analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the 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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals.

Commenter Name: Greg Shubel Letter ID: 0284

Commenter Organization: Inter-Tribal Council of Michigan, Inc Comment ID: 25300

Comment: The presence of hazardous impurities in the CO2 stream are identified as a risk 

and ITCMI ESD recommends that the EPA clearly communicate how it will address 

these impurities often found in the CO2 streams, specifically how such 

impurities will be removed or their impacts mitigated so as not to endanger 

USDWs. 

Response: The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a

percent CO2). Instead, the GS rule addresses the quality and quantity of impurities by requiring

owners or operators to submit information on the source of the CO2 and its physical and chemical

properties. Specifically, the GS rule requires the owner or operator to submit data about the site,

including an analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the 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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals. 

EPA expects 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 low. However, these estimates are

based on limited information, and uncertainties remain about the expected concentrations of

impurities from the various types of CO2 streams. The concentrations of minor and trace elements in

CO2 streams for GS projects are likely to vary by facility, coal composition, plant operating

conditions, and pollution removal technologies.

Commenter Name: Bill Hertz Letter ID: 0500

Commenter Organization: Fertilizer Institute Comment ID: 21207

Comment: Within the chemical process of producing nitrogen fertilizer, CO2 is generated 

as a by-product. This CO2 in many cases is sold into various product streams. 

All members are keenly interested in the enhanced oil recovery aspect of this. 

And in fact, the CO2 stream that we produce is among the cleanest that is out 

there, and is virtually impurity free in many cases. 

Response: PA 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 low. However, these estimates

are based on limited information, and uncertainties remain about the expected concentrations of

impurities from the various types of CO2 streams. The concentrations of minor and trace elements in

CO2 streams for GS projects are likely to vary by facility, coal composition, plant operating

conditions, and pollution removal technologies. Since the GS rule, at §146.81(d), prohibits CO2

80
streams that meet the definition of a hazardous waste under 40 CFR Part 261, owners or operators

will need to characterize their CO2 stream as part of their permit application process to determine

whether the injectate is a RCRA hazardous waste. If the CO2 stream is determined to be a hazardous

waste, injection may only occur in a Class I hazardous waste injection well. 

The GS rule also requires the owner or operator to submit data about the site, including an analysis

of the chemical and physical characteristics of the CO2 stream, as required at §146.82(a)(7)(iv), and

information on the 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 potential for geochemical

reactions between the injectate (CO2) and the host geologic formations, which could result in the

plugging of pore spaces or the dissolution of formation minerals.

EPA clarifies that the GS rule does not apply to capture technologies.

Commenter Name: Doug Louis Letter ID: 0530

Commenter Organization: Kansas Corporation Commission Comment ID: 21338

Comment: Rules that apply to impurities of the CO2 injectate should be further discussed, 

determined and defined for regulatory certainty. The rules should be more 

Response: The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a

percent CO2). Instead, the GS rule addresses the quality and quantity of impurities by requiring

owners or operators to submit information on the source of the CO2 and its physical and chemical

properties. Specifically, the GS rule requires the owner or operator to submit data about the site,

including an analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the 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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals. 

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 low. However, these estimates are

based on limited information, and uncertainties remain about the expected concentrations of

impurities from the various types of CO2 streams. The concentrations of minor and trace elements in

CO2 streams for GS projects are likely to vary by facility, coal composition, plant operating

conditions, and pollution removal technologies.

Commenter Name: Barbara Massoner Letter ID: 0531

Commenter Organization: Legacy Economy Comment ID: 21444

Other EPA Comment Codes and Descriptions: 1260 1.1.1.5 More certainty/stringency is needed 

Comment: We do not want to contaminate our groundwater with those carcinogens. The fact 

is that CCWs, this is a significant issue in that each year our power plants 

produce enough of this stuff to fill a train of coal cars that stretches from 

Manhattan to Los Angeles not just once, not just twice, but three and a half 

times. It is a huge problem and the EPA has pointed out that these toxins are 

carcinogenic and EPA has also stated that there are no regulations for these 

toxins. Therefore I urge the EPA when you are considering these regulations on 

CO2 sequestration that you broaden them to include CCWs. Stricter rules will not 

81
set us back economically, but rather it is going to ensure that the next 

generation has a prosperity to grow like our generation has. 

Response: It is beyond the scope of the GS rule and the UIC Program’s authority to require or set

standards for upstream management of coal combustion wastes (CCWs), also known as coal

combustion residuals (CCRs). The UIC program’s authority under the SDWA is limited to ensuring

that GS projects are sited, constructed, operated, and closed in a manner that protects USDWs. EPA

is separately considering standards for the management of CCRs under RCRA. See 75 Fed. Reg.

35128 (proposed rule).

Comment Code: 1616 1.3.1.3 Fluid movement 

Individual Comments

Commenter Name: John Hanger Letter ID: 0130

Commenter Organization: Pennsylvania Dept. of Env. Protection Comment ID: 21521

Comment: Additional Issues 

-Fluids could be brought to the surface during the drilling, completion and 

operation of the Class VI well. In the event formational fluids are brought to 

the surface during the sequestration process, appropriate measures must be 

taken. The regulation should address the issue of these fluids. 

Response: EPA acknowledges that there are potential risks associated with GS including the

potential that CO2 injection for GS could cause fluid movement, which can endanger USDWs. The

purpose of the Class VI requirements is to minimize and mitigate potential/identified risks through

proper site characterization, well construction, operation, monitoring, post-injection site care, and

site closure. Suitable GS sites must have confining zones that are free of transmissive faults or

fractures and are of sufficient areal extent and integrity to contain the injected CO2 stream and

displaced formation fluids. The formations must allow injection at proposed maximum pressures and

volumes without initiating or propagating fractures in the confining zone(s), as required at

§146.83(a)(2).

The GS rule requires owners or operators to submit extensive data about a proposed GS site to

identify (and eliminate) sites with a potential for unacceptable fluid movement. Information to be

submitted and evaluated at §146.82 includes data on the porosity, permeability, and other

information regarding the suitability of the confining zone; the location of any known or suspected

faults; subsurface geochemistry; and the location of, depth of, and other information regarding any

perforations that may extend into the confining zone. EPA believes that this information, in

conjunction with AoR modeling required at §146.84, will help identify the potential for brine

migration as a result of pressure displacement. Based on this information, the Director and the owner

or operator can identify ways to mitigate this risk prior to injection, or, if necessary, the Director can

deny the permit application. During injection operations, operators must extensively monitor ground

water quality and pressure changes to provide early detection of any unacceptable movement of

fluids or impurities in the subsurface as specified in §146.90. In the event that fluid movement

endangers a USDW, owners or operators must also develop and follow an emergency and remedial

response plan to address any adverse effects associated with the GS operation as specified in §146.94

82
and maintain financial responsibility to address contamination as specified in §146.85.

Commenter Name: Thomas Curtis Letter ID: 0181

Commenter Organization: American Water Works Association (AWWA) Comment ID: 23666

Other EPA Comment Codes and Descriptions: 1610 1.3.1 Risks to USDWs 

Comment: Trespass and Aquifer Displacement: AWWA recommends that the potential for 

trespass be addressed in the final rule. Carbon dioxide plumes may migrate into 

a location that a drinking water utility was planning to utilize, possibly for 

aquifer storage and recovery. What recourse is provided by the proposed 

regulation in the event that trespass occurs, and damages are realized by the 

drinking water utility? Also, movement of the pressure front associated with a 

carbon dioxide plume may cause aquifers to shift in location, potentially moving 

them out of the jurisdiction of their original utility "owner." This can be a 

serious problem in certain portions of the country where ground water resources 

are limited or conflict, and utilities face intense competition for water 

rights. AWWA questions if an appropriate recourse will be provided by the 

sequestration project owner/operator in the event that these water rights issues 

become a reality for the drinking water utility. 

Response: EPA clarifies that owners and operators must perform extensive site characterization and

modeling of the AoR to determine the extent of the CO2 plume prior to approving a GS project. The

financial responsibility requirements at§146.84 require owners and operators to demonstrate and

maintain resources to address emergency and remedial response to adverse events that may occur

associated with GS. This would include impacts to drinking water utilities associated with fluid

displacement.

Commenter Name: Andy Horn Letter ID: 0196

Commenter Organization: Colorado Ground Water Association (CGWA) Comment ID: 23927

Comment: Issue 7. The fate of displaced brines is not sufficiently addressed. 

The regulations need to be more specific on assessing the fate of displaced 

brines in the repository. Large volumes of CO2 will increase reservoir pressures 

and will displace brines laterally and potentially vertically. Based on 2005 CO2 

production rates for Colorado power plants (CCS, 2007) and adding 30% additional 

carbon resulting from the parasitic load, power plants in Colorado can be 

expected to produce an average of 5.5 million metric tons annually. This 

production rate results in a year-round injection rate of approximately 5,500 

gallons per minute of supercritical CO2 for a medium-sized power plant. 

Assuming a reservoir thickness of 300 feet with 10% porosity available to the 

supercritical CO2, this quantity would result in displacement of the brine from 

approximately 0.5 square miles of reservoir annually, or from approximately 25 

square miles over an assumed 50-year project lifetime. A large power plant, 

such as the Craig plant, would displace brine completely from approximately 65 

square miles of such a hypothetical reservoir. Additionally, the volume 

calculations presented here assume the supercritical CO2 will occupy the entire 

thickness of the reservoir, while in reality, the supercritical CO2 can be 

expected to float to the top of the reservoir and spread laterally, migrating 

approximately 8 times the velocity of groundwater flow. In the event CO2 were to 

migrate into portions of the reservoir where pressure is insufficient to 

83
maintain the supercritical state, substantial volume increases could occur which 

could drive brines into shallow portions of the reservoir strata used for 

drinking water sources. The applicants will need to address the fate of these 

displaced brines. 

CCS 2007. October 2007. Final Colorado Greenhouse Gas Inventory and Reference 

Case Projections 1990-2020. Center for Climate Strategies. Available from: 

http://www.coloradoclimate.org/ewebeditpro/items/O14F13894.pdf 

Response: EPA acknowledges that there are potential risks associated with GS including the

potential that CO2 injection for GS could cause fluid movement, which can endanger USDWs. EPA

has funded recent research by LBNL on brine displacement affecting USDWs. In the August 31,

2009, NODA and Request for Comment (74 FR 44802), EPA described a hypothetical, future

scenario of GS in a sedimentary basin that demonstrated the potential for basin-scale hydrologic

impacts of CO2 storage (Birkholzer, et al. 2008). In addition to EPA-funded research, a study by

Nicot (2008) modeled the effect of CO2 injection on up-dip aquifers in the Texas Gulf Coast Basin.

The study concluded that in the Gulf Coast Basin, water displacement due to down-dip injection of

CO2 is not likely to cause significant changes in salinity. EPA expects that, as research on far-field

impacts of GS continues, estimates of storage capacity in such systems will improve. 

As part of its adaptive rulemaking approach, EPA will continue to review available research on fluid

movement. 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 determine if modifications to the requirements are appropriate or

necessary.

The purpose of the Class VI requirements is to minimize and mitigate potential/identified risks

through proper site characterization, well construction, operation, monitoring, post-injection site

care, and site closure. Suitable GS sites must have confining zones that are free of transmissive

faults or fractures and are of sufficient areal extent and integrity to contain the injected CO2 stream

and displaced formation fluids. The formations must allow injection at proposed maximum pressures

and volumes without initiating or propagating fractures in the confining zone(s), as required at

§146.83(a)(2). 

The GS rule requires owners or operators to submit extensive data about a proposed GS site to

identify (and eliminate) sites with a potential for unacceptable fluid movement. Information to be

submitted and evaluated at §146.82 includes data on the porosity, permeability, and other

information regarding the suitability of the confining zone; the location of any known or suspected

faults; subsurface geochemistry; and the location of, depth of, and other information regarding any

perforations that may extend into the confining zone. EPA expects that this information, in

conjunction with AoR modeling required at §146.84, will help identify the potential for brine

migration as a result of pressure displacement. Based on this information, the Director and the owner

or operator can identify ways to mitigate this risk prior to injection, or, if necessary, the Director can

deny the permit application. During injection operations, operators must extensively monitor ground

water quality and pressure changes to provide early detection of any unacceptable movement of

fluids or impurities in the subsurface as specified in §146.90. Operators must also develop and

follow an emergency and remedial response plan to address any adverse effects associated with the

GS operation as specified in §146.94 and maintain financial responsibility to address contamination

as specified in §146.85.

84
Commenter Name: Ronald Evans Letter ID: 0215

Commenter Organization: Denbury Resources, Inc. (DRI) Comment ID: 24274

Comment: commensurate benefits in terms of protecting USDWs. In the case of some 

requirements, the Proposed Rule actually tends to diminish the integrity of a 

storage site and thereby increase the risk of migration of a CO2 plume into 

inappropriate geologic formations. Such a result would obviously run directly 

counter to the Proposed Rule’s fundamental purpose and is not what EPA intends. 

Response: EPA disagrees that the rule requirements would allow owners or operators to diminish

the integrity of a GS site. EPA recognizes that injecting large volumes of CO2 for GS poses unique

challenges that, if not properly managed, could endanger drinking water sources and have other

adverse impacts. However, the final, tailored, Class VI requirements address the large volumes of

CO2 injected, its buoyancy, potential corrosivity in the presence of water, and potential impurities in

the CO2 stream. In addition, EPA expects the tailored permitting, siting, construction, operation,

monitoring, and post-injection site care requirements in the GS rule to prevent leakage from injection

formations and protect USDWs.

EPA believes that building upon the existing UIC requirements (e.g., Class I and Class II well

requirements) to develop the Class VI GS regulation provides a protective foundation for ensuring

protection of USDWs that is based on successful field experience and lessons learned about CO2

injection in other applications. Class I well owners or operators have experience with site

characterization, well construction, and monitoring procedures and technologies that are applicable

to Class VI wells. Class II ER well operators have experience with managing the unique properties

of CO2. To successfully flood a hydrocarbon field with CO2 during an ER operation, the behavior

of injected CO2 must be well understood.

Commenter Name: Jonathon Palm Letter ID: 0222

Commenter Organization: Nevada Division of Environmental Protection, Bureau

of Water Pollution Control

Comment ID:

21641

Other EPA Comment Codes and Descriptions: 1614 1.3.1.2 Impurities in captured CO2; purity

standards for CO2 

Comment: 2. The fluid to be injected into the ground may contain pollutants carried with 

the CO2 that potentially could enter a drinking water source. This follows from 

the first bullet above. Gases could be injected into a confined space with 

insufficient capacity for the volume of gas to be injected. Pressure would build 

up as more gas is pumped in, forcing a breach in the reservoir. Pollutants could 

escape and migrate into a source of drinking water. 

Response: EPA acknowledges that there are potential risks associated with GS, including the

potential that CO2 injection for GS may result in leaching of subsurface materials that could

mobilize contaminants or compromise pore space and endanger USDWs. The purpose of the Class

VI requirements is to minimize and mitigate potential/identified risks through proper site

characterization, well construction, operation, monitoring, post-injection site care, and site closure.

To ensure USDW protection and mitigate risks, the GS regulation requires the owner or operator of

a Class VI well to submit data about the site (during the site characterization process), including

information on the porosity, permeability, mineralogy, and geochemistry of the injection and

confining zones, along with information on the compatibility of the CO2 stream with fluids in the

injection zone and minerals in both the injection and confining zones as specified in §146.82. This

data can help identify potential geochemical reactions that may occur between the injected CO2 and

85
the host geologic formation, as well as help determine the capacity of the proposed injection

formation. EPA adds that computational AoR modeling, required at §146.84, must account for the

physical properties of the receiving formation (based on the collected data described above) and the

properties of the CO2, e.g., injection volumes and rates. Identification of potential reactions prior to

injection would address concerns that formation of carbonic acid could dissolve potential limestone

creating karst features. 

During injection operations, operators must extensively monitor ground water quality to provide

early detection of any unacceptable movement of fluids or impurities in the subsurface as specified

in §146.90. Operators must develop and follow an emergency and remedial response plan to address

any adverse effects associated with the GS operation, including contamination as specified in

§146.94, and provide financial responsibility to address contamination as specified in §146.85.

Commenter Name: Darrick Eugene Letter ID: 0223

Commenter Organization: Texas Carbon Capture and Storage Association Comment ID: 23961

Other EPA Comment Codes and Descriptions: 1220 1.1.1.1 Terminology and definitions 

Comment: Point #4: The use of the term "CO2 buoyancy," enumerated countless times in the 

draft rules, is misleading. The Preamble to the Proposed Rule makes very clear 

that changes to the VIC program for CO2 geologic storage are based among other 

things on the assertion that CO2 is "buoyant". This is simply incorrect. CO2 is 

a non-explosive, non-flammable, non-toxic gas that possesses different physical 

properties than some other injectates or existing formation fluids. These 

physical properties do not include any special buoyancy characteristics or 

properties. Rather, CO2 is simply more dense than some underground fluids or 

gases and less dense than others. Hence the movement of injected CO2 in a 

reservoir, or any type of system containing different fluids or gases, will vary 

based on the relative densities of the various formation fluids or gases that 

are in the reservoir. The various formation fluids will simply segregate based 

on the relative densities of the fluids or gases, including CO2. As a result, CO2 

may be the fluid that sinks to the bottom, rises to the top, or resides 

somewhere in between the top and the bottom within the reservoir system. 

Response: EPA disagrees with the commenter. Field and laboratory studies that evaluated two deep

wells exposed to CO2 for nearly three decades have provided evidence of upward vertical flow of

CO2. In Carey et al (2007), a sample of well cement collected from a section of well in the

confining zone at SACROC showed evidence of cement alteration (carbonation) due to exposure

from CO2. (The study was not able to determine whether the alteration was due to exposure to CO2

in the presence of water, dry CO2, or to a CO2-brine mixture.) In Crow et al (2009), a similar study

was conducted on a CO2 production well that was drilled into and completed in a natural CO2

producing formation. This study concluded that CO2 had caused alteration (carbonation) of the well

cement and acidification of fluids adjacent to the caprock. The study could not determine if the

alteration was due to exposure from CO2 diffusion up into the overlying caprock or by upward CO2

migration within wellbore system defects (perhaps cement-caprock and/or cement-formation

interfaces). In both studies, the CO2 apparently moved from the underlying reservoir into the well

bore section located within the overlying caprock. These observations, especially in conjunction with

the larger CO2 volumes and higher reservoir pressures anticipated with GS, justify the well

construction requirements in the final GS rule in order to prevent deterioration of the materials

between the well casing and the well bore that can result in unacceptable fluid movement. 

86
EPA adds that buoyancy of CO2 is among several unique considerations for large scale GS that

warrant the tailored construction requirements at §146.86. For example, seismic surveys at Sleipner

showed that CO2 had migrated to the top of the 200 to 300 meter thick formation as early as 3 years

after injection began. The overall behavior of CO2 at Sleipner is for it to migrate to the top of the

formation and spread laterally from there (Chadwick et al 2006). Additionally, CO2 has the potential

to be corrosive (in the presence of water or aqueous formation fluids during CO2 injection), and the

volume of CO2 anticipated to be injected in Class VI wells is significantly greater than for Class II

ER/ CO2 injection wells.

Commenter Name: Kurt Waltzer Letter ID: 0250

Commenter Organization: Clean Air Task Force Comment ID: 22304

Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule

language 

Comment: The term "transmissive fault or fracture" should be clarified 

The proposed rule in §146.83(a)(2) requires a confining zone(s) that is free of 

transmissive faults or fractures, while §146.81 defines this term as "A fault or 

fracture that has sufficient permeability and vertical extent to allow fluids to 

move between formations". We suggest the following modification to the 

definition in §146.81(d) in order to avoid unduly restricting movement that is 

merely between formations (compare our comments above on the definition of 

"confining zone"): 

[In the paragraph below the text 

in all CAPS denotes added text. See also EPA-HQ-OW-0390-0250.pdf to see the 

original formatting.] 

"Transmissive fault or fracture means a fault or fracture that has sufficient 

permeability and vertical extent to allow fluids to move between formations

BEYOND A CONFINING ZONE." 

Response: EPA has retained the definition in the final rule. While there may be cases, as the

commenter suggests, where a transmissive fault may exist but not pose a concern for confinement,

i.e., in the context of all other information, EPA believes the definition is accurate. Based on its

evaluation of all public comments and input on the proposed rule and NODA and Request for

Comment EPA has made many revisions to the GS Rule. See the final rule and the geologic site

characterization discussion in the preamble for further discussion on EPA's final approach.

Commenter Name: Mark Singer Letter ID: 0504

Commenter Organization: Green America Project, LLC Comment ID: 21244

Comment: In the Federal Register they say that protecting underground sources of drinking 

water, USDWs, may be permanent, this sequestration may be permanent. May, that 

sounds like a, like permanence would be a happy accident rather than the primary 

objective. If geologic sequestration starts leaking it will be a major 

anthropocentric, anthropogenic source of greenhouse gas. 

Response: EPA recognizes that injecting large volumes of CO2 for GS poses unique challenges that,

if not properly managed, could endanger drinking water sources and have other adverse impacts.

87
However, with proper site selection, the final, tailored, Class VI requirements address the large

volumes of CO2 injected, its buoyancy, potential corrosivity in the presence of water, and potential

impurities in the CO2 stream. In addition, EPA expects the tailored permitting, siting, construction,

operation, monitoring, and post-injection site care requirements in the GS rule to prevent leakage

from injection formations and protect USDWs.

Comment Code: 1620 1.3.2 Induced seismicity 

Individual Comments

Commenter Name: Nancy LaPlaca Letter ID: 0115

Commenter Organization: Bardwell Consulting Comment ID: 22047

Other EPA Comment Codes and Descriptions: 1600 1.3 Risk Associated with CO2 GS 

Comment: Here are the problems with underground injection of CO2: - it's risky: who will 

bear the risk of leakage? - CO2 is heavier than air and displaces air - couple 

incidents in Africa (one in Cameroon) in late 1980's where large "cloud" of CO2 

was released and suffocated 1800 people and 1100 head of cattle. - liquid CO2 is 

very corrosive - injecting CO2 can induce seismic activity 

Response: The final, tailored, Class VI requirements address the large volumes of CO2 injected, its

buoyancy, potential corrosivity in the presence of water, and potential impurities in the CO2 stream.

In addition, EPA expects the tailored permitting, siting, construction, operation, monitoring, and

post-injection site care requirements in the GS rule to prevent leakage from injection formations and

protect USDWs.

Regarding the cost of responding to leaks, the GS rule requires that owners or operators demonstrate

and maintain financial responsibility for corrective action on wells in the AoR, injection well

plugging, post-injection site care and site closure, and emergency and remedial response at GS sites

as specified in §146.85. In the event of contamination or other adverse event to a USDW associated

with GS, the financial instrument(s), such as insurance, bonds, etc., rather than public monies, would

cover necessary response actions. 

EPA disagrees that the CO2 releases at Lake Nyos is a valid analogue for GS. GS sites have little in

common with the physical setting or mechanism that resulted in the release of naturally-occurring

CO2 trapped at the bottom of Lake Nyos, a stratified tropical lake that suddenly overturned through a

process known as "limnic eruption." No injection was associated with this event, and this site would

not have been considered sufficiently geologically stable to be issued a Class VI permit based on the

rigorous site characterization requirements at §146.82 (e.g., including lack of confining units).

GS takes places thousands of feet below the Earth’s surface within porous spaces in deep rock

formations. CO2 is injected for GS through technically engineered wells with multiple barriers

designed to isolate the injectate in the well and protect formations outside the well materials. The

injected CO2 is stored in geologic formations underneath confining layers of rock that act as natural

barriers to leakage. It is unlikely that CO2 would escape from a GS site that is properly

characterized, operated, monitored, and closed. During the site selection process, operators of Class

VI wells identify and evaluate the appropriateness of a site for GS of CO2. The evaluation includes

the identification of surface and subsurface features such as deep stratified lakes and other naturally

88
occurring pockets of CO2. Furthermore, during GS operation, injection pressures and formation

conditions are monitored to avoid overpressuring the storage formation.

EPA acknowledges that induced seismicity is a risk that may be associated with GS but maintains

that the risk is low (IPCC, 2005). The GS rule contains several requirements to address seismic risk.

First, as part of the site characterization process, owners or operators must submit information about

the seismic history of and seismic sources near a proposed GS site, data on known or suspected

faults in the AoR, geomechanical information on fractures, stress, ductility, rock strength, and in situ

fluid pressures within the confining zone as specified in §146.82(a)(3). This information is evaluated

by the Director, who determines the suitability of a potential project site for GS. Any sites with the

potential for reopening or reactivation of faults or unacceptable seismic risk that could otherwise

interfere with containment will not be permitted as GS sites. During injection, the pressure in the

injection zone must not exceed 90 percent of the fracture pressure of the injection zone as specified

in §146.88(a); this requirement is intended to prevent the opening of fractures or faults through over

pressurization of the injection zone.

Commenter Name: Rob McCormic Letter ID: 0119

Commenter Organization: Dallas County Park Cities Municipal Utility

District

Comment ID:

22069

Comment: Concerning the proposed rule allowing Geological Sequestration of 

Carbon Dioxide, what safeguards are there against accidently activating or 

reactivating seismic (earthquake) faults at or near a proposed sequestration 

site, particularly with injecting "supercritical" liquid CO2? 

Response: EPA acknowledges that induced seismicity is a risk that may be associated with GS but

maintains that the risk is low (IPCC, 2005). The GS rule contains several requirements to address

seismic risk. First, as part of the site characterization process under §146.82, owners or operators

must submit information about the seismic history of and seismic sources near a proposed GS site;

data on known or suspected faults in the AoR; and geomechanical information on fractures, stress,

ductility, rock strength, and in situ fluid pressures within the confining zone as specified in

§146.82(a)(3). This information is evaluated by the Director, who determines the suitability of a

potential project site for GS. Any sites with the potential for reopening or reactivation of faults or

unacceptable seismic risk that could otherwise interfere with containment will not be permitted as

GS sites. During injection, the pressure in the injection zone must not exceed 90 percent of the

fracture pressure of the injection zone as specified in §146.88(a); this requirement is intended to

prevent the opening of fractures or faults through over-pressurization of the injection zone.

To support consistent interpretation and application of the safeguards related to induced seismicity in

the GS rule, EPA is developing guidance on site characterization for GS projects to assist owners or

operators and Directors in evaluating permit requirements and applications under §146.82. The

guidance provides recommendations to owners or operators regarding information to support

characterizing the regional geology and hydrogeology of a proposed GS site as well as how to

perform the necessary geochemical, geomechanical, and geophysical analyses of the injection and

confining zone. EPA expects that this guidance will assist permit writers and UIC Directors in

making an objective decision about requiring additional confining layers. The guidance can be found

on EPA’s website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Bonnie Lovelace Letter ID: 0152

Commenter Organization: Montana Department of Environmental Quality Comment ID:

89
(MDEQ) 22107

Other EPA Comment Codes and Descriptions: 5220 2.8.2.1 Post-injection monitoring activities 

Comment: 7. EPA clearly identifies the risks of seismic effects from geologic 

sequestration and indicates the need to only select sites that are geologically 

stable. Each state has a geologic survey which monitors seismic activity. 

Further, any area can surprise geologists with activity that was unexpected. [An 

example in Montana would be the usually seismically quiet area near Grass Range 

that surprisingly had a recent event at over 4 on the Richter scale. In fact, 

no areas of Montana are seismically at zero on the Richter scale, but may still 

be appropriate for sequestration.] Each geologic sequestration site should be 

required to add seismic monitoring that is added to the state's monitoring 

network. This monitoring should be started as baseline and continued well after 

closure of injection activities. 

Response: EPA acknowledges that induced seismicity is a risk that may be associated with GS but

maintains that the risk is low (IPCC, 2005). The GS rule contains several requirements to address

seismic risk. First, as part of the site characterization process, owners or operators must submit

information about the seismic history of and seismic sources near a proposed GS site, data on known

or suspected faults in the AoR, geomechanical information on fractures, stress, ductility, rock

strength, and in situ fluid pressures within the confining zone as specified in §146.82(a)(3). This

information is evaluated by the Director, who determines the suitability of a potential project site for

GS. Any sites with the potential for reopening or reactivation of faults or unacceptable seismic risk

that could otherwise interfere with containment will not be permitted as GS sites. During injection,

the pressure in the injection zone must not exceed 90 percent of the fracture pressure of the injection

zone as specified in §146.88(a); this requirement is intended to prevent the opening of fractures or

faults through over pressurization of the injection zone.

Given the emphasis on site selection to reduce the potential for induced seismicity, EPA disagrees

that seismic monitoring is necessary at all GS sites. However, EPA adds that the Director has the

authority to require such monitoring under §146.90(i) if he or she believes this to be appropriate

based on site-specific information. 

EPA does not believe that limiting GS to "stable areas" will provide certainty that seismic events will

not occur. The Agency acknowledges that some regions of the country are at risk for infrequent,

damage-causing seismic events even if such events have not been recorded in the recent historical

record (i.e., in the past several hundred years). For this reason, EPA requires seismic risk to be

evaluated on a site-specific basis, through an analysis of seismic history and an evaluation of known

or suspected faults in the AoR, geomechanical information on fractures, stress, ductility, rock

strength, and in situ fluid pressures within the confining zone as specified in §146.82(a)(3). In

addition, if an adverse event, such as a well failure or evidence of fluid movement were to occur, the

monitoring requirements at §146.90 and emergency and remedial response requirements as specified

in §146.94 provide additional protection.

Commenter Name: James Dooley Letter ID: 0156

Commenter Organization: Joint Global Change Research Institute, Pacific

Northwest National Laboratory

Comment ID:

22658

Comment: - Page 43498, section on "Seismic Events." The first sentence in this section 

is clearly speaking to the potential for CO2 injection to cause seismic activity 

in the future when commercial deployment of CCS becomes more common place. 

90
However, the second sentence and the subsequent discussion of induced seismicity 

at the Rocky Mountain Arsenal are not related to CO2 injection. To be clear, it 

was not CO2 that was being injected into deep geologic formations beneath the 

Rocky Mountain Arsenal. If this section of the preamble is retained in future 

versions of this proposed rule, this section must be rewritten to make it clear 

that the technical literature suggests that poorly managed CO2 injection could 

in the future induce small scale seismic activity. And then if there is a need 

to discuss previous instances where injection of fluids that were not CO2 

triggered seismic activity the language needs to be clear and explicit so the 

reader understands that these are not past instances of poor CO2 injection. 

Response: EPA clarifies that the seismic episodes at the Rocky Mountain Arsenal, which occurred

in the 1960s—before the original UIC regulations were developed—were due to poor site

characterization and well operation, including high, unmonitored injection pressures (73 FR 43498).

While EPA acknowledges that the volumes of CO2 injected at GS sites will likely be larger than the

volumes of waste water injected at the Rocky Mountain Arsenal, injection volume is not the sole

factor that determines induced seismicity. Induced seismicity also depends on other geologic

variables such as pre-existing faults, porosity, and permeability (Sminchak & Gupta, 2003). With

proper site characterization (i.e., pursuant to §146.82), these variables can often be quantified prior

to injection (Sminchak and Gupta, 2003) and used to identify sites capable of safely sustaining

prolonged injection of large volumes with low risk. As long as a site is well-characterized and

monitored, and the injection volume and rate remain within permitted limits set forth by the Director,

the injection of large volumes of fluid should not increase the risk of seismic activity.

EPA does not believe that limiting GS to "stable areas" will provide certainty that seismic events will

not occur. The Agency acknowledges that some regions of the country are at risk for infrequent,

damage-causing seismic events even if such events have not been recorded in the recent historical

record (i.e., in the past several hundred years). For this reason, EPA requires seismic risk to be

evaluated on a site-specific basis, through an analysis of seismic history and an evaluation of known

or suspected faults in the AoR, geomechanical information on fractures, stress, ductility, rock

strength, and in situ fluid pressures within the confining zone as specified in §146.82(a)(3). In

addition, if an adverse event, such as a well failure or evidence of fluid movement were to occur, the

monitoring requirements at §146.90 and emergency and remedial response requirements as specified

in §146.94 provide additional protection.

Commenter Name: Theresa Pugh Letter ID: 0169

Commenter Organization: American Public Power Association Comment ID: 23396

Other EPA Comment Codes and Descriptions: 1260 1.1.1.5 More certainty/stringency is needed 

Comment: Because information and technology related to carbon sequestration are sure to 

develop as more experience is gained, APPA urges EPA to do what it can avoid the 

use of arbitrary or blanket prohibitions or absolutes in the EPA final rule. 

However, APPA believes that there are some common sense prohibitions that may be 

justifiable. For example, EPA should have in the final rule an explanation, 

consistent with the Class I program, that seismic-induced subsurface conveyance 

risks such as major faults, or proximity to sole source aquifer [FN5] 

protections are essential. Sole source aquifers are not the same as deep saline 

aquifers. APPA believes there are some prohibitions that are key to protection 

of USDWs. At the same time we do not want to contribute to "NIMBY" or "not in my 

backyard" or "NUMBY" - or "not under my back yard". What APPA asks for in the 

91
context of seismicity issues are clear-cut and understandable parameters or USGS 

guidelines so that power plant owner/operators don't pursue a geologic formation 

thinking that it is eligible only to learn that the EPA has used a USGS 

designation on seismic risks that would render it disqualified later in the 

permitting process. APPA asks that when the EPA or state directors make 

seismicity conditions that these be subject to notice and comment and be 

published in the Federal Register and the state equivalent publication. It would 

be terrible to have a power plant owner/operator spend time and significant 

money pursuing a geologic formation only to learn after he had spent many 

hundreds of thousands of dollars that the site did not meet the EPA’s seismic 

risk or USGS seismic requirements. Seismicity risk avoidance is a new factor for 

thermal or fossil plants and not one with which we have experience. APPA 

includes in the Appendix a paper from an NETL-funded study on seismic activity 

induced by injection of CO2 into deep saline aquifers [FN6] and an article 

regarding the Greek government’s concerns with injection of CO2 in the 

Mediterranean. [FN7] [See EPA-HQ-OW-2008-0390-0169.pdf for these documents.] 

Including these references to seismic issues does not mean that APPA fears that 

CO2 will cause seismic activity. Instead APPA does not want to see APPA member 

utilities pursue geology which has underlying seismic risks that are unknown to 

the power sector (and perhaps to the state agencies) and misuse critical 

resources, time and money pursuing that location for permitting only to find out 

later that they must start again. Most locations in the U.S. have not had recent 

seismic data assessed at the "fine granular" level needed to target the right 

formations for carbon dioxide geosequestration. This will necessitate the 

support of United States Geologic Survey and other agencies. 

[FN5] A sole source aquifer (SSA) is an underground water supply designated by 

the U.S. EPA as the "sole or principal" source of drinking water for an area 

under Section 1424(e) the Safe Drinking Water Act of 1974. "Sole or principal" 

has been interpreted to mean that the aquifer must supply at least 50 percent of 

the drinking water to persons living over the aquifer; there should be no 

alternate and feasible sources of drinking water that could replace the aquifer. 

[FN6] Issues Related to Seismic Activity Induced by the Injection of CO2 in Deep 

Saline Aquifers, Joel Sminchak and Neeraj Gupta, Battelle Memorial Institute 

[FN7] "Why doesn't Greece like carbon capture?" Leigh Phillips, EU Observer, 

9/23/08, http://euobserver.com/19/26794 

Response: The GS rule, at §146.82(a)(5) requires prospective owners or operators to submit

information on all USDWs within the AoR. EPA expects that this information will include

identification of any sole source aquifers. The GS rule also requires operators to submit extensive

information about the site, including the geologic characteristics of the injection and confining

zones, to demonstrate that the injected CO2 will remain within the target formation. The Director

must consider this information when determining whether GS is acceptable at a given site. EPA

expects that during this evaluation the Director will consider the potential impact of the GS project

on any sole source aquifers.

Regarding seismicity, EPA acknowledges that induced seismicity is a risk that may be associated

with GS but maintains that the risk is low (IPCC, 2005). The GS rule contains several requirements

92
to address seismic risk. First, as part of the site characterization process, owners or operators must

submit information about the seismic history of and seismic sources near a proposed GS site, data on

known or suspected faults in the AoR, geomechanical information on fractures, stress, ductility, rock

strength, and in situ fluid pressures within the confining zone as specified in §146.82(a)(3). This

information is evaluated by the Director, who determines the suitability of a potential project site for

GS. Any sites with the potential for reopening or reactivation of faults or unacceptable seismic risk

that could otherwise interfere with containment will not be permitted as GS sites. During injection,

the pressure in the injection zone must not exceed 90 percent of the fracture pressure of the injection

zone as specified in §146.88(a); this requirement is intended to prevent the opening of fractures or

faults through over pressurization of the injection zone.

EPA clarifies that the rule does not contain any specific requirements describing "seismically

appropriate" areas, and does not believe this is appropriate for all sites. EPA believes such

determinations should be made on a site-specific basis. If such information is available, and the

Director determines it to be relevant to the site characterization, it is in their authority to require

detailed evaluations. However, EPA disagrees that this should be a requirement for all GS projects.

In many cases, UIC Directors will have extensive knowledge of which areas are suitable for GS, but

clarifies that it is the responsibility of Class VI permit applicants to demonstrate the suitability of a

particular site or formation. It is the responsibility of the Director to evaluate the information

collected and submitted by the owner or operator to determine whether a permit for GS at the site is

appropriate.

EPA is developing guidance on site characterization for GS projects to assist owners or operators

and Directors in evaluating permit requirements and applications under §146.82. The guidance

provides recommendations to owners or operators regarding information to support characterizing

the regional geology and hydrogeology of a proposed GS site as well as how to perform the

necessary geochemical, geomechanical, and geophysical analyses of the injection and confining

zone. EPA expects that this guidance will assist permit writers/UIC Directors in making an objective

decision about requiring additional confining layers. The guidance can be found on EPA’s website at

http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

Commenter Name: Thomas Curtis Letter ID: 0181

Commenter Organization: American Water Works Association (AWWA) Comment ID: 23672

Comment: Seismicity: The seismicity requirements in the Area of Review requirements are 

not very prescriptive. AWWA believes there is too much latitude for 

interpretation and that the regulation could be applied inconsistently by 

Directors of different states. AWWA recommends making the language stronger to 

clarify exactly what is meant by the following requirement (§146.82(d)(3)): 

"...information on seismic history including the presence and depth of seismic 

sources and a determination that the seismicity would not interfere with 

containment." A geologic sequestration project should be evaluated on the entire 

risk spectrum using different ranges of seismic activity and distance 

requirements from active faults to determine if the proposed site is acceptable. 

EPA should develop guidance that will assist owner/operators in making the 

appropriate determinations regarding seismic risk for a geologic sequestration 

project. For example, is there a minimum distance that should be provided 

between the potential plume footprint and an area of seismic activity? This 

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

different level of risk due to their comfort with the financial implications. 

93
AWWA does not want to see USDW protection compromised due to faulty assumptions 

about seismic activity in and around a potential project site. 

AWWA recommends that EPA also investigate the need for modeling the potential 

for seismic shifts due to the changes in subsurface pressures associated with 

the carbon dioxide injection process. A literature search should be performed to 

see if either Laurence Berkley National Laboratory or the National Energy 

Technology Laboratory has developed any information on this topic. 

Response: EPA believes that decisions about seismic risk should be made on a site-specific basis.

The Class VI requirements are designed to ensure that, where GS is employed, it is done in a manner

that protects USDWs from endangerment. These requirements include site characterization during

which owners or operators must submit information about the seismic history of and seismic sources

near a proposed GS site, as well as data on known or suspected faults in the AoR, geomechanical

information on fractures, stress, ductility, rock strength, and in situ fluid pressures within the

confining zone as specified in §146.82(a)(3). This information is evaluated by the Director in

conjunction with information about well construction, operation, monitoring, post-injection site care,

and other site-specific information. The Director determines the suitability of a potential project site

for GS. Sites with the potential for reopening or reactivation of faults or unacceptable seismic risk

that could otherwise interfere with containment would not be suitable for GS sites–as owners or

operators seeking to inject CO2 for GS at such sites would not be able to demonstrate USDW

protection from endangerment. 

The final rule also contains operational requirements to ensure USDW protection including injection

pressure limitations. During injection, the pressure in the injection zone must not exceed 90 percent

of fracture pressure of the injection zone as specified in §146.88(a). This requirement is intended to

prevent the opening of fractures or faults through over pressurization of the injection zone. EPA adds

that these requirements are based on extensive study and review of scientific literature and laboratory

and field experience.

EPA clarifies that the rule does not contain any specific requirements describing "seismically

appropriate" areas, and does not believe this is appropriate for all sites. EPA believes such

determinations should be made on a site-specific basis. If such information is available, and the

Director determines it to be relevant to the site characterization, it is in their authority to require

detailed evaluations. However, EPA disagrees that this should be a requirement for all GS projects.

In many cases, UIC Directors will have extensive knowledge of which areas are suitable for GS, but

clarifies that it is the responsibility of Class VI permit applicants to demonstrate the suitability of a

particular site or formation. It is the responsibility of the Director to evaluate the information

collected and submitted by the owner or operator to determine whether a permit for GS at the site is

appropriate. 

To support consistent interpretation and application of the safeguards related to induced seismicity in

the GS rule, EPA is developing guidance on site characterization for GS projects to assist owners or

operators and Directors in evaluating permit requirements and applications under §146.82. The

guidance provides recommendations to owners or operators regarding information to support

characterizing the regional geology and hydrogeology of a proposed GS site as well as how to

perform the necessary geochemical, geomechanical, and geophysical analyses of the injection and

confining zone. EPA expects that this guidance will assist permit writers/UIC Directors in making an

objective decision about requiring additional confining layers. The guidance can be found on EPA’s

website at http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm.

94
Commenter Name: Andy Horn Letter ID: 0196

Commenter Organization: Colorado Ground Water Association (CGWA) Comment ID: 23924

Comment: Issue 4. The proposed regulation is ambiguous on the issue of tectonic stress 

release (earthquakes). 

The proposed regulation should specifically address the issue of triggering 

tectonic stress releases, to avoid problems, such as the generation of 

earthquakes that resulted from deep waste injection at the Rocky Mountain 

arsenal in the 1960s and in other locations such as the Paradox Valley, Colorado 

(Ake, et al, 2005). From 1962 through 1966 the Rocky Mountain Arsenal injected 

a volume of approximately 165 million gallons of waste, or roughly 35 million 

gallons annually. This volume would be dwarfed by the injection volumes 

proposed on the three billion gallons of supercritical CO2 annually. While the 

proposed rule states that the potential for induced seismicity is low, the 

magnitude of the volumes proposed for injection indicate that this issue has the 

potential to present a significant risk to occupants within a GS project Area of 

Review AoR. 

Ake, Jon, Kenneth Mahrer, Daniel O’Connell and Lisa Block, 2005. Deep-Injection 

and Closely Monitored Induced Seismicity at Paradox Valley, Colorado, Bulletin 

of the Seismological Society of America; April 2005; v. 95; no. 2; p. 664-683; 

Response: EPA acknowledges that induced seismicity is a risk that may be associated with GS but

maintains that the risk is low (IPCC, 2005). The GS rule contains several requirements to address

seismic risk. First, as part of the site characterization process, owners or operators must submit

information about the seismic history of and seismic sources near a proposed GS site, data on known

or suspected faults in the AoR, geomechanical information on fractures, stress, ductility, rock

strength, and in situ fluid pressures within the confining zone as specified in §146.82(a)(3). This

information is evaluated by the Director, who determines the suitability of a potential project site for

GS. Any sites with the potential for reopening or reactivation of faults or unacceptable seismic risk

that could otherwise interfere with containment will not be permitted as GS sites. During injection,

the pressure in the injection zone must not exceed 90 percent of the fracture pressure of the injection

zone as specified in §146.88(a); this requirement is intended to prevent the opening of fractures or

faults through over pressurization of the injection zone.

EPA adds that the seismic episodes at the Rocky Mountain Arsenal, which occurred in the 1960s—

before the original UIC regulations were developed—were due to poor site characterization and well

operation, including high, unmonitored injection pressures (73 FR 43498). While EPA acknowledges

that the volumes of CO2 injected at GS sites will likely be larger than the volumes of waste water

injected at the Rocky Mountain Arsenal, injection volume is not the sole factor that determines

induced seismicity. Induced seismicity also depends on other geologic variables such as pre-existing

faults, porosity, and permeability (Sminchak & Gupta, 2003). With proper site characterization (i.e.,

pursuant to §146.82), these variables can often be quantified prior to injection (Sminchak and Gupta,

2003) and used to identify sites capable of safely sustaining prolonged injection of large volumes

with low risk. As long as a site is well-characterized and monitored, and the injection volume and

rate remain within permitted limits set forth by the Director, the injection of large volumes of fluid

should not increase the risk of seismic activity.

EPA does not believe that limiting GS to "stable areas" will provide certainty that seismic events will

95
not occur. The Agency acknowledges that some regions of the country are at risk for infrequent,

damage-causing seismic events even if such events have not been recorded in the recent historical

record (i.e., in the past several hundred years). For this reason, EPA requires seismic risk to be

evaluated on a site-specific basis, through an analysis of seismic history and an evaluation of known

or suspected faults in the AoR, geomechanical information on fractures, stress, ductility, rock

strength, and in situ fluid pressures within the confining zone as specified in §146.82(a)(3). In

addition, if an adverse event, such as a well failure or evidence of fluid movement were to occur, the

monitoring requirements at §146.90 and emergency and remedial response requirements as specified

in §146.94 provide additional protection.

Commenter Name: Kurt Waltzer Letter ID: 0250

Commenter Organization: Clean Air Task Force Comment ID: 22326

Other EPA Comment Codes and Descriptions: 3100 2.1 Proposed Geologic Siting Requirements

(40 CFR 146.83) 

Comment: Seismicity 

Naturally occurring seismicity has been cited as an area of concern for geologic 

sequestration of CO2. We do believe that seismicity merits diligent treatment 

both in the regulations and in project operation, but we see no need for a 

blanket ban of sequestration in seismically active areas. Although some sites - 

especially ones near major active faults - would not be advisable for injection, 

there are plenty of other sites in seismically active areas that would make 

excellent candidates for safe and effective sequestration. Moreover, tools to 

measure, predict and design against the effects of seismic activity are 

available. 

Nature has proven its ability to retain fluids trapped in the subsurface in 

seismically active areas in many instances over hundreds of millions of years, 

even in highly tectonically active regions of the country such as California. 

The potential for slippage for faults to create leakage pathways to USDWs or the 

surface can be managed and effectively minimized through careful siting and 

operational design using well-established tools and methods. The regulations 

should ensure that suitable sites are selected, while high risk areas, such as 

those near major, non-sealing faults or those that demonstrate frequent 

activity, are rejected. The most likely potential CO2 leakage paths would be 

injection wells, and not faults. However, these can be designed to prevent 

leakage and to be resilient to earthquakes. 

We regard a ban on sequestration in seismically active areas unwarranted. We do 

however believe that additional diligence is required in site characterization 

and selection in such areas. The requirement in §146.82(c)(3) should be modified 

as follows: 

Response: EPA agrees that GS should not be banned in any type of environment or geologic setting

and believes that decisions about seismic risk should be made on a site-specific basis. The Class VI

requirements to properly characterize, permit, operate, and monitor a GS project are designed to

ensure that, where GS is employed, it is done in a manner that protects USDWs from endangerment.

These requirements include site characterization during which owners or operators must submit

information about the seismic history of and seismic sources near a proposed GS site, as well as data

96
on known or suspected faults in the AoR, geomechanical information on fractures, stress, ductility,

rock strength, and in situ fluid pressures within the confining zone as specified in §146.82(a)(3).

This information is evaluated by the Director in conjunction with information about well

construction, operation, monitoring, post-injection site care, and other site-specific information. The

Director determines suitability of a potential project site for GS. Sites with the potential for

reopening or reactivation of faults or unacceptable seismic risk that could otherwise interfere with

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

at such sites would not be able to demonstrate USDW protection from endangerment. 

EPA acknowledges that wells in the AoR are potential leakage pathways, and the GS rule contains

rigorous provisions for both injection well construction at §146.86 and corrective action on active or

abandoned wells located in the AoR at §146.84.

Commenter Name: Kurt Waltzer Letter ID: 0250

Commenter Organization: Clean Air Task Force Comment ID: 22327

Other EPA Comment Codes and Descriptions: 1240 1.1.1.3 Suggested changes/edits to rule

language 

Comment: [In the paragraph below the text 

in all CAPS denotes added text. See also EPA-HQ-OW-0390-0250.pdf, to see the 

original formatting.] 

"Information on seismic history including the presence and depth of seismic 

sources and aN ASSESSMENT OF that WHETHER SUCH seismicity would not 

interfere with containment;" 

In addition, language should be added to the minimum criteria for siting in 

§146.83, clarifying that if induced or natural seismicity poses unacceptable 

risks, a permit will not be granted. In order properly to assess the risk of 

significant induced seismicity in light of permitted operating conditions, the 

rule may need to require applicants to submit information beyond what is 

currently required in proposed §146.82. The effects of any seismic events during 

project operation should also be taken into account when updating, or 

considering whether to update, the Area of Review and Corrective Action Plan, 

the Testing and Monitoring Plans, and the Emergency and Remedial Response Plans, 

as well as any other plans as necessary. 

Response: Based on its evaluation of all public comments and input on the proposed rule and

NODA and Request for Comment EPA has made many revisions to the GS Rule. See the final rule

and preamble discussion of geologic site characterization for further discussion on EPA's final

approach.

EPA clarifies that under §146.82(a)(21), the Director has the authority to require additional

information to be submitted with the permit application. EPA agrees that seismic events should be

taken into account when updating the plans or other permit conditions and clarifies that existing

language at §144.39(a)(2) allows the Director to modify the permit when he or she receives new

information that was not available at the time of permit issuance.

Commenter Name: Scott Anderson Letter ID: 0520

97
Commenter Organization: Environmental Defense Fund Comment ID: 21431

Other EPA Comment Codes and Descriptions: 4110 2.4.1.1 Injection pressure limitations; 4710

2.7.1 Proposed submissions required for permit applications (seeking comment) 

Comment: Injection pressure limits. This is very important and we think EPA's about 

halfway toward addressing this properly. The half that seems to be well done is 

that the proposed rule requires quite a bit of geomechanical information to be 

submitted. The kind of information that could be used, should be used to 

determine whether or not there is a risk of induced seismicity and to determine 

whether or not there is risks of reopening otherwise closed faults and fractures 

making them, making what starts out as a non-transmissive fault into a 

transmissive fault. So the proposed rule calls for the information that enables 

that kind of stuff to be calculated, but it fails to require that information to 

be used as part of the permitting process to inform the injection pressure 

limits. Instead the rule uses the traditional sort of injection pressure limit 

from oil and gas regulation that says accepted as a percentage of fracture 

pressure. The problem with that is that these other problems I mentioned, 

induced seismicity and reopening of faults can occur in lower pressures than say 

90% of fracture pressure, it is possible for one to comply with the 90% of 

fracture pressure requirement and yet still cause these other geomechanics 

related problems. 

Response: EPA clarifies that all information about the site, including seismic history and data on

rock mechanics, will be used to inform pressure limitations. 

In response to the concern about induced seismicity and reopening of faults at lower pressures than

90 percent of fracture pressure, EPA believes that the requirement for the owner or operator to

submit data on known or suspected faults and fractures and information on the seismic history of the

site, including the presence and depth of seismic sources and a determination that the seismicity

would not interfere with containment per §146.82(a)(3)(v), will inform the determination of an

appropriate pressure limitation in the permit. This investigation would also identify any sites with the

potential for reopening or reactivation of faults or unacceptable seismic risk that could otherwise

interfere with containment. 

The Director will also review geologic, hydrogeologic, and geomechanical information submitted by

the owner or operator in setting permit conditions. If, based on this information, a lower pressure

limitation is appropriate, the Director has the authority to set a lower limit in the operating permit.

EPA clarifies that fracturing of the confining zone during injection and/or stimulation is also

prohibited at §146.88(a).

Commenter Name: Nancy LaPlaca Letter ID: 0529

Comment ID: 21495

Comment: In addition when you pump liquid CO2 underground, you basically lubricate 

existing faults and here in Denver, in the 1960's, they injected 165 million 

gallons of liquid toxic waste from Rocky Mountain arsenal underneath the Denver 

basin and they created some 1,500 seismic events between 1962 and 1967. Three of 

those events were over magnitude five. My husband was a little boy living here 

then and most people who lived here then and remembered that, remember those 

earthquakes very clearly. 

98
My father-in-law, George Bardwell, mathematician who taught at DU was approached 

by a group of geologists headed by a guy named David Evans who is now deceased. 

David Evans and my father-in-law George E. Bardwell now 84 years old this year 

-- George did a study for them correlating the injection of these liquids with 

seismic events. The more they injected, the more earthquakes there were. The 

less they injected, the less earthquakes and actually George told me that it 

took a long time and they really did not come out with this blue ribbon panel 

report that they were promising for years and years. They went to the press, 

George Bardwell my father-in-law and these geologists and the press would not 

report on it. They went to the government and they said you know what 

government, there is a real problem with this and the government would not 

listen to them either. 

Response: EPA acknowledges that induced seismicity is a risk that may be associated with GS but

maintains that the risk is low (IPCC, 2005). The GS rule contains several requirements to address

seismic risk. First, as part of the site characterization process, owners or operators must submit

information about the seismic history of and seismic sources near a proposed GS site, data on known

or suspected faults in the AoR, geomechanical information on fractures, stress, ductility, rock

strength, and in situ fluid pressures within the confining zone as specified in §146.82(a)(3). This

information is evaluated by the Director, who determines the suitability of a potential project site for

GS. Any sites with the potential for reopening or reactivation of faults or unacceptable seismic risk

that could otherwise interfere with containment will not be permitted as GS sites. During injection,

the pressure in the injection zone must not exceed 90 percent of the fracture pressure of the injection

zone as specified in §146.88(a); this requirement is intended to prevent the opening of fractures or

faults through over pressurization of the injection zone.

EPA adds that the seismic episodes at the Rocky Mountain Arsenal, which occurred in the 1960s—

before the original UIC regulations were developed—were due to poor site characterization and well

operation, including high, unmonitored injection pressures (73 FR 43498). While EPA acknowledges

that the volumes of CO2 injected at GS sites will likely be larger than the volumes of waste water

injected at the Rocky Mountain Arsenal, injection volume is not the sole factor that determines

induced seismicity. Induced seismicity also depends on other geologic variables such as pre-existing

faults, porosity, and permeability (Sminchak & Gupta, 2003). With proper site characterization (i.e.,

pursuant to §146.82), these variables can often be quantified prior to injection (Sminchak and Gupta,

2003) and used to identify sites capable of safely sustaining prolonged injection of large volumes

with low risk. As long as a site is well-characterized and monitored, and the injection volume and

rate remain within permitted limits set forth by the Director, the injection of large volumes of fluid

should not increase the risk of seismic activity.

EPA does not believe that limiting GS to "stable areas" will provide certainty that seismic events will

not occur. The Agency acknowledges that some regions of the country are at risk for infrequent,

damage-causing seismic events even if such events have not been recorded in the recent historical

record (i.e., in the past several hundred years). For this reason, EPA requires seismic risk to be

evaluated on a site-specific basis, through an analysis of seismic history and an evaluation of known

or suspected faults in the AoR, geomechanical information on fractures, stress, ductility, rock

strength, and in situ fluid pressures within the confining zone as specified in §146.82(a)(3). In

addition, if an adverse event, such as a well failure or evidence of fluid movement were to occur, the

monitoring requirements at §146.90 and emergency and remedial response requirements as specified

in §146.94 provide additional protection.

99
Comment Code: 1630 1.3.3 RCRA/hazardous waste issues (seeking comment) 

Individual Comments

Commenter Name: Paul Pike Letter ID: 0111

Commenter Organization: Ameren Corporation on behalf of USWAG Comment ID: 22403

Comment: 4. Of particular importance is the potential for liability under RCRA and 

CERCLA, including Natural Resource Damages, stemming from injection and 

sequestration of carbon dioxide. As EPA can surely appreciate, the potential for 

these openended liabilities will act as a serious deterrent to would-be Owners 

or Operators of Class VI injection wells. Simply put, EPA must mitigate the 

threat of potential RCRA and CERCLA liability to the extent possible in this 

rulemaking. 

With respect to RCRA, it is premature to suggest that the captured and injected 

carbon dioxide is "discarded" and therefore possibly solid waste under RCRA. 

Carbon dioxide is a commodity used in a variety of processes; to the extent that 

there is any possibility that carbon dioxide injection operations could be 

subject to RCRA controls, EPA should create an applicable exemption from RCRA 

under the well-established "contingent management" concept given that the UIC 

permit will ensure that the injected material is not mismanaged. Such an 

exclusion would be legally justified, consistent with the Agency’s past 

promulgation of conditional exclusion rules, and would make sound policy sense 

by removing a potentially significant regulatory barrier to the commercial 

development of carbon dioxide sequestration operations. 

The bottom line is that the potential for interaction with RCRA or liability 

under CERCLA must be mitigated to avoid significant delays and an overall 

chilling effect. USWAG recognizes that while there are some measures the Agency 

can take in the regulatory context to address these concerns, those measures may 

be limited. In the end, USWAG believes that the Agency should consider whether a 

legislative solution is necessary to eliminate these concerns; if so, we 

recommend that the EPA strongly support such a solution. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations. Under the final GS rule, owners or operators will need to determine whether the CO2

stream is hazardous under EPA’s RCRA regulations, and if so, any injection of the hazardous CO2

100
stream may only occur in a Class I hazardous waste injection well.

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit. 

EPA adds that promoting the use of GS is outside the scope of the GS rule. Rather, the purpose of

the GS regulation is to ensure that, where deployed, GS is conducted in a manner that protects

USDWs from endangerment. Furthermore, EPA is promulgating the GS rule under the authority of

the SDWA. To the extent the commenter is seeking interpretations of RCRA or CERCLA, such

interpretations are beyond the scope of this rulemaking.

Commenter Name: Elizabeth Lokey Letter ID: 0112

Commenter Organization: Camco International Comment ID: 22046

Other EPA Comment Codes and Descriptions: 1614 1.3.1.2 Impurities in captured CO2; purity

standards for CO2 

Comment: Currently, the proposed rule (EPA-HQ-OW-2008-0390) defines CO2 that can 

be injected under a class VI designation as the following: 

"CO2 that has been captured from an emission source (e.g. power plant), 

plus incidental associated substances derived from the source materials and the 

capture process, and any substances added to the stream to enable or improve the 

injection process. This subpart does not apply to any carbon dioxide stream that 

meets the definition of a hazardous waste under 40 CFR Part 261." 

This definition is vague and needs clarification in terms of the percentage of 

CO2 in a given volume of gas to allow the CO2 to qualify for this injection 

permit. Otherwise, entire stack emissions or chemicals used in the separation 

process could end up being transported and injected. This could have unintended 

consequences on the reservoirs where the CO2 is stored as minerals could be 

dissolved and allow plumes to spread. 

Response: The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a

percent CO2). Instead, the GS rule addresses the quality and quantity of impurities by requiring

owners or operators to submit information on the source of the CO2 and its physical and chemical

properties. Specifically, the GS rule requires the owner or operator to submit data about the site,

including an analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the 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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals. 

EPA understands that many CO2 streams may be relatively pure, and research indicates that the

101
estimated amounts of impurities in a CO2 stream are likely to be low. However, these estimates are

based on limited information, and uncertainties remain about the expected concentrations of

impurities from the various types of CO2 streams. The concentrations of minor and trace elements in

CO2 streams for GS projects are likely to vary by facility, coal composition, plant operating

conditions, and pollution removal technologies. EPA clarifies that the GS rule does not apply to

capture technologies.

Commenter Name: George Holliday, PhD, PE, BCEE Letter ID: 0114

Commenter Organization: Holliday Environmental Services, Inc. Comment ID: 22516

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: dangerous and 2) unnecessary and should not promulgated. Also, we believe the 

Safe Drinking Water Act is not suited to provide necessary safety to the 

citizenry, because EPA, by promulgating Class VI wells, is authorizing 

construction of a CERCLA imminent hazard substance storage site and a RCRA 

hazardous substance (corrosivity) storage site. Each of these concerns and many 

more are discussed below. We request these comment be made a part of the record 

EPA-HQ-OW-2008-0390. 

Response: EPA disagrees that the final GS rule is authorizing construction of CERCLA imminent

hazard substance storage sites or RCRA hazardous substance storage sites. It is authorizing the

construction and operation of a new class of injection well for purposes of long term storage of

CO2. 

EPA received many comments regarding the applicability of the RCRA regulations and statute to

CO2 streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability to CO2 streams being geologically sequestered. EPA will consider these

comments as part of its development of that proposal. The Agency will consider issues particular to

RCRA in the context of that separate rulemaking, and recommends that the commenter read that

proposed rule when it is published. The Agency notes that commenters who wish to submit

comments on the RCRA proposal will need to do so during the comment period for that rule. 

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 low. However, these estimates are

based on limited information, and uncertainties remain about the expected concentrations of

impurities from the various types of CO2 streams. The concentrations of minor and trace elements in

CO2 streams for GS projects are likely to vary by facility, coal composition, plant operating

conditions, and pollution removal technologies. 

EPA is not authorizing the injection of RCRA hazardous wastes under the terms of the GS rule, since

the GS rule, at §146.81(d), prohibits CO2 streams that meet the definition of a hazardous waste

under 40 CFR Part 261. Under the rule, owners or operators will need to characterize their CO2

stream as part of their permit application process to determine whether the injectate is a RCRA

hazardous waste. If the CO2 stream is determined to be a hazardous waste, injection may only occur

in a Class I hazardous waste injection well. 

The GS rule also requires the owner or operator to submit data about the site, including an analysis

of the chemical and physical characteristics of the CO2 stream, as required at §146.82(a)(7)(iv), and

information on the compatibility of the CO2 stream with fluids in the injection zone and minerals in

102
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 potential for geochemical

reactions between the injectate (CO2) and the host geologic formations, which could result in the

plugging of pore spaces or the dissolution of formation minerals.

EPA clarifies that CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit.

Commenter Name: George Holliday, PhD, PE, BCEE Letter ID: 0114

Commenter Organization: Holliday Environmental Services, Inc. Comment ID: 22532

Other EPA Comment Codes and Descriptions: 1460 1.2.2.2 Oppose EPA's authority to regulate

CO2 injection 

Comment: EPA DOES NOT HAVE PROPER STATUTORY AUTHORITY TO PROPOSE CO2

SEQUESTRATION RULE 

EPA relies on the Safe Drinking Water Act (SDWA) to protect USDWs from CO2 

sequestration. The SDWA authorizes EPA to protect drinking water, not encourage 

indefinite storage of a corrosive, high press fluid. CO2 is known to attack 

carbon and stainless steel, Meyer (2007). The fact that Meyer reported 

stainless steel 404 was badly corroded by "dry" CO2 indicates wet CO2 (carbonic 

acid) is a RCRA corrosive waste, since it meets the RCRA definition of 

corrosive. In addition, the fact a leak of CO2 could enter a building basement 

suffocating the inhabitants, demonstrates CO2 sequestration is not an 

environmental problem, but, when sequestered, it is a pervasive and dangerous 

life threatening hazard. EPA is ill equipped to control potentially unsafe 

activities under the guise of protecting drinking water. 

Meyer, J.P. 2007. "Summary of Carbon Dioxide Enhanced Oil Recovery (CO2EOR) 

Injection Well Technology" prepared for American Petroleum Institute, p 21. 

Response: EPA disagrees that the SDWA does not provide EPA with adequate authority to regulate

underground injection of CO2 for GS or that the GS rule oversteps the boundaries or authority of the

SDWA. The GS regulation, which addresses the injection of CO2 for the purpose of protecting

USDWs from endangerment, is within EPA's authority under the SDWA. Injection wells are

regulated under the authority of Part C of the SDWA (42 U.S.C. 300h et seq.). Under the SDWA,

the underground injection of any "fluid" is subject to the requirements of the UIC program. "Fluid"

is defined under 40 CFR 144.3 as any material or substance which flows or moves, whether in a

semisolid, liquid, sludge, gas or other form or state, and includes liquids, gases, and semisolids (i.e.,

slurries) injected into the subsurface. 

EPA disagrees that properly managed GS projects are dangerous. EPA believes that the GS

requirements, which are based on the long-standing UIC regulatory framework and tailored to meet

103
the unique nature of CO2 injection for GS, appropriately address endangerment risks to USDWs.

The GS rule contains minimum technical criteria for the permitting, geologic site characterization,

AoR and corrective action, well construction, operation, mechanical integrity testing, monitoring,

financial responsibility, injection well plugging, post-injection site care, and site closure of GS wells,

which will ensure that USDWs are protected from endangerment. 

EPA considers the risk of asphyxiation and other chronic and acute health effects from airborne

exposure resulting from CO2 injection activities (even in the case of leakage or accidental exposure)

to be minimal. This finding is based on experience gained in the oil and gas industry, experience

from international GS projects, and evaluation of large scale releases of naturally occurring CO2 (73

FR 43498). 

Please also see the GS final rule preamble sections entitled, “Under What Authority is This

Rulemaking Promulgated?" and "How Does This Rulemaking Relate to Other Federal Authorities

and GS Initiatives?"

Commenter Name: George Holliday, PhD, PE, BCEE Letter ID: 0114

Commenter Organization: Holliday Environmental Services, Inc. Comment ID: 22536

Other EPA Comment Codes and Descriptions: 1460 1.2.2.2 Oppose EPA's authority to regulate

CO2 injection 

Comment: Further, EPA believes they can assume the RCRA type authority for Class VI wells 

under the SDWA. If challenged in court, the court most likely will disagree, 

because the SDWA was written only for protection of USDW. Even the Agency 

suggests the Safe Drinking Water Act is not appropriate to regulate CO2 

sequestration. 

Response: EPA disagrees that the SDWA does not provide the UIC Program with adequate

authority to regulate underground injection of CO2 for GS or that the GS rule oversteps the

boundaries or authority of the SDWA. The GS regulation, which addresses the injection of CO2 for

the purpose of protecting USDWs from endangerment, is within EPA's authority under the SDWA.

Injection wells are regulated under the authority of Part C of the SDWA (42 U.S.C. 300h et seq.).

Under the SDWA, the underground injection of any "fluid" is subject to the requirements of the UIC

program. "Fluid" is defined under 40 CFR 144.3 as any material or substance which flows or moves,

whether in a semisolid, liquid, sludge, gas or other form or state, and includes liquids, gases, and

semisolids (i.e., slurries) injected into the subsurface. 

Please also see the GS final rule preamble sections entitled, “Under What Authority is This

Rulemaking Promulgated?" and "How Does This Rulemaking Relate to Other Federal Authorities

and GS Initiatives?"

Commenter Name: Leslie Savage Letter ID: 0122

Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24733

Comment: The Proposal treats CO2 as a waste. The EPA states in the preamble that it has 

not classified CO2 as a waste or a commodity. However, by using the Class I 

waste injection well requirements as the framework for the Class VI 

requirements, the Proposal implies that the CO2 stream is a waste. This 

implication increases not only the potential liability for carbon dioxide 

sequestration, but also the potential liability for anthropogenic CO2 injection 

104
for the purpose of enhanced recovery of oil and/or natural gas. 

Many provisions of the Proposal address Class VI wells from a waste based 

perspective. With respect to construction, area of review (AoR) and monitoring, 

the Proposal begins with the regulatory framework for Class I non-hazardous 

industrial waste injection well requirements and then adds numerous layers of 

requirements to prevent or detect the escape of CO2 from the injection zone. 

The Proposal excludes CO2 that is a hazardous waste from regulation under the 

Class VI program, but has proposed requirements for Class VI injection wells 

that are more stringent than those for wells used for the injection of hazardous 

waste. RRC strongly disagrees that CO2 buoyancy, corrosivity, and high injection 

volumes for a Class VI project justify a Class I approach. 

Response: EPA disagrees that the requirements in the GS rule are too stringent or overstate the risk

associated with GS. The requirements for Class VI wells are tailored to address the unique nature of

full-scale CO2 GS, including the injection volumes anticipated for long-term storage, the buoyant

and viscous nature of the injectate, and its corrosivity in the presence of water. While the Class I

requirements formed the basis of many of the specific requirements for GS wells, EPA clarifies that

the GS rule is tailored to the unique nature of GS. EPA based many of the GS requirements on the

Class I regulations because, like Class VI wells, Class I wells are typically deep and involve waste

streams that, if not properly managed, can harm the well and lead to contamination. 

EPA also disagrees that the Class VI requirements themselves, or EPA’s consideration of the Class I

requirements, necessarily have any implications for whether a particular material is a RCRA “solid

waste” or implicates CERCLA liability, as EPA understands the comment to suggest. EPA notes that

the GS rule is not promulgated under either of those statutes, and further, the applicability of those

statutes will not be determined under the SDWA or the terms of the GS rule, but rather according to

those statutes themselves and any implementing regulations that may apply. EPA also notes that the

commenter provides no legal analysis explaining why the Class VI rule’s requirements alleged

implication that CO2 is a waste “increases . . . the potential liability for carbon dioxide 

sequestration [or] for anthropogenic CO2 injection for the purpose of enhanced recovery of oil and/or

natural gas.” EPA adds that liability for Class II wells is outside the scope of this rulemaking.

Commenter Name: John Hanger Letter ID: 0130

Commenter Organization: Pennsylvania Dept. of Env. Protection Comment ID: 21522

Comment: -DEP believes that the CO2 for geologic sequestration is a residual waste if it 

does not otherwise qualify as a hazardous waste. Pennsylvania’s Solid Waste 

Management Act and residual waste regulations define disposal to include the 

injection of a residual waste and require a permit for disposal. 

Response: EPA clarifies that the GS rule itself does not change the status of CO2 as a solid waste or

hazardous waste under RCRA. Under the final GS rule, owners or operators will need to determine

whether the CO2 stream is a hazardous waste under EPA’s RCRA regulations, and if so, any

injection of the hazardous CO2 stream may only occur in a Class I hazardous waste injection well.

Commenter Name: Carl Carlsson Letter ID: 0131

Commenter Organization: SUEZ Energy Generation NA, LLC Comment ID: 21527

105
Comment: CO2 as a Hazardous Waste 

Regarding the question of characterizing CO2 streams to determine if they need 

to be regulated as a hazardous waste, SEGNA feels that it is desirable to provide 

regulatory clarity on this issue, and therefore it is appropriate to consider, either 

as part of the rule or as a separate rulemaking, a categorical exemption for CO2 

streams. 

Response: EPA agrees that any requirements for the CO2 stream should be clearly identified. EPA

received many comments regarding the applicability of the RCRA regulations and statute to CO2

streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

EPA clarifies that the GS rule requires owner or operators of Class VI wells to characterize their

injection stream prior to injection, and throughout the operational life of the injection facility. Since

the GS rule, at §146.81(d), prohibits CO2 streams that meet the definition of a hazardous waste

under 40 CFR part 261, owners or operators will need to characterize their CO2 stream as part of

their permit application to determine if the injectate is a RCRA hazardous waste. If so, injection may

only occur in a Class I hazardous waste injection well.

Commenter Name: Dwight Lockwood, PE, QEP Letter ID: 0141

Commenter Organization: Global Energy, Inc. Comment ID: 23104

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment);

4620 2.6.2 Injectate monitoring 

Comment: CO2 as Hazardous Waste (RCRA or CERCLA) 

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

CFR Part 261. We further believe that the stream can be treated to remove 

undesired contaminants to the levels that thresholds are not triggered. 

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

sufficient basis for assurance here. Periodic sampling and analysis on some 

reasonable frequency during injection is acceptable. On the other hand, we do 

not believe that this measurement and reporting needs to be more than perhaps 

quarterly, as the adverse impact of exceedances for relatively short periods is 

not likely to be geologically significant very fast. Corrective action to 

mitigate the effects of an incorrect injection fluid (but not to remedy an 

injection already accomplished) needs to be pragmatic and not onerous. 

3.As with Class I well liability exemptions, Class VI wells, once their 

injectate is characterized and approved (as not triggering CERCLA or RCRA), and 

106
regular sampling of the stream for quality control is implemented then a 

similar exemption is warranted. 

Response: EPA agrees that monitoring of the injectate prior to and during injection is important to

allow for comparison of baseline data and operational-phase monitoring results to provide warning

of potential USDW endangerment. For this reason owners or operators must perform an analysis of

the chemical and physical characteristics of the CO2 stream, as required at §146.82 (a)(7)(iv). In

addition, Section §146.90(a) requires owners or operators to perform analysis of the CO2 stream

during injection operations with sufficient frequency to yield data representative of its chemical and

physical characteristics.

The necessary frequency of injectate analysis will be project-specific and will depend upon the CO2

source and the likelihood of variability in injectate composition. For example, a CO2-capture

process from a coal-fired power plant with a consistent coal source and operating parameters is

likely to produce a CO2 stream with a fairly consistent composition. A process with a changing

composition of coal may have more variability in the purity of the CO2 that is captured. In such a

setting, more frequent sampling may be appropriate. The details of the sampling should be described

in the testing and monitoring plan, which will be approved by the Director based on a review of sitespecific information, including information on the source and characteristics of the injectate.

EPA clarifies that, following an initial characterization of the injectate, EPA expects that the permit

would stipulate the acceptable composition of the injectate (e.g., as CO2 plus an acceptable range of

expected impurities). Any divergence from this would be a permit violation.

EPA notes however, that the final GS rule, which adds new regulations for Class VI wells under the

Safe Drinking Water Act (SDWA), is not making any changes to the RCRA regulations.

Accordingly, the CO2 stream characterization requirements under the GS rule would not substitute

for the obligation of a generator of RCRA solid waste to characterize its waste in accordance with

EPA’s RCRA regulations. Injection of a RCRA hazardous waste may only occur in a Class I

hazardous waste injection well.

EPA notes that CO2 itself is not listed as a hazardous substance under CERCLA, although 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit.

The commenter’s reference to a Class I liability exemption is unclear and not legally correct.

Furthermore, after site closure an owner or operator may remain liable under tort and other remedies,

or under other federal statutes including, 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.

Commenter Name: Patrick Nugent Letter ID: 0143

107
Commenter Organization: Texas Pipeline Association (TPA) Comment ID: 23138

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: 5. The carbon dioxide stream is a commodity not a waste and should be 

regulated as such. EPA should make clear that carbon dioxide injectate is not 

being categorized or regulated as a waste or a pollutant, but rather as a 

commodity. The sequestered carbon dioxide is expected to generate a credit in a 

future carbon credit scheme. At that point, the act of sequestering the carbon 

dioxide will generate an emission credit that can be sold in the open market. 

Accordingly, TPA urges EPA to remain neutral at this point in time in 

characterizing the carbon dioxide stream as a waste or a pollutant in any of its 

regulatory programs. Those kinds of labels would saddle this program with the 

liability schemes imposed by RCRA or CERCLA and would be severely detrimental to 

the development and use of geologic sequestration technology. It is highly 

unlikely that industry will commit the substantial capital required for geologic 

sequestration projects unless and until the potential for liability is clearly 

defined and understood. Such financial commitment is unlikely to be made if 

participants run the risk of incurring open-ended and ruinous liability under 

RCRA and CERCLA. In this regard, Class VI permits should be written as broadly 

as possible, so as to maximize protections that may be provided by federally 

permitted release exemptions. 

Response: EPA clarifies that the GS rule, being issued only under the SDWA, does not affect the

status of, or entities’ potential obligations for managing, or liability for management of, CO2 under

RCRA or CERCLA. While the Class I requirements formed the basis of many of the specific

requirements for GS wells, EPA clarifies that the GS rule is tailored to the unique nature of GS. EPA

based many of the GS requirements on the Class I regulations because, like Class VI wells, Class I

wells are typically deep and involve waste streams that, if not properly managed, can harm the well

and lead to contamination. 

In addition, issues related to carbon crediting are outside the scope of the GS rule. Rather, the

purpose of the GS regulation is to ensure that, where deployed, GS is conducted in a manner that

protects USDWs from endangerment.

Commenter Name: Patrick Nugent Letter ID: 0143

Commenter Organization: Texas Pipeline Association (TPA) Comment ID: 23139

Other EPA Comment Codes and Descriptions: 1614 1.3.1.2 Impurities in captured CO2; purity

standards for CO2 

Comment: 6. Incidental waste streams in the carbon dioxide stream should not cause 

the stream to be characterized as a hazardous waste or hazardous substance. As 

EPA has pointed out, the carbon dioxide stream may have pollutants in it that 

could cause the waste stream to be classified as a hazardous waste. For example. 

the carbon dioxide stream captured from a power plant may include emissions of 

mercury, a hazardous substance. A carbon dioxide stream captured from a gas 

processing plant may have emissions of nitrous oxides or hydrogen sulfides. The 

incidental presence of these waste streams in a carbon dioxide stream should not 

cause the entire carbon dioxide stream to be classified as a hazardous waste or 

a waste. The proposed regulations do not specify content or constituent 

concentration requirements. They merely state that "[t]his subpart does not 

apply to any carbon dioxide stream that meets the definition of a hazardous 

108
waste under 40 CFR part 261." Proposed § 146.81(d). TPA urges EPA to establish a 

content percentage or constituent concentration of a pollutant in the carbon 

dioxide stream before the stream is declared a hazardous waste, or some other 

methodology that would promote the goals of this program without compromising 

environmental protection. The cost of removing the offending constituents or 

pollutants could defeat the economic viability of the carbon sequestration 

project, generate additional detrimental air emissions through the removal 

process and in the end be counter-productive as the best longterm disposal 

option for the pollutant may be to sequester it in a deep well. In short, such 

specifications might restrict the amount or kinds of greenhouse gas fluids that 

could be stored through geologic sequestration technology and may defeat the 

program in its entirety. 

Response: 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 low. However, these

estimates are based on limited information, and uncertainties remain about the expected

concentrations of impurities from the various types of CO2 streams. The concentrations of minor

and trace elements in CO2 streams for GS projects are likely to vary by facility, coal composition,

plant operating conditions, and pollution removal technologies. 

The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a percent CO2).

Instead, the GS rule addresses the quality and quantity of impurities by requiring owners or operators

to submit information on the source of the CO2 and its physical and chemical properties.

Specifically, the GS rule requires the owner or operator to submit data about the site, including an

analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the 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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals. 

EPA received many comments regarding the applicability of the RCRA regulations and statute to

CO2 streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: Kenneth Alexander Letter ID: 0146

Commenter Organization: Old Dominion Electric Cooperative (ODEC) Comment ID: 21724

Other EPA Comment Codes and Descriptions: 1680 1.3.8 Don't overstate risk, don't stigmatize

CO2 

Comment: 5.EPA should be careful not to stigmatize as operations and to take positive 

109
measures to build public acceptance. EPA should avoid characterizing stored CO2 

as a waste. 

Response: EPA clarifies that the GS rule, being issued only under the SDWA, does not affect

whether CO2 is considered a solid waste under RCRA or EPA’s RCRA regulations. 

EPA received many comments regarding the applicability of the RCRA regulations and statute to

CO2 streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule.

Commenter Name: Kenneth Alexander Letter ID: 0146

Commenter Organization: Old Dominion Electric Cooperative (ODEC) Comment ID: 21725

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: 6.EPA must settle the way as activities will relate to RCRA and CERCLA. RCRA is 

simply the wrong tool to use to regulate as of C02 and EPA needs to find a way 

to insure that the onerous requirements of CERCLA, (never intended for as of 

CO2), are not applied to this highly specialized storage operation. 

7. Dealing with these last two hazardous waste issues appears to ODEC to be one 

of the most difficult hurdles standing in the way of commercial deployment of 

full scale as projects and we recognize that Congressional action may be needed. 

Response: EPA agrees that any requirements for the CO2 stream should be clearly identified. EPA

received many comments regarding the applicability of the RCRA regulations and statute to CO2

streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

EPA clarifies that CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

110
section 107, 42 U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit.

Commenter Name: William Kovacs Letter ID: 0148

Commenter Organization: U.S. Chamber of Commerce Comment ID: 21752

Other EPA Comment Codes and Descriptions: 1520 1.2.3 Other authorities (e.g., CAA, MPRSA,

London Convention); 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: For example, if EPA eventually determines that CO2 is hazardous, what are the 

ramifications under the Resource Conservation and Recovery Act (RCRA)?[FN3 42 

U.S.C. §§ 6901 et seq.] Presumably, its stringent "cradle to grave" requirements 

will be imposed on all generators, transporters, and treatment, storage and 

disposal facilities involved in the CCS project. Or, in the event of a release, 

under the Comprehensive Environmental Response, Compensation and Liability Act 

(CERCLA)?[FN4 42 U.S.C. §§ 9601 et seq.] The Clean Air Act? [FN5 42 U.S.C. §§ 

7401 et seq.] If CO2 is deemed a "hazardous air pollutant" under Section 112, it 

will automatically trigger CERCLA liability as it incorporates HAPs in its 

definition of "hazardous substance." [FN6 CERCLA, Section 101(14).] The Clean 

Water Act? [FN7 33 U.S.C. §§ 1251 et seq.] 

Response: Under the final GS rule, owners or operators will need to determine whether the CO2

stream is hazardous under EPA’s RCRA regulations, and if so, any injection of the hazardous CO2

stream may only occur in a Class I hazardous waste injection well. Conversely, Class VI wells

cannot be used for the co-injection of RCRA hazardous wastes (i.e., hazardous wastes that are

injected along with the CO2 stream). 

EPA received many comments regarding the applicability of the RCRA regulations and statute to

CO2 streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit.

111
Commenter Name: William Kovacs Letter ID: 0148

Commenter Organization: U.S. Chamber of Commerce Comment ID: 21766

Other EPA Comment Codes and Descriptions: 1614 1.3.1.2 Impurities in captured CO2; purity

standards for CO2 

Comment: The issue becomes even more acute when you consider that EPA has already 

declined to address the very basic question of how to classify the CO2 stream if 

trace amounts of hazardous constituents get in it prior to injection: 

Because the types of impurities and their concentrations in the CO2 stream are 

likely to vary by facility, coal composition, plant operating conditions, and 

pollution removal technologies, EPA cannot make a categorical determination as 

to whether injected CO2 is hazardous under RCRA. [FN8 Federal Register, Vol. 73 

Fed. Reg. No. 144, pg. 43493 (July 25, 2008)] 

Instead, EPA advocates making determinations about the hazardous classification 

of injected CO2 on a case-by-case basis. In essence, EPA is saying that 

hazardous constituents could be present in the injected CO2 stream, and if they 

are, then it will be treated as hazardous. This approach provides little 

guidance to industry, particularly facility owners and operators who are 

required to characterize their CO2 stream as part of their initial permit 

application. 

Response: EPA agrees that any requirements applicable to CO2 injectate should be clearly identified

to the public and to the regulated community. EPA received many comments regarding the

applicability of the RCRA regulations and statute to CO2 streams that are geologically sequestered

under the final Class VI UIC well requirements. As a result, EPA has decided to initiate a separate

proposed rulemaking specifically to examine the issue of RCRA applicability 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 particular 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 commenters who wish to submit comments on the RCRA proposal

will need to do so during the comment period for that rule. Finally, EPA also notes that the final GS

rule, which adds new regulations for Class VI wells under the Safe Drinking Water Act (SDWA), is

not making any changes to the RCRA regulations. The existing RCRA hazardous waste

characterization regulations apply to evaluations of CO2 streams, and those regulations define which

RCRA solid wastes are regulated as RCRA hazardous wastes – it is not EPA’s position that the

presence of any levels of impurities would necessarily render a CO2 stream a hazardous waste,

without reference to those regulations.

Commenter Name: William Kovacs Letter ID: 0148

Commenter Organization: U.S. Chamber of Commerce Comment ID: 21767

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: Such overwhelming regulatory uncertainty will only serve to deter investment in 

CCS technology and slow the rate at which large-scale commercial CCS projects 

are developed. Instead, EPA needs to examine and explain which environmental 

statutes could be triggered, how they will interact or overlap, and what 

potential liability exists for industry. EPA should also explore the possibility 

of creating regulatory exemptions under RCRA, CERCLA, etc., for injected CO2, 

112
thereby reducing regulatory hurdles for CCS projects. One example of this would 

be to ensure that final Class VI permits have the broadest possible reach to 

maximize the protection offered by CERCLA’s "federally permitted release" [FN9 

CERCLA, Section 107(j).] exemption. This would mean including within the scope 

of the permit for carbon dioxide injection all other CERCLA hazardous 

constituents likely to be contained in the CO2 stream, thus providing some 

comfort to owners and operators that they will not be subject to CERCLA 

liability. When you consider that EPA lacks the authority to transfer well 

ownership between entities, and that owners are therefore liable in perpetuity, 

the need to craft regulatory exemptions becomes clear. 

Response: EPA agrees that any requirements for the CO2 stream should be clearly identified. EPA

received many comments regarding the applicability of the RCRA regulations and statute to CO2

streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

As described above, EPA clarifies that the GS rule requires owner or operators of Class VI wells to

characterize their injection stream prior to injection, and throughout the operational life of the

injection facility. If the CO2 stream is determined to be a hazardous waste, injection may only occur

in a Class I hazardous waste injection well. 

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit. 

EPA adds that providing financial incentives for or promoting the use of GS is outside the scope of

the GS rule.

Commenter Name: William Kovacs Letter ID: 0148

Commenter Organization: U.S. Chamber of Commerce Comment ID: 21772

Other EPA Comment Codes and Descriptions: 1680 1.3.8 Don't overstate risk, don't stigmatize

CO2 

Comment: 4. Why Does the Proposed Rule Treat CO2 like a Hazardous Waste? 

113
Carbon dioxide is not a hazardous waste; yet the proposed rules for CO2 storage 

are, in many ways, far more strict than those for underground injection of 

hazardous wastes under Class I of the UIC program. Many of the construction, 

mechanical integrity, monitoring and financial assurance provisions for Class VI 

wells are more comprehensive and more onerous than those for Class I wells. 

The Chamber does not believe that CO2 should be treated more stringently than 

hazardous waste because it distorts public perception about the safety of carbon 

capture and storage, and it may make securing financial backing for CCS more 

difficult. 

Response: EPA disagrees that the requirements in the GS rule are too stringent or overstate the risk

associated with GS. The requirements for Class VI wells are tailored to address the unique nature of

full-scale CO2 GS, including the injection volumes anticipated for long-term storage, the buoyant

and viscous nature of the injectate, and its corrosivity in the presence of water. 

While the Class I requirements formed the basis of many of the specific requirements for GS wells,

EPA clarifies that the GS rule is tailored to the unique nature of GS. EPA based many of the GS

requirements on the Class I regulations because, like Class VI wells, Class I wells are typically deep

and involve waste streams that, if not properly managed, can harm the well and lead to

contamination.

Commenter Name: Brianne Metzger Letter ID: 0151

Commenter Organization: Spectra Energy Corp Comment ID: 21852

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: III. EPA MUST ADDRESS THE LEGAL UNCERTAINTIES AND IMPEDIMENTS

TO CCS. 

As has been well documented elsewhere, including a recent GAO report, [3] the 

legal uncertainties related to underground injection of CO2, including the 

possible application of CERCLA and RCRA, are a very real legal impediment to 

the viability of carbon capture and geologic sequestration. We agree with the 

GAO’s recommendation that EPA more comprehensively examine CERCLA and RCRA as a 

potential barrier to CCS. As discussed in greater detail below, we believe the 

Agency has sufficient authority to develop responsible policies and regulations 

that provide the requisite protection to owner/operators of GS operations while 

still ensuring the adequate protection of human health and the environment. 

Toward this end, we would ask the EPA to further examine and clearly articulate 

what it believes is the outer bounds of its statutory and regulatory authority 

to provide such legal certainty. If, in the event EPA does not believe it has 

such authority or, for whatever reason, is unwilling to invoke such authority, 

we would request the Administration and the Agency work with Congress to enact 

legislation to bring about the needed legal certainty. 

3 GAO Report, Climate Change, Federal Actions Will Greatly Affect the Viability 

of Carbon Capture and Storage As a Key Mitigation Option, REPORT TO THE 

CHAIRMAN ON THE SELECT COMMITTEE ON ENERGY INDEPENDENCE AND GLOBAL

WARMING, 

HOUSE OF REPRESENTATIVES, GAO-08-1080 (September 2008). 

114
Response: EPA agrees that any requirements for the CO2 stream should be clearly identified. EPA

received many comments regarding the applicability of the RCRA regulations and statute to CO2

streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

The GS Rule is being promulgated appropriately under the SDWA. Injection wells are regulated

under the authority of Part C of the SDWA (42 U.S.C. 300h et seq.). Under the SDWA, the

underground injection of any "fluid" is subject to the requirements of the UIC program. "Fluid" is

defined under 40 CFR 144.3 as any material or substance which flows or moves, whether in a

semisolid, liquid, sludge, gas or other form or state, and includes liquids, gases, and semisolids (i.e.,

slurries) injected into the subsurface. EPA adds that comments related to requesting Congress for

additional authority are outside the scope of this rulemaking.

Commenter Name: Brianne Metzger Letter ID: 0151

Commenter Organization: Spectra Energy Corp Comment ID: 21855

Comment: C. RCRA Should Not Apply To GS Or, Alternatively, EPA Must Clarify And Minimize 

The Potential Applicability And Scope Of RCRA. 

We begin this section by noting that CO2 re-injection from gas processing is 

currently exempt from Subtitle C requirements of RCRA. Therefore, the 

following comments regarding the potential application of RCRA pertains to 

injection of CO2 from non-exempt processes and industries. 

Under the proposed rule, EPA has stated that it "cannot make a categorical 

determination as to whether injected CO2 is hazardous under RCRA." See Rule at 

43503. The Agency goes on to say that if the CO2 stream is considered 

hazardous under RCRA, then the more stringent UIC Class I requirements for 

injection of hazardous waste apply. Consequently, the Agency has defined 

"carbon dioxide stream" to exclude hazardous wastes as defined in 40 C.F.R. 

Part 261 (e.g., wastes that are characteristically hazardous due to pH or 

toxicity). 

For many of the same reasons set forth above for CERCLA, Spectra likewise 

believes that RCRA’s waste regulatory regime is completely unnecessary and 

inappropriate for geologic sequestration of CO2. First, CO2 is neither a 

pollutant, a solid waste,[9] nor a hazardous waste. Second, CO2 has been 

properly and safely injected for decades in the context of enhanced oil 

recovery (EoR), without the regulatory overlay of Subtitle C of RCRA. Third, 

there are other regulatory regimes that can apply to CO2 injection that make 

115
the application of RCRA unnecessary. 

1. RCRA Hazardous Waste Requirements Would Be Costly And Burdensome. 

EPA itself has acknowledged the burden of RCRA and the fact that many of its 

requirements are poorly suited to at least some of the activities to which they 

apply. EPA initiated a rulemaking in 2002 to reduce the burdens associated 

with the RCRA hazardous waste program. 68 Fed. Reg. 61662, 61664 (Oct. 29, 

2003). The agency noted, "[t]he existing hazardous waste regulations require 

the submittal of 334 notifications, reports, certifications, demonstrations, 

and plans from generators and [treatment, storage, and disposal facilities] to 

demonstrate compliance with the RCRA regulations." Id. at 61664. Reporting 

requirements are just one example of RCRA’s burdens. Others include treatment, 

storage, and disposal facility requirements generally, waste manifesting, 

training requirements for transporters and handlers, citizen suit provisions, 

and the fact that hazardous waste regulation often increases one’s exposure to 

Superfund liability. 

While EPA seeks to downplay the potential applicability of RCRA, by opining 

that concentrations of impurities in a CO2 stream are "expected to be very low" 

there is no clear assurance that RCRA does not apply. As currently proposed, 

the EPA has shifted the burden to the owner/operator to determine whether its 

CO2 stream is not a hazardous waste under RCRA. The only way for an 

owner/operator to determine whether its stream is not a hazardous waste is to 

test the CO2 stream or apply "generator knowledge." To require testing for CO2 

streams would be overly burdensome and expensive, particularly given the 

diverse sources of CO2 streams and their varied composition. As well, the high 

variability of CO2 stream composition makes reliance upon "generator knowledge" 

risky if not entirely unworkable. 

2. EPA Has Authority To Exempt CO2 Under Its Contingent Management Approach. 

The Agency has authority under Subtitle C of RCRA to determine which wastes are 

subject to federal hazardous waste regulations. Section 3001 directs the 

Administrator of EPA to 

develop and promulgate criteria for identifying the characteristics of hazardous 

waste, and for listing hazardous waste, which should be subject to the 

provisions of this subchapter, taking into account toxicity, persistence, and 

degradability in nature, potential for accumulation in tissue, and other related 

factors such as flammability, corrosiveness, and other hazardous 

characteristics. Such criteria shall be revised from time to time as may be 

appropriate. 42 U.S.C. § 6921(a). 

It is clear from the language of Section 3001, that Congress left to the EPA the 

discretion to determine which hazardous wastes would be subject to federal 

regulations and which ones would be exempt therefrom. See Military Toxics 

Project v. EPA, 146 F.3d 948, 958 (D.C. Cir. 1998) ("Congress’ broad delegation 

to EPA to develop criteria for listing hazardous wastes . . . indicates that 

Congress intended the agency to have substantial room to exercise its 

116
expertise"). The criteria set forth above enable EPA to take into consideration 

the relative risks posed by different wastes (i.e., some wastes are by nature 

more toxic than others), the capacity for a waste to breakdown and thus become 

less toxic in the environment (i.e., some wastes degrade faster than others), 

how long it takes a waste to degrade, and the potential for human exposure and 

accumulation in tissue. The application of these criteria to CO2 weigh in the 

favor of exempting CO2 injection and disposal from hazardous waste regulations. 

EPA considers the risk of chronic and acute health effects from airborne 

exposure from properly operated CO2 injection as minimal. GS Rule at 43498. It 

likewise considers the risk of adverse impacts to ecosystems from properly 

managed GS injection activities as minimal. Id. Overall, the Agency believes 

that the risks to human health and the environmental from properly managed CO2 

injection activities are minimal. These risks EPA believes will be properly 

addressed and managed through the new Class VI UIC well program. 

Given the minimal risks from properly managed CO2 pursuant to SDWA’s authority, 

EPA should exempt CO2 streams entirely from RCRA hazardous waste regulations 

or, alternatively, establish a "safe harbor" for the injection of CO2, 

including impurities, by clarifying minimum performance standards or testing 

requirements. The concept of a blanket exemption is fully consistent with the 

Agency’s "contingent management" approach under RCRA, whereby certain low-risk 

wastes are exempted entirely from RCRA Subtitle C regulations. See EPA’s 

Contingent Management Technical Background Document, October 29, 1999. 

According to the Agency, 

EPA's longstanding regulatory criteria for determining whether wastes pose 

hazards that require regulatory control incorporate the idea that a waste that 

is otherwise hazardous may not present a hazard if already subject to adequate 

regulation. See, e.g., 40 CFR 261.11(a)(3)(x), which requires EPA to consider 

action taken by other governmental agencies or regulatory programs based on the 

health or environmental hazard posed by the waste.) Thus, where a waste might 

pose a hazard only under limited management scenarios, and other regulatory 

programs already address such scenarios, EPA is not required to classify a waste 

as hazardous waste subject to regulation under Subtitle C. 62 Fed. Reg. 6622, 

6636 (Feb. 12, 1997). The D.C. Circuit Court of Appeals has upheld EPA’s 

contingent management approach on at least three occasions. Edison Electric 

Institute v. EPA, 2 F.3d 438 (D.C. Cir. 1993) (court upheld a temporary 

exemption from Subtitle C for petroleum-contaminated media based on the fact 

that the potential hazards of such materials are already controlled under the 

underground storage tank regulations); NRDC v. EPA, 25 F.3d 1063 (D.C. Cir. 

1994) (court upheld EPA's finding that alternative management standards for used 

oil promulgated under RCRA section 3014 reduced the risks of mismanagement and 

eliminated the need to list as a hazardous waste); Military Toxics Project v. 

EPA, 146 F.3d 948, 958 (D.C. Cir. 1998) (court upheld EPA’s military munitions 

rule as obviating the need to apply RCRA’s hazardous waste regulations). 

As EPA has emphasized before, even the legislative history of Subtitle C 

supports the Agency’s contingent management concept. In a House Report, 

Congress stated that "the basic thrust of this hazardous waste title is to 

117
identify what wastes are hazardous in what quantities, qualities, and 

concentrations, and the methods of disposal which may make such wastes 

hazardous." 62 Fed. Reg. 6622, 6636 (citing H. Rep. No. 94-1491, 94th Cong., 

2d Sess.6 (1976), reprinted in A Legislative History of the Solid Waste 

Disposal Act, as Amended, Congressional Research Service, Vol.1, 567 (1991)). 

3. CO2 Geologic Sequestration Should Be Subject To Bevill Exemptions. 

Further argument for a RCRA exemption, and consistent with the concept of 

contingent management, is the fact that Congress exempted certain wastes from 

regulation under Subtitle C of RCRA. In 1980, when Congress amended the Solid 

Waste Management Act, it opted to temporarily exempt certain high-volume low 

toxicity wastes from the Subtitle C hazardous waste regulatory scheme, 

including, among others, "fly ash waste, bottom ash waste, slag waste and flue 

gas emission control waste generated primarily from the combustion of coal or 

other fossil fuels" (hereafter referred to as "FFC" wastes) 42 U.S.C. § 

6921(b)(3)(A)(i) (emphasis added). This amendment (a/k/a the Bevill 

Amendment), was prompted in large measure by Congress’ concern regarding the 

potential added recycling costs (estimated at $3B annual increase) of 

subjecting fossil-fuel combustion wastes to hazardous waste requirements. 58 

Fed. Reg. 42466, 42468 (Aug. 9, 1993). Under the Bevill Amendment, Congress 

directed EPA to make a regulatory determination on whether or not FFC needed to 

be regulated under Subtitle C. 

As part of the Agency’s regulatory determination, EPA conducted a three-part 

technical analysis evaluating whether (1) the FFC wastes posed human health or 

environmental problems, (2) whether the wastes could pose significant risks at 

any site under current or plausible management scenarios, and (3) whether the 

wastes exhibited any of the characteristics of hazardous waste. EPA’s 

rationale for the iterative analysis was to determine, first, whether the 

wastes posed serious risks, second, whether current management practices and 

federal and state regulatory controls were adequate to manage the risks and, 

third, the economic impact on the industry before regulating the waste as 

hazardous. EPA identified a number of sites with unlined lagoons and ponds 

where FFC wastes clearly had resulted in extensive ground water impacts from 

arsenic, barium, cadmium, chromium, fluoride, lead, mercury, nickel and 

selenium that had leached into the water. Id. at 42475. EPA concluded, 

however, that such sites were ordinarily not located near populations and 

drinking water systems. EPA also concluded that up to 7% of the FFC wastes 

exhibited the characteristics of hazardous waste based on toxicity. Despite 

these negative findings, EPA ultimately made the determination that more 

stringent regulations were not necessary or desirable. 

Based on a plain language reading of the Bevill Amendment, it appears that CO2 

falls within the scope of the exemption as a flue gas emission control waste. 

Similar to FFC wastes, CO2 are a high-volume low toxicity waste when properly 

managed in underground formations. Therefore, we believe the Bevill Amendment 

presents the Agency with another viable option for exempting CO2 from Subtitle 

9 For a waste to be a hazardous waste, it must first be a solid waste. There 

118
is a legitimate question whether CO2 is even a solid waste based on the 

statutory definition of "solid waste" expressly including "contained gaseous 

material." 42 U.S.C. § 1004(27). EPA has consistently interpreted this 

provision as excluding uncontained gases from the definition of solid waste. 

See, e.g., 47 Fed. Reg. 27530 (June 24, 1982) (gases from fume incinerators not 

subject to RCRA, because fumes are not a solid waste); 54 Fed. Reg. 50973 (Dec. 

11, 1989) (uncontainerized gases are excluded from RCRA); In re BP Chemicals 

America, Inc., RCRA Appeal No. 89-4, 1991 WL 208971, at *2 (Admin., Aug. 20, 

1991) (Administrator rejected the argument that otherwise uncontained gas 

passing through piping or the facility made it "contained" and subject to 

RCRA). While CO2 emissions would clearly fit into the "uncontained" gas 

classification, what is unclear is whether the Agency’s interpretation would 

extend to CO2 subsequently captured and injected into an underground formation. 

We believe this merits further clarification by the Agency on what constitutes 

an uncontained vs. contained gas. 

Response: EPA agrees that any requirements for the CO2 stream should be clearly identified. EPA

received many comments regarding the applicability of the RCRA regulations and statute to CO2

streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: Bonnie Lovelace Letter ID: 0152

Commenter Organization: Montana Department of Environmental Quality

(MDEQ)

Comment ID:

22109

Comment: 9. EPA discussed the possibility that some carbon dioxide streams may qualify as 

hazardous waste under 40 CFR 261 and indicates that Class I UIC would regulate. 

owever, this rule set contains requirements that should be applied to geologic 

sequestration no matter which class regulates. Area of Review, mechanical 

integrity, seismic and other requirements should apply to any geologic 

sequestration operations, regardless of well class. EPA should identify those 

requirements and add them to the Class I rules for any geologic sequestration. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

119
who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

EPA adds that revising the requirements for other classes of wells is outside the scope of the GS

rulemaking. 

EPA clarifies that the GS rule requires owner or operators of Class VI wells to characterize their

injection stream prior to injection, and throughout the operational life of the injection facility. Since

the GS rule, at §146.81(d), prohibits CO2 streams that meet the definition of a hazardous waste

under 40 CFR part 261, owners or operators will need to characterize their CO2 stream as part of

their permit application to determine if the injectate is a RCRA hazardous waste. If so, injection may

only occur in a Class I hazardous waste injection well.

Commenter Name: James Childress Letter ID: 0158

Commenter Organization: Gasification Technologies Council (GTC) Comment ID: 23756

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 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 CO2 sequestration projects. 

EPA 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 CO2 as a result of the carbon capture 

process should not limit the storage of the 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 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 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 

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 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. 

120
For purposes of evaluating the potential RCRA status 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 used to 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 when measured 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 sufficient 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 (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 II 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 May8, 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 CO2 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 CO2 in a supercritical state is approximately 

2,500 feet. This, in conjunction with the controls and safeguards required by 

this rule throughout the injection and post-injection period, will ensure that 

CO2 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 H2S 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 (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 H2S and CO2 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 

121
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 information 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 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. 

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. 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 CO2 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. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

122
stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit.

Commenter Name: Skiles Boyd Letter ID: 0160

Commenter Organization: DTE Energy Comment ID: 21271

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: CHARACTERIZATION OF CO2 

The preamble discussion regarding the characterizations of CO2 is confusing. 

The preamble includes an analysis of the potential application of RCRA to CO2 

injection and storage activities that appear to be based upon an assumption that 

CO2 is not a "commodity" but a "waste". Yet EPA does not wish to characterize 

CO2 as either. As the regulated entity that will want to utilize this 

technology in the future, it would help us on several fronts (unnecessary 

regulatory burdens, public acceptance not being the least of these concerns) if 

EPA did reconsider this position and add some clarifying language to the 

regulations. EPA should revisit the application of RCRA and CERCLA regulation 

to the UIC program for CO2 injection. DTE Energy endorses EEI’s recommendation 

for EPA to consider CO2 injected under the UIC program as either exempted or 

excluded from regulation under RCRA or CERCLA or adapt performance standards to 

the injectate that again exclude RCRA and CERCLA regulation. For example, EPA 

could appropriately establish a permit condition that injectate must meet Toxic 

Characteristic Leaching Procedure or pH standards without reference to 

material’s waste status. 

Response: EPA agrees that any requirements for the CO2 stream should be clearly identified. Under

the final GS rule, owners or operators will need to determine whether the CO2 stream is hazardous

under EPA’s RCRA regulations, and if so, any injection of the hazardous CO2 stream may only

occur in a Class I hazardous waste injection well. Conversely, Class VI wells cannot be used for the

co-injection of RCRA hazardous wastes (i.e., hazardous wastes that are injected along with the CO2

stream). 

EPA received many comments regarding the applicability of the RCRA regulations and statute to

CO2 streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

CO2 itself is not listed as a hazardous substance under CERCLA; however, the CO2 stream may

contain a listed hazardous substance (such as mercury) or may mobilize substances in the subsurface

123
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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit.

Commenter Name: Joseph Eutizi Letter ID: 0161

Commenter Organization: San Miguel Electric Cooperative, Inc Comment ID: 21289

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: 6. EPA must settle the way GS activities will relate to RCRA and CERCLA. RCRA is 

simply the wrong tool to use to regulate GS of CO2 and EPA needs to find a way 

to insure that the onerous requirements of CERCLA, (never intended for GS of 

CO2), are not applied to this highly specialized gas storage operation. 

7. Dealing with these last two hazardous waste issues appears to San Miguel to 

be one of the most difficult hurdles standing in the way of commercial 

deployment of full scale GS projects and we recognize that Congressional action 

may be needed. 

Response: EPA agrees that any requirements for the CO2 stream should be clearly identified. EPA

received many comments regarding the applicability of the RCRA regulations and statute to CO2

streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit.

Commenter Name: Sandi Tabor Letter ID: 0162

Commenter Organization: Lignite Energy Council (LEC) Comment ID: 21302

Comment: 3. Categorization of Injected C02 Considered a Hazardous Waste under RCRA -Under 

124
the proposal EPA states that it cannot make a categorical determination as to 

whether injected C02 is hazardous under RCRA. It suggests the burden should be 

on the operators to characterize their C02 stream as part of the permit 

application to determine if the injectate is considered hazardous as defined in 

40 CFR Part 261. RCRA regulates the production, management and disposal of 

wastes and RCRA's potential application in the case of C02 injectate is 

dependent upon the existence of a solid waste. If the material is a solid waste, 

the law requires further analysis to determine if it is also a hazardous waste. 

Injected CO2 should be considered a product or a commodity and not a solid 

waste. Leaving the question to be resolved when operators characterize their C02 

streams with the potential that RCRA liability may attach will be a deterrent to 

C02 storage projects. The LEC urges the EPA to make a determination under its 

RCRA authority that CCS activities meeting Class VI permit requirements do not 

equate to DISCARDING the C02. By so doing, Class VI CO2 injection operations 

would not be considered waste management activities and would not be subject to 

RCRA. 

As further justification for this position, simply consider the success of 

existing acid gas injection operations into depleted oil and gas reservoirs 

conducted under the existing UIC regulations. Low level impurities, such as H2S 

or mercaptans should not trigger a classification under RCRA. The proposed rule 

has adequate protection for drinking water aquifers and addresses corrective 

action, financial assurance requirements, and long-term monitoring after 

closure. These requirements negate the need for any RCRA regulation. 

Response: EPA clarifies that the GS rule itself does not change the status of CO2 as a solid waste or

hazardous waste under RCRA. 

EPA received many comments regarding the applicability of the RCRA regulations and statute to

CO2 streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

The GS rule requires the owner or operator to submit data about the site, including an analysis of the

chemical and physical characteristics of the CO2 stream, as required at §146.82(a)(7)(iv), and

information on the 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 potential for geochemical

reactions between the injectate (CO2) and the host geologic formations, which could result in the

plugging of pore spaces or the dissolution of formation minerals.

125
Commenter Name: James Stine Letter ID: 0163

Commenter Organization: National Rural Electric Cooperative Association

(NRECA)

Comment ID:

21317

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: § EPA must settle the way GS activities will relate to RCRA and CERCLA. RCRA is 

simply the wrong tool to use to regulate GS of CO2 and EPA needs to find a way 

to insure that the onerous requirements of CERCLA, (never intended for GS of 

CO2), are not applied to this highly specialized gas storage operation. 

§ Dealing with these last two hazardous waste issues appears to NRECA to be one 

of the most difficult hurdles standing in the way of commercial deployment of 

full scale GS projects and we recognize that Congressional action may be needed. 

Response: EPA agrees that any requirements for the CO2 stream should be clearly identified. EPA

received many comments regarding the applicability of the RCRA regulations and statute to CO2

streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit.

Commenter Name: James Stine Letter ID: 0163

Commenter Organization: National Rural Electric Cooperative Association

(NRECA)

Comment ID:

21330

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: The CCS Alliance has evaluated technical, market, and policy risks associated 

with CCS deployment. On behalf of the CCS Alliance, Andrew Paterson of Econergy 

International interviewed dozens of market participants earlier this year, 

including project developers, utilities, technology vendors, risk managers, and 

financial providers to assess which risks were considered most likely to occur, 

and which, if they occurred, would be considered to have the greatest impact to 

the project. The CCS Alliance study showed that market participants identified 

one of the highest risk factors to be the lack of clarity in EPA and state 

126
regulations dealing with the technical aspects of injection and with liability. 

NRECA believes that the largest and most important aspect of the proposed UIC 

regulations will be how GS activities are coordinated with RCRA and CERCLA. 

Currently we believe that this is one of the most difficult hurdles standing in 

the way of commercial deployment of full scale GS projects. One way of dealing 

with this issue to avoid classifying injected CO2 as a waste. ******** 

Response: EPA agrees that any requirements for the CO2 stream should be clearly identified. EPA

received many comments regarding the applicability of the RCRA regulations and statute to CO2

streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit.

Commenter Name: James Stine Letter ID: 0163

Commenter Organization: National Rural Electric Cooperative Association

(NRECA)

Comment ID:

21331

Comment: 9. Anecdotal evidence from pilot scale Carbon Sequestration and Storage projects 

seem to suggest that it is not likely that CO2 removed from the flue gas stream 

of a coal-fired power plant would be classified as a RCRA hazardous waste. NRECA 

believes that EPA should specifically exempt CO2 gas streams from coverage by 

RCRA and develop requirements specifically tailored to this material if 

necessary to assure further environmental protection beyond that already 

provided by the UIC permitting process. RCRA is simply not the right tool to use 

in this situation. 

In 2002, EPA found that "the existing hazardous waste regulations require the 

submittal of 334 notifications, reports, certifications, demonstrations and 

plans from generators and TSDFs to demonstrate compliance with RCRA Regulations" 

(See comments of the CCS Alliance). Reporting requirements are just one example 

of RCRA's burdens. Others include TSD facility requirements generally, waste 

manifesting, training requirements for transporters and handlers, citizen suit 

127
provisions, and the fact that hazardous waste regulations implicates Superfund 

liability. And to further expose potential CO2 GS facilities to open-ended 

liabilities, applying RCRA could expose all other waste management units at the 

facility, including units that are in no way related to the injection 

operations, to the full panoply of RCRA's Subtitle C corrective action program. 

If one considers that an injection well could be located at an existing 

industrial site or power plant, it should be very clear how a private party 

would be reluctant to insure or finance a GS project under these conditions. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: Michael Mudd Letter ID: 0167

Commenter Organization: FutureGen Alliance (FGIA) Comment ID: 22464

Comment: Hazardous Waste Exclusion p. 43503, c. 3 

Because the types of impurities and their concentrations in the CO2 stream are 

likely to vary by facility, coal composition, plant operating conditions, and 

pollution removal technologies, EPA cannot make a categorical determination as 

to whether injected CO2 is hazardous under RCRA. Owners or operators will need 

to characterize their CO2 stream as part of their permit application to 

determine if the injectate is considered hazardous as defined in 40 CFR Part 

261. If the injectate is considered hazardous under RCRA, then the more 

stringent UIC Class I requirements for injection of hazardous waste apply. The 

design changes EPA is proposing are meant to address the mobility and 

corrosivity caused by long term GS of CO2, and not the long term storage of 

hazardous wastes. 

By defining ‘‘carbon dioxide stream’’ to exclude hazardous wastes (146.81(d)), 

today’s rule, if finalized, assures that it would apply only to CO2 streams that 

are not hazardous wastes as defined in 40 CFR Part 261. As a result, today’s 

proposed rule would preclude the injection of hazardous wastes in Class VI 

injection wells. EPA seeks comment on this approach and other considerations 

associated with the presence of impurities in the CO2 stream. 

Comment: Relegating CO2 waste streams that designate as hazardous waste to the 

Class I hazardous waste program will prevent their inclusion in the proposed 

Class VI well classification where standards, guidance, and expertise will 

tailored for the properties of the bulk solvent. 

128
GS is being pursued to address the burden of CO2 release to the atmosphere from 

power plants. In burning fossil fuels for power, there is a considerable 

amount of other products of combustion and other components that are typically 

scrubbed or otherwise removed from the off-gas stream to prevent their release 

to the atmosphere. The clean up steps for removing these various gas and 

products of combustion from the CO2 waste stream ultimately impact the power 

plant’s net energy output, which adversely affects the cost of electricity. 

Significantly increasing the cost of electricity will discourage GS. 

If the objective of GS is to reduce and/or reduce the release of CO2 to the 

atmosphere, the delta in energy cost may be made more palatable by combining 

other products of combustion with the CO2 waste stream. Additional technical 

information is needed to understand the merits and risks of co-injection of 

contaminants. A Proposed Rule for GS based on a high-purity CO2 stream prior 

to understanding the trade-offs of co-injection of contaminants seems shortsighted. The Proposed Rule should have provisions and leeway for regulators and 

industry to balance cost, energy conservation, waste reduction, and waste 

management program while protecting USDWs and safety of the public. 

Response: The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a

percent CO2). Instead, the GS rule addresses the quality and quantity of impurities by requiring

owners or operators to submit information on the source of the CO2 and its physical and chemical

properties. Specifically, the GS rule requires the owner or operator to submit data about the site,

including an analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the 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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals. EPA clarifies

that Class VI wells cannot be used for the co-injection of RCRA hazardous wastes (i.e., hazardous

wastes that are injected along with the CO2 stream). 

EPA received many comments regarding the applicability of the RCRA regulations and statute to

CO2 streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: Michael Mudd Letter ID: 0167

Commenter Organization: FutureGen Alliance (FGIA) Comment ID: 22466

Comment: I. Is Injected CO2 considered a Hazardous Waste Under RCRA? II-I. EPA should 

129
specify the information needed to characterize the CO2 stream to determine if 

meets the definition of "Hazardous" as defined in 40 CFR Part 261 

If a CO2 stream is determined to be hazardous per RCRA, can the CO2 stream 

still be injected via wells that are constructed and operated per the Class I 

UIC regulations, or does this preclude injection of the hazardous CO2 stream? 

Response: EPA clarifies that GS rule, at §146.81(d), prohibits the injection of CO2 streams that

meet the definition of a hazardous waste under 40 CFR part 261. Therefore, owners or operators will

need to characterize their CO2 stream as part of their permit application to determine if the injectate

is considered hazardous as defined under RCRA. If the CO2 stream is determined to be a hazardous

waste, injection may only occur in a Class I hazardous waste injection well under 40 CFR Part 146

Subpart G.

Commenter Name: Theresa Pugh Letter ID: 0169

Commenter Organization: American Public Power Association Comment ID: 23364

Comment: Interaction with RCRA -- Pg.33 

APPA believes that RCRA corrective action for the entire power plant would rank 

with parasitic power loss as possibly insurmountable obstacles for geologic 

sequestration. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: Theresa Pugh Letter ID: 0169

Commenter Organization: American Public Power Association Comment ID: 23379

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: 7. Congress must address a number of critical liability issues under CERCLA and 

RCRA to enable widespread commercial deployment of geosequestration of CO2 from 

power plants. That issue primarily is outside the scope of this rulemaking but 

must be acknowledged. Unless these issues are resolved, first generation plants 

cannot progress. As EPA recognized in its ANPR on CO2, this UIC rulemaking 

provides one opportunity to address these issues, while protecting the public 

health and welfare under the Safe Drinking Water Act. 

Response: EPA agrees that overlapping regulatory schemes are undesirable. EPA received many

comments regarding the applicability of the RCRA regulations and statute to CO2 streams that are

130
geologically sequestered under the final Class VI UIC well requirements. As a result, EPA has

decided to initiate a separate proposed rulemaking specifically to examine the issue of RCRA

applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit.

Commenter Name: Theresa Pugh Letter ID: 0169

Commenter Organization: American Public Power Association Comment ID: 23406

Comment: · EPA prematurely assumes that the CO2 injected for GS is a solid waste. The CO2 

that will be captured and injected for long-term storage into Class VI wells is 

an uncontained gas and therefore does not meet the statutory definition of a 

"solid waste" under the Resource Conservation and Recovery Act ("RCRA"). 

Further, it is premature to assume that material will be "discarded" as CO2 is 

currently used as a commodity in a variety of manufacturing processes. To the 

extent there is any possibility that CO2 injection operations could be subject 

to RCRA controls, EPA should exempt such activities from RCRA's corrective 

action program under the well established "contingent management" concept given 

that the UIC permit will ensure that the injected material is not mismanaged. 

APPA is confident that state directors will have strict rules on how the 

injections are managed. On this topic of RCRA and solid waste, APPA defers to 

the Utility Solid Waste Activities Group (USWAG) and recommends those aspects of 

their comments. 

Response: As described above, EPA has decided to initiate a separate proposed rulemaking

specifically to examine the issue of RCRA applicability 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.

Commenter Name: Theresa Pugh Letter ID: 0169

Commenter Organization: American Public Power Association Comment ID: 23415

Comment: Interaction with RCRA 

131
The U.S. EPA seeks comment on the question of whether CO2 that exhibits a 

Resource Conservation and Recovery Act or "RCRA" hazardous waste characteristic 

should be precluded from injection in a Class VI CO2 GS well. Id. at 43503. APPA 

questions the underlying premise behind EPA's discussion regarding the potential 

applicability of the RCRA hazardous waste regulations to CO2 GS. Id. The 

fundamental error in EPA's request for comment on this point is its premature 

assumption that CO2 is being discarded and therefore is a solid waste. A 

material cannot be a RCRA hazardous waste if it is not first a "solid waste." 

See 40 C.F.R. § 261.2. The statutory definition of "solid waste" is limited to 

specified "discarded" materials; a material cannot be a "solid waste" unless it 

has first been "discarded." 42 U.S.C. § 6903 (RCRA § 3001). While there have 

been numerous judicial decisions addressing what constitutes "discard," the 

fundamental holding from these cases is simple and straightforward: Congress 

intended to extend EPA’s authority to regulate "solid waste" under RCRA "only to 

materials that are truly discarded, disposed of, thrown away, or abandoned" 

American Mining Congress v. EPA, 824 F.2d 1177, 1190 (D.C. Cir. 1987) (emphasis 

added). The D.C. Circuit has emphasized that the "plain meaning" of the term 

"solid waste" extends only to materials that are "discarded" and that the term 

"discard" should be interpreted with reference to its ordinary meaning. Ass’n of 

Battery Recyclers, Inc. v. EPA, 208 F.3d 1047, 1051-52 (D.C. Cir. 2000). CO2 is 

a valuable commodity used in a variety of manufacturing operations, including in 

the enhanced oil recovery ("EOR") and enhanced gas recovery ("EGR") production 

process. When used in these commercial oil/gas production applications, CO2 is 

not "discarded" and therefore is not a solid waste. While large volumes of CO2 

will be produced under the carbon capture and sequestration programs 

contemplated by the UIC Class VI program, it is premature for EPA to presume 

that these additional volumes of CO2 will not retain commercial value and that 

their sequestration in Class VI wells automatically means that they have been 

"discarded" as that term has been defined under RCRA. As we have already noted, 

the Agency should refrain from making categorical assumptions associated with 

this still-emerging technology associated with the commercial deployment of CO2 

GS operations, including with respect to the status of captured CO2 destined for 

GS. 

Finally, assuming, for purposes of argument, that CO2 is "discarded" and 

exhibits a hazardous waste characteristic when injected for long-term 

sequestration, there are compelling policy reasons to exclude such activities 

from RCRA regulation. Subjecting these injection operations to regulation under 

a Class I UIC hazardous waste injection permit could expose all other waste 

management units at the power plant facility, including units that are in no way 

related to the injection operations, to the full panoply of RCRA’s Subtitle C 

corrective action program. This is because a Class I UIC hazardous waste 

injection permit is a classified as a RCRA "permit by rule" under RCRA’s 

hazardous waste permit program. See 40 C.F.R. §§ 270.1(c)(1)(i) and 270.64. 

Facilities that have obtained a RCRA permit by rule for the operation of a Class 

I UIC hazardous waste injection well are potentially subject to the full scope 

of RCRA’s corrective action program for all solid waste management units 

("SWMUs") located at the facility. If RCRA were to regulate the CO2 as a waste 

this would make many power plant owner/operators reticent to pursue these 

technologies. See EPA RCRA/Superfund Hotline Monthly Summary, "Corrective Action 

132
for UIC Wells," April 1986 (9502.1986(07)). The specter of RCRA corrective 

action is a significant economic and practical operational obstacle for any 

facility considering whether to seek a permit for a new Class VI well for 

geosequestration. 

The imposition of this obstacle is completely unwarranted. Any well receiving a 

permit under the UIC Program for CO2 GS will be, by definition, protective of 

USDWs. EPA’s RCRA program has established a legally sound process, referred to 

as "contingent management," for the exclusion of materials from hazardous waste 

regulation when such materials are already subject to an alternate regulatory 

regime that ensures the wastes are managed in an environmentally protective 

manner. EPA has employed the contingent management concept in several contexts 

where the Agency determined that other regulatory regimes adequately addressed 

any potential mismanagement scenarios related to certain materials, including 

used oil and military munitions. 

The D.C. Circuit has reviewed EPA's legal theory underlying the contingent 

management concept and found it to be a "permissible construction of the 

statute" - namely, that the statutory definition of "hazardous waste" is 

predicated upon the risks posed by a solid waste when "improperly" managed; 

therefore, "where a waste might pose a hazard only under limited management 

scenarios, and other regulatory programs already address such scenarios, EPA is 

not required to classify a waste as hazardous waste subject to regulation under 

[RCRA] Subtitle C." Military Toxics Project v. EPA, 146 F.3d 948, 958 (D.C. Cir 

1998) (emphasis added). 

APPA believes that RCRA corrective action for the entire power plant would rank 

with parasitic power loss as strong deterrents to geologic sequestration for 

many small municipality power plant owner/operators. We do not want to see these 

CCS projects prevented because of RCRA waste concerns. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: Kyle Isakower Letter ID: 0170

Commenter Organization: American Petroleum Institute Comment ID: 24143

Other EPA Comment Codes and Descriptions: 1220 1.1.1.1 Terminology and definitions 

Comment: Rule Provision: 146.81(d) [Definition - Carbon dioxide stream] 

133
API Comments: Carbon dioxide stream means carbon dioxide, IN ANY PHYSICAL STATE 

OR FORM, AND ANY ASSOCIATED substances derived from the that has been captured 

from an emission source (e.g., a power plant), plus incidental associated 

substances derived from the source materials and the capture process, and any,

ITS PROCESSING, OR substances added to enable or improve the injection process. 

This subpart does not apply to any carbon dioxide stream that meets the 

definition of a hazardous waste under 40 CFR part 261. 

Rationale: Source of CO2 is not an issue in the context of defining the CO2 

stream. The rule applies to the injection of CO2 and should not address the 

origins of the materials since that is beyond the scope of this regulation. 

Original text would have precluded injection of CO2 from some sources. 

Response: The final GS rule retains the definition of a CO2 stream as proposed. The GS regulation

applies to injection of CO2 for the purpose of GS, regardless of the source of the CO2. It is beyond

the scope of the GS rule and the UIC Program’s authority to require or set standards for upstream

generators of CO2 or purification facilities. For purposes of GS, the UIC program’s authority under

the SDWA is limited to ensuring that GS projects are sited, constructed, operated, and closed in a

manner that protects USDWs.

Commenter Name: Erik Silvola Letter ID: 0171

Commenter Organization: Great River Energy Comment ID: 23445

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: 6. EPA must settle the way GS activities will relate to RCRA and CERCLA. RCRA is 

simply the wrong tool to use to regulate GS of CO2 and EPA needs to find a way 

to insure that the onerous requirements of CERCLA, (never intended for GS of 

CO2), are not applied to this highly specialized gas storage operation. 

7. Dealing with these last two hazardous waste issues appears to GRE to be one 

of the most difficult hurdles standing in the way of commercial deployment of 

full scale GS projects and we recognize that Congressional action may be needed. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

CO2 itself is not listed as a hazardous substance 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

134
entirely on the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit.

Commenter Name: James Rower Letter ID: 0173

Commenter Organization: Utility Solid Waste Activities Group (USWAG) Comment ID: 23459

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: • EPA must resolve key policy and legal uncertainties to alleviate financial 

concerns of potential Class VI well Owners or Operators and to encourage 

investment in the development and operation of Class VI CO2 injection wells. 

Issues that must be addressed include the interaction of the Resource 

Conservation and Recovery Act ("RCRA") and the Comprehensive Environmental 

Response, Compensation, and Liability Act ("CERCLA") with Class VI injection 

activities as well as long-term post-injection liability. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit.

Commenter Name: James Rower Letter ID: 0173

Commenter Organization: Utility Solid Waste Activities Group (USWAG) Comment ID: 23463

Comment: • In discussing the potential applicability of RCRA's hazardous waste rules to 

Class VI CO2 injection activities, EPA prematurely assumes that the CO2 is being 

"discarded" and is a solid waste under RCRA. To the extent there is any 

possibility that CO2 injection operations could be subject to RCRA controls, EPA 

should exempt such activities from RCRA regulation under the well-established 

"contingent management" concept, particularly given that the UIC permit will 

135
ensure that the injected material is not mismanaged. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: James Rower Letter ID: 0173

Commenter Organization: Utility Solid Waste Activities Group (USWAG) Comment ID: 23483

Comment: 6. Interaction with RCRA 

The Agency seeks comment on the proposal to preclude the injection of hazardous 

waste into Class VI injection wells. Id. at 43503. USWAG takes issue with the 

underlying premise behind EPA's discussion regarding the potential applicability 

of the RCRA hazardous waste regulations to CO2 GS. Id. The fundamental error in 

EPA's request for comment on this point is its premature assumption that CO2 is 

being discarded and therefore is a solid waste. A material cannot be a RCRA 

hazardous waste if it is not first a "solid waste." See 40 C.F.R. § 261.2. Under 

the statutory definition of "solid waste," a material cannot be a "solid waste" 

unless it has first been "discarded." 42 U.S.C. § 6903 (RCRA § 3001). 

While there have been numerous judicial decisions addressing what constitutes 

"discard," the fundamental holding from these cases is simple and 

straightforward: Congress intended to extend EPA's authority to regulate "solid 

waste" under RCRA "only to materials that are truly discarded, disposed of, 

thrown away, or abandoned" American Mining Congress v. EPA, 824 F.2d 1177, 1190 

(D.C. Cir. 1987) (emphasis added). The D.C. Circuit has emphasized that the 

"plain meaning" of the term "solid waste" extends only to materials that are 

"discarded" and that the term "discard" should be interpreted with reference to 

its ordinary meaning. Ass'n of Battery Recyclers, Inc. v. EPA, 208 F.3d 1047, 

1051-52 (D.C. Cir. 2000). 

CO2 is a valuable commodity used in a variety of manufacturing operations, 

including in the enhanced oil recovery ("EOR") and enhanced gas recovery ("EGR") 

production process. When used in these commercial applications, CO2 is not 

"discarded" and therefore is not a solid waste. While large volumes of CO2 will 

be produced under the CCS programs contemplated by the UIC Class VI Proposal, it 

is premature for EPA to presume that these additional volumes of CO2 will not 

retain commercial value and that their sequestration in Class VI wells 

automatically means that they have been "discarded" as that term has been 

defined under RCRA. As we have already cautioned, the Agency should refrain from 

136
making categorical assumptions associated with this still-emerging technology, 

including with respect to the status of captured CO2 destined for GS. 

Assuming, for purposes of argument, that CO2 is "discarded" and exhibits a 

hazardous waste characteristic when injected for long-term sequestration, there 

are compelling policy reasons to exclude such activities from RCRA regulation. 

Facilities that have obtained a RCRA "permit by rule" for the operation of a 

Class I UIC hazardous waste injection well are potentially subject to the full 

scope of RCRA's corrective action program for all solid waste management units 

("SWMUs") located at the facility, including units that are in no way related to 

the CO2 injection operations. See 40 C.F.R. §§ 270.1 (c)(1 )(i) and 270.64; see 

also EPA RCRA/Superfund Hotline Monthly Summary, "Corrective Action for UIC 

Wells," 9502.1986(07) (April 1986). The potential for RCRA applicability on such 

a broad scale is a significant economic and practical obstacle for any facility 

considering whether to seek a permit for a new Class VI well, as facility-wide 

RCRA corrective action is an administratively complex and exceedingly expensive 

undertaking. 

The imposition of this obstacle is unwarranted because any well receiving a 

permit under the UIC Program for CO2 GS will be, by definition, protective of 

USDWs. EPA's RCRA program has established a legally sound process, referred to 

as "contingent management," for the exclusion of materials from hazardous waste 

regulation when such materials are already subject to an alternate regulatory 

regime that ensures the wastes are managed in an environmentally protective 

manner. As discussed below, where the potential for mismanagement of a waste is 

already adequately addressed by another regulatory regime - as would be the case 

with the injection of CO2 under the Class VI UIC program - regulation of such 

materials under the RCRA's hazardous waste program is duplicative and 

unwarranted. EPA has successfully employed the contingent management concept in 

various contexts where the Agency determined that other regulatory regimes 

adequately addressed any potential mismanagement scenarios related to certain 

materials; examples include regulation of used oil, mixed radioactive/hazardous 

waste, and military munitions. 

The Court of Appeals for the District of Columbia Circuit has reviewed EPA's 

legal theory underlying the contingent management concept and found it to be a 

"permissible construction of the statute," based on the idea that the statutory 

definition of "hazardous waste" is predicated upon the risks posed by a solid 

waste when "improperly" managed. Military Toxics Project v. EPA, 146 F.3d 948, 

958 (D.C. Cir 1998) (emphasis added). Therefore, "where a waste might pose a 

hazard only under limited management scenarios, and other regulatory programs 

already address such scenarios, EPA is not required to classify a waste as 

hazardous waste subject to regulation under [RCRA] Subtitle C." Id. 

Even if such operations were deemed subject to RCRA regulation, including a RCRA 

permit by rule, EPA could - and should - establish a conditional exclusion from 

RCRA regulation for CO2 GS operations. Such an exclusion would be legally 

justified, consistent with the Agency's past promulgation of conditional 

exclusion rules, and would make sound policy sense by removing a potentially 

significant regulatory barrier to the commercial development of CO2 GS 

137
operations. 

Response: EPA clarifies that the GS rule does not address the status of CO2 as a pollutant or a

commodity. Under the SDWA and the UIC program, EPA regulates the injection of a range of

fluids, which may include pollutants and commodities, regardless of how they are characterized, for

the purpose of protecting USDWs.

EPA received many comments regarding the applicability of the RCRA regulations and statute to

CO2 streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: Pamela Faggert Letter ID: 0175

Commenter Organization: Dominion Comment ID: 23529

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: 7. Interaction of CO2 with RCRA and CERCLA 

It is essential that the Agency resolve key policy and legal uncertainties 

regarding the interaction of the Resource Conservation and Recovery Act ("RCRA") 

and the Comprehensive Environmental Response, Compensation, and Liability Act 

("CERCLA or Superfund") with Class VI injection activities. EPA's proposed rule 

refers to the potential presence of unknown or unidentifiable hazardous 

constituents in various streams. See 73 Fed. Reg. at 43,503-04. This leaves 

Class VI permittees with little certainty as to which constituents, whether 

present in the CO2 stream itself, in the receiving underground soil and aquifer, 

or via some reaction between the two, might subject the permittee to liability 

under RCRA or CERCLA. This regulatory uncertainty will make it difficult for CCS 

to attract the investment necessary to ensure its viability as a climate 

mitigation strategy. 

Response: The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a

percent CO2). Instead, the GS rule addresses the quality and quantity of impurities by requiring

owners or operators to submit information on the source of the CO2 and its physical and chemical

properties. Specifically, the GS rule requires the owner or operator to submit data about the site,

including an analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the 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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals. 

138
With respect to RCRA, EPA received many comments regarding the applicability of the RCRA

regulations and statute to CO2 streams that are geologically sequestered under the final Class VI

UIC well requirements. As a result, EPA has decided to initiate a separate proposed rulemaking

specifically to examine the issue of RCRA applicability 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 particular 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 commenters who wish to submit comments on the RCRA proposal will need to do

so during the comment period for that rule. Finally, EPA also notes that the final GS rule, which

adds new regulations for Class VI wells under the Safe Drinking Water Act (SDWA), is not making

any changes to the RCRA regulations.

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” as defined in CERCLA, 42 U.S.C. 9601(10).

Class VI permits will need to be carefully structured to ensure that they prevent potential releases

from the well which are outside the scope of the Class VI permit.

Commenter Name: Pamela Faggert Letter ID: 0175

Commenter Organization: Dominion Comment ID: 23530

Comment: To the extent there is any possibility that CO2 injection operations could be 

subject to RCRA controls, EPA should exempt such activities under the wellestablished "contingent management" concept given that the UIC permit will 

ensure that the injected material is not mismanaged. 

Response: EPA agrees that any requirements for the CO2 stream should be clearly identified. As

described above, EPA has decided to initiate a separate proposed rulemaking specifically to examine

the issue of RCRA applicability 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.

Commenter Name: Pamela Faggert Letter ID: 0175

Commenter Organization: Dominion Comment ID: 23532

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: Further, EPA already has ample civil and criminal enforcement authority under 

the SDWA to address violations of UIC permits, including the ability to impose 

fines of up to $32,500 per day in civil penalties. This authority thus provides 

a significant and independent means of addressing environmental contamination. 

Finally, EPA should support legislative solutions to ensure companies employing 

CCS technologies are assured of reasonable liability protections. While CO2 is 

not listed as a hazardous substance under CERCLA, statutory exemptions under 

both RCRA and CERCLA for a clearly defined set of CO2 injection streams could be 

139
an appropriate device for mitigating liability concerns. Or, a more tailored 

approach to limiting the scope of RCRA and CERCLA liability for certain types of 

CCS projects could be proposed. 

In order to effectively promote CCS as a viable climate mitigation 

strategy, legal uncertainties surrounding potential CERCLA and RCRA 

liability associated with GS wells must be addressed. To this end, EPA 

should employ RCRA's "contingent management" concept and CERCLA's 

"federally permitted release" exemption as regulatory means to limit 

potential liability and uncertainty. In addition, EPA should advocate or 

support legislative solutions to limit Class VI permittee liability 

under these statutes. 

Response: EPA thanks the commenter for their suggestions and clarifies that any comments related

to supporting legislative changes to any environmental statutes are outside the scope of this

rulemaking. Changes to the RCRA and CERCLA statutes are outside the scope of the GS

rulemaking under the SDWA. EPA agrees that any requirements applicable to CO2 injectate should

be clearly identified to the public and to the regulated community. As described above, with respect

to RCRA, EPA has decided to initiate a separate proposed rulemaking specifically to examine the

issue of RCRA applicability 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.

Commenter Name: Kenneth Nemeth Letter ID: 0176

Commenter Organization: Southern States Energy Board Comment ID: 23537

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: Importantly, under the proposed rule, EPA should specify that CO2 is not 

considered hazardous, nor subject to regulation under RCRA or CERCLA, (while the 

rule recognizes that other gases could contaminate the CO2, resulting in hazards 

to USDWs). Equally important, there should not be limitations on formations that 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

With respect to CERCLA, EPA clarifies that CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream

and the environmental media in which it is stored (e.g., soil or ground water). CERCLA exempts

140
from liability, under CERCLA section 107, 42 U.S.C. 9607, certain “federally permitted releases”

(FPR) as defined in CERCLA, 42 U.S.C. 9601(10). Class VI permits will need to be carefully

structured to ensure that they prevent potential releases from the well which are outside the scope of

the Class VI permit.

Commenter Name: Quinlan J. Shea Letter ID: 0177

Commenter Organization: Edison Electric Institute Comment ID: 23559

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: Finally, EEI is concerned about the potential application to CCS activities of 

environmental laws that were, without exception, not intended to apply to CCS or 

even crafted with CCS in mind and that could impose significant obligations and 

potential liabilities not only on project operators, but also potentially on 

other entities in the CO2 chain, such as entities producing the CO2 that is 

ultimately injected. These laws include the Comprehensive Environmental 

Response, Compensation, and Liability Act (CERCLA or Superfund) and RCRA. EEI 

urges EPA to evaluate carefully any proposed treatment of these two laws (or 

others) that it may be considering under the Class VI regulations to ensure that 

any such treatment is necessary and does not serve as an unintended springboard 

for hampering the successful commercialization of CCS. EEI submits that any 

characterization of potentially hazardous constituents in CO2 injectate may be 

addressed as part of the UIC permitting process without addressing any potential 

RCRA jurisdictional issues. 

Response: First, EPA notes that the GS rule is not promulgated under either the RCRA or CERCLA

statutes, and the applicability of those statutes will not be determined under the SDWA or the terms

of the GS rule, but rather according to those statutes themselves and any implementing regulations

that may apply.

EPA received many comments regarding the applicability of the RCRA regulations and statute to

CO2 streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

With respect to CERCLA, EPA clarifies that CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream

and the environmental media in which it is stored (e.g., soil or ground water). CERCLA exempts

from liability, under CERCLA section 107, 42 U.S.C. 9607, certain “federally permitted releases”

(FPR) as defined in CERCLA, 42 U.S.C. 9601(10). Class VI permits will need to be carefully

141
structured to ensure that they prevent potential releases from the well which are outside the scope of

the Class VI permit.

Commenter Name: Quinlan J. Shea Letter ID: 0177

Commenter Organization: Edison Electric Institute Comment ID: 23605

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: J. Issues Related to Potential Application of Other Environmental Laws 

EEI and our members are concerned about the potential application to CCS 

activities of environmental laws that were, without exception, not intended to 

apply to CCS or even crafted with CCS in mind and that could impose significant 

obligations and potential liabilities not only on project operators, but also 

potentially on other entities in the CO2 chain, such as entities producing the 

CO2 that is ultimately injected. These laws include in particular the 

Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA or 

Superfund) and RCRA. EEI agrees that issues related to potential liabilities 

under these laws must be resolved.[FN12] Setting aside for the moment important 

questions of whether either of these laws could apply to CCS activities and, if 

so, precisely how and to what extent, EEI does not disagree with the Agency‘s 

position that drafting a clear exception from either of these regimes may be 

difficult in the sole context of this SDWA UIC rulemaking. Nonetheless, EEI 

urges EPA to evaluate carefully any proposed treatment of these two laws (or 

others) that it may be considering under the Class VI regulations to ensure that 

any such treatment is necessary and does not serve as an unintended springboard 

for hampering the successful commercialization of CCS. 

[FN12] The recent released GAO report on CCS echoes the importance of addressing 

these liability issues. GAO recommends that EPA examine its authorities and 

responsibilities the under RCRA and CERCLA to determine "where additional 

statutory authority might be needed to address key regulatory and legal issues 

related" to CCS. GAO report, supra n. 9, at 52. 

Response: As described above, EPA has decided to initiate a separate proposed rulemaking

specifically to examine the issue of RCRA applicability 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. 

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” as defined in CERCLA, 42 U.S.C. 9601(10).

Class VI permits will need to be carefully structured to ensure that they prevent potential releases

from the well which are outside the scope of the Class VI permit.

Commenter Name: Quinlan J. Shea Letter ID: 0177

142
Commenter Organization: Edison Electric Institute Comment ID: 23606

Comment: To turn briefly to the RCRA issue, EPA comments in the preamble that SDWA is 

currently used to regulate the injection of both "pollutants" and "commodities"; 

therefore, the rules do not need to address the status of CO2 as a pollutant or 

a commodity.[FN13] Regardless, the preamble continues to include an analysis of 

the potential application of RCRA to CO2 injection and storage activities that 

appears to be based upon an assumption that CO2 is in fact not a commodity, but 

a waste. 

As the Agency is aware, RCRA regulates production, management and disposal of 

wastes; RCRA‘s potential application thus depends upon existence of a waste in 

the first instance (more particularly, a solid waste). Once a material is 

deemed to be "discarded" and thus a solid waste, an additional set of parameters 

applies to determine whether that substance is also a hazardous waste and thus 

subject to further regulation. It is likely within EPA’s regulatory ambit 

(albeit under RCRA) to determine that CCS activities meeting permit requirements 

are not equated to discarding the CO2, and EEI recommends that EPA examine that 

approach. 

Further, while the preamble notes that it is unnecessary to label CO2 a waste or 

a commodity for purposes of proposing and implementing UIC regulations for its 

injection and storage, it jumps to an unnecessary and potentially confusing 

discussion of whether injected CO2 may be a hazardous waste, thus perhaps 

implying the assumption that CO2 is a solid waste to begin with. The preamble 

states: 

Because the types of impurities and their concentrations in the CO2 

stream are likely to vary by facility, coal composition, plant operating 

conditions, and pollution removal technologies, EPA cannot make a 

categorical determination as to whether injected CO2 is hazardous under 

RCRA.[FN14] 

Thus, EPA states, operators "will need to characterize their CO2 stream as part 

of their permit application to determine if the injectate is considered 

hazardous" under RCRA, and potential application of RCRA is left to a case-bycase determination depending upon the contents of the injectate. EEI submits 

that any characterization of potentially hazardous constituents in CO2 injectate 

may be addressed as part of the UIC permitting process without addressing any 

potential RCRA jurisdictional issues. For instance, EPA could appropriately 

establish a permit condition that injectate must meet Toxicity Characteristic 

Leaching Procedure or pH standards, without reference to the material‘s waste 

status. 

[FN13] 73 Fed. Reg. 43496, col.3 

[FN14] Id. at 43503, col. 3. 

Response: First, EPA notes that the final GS rule, which adds new regulations for Class VI wells

under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA regulations,

which continue to apply on their own terms. 

143
At the same time, under the final GS rule, owners or operators will need to determine whether the

CO2 stream is hazardous under EPA’s RCRA regulations, and if so, any injection of the hazardous

CO2 stream may only occur in a Class I hazardous waste injection well under 40 CFR Part 146

Subpart G. Conversely, Class VI wells cannot be used for the co-injection of RCRA hazardous

wastes (i.e., hazardous wastes that are injected along with the CO2 stream).

As described above, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule.

Commenter Name: Frederick R. Eames Letter ID: 0178

Commenter Organization: CCS Alliance Comment ID: 23799

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment);

5400 2.9 Proposed Financial Responsibility and Long-Term Care Requirements 

Comment: Single, Clear Liability Structure 

To the extent possible, policymakers should put in place a single, clear 

liability regime for CCS activities. In the context of this rule, EPA has 

considered the possibility of cleanup liability both under the Comprehensive 

Environmental Response, Compensation, and Liability Act ("CERCLA" or 

"Superfund") and the Resource Conservation and Recovery Act ("RCRA), in addition 

to the UIC program. There is also the possibility of liability under state 

statutes and common law. Parties who may be injured in the future must be able 

to resort to a fair liability scheme, but potential applicability of multiple 

schemes is likely to discourage CCS development. 

Response: EPA acknowledges the commenter's concerns regarding the applicability of multiple

statutes to GS projects and the need for a single clear liability regime for owners or operators. As a

federal agency, EPA is working to create a nationally consistent financial responsibility regime

within its authority while providing permitting authorities an appropriate level of flexibility. EPA is

finalizing financial responsibility requirements under authority of the SDWA. EPA believes that the

general authorities provided under SDWA include the authority to set minimum federal requirements

for financial responsibility to ensure that financial resources are available to protect USDWs

throughout the life of the GS project. See the final rule and preamble for further discussion of EPA's

final approach to financial responsibility.

Furthermore, 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 SDWA after site closure if there is

unanticipated migration towards or into a USDW 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, they may

be subject to a civil penalty for each day in which such violation occurs or failure to comply

continues. 

144
The Agency acknowledges and clarifies that, after site closure, an owner or operator may, depending

on the fact scenario and state law, remain liable under state tort law and other remedies, or under

other Statutes including, 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 appreciates the commenter’s suggestions for a single liability scheme for CCS; however, the

GS rule is not promulgated under either RCRA or CERCLA, and making legislation changes or

addressing liability under state statutes and common law is also outside the scope of the GS

rulemaking. EPA also notes that the applicability of RCRA and CERCLA will not be determined

under the SDWA or the terms of the GS rule, but rather according to those statutes themselves and

any implementing regulations that may apply. 

EPA agrees that any requirements applicable to CO2 injectate should be clearly identified to the

public and to the regulated community. EPA received many comments regarding the applicability of

the RCRA regulations and statute to CO2 streams that are geologically sequestered under the final

Class VI UIC well requirements. As a result, EPA has decided to initiate a separate proposed

rulemaking specifically to examine the issue of RCRA applicability 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 particular 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 commenters who wish to submit comments on the RCRA proposal

will need to do so during the comment period for that rule. Finally, EPA also notes that the final GS

rule, which adds new regulations for Class VI wells under the Safe Drinking Water Act (SDWA), is

not making any changes to the RCRA regulations.

Commenter Name: Frederick R. Eames Letter ID: 0178

Commenter Organization: CCS Alliance Comment ID: 23815

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment);

5400 2.9 Proposed Financial Responsibility and Long-Term Care Requirements 

Comment: B. POTENTIAL APPLICABILITY OF RCRA AND CERCLA 

As discussed in greater detail below, the potential applicability of RCRA and 

CERCLA is a key concern. These statutes simply are not designed with the thought 

in mind of encouraging the safe and widespread deployment of a new technology. 

The CCS Alliance believes that many parties involved in the CCS chain of events 

should bear responsibility for safe operation. Rather than apply environmental 

statutes with contentious and litigious histories, Congress should enact a new 

regulatory and liability framework for CCS in place of the multiple regimes that 

now may apply. This is not meant to detract from the progress EPA is making in 

this rulemaking. It merely recognizes the limitations and overlapping structures 

EPA itself has noted. CCS should be subject to a single, clear regulatory 

structure, and a single, clear liability structure. In the meantime, EPA should 

use what interpretive authority it has to limit the applicability of multiple 

statutes and provisions, the applicability of which would discourage CCS. 

Response: EPA acknowledges the commenter's concerns regarding the applicability of multiple

statutes to GS projects and the need for a single clear liability regime for owners or operators. EPA

145
is working to create a nationally consistent financial responsibility regime within its authority while

providing permitting authorities an appropriate level of flexibility. EPA is finalizing financial

responsibility requirements under authority of the SDWA, which includes the authority to set federal

minimum requirements for financial responsibility to ensure that resources are available to protect

USDWs throughout the life of the GS project.

This authority does not extend to release owners or operators from long-term responsibility under

other statutes, such as CERCLA, for potential impacts after the PISC period has ended, or for the

potential economic costs associated with impacts unrelated to USDWs. Under current SDWA

provisions, EPA does not have authority to transfer liability from one entity to another and it does

not provide for the creation of a third party financial instrument where EPA is the trustee.

Under SDWA authority, owners or operators of injection wells must ensure protection of USDWs

from endangerment and are subject to liability 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 poses 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 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. Furthermore, the

financial instrument required under §146.85 will be released if it has not been 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 certain circumstances. For example, an

owner or operator may be held liable even after site closure was approved 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 SDWA after site closure if there is

unanticipated migration towards or into a USDW that causes or threatens imminent and substantial

endangerment to public health. If the owner or operator fails to comply with the order, he or she may

be subject 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 responsibilities are transferred to that new

owner and operator, including all potential liabilities associated with meeting the requirements of that

permit.

Furthermore, after site closure an owner or operator may remain liable under tort and other remedies,

or under other federal statutes including, 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.

Comments requesting congressional legislation on liability for GS are outside of the scope of this

rulemaking.

EPA agrees that identifying and addressing potential barriers to the deployment of CCS, while

146
protecting human health and the environment, is important. As described above, making legislation

changes is outside the scope of the GS rulemaking. Also as described above, EPA has decided to

initiate a separate proposed rulemaking specifically to examine the issue of RCRA applicability 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. 

Furthermore, EPA is promulgating the GS rule under the authority of the SDWA. To the extent the

commenter is seeking interpretations of CERCLA and its related provisions, such as the definition of

a federally permitted release, such interpretations are beyond the scope of this rulemaking.

Commenter Name: Frederick R. Eames Letter ID: 0178

Commenter Organization: CCS Alliance Comment ID: 23835

Comment: VIII. SPECIAL FOCUS: APPLICABILITY OF RCRA 

The Proposed Rule raises the question whether injected CO2 streams will be 

considered "hazardous waste" under RCRA. Rather than apply on top of the SDWA 

another environmental statute that was not designed with the thought of 

encouraging development and deployment of technology to address climate change, 

which is likely to discourage CCS deployment, CCS should be subject to a single. 

clear regulatory structure shaped by consideration of climate change objectives. 

Designating the CO2 stream as a hazardous waste also will result in it being 

considered a "hazardous substance" under CERCLA, the problems with which are 

discussed above. 

The Proposed Rule states: 

Because the types of impurities and their concentrations in the CO2 

stream are likely to vary by facility, coal composition, plant operating 

conditions, and pollution removal technologies, EPA cannot make a 

categorical determination as to whether injected CO2 is hazardous under 

RCRA. Owners and operators will need to characterize their CO2 stream as 

part of their permit application to determine if the injectate is 

considered hazardous as defined in 40 CFR Part 261. If the injectate is 

considered hazardous under RCRA, then the more stringent UIC Class I 

requirements for injection of hazardous waste apply.[FN38] 

[FN38] Proposed Rule, 73 Fed Reg. 43503. 

Where EPA faces an interpretive question about the applicability of RCRA, it 

should avoid applying the statute. As noted above, the CCS Alliance believes 

that in place of existing, ill-suited regulatory regimes, a new single, clear 

regulatory structure should apply to protect the environment. 

Response: EPA agrees that any requirements applicable to CO2 injectate should be clearly identified

to the public and to the regulated community. As mentioned, making legislation changes is outside

the scope of the GS rulemaking. 

As discussed above, EPA received many comments regarding the applicability of the RCRA

regulations and statute to CO2 streams that are geologically sequestered under the final Class VI

147
UIC well requirements. As a result, EPA has decided to initiate a separate proposed rulemaking

specifically to examine the issue of RCRA applicability 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 particular 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 commenters who wish to submit comments on the RCRA proposal will need to do

so during the comment period for that rule.

Commenter Name: Frederick R. Eames Letter ID: 0178

Commenter Organization: CCS Alliance Comment ID: 23836

Comment: A. BURDENS AND BARRIERS OF RCRA 

The UIC regulatory structure proposed by EPA to minimize releases not only 

protects groundwater, but by extension protects human health and the 

environment. RCRA's requirements are extensive, expensive, and ill-suited to 

activities to sequester large volumes of low-toxicity materials, especially when 

such activities will be regulated under the UIC program. 

EPA itself has acknowledged the burden of RCRA and the fact that many of its 

requirements are poorly suited to at least some of the activities to which they 

apply. EPA initiated a rulemaking in 2002 to reduce the burdens associated with 

the RCRA hazardous waste program.[FN39] The Agency noted, "[t]he existing 

hazardous waste regulations require the submittal of 334 notifications, reports, 

certifications, demonstrations, and plans from generators and TSDFs to 

demonstrate compliance with the RCRA regulations."[FN40] Reporting requirements 

are just one example of RCRA's burdens. 

[FN39] Resource Conservation and Recovery Act Burden Reduction Initiative. 67 

Fed. Reg. 2518 (proposed Jan. 17, 2002); see also RCRA Burden Initiative; Final 

Rule, 71 Fed. Reg. 16,862 (Apr. 4,2006). 

[FN40] RCRA Burden Reduction Initiative: Notice of Data Availability, 68 Fed. 

Reg. 61,662, 61,644 (Oct. 29, 2003). 

Given that CCS is a technology that the Agency and a broad array of others want 

to encourage, with this rule more than most others, EPA must consider very 

carefully whether the emission streams involved truly warrant hazardous waste 

regulation. Imposing extensive. burdensome RCRA regulations likely to have 

little benefit for human health and the environment may result in larger 

atmospheric releases of CO2 if this "key" technology is not as widely deployed. 

Class I wells under the UIC program are intended, in part, to regulate hazardous 

waste disposal wells for the injection of hazardous waste, as defined by RCRA. 

If EPA were to determine that CO2 is a hazardous waste under RCRA, CO2 injection 

would be required to meet the more rigorous Class I well requirements, rather 

than the proposed Class VI requirements. Indeed, the construction, permitting, 

operating, monitoring, and post-site closure requirements are much more 

burdensome for Class I hazardous wells than for the other types of injection 

148
wells. For instance, Class I wells have a requirement that there be no migration 

for 10,000 years. Such strict requirements may be appropriate to protect USDWs 

and the environment from certain hazardous wastes, but such requirements were 

not established with CO2 injectate in mind. 

Furthermore, if a facility were required to obtain a Class I UIC hazardous waste 

injection permit, all other waste management units at the facility couId be 

subject to the full extent of RCRA's Subtitle C corrective action program, which 

is an extremely costly and administratively complex program. Determining that 

CO2 constitutes a hazardous waste and subjecting CO2 injection and storage to 

the burdensome Class I well requirements would not promote underground injection 

and storage of CO2. 

Response: The Agency acknowledges the commenter’s concerns over potential barriers to CCS

deployment, and will consider these comments as it examines the issue of RCRA applicability to

CO2 streams being geologically sequestered in a separate Agency action related to RCRA, already

described above. The Agency recommends that the commenter read that proposed rule when it is

published. The Agency notes that commenters who wish to submit comments on the RCRA proposal

will need to do so during the comment period for that rule.

Commenter Name: Frederick R. Eames Letter ID: 0178

Commenter Organization: CCS Alliance Comment ID: 23837

Comment: B. CONTINGENT MANAGEMENT 

Materials already subject to another regulatory regime that will ensure 

environmentally protective management of wastes can be excluded from RCRA 

regulation under "contingent management," a practice EPA has applied in other 

contexts. 

In this Proposed Rule, EPA is proposing a framework it believes is appropriate 

to ensure environmentally protective management of injected CO2. The Agency 

makes clear that the extent of the UIC program limits the purpose of EPA's 

proposal to protection of USDWs; however, the Agency adds that it considers the 

risk of -'chronic and acute health effects from airborne exposure resulting from 

CO2 injection activities (even in the case of leakage or accidental exposure) is 

minimal."[FN41] 

[FN41] Proposed Rule, 73 Fed. Reg. at pp. 43,497-98 (emphasis added). 

EPA has applied the contingent management practice in cases where potential 

mismanagement scenarios are addressed under other regulation. With respect to 

the Proposed Rule, EPA has proposed measures that would limit potential effects 

on human health and the environment by ensuring that the injectate should remain 

contained within the injection zone. The contingent management practice has been 

upheld, with the court holding that where other appropriate management programs 

are in place. hazardous waste classification and regulation are not 

required.[FN42] 

[FN42] See. e.g., Military Toxics Project v. EPA, 146 F. 36 948 (D.C. Cir. 

149
1998). 

Response: As described above, EPA has decided to initiate a separate proposed rulemaking

specifically to examine the issue of RCRA applicability 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. The Agency recommends that the commenter read that proposed rule

when it is published. The Agency notes that commenters who wish to submit comments on the

RCRA proposal will need to do so during the comment period for that rule.

Commenter Name: Frederick R. Eames Letter ID: 0178

Commenter Organization: CCS Alliance Comment ID: 23838

Comment: C. CONDITIONAL EXCLUSION 

If EPA considers that geologic sequestration of CO2 constitutes waste disposal 

that cannot be subject to exclusion from RCRA regulation under a contingent 

management theory, it should establish a conditional exclusion from RCRA 

regulation for geologic sequestration of CO2 injectate. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: Thomas Curtis Letter ID: 0181

Commenter Organization: American Water Works Association (AWWA) Comment ID: 23688

Comment: EPA Request for Comment: Class VI requirements and permits will need to be 

carefully structured to ensure that they do not "authorize" inappropriate 

hazardous releases. This would include clarifying if there are potential 

releases from the well which are outside the scope of the Class VI permit. EPA 

requests comment on particular situations where this might occur. EPA notice 

43504. 

AWWA Response: AWWA agrees with EPA’s assertion that the permits and well 

requirements need to be carefully structured to prevent "authorized" releases of 

hazardous substances into subsurface geologic formations. We are not aware of 

any situations where this might occur, as long as the injectate is properly 

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

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

the formation of a hazardous substance due to reactions with the surrounding 

geologic strata. To prevent this problem from occurring, the geologic 

150
characteristics of the geologic formations should be evaluated prior to 

injection for potential interactions with the injectate stream. If there are 

indications that hazardous substances could be formed, the site should not be 

considered acceptable for carbon sequestration. 

Response: EPA agrees that proper siting, operation, and monitoring are important for protecting

USDWs from endangerment. In addition, the UIC program Director has authority under SDWA

§1423 to address potential compliance issues (e.g., potential releases that may endanger USDWs)

resulting from injection violations in the unlikely event that a remedial response is necessary.

Although EPA anticipates that the need for emergency or remedial actions at GS sites will be rare,

the GS rule requires, at §146.94, that emergency and remedial response plans be developed and

updated to address such events and that owners or operators demonstrate that financial resources are

set aside to implement the plans if necessary, per §146.85.

EPA clarifies that, while the Administrator reserves the right to promulgate regulations designating

additional substances as hazardous under §102 of CERCLA, EPA intends to avoid any potential

overlap of SDWA and CERCLA authority through its comprehensive Class VI requirements.

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit.

Commenter Name: Scott Davis Letter ID: 0187

Commenter Organization: Arizona Public Service Company Comment ID: 25220

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment);

5460 2.9.2 Comments on transfer of liability for long-term care 

Comment: - The final rule must resolve several key policy and legal questions regarding 

underground injection of CO2, including but not limited to implications under 

the Resource Conservation and Recovery Act ("RCRA") and the Comprehensive 

Environmental Response, Compensation and Liability Act ("CERCLA"), and limiting 

post injection liability. 

Response: Under the final GS rule, once an owner 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. Furthermore, 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

certain circumstances. For example, an owner or operator may be held liable for regulatory

noncompliance even after site closure was approved if the Director relied on erroneous information

(e.g., erroneous modeling data) provided by the owner or operator when approving site closure. 

Separate from EPA's authority to enforce regulatory compliance, an owner or operator may be

151
subject to a §1431 response order even after proper site closure 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 present an imminent and substantial endangerment to the health of

persons, and the appropriate State and local authorities have not acted to protect the health of such

persons. The action may include issuing administrative 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 operator may remain liable under tort and other remedies,

or under other federal statutes including, 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.

EPA received many comments regarding the applicability of the RCRA regulations and statute to

CO2 streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

EPA also clarifies that CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the

environmental media in which it is stored (e.g., soil or ground water). CERCLA exempts from

liability, under CERCLA section 107, 42 U.S.C. 9607, certain "federally permitted releases" (FPR)

as defined in CERCLA, 42 U.S.C. 9601(10). Class VI permits will need to be carefully structured to

ensure that they prevent potential releases from the well which are outside the scope of the Class VI

permit.

Commenter Name: G. Graham Holden Letter ID: 0189

Commenter Organization: Oglethorpe Power Corporation Comment ID: 25250

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: 6. EPA should define the way GS activities will relate to the Resource 

Conservation and Recovery Act ("RCRA") and the Comprehensive Environmental 

Response, Compensation and Liability Act ("CERCLA") 42 U.S. §§ 9601, et seq. 

RCRA is simply the wrong tool to use to regulate GS of CO2 and EPA needs to find 

a way to insure that the onerous requirements of CERCLA (never intended for GS 

of CO2) are not applied to this highly specialized storage operation. 

152
7. Appropriately defining the relationship of GS activities with RCRA and CERCLA 

is critical to the commercial deployment of full scale GS projects and may 

require Congressional action. 

Response: EPA agrees that any requirements applicable to CO2 injectate should be clearly identified

to the public and to the regulated community. EPA received many comments regarding the

applicability of the RCRA regulations and statute to CO2 streams that are geologically sequestered

under the final Class VI UIC well requirements. As a result, EPA has decided to initiate a separate

proposed rulemaking specifically to examine the issue of RCRA applicability 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 particular 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 commenters who wish to submit comments on the RCRA proposal

will need to do so during the comment period for that rule. Finally, EPA also notes that the final GS

rule, which adds new regulations for Class VI wells under the Safe Drinking Water Act (SDWA), is

not making any changes to the RCRA regulations.

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190

Commenter Organization: Carbon Sequestration Council Comment ID: 24323

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: D. RCRA/CERCLA Applicability 

In light of the current uses and potential future uses of CO2 for EOR/EGR, EPA 

has taken a sensible approach by proposing to create a new Class VI well 

category based on the injection of the CO2 stream as fluid without 

characterizing that stream as a waste. It is neither necessary nor helpful to 

categorize CO2 as a pollutant or waste, and that would likely prove detrimental 

to technology development. Indeed, we are concerned that EPA’s brief discussion 

of a supposed potential for injected CO2 streams to be characterized as 

hazardous waste (or some type of hazardous release) are causing apprehension and 

could have a significant chilling effect on any future deployment of carbon 

capture and sequestration technologies. Through the work of our engineers and 

scientists with capture technologies and their extensive experience with the 

types of power plant flue gas likely to be sources of CO2 for sequestration, we 

do not believe that captured CO2 streams should trigger the application of 

either RCRA or CERCLA. Accordingly, we encourage EPA to dispel concerns that 

geologic sequestration could be encumbered with those requirements except 

153
possibly through the commingling of a captured CO2 stream with an actual waste 

stream, and we are not suggesting that such commingling should be permissible in 

the GS context. 

Response: EPA thanks the commenter for their views on CCS, and notes that the GS rule is not

promulgated under either the RCRA or CERCLA statutes, and further, the applicability of those

statutes will not be determined under the SDWA or the terms of the GS rule, but rather according to

those statutes themselves and any implementing regulations that may apply.

EPA received many comments regarding the applicability of the RCRA regulations and statute to

CO2 streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” as defined in CERCLA, 42 U.S.C. 9601(10).

Class VI permits will need to be carefully structured to ensure that they prevent potential releases

from the well which are outside the scope of the Class VI permit. 

EPA adds that promoting the use of GS is outside the scope of the GS rule. Rather, the purpose of

the GS regulation is to ensure that, where deployed, GS is conducted in a manner that protects

USDWs from endangerment.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190

Commenter Organization: Carbon Sequestration Council Comment ID: 24324

Comment: 1. RCRA Applicability 

EPA’s Proposal suggests that injected CO2 may be considered hazardous waste for 

RCRA purposes, and defines "carbon dioxide stream" to exclude hazardous waste. 

73 Fed. Reg. at 43503. The premise appears to be that CO2 is solid waste, and 

that a waste determination for such solid waste would turn on the specific 

composition of the CO2 in question. Id. Based on this premise, the preamble 

suggests that "EPA cannot make a categorical determination as to whether 

injected CO2 is hazardous waste under RCRA." Id. 

In fact, there are important categorical determinations that EPA can and should 

154
make with respect to the RCRA status of CO2. We urge EPA to make these 

determinations as follows. 

First, EPA should clarify that gas-phase CO2 is not solid or hazardous waste for 

RCRA purposes and is not subject to any RCRA waste determination requirements. 

The RCRA definition of "solid waste" does not include gaseous material unless it 

is "contained." RCRA 1004(27), 42 U.S.C. 6903(27). EPA has long taken the 

position that gasses do not qualify as "solid waste" under this definition 

unless they are "contained" in a cylinder or similar container. 54 Fed. Reg. 

50968 at 50970, 50973 (December 11, 1989). It follows that gas-phase CO2 streams 

are not solid waste, are not subject to the waste determination requirements of 

40 C.F.R. 262.11, and cannot be considered hazardous waste for RCRA purposes. 

Second, EPA should clarify that supercritical CO2 is not solid or hazardous 

waste for RCRA purposes and is not subject to any RCRA waste determination 

requirements. 

Again, the RCRA definition of solid waste is limited to "solid, liquid, semisolid, or contained gaseous material." RCRA 1004(27). Because supercritical CO2 

is none of these things; a plain reading of the statutory text suggests that 

supercritical CO2 should not be considered "solid waste." This reading of the 

statute makes sense, because RCRA is plainly aimed at the kind of material that 

could end up being dumped into a landfill. Uncontained supercritical CO2 is not 

such a material. Instead, the physical properties of supercritical CO2 are such 

that it would immediately vaporize - becoming an uncontained gas - before it 

could contribute to the contents of a landfill. A related practical 

consideration is the fact that the hazardous characteristics - the broad waste 

determination criteria that provide a primary means for determining when solid 

waste is hazardous waste - are based largely on test methods that are 

inapplicable to materials such as supercritical CO2. In particular, the toxicity 

characteristic depends on test methods that can only be applied to materials 

that are solids or liquids at standard temperatures and pressures. This is 

unsurprising, because the toxicity characteristic was designed to assess the 

threat waste would have in a municipal landfill disposal scenario, a scenario 

that - as already discussed - is inherently inapplicable to uncontained 

supercritical CO2. Accordingly, it makes no legal, policy, or practical sense to 

treat uncontained supercritical CO2 as "solid waste" for RCRA purposes. EPA 

should therefore confirm that uncontained supercritical CO2 is not "solid waste" 

and is not subject to RCRA waste determination requirements. 

It follows that a CO2 stream would only qualify as "solid waste" if it is 

actually in the form of a liquid (i.e., a liquid containing dissolved CO2). In 

such a case, the liquid would meet the statutory definition of "solid waste," 

the requirement to perform a RCRA waste determination would be triggered, and 

the familiar test methods for waste determinations could be applied. 

Response: EPA thanks the commenter for their suggested clarifications on the applicability of

RCRA to CO2 streams being geologically sequestered. As noted elsewhere, EPA received many

comments regarding the applicability of the RCRA regulations and statute to CO2 streams that are

155
geologically sequestered under the final Class VI UIC well requirements. As a result, EPA has

decided to initiate a separate proposed rulemaking specifically to examine the issue of RCRA

applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190

Commenter Organization: Carbon Sequestration Council Comment ID: 24401

Other EPA Comment Codes and Descriptions: 1220 1.1.1.1 Terminology and definitions 

Comment: Rule Provision: 146.81(d) [Definition - Carbon dioxide stream] 

Proposed CCS Group Recommendations: Carbon dioxide stream means carbon dioxide, 

IN ANY PHYSICAL STATE OR FORM, AND ANY ASSOCIATED substances derived from the 

that has been captured from an emission source (e.g., a power plant), plus 

incidental associated substances derived from the source materials and the 

capture process, and any OR ITS PROCESSING, AND substances added to enable or 

improve the injection process. This subpart does not apply to any carbon dioxide 

stream that meets the definition of a hazardous waste under 40 CFR part 261. 

Basis for CCS Group Comments: Source of CO2 is not an issue in the context of 

defining the CO2 stream. The rule applies to the injection of CO2 and should not 

address the origins of the materials since that is beyond the scope of this 

regulation. Original text would have precluded injection of CO2 from some 

sources. 

Response: The final GS rule retains the definition of a CO2 stream as proposed. The GS regulation

applies to injection of CO2 for the purpose of GS, regardless of the source of the CO2. It is beyond

the scope of the GS rule and the UIC Program’s authority to require or set standards for upstream

generators of CO2 or purification facilities. For purposes of GS, the UIC program’s authority under

the SDWA is limited to ensuring that GS projects are sited, constructed, operated, and closed in a

manner that protects USDWs. 

Although the GS regulation does not apply to the source of CO2 streams, the GS rule, at

§146.82(a)(7)(iv), requires the owner or operator to submit data about the site, including an analysis

of the chemical and physical characteristics of the CO2 stream because the concentrations of minor

and trace elements in CO2 streams for GS projects are likely to vary by facility, coal composition,

plant operating conditions, and pollution removal technologies.

Commenter Name: Jeff W. Sheets Letter ID: 0192

Commenter Organization: ConocoPhillips Comment ID: 23899

Comment: RCRA- CO2 should only be considered to be RCRA hazardous if combined with a

RCRA 

156
listed hazardous stream. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: John R. Baza Letter ID: 0193

Commenter Organization: Utah Division of Oil, Gas, and Mining Comment ID: 23916

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: Waste Characterization 

Injected CO2 is not and should not be considered a hazardous waste or regulated 

under RCRA or CERCLA. It is assumed that RCRA or CERCLA wastes would be removed 

from the CO2 stream prior to injection. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: Paul Pike Letter ID: 0198

Commenter Organization: Ameren Corporation Comment ID: 23945

Comment: RCRA Issues 

Ameren is concerned that the CO2 stream being regulated under the Safe Drinking 

Water Act ("SDWA") may be wrongly classified under the Resource Conservation and 

Recovery Act ("RCRA"). It should be unnecessary to label CO2 a waste or a 

commodity for purposes of proposing and implementing UIC regulations for its 

injection and storage, because sites should be developed based on site-specific 

conditions. However, the preamble includes a discussion of whether injected CO2 

may be a hazardous waste, thus perhaps implying the assumption that CO2 is a 

157
solid waste to begin with. The preamble states: 

"Because the types of impurities and their concentrations in the CO2 

stream are likely to vary by facility, coal composition, plant operating 

conditions, and pollution removal technologies, EPA cannot make a 

categorical determination as to whether injected CO2 is hazardous under 

RCRA." 73 Fed. Reg. at 43503 

First, we do not believe that it is the within the jurisdiction of the SDWA to 

evaluate the nature of a material, or if a waste determine whether it is 

hazardous or not. Secondly if we assume, for purposes of argument, that CO2 is 

"discarded" and exhibits a hazardous waste characteristic when injected for 

long-term sequestration, there are compelling policy reasons to exclude such 

activities from RCRA regulation. Subjecting these injection operations to 

regulation under a Class I UIC hazardous waste injection permit could expose all 

other waste management units at the facility, including units that are in no way 

related to the injection operations, to all of RCRA’s Subtitle C corrective 

action program. This is because a Class I UIC hazardous waste injection permit 

is classified as a RCRA "permit by rule" under RCRA’s hazardous waste permit 

program. See 40 C.F.R. §§ 270.1(c)(1)(i) and 270.64. Facilities that have 

obtained a RCRA permit by rule for the operation of a Class I UIC hazardous 

waste injection well are potentially subject to the full scope of RCRA’s 

corrective action program for all solid waste management units located at the 

facility. See EPA RCRA/Superfund Hotline Monthly Summary, "Corrective Action 

for UIC Wells," 9502.1986(07) (April 1986). The specter of RCRA corrective 

action is a significant economic and practical obstacle for any facility 

considering whether to seek a permit for a new Class VI well, as facility-wide 

RCRA corrective action is an administratively complex and exceedingly expensive 

undertaking. 

The imposition of facility-wide RCRA corrective action is unwarranted because 

any well receiving a permit under the UIC Program for CO2 GS will be, by 

definition, protective of USDWs. EPA’s RCRA program has established a legally 

sound process, referred to as "contingent management," for the exclusion of 

materials from hazardous waste regulation when such materials are already 

subject to an alternate regulatory regime that ensures the wastes are managed in 

an environmentally protective manner. As discussed below, where the potential 

for mismanagement of a waste is already adequately addressed by another 

regulatory regime -- as would be the case with the injection of CO2 under the 

Class VI UIC program -- regulation of such materials under the RCRA’s hazardous 

waste program is duplicative and unwarranted. EPA has successfully employed the 

contingent management concept in various contexts where the Agency determined 

that other regulatory regimes adequately addressed any potential mismanagement 

scenarios related to certain materials; examples include regulation of used oil, 

mixed radioactive/hazardous waste, and military munitions. 

The D.C. Circuit has reviewed EPA's legal theory underlying the contingent 

management concept and found it to be a "permissible construction of the 

statute" -- namely, that the statutory definition of "hazardous waste" is 

predicated upon the risks posed by a solid waste when "improperly" managed; 

158
therefore, "where a waste might pose a hazard only under limited management 

scenarios, and other regulatory programs already address such scenarios, EPA is 

not required to classify a waste as hazardous waste subject to regulation under 

[RCRA] Subtitle C." Military Toxics Project v. EPA, 146 F.3d 948, 958 (D.C. Cir 

1998) (emphasis added).Even if such operations were deemed subject to RCRA 

regulation, including a RCRA permit by rule, EPA could -- and should -- 

establish a conditional exclusion from RCRA regulation for CO2 GS operations. 

Such an exclusion would be legally justified, consistent with the Agency's past 

promulgation of conditional exclusion rules, and would make sound policy sense 

by removing a potentially significant regulatory barrier to the commercial 

development of CO2 GS operations. 

Response: EPA agrees CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the

environmental media in which it is stored (e.g., soil or ground water). CERCLA exempts from

liability, under CERCLA section 107, 42 U.S.C. 9607, certain “federally permitted releases” (FPR)

as defined in CERCLA, 42 U.S.C. 9601(10). Class VI permits will need to be carefully structured to

ensure that they prevent potential releases from the well which are outside the scope of the Class VI

permit. 

Under the final GS rule, owners or operators will need to determine whether the CO2 stream is

hazardous under EPA’s RCRA regulations, and if so, any injection of the hazardous CO2 stream

may only occur in a Class I hazardous waste injection well under 40 CFR Part 146 Subpart G.

Conversely, Class VI wells cannot be used for the co-injection of RCRA hazardous wastes (i.e.,

hazardous wastes that are injected along with the CO2 stream).

With respect to RCRA, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: Craig R. Walters Letter ID: 0200

Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24634

Other EPA Comment Codes and Descriptions: 1220 1.1.1.1 Terminology and definitions 

Comment: Rule Provision: 146.81(d) [Definition - Carbon dioxide stream] 

Anadarko Petroleum Corporation (APC) Comments: Carbon dioxide stream means 

carbon dioxide, WHICH WILL BE INJECTED IN ANY PHYSICAL STATE OR DISSOLVED,

AND 

ANY ASSOCIATED substances derived from the that has been captured from an 

159
emission source (e.g., a power plant), plus incidental associated substances 

derived from the source materials and the capture process, and any, ITS 

PROCESSING, OR substances added to enable or improve the injection process. This 

subpart does not apply to any carbon dioxide stream that meets the definition of 

a hazardous waste under 40 CFR part 261. 

Rationale: Source of CO2 is not an issue in the context of defining the CO2 

stream. The rule applies to the injection of CO2 and should not address the 

origins of the materials since that is beyond the scope of this regulation. 

Original text would have precluded injection of CO2 from some sources. 

Response: The final GS rule retains the definition of a CO2 stream as proposed. The GS regulation

applies to injection of CO2 for the purpose of GS, regardless of the source of the CO2. It is beyond

the scope of the GS rule and the UIC Program’s authority to require or set standards for upstream

generators of CO2 or purification facilities. For purposes of GS, the UIC program’s authority under

the SDWA is limited to ensuring that GS projects are sited, constructed, operated, and closed in a

manner that protects USDWs. 

Although the GS regulation does not apply to the source of CO2 streams, the GS rule, at

§146.82(a)(7)(iv), requires the owner or operator to submit data about the site, including an analysis

of the chemical and physical characteristics of the CO2 stream because the concentrations of minor

and trace elements in CO2 streams for GS projects are likely to vary by facility, coal composition,

plant operating conditions, and pollution removal technologies.

With respect to RCRA, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: Chris M. Hobson Letter ID: 0201

Commenter Organization: Southern Company Comment ID: 22158

Comment: Potential interaction with RCRA - Southern Company commends EPA for avoiding 

characterization of the CO2 stream to be injected into Class VI wells. See id. 

at 43503. We, however, are concerned with the Preamble's vague reference to 

potential interaction with the Resource Conservation and Recovery Act ("RCRA"). 

Id. EPA should pursue all available regulatory and legislative avenues to 

preclude applicability of RCRA to Class VI well operations. For example, EPA 

could make use of the established "contingent management" concept, which allows 

for the exclusion of certain materials from RCRA hazardous waste regulation when 

those materials are' adequately regulated under another environmental regime. 

The contingent management approach would allow EPA to sidestep any chilling 

effect that potential RCRA liability would have on CO2 GS operations under the 

UIC Program without jeopardizing protection of USDWs. 

160
Response: EPA agrees that any requirements for the CO2 stream should be clearly identified. With

respect to providing clarity on RCRA, EPA has decided to initiate a separate proposed rulemaking

specifically to examine the issue of RCRA applicability 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 particular 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 commenters who wish to submit comments on the RCRA proposal will need to do

so during the comment period for that rule. Finally, EPA also notes that the final GS rule, which

adds new regulations for Class VI wells under the Safe Drinking Water Act (SDWA), is not making

any changes to the RCRA regulations.

EPA clarifies that the GS rule requires owner or operators of Class VI wells to characterize their

injection stream prior to injection, and throughout the operational life of the injection facility. Since

the GS rule, at §146.81(d), prohibits CO2 streams that meet the definition of a hazardous waste

under 40 CFR part 261, owners or operators will need to characterize their CO2 stream as part of

their permit application to determine if the injectate is a RCRA hazardous waste. If so, injection may

only occur in a Class I hazardous waste injection well. 

EPA adds that promoting the use of GS is outside the scope of the GS rule. Rather, the purpose of

the GS regulation is to ensure that, where deployed, GS is conducted in a manner that protects

USDWs from endangerment.

Commenter Name: Thomas Curtis Letter ID: 0204

Commenter Organization: American Water Works Association (AWWA) Comment ID: 22186

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: - Congress must address liability issues under CERCLA, RCRA and Natural Resource 

Damage Assessment before this technology is commercially deployable. 

Response: EPA agrees that overlapping regulatory schemes are undesirable. EPA clarifies that the

GS rule requires owner or operators of Class VI wells to characterize their injection stream prior to

injection, and throughout the operational life of the injection facility. 

With respect to RCRA, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Comments related to congressional action are outside the scope of this rulemaking.

Commenter Name: Michael Stroben Letter ID: 0209

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Commenter Organization: Duke Energy Comment ID: 22680

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: RCRA AND CERCLA APPLICABILITY 

To encourage adoption and use of the Class VI wells by the regulated community 

EPA must resolve policy and legal issues regarding the applicability of RCRA and 

CERCLA Regulation and liabilities to projects permitted and operated under the 

proposed rule. Subjecting any CO2 GS project to RCRA controls, and failure to 

adequately mitigate the potential for unlimited CERCLA liability will pose a 

serious obstacle to the commercial deployment of GS technology. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: Michael Stroben Letter ID: 0209

Commenter Organization: Duke Energy Comment ID: 22681

Comment: Injection of CO2 into a Cass VI well should not be viewed as disposal of a waste 

subject to RCRA regulation. Alternative scenarios may involve temporary storage 

of a commodity, or containment of a material in an industrial process. If CO2 is 

deemed a waste under the rule, the current RCRA regulations and testing 

guidelines will need to be revised to address characterization of supercritical 

fluids. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: Richard Guinn Letter ID: 0210

Commenter Organization: Eastman Chemical Company Comment ID: 22692

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Comment: 1. EPA needs to categorically exclude CO2 specifically intended for geologic 

storage from the definition of RCRA hazardous waste. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

EPA clarifies that the GS rule requires owner or operators of Class VI wells to characterize their

injection stream prior to injection, and throughout the operational life of the injection facility. Since

the GS rule, at §146.81(d), prohibits CO2 streams that meet the definition of a hazardous waste

under 40 CFR part 261, owners or operators will need to characterize their CO2 stream as part of

their permit application to determine if the injectate is a RCRA hazardous waste. If so, injection may

only occur in a Class I hazardous waste injection well.

Commenter Name: Richard Guinn Letter ID: 0210

Commenter Organization: Eastman Chemical Company Comment ID: 22704

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: #1: Potential Applicability of CFR 40 Part 261 (RCRA). (Ref: page 43503, Section 

I) In the preamble to the ANPR, EPA poses the question of whether injected CO2 

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 CO2 sequestration projects. 

EPA 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 CO2 as a result of the carbon capture 

process should not limit the storage of the CO2 using Class VI wells, especially 

taking into account the diminimus risk of exposure associated with the 

disposition of CO2 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. 

163
Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit.

Commenter Name: Richard Guinn Letter ID: 0210

Commenter Organization: Eastman Chemical Company Comment ID: 22705

Comment: In terms of its approach, we recommend that EPA consider captured CO2 -- 

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 CO2 that 

may be 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 used to 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 when measured 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 sufficient 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 (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 II 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 

164
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 CO2 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 CO2 in a supercritical state is approximately 

2,500 feet. This, in conjunction with the controls and safeguards required by 

this rule throughout the injection and post-injection period, will ensure that 

CO2 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 H2S 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 (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 H2S and CO2 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 operations [4]. 

Accordingly, EPA has sufficient information 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 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. 

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. Semchuck (1996); Underground disposal of acid 

gas in Alberta, Canada: Regulatory concerns and case histories. SPE 35584. pg 

165
181-192. 

3 Bachu, S., K. Haug (2005) In situ characteristics of acid-gas injection 

operations in the Alberta Basin, Western Canada: Demonstration of CO2 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. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

EPA supports the use of CO2 capture technologies that minimize impurities in the CO2 stream.

However, the GS rule does not apply to CO2 sources.

Commenter Name: John King Letter ID: 0211

Commenter Organization: Shell Exploration and Production Company

(SEPCo)

Comment ID:

22754

Comment: - Relationships with other Environmental Laws: 

- EPA should clarify that gas-phase CO2 is not solid or hazardous waste for RCRA 

purposes and is not subject to any RCRA waste determination requirements. 

- EPA should clarify that supercritical CO2 is not solid or hazardous waste for 

RCRA purposes and is not subject to any RCRA waste determination requirements. 

Response: EPA agrees that any requirements for the CO2 stream should be clearly identified. With

respect to RCRA, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

166
wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: John King Letter ID: 0211

Commenter Organization: Shell Exploration and Production Company

(SEPCo)

Comment ID:

22763

Comment: G. RCRA 

SEPCO agrees with the concept that Class VI wells should not be injecting 

hazardous wastes but is proposing some modifications to EPA’s definition of CO2 

stream in the rule. The modifications reflect the fact that the source of CO2 

should not be a factor in the context of defining the CO2 stream. The rule 

applies to the injection of CO2 and should not address the origins of the 

materials since that is beyond the scope of this regulation. The original text 

would have precluded injection of CO2 from some sources. SEPCo contends that the 

question of how CO2 should be accounted for in a GHG management and accounting 

system is beyond the scope of this regulation. More to the issue of 

"impurities", SEPCO objects to any mandated purity standards for CO2. The 

inclusion of impurities in stored CO2 should not be arbitrarily prohibited; 

however, it is recognized that the presence of those impurities at sufficient 

concentrations may trigger the applicability of other statutory limits or 

requirements. Determining the type and levels of impurities in the CO2 stream is 

- absent a compelling public or environmental health risk - best left to 

contractual negotiations between partners in a CCS value chain as opposed to an 

arbitrary regulatory determination. The contracting parties are best able to 

evaluate the types of impurities, their compatibility with the reservoir and 

equipment, and determine the acceptable levels of those impurities in the stored 

CO2. To the extent that there is an overriding public interest in limiting the 

type or level of contaminants, principles of cost-effectiveness and riskmanagement should guide the decision making process. 

With specific respect to RCRA, SEPCo is concerned that EPA’s brief discussion of 

a supposed potential for injected CO2 streams to be characterized as hazardous 

waste (or some type of hazardous release) could have a significant chilling 

effect on the deployment of CO2 capture and sequestration technologies. Based on 

the work of our engineers and scientists with capture technologies and their 

extensive experience with the types of power plant flue gas likely to be sources 

of CO2 for sequestration, we do not believe that captured CO2 streams should 

trigger the application of RCRA. In addition, EPA’s Proposal suggests that 

injected CO2 may be considered hazardous waste for RCRA purposes, and defines 

"carbon dioxide stream" to exclude hazardous waste. 73 Fed. Reg. at 43503. The 

premise appears to be that CO2 is solid waste, and that a waste determination 

for such solid waste would turn on the specific composition of the CO2 in 

question. Id. Based on this premise, the preamble suggests, "EPA cannot make a 

categorical determination as to whether injected CO2 is hazardous waste under 

RCRA." Id. 

Rationale: 

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The RCRA definition of "solid waste" does not include gaseous material unless it 

is "contained." RCRA 1004(27), 42 U.S.C. 6903(27). EPA has long taken the 

position that gasses do not qualify as "solid waste" under this definition 

unless they are "contained" in a cylinder or similar container. 54 Fed. Reg. 

50968 at 50970, 50973 (December 11, 1989). It follows that gas-phase CO2 streams 

are not solid waste, are not subject to the waste determination requirements of 

40 C.F.R. 262.11, and cannot be considered hazardous waste for RCRA purposes. 

The RCRA definition of solid waste is limited to "solid, liquid, semi-solid, or 

contained gaseous material." RCRA 1004(27). Because supercritical CO2 is none of 

these things; a plain reading of the statutory text suggests that supercritical 

CO2 should not be considered "solid waste." This reading of the statute makes 

sense, because RCRA is plainly aimed at the kind of material that could end up 

being dumped into a landfill. Uncontained supercritical CO2 is not such a 

material. Instead, the physical properties of supercritical CO2 are such that it 

would immediately vaporize -- becoming an uncontained gas -- before it could 

contribute to the contents of a landfill. A related practical consideration is 

the fact that the hazardous characteristics -- the broad waste determination 

criteria that provide a primary means for determining when solid waste is 

hazardous waste -- are based largely on test methods that are inapplicable to 

materials such as supercritical CO2. In particular, the toxicity characteristic 

depends on test methods that can only be applied to materials that are solids or 

liquids at standard temperatures and pressures. This is unsurprising, because 

the toxicity characteristic was designed to assess the threat waste would have 

in a municipal landfill disposal scenario, a scenario that -- as already 

discussed -- is inherently inapplicable to supercritical CO2. Accordingly, it 

makes no legal, policy, or practical sense to treat uncontained supercritical 

CO2 as "solid waste" for RCRA purposes. EPA should therefore confirm that 

uncontained supercritical CO2 is not "solid waste" and is not subject to RCRA 

waste determination requirements. 

It follows that a CO2 stream would only qualify as "solid waste" if it is 

actually in the form of a liquid (i.e., a liquid containing dissolved CO2). In 

such a case, the liquid would meet the statutory definition of "solid waste," 

the requirement to perform a RCRA waste determination would be triggered, and 

the familiar test methods for waste determinations could be applied. 

Recommendations: 

There are important categorical determinations that EPA can and should make with 

respect to the RCRA status of CO2. SEPCo recommends the following: 

1. EPA should clarify that gas-phase CO2 is not solid or hazardous waste for 

RCRA purposes and is not subject to any RCRA waste determination requirements. 

2. EPA should clarify that supercritical CO2 is not solid or hazardous waste for 

RCRA purposes and is not subject to any RCRA waste determination requirements. 

3. In order to more clearly illustrate the actual risks of CO2 transport and 

storage, EPA should work to dispel concerns that geologic sequestration could be 

168
encumbered with those requirements except possibly through the commingling of a 

captured CO2 stream with an actual waste stream. 

Response: With respect to RCRA, EPA has decided to initiate a separate proposed rulemaking

specifically to examine the issue of RCRA applicability 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 particular 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 commenters who wish to submit comments on the RCRA proposal will need to do

so during the comment period for that rule. Finally, EPA also notes that the final GS rule, which

adds new regulations for Class VI wells under the Safe Drinking Water Act (SDWA), is not making

any changes to the RCRA regulations.

EPA adds that promoting the use of GS is outside the scope of the GS rule. Rather, the purpose of

the GS regulation is to ensure that, where deployed, GS is conducted in a manner that protects

USDWs from endangerment.

Commenter Name: Paul L. Carpinone Letter ID: 0212

Commenter Organization: Tampa Electric Company Comment ID: 22897

Other EPA Comment Codes and Descriptions: 1200 1.1 General comments about the rulemaking;

1640 1.3.4 CERCLA issues (seeking comment) 

Comment: This rulemaking can resolve some important policy and legal issues and, in doing 

so, help foster the development of a practical, commercially deployable CCS 

regulatory program. For example, the Final Rule can provide much needed clarity 

regarding (1) the potential for liability under the Resource Conservation and 

Recovery Act ("RCRA") and the Comprehensive Environmental Response, 

Compensation, and Liability Act ("CERCLA") resulting from CO2 injection and GS 

activities, and (2) the options for addressing long-term post-injection 

liability for Class VI wells. As discussed below, there are practical regulatory 

and legislative options available to resolve these uncertainties that will help 

assure the public and the regulated community that CO2 UIC activities can be 

conducted in a manner that is both safe and effective. 

Response: EPA agrees that regulatory clarity is important. With respect to RCRA and need for

regulatory clarity, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: Paul L. Carpinone Letter ID: 0212

Commenter Organization: Tampa Electric Company Comment ID: 22903

169
Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: Issues that must be addressed include the interaction of RCRA and CERCLA with 

Class VI injection activities as well as long-term post-injection liability. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Additionally, while CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain "federally permitted releases" (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit. 

The UIC program Director has authority under SDWA §1423 to address potential compliance issues

(e.g., potential releases that may endanger USDWs) resulting from injection violations in the unlikely

event that a remedial response is necessary. Although EPA anticipates that the need for emergency

or remedial actions at GS sites will be rare, the GS rule requires, at §146.94, that emergency and

remedial response plans be developed and updated to address such events and that owners or

operators demonstrate that financial resources are set aside to implement the plans if necessary, per

§146.85.

Regarding long term liability, once an owner 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. Furthermore, 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 certain

circumstances. For example, an owner or operator may be held liable for regulatory noncompliance

even after site closure was approved if the Director relied on erroneous information (e.g., erroneous

modeling data) provided by the owner or operator when approving site closure. 

Separate from EPA's authority to enforce regulatory compliance, an owner or operator may be

subject to a §1431 response order even after proper site closure 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 present an imminent and substantial endangerment to the health of

170
persons, and the appropriate State and local authorities have not acted to protect the health of such

persons. The action may include issuing administrative 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 operator may remain liable under tort and other remedies,

or under other federal statutes including, 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.

Commenter Name: Paul L. Carpinone Letter ID: 0212

Commenter Organization: Tampa Electric Company Comment ID: 22907

Comment: - In discussing the potential applicability of RCRA's hazardous waste rules to 

Class VI CO2 injection activities, EPA prematurely assumes that the CO2 is being 

"discarded" and is a solid waste under RCRA. To the extent there is any 

possibility that CO2 injection operations could be subject to RCRA controls, EPA 

should exempt such activities from RCRA regulation under the well-established 

"contingent management" concept, particularly given that the UIC permit will 

ensure that the injected material is not mismanaged. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: Dennis R. James Letter ID: 0214

Commenter Organization: North American Coal Corporation (NAC) Comment ID: 22961

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: I. Is Injected CO2 Considered a Hazardous Waste Under RCRA? 

J. Is Injected CO2 Considered a Hazardous Substance Under CERCLA? 

Both RCRA and CERCLA are written to deal with hazardous wastes and pollutants at 

or near the surface where they can interact with our biosphere. Geologic 

sequestration of CO2 is, by definition, not impacting the biosphere. Therefore, 

these rules should not apply to the injection of CO2 and associated compounds. 

The chemical environment of deep saline aquifers or deleted oil and gas 

171
reservoirs will be very different from that at the surface. For example, 

hydrogen sulfide (H2S) is a very toxic and hazardous substance in the biosphere. 

However, it commonly occurs in formations at depth as a normal, naturally 

occurring constituent that causes no harm. Thus, the presence of H2S in a CO2 

stream may not only be non-hazardous upon injection but beneficial; it could 

make the injected gas chemically more compatible with the target formation’s 

natural environment. It is more important to consider the impacts of injected 

CO2 and associated substances on the target formation’s environment. Therefore, 

injected CO2 should not be considered a hazardous waste under RCRA or a 

hazardous substance under CERCLA. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

EPA clarifies that CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit.

Commenter Name: Ronald Evans Letter ID: 0215

Commenter Organization: Denbury Resources, Inc. (DRI) Comment ID: 24285

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: III. ANY FINAL RULE MUST CLEARLY ADDRESS POTENTIAL EXPOSURE

UNDER RCRA AND 

CERCLA 

EPA can and should simultaneously protect underground sources of drinking water 

and promote the capture of carbon dioxide. Its strategy in both areas should be 

crafted to avoid unintended consequences. EPA’s goal in this rulemaking should 

be to fulfill its obligations to protect the nation’s USDWs from both naturallyoccurring and man-made contaminants, while at the same time promoting progress 

towards successful commercial-scale carbon capture and storage in order to 

address broader environmental protection concerns. 

172
If EPA is going to address these broader concerns by establishing a framework 

for the injection and sequestration of CO2 in addition to the incidental storage 

that occurs in EOR activities, it must address potentially limitless liability 

under other statutes that EPA administers, including CERCLA [FN40] and RCRA 

[FN41]. Liability under these statutes would act as a strong deterrent to the 

development of CCS. 

Regulated industry has learned a great deal in the last 30 years regarding 

environmental liability. When Congress passed CERCLA, it imposed joint and 

several liability on landowners, transporters, and generators of hazardous 

substances and it made that liability retroactive. Most recently, the Supreme 

Court, in Massachusetts v. EPA, 549 U.S. 497 (2007), recognized that the Clean 

Air Act ("CAA"), with its "capacious" definition of air pollutant, could be used 

to regulate substances (in this case, CO2) which Congress appeared to not intend 

to regulate and whose regulation under many provisions of the CAA (i.e., the 

NAAQS) is awkward at best. One lesson from these statutes and the Courts’ 

interpretation is that regulated industry cannot underestimate its potential 

liability for pollution, irrespective of its compliance with current regulations 

and irrespective of the magnitude of its role in the waste disposal process. 

Accordingly, as EPA attempts to promote efforts to reduce anthropogenic CO2 

emissions, it faces an ever more cautious regulated community. We urge EPA to 

take determined steps to provide regulatory clarity as to compliance obligations 

and potential for liability. 

[40] Comprehensive Environmental Response, Compensation, and Liability Act 

("CERCLA"), 42 U.S.C. §§ 9601-9675. 

[41] Resource Conservation and Recovery Act ("RCRA"), 42 U.S.C. § 6901-6992k. 

Response: EPA agrees that overlapping regulatory schemes are undesirable. EPA received many

comments regarding the applicability of the RCRA regulations and statute to CO2 streams that are

geologically sequestered under the final Class VI UIC well requirements. As a result, EPA has

decided to initiate a separate proposed rulemaking specifically to examine the issue of RCRA

applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

EPA clarifies that CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

173
section 107, 42 U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit.

Commenter Name: Ronald Evans Letter ID: 0215

Commenter Organization: Denbury Resources, Inc. (DRI) Comment ID: 24286

Comment: A. EPA Should Ensure Clarity Regarding the Possible Coverage of CCS under RCRA 

Regarding RCRA, in Section 2.I of the proposal, EPA considers whether the CO2 

stream is a hazardous waste. It notes that the composition of a particular CO2 

stream will depend on the source of CO2, the flue gas scrubbing technology, 

additives, and the CO2 capture technology. EPA concludes that it cannot make a 

"categorical determination" as to whether injected CO2 is hazardous under RCRA. 

Such a determination must be made by owners and operators, however, and a 

positive finding would mean that the well would be subject to UIC Class I 

requirements. Thus, EPA’s failure to resolve this issue could inhibit permitting 

of wells under the proposed new Class VI regime. 

The Proposed Rule asserts that its design changes are meant to address the 

mobility and corrosivity caused by long term geologic sequestration of CO2, and 

not the long term storage of hazardous wastes. EPA seeks comment on its 

definition of "carbon dioxide stream" to exclude hazardous wastes: 

"Carbon dioxide stream means carbon dioxide that has been captured from 

an emission source (e.g., a power plant), plus incidental associated 

substances derived from the source materials and the capture process, 

and any substances added to the stream to enable or improve the 

injection process. This subpart does not apply to any carbon dioxide 

stream that meets the definition of a hazardous waste under 40 CFR part 

261." 

Using its authority under RCRA, EPA has previously excluded certain substances 

from coverage under 40 C.F.R. § 261.2. CO2 is not excluded under this section, 

but it is also not specifically included as a hazardous substance under 40 

C.F.R. § 261.3. Thus, the status of CO2 under RCRA remains a concern. 

A determination that CCS activities are subject to RCRA would subject those 

activities to stringent handling, storage, and disposal procedures above what 

would be required by the Proposed Rule (except with regard to the post-closure 

period for financial responsibility, which, at 30 years, would be less demanding 

than the proposed 50 year term for a Class VI well). Such a finding would serve 

to inhibit the development and adoption of CCS, to the frustration of EPA’s 

larger efforts to reduce CO2 emissions. 

Denbury sets out this basic information only to introduce its specific responses 

to EPA’s statements and request for comment in the proposed rule. RCRA defines 

solid waste to include "discarded material, including solid, liquid, semi-solid, 

or contained gaseous material resulting from industrial . . . operations." 42 

U.S.C. § 6903(27). EPA should clarify that injected CO2 in the form of a 

174
supercritical fluid does not fall within the definition of a solid waste because 

it is neither a liquid nor a contained gaseous material. Moreover, any CO2 

supply that is acquired for value for use in EOR or EGR activities should be 

explicitly excluded as it would not be "discarded" at all, but sold for valuable 

consideration. Were CO2 to not be a solid waste, it would not be subject to 

RCRA’s waste determination provisions. Only in those cases where the CO2 stream 

is in the form of a liquid (which it would not be, at pipeline or reservoir 

conditions) would it be subject to these provisions. 

Using authority granted by RCRA § 3001, EPA has exempted from RCRA’s definition 

of solid waste certain low-toxicity wastes that exist in high-volumes, including 

domestic sewage, mining wastes, and certain nuclear materials, when those 

materials are covered by other laws. Similarly, EPA should consider its 

comprehensive regulation of CCS under the UIC permitting provisions to be a 

sufficient reason to exempt injected supercritical CO2 from RCRA’s coverage as a 

solid waste even where it cannot be sold and used for EOR operations. 

Even if EPA decides not to exclude or exempt injected supercritical CO2 from the 

definition of solid waste, EPA could and should exempt injected CO2 from the 

definition of hazardous waste. A hazardous waste under RCRA is a solid waste 

that, because of its "quantity, concentration, or physical, chemical, or 

infectious characteristics" may pose a substantial present or potential hazard 

to human health or the environment. 42 U.S.C. § 6903(5). Hazardous wastes can be 

specifically listed by EPA, have hazardous characteristics (such as corrosivity, 

reactivity, etc), be mixed with a listed waste, or be derived from a listed 

waste. In the proposed rule, EPA raises the spectre that the injection of CO2 in 

conjunction with hazardous components could cause it to be considered a 

hazardous waste. Because CO2 storage will be closely regulated under the 

proposed rule, EPA should exempt stored CO2 from the definition of hazardous 

waste, as it has done for wastes associated with the exploration, development, 

and production of crude oil, natural gas, and geothermal energy. See Regulatory 

Determination for Oil and Gas and Geothermal Exploration, Development, and 

Production Wastes, 53 Fed. Reg. 25,446 (July 6, 1988). 

Even if at present EPA does not foresee bringing an enforcement action for CCS 

activities, it is important for EPA to exempt CCS activities from RCRA’s 

definition of solid and hazardous waste to foreclose the availability of a 

citizen suit under section 7002, brought, perhaps by anti-CCS activists, and the 

maintenance of which would irreversibly chill CCS projects. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

175
wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

The final GS rule retains the definition of a CO2 stream as proposed. The GS regulation applies to

injection of CO2 for the purpose of GS, regardless of the source of the CO2. It is beyond the scope

of the GS rule and the UIC Program’s authority to require or set standards for upstream generators of

CO2 or purification facilities. For purposes of GS, the UIC program’s authority under the SDWA is

limited to ensuring that GS projects are sited, constructed, operated, and closed in a manner that

protects USDWs. EPA adds that promoting the use of GS is outside the scope of the GS rule.

Commenter Name: Barbara Walz Letter ID: 0216

Commenter Organization: Tri-State Generation and Transmission Association,

Inc.

Comment ID:

22974

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: As the GAO report cautions, EPA must resolve key policy and legal uncertainties 

including the interaction of the Resource Conservation and Recovery Act (RCRA) 

and the Comprehensive Environmental Response, Compensation, and Liability Act 

(CERCLA) with Class VI injection activities and the specter of long-term postinjection liability -to alleviate financial concerns of potential Class VI well 

owners or operators, and to encourage investment in the development and 

operation of Class VI CO2 injection wells. Tri-State recognizes that 

Congressional action may be needed to clear these hurdles standing in the way of 

commercial deployment of full-scale geologic sequestration projects. 

Response: EPA agrees that overlapping regulatory schemes are undesirable. EPA received many

comments regarding the applicability of the RCRA regulations and statute to CO2 streams that are

geologically sequestered under the final Class VI UIC well requirements. As a result, EPA has

decided to initiate a separate proposed rulemaking specifically to examine the issue of RCRA

applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

EPA clarifies that CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit.

176
Commenter Name: Barbara Walz Letter ID: 0216

Commenter Organization: Tri-State Generation and Transmission Association,

Inc.

Comment ID:

22975

Comment: In discussing the potential applicability of RCRA's hazardous waste rules to 

Class VI CO2 injection activities, EPA prematurely assumes that the CO2 is being 

"discarded" and thus is a solid waste under RCRA. Currently, CO2 is a valuable 

commodity that is used in a variety of manufacturing processes and it is too 

early for EPA to summarily conclude -especially given technological advancements 

that will likely be made in the coming years -that CO2 materials managed in Class 

VI wells will be permanently discarded. Tri-State believes that EPA should 

specifically exempt CO2 gas streams from coverage by RCRA, and develop 

requirements specifically tailored to this material if necessary to assure 

further environmental protection beyond that already provided by the UIC 

permitting process. To the extent there is any possibility that CO2 injection 

operations could be subject to RCRA controls, EPA should exempt such activities 

from RCRA's corrective action program under the well-established "contingent 

management" concept, particularly given that the UIC permit will ensure that the 

injected material is not mismanaged. EPA should take steps in the final rule to 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: Olon Plunk Letter ID: 0217

Commenter Organization: Xcel Energy, Inc. Comment ID: 21552

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: In their comments regarding the proposed rule, both the Edison Electric 

Institute (EEI) and the Utility Solid Waste Activity Group (USWAG) present well 

articulated concerns regarding the legal and regulatory issues that could arise 

from the inappropriate treatment of captured CO2 within the context of the 

Resource Conservation and Recovery Act, and the Comprehensive Environmental 

Response, Compensation and Liability Act. Both groups describe potential 

solutions to this issue; Xcel Energy endorses these comments and suggested 

solutions. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability to CO2 streams being geologically sequestered, including

the possible option of a conditional exemption from the RCRA requirements for CO2 GS in Class VI

177
wells. EPA will consider these comments as part of its development of that proposal. The Agency

will consider issues particular to RCRA in the context of that separate rulemaking, and recommends

that the commenter read that proposed rule when it is published. The Agency notes that commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

EPA clarifies that CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit. 

For additional information, please see EPA's responses to specific comments by Edison Electric

Institute and the Utility Solid Waste Activity Group.

Commenter Name: Edward Steadman Letter ID: 0220

Commenter Organization: The Energy and Environmental Research Center at the

University of North Dakota

Comment ID:

21608

Comment: Page 43503. H. Is Injected CO2 Considered a Hazardous Waste under RCRA? 

No. CO2 should not be considered a hazardous waste under RCRA. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: Darrick Eugene Letter ID: 0223

Commenter Organization: Texas Carbon Capture and Storage Association Comment ID: 23956

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: Point #1: The lack of clarification of the CO2 injectate stream which could leadto 

the stream being considered a waste. We recognize and salute EPA's attempt to 

avoid labeling CO2 injection as waste injection. Nevertheless, by tracking 

closely the Class I rules for the injection of hazardous waste (see Attachment 

178
A), the Proposed Rule appears to treat CO2 as a waste. It will be difficult for 

geologic storage to move forward on this basis. 

Also, in choosing not to state a composition specification minimum for CO2, the 

EPA opens the door to having the CO2 injectate stream declared a waste. We feel 

that is a serious weakness, compelling a regulatory approach for a worst-case 

injectate composition stream, and providing a basis for additional regulation 

under the Resources Conservation and Recovery Act (RCRA) or the Comprehensive 

Environmental Response, Compensation, and Liability Act (CERCLA). The failure to 

define the composition specification minimum for CO2 contributes to the 

overly protective approach of the EPA to the geologic storage of CO2. The EPA 

should address this concern by specifically excluding injected supercritical CO2 

for geologic storage from regulation under both RCRA and CERCLA similar to what 

has been done for wastes associated with the exploration, development and 

production of crude oil, natural gas and geothermal energy under RCRA [FN2] 

2 See Regulatory Determination for Oil and Gas and Geothermal Exploration, 

Development, and Production Wastes; Regulatory Determination, 53 Fed. Reg. 25445 

(July 6, 1988) 

Response: The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a

percent CO2). The GS rule, however, addresses the quality and quantity of impurities by requiring

owners or operators to submit information on the source of the CO2 and its physical and chemical

properties. Specifically, the GS rule requires the owner or operator to submit data about the site,

including an analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the 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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals. 

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 low. However, these estimates are

based on limited information, and uncertainties remain about the expected concentrations of

impurities from the various types of CO2 streams. The concentrations of minor and trace elements in

CO2 streams for GS projects are likely to vary by facility, coal composition, plant operating

conditions, and pollution removal technologies. 

With respect to RCRA, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

179
Commenter Name: Andrew Duguid Letter ID: 0226

Commenter Organization: Schlumberger Carbon Services Comment ID: 24001

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: 2. Now that the EPA has introduced the topics of the Comprehensive 

Environmental Response, Compensation, and Liability Act (CERCLA) and the 

Resource Conservation and Recovery Act (RCRA) we urge the EPA to clarify 

the roles of both with respect to CO2 injection under the UIC program. 

Response: EPA received many comments regarding the need for clarity with respect to RCRA

regulations and statute to CO2 streams that are geologically sequestered under the final Class VI

UIC well requirements. As a result, EPA has decided to initiate a separate proposed rulemaking

specifically to examine the issue of RCRA applicability 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 particular 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 commenters who wish to submit comments on the RCRA proposal will need to do

so during the comment period for that rule. Finally, EPA also notes that the final GS rule, which

adds new regulations for Class VI wells under the Safe Drinking Water Act (SDWA), is not making

any changes to the RCRA regulations.

EPA clarifies that CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit.

Commenter Name: Andrew Duguid Letter ID: 0226

Commenter Organization: Schlumberger Carbon Services Comment ID: 24002

Comment: Schlumberger supports the EPA in defining the injected CO2 stream to 

exclude hazardous wastes. We feel that this definition implies that CO2 

itself is not a hazardous waste under RCRA and that the injected CO2 

stream can only be considered a hazardous waste if it is mixed with 

another hazardous waste. 

Schlumberger feels that supercritical and gaseous CO2 do not fit the 

definition of solid waste under RCRA which is limited to "solid, liquid, 

semisolid, and contained gaseous materials" and are therefore not 

regulated under RCRA. We encourage the EPA to explore this possibility 

and if in agreement, to adopt and espouse this position in the preamble 

for the final rule. We further feel that EPA should specify that 

uncontainerized supercritical CO2, like that at injected for CCS, is not 

solid waste and therefore not subject to RCRA waste determination 

requirements. 

180
Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: Neeraj Gupta Letter ID: 0229

Commenter Organization: Battelle Energy Technology (BET) Comment ID: 21827

Other EPA Comment Codes and Descriptions: 1614 1.3.1.2 Impurities in captured CO2; purity

standards for CO2 

Comment: Page 54 CO2 Composition Requirements and Hazardous Waste under RCRA- While we 

agree some chemical impurities may cause CO2 to be designated hazardous waste, 

there must be more clear guidance on this issue. In the MRCSP tests, each 

regulatory agency had different requirements on this issue injectate composition 

and analysis, even for commercial CO2. One agency required injection to cease if 

the injectate was above any maximum contaminant level (MCL) for groundwater, 

which is a large list of chemicals. Another state agency asked for some 

technically infeasible analyses on the CO2 stream (pH, Fluouride, Mercury). 

Some impurities like H2S and hydrocarbons are naturally occurring in most deep 

saline formations anyway, so we would discourage setting limits on these items. 

Another significant aspect is the composition of CO2 derived from various 

industrial, power generation, and capture processes. All of these are likely to 

result in minor differences in chemical compositions. In most cases the 

concentration of hazardous impurities is likely to be very low. The incremental 

environmental impact of these minor or trace impurities in deep formations that 

already have brine and will have CO2 must be demonstrated before these are 

excluded from the Class VI injection wells. EPA is encouraged to evaluate the 

range of potential impurities from various streams, their environmental impact 

if any, and provide more specific guidance on this topic. The evaluation should 

also assess how many of the GS projects could become infeasible due to this 

requirement. Finally, EPA should clarify whether CO2 streams with RCRA level of 

impurities can be injected under Class I permits. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

181
for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations 

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 low. However, these estimates are

based on limited information, and uncertainties remain about the expected concentrations of

impurities from the various types of CO2 streams. The concentrations of minor and trace elements in

CO2 streams for GS projects are likely to vary by facility, coal composition, plant operating

conditions, and pollution removal technologies. 

The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a percent CO2).

Instead, the GS rule addresses the quality and quantity of impurities by requiring owners or operators

to submit information on the source of the CO2 and its physical and chemical properties.

Specifically, the GS rule requires the owner or operator to submit data about the site, including an

analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the 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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals. 

Since the GS rule, at §146.81(d), prohibits the injection of CO2 streams that meet the definition of a

hazardous waste under 40 CFR part 261, injection of a CO2 stream that is determined to be a

hazardous waste may only occur in a Class I hazardous waste injection well.

Commenter Name: Michael E. Moore Letter ID: 0232

Commenter Organization: Blue Source Comment ID: 21896

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment);

2046 1.5.2.3 Continuing to classify CO2 injection for EOR/EGR as Class II/ dividing line between

Class II and Class VI (seeking comment) 

Comment: II. Specific Comments on the Proposed Regulations 

a. Background 

Blue Source’s comments here are focused on a narrow, but critical, aspect of 

EPA’s proposal - namely, whether CO2-EOR operators should have the option of 

participating in EPA’s forthcoming CCS regulatory scheme. [FN1] 

[FN1: We believe that adoption of our comments is a necessary component of ensuring 

that CO2-EOR flourishes as CCS, but other steps need to be taken, too. For 

example, we also believe that EPA needs to ensure that carbon dioxide is not 

regulated as a hazardous waste or substance under statutes such as RCRA and 

CERCLA during storage operations; in a future rulemaking EPA perhaps could do so 

by expanding current exemptions which apply to oil & gas operations to include 

"storage" operations.] 

Response: EPA clarifies that the Class VI GS rule is designed to ensure the protection of USDWs

from endangerment, and does not aim to promote GS deployment. 

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EPA notes that the GS rule is not promulgated under the RCRA or CERCLA statutes, and further,

the applicability of those statutes will not be determined under the SDWA or the terms of the GS

rule, but rather according to those statutes themselves and any implementing regulations that may

apply. EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. 

EPA clarifies that CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit. 

The Agency acknowledges the commenter's concerns regarding the scope and possible impacts of

CERCLA liability on CCS activities, however EPA notes that the GS rule is not promulgated under

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. 

EPA adds that, if it develops regulations in the future, stakeholders will be provided opportunity for

public comment.

Commenter Name: M. Granger Morgan Letter ID: 0233

Commenter Organization: Carnegie Mellon University on behalf of the CCS

Reg Project

Comment ID:

21917

Other EPA Comment Codes and Descriptions: 1210 1.1.1 Comments about the proposed rule 

Comment: 25. Perverse incentives: The stringency of the Class VI rules (relative to the 

other UIC well classes) may create perverse incentives. For example, an operator 

could add hydrogen sulfide to the carbon dioxide stream and then seek a Class I 

permit with less stringent area of review, monitoring, post-injection and 

closure requirements than a Class VI permit. Thus, EPA should review the 

requirements and applicability of Class I wells in conjunction with the proposed 

rulemaking for Class VI wells. 

Response: EPA disagrees with this comment and does not anticipate this type of scenario will take

place because under the final GS rule, owners or operators must determine whether the CO2 stream

is hazardous under EPA’s RCRA regulations; If so, any injection of the hazardous CO2 stream may

183
only occur in a Class I hazardous waste injection well under 40 CFR Part 146 Subpart G. For Class I

hazardous wells, owners or operators are required under 40 CFR 286.6 to demonstrate, to a

reasonable degree of certainty, that there will be no migration of hazardous constituents from the

disposal unit or injection zone for as long as the wastes remain hazardous or for 10,000 years via a

fluid flow no migration petition. EPA anticipates that this may be very difficult to demonstrate for

long-term storage of CO2 at anticipated volumes. Conversely, Class VI wells cannot be used for the

co-injection of RCRA hazardous wastes (i.e., hazardous wastes that are injected along with the CO2

stream).

EPA received many comments related to RCRA applicability to GS sites and has decided to initiate

a separate proposed rulemaking specifically to examine the issue of RCRA applicability 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 particular 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 commenters who wish to submit comments on the

RCRA proposal will need to do so during the comment period for that rule. 

EPA adds that revising the requirements for other classes of wells is outside the scope of the GS

rulemaking.

Commenter Name: Steven B. Corneli Letter ID: 0234

Commenter Organization: NRG Energy, Inc. Comment ID: 23173

Comment: RCRA Applicability 

The preamble of the proposed rule suggests that CO2 injected for GS projects may 

be considered hazardous waste for RCRA purposes. 73 Fed. Reg. at 43503. EPA’s 

brief discussion of the potential for injected CO2 streams to be characterized 

as hazardous waste are causing concern among the electric power industry and 

could have an effect on the future development of carbon capture and 

sequestration projects. The premise that CO2 could be characterized as a 

hazardous waste would likely prove detrimental to project development. The RCRA 

definition of "solid waste" is limited to "solid, liquid, semi-solid, or 

contained gaseous material." RCRA 1004(27). Because the gas and liquid 

(supercritical) phases involved in GS do not meet this definition, reading of 

federal law would suggests that the CO2 stream for GS should not be considered 

a "solid waste". EPA should clarify that the gas and liquid phases of the CO2 

stream is not a solid or hazardous waste for RCRA purposes and therefore not 

subject to RCRA waste determination requirements. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. 

184
Furthermore, EPA disagrees that the Class VI requirements themselves, necessarily have any

implications for whether a particular material is a RCRA “solid waste” or implicates CERCLA

liability, as EPA understands the comment to suggest. EPA notes that the GS rule is not promulgated

under either of those statues, and further, the applicability of those statutes will not be determined

under the SDW or the terms of the GS rule, but rather according to those statues themselves and any

implementing regulations may apply. 

EPA adds that promoting the use of GS is outside the scope of the GS rule. Rather, the purpose of

the GS regulation is to ensure that, where deployed, GS is conducted in a manner that protects

USDWs from endangerment.

Commenter Name: Abbie Krebsbach Letter ID: 0235

Commenter Organization: Montana-Dakota Utilities Co. Comment ID: 23180

Comment: CO2 Not to Be Considered a Hazardous Waste 

Montana-Dakota believes it is critical that any regulation under the UIC program 

does not unnecessarily characterize CO2 as a waste, pollutant or contaminant or 

otherwise unduly stigmatize the injection and GS of CO2. While it is appropriate 

to consider the actual characteristics of CO2 and tailor regulations accordingly, 

unwarranted characterization of CO2 as a hazardous waste, for example, should be 

avoided. 

Response: The GS rule does not address the status of CO2 as a pollutant or commodity. While the

Class I requirements formed the basis of many of the specific requirements for GS wells, EPA

clarifies that the GS rule is tailored to the unique nature of GS. EPA based many of the GS

requirements on the Class I regulations because, like Class VI wells, Class I wells are typically deep

and involve waste streams that, if not properly managed, can harm the well and lead to

contamination. 

With respect to RCRA, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule.

Commenter Name: Abbie Krebsbach Letter ID: 0235

Commenter Organization: Montana-Dakota Utilities Co. Comment ID: 23192

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: Other Law Implications 

Montana-Dakota urges EPA to evaluate carefully any proposed treatment of the 

Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) 

and Resource Conservation and Recovery Act (RCRA), or other laws, that it may be 

185
considering under the Class VI regulations to ensure that any such treatment is 

necessary and does not serve as an unintended springboard for hampering the 

successful commercialization of CCS. Unless CO2 is categorized as a commodity, 

and not as a waste, there could be significant complications in implementing C02 

GS projects. 

Once a material is deemed to be a solid waste, an additional set of parameters 

applies to determine whether that substance is also a hazardous waste and thus 

subject to further regulation. Montana-Dakota recommends that EPA examine an 

approach to determining that CCS activities which meet UIC permit requirements 

are not equated to discarding the CO2. Identifying CO2 as a waste could limit 

the use of stored CO2 in any potential future applications. 

The EPA jumps to an unnecessary and potentially confusing discussion in the 

preamble of whether injected CO2 may be a hazardous waste, potentially implying 

that CO2 is a solid waste to begin with. Montana-Dakota recommends that any 

characterization of potentially hazardous constituents in CO2 injectate may be 

addressed, possibly through Toxicity Characteristic Leaching Procedures, as part 

of the UIC permitting process without addressing any potential RCRA 

jurisdictional issues. This should be examined further by EPA in regard to both 

RCRA and CERCLA implications. 

Response: As described above, the GS rule does not affect the regulatory status of CO2 under

RCRA. Furthermore, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule.

Commenter Name: Robert E. Carter Jr. Letter ID: 0236

Commenter Organization: Indiana Department of Natural Resources (IDNR) Comment ID: 23204

Other EPA Comment Codes and Descriptions: 1680 1.3.8 Don't overstate risk, don't stigmatize

CO2 

Comment: Section II-What Is EPA Proposing? 

Subsection I -Is Injected CO2 Considered a Hazardous Waste Under RCRA ? 

Comment: EPA has attempted to address this very important consideration by 

defining "carbon dioxide stream" in the proposed rule in such a way that those 

CO2 streams which exhibit hazardous characteristics would not be permitted under 

the proposed Class VI well classification but rather must be permitted and 

regulated as Class I wells instead. We are in agreement with those who believe 

that although captured C02 will contain some impurities, in those rare instances 

where concentrations could potentially be viewed as exhibiting RCRA hazardous 

characteristics, such impurities should be able to be removed by appropriate 

treatment methods prior to their storage in underground formations. While it is 

not possible to ignore the obligations and liabilities of waste generators under 

186
RCRA, any perception that CO2 streams could exhibit these characteristics and 

therefore require their management as hazardous wastes would have a very 

chilling effect on the widespread deployment of CCS and GS operations. We would 

prefer that instead of referring to CO2 streams as "waste", they should be 

viewed as an important resource to be managed accordingly. 

Response: The final GS rule retains the definition of a CO2 stream as proposed. The GS regulation

applies to injection of CO2 for the purpose of GS, regardless of the source of the CO2. It is beyond

the scope of the GS rule and the UIC Program’s authority to require or set standards for upstream

generators of CO2 or purification facilities.

With respect to RCRA, EPA received many comments regarding the applicability of the RCRA

regulations and statute to CO2 streams that are geologically sequestered under the final Class VI

UIC well requirements. As a result, EPA has decided to initiate a separate proposed rulemaking

specifically to examine the issue of RCRA applicability 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 particular 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 commenters who wish to submit comments on the RCRA proposal will need to do

so during the comment period for that rule. Finally, EPA also notes that the final GS rule, which

adds new regulations for Class VI wells under the Safe Drinking Water Act (SDWA), is not making

any changes to the RCRA regulations.

Commenter Name: Angie Burckhalter Letter ID: 0239

Commenter Organization: Oklahoma Independent Petroleum Association Comment ID: 23214

Other EPA Comment Codes and Descriptions: 1680 1.3.8 Don't overstate risk, don't stigmatize

CO2 

Comment: EPA has proposed to regulate CO2 as a waste and has proposed regulations that 

are as stringent as or more stringent than EPA’s requirements for Class I 

hazardous waste wells. We think treating CO2 as a waste is the wrong approach as 

it will unnecessarily open up unwarranted concerns, increased burdens and costs, 

and liability issues associated with the use of CO2 in EOR projects. In 

addition, it will prevent or discourage entities from proceeding with projects 

to store CO2 in underground formations or convert depleted Class II EOR wells to 

Class VI CO2 storage wells. We encourage EPA to not consider CO2 as a waste 

product. 

Response: First, EPA notes that the GS rule is not promulgated under either the RCRA or CERCLA

statutes, and the applicability of those statutes will not be determined under the SDWA or the terms

of the GS rule, but rather according to those statutes themselves and any implementing regulations

that may apply. Secondly, EPA disagrees that the Class VI requirements themselves, or EPA’s

consideration of the Class I requirements, necessarily have any implications for whether a particular

material is a RCRA “solid waste” or implicates CERCLA liability, as EPA understands the comment

to suggest. EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability to CO2 streams being geologically sequestered, including

the possible option of a conditional exemption from the RCRA requirements for CO2 GS in Class VI

187
wells. EPA will consider these comments as part of its development of that proposal. The Agency

will consider issues particular to RCRA in the context of that separate rulemaking, and recommends

that the commenter read that proposed rule when it is published. The Agency notes that commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule.

EPA adds that encouraging the use of GS is outside the scope of the GS rule. Rather, the purpose of

the GS regulation is to ensure that, where deployed, GS is conducted in a manner that protects

USDWs from endangerment.

Commenter Name: Mark Bohrer Letter ID: 0241

Commenter Organization: North Dakota Industrial Commission Comment ID: 23228

Other EPA Comment Codes and Descriptions: 1614 1.3.1.2 Impurities in captured CO2; purity

standards for CO2 

Comment: 7. By defining "carbon dioxide stream" to exclude hazardous wastes (146.81(d)), 

EPA’s rule, if finalized, assures that it would apply only to CO2 streams that 

are not hazardous wastes as defined in 40 CFR Part 261. As a result, EPA’s 

proposed rule would preclude the injection of hazardous wastes in Class VI 

injection wells. EPA seeks comment on this approach and other considerations 

associated with the presence of "impurities" in the CO2 stream. EPA Notice 

43503. 

The presence of certain hazardous wastes should not preclude the overall carbon 

dioxide stream from injection into a sequestration zone. The process of 

removing the carbon dioxide and making it suitable for transportation and 

injection should render it relatively pure. The presence of impurities can be 

dealt with at a specific source and the overall waste stream certified for 

injection. If the well construction and geologic setting is suitable to confine 

the carbon dioxide stream and prevent its migration into a USDW, then certain 

impurities and/or hazardous wastes should be allowed. 

Response: 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 low. However, these

estimates are based on limited information, and uncertainties remain about the expected

concentrations of impurities from the various types of CO2 streams. The concentrations of minor

and trace elements in CO2 streams for GS projects are likely to vary by facility, coal composition,

plant operating conditions, and pollution removal technologies. For this reason, the GS rule requires

the owner or operator to submit data about the site, including an analysis of the chemical and

physical characteristics of the CO2 stream, as required at §146.82(a)(7)(iv), and information on the

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 potential for geochemical reactions between the

injectate (CO2) and the host geologic formations, which could result in the plugging of pore spaces

or the dissolution of formation minerals. 

EPA received many comments regarding the applicability of the RCRA regulations and statute to

CO2 streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability to CO2 streams being geologically sequestered, including the possible option

188
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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: Kevin Wanttaja Letter ID: 0248

Commenter Organization: Western Energy Supply and Transmission

Associates

Comment ID:

22247

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: [FN1: See EPA's VEF-Technical_Document_072408, pg. 6.] 

– WEST is concerned about arguments made by some stakeholders that a whole suite 

of environmental laws should be applied to CCS projects, including the 

Comprehensive Environmental Response, Compensation, and Liability Act ("CERCLA") 

and the Resource Conservation and Recovery Act ("RCRA"). These laws applied to 

CCS would impose significant obligations and potential liabilities not only on 

GS operators, but also potentially on other entities in the CO2 abatement chain, 

such as the power plant operators producing the CO2. This would likely chill 

technology advancement and commercialization of CCS. WEST urges EPA to design 

the UIC for CO2 GS program to limit CCS projects' liability under CERCLA and 

RCRA. 

Response: First, EPA notes that the GS rule is not promulgated under either the RCRA or CERCLA

statutes, and the applicability of those statutes will not be determined under the SDWA or the terms

of the GS rule, but rather according to those statutes themselves and any implementing regulations

that may apply. With respect to RCRA, EPA has decided to initiate a separate proposed rulemaking

specifically to examine the issue of RCRA applicability 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 particular 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 commenters who wish to submit comments on the RCRA proposal will need to do

so during the comment period for that rule. 

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit. 

EPA adds that promoting the use of GS is outside the scope of the GS rule. Rather, the purpose of

189
the GS regulation is to ensure that, where deployed, GS is conducted in a manner that protects

USDWs from endangerment.

Commenter Name: James T. Sims Letter ID: 0249

Commenter Organization: Western Business Roundtable Comment ID: 22261

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: 3. Avoid Regulatory Creep - We are extremely concerned by arguments that 

the whole suite of environmental laws -- including the Comprehensive 

Environmental Response, Compensation, and Liability Act ("CERCLA") and the 

Resource Conservation and Recovery Act ("RCRA") -- be applied to CCS projects. 

These laws, if applied broadly to CCS, would impose significant obligations and 

potential liabilities not only on project operators, but also potentially on 

other entities in the CO2 chain, such as entities producing the CO2 that is 

ultimately injected. That would put advancement of CCS commercialization into a 

deep freeze. Such an outcome would clearly be counter-productive. Thus, we 

urge the Agency to pursue options that will limit CCS projects’ liability under 

CERCLA and RCRA. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. 

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit. 

EPA adds that encouraging the use of GS is outside the scope of the GS rule. Rather, the purpose of

the GS regulation is to ensure that, where deployed, GS is conducted in a manner that protects

USDWs from endangerment.

Commenter Name: Walter L. Baker Letter ID: 0253

Commenter Organization: Utah Division of Water Quality Comment ID: 22345

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: DEFINING CO2 STREAM TO EXCLUDE HAZARDOUS WASTE/SUBSTANCE

190
UNDER RCRA/CERCLA 

We consider potential liability under RCRA and/or CERCLA a major deterrent to 

developing and deploying CCGS projects and one that must be addressed. Towards 

removing this as a barrier to CCGS, we strongly encourage EPA to address the 

issues surrounding the composition of the injected CO2 stream. These issues 

include: providing a clear description of the analytical methods for 

characterizing the CO2 stream, providing a clear description of the limitation 

on the CO2 stream composition so as to avoid inclusion under RCRA or CERCLA, and 

investigating thoroughly the possibility of RCRA and CERCLA exemption for CCGS 

while still providing protection to USDWs and other natural resources. Since 

capture and separation technology is still being developed for large stationary 

CO2 sources, it is important to have a clearly defined target for design 

objectives. 

Response: The final GS rule retains the definition of a CO2 stream as proposed. The GS regulation

applies to injection of CO2 for the purpose of GS, regardless of the source of the CO2. It is beyond

the scope of the GS rule and the UIC Program’s authority to require or set standards for upstream

generators of CO2 or purification facilities. For purposes of GS, the UIC program’s authority under

the SDWA is limited to ensuring that GS projects are sited, constructed, operated, and closed in a

manner that protects USDWs. 

With respect to the commenter’s concern about RCRA, EPA has decided to initiate a separate

proposed rulemaking specifically to examine the issue of RCRA applicability 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 particular 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 commenters who wish to submit comments on the RCRA proposal

will need to do so during the comment period for that rule. Finally, EPA also notes that the final GS

rule, which adds new regulations for Class VI wells under the Safe Drinking Water Act (SDWA), is

not making any changes to the RCRA regulations.

Commenter Name: Mike Nasi Letter ID: 0254

Commenter Organization: Clean Coal Technology Foundation of Texas Comment ID: 22365

Comment: As for RCRA, EPA states that it "cannot make a categorical determination as to 

whether injected CO2 is hazardous under RCRA," and further states that "owners 

or operators will need to characterize their CO2 as hazardous under RCRA." These 

statements are inconsistent with EPA's belief that the proposed rule does not 

address CO2 as a commodity or pollutant. Statements such as the one referenced, 

connote that the CO2 stream is a waste. EPA should create a categorical 

exemption under RCRA for CO2 sequestration pursuant to the Class VI VIC program 

under RCRA. 

Response: First, EPA notes that the GS rule is not promulgated under either the RCRA or CERCLA

statutes, and the applicability of those statutes will not be determined under the SDWA or the terms

of the GS rule, but rather according to those statutes themselves and any implementing regulations

that may apply. With respect to RCRA, EPA has decided to initiate a separate proposed rulemaking

specifically to examine the issue of RCRA applicability to CO2 streams being geologically

191
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 particular 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 commenters who wish to submit comments on the RCRA proposal will need to do

so during the comment period for that rule.

Commenter Name: Keith McCoy Letter ID: 0258

Commenter Organization: National Association of Manufacturers Comment ID: 22374

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: The NAM believes that a CCS policy can be designed that promotes a variety of 

public goals, including energy security, economic prosperity and protection of 

public health and the environment. The NAM believes that policy makers, 

building on the knowledge and expertise of energy professionals who have long 

injected carbon into geologic formations to enhance oil recovery, should 

establish a new regime and regulatory scheme which will promote the development 

and commercial deployment of CCS technology. The NAM is concerned, however, 

that EPA regulators may be looking backward, by considering liability schemes 

pursuant to the Superfund and Resource Conservation and Recovery Act (RCRA), as 

models on which to establish a framework for the long-term capture and storage 

of carbon. The NAM does not believe that use of a statute such as Superfund, 

which has been the source of endless litigation, is an appropriate model on 

which to base something as modern as CCS. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit. 

EPA adds that promoting the use of GS is outside the scope of the GS rule. Rather, the purpose of

the GS regulation is to ensure that, where deployed, GS is conducted in a manner that protects

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USDWs from endangerment.

Commenter Name: Michel Paque Letter ID: 0259

Commenter Organization: Ground Water Protection Council Comment ID: 24855

Other EPA Comment Codes and Descriptions: 1220 1.1.1.1 Terminology and definitions 

Comment: EPA Proposal: Carbon dioxide plume means the underground extent, in three 

dimensions, of an injected carbon dioxide stream. 

Carbon dioxide stream means carbon dioxide that has been captured from an 

emission source (e.g., a power plant), plus incidental associated substances 

derived from the source materials and the capture process, and any substances 

added to the stream to enable or improve the injection process. This subpart 

does not apply to any carbon dioxide stream that meets the definition of a 

hazardous waste under 40 CFR part 261. 

GWPC Recommendations: Carbon dioxide stream means carbon dioxide, plus 

associated substances derived from the source materials and any processing, and 

any substances added to the stream to enable or improve the injection process. 

This subpart does not apply to any carbon dioxide stream that meets the 

definition of a hazardous waste under 40 CFR part 261. 

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

Response: The final GS rule retains the definition of a CO2 stream as proposed. The GS regulation

applies to injection of CO2 for the purpose of GS, regardless of the source of the CO2. It is beyond

the scope of the GS rule and the UIC Program’s authority to require or set standards for upstream

generators of CO2 or purification facilities. For purposes of GS, the UIC program’s authority under

the SDWA is limited to ensuring that GS projects are sited, constructed, operated, and closed in a

manner that protects USDWs. The GS rule does not apply to generators of CO2. Additionally, EPA

has received numerous comments regarding the applicability of the RCRA regulations and statute to

CO2 streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: Claire Olson Letter ID: 0260

Commenter Organization: Basin Electric Power Cooperative Comment ID: 22394

Comment: "I. Is Injected CO2 Considered a Hazardous Waste Under RCRA? 

Under the proposal, EPA states that it cannot make a categorical determination 

as to whether injected CO2 is hazardous under RCRA. It suggests the burden 

193
should be on the operators to characterize their CO2 stream as part of the 

permit application to determine if the injectate is considered hazardous as 

defined in 40 CFR Part 261. RCRA regulates the production, management, and 

disposal of wastes and RCRA's potential application in the case of CO2 injectate 

is dependent upon the existence of a solid waste. If the material is a solid 

waste, the law requires further analysis to determine if it is also a hazardous 

waste. 

Injected CO2 should be considered a product or a commodity and not a solid 

waste. Leaving the question to be resolved when operators characterize their CO2 

streams with the potential that RCRA liability may attach will be a deterrent to 

CO2 storage projects. Basin Electric urges the EPA to make a determination under 

its RCRA authority the CCS activities meeting Class VI permit requirement do not 

equate discarding the CO2. By so doing, Class VI CO2 injection operations would 

not be considered waste management activities and would not be subject to RCRA. 

EPA should view CCS as a resource, not a waste. EPA should specifically exempt 

injected CO2 streams from coverage by RCRA and develop requirements tailored to 

this material if necessary to ensure further environmental protection beyond 

that provided by the UIC permitting process. 

As further justification for this position, simply consider the success of 

existing acid gas injection operations into depleted oil and gas reservoirs 

conducted under the existing protective UIC regulations. Impurities, such as H2S 

or mercaptans, should not trigger a classification under RCRA. The proposed rule 

has adequate protection for drinking water aquifers and addresses corrective 

action, financial assurance requirements, and long-term monitoring after 

closure. These requirements negate the need for any RCRA regulation. Basin 

Electric wants to avoid open-ended and enhanced liabilities and risks resulting 

from requirements that do not significantly contribute to health and 

environmental protection. 

Response: EPA clarifies that the GS rule does not address the status of CO2 as a pollutant or a

commodity. Under the SDWA and the UIC program, EPA regulates the injection of a range of

fluids, which may include pollutants and commodities, regardless of how they are characterized, for

the purpose of protecting USDWs. Comments related to existing acid gas injection operations are

outside the scope of the GS rulemaking. 

EPA also notes that the final GS rule, which adds new regulations for Class VI wells under the Safe

Drinking Water Act (SDWA), is not making any changes to the RCRA regulations. However, with

respect to RCRA, EPA received many comments regarding the applicability of the RCRA

regulations and statute to CO2 streams that are geologically sequestered under the final Class VI

UIC well requirements. As a result, EPA has decided to initiate a separate proposed rulemaking

specifically to examine the issue of RCRA applicability 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 particular 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 commenters who wish to submit comments on the RCRA proposal will need to do

so during the comment period for that rule.

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Letter ID: 0263

Commenter Organization: Interstate Oil & Gas Compact Commission Comment ID: 24960

Comment: II . I. Is Injected CO2 Considered a Hazardous Waste Under RCRA? 

H. EPA seeks comment on this approach and other considerations associated with 

the presence of impurities in the CO2 stream. 

IOGCC Response: Injected CO2 is not and should not be considered a hazardous 

waste or regulated under RCRA or CERCLA. It is assumed that RCRA or CERCLA wastes 

Response: 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 low. However, these

estimates are based on limited information, and uncertainties remain about the expected

concentrations of impurities from the various types of CO2 streams. 

With respect to RCRA, EPA received many comments regarding the applicability of the RCRA

regulations and statute to CO2 streams that are geologically sequestered under the final Class VI

UIC well requirements. As a result, EPA has decided to initiate a separate proposed rulemaking

specifically to examine the issue of RCRA applicability 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 particular 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 commenters who wish to submit comments on the RCRA proposal will need to do

so during the comment period for that rule. Finally, EPA also notes that the final GS rule, which

adds new regulations for Class VI wells under the Safe Drinking Water Act (SDWA), is not making

any changes to the RCRA regulations.

Commenter Name: Michael Moore Letter ID: 0265

Commenter Organization: North American Carbon Capture & Storage

Association (NACCSA)

Comment ID:

22872

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: 9. Relationships with other Environmental Laws 

NACCSA is concerned about the potential application of other environmental laws 

to CCS activities. These laws include the Comprehensive Environmental Response, 

Compensation, and Liability Act (CERCLA) and the Resource Conservation and 

Recovery Act (RCRA). Setting aside for the moment the important questions 

of whether either of these laws could apply to CCS activities and, if so, 

precisely how and to what extent, NACCSA understands and does not disagree with 

the Agency's position that drafting a clear exception from either of these 

regimes likely cannot be accomplished through the context of this SDWA UIC 

rulemaking. Nonetheless, NACCSA urges EPA to carefully consider whether to include 

any discussion of these two laws (or others) along with the Class VI regulations, 

as well as the particulars of what any such discussion may contain, to ensure 

that such discussion is necessary and does not serve as an unnecessary and 

unintended springboard for hampering the successful commercialization of CCS. 

195
NACCSA believes that EPA should clarify that supercritical and gaseous CO2 do not 

fit the definition of" solid waste" under RCRA,and that injected CO2 is not solid 

waste that is "disposed of" and thus subject to RCRA regulation. While 

NACCSA acknowledges that such clarification may be best achieved in the context 

of a RCRA rulemaking, the Preamble to the proposed rules appears to make the 

assumption that injected CO2 is a solid waste that is being disposed of in the 

first instance, in the context of its discussion regarding waste 

characterizations that may be required of permitees. Such discussion in the 

Preamble is unnecessary and will only prove harmful to those seeking to move 

forward with CCS projects. Further, any concern about potentially hazardous 

constituents in CO2 injectate may be addressed without addressing any potential 

RCRA implications, as the contents of an injectate must be "characterized" under 

the proposed rules regardless, and permit limitations maybe imposed to address 

the content of injectate without reference to RCRA's provisions. 

In addition, EPA should clarify that the provisions of CERCLA are not triggered by 

Class VI operations. As a preliminary matter, as the Agency is aware, CERCLA 

imposes liability for releases of hazardous substances. EPA indicates in the 

Preamble that whether injected CO2 may be considered a hazardous substance 

"depends entirely on the make-up of the specific CO2 stream and of the environmental 

media . . . in which it is stored," leaving the door open for claims 

of environmental harm arising out of CO2 injection and storage activities. This 

discussion, however, assumes that CO2 injection activities could fall within 

CERCLA's ambit in the first instance. As with the RCRA issue, a determination 

of this issue is unnecessary from the point of view of regulating injection and 

storage of CO2 under the UIC program, and NACCSA urges the Agency to avoid creating 

unnecessary hurdles for the successful commercial deployment of CCS by assuming 

potential applications of other statutes that may not come into play. Regardless, 

even if the provisions of CERCLA could be interpreted to apply to CCS activities, 

NACCSA is opposed to any limitations on the federally permitted release 

exemption from CERCLA liability, which should be given its fullest application in 

the Class VI context. Relatedly, NACCSA encourages the Agency, pursuant to its 

authority under RCRA and CERCLA, to examine possibilities for exemption or 

exclusion from those programs. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

CO2 itself is not listed as a hazardous substance under CERCLA; however, the CO2 stream may

contain a listed hazardous substance (such as mercury) or may mobilize substances in the subsurface

196
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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit.

Commenter Name: William Herz Letter ID: 0266

Commenter Organization: The Fertilizer Institute Comment ID: 22879

Comment: Injected CO2 as a Hazardous Waste under the Resource Conservation and Recovery 

Act (RCRA) 

EPA seeks comment on defining "carbon dioxide stream" to exclude hazardous wastes 

(146.81(d)) in order to assure that it would apply only to CO2 streams that are 

not hazardous wastes as defined in 40 CFR Part 261. As a result, today's proposed 

rule would preclude the injection of hazardous wastes in Class VI injection 

wells. EPA also seeks comment on other considerations associated with the 

presence of impurities in the CO2 stream. (73 Fed. Reg. 43,503) 

TFI understands EPA's concern with the potential for impurities in the CO2 stream 

and the risk that contaminants such as hydrogen sulfide and sulfurous and nitrous 

oxides in the CO2 stream could migrate into a USDW. TFI also agrees that because 

the types of impurities and their concentrations in the CO2 stream are likely to 

vary by facility, plant operating conditions and pollution removal technologies, 

EPA cannot make a categorical determination as to whether injected CO2 is a 

hazardous waste under RCRA. 

TFI asks for greater guidance for potential upstream industrial clients of CO2 

wells. TFI is concerned about the implications of considering the long-term 

storage of CO2 as "discard" as EPA suggests by stating that the CO2 stream needs 

to be non-hazardous. RCRA applicability to carbon sequestration activities would 

discourage industry from engaging in sequestration to avoid associated regulatory 

burdens and potential citizen suits. EPA should therefore interpret its rule to 

exclude GS injectate from RCRA regulation to the greatest degree possible. 

RCRA would apply only where the injectate meets the definitional criteria in 42 

U.S.C. § 6903(27). 

GS injectate should not qualify as a "solid waste" under this definition because 

the injectate is not "discarded" but is recoverable and has commercial value, in 

particular in enhanced oil recovery operation. In other regulatory situations 

EPA has exempted materials from RCRA where the materials are subject to a 

separate regulatory regime providing equivalent environmentally protective 

measures (such as UIC). EPA states in the NPRM that the UIC regulatory scheme is 

adequate to protect USDWs, and that "chronic and acute health effects from 

airborne exposure resulting from CO2 injection activities even in the case 

of leakage or accidental exposure is minimal." 72 Fed. Reg. at 43487-98. EPA has 

relied on "contingent management" (management of materials outside 

of RCRA regulation where a separate regulatory regime provides equivalent 

197
protection) to great effect and in a manner which has been upheld by federal 

courts. See Military Toxics Project v. EPA, 146 F. 3d 948 (D.C. Cir.1998). As 

such, TFI requests that EPA interpret the injectate to not constitute a RCRAregulated waste, or at least to apply contingent management to the injectate to 

avoid RCRA regulation. 

Furthermore, to the extent they are not already expressly exempted, TFI requests 

that the final rule delineate monitoring and/or reporting requirements 

for upstream industrial clients that could provide RCRA liability relief. TFI asks 

that upstream industrial clients providing CO2 streams that are not hazardous 

wastes as defined in 40 CFR Part 261 be provided an exemption from RCRA 

liability. Absent a RCRA exemption, TFI requests that EPA develop contaminant 

limits that would be allowed in CO2 streams from upstream industrial clients. TFI 

also asks that EPA clarify that risks to USDWs from improperly managed GS projects 

-including CO2 migration into USDWs, causing the leaching and mobilization 

of contaminants (e.g., arsenic, lead, and organic compounds), changes in regional 

groundwater flow, and the movement of saltier formation fluids into USDWs, 

causing degradation of water quality (73 Fed. Reg. 43,497) -are solely the 

responsibility of the owner and/or operator of the well. 

Where not otherwise exempted from RCRA, delineation of contaminant levels, 

monitoring and recordkeeping requirements and liability protection are necessary 

to provide the certainty, consistency and transparency to potential upstream 

industrial clients. TFI also is concerned about the consequences of CO2 storage 

prior to injection as related to the potential implications for solid waste 

storage regulations as well as applicable state regulatory obligations on the 

injection of solid waste. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

EPA adds that promoting the use of GS is outside the scope of the GS rule. Rather, the purpose of

the GS regulation is to ensure that, where deployed, GS is conducted in a manner that protects

USDWs from endangerment.

Commenter Name: Bill Hertz Letter ID: 0500

Commenter Organization: Fertilizer Institute Comment ID: 21210

Comment: Now, items that, that need additional regulatory clarity include the liability 

aspects. TFI understands the EPA's concern with the potential for impurities in 

198
the CO2 stream and the risks that contaminants, such as hydrogen sulfide and 

sulfuric and nitrous oxide in the CO2 stream could migrate into a USDW. 

TFI also agrees that because the types of impurities and their concentrations in 

the stream are likely to vary by facility, plant operating conditions, and 

pollution removal technologies, EPA can not make a categorical determination as 

to whether the injected CO2 is hazardous under RCRA. TFI would request greater 

guidance for potential upstream industrial clients in CO2 disposal wells. 

And among the RCRA related questions we would like to discuss before regulations 

are promulgated include the implications of considering the long-term storage of 

CO2 as discard, as the EPA suggests, by stating that CO2 streams need to be nonhazardous, the consequences of CO2 storage prior to injection, and the potential 

implications for solid waste storage regulation, and potential state regulatory 

obligations on the injection of solid waste. Monitoring and/or reporting 

requirements for upstream industrial clients that could provide RCRA liability 

relief. 

Response: The Agency appreciates the concerns regarding the need for clarity when it comes to

RCRA liability in GS. As a result of this comment and numerous others, EPA has decided to initiate

a separate proposed rulemaking specifically to examine the issue of RCRA applicability 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 particular 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 commenters who wish to submit comments on the

RCRA proposal will need to do so during the comment period for that rule. Finally, EPA also notes

that the final GS rule, which adds new regulations for Class VI wells under the Safe Drinking Water

Act (SDWA), is not making any changes to the RCRA regulations.

Commenter Name: Bill Hertz Letter ID: 0500

Commenter Organization: Fertilizer Institute Comment ID: 21212

Comment: We agree with previous comments that in terms of paying or otherwise tagging CO2 

leakage down the road could be a major disincentive for capital investment on 

these types of projects. Because the expectation that a ton of CO2 could be 10 

times or 40 times the current cost would, would really, again, be a disincentive 

for companies to move forward with this. 

We would request, finally, clarification for upstream industrial clients as to 

the appropriate requirements for analyzing the CO2 stream at a frequency 

sufficient to yield representative data of its chemical and physical 

characteristics as cited in the Federal Register Notice. As well as appropriate 

requirements for upstream industrial clients in terms of monitoring and recordkeeping. 

Response: EPA clarifies that promoting the use of GS is outside the scope of the GS rule. Rather,

the purpose of the GS regulation is to ensure that, where deployed, GS is conducted in a manner that

protects USDWs from endangerment. EPA adds that the GS rule does not apply to generators of

CO2.

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Commenter Name: Mike Moore Letter ID: 0532

Commenter Organization: North American Carbon Capture and Storage

Association (NACCSA)

Comment ID:

21373

Comment: Our final area of concern relates to the Agency's comments in the preamble that 

injected carbon dioxide could be deemed a hazardous waste under RCRA and CERCLA. 

NACSA believes it is appropriate for geologically stored carbon dioxide to be 

categorically excluded from the definitions of hazardous waste. NACSA urges the 

Agency to reconsider its positions and the deleterious effect it could have on 

the development of CCS. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit.

Commenter Name: Paul Pike Letter ID: 0535

Commenter Organization: Ameren Corporation on behalf of Utility Solid Waste

Activities Group (USWAG)

Comment ID:

21436

Comment: With respect to RCRA, it is premature to conclude that captured injected carbon 

dioxide is discarded and therefore possibly a solid waste under RCRA. Carbon 

dioxide is a commodity used in a variety of processes currently and we do not 

know exactly what methods or mechanisms will be created as a result to deal with 

CO2. EPA should create an applicable exemption from RCRA under the well 

established contingent management concept given that the UIC will ensure that 

they injected material is not mismanaged. Such an exclusion will be legally 

justified, consistent with past promulgation of excluded rules and it would make 

sound policy since by removing a potentially significant regulatory barrier to 

the commercial development of carbon dioxide sequestration operations. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

200
statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: Paul Pike Letter ID: 0535

Commenter Organization: Ameren Corporation on behalf of Utility Solid Waste

Activities Group (USWAG)

Comment ID:

21437

Other EPA Comment Codes and Descriptions: 1640 1.3.4 CERCLA issues (seeking comment) 

Comment: The bottom line is that the potential for interaction with CERCLA or liability 

in RCRA must be mitigated to avoid significant delays in an overall chilling 

effect on this process. 

Response: EPA clarifies that promoting the use of GS is outside the scope of the GS rule. Rather,

the purpose of the GS regulation is to ensure that, where deployed, GS is conducted in a manner that

protects USDWs from endangerment.

Comment Code: 1640 1.3.4 CERCLA issues (seeking comment) 

Individual Comments

Commenter Name: Paul Pike Letter ID: 0111

Commenter Organization: Ameren Corporation on behalf of USWAG Comment ID: 22402

Comment: 4. Of particular importance is the potential for liability under RCRA and 

CERCLA, including Natural Resource Damages, stemming from injection and 

sequestration of carbon dioxide. As EPA can surely appreciate, the potential for 

these openended liabilities will act as a serious deterrent to would-be Owners 

or Operators of Class VI injection wells. Simply put, EPA must mitigate the 

threat of potential RCRA and CERCLA liability to the extent possible in this 

rulemaking. 

One step that the Agency can take with respect to CERCLA is to ensure that final 

Class VI permits have the broadest possible reach - while remaining protective 

of USDWs - to maximize the protection offered by the federally permitted release 

exemption. This would mean including in the scope of the permit for carbon 

dioxide injection all other CERCLA hazardous constituents likely to be contained 

in the CO2 stream, including those generated during capture and transport as 

well as any that could be formed in the injection zone as a result of the 

injection of carbon dioxide. Similarly, the scope of the authorized "permit 

201
zone" should be as broad as possible while remaining protective of USDWs. 

The bottom line is that the potential for interaction with RCRA or liability 

under CERCLA must be mitigated to avoid significant delays and an overall 

chilling effect. USWAG recognizes that while there are some measures the Agency 

can take in the regulatory context to address these concerns, those measures may 

be limited. In the end, USWAG believes that the Agency should consider whether a 

legislative solution is necessary to eliminate these concerns; if so, we 

recommend that the EPA strongly support such a solution. 

Response: As described above, EPA has decided to initiate a separate proposed rulemaking

specifically to examine the issue of RCRA applicability 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. 

The Agency acknowledges the commenter's concerns regarding the scope and possible impacts of

CERCLA liability on CCS activities, however EPA notes that the GS rule is not promulgated under

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. To the extent the commenter is seeking interpretations of RCRA or

CERCLA, such interpretations are beyond the scope of this rulemaking.

Commenter Name: George Holliday, PhD, PE, BCEE Letter ID: 0114

Commenter Organization: Holliday Environmental Services, Inc. Comment ID: 22516

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: dangerous and 2) unnecessary and should not promulgated. Also, we believe the 

Safe Drinking Water Act is not suited to provide necessary safety to the 

citizenry, because EPA, by promulgating Class VI wells, is authorizing 

construction of a CERCLA imminent hazard substance storage site and a RCRA 

hazardous substance (corrosivity) storage site. Each of these concerns and many 

more are discussed below. We request these comment be made a part of the record 

EPA-HQ-OW-2008-0390. 

Response: EPA disagrees that the final GS rule is authorizing construction of CERCLA imminent

hazard substance storage sites or RCRA hazardous substance storage sites. It is authorizing the

construction and operation of a new class of injection well for purposes of long term storage of

CO2. 

EPA received many comments regarding the applicability of the RCRA regulations and statute to

CO2 streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability to CO2 streams being geologically sequestered. EPA will consider these

comments as part of its development of that proposal. The Agency will consider issues particular to

RCRA in the context of that separate rulemaking, and recommends that the commenter read that

proposed rule when it is published. The Agency notes that commenters who wish to submit

comments on the RCRA proposal will need to do so during the comment period for that rule. 

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 low. However, these estimates are

202
based on limited information, and uncertainties remain about the expected concentrations of

impurities from the various types of CO2 streams. The concentrations of minor and trace elements in

CO2 streams for GS projects are likely to vary by facility, coal composition, plant operating

conditions, and pollution removal technologies. 

EPA is not authorizing the injection of RCRA hazardous wastes under the terms of the GS rule, since

the GS rule, at §146.81(d), prohibits CO2 streams that meet the definition of a hazardous waste

under 40 CFR Part 261. Under the rule, owners or operators will need to characterize their CO2

stream as part of their permit application process to determine whether the injectate is a RCRA

hazardous waste. If the CO2 stream is determined to be a hazardous waste, injection may only occur

in a Class I hazardous waste injection well. 

The GS rule also requires the owner or operator to submit data about the site, including an analysis

of the chemical and physical characteristics of the CO2 stream, as required at §146.82(a)(7)(iv), and

information on the 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 potential for geochemical

reactions between the injectate (CO2) and the host geologic formations, which could result in the

plugging of pore spaces or the dissolution of formation minerals.

EPA clarifies that CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit.

Commenter Name: Sam Kitto Letter ID: 0126

Commenter Organization: National Tribal Air Association Comment ID: 23044

Other EPA Comment Codes and Descriptions: 1614 1.3.1.2 Impurities in captured CO2; purity

standards for CO2 

Comment: Hazardous Substances With respect to hazardous substances, the GS rule would 

prohibit the injection of these substances in Class VI injection wells (e.g., 

specific to geologic sequestration), but the EPA offers no means for removing 

hazardous impurities such as hydrogen sulfide and mercury which are often found 

in CO2 streams, the types that would be sequestered as a result of the rule. In 

the rule, the Agency instead focuses on what is considered a hazardous substance 

under the Comprehensive Environmental Response, Compensation, and Liability Act, 

also known as CERCLA or Superfund; and the potential liability to owners and 

operators of geologic sequestration operations for injection of CO2 and 

associated hazardous substances. 

Indeed, liability is an important matter that needs to be addressed upfront, 

particularly since some Indian tribes and their citizens may one day be engaged 

in geologic sequestration. The EPA must not forget, however, that a primary 

purpose of the GS rule is to prevent endangerment to underground sources of 

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drinking water (USDWs). As such, every effort should be made by the Agency to 

ensure that hazardous substances, at any level, do not find their way into USDWs 

so as to best protect human health and the environment from the harmful impacts 

of these substances. 

The NTAA therefore recommends that the EPA clearly communicate how it will 

address hazardous impurities often found in CO2 streams, specifically how such 

impurities will be removed or their impacts mitigated so as not to endanger 

USDWs. 

Response: EPA agrees that protecting USDWs from endangerment is the primary purpose of the GS

rule, and that the purpose of the tailored requirements in the GS rule is to ensure that GS projects are

permitted sited, constructed, operated, and closed in a manner that avoids releases of CO2 into

USDWs.

The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a percent CO2).

Instead, the GS rule addresses the quality and quantity of impurities by requiring owners or operators

to submit information on the source of the CO2 and its physical and chemical properties.

Specifically, the GS rule requires the owner or operator to submit data about the site, including an

analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the 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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals. 

Because the GS rule, at §146.81(d), prohibits the injection of CO2 streams that meet the definition of

a hazardous waste under 40 CFR part 261, injection of a CO2 stream that is determined to be a

hazardous waste may only occur in a Class I hazardous waste injection well. 

EPA supports the use of CO2 capture technologies that minimize impurities in the CO2 stream, but

clarifies that the GS rule does not address the development or regulation of capture technologies or

technologies for removing impurities from CO2.

EPA is promulgating the GS rule under the authority of the SDWA. To the extent the commenter is

seeking interpretations of RCRA or CERCLA, such interpretations are beyond the scope of this

rulemaking.

Commenter Name: Dwight Lockwood, PE, QEP Letter ID: 0141

Commenter Organization: Global Energy, Inc. Comment ID: 23104

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment); 4620 2.6.2 Injectate monitoring 

Comment: CO2 as Hazardous Waste (RCRA or CERCLA) 

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

CFR Part 261. We further believe that the stream can be treated to remove 

undesired contaminants to the levels that thresholds are not triggered. 

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

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sufficient basis for assurance here. Periodic sampling and analysis on some 

reasonable frequency during injection is acceptable. On the other hand, we do 

not believe that this measurement and reporting needs to be more than perhaps 

quarterly, as the adverse impact of exceedances for relatively short periods is 

not likely to be geologically significant very fast. Corrective action to 

mitigate the effects of an incorrect injection fluid (but not to remedy an 

injection already accomplished) needs to be pragmatic and not onerous. 

3.As with Class I well liability exemptions, Class VI wells, once their 

injectate is characterized and approved (as not triggering CERCLA or RCRA), and 

regular sampling of the stream for quality control is implemented then a 

similar exemption is warranted. 

Response: EPA agrees that monitoring of the injectate prior to and during injection is important to

allow for comparison of baseline data and operational-phase monitoring results to provide warning

of potential USDW endangerment. For this reason owners or operators must perform an analysis of

the chemical and physical characteristics of the CO2 stream, as required at §146.82 (a)(7)(iv). In

addition, Section §146.90(a) requires owners or operators to perform analysis of the CO2 stream

during injection operations with sufficient frequency to yield data representative of its chemical and

physical characteristics.

The necessary frequency of injectate analysis will be project-specific and will depend upon the CO2

source and the likelihood of variability in injectate composition. For example, a CO2-capture

process from a coal-fired power plant with a consistent coal source and operating parameters is

likely to produce a CO2 stream with a fairly consistent composition. A process with a changing

composition of coal may have more variability in the purity of the CO2 that is captured. In such a

setting, more frequent sampling may be appropriate. The details of the sampling should be described

in the testing and monitoring plan, which will be approved by the Director based on a review of sitespecific information, including information on the source and characteristics of the injectate.

EPA clarifies that, following an initial characterization of the injectate, EPA expects that the permit

would stipulate the acceptable composition of the injectate (e.g., as CO2 plus an acceptable range of

expected impurities). Any divergence from this would be a permit violation.

EPA notes however, that the final GS rule, which adds new regulations for Class VI wells under the

Safe Drinking Water Act (SDWA), is not making any changes to the RCRA regulations.

Accordingly, the CO2 stream characterization requirements under the GS rule would not substitute

for the obligation of a generator of RCRA solid waste to characterize its waste in accordance with

EPA’s RCRA regulations. Injection of a RCRA hazardous waste may only occur in a Class I

hazardous waste injection well.

EPA notes that CO2 itself is not listed as a hazardous substance under CERCLA, although 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit.

205
The commenter’s reference to a Class I liability exemption is unclear and not legally correct.

Furthermore, after site closure an owner or operator may remain liable under tort and other remedies,

or under other federal statutes including, 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.

Commenter Name: Patrick Nugent Letter ID: 0143

Commenter Organization: Texas Pipeline Association (TPA) Comment ID: 23138

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: 5. The carbon dioxide stream is a commodity not a waste and should be 

regulated as such. EPA should make clear that carbon dioxide injectate is not 

being categorized or regulated as a waste or a pollutant, but rather as a 

commodity. The sequestered carbon dioxide is expected to generate a credit in a 

future carbon credit scheme. At that point, the act of sequestering the carbon 

dioxide will generate an emission credit that can be sold in the open market. 

Accordingly, TPA urges EPA to remain neutral at this point in time in 

characterizing the carbon dioxide stream as a waste or a pollutant in any of its 

regulatory programs. Those kinds of labels would saddle this program with the 

liability schemes imposed by RCRA or CERCLA and would be severely detrimental to 

the development and use of geologic sequestration technology. It is highly 

unlikely that industry will commit the substantial capital required for geologic 

sequestration projects unless and until the potential for liability is clearly 

defined and understood. Such financial commitment is unlikely to be made if 

participants run the risk of incurring open-ended and ruinous liability under 

RCRA and CERCLA. In this regard, Class VI permits should be written as broadly 

as possible, so as to maximize protections that may be provided by federally 

permitted release exemptions. 

Response: EPA clarifies that the GS rule, being issued only under the SDWA, does not affect the

status of, or entities’ potential obligations for managing, or liability for management of, CO2 under

RCRA or CERCLA. While the Class I requirements formed the basis of many of the specific

requirements for GS wells, EPA clarifies that the GS rule is tailored to the unique nature of GS. EPA

based many of the GS requirements on the Class I regulations because, like Class VI wells, Class I

wells are typically deep and involve waste streams that, if not properly managed, can harm the well

and lead to contamination. 

In addition, issues related to carbon crediting are outside the scope of the GS rule. Rather, the

purpose of the GS regulation is to ensure that, where deployed, GS is conducted in a manner that

protects USDWs from endangerment.

Commenter Name: Kenneth Alexander Letter ID: 0146

Commenter Organization: Old Dominion Electric Cooperative (ODEC) Comment ID: 21725

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: 6.EPA must settle the way as activities will relate to RCRA and CERCLA. RCRA is 

206
simply the wrong tool to use to regulate as of C02 and EPA needs to find a way 

to insure that the onerous requirements of CERCLA, (never intended for as of 

CO2), are not applied to this highly specialized storage operation. 

7. Dealing with these last two hazardous waste issues appears to ODEC to be one 

of the most difficult hurdles standing in the way of commercial deployment of 

full scale as projects and we recognize that Congressional action may be needed. 

Response: EPA agrees that any requirements for the CO2 stream should be clearly identified. EPA

received many comments regarding the applicability of the RCRA regulations and statute to CO2

streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

EPA clarifies that CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit.

Commenter Name: William Kovacs Letter ID: 0148

Commenter Organization: U.S. Chamber of Commerce Comment ID: 21752

Other EPA Comment Codes and Descriptions: 1520 1.2.3 Other authorities (e.g., CAA, MPRSA,

London Convention); 1630 1.3.3 RCRA/hazardous waste issues (seeking comment) 

Comment: For example, if EPA eventually determines that CO2 is hazardous, what are the 

ramifications under the Resource Conservation and Recovery Act (RCRA)?[FN3 42 

U.S.C. §§ 6901 et seq.] Presumably, its stringent "cradle to grave" requirements 

will be imposed on all generators, transporters, and treatment, storage and 

disposal facilities involved in the CCS project. Or, in the event of a release, 

under the Comprehensive Environmental Response, Compensation and Liability Act 

(CERCLA)?[FN4 42 U.S.C. §§ 9601 et seq.] The Clean Air Act? [FN5 42 U.S.C. §§ 

7401 et seq.] If CO2 is deemed a "hazardous air pollutant" under Section 112, it 

will automatically trigger CERCLA liability as it incorporates HAPs in its 

definition of "hazardous substance." [FN6 CERCLA, Section 101(14).] The Clean 

Water Act? [FN7 33 U.S.C. §§ 1251 et seq.] 

Response: Under the final GS rule, owners or operators will need to determine whether the CO2

207
stream is hazardous under EPA’s RCRA regulations, and if so, any injection of the hazardous CO2

stream may only occur in a Class I hazardous waste injection well. Conversely, Class VI wells

cannot be used for the co-injection of RCRA hazardous wastes (i.e., hazardous wastes that are

injected along with the CO2 stream). 

EPA received many comments regarding the applicability of the RCRA regulations and statute to

CO2 streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit.

Commenter Name: William Kovacs Letter ID: 0148

Commenter Organization: U.S. Chamber of Commerce Comment ID: 21767

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: Such overwhelming regulatory uncertainty will only serve to deter investment in 

CCS technology and slow the rate at which large-scale commercial CCS projects 

are developed. Instead, EPA needs to examine and explain which environmental 

statutes could be triggered, how they will interact or overlap, and what 

potential liability exists for industry. EPA should also explore the possibility 

of creating regulatory exemptions under RCRA, CERCLA, etc., for injected CO2, 

thereby reducing regulatory hurdles for CCS projects. One example of this would 

be to ensure that final Class VI permits have the broadest possible reach to 

maximize the protection offered by CERCLA’s "federally permitted release" [FN9 

CERCLA, Section 107(j).] exemption. This would mean including within the scope 

of the permit for carbon dioxide injection all other CERCLA hazardous 

constituents likely to be contained in the CO2 stream, thus providing some 

comfort to owners and operators that they will not be subject to CERCLA 

liability. When you consider that EPA lacks the authority to transfer well 

ownership between entities, and that owners are therefore liable in perpetuity, 

the need to craft regulatory exemptions becomes clear. 

208
Response: EPA agrees that any requirements for the CO2 stream should be clearly identified. EPA

received many comments regarding the applicability of the RCRA regulations and statute to CO2

streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

As described above, EPA clarifies that the GS rule requires owner or operators of Class VI wells to

characterize their injection stream prior to injection, and throughout the operational life of the

injection facility. If the CO2 stream is determined to be a hazardous waste, injection may only occur

in a Class I hazardous waste injection well. 

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit. 

EPA adds that providing financial incentives for or promoting the use of GS is outside the scope of

the GS rule.

Commenter Name: Brianne Metzger Letter ID: 0151

Commenter Organization: Spectra Energy Corp Comment ID: 21852

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: III. EPA MUST ADDRESS THE LEGAL UNCERTAINTIES AND IMPEDIMENTS

TO CCS. 

As has been well documented elsewhere, including a recent GAO report, [3] the 

legal uncertainties related to underground injection of CO2, including the 

possible application of CERCLA and RCRA, are a very real legal impediment to 

the viability of carbon capture and geologic sequestration. We agree with the 

GAO’s recommendation that EPA more comprehensively examine CERCLA and RCRA as a 

potential barrier to CCS. As discussed in greater detail below, we believe the 

Agency has sufficient authority to develop responsible policies and regulations 

that provide the requisite protection to owner/operators of GS operations while 

still ensuring the adequate protection of human health and the environment. 

Toward this end, we would ask the EPA to further examine and clearly articulate 

209
what it believes is the outer bounds of its statutory and regulatory authority 

to provide such legal certainty. If, in the event EPA does not believe it has 

such authority or, for whatever reason, is unwilling to invoke such authority, 

we would request the Administration and the Agency work with Congress to enact 

legislation to bring about the needed legal certainty. 

3 GAO Report, Climate Change, Federal Actions Will Greatly Affect the Viability 

of Carbon Capture and Storage As a Key Mitigation Option, REPORT TO THE 

CHAIRMAN ON THE SELECT COMMITTEE ON ENERGY INDEPENDENCE AND GLOBAL

WARMING, 

HOUSE OF REPRESENTATIVES, GAO-08-1080 (September 2008). 

Response: EPA agrees that any requirements for the CO2 stream should be clearly identified. EPA

received many comments regarding the applicability of the RCRA regulations and statute to CO2

streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

The GS Rule is being promulgated appropriately under the SDWA. Injection wells are regulated

under the authority of Part C of the SDWA (42 U.S.C. 300h et seq.). Under the SDWA, the

underground injection of any "fluid" is subject to the requirements of the UIC program. "Fluid" is

defined under 40 CFR 144.3 as any material or substance which flows or moves, whether in a

semisolid, liquid, sludge, gas or other form or state, and includes liquids, gases, and semisolids (i.e.,

slurries) injected into the subsurface. EPA adds that comments related to requesting Congress for

additional authority are outside the scope of this rulemaking.

Commenter Name: Brianne Metzger Letter ID: 0151

Commenter Organization: Spectra Energy Corp Comment ID: 21853

Comment: A. The Liability Regime Under CERCLA Is Inappropriate For GS And EPA Must 

Minimize To The Fullest Extent Of Its Authority; Alternatively, Congress Must 

Act. 

The potential application of the sweeping liability regime under the 

Comprehensive, Environmental Response, Compensation, and Liability Act of 1980 

("CERCLA") will have an absolute chilling effect on the underground injection 

of CO2. The threat of CERCLA litigation and the potential liability to a GS 

owner or operator is alone significant and could seriously discourage the 

siting and construction of a GS operation. Under CERCLA’s strict liability 

regime, an owner or operator may be held jointly and severally liable for 

response costs related to any release or potential release of a hazardous 

substance from a facility. In addition to federal and state enforcement 

210
actions, CERCLA also authorizes private parties to seek remediation costs from 

an owner/operator who is alleged to have caused an actionable release under 

CERCLA. Therefore, given the extensive size of the CO2 plume, covering tens of 

square miles, a private landowner within the AoR and whose property is situated 

above the CO2 plume could potentially assert a CERCLA claim against an 

owner/operator of a GS operation. In its proposed GS Rule, EPA states as 

follows: 

[W]hether or not there is a hazardous substance that may result in CERCLA 

liability from a sequestration facility depends entirely on the make-up of the 

specific CO2 stream and of the environmental media (e.g., soil, groundwater) in 

which it is stored. 

Unfortunately, the Proposed Rule leaves considerable uncertainty regarding 

potential CERCLA liability. See GAO Report, Climate Change: federal actions 

will greatly affect the viability of carbon capture and storage as key 

mitigation option, GAO-08-1080, September 2008. 

Response: The Agency acknowledges the commenter's concerns regarding the scope and possible

impacts of CERCLA liability on CCS activities, however EPA notes that the GS rule is not

promulgated under 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. To the extent the commenter is seeking interpretations of

RCRA or CERCLA, such interpretations are beyond the scope of this rulemaking.

Commenter Name: Brianne Metzger Letter ID: 0151

Commenter Organization: Spectra Energy Corp Comment ID: 21854

Comment: We oppose the application of CERCLA liability to owner/operators of GS 

facilities, particularly where the owners/operators may have very little 

control, if any, over the migration of the CO2 plume or geochemical reactions 

post-injection. As the Agency has acknowledged, despite all the geologic and 

geochemical data that is developed as part of the UIC permitting process, there 

may be unknown and unanticipated geochemical reactions that occur underground 

post-injection that could constitute a "release" [4] under CERCLA, thereby 

triggering liability. Scenarios that could potentially constitute a release 

under CERCLA include: (1) migration of CO2 from the injection zone into 

another zone or outside the AoR; (2) migration of displaced brine or fluids 

outside the injection zone, (3) geochemical reactions within or outside of the 

injection zone, and (4) atmospheric releases of CO2. Subsurface releases that 

are geologically contained (releases (1) - (3) above), even if they migrate 

beyond the AoR or out of the injection zone, ordinarily will not result in a 

type of release that threatens the ambient environment or presents an imminent 

and substantial endangerment to human health and the environment, unless a USDW 

is endangered. 

It is important to emphasize that CO2 is itself not a "hazardous substance" 

under CERCLA nor under any other federal environmental law. However, as EPA 

points out, some of the impurities potentially contained in a CO2 stream, such 

as mercury and sulfuric acid, are hazardous substances even though their 

211
concentrations, according to EPA, are "expected to be very low." GS Rule at 

43503. Thus, the presence and possible release of these impurities could give 

rise to CERCLA liability. 

Spectra strongly believes that an owner/operator of a GS injection well who 

materially complies with the terms of its UIC permit as a general rule should 

not be subject to CERCLA liability. While there may be limited circumstances, 

such as a catastrophic release of CO2 to the atmosphere,[5] where CERCLA may be 

appropriate, we believe as a general matter CERCLA liability is not necessary 

and serves as a major deterrent to large-scale commercial deployment of GS. 

Consequently, we believe the Agency must seek to establish a "safe harbor" for 

those engaged in GS operations. Such safe harbor must include the CO2 and any 

impurities by clarifying minimum performance standards, employed technologies, 

or testing requirements, which if used, will exempt subsurface releases from 

CERCLA liability. Toward this end, the Agency has suggested that several 

enumerated defenses under CERCLA, such as the "federally permitted release" 

provision, may provide sufficient safe harbor. However, as discussed below, 

Spectra is concerned that this defense is woefully inadequate. 

B. EPA Must Clarify And Expand The Scope Of The "Federally Permitted Release" 

Defense Which Has Been Seriously Eroded By Court Decisions. 

Section 107(j) of CERCLA provides that any release that occurs pursuant to an 

approved federal permit or program is not subject to CERCLA liability.[6] This 

provision is known as the "federally permitted release" exemption. Among the 

list of 11 enumerated federally permitted releases is "any injection of fluids 

authorized under Federal underground injection control programs or State 

programs submitted for Federal approval . . . pursuant to part C of the Safe 

Drinking Water Act" (hereafter referred to as the "UIC Exemption"). 42 U.S.C. 

§ 9601(10)(G). Although the EPA cites the federally permitted release defense 

as a way for an owner/operator to avoid liability, this defense or statutory 

exemption has been seriously eroded in recent years by court decisions. See, 

e.g., Carson Harbor Vill, Ltd. v. Unocal Corp., 287 F. Supp. 2d 1118 (C.D. Cal. 

2003) (court found liability for releases that (1) are not expressly permitted 

(2) exceed the limitations of the permit or (3) occur at a time when there was 

no permit); State of Idaho v. Bunker Hill Company, 635 F.Supp. 665 (D. Idaho 

1986) (court held that a federally permitted release must be expressly 

identified in a permit). [7] 

Given that subsurface plumes from commercial GS operations may encompass 50 

square miles or more (roughly the size of the District of Columbia), this 

defense provides little comfort to an owner/operator of a GS injection facility 

who could incur tens of millions of dollars in response costs under CERCLA. In 

order for this statutory defense to have any meaningful application in the 

context of GS, and to provide the shield Congress intended, EPA must 

resuscitate this provision by providing further clarification of where and how 

it should apply. There is precedent for the Agency providing clarification of 

the scope and extent of the "federally permitted release" exemption in the 

context of air emissions with respect to reporting requirements for releases. 

See Guidance on the CERCLA Section 101(10)(H) Federally Permitted Release 

212
Definition for Certain Air Emissions, 67 Fed. Reg. 18899 (April 17, 2002). As 

EPA acknowledged in this guidance, it is difficult to establish a "bright line" 

for when releases qualify for the release exemption. However, we believe the 

Agency needs to do just that - establish a bright line. 

EPA has the authority and discretion to interpret and further clarify the scope 

and extent of the "federally permitted release" exemption to GS injection. A 

review of the 11 enumerated releases under 101(10) reveals dissimilar text, 

wherein some of the exemptions include phrases like "in compliance with," 

"subject to," "identified in," or "authorized under." The language used for 

the UIC Exemption, does not specifically limit the exemption to compliance with 

or the terms identified in an enforceable permit; rather, the UIC Exemption 

uses a much broader phrase "authorized under." Herein, the UIC Exemption 

applies to the (i) injection of fluids (ii) authorized under (iii) federal or 

an approved state UIC program. The EPA Environmental Appeals Board had 

occasion to construe these 11 exemptions and their dissimilar language and 

reasoned that Congress' use of different phrases must be given due effect. See 

In re Mobil Oil Corporation, EPCRA Appeal No. 94-2, 5 EAD 490, 1994 WL 544260 

(EAB, Sept. 29, 1994) (construing the meaning of the phrase "subject to" and 

the statutory purposes of the Clean Air Act and CERCLA).[8] 

Under the plain language of this UIC Exemption, the Agency has the authority to 

define more broadly (whether pursuant to a permit or outside the context of a 

permit) what fluids and releases are authorized by either the federal or state 

UIC program. This issue is significant in that the Agency has stated in the GS 

Rule: "Class VI requirements and permits will need to be carefully structured 

to ensure that they do not ‘authorize’ inappropriate hazardous releases . . . 

include clarifying if there are potential release from the well which are 

outside the scope of the Class VI permit." GS Rule at 43504. 

First, it is clear that the Agency believes there are certain releases that are 

"inappropriate" and that, if occur, would give rise to CERCLA liability. This 

raises many concerns and more questions than answers. What releases are deemed 

outside the scope of the Class VI permit? Is any subsurface release not 

specifically identified in a UIC permit an inappropriate release? Is an 

unanticipated geochemical reaction an inappropriate release or outside the scope 

of the Class VI permit? Is the migration of a CO2 stream out of the injection 

zone or AoR a release whether or not it endangers a USDW? How would an 

appropriate v. inappropriate release be determined? As evidenced from these 

questions, it is critical that the Agency clarify what is meant by the term 

"inappropriate" hazardous release and in what context such releases may be 

outside the scope of the UIC program. 

Based on the case law, for an owner/operator to maximize its shield under the 

exemption, all potential releases should be identified and authorized under the 

permit, including appropriate and inappropriate ones. Thus, there is clear 

tension between EPA’s statement that no inappropriate release be authorized by 

permit and the current state of the law which requires all releases be 

identified in a permit to benefit from the exemption. 

213
It is unambiguous from the plain text of the statute that Congress intended 

that releases authorized under the SDWA UIC program not be subject to CERCLA 

liability. It is also clear that the Agency has broad authority to clarify 

what releases should be covered under the GS Rule. Therefore, the Agency need 

not wait for the issuance of permits to decide on a case-by-case basis what is 

an appropriate or inappropriate release. EPA should make clear that all 

fluids injected pursuant to an authorized program or an approved permit will 

not give rise to CERCLA liability where the release occurs in and effects only 

subsurface formations and is geologically contained. The Agency could 

authorize, for example, the migration of the CO2 stream outside the injection 

zone or any other release that does threaten ambient air. 

The extension of the UIC Exemption to subsurface or geologically contained 

releases is appropriate in that subsurface releases of CO2 are fundamentally 

different than releases of CO2 to ambient air. Releases of sufficient 

quantities of CO2 to ambient conditions can pose serious health risks and even 

death. Whereas, the slow movement of a CO2 plume in confined subsurface strata 

ordinarily presents little, if any, imminent or substantial risk to human 

health or the environment. EPA has recognized the distinction in the nature 

and risks of subsurface and ambient releases of CO2. See GS Rule at 43498 

("geologic confining systems do not experience . . . rapid and complete 

turnover [of CO2]"). Thus, while the application of CERCLA may still be 

appropriate in the event of releases of CO2 to the ambient air, the statute is 

not necessary to address releases that involve only subsurface locations. 

Unlike the decision in In re Mobil, where the broad interpretation of the 

CERCLA air exemption would leave a gap in the government’s ability to respond 

to a release, in the case of a subsurface release from a GS injection well, no 

such gap would exist, as the Agency has broad authority under SDWA to respond 

appropriately. In addition to civil, criminal and administrative enforcement 

authorities under the UIC program, 42 U.S.C. § 300h-2, and the potential to 

levy substantial monetary penalties, the EPA Administrator has broad emergency 

powers under SDWA to respond to a threat to any source of underground drinking 

water. Specifically, Section 300i says: 

[T]he Administrator, upon receipt of information that a contaminant which is 

present in or is likely to enter a public water system or an underground source 

of drinking water . . . which may present an imminent and substantial 

endangerment to the health of persons, and that appropriate State and local 

authorities have not acted to protect the health of such persons, may take such 

actions as he may deem necessary in order to protect the health of such persons. 

42 U.S.C. § 300i 

Under this emergency authority, the Administrator make take whatever measures 

necessary to protect human health, including ordering any corrective action or 

replacement of drinking water supplies or commencing a civil action for 

appropriate relief, including a restraining order or permanent or temporary 

injunction. Thus, the Agency has adequate authority under SDWA to address any 

release or contamination that presents an endangerment. 

4 The term "release" is broadly defined to mean"any spilling, leaking, pumping, 

214
pouring, emitting, emptying, discharging, injecting, escaping, leaching, 

dumping, or disposing into the environment (including the abandonment or 

discarding of barrels, containers, and other closed receptacles containing any 

hazardous substance or pollutant or contaminant)." 42 U.S.C. § 9601(22). The 

term "release" specifically excludes "emissions from engine exhaust of a motor 

vehicle, rolling stock, aircraft, vessel, or pipeline pumping station engine." 

Although this exemption has not been interpreted by many courts, it does 

represent Congress’ clear intent to exempt CO2 emissions (and other impurities) 

from vehicles or vessels that might otherwise constitute a release under 

CERCLA. Arguably, it also denotes a qualitative distinction between CO2 and 

other hazardous substances for which Congress saw fit to apply CERCLA. 

5 If a catastrophic release of CO2 occurred, it would be the release of CO2 

itself, and not the minute constituents of other impurities contained in the 

CO2, that would arguably threaten human health and the environment. However, 

CO2 is not a hazardous substance and therefore would not trigger release 

reporting requirements under CERCLA or the Emergency Planning And Community 

Right-to-Know Act (EPCRA). Another regulatory regime may be more appropriate 

to deal with this potential scenario. 

6 Section 107(j) says "recovery by any person . . .for response costs or 

damages resulting from a federally permitted release shall be pursuant to 

existing laws in lieu of this section." 

7 See also Kurt Ryland, Saving A Disappearing Exemption To CERCLA Liability, 

N.Y.U. ENV. L.J. (1995). According to the author, federal courts have 

threatened the utility of the exemption through holdings that have weakened the 

protective shield provided by a permit. The author explores these decisions 

and how they leave many unanswered questions concerning the exemption's 

coverage. 

8 In the In re Mobil case, the defendant violated its Clean Air Act permit and 

EPA initiated an enforcement action for the defendant’s failure to provide 

notice of a release under EPCRA. Mobil argued that even if its emissions 

violated any specific permit limit, its emissions were subject to the federal 

permitting release exemption because the emissions were "subject to" a state 

issued implementation plan. Ultimately, the EAB rejected Mobil’s argument 

after concluding that Mobil’s argument would create a gap in the government’s 

ability to respond adequately to air releases of hazardous substances. 

Response: EPA thanks the commenter for their detailed comments and recommendations regarding

the applicability of CERCLA and the scope of the exemption for federally permitted releases, in

response to the Agency’s request. CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Therefore, Class VI requirements and permits will need to be carefully structured to ensure

that they do not “authorize” inappropriate releases, and would need to prevent potential releases from

the well which are outside the scope of the Class VI permit. EPA reiterates that the GS rule is not

promulgated under 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. To the extent the commenter is seeking interpretations of

215
CERCLA and its related provisions, such as the definition of a federally permitted release, such

interpretations are beyond the scope of this rulemaking. 

The UIC program Director has authority under SDWA §1423 to address potential compliance issues

(e.g., potential releases that may endanger USDWs) resulting from injection violations in the unlikely

event that a remedial response is necessary. Although EPA anticipates that the need for emergency

or remedial actions at GS sites will be rare, the GS rule requires, at §146.94, that emergency and

remedial response plans be developed and updated to address such events and that owners or

operators demonstrate that financial resources are set aside to implement the plans if necessary, per

§146.85.

Regarding long term liability, once an owner 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. Furthermore, 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 certain

circumstances. For example, an owner or operator may be held liable for regulatory noncompliance

even after site closure was approved if the Director relied on erroneous information (e.g., erroneous

modeling data) provided by the owner or operator when approving site closure. 

Separate from EPA’s authority to enforce regulatory compliance, an owner or operator may be

subject to a §1431 response order even after proper site closure 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 present an imminent and substantial endangerment to the health of

persons, and the appropriate State and local authorities have not acted to protect the health of such

persons. The action may include issuing administrative 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 operator may remain liable under tort and other remedies,

or under other federal statutes including, 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.

Commenter Name: James Childress Letter ID: 0158

Commenter Organization: Gasification Technologies Council (GTC) Comment ID: 23757

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 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 CO2 containing trace contaminants does not open any regulatory 

pathways for subjecting a geological storage site to Superfund liability. As 

216
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 CO2 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 would 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 CO2 portion of the 

stream and explicitly exclude any trace contaminants. 

By its inherent nature, gasification will provide a stream 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 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 CO2 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. 

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 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. To the extent the commenter is seeking interpretations of RCRA or

CERCLA, such interpretations 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 low. However, the GS rule does

not set generic purity standards for CO2 injectate streams (e.g., a percent CO2). Instead, the GS rule

addresses the quality and quantity of impurities by requiring owners or operators to submit

information on the source of the CO2 and its physical and chemical properties. Specifically, the GS

rule requires the owner or operator to submit data about the site, including an analysis of the

chemical and physical characteristics of the CO2 stream, as required at §146.82(a)(7)(iv), and

information on the 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 potential for geochemical

reactions between the injectate (CO2) and the host geologic formations, which could result in the

plugging of pore spaces or the dissolution of formation minerals.

217
Commenter Name: James Childress Letter ID: 0158

Commenter Organization: Gasification Technologies Council (GTC) Comment ID: 23758

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 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 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 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. 

Response: Again, 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 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.

Commenter Name: Skiles Boyd Letter ID: 0160

Commenter Organization: DTE Energy Comment ID: 21271

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: CHARACTERIZATION OF CO2 

The preamble discussion regarding the characterizations of CO2 is confusing. 

The preamble includes an analysis of the potential application of RCRA to CO2 

injection and storage activities that appear to be based upon an assumption that 

CO2 is not a "commodity" but a "waste". Yet EPA does not wish to characterize 

CO2 as either. As the regulated entity that will want to utilize this 

technology in the future, it would help us on several fronts (unnecessary 

regulatory burdens, public acceptance not being the least of these concerns) if 

EPA did reconsider this position and add some clarifying language to the 

218
regulations. EPA should revisit the application of RCRA and CERCLA regulation 

to the UIC program for CO2 injection. DTE Energy endorses EEI’s recommendation 

for EPA to consider CO2 injected under the UIC program as either exempted or 

excluded from regulation under RCRA or CERCLA or adapt performance standards to 

the injectate that again exclude RCRA and CERCLA regulation. For example, EPA 

could appropriately establish a permit condition that injectate must meet Toxic 

Characteristic Leaching Procedure or pH standards without reference to 

material’s waste status. 

Response: EPA agrees that any requirements for the CO2 stream should be clearly identified. Under

the final GS rule, owners or operators will need to determine whether the CO2 stream is hazardous

under EPA’s RCRA regulations, and if so, any injection of the hazardous CO2 stream may only

occur in a Class I hazardous waste injection well. Conversely, Class VI wells cannot be used for the

co-injection of RCRA hazardous wastes (i.e., hazardous wastes that are injected along with the CO2

stream). 

EPA received many comments regarding the applicability of the RCRA regulations and statute to

CO2 streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit.

Commenter Name: Joseph Eutizi Letter ID: 0161

Commenter Organization: San Miguel Electric Cooperative, Inc Comment ID: 21289

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: 6. EPA must settle the way GS activities will relate to RCRA and CERCLA. RCRA is 

simply the wrong tool to use to regulate GS of CO2 and EPA needs to find a way 

to insure that the onerous requirements of CERCLA, (never intended for GS of 

CO2), are not applied to this highly specialized gas storage operation. 

7. Dealing with these last two hazardous waste issues appears to San Miguel to 

219
be one of the most difficult hurdles standing in the way of commercial 

deployment of full scale GS projects and we recognize that Congressional action 

may be needed. 

Response: EPA agrees that any requirements for the CO2 stream should be clearly identified. EPA

received many comments regarding the applicability of the RCRA regulations and statute to CO2

streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit.

Commenter Name: Sandi Tabor Letter ID: 0162

Commenter Organization: Lignite Energy Council (LEC) Comment ID: 21303

Comment: 4. Categorization of injected C02 as a hazardous substance under CERCLA EPA 

seeks comment on whether Class VI permittees could be exempted from CERCLA under 

its "federally permitted release" provision. First, liability under CERCLA 

depends on whether there has been a disposal of hazardous substances. While CO2 

is not a CERCLA hazardous substance, EPA suggests in the preamble that the 

makeup of a particular injected C02 stream may trigger a CERCLA analysis. 

However, the preamble also states that CERCLA's federally permitted releases 

provision exempts releases in compliance with a UIC permit under SDWA from 

CERCLA liability. This exemption in and of itself should put the issue to rest. 

We urge the EPA to fully address the longterm liability for stored C02 under 

UIC Class VI Well permit. EPA should avoid creating unnecessary hurdles for the 

successful deployment of CCS by preempting the applicability of CERCLA to Class 

VI activities. 

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 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

220
regulations that may apply.

CERCLA exempts from liability, under CERCLA section 107, 42 U.S.C. 9607, certain “federally

permitted releases” as defined in CERCLA, 42 U.S.C. 9601(10). Therefore, Class VI requirements

and permits will need to be carefully structured to ensure that they do not “authorize” inappropriate

releases, and would need to prevent potential releases from the well which are outside the scope of

the Class VI permit. 

The UIC program Director has authority under SDWA §1423 to address potential compliance issues

(e.g., potential releases that may endanger USDWs) resulting from injection violations in the unlikely

event that a remedial response is necessary. Although EPA anticipates that the need for emergency

or remedial actions at GS sites will be rare, the GS rule requires, at §146.94, that emergency and

remedial response plans be developed and updated to address such events and that owners or

operators demonstrate that financial resources are set aside to implement the plans if necessary, per

§146.85.

Regarding long term liability, once an owner 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. Furthermore, 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 certain

circumstances. For example, an owner or operator may be held liable for regulatory noncompliance

even after site closure was approved if the Director relied on erroneous information (e.g., erroneous

modeling data) provided by the owner or operator when approving site closure. 

Separate from EPA’s authority to enforce regulatory compliance, an owner or operator may be

subject to a §1431 response order even after proper site closure 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 present an imminent and substantial endangerment to the health of

persons, and the appropriate State and local authorities have not acted to protect the health of such

persons. The action may include issuing administrative 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 operator may remain liable under tort and other remedies,

or under other federal statutes including, 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.

Commenter Name: James Stine Letter ID: 0163

Commenter Organization: National Rural Electric Cooperative Association

(NRECA)

Comment ID:

21317

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: § EPA must settle the way GS activities will relate to RCRA and CERCLA. RCRA is 

221
simply the wrong tool to use to regulate GS of CO2 and EPA needs to find a way 

to insure that the onerous requirements of CERCLA, (never intended for GS of 

CO2), are not applied to this highly specialized gas storage operation. 

§ Dealing with these last two hazardous waste issues appears to NRECA to be one 

of the most difficult hurdles standing in the way of commercial deployment of 

full scale GS projects and we recognize that Congressional action may be needed. 

Response: EPA agrees that any requirements for the CO2 stream should be clearly identified. EPA

received many comments regarding the applicability of the RCRA regulations and statute to CO2

streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit.

Commenter Name: James Stine Letter ID: 0163

Commenter Organization: National Rural Electric Cooperative Association

(NRECA)

Comment ID:

21330

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: The CCS Alliance has evaluated technical, market, and policy risks associated 

with CCS deployment. On behalf of the CCS Alliance, Andrew Paterson of Econergy 

International interviewed dozens of market participants earlier this year, 

including project developers, utilities, technology vendors, risk managers, and 

financial providers to assess which risks were considered most likely to occur, 

and which, if they occurred, would be considered to have the greatest impact to 

the project. The CCS Alliance study showed that market participants identified 

one of the highest risk factors to be the lack of clarity in EPA and state 

regulations dealing with the technical aspects of injection and with liability. 

NRECA believes that the largest and most important aspect of the proposed UIC 

regulations will be how GS activities are coordinated with RCRA and CERCLA. 

Currently we believe that this is one of the most difficult hurdles standing in 

222
the way of commercial deployment of full scale GS projects. One way of dealing 

with this issue to avoid classifying injected CO2 as a waste. ******** 

Response: EPA agrees that any requirements for the CO2 stream should be clearly identified. EPA

received many comments regarding the applicability of the RCRA regulations and statute to CO2

streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit.

Commenter Name: James Stine Letter ID: 0163

Commenter Organization: National Rural Electric Cooperative Association

(NRECA)

Comment ID:

21332

Comment: 10. Likewise the specter of regulation under Superfund exposes a GS project to 

potentially unknown and open-ended liabilities. Obtaining a UIC permit and 

carefully defining the AoR should go a long way toward protecting the 

environment. Subjecting the project to Superfund, may not significantly increase 

environmental protection, but it would surely increase risks and liabilities for 

the owner/operator. NRECA believes that there may be no other answer than to 

exempt GS projects from superfund. EPA discusses the availability of a shield 

from superfund liability being provided by the "federally permitted release" 

exclusion, however in the event of any unforeseen circumstance or accident that 

is not explicitly identified in the permit, such protection would vanish. 

Unfortunately, NRECA doubts that EPA can find a way to design reliable 

regulatory and liability protection to save GS projects from unnecessary 

involvement with Superfund while ensuring that they "do not authorize 

inappropriate hazardous releases" (ibid at 43504). 

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 that statute will not be determined under the SDWA or

223
the terms of the GS rule, but rather according to the CERCLA statute itself and any implementing

regulations that may apply.

EPA agrees that proper site characterization and AoR studies are important for USDW protection. In

addition, the UIC program Director has authority under SDWA §1423 to address potential

compliance issues (e.g., potential releases that may endanger USDWs) resulting from violations of

the Class VI permit in the unlikely event that a remedial response is necessary. Although EPA

anticipates that the need for emergency or remedial actions at GS sites will be rare, the GS rule

requires, at §146.94, that emergency and remedial response plans be developed and updated to

address such events and that owners or operators demonstrate that financial resources are set aside to

implement the plans if necessary, per §146.85.

Regarding long term liability, once an owner 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. Furthermore, 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 certain

circumstances. For example, an owner or operator may be held liable for regulatory noncompliance

even after site closure was approved if the Director relied on erroneous information (e.g., erroneous

modeling data) provided by the owner or operator when approving site closure. 

Separate from EPA’s authority to enforce regulatory compliance, an owner or operator may be

subject to a §1431 response order even after proper site closure 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 present an imminent and substantial endangerment to the health of

persons, and the appropriate State and local authorities have not acted to protect the health of such

persons. The action may include issuing administrative 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 operator may remain liable under tort and other remedies,

or under other federal statutes including, 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.

Commenter Name: Theresa Pugh Letter ID: 0169

Commenter Organization: American Public Power Association Comment ID: 23365

Comment: Interaction with CERCLA -- Pg. 37 

APPA believes that Congress will need to act to correct the potential for open ended 

CERCLA liability for any contamination resulting from CO2 GS activities 

before commercial deployment should be expected. 

Response: The Agency acknowledges the commenter’s concern regarding the scope and possible

224
impacts of CERCLA liability on CCS activities. EPA notes that the GS rule is not promulgated under

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.

Commenter Name: Theresa Pugh Letter ID: 0169

Commenter Organization: American Public Power Association Comment ID: 23379

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: 7. Congress must address a number of critical liability issues under CERCLA and 

RCRA to enable widespread commercial deployment of geosequestration of CO2 from 

power plants. That issue primarily is outside the scope of this rulemaking but 

must be acknowledged. Unless these issues are resolved, first generation plants 

cannot progress. As EPA recognized in its ANPR on CO2, this UIC rulemaking 

provides one opportunity to address these issues, while protecting the public 

health and welfare under the Safe Drinking Water Act. 

Response: EPA agrees that overlapping regulatory schemes are undesirable. EPA received many

comments regarding the applicability of the RCRA regulations and statute to CO2 streams that are

geologically sequestered under the final Class VI UIC well requirements. As a result, EPA has

decided to initiate a separate proposed rulemaking specifically to examine the issue of RCRA

applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit.

Commenter Name: Theresa Pugh Letter ID: 0169

Commenter Organization: American Public Power Association Comment ID: 23421

Comment: Interaction with CERCLA 

APPA has been bothered by the risks of CERCLA given the complexities of what can 

trigger CERCLA and remediation under the statute’s ARARs. (Applicable or 

Relevant and Appropriate Requirements). A critically important issue on which 

225
EPA seeks comment is the interaction of the CO2 GS regulatory program with the 

Comprehensive Environmental Response, Compensation, and Liability Act 

("CERCLA"). While EPA acknowledges that "CO2 itself is not listed as a hazardous 

substance under CERCLA," the Agency raises the specter of potential CERCLA 

liability if the CO2 stream contains other CERCLA hazardous constituents (e.g., 

mercury), or if other hazardous constituents are formed when the injected CO2 

stream reacts with groundwater (e.g., sulfuric acid). Id. at 43504. As EPA can 

surely appreciate, the potential for open-ended CERCLA liability for any 

contamination resulting from CO2 GS activities will act as a serious deterrent 

to would-be Owners or Operators of Class VI wells and could jeopardize the 

contemplated wide-spread commercial deployment of CO2 GS operations. CERCLA 

liability would be the ultimate disincentive for commercial deployment. APPA 

believes that Congress will need to act to correct this risk before commercial 

deployment should be expected. APPA’s white paper on CERCLA issues by Marianne 

Horinko, former Acting EPA Administrator, and career policy senior manager at 

the U.S. EPA on CERCLA and other waste matters address these points. That paper 

is found in the Appendix. [FN8] [See EPA-HQ-OW-2008-0390-0169.pdf for this document.] 

EPA correctly acknowledges that CERCLA’s "federally permitted release" exemption 

will provide CERCLA protection from those "releases" that fall within the scope 

of a Class VI permit (e.g., contained within the Area of Review ("AoR")), but 

the Agency also recognizes the limitations of this exemption, as it does not 

offer protection for any release of a hazardous substance that is out the scope 

of the Class VI permit (e.g., outside the AoR). Indeed, EPA states that any 

permits will have to "be carefully structured to ensure that they do not 

'authorize' inappropriate hazardous releases," including "potential releases 

from the well which are outside the scope of the Class VI permit." Id. 

APPA appreciates that the contamination issue is extremely important and should 

be addressed in the Final Rule. However, we have no reason to believe that the 

technology and safeguards developed to prevent migration of injected CO2 or its 

constituents will fail. At the same time, the specter of open-ended CERCLA 

liability will impede the ability of Owners or Operators to calculate and 

demonstrate financial responsibility, obtain financial assurance, and obtain the 

initial capital necessary to invest in this important technology. Simply put, 

EPA (and Congress) must mitigate the threat of potential CERCLA liability to the 

extent possible in this rulemaking. 

One step that the Agency can take is to ensure that final Class VI permits for 

individual CO2 GS projects have the broadest possible reach - while remaining 

protective of USDWs - to maximize the protection offered by the Federally 

Permitted Release exemption. This would mean including in the scope of the 

permit for CO2 injection all other CERCLA hazardous constituents likely to be 

contained in the CO2 stream, including those generated during capture and 

transport as well as any that could be formed in the injection zone as a result 

of the injection of CO2. Similarly, the scope of the authorized "permit zone" 

should be as broad as possible while remaining protective of USDWs. This could 

mean, for example, effectively authorizing the migration of constituents 

contained in the CO2 stream (or resulting from injection) outside the scope of 

the AoR, provided that such migration does not directly impact a USDW. 

226
The bottom line is that the potential for unlimited CERCLA liability must be 

mitigated to avoid significant delays and an overall chilling effect for 

geosequestration. APPA recognizes that while there are some measures the Agency 

can take in the regulatory context to address this concern, including those 

described above, those measures may be limited. In the end, APPA believes that a 

legislative solution is critical to eliminate this liability concern. APPA 

recommends that the EPA strongly support such a broader liability solution and 

communicate that support to Congress at the appropriate time. 

[FN8]Marianne Horinko "Carbon Capture and Sequestration Legal and Environmental 

Challenges Ahead," August 2007 

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 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.

As described above, whether the release of any hazardous substances in the CO2 may result in

CERCLA liability from a sequestration facility depends entirely on the composition of the specific

CO2 stream and the environmental media in which it is stored (e.g., soil or ground water). CERCLA

exempts from liability, under CERCLA section 107, 42 U.S.C. 9607, certain “federally permitted

releases” as defined in CERCLA, 42 U.S.C. 9601(10). Class VI permits will need to be carefully

structured to ensure that they prevent potential releases from the well which are outside the scope of

the Class VI permit. 

Comments recommending that EPA support legislation for purposes of creating a broader liability

framework for GS are outside the scope of this rulemaking.

Commenter Name: Kyle Isakower Letter ID: 0170

Commenter Organization: American Petroleum Institute Comment ID: 24220

Comment: Rule Provisions: 73 FR 43504 

EPA Preamble Question: 8. Class VI requirements and permits will need to be 

carefully structured to ensure that they do not "authorize" inappropriate 

hazardous releases. This would include clarifying if there are potential 

releases from the well which are outside the scope of the Class VI permit. EPA 

requests comment on particular situations where this might occur. EPA notice 

43504. 

API Response: Well chosen sites should prevent these conditions from occurring. 

At the same time, permit writers should not write permits so restrictive as to 

make the undertaking of a GS project untenable. EPA should remember that CERCLA 

liability will not only impact owners and operators of GS projects, but also 

hundreds, thousands, and even more numerous pore space owners. EPA should 

consider the threat of subjecting these pore space owners to CERCLA liability. 

Their property interests in the CO2 GS project injection zones could subject 

them to strict, joint, and several liability under CERCLA pursuant to whatever 

227
liability theories might be developed by future litigants seeking compensation 

for response and remediation costs incurred in the cleanup of releases from 

geologic sequestration injection zones. EPA should recognize the significant 

chilling effect CERCLA liability concerns will have on GS projects, and seize 

the opportunity in this rulemaking to alleviate any CERCLA liability concerns to 

the greatest extent possible. 

Response: The Agency thanks the commenter for their comments regarding the scope and possible

impacts of CERCLA liability on CCS activities, and 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 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. To the extent the commenter is seeking interpretations of RCRA or CERCLA, such

interpretations are beyond the scope of this rulemaking.

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain "federally permitted releases" (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit. 

EPA agrees that proper site characterization that meets the requirements of §146.82 and §146.83 is

important for protecting USDWs. Additionally, the UIC program Director has authority under

SDWA §1423 to address potential compliance issues (e.g., potential releases that may endanger

USDWs) resulting from injection violations in the unlikely event that a remedial response is

necessary. Although EPA anticipates that the need for emergency or remedial actions at GS sites will

be rare, the GS rule requires, at §146.94, that emergency and remedial response plans be developed

and updated to address such events and that owners or operators demonstrate that financial resources

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

Regarding long term liability, once an owner 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. Furthermore, 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 certain

circumstances. For example, an owner or operator may be held liable for regulatory noncompliance

even after site closure was approved if the Director relied on erroneous information (e.g., erroneous

modeling data) provided by the owner or operator when approving site closure. 

Separate from EPA's authority to enforce regulatory compliance, an owner or operator may be

subject to a §1431 response order even after proper site closure 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 present an imminent and substantial endangerment to the health of

persons, and the appropriate State and local authorities have not acted to protect the health of such

228
persons. The action may include issuing administrative 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 operator may remain liable under tort and other remedies,

or under other federal statutes including, 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.

EPA adds that promoting the use of GS is outside the scope of the GS rule. Rather, the purpose of

the GS regulation is to ensure that, where deployed, GS is conducted in a manner that protects

USDWs from endangerment.

Commenter Name: Kyle Isakower Letter ID: 0170

Commenter Organization: American Petroleum Institute Comment ID: 24221

Comment: Rule Provisions: 73 FR 43504 

EPA Preamble Question: 9. EPA also requests comment on other considerations 

associated with the presence of impurities in the CO2 stream related to CERCLA. 

EPA Notice 43504. 

API Response: API is concerned that potential CERCLA liabilities will have the 

potential to chill enthusiasm for undertaking GS projects. EPA needs to respond 

clearly and positively to this concern by developing appropriate language in the 

regulations and permits to provide the clarity and assurance needed to promote 

continued research and development for GS projects. 

Response: Again, EPA thanks the commenter for their comments regarding the scope and possible

impacts of CERCLA liability on CCS activities. We reiterate that the GS rule is not promulgated

under 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. To the extent the commenter is seeking interpretations of CERCLA, such

interpretations are beyond the scope of this rulemaking.

Commenter Name: Erik Silvola Letter ID: 0171

Commenter Organization: Great River Energy Comment ID: 23445

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: 6. EPA must settle the way GS activities will relate to RCRA and CERCLA. RCRA is 

simply the wrong tool to use to regulate GS of CO2 and EPA needs to find a way 

to insure that the onerous requirements of CERCLA, (never intended for GS of 

CO2), are not applied to this highly specialized gas storage operation. 

7. Dealing with these last two hazardous waste issues appears to GRE to be one 

of the most difficult hurdles standing in the way of commercial deployment of 

full scale GS projects and we recognize that Congressional action may be needed. 

229
Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit.

Commenter Name: James Rower Letter ID: 0173

Commenter Organization: Utility Solid Waste Activities Group (USWAG) Comment ID: 23459

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: • EPA must resolve key policy and legal uncertainties to alleviate financial 

concerns of potential Class VI well Owners or Operators and to encourage 

investment in the development and operation of Class VI CO2 injection wells. 

Issues that must be addressed include the interaction of the Resource 

Conservation and Recovery Act ("RCRA") and the Comprehensive Environmental 

Response, Compensation, and Liability Act ("CERCLA") with Class VI injection 

activities as well as long-term post-injection liability. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

CO2 itself is not listed as a hazardous substance under CERCLA; however, the CO2 stream may

230
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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit.

Commenter Name: James Rower Letter ID: 0173

Commenter Organization: Utility Solid Waste Activities Group (USWAG) Comment ID: 23484

Comment: 7. Interaction with CERCLA 

An important issue on which EPA seeks comment is the interaction of CERCLA with 

the CO2 GS regulatory program. While EPA acknowledges that "CO2 itself is not 

listed as a hazardous substance under CERCLA," the Agency raises the possibility 

of potential liability under CERCLA, including liability for natural resource 

damages, if the CO2 stream contains other CERCLA hazardous constituents (e.g., 

mercury), or if other hazardous constituents are formed when the injected 

CO2 stream reacts with groundwater.[FN3] 73 Fed. Reg. at 43504. The potential for 

open-ended CERCLA liability for any contamination resulting from CO2 GS 

activities will act as a serious deterrent to would-be Owners or Operators of 

Class VI wells and could jeopardize the contemplated wide-spread commercial 

deployment of CO2 GS operations. 

EPA correctly acknowledges that CERCLA's "federally permitted release" exemption 

will provide CERCLA protection from those releases that fall within the scope of 

a Class VI permit (e.g., contained within the AoR), but the Agency also 

recognizes the limitations of this exemption, as it does not offer protection 

for any release of a hazardous substance that is beyond the scope of the Class 

VI permit (e.g., outside the AoR). Indeed, EPA states that any permits will have 

to "be carefully structured to ensure that they do not 'authorize' inappropriate 

hazardous releases," including "potential releases from the well which are 

outside the scope of the Class VI permit." Id. 

USWAG appreciates that the contamination issue is extremely important. At the 

same time, the potential for open-ended CERCLA liability will impede the ability 

of Owners or Operators to calculate and demonstrate financial responsibility, 

obtain financial assurance, and acquire the initial capital necessary to invest 

in this important technology. The specter of CERCLA liability will serve as a 

significant barrier to the commercial development of CO2 GS -unnecessarily so, 

given EPA's ample civil and criminal enforcement authority under the SDWA for 

violations of UIC permits (see SDWA § 1423(b), 42 U.S.C. § 300h-2(b) 

(authorizing the imposition of $32,500 per day civil penalties and/or criminal 

penalties and imprisonment)). EPA must mitigate the threat of potential CERCLA 

liability to the extent possible in this rulemaking. 

One step that the Agency can take is to ensure that final Class VI permits for 

individual CO2GS projects have the broadest possible reach while remaining 

231
protective of USDWs in order to maximize the protection offered by the federally 

permitted release exemption. This would mean including in the scope of the 

permit for CO2 injection all other CERCLA hazardous constituents likely to be 

contained in the CO2 stream, including those generated during capture and 

transport as well as any that could be formed in the injection zone as a result 

of the injection of CO2. Similarly, the scope of the authorized "permit zone" 

should be as broad as possible while remaining protective of USDWs. This could 

mean, for example, effectively authorizing the migration of constituents 

contained in the CO2 stream (or resulting from injection) outside the scope of 

the AoR, provided that such migration does not directly impact a USDW. 

We understand that EPA's authority in this rulemaking is limited by the SDWA. 

However, given the importance of this issue from a public policy perspective, we 

urge EPA to take whatever regulatory measures are available to mitigate the 

chilling effect that the potential for such open-ended liability could have on 

CO2 GS operations, and then consider whether a legislative solution is necessary 

to eliminate this concern. If so, we recommend that EPA strongly support such a 

solution. 

[FN3] In the Preamble to the Proposal, EPA suggests that sulfuric acid is one 

such hazardous substance that could be formed when the injected CO2 stream 

reacts with groundwater; it is extremely unlikely that sulfuric acid would be 

produced as a result of the injectate reacting with groundwater. 

Response: The Agency thanks the commenter for their 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. As the commenter points out, the GS rule is not

promulgated under 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. To the extent the commenter is seeking interpretations of

CERCLA and its related provisions, such as the definition of a federally permitted release, such

interpretations are beyond the scope of this rulemaking.

Commenter Name: Pamela Faggert Letter ID: 0175

Commenter Organization: Dominion Comment ID: 23529

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: 7. Interaction of CO2 with RCRA and CERCLA 

It is essential that the Agency resolve key policy and legal uncertainties 

regarding the interaction of the Resource Conservation and Recovery Act ("RCRA") 

and the Comprehensive Environmental Response, Compensation, and Liability Act 

("CERCLA or Superfund") with Class VI injection activities. EPA's proposed rule 

refers to the potential presence of unknown or unidentifiable hazardous 

constituents in various streams. See 73 Fed. Reg. at 43,503-04. This leaves 

Class VI permittees with little certainty as to which constituents, whether 

present in the CO2 stream itself, in the receiving underground soil and aquifer, 

or via some reaction between the two, might subject the permittee to liability 

under RCRA or CERCLA. This regulatory uncertainty will make it difficult for CCS 

232
to attract the investment necessary to ensure its viability as a climate 

mitigation strategy. 

Response: The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a

percent CO2). Instead, the GS rule addresses the quality and quantity of impurities by requiring

owners or operators to submit information on the source of the CO2 and its physical and chemical

properties. Specifically, the GS rule requires the owner or operator to submit data about the site,

including an analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the 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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals. 

With respect to RCRA, EPA received many comments regarding the applicability of the RCRA

regulations and statute to CO2 streams that are geologically sequestered under the final Class VI

UIC well requirements. As a result, EPA has decided to initiate a separate proposed rulemaking

specifically to examine the issue of RCRA applicability 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 particular 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 commenters who wish to submit comments on the RCRA proposal will need to do

so during the comment period for that rule. Finally, EPA also notes that the final GS rule, which

adds new regulations for Class VI wells under the Safe Drinking Water Act (SDWA), is not making

any changes to the RCRA regulations.

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” as defined in CERCLA, 42 U.S.C. 9601(10).

Class VI permits will need to be carefully structured to ensure that they prevent potential releases

from the well which are outside the scope of the Class VI permit.

Commenter Name: Pamela Faggert Letter ID: 0175

Commenter Organization: Dominion Comment ID: 23531

Comment: EPA also should incorporate in its Final Rule application of CERCLA's "federally 

permitted release" exemption to Class VI permits, which would minimize the 

potential for CERCLA liability attaching to Owners or Operators of Class VI 

injection wells. This would mean including in the scope of the Class VI permit 

all CERCLA hazardous constituents likely to be contained in the CO2 stream, 

including those generated during capture and transport, as well as any that 

could be formed in the injection zone. 

Response: The Agency thanks the commenter for their comments regarding the CERCLA exemption

for federally-permitted releases. EPA notes that the GS rule is not promulgated under CERCLA,

233
therefore the applicability and interpretation of that statute are outside the scope of this rulemaking

and 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.

Commenter Name: Pamela Faggert Letter ID: 0175

Commenter Organization: Dominion Comment ID: 23532

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: Further, EPA already has ample civil and criminal enforcement authority under 

the SDWA to address violations of UIC permits, including the ability to impose 

fines of up to $32,500 per day in civil penalties. This authority thus provides 

a significant and independent means of addressing environmental contamination. 

Finally, EPA should support legislative solutions to ensure companies employing 

CCS technologies are assured of reasonable liability protections. While CO2 is 

not listed as a hazardous substance under CERCLA, statutory exemptions under 

both RCRA and CERCLA for a clearly defined set of CO2 injection streams could be 

an appropriate device for mitigating liability concerns. Or, a more tailored 

approach to limiting the scope of RCRA and CERCLA liability for certain types of 

CCS projects could be proposed. 

In order to effectively promote CCS as a viable climate mitigation 

strategy, legal uncertainties surrounding potential CERCLA and RCRA 

liability associated with GS wells must be addressed. To this end, EPA 

should employ RCRA's "contingent management" concept and CERCLA's 

"federally permitted release" exemption as regulatory means to limit 

potential liability and uncertainty. In addition, EPA should advocate or 

support legislative solutions to limit Class VI permittee liability 

under these statutes. 

Response: EPA thanks the commenter for their suggestions and clarifies that any comments related

to supporting legislative changes to any environmental statutes are outside the scope of this

rulemaking. Changes to the RCRA and CERCLA statutes are outside the scope of the GS

rulemaking under the SDWA. EPA agrees that any requirements applicable to CO2 injectate should

be clearly identified to the public and to the regulated community. As described above, with respect

to RCRA, EPA has decided to initiate a separate proposed rulemaking specifically to examine the

issue of RCRA applicability 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.

Commenter Name: Kenneth Nemeth Letter ID: 0176

Commenter Organization: Southern States Energy Board Comment ID: 23537

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: Importantly, under the proposed rule, EPA should specify that CO2 is not 

considered hazardous, nor subject to regulation under RCRA or CERCLA, (while the 

rule recognizes that other gases could contaminate the CO2, resulting in hazards 

to USDWs). Equally important, there should not be limitations on formations that 

234
Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

With respect to CERCLA, EPA clarifies that CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream

and the environmental media in which it is stored (e.g., soil or ground water). CERCLA exempts

from liability, under CERCLA section 107, 42 U.S.C. 9607, certain “federally permitted releases”

(FPR) as defined in CERCLA, 42 U.S.C. 9601(10). Class VI permits will need to be carefully

structured to ensure that they prevent potential releases from the well which are outside the scope of

the Class VI permit.

Commenter Name: Quinlan J. Shea Letter ID: 0177

Commenter Organization: Edison Electric Institute Comment ID: 23559

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: Finally, EEI is concerned about the potential application to CCS activities of 

environmental laws that were, without exception, not intended to apply to CCS or 

even crafted with CCS in mind and that could impose significant obligations and 

potential liabilities not only on project operators, but also potentially on 

other entities in the CO2 chain, such as entities producing the CO2 that is 

ultimately injected. These laws include the Comprehensive Environmental 

Response, Compensation, and Liability Act (CERCLA or Superfund) and RCRA. EEI 

urges EPA to evaluate carefully any proposed treatment of these two laws (or 

others) that it may be considering under the Class VI regulations to ensure that 

any such treatment is necessary and does not serve as an unintended springboard 

for hampering the successful commercialization of CCS. EEI submits that any 

characterization of potentially hazardous constituents in CO2 injectate may be 

addressed as part of the UIC permitting process without addressing any potential 

RCRA jurisdictional issues. 

Response: First, EPA notes that the GS rule is not promulgated under either the RCRA or CERCLA

statutes, and the applicability of those statutes will not be determined under the SDWA or the terms

of the GS rule, but rather according to those statutes themselves and any implementing regulations

that may apply.

EPA received many comments regarding the applicability of the RCRA regulations and statute to

235
CO2 streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

With respect to CERCLA, EPA clarifies that CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream

and the environmental media in which it is stored (e.g., soil or ground water). CERCLA exempts

from liability, under CERCLA section 107, 42 U.S.C. 9607, certain “federally permitted releases”

(FPR) as defined in CERCLA, 42 U.S.C. 9601(10). Class VI permits will need to be carefully

structured to ensure that they prevent potential releases from the well which are outside the scope of

the Class VI permit.

Commenter Name: Quinlan J. Shea Letter ID: 0177

Commenter Organization: Edison Electric Institute Comment ID: 23605

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: J. Issues Related to Potential Application of Other Environmental Laws 

EEI and our members are concerned about the potential application to CCS 

activities of environmental laws that were, without exception, not intended to 

apply to CCS or even crafted with CCS in mind and that could impose significant 

obligations and potential liabilities not only on project operators, but also 

potentially on other entities in the CO2 chain, such as entities producing the 

CO2 that is ultimately injected. These laws include in particular the 

Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA or 

Superfund) and RCRA. EEI agrees that issues related to potential liabilities 

under these laws must be resolved.[FN12] Setting aside for the moment important 

questions of whether either of these laws could apply to CCS activities and, if 

so, precisely how and to what extent, EEI does not disagree with the Agency‘s 

position that drafting a clear exception from either of these regimes may be 

difficult in the sole context of this SDWA UIC rulemaking. Nonetheless, EEI 

urges EPA to evaluate carefully any proposed treatment of these two laws (or 

others) that it may be considering under the Class VI regulations to ensure that 

any such treatment is necessary and does not serve as an unintended springboard 

for hampering the successful commercialization of CCS. 

[FN12] The recent released GAO report on CCS echoes the importance of addressing 

these liability issues. GAO recommends that EPA examine its authorities and 

236
responsibilities the under RCRA and CERCLA to determine "where additional 

statutory authority might be needed to address key regulatory and legal issues 

related" to CCS. GAO report, supra n. 9, at 52. 

Response: As described above, EPA has decided to initiate a separate proposed rulemaking

specifically to examine the issue of RCRA applicability 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. 

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” as defined in CERCLA, 42 U.S.C. 9601(10).

Class VI permits will need to be carefully structured to ensure that they prevent potential releases

from the well which are outside the scope of the Class VI permit.

Commenter Name: Quinlan J. Shea Letter ID: 0177

Commenter Organization: Edison Electric Institute Comment ID: 23607

Comment: As to CERCLA, the preamble states that the statute "exempts from liability 

certain 'federally permitted releases' including releases in compliance with a 

UIC permit under SDWA. Therefore, Class VI requirements and permits will need 

to be carefully structured to ensure that they do not 'authorize' inappropriate 

hazardous releases. This would include clarifying if there are potential 

releases from the well which are outside the scope of the Class VI permit." The 

preamble continues on to request comment on "particular situations where this 

might occur" as well as more generally on "other considerations associated with 

the presence of impurities in the CO2 stream related to CERCLA." This 

discussion implies that, in the first instance, activities associated with CCS 

could be subject to CERCLA. 

EEI acknowledges that limits exist on EPA‘s ability to affect issues related to 

potential CERCLA liability in the context of this SDWA rulemaking. Nonetheless, 

EEI submits that EPA should seek to provide as much clarity and certainty as 

possible in this context to allow for the most expansive application of CERCLA‘s 

federally permitted release exemption as appropriate to activities permitted 

under the proposed rules. Insofar as the contents of a given CO2 stream will be 

characterized for permitting purposes and, as the permit may identify particular 

impurities in the stream, the presence of such impurities would fall squarely 

within the federally permitted release exemption should not result in 

"inappropriate hazardous releases." Further, the application of the federally 

permitted release exemption to the expected, intended composition of the 

injectate does not inappropriately undermine other limits on the application of 

the federally permitted release exemption that may exist, potentially including 

situations where an impurity not contemplated by the permit writer is introduced 

into the stream or where hazardous substances in the injectate cause the 

incurrence of response costs where material permit compliance has not been 

237
maintained. 

Furthermore, as noted above, the preamble‘s discussion is based on the 

assumption that CERCLA would be triggered in the first instance. As the Agency 

is aware, CERCLA liability (at minimum for certain classes of potentially 

responsible parties) turns to a significant extent on whether there has been 

"disposal" of hazardous substances. As with the RCRA issue, a determination of 

this issue is unnecessary from the perspective of regulating injection and 

storage of CO2 under the UIC program, and EEI urges the Agency to avoid creating 

unnecessary hurdles for the successful commercial deployment of CCS by assuming 

potential applications of other statutes that may not come into play. EEI also 

encourages the Agency, pursuant to its authority under RCRA and CERCLA, to 

examine possibilities for exemption or exclusion from those programs. 

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 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. To the extent the commenter is seeking interpretations of CERCLA and

its related provisions, such as the definition of a federally permitted release, such interpretations are

beyond the scope of this rulemaking. 

With respect to the commenter’s reference to RCRA, EPA received many comments regarding the

applicability of the RCRA regulations and statute to CO2 streams that are geologically sequestered

under the final Class VI UIC well requirements. As a result, EPA has decided to initiate a separate

proposed rulemaking specifically to examine the issue of RCRA applicability 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 particular 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 commenters who wish to submit comments on the RCRA proposal

will need to do so during the comment period for that rule.

Commenter Name: Frederick R. Eames Letter ID: 0178

Commenter Organization: CCS Alliance Comment ID: 23799

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment); 5400 2.9 Proposed Financial Responsibility and Long-Term Care Requirements 

Comment: Single, Clear Liability Structure 

To the extent possible, policymakers should put in place a single, clear 

liability regime for CCS activities. In the context of this rule, EPA has 

considered the possibility of cleanup liability both under the Comprehensive 

Environmental Response, Compensation, and Liability Act ("CERCLA" or 

"Superfund") and the Resource Conservation and Recovery Act ("RCRA), in addition 

to the UIC program. There is also the possibility of liability under state 

statutes and common law. Parties who may be injured in the future must be able 

to resort to a fair liability scheme, but potential applicability of multiple 

schemes is likely to discourage CCS development. 

238
Response: EPA acknowledges the commenter's concerns regarding the applicability of multiple

statutes to GS projects and the need for a single clear liability regime for owners or operators. As a

federal agency, EPA is working to create a nationally consistent financial responsibility regime

within its authority while providing permitting authorities an appropriate level of flexibility. EPA is

finalizing financial responsibility requirements under authority of the SDWA. EPA believes that the

general authorities provided under SDWA include the authority to set minimum federal requirements

for financial responsibility to ensure that financial resources are available to protect USDWs

throughout the life of the GS project. See the final rule and preamble for further discussion of EPA's

final approach to financial responsibility.

Furthermore, 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 SDWA after site closure if there is

unanticipated migration towards or into a USDW 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, they may

be subject to a civil penalty for each day in which such violation occurs or failure to comply

continues. 

The Agency acknowledges and clarifies that, after site closure, an owner or operator may, depending

on the fact scenario and state law, remain liable under state tort law and other remedies, or under

other Statutes including, 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 appreciates the commenter’s suggestions for a single liability scheme for CCS; however, the

GS rule is not promulgated under either RCRA or CERCLA, and making legislation changes or

addressing liability under state statutes and common law is also outside the scope of the GS

rulemaking. EPA also notes that the applicability of RCRA and CERCLA will not be determined

under the SDWA or the terms of the GS rule, but rather according to those statutes themselves and

any implementing regulations that may apply. 

EPA agrees that any requirements applicable to CO2 injectate should be clearly identified to the

public and to the regulated community. EPA received many comments regarding the applicability of

the RCRA regulations and statute to CO2 streams that are geologically sequestered under the final

Class VI UIC well requirements. As a result, EPA has decided to initiate a separate proposed

rulemaking specifically to examine the issue of RCRA applicability 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 particular 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 commenters who wish to submit comments on the RCRA proposal

will need to do so during the comment period for that rule. Finally, EPA also notes that the final GS

rule, which adds new regulations for Class VI wells under the Safe Drinking Water Act (SDWA), is

not making any changes to the RCRA regulations.

Commenter Name: Frederick R. Eames Letter ID: 0178

Commenter Organization: CCS Alliance Comment ID: 23815

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment); 5400 2.9 Proposed Financial Responsibility and Long-Term Care Requirements 

239
Comment: B. POTENTIAL APPLICABILITY OF RCRA AND CERCLA 

As discussed in greater detail below, the potential applicability of RCRA and 

CERCLA is a key concern. These statutes simply are not designed with the thought 

in mind of encouraging the safe and widespread deployment of a new technology. 

The CCS Alliance believes that many parties involved in the CCS chain of events 

should bear responsibility for safe operation. Rather than apply environmental 

statutes with contentious and litigious histories, Congress should enact a new 

regulatory and liability framework for CCS in place of the multiple regimes that 

now may apply. This is not meant to detract from the progress EPA is making in 

this rulemaking. It merely recognizes the limitations and overlapping structures 

EPA itself has noted. CCS should be subject to a single, clear regulatory 

structure, and a single, clear liability structure. In the meantime, EPA should 

use what interpretive authority it has to limit the applicability of multiple 

statutes and provisions, the applicability of which would discourage CCS. 

Response: EPA acknowledges the commenter's concerns regarding the applicability of multiple

statutes to GS projects and the need for a single clear liability regime for owners or operators. EPA

is working to create a nationally consistent financial responsibility regime within its authority while

providing permitting authorities an appropriate level of flexibility. EPA is finalizing financial

responsibility requirements under authority of the SDWA, which includes the authority to set federal

minimum requirements for financial responsibility to ensure that resources are available to protect

USDWs throughout the life of the GS project.

This authority does not extend to release owners or operators from long-term responsibility under

other statutes, such as CERCLA, for potential impacts after the PISC period has ended, or for the

potential economic costs associated with impacts unrelated to USDWs. Under current SDWA

provisions, EPA does not have authority to transfer liability from one entity to another and it does

not provide for the creation of a third party financial instrument where EPA is the trustee.

Under SDWA authority, owners or operators of injection wells must ensure protection of USDWs

from endangerment and are subject to liability 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 poses 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 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. Furthermore, the

financial instrument required under §146.85 will be released if it has not been 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 certain circumstances. For example, an

owner or operator may be held liable even after site closure was approved 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 SDWA after site closure if there is

unanticipated migration towards or into a USDW that causes or threatens imminent and substantial

endangerment to public health. If the owner or operator fails to comply with the order, he or she may

240
be subject 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 responsibilities are transferred to that new

owner and operator, including all potential liabilities associated with meeting the requirements of that

permit.

Furthermore, after site closure an owner or operator may remain liable under tort and other remedies,

or under other federal statutes including, 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.

Comments requesting congressional legislation on liability for GS are outside of the scope of this

rulemaking.

EPA agrees that identifying and addressing potential barriers to the deployment of CCS, while

protecting human health and the environment, is important. As described above, making legislation

changes is outside the scope of the GS rulemaking. Also as described above, EPA has decided to

initiate a separate proposed rulemaking specifically to examine the issue of RCRA applicability 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. 

Furthermore, EPA is promulgating the GS rule under the authority of the SDWA. To the extent the

commenter is seeking interpretations of CERCLA and its related provisions, such as the definition of

a federally permitted release, such interpretations are beyond the scope of this rulemaking.

Commenter Name: Frederick R. Eames Letter ID: 0178

Commenter Organization: CCS Alliance Comment ID: 23833

Comment: VII. SPECIAL FOCUS: APPLICABILITY OF CERCLA 

The Proposed Rule raises the question whether the injected CO2 stream[FN27]" 

will be considered a "hazardous substance" under CERCLA. 

[FN27] The rule uses the terms "carbon dioxide stream" and "injectate" 

interchangeably. EPA's proposed definition of these terms includes CO2 "plus 

incidental associated substances derived from the source materials and the 

capture process, and any substances added to the stream to enable or improve the 

injection process. This subpart does not apply to any carbon dioxide stream that 

meets the definition of a hazardous waste under 40 CFR Part 261." 

The Proposed Rule states: 

While CO2 itself is not listed as a hazardous substance under CERCLA, 

the CO2 stream may contain other substances such as mercury that are 

hazardous substances or the constituents of the CO2 stream could react 

with groundwater to produce listed hazardous substances such as sulfuric 

acid. Thus, whether or not there is a "hazardous substance" that may 

241
result in CERCLA liability from a sequestration facility depends 

entirely on the make-up of the specific CO2 and of the environmental 

media (e.g., soil, groundwater) in which it is stored. 

A mechanism must be in place to address liability for releases from GS sites. 

However, Superfund has had a number of problems that EPA should carefully 

consider in the context of a regulatory regime the Agency hopes will encourage 

deployment of CCS. Cleanups sometimes have been delayed by decades, lawsuits can 

stretch for years and involve numerous parties, and cleanups have been far too 

costly. EPA should use its interpretive authority to limit the applicability of 

Superfund and respond to releases under other authorities. Ultimately, Congress 

should adopt a new response and liability system recognizing the policy goals, 

scale, and other special features of CCS that is unburdened by the problems of 

Superfund. 

A. RELEVANT PROBLEMS WITH SUPERFUND 

Superfund imposes a strict, joint, and several liability scheme upon facility 

owners and operators, parties who arrange for treatment, storage, 

transportation, or disposal of hazardous substances; and transporters of 

hazardous substances. This strict, joint, and several liability scheme, in 

conjunction with other features of Superfund, particularly what many consider to 

be inordinately high cleanup costs, frequently results in expensive and lengthy 

lawsuits and delayed cleanups. Superfund also has been criticized for remedies 

that are far more aggressive than the risks warrant. 

B. SUPERFUND APPLICABILITY 

EPA's authority to order cleanups under CERCLA is triggered whenever any 

"hazardous substance" is released or there is a substantial threat of such a 

release into the environment. The Agency is considering whether the injectate, 

substances mobilized as a result of injection, or substances formed by 

geochemical reactions between the injectate and underground materials will 

trigger the "hazardous substance" definition. 

While EPA correctly notes that CO2 is not now a hazardous substance, that may 

not continue to be the case given Massachusetts v. EPA,[FN28] in which the 

Supreme Court ruled that CO2 is a pollutant and directed the EPA to determine 

whether or how it should be regulated. Such a decision could affect whether CO2 

is determined to be a hazardous substance under CERCLA. 

[FN28] Massachusetts v. EPA, 549 U.S. 497 (2007). 

CERCLA defines a hazardous substance to include "any hazardous air pollutant 

listed under section 112 of the Clean Air Act . . . ."[FN29] CO2 is not on this 

list at present. However, Section 112 authorizes EPA to add a compound to the 

list if the Agency finds that emissions of the compound "may reasonably be 

anticipated to cause adverse effects to human health or adverse environmental 

effects."[FN30] If in response to Massachusetts v. EPA, EPA were to decide to 

regulate CO2 under Section 112, releases of CO2, even without the presence of 

242
or interaction with hazardous substances, would be subject to Superfund 

liability. 

[FN29] 42 U.S. C. $9601. 

[FN30] 42 U.S. C. $7411. 

EPA also notes that the presence of other materials or the injectate's reaction 

with other substances underground may result in it becoming a hazardous 

substance. These post-injection geochemical reactions are of significant concern 

because CO2 injectate considered non-hazardous upon injection could, over time, 

react with underground materials, potentially creating a hazardous substance and 

triggering unintended and unanticipated Superfund applicability. 

Triggering application of the "hazardous substance" definition under Superfund 

to CO2, either pre- or post-injection, will create concerns about liability that 

will not encourage CCS development and, as our research cited above suggests. 

likely will be an impediment to the investment and risk management needed for 

CCS projects. 

C. FEDERALLY PERMITTED RELEASE EXEMPTION 

Superfund liability does not apply to a "federally permitted release," pursuant 

to Section 107(j).[FN31] The Proposed Rule notes that parties may be able to 

avoid Superfund liability through this exception. However, this exception likely 

would not apply in cases where injectate accidentally has been released from a 

storage site. Both EPA [FN32] and the courts [FN33] have interpreted the 

federally permitted release exemption to apply to releases that are in compliance 

with a permit, but not to accidental releases. It potentially may not apply 

where injectate remains safely within a containment zone, but beyond the area 

for which a permit was granted. The EPA should consider the potential for 

triggering Superfund liability in determining how it writes permits, 

particularly in cases where the CO2 remains safely stored. 

[FN31] 42 U.S.C. # 9607. 

[FN32] "In most circumstances, releases resulting from accidents and 

maifunctions do not qualify for the federally permitted release exemption as 

defined in CERCLA section 101(10)(H). Releases due to accidents and 

malfunctions, because they are by definition not anticipated, are difficult to 

subject to controls which limit or eliminate emissions. Congress did not intend 

to exempt unanticipated releases such as accidents and malfunctions from CERCLA 

section 103. An accidental release not in compliance with a permit would be 

subject to response costs and damages claims under Superfund in addition ot the 

provisions of the SDWA and state and common law." Guidance on the CERCLA Section 

101(10)(H) Federally Permitted Release Definition for Certain Air Emissions, 67 

Fed. Reg. 18899, 18903 (Apr. 17,2002). 

[FN33] See United States v. Iron Mountain Mines. Inc., 812 F. Supp. 1528. 

1540-41 (E.D. Cal. 1992) ("Congress considered the interplay between FWPCA and 

243
CERCLA when it enacted the latter statute, but declined to exempt municipal 

sewer authorities from its broad reach . . FWPCA exemption extends to industrial 

discharges into POTWs, indicating that Congress specifically intended for CERCLA 

liability to reach releases from sewers or POTWs.") Reading Co. v. City of 

Philadelphia, 823 F. Supp. 1218, 1230-31 (E.D. Penn. 1993) (Toxic Substances 

Control Act (TSCA) compliance is insufficient to invoke the RCRA exemption under 

CERCLA); Westfarm Associates Ltd. Partnership v. International Fabricare Inst., 

1993 U.S. Dist. LEXIS 19952 (D.Md. 1993). See also Idaho v. Bunker Hill Co., 635 

F. Supp. 665, 673 (D. Idaho 1986); Reporting Exemptions for Federally Permitted 

Releases of Hazardous Substances, 53 Fed. Reg. 27,268-81 (proposed July 19, 

1988) (to be codified at 40 C.F.R. $$ 117.12, 302.3, 302.6, 355). 

If Superfund does not apply because of the exemption, remedies may be obtained 

under other law. CERCLA's federally permitted release exemption states that 

"recovery . . . for response costs . . . resulting from a federally permitted 

release shall be pursuant to existing law in lieu of [CERCLA]."[FN34] 

[FN34] 42 U.S. C. $ 9607(j) (2006). 

Response: CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit. Furthermore,

EPA is promulgating the GS rule under the authority of the SDWA. To the extent the commenter is

seeking interpretations of CERCLA and its related provisions, such as the definition of a federally

permitted release, such interpretations are beyond the scope of this rulemaking. 

The UIC program Director has authority under SDWA §1423 to address potential compliance issues

(e.g., potential releases that may endanger USDWs) resulting from injection violations in the unlikely

event that a remedial response is necessary. Although EPA anticipates that the need for emergency

or remedial actions at GS sites will be rare, the GS rule requires, at §146.94, that emergency and

remedial response plans be developed and updated to address such events and that owners or

operators demonstrate that financial resources are set aside to implement the plans if necessary, per

§146.85.

EPA clarifies that, while the Administrator reserves the right to promulgate regulations designating

additional substances as hazardous under §102 of CERCLA, EPA intends to avoid any potential

overlap of SDWA and CERCLA authority through its comprehensive Class VI requirements.

CERCLA exempts from liability, under CERCLA section 107, 42 U.S.C. 9607, certain “federally

permitted releases” (FPR) as defined in CERCLA, 42 U.S.C. 9601(10). Therefore, Class VI

requirements and permits will need to be carefully structured to ensure that they do not “authorize”

inappropriate releases, and would need to prevent potential releases from the well which are outside

the scope of the Class VI permit.

244
Commenter Name: Frederick R. Eames Letter ID: 0178

Commenter Organization: CCS Alliance Comment ID: 23834

Other EPA Comment Codes and Descriptions: 5400 2.9 Proposed Financial Responsibility and

Long-Term Care Requirements 

Comment: D. POTENTIAL EFFECT OF SUPERFUND ON CCS DEPLOYMENT 

The CCS Alliance conducted a Risk Study earlier this year, surveying more than 

30 executives in companies involved with or considering CCS deployment.[FN35] 

the purpose of the Risk Study was to identify policy, technical, and market 

risks that could pose barriers to proceeding with CCS projects. Respondents were 

asked to rate the likelihood of a policy, technical, or market factor occurring, 

as well as the severity of the impact to a CCS project if it did occur. The 

product of the likelihood and the severity of impact to the project for each 

surveyed issue generated a risk ranking. 

[FN35] Risk Study for Commercial Deployment of CCS: Factors Affecting Financing 

for Early Plants, CCS Alliance (July 2008). 

Three of the top eight concerns identified by respondents related to liability 

for CCS, including lack of clarity in the applicability of federal and state 

liability regimes. As the following chart demonstrates, particularly results for 

responses to questions 17,31, and 34. executives are very much concerned with 

the risks associated with the lack of clarity in state and federal regulations 

and liability regimes, as well as with liability over the long-term. 

[Please see Comment Pdf for Chart, pg. 38] 

Moreover, a recent GAO report emphasizes the concern about liability: 

EPA's 2007 UIC workshop, attended by more than 200 stakeholders, 

revealed liability associated with unintended migration of injected CO2 

to be a critical concern. Similarly, 19 of the 20 stakeholders we 

interviewed told us that liability related to CO2 storage was a large or 

very large barrier to deployment of CCS at commercial scale, with some 

noting that liability concerns have already negatively impacted 

companies' ability to initiate CCS projects. For example. two 

stakeholders reported that these concerns have already made it difficult 

to obtain insurance for CCS projects. [FN36] 

[FN36] U.S. GAO, GAO-08-1080. FEDERAL ACTIONS WlLL GREATLY AFFECT THE

VIABILITY 

OF CARBON CAPTURE AND STORAGE AS A KEY MITIGATION OPTION 25 (2008). 

Although we currently are aware of no report specifically stating that liability 

under Superfund is the principal liability concern among CCS proponents, it 

clearly is a significant issue that has been raised repeatedly, including 

through EPA advisory processes and the imposition of which would negatively 

affect future investment in CCS technologies.[FN37] 

[FN37] EPA's Advanced Coal Technology Work Group Final Report recommends that 

245
EPA's UIC rulemaking proposal should "include a thorough discussion of. . 

liability implications under other statutes (CERCLA, RCRA, etc.) and potential 

linkages and impacts (or lack thereof) for CCS projects." U.S. ENVIRONMEKTAL 

PROTECTION AGENCY, FINAL REPORT: ADVANCED COAL TECHNOLOGY WORK

GROUP REPORT 5 

(Jan. 29,2008). 

Response: As described above, EPA is working to create a nationally consistent financial

responsibility regime within its authority while providing permitting authorities and owners or

operators an appropriate level of flexibility. EPA believes that the general authorities provided under

SDWA include the authority to set federal minimum requirements for financial responsibility to

ensure that resources are available to protect USDWs throughout the life of the GS project.

However, this authority does not extend to release owners or operators from long-term responsibility

of other environmental statutes, such as CERCLA, for potential impacts to USDWs after the PISC

period has ended, or for the potential economic costs associated with activities with impacts

unrelated to USDWs (e.g., risks to air, or ecosystems). 

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 SDWA after site closure if there is

unanticipated migration towards or into a USDW 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, they may

be subject to a civil penalty for each day in which such violation occurs or failure to comply

continues. 

Furthermore, the Agency clarifies that, after site closure, an owner or operator may, depending on

the fact scenario, remain liable under tort and other remedies, or under other Statutes including, 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. 

See the final rule and preamble for further discussion of final approach to financial responsibility for

GS projects. 

As described above, whether the presence of hazardous substances in CO2 streams may result in

CERCLA liability from a sequestration facility depends entirely on the composition of the specific

CO2 stream and the environmental media in which it is stored (e.g., soil or ground water). CERCLA

exempts from liability, under CERCLA section 107, 42 U.S.C. 9607, certain “federally permitted

releases” (FPR) as defined in CERCLA, 42 U.S.C. 9601(10). Class VI permits will need to be

carefully structured to ensure that they prevent potential releases from the well which are outside the

scope of the Class VI permit.

Furthermore, EPA is promulgating the GS rule under the authority of the SDWA. To the extent the

commenter is seeking interpretations of CERCLA and its related provisions, such as the definition of

a federally permitted release, such interpretations are beyond the scope of this rulemaking.

Commenter Name: Lee O. Fuller Letter ID: 0179

Commenter Organization: Independent Petroleum Association of America et

al.

Comment ID:

23613

Comment: EPA has requested comments on the application of the Comprehensive Environmental 

246
Response, Compensation, and Liability Act (CERCLA or Superfund) to Class VI 

wells. Because of the interrelation of Class VI and Class II CO2 EOR operations, 

we offer the following observations. EPA states that CO2 is not a listed 

hazardous substance under Superfund - nor should it be. Rather EPA focuses on 

the potential for such substances to be included in a carbon capturing operation 

or for the presence of CO2 to react in GS. We do not believe that CO2 GS 

operations reasonably fall under the scope of Superfund. As long as 

compositional controls are specified, it is not a hazardous substance nor is it 

a pollutant or contaminant under the Superfund definition. Assuming that some 

other chemicals could be present and trigger Superfund’s application, UIC 

program operations fall under Superfund’s "federally permitted releases" 

limitations. This provision allows EPA to respond to a release or threat of a 

release assuring environmental protection. Recovery of the response costs would 

have to be sought under other federal or state laws rather than CERCLA. However, 

UIC operations under federal and state regulatory programs already provide for 

mechanisms to correct for failures and, in fact, these operations have proven to 

be very effective. Unfortunately, we believe that EPA’s focus on the potential 

application of Superfund creates the appearance of risks that will impede the 

development of GS wells. More importantly, as stated above, from our perspective 

the threat of new liability exposure can chill CO2 EOR and risk both billions of 

barrels of American oil production and a valuable and expedient mechanism for 

sequestration. 

Response: CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain "federally permitted releases" (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit. 

Furthermore, EPA is promulgating the GS rule under the authority of the SDWA. To the extent the

commenter is seeking interpretations of CERCLA and its related provisions, such as the definition of

a federally permitted release, such interpretations are beyond the scope of this rulemaking. 

The UIC program Director has authority under SDWA §1423 to address potential compliance issues

(e.g., potential releases that may endanger USDWs) resulting from injection violations in the unlikely

event that a remedial response is necessary. Although EPA anticipates that the need for emergency

or remedial actions at GS sites will be rare, the GS rule requires, at §146.94, that emergency and

remedial response plans be developed and updated to address such events and that owners or

operators demonstrate that financial resources are set aside to implement the plans if necessary, per

§146.85.

Regarding long term liability, once an owner 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. Furthermore, 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

247
may be held liable for regulatory noncompliance (including violation of 40 CFR 144.12) in certain

circumstances. For example, an owner or operator may be held liable for regulatory noncompliance

even after site closure was approved if the Director relied on erroneous information (e.g., erroneous

modeling data) provided by the owner or operator when approving site closure. 

Separate from EPA's authority to enforce regulatory compliance, an owner or operator may be

subject to a §1431 response order even after proper site closure 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 present an imminent and substantial endangerment to the health of

persons, and the appropriate State and local authorities have not acted to protect the health of such

persons. The action may include issuing administrative 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 operator may remain liable under tort and other remedies,

or under other federal statutes including, 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.

Commenter Name: Scott Davis Letter ID: 0187

Commenter Organization: Arizona Public Service Company Comment ID: 25220

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment); 5460 2.9.2 Comments on transfer of liability for long-term care 

Comment: - The final rule must resolve several key policy and legal questions regarding 

underground injection of CO2, including but not limited to implications under 

the Resource Conservation and Recovery Act ("RCRA") and the Comprehensive 

Environmental Response, Compensation and Liability Act ("CERCLA"), and limiting 

post injection liability. 

Response: Under the final GS rule, once an owner 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. Furthermore, 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

certain circumstances. For example, an owner or operator may be held liable for regulatory

noncompliance even after site closure was approved if the Director relied on erroneous information

(e.g., erroneous modeling data) provided by the owner or operator when approving site closure. 

Separate from EPA's authority to enforce regulatory compliance, an owner or operator may be

subject to a §1431 response order even after proper site closure 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 present an imminent and substantial endangerment to the health of

persons, and the appropriate State and local authorities have not acted to protect the health of such

persons. The action may include issuing administrative orders or commencing a civil action for

248
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 operator may remain liable under tort and other remedies,

or under other federal statutes including, 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.

EPA received many comments regarding the applicability of the RCRA regulations and statute to

CO2 streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

EPA also clarifies that CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the

environmental media in which it is stored (e.g., soil or ground water). CERCLA exempts from

liability, under CERCLA section 107, 42 U.S.C. 9607, certain "federally permitted releases" (FPR)

as defined in CERCLA, 42 U.S.C. 9601(10). Class VI permits will need to be carefully structured to

ensure that they prevent potential releases from the well which are outside the scope of the Class VI

permit.

Commenter Name: G. Graham Holden Letter ID: 0189

Commenter Organization: Oglethorpe Power Corporation Comment ID: 25250

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: 6. EPA should define the way GS activities will relate to the Resource 

Conservation and Recovery Act ("RCRA") and the Comprehensive Environmental 

Response, Compensation and Liability Act ("CERCLA") 42 U.S. §§ 9601, et seq. 

RCRA is simply the wrong tool to use to regulate GS of CO2 and EPA needs to find 

a way to insure that the onerous requirements of CERCLA (never intended for GS 

of CO2) are not applied to this highly specialized storage operation. 

7. Appropriately defining the relationship of GS activities with RCRA and CERCLA 

is critical to the commercial deployment of full scale GS projects and may 

require Congressional action. 

249
Response: EPA agrees that any requirements applicable to CO2 injectate should be clearly identified

to the public and to the regulated community. EPA received many comments regarding the

applicability of the RCRA regulations and statute to CO2 streams that are geologically sequestered

under the final Class VI UIC well requirements. As a result, EPA has decided to initiate a separate

proposed rulemaking specifically to examine the issue of RCRA applicability 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 particular 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 commenters who wish to submit comments on the RCRA proposal

will need to do so during the comment period for that rule. Finally, EPA also notes that the final GS

rule, which adds new regulations for Class VI wells under the Safe Drinking Water Act (SDWA), is

not making any changes to the RCRA regulations.

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190

Commenter Organization: Carbon Sequestration Council Comment ID: 24323

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: D. RCRA/CERCLA Applicability 

In light of the current uses and potential future uses of CO2 for EOR/EGR, EPA 

has taken a sensible approach by proposing to create a new Class VI well 

category based on the injection of the CO2 stream as fluid without 

characterizing that stream as a waste. It is neither necessary nor helpful to 

categorize CO2 as a pollutant or waste, and that would likely prove detrimental 

to technology development. Indeed, we are concerned that EPA’s brief discussion 

of a supposed potential for injected CO2 streams to be characterized as 

hazardous waste (or some type of hazardous release) are causing apprehension and 

could have a significant chilling effect on any future deployment of carbon 

capture and sequestration technologies. Through the work of our engineers and 

scientists with capture technologies and their extensive experience with the 

types of power plant flue gas likely to be sources of CO2 for sequestration, we 

do not believe that captured CO2 streams should trigger the application of 

either RCRA or CERCLA. Accordingly, we encourage EPA to dispel concerns that 

geologic sequestration could be encumbered with those requirements except 

possibly through the commingling of a captured CO2 stream with an actual waste 

stream, and we are not suggesting that such commingling should be permissible in 

the GS context. 

250
Response: EPA thanks the commenter for their views on CCS, and notes that the GS rule is not

promulgated under either the RCRA or CERCLA statutes, and further, the applicability of those

statutes will not be determined under the SDWA or the terms of the GS rule, but rather according to

those statutes themselves and any implementing regulations that may apply.

EPA received many comments regarding the applicability of the RCRA regulations and statute to

CO2 streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” as defined in CERCLA, 42 U.S.C. 9601(10).

Class VI permits will need to be carefully structured to ensure that they prevent potential releases

from the well which are outside the scope of the Class VI permit. 

EPA adds that promoting the use of GS is outside the scope of the GS rule. Rather, the purpose of

the GS regulation is to ensure that, where deployed, GS is conducted in a manner that protects

USDWs from endangerment.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190

Commenter Organization: Carbon Sequestration Council Comment ID: 24325

Comment: 2. CERCLA Applicability 

The proposed rule raises the specter of CERCLA liability arising out of CO2 

geologic sequestration (GS) projects. Specifically, in Section II.D. of the 

preamble, EPA notes several "potential USDW impacts," including the potential 

that the injected CO2 could (1) force native brines into USDWs; (2) contain 

impurities; or (3) cause naturally occurring or otherwise pre-existing chemicals 

to be mobilized within the injection zone, for example, via the formation of 

carbonic acid and its leaching effects. 73 Fed. Reg. 43492, 43497 (July 25, 

2008). EPA then goes so far as to suggest that "The migration of formation 

fluids containing mobilized contaminants could cause endangerment of USDWs." Id. 

EPA reiterates some of these concerns under preamble Section 2.J., under the 

heading "Is injected CO2 considered a hazardous substance under CERCLA?" 73 Fed. 

Reg. at 43503-04. EPA indicates that CO2, while not itself a CERCLA "hazardous 

251
substance," could contain hazardous substance impurities. EPA indicates further 

that "the CO2 stream could react with groundwater to produce listed hazardous 

substances such as sulfuric acid." 73 Fed. Reg. at 43504. (It is unclear whether 

the reference to groundwater means injection zone formation fluids or USDW 

formation fluids.) In short, the CERCLA liability concerns flagged by EPA arise 

out of two basic scenarios: (1) pre-existing hazardous substances, or hazardous 

substance impurities or reaction products moving into or within the injection 

zone; and (2) these hazardous substances (or displaced brines) migrating from 

the injection zone. 

EPA also states: 

CERCLA exempts from liability certain "federally permitted releases" 

including releases in compliance with a UIC permit under SDWA. 

Therefore, Class VI requirements and permits will need to be carefully 

structured to ensure that they do not "authorize" inappropriate 

hazardous releases. This would include clarifying if there are potential 

releases from the well which are outside the scope of the Class VI 

permit. 

73 Fed. Reg. at 43504. 

The first concern raised by EPA does not appear to pose a very serious concern 

because injection into a permitted injection does not constitute a release under 

CERCLA. EPA has issued some relevant guidance in the UIC context. Specifically, 

EPA has concluded that the emplacement of fluids into an injection zone through 

an authorized injection well does not constitute a "release" for purposes of 

RCRA or CERCLA. See 50 Fed. Reg. 28712 (July 15, 1985). EPA relied upon CERCLA’s 

definition of "release," which requires hazardous substances to make it into the 

"environment." Under EPA’s interpretation, UIC injection zones do not constitute 

the "environment," but rather the injection zone is essentially part of the 

injection well system. Id. at 28713. One of the key elements for CERCLA 

liability is a release (or threatened release) of hazardous substances. 

Therefore, at least with respect to hazardous substances remaining in the 

injection zone, one of the key elements for CERCLA liability would not be met, 

regardless of whether the hazardous substances were in the discharge stream, 

mobilized pre-existing substances, or in-situ reaction products. For 

clarification, EPA should reiterate this interpretation in the preamble to the 

final GS rule. 

Notwithstanding this interpretation, significant CERCLA liability concerns could 

remain with respect to any migration from the injection zone. While we are 

unaware of any attempt to date by EPA or another government agency or private 

party, to apply CERCLA to a UIC site in such a scenario, or any similar context, 

the mere possibility is a significant concern that should be addressed by EPA in 

order to avoid serious discouragement of development and investment in CO2 GS 

projects. EPA should clarify in the final regulations the so-called "federally 

permitted release" exemption from CERCLA liability for purposes of the UIC 

program, as referenced by EPA in the preamble to the GS proposal. 73 Fed. Reg. 

at 43504. The FPR exemption affects two separate CERCLA areas: (1) release 

252
reporting and (2) cleanup liability. The FPR exemption operates differently in 

each area, and is more accurately characterized as two separate exemptions. 

Under CERCLA’s release reporting provisions, certain releases of hazardous 

substances are subject to a one-time notification requirement, but FPRs are 

exempt: 

Any person in charge of a vessel or an offshore or an onshore facility 

shall, as soon as he has knowledge of any release (other than a 

federally permitted release) of a hazardous substance from such vessel 

or facility in quantities equal to or greater than those determined 

pursuant to CERCLA - Sec. 9602 of this title, immediately notify the 

National Response Center.... 

42 USC § 9603(a). FPR is in turn defined to include various types of 

releases/discharges authorized under any of several federal or delegated state 

regulatory programs including "(G) any injection of fluids authorized under 

Federal underground injection control programs or State programs submitted for 

Federal approval (and not disapproved by the Administrator of the Environmental 

Protection Agency) pursuant to part C of the Safe Drinking Water Act [42 U.S.C. 

300h et seq.] ... 42 USC § 9601(10) (emphasis added). To apply the FPR exemption 

in the release reporting context, the issue for UIC permittees would simply be 

whether the release at issue was an authorized injection of fluids. If so, the 

release would not have to be reported. The FPR for cleanup liability purposes is 

more complicated. 

CERCLA § 107(j) states: 

Recovery by any person (including the United States or any State or 

Indian tribe) for response costs or damages resulting from a federally 

permitted release shall be pursuant to existing law in lieu of this 

section. Nothing in this paragraph shall affect or modify in any way the 

obligations or liability of any person under any other provision of 

State or Federal law, including common law, for damages, injury, or loss 

resulting from a release of any hazardous substance or for removal or 

remedial action or the costs of removal or remedial action of such 

hazardous substance.... 

42 USC § 9607(j). First, it is important to understand that the FPR exemption 

from cleanup liability only forecloses a CERCLA action; otherwise-viable actions 

under other laws remain viable, and are not affected. An aggrieved party would 

be free to assert claims based on any number of other causes of action typically 

utilized in hazardous substance contamination cases, such as common law claims 

for trespass, nuisance, negligence, strict liability, or "toxic tort," or 

statutory claims arising under state groundwater protection or cleanup liability 

laws. 

More importantly, in comparison with the release reporting context, the FPR 

exemption from cleanup liability applies not to the FPR directly, but rather to 

"response costs or damages resulting from" the FPR. This parallels CERCLA’s 

253
liability imposing provisions, which require a release of hazardous substances 

from a facility "which causes the incurrence of response costs." This exemption 

is obviously broader than just the FPR itself in that any resulting costs are 

covered. In other words, the measure of the scope of the exemption for liability 

purposes is not limited to whether the release qualifies as a FPR, but rather 

whether the costs at issue result from the FPR. 

With respect to UIC wells, if the emplacement of fluids through a well is 

authorized by the permit, the resulting costs due to the various circumstances 

identified by EPA - in-situ reaction or mobilization, migration, etc. - remain 

ultimately the result of the FPR, and would be covered by the liability 

exemption. In other words, but for the authorized injection, the costs would not 

have been incurred. Therefore, the FPR exemption should apply to the scenarios 

identified by EPA in the preamble, with the exception of costs incurred due 

solely to unauthorized releases - i.e., releases resulting from unauthorized 

injection. 

The scope of the FPR exemption in the CERCLA cleanup liability context has been 

interpreted narrowly by some courts, but none of the cases involved UIC sites. 

In promulgating the final rule, EPA could provide a more reasoned analysis of 

the FPR exemption, and dispel any unwarranted concerns about CERCLA liability. 

EPA realized over 20 years ago that CERCLA’s FPR exemption needed additional 

clarification with respect to both release reporting and liability issues. EPA 

issued proposed rules in 1983 and 1988 that were never finalized. See 53 Fed. 

Reg. 27267 (July 19, 1988). Most of the attention, however, focused on the 

release reporting issues, rather then the cleanup liability issues. 54 Fed. Reg. 

29305, 29307 (July 11, 1989). EPA did observe in the preamble to the proposal 

that an "underground injection of hazardous substances permitted under an 

[authorized state or EPA program] is considered federally permitted for purposes 

of CERCLA notification." (53 Fed. Reg. at 27273). EPA did not find it necessary 

to propose any amendments to the UIC program regulations. 

Having raised these CERCLA issues in its proposal, EPA should take the present 

opportunity to provide a regulatory clarification of the existing exemption from 

CERCLA cleanup liability for UIC projects. EPA should clarify that the scope of 

"authorized injection of fluids" which defines the FPR exemption should be 

provided by the definition of CO2 stream, which should define the scope of the 

permitted injection to include: 

[Any] carbon dioxide that has been captured from any source, plus 

incidental associated substances derived from the source materials or a 

capture process, and any substances added to the stream to enable or 

improve the injection process. 

73 Fed. Reg. at 43535, proposed 40 CFR §146.81(d), definition of "Carbon dioxide 

stream" (with our proposed modifications). For further clarification, EPA could 

provide that only the injection under a Class VI permit of streams failing to 

meet this definition would fall outside the scope of the "authorized injection 

of fluids" unless expressly authorized for injection in the permit covering the 

well. EPA should also address CERCLA § 107(j) and provide an appropriate 

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clarification of the broad array of potential response costs or damages it would 

consider to result from an authorized UIC project, e.g. costs to address the 

migration of impurities, mobilized pre-existing contaminants, or displaced 

brines. 

Although the risk of a CO2GS project giving rise to CERCLA liability is 

relatively low, raising the prospect of any potential for CERCLA liability may 

be so chilling as to significantly curtail efforts to develop CO2GS projects. 

CERCLA’s far-reaching liability web and the tremendous costs that can be imposed 

on parties potentially liable under CERCLA are now well-known. Also well-known 

is the reluctance of businesses and investors to support projects faced with a 

potential for liabilities of a CERCLA-scale. For example, the impacts of CERCLA 

on the commercial/industrial property market in the late 1980’s and early 1990’s 

were devastating to many urban centers. To avoid incurring CERCLA liability, 

property owners and prospective purchasers simply avoided deals involving 

properties with any potential hazardous substance contamination. This 

contributed to the so-called "brownfield" problem of unused or underutilized 

properties being shunned due to potential or actual contamination, and the 

associated CERCLA liability concerns. This in turn led to the expansion of 

development to previously undeveloped "greenfields" sites that, while less risky 

from a CERCLA perspective, raised their own array of concerns such as urban 

sprawl, infrastructure costs, etc. In response to the negative impacts of 

potential CERCLA liability, EPA and many states have gone to great lengths over 

the last ten years to alleviate liability concerns and encourage brownfield 

development projects. Similarly, EPA should recognize the significant chilling 

effect that CERCLA liability concerns would have on the development and 

deployment CO2GS projects, especially in this era of high volatility in the 

investment markets. EPA should use the opportunity in this rulemaking to 

alleviate unwarranted CERCLA liability concerns to the greatest extent possible. 

Even more troubling than the potential negative impact on the investment 

community is the threat of subjecting hundreds, thousands, and even more 

numerous pore space owners to CERCLA liability. Their property interests in 

potential deep subsurface CO2GS project injection zones could subject them to 

strict, joint, and several liability under CERCLA pursuant to liability theories 

that could be conjured up by future litigants seeking compensation for 

investigation response - and possibly remediation - costs claimed to be incurred 

as a result of releases from geologic sequestration injection zones. The 

discussion of what might be required to acquire any necessary rights to conduct 

CO2GS projects is complex enough already without even beginning to consider how 

the willingness of pore space owners to participate might be obliterated by the 

uncertainties of CERCLA liabilities hanging over their heads. 

In short, EPA needs to seize the opportunity to dispel the specter of CERCLA 

liability raised in its preamble by developing appropriate language to provide 

the clarity and assurance needed to promote continued research, development and 

deployment of CO2GS projects. 

Response: CO2 itself is not listed as a hazardous substance under CERCLA; however, the CO2

stream may contain a listed hazardous substance (such as mercury) or may mobilize substances in

255
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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain "federally permitted releases" (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit. 

Furthermore, EPA is promulgating the GS rule under the authority of the SDWA. To the extent the

commenter is seeking interpretations of CERCLA and its related provisions, such as the definition of

a federally permitted release, such interpretations are beyond the scope of this rulemaking. 

The UIC program Director has authority under SDWA §1423 to address potential compliance issues

(e.g., potential releases that may endanger USDWs) resulting from injection violations in the unlikely

event that a remedial response is necessary. Although EPA anticipates that the need for emergency

or remedial actions at GS sites will be rare, the GS rule requires, at §146.94, that emergency and

remedial response plans be developed and updated to address such events and that owners or

operators demonstrate that financial resources are set aside to implement the plans if necessary, per

§146.85.

Regarding long term liability, once an owner 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. Furthermore, 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 certain

circumstances. For example, an owner or operator may be held liable for regulatory noncompliance

even after site closure was approved if the Director relied on erroneous information (e.g., erroneous

modeling data) provided by the owner or operator when approving site closure. 

Separate from EPA's authority to enforce regulatory compliance, an owner or operator may be

subject to a §1431 response order even after proper site closure 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 present an imminent and substantial endangerment to the health of

persons, and the appropriate State and local authorities have not acted to protect the health of such

persons. The action may include issuing administrative 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 operator may remain liable under tort and other remedies,

or under other federal statutes including, 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.

EPA adds that promoting the use of GS is outside the scope of the GS rule. Rather, the purpose of

the GS regulation is to ensure that, where deployed, GS is conducted in a manner that protects

USDWs from endangerment.

256
Commenter Name: Robert F. Van Voorhees Letter ID: 0190

Commenter Organization: Carbon Sequestration Council Comment ID: 24513

Comment: Rule Provisions or Federal Register Cite: 73 FR 43504 

EPA Preamble Question: 8. Class VI requirements and permits will need to be 

carefully structured to ensure that they do not "authorize" inappropriate 

hazardous releases. This would include clarifying if there are potential 

releases from the well which are outside the scope of the Class VI permit. EPA 

requests comment on particular situations where this might occur. EPA notice 

43504. 

CSC Response: Well chosen sites should prevent these conditions from occurring. 

At the same time, permit writers should not write permits so restrictive as to 

make the undertaking of a GS project untenable. EPA should remember that CERCLA 

liability will not only impact owners and operators of GS projects, but also 

hundreds, thousands, and even more numerous pore space owners. EPA should 

consider the threat of subjecting these pore space owners to CERCLA liability. 

Their property interests in the CO2 GS project injection zones could subject 

them to strict, joint, and several liability under CERCLA pursuant to whatever 

liability theories might be developed by future litigants seeking compensation 

for response and remediation costs incurred in the cleanup of releases from 

geologic sequestration injection zones. EPA should recognize the significant 

chilling effect CERCLA liability concerns will have on GS projects, and seize 

the opportunity in this rulemaking to alleviate any CERCLA liability concerns to 

the greatest extent possible. 

Rule Provisions or Federal Register Cite: 73 FR 43504 

EPA Preamble Question: 9. EPA also requests comment on other considerations 

associated with the presence of impurities in the CO2 stream related to CERCLA. 

EPA Notice 43504. 

CSC Response: CSC is concerned that potential CERCLA liabilities will have the 

potential to chill enthusiasm for undertaking GS projects. EPA needs to respond 

clearly and positively to this concern by developing appropriate language in the 

regulations and permits to provide the clarity and assurance needed to promote 

continued research and development for GS projects. 

Response: As described above, whether the presence of hazardous substances in the CO2 may result

in CERCLA liability from a sequestration facility depends entirely on the composition of the specific

CO2 stream and the environmental media in which it is stored (e.g., soil or ground water). CERCLA

exempts from liability, under CERCLA section 107, 42 U.S.C. 9607, certain “federally permitted

releases” (FPR) as defined in CERCLA, 42 U.S.C. 9601(10). Class VI permits will need to be

carefully structured to ensure that they prevent potential releases from the well which are outside the

scope of the Class VI permit. Furthermore, EPA is promulgating the GS rule under the authority of

the SDWA. To the extent the commenter is seeking interpretations of CERCLA and its related

provisions, such as the definition of a federally permitted release, such interpretations are beyond the

scope of this rulemaking. 

EPA adds that promoting the use of GS is outside the scope of the GS rule. Rather, the purpose of

the GS regulation is to ensure that, where deployed, GS is conducted in a manner that protects

257
USDWs from endangerment.

Commenter Name: Jeff W. Sheets Letter ID: 0192

Commenter Organization: ConocoPhillips Comment ID: 23900

Comment: CERCLA- CO2 injection under UIC permits will meet EPA's requirements and area of 

review along with all permitting requirements; which will ensure appropriate 

injection and handling. We are very concerned that by raising this issue, EPA 

opens broad concern and uncertainty which could seriously jeopardize progress on 

CCS. 

Response: CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit. 

Furthermore, EPA is promulgating the GS rule under the authority of the SDWA. To the extent the

commenter is seeking interpretations of CERCLA and its related provisions, such as the definition of

a federally permitted release, such interpretations are beyond the scope of this rulemaking. 

EPA agrees that proper site characterization and operation of a GS project is important for protecting

USDWs from endangerment. The UIC program Director also has authority under the SDWA to

address potential compliance issues (e.g., potential releases that may endanger USDWs) resulting

from injection violations in the unlikely event that a remedial response is necessary. Although EPA

anticipates that the need for emergency or remedial actions at GS sites will be rare, the GS rule

requires, at §146.94, that emergency and remedial response plans be developed and updated to

address such events and that owners or operators demonstrate that financial resources are set aside to

implement the plans if necessary, per §146.85.

EPA adds that promoting the use of GS is outside the scope of the GS rule. Rather, the purpose of

the GS regulation is to ensure that, where deployed, GS is conducted in a manner that protects

USDWs from endangerment.

Commenter Name: John R. Baza Letter ID: 0193

Commenter Organization: Utah Division of Oil, Gas, and Mining Comment ID: 23916

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: Waste Characterization 

Injected CO2 is not and should not be considered a hazardous waste or regulated 

under RCRA or CERCLA. It is assumed that RCRA or CERCLA wastes would be removed 

from the CO2 stream prior to injection. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

258
statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: Craig R. Walters Letter ID: 0200

Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24575

Comment: Rule Provisions: 73 FR 43504 

EPA Rule Issue: 8. Class VI requirements and permits will need to be carefully 

structured to ensure that they do not "authorize" inappropriate hazardous 

releases. This would include clarifying if there are potential releases from the 

well which are outside the scope of the Class VI permit. EPA requests comment on 

particular situations where this might occur. EPA notice 43504. 

Anadarko Petroleum Corporation (APC) Response: Well chosen sites should prevent 

these conditions from occurring. At the same time, permit writers should not 

write permits so restrictive as to make the undertaking of a GS project 

untenable. EPA should remember that CERCLA liability will not only impact owners 

and operators of GS projects, but also hundreds, thousands, and even more 

numerous pore space owners. EPA should consider the threat of subjecting these 

pore space owners to CERCLA liability. Their property interests in the CO2 GS 

project injection zones could subject them to strict, joint, and several 

liability under CERCLA pursuant to whatever liability theories might be conjured 

up by future litigants seeking compensation for response and remediation costs 

incurred in the cleanup of releases from geologic sequestration injection zones. 

EPA should recognize the significant chilling effect CERCLA liability concerns 

will have on GS projects, and seize the opportunity in this rulemaking to 

alleviate any CERCLA liability concerns to the greatest extent possible. 

Response: CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit. 

Furthermore, EPA is promulgating the GS rule under the authority of the SDWA. To the extent the

commenter is seeking interpretations of CERCLA and its related provisions, such as the definition of

a federally permitted release, such interpretations are beyond the scope of this rulemaking. 

259
EPA agrees that proper site characterization and operation of a GS project is important for protecting

USDWs from endangerment. The UIC program Director also has authority under the SDWA to

address potential compliance issues (e.g., potential releases that may endanger USDWs) resulting

from injection violations in the unlikely event that a remedial response is necessary. Although EPA

anticipates that the need for emergency or remedial actions at GS sites will be rare, the GS rule

requires, at §146.94, that emergency and remedial response plans be developed and updated to

address such events and that owners or operators demonstrate that financial resources are set aside to

implement the plans if necessary, per §146.85.

EPA adds that promoting the use of GS is outside the scope of the GS rule. Rather, the purpose of

the GS regulation is to ensure that, where deployed, GS is conducted in a manner that protects

USDWs from endangerment.

Commenter Name: Craig R. Walters Letter ID: 0200

Commenter Organization: Anadarko Petroleum Corporation Comment ID: 24576

Comment: Rule Provisions: 73 FR 43504 

EPA Rule Issue: 9. EPA also requests comment on other considerations associated 

with the presence of impurities in the CO2 stream related to CERCLA. EPA Notice 

43504. 

Anadarko Petroleum Corporation (APC) Response: APC is concerned that potential 

CERCLA liabilities will have the potential to chill enthusiasm for undertaking 

GS projects. EPA needs to respond clearly and positively to this concern by 

developing appropriate language to provide the clarity and assurance needed to 

promote continued research and development for GS projects. 

Response: As described above, promoting the use of GS is outside the scope of the GS rule. Rather,

the purpose of the GS regulation is to ensure that, where deployed, GS is conducted in a manner that

protects USDWs from endangerment.

Commenter Name: Chris M. Hobson Letter ID: 0201

Commenter Organization: Southern Company Comment ID: 22159

Comment: Potential interaction with CERCLA - EPA also raises the potential for liability 

under the Comprehensive Environmental Response, Compensation, and Liability Act 

("CERCLA") stemming from CO2 GS operations. 73 Fed. Reg. at 43504. The potential 

for liability under CERCLA will have similar adverse implications as the 

potential for RCRA applicability _ specifically, potential CERCLA liability will 

act as a significant deterrent to participation or investment in CO2 GS 

projects. Southern Company again encourages EPA to pursue whatever regulatory 

and/or legislative avenues are available to remove this obstacle without 

jeopardizing the Program's standard of protection of USDWs. 

Response: CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

260
which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit. Furthermore,

EPA is promulgating the GS rule under the authority of the SDWA. To the extent the commenter is

seeking interpretations of CERCLA and its related provisions, such as the definition of a federally

permitted release, such interpretations are beyond the scope of this rulemaking. 

EPA adds that promoting the use of GS is outside the scope of the GS rule. Rather, the purpose of

the GS regulation is to ensure that, where deployed, GS is conducted in a manner that protects

USDWs from endangerment.

Commenter Name: Thomas Curtis Letter ID: 0204

Commenter Organization: American Water Works Association (AWWA) Comment ID: 22186

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: - Congress must address liability issues under CERCLA, RCRA and Natural Resource 

Damage Assessment before this technology is commercially deployable. 

Response: EPA agrees that overlapping regulatory schemes are undesirable. EPA clarifies that the

GS rule requires owner or operators of Class VI wells to characterize their injection stream prior to

injection, and throughout the operational life of the injection facility. 

With respect to RCRA, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Comments related to congressional action are outside the scope of this rulemaking.

Commenter Name: Michael Stroben Letter ID: 0209

Commenter Organization: Duke Energy Comment ID: 22680

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: RCRA AND CERCLA APPLICABILITY 

To encourage adoption and use of the Class VI wells by the regulated community 

EPA must resolve policy and legal issues regarding the applicability of RCRA and 

CERCLA Regulation and liabilities to projects permitted and operated under the 

proposed rule. Subjecting any CO2 GS project to RCRA controls, and failure to 

adequately mitigate the potential for unlimited CERCLA liability will pose a 

serious obstacle to the commercial deployment of GS technology. 

261
Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: Michael Stroben Letter ID: 0209

Commenter Organization: Duke Energy Comment ID: 22682

Comment: Injection of CO2 into vast areas underlying multiple political jurisdictions and 

surface properties owned by multiple parties was not anticipated when "Superfund 

liability" was initially conceived. Failure to address liability uncertainties 

via a permitted injection exemption or by a mechanism for transfer of long-term 

liability to government bodies will be a disincentive to commercial deployment 

of GS technology. 

Response: CERCLA exempts from liability, under CERCLA section 107, 42 U.S.C. 9607, certain

“federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C. 9601(10). Therefore, Class

VI requirements and permits will need to be carefully structured to ensure that they do not

“authorize” inappropriate releases, and would need to prevent potential releases from the well which

are outside the scope of the Class VI permit. 

Regarding long term liability, once an owner 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. Furthermore, 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 certain

circumstances. For example, an owner or operator may be held liable for regulatory noncompliance

even after site closure was approved if the Director relied on erroneous information (e.g., erroneous

modeling data) provided by the owner or operator when approving site closure. 

Separate from EPA’s authority to enforce regulatory compliance, an owner or operator may be

subject to a §1431 response order even after proper site closure 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 present an imminent and substantial endangerment to the health of

persons, and the appropriate State and local authorities have not acted to protect the health of such

persons. The action may include issuing administrative 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. 

262
Furthermore, after site closure an owner or operator may remain liable under tort and other remedies,

or under other federal statutes including, 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.

EPA adds that promoting the use of GS is outside the scope of the GS rule. Rather, the purpose of

the GS regulation is to ensure that, where deployed, GS is conducted in a manner that protects

USDWs from endangerment.

Commenter Name: Richard Guinn Letter ID: 0210

Commenter Organization: Eastman Chemical Company Comment ID: 22693

Comment: 2. EPA must emphatically conclude that CO2 containing trace contaminants does 

not open any regulatory pathways to subjecting a geological storage site to 

Superfund liability. 

Response: CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit. 

EPA clarifies that, while the Administrator reserves the right to promulgate regulations designating

additional substances as hazardous under §102 of CERCLA, EPA intends to avoid any potential

overlap of SDWA and CERCLA authority through its comprehensive Class VI requirements.

Commenter Name: Richard Guinn Letter ID: 0210

Commenter Organization: Eastman Chemical Company Comment ID: 22694

Other EPA Comment Codes and Descriptions: 5460 2.9.2 Comments on transfer of liability for

long-term care 

Comment: 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. 

Response: As described above, CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit. 

Regarding long term liability, once an owner 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

263
noncompliance. Furthermore, 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 certain

circumstances. For example, an owner or operator may be held liable for regulatory noncompliance

even after site closure was approved if the Director relied on erroneous information (e.g., erroneous

modeling data) provided by the owner or operator when approving site closure. 

Separate from EPA’s authority to enforce regulatory compliance, an owner or operator may be

subject to a §1431 response order even after proper site closure 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 present an imminent and substantial endangerment to the health of

persons, and the appropriate State and local authorities have not acted to protect the health of such

persons. The action may include issuing administrative 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 operator may remain liable under tort and other remedies,

or under other federal statutes including, 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.

Commenter Name: Richard Guinn Letter ID: 0210

Commenter Organization: Eastman Chemical Company Comment ID: 22704

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: #1: Potential Applicability of CFR 40 Part 261 (RCRA). (Ref: page 43503, Section 

I) In the preamble to the ANPR, EPA poses the question of whether injected CO2 

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 CO2 sequestration projects. 

EPA 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 CO2 as a result of the carbon capture 

process should not limit the storage of the CO2 using Class VI wells, especially 

taking into account the diminimus risk of exposure associated with the 

disposition of CO2 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 

264
therefore can be injected into Class II wells. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit.

Commenter Name: Richard Guinn Letter ID: 0210

Commenter Organization: Eastman Chemical Company Comment ID: 22706

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 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 CO2 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 CO2 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 would be 

265
inconsistent with existing practice in the UIC program, impractical, and fatal 

to the future of CCS to limit Class VI permits solely to the CO2 portion of the 

stream and explicitly exclude any trace contaminants. 

Response: As described above, whether the presence of hazardous substances in the CO2 may result

in CERCLA liability from a sequestration facility depends entirely on the composition of the specific

CO2 stream and the environmental media in which it is stored (e.g., soil or ground water). CERCLA

exempts from liability, under CERCLA section 107, 42 U.S.C. 9607, certain “federally permitted

releases” (FPR) as defined in CERCLA, 42 U.S.C. 9601(10). Class VI permits will need to be

carefully structured to ensure that they prevent potential releases from the well which are outside the

scope of the Class VI permit. 

EPA adds that promoting the use of GS is outside the scope of the GS rule. Rather, the purpose of

the GS regulation is to ensure that, where deployed, GS is conducted in a manner that protects

USDWs from endangerment.

Commenter Name: Richard Guinn Letter ID: 0210

Commenter Organization: Eastman Chemical Company Comment ID: 22708

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 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 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 threat of long-term Superfund liability, a 

threat that could be fatal to the viability of CCS. 

Response: As described above, whether the presence of hazardous substances in the CO2 may result

in CERCLA liability from a sequestration facility depends entirely on the composition of the specific

CO2 stream and the environmental media in which it is stored (e.g., soil or ground water). CERCLA

exempts from liability, under CERCLA section 107, 42 U.S.C. 9607, certain “federally permitted

releases” (FPR) as defined in CERCLA, 42 U.S.C. 9601(10). Class VI permits will need to be

carefully structured to ensure that they prevent potential releases from the well which are outside the

scope of the Class VI permit.

Commenter Name: Paul L. Carpinone Letter ID: 0212

Commenter Organization: Tampa Electric Company Comment ID: 22897

Other EPA Comment Codes and Descriptions: 1200 1.1 General comments about the rulemaking;

1630 1.3.3 RCRA/hazardous waste issues (seeking comment) 

Comment: This rulemaking can resolve some important policy and legal issues and, in doing 

so, help foster the development of a practical, commercially deployable CCS 

regulatory program. For example, the Final Rule can provide much needed clarity 

regarding (1) the potential for liability under the Resource Conservation and 

Recovery Act ("RCRA") and the Comprehensive Environmental Response, 

Compensation, and Liability Act ("CERCLA") resulting from CO2 injection and GS 

266
activities, and (2) the options for addressing long-term post-injection 

liability for Class VI wells. As discussed below, there are practical regulatory 

and legislative options available to resolve these uncertainties that will help 

assure the public and the regulated community that CO2 UIC activities can be 

conducted in a manner that is both safe and effective. 

Response: EPA agrees that regulatory clarity is important. With respect to RCRA and need for

regulatory clarity, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: Paul L. Carpinone Letter ID: 0212

Commenter Organization: Tampa Electric Company Comment ID: 22903

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: Issues that must be addressed include the interaction of RCRA and CERCLA with 

Class VI injection activities as well as long-term post-injection liability. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Additionally, while CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain "federally permitted releases" (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit. 

The UIC program Director has authority under SDWA §1423 to address potential compliance issues

267
(e.g., potential releases that may endanger USDWs) resulting from injection violations in the unlikely

event that a remedial response is necessary. Although EPA anticipates that the need for emergency

or remedial actions at GS sites will be rare, the GS rule requires, at §146.94, that emergency and

remedial response plans be developed and updated to address such events and that owners or

operators demonstrate that financial resources are set aside to implement the plans if necessary, per

§146.85.

Regarding long term liability, once an owner 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. Furthermore, 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 certain

circumstances. For example, an owner or operator may be held liable for regulatory noncompliance

even after site closure was approved if the Director relied on erroneous information (e.g., erroneous

modeling data) provided by the owner or operator when approving site closure. 

Separate from EPA's authority to enforce regulatory compliance, an owner or operator may be

subject to a §1431 response order even after proper site closure 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 present an imminent and substantial endangerment to the health of

persons, and the appropriate State and local authorities have not acted to protect the health of such

persons. The action may include issuing administrative 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 operator may remain liable under tort and other remedies,

or under other federal statutes including, 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.

Commenter Name: Dennis R. James Letter ID: 0214

Commenter Organization: North American Coal Corporation (NAC) Comment ID: 22961

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: I. Is Injected CO2 Considered a Hazardous Waste Under RCRA? 

J. Is Injected CO2 Considered a Hazardous Substance Under CERCLA? 

Both RCRA and CERCLA are written to deal with hazardous wastes and pollutants at 

or near the surface where they can interact with our biosphere. Geologic 

sequestration of CO2 is, by definition, not impacting the biosphere. Therefore, 

these rules should not apply to the injection of CO2 and associated compounds. 

The chemical environment of deep saline aquifers or deleted oil and gas 

reservoirs will be very different from that at the surface. For example, 

268
hydrogen sulfide (H2S) is a very toxic and hazardous substance in the biosphere. 

However, it commonly occurs in formations at depth as a normal, naturally 

occurring constituent that causes no harm. Thus, the presence of H2S in a CO2 

stream may not only be non-hazardous upon injection but beneficial; it could 

make the injected gas chemically more compatible with the target formation’s 

natural environment. It is more important to consider the impacts of injected 

CO2 and associated substances on the target formation’s environment. Therefore, 

injected CO2 should not be considered a hazardous waste under RCRA or a 

hazardous substance under CERCLA. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

EPA clarifies that CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit.

Commenter Name: Ronald Evans Letter ID: 0215

Commenter Organization: Denbury Resources, Inc. (DRI) Comment ID: 24285

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: III. ANY FINAL RULE MUST CLEARLY ADDRESS POTENTIAL EXPOSURE

UNDER RCRA AND 

CERCLA 

EPA can and should simultaneously protect underground sources of drinking water 

and promote the capture of carbon dioxide. Its strategy in both areas should be 

crafted to avoid unintended consequences. EPA’s goal in this rulemaking should 

be to fulfill its obligations to protect the nation’s USDWs from both naturallyoccurring and man-made contaminants, while at the same time promoting progress 

towards successful commercial-scale carbon capture and storage in order to 

address broader environmental protection concerns. 

269
If EPA is going to address these broader concerns by establishing a framework 

for the injection and sequestration of CO2 in addition to the incidental storage 

that occurs in EOR activities, it must address potentially limitless liability 

under other statutes that EPA administers, including CERCLA [FN40] and RCRA 

[FN41]. Liability under these statutes would act as a strong deterrent to the 

development of CCS. 

Regulated industry has learned a great deal in the last 30 years regarding 

environmental liability. When Congress passed CERCLA, it imposed joint and 

several liability on landowners, transporters, and generators of hazardous 

substances and it made that liability retroactive. Most recently, the Supreme 

Court, in Massachusetts v. EPA, 549 U.S. 497 (2007), recognized that the Clean 

Air Act ("CAA"), with its "capacious" definition of air pollutant, could be used 

to regulate substances (in this case, CO2) which Congress appeared to not intend 

to regulate and whose regulation under many provisions of the CAA (i.e., the 

NAAQS) is awkward at best. One lesson from these statutes and the Courts’ 

interpretation is that regulated industry cannot underestimate its potential 

liability for pollution, irrespective of its compliance with current regulations 

and irrespective of the magnitude of its role in the waste disposal process. 

Accordingly, as EPA attempts to promote efforts to reduce anthropogenic CO2 

emissions, it faces an ever more cautious regulated community. We urge EPA to 

take determined steps to provide regulatory clarity as to compliance obligations 

and potential for liability. 

[40] Comprehensive Environmental Response, Compensation, and Liability Act 

("CERCLA"), 42 U.S.C. §§ 9601-9675. 

[41] Resource Conservation and Recovery Act ("RCRA"), 42 U.S.C. § 6901-6992k. 

Response: EPA agrees that overlapping regulatory schemes are undesirable. EPA received many

comments regarding the applicability of the RCRA regulations and statute to CO2 streams that are

geologically sequestered under the final Class VI UIC well requirements. As a result, EPA has

decided to initiate a separate proposed rulemaking specifically to examine the issue of RCRA

applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

EPA clarifies that CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

270
section 107, 42 U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit.

Commenter Name: Ronald Evans Letter ID: 0215

Commenter Organization: Denbury Resources, Inc. (DRI) Comment ID: 24287

Comment: B. EPA Should Exclude Injection and Geologic Storage of CO2 from Coverage Under 

CERCLA 

Regarding CERCLA liability, in section II.J of the preamble to the Proposed 

Rule, EPA notes that the CO2 stream may contain hazardous substances or that the 

CO2 stream could react with groundwater to produce hazardous substances, and 

concludes that "whether or not there is a ‘hazardous substance’ that may result 

in CERCLA liability from a sequestration facility depends entirely on the makeup of the specific CO2 stream and of the environmental media (e.g., soil, 

groundwater) in which it is stored." 73 Fed. Reg. at 43,504. EPA notes that 

CERCLA exempts from liability certain "federally permitted releases," including 

releases in compliance with a UIC permit under SDWA, and recognizes that Class 

VI permits will need to be structured to not permit "inappropriate hazardous 

releases." Id. EPA also requests comment on "particular situations" where there 

exists the potential for "releases from the well which are outside the scope of 

the Class VI permit." EPA requests comment on "other considerations associated 

with the presence of impurities in the CO2 stream related to CERCLA." 

Denbury is concerned that any potential for CERCLA liability will deter efforts 

to develop CCS projects. Under CERCLA, private parties or government entities 

can sue to recover "response costs" associated with any "release" from a 

"facility" of a "hazardous substance." Liability is retroactive, joint and 

several, and falls upon both current and past owners of facilities, and on those 

who generated or transported those "hazardous substances." 42 U.S.C. § 9607(a). 

The broad nature of CERCLA liability makes it a vigorous means of addressing 

sites contaminated with hazardous substances, but when applied to CCS would 

serve to discourage regulated parties who would otherwise undertake carbon 

sequestration. 

Pure CO2 is non-toxic at low concentrations and is not a listed hazardous waste 

under environmental statutes that CERCLA cross-references in defining "hazardous 

substances." While it is certainly the case that CO2 is not the type of 

"hazardous substance" that Congress envisioned when it enacted CERCLA, the 

definition that Congress included in the statute is reminiscent of the 

"capacious" definition of "air pollutant" that the Supreme Court gave effect to 

in Massachusetts v. EPA, 549 U.S. 497 (2007), to apply provisions of the Clean 

Air Act to CO2, something that Congress showed no intent to do when it enacted 

the Clean Air Act. To avoid a similar outcome here, the EPA should define that 

the injection of CO2 under a Class VI permit constitutes a "federally permitted 

release." 

EPA’s definition of "federally permitted release" includes "any injection of 

fluids authorized under Federal underground injection control programs or State 

271
programs submitted for Federal approval . . . pursuant to part C of the Safe 

Drinking Water Act . . ." 42 U.S.C. § 9601(10). CERCLA exempts a federally 

permitted release from response cost recovery actions. 42 U.S.C. § 9607(j) 

("Recovery by any person (including the United States or any State or Indian 

tribe) for response costs or damages resulting from a federally permitted 

release shall be pursuant to existing law in lieu of this section.") In the 

past, EPA has made only minimal efforts to clarify the scope of the federally 

permitted release exemption (the "FPR exemption"). In 1988, it stated in the 

preamble to a proposed rule that would have clarified the FPR exemption that 

"any underground injection of hazardous substances permitted under a State 

program . . . or EPA-administered program, is considered federally permitted for 

purposes of CERCLA notification." Reporting Exemptions for Federally Permitted 

Releases of Hazardous Substances; Proposed Rule, 53 Fed. Reg. 27,268, 27,273 

(Jul. 19, 1988). EPA did not finalize that proposal. EPA should use the present 

proposed rulemaking to reaffirm that an authorized release under the UIC program 

qualifies for the exemption from CERCLA cleanup liability under section 9607. 

To be sure, this would be a narrow exemption, because EPA has also taken the 

position that the FPR exemption does not apply to accidental releases. See 

Guidance on the CERCLA Section 101(10)(H) Federally Permitted Release Definition 

for Certain Air Emissions, 67 Fed. Reg. 18,899, 18,903 (Apr. 17, 2002). In U.S. 

v. United Nuclear Corp., EPA took the position that seepage from uranium 

tailings ponds into groundwater was not part of the permitted activity. 814 F. 

Supp. 1552 (D.N.M. 1992). In Idaho v. Bunker Hill, the court accepted a state’s 

claim that CERCLA liability will attach to releases "which were not expressly 

permitted in the various permits, which exceeded the limitations established by 

the permits, or which occurred during a time period when there were no permits." 

635 F. Supp. 665, 673-74 (D. Idaho 1986). Accordingly, EPA could recognize the 

applicability of the FPR exemption without significantly revising its position 

on the FPR. 

Yet another basis on which to exclude injected supercritical CO2 from CERCLA’s 

ambit is the fact that CO2 is currently a commodity - whether used in the food 

and beverage industry or for EOR - and will likely remain so for years to come. 

Denbury currently has contracts to purchase anthropogenic CO2 from multiple 

sources. While the price of the CO2 varies, it has a significant value to 

Denbury and other EOR operators. As discussed above, the most realistic path for 

storage of CO2 over the next several years is incidentally in oil and gas 

bearing formations. Thus, captured anthropogenic CO2 will be a commodity for 

purposes of EOR for many years.[FN42] Further, Denbury or other EOR operators 

may need to access the stored CO2 for use in future EOR operations or for other 

unforeseen purposes where the use of supercritical substances is necessary and 

desirable. The proposed rule should thus recognize these factors and clearly 

classify CO2 as a commodity that is excluded from CERCLA’s coverage. 

To be sure, EPA does not have the authority to protect CCS operations from 

liability under state statutes and common law, and Denbury is not suggesting 

that EPA attempt to do so in the context of this rulemaking. However, Denbury is 

asking EPA to use its authority under laws it administers, to reduce the overall 

risk of exposure for companies engaging in CCS under a UIC permit regime. 

272
[42] See also Ferguson, et al., supra text accompanying note 34, (estimating 

potential market for CO2 for EOR purposes around 7,500 million metric tonnes 

between now and 2030). 

Response: CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain “federally permitted releases” as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit. EPA is

promulgating this rule under the authority of SDWA. To the extent that the commenter is seeking

interpretation of CERCLA and its related provisions, such interpretations are outside the scope of

this rulemaking.

The UIC program Director has authority under SDWA §1423 to address potential compliance issues

(e.g., potential releases that may endanger USDWs) resulting from injection violations in the unlikely

event that a remedial response is necessary. Although EPA anticipates that the need for emergency

or remedial actions at GS sites will be rare, the GS rule requires, at §146.94, that emergency and

remedial response plans be developed and updated to address such events and that owners or

operators demonstrate that financial resources are set aside to implement the plans if necessary, per

§146.85.

EPA clarifies that, while the Administrator reserves the right to promulgate regulations designating

additional substances as hazardous under §102 of CERCLA, EPA intends to avoid any potential

overlap of SDWA and CERCLA authority through its comprehensive Class VI requirements.

EPA adds that promoting or encouraging the use of GS is outside the scope of the GS rule. Rather,

the purpose of the GS regulation is to ensure that, where deployed, GS is conducted in a manner that

protects USDWs from endangerment.

Commenter Name: Barbara Walz Letter ID: 0216

Commenter Organization: Tri-State Generation and Transmission Association,

Inc.

Comment ID:

22974

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: As the GAO report cautions, EPA must resolve key policy and legal uncertainties 

including the interaction of the Resource Conservation and Recovery Act (RCRA) 

and the Comprehensive Environmental Response, Compensation, and Liability Act 

(CERCLA) with Class VI injection activities and the specter of long-term postinjection liability -to alleviate financial concerns of potential Class VI well 

owners or operators, and to encourage investment in the development and 

operation of Class VI CO2 injection wells. Tri-State recognizes that 

Congressional action may be needed to clear these hurdles standing in the way of 

commercial deployment of full-scale geologic sequestration projects. 

273
Response: EPA agrees that overlapping regulatory schemes are undesirable. EPA received many

comments regarding the applicability of the RCRA regulations and statute to CO2 streams that are

geologically sequestered under the final Class VI UIC well requirements. As a result, EPA has

decided to initiate a separate proposed rulemaking specifically to examine the issue of RCRA

applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

EPA clarifies that CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit.

Commenter Name: Barbara Walz Letter ID: 0216

Commenter Organization: Tri-State Generation and Transmission Association,

Inc.

Comment ID:

22976

Comment: injected material is not mismanaged. EPA should take steps in the final rule to 

minimize the potential for CERCLA liability attaching to owners of operators of 

Class VI injection wells by issuing permits that take full advantage of CERCLA's 

"federally permitted release" exemption. 

Response: CERCLA exempts from liability, under CERCLA section 107, 42 U.S.C. 9607, certain

“federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C. 9601(10). Therefore, Class

VI requirements and permits will need to be carefully structured to ensure that they do not

“authorize” inappropriate releases, and would need to prevent potential releases from the well which

are outside the scope of the Class VI permit. EPA is promulgating this rule under the SDWA. To the

extent that the commenter is seeking interpretations of CERCLA and its related provisions, such

interpretations are outside the scope of this rulemaking.

Regarding long term liability, once an owner 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. Furthermore, 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 certain

circumstances. For example, an owner or operator may be held liable for regulatory noncompliance

even after site closure was approved if the Director relied on erroneous information (e.g., erroneous

modeling data) provided by the owner or operator when approving site closure. 

274
Separate from EPA’s authority to enforce regulatory compliance, an owner or operator may be

subject to a §1431 response order even after proper site closure 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 present an imminent and substantial endangerment to the health of

persons, and the appropriate State and local authorities have not acted to protect the health of such

persons. The action may include issuing administrative 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 operator may remain liable under tort and other remedies,

or under other federal statutes including, 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.

Commenter Name: Olon Plunk Letter ID: 0217

Commenter Organization: Xcel Energy, Inc. Comment ID: 21552

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: In their comments regarding the proposed rule, both the Edison Electric 

Institute (EEI) and the Utility Solid Waste Activity Group (USWAG) present well 

articulated concerns regarding the legal and regulatory issues that could arise 

from the inappropriate treatment of captured CO2 within the context of the 

Resource Conservation and Recovery Act, and the Comprehensive Environmental 

Response, Compensation and Liability Act. Both groups describe potential 

solutions to this issue; Xcel Energy endorses these comments and suggested 

solutions. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

EPA clarifies that CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

275
which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit. 

For additional information, please see EPA's responses to specific comments by Edison Electric

Institute and the Utility Solid Waste Activity Group.

Commenter Name: Edward Steadman Letter ID: 0220

Commenter Organization: The Energy and Environmental Research Center at the

University of North Dakota

Comment ID:

21609

Comment: Page 43504. J. Is Injected CO2 Considered a Hazardous Waste under CERCLA? 

No. CO2 should not be considered a hazardous waste under CERCLA. 

Response: CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit. 

EPA is promulgating this rule under SDWA. To the extent that commenter is seeking interpretations

of CERCLA and its related provisions, such interpretations are outside the scope of this rulemaking. 

EPA clarifies that, while the Administrator reserves the right to promulgate regulations designating

additional substances as hazardous under §102 of CERCLA, EPA intends to avoid any potential

overlap of SDWA and CERCLA authority through its comprehensive Class VI requirements.

Commenter Name: Darrick Eugene Letter ID: 0223

Commenter Organization: Texas Carbon Capture and Storage Association Comment ID: 23956

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: Point #1: The lack of clarification of the CO2 injectate stream which could leadto 

the stream being considered a waste. We recognize and salute EPA's attempt to 

avoid labeling CO2 injection as waste injection. Nevertheless, by tracking 

closely the Class I rules for the injection of hazardous waste (see Attachment 

A), the Proposed Rule appears to treat CO2 as a waste. It will be difficult for 

geologic storage to move forward on this basis. 

Also, in choosing not to state a composition specification minimum for CO2, the 

EPA opens the door to having the CO2 injectate stream declared a waste. We feel 

that is a serious weakness, compelling a regulatory approach for a worst-case 

injectate composition stream, and providing a basis for additional regulation 

under the Resources Conservation and Recovery Act (RCRA) or the Comprehensive 

276
Environmental Response, Compensation, and Liability Act (CERCLA). The failure to 

define the composition specification minimum for CO2 contributes to the 

overly protective approach of the EPA to the geologic storage of CO2. The EPA 

should address this concern by specifically excluding injected supercritical CO2 

for geologic storage from regulation under both RCRA and CERCLA similar to what 

has been done for wastes associated with the exploration, development and 

production of crude oil, natural gas and geothermal energy under RCRA [FN2] 

2 See Regulatory Determination for Oil and Gas and Geothermal Exploration, 

Development, and Production Wastes; Regulatory Determination, 53 Fed. Reg. 25445 

(July 6, 1988) 

Response: The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a

percent CO2). The GS rule, however, addresses the quality and quantity of impurities by requiring

owners or operators to submit information on the source of the CO2 and its physical and chemical

properties. Specifically, the GS rule requires the owner or operator to submit data about the site,

including an analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the 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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals. 

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 low. However, these estimates are

based on limited information, and uncertainties remain about the expected concentrations of

impurities from the various types of CO2 streams. The concentrations of minor and trace elements in

CO2 streams for GS projects are likely to vary by facility, coal composition, plant operating

conditions, and pollution removal technologies. 

With respect to RCRA, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

Commenter Name: Andrew Duguid Letter ID: 0226

Commenter Organization: Schlumberger Carbon Services Comment ID: 24001

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: 2. Now that the EPA has introduced the topics of the Comprehensive 

Environmental Response, Compensation, and Liability Act (CERCLA) and the 

Resource Conservation and Recovery Act (RCRA) we urge the EPA to clarify 

the roles of both with respect to CO2 injection under the UIC program. 

277
Response: EPA received many comments regarding the need for clarity with respect to RCRA

regulations and statute to CO2 streams that are geologically sequestered under the final Class VI

UIC well requirements. As a result, EPA has decided to initiate a separate proposed rulemaking

specifically to examine the issue of RCRA applicability 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 particular 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 commenters who wish to submit comments on the RCRA proposal will need to do

so during the comment period for that rule. Finally, EPA also notes that the final GS rule, which

adds new regulations for Class VI wells under the Safe Drinking Water Act (SDWA), is not making

any changes to the RCRA regulations.

EPA clarifies that CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit.

Commenter Name: Andrew Duguid Letter ID: 0226

Commenter Organization: Schlumberger Carbon Services Comment ID: 24003

Comment: The preamble of the draft points out that under federally permitted 

release provision of CERCLA releases in compliance with a UIC permit are 

exempt from liability under CERCLA. Schlumberger fails to see how the 

any releases under the proposed rule that involves both characterization 

of the injection stream and characterization of the subsurface can fall 

outside the federally permitted release provision. We urge the EPA to 

better clarify any cases where injection of CO2 in accordance with a UIC 

permit is not released from liability under the federally permitted 

release provision of CERCLA. We cannot envision a permit being issued 

for an injection that could cause an unintended release, especially, in 

light of the information that is required in the permit application on 

the composition of the injection stream and on the chemical makeup of 

the subsurface. 

Response: CERCLA exempts from liability, under CERCLA section 107, 42 U.S.C. 9607, certain

“federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C. 9601(10). Therefore, Class

VI requirements and permits will need to be carefully structured to ensure that they do not

“authorize” inappropriate releases, and would need to prevent potential releases from the well which

are outside the scope of the Class VI permit. Furthermore, EPA is promulgating the GS rule under

the authority of the SDWA. To the extent the commenter is seeking interpretations of CERCLA and

its related provisions, such as the definition of a federally permitted release, such interpretations are

beyond the scope of this rulemaking.

278
Commenter Name: Michael E. Moore Letter ID: 0232

Commenter Organization: Blue Source Comment ID: 21896

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment); 2046 1.5.2.3 Continuing to classify CO2 injection for EOR/EGR as Class II/ dividing line

between Class II and Class VI (seeking comment) 

Comment: II. Specific Comments on the Proposed Regulations 

a. Background 

Blue Source’s comments here are focused on a narrow, but critical, aspect of 

EPA’s proposal - namely, whether CO2-EOR operators should have the option of 

participating in EPA’s forthcoming CCS regulatory scheme. [FN1] 

[FN1: We believe that adoption of our comments is a necessary component of ensuring 

that CO2-EOR flourishes as CCS, but other steps need to be taken, too. For 

example, we also believe that EPA needs to ensure that carbon dioxide is not 

regulated as a hazardous waste or substance under statutes such as RCRA and 

CERCLA during storage operations; in a future rulemaking EPA perhaps could do so 

by expanding current exemptions which apply to oil & gas operations to include 

"storage" operations.] 

Response: EPA clarifies that the Class VI GS rule is designed to ensure the protection of USDWs

from endangerment, and does not aim to promote GS deployment. 

EPA notes that the GS rule is not promulgated under the RCRA or CERCLA statutes, and further,

the applicability of those statutes will not be determined under the SDWA or the terms of the GS

rule, but rather according to those statutes themselves and any implementing regulations that may

apply. EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. 

EPA clarifies that CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit. 

The Agency acknowledges the commenter's concerns regarding the scope and possible impacts of

CERCLA liability on CCS activities, however EPA notes that the GS rule is not promulgated under

279
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. 

EPA adds that, if it develops regulations in the future, stakeholders will be provided opportunity for

public comment.

Commenter Name: Steven B. Corneli Letter ID: 0234

Commenter Organization: NRG Energy, Inc. Comment ID: 23174

Comment: CERCLA Applicability 

The preamble of the proposed rule suggests that CERCLA liability may arise out 

of CO2 GS projects due to "potential USDW impacts", presence of impurities in 

the stream, and the potential for reaction products to migrate from the 

injection zone. 73 Fed. Reg. 43492, 43497 (July 25, 2008). EPA also states that 

(CERCLA exempts from liability certain "federally permitted releases" including 

releases in compliance with a UIC permit under SDWA. Therefore, Class VI 

requirements and permits will need to be carefully structured to ensure that 

they do not "authorize" inappropriate hazardous releases. This would include 

clarifying if there are potential releases from the well which are outside the 

scope of the Class VI permit.) 73 Fed. Reg. at 43504. 

EPA’s suggestion that CERCLA liability may apply to CO2 GS projects raises 

concern among the electric power industry. Because EPA raised this as a 

potential issue, businesses and investors may be reluctant to support GS 

projects faced with a potential for CERCLA liability hanging over their heads. 

In order to prevent any discouragement of development in CO2 GS projects, EPA 

should provide confirmation in the final regulations that injection of CO2 into 

a permitted injection zone does not constitute a "release" for purposes of RCRA 

or CERCLA. EPA should also take the opportunity to dispel the CERCLA liability 

concerns by developing appropriate language to provide the clarity and assurance 

needed to promote continued research, development and deployment of CO2 GS 

projects. 

Response: EPA notes that the GS rule is not promulgated under the RCRA or CERCLA statutes,

and further, the applicability of those statutes will not be determined under the SDWA or the terms

of the GS rule, but rather according to those statutes themselves and any implementing regulations

that may apply EPA received many comments regarding the applicability of the RCRA regulations

and statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. CO2 itself is not listed as a hazardous substance 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

280
sulfuric acid). Whether such substances may result in CERCLA liability from a sequestration facility

depends entirely on the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit. 

The UIC program Director has authority under SDWA §1423 to address potential compliance issues

(e.g., potential releases that may endanger USDWs) resulting from injection violations in the unlikely

event that a remedial response is necessary. Although EPA anticipates that the need for emergency

or remedial actions at GS sites will be rare, the GS rule requires, at §146.94, that emergency and

remedial response plans be developed and updated to address such events and that owners or

operators demonstrate that financial resources are set aside to implement the plans if necessary, per

§146.85.

EPA adds that promoting the use of GS is outside the scope of the GS rule. Rather, the purpose of

the GS regulation is to ensure that, where deployed, GS is conducted in a manner that protects

USDWs from endangerment.

Commenter Name: Abbie Krebsbach Letter ID: 0235

Commenter Organization: Montana-Dakota Utilities Co. Comment ID: 23192

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: Other Law Implications 

Montana-Dakota urges EPA to evaluate carefully any proposed treatment of the 

Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) 

and Resource Conservation and Recovery Act (RCRA), or other laws, that it may be 

considering under the Class VI regulations to ensure that any such treatment is 

necessary and does not serve as an unintended springboard for hampering the 

successful commercialization of CCS. Unless CO2 is categorized as a commodity, 

and not as a waste, there could be significant complications in implementing C02 

GS projects. 

Once a material is deemed to be a solid waste, an additional set of parameters 

applies to determine whether that substance is also a hazardous waste and thus 

subject to further regulation. Montana-Dakota recommends that EPA examine an 

approach to determining that CCS activities which meet UIC permit requirements 

are not equated to discarding the CO2. Identifying CO2 as a waste could limit 

the use of stored CO2 in any potential future applications. 

The EPA jumps to an unnecessary and potentially confusing discussion in the 

preamble of whether injected CO2 may be a hazardous waste, potentially implying 

that CO2 is a solid waste to begin with. Montana-Dakota recommends that any 

characterization of potentially hazardous constituents in CO2 injectate may be 

addressed, possibly through Toxicity Characteristic Leaching Procedures, as part 

of the UIC permitting process without addressing any potential RCRA 

jurisdictional issues. This should be examined further by EPA in regard to both 

RCRA and CERCLA implications. 

281
Response: As described above, the GS rule does not affect the regulatory status of CO2 under

RCRA. Furthermore, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule.

Commenter Name: Mark Bohrer Letter ID: 0241

Commenter Organization: North Dakota Industrial Commission Comment ID: 23229

Comment: 8. Class VI requirements and permits will need to be carefully structured to 

ensure that they do not "authorize" inappropriate hazardous releases. This 

would include clarifying if there are potential releases from the well which are 

outside the scope of the Class VI permit. EPA requests comment on particular 

situations where this might occur. EPA Notice 43504. 

Carbon dioxide should not be classified as a hazardous waste. Carbon dioxide is 

not hazardous or toxic under normal conditions. CERCLA liability will not only 

impact owners and operators of carbon dioxide sequestration projects, but also 

pore space owners. Subjecting pore space owners to CERCLA liability and joint 

and several liability under CERCLA will greatly hamper carbon dioxide 

sequestration projects. EPA should take the opportunity in this rulemaking to 

alleviate any CERCLA liability concerns. 

9. EPA also requests comment on other considerations associated with the 

presence of impurities in the CO2 stream related to CERCLA. EPA Notice 43504. 

CERCLA should not apply to carbon dioxide sequestration. EPA needs to provide 

assurances to facilitate carbon dioxide sequestration projects. 

Response: EPA notes that the GS rule is not promulgated under the RCRA or CERCLA statutes,

and further, the applicability of those statutes will not be determined under the SDWA or the terms

of the GS rule, but rather according to those statutes themselves and any implementing regulations

that may apply. To the extent the commenter is seeking interpretations of CERCLA or RCRA and its

related provisions, such interpretations are beyond the scope of this rulemaking. 

EPA received many comments regarding the applicability of the RCRA regulations and statute to

CO2 streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. CO2 itself is not listed as a hazardous substance under CERCLA however, the CO2 stream

282
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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit.

Commenter Name: Kristin Henry Letter ID: 0242

Commenter Organization: Sierra Environmental Law Program, Sierra Club Comment ID: 23327

Comment: VII. The Rule Should Specify That an Intrusion Into a USDW is Not a "Federally 

Permitted Release" Under CERCLA. 

The rule itself, rather than individual permits, should assure that Class VI 

permits do not allow responsible parties to avoid CERCLA liability on grounds 

that a release constitutes a "federally permitted release." 

EPA notes in the preamble to the proposed rule, 73 Fed. Reg 43504, that CERCLA 

exempts from liability certain "federally permitted releases, including releases 

in compliance in a UIC permit under the Safe Drinking Water Act." EPA further 

notes that "Class VI requirements and permits will need to be carefully 

structured to ensure that they do not ‘authorize’ inappropriate hazardous 

releases." EPA should go further and effectively prohibit Class VI permit 

conditions that would make the "federally permitted release" defense available 

should injected fluids or displaced formation fluids enter or endanger USDWs. 

This prohibition should be added to Subpart E - Permit Conditions, or to any 

other appropriate section of the rule. 

Response: CERCLA exempts from liability, under CERCLA section 107, 42 U.S.C. 9607, certain

“federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C. 9601(10). Therefore, Class

VI requirements and permits will need to be carefully structured to ensure that they do not

“authorize” inappropriate releases, and would need to prevent potential releases from the well which

are outside the scope of the Class VI permit. Furthermore, EPA is promulgating the GS rule under

the authority of the SDWA. To the extent the commenter is seeking interpretations of CERCLA and

its related provisions, such as the definition of a federally permitted release, such interpretations are

beyond the scope of this rulemaking. 

The UIC program Director has authority under SDWA §1423 to address potential compliance issues

(e.g., potential releases that may endanger USDWs) resulting from injection violations in the unlikely

event that a remedial response is necessary. Although EPA anticipates that the need for emergency

or remedial actions at GS sites will be rare, the GS rule requires, at §146.94, that emergency and

remedial response plans be developed and updated to address such events and that owners or

operators demonstrate that financial resources are set aside to implement the plans if necessary, per

§146.85.

Regarding long term liability, once an owner 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

283
noncompliance. Furthermore, 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 certain

circumstances. For example, an owner or operator may be held liable for regulatory noncompliance

even after site closure was approved if the Director relied on erroneous information (e.g., erroneous

modeling data) provided by the owner or operator when approving site closure. 

Separate from EPA’s authority to enforce regulatory compliance, an owner or operator may be

subject to a §1431 response order even after proper site closure 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 present an imminent and substantial endangerment to the health of

persons, and the appropriate State and local authorities have not acted to protect the health of such

persons. The action may include issuing administrative 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 operator may remain liable under tort and other remedies,

or under other federal statutes including, 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.

Commenter Name: Kevin Wanttaja Letter ID: 0248

Commenter Organization: Western Energy Supply and Transmission

Associates

Comment ID:

22247

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: [FN1: See EPA's VEF-Technical_Document_072408, pg. 6.] 

– WEST is concerned about arguments made by some stakeholders that a whole suite 

of environmental laws should be applied to CCS projects, including the 

Comprehensive Environmental Response, Compensation, and Liability Act ("CERCLA") 

and the Resource Conservation and Recovery Act ("RCRA"). These laws applied to 

CCS would impose significant obligations and potential liabilities not only on 

GS operators, but also potentially on other entities in the CO2 abatement chain, 

such as the power plant operators producing the CO2. This would likely chill 

technology advancement and commercialization of CCS. WEST urges EPA to design 

the UIC for CO2 GS program to limit CCS projects' liability under CERCLA and 

RCRA. 

Response: First, EPA notes that the GS rule is not promulgated under either the RCRA or CERCLA

statutes, and the applicability of those statutes will not be determined under the SDWA or the terms

of the GS rule, but rather according to those statutes themselves and any implementing regulations

that may apply. With respect to RCRA, EPA has decided to initiate a separate proposed rulemaking

specifically to examine the issue of RCRA applicability 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

284
proposal. The Agency will consider issues particular to RCRA in the context of that separate

rulemaking, and recommends that the commenter read that proposed rule when it is published. The

Agency notes that commenters who wish to submit comments on the RCRA proposal will need to do

so during the comment period for that rule. 

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit. 

EPA adds that promoting the use of GS is outside the scope of the GS rule. Rather, the purpose of

the GS regulation is to ensure that, where deployed, GS is conducted in a manner that protects

USDWs from endangerment.

Commenter Name: James T. Sims Letter ID: 0249

Commenter Organization: Western Business Roundtable Comment ID: 22261

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: 3. Avoid Regulatory Creep - We are extremely concerned by arguments that 

the whole suite of environmental laws -- including the Comprehensive 

Environmental Response, Compensation, and Liability Act ("CERCLA") and the 

Resource Conservation and Recovery Act ("RCRA") -- be applied to CCS projects. 

These laws, if applied broadly to CCS, would impose significant obligations and 

potential liabilities not only on project operators, but also potentially on 

other entities in the CO2 chain, such as entities producing the CO2 that is 

ultimately injected. That would put advancement of CCS commercialization into a 

deep freeze. Such an outcome would clearly be counter-productive. Thus, we 

urge the Agency to pursue options that will limit CCS projects’ liability under 

CERCLA and RCRA. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. 

CO2 itself is not listed as a hazardous substance under CERCLA; however, the CO2 stream may

contain a listed hazardous substance (such as mercury) or may mobilize substances in the subsurface

285
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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit. 

EPA adds that encouraging the use of GS is outside the scope of the GS rule. Rather, the purpose of

the GS regulation is to ensure that, where deployed, GS is conducted in a manner that protects

USDWs from endangerment.

Commenter Name: Kurt Waltzer Letter ID: 0250

Commenter Organization: Clean Air Task Force Comment ID: 22283

Other EPA Comment Codes and Descriptions: 1200 1.1 General comments about the rulemaking;

2020 1.5.1 Support Class VI designation 

Comment: We consider the Phase III Deployment Phase of the Department of Energy’s (DOE) 

Regional Partnership Program to be very worthwhile, but we do not consider the 

completion of this program to be a prerequisite for either commercial 

implementation of CCS or for the promulgation of a sound and protective rule. 

The DOE’s program has limited funds available through appropriations, and its 

demonstration projects will be of limited scale and duration. In addition, it 

focuses as much or more on the optimum way to apply existing technologies as it 

does on fundamental research or even demonstrations that particular technologies 

"work." Our scientific and practical understanding and experience in GS itself, 

as well as in related underground injection activities, is sufficient to 

construct and operate the first large-scale, commercial plants in the U.S., 

provided they are regulated adequately. In that respect, we do not consider the 

proposed rule premature, but a very timely and necessary development. 

The rule itself, rather than individual permits, should assure that Class VI 

permits do not allow responsible parties to avoid CERCLA liability on grounds 

that a release constitutes a "federally permitted release" 

Response: EPA agrees that tailored requirements for Class VI wells are necessary to address the

unique nature of injecting large volumes of CO2 and to ensure that USDWs are protected from

endangerment. The GS rule contains tailored requirements for the permitting, geologic site

characterization, AoR and corrective action, well construction, operation, mechanical integrity

testing, monitoring, well plugging, post-injection site care, and site closure of GS wells that directly

address issues unique to the nature of large-scale CO2 injection for GS.

EPA believes, as supported by the rule's administrative record, that sufficient data and experience

currently exist to develop UIC regulations for GS wells. The GS rulemaking builds upon decades of

knowledge about safe injection practices. While developing the GS regulation, EPA has evaluated

relevant GS research, including projects conducted by the seven regional carbon sequestration

partnerships funded by the U.S. Department of Energy and coordinated through the National Energy

Technology Laboratory (NETL), and several international projects. Additionally, EPA's Office of

Water continues to fund research at the Lawrence Berkeley National Laboratory examining the

effects of CO2 interaction with ground water aquifers and any potential mobilization of trace

286
elements that may occur.

CERCLA exempts from liability, under CERCLA section 107, 42 U.S.C. 9607, certain "federally

permitted releases" (FPR) as defined in CERCLA, 42 U.S.C. 9601(10). Therefore, Class VI

requirements and permits will need to be carefully structured to ensure that they do not 'authorize'

inappropriate releases, and would need to prevent potential releases from the well which are outside

the scope of the Class VI permit. Furthermore, EPA is promulgating the GS rule under the authority

of the SDWA. To the extent the commenter is seeking interpretations of CERCLA and its related

provisions, such as the definition of a federally permitted release, such interpretations are beyond the

scope of this rulemaking. 

The UIC program Director has authority under SDWA §1423 to address potential compliance issues

(e.g., potential releases that may endanger USDWs) resulting from injection violations in the unlikely

event that a remedial response is necessary. Although EPA anticipates that the need for emergency

or remedial actions at GS sites will be rare, the GS rule requires, at §146.94, that emergency and

remedial response plans be developed and updated to address such events and that owners or

operators demonstrate that financial resources are set aside to implement the plans if necessary, per

§146.85.

Regarding long term liability, once an owner 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. Furthermore, 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 certain

circumstances. For example, an owner or operator may be held liable for regulatory noncompliance

even after site closure was approved if the Director relied on erroneous information (e.g., erroneous

modeling data) provided by the owner or operator when approving site closure. 

Separate from EPA's authority to enforce regulatory compliance, an owner or operator may be

subject to a §1431 response order even after proper site closure 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 present an imminent and substantial endangerment to the health of

persons, and the appropriate State and local authorities have not acted to protect the health of such

persons. The action may include issuing administrative 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 operator may remain liable under tort and other remedies,

or under other federal statutes including, 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.

EPA recognizes the significant amount of data generated by the DOE partnerships and agrees that

sufficient data have been collected to inform the final GS rule. EPA has evaluated permits and

reviewed operational data and information associated with the seven regional carbon sequestration

partnerships funded by the U.S. Department of Energy and coordinated through the National Energy

287
Technology Laboratory. EPA believes that these projects form a solid basis for finalizing the GS

requirements, and agrees there is no reason to wait until all phases of the DOE demonstration tests

are complete.

Commenter Name: Kurt Waltzer Letter ID: 0250

Commenter Organization: Clean Air Task Force Comment ID: 22284

Comment: EPA notes in the preamble to the proposed rule (73 Fed. Reg. 43504) that CERCLA 

exempts from liability certain "federally permitted releases, including releases 

in compliance with a UIC permit under the Safe Drinking Water Act." EPA further 

notes that "Class VI requirements and permits will need to be carefully 

structured to ensure that they do not ‘authorize’ inappropriate hazardous 

releases." Our Environmental NGO Group strongly urges EPA to go further and 

effectively prohibit Class VI permit conditions that would make the "federally 

permitted release" defense available should injected fluids or displaced 

formation fluids enter or endanger USDWs. We suggest that such a prohibition be 

added to Subpart E - Permit Conditions, or to any other section of the rule that 

EPA finds appropriate. 

Response: CERCLA exempts from liability, under CERCLA section 107, 42 U.S.C. 9607, certain

"federally permitted releases" (FPR) as defined in CERCLA, 42 U.S.C. 9601(10). Therefore, Class

VI requirements and permits will need to be carefully structured to ensure that they do not

"authorize" inappropriate releases, and would need to prevent potential releases from the well which

are outside the scope of the Class VI permit. Furthermore, EPA is promulgating the GS rule under

the authority of the SDWA. To the extent the commenter is seeking interpretations of CERCLA and

its related provisions, such as the definition of a federally permitted release, such interpretations are

beyond the scope of this rulemaking. 

The UIC program Director has authority under SDWA §1423 to address potential compliance issues

(e.g., potential releases that may endanger USDWs) resulting from injection violations in the unlikely

event that a remedial response is necessary. Although EPA anticipates that the need for emergency

or remedial actions at GS sites will be rare, the GS rule requires, at §146.94, that emergency and

remedial response plans be developed and updated to address such events and that owners or

operators demonstrate that financial resources are set aside to implement the plans if necessary, per

§146.85.

Regarding long term liability, once an owner 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. Furthermore, 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 certain

circumstances. For example, an owner or operator may be held liable for regulatory noncompliance

even after site closure was approved if the Director relied on erroneous information (e.g., erroneous

modeling data) provided by the owner or operator when approving site closure. 

Separate from EPA's authority to enforce regulatory compliance, an owner or operator may be

subject to a §1431 response order even after proper site closure 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

288
or an USDW, which may present an imminent and substantial endangerment to the health of

persons, and the appropriate State and local authorities have not acted to protect the health of such

persons. The action may include issuing administrative 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 operator may remain liable under tort and other remedies,

or under other federal statutes including, 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.

EPA recognizes the significant amount of data generated by the DOE partnerships and agrees that

sufficient data have been collected to inform the final GS rule. EPA has evaluated permits and

reviewed operational data and information associated with the seven regional carbon sequestration

partnerships funded by the U.S. Department of Energy and coordinated through the National Energy

Technology Laboratory. EPA believes that these projects form a solid basis for finalizing the GS

requirements, and agrees there is no reason to wait until all phases of the DOE demonstration tests

are complete.

Commenter Name: Walter L. Baker Letter ID: 0253

Commenter Organization: Utah Division of Water Quality Comment ID: 22345

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: DEFINING CO2 STREAM TO EXCLUDE HAZARDOUS WASTE/SUBSTANCE

UNDER RCRA/CERCLA 

We consider potential liability under RCRA and/or CERCLA a major deterrent to 

developing and deploying CCGS projects and one that must be addressed. Towards 

removing this as a barrier to CCGS, we strongly encourage EPA to address the 

issues surrounding the composition of the injected CO2 stream. These issues 

include: providing a clear description of the analytical methods for 

characterizing the CO2 stream, providing a clear description of the limitation 

on the CO2 stream composition so as to avoid inclusion under RCRA or CERCLA, and 

investigating thoroughly the possibility of RCRA and CERCLA exemption for CCGS 

while still providing protection to USDWs and other natural resources. Since 

capture and separation technology is still being developed for large stationary 

CO2 sources, it is important to have a clearly defined target for design 

objectives. 

Response: The final GS rule retains the definition of a CO2 stream as proposed. The GS regulation

applies to injection of CO2 for the purpose of GS, regardless of the source of the CO2. It is beyond

the scope of the GS rule and the UIC Program’s authority to require or set standards for upstream

generators of CO2 or purification facilities. For purposes of GS, the UIC program’s authority under

the SDWA is limited to ensuring that GS projects are sited, constructed, operated, and closed in a

manner that protects USDWs. 

With respect to the commenter’s concern about RCRA, EPA has decided to initiate a separate

289
proposed rulemaking specifically to examine the issue of RCRA applicability 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 particular 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 commenters who wish to submit comments on the RCRA proposal

will need to do so during the comment period for that rule. Finally, EPA also notes that the final GS

rule, which adds new regulations for Class VI wells under the Safe Drinking Water Act (SDWA), is

not making any changes to the RCRA regulations.

Commenter Name: Mike Nasi Letter ID: 0254

Commenter Organization: Clean Coal Technology Foundation of Texas Comment ID: 22364

Comment: EPA must also mitigate the threat of potential RCRA and CERCLA liability to the 

extent possible. With respect to CERCLA liability, CERCLA exempts from liability 

certain "federally permitted releases" including released in compliance with a 

UIC permit under SDWA. Because of this exemption, in the proposed rules, EPA 

states that Class VI requirements and permits must be carefully structured to 

ensure that they do not authorize inappropriate hazardous releases. This is an 

issue of particular importance, as the presence of CERCLA liability could have a 

crippling effect on large scale commercial deployment of carbon capture and 

storage technology. To eliminate any such barriers, EPA should include in the 

scope of the permit all CERCLA hazardous substances that are likely to be 

contained in the CO2 stream, including those generated during capture and 

transport as well as any constituents that are formed in the injection zone as a 

result of the injection of CO2. 

Response: EPA notes that the GS rule is not promulgated under the RCRA or CERCLA statutes,

and further, the applicability of those statutes will not be determined under the SDWA or the terms

of the GS rule, but rather according to those statutes themselves and any implementing regulations

that may apply. To the extent the commenter is seeking interpretations of CERCLA or RCRA, such

interpretations are beyond the scope of this rulemaking. 

EPA received many comments regarding the applicability of the RCRA regulations and statute to

CO2 streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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 particular 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 commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule. 

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

290
U.S.C. 9607, certain "federally permitted releases" as defined in CERCLA, 42 U.S.C. 9601(10).

Class VI permits will need to be carefully structured to ensure that they prevent potential releases

from the well which are outside the scope of the Class VI permit. 

CERCLA exempts from liability, under CERCLA section 107, 42 U.S.C. 9607, certain "federally

permitted releases" (FPR) as defined in CERCLA, 42 U.S.C. 9601(10). Therefore, Class VI

requirements and permits will need to be carefully structured to ensure that they do not 'authorize'

inappropriate releases, and would need to prevent potential releases from the well which are outside

the scope of the Class VI permit. 

The UIC program Director has authority under SDWA §1423 to address potential compliance issues

(e.g., potential releases that may endanger USDWs) resulting from injection violations in the unlikely

event that a remedial response is necessary. Although EPA anticipates that the need for emergency

or remedial actions at GS sites will be rare, the GS rule requires, at §146.94, that emergency and

remedial response plans be developed and updated to address such events and that owners or

operators demonstrate that financial resources are set aside to implement the plans if necessary, per

§146.85.

Regarding long term liability, once an owner 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. Furthermore, 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 certain

circumstances. For example, an owner or operator may be held liable for regulatory noncompliance

even after site closure was approved if the Director relied on erroneous information (e.g., erroneous

modeling data) provided by the owner or operator when approving site closure. 

Separate from EPA's authority to enforce regulatory compliance, an owner or operator may be

subject to a §1431 response order even after proper site closure 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 present an imminent and substantial endangerment to the health of

persons, and the appropriate State and local authorities have not acted to protect the health of such

persons. The action may include issuing administrative 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 operator may remain liable under tort and other remedies,

or under other federal statutes including, 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.

Commenter Name: Keith McCoy Letter ID: 0258

Commenter Organization: National Association of Manufacturers Comment ID: 22374

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

291
Comment: The NAM believes that a CCS policy can be designed that promotes a variety of 

public goals, including energy security, economic prosperity and protection of 

public health and the environment. The NAM believes that policy makers, 

building on the knowledge and expertise of energy professionals who have long 

injected carbon into geologic formations to enhance oil recovery, should 

establish a new regime and regulatory scheme which will promote the development 

and commercial deployment of CCS technology. The NAM is concerned, however, 

that EPA regulators may be looking backward, by considering liability schemes 

pursuant to the Superfund and Resource Conservation and Recovery Act (RCRA), as 

models on which to establish a framework for the long-term capture and storage 

of carbon. The NAM does not believe that use of a statute such as Superfund, 

which has been the source of endless litigation, is an appropriate model on 

which to base something as modern as CCS. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit. 

EPA adds that promoting the use of GS is outside the scope of the GS rule. Rather, the purpose of

the GS regulation is to ensure that, where deployed, GS is conducted in a manner that protects

USDWs from endangerment.

Commenter Name: Michel Paque Letter ID: 0259

Commenter Organization: Ground Water Protection Council Comment ID: 24812

Comment: EPA Rule Issue: 8. Class VI requirements and permits will need to be carefully 

structured to ensure that they do not "authorize" inappropriate hazardous 

releases. This would include clarifying if there are potential releases from the 

well which are outside the scope of the Class VI permit. EPA requests comment on 

particular situations where this might occur. EPA notice 43504. 

292
GWPC CO2 Committee Response: CERCLA application should be avoided or sorted out 

and affirmed by Congress to indicate that it would not apply; municipal 

operators have major concern over this potential because cities will be around 

long-term and look like deep pockets 

As EPA has noted, CERCLA liability does not apply to federally permitted 

releases (FPRs), including releases covered by a UIC permit, even if GS would 

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

downstream reactions or transformations resulting from FPRs. Accordingly, there 

appears to be little real potential for CERCLA liability resulting from GS. Yet 

EPA needs to clarify that CERCLA liability is extremely unlikely to result from 

any GS operation that has not injected streams that are not covered by its UIC 

permit. 

Rationale: Even the potential for CERCLA liability is viewed with such 

apprehension because of the overwhelmingly negative effects that such liability 

has had on the investing community, however, that EPA’s discussion of that 

possibility without substantial clarification is very likely to have a chilling 

effect on the support for development and deployment of CCS technologies. 

Response: CERCLA exempts from liability, under CERCLA section 107, 42 U.S.C. 9607, certain

“federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C. 9601(10). Therefore, Class

VI requirements and permits will need to be carefully structured to ensure that they do not

“authorize” inappropriate releases, and would need to prevent potential releases from the well which

are outside the scope of the Class VI permit. 

Furthermore, EPA is promulgating the GS rule under the authority of the SDWA. To the extent the

commenter is seeking interpretations of CERCLA and its related provisions, such as the definition of

a federally permitted release, such interpretations are beyond the scope of this rulemaking. 

The UIC program Director has authority under SDWA §1423 to address potential compliance issues

(e.g., potential releases that may endanger USDWs) resulting from injection violations in the unlikely

event that a remedial response is necessary. Although EPA anticipates that the need for emergency

or remedial actions at GS sites will be rare, the GS rule requires, at §146.94, that emergency and

remedial response plans be developed and updated to address such events and that owners or

operators demonstrate that financial resources are set aside to implement the plans if necessary, per

§146.85.

Regarding long term liability, once an owner 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. Furthermore, 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 certain

circumstances. For example, an owner or operator may be held liable for regulatory noncompliance

even after site closure was approved if the Director relied on erroneous information (e.g., erroneous

modeling data) provided by the owner or operator when approving site closure. 

Separate from EPA’s authority to enforce regulatory compliance, an owner or operator may be

subject to a §1431 response order even after proper site closure is approved under §146.93. Under

293
§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 present an imminent and substantial endangerment to the health of

persons, and the appropriate State and local authorities have not acted to protect the health of such

persons. The action may include issuing administrative 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 operator may remain liable under tort and other remedies,

or under other federal statutes including, 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.

EPA adds that promoting the use of GS is outside the scope of the GS rule. Rather, the purpose of

the GS regulation is to ensure that, where deployed, GS is conducted in a manner that protects

USDWs from endangerment.

Commenter Name: Michel Paque Letter ID: 0259

Commenter Organization: Ground Water Protection Council Comment ID: 24813

Other EPA Comment Codes and Descriptions: 1614 1.3.1.2 Impurities in captured CO2; purity

standards for CO2 

Comment: EPA Notice Questions: 73 FR 43504 

EPA Rule Issue: 9. EPA also requests comment on other considerations associated 

with the presence of impurities in the CO2 stream related to CERCLA. EPA Notice 

43504. 

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

stream that would defeat capture, compression, transport or GS, and these can be 

addressed through the use of special materials in many cases. The focus should 

be on compatibility rather than on any need for purification. 

Response: The GS rule does not set generic purity standards for CO2 injectate streams (e.g., a

percent CO2). Instead, the GS rule addresses the quality and quantity of impurities by requiring

owners or operators to submit information on the source of the CO2 and its physical and chemical

properties. Specifically, the GS rule requires the owner or operator to submit data about the site,

including an analysis of the chemical and physical characteristics of the CO2 stream, as required at

§146.82(a)(7)(iv), and information on the 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 potential

for geochemical reactions between the injectate (CO2) and the host geologic formations, which

could result in the plugging of pore spaces or the dissolution of formation minerals.

Commenter Name: Claire Olson Letter ID: 0260

Commenter Organization: Basin Electric Power Cooperative Comment ID: 22395

Comment: "J. Is Injected CO2 Considered a Hazardous Substance Under CERCLA?" 

294
EPA seeks comment on whether Class VI permittees could be exempt from CERCLA 

under its "federally permitted release" provision. First, liability under CERCLA 

depends on whether there has been a disposal of hazardous substances. While CO2 

is not a CERCLA hazardous substance, EPA suggests in the preamble that the 

makeup of a particular injected CO2 stream may trigger a CERCLA analysis. 

However, the preamble also states that CERCLA's "federally permitted releases" 

provision exempts releases in compliance with a UIC Permit under the Safe 

Drinking Water Act (SDWA) from CERCLA liability. This exemption in and of itself 

should put the issue to rest. EPA should make clear that this exclusion provides 

a shield from Superfund liability. We urge the EPA to address the longterm 

liability for stored CO2 within the UIC Class VI Well Permit. EPA should avoid 

creating unnecessary hurdles for the successful deployment of CCS by assuming 

that potential applications of other statutes that may come into play. 

Basin Electric requests that EPA recognizes that CO2 injection and storage is 

exempt from CERCLA liabilities and regulates this activity by compliance with 

the UIC Class VI Well Permit. Also, please see previous comments on the 

exclusion of the injected CO2 stream as a hazardous waste (RCRA). If the UIC 

Program cannot coordinate these exclusions for RCRA and CERCLA, BEPC requests 

that a legislative option be considered. 

EPA should establish a single, clear, and reasonable regulatory structure for 

managing risks and liabilities for CCS projects. The process to obtain a UIC 

Class VI Permit and defining the Area of Review (AoR) will provide proper 

protections of the USDWS, environment, and health. 

Response: CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain "federally permitted releases" as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit. 

Furthermore, EPA is promulgating the GS rule under the authority of the SDWA. To the extent the

commenter is seeking interpretations of CERCLA and its related provisions, such as the definition of

a federally permitted release, such interpretations are beyond the scope of this rulemaking. 

The UIC program Director has authority under SDWA §1423 to address potential compliance issues

(e.g., potential releases that may endanger USDWs) resulting from injection violations in the unlikely

event that a remedial response is necessary. Although EPA anticipates that the need for emergency

or remedial actions at GS sites will be rare, the GS rule requires, at §146.94, that emergency and

remedial response plans be developed and updated to address such events and that owners or

operators demonstrate that financial resources are set aside to implement the plans if necessary, per

§146.85.

Regarding long term liability, once an owner or operator has met all regulatory requirements under

295
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. Furthermore, 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 certain

circumstances. For example, an owner or operator may be held liable for regulatory noncompliance

even after site closure was approved if the Director relied on erroneous information (e.g., erroneous

modeling data) provided by the owner or operator when approving site closure. 

Separate from EPA's authority to enforce regulatory compliance, an owner or operator may be

subject to a §1431 response order even after proper site closure 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 present an imminent and substantial endangerment to the health of

persons, and the appropriate State and local authorities have not acted to protect the health of such

persons. The action may include issuing administrative 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 operator may remain liable under tort and other remedies,

or under other federal statutes including, 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: 0263

Commenter Organization: Interstate Oil & Gas Compact Commission Comment ID: 24961

Comment: II. J. Is Injected CO2 Considered a Hazardous Substance Under CERCLA? 

1. EPA requests comment on particular situations where this might occur. EPA also 

requests comment on other considerations associated with the presence 

of impurities in the CO2 stream related to CERCLA. 

IOGCC Response: Injected CO2 is not and should not be considered a hazardous 

waste or regulated under RCRAor CERCLA. It is assumed that RCRA or CERCLA wastes 

would be removed from the CO2 stream prior to storage. 

Response: CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain “federally permitted releases” as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit. 

With respect to the commenter’s reference to RCRA, EPA received many comments regarding the

296
applicability of the RCRA regulations and statute to CO2 streams that are geologically sequestered

under the final Class VI UIC well requirements. As a result, EPA has decided to initiate a separate

proposed rulemaking specifically to examine the issue of RCRA applicability 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 particular 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 commenters who wish to submit comments on the RCRA proposal

will need to do so during the comment period for that rule.

Commenter Name: Michael Moore Letter ID: 0265

Commenter Organization: North American Carbon Capture & Storage

Association (NACCSA)

Comment ID:

22872

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: 9. Relationships with other Environmental Laws 

NACCSA is concerned about the potential application of other environmental laws 

to CCS activities. These laws include the Comprehensive Environmental Response, 

Compensation, and Liability Act (CERCLA) and the Resource Conservation and 

Recovery Act (RCRA). Setting aside for the moment the important questions 

of whether either of these laws could apply to CCS activities and, if so, 

precisely how and to what extent, NACCSA understands and does not disagree with 

the Agency's position that drafting a clear exception from either of these 

regimes likely cannot be accomplished through the context of this SDWA UIC 

rulemaking. Nonetheless, NACCSA urges EPA to carefully consider whether to include 

any discussion of these two laws (or others) along with the Class VI regulations, 

as well as the particulars of what any such discussion may contain, to ensure 

that such discussion is necessary and does not serve as an unnecessary and 

unintended springboard for hampering the successful commercialization of CCS. 

NACCSA believes that EPA should clarify that supercritical and gaseous CO2 do not 

fit the definition of" solid waste" under RCRA,and that injected CO2 is not solid 

waste that is "disposed of" and thus subject to RCRA regulation. While 

NACCSA acknowledges that such clarification may be best achieved in the context 

of a RCRA rulemaking, the Preamble to the proposed rules appears to make the 

assumption that injected CO2 is a solid waste that is being disposed of in the 

first instance, in the context of its discussion regarding waste 

characterizations that may be required of permitees. Such discussion in the 

Preamble is unnecessary and will only prove harmful to those seeking to move 

forward with CCS projects. Further, any concern about potentially hazardous 

constituents in CO2 injectate may be addressed without addressing any potential 

RCRA implications, as the contents of an injectate must be "characterized" under 

the proposed rules regardless, and permit limitations maybe imposed to address 

the content of injectate without reference to RCRA's provisions. 

In addition, EPA should clarify that the provisions of CERCLA are not triggered by 

Class VI operations. As a preliminary matter, as the Agency is aware, CERCLA 

imposes liability for releases of hazardous substances. EPA indicates in the 

297
Preamble that whether injected CO2 may be considered a hazardous substance 

"depends entirely on the make-up of the specific CO2 stream and of the environmental 

media . . . in which it is stored," leaving the door open for claims 

of environmental harm arising out of CO2 injection and storage activities. This 

discussion, however, assumes that CO2 injection activities could fall within 

CERCLA's ambit in the first instance. As with the RCRA issue, a determination 

of this issue is unnecessary from the point of view of regulating injection and 

storage of CO2 under the UIC program, and NACCSA urges the Agency to avoid creating 

unnecessary hurdles for the successful commercial deployment of CCS by assuming 

potential applications of other statutes that may not come into play. Regardless, 

even if the provisions of CERCLA could be interpreted to apply to CCS activities, 

NACCSA is opposed to any limitations on the federally permitted release 

exemption from CERCLA liability, which should be given its fullest application in 

the Class VI context. Relatedly, NACCSA encourages the Agency, pursuant to its 

authority under RCRA and CERCLA, to examine possibilities for exemption or 

exclusion from those programs. 

Response: EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule. Finally, EPA also notes that the final GS rule, which adds new regulations for Class VI

wells under the Safe Drinking Water Act (SDWA), is not making any changes to the RCRA

regulations.

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42 U.S.C.

9601(10). Class VI permits will need to be carefully structured to ensure that they prevent potential

releases from the well which are outside the scope of the Class VI permit.

Commenter Name: William Herz Letter ID: 0266

Commenter Organization: The Fertilizer Institute Comment ID: 22880

Comment: Consideration of Injected CO2 as a Hazardous Substance under the Comprehensive 

Environmental Response Compensation and Liability Act (CERCLA) 

TFI also asks for additional clarification on potential CERCLA liability. We agree 

with EPA's interpretation in the proposed rule that the release of CO2, if the 

rule is adopted as proposed, would constitute a" federally permitted release" as 

defined in CERCLA,42 U.S.C. § 9601 (10), and that CERCLA exempts from liability 

298
releases in compliance with a UIC permit under SDWA (73 Fed. Reg. 43,503). 

However, we remain concerned about potential CERCLA liability for upstream 

industrial clients of sequestration wells, especially for comingled CO2 streams 

and for injectate stream constituents that could react with groundwater to 

produce listed hazardous substances. 

If EPA, as it has stated, desires to encourage implementation of carbon 

sequestration technology by industry, it should exempt such activities from 

CERCLA liability. If EPA should decide against such an exemption, TFI asks that 

EPA include regulatory language governing monitoring and/or reporting requirements 

for upstream industrial clients of sequestration wells that would provide CERCLA 

liability relief or exclusion in the promulgated rule. For example, EPA could 

provide in the rule that upstream industrial clients providing CO2 streams could 

make certain demonstrations of conditions under which EPA will not consider the 

injectate exempt from the purview of CERCLA. This exemption should apply, by 

extension, to any claims brought against upstream clients of sequestration wells 

for natural resource damages. Furthermore, TFI requests that EPA develop 

monitoring report requirements which provide the basis of establishing the 

injectate as a "federally permitted release" as defined in CERCLA. Where these 

reports indicate no presence of CERCLA hazardous substances, the injectate should 

be considered a "federally permitted release" exempt from CERCLA liability. 

EPA should clarify in the rule that CO2, absent impurities constituting hazardous 

substances or with the potential to react with groundwater constituents to form 

hazardous substances, is not itself a CERCLA hazardous substance. This liability 

exemption for "federally permitted releases" should extend to upstream clients of 

sequestration wells even for accidental releases or where releases from the well 

are not in accordance with the well operator's UIC permit. As an alternative, 

EPA should establish contaminant limits in the injectate of upstream clients of 

sequestration wells. 

TFI requests clarification for upstream industrial clients as to the appropriate 

requirements for "analyz[ing] the CO2 stream at a frequency sufficient to yield 

data representative of its chemical and physical characteristics" (73 Fed. Reg. 

43,514 and 73 Fed. Reg. 43,549), as well as appropriate requirements for upstream 

industrial clients in terms of monitoring and recordkeeping. TFI suggests a semiannual monitoring report and a three-year post injectate or site closure data 

retention period for upstream industrial clients similar to that proposed for 

owners or operators of Class VI wells (73 Fed. Reg. 43,517), regardless of the 

post-closure site care period selected (73 Fed. Reg. 43,518). 

TFI also asks that EPA include regulatory language providing liability protection 

or exclusion for upstream industrial clients in the event of potential future 

liability in the event of leaks, well failure or release of reaction products. 

Response: CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

299
section 107, 42 U.S.C. 9607, certain "federally permitted releases" (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit. 

Furthermore, EPA is promulgating the GS rule under the authority of the SDWA. To the extent the

commenter is seeking interpretations of CERCLA and its related provisions, such as the definition of

a federally permitted release, such interpretations are beyond the scope of this rulemaking. 

The UIC program Director has authority under SDWA §1423 to address potential compliance issues

(e.g., potential releases that may endanger USDWs) resulting from injection violations in the unlikely

event that a remedial response is necessary. Although EPA anticipates that the need for emergency

or remedial actions at GS sites will be rare, the GS rule requires, at §146.94, that emergency and

remedial response plans be developed and updated to address such events and that owners or

operators demonstrate that financial resources are set aside to implement the plans if necessary, per

§146.85.

Regarding long term liability, once an owner 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. Furthermore, 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 certain

circumstances. For example, an owner or operator may be held liable for regulatory noncompliance

even after site closure was approved if the Director relied on erroneous information (e.g., erroneous

modeling data) provided by the owner or operator when approving site closure. 

Separate from EPA's authority to enforce regulatory compliance, an owner or operator may be

subject to a §1431 response order even after proper site closure 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 present an imminent and substantial endangerment to the health of

persons, and the appropriate State and local authorities have not acted to protect the health of such

persons. The action may include issuing administrative 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 operator may remain liable under tort and other remedies,

or under other federal statutes including, 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.

Commenter Name: Bill Hertz Letter ID: 0500

Commenter Organization: Fertilizer Institute Comment ID: 21211

Comment: We would also raise the CERCLA issue and the CERCLA liability issue. We agree 

with the EPA's interpretation in the proposed rule that the release of CO2 

constitutes a federally permitted release as defined in CERCLA 42 USC 9601. 

300
However, we remain concerned about potential CERCLA liability for upstream 

industrial clients, especially for comingled injectate streams, and for 

injectate stream constituents that could react with ground water to produce 

listed hazardous substances. 

TFI would request EPA include regulatory language governing monitoring, 

reporting requirements for upstream industrial clients that would provide CERCLA 

liability relief for exclusion in the promulgated rule. We would request that 

EPA include regulatory language providing liability protection or exclusion in 

the, and a potential liability in the event of leaks, well failure, or the 

release of reaction products. 

Response: CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in

which it is stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA

section 107, 42 U.S.C. 9607, certain “federally permitted releases” (FPR) as defined in CERCLA, 42

U.S.C. 9601(10). Class VI permits will need to be carefully structured to ensure that they prevent

potential releases from the well which are outside the scope of the Class VI permit. 

The UIC program Director has authority under SDWA §1423 to address potential compliance issues

(e.g., potential releases that may endanger USDWs) resulting from injection violations in the unlikely

event that a remedial response is necessary. Although EPA anticipates that the need for emergency

or remedial actions at GS sites will be rare, the GS rule requires, at §146.94, that emergency and

remedial response plans be developed and updated to address such events and that owners or

operators demonstrate that financial resources are set aside to implement the plans if necessary, per

§146.85.

Regarding long term liability, once an owner 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. Furthermore, 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 certain

circumstances. For example, an owner or operator may be held liable for regulatory noncompliance

even after site closure was approved if the Director relied on erroneous information (e.g., erroneous

modeling data) provided by the owner or operator when approving site closure. 

Separate from EPA’s authority to enforce regulatory compliance, an owner or operator may be

subject to a §1431 response order even after proper site closure 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 present an imminent and substantial endangerment to the health of

persons, and the appropriate State and local authorities have not acted to protect the health of such

persons. The action may include issuing administrative 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. 

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Furthermore, after site closure an owner or operator may remain liable under tort and other remedies,

or under other federal statutes including, 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.

EPA adds that it is beyond the scope of the GS rule and the UIC Program’s authority to require or

set standards for upstream generators of CO2 or purification facilities.

Commenter Name: Paul Pike Letter ID: 0535

Commenter Organization: Ameren Corporation on behalf of Utility Solid Waste

Activities Group (USWAG)

Comment ID:

21435

Comment: Of particular importance is also potential for liability under CERCLA including 

the natural resources damages cases stemming from injection and sequestration of 

carbon dioxide. As EPA can surely appreciate the potential for these opening 

liabilities will act as a serious deterrent for would-be owners and operators of 

these injection wells. Simply put, EPA must mitigate the threat of potential 

CERCLA liability to the extent possible in the rulemaking. 

One step that the Agency can take with respect to CERCLA is to ensure that the 

Class VI permits have the broadest possible reach or meaning protective of 

drinking waters. To maximize this protection offered by the federally permitted 

release exemption, this would mean including the scope of the permit for carbon 

dioxide injection, all other CERCLA hazardous constituents likely to be 

contained in the CO2 stream including those generated along with the carbon 

capture and transport and in the injection zone. 

Similarly the scope of the authorized permit zone should be as broad as possible 

while remaining protective of drinking water. 

Response: CERCLA exempts from liability, under CERCLA section 107, 42 U.S.C. 9607, certain

"federally permitted releases" (FPR) as defined in CERCLA, 42 U.S.C. 9601(10). Therefore, Class

VI requirements and permits will need to be carefully structured to ensure that they do not 'authorize'

inappropriate releases, and would need to prevent potential releases from the well which are outside

the scope of the Class VI permit. 

Furthermore, EPA is promulgating the GS rule under the authority of the SDWA. To the extent the

commenter is seeking interpretations of CERCLA and its related provisions, such as the definition of

a federally permitted release, such interpretations are beyond the scope of this rulemaking. 

CO2 itself is not listed as a hazardous substance 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 the composition of the specific CO2 stream and the environmental media in which it is

stored (e.g., soil or ground water). CERCLA exempts from liability, under CERCLA section 107, 42

U.S.C. 9607, certain "federally permitted releases" 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

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from the well which are outside the scope of the Class VI permit. 

The UIC program Director has authority under SDWA §1423 to address potential compliance issues

(e.g., potential releases that may endanger USDWs) resulting from injection violations in the unlikely

event that a remedial response is necessary. Although EPA anticipates that the need for emergency

or remedial actions at GS sites will be rare, the GS rule requires, at §146.94, that emergency and

remedial response plans be developed and updated to address such events and that owners or

operators demonstrate that financial resources are set aside to implement the plans if necessary, per

§146.85. 

Regarding long term liability, once an owner 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. Furthermore, 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 certain

circumstances. For example, an owner or operator may be held liable for regulatory noncompliance

even after site closure was approved if the Director relied on erroneous information (e.g., erroneous

modeling data) provided by the owner or operator when approving site closure. 

Separate from EPA's authority to enforce regulatory compliance, an owner or operator may be

subject to a §1431 response order even after proper site closure 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 present an imminent and substantial endangerment to the health of

persons, and the appropriate State and local authorities have not acted to protect the health of such

persons. The action may include issuing administrative 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 operator may remain liable under tort and other remedies,

or under other federal statutes including, 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.

Commenter Name: Paul Pike Letter ID: 0535

Commenter Organization: Ameren Corporation on behalf of Utility Solid Waste

Activities Group (USWAG)

Comment ID:

21437

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: The bottom line is that the potential for interaction with CERCLA or liability 

in RCRA must be mitigated to avoid significant delays in an overall chilling 

effect on this process. 

Response: EPA clarifies that promoting the use of GS is outside the scope of the GS rule. Rather,

the purpose of the GS regulation is to ensure that, where deployed, GS is conducted in a manner that

protects USDWs from endangerment.

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Comment Code: 1650 1.3.5 Human health impacts 

Individual Comments

Commenter Name: Sam Kitto Letter ID: 0126

Commenter Organization: National Tribal Air Association Comment ID: 23047

Other EPA Comment Codes and Descriptions: 1660 1.3.6 Ecosystem impacts (soil, air, surface

water) 

Comment: Environmental Impacts 

The EPA is proposing to do something of a significant magnitude for the first 

time which is the injection of substantial amounts of carbon dioxide into the 

ground at high pressures. The EPA is seeking to control a pollutant that is very 

buoyant and corrosive, and with a technology that has to be fully tested. As 

such, the NTAA is concerned about the potential environmental impacts of 

geologic sequestration to the nation’s Indian tribes. 

While geologic sequestration could likely affect tribal property rights - i.e., 

the diminishment of mineral rights values and cause property damage, it is its 

potential harm to humans and the environment which most concern the NTAA. The 

World Resources Institute recently communicated in its report Guidelines for 

Carbon Dioxide Capture, Transport and Storage, that "risks to people and 

ecosystems [can] arise from the potential for CO2 to accumulate in low-lying 

areas or areas with poor ventilation. If CO2 leaks to the surface in areas with 

poor ventilation, such as basements or shallow dips in the ground, it can 

accumulate to levels that could cause stress or even asphyxiation in humans and 

animals." Unfortunately, owners and operations of geologic sequestration 

operations will not be held liable for such injuries as the GS rule solely 

focuses on the protection of USDWs (e.g., prevention of CO2 migration into 

USDWs). While the EPA might be correct in its understanding that geologic 

sequestration impacts to air, human health and ecosystems are outside the scope 

of the Safe Drinking Water Act, this does not negate the Agency’s trust 

responsibility to best manage and preserve tribal lands from any undue outside 

influences, and in this case, CO2 leakage as a result of geologic sequestration. 

Response: EPA acknowledges that there are potential risks associated with GS. The purpose of the

Class VI requirements is to minimize and mitigate potential/identified risks through proper site

characterization, well construction, operation, monitoring, post-injection site care, and site closure

and to ensure protection of USDWs. EPA believes that the measures in the GS rule that directly

mitigate the possibility of CO2 leakage out of the injection zone will also indirectly mitigate the

risks to receptors mentioned by the commenters, including fresh water, wildlife, ecosystems, and

agriculture. 

EPA adds that Class VI well owners and operators must site, construct, operate, monitor, and close

their wells in a manner that protects USDWs, and Class VI permits will set forth rigorous technical

requirements to ensure careful planning, operation, and closure of GS projects. Failure to meet these

requirements would be considered a violation of the permit and would be subject to applicable civil,

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criminal, or administrative penalties.

EPA also notes that owners or operators of Class VI wells must ensure that resources are available to

prevent endangerment of USDWs from improper plugging, remediation, and management of wells.

The GS rule requires that owners or operators demonstrate and maintain financial responsibility for

corrective action on wells in the AoR, injection well plugging, post-injection site care and site

closure, and emergency and remedial response at GS sites as specified in §146.85. In the event of

contamination or other adverse event associated with GS, the financial instrument(s), such as

insurance, bonds, etc., rather than public monies, would cover necessary response actions. 

EPA believes that sufficient data and experience currently exist to develop regulations for Class VI

wells. The GS rulemaking builds upon decades of knowledge about safe injection practices regulated

by the UIC Program. While developing the GS regulation, EPA has evaluated relevant GS research,

including projects conducted by the seven Regional Carbon Sequestration Partnerships (RCSPs)

funded by DOE and coordinated through the National Energy Technology Laboratory (NETL), and

several international projects. 

Industry also has decades of experience with well construction and operation. For example, the oil

and gas industry has experience drilling and cementing wells in very deep formations, in a variety of

environments (e.g., high-pressure and low-pressure formations), and for a variety of uses (e.g.,

injection, oil and gas production, monitoring). EPA believes that this experience has led to the

development of well materials and construction and operating procedures that are applicable to Class

VI wells.

EPA adds that, in the process of developing the GS rule, it consulted with tribal representatives to

facilitate ongoing communication throughout the rulemaking process. Please see the next response

for additional information. EPA is committed to protecting USDWs on tribal lands through

implementation of the GS rule.

Commenter Name: Dwight Lockwood, PE, QEP Letter ID: 0141

Commenter Organization: Global Energy, Inc. Comment ID: 23095

Comment: 1.Global concurs with the EPA view that the risk of asphyxiation and acute or 

chronic health effects is minimal. Pipeline leaks are rare and readily managed 

by existing authorities. Similarly wellhead and well leaks are uncommon and are 

readily managed with current technologies. EPA proposals for surface and downResponse: EPA recognizes that injecting large volumes of CO2 for GS poses unique challenges that,

if not properly managed, could endanger drinking water sources and have other adverse impacts.

However, with proper site selection, the final, tailored, Class VI requirements address the large

volumes of CO2 injected, its buoyancy, potential corrosivity in the presence of water, and potential

impurities in the CO2 stream. In addition, EPA expects the tailored permitting, siting, construction,

operation, monitoring, and post-injection site care requirements in the GS rule to prevent leakage

from injection formations and protect USDWs. EPA adds that pipeline leaks and risk of asphyxiation

are outside the scope of the GS rulemaking.

Commenter Name: Thomas Curtis Letter ID: 0181

Commenter Organization: American Water Works Association (AWWA) Comment ID: 23663

Other EPA Comment Codes and Descriptions: 1610 1.3.1 Risks to USDWs 

Comment: EPA should also consider the risk associated with the potential exposure of any 

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contaminants that are released to the surface. While we recognize that a gradual 

leak may have little impact, the potential of a catastrophic leak is always 

present. EPA should be mindful during the rulemaking process of not only the 

risk to drinking water, but also of other potential risks from exposure to other 

constituents such as pH, lead and copper, iron, hardness, silica and boron. 

These are compound for which no MCLs have been developed but still impact 

drinking water quality and increase the necessary treatment costs. There could 

be potential health impacts due to long-term exposure to contaminant levels 

below the established MCLs. Also, beneficial uses of groundwater could also be 

impacted by increases of these compounds in the aquifers. Owners/operators could 

be in compliance with the regulation, but could be degrading an aquifer by 

contaminating it with compounds for which MCLs do not exist. 

Response: EPA acknowledges that there are potential risks associated with GS, including the

potential for leakage of CO2 into USDWs, which could result in the mobilization of substances that

could pose threats to USDWs or human health or could increase treatment costs. The purpose of the

Class VI requirements is to minimize and mitigate potential/identified risks through proper site

characterization, well construction, operation, monitoring, post-injection site care, and site closure.

The mandate of the UIC Program, and the GS rule, is to protect USDWs from endangerment that

may be caused by underground injection. The GS rule accomplishes this through requirements

tailored to address the unique nature of GS, including the large volumes of CO2 injected, its

buoyancy and potential corrosivity in the presence of water, and impurities in the CO2 stream. Many

of these requirements specifically address the potential for mobilized substances to affect USDWs.

The GS rule is concerned with the migration of CO2 and displacement of native fluids that may

result in endangerment of USDWs.

For example, the owner or operator must submit data about the site, including information on the

porosity, permeability, mineralogy, and geochemistry of the targeted injection and confining zones.

Operators must also present information on the compatibility of the CO2 stream with fluids in the

injection zone and minerals in both the injection and confining zones as specified in §146.82(c)(3).

The data will help identify potential geochemical reactions between the injected CO2 and the host

geologic formations, which could result in the plugging of pore spaces or the dissolution of

formation minerals. During injection operations, operators must extensively monitor ground water

quality to provide early detection of any unacceptable movement of fluids or impurities in the

subsurface as specified in §146.90. Operators must develop and follow an emergency and remedial

response plan to address any adverse effects associated with the GS operation as specified in §146.94

and provide financial responsibility to address contamination as specified in §146.85. 

Recent research has focused on addressing this concern. EPA is funding research at the Lawrence

Berkeley National Laboratory (LBNL) on potential USDW impacts associated with mobilization of

trace elements. In the August 31, 2009, Notice of Data Availability and Request for Comment (74

FR 44802), EPA published the results of the study, which evaluated the potential for GS to cause

changes in ground water quality as a result of CO2 leakage and subsequent mobilization of trace

elements such as arsenic, barium, cadmium, mercury, lead, antimony, selenium, zinc, and uranium

(Birkholzer et al., 2008a). In the study, LBNL estimated the amount of trace elements from native

mineral species that could potentially be mobilized by the intrusion of CO2 and the potential ground

water concentrations that could result, to determine the potential for drinking water standards to be

exceeded. Results from this model simulation suggest that if CO2 were to leak into a shallow

aquifer, the potential for mobilization of lead and arsenic could be enhanced, causing increases in the

concentration of these trace elements in ground water. The Agency continues to monitor research

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related to CO2 confinement, potential for CO2 leakage, and mobilization of trace elements. 

EPA adds that concerns about contaminants that cause health effects but do not have maximum

contaminant levels should be addressed as part of the review process for the national primary

drinking water regulations; such concerns are outside the scope of this rulemaking. EPA has also

examined potential methods for conducting treatment of water affected by a CO2 leak; this study is

presented in the final rulemaking docket.

Commenter Name: Thomas Curtis Letter ID: 0181

Commenter Organization: American Water Works Association (AWWA) Comment ID: 23712

Other EPA Comment Codes and Descriptions: 1530 1.2.3.1 State regulatory efforts on GS

(seeking comment) 

Comment: Category: State Capacity 

EPA Request for Comment: EPA seeks comment on any aspects of the ongoing State 

efforts to regulate the GS of CO2 and how these efforts might be used to better 

inform a final Federal rulemaking. EPA Notice 43497. 

AWWA Response: From our perspective, EPA’s proposed rule appears to be focused 

on preventing brine from formations where carbon dioxide was stored from 

reaching USDWs and/or from preventing carbon dioxide that reaches USDWs from 

causing primary MCLs to be exceeded. This focus may not be adequate from the 

standpoint of protecting source water and beneficial use aquifers from 

detrimental changes in water quality other than the exceedance of primary MCLs. 

Other water quality impacts could be observed such as increased concentrations 

of iron, manganese and TDS, as well as lowered pH, all of which have secondary 

MCLs. Increases in the concentrations of silica and boron, which do not 

currently have MCLs but can significantly degrade water quality, are also likely 

to occur. 

This past year, the State of Washington adopted carbon sequestration regulations 

which AWWA recommends that EPA review and incorporate some of the language into 

the final regulation. The Washington regulations require that the owner or 

operator must demonstrate that the "design and construction standards of all 

facility structures and wells are sufficient to prevent migration of carbon 

dioxide or nonpotable water that will degrade water quality or impact beneficial 

uses outside the geologic containment system." The language in this regulation 

provides protection mechanisms for groundwater sources that may not be used as 

USDWs but have other beneficial uses, such use as industrial applications or 

agriculture. Given the stresses that the drinking water industry is facing with 

respect to water resources, AWWA recommends that the monitoring requirements in 

the final rule be extended to protect against aquifer contamination beyond that 

which is associated with compounds that have primary MCLs. 

Response: EPA recognizes the complexity and importance of states' approaches to managing GS

and is aware that states are currently in various stages of developing statutory frameworks,

regulations, workgroups, technical guidance, and strategies for addressing CCS and GS. 

Throughout the regulatory development process for the Class VI regulation, EPA monitored states'

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regulatory and legislative development efforts and approaches. In EPA's August 31, 2009, Notice of

Data Availability (NODA) and Request for Comment, the Agency described its ongoing monitoring

of states' regulatory efforts and approaches and how the Agency is considering this information as it

develops guidance on the primacy application and approval process for Class VI wells. Information

about these state activities may be found in the docket for the GS rule.

EPA clarifies that the UIC program’s authority applies to protection of USDWs from endangerment.

SDWA §1421(d)(2) states that “underground injection endangers drinking water sources if such

injection may result in the presence in underground water which supplies or can reasonably be

expected to supply any public water system of any contaminant, and if the presence of such

contaminant may result in such system’s not complying with any primary drinking water regulation

or may otherwise adversely affect the health of person.” EPA disagrees that the GS rule is only

focused on MCL contamination as it relates to endangerment; rather the rule also focuses on “adverse

effects on the health of person[s].” This does not necessarily require a showing of non-compliance

with an MCL. 

EPA clarifies that the UIC regulations apply only to underground injection wells and injection

activities, and not to "facility structures” that are not considered to be wells under §144.3. 

Under §146.94, if the owner or operator obtains evidence that injection may cause endangerment to a

USDW, he or she must stop injection and implement the emergency and remedial response plan for

that well. With proper site selection, the final, tailored, Class VI requirements address the large

volumes of CO2 injected, its buoyancy, potential corrosivity in the presence of water, and potential

impurities in the CO2 stream. In addition, the tailored permitting, siting, construction, operation,

monitoring, and post-injection site care requirements in the GS rule are intended to prevent leakage

from injection formations and protect USDWs.

Commenter Name: M. Granger Morgan Letter ID: 0233

Commenter Organization: Carnegie Mellon University on behalf of the CCS

Reg Project

Comment ID:

21906

Other EPA Comment Codes and Descriptions: 1500 1.2.2.2.4 Some other agency should regulate

GS; 1660 1.3.6 Ecosystem impacts (soil, air, surface water) 

Comment: 15. Potential Health or Environmental Impacts other than to Groundwater: While 

we believe that the risk of health or environmental impacts other than to 

groundwater is very slight for sites that are well-characterized and welloperated, we understand that this is a topic of concern to the public. The 

inability of the proposed UIC Class VI rules to address these concerns carries 

the potential to undermine public acceptance of CCS. Should such impacts occur 

under the proposed UIC Class VI rules, some other regulator would need to 

intervene. It would be preferable, and more efficient, to have site permitting 

conducted by a program with the authority to manage all potential risks from CO2 

injection comprehensively. 

Response: EPA agrees that properly managed GS projects present lower risk. EPA believes that the

GS requirements, which are based on the long-standing UIC regulatory framework and tailored to

meet the unique nature of CO2 injection for GS, appropriately address endangerment risks to

USDWs. The GS rule contains minimum technical criteria for the permitting, geologic site

characterization, AoR and corrective action, well construction, operation, mechanical integrity

testing, monitoring, financial responsibility, injection well plugging, post-injection site care, and site

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closure of GS wells, which will ensure that USDWs are protected from endangerment. 

EPA acknowledges that the issue of GS falls within the broader context of CCS, but clarifies that the

scope of the GS regulation is limited to injection of CO2, and that all requirements in the GS rule are

designed for the purpose of protecting USDWs from endangerment. The SDWA does not provide the

UIC Program with the authority to develop regulations for all areas related to GS, such as releases to

the atmosphere. 

EPA believes that the creation of a new injection well class (VI) under the existing UIC Program is

necessary to enable deployment of GS as a climate change mitigation technology in a manner that

protects USDWs from endangerment. EPA agrees that the UIC Program, under the authority of the

SDWA, provides a strong framework for regulating injection of CO2 for GS and adds that the GS

regulation tailors the UIC requirements to address the unique issues associated with large-scale GS

including large injection volumes, the relative buoyancy of CO2, its corrosivity in the presence of

water, the potential presence of impurities in captured CO2, and its mobility within subsurface

geologic formations.

To the comment that the geologic siting requirements could create a negative public perception, EPA

believes that a demonstration to the public, through the promulgation of the GS rule, that extensive

data have been collected and evaluated will likely improve confidence in the project and help

address public questions and concerns.

Regarding the suggestion to develop an integrated permitting process that addresses the entire CCS

process, EPA clarifies that the UIC Program's authority is limited to ensuring that GS projects

protect USDWs from endangerment. Oversight of the capture and transport of CO2 is outside of

SDWA authority. EPA acknowledges that GS falls within the broader context of CCS and the need

for regulatory clarity to ensure that USDWs are protected from endangerment. In developing 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 States Geological Survey; Bureau of Ocean

Energy Management, Regulation, and Enforcement, formerly the Minerals Management Service; and

the Bureau of Land Management). The Agency continues to evaluate 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 Comprehensive Environmental Response, Compensation, and

Liability Act; and the Marine Protection, Research 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 entitled "How Does This Rulemaking Relate to Other Federal Authorities and GS

and CCS Activities?" in the preamble to the final GS rule.

Commenter Name: Lori Mathieu Letter ID: 0283

Commenter Organization: Connecticut Department of Health Comment ID: 25296

Comment: 1. In order to ensure long term drinking water quality for the state 

of Connecticut's numerous sources of public drinking water, more information 

needs to be obtained prior to implementation of the proposed rule. Given the 

state's small size, density of population and distribution of existing and 

potential public drinking water sources, implementation of the proposed rule 

without further evaluation of potential public health and drinking water quality 

impacts would not be recommended at this time. 

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Response: EPA believes that sufficient data and experience currently exist to develop regulations for

Class VI wells. The GS rulemaking builds upon decades of knowledge about safe injection practices

regulated by the UIC Program. While developing the GS regulation, EPA has evaluated relevant GS

research, including projects conducted by the seven Regional Carbon Sequestration Partnerships

(RCSPs) funded by DOE and coordinated through the National Energy Technology Laboratory

(NETL), and several international projects. 

In response to the commenter’s concerns about injection in their state, EPA notes that if a state has

primacy for the Class VI program it may choose to ban Class VI wells altogether or put additional

limitations or constraints on its usage.

Comment Code: 1655 1.3.5.1 Concerns about Lake Nyos and Mammoth Mountain-type events 

Individual Comments

Commenter Name: Emily Rochon Letter ID: 0129

Commenter Organization: Greenpeace International Comment ID: 23062

Comment: Beyond these problems inherent with any attempt at carbon capture and storage, 

there is a high potential for catastrophic results from a flawed CCS program. 

The greatest risk from CCS is for a leak to occur and the integrity of the 

storage space to be compromised. This is not only a highly dangerous risk, but a 

highly likely one as well. A natural example of the danger of CO2 leakage 

occurred at Lake Nyos, Cameroon in 1986. Following a volcanic eruption, large 

quantities of CO2 that had accumulated on the bottom of the lake were suddenly 

released, killing 1700 people and thousands of cattle over a range of 15 

miles.[FN6 6 Diesendorf, M, 2006. Can geosequestration save the coal industry?, 

in J Byrne, L Glvoer & N Toly (eds), Transforming power: Energy as a social 

project, Energy and Environmental Policy Series vol. 9, 2006, pp. 223-248.] 

Response: EPA disagrees that the CO2 releases at Lake Nyos is a valid analogue for GS. GS sites

have little in common with the physical setting or mechanism that resulted in the release of

naturally-occurring CO2 trapped at the bottom of Lake Nyos, a stratified tropical lake that suddenly

overturned through a process known as "limnic eruption." No injection was associated with this

event, and this site would not have been considered sufficiently geologically stable to be issued a

Class VI permit based on the rigorous site characterization requirements at §146.82 (e.g., including

lack of confining units).

GS takes places thousands of feet below the Earth’s surface within porous spaces in deep rock

formations. CO2 is injected for GS through technically engineered wells with multiple barriers

designed to isolate the injectate in the well and protect formations outside the well materials. The

injected CO2 is stored in geologic formations underneath confining layers of rock that act as natural

barriers to leakage. It is unlikely that CO2 would escape from a GS site that is properly

characterized, operated, monitored, and closed. During the site selection process, operators of Class

VI wells identify and evaluate the appropriateness of a site for GS of CO2. The evaluation includes

the identification of surface and subsurface features such as deep stratified lakes and other naturally

occurring pockets of CO2. Furthermore, during GS operation, injection pressures and formation

conditions are monitored to avoid overpressuring the storage formation.

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Commenter Name: Carl Carlsson Letter ID: 0131

Commenter Organization: SUEZ Energy Generation NA, LLC Comment ID: 21526

Other EPA Comment Codes and Descriptions: 1680 1.3.8 Don't overstate risk, don't stigmatize

CO2 

Comment: Risks Associated with CO2 GS 

SEGNA agrees that all potential risks associated with geological sequestration of 

CO2 should be addressed, and that the public must be adequately informed. 

However, references to the large and rapid releases of CO2 from volcanic lakes, 

as occurred in Cameroon in the 1980's, must be presented carefully to more 

clearly demonstrate that geological sequestration--deep underground and under 

confining strata--is a completely different process and does not represent a risk 

to human health and the environment comparable to the referenced incident in 

Cameroon. The language in any subsequent documents issued by EPA should 

make this point more forcefully to avoid public confusion regarding the actual risk. 

Response: The Agency believes it appropriately characterized the limnic eruption at Lake Nyos as a

rare and naturally-occurring lake turnover event that is characteristic of stratified lakes in warm

climates. The event at Lake Nyos, during which naturally-occurring CO2 trapped at the bottom of

the Lake was released to the atmosphere, is not a valid analogue for GS. The preamble highlighted

differences between the lithologic reservoirs that may serve as storage formations for CO2 and the

processes occurring at Lake Nyos and other stratified tropical lakes (73 FR 43498).

Commenter Name: James Dooley Letter ID: 0156

Commenter Organization: Joint Global Change Research Institute, Pacific

Northwest National Laboratory

Comment ID:

22657

Comment: - Page 43498. The USEPA is to be commended for the passage here on Lake Nyos 

and Lake Monoun and in particular for the forcefulness with which the draft 

Class VI rule makes it clear that these are not analogous to CO2 injected into a 

deep geologic formation. 

Response: EPA acknowledges the comment.

Commenter Name: Edward Steadman Letter ID: 0220

Commenter Organization: The Energy and Environmental Research Center at the

University of North Dakota

Comment ID:

21588

Comment: Page 43498. This page includes a very good and reasonable description of the 

relative inapplicability of the Lake Nyos incident as an analog for possible 

negative consequences of a large CO2 leak from a geologic storage site. 

Response: EPA acknowledges the comment.

Commenter Name: Dave Bufalo Letter ID: 0522

Comment ID: 21467

Comment: With respect to the injection of CO2 and its affect on water quality, I am most 

concerned about a potential catastrophic failure of the environment system. 

There is a lake in Africa that somehow or another evolved a tremendous amount of 

carbon dioxide in one massive instantaneous release and it killed all the 

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villagers within some radius of that. So the issue is, do we have fault systems 

that may allow this to happen and what then is the proximity of the local 

population base? That is my primary concern. 

If we have a gradual leak of CO2 from a containment system, I do not see that as 

catastrophic. It was once in the atmosphere, it has under gone sequestration and 

now it comes back out. So be it. 

Response: EPA disagrees that the CO2 releases at Lake Nyos is a valid analogue for GS. GS sites

have little in common with the physical setting or mechanism that resulted in the release of

naturally-occurring CO2 trapped at the bottom of Lake Nyos, a stratified tropical lake that suddenly

overturned through a process known as "limnic eruption." No injection was associated with this

event, and this site would not have been considered sufficiently geologically stable to be issued a

Class VI permit based on the rigorous site characterization requirements at §146.82 (e.g., including

lack of confining units).

GS takes places thousands of feet below the Earth’s surface within porous spaces in deep rock

formations. CO2 is injected for GS through technically engineered wells with multiple barriers

designed to isolate the injectate in the well and protect formations outside the well materials. The

injected CO2 is stored in geologic formations underneath confining layers of rock that act as natural

barriers to leakage. It is unlikely that CO2 would escape from a GS site that is properly

characterized, operated, monitored, and closed. During the site selection process, operators of Class

VI wells identify and evaluate the appropriateness of a site for GS of CO2. The evaluation includes

the identification of surface and subsurface features such as deep stratified lakes and other naturally

occurring pockets of CO2. Furthermore, during GS operation, injection pressures and formation

conditions are monitored to avoid overpressuring the storage formation. 

This evaluation must also identify the presence of faults. Suitable GS sites must have confining

zones that are free of transmissive faults or fractures and are of sufficient areal extent and integrity

to contain the injected CO2 stream and displaced formation fluids. The formations must allow

injection at proposed maximum pressures and volumes without initiating or propagating fractures in

the confining zone(s), as required at§146.83(a)(2).

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

Individual Comments

Commenter Name: Sam Kitto Letter ID: 0126

Commenter Organization: National Tribal Air Association Comment ID: 23047

Other EPA Comment Codes and Descriptions: 1650 1.3.5 Human health impacts 

Comment: Environmental Impacts 

The EPA is proposing to do something of a significant magnitude for the first 

time which is the injection of substantial amounts of carbon dioxide into the 

ground at high pressures. The EPA is seeking to control a pollutant that is very 

buoyant and corrosive, and with a technology that has to be fully tested. As 

such, the NTAA is concerned about the potential environmental impacts of 

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geologic sequestration to the nation’s Indian tribes. 

While geologic sequestration could likely affect tribal property rights - i.e., 

the diminishment of mineral rights values and cause property damage, it is its 

potential harm to humans and the environment which most concern the NTAA. The 

World Resources Institute recently communicated in its report Guidelines for 

Carbon Dioxide Capture, Transport and Storage, that "risks to people and 

ecosystems [can] arise from the potential for CO2 to accumulate in low-lying 

areas or areas with poor ventilation. If CO2 leaks to the surface in areas with 

poor ventilation, such as basements or shallow dips in the ground, it can 

accumulate to levels that could cause stress or even asphyxiation in humans and 

animals." Unfortunately, owners and operations of geologic sequestration 

operations will not be held liable for such injuries as the GS rule solely 

focuses on the protection of USDWs (e.g., prevention of CO2 migration into 

USDWs). While the EPA might be correct in its understanding that geologic 

sequestration impacts to air, human health and ecosystems are outside the scope 

of the Safe Drinking Water Act, this does not negate the Agency’s trust 

responsibility to best manage and preserve tribal lands from any undue outside 

influences, and in this case, CO2 leakage as a result of geologic sequestration. 

Response: EPA acknowledges that there are potential risks associated with GS. The purpose of the

Class VI requirements is to minimize and mitigate potential/identified risks through proper site

characterization, well construction, operation, monitoring, post-injection site care, and site closure

and to ensure protection of USDWs. EPA believes that the measures in the GS rule that directly

mitigate the possibility of CO2 leakage out of the injection zone will also indirectly mitigate the

risks to receptors mentioned by the commenters, including fresh water, wildlife, ecosystems, and

agriculture. 

EPA adds that Class VI well owners and operators must site, construct, operate, monitor, and close

their wells in a manner that protects USDWs, and Class VI permits will set forth rigorous technical

requirements to ensure careful planning, operation, and closure of GS projects. Failure to meet these

requirements would be considered a violation of the permit and would be subject to applicable civil,

criminal, or administrative penalties.

EPA also notes that owners or operators of Class VI wells must ensure that resources are available to

prevent endangerment of USDWs from improper plugging, remediation, and management of wells.

The GS rule requires that owners or operators demonstrate and maintain financial responsibility for

corrective action on wells in the AoR, injection well plugging, post-injection site care and site

closure, and emergency and remedial response at GS sites as specified in §146.85. In the event of

contamination or other adverse event associated with GS, the financial instrument(s), such as

insurance, bonds, etc., rather than public monies, would cover necessary response actions. 

EPA believes that sufficient data and experience currently exist to develop regulations for Class VI

wells. The GS rulemaking builds upon decades of knowledge about safe injection practices regulated

by the UIC Program. While developing the GS regulation, EPA has evaluated relevant GS research,

including projects conducted by the seven Regional Carbon Sequestration Partnerships (RCSPs)

funded by DOE and coordinated through the National Energy Technology Laboratory (NETL), and

several international projects. 

Industry also has decades of experience with well construction and operation. For example, the oil

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and gas industry has experience drilling and cementing wells in very deep formations, in a variety of

environments (e.g., high-pressure and low-pressure formations), and for a variety of uses (e.g.,

injection, oil and gas production, monitoring). EPA believes that this experience has led to the

development of well materials and construction and operating procedures that are applicable to Class

VI wells.

EPA adds that, in the process of developing the GS rule, it consulted with tribal representatives to

facilitate ongoing communication throughout the rulemaking process. Please see the next response

for additional information. EPA is committed to protecting USDWs on tribal lands through

implementation of the GS rule.

Commenter Name: Emily Rochon Letter ID: 0129

Commenter Organization: Greenpeace International Comment ID: 23064

Comment: contaminating fresh water reservoirs in their path. Infiltration of saline water 

into groundwater or the shallow subsurface impacts wildlife habitats, restricts 

or eliminates agricultural uses of land, and pollutes aquifers and surface water 

bodies.[FN7 7 Kharaka Y K, Cole D R, Hovorka S D, Gunter W D, Knauss K G & 

Freifeld B M, ‘Gas-water-rock interactions in frio formation following CO2 

injection: Implications for the storage of greenhouse gases in sedimentary 

basins’, Geology, vol., 34, no. 7, 2006, pp. 577-580.] The efficiency of 

Response: EPA acknowledges that there are potential risks associated with GS. The purpose of the

Class VI requirements is to minimize and mitigate potential/identified risks through proper site

characterization, well construction, operation, monitoring, post-injection site care, and site closure

and to ensure protection of USDWs. EPA believes that the measures in the GS rule that directly

mitigate the possibility of CO2 leakage out of the injection zone will also indirectly mitigate the

risks to receptors mentioned by the commenters, including fresh water, wildlife, ecosystems, and

agriculture.

Commenter Name: Dwight Lockwood, PE, QEP Letter ID: 0141

Commenter Organization: Global Energy, Inc. Comment ID: 23097

Comment: 2.Global also agrees that, adverse impacts to ecosystems from CO2 injection 

activities, is similarly minimal. Leaks will be small and flora do benefit from 

CO2 for growth. 

Response: EPA acknowledges that there are potential risks associated with GS. The purpose of the

Class VI requirements is to minimize and mitigate potential/identified risks through proper site

characterization, well construction, operation, monitoring, post-injection site care, and site closure

and to ensure protection of USDWs. EPA believes that the measures in the GS rule that directly

mitigate the possibility of CO2 leakage out of the injection zone will also indirectly mitigate the

risks to receptors mentioned by the commenters, including fresh water, wildlife, ecosystems, and

agriculture.

Commenter Name: Thomas Curtis Letter ID: 0181

Commenter Organization: American Water Works Association (AWWA) Comment ID: 23668

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

of the SDWA such as those to air and human health if there is a massive leak. 

Could there be any conflicts or overlaps with the Clean Air Act or the Clean 

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Water Act? Are other Program Offices within EPA planning on looking at this 

proposal? This review by other EPA Program Offices would seem to be necessary 

given the potential impacts that could arise if there is a failure of the 

confining layer. 

Response: EPA acknowledges that there are potential risks associated with GS. The purpose of the

Class VI requirements is to minimize and mitigate potential/identified risks through proper site

characterization, well construction, operation, monitoring, post-injection site care, and site closure

and to ensure protection of USDWs. EPA believes that the measures in the GS rule that directly

mitigate the possibility of CO2 leakage out of the injection zone will also indirectly mitigate the

risks to receptors mentioned by the commenters, including fresh water, wildlife, ecosystems, and

agriculture. 

EPA acknowledges that GS falls within the broader context of CCS and acknowledges that

regulatory clarity is essential for enabling GS to move forward in a manner that protects human

health and the environment. The Agency is working to identify areas related to GS that could be

addressed under other statutes to ensure that GS is conducted in a manner that is protective of human

health and the environment. Additionally, the Agency is and will continue to coordinate internally

and with other Federal agencies involved in GS and CCS, including the Minerals Management

Service, Bureau of Land Management, and the United States Geological Survey, to promote

consistency in existing and future GS initiatives.

Commenter Name: Richard Guinn Letter ID: 0210

Commenter Organization: Eastman Chemical Company Comment ID: 22709

Comment: 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. 

Response: EPA acknowledges that there are potential risks associated with GS. The purpose of the

Class VI requirements is to minimize and mitigate potential/identified risks through proper site

characterization, well construction, operation, monitoring, post-injection site care, and site closure

and to ensure protection of USDWs. The Agency clarifies that, under SDWA authority, the

requirements do not explicitly protect against CO2 leakage to the surface. However, the GS rule

requires that CO2 injected for GS remain confined in the injection zone. Leakage outside of the

injection zone/to the surface would be a permit violation. 

The Agency clarifies that compliance with OSHA guidelines for GS is outside of the scope of the GS

rule. However, EPA believes that the measures in the GS rule that mitigate the possibility of CO2

leakage out of the injection zone will also mitigate the risks to humans, both on-site and off-site.

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Commenter Name: M. Granger Morgan Letter ID: 0233

Commenter Organization: Carnegie Mellon University on behalf of the CCS

Reg Project

Comment ID:

21906

Other EPA Comment Codes and Descriptions: 1500 1.2.2.2.4 Some other agency should regulate

GS; 1650 1.3.5 Human health impacts 

Comment: 15. Potential Health or Environmental Impacts other than to Groundwater: While 

we believe that the risk of health or environmental impacts other than to 

groundwater is very slight for sites that are well-characterized and welloperated, we understand that this is a topic of concern to the public. The 

inability of the proposed UIC Class VI rules to address these concerns carries 

the potential to undermine public acceptance of CCS. Should such impacts occur 

under the proposed UIC Class VI rules, some other regulator would need to 

intervene. It would be preferable, and more efficient, to have site permitting 

conducted by a program with the authority to manage all potential risks from CO2 

injection comprehensively. 

Response: EPA agrees that properly managed GS projects present lower risk. EPA believes that the

GS requirements, which are based on the long-standing UIC regulatory framework and tailored to

meet the unique nature of CO2 injection for GS, appropriately address endangerment risks to

USDWs. The GS rule contains minimum technical criteria for the permitting, geologic site

characterization, AoR and corrective action, well construction, operation, mechanical integrity

testing, monitoring, financial responsibility, injection well plugging, post-injection site care, and site

closure of GS wells, which will ensure that USDWs are protected from endangerment. 

EPA acknowledges that the issue of GS falls within the broader context of CCS, but clarifies that the

scope of the GS regulation is limited to injection of CO2, and that all requirements in the GS rule are

designed for the purpose of protecting USDWs from endangerment. The SDWA does not provide the

UIC Program with the authority to develop regulations for all areas related to GS, such as releases to

the atmosphere. 

EPA believes that the creation of a new injection well class (VI) under the existing UIC Program is

necessary to enable deployment of GS as a climate change mitigation technology in a manner that

protects USDWs from endangerment. EPA agrees that the UIC Program, under the authority of the

SDWA, provides a strong framework for regulating injection of CO2 for GS and adds that the GS

regulation tailors the UIC requirements to address the unique issues associated with large-scale GS

including large injection volumes, the relative buoyancy of CO2, its corrosivity in the presence of

water, the potential presence of impurities in captured CO2, and its mobility within subsurface

geologic formations.

To the comment that the geologic siting requirements could create a negative public perception, EPA

believes that a demonstration to the public, through the promulgation of the GS rule, that extensive

data have been collected and evaluated will likely improve confidence in the project and help

address public questions and concerns.

Regarding the suggestion to develop an integrated permitting process that addresses the entire CCS

process, EPA clarifies that the UIC Program's authority is limited to ensuring that GS projects

protect USDWs from endangerment. Oversight of the capture and transport of CO2 is outside of

SDWA authority. EPA acknowledges that GS falls within the broader context of CCS and the need

for regulatory clarity to ensure that USDWs are protected from endangerment. In developing the

final GS rule, the Office of Water coordinated with other Agency program offices and across federal

316
agencies (e.g., with the Department of Energy; United States Geological Survey; Bureau of Ocean

Energy Management, Regulation, and Enforcement, formerly the Minerals Management Service; and

the Bureau of Land Management). The Agency continues to evaluate 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 Comprehensive Environmental Response, Compensation, and

Liability Act; and the Marine Protection, Research 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 entitled "How Does This Rulemaking Relate to Other Federal Authorities and GS

and CCS Activities?" in the preamble to the final GS rule.

Commenter Name: Dag Nummedal Letter ID: 0533

Commenter Organization: Colorado Energy Resource Institute Comment ID: 21479

Other EPA Comment Codes and Descriptions: 1310 1.1.2.4 Comments on other "out of scope"

issues, e.g., pore space ownership 

Comment: The last part then gets at the biosphere. A lot of people think I believe that 

the subsurface beneath our feet consists mostly of rocks only. It does not. 

Turns out that we have a very extensive community of microorganisms that go deep 

down. In the deepest gold mines in South Africa, people are recovering microbes. 

And these microbes play a fundamental roles in the geochemical and radiological 

reactions. In fact in all different rocks, whether they be hard rocks where we 

get gold and silver and copper and whatnot, there are organisms related and are 

present in both deep hard rock mines, those organisms that are found on 

limestones. We can look at that as potentially large carbon sequestration. 

Reservoirs contain a lot of bacteria, microbes in coal. Coal seams potentially 

are great places to store CO2 partly because some of the microbes will actually 

use the hydrogen as in the electron donor and then reduce the CO2 into methane. 

And we add hydrogen to the C and the O's and it produces methane and oxygen and 

water. And then if you can get that reaction to work in commercial and 

industrial settings in the subsurface, then you can actually use CO2 in the 

subsurface, in the coal seams, the same way that we are increasingly using CO2 

in algal farms. Algal biofuels which most people are strongly in favor of. 

Environmentally algal biofuels are probably very good and what you do of course, 

algae have to eat something, they eat CO2. Now if you can get the microbes in 

this subsurface, in the coal seams, to do the same thing basically converting 

that CO2 into methane and regenerate the methane, you can have a sustained 

production of methane which can be trapped and captured and used as it leaves a 

much cleaner fuel than coal and oils for a long time while you are storing CO2 

in the process. I think it is a very encouraging future technology. 

And that will then also be a significant part of the research that we are 

attracted, that we are here proposing. 

Response: EPA acknowledges that there are potential risks associated with GS. The purpose of the

Class VI requirements is to minimize and mitigate potential/identified risks through proper site

characterization, well construction, operation, monitoring, post-injection site care, and site closure

and to ensure protection of USDWs. The Agency clarifies that, under SDWA authority, the

requirements do not explicitly protect against CO2 leakage to the surface. However, the GS rule

requires that CO2 injected for GS remain confined in the injection zone. Leakage outside of the

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injection zone/to the surface would be a permit violation. 

In response to the comment suggesting "harnessing biological activity"—such as underground

microbes—to consume CO2, the Agency clarifies that the GS rule does not preclude or endorse the

use of specific technologies (e.g., microbes) for GS provided they are used in conjunction with

appropriately sited, constructed, operated, and monitored injection wells to ensure protection of

USDWs.

Comment Code: 1670 1.3.7 Other/miscellaneous risks 

Individual Comments

Commenter Name: George Holliday, PhD, PE, BCEE Letter ID: 0114

Commenter Organization: Holliday Environmental Services, Inc. Comment ID: 22517

Comment: The Environmental Protection Agency at 73 FR 43492-43541 requests comments 

regarding the proposal to prepare regulations for an unknown number of Class VI 

wells. Class VI wells are in reality, manmade explosive devices storing buoyant 

carbon dioxide sequestered deep in the earth under supercritical pressure 

conditions. Many persons designing these wells are of unknown technical 

ability, e.g., not professional Engineers (P.E.). There are no safe guards to 

prevent organizations from simply seeking monetary rewards, without being 

required to see the project to completion. Further, the well designs and 

Response: EPA disagrees that injection wells are dangerous devices. EPA recognizes that injecting

large volumes of CO2 for GS poses unique challenges that, if not properly managed, could endanger

drinking water sources and have other adverse impacts. However, with proper site selection, the

final, tailored, Class VI requirements address the large volumes of CO2 injected, its buoyancy,

potential corrosivity in the presence of water, and potential impurities in the CO2 stream. In addition,

EPA expects the tailored permitting, siting, construction, operation, monitoring, and post-injection

site care requirements in the GS rule to prevent leakage from injection formations and protect

USDWs.

EPA believes that building upon the existing UIC requirements (e.g., Class I and Class II well

requirements) to develop the Class VI GS regulation provides a foundation for protecting USDWs

based on success, field experience, and lessons learned about CO2 injection in other applications.

Class I well owners or operators have experience with site characterization, well construction, and

monitoring procedures and technologies that are applicable to Class VI wells. Class II ER well

operators have experience with managing the unique properties of CO2. To successfully flood a

hydrocarbon field with CO2 during an ER operation, the behavior of injected CO2 must be well

understood. 

EPA disagrees that the people designing and regulating wells lack technical training for effective

oversight of Class VI wells. Most permitting authorities’ staff have years of experience with the

current UIC injection well classes and have relevant specialties in geology, engineering, and related

disciplines. Injection well owners and operators represent industries with decades of experience

injecting a variety of fluids, including CO2. Industry also has decades of experience with well

construction and operation. For example, the oil and gas industry has experience drilling and

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cementing wells in very deep formations, in a variety of environments (e.g., high-pressure and lowpressure formations), and for a variety of uses (e.g., injection, oil and gas production, monitoring).

EPA believes that this experience has led to the development of well materials and construction and

operating procedures that are applicable to Class VI wells.

Commenter Name: George Holliday, PhD, PE, BCEE Letter ID: 0114

Commenter Organization: Holliday Environmental Services, Inc. Comment ID: 22518

Other EPA Comment Codes and Descriptions: 4710 2.7.1 Proposed submissions required for

permit applications (seeking comment) 

Comment: required to see the project to completion. Further, the well designs and 

operations would be approved by Agency technically untrained employees, who are 

not Professional Engineers and supervised by a Regional Director who is neither 

an engineer nor a Professional Engineer. 

The Agency proposes using untrained EPA employees who are not required to 

demonstrate their CO2 sequestration technical knowledge by completing and 

passing a written examination. Further, the Agency proposes to sequester 

Response: As described above, EPA disagrees that the people designing and regulating wells lack

technical training for effective oversight of Class VI wells. Most permitting authority staff have years

of experience with the current UIC injection well classes and have relevant specialties in geology,

engineering, and related disciplines. Injection well owners and operators represent industries with

decades of experience injecting a variety of fluids, including CO2. EPA believes that this experience

has led to the development of well materials and construction and operating procedures that are

applicable to Class VI wells.

Commenter Name: George Holliday, PhD, PE, BCEE Letter ID: 0114

Commenter Organization: Holliday Environmental Services, Inc. Comment ID: 22521

Other EPA Comment Codes and Descriptions: 4710 2.7.1 Proposed submissions required for

permit applications (seeking comment) 

Comment: The sequestration of CO2 represents a money-making scheme for a "political" 

pollutant, which will encourage unqualified organizations and speculators to 

seek Class VI injection permits. These unqualified organizations will find 

unqualified consultants to prepare documents supporting the permit applications. 

EPA, in the instant proposed rule, suggests several financial responsibility 

schemes to avoid unqualified organizations and speculators from creating a 

disaster, but EPA and states do not know how to assure financial responsibility 

as demonstrated by the lack specificity within the proposed rule. Rules 

proposed with this lack of specificity, typically result in EPA selecting final 

rule wording, which received no comments during the proposal stage. This gives 

EPA free rein to select regulation wording not reviewed by the commenting 

public, and not alluded to during the proposal. 

One of the most frightening aspects of the proposed rule is EPA imposes no 

technical qualification requirements on EPA review personnel. Thus, a well 

written, but inaccurate document, can easily be accepted by EPA, when 

technically unqualified reviewers are used. If qualified reviewers were used, 

the application would be rejected. 

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Response: As described above, EPA disagrees with the assertion that the staff reviewing permit

applications does not have adequate technical knowledge to review and approve Class VI permits.

EPA will be facilitating training on the GS rule requirements for states and Regional staff in addition

to providing guidance on implementation of the Class VI UIC program.

EPA clarifies that the person who signs a permit application must certify that the application is

accurate and that data was collected in accordance with a system designed to ensure that qualified

personnel evaluate the data. EPA believes that assigning this responsibility to the signatories will

ensure that the work has been properly supervised. Failure to meet this requirement would subject

the owner or operator of the well to applicable civil, criminal, or administrative penalties under

SDWA §1423.

EPA adds that owners or operators of Class VI wells must ensure that resources are available to

prevent endangerment of USDWs from improper plugging, remediation, and management of wells.

For this reason, the GS rule requires that owners or operators demonstrate and maintain financial

responsibility for corrective action on wells in the AoR, injection well plugging, post-injection site

care and site closure, and emergency and remedial response at GS sites as specified in §146.85. EPA

has revised the requirements in the final rule to provide more specifics. In the event of contamination

or other adverse event that endangers a USDW during the life of the GS project, the financial

instrument(s), such as insurance, bonds, etc., rather than public monies, would cover necessary

response actions. 

EPA adds that Class VI well owners and operators must site, construct, operate, monitor, and close

their wells in a manner that protects USDWs, and Class VI permits will set forth rigorous technical

requirements to ensure careful planning, operation, and closure of GS projects. 

EPA adds that the requirements in the final GS rule, including all changes from the proposed rule,

are based on consideration of public comments received in response to the proposed rule and its

subsequent Notice of data Availability and Request for Comment issued on August 31, 2009 (74 FR

44802).

Commenter Name: George Holliday, PhD, PE, BCEE Letter ID: 0114

Commenter Organization: Holliday Environmental Services, Inc. Comment ID: 22529

Other EPA Comment Codes and Descriptions: 4710 2.7.1 Proposed submissions required for

permit applications (seeking comment) 

Comment: LACK OF QUALIFIED EPA PERSONNEL 

EPA requests comments on many aspects of CO2. For example at 73 FR 43514, col. 

2, EPA request help learning to track CO2 underground plumes. I have worked 

with the UIC rules as a commenter since 1979. At no time did EPA use an EPA 

Professional Engineer (P.E.) for developing the UIC rules. During the initial 

stages of writing the 1979 draft rules, EPA used an Ancient English graduate as 

the Agency lead technical supervisor. Ancient English is not considered a 

technical background. 

I have not found any of the current EPA UIC Regional employees to be 

professional engineers. When I requested the information in writing from EPA, I 

was told privacy laws prohibited providing such information. Reviewing and 

understanding CO2 sequestration projects is a technically exacting task. 

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Assigning an EPA non-Professional Engineer to this review task exposes the U.S. 

public to severe risk. Placing the final approval in the hands of a Regional 

Administrator, who traditionally is not an engineer, means the EPA is 

disregarding public safety. At a minimum, the reviewing engineer and Regional 

Administrator must be Professional Engineers. EPA at 40 CFR Part 112 requires a 

Professional Engineer certify a Spill Prevention, Control and Countermeasure 

(SPCC) Plan, which typically is intrinsically a simple non-technical document, 

but EPA does not rely on EPA Professional Engineers to review high pressure, 

corrosive fluid injection projects, that are highly technical and intrinsically 

unsafe. 

EPA has likened Class VI projects to Class I hazardous waste injection wells and 

Class II CO2 enhanced recovery wells. It is true Class I disposal wells 

sequester hazardous waste, but these wastes are not buoyant and typically are 

combined with other waste to make them non-corrosive. FURTHER, THE AGENCY HAS 

BEEN REVIEWING CLASS II WELL PLANS SUBMITTED BY EXPERIENCED OIL AND GAS

COMPANY 

ENGINEERS. An anticipated shortage of trained oil and gas industry engineers 

(Bryant, 2007) and the political nature of CO2 sequestration projects ( 

www.wecansolveit.org) will attract spectators, who do not intend to see the 

project through to completion. Thus, the Agency may be forced to correct many 

problems caused by poor review and oversight on the part of the untrained EPA 

employees 

Bryant, S., 2007. Geologic CO2 Storage - Can the Oil and Gas Industry Help 

Save the Planet? J Pet. Tech (JPT), p 98-105, September 

Response: As described previously, most permitting authority staff have years of experience with

the current UIC injection well classes and have relevant specialties in geology, engineering, and

related disciplines. Additionally, EPA will coordinate with and assist states, e.g., through guidance

and on-line and in-person training, to help them address problematic technical and policy issues.

Commenter Name: George Holliday, PhD, PE, BCEE Letter ID: 0114

Commenter Organization: Holliday Environmental Services, Inc. Comment ID: 22530

Other EPA Comment Codes and Descriptions: 3800 2.3 Proposed Injection Well Construction

Requirements (40 CFR 146.86) 

Comment: The mixture of hazardous wastes associated with Class I injection wells do not 

aggressively attack carbon steel or cement. Also, hazardous waste will not 

change phase, as supercritical CO2 does when the pressure is decreased. The 

change in fluid phase results in formation of a gas, which is large in volume 

and more redily able to find its way to the surface of the earth through minute 

cracks. The earth’s surface is full of examples of oil seeps, e.g., the 

underwater seeks at Santa Barbara, California, and oil seeps in and around the 

Pennsylvania oil fields, to name a few areas where leaks are known to occur. 

The hazardous wastes stored in Class I wells are retained underground because, 

the column of waste formed when a leak occurs, provides a controlling head of 

weighted fluid. In the case of CO2 the hydraulic head, in the event of a leak, 

becomes less as the over burden pressure reduces. This is a much more dangerous 

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condition than experienced with Class I wells. 

Class II enhanced oil recovery (EOR) wells are not abandoned with a high 

residual head of buoyant gas. Typically, the well is produced until the field 

becomes un-economical (too depleted) to produce. This, unlike the CO2 

sequestration wells is not under high supercritical pressure (2200 psig 

pressure) at the time of abandonment. Also, a Class II CO2 injection well is 

associated with oil producing operations, which can be protected from corrosion 

by injecting corrosion inhibitor into the producing well during the producing 

phase. 

Response: EPA believes that the construction requirements at §146.86 provide an appropriate level

of protection from endangerment to USDWs that is based upon the existing UIC framework for deep

wells. The new tailored approach was designed to address the general risks deep injection may pose

to USDWs and was tailored specifically to address the unique nature of CO2 GS (i.e., 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). 

EPA recognizes that injecting large volumes of CO2 for GS poses unique challenges that, if not

properly managed, could endanger drinking water sources and have other adverse impacts. However,

with proper site selection, the final, tailored, Class VI requirements address the large volumes of

CO2 injected, its buoyancy, potential corrosivity in the presence of water, and potential impurities in

the CO2 stream. In addition, EPA expects the tailored permitting, siting, construction, operation,

monitoring, and post-injection site care requirements in the GS rule to prevent leakage from injection

formations and protect USDWs.

EPA believes that building upon the existing UIC requirements (e.g., Class I and Class II well

requirements) to develop the Class VI GS regulation provides a foundation for protecting USDWs

based on success, field experience, and lessons learned about CO2 injection in other applications.

Class I well owners or operators have experience with site characterization, well construction, and

monitoring procedures and technologies that are applicable to Class VI wells. Class II ER well

operators have experience with managing the unique properties of CO2. To successfully flood a

hydrocarbon field with CO2 during an ER operation, the behavior of injected CO2 must be well

understood.

Commenter Name: Edward Steadman Letter ID: 0220

Commenter Organization: The Energy and Environmental Research Center at the

University of North Dakota

Comment ID:

21589

Other EPA Comment Codes and Descriptions: 5280 2.8.2.4 USDW non-endangerment

demonstrations 

Comment: Page 43498. Regarding the statement, "the measures outlined in today’s proposed 

rulemaking to prevent endangerment of USDWs may also prevent migration of CO2 to 

the subsurface." 

This statement is fine, as long as protecting leakage to the atmosphere does not 

lead to stricter measures than would be required to protect USDWs. For example, 

regulations should be driven by a desire to maintain a leakage rate below a 

certain percentage of the injected volume, unless that percentage can be 

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demonstrated to adversely affect USDWs. Another way to state it is this: a 1% 

leakage rate may or may not adversely affect USDWs; therefore, a 1% rate should 

not necessarily be unacceptable. 

Response: EPA clarifies that all requirements in the GS rule are for the purpose of preventing

endangerment to USDWs, and that the tailored permitting, siting, construction, operation,

monitoring, and post-injection site care requirements in the GS rule are intended to prevent leakage

from injection formations and protect USDWs. 

EPA acknowledges that there are potential risks associated with GS. The purpose of the Class VI

requirements is to minimize and mitigate potential/identified risks through proper site

characterization, well construction, operation, monitoring, post-injection site care, and site closure

and to ensure protection of USDWs. The Agency clarifies that, under SDWA, EPA does not have

the authority to directly regulate air emissions via CO2 leakage to the surface. However, the GS rule

requires that CO2 injected for GS remain confined in the injection zone. Leakage outside of the

injection zone as defined in a Class VI permit, which may be evidenced by leakage to the surface,

would be a permit violation if a USDW is endangered.

Commenter Name: Mary Munn Letter ID: 0273

Commenter Organization: Fond du Lac Reservation Comment ID: 24089

Comment: · Fond du Lac will defer to the experts in the case of pipeline and well 

integrity and the long term safety of geologic sequestration of carbon dioxide. 

However, the skill of deep drilling brings to mind the mudflow disaster of 

Sidoarjo Porong, East-Java Indonesia, which began in May 2006 and is still 

flowing to this day. 

Response: EPA disagrees that the CO2 release at Sidoarjo is a valid analogue for GS. The situation

at Sidoarjo is not analogous to GS because the eruption of the naturally-occurring CO2 at Sidoarjo

was due to the highly over-pressurized natural geologic conditions in the region (and associated lack

of an impermeable and extensive confining zone). No injection was associated with this event, and

this site would not have been considered sufficiently geologically stable to be issued a Class VI

permit based on the rigorous site characterization requirements at §146.82 (e.g., including lack of

confining units).

GS takes places thousands of feet below the Earth’s surface within porous spaces in deep rock

formations. CO2 is injected for GS through technically engineered wells with multiple barriers

designed to isolate the injectate in the well and protect formations outside the well materials. The

injected CO2 is stored in geologic formations underneath confining layers of rock that act as natural

barriers to leakage. It is unlikely that CO2 would escape from a GS site that is properly

characterized, operated, monitored, and closed. During the site selection process, operators of Class

VI wells identify and evaluate the appropriateness of a site for GS of CO2. The evaluation includes

the identification of surface and subsurface features such as deep stratified lakes and other naturally

occurring pockets of CO2. Furthermore, during GS operation, injection pressures and formation

conditions are monitored to avoid overpressuring the storage formation.

Commenter Name: Brad Kallio Letter ID: 0502

Comment ID: 21231

Comment: Everybody's kind of heard of Murphy's Law, I tend to live by it being a -- 

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various things that I repair in my world. But typically, anytime you do anything 

like this where you're putting yourself into a potential to, let's say something 

does go wrong, there is a crack or a movement, or something that happens 

geologically that stresses it, where does this gooey carbon dioxide go? And in 

my world it finds its way. 

And you get it in the water, I don't know, what is it, 20 percent of the world's 

fresh water is in Michigan and around the, the lakes around here. That concerns 

me because it's a time bomb just waiting to go off. Instead, maybe a hundred 

years, so far they've got it where it looks like it might be all right. But, 

okay, that would be my grandkids that have to deal with the problem. 

Response: EPA recognizes that injecting large volumes of CO2 for GS poses unique challenges that,

if not properly managed, could endanger drinking water sources and have other adverse impacts.

However, with proper site selection, the final, tailored, Class VI requirements address the large

volumes of CO2 injected, its buoyancy, potential corrosivity in the presence of water, and potential

impurities in the CO2 stream. In addition, EPA expects the tailored permitting, siting, construction,

operation, monitoring, and post-injection site care requirements in the GS rule to prevent leakage

from injection formations and protect USDWs.

EPA acknowledges the importance of protecting drinking water supplies and adds that all of the

requirements in the GS rule are for the purposes of protecting underground sources of drinking water

from endangerment.

Commenter Name: Scott Anderson Letter ID: 0520

Commenter Organization: Environmental Defense Fund Comment ID: 21429

Other EPA Comment Codes and Descriptions: 1270 1.1.2 Comments on other rules/issues 

Comment: The rule I believe, I believe the preamble does mention the possibility of 

interference among projects, but whether or not that is the case, we think it is 

important that the rule contain a provision to head off potential interference 

among projects. The idea that seems to make sense to us is to flatly say that a 

project cannot interfere with the effectiveness of a preexisting project and 

anytime there is an overlap in the pressure fronts or footprint or however else 

you might define it, we think there ought to be inquiry made as to whether that 

would constitute interference. A rule like that would force projects in a single 

basin or brine formation to space themselves at least somewhat properly. 

Response: EPA anticipates that the impacts of multiple operators injecting into hydraulically

connected formations will be accounted for in the initial AoR calculation. EPA adds that the owner

or operator must demonstrate, in the proposed AoR and corrective action plan, to the satisfaction of

the Director that the modeled AoR will be based on detailed geologic data collected on the site and

includes consideration of existing conditions such as the presence of multiple operators. EPA adds

that if any new GS projects are permitted within the AoR of a GS project between AoR evaluations,

the AoR reevaluation must address such projects. EPA also expects that the permitting of the newer

GS project will have considered the presence of an existing GS project.

Comment Code: 1680 1.3.8 Don't overstate risk, don't stigmatize CO2 

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Individual Comments

Commenter Name: Karl R. Moor Letter ID: 0109

Commenter Organization: Southern Company, on behalf of Edison Electric

Institute (EEI)

Comment ID:

21992

Other EPA Comment Codes and Descriptions: 1330 1.1.3.1 Support use of GS in general 

Comment: Key Messages 

We have two key messages for EPA today: 

First, the regulations can and should promote the development and deployment of 

carbon capture and storage while protecting underground sources of drinking 

water without unduly stigmatizing carbon dioxide injection and storage. Carbon 

dioxide has been injected for years for enhanced oil recovery and enhanced gas 

recovery without incident. 

Response: EPA does not believe that the GS regulation stigmatizes CO2 injection. However, EPA

believes that injecting large volumes of CO2 for GS poses unique challenges that, if not properly

managed, could endanger drinking water sources and have other adverse impacts. The final, tailored,

Class VI requirements address the large volumes of CO2 injected, its buoyancy, potential corrosivity

in the presence of water, and potential impurities in the CO2 stream. In addition, EPA expects the

tailored permitting, siting, construction, operation, monitoring, and post-injection site care

requirements in the GS rule to prevent leakage from injection formations and protect USDWs.

EPA believes that building upon the existing UIC requirements (e.g., Class I and Class II well

requirements) to develop the Class VI GS regulation provides a foundation for protecting USDWs

based on success, field experience, and lessons learned about CO2 injection in other applications.

Class I well owners or operators have experience with site characterization, well construction, and

monitoring procedures and technologies that are applicable to Class VI wells. Class II ER well

operators have experience with managing the unique properties of CO2. To successfully flood a

hydrocarbon field with CO2 during an ER operation, the behavior of injected CO2 must be well

understood.

Commenter Name: Karl R. Moor Letter ID: 0109

Commenter Organization: Southern Company, on behalf of Edison Electric

Institute (EEI)

Comment ID:

21994

Comment: EEI urges EPA to work to ensure the regulations do not stigmatize carbon 

geologic storage, which would create public confusion and hamper development of 

a critical carbon reduction technology. 

As I noted, EPA has recognized that it has two goals for the proposed rules for 

geologic storage of carbon dioxide: the protection of underground sources of 

drinking water and the promotion of carbon capture and storage. EEI urges EPA 

to keep both of these goals in mind and to work to ensure that the regulatory 

regime that is ultimately adopted is designed to facilitate - not delay or 

discourage - the successful commercial-scale development of carbon capture and 

storage. The potential emissions benefits of commercial-scale carbon storage 

are too large and too important to ignore in the context of these regulations. 

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While our written comments will discuss some of the specific ways that the 

proposed regulations can support the development of appropriately sited storage 

projects, I would also like to bring to your attention today the importance of 

creating an accurate public perception of the risks and rewards of carbon 

geologic storage. 

In its laudable efforts to protect sources of drinking water - an important 

goal, as we all agree - EPA has inadvertently stigmatized carbon dioxide 

injection and storage. In reviewing the proposal, EEI and its members became 

very concerned that the proposed regulations repeatedly mischaracterized the 

possible risks posed by carbon dioxide injection and storage. 

Indeed, while carbon dioxide is not a hazardous waste and is, in fact, found in 

the ambient air in abundance, the proposed rules for CO2 storage are, in many 

ways, stricter than those for underground injection of hazardous wastes under 

Class I of the UIC program. Many of the construction, mechanical integrity, 

monitoring and financial assurance provisions for Class VI wells are more 

comprehensive and more strict than those for Class I wells. 

However, carbon dioxide is not a hazardous waste and does not warrant treatment 

akin to or more stringent than given to hazardous wastes. The increased 

regulatory burden placed on Class VI wells by the proposed regulation is of 

concern to EEI and its members, who are potential owners and operators of CCS 

projects. We are also concerned that by imposing such stringent measures EPA 

would be unduly stigmatizing carbon geologic storage. 

Our industry knows first-hand the importance of accurate public perceptions when 

it comes to the siting and permitting of needed infrastructure expansions or 

improvements. In the preamble to its proposal, EPA finds that the public should 

participate in the permitting process for carbon dioxide storage projects. 

Today we ask EPA to ensure that the public fully understands that it is very 

unlikely carbon geologic storage projects will harm underground sources of 

drinking water or human health, so that its participation in the permitting 

process is appropriately informed. EPA can help create accurate public 

perceptions about carbon capture and storage by retooling the proposed 

regulations to tie requirements to actual risks more closely. In addition, EPA 

should remove elements that serve only to fan the flames of fear without 

offering increased protection to underground sources of drinking water. 

Response: EPA disagrees that the GS regulation overstates or mischaracterizes the risk of CO2

injection. EPA recognizes that injecting large volumes of CO2 for GS poses unique challenges that,

if not properly managed, could endanger drinking water sources and have other adverse impacts.

However, the final, tailored, Class VI requirements address the large volumes of CO2 injected, its

buoyancy, potential corrosivity in the presence of water, and potential impurities in the CO2 stream.

In addition, EPA expects the tailored permitting, siting, construction, operation, monitoring, and

post-injection site care requirements in the GS rule to prevent leakage from injection formations and

protect USDWs.

EPA acknowledges the comment about flexibility, and believes that the Class VI requirements

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balance site-specific flexibility with USDW protection. Rather than setting performance or

technology-based standards for GS projects, EPA is adopting a flexible approach, where operators of

GS projects would develop and implement site-specific plans for delineating the AoR, testing and

monitoring the site, performing corrective action, and post-injection site care. EPA believes that the

plans—which would be reviewed and approved by the Director and periodically updated throughout

the life of the project—promote an ongoing dialogue between the operator and the Director that will

encourage use of the most appropriate technologies for a particular project.

EPA agrees that informing the public on all aspects of GS projects is important. The Agency believes

that a demonstration to the public that extensive data have been collected and evaluated would likely

improve confidence in the project and help address public questions and concerns.

Commenter Name: Karl R. Moor Letter ID: 0109

Commenter Organization: Southern Company, on behalf of Edison Electric

Institute (EEI)

Comment ID:

22001

Comment: EEI and its members urge EPA encouragement of carbon capture and storage to be 

reflected in the final regulations, and recommend that the final regulations 

serve this purpose by appropriately characterizing carbon dioxide and its risks. 

The final regulations should be carefully crafted, therefore, to avoid creating 

a public stigma around this critical GHG emissions control technology. 

Response: EPA disagrees that the GS regulation overstates the risk of CO2 injection. EPA

recognizes that injecting large volumes of CO2 for GS poses unique challenges that, if not properly

managed, could endanger drinking water sources and have other adverse impacts. However, the final,

tailored, Class VI requirements address the large volumes of CO2 injected, its buoyancy, potential

corrosivity in the presence of water, and potential impurities in the CO2 stream. In addition, EPA

expects the tailored permitting, siting, construction, operation, monitoring, and post-injection site

care requirements in the GS rule to prevent leakage from injection formations and protect USDWs.

Commenter Name: Leslie Savage Letter ID: 0122

Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24731

Comment: The Proposal fails to promote and encourage geosequestration of CO2. EPA’s 

stated goals for this proposal are to protect Underground Sources of Drinking 

Water (USDWs) while promoting carbon capture and storage. As the proposal 

stands, the regulations would succeed in protecting USDWs, but would fail to 

successfully promote carbon capture and storage in any significant way. 

Therefore, under the current regulatory scenario, CO2 will continue to be 

released to the atmosphere in greater amounts than would ever leak from a 

properly sited, constructed, and operated CO2 storage facility. One reason for 

the failure is that the proposal overestimates the risk of CO2 sequestration 

and, as a result, creates an overestimated implied liability. Another reason is 

that the Proposal taints the technology by implying that CO2 is a waste. 

Finally, the proposal includes insufficient flexibility to account for the 

geographic variability of potential sites across the country. In summary, the 

RRC is concerned that the Proposal overestimates the risks of CO2 geologic 

sequestration, and creating barriers to rapid implementation of the technology 

rather than encouraging or providing incentives to mobilize large-scale 

projects. 

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The Proposal treats CO2 as a waste. The EPA states in the preamble that it has 

not classified CO2 as a waste or a commodity. However, by using the Class I 

waste injection well requirements as the framework for the Class VI 

requirements, the Proposal implies that the CO2 stream is a waste. This 

implication increases not only the potential liability for carbon dioxide 

sequestration, but also the potential liability for anthropogenic CO2 injection 

for the purpose of enhanced recovery of oil and/or natural gas. 

Many provisions of the Proposal address Class VI wells from a waste based 

perspective. With respect to construction, area of review (AoR) and monitoring, 

the Proposal begins with the regulatory framework for Class I non-hazardous 

industrial waste injection well requirements and then adds numerous layers of 

requirements to prevent or detect the escape of CO2 from the injection zone. 

The Proposal excludes CO2 that is a hazardous waste from regulation under the 

Class VI program, but has proposed requirements for Class VI injection wells 

that are more stringent than those for wells used for the injection of hazardous 

waste. RRC strongly disagrees that CO2 buoyancy, corrosivity, and high injection 

volumes for a Class VI project justify a Class I approach. 

Response: EPA clarifies that the purpose of the GS rule is not to promote GS in specific settings,

nor does it limit injection activities to any specific type of formation, geographic region, or depth.

The focus of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that is

protective of USDWs. 

EPA disagrees that the GS regulation overstates the risk of CO2 injection. EPA recognizes that

injecting large volumes of CO2 for GS poses unique challenges that, if not properly managed, could

endanger drinking water sources and have other adverse impacts. However, with proper site

selection, the final, tailored, Class VI requirements address the large volumes of CO2 injected, its

buoyancy, potential corrosivity in the presence of water, and potential impurities in the CO2 stream.

In addition, EPA expects the tailored permitting, siting, construction, operation, monitoring, and

post-injection site care requirements in the GS rule to prevent leakage from injection formations and

protect USDWs. EPA adds that the requirements of the GS rule are tailored to the nature of the CO2

itself, and do not address or imply anything regarding the status of CO2 as a pollutant, commodity,

or waste. EPA does not believe the GS rule creates any implication for an increase in potential

liability for GS or CO2 injection related to EOR. 

EPA disagrees that the GS rule has “tainted” technology by using the Class I regulations as a

baseline for the Class VI regulations. Additionally, EPA disagrees that the GS rule provides

insufficient flexibility to account for geographic variability. EPA has taken a regulatory approach

that promotes USDW protection, incorporates flexibility or the discretion of the permitting authority

when appropriate, seeks to limit burden on owners or operators and permitting agencies, and

provides a foundation for national consistency in permitting of GS projects. For example, under the

final rule, many of the permit requirements must be established through site-specific plans (e.g.,

AoR and corrective action plan, testing and monitoring plan, etc.) developed by the owner or

operator and approved by the Director. 

Furthermore, EPA recognizes that technologies will evolve and improve over time, and for these

reasons, the Agency is using an adaptive approach to regulate GS injection. The Agency plans, every

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six years, to collect and review data on GS projects to determine whether the appropriate amount and

types of information and appropriate documentation are being collected, and to determine if

modifications to the requirements are appropriate or necessary.

Commenter Name: Leslie Savage Letter ID: 0122

Commenter Organization: Railroad Commission of Texas (RRC) Comment ID: 24734

Comment: The Proposal overestimates the risks of CO2 injection and sequestration. As 

noted in the preamble, naturally occurring CO2 has been trapped in subsurface 

formations for eons. Texas and numerous other states have over 35 years of 

experience in injection of large amounts of CO2 into geologic formations to 

enhanced oil recovery. Over 35 million tons of CO2 are injected annually in more 

than 70 projects in the United States. 

In most cases, with appropriate site selection, construction, monitoring, and 

testing, the risks of CO2 geologic sequestration would be comparable to the 

risks of current activities such as natural gas storage, EOR and deep 

underground disposal of acid gas. In those instances any regulations for Class 

VI wells should reflect more closely UIC Class II standards instead of the more 

stringent Class I well standards. 

Both the Class VI and the Class II programs have the same goals - protection of 

USDWs. Yet, EPA’s proposal implies that when the purpose of the injection 

switches from enhanced recovery to sequestration, the risks to USDWs are 

significantly magnified. The RRC does not agree that the volume and duration of 

CO2 injection and placement are sufficiently different in measurable effect on 

the underground to justify the extra layers of requirements. 

However, rather than beginning its CO2 geologic sequestration framework with the 

Class II well program, EPA begins with the framework of Class I non-hazardous 

industrial waste injection well requirements and adds then numerous layers of 

overly redundant requirements to prevent or detect the escape of CO2 from the 

injection zone. The implication seems to be that EPA believes that the Class II 

program is not sufficiently stringent. This implication is a major concern for 

the RRC. 

In addition, the heightened stringency in the proposed requirements for Class VI 

injection wells suggests that geological sequestration of CO2 is as much or more 

dangerous than underground injection of other substances. The Proposal includes 

numerous examples of this heightened stringency: 

Response: As described above, EPA disagrees that the GS rule overstates the risk of CO2 injection.

While EPA recognizes that industry has decades of experience injecting CO2 for EOR and EGR,

EPA believes that injection for the primary purpose of long term storage is sufficiently different

from Class II ER operations and warrants tailored requirements, which is why the GS rule used the

Class I regulations as its baseline. For example, the volume of CO2 anticipated to be injected in

Class VI wells is significantly greater than for Class II wells. Reservoir pressure conditions will also

be different, with Class VI injection operations involving large volumes of CO2 and likely having

higher pressures within their storage formations than Class II ER projects. 

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EPA disagrees that the tailored requirements of the GS rule suggest that GS of CO2 is any more

risky or dangerous than underground injection of other substances. EPA expects that the tailored

permitting, siting, construction, operation, monitoring, and post-injection site care requirements in

the GS rule will prevent leakage from injection formations and protect USDWs.

Commenter Name: Carl Carlsson Letter ID: 0131

Commenter Organization: SUEZ Energy Generation NA, LLC Comment ID: 21526

Other EPA Comment Codes and Descriptions: 1655 1.3.5.1 Concerns about Lake Nyos and

Mammoth Mountain-type events 

Comment: Risks Associated with CO2 GS 

SEGNA agrees that all potential risks associated with geological sequestration of 

CO2 should be addressed, and that the public must be adequately informed. 

However, references to the large and rapid releases of CO2 from volcanic lakes, 

as occurred in Cameroon in the 1980's, must be presented carefully to more 

clearly demonstrate that geological sequestration--deep underground and under 

confining strata--is a completely different process and does not represent a risk 

to human health and the environment comparable to the referenced incident in 

Cameroon. The language in any subsequent documents issued by EPA should 

make this point more forcefully to avoid public confusion regarding the actual risk. 

Response: The Agency believes it appropriately characterized the limnic eruption at Lake Nyos as a

rare and naturally-occurring lake turnover event that is characteristic of stratified lakes in warm

climates. The event at Lake Nyos, during which naturally-occurring CO2 trapped at the bottom of

the Lake was released to the atmosphere, is not a valid analogue for GS. The preamble highlighted

differences between the lithologic reservoirs that may serve as storage formations for CO2 and the

processes occurring at Lake Nyos and other stratified tropical lakes (73 FR 43498).

Commenter Name: Anonymous2 Letter

ID: 0133

Commenter Organization: Sierra Club National Global Warming and Energy

Committee and Sierra Club California-Nevada Regional Conservation Committee on

Energy and Climate Change

Comment

ID: 21599

Comment: CO2 as a Valuable Commodity: Re-frame public perceptions of CO2 as a hazardous 

waste material by funding CCS demonstration projects which biologically or 

chemically transform CO2 into valuable products. 

Response: EPA recognizes that injecting large volumes of CO2 for GS poses unique challenges that,

if not properly managed, could endanger drinking water sources and have other adverse impacts.

However, with proper site selection, the final, tailored, Class VI requirements address the large

volumes of CO2 injected, its buoyancy, potential corrosivity in the presence of water, and potential

impurities in the CO2 stream. In addition, the tailored permitting, siting, construction, operation,

monitoring, and post-injection site care requirements in the GS rule are intended to prevent leakage

from injection formations and protect USDWs.

EPA adds that the requirements of the GS rule are tailored to the nature of the CO2 itself, and do not

address the status of CO2 as either a pollutant, commodity, or waste. The comment regarding

funding of CCS demonstration projects is outside the scope of this rulemaking.

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Commenter Name: Patrick Nugent Letter ID: 0143

Commenter Organization: Texas Pipeline Association (TPA) Comment ID: 23125

Comment: The importance of protecting drinking water is obvious, and no one in the oil 

and gas industry is seeking to cut regulatory corners. TPA is simply urging EPA 

to recognize both the need for flexibility in the regulatory regime and the 

importance of fostering public confidence in the safety of geologic 

sequestration technology. 

Response: EPA recognizes that injecting large volumes of CO2 for GS poses unique challenges that,

if not properly managed, could endanger drinking water sources and have other adverse impacts.

However, with proper site selection, the final, tailored, Class VI requirements address the large

volumes of CO2 injected, its buoyancy, potential corrosivity in the presence of water, and potential

impurities in the CO2 stream. In addition, EPA expects the tailored permitting, siting, construction,

operation, monitoring, and post-injection site care requirements in the GS rule to prevent leakage

from injection formations and protect USDWs. Thus, EPA believes that the GS rule will foster

public confidence in the safety of GS. 

EPA agrees that flexibility is important. EPA notes that, under the final rule, many of the permit

requirements will be established through site-specific plans developed by the owner or operator and

approved by the Director. Consequently, EPA anticipates that owners or operators will consult with

the Director as they develop, implement, and update these plans. The final GS regulation gives the

Director discretion to set permit criteria that are appropriate to site-specific conditions. The

regulation provides flexibility to select appropriate sites and target formations (under §146.82), well

construction specifics (under §146.86), and testing and monitoring regimes (under §146.90),

provided the owner or operator can demonstrate that the injection and storage will not endanger

USDWs and that minimum requirements for the site are met. 

In addition, the final rule affords the Director flexibility to approve alternatives to the requirements

in some cases. For example, the Director may in certain situations modify the length of the postinjection site care period, allow the use of alternate methods for mechanical integrity testing (if

approved by EPA), and waive the requirement that wells be designed to inject below the lowermost

USDW.

Commenter Name: Kenneth Alexander Letter ID: 0146

Commenter Organization: Old Dominion Electric Cooperative (ODEC) Comment ID: 21724

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: 5.EPA should be careful not to stigmatize as operations and to take positive 

measures to build public acceptance. EPA should avoid characterizing stored CO2 

as a waste. 

Response: EPA clarifies that the GS rule, being issued only under the SDWA, does not affect

whether CO2 is considered a solid waste under RCRA or EPA’s RCRA regulations. 

EPA received many comments regarding the applicability of the RCRA regulations and statute to

CO2 streams that are geologically sequestered under the final Class VI UIC well requirements. As a

result, EPA has decided to initiate a separate proposed rulemaking specifically to examine the issue

of RCRA applicability 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

331
consider these comments as part of its development of that proposal. The Agency will consider

issues particular to RCRA in the context of that separate rulemaking, and recommends that the

commenter read that proposed rule when it is published. The Agency notes that commenters who

wish to submit comments on the RCRA proposal will need to do so during the comment period for

that rule.

Commenter Name: William Kovacs Letter ID: 0148

Commenter Organization: U.S. Chamber of Commerce Comment ID: 21772

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: 4. Why Does the Proposed Rule Treat CO2 like a Hazardous Waste? 

Carbon dioxide is not a hazardous waste; yet the proposed rules for CO2 storage 

are, in many ways, far more strict than those for underground injection of 

hazardous wastes under Class I of the UIC program. Many of the construction, 

mechanical integrity, monitoring and financial assurance provisions for Class VI 

wells are more comprehensive and more onerous than those for Class I wells. 

The Chamber does not believe that CO2 should be treated more stringently than 

hazardous waste because it distorts public perception about the safety of carbon 

capture and storage, and it may make securing financial backing for CCS more 

difficult. 

Response: EPA disagrees that the requirements in the GS rule are too stringent or overstate the risk

associated with GS. The requirements for Class VI wells are tailored to address the unique nature of

full-scale CO2 GS, including the injection volumes anticipated for long-term storage, the buoyant

and viscous nature of the injectate, and its corrosivity in the presence of water. 

While the Class I requirements formed the basis of many of the specific requirements for GS wells,

EPA clarifies that the GS rule is tailored to the unique nature of GS. EPA based many of the GS

requirements on the Class I regulations because, like Class VI wells, Class I wells are typically deep

and involve waste streams that, if not properly managed, can harm the well and lead to

contamination.

Commenter Name: William Kovacs Letter ID: 0148

Commenter Organization: U.S. Chamber of Commerce Comment ID: 21773

Other EPA Comment Codes and Descriptions: 1250 1.1.1.4 Flexibility is needed (performancebased standards) 

Comment: a. Distorts Public Perception 

By making the proposed rule so strict, the public may unduly perceive CCS as a 

dangerous activity. Consider that the proposed rule requires a secondary 

containment field for CO2 storage. Such a requirement is unprecedented both 

domestically, in the UIC program (including for storage of hazardous wastes in 

Class I wells), as well as internationally. [FN10 Countries such as Norway, 

Canada, and Australia, which have carbon capture and storage projects currently 

underway, do not require secondary containment zones, and in fact, those 

countries regulate CCS using existing petroleum laws.] Singling out carbon 

332
capture and storage for this heightened and substantially more rigorous 

requirement would suggest to the public that EPA thinks geologic storage of 

carbon dioxide is more dangerous than the underground injection of other 

substances. Since EPA is the agency charged with protecting the environment, the 

public could be easily swayed by EPA’s apparent apprehension of carbon capture 

and storage as currently embodied in the proposed regulations. In order to 

create a regulatory scheme that fosters carbon capture and storage development 

and deployment, EPA should reconsider how it has characterized carbon dioxide 

injection -- both explicitly and implicitly -- in its final regulations. 

Response: EPA disagrees that the GS regulation overstates the risk of CO2 injection. EPA

recognizes that injecting large volumes of CO2 for GS poses unique challenges that, if not properly

managed, could endanger drinking water sources and have other adverse impacts. However, with

proper site selection, the final, tailored, Class VI requirements address the large volumes of CO2

injected, its buoyancy, potential corrosivity in the presence of water, and potential impurities in the

CO2 stream. In addition, EPA expects the tailored permitting, siting, construction, operation,

monitoring, and post-injection site care requirements in the GS rule to prevent leakage from injection

formations and protect USDWs.

EPA also disagrees that the tailored requirements will create a negative public perception of GS. The

Agency believes that a demonstration to the public that GS projects are meeting the GS rule's tailored

requirements will likely improve confidence in the project and help address public questions and

concerns.

Regarding secondary containment, EPA retains the requirement to identify additional

containment/confining zones, if required by the Director, as proposed, at §146.83(b). EPA

acknowledges that such additional zones may not be needed in all circumstances, and clarifies that

this requirement is at the Director's discretion, based on his or her understanding of a particular site.

EPA believes that, in some situations, the presence of additional confining and containment zones

above the primary (i.e., lowermost) confining zone can improve USDW protection. These layers

could further impede vertical fluid movement and allow for pressure dissipation, and also provide

additional sites for monitoring, mitigation, and remediation. The Agency's decision is supported by

commenters representing states, water associations, and an electric utility who assert that these

requirements promote a flexible, risk-based, site-specific approach to characterizing and permitting a

site for GS projects, and are intended to improve understanding of the project as a whole and

promote better modeling of the site. While other countries may not require such additional

protection, EPA believes that providing the Director this additional discretion is an important

element of assuring that GS activities will not endanger USDWs.

Commenter Name: Skiles Boyd Letter ID: 0160

Commenter Organization: DTE Energy Comment ID: 21275

Comment: the long term obligations and risks associated with a GS project. " As a 

regulated entity, wanting to deploy this technology, it would help with securing 

financial support for the project and with public acceptance if the risks of 

this technology were more accurately reflected by the regulations. We are 

concerned that imposing such strict regulations would unduly stigmatize geologic 

storage. 

Response: EPA disagrees that the GS regulation overstates the risk of CO2 injection. EPA

333
recognizes that injecting large volumes of CO2 for GS poses unique challenges that, if not properly

managed, could endanger drinking water sources and have other adverse impacts. However, with

proper site selection, the final, tailored, Class VI requirements address the large volumes of CO2

injected, its buoyancy, potential corrosivity in the presence of water, and potential impurities in the

CO2 stream. In addition, EPA expects the tailored permitting, siting, construction, operation,

monitoring, and post-injection site care requirements in the GS rule to prevent leakage from injection

formations and protect USDWs.

Commenter Name: Joseph Eutizi Letter ID: 0161

Commenter Organization: San Miguel Electric Cooperative, Inc Comment ID: 21288

Comment: 5. EPA should be careful not to stigmatize GS operations and to take positive 

measures to build public acceptance. EPA should avoid characterizing stored CO2 

as a waste. 

Response: EPA does not believe that the tailored requirements will create a negative public

perception of GS. The Agency believes that a demonstration to the public that GS projects are

meeting the GS rule's tailored requirements would likely improve confidence in the project and help

address public questions and concerns.

EPA adds that the requirements of the GS rule are tailored to the nature of the CO2 itself, and do not

address the status of CO2 as either a pollutant, commodity, or waste.

Commenter Name: James Stine Letter ID: 0163

Commenter Organization: National Rural Electric Cooperative Association

(NRECA)

Comment ID:

21316

Comment: § EPA should be careful not to stigmatize GS operations and to take positive 

measures to build public acceptance. EPA should avoid characterizing stored CO2 

as a waste. 

Response: EPA does not believe that the tailored requirements will create a negative public

perception of GS. The Agency believes that a demonstration to the public that GS projects are

meeting the GS rule's tailored requirements would likely improve confidence in the project and help

address public questions and concerns.

EPA adds that the requirements of the GS rule are tailored to the nature of the CO2 itself and risks

associated with the injection of CO2, and do not address the status of CO2 as either a pollutant,

commodity, or waste.

Commenter Name: James Stine Letter ID: 0163

Commenter Organization: National Rural Electric Cooperative Association

(NRECA)

Comment ID:

21328

Other EPA Comment Codes and Descriptions: 1480 1.2.2.2.2 CO2 is not a pollutant 

Comment: 7. EPA should view CCS as a resource, not a waste. NRECA endorses the view of 

the Interstate Oil and Gas Compact Commission ("IOGCC") that CO2 should be 

treated in any regulatory regime as a resource and not as a waste. As an initial 

matter, CO2 has a commercial value for EOR operators. A number of commercial 

operations exist solely for the extraction and sale of natural CO2. Moreover, 

anthropogenic CO2 may have a commercial value for traders in carbon emissions 

334
reduction credits, once the CO2 is captured and stored. While the reason for 

capturing the CO2 may be to prevent it from entering the earth’s atmosphere, it 

nonetheless will have a commercial value when stored. Also, states that 

currently regulate CO2 injections for EOR operations do so under a resource 

management framework. Surface Transportation Boards, which are responsible for 

the economic regulation of CO2 interstate pipelines, also view CO2 as a 

commodity. Characterization as a waste would have a chilling effect on the 

development of CCS projects. 

Response: EPA clarifies that the requirements of the GS rule are tailored to the nature of the CO2

itself and risks associated with the injection of CO2, and do not address the status of CO2 as either a

pollutant, commodity or waste. In addition, whether or not a fluid could be sold on the market as a

commodity does not override EPA's authority under the SDWA to protect USDWs from

endangerment. 

Under the SDWA, the injection of any "fluid" is subject to the requirements of the UIC program.

"Fluid" is defined under 40 CFR 144.3 as any material or substance which flows or moves, whether

in a semisolid, liquid, sludge, gas or other form or state, and it includes liquids, gases, and

semisolids (i.e., slurries) injected into the subsurface. 

EPA stresses that the focus of the GS rule is to ensure that, where GS is deployed, it is conducted in

a manner that protects USDWs.

Commenter Name: James Stine Letter ID: 0163

Commenter Organization: National Rural Electric Cooperative Association

(NRECA)

Comment ID:

21329

Other EPA Comment Codes and Descriptions: 1480 1.2.2.2.2 CO2 is not a pollutant 

Comment: 8. The General Accounting Office ("GAO") recently issued a report entitled 

"Climate Change -- Federal Actions Will Greatly Affect the Viability of Carbon 

Capture and Storage As a Key Mitigation Option" (GAO-08-1080, September 2008) 

("GAO Report"). GAO cites a National Academy of Sciences ("NAS") report 

emphasizing that a largescale CO2 UIC program cannot be successful "if a 

significant fraction of the public views it as dangerous or unacceptable" and, 

therefore, CO2 storage technologies must not only be safe and effective, they 

must be presented "to the public and the regulatory community in such a way as 

to instill confidence that they are in fact safe and effective." Id. at 49 

(citing NAS, Prospective Evaluation). This is another reason EPA should not 

characterize CO2 as a waste. ********* 

Response: As described above, EPA clarifies that the GS rule does not address the status of CO2 as

either a pollutant or a commodity or a waste. 

EPA believes that the creation of a new injection well class (VI) under the existing UIC Program is

necessary to enable deployment of GS as a climate change mitigation technology in a manner that

protects USDWs from endangerment. EPA agrees that the UIC Program, under the authority of the

SDWA, provides a strong framework for regulating injection of CO2 for GS and adds that the GS

regulation tailors the UIC requirements to address the unique issues associated with large-scale GS

including large injection volumes, the relative buoyancy of CO2, its corrosivity in the presence of

water, the potential presence of impurities in captured CO2, and its mobility within subsurface

335
geologic formations.

Commenter Name: Erik Silvola Letter ID: 0171

Commenter Organization: Great River Energy Comment ID: 23444

Comment: 5. EPA should be careful not to stigmatize GS operations and to take positive 

measures to build public acceptance. EPA should avoid characterizing stored CO2 

as a waste. 

Response: EPA does not believe that the tailored requirements will create a negative public

perception of GS. The Agency believes that a demonstration to the public that GS projects are

meeting the GS rule's tailored requirements would likely improve confidence in the project and help

address public questions and concerns.

EPA adds that the requirements of the GS rule are tailored to the nature of the CO2 itself and risks

associated with the injection of CO2, and do not address the status of CO2 as either a pollutant,

commodity, or waste.

Commenter Name: James Rower Letter ID: 0173

Commenter Organization: Utility Solid Waste Activities Group (USWAG) Comment ID: 23471

Comment: at 42-23. Finally, GAO cites a National Academy of Sciences ("NAS") report 

emphasizing that a large-scale CO2 UIC program cannot be successful "if a 

significant fraction of the public views it as dangerous or unacceptable," 

concluding that CO2 storage technologies must not only be safe and effective, 

they must be presented "to the public and the regulatory community in such a way 

as to instill confidence that they are in fact safe and effective." Id. at 49 

(quoting National Research Council, NAS, Prospective Evaluation of Applied 

Energy Research and Development at DOE (Phase Two) (2007)). 

Response: EPA does not believe that the tailored requirements will create a negative public

perception of GS. The Agency believes that a demonstration to the public that GS projects are

meeting the GS rule's tailored requirements would likely improve confidence in the project and help

address public questions and concerns.

Commenter Name: Lee O. Fuller Letter ID: 0179

Commenter Organization: Independent Petroleum Association of America et

al.

Comment ID:

23612

Other EPA Comment Codes and Descriptions: 1480 1.2.2.2.2 CO2 is not a pollutant 

Comment: Second, these concerns similarly arise regarding the characterization of CO2 in 

the GS process. Currently, for EOR operations, CO2 is essentially treated as a 

commercial chemical. This characterization is significant because of the 

connotation that characterization as a pollutant or a hazardous waste implies. 

CO2 has not been declared either a pollutant or a hazardous substance under any 

federal law. Suggesting that it should be so classified (or even a treatment in 

policy that would indirectly point to it as such) as a part of this rulemaking 

implies a risk that is not consistent with its use in EOR. Indeed, implicit in 

such an implication is a liability threat that would chill further development 

of CO2 EOR with no incremental environmental benefit. However, we do recognize 

that compositional controls over what is injected may be necessary. This does 

336
not seem to be addressed in the draft rules. 

Response: Under §146.82(a)(7), owners or operators of GS wells must characterize their CO2

stream as part of their permit application. If the injectate is determined to meet the definition of a

hazardous waste under RCRA, and as defined in 40 CFR Part 261, the stringent UIC Class I

hazardous waste requirements for injection of hazardous waste apply. Thus, injection of corrosive

CO2 into Class VI wells is prohibited. In addition, owners or operators must periodically monitor

their injectate throughout injection operations under §146.90(a). 

EPA adds that the requirements of the GS rule are tailored to the nature of the CO2 itself and risks

imposed by the injection of CO2, and do not address the status of CO2 as either a pollutant,

commodity, or waste.

Commenter Name: G. Graham Holden Letter ID: 0189

Commenter Organization: Oglethorpe Power Corporation Comment ID: 25249

Comment: 5. EPA should be careful not to stigmatize GS operations and to take positive 

measures to build public acceptance. EPA should avoid characterizing stored CO2 

as a waste. 

Response: EPA does not believe that the tailored requirements will create a negative public

perception of GS. The Agency believes that a demonstration to the public that GS projects are

meeting the GS rule's tailored requirements would likely improve confidence in the project and help

address public questions and concerns.

EPA adds that the requirements of the GS rule are tailored to the nature of the CO2 itself and risks

associated with the injection of CO2, and do not address the status of CO2 as either a pollutant,

commodity, or waste.

Commenter Name: Robert F. Van Voorhees Letter ID: 0190

Commenter Organization: Carbon Sequestration Council Comment ID: 24328

Other EPA Comment Codes and Descriptions: 1200 1.1 General comments about the rulemaking 

Comment: 2. Rules that Stigmatize GS or Burden it Excessively Would Not be in the Public 

Interest. 

The magnitude of the regulatory burdens imposed by the proposed Class VI 

requirements are of concern for several reasons. First, unnecessary regulatory 

burdens would act as a direct impediment and disincentive to the development of 

GS projects. Less directly, the imposition of unreasonably stringent regulatory 

requirements - particularly requirements for multiple layers of requirements 

addressing the same basic risks - inherently magnify the impression of risk and 

could thus stigmatize GS and discourage investment in GS projects. EPA should 

recognize that "more regulation" - particularly the "belt-and-suspenders plus 

more belts and more suspenders" approach reflected in the proposed rule - is not 

"better regulation" in the GS context. To the contrary, overly-burdensome 

regulation - to the extent it effectively impedes or deters use of a promising 

technology - could prove counterproductive. 

We understand the importance of public perception when it comes to the siting 

337
and permitting of needed infrastructure, and believe strongly in the need to 

ensure that the public has accurate information. To facilitate the public’s 

appreciation of the merits of GS, we urge EPA to ensure that it does not 

overstate the risks associated with CO2 injection or understate the justified 

confidence with which many potential issues and concerns can be addressed. 

Similarly, we urge EPA to avoid the imposition of regulatory requirements that 

are so disproportionate to the risks involved that they may do more to incite 

than address public concerns. To this end, EPA should scale back its regulatory 

requirements to more accurately reflect the magnitude of actual risks and to 

ensure that any requirements imposed are truly necessary for the protection of 

USDWs. 

EPA should also consider the effect its regulations might have on the ability to 

secure critical financial backing for GS projects. Any exaggerated impression of 

the risks involved in GS could adversely influence financial institutions and 

impede efforts to obtain financing. The recent turmoil in the financial markets 

highlights how challenging the financing of new technologies may become. In a 

credit-constrained world, investors will be wary of putting their limited funds 

behind GS projects if they believe they are likely to endanger the environment 

or public health. Accordingly, EPA should recognize the importance of the 

messages that it sends the financial world through the regulations it imposes. 

Permanent storage of CO2 can be accomplished safely and without harm to the 

environment as long as we apply the right knowledge base, detailed site-specific 

information, technical expertise, and sound management practices. However, we 

cannot implement an effective regulatory program for sequestering CO2 if the 

rules are based on the erroneous premise that CO2 represents an extreme hazard. 

It is therefore important that EPA send accurate messages about the nature of 

CO2 and the actual magnitude of the risks associated with GS. It is also 

critical that EPA strike an appropriate balance by addressing the risks 

associated with GS without creating a regime that effectively hinders or deters 

use of this key technology for reduction of carbon emissions. 

Response: EPA disagrees that the GS regulation overstates the risk of CO2 injection. EPA

recognizes that injecting large volumes of CO2 for GS poses unique challenges that, if not properly

managed, could endanger drinking water sources and have other adverse impacts. However, with

proper site selection, the final, tailored, Class VI requirements address the large volumes of CO2

injected, its buoyancy, potential corrosivity in the presence of water, and potential impurities in the

CO2 stream. In addition, EPA expects the tailored permitting, siting, construction, operation,

monitoring, and post-injection site care requirements in the GS rule to prevent leakage from injection

formations and protect USDWs.

EPA does not believe that the tailored requirements will create a negative public perception of GS.

The Agency believes that a demonstration to the public that GS projects are meeting the GS rule's

tailored requirements will likely improve confidence in the project and help address public questions

and concerns.

Regarding the ability of owners or operators to secure financial backing for GS projects, EPA

believes that, like the public, financing entities will have improved confidence in projects that

incorporate multiple protective requirements. Please see the discussion of financial responsibility in

338
the preamble to the final GS rule.

Commenter Name: Richard Guinn Letter ID: 0210

Commenter Organization: Eastman Chemical Company Comment ID: 22701

Comment: 10. EPA should not stigmatize geological storage of CO2 such as can be inferred 

by having requirements for Class VI wells that are more restrictive than for 

Class II wells. 

Response: EPA disagrees that the requirements in the GS regulation will stigmatize GS. EPA

recognizes that injecting large volumes of CO2 for GS poses unique challenges that, if not properly

managed, could endanger drinking water sources and have other adverse impacts. However, with

proper site selection, the final, tailored, Class VI requirements address the large volumes of CO2

injected, its buoyancy, potential corrosivity in the presence of water, and potential impurities in the

CO2 stream. In addition, EPA expects the tailored permitting, siting, construction, operation,

monitoring, and post-injection site care requirements in the GS rule to prevent leakage from injection

formations and protect USDWs.

EPA believes that injection for the primary purpose of long term storage is sufficiently different

from Class II ER operations and warrants tailored requirements. For example, the volume of CO2

anticipated to be injected in Class VI wells is significantly greater than for Class II wells. Reservoir

pressure conditions will also be different, with Class VI injection operations involving large volumes

of CO2 and likely having higher pressures within their storage formations than Class II ER projects.

Commenter Name: John King Letter ID: 0211

Commenter Organization: Shell Exploration and Production Company

(SEPCo)

Comment ID:

22760

Comment: D. Rules that Stigmatize GS or Burden it Excessively Would Not be in the Public 

Interest. 

The magnitude of the regulatory burdens imposed by the proposed Class VI 

requirements is of concern for several reasons. First, unnecessary regulatory 

burdens would act as a direct impediment and disincentive to the development of 

GS projects. Less directly, the imposition of unreasonably stringent regulatory 

requirements - particularly requirements for multiple layers of protections 

addressing the same basic risk - inherently magnify the impression of risk and 

could thus stigmatize GS and deter investment in GS projects. 

SEPCo understands the importance of public perception when it comes to the 

siting and permitting of needed infrastructure, and believes strongly in the 

need to ensure that the public has accurate information to inform it. To 

facilitate the public’s appreciation of the merits of GS, SEPCo urges EPA to 

ensure that it does not overstate the risks associated with CO2 injection or 

understate the justified confidence with which many potential issues and 

concerns can be addressed Similarly, SEPCo urges EPA to avoid the imposition of 

regulatory requirements that are so disproportionate to the risks involved that 

they may do more to amplify than address public concerns. To this end, EPA 

should scale back its regulatory requirements to more accurately reflect the 

magnitude of actual risks and to ensure that the requirements imposed are 

339
necessary for the protection of USDWs. 

SEPCo believes that permanent storage of CO2 can be accomplished safely and 

without harm to the environment by utilizing the appropriate knowledge base, 

detailed site-specific information, technical expertise, and sound management 

practices. It is therefore important that EPA send accurate messages about the 

nature of CO2 and the actual magnitude of the risks associated with GS. It is 

also critical that EPA strike an appropriate balance by addressing the risks 

associated with GS without creating a regime that effectively hinders or deters 

use of this key technology for reduction of CO2 emissions to the atmosphere. 

Recommendations: 

EPA should consider that overly-burdensome regulation - to the extent it 

effectively impedes or deters use of a "promising technology" for the reduction 

of greenhouse gas emissions - could prove environmentally counterproductive, 

given potential operators inability to deploy GS projects. 

Response: EPA disagrees that the GS regulation overstates the risk of CO2 injection or that it is

“overly burdensome.” EPA recognizes that injecting large volumes of CO2 for GS poses unique

challenges that, if not properly managed, could endanger drinking water sources and have other

adverse impacts. However, with proper site selection, the final, tailored, Class VI requirements

address the large volumes of CO2 injected, its buoyancy, potential corrosivity in the presence of

water, and potential impurities in the CO2 stream. In addition, EPA expects the tailored permitting,

siting, construction, operation, monitoring, and post-injection site care requirements in the GS rule to

prevent leakage from injection formations and protect USDWs.

EPA does not believe that the tailored requirements will create a negative public perception of GS.

The Agency believes that a demonstration to the public that GS projects are meeting the GS rule's

tailored requirements will likely improve confidence in the project and help address public questions

and concerns.

Commenter Name: Paul L. Carpinone Letter ID: 0212

Commenter Organization: Tampa Electric Company Comment ID: 22904

Other EPA Comment Codes and Descriptions: 1210 1.1.1 Comments about the proposed rule 

Comment: - In many instances the proposed requirements for Class VI CO2 GS wells are 

unnecessarily more stringent than existing requirements for other well classes 

under the UIC Program. While it is essential that the Final Rule be protective 

of USDWs, many of the more rigorous requirements proposed for Class VI wells are 

not warranted by findings of unique risks posed by CO2 GS wells. The Final Rule 

should craft requirements that protect USDWs while avoiding the imposition of 

unnecessary costs or the inappropriate creation of a negative public perception 

of CO2 GS projects. 

Response: EPA disagrees that the GS regulation overstates the risk of CO2 injection or that it is

unnecessarily stringent. EPA recognizes that injecting large volumes of CO2 for GS poses unique

challenges that, if not properly managed, could endanger drinking water sources and have other

adverse impacts. However, with proper site selection, the final, tailored, Class VI requirements

address the large volumes of CO2 injected, its buoyancy, potential corrosivity in the presence of

340
water, and potential impurities in the CO2 stream. In addition, EPA expects the tailored permitting,

siting, construction, operation, monitoring, and post-injection site care requirements in the GS rule to

prevent leakage from injection formations and protect USDWs.

EPA does not believe that the tailored requirements will create a negative public perception of GS.

The Agency believes that a demonstration to the public that GS projects are meeting the GS rule's

tailored requirements will likely improve confidence in the project and help address public questions

and concerns.

Commenter Name: Barbara Walz Letter ID: 0216

Commenter Organization: Tri-State Generation and Transmission Association,

Inc.

Comment ID:

22968

Other EPA Comment Codes and Descriptions: 1480 1.2.2.2.2 CO2 is not a pollutant 

Comment: C. EPA should view CO2 as a resource, not a waste. CO2 has a commercial value for 

enhanced oil recovery operators. A number of commercial operations exist solely 

for the extraction and sale of natural CO2. Moreover, anthropogenic CO2 may have a 

commercial value for traders in carbon emissions reduction credits, once the 

CO2 is captured and stored. While the reason for capturing the CO2 may be to 

prevent it from entering the earth's atmosphere, it nonetheless will have a 

commercial value when stored. Also, states that currently regulate CO2 injections 

for enhanced oil recovery operations do so under a resource management 

framework. Surface Transportation Boards, which are responsible for the economic 

regulation of CO2 interstate pipelines, also view CO2 as a commodity. 

Characterization as a waste would have a chilling effect on the development of 

carbon capture and storage projects. 

Response: EPA clarifies that the GS rule does not address the status of CO2 as either a pollutant,

waste, or a commodity. In addition, whether or not a fluid could be sold on the market as a

commodity does not override EPA's authority under the SDWA to protect USDWs from

endangerment. EPA stresses that the focus of the GS rule is to ensure that, where GS is deployed, it

is conducted in a manner that protects USDWs. 

Under the SDWA, the injection of any "fluid" is subject to the requirements of the UIC program.

"Fluid" is defined under 40 CFR 144.3 as any material or substance which flows or moves, whether

in a semisolid, liquid, sludge, gas or other form or state, and it includes liquids, gases, and

semisolids (i.e., slurries) injected into the subsurface. 

Under §146.82(a)(7), owners or operators of GS wells must characterize their CO2 stream as part of

their permit application. If the injectate is determined to meet the definition of a hazardous waste

under RCRA, and as defined in 40 CFR Part 261, the stringent UIC Class I hazardous waste

requirements for injection of hazardous waste apply. Thus, injection of corrosive CO2 into Class VI

wells is prohibited. In addition, owners or operators must periodically monitor their injectate

throughout injection operations under §146.90(a).

Commenter Name: Barbara Walz Letter ID: 0216

Commenter Organization: Tri-State Generation and Transmission Association,

Inc.

Comment ID:

22973

Comment: E. The General Accounting Office (GAO) issued in September 2008 a report 

341
entitled Climate Change Federal Actions Will Greatly Affect the Viability 

of Carbon Capture and Storage As a Key Mitigation Option (GAO-08-1080). GAO cites 

a National Academy of Sciences report emphasizing that a large-scale CO2 UIC 

program cannot be successful "if a significant fraction of the public views it 

as dangerous or unacceptable" and, therefore, CO2 storage technologies must not 

only be safe and effective, they must be presented "to the public and the 

regulatory community in such a way as to instill confidence that they are in 

fact safe and effective." 

Response: EPA recognizes that injecting large volumes of CO2 for GS poses unique challenges that,

if not properly managed, could endanger drinking water sources and have other adverse impacts.

However, with proper site selection, the final, tailored, Class VI requirements address the large

volumes of CO2 injected, its buoyancy, potential corrosivity in the presence of water, and potential

impurities in the CO2 stream. In addition, the tailored permitting, siting, construction, operation,

monitoring, and post-injection site care requirements in the GS rule are intended to prevent leakage

from injection formations and protect USDWs.

EPA does not agree that the tailored requirements will create a negative public perception of GS.

The Agency believes that a demonstration to the public that GS projects are meeting the GS rule's

tailored requirements would likely improve confidence in the project and help address public

questions and concerns.

Commenter Name: Olon Plunk Letter ID: 0217

Commenter Organization: Xcel Energy, Inc. Comment ID: 21551

Other EPA Comment Codes and Descriptions: 1480 1.2.2.2.2 CO2 is not a pollutant 

Comment: CO2 Characterization 

CO2 is produced continually by natural process throughout the natural world and 

poses no significant hazard to human health when properly managed. EPA is 

correct to note in the proposed rule that a potential barrier to CCS and 

geologic storage involves how the captured CO2 is treated within existing 

regulatory frameworks. EPA is incorrect, however, to suggest or presume that 

captured CO2 is a waste, or that geologic storage via a Class VI well 

constitutes disposal. In several instances, the proposed rule refers to CO2 as a 

potential hazardous waste and suggests the need for regulatory requirements for 

Class VI wells that exceed those deemed necessary for Class I hazardous waste 

injection wells. Creating such a regulatory framework that implies an undue 

level of risk associated with geologic storage is misleading and could 

stigmatize proposed projects in the eyes of both the public and investors. 

Response: EPA clarifies that the GS rule does not address the status of CO2 as either a pollutant or

a commodity. In addition, whether or not a fluid could be sold on the market as a commodity does

not override EPA's authority under the SDWA to protect USDWs from endangerment. EPA stresses

that the focus of the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that

protects USDWs. 

Under the SDWA, the injection of any "fluid" is subject to the requirements of the UIC program.

"Fluid" is defined under 40 CFR 144.3 as any material or substance which flows or moves, whether

in a semisolid, liquid, sludge, gas or other form or state, and it includes liquids, gases, and

342
semisolids (i.e., slurries) injected into the subsurface. 

Under §146.82(a)(7), owners or operators of GS wells must characterize their CO2 stream as part of

their permit application. If the injectate is determined to meet the definition of a hazardous waste

under RCRA, and as defined in 40 CFR Part 261, the stringent UIC Class I hazardous waste

requirements for injection of hazardous waste apply. Thus, injection of corrosive CO2 into Class VI

wells is prohibited. In addition, owners or operators must periodically monitor their injectate

throughout injection operations under §146.90(a). 

EPA disagrees that the GS regulation overstates the risk of CO2 injection or implies an undue level

of risk. EPA recognizes that injecting large volumes of CO2 for GS poses unique challenges that, if

not properly managed, could endanger drinking water sources and have other adverse impacts.

However, with proper site selection, the final, tailored, Class VI requirements address the large

volumes of CO2 injected, its buoyancy, potential corrosivity in the presence of water, and potential

impurities in the CO2 stream. In addition, EPA expects the tailored permitting, siting, construction,

operation, monitoring, and post-injection site care requirements in the GS rule to prevent leakage

from injection formations and protect USDWs.

EPA does not agree that the tailored requirements will create a negative public perception of GS.

The Agency believes that a demonstration to the public that GS projects are meeting the GS rule's

tailored requirements will likely improve confidence in the project and help address public questions

and concerns.

Regarding the ability of owners or operators to secure investment in GS projects, EPA believes that

financing entities will have improved confidence in projects that incorporate multiple protective

requirements.

Commenter Name: Edward Steadman Letter ID: 0220

Commenter Organization: The Energy and Environmental Research Center at the

University of North Dakota

Comment ID:

21574

Other EPA Comment Codes and Descriptions: 1480 1.2.2.2.2 CO2 is not a pollutant 

Comment: It is important to be mindful that CO2, relative to other common and not-socommon injectates, is relatively innocuous. Increasing concentrations are easily 

detected in groundwater through simple monitoring of pH. Carbon dioxide in 

groundwater poses minimal acute or chronic threat to human health or the 

environment, especially when compared to other materials that have been 

classified as hazardous. As long as potential injection sites are appropriately 

characterized and judiciously selected and injection operations are designed and 

conducted according to longstanding engineering and regulatory standards, the 

leakage of CO2 into underground sources of drinking water (USDW) is likely to be 

a preventable and infrequent occurrence. In the rare event that CO2 should leak 

into USDWs, it is also important to note that its primary effect on groundwater 

will be to form a weak acid (carbonic acid) and lower pH, which can be 

relatively easily mitigated by a variety of commonly used, simple remediation 

practices. 

Response: In response to the comment that CO2 is relatively innocuous and that the primary effect

of a leak to groundwater will be to form a weak acid and lower pH, EPA clarifies that the mission of

the UIC Program is to protect USDWs from injection activity that may endanger USDWs. Reduction

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in pH may also lead to mobilization of contaminants (e.g., arsenic, lead, and organic compounds),

which can degrade water quality. In addition, the migration of formation fluids containing mobilized

contaminants could cause endangerment of USDWs (Birkholzer et al., 2008a). 

EPA believes that the creation of a new injection well class (VI) under the existing UIC Program is

necessary to enable deployment of GS as a climate change mitigation technology in a manner that

protects USDWs from endangerment. EPA agrees that the UIC Program, under the authority of the

SDWA, provides a strong framework for regulating injection of CO2 for GS and adds that the GS

regulation tailors the UIC requirements to address the unique issues associated with large-scale GS

including large injection volumes, the relative buoyancy of CO2, its corrosivity in the presence of

water, the potential presence of impurities in captured CO2, and its mobility within subsurface

geologic formations.

EPA disagrees that the GS regulation overstates the risk of CO2 injection. EPA recognizes that

injecting large volumes of CO2 for GS poses unique challenges that, if not properly managed, could

endanger drinking water sources and have other adverse impacts. However, with proper site

selection, the final, tailored, Class VI requirements address the large volumes of CO2 injected, its

buoyancy, potential corrosivity in the presence of water, and potential impurities in the CO2 stream.

In addition, EPA expects the tailored permitting, siting, construction, operation, monitoring, and

post-injection site care requirements in the GS rule to prevent leakage from injection formations and

protect USDWs. 

EPA adds that the requirements of the GS rule are tailored to the nature of the CO2 itself and risks

associated with the injection of CO2, and do not address the status of CO2 as either a pollutant,

commodity, or waste.

Commenter Name: Pamela A. Lacey Letter ID: 0228

Commenter Organization: American Gas Association Comment ID: 21807

Comment: policymakers can be achieved. GAO Report at 3-5. A National Academy of Sciences 

("NAS") report emphasized that a large-scale CO2 UIC program cannot be 

successful "if a significant fraction of the public views it as dangerous or 

unacceptable" and, therefore, CO2 storage technologies must not only be safe and 

effective, they must be presented "to the public and the regulatory community in 

such a way as to instill confidence that they are in fact safe and effective." 

Id. at 49 (citing NAS, Prospective Evaluation). We offer the foregoing comments 

Response: EPA disagrees that the GS regulation overstates the risk of CO2 injection. EPA

recognizes that injecting large volumes of CO2 for GS poses unique challenges that, if not properly

managed, could endanger drinking water sources and have other adverse impacts. However, with

proper site selection, the final, tailored, Class VI requirements address the large volumes of CO2

injected, its buoyancy, potential corrosivity in the presence of water, and potential impurities in the

CO2 stream. In addition, EPA expects the tailored permitting, siting, construction, operation,

monitoring, and post-injection site care requirements in the GS rule to prevent leakage from injection

formations and protect USDWs.

EPA does not agree that the tailored requirements will create a negative public perception of GS.

The Agency believes that a demonstration to the public that GS projects are meeting the GS rule's

tailored requirements would likely improve confidence in the project and help address public

questions and concerns.

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Commenter Name: A. James Mayer Letter ID: 0230

Commenter Organization: A. J. Mayer International on behalf of the American

Energy Security Initiative

Comment ID:

21872

Other EPA Comment Codes and Descriptions: 1450 1.2.2.1 Oppose the GS rulemaking 

Comment: GENERAL COMMENTS AND CONCERNS ABOUT THE PROPOSED UIC RULE 

1. It is strongly recommended that the EPA promote and encourage, not block and 

erect barriers to, geosequestration of CO2 for both productive and nonproductive uses of CO2. 

EPA’s stated goals for this proposal are to protect Underground Sources of 

Drinking Water (USDWs) while promoting carbon capture and storage. The proposed 

regulations would succeed in protecting USDWs, but would fails to promote carbon 

capture and storage. The Proposed Rule overestimates the risks of CO2 geologic 

sequestration and creates barriers to rapid technology development and 

commercial scale deployment projects that will greatly benefit American (as 

noted in the preceding narrative). 

Response: EPA disagrees that the requirements in the GS rule overstate the risk associated with GS.

The requirements for Class VI wells are tailored to address the unique nature of full-scale CO2 GS,

including the volumes of CO2 being anticipated for long-term storage, the buoyant nature of the

injectate, its mobility within subsurface geologic formations, and its corrosivity in the presence of

water.

EPA believes that the creation of a new injection well class (VI) under the existing UIC Program is

necessary to enable deployment of GS as a climate change mitigation technology in a manner that

protects USDWs from endangerment. EPA agrees that the UIC Program, under the authority of the

SDWA, provides a strong framework for regulating injection of CO2 for GS and adds that the GS

regulation tailors the UIC requirements to address the unique issues associated with large-scale GS

including large injection volumes, the relative buoyancy of CO2, its corrosivity in the presence of

water, the potential presence of impurities in captured CO2, and its mobility within subsurface

geologic formations.

In response to comments that the GS rule could impede technology, EPA stresses that the purpose of

the GS rule is to ensure that, where GS is deployed, it is conducted in a manner that protects USDWs

from endangerment.

Commenter Name: A. James Mayer Letter ID: 0230

Commenter Organization: A. J. Mayer International on behalf of the American

Energy Security Initiative

Comment ID:

21883

Comment: 6. The Proposed Rule overestimates the risks of CO2 injection. 

The Proposal Rule implies that when the purpose of the injection switches from 

enhanced recovery to sequestration, the risks to USDWs are significantly 

magnified. With appropriate site selection, construction, monitoring, and 

testing, the risks of CO2 geologic sequestration would be comparable to the 

risks of current activities such as natural gas storage and enhanced recovery of 

oil. 

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EPA begins with the framework of Class I non-hazardous industrial waste 

injection well requirements and adds additional layers of redundant requirements 

to prevent or detect the escape of CO2 from the injection zone. EPA apparently 

believes that the Class II program is not sufficiently protective. 

Response: EPA disagrees that the GS regulation overstates or overestimates the risk of CO2

injection. EPA recognizes that injecting large volumes of CO2 for GS poses unique challenges that,

if not properly managed, could endanger drinking water sources and have other adverse impacts.

However, with proper site selection, the final, tailored, Class VI requirements address the large

volumes of CO2 injected, its buoyancy, potential corrosivity in the presence of water, and potential

impurities in the CO2 stream. In addition, EPA expects the tailored permitting, siting, construction,

operation, monitoring, and post-injection site care requirements in the GS rule to prevent leakage

from injection formations and protect USDWs.

EPA believes that injection for the primary purpose of long-term storage is sufficiently different

from Class II ER operations and warrants tailored requirements. For example, the volume of CO2

anticipated to be injected in Class VI wells is significantly greater than for Class II wells. Reservoir

pressure conditions will also be different, with Class VI injection operations involving large volumes

of CO2 and likely having higher pressures within their storage formations than Class II ER projects.

Commenter Name: Robert E. Carter Jr. Letter ID: 0236

Commenter Organization: Indiana Department of Natural Resources (IDNR) Comment ID: 23204

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: Section II-What Is EPA Proposing? 

Subsection I -Is Injected CO2 Considered a Hazardous Waste Under RCRA ? 

Comment: EPA has attempted to address this very important consideration by 

defining "carbon dioxide stream" in the proposed rule in such a way that those 

CO2 streams which exhibit hazardous characteristics would not be permitted under 

the proposed Class VI well classification but rather must be permitted and 

regulated as Class I wells instead. We are in agreement with those who believe 

that although captured C02 will contain some impurities, in those rare instances 

where concentrations could potentially be viewed as exhibiting RCRA hazardous 

characteristics, such impurities should be able to be removed by appropriate 

treatment methods prior to their storage in underground formations. While it is 

not possible to ignore the obligations and liabilities of waste generators under 

RCRA, any perception that CO2 streams could exhibit these characteristics and 

therefore require their management as hazardous wastes would have a very 

chilling effect on the widespread deployment of CCS and GS operations. We would 

prefer that instead of referring to CO2 streams as "waste", they should be 

viewed as an important resource to be managed accordingly. 

Response: The final GS rule retains the definition of a CO2 stream as proposed. The GS regulation

applies to injection of CO2 for the purpose of GS, regardless of the source of the CO2. It is beyond

the scope of the GS rule and the UIC Program’s authority to require or set standards for upstream

generators of CO2 or purification facilities.

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With respect to RCRA, EPA received many comments regarding the applicability of the RCRA

regulations and statute to CO2 streams that are geologically sequestered under the final Class VI

UIC well requirements. As a result, EPA has decided to initiate a separate proposed rulemaking

specifically to examine the issue of RCRA applicability 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 particular 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 commenters who wish to submit comments on the RCRA proposal will need to do

so during the comment period for that rule. Finally, EPA also notes that the final GS rule, which

adds new regulations for Class VI wells under the Safe Drinking Water Act (SDWA), is not making

any changes to the RCRA regulations.

Commenter Name: Angie Burckhalter Letter ID: 0239

Commenter Organization: Oklahoma Independent Petroleum Association Comment ID: 23214

Other EPA Comment Codes and Descriptions: 1630 1.3.3 RCRA/hazardous waste issues (seeking

comment) 

Comment: EPA has proposed to regulate CO2 as a waste and has proposed regulations that 

are as stringent as or more stringent than EPA’s requirements for Class I 

hazardous waste wells. We think treating CO2 as a waste is the wrong approach as 

it will unnecessarily open up unwarranted concerns, increased burdens and costs, 

and liability issues associated with the use of CO2 in EOR projects. In 

addition, it will prevent or discourage entities from proceeding with projects 

to store CO2 in underground formations or convert depleted Class II EOR wells to 

Class VI CO2 storage wells. We encourage EPA to not consider CO2 as a waste 

product. 

Response: First, EPA notes that the GS rule is not promulgated under either the RCRA or CERCLA

statutes, and the applicability of those statutes will not be determined under the SDWA or the terms

of the GS rule, but rather according to those statutes themselves and any implementing regulations

that may apply. Secondly, EPA disagrees that the Class VI requirements themselves, or EPA’s

consideration of the Class I requirements, necessarily have any implications for whether a particular

material is a RCRA “solid waste” or implicates CERCLA liability, as EPA understands the comment

to suggest. EPA received many comments regarding the applicability of the RCRA regulations and

statute to CO2 streams that are geologically sequestered under the final Class VI UIC well

requirements. As a result, EPA has decided to initiate a separate proposed rulemaking specifically to

examine the issue of RCRA applicability 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 particular 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 commenters

who wish to submit comments on the RCRA proposal will need to do so during the comment period

for that rule.

EPA adds that encouraging the use of GS is outside the scope of the GS rule. Rather, the purpose of

the GS regulation is to ensure that, where deployed, GS is conducted in a manner that protects

USDWs from endangerment.

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Commenter Name: Robert F. Voorhees Letter ID: 0243

Commenter Organization: Underground Injection Technology Group (UIT

Group)

Comment ID:

23340

Comment: sequestration projects. However, the UIT Group’s specific concern is that the 

proposed Class VI regulations are so excessive in some respects that they could 

effectively undermine public confidence in the UIC program for other classes of 

injection wells, including Class I injection wells. 

Response: EPA disagrees that the GS regulation overstates the risk of CO2 injection or that it is

excessive. EPA recognizes that injecting large volumes of CO2 for GS poses unique challenges that,

if not properly managed, could endanger drinking water sources and have other adverse impacts.

However, with proper site selection, the final, tailored, Class VI requirements address the large

volumes of CO2 injected, its buoyancy, potential corrosivity in the presence of water, and potential

impurities in the CO2 stream. In addition, EPA expects the tailored permitting, siting, construction,

operation, monitoring, and post-injection site care requirements in the GS rule to prevent leakage

from injection formations and protect USDWs.

EPA also disagrees that the tailored requirements will create a negative public perception of GS. The

Agency believes that a demonstration to the public that GS projects are meeting the GS rule's tailored

requirements would likely improve confidence in the project and help address public questions and

concerns.

Commenter Name: James T. Sims Letter ID: 0249

Commenter Organization: Western Business Roundtable Comment ID: 22260

Other EPA Comment Codes and Descriptions: 1480 1.2.2.2.2 CO2 is not a pollutant 

Comment: 2. Appropriately Characterize CO2 - We strongly urge EPA to be very careful in 

its characterization of CO2 under the UIC program. As has been previously 

noted, a successful climate change control program will necessarily be predicated 

on development of -- and public support for -- CCS. EPA could inadvertently, 

and inappropriately, stigmatize CCS, if it veers into an unwarranted 

categorization of CO2 as a pollutant or a hazardous waste. Such suggestions 

would imply a liability risk that would chill further development of both CCS and 

Enhanced Oil Recovery (EOR) operations. 

Response: EPA disagrees that the requirements in the GS rule overstate the risk associated with GS

or imply that CO2 is a waste. The requirements for Class VI wells are tailored to address the unique

nature of full-scale CO2 GS, including the injection volumes anticipated for long-term storage, the

buoyant nature of the injectate, its corrosivity in the presence of water, and its mobility within

subsurface geologic formations. 

In addition, although the requirements were based on the existing regulatory framework for deep

wells, including Class I wells, the GS rule does not address the status of CO2 as a pollutant or

commodity. While the Class I requirements formed the basis of many of the specific requirements

for GS wells, EPA clarifies that the GS rule is tailored to the unique nature of GS. EPA based many

of the GS requirements on the Class I regulations because, like Class VI wells, Class I wells are

typically deep and involve waste streams that, if not properly managed, can harm the well and lead

to contamination. 

Under §146.82(a)(7), owners or operators of GS wells must characterize their CO2 stream as part of

348
their permit application. If the injectate is determined to meet the definition of a hazardous waste

under RCRA, and as defined in 40 CFR Part 261, the stringent UIC Class I hazardous waste

requirements for injection of hazardous waste apply. Thus, injection of corrosive CO2 into Class VI

wells is prohibited. In addition, owners or operators must periodically monitor their injectate

throughout injection operations under §146.90(a). 

EPA adds that the requirements of the GS rule are tailored to the nature of the CO2 itself and risks

associated with the injection of CO2, and do not address the status of CO2 as either a pollutant,

commodity, or waste.

Commenter Name: James T. Sims Letter ID: 0249

Commenter Organization: Western Business Roundtable Comment ID: 22262

Comment: 4. Characterize Carefully Risks of the Geologic Sequestration of CO2 - It is, of 

course, crucial that the final rule meet EPA’s objective of protecting drinking 

water supplies. We are concerned, however, that some of the more stringent 

requirements being proposed for Class VI wells are not supported by findings of 

unique risks actually posed by CCS wells. EPA’s regulations should be based 

upon an accurate characterization of the potential risks posed by the geologic 

sequestration of CO2 and be specifically tailored accordingly to address those 

identified risks. This will ensure that EPA meets its obligation to provide 

appropriate protection of underground sources of drinking water, while avoiding 

unnecessary regulations that may hamper CCS or EOR projects from going forward 

or call into question the general safety of CO2 storage. 

Response: EPA disagrees that the GS regulation overstates the risk of CO2 injection or that the

requirements are not supported by findings associated with CO2’s unique risks. EPA recognizes that

injecting large volumes of CO2 for GS poses unique challenges that, if not properly managed, could

endanger drinking water sources and have other adverse impacts. However, with proper site

selection, the final, tailored, Class VI requirements address the large volumes of CO2 injected, its

buoyancy, potential corrosivity in the presence of water, and potential impurities in the CO2 stream.

In addition, EPA expects the tailored permitting, siting, construction, operation, monitoring, and

post-injection site care requirements in the GS rule to prevent leakage from injection formations and

protect USDWs.

EPA adds that the intent of the GS rule is not to promote CCS; rather, the purpose of the rule is to

ensure that, where deployed, GS is performed in a manner that protects USDWs from endangerment.

Commenter Name: Mike Nasi Letter ID: 0254

Commenter Organization: Clean Coal Technology Foundation of Texas Comment ID: 22360

Comment: We believe that most of our concerns with the proposed rule would be resolved if 

EPA would better recognize CO2 as a unique substance that does not pose 

toxicological risk and, in fact, is often managed as a commodity. As such, CO2 

should not be regulated under traditional principles applied by EPA to wastes 

and hazardous substances. It is likely that CO2 will ultimately be regulated in 

the United States to address global climate change issues, but that regulatory 

regime will not and should not create a legal or technical basis to regulate CO2 

storage in the same manner that EPA has historically regulated wastes and 

hazardous substances. We understand the need to build in regulatory safeguards 

349
to ensure that CO2 is not released into the atmosphere. We recommend, however, 

that EPA not lose sight of the fact that the toxicological basis for much of the 

regulatory regime governing the injection of wastes does not justify the same 

approach for CO2 which is being subjected to regulation due to climatological, 

not toxicological, concerns. 

Response: EPA disagrees that the GS regulation overstates the risk of CO2 injection. EPA

recognizes that injecting large volumes of CO2 for GS poses unique challenges that, if not properly

managed, could endanger drinking water sources and have other adverse impacts. However, with

proper site selection, the final, tailored, Class VI requirements address the large volumes of CO2

injected, its buoyancy, potential corrosivity in the presence of water, and potential impurities in the

CO2 stream. In addition, EPA expects the tailored permitting, siting, construction, operation,

monitoring, and post-injection site care requirements in the GS rule to prevent leakage from injection

formations and protect USDWs.

EPA adds that the requirements of the GS rule are tailored to the nature of the CO2 itself and risks

associated with the injection of CO2, and do not address the status of CO2 as either a pollutant or a

commodity.

Commenter Name: Ken Miller Letter ID: 0257

Commenter Organization: ExxonMobil Production Company Comment ID: 22369

Other EPA Comment Codes and Descriptions: 1200 1.1 General comments about the rulemaking 

Comment: ExxonMobil has participated extensively in the preparation of the comments 

submitted by the American Petroleum Institute (API) on this proposed rule and 

endorses their comments. We share the concerns raised by the API in their 

comments. Specific concerns are with use of the Class I UIC (Industrial/Hazardous 

Waste) program as the basis for the proposed rules, the proposed prohibition of 

injection above the lowermost underground source of drinking water, and the 

proposed 50 year post closure monitoring period. In each of these cases, the EPA 

has not fully leveraged on industry's successful experience with the Class II EOR 

program and instead, by building on the Class I program, is proposing 

requirements that are overly restrictive and could have a significant chilling 

effect on the commercial scale implementation of GS. It is our position Ihat 

ExxonMobil's and industry's experience with CO2 based EOR provides a sound basis 

from which to form an environmentally sound regulatory framework for GS. 

Response: EPA disagrees that the GS regulation is overly restrictive. EPA recognizes that injecting

large volumes of CO2 for GS poses unique challenges that, if not properly managed, could endanger

drinking water sources and have other adverse impacts. However, with proper site selection, the

final, tailored, Class VI requirements address the large volumes of CO2 injected, its buoyancy,

potential corrosivity in the presence of water, and potential impurities in the CO2 stream. In addition,

EPA expects the tailored permitting, siting, construction, operation, monitoring, and post-injection

site care requirements in the GS rule to prevent leakage from injection formations and protect

USDWs.

While EPA recognizes that industry has decades of experience injecting CO2 for ER, EPA believes

that injection for the primary purpose of long term storage is sufficiently different from Class II ER

operations and warrants tailored requirements. For example, the volume of CO2 anticipated to be

injected in Class VI wells is significantly greater than for Class II wells. Reservoir pressure

350
conditions will also be different, with Class VI injection operations involving large volumes of CO2

and likely having higher pressures within their storage formations than Class II ER projects.

EPA adds that the intent of the GS rule is not to promote CCS; rather, the purpose of the rule is to

ensure that, where deployed, GS performed in a manner that protects USDWs from endangerment.

Commenter Name: Claire Olson Letter ID: 0260

Commenter Organization: Basin Electric Power Cooperative Comment ID: 22386

Comment: III. General Comments 

EPA must be careful to avoid labeling sequestered CO2 as a waste, pollutant or 

contaminant. Regulations should require storage operators to properly 

characterize the CO2 they intend to store and protocols for storage should be 

based on that characterization. Broad sweeping characterizations of sequestered 

CO2 as hazardous waste, however, should be avoided due to the potential 

deterrent such characterizations will have on entities attempting to develop 

carbon capture and sequestration (CCS) projects. 

Response: EPA adds that the requirements of the GS rule are tailored to the nature of the CO2 itself

and risks associated with the injection of CO2, and do not address the status of CO2 as either a

pollutant, commodity, or waste. 

Finally, EPA notes that the intent of the GS rule is not to promote CCS; rather, the purpose of the

rule is to ensure that, where deployed, GS performed in a manner that protects USDWs from

endangerment.

Commenter Name: Karl R. Moor Letter ID: 0501

Commenter Organization: Southern Company Comment ID: 21158

Comment: Carbon dioxide has been injected for years in enhanced oil recovery, and that's 

been done largely without incident. 

And second, we believe that the regulation should be sufficiently flexible to 

take into consideration the site-specific characteristics and performance based 

measures. It should be sufficiently adaptable to incorporate lessons learned 

from ongoing pilot and demonstration projects like that at our Plant Daniel. 

To elaborate on these points I would say that EEI urges the agency to ensure 

that the regulations do not stigmatize storage, which, and the reason for that 

is we, it's a very fine line between appropriate regulatory guidance and sending 

this to the public that says that this technology is inherently dangerous, and 

that storage projects themselves are, make bad neighbors. As I've noted, EPA has 

stated these two goals themselves, that it simultaneously wants to protect 

drinking water and promote CCS. 

That in keeping, keeping these two goals from working against each other we 

believe that the emphasis should be placed in the regulations and all that 

follows, that CO2 is not a hazardous waste, a hazardous waste, and it's found in 

the ambient air. And as a result CO2, taking a regulatory approach to CO2, that 

351
in many ways is stricter than the underground injection of hazardous waste is, 

is in some small sense regulatory overkill. 

Many of the construction, mechanical integrity, monitoring, and financial 

responsibility provisions for Class VI Wells are more comprehensive in this 

proposal than they are for Class I Wells. The increased regulatory burden that 

this will place on the industry and upon those who want to undertake CCS 

projects would be substantial. 

Our industry knows firsthand, unfortunately, what, why it is so important that 

the public have an accurate perception of the risks and the rewards behind 

technologies, particular in their early stages of development. And in the 

preamble to this proposal EPA finds that the public should participate in the 

permitting process, in fact, have taken some innovative approaches to 

encouraging greater public participation. 

And we ask today that EPA help communicate to the public that it'd be very 

unlikely, and I would stress that, very unlikely that carbon geological storage 

would harm underground sources of water, or for that matter affect human health 

adversely. 

EPA can, I think, help do that by retooling the proposed regulations and to tie 

the requirements to the actual risks more closely. In addition, the EPA should 

remove the elements that serve only to fan the claims of public misperception, 

but having increased the protection of underground sources of ground water. 

Response: EPA disagrees that the GS regulation overstates the risk of CO2 injection. EPA

recognizes that injecting large volumes of CO2 for GS poses unique challenges that, if not properly

managed, could endanger drinking water sources and have other adverse impacts. However, with

proper site selection, the final, tailored, Class VI requirements address the large volumes of CO2

injected, its buoyancy, potential corrosivity in the presence of water, and potential impurities in the

CO2 stream. In addition, EPA expects the tailored permitting, siting, construction, operation,

monitoring, and post-injection site care requirements in the GS rule to prevent leakage from injection

formations and protect USDWs. 

While EPA recognizes that industry has decades of experience injecting CO2 for ER, EPA believes

that injection for the primary purpose of long term storage is sufficiently different from Class II ER

operations and warrants tailored requirements. For example, the volume of CO2 anticipated to be

injected in Class VI wells is significantly greater than for Class II wells. Reservoir pressure

conditions will also be different, with Class VI injection operations involving large volumes of CO2

and likely having higher pressures within their storage formations than Class II ER projects.

EPA has taken a regulatory approach that promotes USDW protection, incorporates flexibility or the

discretion of the permitting authority when appropriate, seeks to limit burden on owners or operators

and permitting agencies, and provides a foundation for national consistency in permitting of GS

projects. For example, under the final rule, many Class VI permit requirements must be established

through site-specific plans (e.g., AoR and corrective action plan, testing and monitoring plan, etc.)

developed by the owner or operator and approved by the Director. Consequently EPA expects that

owners or operators will consult with the Director as they develop, implement, and update these

plans. Additionally, the Director has the discretion to approve alternatives to the requirements in

352
some cases. For example, the Director may in certain situations modify the length of the postinjection site care period or approve an alternative post-injection site care timeframe as part of the

permitting process under §146.93, allow the use of alternate methods for mechanical integrity testing

(if approved by EPA) under §146.89, and waive the requirement that wells be designed to inject

below the lowermost USDW under §146.95.

EPA also disagrees that the tailored requirements will create a negative public perception of GS. The

Agency believes that a demonstration to the public that GS projects are meeting the GS rule's tailored

requirements would likely improve confidence in the project and help address public questions and

concerns.

Commenter Name: Olon Plunk Letter ID: 0536

Commenter Organization: Xcel Energy Comment ID: 21379

Comment: If we as a nation want CO2 sequestration to become a viable and near term option 

for dealing with carbon emissions, we cannot make obtaining approval for 

sequestration projects so difficult, time consuming or expensive that it 

recreates the very barrier that the lack of clear regulatory requirements 

presented in the first place. We cannot implement an effective regulatory 

program for sequestering CO2 if the rules are based on the erroneous premise 

that CO2 represents an extreme hazard. It is important in these rules that we 

send the right message to the public about the nature of the CO2 gas we are 

dealing with. 

It is likewise critical in these new rules that we strike the right balance 

between addressing realistic risks associated with storing CO2 versus creating a 

regime that effectively hinders rather than facilitates a key climate mitigation 

strategy. 

We know that more and larger sequestration demonstration projects should be 

funded and undertaken. We agree that careful monitoring of well integrity, plume 

migration and the like is necessary. On the other hand, we already have decades 

of experience in the underground injection of CO2 and other much more hazardous 

materials. Tens of millions of dollars have been spent doing measurements and 

monitoring studies at large sequestration projects like Weyburn and Sleipner and 

DOE is in the process of spending many millions more on projects sponsored by 

the various regional sequestration partnerships. 

Other countries are doing their own sequestration demonstrations and related 

research. The real goal is to strike a reasonable balance between how much is 

required and would have to be spent in the way of well and ground water 

monitoring, plume tracking and all the rest versus the level of risk presented 

by a given project. Considering what we have already learned about the 

characteristics of CO2 geologic storage and the effecticy of various monitoring 

and management practices. 

Response: EPA disagrees that the GS regulation overstates the risk of CO2 injection. EPA

recognizes that injecting large volumes of CO2 for GS poses unique challenges that, if not properly

managed, could endanger drinking water sources and have other adverse impacts. However, with

proper site selection, the final, tailored, Class VI requirements address the large volumes of CO2

353
injected, its buoyancy, potential corrosivity in the presence of water, and potential impurities in the

CO2 stream. In addition, EPA expects the tailored permitting, siting, construction, operation,

monitoring, and post-injection site care requirements in the GS rule to prevent leakage from injection

formations and protect USDWs.

EPA also disagrees that the tailored requirements will create a negative public perception of GS. The

Agency believes that a demonstration to the public that GS projects are meeting the GS rule's tailored

requirements would likely improve confidence in the project and help address public questions and

concerns.

EPA adds that the intent of the GS rule is not to promote CCS; rather, the purpose of the rule is to

ensure that, where deployed, GS performed in a manner that protects USDWs from endangerment.

354