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November 24, 2008

Submitted via online comment system at:

www.regulations.gov

RE: Comments of Greenpeace USA on: EPA-HQ-OW-2008-0390-0001

To Whom It May Concern:

On behalf of Greenpeace USA, we are writing in response to the request for comments on the

Underground Injection Control (UIC) Program: Federal Requirements for Class VI Injection

Wells for the Geologic Sequestration of Carbon Dioxide - Proposed Rule.

Greenpeace is an independent campaigning organization that uses peaceful direct action and

creative communication to expose global environmental problems and to promote solutions that

are essential to a green and peaceful future.

Action is needed to reduce greenhouse gas emissions

In 2007, the UN Intergovernmental Panel on Climate Change said warming of the climate

system is unequivocal and directly linked to human activity, primarily the burning of fossil fuels.

Global warming threatens America and the world with more frequent and more severe storms,

new outbreaks of diseases and crop pests, and massive coastal flooding. Scientists have

documented that Arctic sea ice is melting rapidly and the Western United States already may be

in permanent drought. The climate crisis requires urgent action. To avoid the worst effects,

global greenhouse gas emissions must peak by 2015 and then start falling by at least 50% by

2050, compared to 1990 levels. Developed countries must reduce their greenhouse gas

emissions by at least 25 percent below 1990 levels by 2020, and at least 80 percent below 1990

levels by 2050.

1

Coal is the largest emitter of global warming pollution in our country. In fact, emissions from

coal-fired power plants are responsible for 40 percent of the global warming pollution in today’s

atmosphere.

2 Yet world governments are planning to build hundreds of coal power plants in the

next decade. If such plans go ahead it will be impossible for governments to reduce greenhouse

gas emissions enough to seriously tackle climate change.

Carbon Capture and Storage (CCS) as a False Solution

As carbon capture and storage is increasingly discussed as a possible mitigation option by

some governments, it is necessary to highlight some critical limitations and concerns

surrounding this technology. Serious problems are inherent with any CCS program. CCS is a

very cost intensive procedure, it increases the costs of power generation by 40 to 80%

compared with conventional power plants (depending on the location of the plant and the

storage site, and the transport and capture technology used). In addition to the extra costs of

operation, the US Department of Energy calculates that installing carbon capture systems will

almost double plant costs.

3 This will lead to electricity price hikes of anywhere between 21 and

91%.

4 Additionally, using CCS technology greatly reduces the efficiency of power plants, up to

30% more fossil fuel must be burned to achieve the same power output.

5 Finally, CCS produces
considerable additional long-term costs. Monitoring and verification over decades is necessary

to guarantee the retention of the stored carbon dioxide. To have any potential climate benefit,

buried CO2 must remain underground forever. However, safe, permanent storage cannot be

assured; the world has no experience with the deliberate long-term storage of anything, let

alone CO2. The longest running storage project, Sleipner in Norway, is only 12 years old.

While some geological reservoirs could have the specific combination of physical features and

chemical processes that trap injected CO2 and essentially hold it for all time, there is insufficient

data or practical experience to know whether there are enough.

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.

6

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 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.

7 The efficiency of 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”.

8 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.

9 The implications for

climate mitigation as well as the other environmental and public health risks make leakage a

serious concern.

For CCS to have a significant impact in reducing atmospheric concentrations of CO2 to reduce

climate change, a significant amount would have to be stored. The IEA estimates that for CCS

to deliver any meaningful climate mitigation effects by 2050, 6000 projects each injecting a

million tons of CO2 per year into the ground would be required.

10 At the moment, it is not clear

that it will be technically feasible to capture and bury this much carbon, i.e. whether there are

enough storage sites, or that they will be located close enough to power plants. National level

estimates are largely based on modeled average values and therefore remain a source of

considerable uncertainty.

11 The vast majority of these estimates quantify technical capacity

assuming that the whole of a reservoir is accessible to store CO2 in its pore volume. This can

easily lead to unrealistically high numbers as the fraction of pore volume that can be used for

CO2 storage is site-specific and depends on factors such as injection rate, relative permeability,

density and mobility of fluids and rock heterogeneity.

12 Transport of CO2 over distances greater

than 60 miles is likely to be prohibitively expensive.

13

It is important to note however that the

more CO2 that is stored, the greater the amount that would be released to the atmosphere if any

leakage rate is accepted. 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.

14

It must be reiterated that monitoring and verification of CO2 storage sites is a long-term task. It

does not end when the storage reservoir is capped. Post-operational monitoring over hundreds

of years is essential. Significant risks continue to exist and must be monitored both to prevent a

catastrophic short term release as well as long-term slow leakage. Even if it is feasible to bury

hundreds of thousands of gigatons of CO2, there is no way to guarantee that storage locations

will be appropriately designed and managed over the timescales required.

Greenpeace’s concerns and comments on requirements for any successful regulation

Given the serious potential risks of CCS and the consequences of improper CO2 storage there

are a number of critical areas that any regulation allowing CCS must address. Since the breadth

and enforceability of the SDWA is not sufficient to address all of these concerns we urge that

before any CCS is permitted a comprehensive regulatory structure is put in place.

Greenpeace would urge that at the moment it is too early to propose rules for a nascent industry

like CCS that is not fully understood. The ability to safely deploy carbon capture and

sequestration on a commercial-scale has not been proven and will not be fully understood until

pilot projects are completed and reviewed. The Environmental Protection Agency and

Department of Energy should await the completion of these studies in order to be able to make

an informed set of regulations with full understanding of the effects and consequences. Delaying

the creation of the regulatory process until it is fully understood will prevent companies from

investing in processes that could have severe undesirable consequences.

When it is the appropriate time to devise a regulatory structure for the creation and oversight of

the carbon storage and sequestration industry it is critical that the regulation is comprehensive

and complete. Given the myriad of risks associated with CCS, our concern would be that the

Safe Drinking Water Act is not of sufficient scope and enforceability to handle a regulatory field

as broad as CCS. While there are significant and dangerous connections between underground

carbon storage and drinking water, there are many other significant impacts outside of the

purview of that act. We cannot emphasize strongly enough the absolute need that any

regulation of CCS be comprehensive and inclusive of all areas of the capture, storage, and

monitoring. It is simply not possible for such a complex and potentially dangerous process to be

adequately regulated with piecemeal regulations.

A final essential consideration that must be taken into account is the vital issue of liability for

geologically sequestered CO2. Once the CO2 has been pumped into the ground there must be a

clear and definitive procedure for determining who is responsible for continued monitoring of the

safety of the site and who is liable for any damages caused by leaks or other failures. The

mechanism for detailing the legal and financial liability in such a circumstance absolutely must

be established before any CCS projects can be allowed to begin.

While Greenpeace deems it necessary that regulation that is more comprehensive is drafted

before allowing any CCS, there are still aspects of these proposed regulations where we have

comments.

Comments on this specific proposed regulation

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.

15 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.

16 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.

17

Given the risk of corrosion and leakage, we are strongly supportive of proposal’s language

regarding the use of anti-corrosive cements and only allowing anti-corrosive materials for wells.

This is an essential requirement to reduce the risks of leaks in the wells which will likely pass

through drinking water reservoir and pose the most severe risk to the water supply.

Another part of the proposal that we support is the language detailing the procedure for postclosure site care. It is key that after a carbon storage site is closed that it continues to be

monitored and we support the 50-year timeframe written in the proposal. Greenpeace however

could not be supportive of any length of time shorter than this or any potential allowance for

early termination of the post-closure site care.

Conclusion

Greenpeace would urge the United States not to divert resources from proven solutions to

climate change such as wind and solar power and energy efficiency to invest in risky technology

such as CCS. However, should such plans be approved it is critical that the regulatory structure

is in place to minimize the risk and assign proper financial and legal liability for any damages

resulting from the carbon storage. There are aspects of the proposed regulation that are

consistent with what Greenpeace believes must be done, however a more comprehensive

regulatory structure is what is truly needed before any carbon capture and sequestration project

can be allowed to start.

For additional information on concerns regarding Carbon Capture and Storage please see the

attached report “False Hope: Why Carbon Capture and Storage Won’t Save the Climate”.

Sincerely,

Emily Rochon

Climate and Energy Campaigner

Greenpeace International

Ottho Heldringstraat 5

1066 AZ Amsterdam

The Netherlands

Jonathan Wiggins

Global Warming Campaign

Greenpeace USA

702 H Street, NW

Washington, DC 20001
References

1

IPCC, 2007: Climate Change 2007: Fourth Assessment Report of the Intergovernmental Panel on Climate Change

[Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.)]. Cambridge

University Press, Cambridge, United Kingdom and New York, NY, USA, 996 pp.

2 U.S. Environmental Protection Agency, "Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2005," April

2007. Based on calculation of CO2 emissions from tables 3-1 and 3-3.

3 National Energy Technology Laboratory (NETL), 2007, Cost and Performance Baseline for Fossil Energy Plants,

NETL, August 2007, < http://www.netl.doe.gov/energy-analyses/pubs/Bituminous Baseline_Final Report.pdf>

4 Rubin, E et al., 2005. Technical Summary in IPCC Special Report on Carbon Dioxide Capture and Storage, B. Metz

et al., Editors. 2005, Cambridge University Press: Cambridge, U.K.

5 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.

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.

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.

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.

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

<http://web.mit.edu/coal/The_Future_of_Coal.pdf>.

10

International Energy Agency (IEA) Greenhouse Gas R&D Programme, 2007. CO2 capture ready plants, 2007/4,

May 2007.

11 Gough, C & Shackley, S, 2006. Towards a Multi-Criteria Methodology for Assessment of Geological Carbon

Storage Options, Climactic Change 74, 2006, pp. 141-174.

12

Ibid

13 CSIRO submission to the Australian Parliamentary House of Representatives Inquiry in Geosequestration

Technology, August 2006.

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.

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.

16 Pruess K., Xu T., Apps J., Garcia J. (2003): Numerical modeling of aquifer disposal of CO2. SPE Journal, 49-60

17 Knauss K., Johnson J., Steefel C. (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
This document is not available in Regulations.gov since it 

contains copyrighted material that may not be reproduced 

without consent of the copyright holder. 

Contact the EPA Docket Center, Public Reading Room to view 

or receive a copy of this document. Requests for copies may be 

made as follows: 

In person/writing: 

Environmental Protection Agency, Docket Center 

1301 Constitution Ave NW, 2822T, Room 3334 

Washington, DC. 20004 

Telephone: 

202-566-1744 

Fax: 

202-566- 9744 

Email: 

docket-customerservice@epa.gov
Letter ID: 0129 

Commenter: Emily Rochon 

Organization: Greenpeace International 

Letter ID: 0129 Comment ID: 23060 Letter Lines: 31 to 57 

Comment Code: 1280 1.1.2.1 General comments on climate change/ global warming 

Comment: Action is needed to reduce greenhouse gas emissions 

In 2007, the UN Intergovernmental Panel on Climate Change said warming of the 

climate system is unequivocal and directly linked to human activity, primarily 

the burning of fossil fuels. Global warming threatens America and the world with 

more frequent and more severe storms, new outbreaks of diseases and crop pests, 

and massive coastal flooding. Scientists have documented that Arctic sea ice is 

melting rapidly and the Western United States already may be in permanent 

drought. The climate crisis requires urgent action. To avoid the worst effects, 

global greenhouse gas emissions must peak by 2015 and then start falling by at 

least 50% by 2050, compared to 1990 levels. Developed countries must reduce 

their greenhouse gas emissions by at least 25 percent below 1990 levels by 2020, 

and at least 80 percent below 1990 levels by 2050.[FN1 1 IPCC, 2007: Climate 

Change 2007: Fourth Assessment Report of the Intergovernmental Panel on Climate 

Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. 

Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United 

Kingdom and New York, NY, USA, 996 pp.] 

Coal is the largest emitter of global warming pollution in our country. In fact, 

emissions from coal-fired power plants are responsible for 40 percent of the 

global warming pollution in today’s atmosphere.[FN2 2 U.S. Environmental 

Protection Agency, "Inventory of U.S. Greenhouse Gas Emissions and Sinks: 

1990-2005," April 2007. Based on calculation of CO2 emissions from tables 3-1 

and 3-3.] Yet world governments are planning to build hundreds of coal power 

plants in the next decade. If such plans go ahead it will be impossible for 

governments to reduce greenhouse gas emissions enough to seriously tackle 

climate change. 

Individual Response: EPA clarifies that mitigating climate change and regulating the use of 

coal are outside the scope of the Class VI GS rulemaking. The purpose of the Class VI GS rule is 

to ensure consistency in permitting underground injection of CO2 at GS operations across the 

United States and provide requirements to prevent endangerment of USDWs in anticipation of 

the eventual use of GS to reduce CO2 emissions The requirements apply to owners or operators 

of wells that will be used to inject CO2 into the subsurface for the purpose of long-term storage. 

Letter ID: 0129 Comment ID: 23061 Letter Lines: 59 to 89 

1
Comment Code: 1340 1.1.3.2 Oppose use of GS in general 

Comment: Carbon Capture and Storage (CCS) as a False Solution 

As carbon capture and storage is increasingly discussed as a possible mitigation 

option by some governments, it is necessary to highlight some critical 

limitations and concerns surrounding this technology. Serious problems are 

inherent with any CCS program. CCS is a very cost intensive procedure, it 

increases the costs of power generation by 40 to 80% compared with conventional 

power plants (depending on the location of the plant and the storage site, and 

the transport and capture technology used). In addition to the extra costs of 

operation, the US Department of Energy calculates that installing carbon capture 

systems will almost double plant costs.[FN3 3 National Energy Technology 

Laboratory (NETL), 2007, Cost and Performance Baseline for Fossil Energy Plants, 

NETL, August 2007, < http://www.netl.doe.gov/energy-analyses/pubs/Bituminous 

Baseline_Final Report.pdf>] This will lead to electricity price hikes of 

anywhere between 21 and 91%.[FN4 4 Rubin, E et al., 2005. Technical Summary in 

IPCC Special Report on Carbon Dioxide Capture and Storage, B. Metz et al., 

Editors. 2005, Cambridge University Press: Cambridge, U.K.] Additionally, using 

CCS technology greatly reduces the efficiency of power plants, up to 30% more 

fossil fuel must be burned to achieve the same power output.[FN5 5 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.] Finally, CCS produces considerable additional long-term costs. 

Monitoring and verification over decades is necessary to guarantee the retention 

of the stored carbon dioxide. To have any potential climate benefit, buried CO2 

must remain underground forever. However, safe, permanent storage cannot be 

assured; the world has no experience with the deliberate long-term storage of 

anything, let alone CO2. The longest running storage project, Sleipner in 

Norway, is only 12 years old. While some geological reservoirs could have the 

specific combination of physical features and chemical processes that trap 

injected CO2 and essentially hold it for all time, there is insufficient data or 

practical experience to know whether there are enough. 

Individual Response: EPA does not believe that GS is dangerous. 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 liquids for decades. The GS regulation enhances this existing 

framework with requirements for GS wells that are tailored to the unique nature of large scale 

GS of CO2. These additional protective requirements include more extensive geologic testing, 

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 acknowledges that, because all GS in the U.S. is associated with pilot projects, there are 

unknowns regarding how GS projects will unfold and the practicalities of permitting, operating, 

monitoring, and closing a GS project. As a result, EPA is using an adaptive approach to 

2
regulating GS. EPA plans, every six years, to collect and review data on GS projects to 

determine whether the appropriate amount and types of information and appropriate 

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

appropriate or necessary. 

EPA clarifies that CCS operations and regulation of energy costs are not within the UIC 

Program’s authority. For additional information on EPA’s final regulatory approach, please see 

the final rule and preamble as well as the rulemaking docket. 

Letter ID: 0129 Comment ID: 23062 Letter Lines: 91 to 101 

Comment Code: 1655 1.3.5.1 Concerns about Lake Nyos and Mammoth Mountain-type events 

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.] 

Individual 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. 

3
Letter ID: 0129 Comment ID: 23063 Letter Lines: 102 to 107 

Comment Code: 1612 1.3.1.1 Leaching and mobilization of contaminants; reactions in injection 

zone 

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 

Individual 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 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. 

Letter ID: 0129 Comment ID: 23064 Letter Lines: 108 to 114 

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

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 

4
injection: Implications for the storage of greenhouse gases in sedimentary 

basins’, Geology, vol., 34, no. 7, 2006, pp. 577-580.] The efficiency of 

Individual 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. 

Letter ID: 0129 Comment ID: 23065 Letter Lines: 115 to 129 

Comment Code: 1600 1.3 Risk Associated with CO2 GS 

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. 

Individual 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 

5
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 evidenced by leakage to the surface, would be a permit violation if a 

USDW is endangered. 

Letter ID: 0129 Comment ID: 23066 Letter Lines: 131 to 153 

Comment Code: 1370 1.1.3.5 US storage capacity 

Comment: For CCS to have a significant impact in reducing atmospheric concentrations of 

CO2 to reduce climate change, a significant amount would have to be stored. The 

IEA estimates that for CCS to deliver any meaningful climate mitigation effects 

by 2050, 6000 projects each injecting a million tons of CO2 per year into the 

ground would be required.[FN10 10 International Energy Agency (IEA) Greenhouse 

Gas R&D Programme, 2007. CO2 capture ready plants, 2007/4, May 2007.] At the 

moment, it is not clear that it will be technically feasible to capture and bury 

this much carbon, i.e. whether there are enough storage sites, or that they will 

be located close enough to power plants. National level estimates are largely 

based on modeled average values and therefore remain a source of considerable 

uncertainty.[FN11 11 Gough, C & Shackley, S, 2006. Towards a Multi-Criteria 

Methodology for Assessment of Geological Carbon Storage Options, Climactic 

Change 74, 2006, pp. 141-174.] The vast majority of these estimates quantify 

technical capacity assuming that the whole of a reservoir is accessible to store 

CO2 in its pore volume. This can easily lead to unrealistically high numbers as 

the fraction of pore volume that can be used for CO2 storage is site-specific 

and depends on factors such as injection rate, relative permeability, density 

and mobility of fluids and rock heterogeneity. [FN12 12 Ibid ] Transport of CO2 

over distances greater than 60 miles is likely to be prohibitively 

expensive.[FN13 13 CSIRO submission to the Australian Parliamentary House of 

Representatives Inquiry in Geosequestration Technology, August 2006.] It is 

important to note however that the more CO2 that is stored, the greater the 

amount that would be released to the atmosphere if any leakage rate is accepted. 

Individual Response: The UIC program’s authority under the SDWA focuses on ensuring that 

underground injection control activities, such as GS projects, are permitted, sited, constructed, 

operated, monitored, and closed in a manner that is protective of USDWs. Ensuring storage 

capacity is outside the scope of the Class VI GS rulemaking. 

EPA clarifies that other federal agencies (e.g., DOE and the U.S. Geological Survey) have 

6
conducted research on available storage capacity and made determinations of the feasibility of 

capturing and storing CO2 at the scales needed to address climate change. These agencies, along 

with private entities, have identified large areas for potential sequestration in capacity studies. 

For example, in 2008, USGS initiated development of a methodology for estimating the capacity 

to store CO2 in geologic formations of the United States. In 2009, USGS published a proposed, 

risk-based methodology for GS capacity estimation. This report, Development of a Probabilistic 

Assessment Methodology for Evaluation of Carbon Dioxide Storage, is available at 

http://pubs.usgs.gov/of/2009/1035/ofr2009-1035.pdf and is available in the rulemaking docket. 

Letter ID: 0129 Comment ID: 23067 Letter Lines: 154 to 161 

Comment Code: 1600 1.3 Risk Associated with CO2 GS 

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.] 

Individual 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). 

7
Letter ID: 0129 Comment ID: 23068 Letter Lines: 163 to 170 

Comment Code: 5000 2.8 Proposed Well Plugging and Post-Injection Site Care Requirements 

Comment Code: 5400 2.9 Proposed Financial Responsibility and Long-Term Care 

Requirements 

Comment: It must be reiterated that monitoring and verification of CO2 storage sites is a 

long-term task. It does not end when the storage reservoir is capped. Postoperational monitoring over hundreds of years is essential. Significant risks 

continue to exist and must be monitored both to prevent a catastrophic short 

term release as well as long-term slow leakage. Even if it is feasible to bury 

hundreds of thousands of gigatons of CO2, there is no way to guarantee that 

storage locations will be appropriately designed and managed over the timescales 

required. 

Individual Response: EPA agrees that post-injection monitoring should continue for an 

extended time, but disagrees that hundreds of years of monitoring would be needed. EPA 

believes that a 50 year post-injection site care timeframe represents a reasonable and protective 

monitoring period. EPA bases this on a review of research studies, industry reports, existing 

environmental programs, and evaluation of public comments. Furthermore, EPA believes that a 

50-year default post-injection site care timeframe is not overly burdensome, does not exaggerate 

the risks associated with GS, is consistent with other environmental programs, and sufficiently 

protects USDWs from endangerment. For this reason, the final GS regulation retains the 50 year 

post-injection site care timeframe, as specified in §146.93(b)(1). 

The GS rule provides the Director with discretion to extend the timeframe (e.g., if, after 50 years, 

monitoring data indicates that the CO2 plume may endanger a USDW), or shorten the timeframe 

(if the owner or operator can demonstrate that the GS project does not pose an endangerment to 

USDWs), under 146.93(b)(2). Such a demonstration will be site-specific, and based on pressure 

monitoring and USDW impacts. EPA clarifies that in no cases will site closure be authorized 

until the owner or operator demonstrates to the satisfaction of the Director that the site no longer 

poses a risk of endangerment to USDWs. 

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. 

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, his or her 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 

8
site closure. 

Additionally, an owner or operator may always be subject to any action, such as administrative 

orders or civil actions, 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. Please see further clarification on the issue of long term liability in 

the preamble of the final rule. 

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, the 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: 0129 Comment ID: 23069 Letter Lines: 172 to 202 

Comment Code: 1500 1.2.2.2.4 Some other agency should regulate GS 

Comment Code: 1510 1.2.2.3 Need for additional study 

Comment: Greenpeace’s concerns and comments on requirements for any successful regulation 

Given the serious potential risks of CCS and the consequences of improper CO2 

storage there are a number of critical areas that any regulation allowing CCS 

must address. Since the breadth and enforceability of the SDWA is not sufficient 

to address all of these concerns we urge that before any CCS is permitted a 

comprehensive regulatory structure is put in place. 

Greenpeace would urge that at the moment it is too early to propose rules for a 

nascent industry like CCS that is not fully understood. The ability to safely 

deploy carbon capture and sequestration on a commercial-scale has not been 

proven and will not be fully understood until pilot projects are completed and 

reviewed. The Environmental Protection Agency and Department of Energy should 

await the completion of these studies in order to be able to make an informed 

set of regulations with full understanding of the effects and consequences. 

Delaying the creation of the regulatory process until it is fully understood 

will prevent companies from investing in processes that could have severe 

undesirable consequences. 

9
When it is the appropriate time to devise a regulatory structure for the 

creation and oversight of the carbon storage and sequestration industry it is 

critical that the regulation is comprehensive and complete. Given the myriad of 

risks associated with CCS, our concern would be that the Safe Drinking Water Act 

is not of sufficient scope and enforceability to handle a regulatory field as 

broad as CCS. While there are significant and dangerous connections between 

underground carbon storage and drinking water, there are many other significant 

impacts outside of the purview of that act. We cannot emphasize strongly enough 

the absolute need that any regulation of CCS be comprehensive and inclusive of 

all areas of the capture, storage, and monitoring. It is simply not possible for 

such a complex and potentially dangerous process to be adequately regulated with 

piecemeal regulations. 

Individual Response: EPA believes that sufficient data and experience currently exist to 

develop regulations for GS wells. The GS rulemaking builds upon decades of knowledge about 

safe injection practices regulated by the UIC Program. 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 is monitoring 

international GS efforts currently operating on a commercial scale. These include 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). These projects are designed to operate for decades and plan to cumulatively inject 

over 200 MT of CO2. A paper summarizing EPA's research on international GS projects and 

legislation is in the rulemaking docket. 

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 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 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 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 

10
(e.g., with the Department of Energy; United States Geological Survey; Bureau of Ocean Energy 

Management, Regulation, and Enforcement, formerly the Minerals Management Service; 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. 

Letter ID: 0129 Comment ID: 23070 Letter Lines: 204 to 210 

Comment Code: 5400 2.9 Proposed Financial Responsibility and Long-Term Care 

Requirements 

Comment: A final essential consideration that must be taken into account is the vital 

issue of liability for geologically sequestered CO2. Once the CO2 has been 

pumped into the ground there must be a clear and definitive procedure for 

determining who is responsible for continued monitoring of the safety of the 

site and who is liable for any damages caused by leaks or other failures. The 

mechanism for detailing the legal and financial liability in such a circumstance 

absolutely must be established before any CCS projects can be allowed to begin. 

Individual Response: EPA agrees that assuring financial responsibility for post-injection site 

care and site closure is an important component of ensuring that USDWs are protected; the GS 

rule, at §146.85 requires owners or operators to maintain financial responsibility throughout the 

post-injection site care timeframe. 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. EPA adds that owners or operators must perform extensive post-injection 

site monitoring until it can be demonstrated that the GS site no longer poses a risk of 

endangerment to USDWs, as required at §146.93. For additional information, please see the 

discussion of post-injection site care in the final rule and preamble. 

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 

11
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. 

Letter ID: 0129 Comment ID: 23071 Letter Lines: 218 to 236 

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

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. 

(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] 

Individual 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. 

Letter ID: 0129 Comment ID: 23072 Letter Lines: 238 to 242 

12
Comment Code: 3862 2.3.3.1 Use of corrosion-resistant construction materials (seeking 

comment) 

Comment Code: 3864 2.3.3.2 Use of corrosion-resistant cements (seeking comment) 

Comment: Given the risk of corrosion and leakage, we are strongly supportive of 

proposal’s language regarding the use of anti- corrosive cements and only 

allowing anti-corrosive materials for wells. This is an essential requirement to 

reduce the risks of leaks in the wells which will likely pass through drinking 

water reservoir and pose the most severe risk to the water supply. Another part 

Individual Response: EPA agrees that cement that is compatible with the CO2 and formation 

fluids will enhance Class VI well integrity. In the interest of USDW protection, the Agency 

requires that the materials used in Class VI wells must be compatible with fluids with which they 

may come in contact, as specified in §146.86(b)(1). 

EPA adds that the requirements at §146.86(b)(1) state that the materials must meet or exceed 

standards developed for such materials by the American Petroleum Institute, ASTM 

International, or comparable standards acceptable to the Director. This requirement invokes the 

expertise of these bodies and allows the use of technologies that are yet to be developed. 

See the discussion of Class VI well construction requirements in the preamble to the final GS 

rule for additional information. Additionally, EPA is developing guidance on the construction of 

Class VI wells. This guidance will be available on EPA’s website at 

http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm. 

Letter ID: 0129 Comment ID: 23073 Letter Lines: 242 to 248 

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

Comment: water reservoir and pose the most severe risk to the water supply. Another part 

of the proposal that we support is the language detailing the procedure for 

post-closure site care. It is key that after a carbon storage site is closed 

that it continues to be monitored and we support the 50-year timeframe written 

in the proposal. Greenpeace however could not be supportive of any length of 

time shorter than this or any potential allowance for early termination of the 

ost-closure site care. 

Individual Response: EPA agrees with commenters that a 50 year post-injection site care 

timeframe represents a reasonable and protective post-injection site monitoring period in most 

cases and available data, including data submitted by commenters, do not support a different 

default timeframe. EPA bases this on a review of research studies, industry reports, and existing 

environmental programs, and evaluation of public comments. Furthermore, EPA believes that a 

50-year default post-injection site care timeframe is not overly burdensome, does not exaggerate 

the risks associated with GS, is consistent with other environmental programs, and sufficiently 

protects USDWs from endangerment. For this reason, the final GS regulation retains the 50 year 

post-injection site care timeframe, as specified in §146.93(b)(1). 

13
However, EPA disagrees that a 50 year post-injection site care timeframe should be an absolute 

minimum. Rather, EPA believes, as some commenters suggest, that there will be circumstances 

where it can be demonstrated in less than 50 years that the plume and pressure front no longer 

pose a risk of endangerment to USDWs. For this reason, the GS rule offers owners or operators 

flexibility regarding the duration of the PISC timeframe by: (1) allowing the Director discretion 

to shorten or lengthen the PISC timeframe during the post-injection period based on site-specific 

data, pursuant to requirements at §146.93(b); or (2) affording the Director discretion to allow a 

Class VI well owner or operator to demonstrate, during the permitting process based on 

substantial data, that an alternative PISC timeframe may be appropriate if it ensures nonendangerment of USDWs pursuant to requirements at §146.93(c). 

EPA believes that a default post-injection site care timeframe of 50 years, with flexibility to 

adjust the timeframe for a limited number of GS projects during the permitting process where 

substantial data exists to demonstrate that an alternative timeframe would be protective of 

USDWs, or based on data collected during the PISC period, is appropriate to address the range of 

sites where GS is anticipated to occur, to accommodate site-specific circumstances and various 

geologic conditions, and addresses commenters’ concerns, while ensuring USDW protection. 

Both approaches will utilize site-specific data, and be based on pressure monitoring and USDW 

impacts as the commenter suggests. 

Letter ID: 0129 Comment ID: 23074 Letter Lines: 252 to 254 

Comment Code: 1280 1.1.2.1 General comments on climate change/ global warming 

Comment: Greenpeace would urge the United States not to divert resources from proven 

solutions to climate change such as wind and solar power and energy efficiency 

to invest in risky technology such as CCS. However, should such plans be 

Individual Response: EPA clarifies that other climate change mitigation technologies such as 

wind and solar power and energy efficiency, are not within the UIC program’s authority and 

outside the scope of this rulemaking. EPA emphasizes that the UIC program’s authority under 

the SDWA is focused on ensuring that Class VI CO2 injection projects are permitted, sited, 

constructed, operated, monitored, and closed in a manner that protects USDWs from 

endangerment. 

Letter ID: 0129 Comment ID: 23075 Letter Lines: 254 to 257 

Comment Code: 5400 2.9 Proposed Financial Responsibility and Long-Term Care 

Requirements 

Comment: to invest in risky technology such as CCS. However, should such plans be 

approved it is critical that the regulatory structure is in place to minimize 

the risk and assign proper financial and legal liability for any damages 

14
resulting from the carbon storage. There are aspects of the proposed regulation 

Individual Response: EPA agrees that assuring financial responsibility for corrective action on 

wells in the AoR, injection well plugging, PISC and site closure, and emergency and remedial 

response at GS sites is an important component of ensuring that USDWs are protected. 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. 

EPA has specified acceptable financial responsibility instruments in the final regulation at 

§146.85. Additionally, EPA is developing guidance (available on EPA's website at 

http://water.epa.gov/type/groundwater/uic/wells_sequestration.cfm) that describes the types of 

financial instruments that owners or operators may use to meet financial responsibility 

requirements for GS wells. EPA plans to take the concerns expressed by commenters on the 

proposed regulation, including the acceptability of various financial instruments and the 

timeframe for PISC, into consideration as it develops the financial responsibility guidance. 

Letter ID: 0129 Comment ID: 23076 Letter Lines: 258 to 260 

Comment Code: 1260 1.1.1.5 More certainty/stringency is needed 

Comment Code: 1500 1.2.2.2.4 Some other agency should regulate GS 

Comment Code: 1510 1.2.2.3 Need for additional study 

Comment: that are consistent with what Greenpeace believes must be done, however a more 

comprehensive regulatory structure is what is truly needed before any carbon 

capture and sequestration project can be allowed to start. 

Individual Response: As described above, EPA 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. 

Further, as described above, 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. 

15