This comment letter response contains two parts:   

(1) The original submittal from the commenter.

(2) A data base printout of EPA’s response to each point raised by the commenter.

Notes about the response letters:

• The response letters were generated by a data base used to track the content of all public

comment submittals and ensure that the Agency responds to each. Each comment letter

was assigned a Letter ID that corresponds to the last four digits of the docket number of the

original comment (as posted on www.regulations.gov).

• Each response letter includes: comment text; an EPA‐assigned comment code; and an

individual response. These are described and explained below.  

• The data base contains Comment text from the letters submitted by commenters.  

Many hard copy letters were scanned into electronic format for inclusion in the data

base. As a result, there may be some typographical errors attributable to optical

character recognition issues.  However, all original submittals were reviewed in the

process of drafting responses to ensure that the comment content was understood and

appropriately addressed.

• The content of each comment letter was divided into topic areas and assigned a unique

Comment ID.  Additionally, one or more Comment Codes (i.e., unique topic area ID) was

assigned to each discrete point raised by a commenter. This information was added to

the data base. To inform final rulemaking decisions, all comments and information

received on a given topic were reviewed by technical experts in each rule area (e.g., on

construction requirements).  

• Following decisions on the final rule requirements, Individual responses were drafted

by topic area to ensure completeness and consistency of the responses with the final

rule and other responses to similar comments.  Each discrete point made by a

commenter was given a unique response.

• Upon completion of comment responses, all information was entered into the data base.

Each letter response is a compilation of each comment and its individual response,

compiled in the order of the original comment letter.  As a result of this process, there is

repetition in the response text.  The Agency believes this approach ensures completeness

and attention to each comment letter that was submitted.   

• All comments in a topic area were reviewed, evaluated, and responded to concurrently.  

Responses on each topic area are compiled and are also available in the rulemaking docket.
October 15, 2009

U. S. Environmental Protection Agency

Docket ID No. EPA-HQ-OW-2008-0390 

Office of Groundwater and Drinking Water (OGWDW)

Mail Code: 4101TT

1200 Pennsylvania Ave. NW

Washington, DC 20460

RE: Federal Requirements Under the Underground Injection Control (UIC) Program 

for Carbon Dioxide Geosequestration Wells, Notice of Data Availability 

Dear Water Docket:

The American Water Works Association (AWWA) and the Association of Metropolitan 

Water Agencies (AMWA) are submitting this joint letter to comment on the proposed 

Underground Injection Control (UIC) Program for carbon dioxide geosequestration 

wells. AMWA and AWWA together represent drinking water utilities of all sizes that 

serve more than 90% of the U.S. population. Climate change will have significant 

impacts on water resources and while we recognize the need for strategies to address 

mitigation of greenhouse gases (GHG), we also strongly believe that any strategy 

deployed for this purpose should protect our water resources above all else.

AWWA and AMWA are extremely concerned about the potential for the construction of 

underground injection wells that simultaneously produce oil and sequester carbon 

dioxide. Currently, oil production is regulated using the Class II requirements and 

geologic sequestration will be regulated using the new Class VI requirements. There 

are significant differences in the permitting and operation of these two classes, and 

companies may try to bypass some of the new Class VI requirements by designing and 

operating the system for several years as a Class II project before converting it to 

geologic sequestration. 

Geologic sequestration and oil production are two completely different industrial 

operations. An enhanced oil recovery (EOR) project should not be considered as a 

simultaneous carbon dioxide sequestration project as well simply because a portion of 

the carbon dioxide injected during the EOR process is not recovered. There is a 

significant amount of effort involved in meeting the Class VI well requirements for 

groundwater monitoring, area of review, construction methods and materials, and public 

notification. The Class VI requirements provide for strict protection of underground 

sources of drinking water (USDWs) and these protective measures are completely 

The Authoritative Resource on Safe WaterSM
negated if the oil/gas industry is allowed to use the less stringent Class II wells for 

carbon dioxide sequestration. As a result, the potential exists for a significant amount of 

USDW contamination since the Class VI protective measures would not be required for 

Class II wells that simultaneously produce oil and sequester carbon dioxide. 

AWWA and AMWA’s position is unequivocal: EPA must not develop regulations for 

wells that would simultaneously produce oil and sequester CO2. Geologic sequestration 

technology itself is still being heavily researched and we currently know little about the 

long term impacts of sequestering large amounts CO2. The research community needs 

to have a much better understanding of this technology before we expand the ability of 

the energy industry to implement commercial-scale operation of this type of nontraditional geologic sequestration technology. We need a measured approach to the 

implementation of geologic sequestration, not a hurried approach that does not address 

the potential for unintended consequences with unproven technology. 

It is imperative that theoretical and observational research continue and be very 

comprehensive. While the UIC program has a long history, the injection of CO2 into the 

ground is a process that is not well understood. Given its buoyancy characteristic, CO2

is much different than other historically injected substances and the behavior of the 

compound under severe pressures and temperatures is not well known. We strongly 

recommend that EPA continue to work with DOE to perform theoretical modeling and 

observational research to gain a better understanding of the carbon sequestration 

process and the effects of CO2 injection on saline aquifers and the subsurface geology. 

This information will be essential to determining where geologic sequestration should be 

permitted.

In summary, given that geologic sequestration technology is still in its infancy, we urge 

EPA to exercise caution and not permit injection wells that allow for the simultaneous

production of oil and sequestration of carbon dioxide at this time. EPA needs to ensure 

the protection of USDWs and future USDWs from harmful unintended consequences.

Sincerely,

Diane VanDe Hei Tom Curtis

Executive Director, AMWA Deputy Executive Director, AWWA

Cc: Peter Silva, OW

Cynthia Dougherty, OGWDW

 Steve Heare, OGWDW
Letter ID: 0365  

Commenter: Diane VanDe Hei  

Organization: Association of Metropolitan Water Agencies (AMWA)  

Letter ID: 0365 Comment ID: 28281 Letter Lines: 35 to 39  

Comment Code: 6000 6. Other Comments that are Out of Scope for the NODA  

Comment: utilities of all sizes that serve more than 90% of the U.S. population. Climate  

change will have significant impacts on water resources and while we recognize  

the need for strategies to address mitigation of greenhouse gases (GHG), we also  

strongly believe that any strategy deployed for this purpose should protect our  

water resources above all else.  

Individual Response: This comment pertains to EPA’s proposed GS rule (73 FR 43492) and is outside the

scope of the Notice of Data Availability. Please see responses to comments on the proposed rule for

EPA’s response to similar comments.  

Letter ID: 0365 Comment ID: 28282 Letter Lines: 41 to 91  

Comment Code: 5700 5.14. Comments on Other Aspects of the Proposed Rule  

Comment: AWWA and AMWA are extremely concerned about the potential for the construction  

of underground injection wells that simultaneously produce oil and sequester  

carbon dioxide. Currently, oil production is regulated using the Class II  

requirements and geologic sequestration will be regulated using the new Class VI  

requirements. There are significant differences in the permitting and operation  

of these two classes, and companies may try to bypass some of the new Class VI  

requirements by designing and operating the system for several years as a Class  

II project before converting it to geologic sequestration.  

Geologic sequestration and oil production are two completely different  

industrial operations. An enhanced oil recovery (EOR) project should not be  

considered as a simultaneous carbon dioxide sequestration project as well simply  

because a portion of the carbon dioxide injected during the EOR process is not  

recovered. There is a significant amount of effort involved in meeting the  

Class VI well requirements for groundwater monitoring, area of review,  

construction methods and materials, and public notification. The Class VI  
requirements provide for strict protection of underground sources of drinking  

water (USDWs) and these protective measures are completely negated if the  

oil/gas industry is allowed to use the less stringent Class II wells for carbon  

dioxide sequestration. As a result, the potential exists for a significant  

amount of USDW contamination since the Class VI protective measures would not be  

required for Class II wells that simultaneously produce oil and sequester carbon  

dioxide.  

AWWA and AMWA's position is unequivocal: EPA must not develop regulations for  

wells that would simultaneously produce oil and sequester CO2. Geologic sequestration  

technology itself is still being heavily researched and we currently know little about the  

long term impacts of sequestering large amounts CO2. The research community needs  

to have a much better understanding of this technology before we expand the ability of  

the energy industry to implement commercial‐scale operation of this type of non‐  

traditional geologic sequestration technology. We need a measured approach to the  

implementation of geologic sequestration, not a hurried approach that does not address  

the potential for unintended consequences with unproven technology.  

It is imperative that theoretical and observational research continue and be  

very comprehensive. While the UIC program has a long history, the injection of  

CO2 into the ground is a process that is not well understood. Given its  

buoyancy characteristic, CO2 is much different than other historically injected  

substances and the behavior of the compound under severe pressures and  

temperatures is not well known. We strongly recommend that EPA continue to work  

with DOE to perform theoretical modeling and observational research to gain a  

better understanding of the carbon sequestration process and the effects of CO2  

injection on saline aquifers and the subsurface geology. This information will  

be essential to determining where geologic sequestration should be permitted.  

In summary, given that geologic sequestration technology is still in its  

infancy, we urge EPA to exercise caution and not permit injection wells that  

allow for the simultaneous production of oil and sequestration of carbon dioxide  

at this time. EPA needs to ensure the protection of USDWs and future USDWs from  

harmful unintended consequences.  

Individual Response: This comment pertains to EPA’s proposed GS rule (73 FR 43492) and is outside the

scope of the Notice of Data Availability. Please see responses to comments on the proposed rule for

EPA’s response to similar comments.