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 14, 2009 

Water Docket 

Environmental Protection Agency 

Mailcode: 4101T 

1200 Pennsylvania Ave., NW 

Washington DC 20460 

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

The North Dakota Industrial Commission, Oil and Gas Division (NDIC) offers the 

following comments on EPA’s Proposed Federal Requirements under the 

Underground Injection Control (UIC) Program for Carbon Dioxide (CO2) Geologic 

Sequestration (GS) wells; Notice of Data Availability (NODA). 

The NDIC is strongly supportive of the increased flexibility to UIC Program Directors in 

this proposal. This will promote a common sense approach which allows consideration 

of local and regional geologic conditions for more site-specific assessment and allows 

for injection into different formation types where appropriate based on regulatory 

flexibility. 

Injection of CO2 above the lowermost formation containing a USDW can be done safely 

where determined appropriate while protecting all USDWs. This is currently being done 

in enhanced oil recovery projects in the United States. In fact due to the buoyancy of 

CO2, there is less risk to USDWs below the injection zone. 

Injection of CO2 above the lowermost formation containing a USDW allows for injection 

into multiple stratified formations which allows for greater cumulative capacity. This 

may further reduce risk by maximizing the storage of each well and minimizing the 

number of wells penetrating confining zones or USDWs; these penetrations are one of 

the biggest risk factors. 

Accessing USDWs below a GS site is not technically challenging. Industry has 

developed the ability to safely drill through over-pressured reservoirs which may be 

analogous to GS sites. There are several formations in North Dakota which are overpressured and the industry routinely can safely drill through these by taking the 

appropriate precautions. 

The critical component to confining any injection stream is suitable top and bottom 

confining zones, regardless of the location of a USDW. NODA page 44809 states, 

“placing distance between the injection formation and USDWs decreases risks to 

USDWs”. Distance may help but is not the definitive factor. It will not compensate for 

poor site characteristics. Neither does lack of distance defeat a site that is properly 

designed and sited. The ability of the confining zones to sequester the injection stream 

must be taken into account, along with distance, in determining whether the site is 
suitable. Site selection must focus on the trapping and confinement characteristics 

without giving undue deference to distance. 

While the NDIC is supportive of allowing injection of CO2 above a USDW, the proposed 

waiver process is too onerous. EPA has not shown how injection above a USDW poses 

any additional risk which warrants the significant increase in permitting requirements. 

Injection below the lowermost USDW or above a USDW both require confinement of the 

injection stream and formation fluids from upward or downward migration, there is no 

difference. 

Since there is no real additional risk, the following areas highlighted in the NODA are 

unnecessary: supplement to Emergency Response Plan; additional financial 

responsibility; need to identify alternative injection sites; community needs, demands, 

and supply from drinking water resources; planned needs, potential and/or future use of 

USDWs and non-USDWs in area; planned or permitted water, hydrocarbon, or mineral 

resource exploitation potential of the proposed injection formation and other formations 

both above and below the injection zone to determine if there are any plans to drill 

through the formation to access resources in or beneath the proposed injection zone; 

proposed plan for securing alternative resources or treating USDW in the event of 

contamination related to Class VI injection activity; more stringent injection pressure 

limitations; and increased formation fluid and ground water sampling and monitoring 

above and below the injection zone in concert with local water suppliers. 

One item of particular concern is the planned needs, potential and/or future use of 

USDWs and non-USDWs in area. The inclusion of non-USDWs is broad and 

undefined. What non-USDWs are of concern and why? This information on these 

formations, if not the injection or confining zones, is of little value and provides no 

additional protection. Nothing about the location of the injection zone being located 

above a USDW makes this any more relevant than if the injection zone is below the 

lowermost USDW 

Another area of concern is the community needs, demands, and supply from drinking 

water resources, and the planned needs, potential and/or future use of USDWs and 

non-USDWs in area. This appears to require something similar to an aquifer exemption 

for the entire stratigraphic column. 

Also of concern is the planned or permitted water, hydrocarbon, or mineral resource 

exploitation potential of the proposed injection formation and other formations both 

above and below the injection zone to determine if there are any plans to drill through 

the formation to access resources in or beneath the proposed injection zone. The same 

exploitation of various formations can also take place if the injection is limited to below 

the lowermost USDW. This information is of little value and provides no additional 

protection. 

The inclusion of the Public Water Supply Supervision (PWSS) Program Director in the 

decision process adds an additional layer of bureaucracy, is duplicative, and is 
inefficient. Final decision authority must be with the agency granted primacy for 

regulation of CO2 sequestration. EPA must not dictate to states that have primacy 

which agencies must approve an application. The PWSS Program Director can have 

input and participate through the normal public participation process. 

In summary, the above listed additional requirements are not necessary because risk is 

actually less to USDWs below a GS project that is properly sited and constructed. The 

risk is the same to any USDWs above the GS project which most likely will be present 

whether injection takes place below the lowermost USDW or above it. 

Respectfully submitted, 

Mark Bohrer 

Petroleum Engineer/UIC Manager 

North Dakota Industrial Commission 

Oil and Gas Division 

600 E Blvd-Dept 405 

Bismarck ND 58505-0405 

mbohrer@nd.gov 

(701) 328-8020 
Letter ID: 0343  

Commenter: Mark Bohrer  

Organization: North Dakota Industrial Commission (NDIC)  

Letter ID: 0343 Comment ID: 27867 Letter Lines: 32 to 36  

Comment Code: 3210 3.2.1. Comments Generally in Support of the Approach  

Comment: The NDIC is strongly supportive of the increased flexibility to UIC Program  

Directors in this proposal. This will promote a common sense approach which  

allows consideration of local and regional geologic conditions for more site‐  

specific assessment and allows for injection into different formation types  

where appropriate based on regulatory flexibility.  

Individual Response: The final GS rule at §146.95 establishes a process by which owners and operators

can seek a waiver of the Class VI injection depth requirements. EPA agrees that a flexible, site‐specific

approach to waiver determinations (and all Class VI permitting decisions) is appropriate. Site‐specific

demonstrations of injection zone integrity along with proper well construction, operation, monitoring,

and post closure site care are the best way to ensure USDW safety while allowing flexibility for GS above

or between USDWs. EPA believes that the additional requirements that apply to owners or operators of

Class VI wells granted a waiver of the injection depth requirements will provide additional

considerations for the owner or operator and Director when permitting such wells to ensure protection

of all USDWs.  

The Agency believes the waiver 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.  

Letter ID: 0343 Comment ID: 27868 Letter Lines: 38 to 54  

Comment Code: 3210 3.2.1. Comments Generally in Support of the Approach  
Comment: Injection of CO2 above the lowermost formation containing a USDW can be done  

safely where determined appropriate while protecting all USDWs. This is  

currently being done in enhanced oil recovery projects in the United States. In  

fact due to the buoyancy of CO2, there is less risk to USDWs below the injection  

zone.  

Injection of CO2 above the lowermost formation containing a USDW allows for  

injection into multiple stratified formations which allows for greater  

cumulative capacity. This may further reduce risk by maximizing the storage of  

each well and minimizing the number of wells penetrating confining zones or  

USDWs; these penetrations are one of the biggest risk factors.  

Accessing USDWs below a GS site is not technically challenging. Industry has  

developed the ability to safely drill through over‐pressured reservoirs which  

may be analogous to GS sites. There are several formations in North Dakota  

which are over‐ pressured and the industry routinely can safely drill through  

these by taking the appropriate precautions.  

Individual Response: EPA agrees that there are some situations where injection into non‐USDW

formations above the lowermost USDW can be performed in a manner that protects USDWs. The final

GS rule at §146.95 establishes a process by which owners and operators can seek a waiver of the Class

VI injection depth requirements.  

EPA believes that that injection for the purpose of GS into non‐USDW formations above the lowermost

USDW warrants tailored requirements to address the unique challenges and risks relative to injection

below the lowermost USDW. For example, there is a risk of downward migration of fluids if there is no

lower confining layer or inadequate confinement. In addition, there is potential that wells will be drilled

through the injection zone in the future to reach USDWs. EPA believes that the additional requirements

that apply to owners or operators of Class VI wells granted a waiver of the injection depth requirements

at §146.95 will provide additional considerations for the owner or operator and Director when

permitting such wells to ensure protection of all USDWs.

EPA acknowledges that technologies exist to address the challenges associated with GS and injection

that will be conducted under the waiver approach, e.g., to inject through over‐pressured formations.

However, EPA also believes that additional considerations are necessary when permitting such wells to

ensure protection of all USDWs and that the additional requirements that apply to owners or operators

of Class VI wells granted a waiver of the injection depth requirements at §146.95 will provide this

protection.  
Letter ID: 0343 Comment ID: 27869 Letter Lines: 56 to 65  

Comment Code: 3100 3.1. Comments on Concerns About Injection Depth for Class VI Wells  

Comment: The critical component to confining any injection stream is suitable top and  

bottom confining zones, regardless of the location of a USDW. NODA page 44809  

states, "placing distance between the injection formation and USDWs decreases  

risks to USDWs". Distance may help but is not the definitive factor. It will  

not compensate for poor site characteristics. Neither does lack of distance  

defeat a site that is properly designed and sited. The ability of the confining  

zones to sequester the injection stream must be taken into account, along with  

distance, in determining whether the site is suitable. Site selection must  

focus on the trapping and confinement characteristics without giving undue  

deference to distance.  

Individual Response: EPA agrees that suitable confining layers (e.g., low‐permeability, low‐porosity

formations identified through proper site characterization process) along with proper well construction,

operation, monitoring, and post‐injection site care are key to protecting USDWs from endangerment.

Additionally, the Agency believes that distance between the injection zone and USDWs can impede

vertical fluid movement, allow for pressure dissipation, and provide additional sites for monitoring,

mitigation, and remediation if conditions warrant.  

Owners and operators seeking waivers must provide a supplemental report (the GS Class VI injection

depth waiver application report) referenced at §146.82(d) and outlined at §146.95(a) with additional,

site‐specific information including: additional information about the injection zone; identification of

confining units above and below the injection zone; tailored AoR modeling above and below the

injection zone; a demonstration that well design is appropriate and protective of USDWs, in lieu of

specific requirements at §146.86; a description of how monitoring will be tailored for injection

above/between USDWs; and information about public water supplies in the AoR.  

Letter ID: 0343 Comment ID: 27870 Letter Lines: 67 to 72  

Comment Code: 3240 3.2.4. Comments that the Approach Requests Too Much Data (seeking comment)  

Comment: While the NDIC is supportive of allowing injection of CO2 above a USDW, the  

proposed waiver process is too onerous. EPA has not shown how injection above a  

USDW poses any additional risk which warrants the significant increase in  

permitting requirements. Injection below the lowermost USDW or above a USDW both  

require confinement of the injection stream and formation fluids from upward or  
downward migration, there is no difference.  

Individual Response: EPA believes that the information required to obtain a waiver is necessary to

ensure that the owner or operator collects information and demonstrates to the Director that the

injection zone is suitable for GS, is confined by confining units above and below the injection zone, and

that well construction, operation, and monitoring are tailored for the site and take into consideration

the presence of USDWs above and below the injection zone. Because USDW protection is the priority of

the GS rule, owners or operators seeking waivers must provide a supplemental report (the GS Class VI

injection depth waiver application report), referenced at §146.82(d) and outlined at §146.95(a), with

their Class VI permit applications. This report, suggested by commenters, is designed to ensure that all

waiver information is discrete (from the permit application) and can be made available to the Director,

PWSS Directors, and the public when the waiver is publicly noticed with the draft Class VI permit

application. The Agency believes that this report and requirements at §146.95 are complementary and

not redundant of the Class VI permit application requirements. Furthermore, to eliminate concerns

about duplication or redundancy, the requirements at §146.82(d) clarify that the supplemental report is

not part of the permit application.  

EPA believes that that injection for the purpose of GS into non‐USDW formations above the lowermost

USDW warrants tailored requirements to address the unique challenges and risks relative to injection

below the lowermost USDW. For example, there is a risk of downward migration of fluids if there is no

lower confining layer or inadequate confinement. In addition, there is potential that wells will be drilled

through the injection zone in the future to reach USDWs. EPA believes that the additional requirements

that apply to owners or operators of Class VI wells granted a waiver of the injection depth requirements

at §146.95 will provide additional considerations for the owner or operator and Director when

permitting such wells to ensure protection of all USDWs.  

Letter ID: 0343 Comment ID: 27871 Letter Lines: 74 to 87  

Comment Code: 3300 3.3. Comments on Specific Elements of the Waiver Approach  

Comment: Since there is no real additional risk, the following areas highlighted in the  

NODA are unnecessary: supplement to Emergency Response Plan; additional  

financial responsibility; need to identify alternative injection sites;  

community needs, demands, and supply from drinking water resources; planned  

needs, potential and/or future use of USDWs and non‐USDWs in area; planned or  

permitted water, hydrocarbon, or mineral resource exploitation potential of the  

proposed injection formation and other formations both above and below the  

injection zone to determine if there are any plans to drill through the  

formation to access resources in or beneath the proposed injection zone;  

proposed plan for securing alternative resources or treating USDW in the event  
of contamination related to Class VI injection activity; more stringent  

injection pressure limitations; and increased formation fluid and ground water  

sampling and monitoring above and below the injection zone in concert with local  

water suppliers.  

Individual Response: EPA believes that that injection for the purpose of GS into non‐USDW formations

above the lowermost USDW warrants tailored requirements to address the unique challenges and risks

relative to injection below the lowermost USDW. For example, there is a risk of downward migration of

fluids if there is no lower confining layer or inadequate confinement. In addition, there is potential that

wells will be drilled through the injection zone in the future to reach USDWs. EPA believes that the

additional requirements that apply to owners or operators of Class VI wells granted a waiver of the

injection depth requirements at §146.95 will provide additional considerations when permitting such

wells to ensure protection of all USDWs.  

Letter ID: 0343 Comment ID: 27872 Letter Lines: 89 to 108  

Comment Code: 3300 3.3. Comments on Specific Elements of the Waiver Approach  

Comment: One item of particular concern is the planned needs, potential and/or future use  

of USDWs and non‐USDWs in area. The inclusion of non‐USDWs is broad and  

undefined. What non‐USDWs are of concern and why? This information on these  

formations, if not the injection or confining zones, is of little value and  

provides no additional protection. Nothing about the location of the injection  

zone being located above a USDW makes this any more relevant than if the  

injection zone is below the lowermost USDW  

Another area of concern is the community needs, demands, and supply from  

drinking water resources, and the planned needs, potential and/or future use of  

USDWs and non‐USDWs in area. This appears to require something similar to an  

aquifer exemption for the entire stratigraphic column.  

Also of concern is the planned or permitted water, hydrocarbon, or mineral  

resource exploitation potential of the proposed injection formation and other  

formations both above and below the injection zone to determine if there are any  

plans to drill through the formation to access resources in or beneath the  

proposed injection zone. The same exploitation of various formations can also  

take place if the injection is limited to below the lowermost USDW. This  

information is of little value and provides no additional protection.  

Individual Response: The requirements for consideration of 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 planned or permitted water, hydrocarbon, or mineral resource exploitation potential

are designed to ensure that USDW protection, site‐specific drinking water resource issues, and the use

and impact of GS technologies are considered and documented. The final GS rule retains these

considerations at §146.95(b).  

Letter ID: 0343 Comment ID: 27873 Letter Lines: 110 to 116  

Comment Code: 3350 3.3.5. Requirement to Submit Waiver Application to UIC and PWSS Program

Directors  

Comment: The inclusion of the Public Water Supply Supervision (PWSS) Program Director in  

the decision process adds an additional layer of bureaucracy, is duplicative,  

and is inefficient. Final decision authority must be with the agency granted  

primacy for regulation of CO2 sequestration. EPA must not dictate to states  

that have primacy which agencies must approve an application. The PWSS Program  

Director can have input and participate through the normal public participation  

process.  

Individual Response: The final GS rule includes a requirement that the UIC Program Director consult

with the PWSS Directors of all states, Territories, and Tribes having jurisdiction within the AoR of a well

for which a waiver is sought as specified in §146.95(b)(2). EPA believes this process is necessary and

appropriate to ensure that water system concerns are considered when evaluating a waiver application.

EPA requires that this consultation be documented to ensure transparent public disclosure of all

information evaluated by the Directors and their respective recommendations. EPA clarifies that the

PWSS director does not have "veto power" over a UIC permitting decision; instead, the role of the PWSS

Director is to ensure consideration of water system and water resource issues where injection into non‐

USDW formations above the lowermost USDW is being considered. Due to the unique nature of the

injection depth waiver process and in an effort to ensure national consistency and application of the

requirements, the requirement at §146.95(d) indicates that the Regional Administrator makes the final

determination regarding waiver issuance following an evaluation of all site‐specific information, public

notice, and recommendations from the UIC Director. EPA believes that UIC Program staff is in the

appropriate position to evaluate the technical details of the waiver application, in concert with the UIC

permit application, to inform the Regional Administrator’s decision. EPA adds that adoption of the

waiver process will remain at the discretion of individual UIC programs.  

EPA believes that the consultative communication between the UIC Director and PWSS Directors will

enable a comprehensive evaluation of resource concerns and increase USDW protection. EPA adds that

it does not anticipate that the PWSS director would perform the same level of review as the UIC Director

and anticipates states would determine the level of PWSS review.  
Letter ID: 0343 Comment ID: 28566 Letter Lines: 50 to 54  

Comment Code: 3420 3.4.2. Request for Information on Areas Where Injection Depth and USDWs Are a

Concern (seeking comment)  

Comment: Accessing USDWs below a GS site is not technically challenging. Industry has  

developed the ability to safely drill through over‐pressured reservoirs which  

may be analogous to GS sites. There are several formations in North Dakota  

which are over‐ pressured and the industry routinely can safely drill through  

these by taking the appropriate precautions.  

Individual Response: EPA acknowledges that technologies and past experience exist to inject through

over‐pressured formations while maintaining zonal isolation (e.g., oil and gas industry experience in

drilling through shallow pockets of gas or other zones that have higher pressures). EPA has reviewed

information on these types of projects and has determined that, if properly constructed, wells can be

drilled through pressurized zones without causing fluid movement. However, to provide additional

USDW protection and ensure that any planned drilling is conducted appropriately, the final GS rule

requires the Director to consider planned or permitted water, hydrocarbon, or mineral resource

exploitation potential of the proposed injection formation and other formations both above and below

the injection zone to determine if there are any plans to drill through the formation to access resources

in or beneath the proposed injection zone/formation as specified in §146.95(b)(1)(vii).