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.

# Or-ei!on

Theodore R

. Kulongoski, Governor

November 26, 2008

Water Docket,

Environmental Protection Agency,

Mailcode : 2822T,

1200 Pennsylvania Ave

., NW

., Washington, DC 20460

RE : Docket ID No

. EPA-HQ-OW-2008-0390 p

. 1 

# 2a+o~
-- ~3'1D

Water Resources Department
North Mall Office Building

725 Summer Street NE, Suite A

Salem, OR 97301-1266

503-986-0900
FAX 503-986-0904



# DEC 0 4 2008

The Oregon Water Resources Department thanks you for the opportunity to provide these comments on proposed UIC rules for carbon dioxide geologic sequestration wells

.

III Proposed Regulatory Alternatives

We recommend alternative #3

.

These rules are more of a performance standard than construction standards

. In order to fully protect groundwater aquifers and the environment, the rules should more fully regulate the construction of class VI wells by the use of detailed construction standards along with performance standards

. ,

146 .86 Injection Well Construction Requirements

. (b)(3) This rule indicates that the wells can be grouted with cement in one or more stages

. The problem

with cementing in stages is that it is possible to have cold joints that may allow the movement of water or fluids within the annular space

. We would prefer that the grout be placed in one continuous operation without a significant interruption

. Significant interruption

means that the grout should not be allowed to set up to a point that a cold joint would be created when continuing to place grout after an interruption

. We suggest that the interruption should not be more than 72 hours if Portland Cement is used, 48 hours if High Early Strength Type III Portland Cement is used or 6 hours if High-Alumina Cement is used

. Other interruption times would vary depending on the final set time of the proposed grout

.

We also suggest that there be a requirement that the continuous cementing take a minimum amount of grout to complete the seal

. For example, the rules should require that a minimum of 120% to 130%

of the estimated volume of sealing material be used when sealing

. Although this wouldn't guarantee an adequate seal, the chances of a sufficient seal would be much greater with the appropriate amount of grout

. Too little grout would raise a red flag

.



# NOV 2 8 2008Docket ID No

. EPA-HQ-OW-2008-0390

November 26, 2008 Page 2 p

. 2

146 .87 Logging, Sampling, and Testing prior to Injection well Operation

. (b) This rule states that the Director may accept cores from nearby wells if the owner or operator can demonstrate that core retrieval is not possible and that such cores are representative of conditions at the well

. The problem is that cores from nearby wells may not be indicative of the conditions at the well being constructed

. If possible a down-hole video should be made to accurately show

the conditions at the well site

.

146 .89 Mechanical Integrity

. This rule uses the term "significant" in a number of places when describing leaks

. There should be either a definition of "significant" or the wells should be adequately sealed so that there are no leaks

.

146 .90 Testing and Monitoring Requirements

. (c) We support extensive corrosion monitoring and control, at least until collectively we know more about how

cement will react to long-term contact with C02

.

146 .92 Injection Well Plugging

. The rules describe plugs as a way to abandon class VI wells

. In order to ensure that these wells are properly abandoned and that they don't become a health hazard or a health threat in the future the abandonment of class VI wells should consist of completely filling them from the bottom up to land surface with an approved sealant (i .e

. cement)

. This assumes that the well was properly constructed in the first place

. If the well wasn't constructed properly in the first place then another abandonment method may be necessary to properly protect the groundwater resource

.

146 .93 Post-Injection Site Care and Site Closure

. (e) We ask that the site closure reports be posted on-line

.

Sincerely,



# ' Do-, Wt 

# *

a 

# a

Donn Miller Hydrogeologist

Cc : Barbara Priest, Oregon Department of Environmental QualityLetter ID: 0270

Commenter: Donn Miller Organization: State of Oregon, Water Resources Department

Letter ID: 0270 Comment ID: 22885 Letter Lines: 42 to 49

Comment Code: 2300 1.7 Comments on the Alternatives Considered

Comment: III Proposed Regulatory Alternatives

We recommend alternative #3.

These rules are more of a performance stan dard than construction standards. In order to fully protect groundwater aquifers and the environment, the rules should more fully regulate the construction of class VI wells by the use of detailed construction standards along w ith performance standards.

Individual Response: EPA agrees with the commenters that Regulatory Alternative 3 is appropriate. The technical requirements in Alte rnative 3 (and the final GS rule) build upon the long-standing UIC regulatory framework for deep we lls and are appropriately tailored to address the unique nature of full-scale CO2 GS, includi ng the volumes of CO2 to be injected, the buoyant and mobile nature of th e injectate, and its corrosivity in the presence of water.

The tailored approach in this alternative (a nd the final GS rule) modifies the existing UIC requirements for site characterization, area of review, well construction, mechanical integrity testing, monitoring, well plugging, post -injection site care, and site closure, to address full-scale GS. This approach promotes USDW protection, inco rporates flexibility or the discretion of the permitting authority when appropriate, seeks to limit burden on owners or operators and permitting agencies, and provides a foundation fo r national consistency in permitting of GS projects.

EPA adds that the construction requirements at §146.86 provide an appropriate level of protection from endangerment to USDWs that is based upon the existi ng UIC framework for deep wells. The new tailored construction require ments in the final GS rule offer a balance between specific standards and flexibility to ad dress site-specific conditi ons and are tailored to address the unique nature of CO 2 GS (i.e., very large volumes, very long time-periods, and pressurized reservoirs).

Letter ID: 0270 Comment ID: 22886 Letter Lines: 51 to 70

Comment Code: 3824 2.3.1.2 Cementing of long-string casing (seeking comment)

Comment: 146.86 Injection Well Construction Requirements.

1(b)(3) This rule indicates that the wells can be grouted with cement in one or more stages. The problem with cementing in stages is that it is possible to have cold joints that may allow the movement of water or fluids within the annular space. We would prefer that the grout be pl aced in one continuous operation without a significant interruption. Significant inte rruption means that the grout should not be allowed to set up to a point that a cold joint would be created when continuing to place grout after an in terruption. We suggest that the interruption should not be more than 72 hours if Portland Cement is used, 48 hours if High Early Strength Type III Port land Cement is used or 6 hours if High-Alumina Cement is used. Other interru ption times would vary depending on the final set time of the proposed grout.

We also suggest that there be a requireme nt that the continuous cementing take a minimum amount of grout to complete the seal . For example, the rules should require that a minimum of 120% to 130% of th e estimated volume of sealing material be used when sealing. Although this woul dn't guarantee an adequate seal, the chances of a sufficient seal would gr eater with the appropriate amount of grout. Too little grout would raise a red flag.

Individual Response: EPA believes that staged cementing of long-string casing cement is acceptable with very long casing lengths where one continuous cementing cannot be performed. EPA agrees that the period between grouting jobs should be minimi zed, although that period, known in the industry as "waiting for cement," is depe ndent on the time that it takes for the grout in any one stage to set up and cure. As soon as the grout is finished in one stage the staging equipment is moved and new grout is poured.

EPA adds that the specifics the commenter men tions should be addressed on an individual project basis. With their permit applications, ope rators must submit well construction procedures, as specified in §146.82 (a)(12), that demonstrate that the well, as constructed, will prevent unacceptable fluid movement; allow the use of ap propriate testing devices and workover tools;and allow continuous monitoring of the annulus space between the injection tubing and longstring casing, as specified in §146.86(a). The Director will evaluate the pro cedures in the context

of other data about the site. S ee the discussion of Class VI well construction requirements in the preamble to the final GS rule for additiona l 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/gr oundwater/uic/wells_se questration.cfm.

Letter ID: 0270 Comment ID: 22887 Letter Lines: 72 to 79

Comment Code: 3866 2.3.3.3 Logging and testing requirements (40 CFR 146.87)

Comment: 146.87 Logging, Sampling, and Testing prior to Injection well Operation.

(b) This rule states that the Director may accept cores from nearby wells if the owner or operator can demonstrate that core retrieval is not possi ble and that such cores are representative of conditions at th e well. The problem is that cores from

2nearby wells may not be indicative of the conditions at the well being constructed. If possible a dow n-hole video should be made to accurately show the

conditions at the well site.

Individual Response: EPA clarifies that §146.87(b) allows information on cores from nearby wells to be submitted only if the operator can dem onstrate that core retrieval is not possible and that cores from nearby wells are representative of conditions at the Class VI well. If the Director approves the use of alternate core s and determines that additional logs, such as video logs, are necessary to evaluate the site, he/she has authority under §146.87(a)(5) to require additional

information.

Letter ID: 0270 Comment ID: 22888 Letter Lines: 81 to 85

Comment Code: 1220 1.1.1.1 Terminology and definitions

Comment Code: 4500 2.5 Proposed Mechanical Integrity Testing (MIT) Requirements (40 CFR 146.89)

Comment: 146.89 Mechanical Integrity.

This rule uses the term "significant" in a number of places when describing

leaks. There should be either a definition of "significant" or the wells should be adequately sealed so that there are no leaks.

Individual Response: A properly designed and operated we ll should have no leakage in the casing, tubing, or packer and no fluid movement into a USDW th rough channels adjacent to the

wellbore. While the intent of MITs is to detect these types of pr oblems as early as possible, the goal of the well design and constr uction requirements at §146.86 is th e complete absence of such problems. EPA clarifies that the purpose of the "significant leakage" language in this narrow context is simply to avoid triggering corrective actions for essentially de minimis situations. Determining whether a MIT result should trigger follow-up action is necessarily a case and sitespecific situation; as a result, EPA does not believe it is appropriate to define the term "significant leakage" in the c ontext of MITs. In addition, EPA has not defined this term for purposes of other injection well classes and this has not been shown to hinder permitting authorities' and owners or operators' ability to assess whether injection wells have adequate mechanical integrity. EPA believes that this appro ach allows states flexib ility, will not interfere with the implementation of existing UIC program s, and maintains protection of USDWs from endangerment.

In keeping with its adaptive rule making approach, the Agency plan s to collect and review data every six years on early GS proj ects, including MIT da ta, to determine whether the appropriate amount and types of information and appropria te documentation are being collected, and to determine if modifications to the requirements are appropriate or necessary. For additional information, please see the discussion of MITs in the final rule preamble.

3Letter ID: 0270 Comment ID: 22889 Letter Lines: 87 to 91

Comment Code: 4630 2.6.3 Corrosion monitoring

Comment: 146.90 Testing and Monitoring Requirements.

(c) We support extensive corrosion monito ring and control, at least until collectively we know more about how cement will react to long-term contact with

CO2.

Individual Response: EPA agrees that corrosion monitoring is appropriate given the potentially

corrosive nature of the CO2 stream. CO2 in the presence of water becomes acidic, potentially accelerating corrosion of well materials. The CO2 stream for a GS project may also contain small volumes of impurities that could contribute to corrosion. For these reasons, the final rule requires quarterly corrosion monitoring at §146.90(c).

Letter ID: 0270 Comment ID: 22890 Letter Lines: 93 to 103

Comment Code: 5100 2.8.1 Injection well plugging activ ities (seeking comment) (40 CFR 146.92)

Comment: 146.92 Injection Well Plugging.

The rules describe plugs as a way to abandon class VI wells.

In order to ensure that these wells ar e properly abandoned and that they don't

become a health hazard or a health threat in the future the abandonment of class VI wells should consist of completely filling them from the bottom up to land surface with an approved sealant (i.e. cement). Th is assumes that the well was properly constructed in the first place. If the we ll wasn't constructed properly in the first place then another abandonment method maybe necessary to properly protect the groundwater resource.

Individual Response: EPA requires that, to protect USDWs from endangerment, injection wells must be plugged in a manner to ensure that the well will not serve as a conduit for future fluid movement into USDWs. This may be accomplished in a number of ways using a number of different types of materials. In the case of GS wells, the plugging materials must be compatible

with CO2.

EPA disagrees that Class VI wells need to be completely filled from the bottom of the well to the land surface with an approved cement in order to protect USDWs from endangerment. Most experts agree that a series of plugs separated by adequate well bore fluid (e.g., drilling mud) is considered to be adequate protection, and th at the time and expense of continuous cementing may not be practical or necessary to prevent fl uid migration and in some cases, other methods are equally protective. (Source: Technical Assistance Document: Cementing for the Plugging and Abandonment of Injection Wells, 1989) The Class VI well plugging requirements at §146.92

4are very similar to those for Class I wells, with additional considerations that the materials used are compatible with CO2.

EPA adds that the Director must approve the owner or operator's inj ection well plugging plan. Additionally, while EPA believes the requirements for well plugging are ade quately protective of USDWs, if there is reason to believe that completely filling the well is necessary to protect USDWs from endangerment, nothing in th e federal regulation precludes this.

Letter ID: 0270 Comment ID: 22891 Letter Lines: 105 to 106

Comment Code: 5300 2.8.3 Site closure activities (40 CFR 146.93)

Comment: 146.93 Post-Injection Site Care and Site Closure. (e) We ask that the site clos ure reports be posted on-line.

Individual Response: EPA disagrees that the owner or opera tor should not be responsible for record retention such as site closure reports. EPA believes that the requirements that the owner or operator retain for ten years following site closure, records collected during the post-injection site care period at §146.93(f) and §146.93(h) are a ppropriate for the post-injection and site closure period to ensure that data are availabl e to support non-endangerment demonstrations and to address any concerns that may arise following site closure. This data will also support EPA's review of project data as part of the adaptive rulemaking approach.

In response to the suggestion that the site closure reports be po sted on-line, this information would be part of the administrative record on the site, and specific options for access to those records would be the decision of the permitting authority.

5