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.K C C S t a f f c o m m e n t s f

o r E P A p u b l i c h e a r i n g o f p r o p o s e d C O 2 s t o r a g e r u l e s , O c t o b e r 2

, 2 0 0 8

I a m D o u g L o u i s

, D i r e c t o r o f t h e O i l a n d G a s D i v i s i o n o f t h e K a n s a s C o r p o r a t i o n

C o m m i s s i o n

. I a m h e r e t o d a y t o o f f e r K C C s t a f

f ’ s c o m m e n t s a b o u t t h e E P A ’ s p r o p o s e d

r u l e s f o r t h e u n d e r g r o u n d i n

j e c t i o n o f c a r

b o n d i o x i d e f

o r t h e p u r p o s e o f g e o l o g i c

s e q u e s t r a t i o n

.

I n t r o d u c t i o n

I n t h e 2 0 0 7 K a n s a s L e g i s l a t i v e s e s s i o n

, H B 2 4 1 9 w a s p a s s e d a n d s i g n e d b y G o v e r n o r

S e b e l i u s t h a t d i r e c t e d t h e K a n s a s C o r p o r a t i o n C o m m i s s i o n t o w r i t e r e g u l a t i o n s r e g a r d i n g

t h e s u b s u r f

a c e i n j e c t i o n o f C O 2 f

o r s e q u e s t r a t i o n

. K a n s a s i s o n e o f o n l y a f e w s t a t e s t h a t

h a v e w r i t t e n

, o r a r e i n t h e p r o c e s s o f w r i t i n g

, r e g u l a t i o n s r e g a r d i n g c a r b o n s e q u e s t r a t i o n

. A f t e r c a r e f u l e x a m i n a t i o n o f E P A ’ s p r o p o s e d r u l e s

, a n d t h e r u l e s t h a t K a n s a s h a s w r i t t e n

, I w o u l d l i k e t o o f

f e r t h e s e b r i e f c o m m e n t s a n d p o s e a f e w q u e s t i o n s

.

E x i s t i n g C O 2 p r o

j e c t s

F o r s t a t e s t h a t w i l l h a v e e x i s t i n g C O 2 r u l e s

. W h a t w i l l h a p p e n t o p r o j e c t s t h a t a r e

p e r m i t t e d a s C l a s s V

- e x p e r i m e n t a l w e l l s a f t e r t h e E P A p a s s e s i t s r u l e b u t b e f o r e t h e

s t a t e s a d o p t E P A ’ s r u l e s ? A n o t h e r c o n c e p t t h a t n e e d s t o b e f u l l y d i s c u s s e d i s f

u l l

- s c a l e

( n o t e x p e r i m e n t a l ) i n

j e c t i o n f a c i l i t i e s t h a t a r e a p p l i e d f o r b e f o r e t h e p r o p o s e d E P A r u l e s

a r e a d o p t e d

. H o w w i l l t h e y b e p e r m i t t e d ( i

. e

. w h a t c l a s s ) a n d w h o w i l l p e r m i t t h e m ? T h e

p r o p o s e d r u l e s s h o u l d a d d r e s s t h e s e s p e c i f i c s c e n a r i o s

.

G r a n d f a t h e r i n g C l a s s I I w e l l s t o C l a s s V I w e l l s

.

I t i s b e l i e v e d a g r e a t d e a l o f p o t e n t i a l s t o r a g e o f C O 2 e x i s t s i n E O R

- C O 2 f l o o d s a f t e r o i l

p r o d u c t i o n c e a s e s

. I t i s m y c o n c e r n t h a t E P A ’ s s t r i n g e n t s t a n d a r d s f o r w e l l c e m e n t i n g

,

m o n i t o r i n g a n d f

i n a n c i a l a s s u r a n c e w i l l d i s c o u r a g e o i l o p e r a t o r s u s i n g t h i s a d d i t i o n a l

p o r e s p a c e f

o r s e q u e s t r a t i o n

, t h u s c a u s i n g w a s t e

. I f a C O 2

- E O R o p e r a t i o n h a s

s u c c e s s f u l l y o p e r a t e d f

o r m a n y y e a r s

, w h y s h o u l d t h e s t a n d a r d s b e r a i s e d s i m p l y b e c a u s e

i t u n d e r g o e s a w e l l c l a s s i f i c a t i o n c h a n g e ?

R u l e s t h a t a p p l y t o i m p u r i t i e s o f t h e C O 2 i n j e c t a t e s h o u l d b e f

u r t h e r d i s c u s s e d

, d e t e r m i n e d a n d d e f

i n e d f o r p e r m i t t i n g c e r t a i n t y

.

T h e r u l e s h o u l d b e m o r e s p e c i f i c a s t o w h a t g e o c h e m i c a l d a t a n e e d s t o c o l l e c t e d ( i

. e

. f r o m t h e i n

j e c t i o n f o r m a t i o n

, t h e c o n f

i n i n g l a y e r o r f

r o m t h e U S D W ? )

K C C s t a f f f i n d s t h e c o n c e p t o f a d d i t i o n a l c o n t a i n m e n t z o n e s a b o v e t h e c o n f i n i n g z o n e s t o

b e c o n f u s i n g a n d u n n e c e s s a r y

. I f t h e i n j e c t i o n z o n e a n d c o n f

i n i n g z o n e a r e c o m p e t e n t

,

w e l l u n d e r s t o o d a n d m o n i t o r e d

, t h e r e i s n o n e e d t o h a v e a c o s t l y a n d u n n e e d e d s y s t e m o fr e d u n d a n t c o n t a i n m e n t z o n e s a b o v e t h e t w o

. F u t h e r m o r e

, t h e t e r m “ c o n t a i n m e n t z o n e ” i s

n o t f o u n d i n t h e d e f

i n i t i o n s s e c t i o n n o r f

u l l y e x p l a i n e d

.

K C C S t a f f a g r e e s t h e m o s t a c c u r a t e a n d r e a l i s t i c m e t h o d o f d e t e r m i n i n g A O R u s e s

c o m p u t a t i o n a l m o d e l s

, w h i c h a r e u p d a t e d r e g u l a r l y i n c o n j u n c t i o n w i t h m o n i t o r i n g o f

p h y s i c a l p a r a m e t e r s

. A p r e s c r i b e d f i x e d r a d i u s s u r r o u n d i n g i n d i v i d u a l w e l l s w o u l d n o t

b e a n a p p r o p r i a t e d e t e r m i n a t i o n o f A O R f o r a c o m p l e x d y n a m i c C O 2 s t o r a g e f a c i l i t y

.

P h a s e d c o r r e c t i v e a c t i o n f o r G S w e l l s t h a t l i e i n f

r o n t o f t h e p a t h o f a C O 2 p l u m e w o u l d

a l l o w c o m p a n i e s t o c o n c e n t r a t e c u r r e n t c a p i t a l e x p e n d i t u r e s o n w e l l s t h a t r e p r e s e n t t h e

h i g h e s t r i s k

. W e l l s t h a t m i g h t b e a f f e c t e d i n t h e d i s t a n t f

u t u r e w o u l d b e d e e m e d a l o w e r

r i s k t h u s g i v e n a l o w e r p r i o r i t y

.

P r o p o s e d I n

j e c t i o n W e l l C o n s t r u c t i o n R e q u i r e m e n t s

T h e p r o p o s e d r u l e r e q u i r e s t h e l o n g

- s t r i n g c a s i n g t o b e c e m e n t e d i n p l a c e a l o n g i t s e n t i r e

l e n g t h

. I n a s i g n i f

i c a n t a r e a o f K a n s a s

, c e m e n t c a n n o t b e c i r c u l a t e d t o s u r f a c e i n t h e

b o r e h o l e

- c a s i n g a n n u l u s o n t h e p r i m a r y c e m e n t i n g j o b

. T o a c c o m p l i s h a c o n t i n u o u s

c e m e n t e d i n t e r v a l w o u l d i n v o l v e n u m e r o u s p i p e p e r f o r a t i o n s a n d c e m e n t s q u e e z i n g

o p e r a t i o n s

. T h i s a d d i t i o n a l “ r e m e d i a l ” w o r k s a c r i f i c e s m e c h a n i c a l i n t e g r i t y o f t h e p i p e

f o r a m a r g i n a l p o s s i b i l i t y o f a d d i t i o n a l i s o l a t i o n o f t h e i n j e c t i o n z o n e

. C o n s i d e r i n g t h e s e

u n i q u e c o n d i t i o n s a n d a s s o c i a t e d r i s k

, K a n s a s ’ r e g u l a t i o n s p r e s c r i b e a n i n t e r v a l o f 5 0 0

f e e t o f c e m e n t e d i n t e r v a l a b o v e t h e i n j e c t i o n z o n e

.

K C C s t a f f b e l i e v e s a n e x o t i c b l e n d o f C O 2 r e s i s t a n t c e m e n t i s n o t w a r r a n t e d c o n s i d e r i n g

t h e p r o v e n r e c o r d o f C O 2

- E O R w e l l

- c o n s t r u c t i o n h i s t o r y

.

P r o p o s e d I n

j e c t i o n W e l l O p e r a t i n g R e q u i r e m e n t s

I n t h e p r o p o s e d r u l e

, E P A i s s e e k i n g c o m m e n t o n t h e u s e o f t r a c e r m a t e r i a l f o r d e t e c t i o n

o f f u g i t i v e C O 2

. K C C s t a f

f ’ s o p i n i o n i s t h e c o m p a r i s o n o f b a s e l i n e C O 2 l e v e l s t o

m o n i t o r e d l e v e l s w o u l d p r o v i d e t h e s a m e i n f o r m a t i o n

, a s w o u l d c o s t l y a n d p o t e n t i a l l y

h a r m f u l t r a c e r m a t e r i a l

.

I n o u r o p i n i o n

, e x t e r n a l m e c h a n i c a l t e s t i n g a t a o n e

- y e a r f r e q u e n c y i s e x c e s s i v e a n d n o t

w a r r a n t e d

. T h e f

r e q u e n c y w h i c h K a n s a s r e q u i r e s i n t h e i r r e g u l a t i o n s i s o n c e e v e r y f o u r

y e a r s

.

P r o p o s e d W e l l P l u g g i n g , P o s t

- I n j e c t i o n S i t e C a r e , a n d S i t e C l o s u r e R e q u i r e m e n t s

T h e p r o p o s e d r u l e s e t s t h e p o s t

- i n j e c t i o n s i t e c a r e p e r i o d a t a d e f a u l t p e r i o d o f 5 0 y e a r s

. K C C s t a f f a g r e e s t h e U I C p r o g r a m D i r e c t o r s h o u l d h a v e t h e a u t h o r i t y t o s h o r t e n o r

l e n g t h e n t h e p o s t

- i n

j e c t i o n s i t e c a r e p e r i o d i f t h e o w n e r / o p e r a t o r d e m o n s t r a t e s a d i f f e r e n t

t i m e p e r i o d i s a p p r o p r i a t e

.P r o p o s e d F i n a n c i a l R e s p o n s i b i l i t y a n d L o n g

- t e r m C a r e R e q u i r e m e n t s

T h e p r o p o s e d r u l e s t a t e s E P A w i l l p r o v i d e g u i d a n c e

, t o b e d e v e l o p e d a t a l a t e r d a t e

,

w h i c h d e s c r i b e s r e c o m m e n d e d t y p e s o f o w n e r / o p e r a t o r f

i n a n c i a l r e s p o n s i b i l i t y

. O n s u c h

a n i m p o r t a n t c o n c e p t

, s h o u l d n ’ t i t b e a d d r e s s e d i n t h e p r o p o s e d r u l e r a t h e r t h a n c l a r i f i e d

t h r o u g h g u i d a n c e ?

C o n c l u s i o n

I t i s o u r h o p e t h e E P A w i l l f u l l y f u n d t h e C l a s s V I p r o g r a m i f i t d e s i r e s s t a t e s t o

a d m i n i s t e r t h e p r o g r a m

. T h e 1 4 2 5 p r o g r a m w e a d m i n i s t e r i s n o t f u l l y f u n d e d a n d h a s

s e e n c u t s e a c h y e a r f

o r t h e p a s t t h r e e f

i s c a l y e a r s

. I t h a s a l s o b e c o m e i n c r e a s i n g l y

d i f f i c u l t f o r s t a t e s t o m a n a g e p r i m a c y p r o g r a m s t h a t d e m a n d i n c r e a s i n g b u d g e t s b u t

u n d e r g o a n n u a l f

u n d i n g d e c r e a s e s

. T h a n k y o u f o r t h i s o p p o r t u n i t y t o s h a r e o u r c o n c e r n s

a n d q u e s t i o n s

.Letter ID: 0121

Commenter: Doug Louis

Organization: Kansas Corporation Commission

Letter ID: 0121 Comment ID: 22073 Letter Lines: 35 to 48

Comment Code: 2060 1.5.3 Comments on grandfathering of existing wells (seeking comment)

Comment: For states that will have existing CO2 ru les. What will happen to projects that

are permitted as Class V-experimental wells after the EPA passes its rule but

before the states adopt EPA’s rules? A nother concept that needs to be fully

discussed is full-scale (not experimental ) injection facilities that are applied

for before the proposed EPA rules are a dopted. How will they be permitted (i.e.

what class) and who will permit them? The proposed rules should address these

specific scenarios.

Grandfathering Class II wells to Class VI wells.

It is believed a great deal of potential storage of CO2 exists in EOR-CO2 floods

after oil production c eases. It is my concern that EPA’s stringent standards for

well cementing, monitoring and financial a ssurance will discourag e oil operators

using this additional pore space for seque stration, thus causing waste. If a

Individual Response: Experimental GS research projects will continue to be regulated as Class

V experimental technology wells as long as they remain of an expe rimental nature. EPA clarifies

that existing experimental GS projects may be permitted as described in UIC Program Guidance

#83: Using the Class V Experimental Technology Well Classification for Pilot Carbon Geologic

Sequestration Projects, which provided informati on for permitting authorities to consider when

permitting experimental GS projects (i.e., those projects that are designed to test new, unproven

technologies, per the definition of a Class V experimental technology well). EPA adds that,

following finalization of the GS rule, all GS projec ts that are not for experimental purposes must

be re-permitted as Class VI wells and be subject to the final GS requirements. EPA expects that,

after promulgation of the final rule, a limited numbe r of experimental injection projects to test

GS technology will continue, e.g., to inform the t echnology associated with GS into basalts, coal

seams, and salt domes.

The Agency also clarifies that it does not consider it appropriate to permit CO2 injection wells

that are testing the injectivity or appropriateness of an individual forma tion (e.g., as a prelude to

a commercial-scale operation) as Class V expe rimental technology wells. Such wells must be

permitted as Class VI wells.

EPA is preparing an addendum to UICPG #83 that describes the use of th e Class V experimental

technology well classification to clarify perm itting for Class V wells. This addendum will

address shifting of Class V experi mental projects to full-scale GS projects and the future use of

the Class V experimental technology well s ubclass for research a nd testing of new GS

1technologies. This guidance will be available on EPA’s website at

http://water.epa.gov/type/groundwat er/uic/wells_se questration.cfm.

EPA clarifies that projects that are to become commercial immediately can be permitted as Class

I industrial well until the GS rule becomes effective.

In response to the comment that ER operators will be discouraged from pursuing GS or using

additional pore space for storage is outside the scope of the ru lemaking. EPA clarifies that the

purpose of the GS rule is not to incentivize the use of GS or to address the use of pore space but

to ensure that, where GS is deployed, it is conducted in a manner that does not endanger

USDWs. Furthermore, based on evaluation of ava ilable project data, EPA believes that the Class

VI requirements are not overly stringent and reflect the operation, monitoring, and modeling

currently conducted at seve ral existing GS sites.

Letter ID: 0121 Comment ID: 22074 Letter Lines: 43 to 50

Comment Code: 2046 1.5.2.3 Continuing to classify CO2 in jection for EOR/EGR as Class II/

dividing line between Class II and Class VI (seeking comment)

Comment Code: 2064 1.5.3.2 Grandfathering construction of Class II wells (seeking comment)

Comment: Grandfathering Class II wells to Class VI wells.

It is believed a great deal of potential storage of CO2 exists in EOR-CO2 floods

after oil production c eases. It is my concern that EPA’s stringent standards for

well cementing, monitoring and financial a ssurance will discourag e oil operators

using this additional pore space for seque stration, thus causing waste. If a

CO2-EOR operation has succe ssfully operated for many years, why should the

standards be raised simply because it undergoes a well classification change?

Individual Response: Underground injection for the primar y purpose of long term storage is

sufficiently different from Cla ss II ER operations and warrants ta ilored requirements provided in

the GS rulemaking. For example, the volume of CO2 anticipated to be injected in Class VI wells

is significantly greater than for Class II well s. Reservoir pressure conditions will also be

different, with Class VI injection operations i nvolving large volumes of CO2 and likely having

higher pressures within thei r storage formations than Class II ER projects.

In response to the comment that ER operators will be discouraged from pursuing GS or using

additional pore space for storage, EPA clarifies that the purpose of the GS rule is not to

incentivize or encourage the use of GS or to a ddress the use of pore spac e. The purpose of the

GS rule is to ensure that, where GS is deployed, it is conducted in a manner that does not

endanger USDWs. Furthermore, based on the administrative record, which includes the

evaluation of available project da ta, EPA believes that the Class VI requirements are not overly

stringent and reflect the opera tion, monitoring, and modeling cu rrently conducted at several

existing GS sites

2Letter ID: 0121 Comment ID: 22075 Letter Lines: 52 to 53

Comment Code: 1614 1.3.1.2 Impurities in captured CO 2; purity standards for CO2

Comment: Rules that apply to impurities of the CO 2 injectate should be further discussed,

determined and defined for permitting certainty.

Individual Response: EPA recognizes that many CO2 str eams may be relatively pure, and

research indicates that the estimated amounts of impurities in a CO2 stream are likely to be low.

However, these estimates are based on limited in formation, and uncertainties remain about the

expected concentrations of impurities from the va rious types of CO2 streams. The concentrations

of minor and trace elements in CO2 streams for GS projects are likely to vary by facility, coal

composition, plant operating conditions, and pollution removal technologies.

The GS rule does not set generic purity standa rds 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 sour ce of the CO2 and its physical and chemical

properties. Specifically, the GS rule requires the owner or operator to subm it 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 compatib ility of the CO2 stream with fluids in the

injection zone and minerals in both the injection and the confini ng zones and the materials used

to construct the well, per §146.82(c)(3). This info rmation 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 orthe dissolution of formation

minerals.

Since the GS rule, at §146.81(d), prohibits the inj ection 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 Cla ss I hazardous waste injection well.

Letter ID: 0121 Comment ID: 22076 Letter Lines: 55 to 56

Comment Code: 4660 2.6.6 Geochemical monitoring

Comment: The rule should be more specific as to wh at geochemical data needs to collected

(i.e. from the injection formation, the confining layer or from the USDW?)

Individual Response: Section §146.90(d) requires period ic monitoring of the ground water

quality and geochemical changes above the confin ing zone(s). Monitoring above the confining

layer will provide an indication of upward move ment of CO2 that might endanger a USDW. The

exact number of formations to be tested will, however, be based on site-specific characteristics

and vulnerabilities and described in the Di rector-approved testing and monitoring plan.

EPA is developing guidance on testing and mon itoring to assist owne rs or operators and

Directors in evaluating requi rements under §146.90, including pr oposed monitoring plans. The

guidance describes available technologies a nd recommended approaches for implementing a

3testing and monitoring plan, including pre-ope rational geophysical l ogging and testing of

injection wells, MITs, injecti on well testing during operation, groundwater quality monitoring,

tracking the CO2 plume and pressure front, a nd soil gas and surface air monitoring which may

be required by the UIC Director for specific GS projects. Th e guidance can be found on EPA’s

website at http://water.epa.gov/type/gr oundwater/uic/wells_se questration.cfm.

Letter ID: 0121 Comment ID: 22077 Letter Lines: 58 to 63

Comment Code: 3120 2.1.2 Need to identify additional confining and containment zones

(seeking comment)

Comment: KCC staff finds the concept of additional containment zones above the confining

zones to be confusing and unnecessary. If the injection zone and confining zone

are competent, well understood and monitored, there is no need to have a costly

and unneeded system of redundant containment zones above the two. Futhermore,

the term "containment zone" is not found in the definitions section nor fully

explained.

Individual Response: EPA retains the requirement to iden tify additional containment/confining

zones, if required by the Di rector, as proposed (§146.83(b)). EPA acknowledges that such

additional zones may not be needed in all circumst ances, and clarifies that this requirement is at

the Director's discretion, based on his or her understanding of a part icular site. EPA believes that,

in some situations, the presence of additional confining and containment zones above the

primary (i.e., lowermost) confining zone can improve USDW protecti on. These layers could

further impede vertical fluid movement and al low for pressure dissipation, and also provide

additional sites for monitoring, mitigation, and re mediation. The Agency's decision is supported

by commenters representing states, water associati ons, and an electric utility who assert that

these requirements promote a flexible, risk-base d, site-specific approach to characterizing and

permitting a site for GS projects, and are intende d to improve understanding of the project as a

whole and promote better modeling of the site.

EPA clarifies that the GS rule defines confining zone as "a geologic formation, group of

formations, or part of a formation stratigraphica lly overlying the injection zone that acts as

barrier to fluid movement." (§146.81(d)).

EPA is developing guidance on site characterization for GS projects to assist owners or operators

and Directors in evaluating permit requirements and applications under §146.82. The guidance

provides recommendations regard ing characterizing the region al geology and hydrogeology of a

proposed GS site as well as performing th e necessary geochemical, geomechanical, and

geophysical analyses of the injection and confin ing zone. EPA expects that this guidance will

assist permit writers in making an objective deci sion about requiring additional confining layers.

The guidance can be found on EPA’s website at

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

4Letter ID: 0121 Comment ID: 22078 Letter Lines: 65 to 69

Comment Code: 3310 2.2.1.1 Comments in favor of requiring computational models to

delineate the AoR (seeking comment)

Comment: KCC Staff agrees the most accurate and r ealistic method of determining AOR uses

computational models, which are updated re gularly in conjunction with monitoring

of physical parameters. A pr escribed fixed radius surr ounding individual wells

would not be an appropriate determina tion of AOR for a complex dynamic CO2

storage facility.

Individual Response: EPA agrees that predicting the comp lex multiphase, buoyant flow of the

CO2, co-injectates, and compounds that may be mobilized due to injection requires the

sophistication of comput ational models, as required at §146.8 4(c)(1). Models can predict CO2

fate and transport, as well as changes in forma tion pressure, in three dimensions, as a function of

time in order to delineate the subsurface storage site and the AoR. Models can account for sitespecific and predicted operating conditions as well as geologi c heterogeneities and potential

migration through faults, fractures, and artificial penetrations.

Letter ID: 0121 Comment ID: 22079 Letter Lines: 71 to 74

Comment Code: 3630 2.2.4.1 Comments in favor of allowing phased corrective action

Comment: Phased corrective action for GS wells that lie in front of the path of a CO2

plume would allow companies to concentrat e current capital e xpenditures on wells

that represent the highest risk. Wells th at might be affected in the distant

future would be deemed a lower ri sk thus given a lower priority.

Individual Response: EPA acknowledges the commenter’s s upport of phased corrective action

and agrees that phased corrective action may provide many benefits to a project including, but

not limited to, spreading the burden of cost, avoi ding delays in project start-up, allowing for use

of future, improved corrective act ion techniques and addressing unanticipated changes in the

movement of the CO2 plume or pressure front . EPA believes that the phased corrective action

approach is appropriate for GS projects, and retained it at §146.84(b)(2)(iv) in the final GS

regulation. EPA clarifies th at wells that might not be affected for some time are not necessarily

considered to pose a lower risk; rather they are co nsidered to not pose a risk for the first several

years of injection.

Letter ID: 0121 Comment ID: 22080 Letter Lines: 78 to 86

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

Comment: The proposed rule requires the long-string casing to be cemented in place along

its entire length. In a significant area of Kansas, cement cannot be circulated

to surface in the borehole-casing annu lus on the primary cementing job. To

5accomplish a continuous cemented interval would involve numerous pipe

perforations and cement squeezing operati ons. This additional "remedial" work

sacrifices mechanical integrity of the pipe for a marginal possibility of

additional isolation of the injection zone. Considering these unique conditions

and associated risk, Kansas’ regulations prescribe an interval of 500 feet of

cemented interval above the injection zone . KCC staff believes an exotic blend

Individual Response: The final GS rule at §146.86(b)(3) re quires that the long-string casing

extend to the injection zone and be cemented by ci rculating cement to the surface in one or more

stages. It does not, however, specify how cementing would be accomplished, and gives

flexibility to the owner or ope rator to propose alternate methods to provide a sufficient amount

of cement to meet the standard that USDWs ar e protected from endangerment, subject to the

approval of the Director. EPA adds that, unde r §146.86(b)(4), the Dire ctor may approve an

alternative method of cementing in cases where the cement cannot be recirculated to the surface,

provided the owner or operator can demonstrate by using logs th at the cement does not allow

fluid movement behind the wellbore.

The construction requirements at §146.86 offer flex ibility to the owner or operator to propose

well construction procedures that are appropriate to the site-speci fic conditions of the project.

With their permit applications, operators must submit well construction pr ocedures, as specified

at §146.82(a)(12), that demonstrate that the well as constructed will prevent unacceptable fluid

movement; allow the use of appropriate tes ting devices and workove r tools; and allow

continuous monitoring of the annul us space between the injection tubing and long-string casing,

as specified at §146.86(a). The Dire ctor will evaluate the propos ed well construction procedures

in the context of other data about the site. EPA has evaluated the cementing requirements for

other well classes and believes that flexibility can be afforded while ensuring that USDWs are

protected.

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: 0121 Comment ID: 22081 Letter Lines: 86 to 88

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

Comment: cemented interval above the injection zone . KCC staff believes an exotic blend

of CO2 resistant cement is not warranted considering the proven record of CO2-

EOR well-construction history.

Individual Response: EPA recognizes that the oil and gas industry has decades of experience

injecting CO2 for the purpose of enhanced reco very, and that this practice has led to the

development of many corrosion mitigation measures that would be appropriate for the design of

Class VI wells. The rule does not specify material s to be used; rather, it provides owners or

operators with the flexibility to choose, as l ong as the materials used in Class VI wells are

6compatible with fluids with which they may co me into contact and meet or exceed standards

developed for such materials by API or ASTM In ternational, or comparable standards approved

by the Director, as provi ded at §146.86(b)(1).

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

rule for additional information. Additionally, EP A 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: 0121 Comment ID: 22082 Letter Lines: 90 to 95

Comment Code: 4490 2.4.5 Use of tracers and potential im pact on human health or ecosystems

(seeking comment)

Comment: Proposed Injection Well Operating Requirements

In the proposed rule, EPA is seeking comment on the use of tracer material for

detection of fugitive CO2. KCC staff’s opinion is the comparison of baseline CO2

levels to monitored levels would provide the same information, as would costly

and potentially harmfu l tracer material.

Individual Response: In the final rule, EPA does not require the use of tracers at all GS sites;

however, the Director has discreti on to require their us e if he/she determin es that the use of

tracers could improve monitoring of the site and enhance USDW protection from endangerment.

If an owner or operator proposes th e use of tracers at a GS site, EPA anticipates that the specific

tracers to be used would be described in the testing and monitoring plan, which the Director

would evaluate in the context of other information about the GS site. The Director would assess

the use of tracers in the contex t of site-specific information, including risks to USDWs.

Letter ID: 0121 Comment ID: 22083 Letter Lines: 97 to 99

Comment Code: 4546 2.5.2.2 MIT frequency (seeking comment)

Comment: In our opinion, external mechanical testing at a one-year freque ncy is excessive

and not warranted. The frequency which Kans as requires in thei r regulations is

once every four years.

Individual Response: EPA disagrees that the annual mechani cal integrity testing is excessive.

EPA retains the requirement that owners or ope rators of Class VI wells must demonstrate

injection well external mech anical integrity at least once annually under §146.89(c). EPA

believes this is justifiable for the protecti on of USDWs from endangerment given the unique

nature of CO2 GS relative to other injection operations, including the pote ntial corrosive impact

of CO2 in the presence of water and impurities on well materials, the potential geomechanical

impacts to well integrity due to CO2 phase ch anges, the temperature and pressure effects

7associated with injecting supercritical CO2, and the buoyant nature of th e injected CO2. Because

of the unknown long-term effects of CO2 GS, EPA chose a more cons ervative initial approach in

the early stages of deployment for GS.

EPA is using an adaptive approach to regulati ng GS. The Agency plans to collect and review

data every six years on GS projects, including MI T data, to determine whether the appropriate

amount and types of information and appropria te documentation are being collected, and to

determine if modifications to the requir ements are appropriate or necessary.

Letter ID: 0121 Comment ID: 22084 Letter Lines: 103 to 108

Comment Code: 5260 2.8.2.3 Adjusting the post-injecti on timeframe (seeking comment)

Comment: The proposed rule sets the post-injection site care pe riod at a default period

of 50 years.

KCC staff agrees the UIC program Director should have the authority to shorten

or lengthen the post-injection site care period if the owner/operator

demonstrates a different tim e period is appropriate.

Individual Response: EPA acknowledges the commenter’s s upport; the final GS regulation

retains this provision at §146.93(b)(2). Such a de monstration will be site -specific, and based on

pressure monitoring and USDW impacts.

Letter ID: 0121 Comment ID: 22085 Letter Lines: 110 to 115

Comment Code: 5430 2.9.1 Comments on proposed financia l responsibility requirements (40

CFR 146.85)

Comment: Proposed Financial Responsibility a nd Long-term Care Requirements

The proposed rule states EPA will provide guidance, to be deve loped at a later

date, which describes recommended types of owner/operator financial

responsibility. On such an important con cept, shouldn’t it be addressed in the

proposed rule rather than clarified through guidance?

Individual Response: EPA clarifies that the final rule now specifies at §146.85(a)(1) the types

of financial responsibility instruments perm itted for Class VI wells. EPA believes it is

appropriate to allow a flexible approach for fi nancial responsibility. U nder the final GS rule

owners or operators may choose fr om a variety of financial instru ments to meet their obligations

under financial responsibili ty provisions, provided the Director determines that the owner or

operator's proposed financial respon sibility demonstration is ade quate to ensure protection of

USDWs which includes paying for corrective action on wells in the AoR, injection well

plugging, PISC and site closure, and emergency and remedial response. See the final rule and

preamble for further discussion of EPA's fi nal approach to financial responsibility.

8Owners or operators have the flexibility to choose from a variety of financial instruments to meet

their financial responsibility obligations. Owners or operators may use one or multiple financial

responsibility instruments for well plugging a nd PISC (§146.85(a)(6)). However EPA will not

allow for a separate financial responsibility demonstration fo r well plugging and PISC (i.e., a

demonstration submitted prior to well plugging and the beginning of the post-injection site care

period rather than with the permit application). A demonstration of financial responsibility for all

phases of the GS project will be required prior to the issuance of a Class VI permit

(§146.85(a)(5)(i)).

EPA is developing guidance to help owners or op erators, permitting authorities, and third parties

choose and evaluate appropriate financial methods , and states may set more specific financial

responsibility requirements if they so choose. Th e guidance will be available on EPA's website at

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

Letter ID: 0121 Comment ID: 22086 Letter Lines: 117 to 124

Comment Code: 5600 2.11 Comments related to UIC Program primacy for Class VI wells

Comment: Conclusion

It is our hope the EPA will fully fund the Class VI program if it desires states

to administer the program. The 1425 program we administer is not fully funded

and has seen cuts each year for the past three fiscal years. It has also become

increasingly difficult for states to manage primacy programs that demand

increasing budgets but undergo annual funding decreases. Th ank you for this

opportunity to share our c oncerns and questions.

Individual Response: EPA acknowledges that there may be technical and administrative

challenges including resource concerns , and will work closely with the states to assist them in

resolving funding issues or acquiri ng the resources, personnel, and training needed to address the

unique technical challenges associated with GS.

EPA will also incorporate Class VI wells into the UIC Program's grant allocation process. The

States/Tribes/Territories must also demonstrate th at they have adequate resources to implement

the program through matching resources against those allocated by the UIC Program's grant

allocation formula. Currently, primacy programs ar e required to meet a minimum of 25 percent

matching requirement.

9