Post-Injection Site Care and Site Closure Plan for ADM CCS#2 Page E1 of 28

Permit Number: IL-115-6A-0001 

ATTACHMENT E: POST-INJECTION SITE CARE AND SITE CLOSURE PLAN 

Facility Information

Facility name: Archer Daniels Midland, CCS#2 Well 

 IL-115-6A-0001 

Facility contact: Mr. Mark Burau, Plant Manager, 

4666 Faries Parkway, Decatur, IL, 

(217) 424-5750, mark.burau@adm.com

Well location: Decatur, Macon County, IL; 

39o53’08”, -89o53’19” 

This Post-Injection Site Care and Site Closure (PISC) plan describes the activities that ADM will 

perform to meet the requirements of 40 CFR 146.93. ADM will monitor ground water quality 

and track the position of the carbon dioxide plume and pressure front for ten (10) years. This 

alternative post-injection site care timeframe was approved by EPA, but ADM may not cease 

post-injection monitoring until a demonstration of non-endangerment of USDWs has been 

approved by the UIC Program Director pursuant to 40 CFR 146.93(b)(3). Following approval for 

site closure, ADM will plug all monitoring wells, restore the site to its original condition, and 

submit a Site Closure report and associated documentation. 

Pre- and Post-Injection Pressure Differential 

The formation pressure at the injection well is predicted to decline rapidly within the first 4 years 

following cessation of injection. Based on the modeling of the pressure front as part of the AoR 

delineation, pressure is expected to decrease to pre-injection levels by the end of the PISC 

timeframe. Additional information on the projected post-injection pressure declines and 

differentials is presented in the permit application and the Area of Review and Corrective Action 

Plan (Attachment B to this permit). 

Predicted Position of the CO2 Plume and Associated Pressure Front at Site Closure

Figure 1 shows the predicted extent of the plume and pressure front at the end of the 10 year 

PISC timeframe, representing the maximum extent of the plume and pressure front. This map is 

based on the final AoR delineation modeling results submitted in January 2014, per 40 CFR 

146.84. 
Post-Injection Site Care and Site Closure Plan for ADM CCS#2 Page E2 of 28

Permit Number: IL-115-6A-0001 

Figure 1: Predicted Extent of the CO2 plume and pressure front at site closure (Est Yr 2030)

Post-Injection Monitoring Plan

Performing ground water quality monitoring and plume and pressure front tracking as described 

in the following sections during the post-injection phase will meet the requirements of 40 CFR 

146.93(b)(1). The results of all post-injection phase testing and monitoring will be submitted 

annually, within 60 days of the anniversary date of the date on which injection ceases, as 

described under “Schedule for Submitting Post-Injection Monitoring Results,” below. 

A quality assurance and surveillance plan (QASP) for all testing and monitoring activities during 

the injection and post injection phases is provided in the Appendix to the Testing and Monitoring 

Plan. 

Ground Water Quality Monitoring

Tables 1 and 2 present the planned direct and indirect monitoring methods, locations, and 

frequencies for ground water quality monitoring above the confining zone in the Quaternary 

and/or Pennsylvanian strata, the St. Peter Formation, and the Ironton-Galesville Sandstone. All 

of the monitoring wells are located on ADM property. Figure 2 shows the locations of the 

monitoring wells.
Post-Injection Site Care and Site Closure Plan for ADM CCS#2 Page E3 of 28

Permit Number: IL-115-6A-0001 

Table 1. Post-Injection Phase Direct Ground Water Monitoring Above Confining Zone (1,2)

Target 

Formation

Monitoring 

Activity

Monitoring 

Location(s)

Frequency: 

Year 1

Frequency: 

Years 2-3 

Frequency: 

Years 4-9 

Frequency: 

Year 10

Quaternary 

and/or 

Pennsylvanian 

strata

Fluid sampling

Shallow 

monitoring wells: 

MVA10LG, 

MVA11LG, 

MVA12LG, 

MVA13LG

Annual Annual Annual Annual

Distributed 

Temperature 

Sensing 

(DTS)

CCS#1 Continuous None None None

CCS#2 Continuous None None None

St. Peter 

Fluid sampling GM#2 Annual Annual Annual Annual

Pressure/ 

temperature 

monitoring

GM#2 Continuous Continuous Annual Annual

DTS

CCS#1 Continuous None None None

CCS#2 Continuous None None None

IrontonGalesville

Fluid sampling VW#2 Annual Annual Annual Annual

Pressure/ 

temperature 

monitoring

VW#2 Continuous Continuous Annual Annual

DTS

CCS#1 Continuous None None None

CCS#2 Continuous None None None

Notes: 

1. Collection and recording of continuous monitoring data will occur at the frequencies described in Table 4.

2. Annual sampling and monitoring will occur up to 45 days before the anniversary date of cessation of injection or 

alternatively scheduled with the prior approval of the UIC Program Director.
Post-Injection Site Care and Site Closure Plan for ADM CCS#2 Page E4 of 28

Permit Number: IL-115-6A-0001 

Table 2. Post-Injection Phase Indirect Ground Water Monitoring Above the Confining Zone (1)

Target Formation Monitoring 

Activity

Monitoring 

Location(s)

Frequency: 

Year 1

Frequency: 

Years 2-3 

Frequency: 

Years 4-9 

Frequency: 

Year 10

Quaternary and/or 

Pennsylvanian 

strata

Pulse Neutron 

Logging/RST

VW#1 Year 1 Year 3 Year 5, 

Year 7 Year 10

VW#2 Year 1 Year 3 Year 5, 

Year 7 Year 10

CCS#1 Year 1 Year 3 Year 5, 

Year 7 Year 10

CCS#2 Year 1 Year 3 Year 5, 

Year 7 Year 10

St. Peter Pulse Neutron 

Logging/RST

VW#1 Year 1 Year 3 Year 5, 

Year 7 Year 10

VW#2 Year 1 Year 3 Year 5, 

Year 7 Year 10

CCS#1 Year 1 Year 3 Year 5, 

Year 7 Year 10

CCS#2 Year 1 Year 3 Year 5, 

Year 7 Year 10

Ironton-Galesville Pulse Neutron 

Logging/RST

VW#1 Year 1 Year 3 Year 5, 

Year 7 Year 10

VW#2 Year 1 Year 3 Year 5, 

Year 7 Year 10

CCS#1 Year 1 Year 3 Year 5, 

Year 7 Year 10

CCS#2 Year 1 Year 3 Year 5, 

Year 7 Year 10

Note 1: Logging surveys will occur within 45 days before the anniversary date of cessation of injection or 

alternatively scheduled with the prior approval of the UIC Program Director.
Post-Injection Site Care and Site Closure Plan for ADM CCS#2 Page E5 of 28

Permit Number: IL-115-6A-0001 

Table 3 identifies the parameters to be monitored and the analytical methods ADM will employ.

Table 3. Indirect Summary of analytical and field parameters for groundwater samples

Parameters Analytical Methods (1)

Quaternary/Pennsylvanian

Cations:

Al, Ba, Mn, As, Cd, Cr, Cu, Pb, Sb Se, and Tl

ICP-MS,

EPA Method 6020

Cations:

Ca, Fe, K, Mg, Na, and Si

ICP-OES,

EPA Method 6010B

Anions: 

Br, Cl, F, NO3, and SO4

Ion Chromatography,

EPA Method 300.0

Dissolved CO2

Coulometric titration, 

ASTM D513-11

Total Dissolved Solids Gravimetry; APHA 2540C

Water Density(field) Oscillating body method

Alkalinity APHA 2320B

pH (field) EPA 150.1

Specific conductance (field) APHA 2510

Temperature (field) Thermocouple

St Peter 

Cations:

Al, Ba, Mn, As, Cd, Cr, Cu, Pb, Sb Se, and Tl

ICP-MS,

EPA Method 6020

Cations:

Ca, Fe, K, Mg, Na, and Si

ICP-OES,

EPA Method 6010B

Anions: 

Br, Cl, F, NO3, and SO4

Ion Chromatography,

EPA Method 300.0

Dissolved CO2

Coulometric titration, 

ASTM D513-11

Isotopes: δ13C of DIC Isotope ratio mass spectrometry

Total Dissolved Solids Gravimetry; APHA 2540C

Water Density(field) Oscillating body method

Alkalinity APHA 2320B

pH (field) EPA 150.1

Specific conductance (field) APHA 2510

Temperature (field) Thermocouple

Ironton-Galesville

Cations:

Al, Ba, Mn, As, Cd, Cr, Cu, Pb, Sb Se, and Tl

ICP-MS,

EPA Method 6020

Cations:

Ca, Fe, K, Mg, Na, and Si

ICP-OES,

EPA Method 6010B

Anions: 

Br, Cl, F, NO3, and SO4

Ion Chromatography,

EPA Method 300.0

Dissolved CO2

Coulometric titration, 

ASTM D513-11
Post-Injection Site Care and Site Closure Plan for ADM CCS#2 Page E6 of 28

Permit Number: IL-115-6A-0001 

Parameters Analytical Methods (1)

Isotopes: δ13C of DIC Isotope ratio mass spectrometry

Total Dissolved Solids Gravimetry; APHA 2540C

Water Density(field) Oscillating body method

Alkalinity APHA 2320B

pH (field) EPA 150.1

Specific conductance (field) APHA 2510

Temperature (field) Thermocouple

ICP = inductively coupled plasma; MS = mass spectrometry; OES = optical emission spectrometry; GC-P = gas 

chromatography - pyrolysis.

Note 1: An equivalent method may be employed with prior approval of the UIC Program Director. 

• Sampling will be performed as described in section B.2 of the QASP; this section of the 

QASP describes the ground water sampling methods to be employed, including sampling 

SOPs (section B.2.a/b), and sample preservation (section B.2.g). 

• Sample handling and custody will be performed as described in section B.3 of the QASP. 

• Quality control will be ensured using the methods described in section B.5 of the QASP.

Table 4. Sampling and Recording Frequencies for Continuous Monitoring

Well Condition Minimum sampling 

frequency: once every

Minimum recording 

frequency: once every

For continuous monitoring of the injection well: 5 seconds 5 minutes 1

For the well when shut-in: 4 hours 4 hours

1 This can be an average of the sampled readings over the previous 5-minute recording interval, or the maximum 

(or minimum, as appropriate) value identified over that recording interval. 

Notes:

Sampling frequency refers to how often the monitoring device obtains data from the well for a particular 

parameter. For example, a recording device might sample a pressure transducer monitoring injection pressure 

once every two seconds and save this value in memory.

Recording frequency refers to how often the sampled information gets recorded to digital format (such as a 

computer hard drive). Following the same example above, the data from the injection pressure transducer might 

be recorded to a hard drive once every minute.
Post-Injection Site Care and Site Closure Plan for ADM CCS#2 Page E7 of 28

Permit Number: IL-115-6A-0001 

Figure 2: Location of existing shallow groundwater monitoring wells and planned deep wells.
Post-Injection Site Care and Site Closure Plan for ADM CCS#2 Page E8 of 28

Permit Number: IL-115-6A-0001 

Carbon Dioxide Plume and Pressure Front Tracking

ADM will employ direct and indirect methods to track the extent of the carbon dioxide plume 

and the presence or absence of elevated pressure. 

Table 5 presents the direct and indirect methods that ADM will use to monitor the CO2 plume, 

including the activities, locations, and frequencies ADM will employ. ADM will conduct fluid 

sampling and analysis to detect changes in ground water in order to directly monitor the carbon 

dioxide plume. The parameters to be analyzed as part of fluid sampling in the Mt. Simon (and 

associated analytical methods) are presented in Table 6. Indirect plume monitoring will be 

employed using pulsed neutron capture/reservoir saturation tool (RST) logs to monitor CO2

saturation and 3D surface seismic surveys. Quality assurance procedures for seismic monitoring 

methods are presented in Section B.9 of the QASP. 

Table 5. Post-Injection Phase Plume Monitoring 

Target 

Formation

Monitoring 

Activity

Monitoring 

Location(s)

Frequency: 

Year 1

Frequency: 

Years 2-3 

Frequency: 

Years 4-9 

Frequency: 

Year 10

Direct Plume Monitoring

Mt. Simon Fluid 

sampling VW#2 Annual Annual Annual Annual

Indirect Plume Monitoring 

Mt. Simon

Pulse Neutron 

Logging/RST

VW#1 Year 1 Year 3 Year 5, 

Year 7 Year 10

VW#2 Year 1 Year 3 Year 5, 

Year 7 Year 10

CCS#1 Year 1 Year 3 Year 5, 

Year 7 Year 10

CCS#2 Year 1 Year 3 Year 5, 

Year 7 Year 10

3D surface 

seismic survey

Northern extent of 

plume area (fold 

coverage ~ 600 

acres)

Once 

(Year 1)

(Est 2020)

None None

Once 

(Year 10)

(Est 2030)

Note 1: Sampling and geophysical surveys will occur within 45 days before the anniversary date of cessation of 

injection or alternatively scheduled with the prior approval of the UIC Program Director.

Note 2: Seismic surveys will be performed in the 4th quarter before or the 1st quarter of the calendar year shown or 

alternatively scheduled with the prior approval of the UIC Program Director.
Post-Injection Site Care and Site Closure Plan for ADM CCS#2 Page E9 of 28

Permit Number: IL-115-6A-0001 

Table 6. Summary of analytical and field parameters for fluid sampling in the Mt. Simon (1) 

Parameters Analytical Methods (1)

Cations:

Al, Ba, Mn, As, Cd, Cr, Cu, Pb, Sb Se, and Tl

ICP-MS,

EPA Method 6020

Cations:

Ca, Fe, K, Mg, Na, and Si

ICP-OES,

EPA Method 6010B

Anions: 

Br, Cl, F, NO3, and SO4

Ion Chromatography,

EPA Method 300.0

Dissolved CO2

Coulometric titration, 

ASTM D513-11

Isotopes: δ13C of DIC Isotope ratio mass spectrometry

Total Dissolved Solids Gravimetry; APHA 2540C

Water Density(field) Oscillating body method

Alkalinity APHA 2320B

pH (field) EPA 150.1

Specific conductance (field) APHA 2510

Temperature (field) Thermocouple

ICP = inductively coupled plasma; MS = mass spectrometry; OES = optical emission spectrometry; GCP = gas chromatography - pyrolysis.

Note 1: An equivalent method may be employed with the prior approval of the UIC Program Director.

Table 7 presents the direct and indirect methods that ADM will use to monitor the pressure front, 

including the activities, locations, and frequencies ADM will employ. 

ADM will deploy pressure/temperature monitors and distributed temperature sensors to directly 

monitor the position of the pressure front. Passive seismic monitoring using a combination of 

borehole and surface seismic stations to detect local events over M 1.0 within the AoR will also 

be performed. Quality assurance procedures for seismic monitoring methods are presented in 

Section B.9 of the QASP. 
Post-Injection Site Care and Site Closure Plan for ADM CCS#2 Page E10 of 28

Permit Number: IL-115-6A-0001 

Table 7. Post-Injection Phase Pressure Front Monitoring (1,2)

Target 

Formation

Monitoring 

Activity

Monitoring 

Location(s)

Frequency: 

Year 1

Frequency: 

Years 2-3 

Frequency: 

Years 4-9 

Frequency: 

Year 10

Direct Pressure Front Monitoring

Mt. Simon

Pressure/ 

temperature 

monitoring

VW#2 Continuous

4 Intervals

Continuous

4 Intervals

Continuous

4 Intervals

Continuous

4 Intervals

CCS#1 Continuous Continuous Annual Annual

CCS#2 Continuous Continuous Annual Annual

Distributed 

Temperature 

Sensing 

(DTS)

CCS#1 Continuous None None None

CCS#2 Continuous None None None

Other Monitoring

Multiple Passive 

seismic

A combination 

of borehole and 

surface seismic 

stations located 

within the AoR.

Continuous Continuous Continuous Continuous

Note 1: Collection and recording of continuous monitoring data will occur at the frequencies described in Table 4.

Note 2: Annual monitoring surveys will occur up to 45 days before the anniversary date of cessation of injection or 

alternatively scheduled with the prior approval of the UIC Program Director.

Schedule for Submitting Post-Injection Monitoring Results

All post-injection site care monitoring data and monitoring results (i.e., resulting from the ground 

water monitoring and plume and pressure front tracking described above) will be submitted to 

EPA in annual reports. These reports will be submitted each year, within 60 days following the 

anniversary date of the date on which injection ceases or alternatively with the prior approval of 

the UIC Program Director. 

The annual reports will contain information and data generated during the reporting period; i.e. 

seismic data acquisition, well-based monitoring data, sample analysis, and the results from 

updated site models. 

Alternative Post-Injection Site Care Timeframe

ADM will conduct post-injection monitoring for ten years following the cessation of injection 

operations. ADM demonstrated that an alternative PISC timeframe is appropriate, pursuant to 40 

CFR 146.93(c)(1). This demonstration is based on the computational modeling to delineate the 

AoR; predictions of plume migration, pressure decline, and carbon dioxide trapping; site-specific 

geology; well construction; and the distance between the injection zone and the nearest USDWs.
Post-Injection Site Care and Site Closure Plan for ADM CCS#2 Page E11 of 28

Permit Number: IL-115-6A-0001 

ADM will conduct all of the monitoring described under “Ground Water Quality Monitoring” 

and “Carbon Dioxide Plume and Pressure Front Tracking” above and report the results as 

described under the “Schedule for Submitting Post-Injection Monitoring Results.” This will 

continue until ADM demonstrates, based on monitoring and other site-specific data, that no 

additional monitoring is needed to ensure that the project does not pose an endangerment to any 

USDWs, per the requirements at 40 CFR 146.93(b)(2) or (3).

If any of the information on which the demonstration was based changes or the actual behavior 

of the site varies significantly from modeled predictions, e.g., as a result of an AoR reevaluation, 

ADM may update this PISC and Site Closure Plan pursuant to 40 CFR 146.93(a)(4). ADM will

update the PISC and Site Closure Plan, within six months of ceasing injection or demonstrate 

that no update is needed and as necessary during the duration of the PISC timeframe. 

Non-Endangerment Demonstration Criteria

Prior to approval of the end of the PISC period, the operator will submit a demonstration of nonendangerment of USDWs to the UIC Program Director, per 40 CFR 146.93(b)(2) or (3). 

The operator will issue a report to the UIC Program Director. This report will make a 

demonstration of USDW non-endangerment based on the evaluation of the site monitoring 

data used in conjunction with the project’s computational model. The report will detail how the 

non-endangerment demonstration evaluation uses site-specific conditions to confirm and 

demonstrate non-endangerment. The report will include all relevant monitoring data and 

interpretations upon which the non-endangerment demonstration is based, model 

documentation and all supporting data, and any other information necessary for the UIC 

Program Director to review the analysis. The report will include the following sections:

Summary of Existing Monitoring Data 

A summary of all previous monitoring data collected at the site, pursuant to the Testing and 

Monitoring Plan (Attachment C of this permit) and this PISC and Site Closure Plan, including 

data collected during the injection and PISC phases of the project, will be submitted to help 

demonstrate non-endangerment. Data submittals will be in a format acceptable to the UIC 

Program Director [40 CFR 146.91(e)], and will include a narrative explanation of monitoring 

activities, including the dates of all monitoring events, changes to the monitoring program over 

time, and an explanation of all monitoring infrastructure that has existed at the site. Data will 

be compared with baseline data collected during site characterization [40 CFR 146.82(a)(6) 

and 146.87(d)(3)]. 

Comparison of Monitoring Data and Model Predictions and Model Documentation 

The results of computational modeling used for AoR delineation and for demonstration of an 

alternative PISC timeframe will be compared to monitoring data collected during the 

operational and the PISC period. The data will include time-lapse temperature, pressure, 

ground water analysis, passive seismic, and geophysical surveys (i.e. logging, operating-phase

VSP, and 3D surface seismic surveys), used to update the computational model and to monitor 

the site. Data generated during the PISC period will be used to help show that the 
Post-Injection Site Care and Site Closure Plan for ADM CCS#2 Page E12 of 28

Permit Number: IL-115-6A-0001 

computational model accurately represents the storage site and can be used as a proxy to 

determine the plume’s properties and size. The operator will demonstrate this degree of 

accuracy by comparing the monitoring data obtained during the PISC period against the 

model’s predicted properties (i.e. plume location, rate of movement, and pressure decay). 

Statistical methods will be employed to correlate the data and confirm the model’s ability to 

accurately represent the storage site. The validation of the computational model with the large 

volume of available data will be a significant element to support the non-endangerment 

demonstration. Further, the validation of the complete model over the areas, and at the 

points, where direct data collection has taken place will help to ensure confidence in the 

model for those areas where surface infrastructure preclude geophysical data collection and

where direct observation wells cannot be placed. 

Evaluation of Carbon Dioxide Plume 

The operator will use a combination of time-lapse RST logs, time-lapse VSP surveys, and 

potentially other seismic methods (2D or 3D surveys) to locate and track the extent of the CO2

plume. Figure 3 and Figure 4 present examples of how the data may be correlated against the 

model prediction. In Figure 3, a series of RST logs are compared against the model’s predicted 

plume vertical extent at a specific point location at a specified time interval. A good correlation 

between the two data sets will help provide strong evidence in validating the model’s ability to 

represent the storage system. Similarly, Figure 4 illustrates a comparison of the time-lapse 

VSPs against the predicted spatial extent of the plume at a specified time interval. Also, 

limited 2D and 3D seismic surveys may be employed to determine the plume location at 

specific times. The data produced by these activities will be compared against the model using 

statistical methods to validate the model’s ability to accurately represent the storage site.

Regarding the separate-phase carbon dioxide plume, the PISC monitoring data will be used to 

support a demonstration of the stabilization of the CO2 plume as the reservoir pressure returns 

toward its pre-injection state. The storage site (Mt. Simon) is considered to be an open reservoir 

system with a regional dip oriented NW (up-dip) to SE (down-dip) and having excellent 

porosity (20%) and permeability (120 mD). Locally, the storage interval has thin stratigraphic 

bands of low permeability siltstone to mudstone. These bands act as baffles that restrict the 

plume’s vertical movement. Modeling performed to delineate the plume and pressure front 

predicts that, during the PISC period, the CO2 will gradually rise through the reservoir until it 

encounters a baffle at which time it pools and spreads laterally. Based on the results of a 50 

year post injection simulation, the top of the CO2 plume is about 900 vertical feet below the 

primary seal formation (Eau Claire Shale). Additionally, the model predicts that over half the 

CO2 will have become immobilized within the formation. This, in conjunction with the 

reservoir pressure returning to its pre-injection state, will be used to indicate there is essentially 

no driving force to cause significant plume movement. Indeed, the middle Mt. Simon contains 

intervals of eolian sandstone which are very tightly cemented by quartz overgrowths with some 

facies having permeabilities <0.01 mD. These intervals will act as more than a baffle and will 

significantly impede any vertical plume migration due to buoyancy forces. 

 
Post-Injection Site Care and Site Closure Plan for ADM CCS#2 Page E13 of 28

Permit Number: IL-115-6A-0001 

Figure 3: Comparison of the time-lapse RST logs against the predicted vertical extent of the 

plume at a specific time interval during the operational and PISC period can provide validation 

of the model’s accuracy. 

Figure 4: Comparison of the time-lapse VSPs against the predicted spatial extent of the plume at 

specific time intervals during the operational and PISC period can provide validation of the 

model’s accuracy.

Time Lapse RST logs show the development 

of the vertical extent of CO2 over time.

Time Lapse VSP surveys show the development of the 

vertical and lateral extent of CO2 over time.
Post-Injection Site Care and Site Closure Plan for ADM CCS#2 Page E14 of 28

Permit Number: IL-115-6A-0001 

Figure 5: Comparison of the time-lapse surface 3D against the predicted spatial extent of the plume at specific time 

intervals during the operational and PISC period can provide validation of the model’s accuracy.

The stabilization of the site conditions combined with the site’s characteristic of not having any 

local penetrations of the seal formation will be the central focus of the operator’s demonstration of 

non-endangerment. Equalization of plume to the site’s pre-injection conditions will be one 

element in demonstrating non-endangerment. To demonstrate this, a case was examined to 

determine how long it would take a slowly expanding plume to reach the nearest penetration of 

the seal formation. Shown in Figure 9, the closest penetration of the seal formation is 

approximately 17 miles from the injection well. Assuming the plume continues to grow at 1% per 

year, it would take over 600 years for the plume to reach this plugged and abandoned well. 

Because this well is down dip from the injection well, it is likely the plume will never reach this 

location. 

Evaluation of Mobilized Fluids

In addition to carbon dioxide, mobilized fluids may pose a risk to USDWs. These include 

native fluids that are high in TDS and therefore may impair a USDW, and fluids containing 

mobilized drinking water contaminants (e.g., arsenic, mercury, hydrogen sulfide). The 

geochemical data collected from monitoring wells will be used to demonstrate that no 

mobilized fluids have moved above the seal formation and therefore after the PISC period 
Post-Injection Site Care and Site Closure Plan for ADM CCS#2 Page E15 of 28

Permit Number: IL-115-6A-0001 

would not pose a risk to USDWs. In order to demonstrate non-endangerment, the operator will

compare the operational and PISC period samples from layers above the injection zone, 

including the lowermost USDW, against the pre-injection baseline samples. This comparison 

will support a demonstration that no significant changes in the fluid properties of the overlying 

formations have occurred and that no mobilized formation fluids have moved through the seal 

formation. This validation of seal integrity will help demonstrate that the injectate and or 

mobilized fluids would not represent an endangerment to any USDWs. 

Additionally, RST logs will be used to monitor the salinity of the reservoir fluids in the 

observation zone above the Eau Claire Shale seal. Figure 6 shows the relationship between 

salinity and sigma for two different temperatures while Table 8 shows the compositions of the 

ground water at various intervals. This table shows the difference between the salinity level of 

the Mt Simon and the Ironton Galesville (the interval directly above the confining zone). By 

comparing the time lapse RST logs against the pre-injection baseline logs, the operator will be 

able to monitor any changes in reservoir fluid salinity. RST logs indicating steady salinity 

levels within each zone would indicate no movement of fluids out of the storage unit, 

confirming the integrity of the well and seal formation. 

Figure 6: The red and blue lines show the relationship between salinity and sigma for at 100°F and 200°F.
Post-Injection Site Care and Site Closure Plan for ADM CCS#2 Page E16 of 28

Permit Number: IL-115-6A-0001 

Table 8. Fluid parameters for the Pennsylvanian, Ironton-Galesville, and Mt Simon.

Constituent Pennsylvanian Ironton-Galesville Mt. Simon

Conductivity (mS/cm) 1.5 80 170

TDS (mg/L) 1,000 65,600 190,000

Cl- (mg/L) 170 36,900 120,000

Br- (mg/L) 1 180 680

Alkalinity (mg/L) 380 130 80

Na+ (mg/L) 140 17,200 50,000

Ca2+ (mg/L) 100 5,200 19,000

K+ (mg/L) 1 520 1,700

Mg2+ (mg/L) 50 950 1,800

pH (units) 7.2 6.9 5.9

Evaluation of Reservoir Pressure 

The operator will also support a demonstration of non-endangerment to USDWs by showing 

that during the PISC period, the pressure within the Mt. Simon rapidly decreases toward its 

pre-injection static reservoir pressure. Because the increased pressure during injection is the

primary driving force for fluid movement that may endanger a USDW, the decay in the 

pressure differentials will provide strong justification that the injectate does not pose a risk to 

any USDWs. 

The operator will monitor the downhole reservoir pressure at various locations and intervals 

using a combination of surface and downhole pressure gauges. The measured pressure at a 

specific depth interval will be compared against the pressure predicted by the computational 

model. Agreement between the actual and the predicted values will help validate the accuracy 

of the model and further demonstrate non-endangerment. Figure 7 provides an illustrative 

example of how the operator will demonstrate agreement between the computational model 

prediction and the actual measured parameters at the various monitoring wells and respective 

measurement depths. This figure shows that during the 10 years of the PISC period, the actual 

reservoir pressure (red line) falls to pre-injection levels and has a decay rate similar to the rate 

predicted by the model. Based on risk-based criteria listed in the PISC and Site Closure Plan, 

pressure decline toward pre-injection levels is one factor indicative of USDW nonendangerment. The close alignment between the predicted and actual pressures will further 

validate the model’s accuracy in representing the reservoir system.
Post-Injection Site Care and Site Closure Plan for ADM CCS#2 Page E17 of 28

Permit Number: IL-115-6A-0001 

Figure 7: Illustration of Verification Well #2 comparison of actual dP versus the predicted monitoring interval dP during 

PISC period through year 2030.

One of the key comparisons that may be made is between the observed injection reservoir 

pressure and the model predicted pressure. Figure 8 shows the differential reservoir pressure 

predicted for three years after injection ceases relative to original static reservoir pressure. The 

contour southwest of the CCS#2 well is the 10 psi contour as predicted by the computational 

model. Direct observations will be utilized during the PISC period to verify that pressure 

observations at CCS#2 have declined in conformance with the model. Pressure decline to this 

level within this time frame is an indication of the excellent lateral continuity within the 

regionally extensive, open Mt. Simon reservoir. Observed reduction of reservoir pressure to this 

extent would help validate the model and indicate substantial reduction in the potential of 

injection-pressure induced brine or CO2 migration.

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120

130

140

150

160

2010 2015 2020 2025 2030

VW#2 - Pressure Differentials [P(ti)-P(t0)]

 6,800

Actual 6,800

Pressure Port

Mean Depth (ft) 

Year

(P[t]-P[0]) [psi]
Post-Injection Site Care and Site Closure Plan for ADM CCS#2 Page E18 of 28

Permit Number: IL-115-6A-0001 

Figure 8: Direct pressure measurements at CCS#1, CCS#2, & VW#2 will support the 10 psi differential pressure contour 

as predicted by the flow model (inside red circle) shown at January 1, 2023.

Evaluation of Potential Conduits for Fluid Movement

As shown in the alternative PISC timeframe demonstration, other than the project wells, there 

are no potential conduits for fluid movement, or leakage pathways within the AoR. As shown in 

Figure 9, the closest penetration of the seal formation is approximately 17 miles from the 

injection well. Based on the computational model, if the plume were to continue to grow at 1% 

per year it would take over 600 years for the plume to reach this well. Because this well is down 

dip from the injection well, it is likely the plume will never reach this location. Based on this 

information, the potential for fluid movement through artificial penetrations of the seal 

formation does not present a risk of endangerment to any USDWs. 

Aggregate reservoir pressure has 

returned to pre-injection conditions

10 psi dP contour
Post-Injection Site Care and Site Closure Plan for ADM CCS#2 Page E19 of 28

Permit Number: IL-115-6A-0001 

Figure 9: The closest penetration the seal formation (Eu Claire) is 17.2 miles from CCS#2. Based on a plume 

growth of 1.0% per year, it would take over 600 years for the project’s CO2 plume to reach this well.

Evaluation of Passive Seismic Data

Finally, passive seismic monitoring will be used to help further demonstrate seal formation 

integrity. The operator will provide seismic monitoring data showing that no seismic events 

have occurred that would indicate fracturing or fault activation near or through the seal 

formation. This validation of seal integrity will provide further support for a demonstration 

that the CO2 plume is no longer an endangerment to any USDWs. Figure 10 illustrates how 

these data could be presented. This figure shows a subset of locatable microseismic events 

occurring during part of the IBDP project’s operational period. From this figure one can see 

that a majority of the microseismic events occur in the lower Mt Simon and the Precambrian 

basement. No events are observed near the Eau Claire seal formation indicating that no 

fracturing or fault activation is occurring within this formation. This provides additional 

verification of the Eau Claire formation’s seal integrity and indicates that to date the response 

to the imposed fluid pressures due to injection are confined to the vicinity of the injection zone 

and below. 
Post-Injection Site Care and Site Closure Plan for ADM CCS#2 Page E20 of 28

Permit Number: IL-115-6A-0001 

Figure 10: Visual representation showing the microseismic activity occurring during the injection and post 

injection periods. (Figure provided by IBDP project)

Site Closure Plan

ADM will conduct site closure activities to meet the requirements of 40 CFR 146.93(e) as 

described below. ADM will submit a final Site Closure Plan and notify the permitting agency at 

least 120 days prior of its intent to close the site. Once the permitting agency has approved 

closure of the site, ADM will plug the verification well(s) and geophysical well(s); restore the 

site and move out all equipment; and submit a site closure report to EPA. The activities, as 

described below, represent the planned activities based on information provided to EPA in 

November 2013. The actual site closure plan may employ different methods and procedures. A 

final Site Closure Plan will be submitted to the UIC Program Director for approval with the 

notification of the intent to close the site. 

Injection Period

PISC Period

Microseismic Locations

CCS2
Post-Injection Site Care and Site Closure Plan for ADM CCS#2 Page E21 of 28

Permit Number: IL-115-6A-0001 

Plugging the Verification Well(s)

The well will be flushed with a kill weight brine fluid. A minimum of three tubing volumes will 

be injected without exceeding fracture pressure. A final external MIT will be conducted to 

ensure mechanical integrity. Detailed plugging procedures are provided below. All casing in 

this well will be cemented to surface and will not be retrievable at abandonment. After injection 

ceases and after the appropriate post-injection monitoring period is finished, the completion 

equipment will be removed from the well.

Type and Quantity of Plugging Materials, Depth Intervals

The volume and depth of the plug or plugs will depend on the final geology and downhole 

conditions of the well as assessed during construction. Well cementing software (e.g. 

Schlumberger’s CemCade) will be used to model the plugging and aid in the plug design. The 

cements used for plugging will be tested in the lab prior to plug placement and both wet and dry

samples will be collected during plugging for each plug to ensure quality of the plug. 

All of the casing strings will be cut off at least 3 feet below the surface, below the plow line. A 

blanking plate with the required permit information will be welded to the top of the cutoff 

casing.

Volume Calculations

Volumes will be calculated for the specific abandonment wellbore environment based on desired 

plug diameter and length required. The methodology employed will be to: 

1) Choose the following: 

a. Length of the cement plug desired.

b. Desired setting depth of base of plug. 

c. Amount of spacer to be pumped ahead of the slurry. 

2) Determine the following:

a. Number of sacks of cement required. 

b. Volume of spacer to be pumped behind the slurry to balance the plug. 

c. Plug length before the pipe is withdrawn. 

d. Length of mud freefall in drill pipe. 

e. Displacement volume required to spot the plug. 
Post-Injection Site Care and Site Closure Plan for ADM CCS#2 Page E22 of 28

Permit Number: IL-115-6A-0001 

Plugging and Abandonment Procedure:

At the end of the serviceable life of the verification well, the well will be plugged and 

abandoned. In summary, the plugging procedure will consist of removing all components of the 

completion system and then placing cement plugs along the entire length of the well. Prior to 

placing the cement plugs, casing inspection and temperature logs will be run confirming external 

mechanical integrity. If a loss of integrity is discovered then a plan to repair using the cement 

squeeze method will be prepared and submitted to the agency for review and approval. At the 

surface, the well head will be removed; and the casing will be cut off 3 feet below surface. A 

detailed procedure follows:

1. Move in workover unit with pump and tank. 

2. Record bottom hole pressure using down hole instrumentation and calculate kill fluid 

density. Pressure test annulus as per annual MIT requirements. 

3. Fill both tubings with kill weight brine as calculated from Bottom hole pressure 

measurement (expected approximately 9.5 ppg). 

4. Nipple down well head and nipple up BOPs. 

5. Remove all completion equipment from well. 

6. Keep hole full with workover brine of sufficient density to maintain well control. 

7. Log well with CBL, temperature, mechanical inspection log to confirm external 

mechanical integrity.

8. Pick up work string (either 2 7/8’’ or 3 1⁄2’’) and trip in hole to PBTD. 

9. Circulate hole two wellbore volumes to ensure that uniform density fluid is in the well.

10. The lower section of the well will be plugged using CO2 resistant cement from TD 

around 7000ft to around 1000ft above the top of the Eau Claire formation (to 

approximately 4000 ft). This will be accomplished by placing plugs in 500 foot 

increments. Using a density of 15.9 ppg slurry with a yield of 1.11 cf/sk, approximately 

360 sacks of cement will be required (to incorporate a safety factor, 423 sacks are 

assumed: 3000 ft X .1305 cu ft/ft x 1.2 excess / 1.11 cf/sk = 423 sacks). Actual cement 

volume will depend upon actual weight of the casing within the plugged zone. This will 

require at least six plugs of 500 feet in length. No more than two plugs will be set before 

cement is allowed to set and plugs verified by setting work string weight down onto the 

plug. 

11. Pull ten stands of tubing (600 ft) out and shut down overnight to wait on cement curing. 

12. After appropriate waiting period, TIH ten stands and tag the plug. Resume plugging 

procedure as before and continue placing plugs until the last plug reaches the surface. 

13. Nipple down BOPs. 

14. Remove all well head components and cut off all casings below the plow line. 

15. Finish filling well with cement from the surface if needed. Total of approximately 442 

sacks total cement used in all remaining plugs above 4000 feet (4000 ft X .1305 cu ft/ft / 

1.18 cu ft/sk = 442 sks). Cement calculations based on using Class A cement from 4000 

ft back to surface with a density of 15.6 ppg and a yield of 1.18 cu ft /sk. Lay down all 

work string, etc. Clean cellar to where a plate can be welded with well name onto lowest 

casing string at 3 feet, or as per permitting agency directive. 

16. If required, install permanent marker back to surface on which all pertinent well 

information is inscribed. 
Post-Injection Site Care and Site Closure Plan for ADM CCS#2 Page E23 of 28

Permit Number: IL-115-6A-0001 

17. Fill cellar with topsoil.

18. Rig down workover unit and move out all equipment. Haul off all workover fluids for 

proper disposal. 

19. Reclaim surface to normal grade and reseed location. 

20. Complete plugging forms and send in with charts and all lab information to the regulatory 

agency. Plugging report shall be certified as accurate by ADM and shall be submitted 

within 60 days after plugging is completed. 

Note: 7,000 ft 5 1⁄2” 17 #/ft (7000 ft X .1305 cu ft/ft = 914 cu ft) casing requires an estimated 

914 cubic feet of cement to fill 14 plugs. An excess factor of 20% is being suggested on the 

lower 3000ft to accommodate cement that might be lost to the formation so total material used 

would be 423 sacks of EverCRETE CO2 resistant cement and 442 sack Class A/H cement. 

Approximately five days are required from move in to move out, depending on the operations at 

hand and the physical constraints of the well, weather, and other conditions. 

See the figure below for a plugging schematic. (Perforation zone(s) are estimated. Well plugging 

plan will be updated and submitted with the well completion report.)
Post-Injection Site Care and Site Closure Plan for ADM CCS#2 Page E24 of 28

Permit Number: IL-115-6A-0001 

Figure 11: Representative Plugging schematic - verification well. 
Post-Injection Site Care and Site Closure Plan for ADM CCS#2 Page E25 of 28

Permit Number: IL-115-6A-0001 

Plugging the Geophysical Well(s) 

At the end of the serviceable life of the well, the well will be plugged and abandoned utilizing 

the following procedure: 

1. Notify the permitting agency of abandonment at least 60 days prior to plugging the well. 

2. Remove any monitoring equipment from well bore. Well will contain fresh water or a 

mixture of fresh water and native St. Peter formation water.

3. Nipple down well head and connect cement pump truck to 4 1⁄2 inch casing. Establish 

injection rate with fresh water. Mix and pump 247 sacks Class A cement (15.9 ppg). 

Slow injection rate to 1⁄2 bbl/min as cement starts to enter St. Peter perforations. Continue 

squeezing cement into formation until a squeeze pressure of 500 psi is obtained. Monitor 

static cement level in casing for 12 hours and fill with cement if needed to top out. Plan 

to have 50 sacks additional cement above calculated volume on location to top out if 

needed. (To incorporate a safety factor, 255 sacks are assumed: 3450 ft X .0873 cu ft/ft / 

1.18 cu ft/sk = 255 sacks.) 

4. After cement cures, cut off all well head components and cut off all casings below the 

plow line. 

5. Install permanent marker at surface, or as required by the permitting agency. 

6. Reclaim surface to normal grade and reseed location.

See the figure below for a plugging schematic. 
Post-Injection Site Care and Site Closure Plan for ADM CCS#2 Page E26 of 28

Permit Number: IL-115-6A-0001 

Figure 12: Representative Plugging schematic - geophysical well.
Post-Injection Site Care and Site Closure Plan for ADM CCS#2 Page E27 of 28

Permit Number: IL-115-6A-0001 

Planned Remedial/Site Restoration Activities

To restore the site to its pre-injection condition following site closure, ADM will be guided by 

the state rules for plugging and abandonment of wells located on leased property under The 

Illinois Oil and Gas Act: Title 62: Mining Chapter I: Department of Natural Resources - Part 

240, Section 240.1170 - Plugging Fluid Waste Disposal and Well Site Restoration. 

The following steps will be taken:

1. The free liquid fraction of the plugging fluid waste, which may consist of produced water 

and/or crude oil, shall be removed from the pit and disposed of in accordance with state 

and federal regulations (e.g., injection or in above ground tanks or containers pending 

disposal) prior to restoration. The remaining plugging fluid wastes shall be disposed of by 

on-site burial.

2. All plugging pits shall be filled and leveled in a manner that allows the site to be returned 

to original use with no subsidence or leakage of fluids, and where applicable, with 

sufficient compaction to support farm machinery. 

3. All drilling and production equipment, machinery, and equipment debris shall be 

removed from the site. 

4. Casing shall be cut off at least four (4) feet below the surface of the ground, and a steel 

plate welded on the casing or a mushroomed cap of cement approximately one (1) foot in 

thickness shall be placed over the casing so that the top of the cap is at least three (3) feet 

below ground level. 

5. Any drilling rat holes shall be filled with cement to no lower than four (4) feet and no 

higher than three (3) feet below ground level. 

6. The well site and all excavations, holes and pits shall be filled and the surface leveled. 

Site Closure Report

A site closure report will be prepared and submitted within 90 days following site closure, 

documenting the following: 

• Plugging of the verification and geophysical wells (and the injection well if it has not 

previously been plugged), 

• Location of sealed injection well on a plat of survey that has been submitted to the local 

zoning authority, 

• Notifications to state and local authorities as required at 40 CFR 146.93(f)(2), 

• Records regarding the nature, composition, and volume of the injected CO2, and 

• Post-injection monitoring records.

ADM will record a notation to the property’s deed on which the injection well was located that 

will indicate the following:

• That the property was used for carbon dioxide sequestration, 
Post-Injection Site Care and Site Closure Plan for ADM CCS#2 Page E28 of 28

Permit Number: IL-115-6A-0001 

• The name of the local agency to which a plat of survey with injection well location was 

submitted,

• The volume of fluid injected, 

• The formation into which the fluid was injected, and 

• The period over which the injection occurred. 

The site closure report will be submitted to the permitting agency and maintained by the operator 

for a period of 10 years following site closure. Additionally, the operator will maintain the 

records collected during the PISC period for a period of 10 years after which these records will 

be delivered to the Director. 

Quality Assurance and Surveillance Plan (QASP) 

The Quality Assurance and Surveillance Plan is presented in the Appendix of the Testing and 

Monitoring Plan.