### UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 5 77 WEST JACKSON BOULEVARD CHICAGO, IL 60604-3590



## JIIOV 

## J. 4 2Q13 REPLYTO THEATTENTION OF:



### CERTIFIED MAIL 7001 0320 0005 8923 4123 RETURNRECEIPT REQUESTED

Kenneth K. Hmphreys ChiefExecutive Officer FutureGenIndustrial Alliance, Inc. 73 Central Park Plaza East Jacksonville, Illinois 62650 WU-16J



### Subject: Requestfor AdditionalInformation RegardingFutureGen2.0 Wells, United States Environmental Protection Agency Underground Injection Control (UIC) PermitApplications for Four Geologic SequestrationWells; United States EnvironmentalProtection Agency UIC PermitNos. IL-137-6A-0001, -0002, -0003, & 

### -0004

Dear Mr. 

### Humphreys:

In order to complete our review ofFutureGen'spermit applications, we need additional information describedin the enclosure withthis letter. Please submit any informationno later than 30 

### days from the receipt ofthis letter.
Inquiries concerning the contents ofthe enclosure may be directedto Jeffrey McDonald ofmy staffbytelephone at (312) 353-6288 orby email to mcdonald.jeffrey@epa.gov.

cc: StephenNightingale, IEPA

Enclosure

### Requests based on the text application

Section Section Title Request Number 3.1.2 Physical Processes Modeled Page 3.3 ofthe permit application states that laboratory investigations for quantifying the importance ofchemical reactions are being conducted. Are any results available? Modeling considering reactive transport may need to be conducted ifthe lab results indicate significant iron carbonate precipitation that changes injection zone porosity. 3.1.3.2 h1trinsic permeability in the A "curve permKCal" is referenced, butthe location ofthe h1jection Zone curve isn'tclear. Please provide a copy orfurther explain. 3.1.3.2 Intrinsic penneability in the No hydrologic tests were conducted in tl1e Elmhurst illjection Zone fonnation to measure a Permeability-Thickness Product and

no ELAN calculation was given. How was a PenneabilityThickness Product detennined for the Elmhurst fonnation? 3.1.3.2 Vertical Penneability Kv/Kh measured in 20 core plug pairs; highly related to presence ofmudstone/shale; sparse data led to use of literature values. Given that 20 ratios were successfully determined, how do they compare to the literature values? 3.1.3.2 Capillary Pressure and Datawas used from the Manlove field to generate BrooksSaturation Fnnctions Corey parameters for four differentpermeability ranges, shown in Table 3.5. Please provide a citation for this information. 3.1.3.3 Temperature We believe 6.72"3 should be 6.72 X 10"3 °F/ft? 3.1.3.3 Temperature Why is regression used rathertl1an measured data? 3.1.5 Representative Case Scenario Section 3.1.5 ofthe permit application notes that the design of Description the injection wells was chosen to "avoid sensitive areas" (p. 3.26). What are these "sensitive areas" and how were they identified? Is tl1is the reason the horizontal well legs are not evenly distributed in a radial fashion? 3.1.6 Computational Model Results It would be helpful to have a verbal description ofthe changes between figures in a series: e.g., the 70yr figure in 3.21 has a wide area in green buttl1e othertllree do not: what does this tell us? Itis extremely difficulttojudge scale from these figures. Please provide dinlensions ofplume and pressure front overtime, together. A map view, such as Fig. 3.25, would be ideal. What is the largest extent ofthe plume and when does this occur? Becausethese figures are not all at the same scale, they are hard to compare. 3.1.6 Computational Model Results Please provide figures beyondyear 70. We suggest figures to year 100. 3.1.10 Parameter Sensitivity and 32 cases were defined using "quasiMonte Carlo" approach. Uncertainty This approach shouldbe describedandpossibly cited. 3.1.10 Parameter Sensitivity and The pennitapplication states that 32 cases were defined from Uncertainty the representative case model. The parameter values used for these 32 cases should be presented in a table.

### Requests based onthe online GS data tool modelinginput

Tab Request Model Domain In the permit application and the Input Advisor submission, subsurface locations

arereferred to both in terms ofdepth (with respect to the ground surface or the kelly bushing) and elevation (with respect to sea level). Forexample, the top ofthe open interval is described as 3,850 ft below ground surface on p. 3.26 ofthe permit application, while the Input Advisor submission refers to this location as having an elevation of-3,220 ft. Is it correctto asswne that all ofthe Z coordinate values submitted in the Input Advisorrepresent elevations relative to sea level and are consistent (e.g., z coordinates provided for well intervals)? Rock Properties The saturation function/relative permeability spreadsheet submittedviathe h1put Advisor defines the Brooks-Corey function for the relative permeability and satmation functions and provides corresponding parameters for different layers. It wouldbe helpful ifthe functional fonns ofBrooks-Coreyfor the relative permeability and saturation functions were also provided in the spreadsheet Rock Properties Horizontal intrinsicpermeabilities of the confiningzones (seep. 3.7 ofthe permit application). Because ofthereliability issues associated with ELAN log-derived permeabilities below a certain limit (0.01 mD), FutmeGenused the horizontal Klinkenberg permeabilities for each model layer. Was there any correction applied tothe Klinkenberg penneabilitiesused for the confining zone layers, particularly because these may represent tight porous formations? Rock Properties Residualsaturation. As shown in the "Sat-function-rei-perm" spreadsheet, residual aqueous saturation values used in the FutmeGenAoRmodel range from 0.0597 to 0.0810. Residual aqueous satmation values found inthe literatme for the Mt Simon Sandstone range from approximately 0.2 to 

### OA (Zhou et aL, 2010; Bandilla et aL, 2012b; Krevor et aL, 2012; Matthias et aL, 2013). Itis expectedthat sitespecific capillary pressure and residual aqueous satmation data for the FutmeGen site will be generated after pre-injection testing ofthe proposed wells. However, an explanation ofthe effects ofthis selection onplume and pressure-front development may need to beprovided. Model Output Surfaceflux. Forthe flux output files, two areas ( 4 mix4 mi and 8 mix 8 mi) were selected and fluxes were defined across the east, west, north, and south boundaries ofboth ofthose areas, as well as the top ofthe Franconia and the top ofthe Proviso. What are the i,j, k indexes that define the 4 mix 4 mi and 8 mix 8 mi areas? AoRPressure Front Criticalpressure calculation. As mentioned inthe previous Request for Additional Delineation hlionnationfrom EPA, it is recommended thatFutmeGen explores altemative methods as well for the critical pressure determination, such as such as those described byNicolet aL (2008) Birkholzeret aL (2011); orBandilla et aL (2012). AoRPressure Front Pressure differential/simulation time. Despite not calculating a critical pressure Delineation withrespect to the lowermostUSDW, FutmeGen did apply a pressure differential of31.45 psi to determine sinmlation tinles-this value is described as "the pressure differential needed to force fluids from the injection zone into the surficial alluvial aquifer system through a hypothetical conduit" (p. 3.25). In other words, it was not calculated with respectto the lowermost USDW, but ratherthe aquifer currently in

use as a drinking water source. The footprint ofthis pressme front indicates a larger areathat may be impacted by injection compared to the footprint ofthe separate-phase plume. FutnreGen acknowledged this pressure effect when identifying artificial penetrations and evaluated two wells thatpenetrate the Mt.Simon outside ofthe delineated AoR, about 16 mi south-southwest ofthe proposed storage site, noting "Although these wells are well outside the AoR, they are within the region where increased pressures inthe injection zone are expected and were therefore considered for additional review" (p. 3.43).What calculations were used to determine this value of31.45 psi? AoR Pressure Front Temperature in St. Peter (WWW). Is 73°F, determined at the subsea elevation ofDelineation 1,129 ft, measured at the stratigraphic well (API#12-137-22132-00)? This value does not match the resulting temperature for this elevation based on the linearregression relationship given in Figure 3.13 -which indicates a temperature of about 82°F at a depth of 1,762.96 bkb (-1,129 ft subsea elevation).

Suggested References: Bandilla, K.W., S.R. Kraemer and J.T. Birkholzer. 2012a. Using semi-analytic solutions to approximate the areaofpotential impact for carbon dioxide injection. International Journal ofGreenhouse Gas Control 8: 196-204.

Birkholzer, J.T., 

### Q. Zhou, A. Curtis and S. Finsterle. 2011. A sensitivity study on regional pressure buildup from large-scale C02 storage projects. 1Oth International Conference on Greenhouse Gas Control Teclmologies, 19-23 September 2010, Amsterdam. Energy Procedia4(2011): 4371-4378.

Nicot, J.-P., C.M. Oldenburg, S.L. Bryant and S.D. Hovorka. 2008. Pressure perturbations from geologic carbon sequestration: Area-of-reviewboundaries and borehole leakage driving forces. 9th International Conference on Greenhouse Gas Control Teclmologies, 16-20 November 2008, Washington, D.C.